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Sample records for energy focused ion

  1. Ion energy distribution near a plasma meniscus for multielement focused ion beams

    SciTech Connect

    Mathew, Jose V.; Bhattacharjee, Sudeep

    2009-05-01

    The axial ion energy spread near a plasma meniscus for multielement focused ion beams is investigated experimentally in atomic and molecular gaseous plasmas of krypton, argon, and hydrogen by tailoring the magnetic field in the region. In the case of magnetic end plugging, the ion energy spread reduces by approx50% near the meniscus as compared to the bulk plasma, thereby facilitating beam focusing. A quadrupole filter can be used to control the mean energy of the ions. Comparison with standard Maxwellian and Druyvesteyn distributions with the same mean energy indicates that the ion energy distribution in the meniscus is deficient in the population of low and high energy tail ions, resulting in a Gaussian-like profile with a spread of approx4 and approx5 eV for krypton and argon ions, respectively. By carefully tuning the wave power, plasma collisionality, and the magnetic field in the meniscus, the spread can be made lower than that of liquid metal ion sources, for extracting focused ion beams of other elements with adequate current density, for research and applications in nanosystems

  2. Ion focusing

    DOEpatents

    Cooks, Robert Graham; Baird, Zane; Peng, Wen-Ping

    2017-01-17

    The invention generally relates to apparatuses for focusing ions at or above ambient pressure and methods of use thereof. In certain embodiments, the invention provides an apparatus for focusing ions that includes an electrode having a cavity, at least one inlet within the electrode configured to operatively couple with an ionization source, such that discharge generated by the ionization source is injected into the cavity of the electrode, and an outlet. The cavity in the electrode is shaped such that upon application of voltage to the electrode, ions within the cavity are focused and directed to the outlet, which is positioned such that a proximal end of the outlet receives the focused ions and a distal end of the outlet is open to ambient pressure.

  3. Ion focusing

    SciTech Connect

    Cooks, Robert Graham; Baird, Zane; Peng, Wen-Ping

    2015-11-10

    The invention generally relates to apparatuses for focusing ions at or above ambient pressure and methods of use thereof. In certain embodiments, the invention provides an apparatus for focusing ions that includes an electrode having a cavity, at least one inlet within the electrode configured to operatively couple with an ionization source, such that discharge generated by the ionization source is injected into the cavity of the electrode, and an outlet. The cavity in the electrode is shaped such that upon application of voltage to the electrode, ions within the cavity are focused and directed to the outlet, which is positioned such that a proximal end of the outlet receives the focused ions and a distal end of the outlet is open to ambient pressure.

  4. Ion energy distribution near a plasma meniscus with beam extraction for multi element focused ion beams

    SciTech Connect

    Mathew, Jose V.; Paul, Samit; Bhattacharjee, Sudeep

    2010-05-15

    An earlier study of the axial ion energy distribution in the extraction region (plasma meniscus) of a compact microwave plasma ion source showed that the axial ion energy spread near the meniscus is small ({approx}5 eV) and comparable to that of a liquid metal ion source, making it a promising candidate for focused ion beam (FIB) applications [J. V. Mathew and S. Bhattacharjee, J. Appl. Phys. 105, 96101 (2009)]. In the present work we have investigated the radial ion energy distribution (IED) under the influence of beam extraction. Initially a single Einzel lens system has been used for beam extraction with potentials up to -6 kV for obtaining parallel beams. In situ measurements of IED with extraction voltages upto -5 kV indicates that beam extraction has a weak influence on the energy spread ({+-}0.5 eV) which is of significance from the point of view of FIB applications. It is found that by reducing the geometrical acceptance angle at the ion energy analyzer probe, close to unidirectional distribution can be obtained with a spread that is smaller by at least 1 eV.

  5. A superconducting multipole lens for focusing high energy ions

    NASA Astrophysics Data System (ADS)

    Datzmann, G.; Dollinger, G.; Hinderer, G.; Körner, H.-J.

    1999-10-01

    At the Munich 15 MV tandem accelerator a new two stage microprobe system Supraleitendes Nanoskop für Angewandte Kernphysikalische Experimente (SNAKE) is currently under construction. In contrast to existing facilities, it is projected to focus up to 30 MeV protons as well as heavy ions with maximum energies of 200 MeV q2/ A to a submicron beam spot. In order to achieve this goal, a superconducting lens with inherent multipole corrections and special shaped edges with respect to fringe field calculations was designed. The introduction of superconductivity enables a pole tip field of 1.2 T at 10 mm bore radius and the possibility of auto correction mechanisms. An implemented electrostatic octupole for active field correction will have a maximum field strength in the same order of magnitude as the intrinsic magnetic octupole correction. For an analytical test of the novel concepts of this lens, a multipole detection device on the rotating coil principle has been built. It is capable of measuring small multipole contributions on a strong quadrupole field.

  6. Energy spectrum of argon ions emitted from Filippov type Sahand plasma focus

    NASA Astrophysics Data System (ADS)

    Mohammadnejad, M.; Pestehe, S. J.; Mohammadi, M. A.

    2013-07-01

    The energy and flux of the argon ions produced in Sahand plasma focus have been measured by employing a well-designed Faraday cup. The secondary electron emission effects on the ion signals are simulated and the dimensions of Faraday cup are optimized to minimize these effects. The measured ion energy spectrum is corrected for the ion energy loss and charge exchange in the background gas. The effects of the capacitor bank voltage and working gas pressure on the ion energy spectrum are also investigated. It has been shown that the emitted ion number per energy increases as the capacitor bank voltage increases. Decreasing the working gas pressure leads to the increase in the number of emitted ion per energy.

  7. Energy spectrum of argon ions emitted from Filippov type Sahand plasma focus.

    PubMed

    Mohammadnejad, M; Pestehe, S J; Mohammadi, M A

    2013-07-01

    The energy and flux of the argon ions produced in Sahand plasma focus have been measured by employing a well-designed Faraday cup. The secondary electron emission effects on the ion signals are simulated and the dimensions of Faraday cup are optimized to minimize these effects. The measured ion energy spectrum is corrected for the ion energy loss and charge exchange in the background gas. The effects of the capacitor bank voltage and working gas pressure on the ion energy spectrum are also investigated. It has been shown that the emitted ion number per energy increases as the capacitor bank voltage increases. Decreasing the working gas pressure leads to the increase in the number of emitted ion per energy.

  8. Energy spectrum of argon ions emitted from Filippov type Sahand plasma focus

    SciTech Connect

    Mohammadnejad, M.; Pestehe, S. J.; Mohammadi, M. A.

    2013-07-15

    The energy and flux of the argon ions produced in Sahand plasma focus have been measured by employing a well-designed Faraday cup. The secondary electron emission effects on the ion signals are simulated and the dimensions of Faraday cup are optimized to minimize these effects. The measured ion energy spectrum is corrected for the ion energy loss and charge exchange in the background gas. The effects of the capacitor bank voltage and working gas pressure on the ion energy spectrum are also investigated. It has been shown that the emitted ion number per energy increases as the capacitor bank voltage increases. Decreasing the working gas pressure leads to the increase in the number of emitted ion per energy.

  9. Fabrication of a TEM sample of ion-irradiated material using focused ion beam microprocessing and low-energy Ar ion milling.

    PubMed

    Jin, Hyung-Ha; Shin, Chansun; Kwon, Junhyun

    2010-01-01

    Cross-section-view TEM samples of ion-irradiated material are successfully fabricated using a focused ion beam (FIB) system and low-energy Ar ion milling. Ga ion-induced damages in FIB processing are reduced remarkably by the means of low-energy Ar ion milling. There are optimized ion milling conditions for the reduction and removal of the secondary artifacts such as defects and ripples. Incident angles and accelerated voltages are especially more important factors on the preservation of a clean surface far from secondary defects and surface roughing due to Ga and Ar ion bombardment.

  10. High energy focused ion beam technology and applications at the Louisiana Accelerator Center

    NASA Astrophysics Data System (ADS)

    Glass, G. A.; Dymnikov, A. D.; Rout, B.; Zachry, D. P.

    2007-07-01

    The high energy focused ion beam (HEFIB) system at the Louisiana Accelerator Center (LAC) of the University of Louisiana at Lafayette, Lafayette, USA, is constructed on one of the beamlines of a National Electrostatics Corporation 1.7 MV 5SDH-2 tandem accelerator. The HEFIB system has several components, including a versatile magnetic quadrupole sextuplet lens focusing system defined as the Russian magnetic sextuplet (RMS) system having the same demagnifications, the same focal lengths and the same positions of the focal points in xz and yz planes as the Russian quadruplet and a one-piece concrete supporting base and integrated endstation with air isolation. A review of recent microlithography and HEFIB system developments at LAC are presented, as well as new results using heavy ion (HI) beam lithography on crystalline silicon.

  11. Collective Focusing of Intense Ion Beam Pulses for High-energy Density Physics Applications

    SciTech Connect

    Dorf, Mikhail A.; Kaganovich, Igor D.; Startsev, Edward A.; Davidson, Ronald C.

    2011-04-27

    The collective focusing concept in which a weak magnetic lens provides strong focusing of an intense ion beam pulse carrying a neutralizing electron background is investigated by making use of advanced particle-in-cell simulations and reduced analytical models. The original analysis by Robertson Phys. Rev. Lett. 48, 149 (1982) is extended to the parameter regimes of particular importance for several high-energy density physics applications. The present paper investigates (1) the effects of non-neutral collective focusing in a moderately strong magnetic field; (2) the diamagnetic effects leading to suppression of the applied magnetic field due to the presence of the beam pulse; and (3) the influence of a finite-radius conducting wall surrounding the beam cross-section on beam neutralization. In addition, it is demonstrated that the use of the collective focusing lens can significantly simplify the technical realization of the final focusing of ion beam pulses in the Neutralized Drift Compression Experiment-I (NDCX-I) , and the conceptual designs of possible experiments on NDCX-I are investigated by making use of advanced numerical simulations. 2011 American Institute of Physics

  12. High-Energy Ion Acceleration Mechanisms in a Dense Plasma Focus Z-Pinch

    NASA Astrophysics Data System (ADS)

    Higginson, D. P.; Link, A.; Schmidt, A.; Welch, D.

    2016-10-01

    The compression of a Z-pinch plasma, specifically in a dense plasma focus (DPF), is known to accelerate high-energy electrons, ions and, if using fusion-reactant ions (e.g. D, T), neutrons. The acceleration of particles is known to coincide with the peak constriction of the pinch, however, the exact physical mechanism responsible for the acceleration remains an area of debate and uncertainty. Recent work has suggested that this acceleration is linked to the growth of an m =0 (sausage) instability that evacuates a region of low-density, highly-magnetized plasma and creates a strong (>MV/cm) electric field. Using the fully kinetic particle-in-cell code LSP in 2D-3V, we simulate the compression of a 2 MA, 35 kV DPF plasma and investigate in detail the formation of the electric field. The electric field is found to be predominantly in the axial direction and driven via charge-separation effects related to the resistivity of the kinetic plasma. The strong electric and magnetic fields are shown to induce non-Maxwellian distributions in both the ions and electrons and lead to the acceleration of high-energy tails. We compare the results in the kinetic simulations to assumptions of magnetohydrodynamics (MHD). Prepared by LLNL under Contract DE-AC52-07NA27344.

  13. Study of the effects of focused high-energy boron ion implantation in diamond

    NASA Astrophysics Data System (ADS)

    Ynsa, M. D.; Agulló-Rueda, F.; Gordillo, N.; Maira, A.; Moreno-Cerrada, D.; Ramos, M. A.

    2017-08-01

    Boron-doped diamond is a material with a great technological and industrial interest because of its exceptional chemical, physical and structural properties. At modest boron concentrations, insulating diamond becomes a p-type semiconductor and at higher concentrations a superconducting metal at low temperature. The most conventional preparation method used so far, has been the homogeneous incorporation of boron doping during the diamond synthesis carried out either with high-pressure sintering of crystals or by chemical vapour deposition (CVD) of films. With these methods, high boron concentration can be included without distorting significantly the diamond crystalline lattice. However, it is complicated to manufacture boron-doped microstructures. A promising alternative to produce such microstructures could be the implantation of focused high-energy boron ions, although boron fluences are limited by the damage produced in diamond. In this work, the effect of focused high-energy boron ion implantation in single crystals of diamond is studied under different irradiation fluences and conditions. Micro-Raman spectra of the sample were measured before and after annealing at 1000 °C as a function of irradiation fluence, for both superficial and buried boron implantation, to assess the changes in the diamond lattice by the creation of vacancies and defects and their degree of recovery after annealing.

  14. Hydrogen microscopy and analysis of DNA repair using focused high energy ion beams

    NASA Astrophysics Data System (ADS)

    Dollinger, G.; Bergmaier, A.; Hauptner, A.; Dietzel, S.; Drexler, G. A.; Greubel, C.; Hable, V.; Reichart, P.; Krücken, R.; Cremer, T.; Friedl, A. A.

    2006-08-01

    The ion microprobe SNAKE (Supraleitendes Nanoskop für Angewandte Kernphysikalische Experimente) at the Munich 14 MV tandem accelerator achieves beam focussing by a superconducting quadrupole doublet and can make use of a broad range of ions and ion energies, i.e. 4-28 MeV protons or up to 250 MeV gold ions. Due to these ion beams, SNAKE is particularly attractive for ion beam analyses in various fields. Here we describe two main applications of SNAKE. One is the unique possibility to perform three-dimensional hydrogen microscopy by elastic proton-proton scattering utilizing high energy proton beams. The high proton energies allow the analysis of samples with a thickness in the 100 μm range with micrometer resolution and a sensitivity better than 1 ppm. In a second application, SNAKE is used to analyse protein dynamics in cells by irradiating live cells with single focussed ions. Fluorescence from immunostained protein 53BP1 is used as biological track detector after irradiation of HeLa cells. It is used to examine the irradiated region in comparison with the targeted region. Observed patterns of fluorescence foci agree reasonably well with irradiation patterns, indicating an overall targeting accuracy of about 2 μm while the beam spot size is less than 0.5 μm in diameter. This performance shows successful adaptation of SNAKE for biological experiments where cells are targeted on a sub-cellular level by energetic ions.

  15. Focused ion beam system

    DOEpatents

    Leung, K.; Gough, R.A.; Ji, Q.; Lee, Y.Y.

    1999-08-31

    A focused ion beam (FIB) system produces a final beam spot size down to 0.1 {mu}m or less and an ion beam output current on the order of microamps. The FIB system increases ion source brightness by properly configuring the first (plasma) and second (extraction) electrodes. The first electrode is configured to have a high aperture diameter to electrode thickness aspect ratio. Additional accelerator and focusing electrodes are used to produce the final beam. As few as five electrodes can be used, providing a very compact FIB system with a length down to only 20 mm. Multibeamlet arrangements with a single ion source can be produced to increase throughput. The FIB system can be used for nanolithography and doping applications for fabrication of semiconductor devices with minimum feature sizes of 0.1 m or less. 13 figs.

  16. Focused ion beam system

    SciTech Connect

    Leung, K.; Gough, R.A.; Ji, Q.; Lee, Y.Y.

    1999-08-31

    A focused ion beam (FIB) system produces a final beam spot size down to 0.1 {mu}m or less and an ion beam output current on the order of microamps. The FIB system increases ion source brightness by properly configuring the first (plasma) and second (extraction) electrodes. The first electrode is configured to have a high aperture diameter to electrode thickness aspect ratio. Additional accelerator and focusing electrodes are used to produce the final beam. As few as five electrodes can be used, providing a very compact FIB system with a length down to only 20 mm. Multibeamlet arrangements with a single ion source can be produced to increase throughput. The FIB system can be used for nanolithography and doping applications for fabrication of semiconductor devices with minimum feature sizes of 0.1 m or less. 13 figs.

  17. Focused ion beam system

    DOEpatents

    Leung, Ka-Ngo; Gough, Richard A.; Ji, Qing; Lee, Yung-Hee Yvette

    1999-01-01

    A focused ion beam (FIB) system produces a final beam spot size down to 0.1 .mu.m or less and an ion beam output current on the order of microamps. The FIB system increases ion source brightness by properly configuring the first (plasma) and second (extraction) electrodes. The first electrode is configured to have a high aperture diameter to electrode thickness aspect ratio. Additional accelerator and focusing electrodes are used to produce the final beam. As few as five electrodes can be used, providing a very compact FIB system with a length down to only 20 mm. Multibeamlet arrangements with a single ion source can be produced to increase throughput. The FIB system can be used for nanolithography and doping applications for fabrication of semiconductor devices with minimum feature sizes of 0.1 .mu.m or less.

  18. Ion Beam Emission within a Low Energy Focus Plasma (0.1 kJ) Operating with Hydrogen

    NASA Astrophysics Data System (ADS)

    El-Aragi, Gamal M.

    2010-07-01

    An investigation of energetic ion beam emission from a low energy plasma focus (0.1 kJ Mather type) device operating with hydrogen gas is studied. The ion beam emission is investigated using time-integrated and time-resolved detectors. The present plasma focus device is powered by a capacitor bank of 1 μF at 18 kV maximum charging voltage. The correlation of ion beam intensity with filling gas pressure indicates that the beam emission is maximized at the optimum pressure for the focus formation at peak current. Energy of ions is determined with a time-of-flight (TOF) method, taking into account distance from the center electrode to the detection plane.

  19. High current density ion beam obtained by a transition to a highly focused state in extremely low-energy region.

    PubMed

    Hirano, Y; Kiyama, S; Fujiwara, Y; Koguchi, H; Sakakita, H

    2015-11-01

    A high current density (≈3 mA/cm(2)) hydrogen ion beam source operating in an extremely low-energy region (E(ib) ≈ 150-200 eV) has been realized by using a transition to a highly focused state, where the beam is extracted from the ion source chamber through three concave electrodes with nominal focal lengths of ≈350 mm. The transition occurs when the beam energy exceeds a threshold value between 145 and 170 eV. Low-level hysteresis is observed in the transition when E(ib) is being reduced. The radial profiles of the ion beam current density and the low temperature ion current density can be obtained separately using a Faraday cup with a grid in front. The measured profiles confirm that more than a half of the extracted beam ions reaches the target plate with a good focusing profile with a full width at half maximum of ≈3 cm. Estimation of the particle balances in beam ions, the slow ions, and the electrons indicates the possibility that the secondary electron emission from the target plate and electron impact ionization of hydrogen may play roles as particle sources in this extremely low-energy beam after the compensation of beam ion space charge.

  20. High current density ion beam obtained by a transition to a highly focused state in extremely low-energy region

    SciTech Connect

    Hirano, Y. E-mail: hirano.yoichi@phys.cst.nihon-u.ac.jp; Kiyama, S.; Koguchi, H.; Fujiwara, Y.; Sakakita, H.

    2015-11-15

    A high current density (≈3 mA/cm{sup 2}) hydrogen ion beam source operating in an extremely low-energy region (E{sub ib} ≈ 150–200 eV) has been realized by using a transition to a highly focused state, where the beam is extracted from the ion source chamber through three concave electrodes with nominal focal lengths of ≈350 mm. The transition occurs when the beam energy exceeds a threshold value between 145 and 170 eV. Low-level hysteresis is observed in the transition when E{sub ib} is being reduced. The radial profiles of the ion beam current density and the low temperature ion current density can be obtained separately using a Faraday cup with a grid in front. The measured profiles confirm that more than a half of the extracted beam ions reaches the target plate with a good focusing profile with a full width at half maximum of ≈3 cm. Estimation of the particle balances in beam ions, the slow ions, and the electrons indicates the possibility that the secondary electron emission from the target plate and electron impact ionization of hydrogen may play roles as particle sources in this extremely low-energy beam after the compensation of beam ion space charge.

  1. Comparative study of ion, x-ray and neutron emission in a low energy plasma focus

    NASA Astrophysics Data System (ADS)

    Zakaullah, M.; Akhtar, Ijaz; Waheed, A.; Alamgir, Khalid; Shah, Anwar Z.; Murtaza, G.

    1998-05-01

    In a low energy (2.3 kJ) Mather-type deuterium plasma focus, neutron and x-ray emission is investigated by time integrated and time resolved detectors. CR-39 nuclear track ion detectors are employed for measuring charged particle angular distribution. Correlation of charged particles with neutron and x-ray emission is also investigated. The neutron emission profile is found to be composed of two pulses, the intensity and anisotropy of which vary with the filling pressure. The charged particle flux is maximum with high fluence anisotropy for the pressure range 2.5-3.0 mbar which is also the optimum pressure for high neutron emission with low fluence anisotropy 0963-0252/7/2/015/img9. The high neutron emission with low fluence anisotropy is attributed to the presence of trapped deuterons in an anomalous magnetic field. The relevant pressure range generates favourable conditions for plasma density and pinch filament diameter. X-ray emission is generally high at low pressure. For the pressure range of 2.5-4.0 mbar, the axial neutron detector registers a hard x-ray pulse, which may escape through a half inch thick Cu flange. These results suggest that at low pressures, the collapsing current sheath interacts with the anode end and causes intense low energy 0963-0252/7/2/015/img10 x-ray emission, but the neutron emission remains low. X-rays are dominantly Cu 0963-0252/7/2/015/img11. In the narrow pressure regime 2.5-3.0 mbar, the current sheath forms a pinch filament leading to high neutron yield with low fluence anisotropy.

  2. Lateral damage in graphene carved by high energy focused gallium ion beams

    SciTech Connect

    Liao, Zhongquan; Zhang, Tao; Jordan, Rainer; Gall, Martin; Rosenkranz, Rüdiger; Dianat, Arezoo; Cuniberti, Gianaurelio; and others

    2015-07-06

    Raman mapping is performed to study the lateral damage in supported monolayer graphene carved by 30 keV focused Ga{sup +} beams. The evolution of the lateral damage is tracked based on the profiles of the intensity ratio between the D (1341 cm{sup −1}) and G (1582 cm{sup −1}) peaks (I{sub D}/I{sub G}) of the Raman spectra. The I{sub D}/I{sub G} profile clearly reveals the transition from stage 2 disorder into stage 1 disorder in graphene along the direction away from the carved area. The critical lateral damage distance spans from <1 μm up to more than 30 μm in the experiment, depending on the parameters used for carving the graphene. The wide damage in the lateral direction is attributed to the deleterious tail of unfocused ions in the ion beam probe. The study raises the attention on potential sample damage during direct patterning of graphene nanostructures using the focused ion beam technique. Minimizing the total carving time is recommended to mitigate the lateral damage.

  3. Lateral damage in graphene carved by high energy focused gallium ion beams

    NASA Astrophysics Data System (ADS)

    Liao, Zhongquan; Zhang, Tao; Gall, Martin; Dianat, Arezoo; Rosenkranz, Rüdiger; Jordan, Rainer; Cuniberti, Gianaurelio; Zschech, Ehrenfried

    2015-07-01

    Raman mapping is performed to study the lateral damage in supported monolayer graphene carved by 30 keV focused Ga+ beams. The evolution of the lateral damage is tracked based on the profiles of the intensity ratio between the D (1341 cm-1) and G (1582 cm-1) peaks (ID/IG) of the Raman spectra. The ID/IG profile clearly reveals the transition from stage 2 disorder into stage 1 disorder in graphene along the direction away from the carved area. The critical lateral damage distance spans from <1 μm up to more than 30 μm in the experiment, depending on the parameters used for carving the graphene. The wide damage in the lateral direction is attributed to the deleterious tail of unfocused ions in the ion beam probe. The study raises the attention on potential sample damage during direct patterning of graphene nanostructures using the focused ion beam technique. Minimizing the total carving time is recommended to mitigate the lateral damage.

  4. Measurement of the Energy of Nitrogen Ions Produced in Filippov Type Plasma Focus Used for the Nitriding of Titanium

    NASA Astrophysics Data System (ADS)

    Ghareshabani, E.; Mohammadi, M. A.

    2012-12-01

    In this paper the nitrogen ion properties (maximum energy, current density and the most probable energy) are investigated by using Faraday cup in a time of flight method. These ions are produced in a Filippov type plasma focus (Sahand Facility) device and the Faraday cup was placed in a distance range of 18-24 cm from the top of the anode. Maximum and minimum most probable ion energies are 76 and 8.5 keV for the distance range of 18 and 24 cm, respectively. The displacement from 18 to 24 cm at top of the anode the ion current density varies from 4.5 × 106 to 3.2 × 105 (A m-2). For the investigation of the effect of ions bombardment of materials at different positions, at the optimum working conditions of 14 kV as a working voltage, and 0.25 Torr as a gas pressure, titanium samples are placed in a distance of 21, 22, 23 and 24 cm from the top of the anode (θ = 0) and each sample is put under irradiation for 30 plasma shots. The structure of the nitrided surfaces and their morphologies are characterized by X-ray diffractometry and by scanning electron microscopy, respectively. The average crystallite size deduced for (200) and (222) planes of TiN deposited with 30 shots in different distances are estimate to be from ~13 to ~38 nm.

  5. Acceleration of low-energy ions at parallel shocks with a focused transport model

    SciTech Connect

    Zuo, Pingbing; Zhang, Ming; Rassoul, Hamid K.

    2013-03-19

    Here we present a test particle simulation on the injection and acceleration of low-energy suprathermal particles by parallel shocks with a focused transport model. The focused transport equation contains all necessary physics of shock acceleration, but avoids the limitation of diffusive shock acceleration (DSA) that requires a small pitch angle anisotropy. This simulation verifies that the particles with speeds of a fraction of to a few times the shock speed can indeed be directly injected and accelerated into the DSA regime by parallel shocks. At higher energies starting from a few times the shock speed, the energy spectrum of accelerated particles is a power law with the same spectral index as the solution of standard DSA theory, although the particles are highly anisotropic in the upstream region. The intensity, however, is different from that predicted by DSA theory, indicating a different level of injection efficiency. It is found that the shock strength, the injection speed, and the intensity of an electric cross-shock potential (CSP) jump can affect the injection efficiency of the low-energy particles. A stronger shock has a higher injection efficiency. In addition, if the speed of injected particles is above a few times the shock speed, the produced power-law spectrum is consistent with the prediction of standard DSA theory in both its intensity and spectrum index with an injection efficiency of 1. CSP can increase the injection efficiency through direct particle reflection back upstream, but it has little effect on the energetic particle acceleration once the speed of injected particles is beyond a few times the shock speed. Finally, this test particle simulation proves that the focused transport theory is an extension of DSA theory with the capability of predicting the efficiency of particle injection.

  6. Acceleration of low-energy ions at parallel shocks with a focused transport model

    DOE PAGES

    Zuo, Pingbing; Zhang, Ming; Rassoul, Hamid K.

    2013-03-19

    Here we present a test particle simulation on the injection and acceleration of low-energy suprathermal particles by parallel shocks with a focused transport model. The focused transport equation contains all necessary physics of shock acceleration, but avoids the limitation of diffusive shock acceleration (DSA) that requires a small pitch angle anisotropy. This simulation verifies that the particles with speeds of a fraction of to a few times the shock speed can indeed be directly injected and accelerated into the DSA regime by parallel shocks. At higher energies starting from a few times the shock speed, the energy spectrum of acceleratedmore » particles is a power law with the same spectral index as the solution of standard DSA theory, although the particles are highly anisotropic in the upstream region. The intensity, however, is different from that predicted by DSA theory, indicating a different level of injection efficiency. It is found that the shock strength, the injection speed, and the intensity of an electric cross-shock potential (CSP) jump can affect the injection efficiency of the low-energy particles. A stronger shock has a higher injection efficiency. In addition, if the speed of injected particles is above a few times the shock speed, the produced power-law spectrum is consistent with the prediction of standard DSA theory in both its intensity and spectrum index with an injection efficiency of 1. CSP can increase the injection efficiency through direct particle reflection back upstream, but it has little effect on the energetic particle acceleration once the speed of injected particles is beyond a few times the shock speed. Finally, this test particle simulation proves that the focused transport theory is an extension of DSA theory with the capability of predicting the efficiency of particle injection.« less

  7. Focused ion beam source method and apparatus

    DOEpatents

    Pellin, Michael J.; Lykke, Keith R.; Lill, Thorsten B.

    2000-01-01

    A focused ion beam having a cross section of submicron diameter, a high ion current, and a narrow energy range is generated from a target comprised of particle source material by laser ablation. The method involves directing a laser beam having a cross section of critical diameter onto the target, producing a cloud of laser ablated particles having unique characteristics, and extracting and focusing a charged particle beam from the laser ablated cloud. The method is especially suited for producing focused ion beams for semiconductor device analysis and modification.

  8. Prize for Industrial Applications of Physics Talk: Low energy spread Ion source for focused ion beam systems-Search for the holy grail

    NASA Astrophysics Data System (ADS)

    Ward, Bill

    2011-03-01

    In this talk I will cover my personal experiences as a serial entrepreneur and founder of a succession of focused ion beam companies (1). Ion Beam Technology, which developed a 200kv (FIB) direct ion implanter (2). Micrion, where the FIB found a market in circuit edit and mask repair, which eventually merged with FEI corporation. and (3). ALIS Corporation which develop the Orion system, the first commercially successful sub-nanometer helium ion microscope, that was ultimately acquired by Carl Zeiss corporation. I will share this adventure beginning with my experiences in the early days of ion beam implantation and e-beam lithography which lead up to the final breakthrough understanding of the mechanisms that govern the successful creation and operation of a single atom ion source.

  9. Cold atomic beam ion source for focused ion beam applications

    NASA Astrophysics Data System (ADS)

    Knuffman, B.; Steele, A. V.; McClelland, J. J.

    2013-07-01

    We report measurements and modeling of an ion source that is based on ionization of a laser-cooled atomic beam. We show a high brightness and a low energy spread, suitable for use in next-generation, high-resolution focused ion beam systems. Our measurements of total ion current as a function of ionization conditions support an analytical model that also predicts the cross-sectional current density and spatial distribution of ions created in the source. The model predicts a peak brightness of 2 × 107 A m-2 sr-1 eV-1 and an energy spread less than 0.34 eV. The model is also combined with Monte-Carlo simulations of the inter-ion Coulomb forces to show that the source can be operated at several picoamperes with a brightness above 1 × 107 A m-2 sr-1 eV-1. We estimate that when combined with a conventional ion focusing column, an ion source with these properties could focus a 1 pA beam into a spot smaller than 1 nm. A total current greater than 5 nA was measured in a lower-brightness configuration of the ion source, demonstrating the possibility of a high current mode of operation.

  10. Cold atomic beam ion source for focused ion beam applications

    SciTech Connect

    Knuffman, B.; Steele, A. V.; McClelland, J. J.

    2013-07-28

    We report measurements and modeling of an ion source that is based on ionization of a laser-cooled atomic beam. We show a high brightness and a low energy spread, suitable for use in next-generation, high-resolution focused ion beam systems. Our measurements of total ion current as a function of ionization conditions support an analytical model that also predicts the cross-sectional current density and spatial distribution of ions created in the source. The model predicts a peak brightness of 2 × 10{sup 7} A m{sup −2} sr{sup −1} eV{sup −1} and an energy spread less than 0.34 eV. The model is also combined with Monte-Carlo simulations of the inter-ion Coulomb forces to show that the source can be operated at several picoamperes with a brightness above 1 × 10{sup 7} A m{sup −2} sr{sup −1} eV{sup −1}. We estimate that when combined with a conventional ion focusing column, an ion source with these properties could focus a 1 pA beam into a spot smaller than 1 nm. A total current greater than 5 nA was measured in a lower-brightness configuration of the ion source, demonstrating the possibility of a high current mode of operation.

  11. Ion beam mixing by focused ion beam

    NASA Astrophysics Data System (ADS)

    Barna, Árpád; Kotis, László; Lábár, János L.; Osváth, Zoltán; Tóth, Attila L.; Menyhárd, Miklós; Zalar, Anton; Panjan, Peter

    2007-09-01

    Si amorphous (41 nm)/Cr polycrystalline (46 nm) multilayer structure was irradiated by 30 keV Ga+ ions with fluences in the range of 25-820 ions/nm2 using a focused ion beam. The effect of irradiation on the concentration distribution was studied by Auger electron spectroscopy depth profiling, cross-sectional transmission electron microscopy, and atomic force microscopy. The ion irradiation did not result in roughening on the free surface. On the other hand, the Ga+ irradiation produced a strongly mixed region around the first Si/Cr interface. The thickness of mixed region depends on the Ga+ fluence and it is joined to the pure Cr matrix with an unusual sharp interface. With increasing fluence the width of the mixed region increases but the interface between the mixed layer and pure Cr remains sharp. TRIDYN simulation failed to reproduce this behavior. Assuming that the Ga+ irradiation induces asymmetric mixing, that is during the mixing process the Cr can enter the Si layer, but the Si cannot enter the Cr layer, the experimental findings can qualitatively be explained.

  12. Electron density profile measurements at a self-focusing ion beam with high current density and low energy extracted through concave electrodes

    SciTech Connect

    Fujiwara, Y. Nakamiya, A.; Sakakita, H.; Hirano, Y.; Kiyama, S.; Koguchi, H.

    2014-02-15

    The self-focusing phenomenon has been observed in a high current density and low energy ion beam. In order to study the mechanism of this phenomenon, a special designed double probe to measure the electron density and temperature is installed into the chamber where the high current density ion beam is injected. Electron density profile is successfully measured without the influence of the ion beam components. Estimated electron temperature and density are ∼0.9 eV and ∼8 × 10{sup 8} cm{sup −3} at the center of ion beam cross section, respectively. It was found that a large amount of electrons are spontaneously accumulated in the ion beam line in the case of self-forcing state.

  13. The ANSTO high energy heavy ion microprobe

    NASA Astrophysics Data System (ADS)

    Siegele, Rainer; Cohen, David D.; Dytlewski, Nick

    1999-10-01

    Recently the construction of the ANSTO High Energy Heavy Ion Microprobe (HIMP) at the 10 MV ANTARES tandem accelerator has been completed. The high energy heavy ion microprobe focuses not only light ions at energies of 2-3 MeV, but is also capable of focusing heavy ions at high energies with ME/ q2 values up to 150 MeV amu and greater. First performance tests and results are reported here.

  14. ION BEAM FOCUSING MEANS FOR CALUTRON

    DOEpatents

    Backus, J.G.

    1959-06-01

    An ion beam focusing arrangement for calutrons is described. It provides a virtual focus of origin for the ion beam so that the ions may be withdrawn from an arc plasma of considerable width providing greater beam current and accuracy. (T.R.H.)

  15. Nanofabrication by Focused Ion Beam

    DTIC Science & Technology

    1993-09-28

    MASTER COPY KEEP THIS COPY FOR REPRODUCTION PURPOSES AD-A271 290 )N PAGE orhan Sand .01fMI.,r re ~’.nq tn., Oiurda N0o.me 0& Of .018l 04v~~t P - .L...Institute of Technology Cambridge, MA 02139 APPROVED FOR PUBLIC RELEASE; N, S c; . DISTRIBUTION UNLIMITED u..d.. `. B y .. . . . . . .. Dist A-jr I...defined sidewalls indicate that much finer lithography would be possible with a1 more optimum beam. b ) Preferential Oxide growth after ion exposure. (In

  16. Focused electron and ion beam systems

    DOEpatents

    Leung, Ka-Ngo; Reijonen, Jani; Persaud, Arun; Ji, Qing; Jiang, Ximan

    2004-07-27

    An electron beam system is based on a plasma generator in a plasma ion source with an accelerator column. The electrons are extracted from a plasma cathode in a plasma ion source, e.g. a multicusp plasma ion source. The beam can be scanned in both the x and y directions, and the system can be operated with multiple beamlets. A compact focused ion or electron beam system has a plasma ion source and an all-electrostatic beam acceleration and focusing column. The ion source is a small chamber with the plasma produced by radio-frequency (RF) induction discharge. The RF antenna is wound outside the chamber and connected to an RF supply. Ions or electrons can be extracted from the source. A multi-beam system has several sources of different species and an electron beam source.

  17. Energy- and time-resolved measurements of fast ions emitted from plasma-focus discharges by means of a Thomson spectrometer

    NASA Astrophysics Data System (ADS)

    Kwiatkowski, R.; Czaus, K.; Paduch, M.; Sadowski, M. J.; Skladnik-Sadowska, E.; Zaloga, D. R.; Zielinska, E.; Żebrowski, J.

    2015-09-01

    The paper presents results of time-resolved measurements of fast deuterons emitted from high-current discharges of the Plasma-Focus (PF) type. The measurements were performed in a modified PF-1000U facility which is operated at the IFPiLM in Warsaw, Poland. The device was equipped with a fast-acting gas valve placed inside the inner electrode and oriented along the z-axis. The valve could inject a small volume of a chosen gas in front of this electrode. The PF discharges were initiated at the initial deuterium pressure equal to 1.6 or 2 hPa, with or without the use of the gas-puffing. Such discharges emitted intense beams of accelerated primary ions and X-ray pulses as well as products of nuclear fusion reactions. The reported measurements of the fast ion beams were performed by means of a Thomson-type spectrometer located at a chosen distance at the z-axis and equipped with miniature scintillation detectors. These detectors were placed in different points upon the deuteron parabola which corresponded to determined energy values. The detectors configuration allowed us to determine instants of the ion emission (using a TOF technique) and to compare them with instants of the X-ray emission. The collected data provided important information about emission characteristics of the modified PF-1000U facility.

  18. Monte Carlo simulations of nanoscale focused neon ion beam sputtering.

    PubMed

    Timilsina, Rajendra; Rack, Philip D

    2013-12-13

    A Monte Carlo simulation is developed to model the physical sputtering of aluminum and tungsten emulating nanoscale focused helium and neon ion beam etching from the gas field ion microscope. Neon beams with different beam energies (0.5-30 keV) and a constant beam diameter (Gaussian with full-width-at-half-maximum of 1 nm) were simulated to elucidate the nanostructure evolution during the physical sputtering of nanoscale high aspect ratio features. The aspect ratio and sputter yield vary with the ion species and beam energy for a constant beam diameter and are related to the distribution of the nuclear energy loss. Neon ions have a larger sputter yield than the helium ions due to their larger mass and consequently larger nuclear energy loss relative to helium. Quantitative information such as the sputtering yields, the energy-dependent aspect ratios and resolution-limiting effects are discussed.

  19. The Ion Conveyor. An ion focusing and conveying device.

    PubMed

    Colburn, Alex W; Giannakopulos, A E; Derrick, Peter J

    2004-01-01

    The control and transmission of ions or small charged droplets in the intermediate to high-pressure regime is of primary importance in areas such as atmospheric pressure ionisation. Where small apertures separate differentially pumped vacuum regions in the inlet systems to mass spectrometers, a large proportion of the available ion current is lost to the surrounding electrode structures. A new ion-optical device, named the ion conveyor, incorporating electrodynamic focusing and conveying of charged entities is described. Results from ion-optical simulations are presented demonstrating the performance of the device in various operating modes and electrode configurations.

  20. Focused Ion Beam Technology for Optoelectronic Devices

    NASA Astrophysics Data System (ADS)

    Reithmaier, J. P.; Bach, L.; Forchel, A.

    2003-08-01

    High-resolution proximity free lithography was developed using InP as anorganic resist for ion beam exposure. InP is very sensitive on ion beam irradiation and show a highly nonlinear dose dependence with a contrast function comparable to organic electron beam resists. In combination with implantation induced quantum well intermixing this new lithographic technique based on focused ion beams is used to realize high performance nano patterned optoelectronic devices like complex coupled distributed feedback (DFB) and distributed Bragg reflector (DBR) lasers.

  1. Focused-Ion-Beam Material Removal Rates

    DTIC Science & Technology

    1993-09-01

    AD-A270 852 SIll II 111111111 lillI I ARMY RESEARCH LABORATORY Focused -Ion-Beam Material Removal Rates by Bruce GeOl ARL-MR-1 14 September 1993 93...DATES COVERED September 1993 Summary, January 1991-present 4. TITLE AND SUBTITLE 5. FUNDING NUMBERS Focused -Ion-Beam Material Removal Rates PE: 91A 6...AUTHOR( S ) Bruce Geil 7. PERFORMING ORGANIZATION NAME( S ) AND ADDRESS(ES) 8. PERFORMING ORGANIZATION U.S. Army Research Laboratory REPORT NUMBER Attn

  2. Focused ion beam micromilling and articles therefrom

    DOEpatents

    Lamartine, B.C.; Stutz, R.A.

    1998-06-30

    An ultrahigh vacuum focused ion beam micromilling apparatus and process are disclosed. Additionally, a durable data storage medium using the micromilling process is disclosed, the durable data storage medium capable of storing, e.g., digital or alphanumeric characters as well as graphical shapes or characters. 6 figs.

  3. Focused ion beam micromilling and articles therefrom

    DOEpatents

    Lamartine, Bruce C.; Stutz, Roger A.

    1998-01-01

    An ultrahigh vacuum focused ion beam micromilling apparatus and process are isclosed. Additionally, a durable data storage medium using the micromilling process is disclosed, the durable data storage medium capable of storing, e.g., digital or alphanumeric characters as well as graphical shapes or characters.

  4. A subnanosecond pulsed ion source for micrometer focused ion beams.

    PubMed

    Höhr, C; Fischer, D; Moshammer, R; Dorn, A; Ullrich, J

    2008-05-01

    A new, compact design of an ion source delivers nanosecond pulsed ion beams with low emittance, which can be focused to micrometer size. By using a high-power, 25 fs laser pulse focused into a gas region of 10(-6) mbar, ions at very low temperatures are produced in the small laser focal volume of 5 mum diameter by 20 mum length through multiphoton ionization. These ions are created in a cold environment, not in a hot plasma, and, since the ionization process itself does not significantly heat them, have as a result essentially room temperature. The generated ion pulse, up to several thousand ions per pulse, is extracted from the source volume with ion optical elements that have been carefully designed by simulation calculations. Externally triggered, its subnanosecond duration and even smaller time jitter allow it to be superimposed with other pulsed particle or laser beams. It therefore can be combined with any type of collision experiment where the size and the time structure of the projectile beam crucially affect the achievable experimental resolution.

  5. Metal assisted focused-ion beam nanopatterning

    NASA Astrophysics Data System (ADS)

    Kannegulla, Akash; Cheng, Li-Jing

    2016-09-01

    Focused-ion beam milling is a versatile technique for maskless nanofabrication. However, the nonuniform ion beam profile and material redeposition tend to disfigure the surface morphology near the milling areas and degrade the fidelity of nanoscale pattern transfer, limiting the applicability of the technique. The ion-beam induced damage can deteriorate the performance of photonic devices and hinders the precision of template fabrication for nanoimprint lithography. To solve the issue, we present a metal assisted focused-ion beam (MAFIB) process in which a removable sacrificial aluminum layer is utilized to protect the working material. The new technique ensures smooth surfaces and fine milling edges; in addition, it permits direct formation of v-shaped grooves with tunable angles on dielectric substrates or metal films, silver for instance, which are rarely achieved by using traditional nanolithography followed by anisotropic etching processes. MAFIB was successfully demonstrated to directly create nanopatterns on different types of substrates with high fidelity and reproducibility. The technique provides the capability and flexibility necessary to fabricate nanophotonic devices and nanoimprint templates.

  6. Laser energized traveling wave accelerator - a novel scheme for simultaneous focusing, energy selection and post-acceleration of laser-driven ions

    NASA Astrophysics Data System (ADS)

    Kar, Satyabrata

    2015-11-01

    All-optical approaches to particle acceleration are currently attracting a significant research effort internationally. Where intense laser driven proton beams, mainly by the so called Target Normal Sheath Acceleration mechanism, have attractive properties such as brightness, laminarity and burst duration, overcoming some of the inherent shortcomings, such as large divergence, broad spectrum and slow ion energy scaling poses significant scientific and technological challenges. High power lasers are capable of generating kiloampere current pulses with unprecedented short duration (10s of picoseconds). The large electric field from such localized charge pulses can be harnessed in a traveling wave particle accelerator arrangement. By directing the ultra-short charge pulse along a helical path surrounding a laser-accelerated ion beams, one can achieve simultaneous beam shaping and re-acceleration of a selected portion of the beam by the components of the associated electric field within the helix. In a proof-of-principle experiment on a 200 TW university-scale laser, we demonstrated post-acceleration of ~108 protons by ~5 MeV over less than a cm of propagation - i.e. an accelerating gradient ~0.5 GeV/m, already beyond what can be sustained by conventional accelerator technologies, with dynamic beam collimation and energy selection. These results open up new opportunities for the development of extremely compact and cost-effective ion accelerators for both established and innovative applications.

  7. Focused ion beams using a high-brightness plasma source

    NASA Astrophysics Data System (ADS)

    Guharay, Samar

    2002-10-01

    High-brightness ion beams, with low energy spread, have merits for many new applications in microelectronics, materials science, and biology. Negative ions are especially attractive for the applications that involve beam-solid interactions. When negative ions strike a surface, especially an electrically isolated surface, the surface charging voltage is limited to few volts [1]. This property can be effectively utilized to circumvent problems due to surface charging, such as device damage and beam defocusing. A compact plasma source, with the capability to deliver either positive or negative ion beams, has been developed. H- beams from this pulsed source showed brightness within an order of magnitude of the value for beams from liquid-metal ion sources. The beam angular intensity is > 40 mAsr-1 and the corresponding energy spread is <2.5 eV [2]. Using a simple Einzel lens with magnification of about 0.1, a focused current density of about 40 mAcm-2 is obtained. It is estimated that an additional magnification of about 0.1 can yield a focused current density of > 1 Acm-2 and a spot size of 100 nm. Such characteristics of focused beam parameters, using a dc source, will immediately open up a large area of new applications. [1] P. N. Guzdar, A. S. Sharma, S. K. Guharay, "Charging of substrates irradiated by particle beams" Appl. Phys. Lett. 71, 3302 (1997). [2] S. K. Guharay, E. Sokolovsky, J. Orloff, "Characteristics of ion beams from a Penning source for focused ion beam applications" J. Vac. Sci Technol. B17, 2779 (1999).

  8. Ion-beam focusing in a double-plasma device

    NASA Technical Reports Server (NTRS)

    Johnson, James C.; D'Angelo, Nicola; Merlino, Robert L.

    1988-01-01

    The authors studied the propagation of a low-energy charge-neutralized ion beam injected into the target region of a long double-plasma device. A magnetic field of up to about 180 G may be applied along the axis of the device. As a result of charge exchange collisions, the ion beam is attenuated as it propagates into the target region. However, under certain conditions of magnetic field strength and neutral gas pressure, the authors have observed a `reemergence' of the beam on axis far downstream in the target. This reemergence of the ion beam is attributed to a focusing of the ions by a self-consistently produced radial ambipolar electric field. The effect may be expected to occur in other types of plasma devices as well, whenever a sufficiently large radially inward electric field is present.

  9. Close Up Special Focus: Energy.

    ERIC Educational Resources Information Center

    Mayer, Fritz; And Others

    Designed to accompany a 30-minute seminar televised over the Cable Satellite Public Affairs Network (C-SPAN), this handbook contains 4 readings on energy for high school students. Following an introduction on energy policy formulation, the first selection outlines the role of nuclear energy in America's future. Included are insets on the operation…

  10. Close Up Special Focus: Energy.

    ERIC Educational Resources Information Center

    Mayer, Fritz; And Others

    Designed to accompany a 30-minute seminar televised over the Cable Satellite Public Affairs Network (C-SPAN), this handbook contains 4 readings on energy for high school students. Following an introduction on energy policy formulation, the first selection outlines the role of nuclear energy in America's future. Included are insets on the operation…

  11. Combined electron and focused ion beam system for improvement of secondary ion yield in secondary ion mass spectrometry instrument

    SciTech Connect

    Ji, L.; Ji, Q.; Leung, K.-N.; Gough, R. A.

    2006-10-16

    Using a combined electron and focused ion beam system to improve performance of secondary ion mass spectrometry instruments has been investigated experimentally. The secondary ion yield for an Al target has been enhanced to about one order of magnitude higher with the postionization induced by the low energy electrons in the combined beam. It can be further improved with the increase of electron beam current. When the combined beam is applied to insulating targets, sample charging is also eliminated. For Teflon targets, the secondary ion signal is increased by more than a factor of 20.

  12. A Scaled Final Focus Experiment for Heavy Ion Fusion

    SciTech Connect

    MacLaren, Stephan Alexander

    2000-09-19

    A one-tenth dimensionally scaled version of a final focus sub-system design for a heavy ion fusion driver is built and tested. By properly scaling the physics parameters that relate particle energy and mass, beam current, beam emittance, and focusing field, the transverse dynamics of a driver scale final focus are replicated in a small laboratory beam. The experiment uses a 95 μA beam of 160 keV Cs+ ions to study the dynamics as the beam is brought to a ballistic focus in a lattice of six quadrupole magnets. Diagnostic stations along the experiment track the evolution of the transverse phase space of the beam. The measured focal spot size is consistent with calculations and the report of the design on which the experiment is based. By uniformly varying the strengths of the focusing fields in the lattice, the chromatic effect of a small energy deviation on the spot size can be reproduced. This is done for ±1% and ±2% shifts and the changes in the focus are measured. Additionally, a 400 μA beam is propagated through the experiment and partially neutralized after the last magnet using electrons released from a hot tungsten filament. The increase in beam current allows for the observation of significant effects on both the size and shape of the focal spot when the electrons are added.

  13. Atomic layer deposition ultrathin film origami using focused ion beams

    NASA Astrophysics Data System (ADS)

    Supekar, O. D.; Brown, J. J.; Eigenfeld, N. T.; Gertsch, J. C.; Bright, V. M.

    2016-12-01

    Focused ion beam (FIB) micromachining is a powerful tool for maskless lithography and in recent years FIB has been explored as a tool for strain engineering. Ion beam induced deformation can be utilized as a means for folding freestanding thin films into complex 3D structures. FIB of high energy gallium (Ga+) ions induces stress by generation of dislocations and ion implantation within material layers, which create creases or folds upon mechanical relaxation enabled by motion of the material layers. One limitation on such processing is the ability to fabricate flat freestanding thin film structures. This capability is limited by the residual stresses formed during processing and fabrication of the films, which can result in initial curvature and deformation of films upon release from a sacrificial fabrication layer. This paper demonstrates folding in freestanding ultrathin films (<40 nm thin) of heterogeneous composition (metal, insulator, semiconductor, etc) with large lateral dimension structures (aspect ratio >1:1000) by ion-induced stress relaxation. The ultrathin flat structures are fabricated using atomic layer deposition on sacrificial polyimide. We have demonstrated vertical folding with 30 keV Ga+ ions in structures with lateral dimensions varying from 10 to 50 μm.

  14. Atomic layer deposition ultrathin film origami using focused ion beams.

    PubMed

    Supekar, O D; Brown, J J; Eigenfeld, N T; Gertsch, J C; Bright, V M

    2016-12-09

    Focused ion beam (FIB) micromachining is a powerful tool for maskless lithography and in recent years FIB has been explored as a tool for strain engineering. Ion beam induced deformation can be utilized as a means for folding freestanding thin films into complex 3D structures. FIB of high energy gallium (Ga(+)) ions induces stress by generation of dislocations and ion implantation within material layers, which create creases or folds upon mechanical relaxation enabled by motion of the material layers. One limitation on such processing is the ability to fabricate flat freestanding thin film structures. This capability is limited by the residual stresses formed during processing and fabrication of the films, which can result in initial curvature and deformation of films upon release from a sacrificial fabrication layer. This paper demonstrates folding in freestanding ultrathin films (<40 nm thin) of heterogeneous composition (metal, insulator, semiconductor, etc) with large lateral dimension structures (aspect ratio >1:1000) by ion-induced stress relaxation. The ultrathin flat structures are fabricated using atomic layer deposition on sacrificial polyimide. We have demonstrated vertical folding with 30 keV Ga(+) ions in structures with lateral dimensions varying from 10 to 50 μm.

  15. Industry focus: industrial wood energy

    SciTech Connect

    Not Available

    1982-01-01

    A special feature including a buyers' guide for wood energy equipment and 5 articles by separate authors: Beijer, J. Reforestation plan aims to make steel from trees. 11-12. Eucalypts grown on the Minas Gerais hills in south-central Brazil will soon become the prime source of charcoal for the blast furnaces of Florestal Acesita steel mill. Simpson, W.; Tschernitz, J. Low-cost solar dry kiln gets trial in Sri Lanka. p. 13 Fraser, H.R. Wood-fueled power plant heats debate in Germany. 14-15. Orr, A. Cogeneration - how to get double duty from energy. 16-17. Fraser, H.R. Energy (methanol) from wood is goal of ambitious Brazilian plant. p.18.

  16. Radio frequency sustained ion energy

    DOEpatents

    Jassby, Daniel L.; Hooke, William M.

    1977-01-01

    Electromagnetic (E.M.) energy injection method and apparatus for producing and sustaining suprathermal ordered ions in a neutral, two-ion-species, toroidal, bulk equilibrium plasma. More particularly, the ions are produced and sustained in an ordered suprathermal state of existence above the average energy and velocity of the bulk equilibrium plasma by resonant rf energy injection in resonance with the natural frequency of one of the ion species. In one embodiment, the electromagnetic energy is injected to clamp the energy and velocity of one of the ion species so that the ion energy is increased, sustained, prolonged and continued in a suprathermal ordered state of existence containing appreciable stored energy that counteracts the slowing down effects of the bulk equilibrium plasma drag. Thus, selective deuteron absorption may be used for ion-tail creation by radio-frequency excitation alone. Also, the rf can be used to increase the fusion output of a two-component neutral injected plasma by selective heating of the injected deuterons.

  17. Developments in focused ion beam metrology

    NASA Astrophysics Data System (ADS)

    Salen, Jesse A.; Athas, Gregory J.; Barnes, Drew; Bassom, Neil J.; Yansen, Don E.

    1998-09-01

    We present the ability of a focused ion beam system (FIB) to perform as an effective metrology tool. This feature is a benefit in areas where FIB technology is or can be used, or where pre-measurement cross-sectioning is required, such as the case in thin film head trimming, integrated circuit inspection, and micro-electromechanical device (MEMS) development. The FIB is a proven tool for taking high- resolution images, performing mills and depositions, and cross-sectioning samples. We demonstrate the FIB's ability to perform these tasks in a repeatable manner and take accurate measurements independently of the operator. First, we find a quantitative method for analyzing the image quality in order to remove any operator discrepancy. We show that this task can be achieved by analyzing the FIB's Modulation Transfer Function (MTF). The MTF is a proven method for measuring the quality of light optics, but has never been used as a standard in FIB imaging because sub- 100m pitch resolution targets can not easily be fabricated; however, we demonstrate a new method for obtaining the MTF. By correlating changes in FIB parameters to changes in the MTF, we have a FIB image standard, as well as an image calibration tool that is transparent to the operator. Second, we describe how current FIB software can use an automated 'measure tool' to take accurate measurements independently of the operator. We show that when using both these methods, the FIB is a repeatable metrology tool for a variety of applications.

  18. Development of a focused ion beam micromachining system

    SciTech Connect

    Pellerin, J.G.; Griffis, D.; Russell, P.E.

    1988-12-01

    Focused ion beams are currently being investigated for many submicron fabrication and analytical purposes. An FIB micromachining system consisting of a UHV vacuum system, a liquid metal ion gun, and a control and data acquisition computer has been constructed. This system is being used to develop nanofabrication and nanomachining techniques involving focused ion beams and scanning tunneling microscopes.

  19. Needs of Non Energy-Focused Contractors

    SciTech Connect

    Liaukus, C.

    2012-12-01

    To better understand the informational needs of non energy-focused contractors, including what information they need to motivate them to become energy-focused, the BARA team studied the type of information provided by the national programs, trade associations, and manufacturers that were researched for the related technical report: Effective Communication of Energy Efficiency. While that report focused on the delivery method, format, and strategy of the information, this study examines the content being put forward.

  20. Needs of Non-Energy Focused Contractors

    SciTech Connect

    Liakus, C.

    2012-12-01

    To better understand the informational needs of non-energy focused contractors, including what information they need to motivate them to become energy-focused, the BARA team studied the type of information provided by the national programs, trade associations, and manufacturers that were researched for the related technical report: Effective Communication of Energy Efficiency. While that report focused on the delivery method, format, and strategy of the information, this study examines the content being put forward.

  1. Nuclear fusion of advanced fuels using converging focused ion beams

    NASA Astrophysics Data System (ADS)

    Egle, Brian James

    The Six Ion Gun Fusion Experiment (SIGFE) was designed and built to investigate a possible avenue to increase the reaction rate efficiency of the D-D and D-3He nuclear fusion reactions in Inertial Electrostatic Confinement (IEC) devices to the levels required for several non-electric applications of nuclear fusion. The SIGFE is based on the seminal IEC experiment published by Hirsch in 1967, and is the first experiment to recreate the results and unique features of the Hirsch device. The SIGFE used six identical ion beams to focus and converge deuterium and helium-3 ions into a sphere of less than 2 mm at nearly mono-energetic ion energies up to 150 keV. With improved ion optics and diagnostics, the SIGFE concluded that within the investigated parameter space, the region where the ion beams converged accounted for less than 0.2% of the total D-D fusion reactions. The maximum D-D fusion rates were observed when the ion beams were intentionally defocused to strike the inside surface of the cathode lenses. In this defocused state, the total D-D fusion rate increased when the chamber pressure was decreased. The maximum D-D fusion rate was 4.3 x 107 neutrons per second at a cathode voltage of -130 kV, a total cathode current of 10 mA, and a chamber pressure of 27 mPa. The D and 3He ion beams were produced in six self-contained ion gun modules. The modules were each capable of at least 4 mA of ion current while maintaining a main chamber pressure as low as 13 mPa. The theoretically calculated extractable ion current agreed with the experiment within a factor of 2. A concept was also developed and evaluated for the production of radioisotopes from the 14.7 MeV D-3He fusion protons produced in an IEC device. Monte Carlo simulations of this concept determined that a D-3He fusion rate on the order of 1011 s-1 would be required for an IEC device to produce 1 mCi of the 11C radioisotope.

  2. Scattering effects in passive foil focusing of ion beams

    DOE PAGES

    Yuen, Albert; Lund, Steven M.; Barnard, John J.; ...

    2015-09-11

    A stack of thin, closely spaced conducting foils has been investigated by Lund et al. [Phys. Rev. ST Accel. Beams 16, 044202 (2013)] as a passive focusing lens for intense ion beams. The foils mitigate space-charge defocusing forces to enable the beam self-magnetic field to focus. In this study, we analyze possible degradation of focusing due to scattering of beam ions resulting from finite foil thickness using an envelope model and numerical simulations with the particle-in-cell code WARP. Ranges of kinetic energy where scattering effects are sufficient to destroy passive focusing are quantified. The scheme may be utilized to focusmore » protons produced in intense laser-solid accelerator schemes. The spot size of an initially collimated 30 MeV proton beam with initial rms radius 200 μm, perveance Q=1.8×10-2, and initial transverse emittance ϵx,rms=0.87 mm mrad propagating through a stack of 6.4 μm thick foils, spaced 100 μm apart, gives a 127.5 μm spot with scattering and a 81.0 μm spot without scattering, illustrating the importance of including scattering effects.« less

  3. Revitalize Electrical Program with Renewable Energy Focus

    ERIC Educational Resources Information Center

    Karns, Robert J.

    2012-01-01

    Starting a renewable energy technology (RET) program can be as simple as shifting the teaching and learning focus of a traditional electricity program toward energy production and energy control systems. Redirecting curriculum content and delivery to address photovoltaic solar (PV solar) technology and small wind generation systems is a natural…

  4. Revitalize Electrical Program with Renewable Energy Focus

    ERIC Educational Resources Information Center

    Karns, Robert J.

    2012-01-01

    Starting a renewable energy technology (RET) program can be as simple as shifting the teaching and learning focus of a traditional electricity program toward energy production and energy control systems. Redirecting curriculum content and delivery to address photovoltaic solar (PV solar) technology and small wind generation systems is a natural…

  5. Focused Ion Beam Fabrication of Microelectronic Structures

    DTIC Science & Technology

    1990-12-01

    writ- (5400 A thick, - 50 at. % Au), pumping out the organome- ing across preevaporated metal (Au, W, AL, and NiCr ) con- tallic gas and then sputtering ...surface interaction is multifaceted. Energetic ions (the relevant range in this field has been 1-300 keV) incident on a surface will: a) sputter off...main commercial applications of these columns, namely, photomask repair and integrated circuit restructuring, diagnostics and repair, exploit sputtering

  6. Focused ion beam lithography and anodization combined nanopore patterning.

    PubMed

    Lu, Kathy; Zhao, Jingzhong

    2010-10-01

    In this study, focused ion beam lithography and anodization are combined to create different nanopore patterns. Uniform-, alternating-, and gradient-sized shallow nanopore arrays are first made on high purity aluminum by focused ion beam lithography. These shallow pore arrays are then used as pore initiation sites during anodization by different electrolytes. Depending on the nature of the anodization electrolyte, the nanopore patterns by focused ion beam lithography play different roles in further pore development during anodization. The pore-to-pore distance by focused ion beam lithography should match with that by anodization for guided pore development to be effective. Ordered and heterogeneous nanopore arrays are obtained by the focused ion beam lithography and anodization combined approach.

  7. EDITORIAL: Focus on Heavy Ions in Biophysics and Medical Physics FOCUS ON HEAVY IONS IN BIOPHYSICS AND MEDICAL PHYSICS

    NASA Astrophysics Data System (ADS)

    Durante, Marco

    2008-07-01

    include carcinogenesis, late degenerative tissue effects (including damage to the central nervous system), and hereditary effects. For these studies, microbeams represent an essential tool, considering that in space each cell in the human body will not experience more than one heavy-ion traversal. Both NASA and ESA are investing important resources in ground-based space radiation research programs, to reduce risk uncertainty and to develop countermeasures. For both cancer therapy and space radiation protection a better understanding of the effects of energetic heavy ions is needed. Physics should be improved, especially the measurements of nuclear fragmentation cross-sections, and the transport calculations. Biological effects need to be studied in greater detail, and clearly only understanding the mechanisms of heavy-ion induced biological damage will reduce the uncertainty on late effects in humans. This focus issue of New Journal of Physics aims to provide the state-of-the-art of the biophysics of energetic heavy ions and to highlight the areas where more research is urgently needed for therapy and the space program. Focus on Heavy Ions in Biophysics and Medical Physics Contents Heavy ion microprobes: a unique tool for bystander research and other radiobiological applications K O Voss, C Fournier and G Taucher-Scholz Heavy ions light flashes and brain functions: recent observations at accelerators and in spaceflight L Narici Clinical advantages of carbon-ion radiotherapy Hirohiko Tsujii, Tadashi Kamada, Masayuki Baba, Hiroshi Tsuji, Hirotoshi Kato, Shingo Kato, Shigeru Yamada, Shigeo Yasuda, Takeshi Yanagi, Hiroyuki Kato, Ryusuke Hara, Naotaka Yamamoto and Junetsu Mizoe Heavy-ion effects: from track structure to DNA and chromosome damage F Ballarini, D Alloni, A Facoetti and A Ottolenghi Shielding experiments with high-energy heavy ions for spaceflight applications C Zeitlin, S Guetersloh, L Heilbronn, J Miller, N Elkhayari, A Empl, M LeBourgeois, B W Mayes, L Pinsky

  8. Low energy ion-molecule reactions

    SciTech Connect

    Farrar, J.M.

    1993-12-01

    This project is concerned with elucidating the dynamics of elementary ion-molecule reactions at collision energies near and below 1 eV. From measurements of the angular and energy distributions of the reaction products, one can infer intimathe details about the nature of collisions leading to chemical reaction, the geometries and lifetimes of intermediate complexes that govern the reaction dynamics, and the collision energy dependence of these dynamical features. The author employs crossed-beam low energy mass spectrometry technology developed over the last several years, with the focus of current research on proton transfer and hydrogen atom transfer reactions of te O{sup {minus}} ion with species such as HF, H{sub 2}O, and NH{sub 3}.

  9. Imaging nanophotonic modes of microresonators using a focused ion beam

    NASA Astrophysics Data System (ADS)

    Twedt, Kevin A.; Zou, Jie; Davanco, Marcelo; Srinivasan, Kartik; McClelland, Jabez J.; Aksyuk, Vladimir A.

    2016-01-01

    Optical microresonators have proven powerful in a wide range of applications, including cavity quantum electrodynamics, biosensing, microfludics, cavity optomechanics and optical frequency combs. Their performance depends critically on the exact distribution of optical energy, confined and shaped by the nanoscale device geometry. Near-field optical probes can image this distribution, but the physical probe necessarily perturbs the near field, which is particularly problematic for sensitive high-quality-factor resonances. We present a new approach to mapping nanophotonic modes that uses a controllably small and local optomechanical perturbation introduced by a focused lithium ion beam. An ion beam (radius of ≈50 nm) induces a picometre-scale deformation of the resonator surface, which we detect through shifts in the optical resonance wavelengths. We map five modes of a silicon microdisk resonator (Q ≥ 20,000) with high spatial and spectral resolution. Our technique also enables in situ observation of ion implantation damage and relaxation dynamics in a silicon lattice.

  10. Imaging Nanophotonic Modes of Microresonators using a Focused Ion Beam

    PubMed Central

    Twedt, Kevin A.; Zou, Jie; Davanco, Marcelo; Srinivasan, Kartik; McClelland, Jabez J.; Aksyuk, Vladimir A.

    2016-01-01

    Optical microresonators have proven powerful in a wide range of applications, including cavity quantum electrodynamics1–3, biosensing4, microfludics5, and cavity optomechanics6–8. Their performance depends critically on the exact distribution of optical energy, confined and shaped by the nanoscale device geometry. Near-field optical probes9 can image this distribution, but the physical probe necessarily perturbs the near field, which is particularly problematic for sensitive high quality factor resonances10,11. We present a new approach to mapping nanophotonic modes that uses a controllably small and local optomechanical perturbation introduced by a focused lithium ion beam12. An ion beam (radius ≈50 nm) induces a picometer-scale dynamic deformation of the resonator surface, which we detect through a shift in the optical resonance wavelength. We map five modes of a silicon microdisk resonator (Q≥20,000) with both high spatial and spectral resolution. Our technique also enables in-situ observation of ion implantation damage and relaxation dynamics in a silicon lattice13,14. PMID:27087832

  11. Ion energy analyzer for measurement of ion turbulent transport

    NASA Astrophysics Data System (ADS)

    Sokolov, V.; Sen, A. K.

    2012-10-01

    For local measurement of radial ion thermal transport, we developed a novel time-resolved gridded ion energy analyzer. The turbulent thermal flux is obtained by correlating fluctuations of ion temperature, plasma density and plasma velocity. The simultaneous measurement of the ion current fluctuations from an ion energy analyzer tilde I_{IEA} (t) and the fluctuation of ion saturation current from a conventional Langmuir probe tilde I_{LP} (t) allow us to determine local fluctuations of ion temperature tilde T_i (t). To reduce the effect of plasma potential fluctuations in the energy analyzer measurements, we use special a compensative circuit loop.

  12. A Nanoscale-Localized Ion Damage Josephson Junction Using Focused Ion Beam and Ion Implanter.

    PubMed

    Wu, C H; Ku, W S; Jhan, F J; Chen, J H; Jeng, J T

    2015-05-01

    High-T(c) Josephson junctions were fabricated by nanolithography using focused ion beam (FIB) milling and ion implantation. The junctions were formed in a YBa2Cu3O7-x, thin film in regions defined using a gold-film mask with 50-nm-wide (top) slits, engraved by FIB. The focused ion beam system parameters for dwell time and passes were set to remove gold up to a precise depth. 150 keV oxygen ions were implanted at a nominal dose of up to 5 x 10(13) ions/cm2 into YBa2Cu3O7-x microbridges through the nanoscale slits. The current-voltage curves of the ion implantation junctions exhibit resistive-shunted-junction-like behavior at 77 K. The junction had an approximately linear temperature dependence of critical current. Shapiro steps were observed under microwave irradiation. A 50-nm-wide slit and 0-20-nm-thick buffer layers were chosen in order to make Josephson junctions due to the V-shape of the FIB-milled trench.

  13. Atomistic simulations of focused ion beam machining of strained silicon

    NASA Astrophysics Data System (ADS)

    Guénolé, J.; Prakash, A.; Bitzek, E.

    2017-09-01

    The focused ion beam (FIB) technique has established itself as an indispensable tool in the material science community, both to analyze samples and to prepare specimens by FIB milling. In combination with digital image correlation (DIC), FIB milling can, furthermore, be used to evaluate intrinsic stresses by monitoring the strain release during milling. The irradiation damage introduced by such milling, however, results in a change in the stress/strain state and elastic properties of the material; changes in the strain state in turn affect the bonding strength, and are hence expected to implicitly influence irradiation damage formation and sputtering. To elucidate this complex interplay between strain, irradiation damage and sputtering, we perform TRIM calculations and molecular dynamics simulations on silicon irradiated by Ga+ ions, with slab and trench-like geometries, whilst simultaneously applying uniaxial tensile and compressive strains up to 4%. In addition we calculate the threshold displacement energy (TDE) and the surface binding energy (SBE) for various strain states. The sputter rate and amount of damage produced in the MD simulations show a clear influence of the strain state. The SBE shows no significant dependence on strain, but is strongly affected by surface reconstructions. The TDE shows a clear strain-dependence, which, however, cannot explain the influence of strain on the extent of the induced irradiation damage or the sputter rate.

  14. Applications of focused ion beam systems in gunshot residue investigation.

    PubMed

    Niewöhner, L; Wenz, H W

    1999-01-01

    Scanning ion microscopy technology has opened a new door to forensic scientists, allowing the GSR investigator to see inside a particle's core. Using a focused ion beam, particles can be cross-sectioned, revealing interior morphology and character that can be utilized for identification of the ammunition manufacturer.

  15. Funnel cone for focusing intense ion beams on a target

    SciTech Connect

    Bieniosek, F.M.; Henestroza, E.; Ni, P.

    2009-10-05

    We describe a funnel cone for concentrating an ion beam on a target. The cone utilizes the reflection characteristic of ion beams on solid walls to focus the incident beam andincrease beam intensity on target. The cone has been modeled with the TRIM code. A prototype has been tested and installed for use in the 350-keV K+ NDCX target chamber.

  16. Diagnostics of ion beam generated from a Mather type plasma focus device

    SciTech Connect

    Lim, L. K. Ngoi, S. K. Wong, C. S. Yap, S. L.

    2014-03-05

    Diagnostics of ion beam emission from a 3 kJ Mather-type plasma focus device have been performed for deuterium discharge at low pressure regime. Deuterium plasma focus was found to be optimum at pressure of 0.2 mbar. The energy spectrum and total number of ions per shot from the pulsed ion beam are determined by using biased ion collectors, Faraday cup, and solid state nuclear track detector CR-39. Average energy of the ion beam obtained is about 60 keV. Total number of the ions has been determined to be in the order of 10{sup 11} per shot. Solid state nuclear track detectors (SSNTD) CR39 are employed to measure the particles at all angular direction from end on (0°) to side on (90°). Particle tracks are registered by SSNTD at 30° to 90°, except the one at the end-on 0°.

  17. Multi-slit triode ion optical system with ballistic beam focusing

    SciTech Connect

    Davydenko, V. Amirov, V.; Gorbovsky, A.; Deichuli, P.; Ivanov, A.; Kolmogorov, A.; Kapitonov, V.; Mishagin, V.; Shikhovtsev, I.; Sorokin, A.; Stupishin, N.; Karpushov, A. N.; Smirnov, A.; Uhlemann, R.

    2016-02-15

    Multi-slit triode ion-optical systems with spherical electrodes are of interest for formation of intense focused neutral beams for plasma heating. At present, two versions of focusing multi-slit triode ion optical system are developed. The first ion optical system forms the proton beam with 15 keV energy, 140 A current, and 30 ms duration. The second ion optical system is intended for heating neutral beam injector of Tokamak Configuration Variable (TCV). The injector produces focused deuterium neutral beam with 35 keV energy, 1 MW power, and 2 s duration. In the later case, the angular beam divergence of the neutral beam is 20-22 mrad in the direction across the slits of the ion optical system and 12 mrad in the direction along the slits.

  18. Applications of the Lithium Focused Ion Beam: Nanoscale Electrochemistry and Microdisk Mode Imaging

    NASA Astrophysics Data System (ADS)

    McGehee, William; Takeuchi, Saya; Michels, Thomas; Oleshko, Vladimir; Aksyuk, Vladimir; Soles, Christopher; McClelland, Jabez; CenterNanoscale Science; Technology at NIST Collaboration; Materials Measurement Laboratory at NIST Collaboration

    2016-05-01

    The NIST-developed lithium Focused-Ion-Beam (LiFIB) system creates a low-energy, picoampere-scale ion beam from a photoionized gas of laser-cooled atoms. The ion beam can be focused to a <30 nm spot and scanned across a sample. This enables imaging through collection of ion-induced secondary electrons (similar to SEM) as well as the ability to selectively deposit lithium-ions into nanoscale volumes in a material. We exploit this second ability of the LiFIB to selectively ''titrate'' lithium ions as a means of probing the optical modes in microdisk resonators as well as for exploring nanoscale, Li-ion electrochemistry in battery-relevant materials. We present an overview of both measurements, including imaging of the optical mode in a silicon microdisk and a comparison of FIB and electrochemical lithiation of tin.

  19. High energy H- ion transport and stripping

    SciTech Connect

    Chou, W.; /Fermilab

    2005-05-01

    During the Proton Driver design study based on an 8 GeV superconducting RF H{sup -} linac, a major concern is the feasibility of transport and injection of high energy H{sup -} ions because the energy of H{sup -} beam would be an order of magnitude higher than the existing ones. This paper will focus on two key technical issues: (1) stripping losses during transport (including stripping by blackbody radiation, magnetic field and residual gases); (2) stripping efficiency of carbon foil during injection.

  20. Mini RF-driven ion source for focused ion beam system

    SciTech Connect

    Jiang, X.; Ji, Q.; Chang, A.; Leung, K.N.

    2002-08-02

    Mini RF-driven ion sources with 1.2 cm and 1.5 cm inner chamber diameter have been developed at Lawrence Berkeley National Laboratory. Several gas species have been tested including argon, krypton and hydrogen. These mini ion sources operate in inductively coupled mode and are capable of generating high current density ion beams at tens of watts. Since the plasma potential is relatively low in the plasma chamber, these mini ion sources can function reliably without any perceptible sputtering damage. The mini RF-driven ion sources will be combined with electrostatic focusing columns, and are capable of producing nano focused ion beams for micro machining and semiconductor fabrications.

  1. High-brightness Cs focused ion beam from a cold-atomic-beam ion source

    NASA Astrophysics Data System (ADS)

    Steele, A. V.; Schwarzkopf, A.; McClelland, J. J.; Knuffman, B.

    2017-06-01

    We present measurements of focal spot size and brightness in a focused ion beam system utilizing a laser-cooled atomic beam source of Cs ions. Spot sizes as small as (2.1 ± 0.2) nm (one standard deviation) and reduced brightness values as high as (2.4 ± 0.1) × 107 A m-2 Sr-1 eV-1 are observed with a 10 keV beam. This measured brightness is over 24 times higher than the highest brightness observed in a Ga liquid metal ion source. The behavior of brightness as a function of beam current and the dependence of effective source temperature on ionization energy are examined. The performance is seen to be consistent with earlier predictions. Demonstration of this source with very high brightness, producing a heavy ionic species such as Cs+, promises to allow significant improvements in resolution and throughput for such applications as next-generation circuit edit and nanoscale secondary ion mass spectrometry.

  2. Development of a linear-type double reflectron for focused imaging of photofragment ions from mass-selected complex ions

    NASA Astrophysics Data System (ADS)

    Okutsu, Kenichi; Nakashima, Yuji; Yamazaki, Kenichiro; Fujimoto, Keita; Nakano, Motoyoshi; Ohshimo, Keijiro; Misaizu, Fuminori

    2017-05-01

    An ion imaging apparatus with a double linear reflectron mass spectrometer has been developed, in order to measure velocity and angular distributions of mass-analyzed fragment ions produced by photodissociation of mass-selected gas phase complex ions. The 1st and the 2nd linear reflectrons were placed facing each other and controlled by high-voltage pulses in order to perform the mass-separation of precursor ions in the 1st reflectron and to observe the focused image of the photofragment ions in the 2nd reflectron. For this purpose, metal meshes were attached on all electrodes in the 1st reflectron, whereas the mesh was attached only on the last electrode in the 2nd reflectron. The performance of this apparatus was evaluated using imaging measurement of Ca+ photofragment ions from photodissociation reaction of Ca+Ar complex ions at 355 nm photoexcitation. The focused ion images were obtained experimentally with the double linear reflectron at the voltages of the reflection electrodes close to the predictions by ion trajectory simulations. The velocity and angular distributions of the produced Ca+ ([Ar] 4p1, 2P3/2) ion were analyzed from the observed images. The binding energy D0 of Ca+Ar in the ground state deduced in the present measurement was consistent with those determined theoretically and by spectroscopic measurements. The anisotropy parameter β of the transition was evaluated for the first time by this instrument.

  3. Whole-Cell Imaging at Nanometer Resolutions Using Fast and Slow Focused Helium Ions

    PubMed Central

    Chen, Xiao; Udalagama, Chammika N.B.; Chen, Ce-Belle; Bettiol, Andrew A.; Pickard, Daniel S.; Venkatesan, T.; Watt, Frank

    2011-01-01

    Observations of the interior structure of cells and subcellular organelles are important steps in unraveling organelle functions. Microscopy using helium ions can play a major role in both surface and subcellular imaging because it can provide subnanometer resolutions at the cell surface for slow helium ions, and fast helium ions can penetrate cells without a significant loss of resolution. Slow (e.g., 10–50 keV) helium ion beams can now be focused to subnanometer dimensions (∼0.25 nm), and keV helium ion microscopy can be used to image the surfaces of cells at high resolutions. Because of the ease of neutralizing the sample charge using a flood electron beam, surface charging effects are minimal and therefore cell surfaces can be imaged without the need for a conducting metallic coating. Fast (MeV) helium ions maintain a straight path as they pass through a cell. Along the ion trajectory, the helium ion undergoes multiple electron collisions, and for each collision a small amount of energy is lost to the scattered electron. By measuring the total energy loss of each MeV helium ion as it passes through the cell, we can construct an energy-loss image that is representative of the mass distribution of the cell. This work paves the way to use ions for whole-cell investigations at nanometer resolutions through structural, elemental (via nuclear elastic backscattering), and fluorescence (via ion induced fluorescence) imaging. PMID:21961606

  4. Focused ion beam scanning electron microscopy in biology.

    PubMed

    Kizilyaprak, C; Daraspe, J; Humbel, B M

    2014-06-01

    Since the end of the last millennium, the focused ion beam scanning electron microscopy (FIB-SEM) has progressively found use in biological research. This instrument is a scanning electron microscope (SEM) with an attached gallium ion column and the 2 beams, electrons and ions (FIB) are focused on one coincident point. The main application is the acquisition of three-dimensional data, FIB-SEM tomography. With the ion beam, some nanometres of the surface are removed and the remaining block-face is imaged with the electron beam in a repetitive manner. The instrument can also be used to cut open biological structures to get access to internal structures or to prepare thin lamella for imaging by (cryo-) transmission electron microscopy. Here, we will present an overview of the development of FIB-SEM and discuss a few points about sample preparation and imaging.

  5. Nanometer scale patterning using focused ion beam milling

    SciTech Connect

    Petit, D.; Faulkner, C.C.; Johnstone, S.; Wood, D.; Cowburn, R.P.

    2005-02-01

    We report on the performance of focused ion beam (FIB) milling in order to produce nanometer scale devices. Resolution issues have been systematically studied as a function of emission current and working distance, by imaging single pixel lines FIB milled into thin bismuth films deposited on oxidized silicon. The ion beam profile has been measured, and by carefully optimizing the milling conditions, 40 nm Hall probe sensors have been fabricated.

  6. Radii broadening due to molecular collision in focused ion beams

    NASA Astrophysics Data System (ADS)

    Komuro, Masanori

    1988-01-01

    Point exposures of poly(methyl methacrylate) resist are carried out with focused ion beams of Si++ and Au++ from a liquid AuSi ion source in order to obtain a current density distribution in the probe. All the distributions are composed of a main Gaussian distribution and a long tail dependent on r-3.3 (r means radial distance). The magnitude of this tail increases with the increase in ambient pressure of the ion-drifting space. When the probe is steered at the corner of deflection field, two types of clear ghost patterns appear: (1) circular patterns and (2) lines trailing from the main spot toward the deflection center. It is revealed that they are produced by exposures to ions or energetic neutrals generated with charge transfer collision of the primary ions with residual gas molecules. It is shown that the long tail in the current density distribution is also due to scattering with the residual gas molecules.

  7. Atomic-scale thermocapillary flow in focused ion beam milling

    NASA Astrophysics Data System (ADS)

    Das, Kallol; Johnson, Harley; Freund, Jonathan

    2016-11-01

    Focused ion beams (FIB) offer an attractive tool for nanometer-scale manufacturing and material processing, particularly because they can be focused to a few nanometer diameter spot. This motivates their use for many applications, such as sample preparation for transmission electron microscopy (TEM), forming nanometer scale pores in thin films for DNA sequencing. Despite its widespread use, the specific mechanisms of FIB milling, especially at high ion fluxes for which significant phase change might occur, remains incompletely understood. Here we investigate the process of nanopore fabrication in thin Si films using molecular dynamics simulation where Ga+ ions are used as the focused ions. For a range of ion intensities in a realistic configuration, a recirculating melt region develops, which is seen to flow with a symmetrical pattern, counter to how it would flow were it is driven by the ion momentum flux. Such flow is potentially important for the shape and composition of the formed structures. Relevant stress scales and estimated physical properties of silicon under these extreme conditions support the importance thermocapillary effects. A continuum flow model with Marangoni forcing reproduces the flow.

  8. Micrometer-Scale Machining of Metals and Polymers Enabled by Focused Ion Beam Sputtering

    SciTech Connect

    Adams, D.P.; Benavides, G.L.; Vasile, M.J.

    1998-12-22

    This work combines focused ion beam sputtering and ultra-precision machining for microfabrication of metal alloys and polymers. Specifically, micro-end mills are made by Ga ion beam sputtering of a cylindrical tool shank. Using an ion energy of 20keV, the focused beam defines the tool cutting edges that have submicrometer radii of curvature. We demonstrate 25 {micro}m diameter micromilling tools having 2, 4 and 5 cutting edges. These tools fabricate fine channels, 26-28 microns wide, in 6061 aluminum, brass, and polymethyl methacrylate. Micro-tools are structurally robust and operate for more than 5 hours without fracture.

  9. Solenoidal Fields for Ion Beam Transport and Focusing

    SciTech Connect

    Lee, Edward P.; Leitner, Matthaeus

    2007-11-01

    In this report we calculate time-independent fields of solenoidal magnets that are suitable for ion beam transport and focusing. There are many excellent Electricity and Magnetism textbooks that present the formalism for magnetic field calculations and apply it to simple geometries [1-1], but they do not include enough relevant detail to be used for designing a charged particle transport system. This requires accurate estimates of fringe field aberrations, misaligned and tilted fields, peak fields in wire coils and iron, external fields, and more. Specialized books on magnet design, technology, and numerical computations [1-2] provide such information, and some of that is presented here. The AIP Conference Proceedings of the US Particle Accelerator Schools [1-3] contain extensive discussions of design and technology of magnets for ion beams - except for solenoids. This lack may be due to the fact that solenoids have been used primarily to transport and focus particles of relatively low momenta, e.g. electrons of less than 50 MeV and protons or H- of less than 1.0 MeV, although this situation may be changing with the commercial availability of superconducting solenoids with up to 20T bore field [1-4]. Internal reports from federal laboratories and industry treat solenoid design in detail for specific applications. The present report is intended to be a resource for the design of ion beam drivers for Inertial Fusion Energy [1-5] and Warm Dense Matter experiments [1-6], although it should also be useful for a broader range of applications. The field produced by specified currents and material magnetization can always be evaluated by solving Maxwell's equations numerically, but it is also desirable to have reasonably accurate, simple formulas for conceptual system design and fast-running beam dynamics codes, as well as for general understanding. Most of this report is devoted to such formulas, but an introduction to the Tosca{copyright} code [1-7] and some numerical

  10. An electron cyclotron resonance ion source based low energy ion beam platform

    SciTech Connect

    Sun, L. T.; Shang, Y.; Ma, B. H.; Zhang, X. Z.; Feng, Y. C.; Li, X. X.; Wang, H.; Guo, X. H.; Song, M. T.; Zhao, H. Y.; Zhang, Z. M.; Zhao, H. W.; Xie, D. Z.

    2008-02-15

    To satisfy the requirements of surface and atomic physics study in the field of low energy multiple charge state ion incident experiments, a low energy (10 eV/q-20 keV/q) ion beam platform is under design at IMP. A simple test bench has been set up to test the ion beam deceleration systems. Considering virtues such as structure simplicity, easy handling, compactness, cost saving, etc., an all-permanent magnet ECRIS LAPECR1 [Lanzhou all-permanent magnet electron cyclotron resonance (ECR) ion source No. 1] working at 14.5 GHz has been adopted to produce intense medium and low charge state ion beams. LAPECR1 source has already been ignited. Some intense low charge state ion beams have been produced on it, but the first test also reveals that many problems are existing on the ion beam transmission line. The ion beam transmission mismatches result in the depressed performance of LAPECR1, which will be discussed in this paper. To obtain ultralow energy ion beam, after being analyzed by a double-focusing analyzer magnet, the selected ion beam will be further decelerated by two afocal deceleration lens systems, which is still under design. This design has taken into consideration both ions slowing down and also ion beam focusing. In this paper, the conceptual design of deceleration system will be discussed.

  11. Advances of focused ion beam in micromachining technology

    NASA Astrophysics Data System (ADS)

    Zhang, S. J.; Fang, F. Z.; Hu, X. T.

    2007-12-01

    The applications of focused ion beam (FIB) technology in micromachining has advantages over other micromachining technologies, such as high feature resolution, capable markless process, rapid prototyping and adaptive for various materials and geometries. FIB direct-writing techniques are explored for their excellent abilities in micromachining. In addition to FIB technology and its principles for imaging, milling and deposition, a typical FIB system is presented. The key to FIB direct-writing technology is to operate a FIB with a proper beam size, shape, current and energy to remove or add a required amount of material from a pre-defined location in a controlled manner. In this way, high-precision and complicated three-dimensional structures with controlled profiles can be fabricated. Several examples of using milling technique for making high-quality microdevices or high-precision microcomponents for optical and other applications are given. The demonstration of milling a narrow readout gap at an oblique angle on a microaccelerometer shows a FIB's application on a small but accurate post-processing step on a micromechanical device. The diffractive optical element (DOE) with continuous relief and submicron feature size fabricated by FIB milling is also presented to prove high resolution and accurate relief control. Furthermore, FIB milling is used to shape a variety of cutting tools with extremely precise dimensions and complex tool face shapes.

  12. Evolution of tungsten film deposition induced by focused ion beam

    NASA Astrophysics Data System (ADS)

    Langfischer, H.; Basnar, B.; Hutter, H.; Bertagnolli, E.

    2002-07-01

    Direct write metallization is an important approach for circuit modification and prototyping. We investigate the evolution of the chemical vapor deposition of tungsten induced by a 50 keV focused Ga+ ion beam. Time resolved imaging in combination with atomic force microscopy reveals that chemical vapor deposition of tungsten by focused ion beam proceeds via two clearly distinguishable regimes of layer growth. Deposition starts with the nucleation of nanoscale tungsten deposits scattered over the substrate surface. Despite local impacts of the ion beam within the irradiated area of the substrate the localization of the nucleation spots is not correlated to the scan path of the ion beam. The nanoscale tungsten particles preserve their position and typical shape during further deposition. Only after merging of the particles into a contiguous tungsten layer, does the second regime of growth characterized by deposition of tungsten on a tungsten surface set in. In this regime the deposition process is determined by the total ion dose and the average current density the sample was subjected to. Deposition yields up to 3.5 atoms per incident gallium ion are achieved. The layer quality is determined by Auger electron analysis, which shows fractions of Ga, C, Si and O in the W layer. Depth profiling by secondary ion mass spectroscopy showed the depth profiles of these constituents and confirmed the existence of a 50-100 nm thick transition zone between the tungsten layer and the substrate. Electrical resistivity of metal layers of 250 mu Omega cm and current densities up to 3.5 x106 A/cm2 are measured by means of van der Pauw test structures. In order to give a concise description of the experimental findings the data were interpreted utilizing an analytic model that mainly incorporates the precursor gas coverage, precursor gas transformation cross section and ion induced sputtering. The critical ion current density, where ion sputtering exceeds the deposition, was

  13. Effects on focused ion beam irradiation on MOS transistors

    SciTech Connect

    Campbell, A.N.; Peterson, K.A.; Fleetwood, D.M.; Soden, J.M.

    1997-04-01

    The effects of irradiation from a focused ion beam (FIB) system on MOS transistors are reported systematically for the first time. Three MOS transistor technologies, with 0.5, 1, and 3 {mu}m minimum feature sizes and with gate oxide thicknesses ranging from 11 to 50 nm, were analyzed. Significant shifts in transistor parameters (such as threshold voltage, transconductance, and mobility) were observed following irradiation with a 30 keV Ga{sup +} focused ion beam with ion doses varying by over 5 orders of magnitude. The apparent damage mechanism (which involved the creation of interface traps, oxide trapped charge, or both) and extent of damage were different for each of the three technologies investigated.

  14. Ultrahigh vacuum focused ion beam micromill and articles therefrom

    DOEpatents

    Lamartine, B.C.; Stutz, R.A.

    1998-02-24

    An ultrahigh vacuum focused ion beam micromilling apparatus and process are disclosed. Additionally, a durable data storage medium using the micromilling process is disclosed, the durable data storage medium capable of storing, e.g., digital or alphanumeric characters as well as graphical shapes or characters. 6 figs.

  15. Ultrahigh vacuum focused ion beam micromill and articles therefrom

    DOEpatents

    Lamartine, Bruce C.; Stutz, Roger A.

    1998-01-01

    An ultrahigh vacuum focused ion beam micromilling apparatus and process are isclosed. Additionally, a durable data storage medium using the micromilling process is disclosed, the durable data storage medium capable of storing, e.g., digital or alphanumeric characters as well as graphical shapes or characters.

  16. Self-focusing of ion-acoustic surface waves

    NASA Astrophysics Data System (ADS)

    Stenflo, L.; Gradov, O. M.

    1996-06-01

    An electrostatic ion-acoustic surface wave propagating along the boundary of a semi-infinite plasma is considered. It is shown that a nonlinear Schrödinger equation can describe the development of the wave amplitude. The self-focusing length of a wave beam is estimated.

  17. Ion creation, ion focusing, ion/molecule reactions, ion separation, and ion detection in the open air in a small plastic device.

    PubMed

    Baird, Zane; Wei, Pu; Cooks, R Graham

    2015-02-07

    A method is presented in which ions are generated and manipulated in the ambient environment using polymeric electrodes produced with a consumer-grade 3D printer. The ability to focus, separate, react, and detect ions in the ambient environment is demonstrated and the data agree well with simulated ion behaviour.

  18. Plasma focus ion beam fluence and flux—For various gases

    SciTech Connect

    Lee, S.; Saw, S. H.

    2013-06-15

    A recent paper derived benchmarks for deuteron beam fluence and flux in a plasma focus (PF) [S. Lee and S. H. Saw, Phys. Plasmas 19, 112703 (2012)]. In the present work we start from first principles, derive the flux equation of the ion beam of any gas; link to the Lee Model code and hence compute the ion beam properties of the PF. The results show that, for a given PF, the fluence, flux, ion number and ion current decrease from the lightest to the heaviest gas except for trend-breaking higher values for Ar fluence and flux. The energy fluence, energy flux, power flow, and damage factors are relatively constant from H{sub 2} to N{sub 2} but increase for Ne, Ar, Kr and Xe due to radiative cooling and collapse effects. This paper provides much needed benchmark reference values and scaling trends for ion beams of a PF operated in any gas.

  19. Ion Beam Measurements of a Dense Plasma Focus Device Using CR 39 Nuclear Track Detectors

    NASA Astrophysics Data System (ADS)

    Ngoi, S. K.; Yap, S. L.; Wong, C. S.; Saadah, A. R.

    2008-05-01

    The project is carried out using a small Mather type plasma focus device powered by a 15 kV, 30 μF capacitor. The filling gas used is argon. The ion beam generated is investigated by both time resolved and time integrated methods. Investigation on the dynamic of the current sheath is also carried out in order to obtain an optimum condition for ion beam production. The angular distribution of the ion emission is measured at positions of 0° (end-on), 45° and 90° (side-on) by using CR-39 nuclear track detectors. The divergence of the ion beam is also determined using these detectors. A biased ion collector is used for time resolved measurement of the ion beam. Time of flight technique is employed for the determination of the ion beam energy. Average ion beam energy obtained is about 180 keV. The ion beam produced can be used for applications such as material surface modification and ion implantation.

  20. Electrostatic lens to focus an ion beam to uniform density

    DOEpatents

    Johnson, Cleland H.

    1977-01-11

    A focusing lens for an ion beam having a gaussian or similar density profile is provided. The lens is constructed to provide an inner zero electrostatic field, and an outer electrostatic field such that ions entering this outer field are deflected by an amount that is a function of their distance from the edge of the inner field. The result is a beam that focuses to a uniform density in a manner analogous to that of an optical ring lens. In one embodiment, a conically-shaped network of fine wires is enclosed within a cylindrical anode. The wire net together with the anode produces a voltage field that re-directs the outer particles of the beam while the axial particles pass undeflected through a zero field inside the wire net. The result is a focused beam having a uniform intensity over a given target area and at a given distance from the lens.

  1. Neutral beamline with improved ion energy recovery

    DOEpatents

    Dagenhart, William K.; Haselton, Halsey H.; Stirling, William L.; Whealton, John H.

    1984-01-01

    A neutral beamline generator with unneutralized ion energy recovery is provided which enhances the energy recovery of the full energy ion component of the beam exiting the neutralizer cell of the beamline. The unneutralized full energy ions exiting the neutralizer are deflected from the beam path and the electrons in the cell are blocked by a magnetic field applied transverse to the beamline in the cell exit region. The ions, which are generated at essentially ground potential and accelerated through the neutralizer cell by a negative acceleration voltage, are collected at ground potential. A neutralizer cell exit end region is provided which allows the magnetic and electric fields acting on the exiting ions to be closely coupled. As a result, the fractional energy ions exiting the cell with the full energy ions are reflected back into the gas cell. Thus, the fractional energy ions do not detract from the energy recovery efficiency of full energy ions exiting the cell which can reach the ground potential interior surfaces of the beamline housing.

  2. Neutral beamline with improved ion energy recovery

    DOEpatents

    Kim, Jinchoon

    1984-01-01

    A neutral beamline employing direct energy recovery of unneutralized residual ions is provided which enhances the energy recovery of the full energy ion component of the beam exiting the neutralizer cell, and thus improves the overall neutral beamline efficiency. The unneutralized full energy ions exiting the neutralizer are deflected from the beam path and the electrons in the cell are blocked by a magnetic field applied transverse to the beam direction in the neutral izer exit region. The ions which are generated at essentially ground potential and accelerated through the neutralizer cell by a negative acceleration voltage are collected at ground potential. A neutralizer cell exit end region is provided which allows the magnetic and electric fields acting on the exiting ions to be loosely coupled. As a result, the fractional energy ions exiting the cell are reflected onto and collected at an interior wall of the neutralizer formed by the modified end geometry, and thus do not detract from the energy recovery efficiency of full energy ions exiting the cell. Electrons within the neutralizer are prevented from exiting the neutralizer end opening by the action of crossed fields drift (ExB) and are terminated to a collector collar around the downstream opening of the neutralizer. The correct combination of the extended neutralizer end structure and the magnet region is designed so as to maximize the exit of full energy ions and to contain the fractional energy ions.

  3. Molecular ion sources for low energy semiconductor ion implantation (invited).

    PubMed

    Hershcovitch, A; Gushenets, V I; Seleznev, D N; Bugaev, A S; Dugin, S; Oks, E M; Kulevoy, T V; Alexeyenko, O; Kozlov, A; Kropachev, G N; Kuibeda, R P; Minaev, S; Vizir, A; Yushkov, G Yu

    2016-02-01

    Smaller semiconductors require shallow, low energy ion implantation, resulting space charge effects, which reduced beam currents and production rates. To increase production rates, molecular ions are used. Boron and phosphorous (or arsenic) implantation is needed for P-type and N-type semiconductors, respectively. Carborane, which is the most stable molecular boron ion leaves unacceptable carbon residue on extraction grids. A self-cleaning carborane acid compound (C4H12B10O4) was synthesized and utilized in the ITEP Bernas ion source resulting in large carborane ion output, without carbon residue. Pure gaseous processes are desired to enable rapid switch among ion species. Molecular phosphorous was generated by introducing phosphine in dissociators via 4PH3 = P4 + 6H2; generated molecular phosphorous in a pure gaseous process was then injected into the HCEI Calutron-Bernas ion source, from which P4(+) ion beams were extracted. Results from devices and some additional concepts are described.

  4. Molecular ion sources for low energy semiconductor ion implantation (invited)

    NASA Astrophysics Data System (ADS)

    Hershcovitch, A.; Gushenets, V. I.; Seleznev, D. N.; Bugaev, A. S.; Dugin, S.; Oks, E. M.; Kulevoy, T. V.; Alexeyenko, O.; Kozlov, A.; Kropachev, G. N.; Kuibeda, R. P.; Minaev, S.; Vizir, A.; Yushkov, G. Yu.

    2016-02-01

    Smaller semiconductors require shallow, low energy ion implantation, resulting space charge effects, which reduced beam currents and production rates. To increase production rates, molecular ions are used. Boron and phosphorous (or arsenic) implantation is needed for P-type and N-type semiconductors, respectively. Carborane, which is the most stable molecular boron ion leaves unacceptable carbon residue on extraction grids. A self-cleaning carborane acid compound (C4H12B10O4) was synthesized and utilized in the ITEP Bernas ion source resulting in large carborane ion output, without carbon residue. Pure gaseous processes are desired to enable rapid switch among ion species. Molecular phosphorous was generated by introducing phosphine in dissociators via 4PH3 = P4 + 6H2; generated molecular phosphorous in a pure gaseous process was then injected into the HCEI Calutron-Bernas ion source, from which P4+ ion beams were extracted. Results from devices and some additional concepts are described.

  5. Development of Superconducting Focusing Quadrupoles for Heavy Ion Drivers

    SciTech Connect

    Martovetsky, N; Manahan, R; Lietzke, A F

    2001-09-10

    Heavy Ion Fusion (HIF) is exploring a promising path to a practical inertial-confinement fusion reactor. The associated heavy ion driver will require a large number of focusing quadrupole magnets. A concept for a superconducting quadrupole array, using many simple racetrack coils, was developed at LLNL. Two, single-bore quadrupole prototypes of the same design, with distinctly different conductor, were designed, built, and tested. Both prototypes reached their short sample currents with little or no training. Magnet design, and test results, are presented and discussed.

  6. Rechargeable dual-metal-ion batteries for advanced energy storage.

    PubMed

    Yao, Hu-Rong; You, Ya; Yin, Ya-Xia; Wan, Li-Jun; Guo, Yu-Guo

    2016-04-14

    Energy storage devices are more important today than any time before in human history due to the increasing demand for clean and sustainable energy. Rechargeable batteries are emerging as the most efficient energy storage technology for a wide range of portable devices, grids and electronic vehicles. Future generations of batteries are required to have high gravimetric and volumetric energy, high power density, low price, long cycle life, high safety and low self-discharge properties. However, it is quite challenging to achieve the above properties simultaneously in state-of-the-art single metal ion batteries (e.g. Li-ion batteries, Na-ion batteries and Mg-ion batteries). In this contribution, hybrid-ion batteries in which various metal ions simultaneously engage to store energy are shown to provide a new perspective towards advanced energy storage: by connecting the respective advantages of different metal ion batteries they have recently attracted widespread attention due to their novel performances. The properties of hybrid-ion batteries are not simply the superposition of the performances of single ion batteries. To enable a distinct description, we only focus on dual-metal-ion batteries in this article, for which the design and the benefits are briefly discussed. We enumerate some new results about dual-metal-ion batteries and demonstrate the mechanism for improving performance based on knowledge from the literature and experiments. Although the search for hybrid-ion batteries is still at an early age, we believe that this strategy would be an excellent choice for breaking the inherent disadvantages of single ion batteries in the near future.

  7. Intermediate energy heavy ion reactions

    NASA Astrophysics Data System (ADS)

    Grégoire, C.; Tamain, B.

    The intermediate energy heavy ion induced reactions are extensively studied for several years. In this paper, we try to summarize the present knowledge. The peripheral reactions appear to be intermediate between the fragmentation and the deep inelastic regimes. Many questions remain open concerning the energy relaxation mechanisms and an eventual participant zone creation. In the case of central collisions, it has been shown that very hot nuclei can be built. The fusion limits are discussed and the very hot nuclei properties are considered. In some cases, hot spot formation or compression effects could play a role. Multifragmentation is discussed as a possible decay channel. In all these aspects, a difficult question concerns the validity of the temperature concept and more generally of collective thermodynamical variables. Such collective effects have been investigated in pion production experiments. Les réactions induites par ions lourds d'énergie intermédiaire sont très étudiées depuis quelques années. Dans cet article, nous essayons de résumer l'état actuel des connaissances. Les mécanismes mis en jeu dans les collisions périphériques sont intermédiaires entre les collisions très inélastiques et la fragmentation. La cible joue clairement un rôle déterminant et des effets importants de champ moyen demeurent. De nombreuses questions restent sans réponse comme par exemple les mécanismes de relaxation d'énergie ou l'existence d'une éventuelle zone participante. Dans le cas des collisions centrales, il a pu être montré que des noyaux très chauds sont fabriqués. Les limites au processus de fusion et les propriétés des noyaux très chauds sont discutées. Dans certains cas, des effets de compression ou de points chauds peuvent être envisagés. La multifragmentation est une voie de désexcitation possible. Une importante question concerne la validité du concept de température et plus généralement la notion de variable collective

  8. Atomic-scale thermocapillary flow in focused ion beam milling

    SciTech Connect

    Das, K.; Johnson, H. T.; Freund, J. B.

    2015-05-15

    Focused ion beams provide a means of nanometer-scale manufacturing and material processing, which is used for applications such as forming nanometer-scale pores in thin films for DNA sequencing. We investigate such a configuration with Ga{sup +} bombardment of a Si thin-film target using molecular dynamics simulation. For a range of ion intensities in a realistic configuration, a recirculating melt region develops, which is seen to flow with a symmetrical pattern, counter to how it would flow were it driven by the ion momentum flux. Such flow is potentially important for the shape and composition of the formed structures. Relevant stress scales and estimated physical properties of silicon under these extreme conditions support the importance thermocapillary effects. A flow model with Marangoni forcing, based upon the temperature gradient and geometry from the atomistic simulation, indeed reproduces the flow and thus could be used to anticipate such flows and their influence in applications.

  9. Focused Ion Beam Induced Effects on MOS Transistor Parameters

    SciTech Connect

    Abramo, Marsha T.; Antoniou, Nicholas; Campbell, Ann N.; Fleetwood, Daniel M.; Hembree, Charles E.; Jessing, Jeffrey R.; Soden, Jerry M.; Swanson, Scot E.; Tangyunyong, Paiboon; Vanderlinde, William E.

    1999-07-28

    We report on recent studies of the effects of 50 keV focused ion beam (FIB) exposure on MOS transistors. We demonstrate that the changes in value of transistor parameters (such as threshold voltage, V{sub t}) are essentially the same for exposure to a Ga+ ion beam at 30 and 50 keV under the same exposure conditions. We characterize the effects of FIB exposure on test transistors fabricated in both 0.5 {micro}m and 0.225 {micro}m technologies from two different vendors. We report on the effectiveness of overlying metal layers in screening MOS transistors from FIB-induced damage and examine the importance of ion dose rate and the physical dimensions of the exposed area.

  10. Nanostructured Arrays Formed by Finely Focused Ion Beams

    SciTech Connect

    Budai, J.D.; Datsos, P.G.; Feldman, L.C.; Heinig, K.-H.; Meldrum, A.; Strobel, M.; Thomas, K.A.; Warmack, R.J.; White, C.W.; Zuhr, R.A.

    1998-11-30

    Amorphous, polycrystalline, and single crystal nanometer dimension particles can be formed in a variety of substrates by ion implantation and subsequent annealing. Such composite colloidal materials exhibit unique optical properties that could be useful in optical devices, switches, and waveguides. However colloids formed by blanket implantation are not uniform in size due to the nonuniform density of the implant, resulting in diminution of the size dependent optical properties. The object of the present work is to form more uniform size particles arranged in a 2-dimensional lattice by using a finely focused ion beam to implant identical ion doses only into nanometer size regions located at each point of a rectangular lattice. Initial work is being done with a 30 keV Ga beam implanted into Si. Results of particle formation as a function of implant conditions as analyzed by Rutherford backscattering, x-ray analysis, atomic force microscopy, and both scanning and transmission electron microscopy will be presented and discussed.

  11. An ion beam deceleration lens for ultra-low-energy ion bombardment of naked DNA

    NASA Astrophysics Data System (ADS)

    Thopan, P.; Prakrajang, K.; Thongkumkoon, P.; Suwannakachorn, D.; Yu, L. D.

    2013-07-01

    Study of low-energy ion bombardment effect on biological living materials is of significance. High-energy ion beam irradiation of biological materials such as organs and cells has no doubt biological effects. However, ion energy deposition in the ion-bombarded materials dominantly occurs in the low-energy range. To investigate effects from very-low-energy ion bombardment on biological materials, an ion beam deceleration lens is necessary for uniform ion energy lower than keV. A deceleration lens was designed and constructed based on study of the beam optics using the SIMION program. The lens consisted of six electrodes, able to focus and decelerate primary ion beam, with the last one being a long tube to obtain a parallel uniform exiting beam. The deceleration lens was installed to our 30-kV bioengineering-specialized ion beam line. The final decelerated-ion energy was measured using a simple electrostatic field to bend the beam to range from 10 eV to 1 keV controlled by the lens parameters and the primary beam condition. In a preliminary test, nitrogen ion beam at 60 eV decelerated from a primary 20-keV beam bombarded naked plasmid DNA. The original DNA supercoiled form was found to change to relaxed and linear forms, indicating single or double strand breaks. The study demonstrated that the ion bombardment with energy as low as several-tens eV was possible to break DNA strands and thus potential to cause genetic modification of biological cells.

  12. FABRICATION OF BISMUTH NANOWIRE DEVICES USING FOCUSED ION BEAM MILLING

    SciTech Connect

    Cheng, H. H.; Alkaisi, M. M.; Wu, S. E.; Liu, C. P.

    2009-07-23

    In this work, a focused ion beam (FIB) milling process has been developed to fabricate 50 nm Bi nanowire and transistor structures using FEI-200 dual beam FIB system. For the fabrication, 50 nm bismuth film was thermally evaporated through EBL patterned PMMA windows onto SiO{sub 2} substrates with pre-defined contact pads. Bi nanowire widths ranging from 30 nm to 100 nm have been successfully fabricated by milling out unwanted areas using 30 KeV Ga+ ion beam. A single-pixel-line ion beam blanking technique has been utilised to fabricate Bi nanowire as small as 30 nm in diameter and few micrometers long. In order to form good ohmic contacts for sub 50 nm bismuth nanowires, a drill-and-fill process has been developed using FIB to sputter away the surface oxide of bismuth after the in-situ platinum nanowire contacts deposition. To our knowledge, this is the first time a focused ion beam process has been used to fabricate bismuth nanowire. The fabricated Bi nanowires were electrically characterised using a semiconductor analyser that showed good ohmic contact to the electrodes. In this paper, the fabrication experiments and the characterisation results for Bi nanowires as small as 50 nm in diameter are presented. Several FIB issues involved in Bi device making and ohmic contacts to Bi nanowires will also be discussed.

  13. Ion sources for energy extremes of ion implantation (invited)

    SciTech Connect

    Hershcovitch, A.; Johnson, B. M.; Batalin, V. A.; Kropachev, G. N.; Kuibeda, R. P.; Kulevoy, T. V.; Kolomiets, A. A.; Pershin, V. I.; Petrenko, S. V.; Rudskoy, I.; Seleznev, D. N.; Bugaev, A. S.; Gushenets, V. I.; Litovko, I. V.; Oks, E. M.; Yushkov, G. Yu.; Masunov, E. S.; Polozov, S. M.; Poole, H. J; Storozhenko, P. A.

    2008-02-15

    For the past four years a joint research and development effort designed to develop steady state, intense ion sources has been in progress with the ultimate goal to develop ion sources and techniques that meet the two energy extreme range needs of meV and hundreads of eV ion implanters. This endeavor has already resulted in record steady state output currents of high charge state of antimony and phosphorus ions: P{sup 2+} [8.6 pmA (particle milliampere)], P{sup 3+} (1.9 pmA), and P{sup 4+} (0.12 pmA) and 16.2, 7.6, 3.3, and 2.2 pmA of Sb{sup 3+}Sb{sup 4+}, Sb{sup 5+}, and Sb{sup 6+} respectively. For low energy ion implantation, our efforts involve molecular ions and a novel plasmaless/gasless deceleration method. To date, 1 emA (electrical milliampere) of positive decaborane ions was extracted at 10 keV and smaller currents of negative decaborane ions were also extracted. Additionally, boron current fraction of over 70% was extracted from a Bernas-Calutron ion source, which represents a factor of 3.5 improvement over currently employed ion sources.

  14. ION SOURCES FOR ENERGY EXTREMES OF ION IMPLANTATION.

    SciTech Connect

    HERSCHCOVITCH,A.; JOHNSON, B.M.; BATALIN, V.A.; KROPACHEV, G.N.; KUIBEDA, R.P.; KULEVOY, T.V.; KOLOMIETS, A.A.; PERSHIN, V.I.; PETRENKO, S.V.; RUDSKOY, I.; SELEZNEV, D.N.; BUGAEV, A.S.; GUSHENETS, V.I.; LITOVKO, I.V.; OKS, E.M.; YUSHKOV, G. YU.; MASEUNOV, E.S.; POLOZOV, S.M.; POOLE, H.J.; STOROZHENKO, P.A.; SVAROVSKI, YA.

    2007-08-26

    For the past four years a joint research and development effort designed to develop steady state, intense ion sources has been in progress with the ultimate goal to develop ion sources and techniques, which meet the two energy extreme range needs of mega-electron-volt and 100's of electron-volt ion implanters. This endeavor has already resulted in record steady state output currents of high charge state of Antimony and Phosphorous ions: P{sup 2+} (8.6 pmA), P{sup 3+} (1.9 pmA), and P{sup 4+} (0.12 pmA) and 16.2, 7.6, 3.3, and 2.2 pmA of Sb{sup 3+} Sb{sup 4+}, Sb{sup 5+}, and Sb{sup 6+} respectively. For low energy ion implantation our efforts involve molecular ions and a novel plasmaless/gasless deceleration method. To date, 1 emA of positive Decaborane ions were extracted at 10 keV and smaller currents of negative Decaborane ions were also extracted. Additionally, Boron current fraction of over 70% was extracted from a Bemas-Calutron ion source, which represents a factor of 3.5 improvement over currently employed ion sources.

  15. Superconducting focusing quadrupoles for heavy ion fusion experiments

    SciTech Connect

    Sabbi, G.L.; Faltens, A.; Leitner, M.; Lietzke, A.; Seidl, P.; Barnard, J.; Lund, S.; Martovetsky, N.; Gung, C.; Minervini, J.; Radovinsky, A.; Schultz, J.; Meinke, R.

    2003-05-01

    The Heavy Ion Fusion (HIF) Program is developing superconducting focusing magnets for both near-term experiments and future driver accelerators. In particular, single bore quadrupoles have been fabricated and tested for use in the High Current Experiment (HCX) at Lawrence Berkeley National Laboratory (LBNL). The next steps involve the development of magnets for the planned Integrated Beam Experiment (IBX) and the fabrication of the first prototype multi-beam focusing arrays for fusion driver accelerators. The status of the magnet R&D program is reported, including experimental requirements, design issues and test results.

  16. Heavy-ion fusion final focus magnet shielding designs

    SciTech Connect

    Latkowski, J F; Meier, W R

    2000-10-11

    At the Thirteenth International Symposium on Heavy Ion Inertial Fusion (HIF Symposium), we presented magnet shielding calculations for 72-, 128, 200, and 288-beam versions of the HYLIFE-II power plant design. In all cases, we found the radiation-limited lifetimes of the last set of final focusing magnets to be unacceptably short. Since that time, we have completed follow-on calculations to improve the lifetime of the 72-beam case. Using a self-consistent final focusing model, we vary parameters such as the shielding thicknesses and compositions, focusing length, angle-of-attack to the target, and the geometric representation of the flibe pocket, chamber, and blanket. By combining many of these shielding features, we are able to demonstrate a magnet shielding design that would enable the last set of final focusing magnets to survive for the lifetime of the power plant.

  17. Whole-cell imaging at nanometer resolutions using fast and slow focused helium ions.

    PubMed

    Chen, Xiao; Udalagama, Chammika N B; Chen, Ce-Belle; Bettiol, Andrew A; Pickard, Daniel S; Venkatesan, T; Watt, Frank

    2011-10-05

    Observations of the interior structure of cells and subcellular organelles are important steps in unraveling organelle functions. Microscopy using helium ions can play a major role in both surface and subcellular imaging because it can provide subnanometer resolutions at the cell surface for slow helium ions, and fast helium ions can penetrate cells without a significant loss of resolution. Slow (e.g., 10-50 keV) helium ion beams can now be focused to subnanometer dimensions (∼0.25 nm), and keV helium ion microscopy can be used to image the surfaces of cells at high resolutions. Because of the ease of neutralizing the sample charge using a flood electron beam, surface charging effects are minimal and therefore cell surfaces can be imaged without the need for a conducting metallic coating. Fast (MeV) helium ions maintain a straight path as they pass through a cell. Along the ion trajectory, the helium ion undergoes multiple electron collisions, and for each collision a small amount of energy is lost to the scattered electron. By measuring the total energy loss of each MeV helium ion as it passes through the cell, we can construct an energy-loss image that is representative of the mass distribution of the cell. This work paves the way to use ions for whole-cell investigations at nanometer resolutions through structural, elemental (via nuclear elastic backscattering), and fluorescence (via ion induced fluorescence) imaging. Copyright © 2011 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  18. Contamination analysis of radioactive samples in focused ion beam instruments.

    PubMed

    Evelan, Audrey Ruth; Brey, Richard R

    2013-02-01

    The use of Focused Ion Beam (FIB) instrument's to analyze and prepare samples that are radioactive requires attentiveness to the materials that are dislodged and free inside the chamber. Radioactive sputtered material must be understood even when observed at trace concentrations. Measurements using liquid scintillation counting and high purity germanium detectors were used to evaluate contamination on accessible surfaces inside a focused ion beam chamber that was used in the preparation of samples that were radioactive. The maximum removable contamination found was 0.27 0.4 Bq cm(-2), on the focused ion beam wall with 0.24 0.019 Bq cm(-2) on the door. Although these magnitudes of removable contamination are inconsequential for activation products, these same magnitudes of actinides, for example 239Pu, would represent 3.2% of an Annual Limit of Intake. This might be considered significant if one examines the relatively infrequent use of this device for the preparation of radioactive samples. Predicted activities of sputtered material were found using the software Transport of Ions in Matter, estimating that 0.003% of a radioactive samples activity is released into the FIB chamber. A used secondary electron detector's activity was measured to be 383.7 8.1 Bq. Preferential build-up of sputtered materials due to temperature or static charge gradients was considered. No temperature gradients were observed. Static charge gradients were measured inside the chamber varying between 0.057% below the mean to 34% higher than the mean. However, the magnitudes of contamination measured did not correlate to static charge gradients. Deposition in the chamber appears to have no mechanical cause but rather is sporadic however, measureable. Experience to date has been limited to samples of low activity; nevertheless, contamination inside the chamber was observed. Users should anticipate higher levels of readily dispersible radioactive contamination within the FIB as sample activity

  19. Mean excitation energies for molecular ions

    NASA Astrophysics Data System (ADS)

    Jensen, Phillip W. K.; Sauer, Stephan P. A.; Oddershede, Jens; Sabin, John R.

    2017-03-01

    The essential material constant that determines the bulk of the stopping power of high energy projectiles, the mean excitation energy, is calculated for a range of smaller molecular ions using the RPA method. It is demonstrated that the mean excitation energy of both molecules and atoms increase with ionic charge. However, while the mean excitation energies of atoms also increase with atomic number, the opposite is the case for mean excitation energies for molecules and molecular ions. The origin of these effects is explained by considering the spectral representation of the excited state contributing to the mean excitation energy.

  20. Medium energy heavy ion operations at RHIC

    SciTech Connect

    Drees, K.A.; Ahrens, L.; Bai, M.; Beebe-Wang, J.; Blackler, I.M.C.; Blaskiewicz, M.; Brown, K.A.; Brennan, M.; Bruno, D.; Butler, J.; Carlson, C.; Connolly, R.; D'Ottavio, T.; Fischer, W.; Fu, W.; Gassner, D.; Harvey, M.; Hayes, T.; Huang, H.; Hulsart, R.; Ingrassia, P.; Kling, N.; Lafky, M.; Laster, J.; Lee, R.C.; Litvinenko, V.; Luo, Y.; MacKay, W.W.; Marr, G.; Mapes. M.; Marusic, A.; Mernick, K.; Michnoff, R.; Minty, M.; Montag, C.; Morris, J.; Naylor, C.; Nemesure, S.; Pilat, F.; Ptitsyn, V.; Robert-Demolaize, G.; Roser, T.; Sampson, P.; Satogata, T.; Schoefer, V.; Schultheiss, C.; Severino, F.; Shrey, T.; Smith, K.S.; Tepikian, S.; Thieberger, P.; Trbojevic, D.; Tsoupas, N.; Tuozzolo, J.; van Kuik, B.; Wilinski, M.; Zaltsman, A.; Zeno, K.; Zhang, S.Y.

    2011-03-28

    As part of the search for a phase transition or critical point on the QCD phase diagram, an energy scan including 5 different energy settings was performed during the 2010 RHIC heavy ion run. While the top beam energy for heavy ions is at 100 GeV/n and the lowest achieved energy setpoint was significantly below RHICs injection energy of approximately 10 GeV/n, we also provided beams for data taking in a medium energy range above injection energy and below top beam energy. This paper reviews RHIC experience and challenges for RHIC medium energy operations that produced full experimental data sets at beam energies of 31.2 GeV/n and 19.5 GeV/n. The medium energy AuAu run covered two beam energies, both above the RHIC injection energy of 9.8 GeV but well below the standard store energy of 100 GeV (see table 1). The low energy and full energy runs with heavy ions in FY10 are summarized in [1] and [2]. Stochastic Cooling ([3]) was only used for 100 GeV beams and not used in the medium energy run. The efficiency of the transition from 100 GeV operation to 31.2 GeV and then to 19.5 GeV was remarkable. Setup took 32 h and 19 h respectively for the two energy settings. The time in store, defined to be the percentage of time RHIC provides beams in physics conditions versus calendar time, was approximately 52% for the entire FY10 heavy ion run. In both medium energy runs it was well above this average, 68% for 31.5 GeV and 82% for 19.5 GeV. For both energies RHIC was filled with 111 bunches with 1.2 10{sup 9} and 1.3 10{sup 9} ions per bunch respectively.

  1. Drift Compression and Final Focus Options for Heavy Ion Fusion

    SciTech Connect

    Hong Qin; Ronald C. Davidson; John J. Barnard; Edward P. Lee

    2005-02-14

    A drift compression and final focus lattice for heavy ion beams should focus the entire beam pulse onto the same focal spot on the target. We show that this requirement implies that the drift compression design needs to satisfy a self-similar symmetry condition. For un-neutralized beams, the Lie symmetry group analysis is applied to the warm-fluid model to systematically derive the self-similar drift compression solutions. For neutralized beams, the 1-D Vlasov equation is solved explicitly, and families of self-similar drift compression solutions are constructed. To compensate for the deviation from the self-similar symmetry condition due to the transverse emittance, four time-dependent magnets are introduced in the upstream of the drift compression such that the entire beam pulse can be focused onto the same focal spot.

  2. Optical fiber plasmonic lens for near-field focusing fabricated through focused ion beam

    NASA Astrophysics Data System (ADS)

    Sloyan, Karen; Melkonyan, Henrik; Moreira, Paulo; Dahlem, Marcus S.

    2017-02-01

    We report on numerical simulations and fabrication of an optical fiber plasmonic lens for near-field focusing applications. The plasmonic lens consists of an Archimedean spiral structure etched through a 100 nm-thick Au layer on the tip of a single-mode SM600 optical fiber operating at a wavelength of 632:8 nm. Three-dimensional finite-difference time-domain computations show that the relative electric field intensity of the focused spot increases 2:1 times when the number of turns increases from 2 to 12. Furthermore, a reduction of the intensity is observed when the initial inner radius is increased. The optimized plasmonic lens focuses light into a spot with a full-width at half-maximum of 182 nm, beyond the diffraction limit. The lens was fabricated by focused ion beam milling, with a 200nm slit width.

  3. Safety focused modeling of lithium-ion batteries: A review

    NASA Astrophysics Data System (ADS)

    Abada, S.; Marlair, G.; Lecocq, A.; Petit, M.; Sauvant-Moynot, V.; Huet, F.

    2016-02-01

    Safety issues pertaining to Li-ion batteries justify intensive testing all along their value chain. However, progress in scientific knowledge regarding lithium based battery failure modes, as well as remarkable technologic breakthroughs in computing science, now allow for development and use of prediction tools to assist designers in developing safer batteries. Subsequently, this paper offers a review of significant modeling works performed in the area with a focus on the characterization of the thermal runaway hazard and their relating triggering events. Progress made in models aiming at integrating battery ageing effect and related physics is also discussed, as well as the strong interaction with modeling-focused use of testing, and the main achievements obtained towards marketing safer systems. Current limitations and new challenges or opportunities that are expected to shape future modeling activity are also put in perspective. According to market trends, it is anticipated that safety may still act as a restraint in the search for acceptable compromise with overall performance and cost of lithium-ion based and post lithium-ion rechargeable batteries of the future. In that context, high-throughput prediction tools capable of screening adequate new components properties allowing access to both functional and safety related aspects are highly desirable.

  4. Preliminary Studies of Ions Emission in a Small Plasma Focus Device of Hundreds of Joules

    NASA Astrophysics Data System (ADS)

    Moreno, José; Pavez, Cristian; Soto, Leopoldo; Tarifeño, Ariel; Reymond, Piotr; Verschueren, Nicolás; Ariza, Pablo

    2009-01-01

    Ion beam emission in plasma focus (PF) discharges was originally investigated to explain the strong forward anisotropy observed in the neutron. Several properties of PF emitted deuteron beams have been measured, including their angular distributions and energy spectra in devices operating with energies from 1 kJ to 1 MJ. At present there is a growing interest in the development of very small PF devices operating under 1 kJ. As part of the characterization program of the very low energy PF devices (<1 kJ) developed at the Chilean Nuclear Energy Commission, the charges particle emission in hydrogen (H2) and mixture (H2+%Ar) are being studied. In order to obtain an estimation of the ions energy spectrum and ionization grade, by using time of flight method, a graphite collector system operating in the bias ion collector mode was constructed and it is being used. Preliminary results of the ion beams measurements in different experimental conditions, at a plasma focus device of 400 joules (PF-400 J) are presented.

  5. Preliminary Studies of Ions Emission in a Small Plasma Focus Device of Hundreds of Joules

    SciTech Connect

    Moreno, Jose; Pavez, Cristian; Soto, Leopoldo; Tarifeno, Ariel; Reymond, Piotr; Verschueren, Nicolas; Ariza, Pablo

    2009-01-21

    Ion beam emission in plasma focus (PF) discharges was originally investigated to explain the strong forward anisotropy observed in the neutron. Several properties of PF emitted deuteron beams have been measured, including their angular distributions and energy spectra in devices operating with energies from 1 kJ to 1 MJ. At present there is a growing interest in the development of very small PF devices operating under 1 kJ. As part of the characterization program of the very low energy PF devices (<1 kJ) developed at the Chilean Nuclear Energy Commission, the charges particle emission in hydrogen (H{sub 2}) and mixture (H{sub 2}+%Ar) are being studied. In order to obtain an estimation of the ions energy spectrum and ionization grade, by using time of flight method, a graphite collector system operating in the bias ion collector mode was constructed and it is being used. Preliminary results of the ion beams measurements in different experimental conditions, at a plasma focus device of 400 joules (PF-400 J) are presented.

  6. Chemically Induced Phase Transformation in Austenite by Focused Ion Beam

    NASA Astrophysics Data System (ADS)

    Basa, Adina; Thaulow, Christian; Barnoush, Afrooz

    2013-11-01

    A highly stable austenite phase in a super duplex stainless steel was subjected to a combination of different gallium ion doses at different acceleration voltages. It was shown that contrary to what is expected, an austenite to ferrite phase transformation occurred within the focused ion beam (FIB) milled regions. Chemical analysis of the FIB milled region proved that the gallium implantation preceded the FIB milling. High resolution electron backscatter diffraction analysis also showed that the phase transformation was not followed by the typical shear and plastic deformation expected from the martensitic transformation. On the basis of these observations, it was concluded that the change in the chemical composition of the austenite and the local increase in gallium, which is a ferrite stabilizer, results in the local selective transformation of austenite to ferrite.

  7. Sputtering Threshold Energies of Heavy Ions

    NASA Technical Reports Server (NTRS)

    Mantenieks, Maris A.

    1999-01-01

    Sputter erosion in ion thrusters has been measured in lifetests at discharge voltages as low as 25 V. Thruster operation at this discharge voltage results in component erosion rates sufficiently low to satisfy most mission requirements. It has been recognized that most of the internal sputtering in ion thrusters is done by doubly charged ions. Knowledge of the sputtering threshold voltage of a xenon molybdenum system would be beneficial in understanding the sputtering process as well as making more accurate calculations of the sputtering rates of ion thruster components. Sputtering threshold energies calculated from various formulations found in the literature results in values ranging from 28 to 200 eV. It is evident that some of these formulations cannot be relied upon to provide sputtering thresholds with any degree of accuracy. This paper re-examines the threshold energies measurements made in the early sixties by Askerov and Sena, and Stuart and Wehner. The threshold voltages as derived by Askerov and au have been reevaluated by using a different extrapolation method of sputter yields at low ion energies. The resulting threshold energies are in general similar to those measured by Stuart and Wehner. An empirical relationship is derived,for mercury and xenon ions for the ratio of the sputtering threshold energy to the sublimation energy as a function of the ratio of target to ion atomic mass.

  8. Ion Emittance Growth Due to Focusing Modulation from Slipping Electron Bunch

    SciTech Connect

    Wang, G.

    2015-02-17

    Low energy RHIC operation has to be operated at an energy ranging from γ = 4.1 to γ = 10. The energy variation causes the change of revolution frequency. While the rf system for the circulating ion will operate at an exact harmonic of the revolution frequency (h=60 for 4.5 MHz rf and h=360 for 28 MHz rf.), the superconducting rf system for the cooling electron beam does not have a frequency tuning range that is wide enough to cover the required changes of revolution frequency. As a result, electron bunches will sit at different locations along the ion bunch from turn to turn, i.e. the slipping of the electron bunch with respect to the circulating ion bunch. At cooling section, ions see a coherent focusing force due to the electrons’ space charge, which differs from turn to turn due to the slipping. We will try to estimate how this irregular focusing affects the transverse emittance of the ion bunch.

  9. Evaluation of neon focused ion beam milling for TEM sample preparation.

    PubMed

    Pekin, T C; Allen, F I; Minor, A M

    2016-10-01

    Gallium-based focused ion beams generated from liquid-metal sources are widely used in micromachining and sample preparation for transmission electron microscopy, with well-known drawbacks such as sample damage and contamination. In this work, an alternative (neon) focused ion beam generated by a gas field-ionization source is evaluated for the preparation of electron-transparent specimens. To do so, electron-transparent sections of Si and an Al alloy are prepared with both Ga and Ne ion beams for direct comparison. Diffraction-contrast imaging and energy dispersive x-ray spectroscopy are used to evaluate the relative damage induced by the two beams, and cross-sections of milled trenches are examined to compare the implantation depth with theoretical predictions from Monte Carlo simulations. Our results show that for the beam voltages and materials systems investigated, Ne ion beam milling does not significantly reduce the focused ion beam induced artefacts. However, the Ne ion beam does enable more precise milling and may be of interest in cases where Ga contamination cannot be tolerated. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.

  10. Focused Ion Beam Microscopy of ALH84001 Carbonate Disks

    NASA Technical Reports Server (NTRS)

    Thomas-Keprta, Kathie L.; Clemett, Simon J.; Bazylinski, Dennis A.; Kirschvink, Joseph L.; McKay, David S.; Vali, Hojatollah; Gibson, Everett K., Jr.; Romanek, Christopher S.

    2005-01-01

    Our aim is to understand the mechanism(s) of formation of carbonate assemblages in ALH84001. A prerequisite is that a detailed characterization of the chemical and physical properties of the carbonate be established. We present here analyses by transmission electron microscopy (TEM) of carbonate thin sections produced by both focused ion beam (FIB) sectioning and ultramicrotomy. Our results suggest that the formation of ALH84001 carbonate assemblages were produced by considerably more complex process(es) than simple aqueous precipitation followed by partial thermal decomposition as proposed by other investigators [e.g., 1-3].

  11. Effects of a dielectric material in an ion source on the ion beam current density and ion beam energy

    SciTech Connect

    Fujiwara, Y. Sakakita, H.; Nakamiya, A.; Hirano, Y.; Kiyama, S.

    2016-02-15

    To understand a strong focusing phenomenon that occurs in a low-energy hydrogen ion beam, the electron temperature, the electron density, and the space potential in an ion source with cusped magnetic fields are measured before and after the transition to the focusing state using an electrostatic probe. The experimental results show that no significant changes are observed before or after the transition. However, we found unique phenomena that are characterized by the position of the electrostatic probe in the ion source chamber. Specifically, the extracted ion beam current density and energy are obviously enhanced in the case where the electrostatic probe, which is covered by a dielectric material, is placed close to an acceleration electrode.

  12. Laser and focused ion beam combined machining for micro dies.

    PubMed

    Yoshida, Y; Okazaki, W; Uchida, T

    2012-02-01

    We have developed a laser and focused ion beam (FIB) compound process for press mold dies of a micro lens array (MLA) and a micro needle array (MNA) in a glassy carbon (GC). The press mold die of the MLA was roughly fabricated by UV-YAG laser. After this process, we finished this surface by scanning FIB. As a result, higher accuracy and good roughness of surface profile can be realized. An optical glass is used to confirm the shape of lens. Moreover, we fabricated 6 × 6 through-holes in the GC by the spiral drilling in addition to the focus position movement of the UV laser for press mold die of the MNA. After the FIB process, we were able to make the needle die of surface and hole wall roughness less than 0.9 μm. A silicon rubber is used to confirm the shape of the holes.

  13. Laser and focused ion beam combined machining for micro diesa)

    NASA Astrophysics Data System (ADS)

    Yoshida, Y.; Okazaki, W.; Uchida, T.

    2012-02-01

    We have developed a laser and focused ion beam (FIB) compound process for press mold dies of a micro lens array (MLA) and a micro needle array (MNA) in a glassy carbon (GC). The press mold die of the MLA was roughly fabricated by UV-YAG laser. After this process, we finished this surface by scanning FIB. As a result, higher accuracy and good roughness of surface profile can be realized. An optical glass is used to confirm the shape of lens. Moreover, we fabricated 6 × 6 through-holes in the GC by the spiral drilling in addition to the focus position movement of the UV laser for press mold die of the MNA. After the FIB process, we were able to make the needle die of surface and hole wall roughness less than 0.9 μm. A silicon rubber is used to confirm the shape of the holes.

  14. Focus On: Energy Conservation Practices in Schools.

    ERIC Educational Resources Information Center

    Massachusetts State Dept. of Education, Boston.

    This pamphlet briefly describes 23 effective energy conservation programs in Massachusetts schools today. These practices range from changes in classroom lighting fixtures to complete heating system redesign. Each program represents an effort by school systems to adapt to changing energy needs and available resources. Each entry describes the…

  15. Focus On: Energy Conservation Practices in Schools.

    ERIC Educational Resources Information Center

    Massachusetts State Dept. of Education, Boston.

    This pamphlet briefly describes 23 effective energy conservation programs in Massachusetts schools today. These practices range from changes in classroom lighting fixtures to complete heating system redesign. Each program represents an effort by school systems to adapt to changing energy needs and available resources. Each entry describes the…

  16. The periodic focusing ion funnel: theory, design, and experimental characterization by high-resolution ion mobility-mass spectrometry.

    PubMed

    Fort, Kyle L; Silveira, Joshua A; Russell, David H

    2013-10-15

    Simulation-based development and experimental characterization of a DC-only ion funnel is described herein. Radial ion confinement is achieved via periodic focusing whereby a collisionally dampened effective potential is generated in the inertial frame of an ion traversing the device with appreciable velocity. The new device, termed a periodic focusing ion funnel (PF IF), provides an efficient alternative to the rf ion funnel providing high ion transmission with fewer electrodes, simplified electrical circuitry, and reduced power supply requirements. The utility of the PF IF for structural ion mobility-mass spectrometry (IM-MS) studies is demonstrated using model peptide ions (bradykinin, gramicidin S, and trpzip 1).

  17. Bright focused ion beam sources based on laser-cooled atoms

    PubMed Central

    McClelland, J. J.; Steele, A. V.; Knuffman, B.; Twedt, K. A.; Schwarzkopf, A.; Wilson, T. M.

    2016-01-01

    Nanoscale focused ion beams (FIBs) represent one of the most useful tools in nanotechnology, enabling nanofabrication via milling and gas-assisted deposition, microscopy and microanalysis, and selective, spatially resolved doping of materials. Recently, a new type of FIB source has emerged, which uses ionization of laser cooled neutral atoms to produce the ion beam. The extremely cold temperatures attainable with laser cooling (in the range of 100 μK or below) result in a beam of ions with a very small transverse velocity distribution. This corresponds to a source with extremely high brightness that rivals or may even exceed the brightness of the industry standard Ga+ liquid metal ion source. In this review we discuss the context of ion beam technology in which these new ion sources can play a role, their principles of operation, and some examples of recent demonstrations. The field is relatively new, so only a few applications have been demonstrated, most notably low energy ion microscopy with Li ions. Nevertheless, a number of promising new approaches have been proposed and/or demonstrated, suggesting that a rapid evolution of this type of source is likely in the near future. PMID:27239245

  18. Bright focused ion beam sources based on laser-cooled atoms

    SciTech Connect

    McClelland, J. J.; Wilson, T. M.; Steele, A. V.; Knuffman, B.; Schwarzkopf, A.; Twedt, K. A.

    2016-03-15

    Nanoscale focused ion beams (FIBs) represent one of the most useful tools in nanotechnology, enabling nanofabrication via milling and gas-assisted deposition, microscopy and microanalysis, and selective, spatially resolved doping of materials. Recently, a new type of FIB source has emerged, which uses ionization of laser cooled neutral atoms to produce the ion beam. The extremely cold temperatures attainable with laser cooling (in the range of 100 μK or below) result in a beam of ions with a very small transverse velocity distribution. This corresponds to a source with extremely high brightness that rivals or may even exceed the brightness of the industry standard Ga{sup +} liquid metal ion source. In this review, we discuss the context of ion beam technology in which these new ion sources can play a role, their principles of operation, and some examples of recent demonstrations. The field is relatively new, so only a few applications have been demonstrated, most notably low energy ion microscopy with Li ions. Nevertheless, a number of promising new approaches have been proposed and/or demonstrated, suggesting that a rapid evolution of this type of source is likely in the near future.

  19. Molecular ion sources for low energy semiconductor ion implantation (invited)

    SciTech Connect

    Hershcovitch, A.; Gushenets, V. I.; Bugaev, A. S.; Oks, E. M.; Vizir, A.; Yushkov, G. Yu.; Seleznev, D. N.; Kulevoy, T. V.; Kozlov, A.; Kropachev, G. N.; Kuibeda, R. P.; Minaev, S.; Dugin, S.; Alexeyenko, O.

    2016-02-15

    Smaller semiconductors require shallow, low energy ion implantation, resulting space charge effects, which reduced beam currents and production rates. To increase production rates, molecular ions are used. Boron and phosphorous (or arsenic) implantation is needed for P-type and N-type semiconductors, respectively. Carborane, which is the most stable molecular boron ion leaves unacceptable carbon residue on extraction grids. A self-cleaning carborane acid compound (C{sub 4}H{sub 12}B{sub 10}O{sub 4}) was synthesized and utilized in the ITEP Bernas ion source resulting in large carborane ion output, without carbon residue. Pure gaseous processes are desired to enable rapid switch among ion species. Molecular phosphorous was generated by introducing phosphine in dissociators via 4PH{sub 3} = P{sub 4} + 6H{sub 2}; generated molecular phosphorous in a pure gaseous process was then injected into the HCEI Calutron-Bernas ion source, from which P{sub 4}{sup +} ion beams were extracted. Results from devices and some additional concepts are described.

  20. Focusing giga-electronvolt heavy ions to micrometers at the Institute of Modern Physics.

    PubMed

    Sheng, Lina; Du, Guanghua; Guo, Jinlong; Wu, Ruqun; Song, Mingtao; Yuan, Youjin; Xiao, Guoqing

    2013-05-01

    To study the radiation effect of cosmic heavy ions of low fluxes in electronics and living samples, a focusing heavy ion microbeam facility, for ions with energies of several MeV/u up to 100 MeV/u, was constructed in the Institute of Modern Physics of the Chinese Academy of Sciences. This facility has a vertical design and an experiment platform for both in-vacuum analysis and in-air irradiation. Recently, microbeam of (12)C(6+) with energy of 80.55 MeV/u was successfully achieved at this interdisciplinary microbeam facility with a full beam spot size of 3 μm × 5 μm on target in air. Different from ions with energy of several MeV/u, the very high ion energy of hundred MeV/u level induces problems in beam micro-collimation, online beam spot diagnosis, radiation protection, etc. This paper presents the microbeam setup, difficulties in microbeam formation, and the preliminary experiments performed with the facility.

  1. Analytical possibilities of highly focused ion beams in biomedical field

    NASA Astrophysics Data System (ADS)

    Ren, M. Q.; Ji, X.; Vajandar, S. K.; Mi, Z. H.; Hoi, A.; Walczyk, T.; van Kan, J. A.; Bettiol, A. A.; Watt, F.; Osipowicz, T.

    2017-09-01

    At the Centre for Ion Beam Applications (CIBA), a 3.5 MV HVEE Singletron™ accelerator serves to provide MeV ion beams (mostly protons or He+) to six state-of-the-art beam lines, four of which are equipped with Oxford triplet magnetic quadrupole lens systems. This facility is used for a wide range of research projects, many of which are in the field of biomedicine. Here we presented a discussion of currently ongoing biomedical work carried out using two beamlines: The Nuclear Microscopy (NM) beamline is mainly used for trace elemental quantitative mapping using a combination of Particle Induced X-ray Emission (PIXE), to measure the trace elemental concentration of inorganic elements, Rutherford Backscattering Spectrometry (RBS), to characterise the organic matrix, and Scanning Transmission Ion Microscopy (STIM) to provide information on the lateral areal density variations of the specimen. Typically, a 2.1 MeV proton beam, focused to 1-2 μm spot size with a current of 100 pA is used. The high resolution single cell imaging beamline is equipped with direct STIM to image the interior structure of single cells with proton and alpha particles of sub-50 nm beam spot sizes. Simultaneously, forward scattering transmission ion microscopy (FSTIM) is utilized to generate images with improved contrast of nanoparticles with higher atomic numbers, such as gold nanoparticles, and fluorescent nanoparticles can be imaged using Proton Induced Fluorescence (PIF). Lastly, in this facility, RBS has been included as an option if required to determine the depth distribution of nanoparticles in cells, albeit with reduced spatial resolution.

  2. A compact broadband ion beam focusing device based on laser-driven megagauss thermoelectric magnetic fields

    SciTech Connect

    Albertazzi, B.; D'Humières, E.; Lancia, L.; Antici, P.; Dervieux, V.; Nakatsutsumi, M.; Romagnani, L.; Fuchs, J.; Böcker, J.; Swantusch, M.; Willi, O.; Bonlie, J.; Cauble, B.; Shepherd, R.; Breil, J.; Feugeas, J. L.; Nicolaï, P.; Tikhonchuk, V. T.; Chen, S. N.; Sentoku, Y.; and others

    2015-04-15

    Ultra-intense lasers can nowadays routinely accelerate kiloampere ion beams. These unique sources of particle beams could impact many societal (e.g., proton-therapy or fuel recycling) and fundamental (e.g., neutron probing) domains. However, this requires overcoming the beam angular divergence at the source. This has been attempted, either with large-scale conventional setups or with compact plasma techniques that however have the restriction of short (<1 mm) focusing distances or a chromatic behavior. Here, we show that exploiting laser-triggered, long-lasting (>50 ps), thermoelectric multi-megagauss surface magnetic (B)-fields, compact capturing, and focusing of a diverging laser-driven multi-MeV ion beam can be achieved over a wide range of ion energies in the limit of a 5° acceptance angle.

  3. A compact broadband ion beam focusing device based on laser-driven megagauss thermoelectric magnetic fields.

    PubMed

    Albertazzi, B; d'Humières, E; Lancia, L; Dervieux, V; Antici, P; Böcker, J; Bonlie, J; Breil, J; Cauble, B; Chen, S N; Feugeas, J L; Nakatsutsumi, M; Nicolaï, P; Romagnani, L; Shepherd, R; Sentoku, Y; Swantusch, M; Tikhonchuk, V T; Borghesi, M; Willi, O; Pépin, H; Fuchs, J

    2015-04-01

    Ultra-intense lasers can nowadays routinely accelerate kiloampere ion beams. These unique sources of particle beams could impact many societal (e.g., proton-therapy or fuel recycling) and fundamental (e.g., neutron probing) domains. However, this requires overcoming the beam angular divergence at the source. This has been attempted, either with large-scale conventional setups or with compact plasma techniques that however have the restriction of short (<1 mm) focusing distances or a chromatic behavior. Here, we show that exploiting laser-triggered, long-lasting (>50 ps), thermoelectric multi-megagauss surface magnetic (B)-fields, compact capturing, and focusing of a diverging laser-driven multi-MeV ion beam can be achieved over a wide range of ion energies in the limit of a 5° acceptance angle.

  4. Energetic Ion Beam Production by a Low-Pressure Plasma Focus Discharge

    SciTech Connect

    Lim, L. K.; Yap, S. L.; Wong, C. S.

    2011-03-30

    Energetic ion beam emissions in a 3 kJ Mather type plasma focus operating at low-pressure regime are investigated. Deuterium gas is used and the discharge is operated in a low-pressure regime of below 1 mbar. Formation of the current sheath during the breakdown phase at the back wall is assisted by a set delayed trigger pulse. Energetic and intense ion beams with good reproducibility have been obtained for the operating pressure ranging from 0.05 mbar to 0.5 mbar. Deuteron beam is determined by time resolved measurement by making use of three biased ion collectors placed at the end on direction. The average energies of deuteron beams are resolved by using time-of flight method. Correlation between the ion emissions and the current sheath dynamics is also discussed.

  5. Low energy ion beam dynamics of NANOGAN ECR ion source

    NASA Astrophysics Data System (ADS)

    Kumar, Sarvesh; Mandal, A.

    2016-04-01

    A new low energy ion beam facility (LEIBF) has been developed for providing the mass analyzed highly charged intense ion beams of energy ranging from a few tens of keV to a few MeV for atomic, molecular and materials sciences research. The new facility consists of an all permanent magnet 10 GHz electron cyclotron resonance (ECR) ion source (NANOGAN) installed on a high voltage platform (400 kV) which provides large currents of multiply charged ion beams. Higher emittance at low energy of intense ion beam puts a tremendous challenge to the beam optical design of this facility. The beam line consists of mainly the electrostatic quadrupoles, an accelerating section, analyzing cum switching magnet and suitable beam diagnostics including vacuum components. The accelerated ion beam is analyzed for a particular mass to charge (m/q) ratio as well as guided to three different lines along 75°, 90° and 105° using a large acceptance analyzing cum switching magnet. The details of transverse beam optics to all the beam lines with TRANSPORT and GICOSY beam optics codes are being described. Field computation code, OPERA 3D has been utilized to design the magnets and electrostatic quadrupoles. A theoretical estimation of emittance for optimized geometry of ion source is given so as to form the basis of beam optics calculations. The method of quadrupole scan of the beam is used to characterize the emittance of the final beam on the target. The measured beam emittance increases with m/q ratios of various ion beams similar to the trend observed theoretically.

  6. Low energy ion distribution around the Moon

    NASA Astrophysics Data System (ADS)

    Saito, Y.; Yokota, S.; Tanaka, T.; Asamura, K.; Nishino, M. N.; Yamamoto, T.; Tsunakawa, H.

    2009-04-01

    More than a year has passed since MAP-PACE onboard KAGUYA (SELENE) started continuous observation of the low energy charged particles around the Moon from 100km-altitude polar orbit. MAP (MAgnetic field and Plasma experiment) was developed for the comprehensive measurement of the magnetic field and three-dimensional plasma around the Moon. MAP consists of MAP-LMAG (Lunar MAGnetometer) and MAP-PACE (Plasma energy Angle and Composition Experiment). MAP-PACE consists of 4 sensors: ESA (Electron Spectrum Analyzer)-S1, ESA-S2, IMA (Ion Mass Analyzer), and IEA (Ion Energy Analyzer). Since each sensor has hemispherical field of view, two electron sensors and two ion sensors that are installed on the spacecraft panels opposite to each other can make full 3-dimensional measurements of low energy electrons and ions. One of the ion sensors IMA is an energy mass spectrometer. IMA measures mass identified ion energy spectra that have never been obtained at 100km altitude around the Moon. Low energy charged particles around the Moon were vigorously observed by Moon orbiting satellites and plasma instrumentation placed on the lunar surface in 1960s and 1970s. Though there were some satellites that explored the Moon afterwards, most of them were dedicated to the global mapping of the lunar surface. There has been almost no new information about the low energy charged particles around the Moon except the low energy electron measurement by Lunar Prospector, the lunar wake plasma data obtained by WIND during its Moon fly-by, and reports on remote detection of the lunar ions, lunar electrons and ULF waves generated by electron beams around the lunar wake. The newly observed data show characteristic ion distributions around the Moon. Besides the solar wind, MAP-PACE-IMA discovered four clearly distinguishable ion distributions: 1) Solar wind ions reflected/scattered at the lunar surface, 2) Solar wind ions reflected by magnetic anomalies on the lunar surface, 3) Ions that are

  7. Measurements of low energy auroral ions

    NASA Astrophysics Data System (ADS)

    Urban, A.

    1981-12-01

    Ion measurements in the energy range 0.1-30 keV observed during the 'Substorm Phenomena' and 'Porcupine' campaigns are summarized. Acceleration of the ions by an electrostatic field aligned parallel to the magnetic field is identified and found to be accompanied by intense electron precipitation. On the other hand, deceleration of the ions is observed in other field-aligned current sheets which are indicated by the electron and magnetic field measurements. Temporal successive monoenergetic ion variations suggest energy dispersion and a location of the source region at 9 earth radii. What is more, ion fluxes higher than those of the electrons are measured at pitch angles parallel to the magnetic field. It is noted that each of the examples was observed during different flights.

  8. EDITORIAL: Focus on High Energy Cosmic Rays FOCUS ON HIGH ENERGY COSMIC RAYS

    NASA Astrophysics Data System (ADS)

    Teshima, Masahiro; Watson, Alan A.

    2009-06-01

    The topic of high-energy cosmic rays has recently attracted significant attention. While the AGASA and HiRes Observatories have closed after many years of successful operation, the Pierre Auger Observatory began taking data in January 2004 and the first results have been reported. Plans for the next generation of instruments are in hand: funding is now being sought for the northern phase of the Auger Observatory and plans for a space detector, JEM-EUSO, to be launched in 2013-14 are well advanced with the long-term target of a dedicated satellite for the 2020s. It therefore seemed an appropriate time to make a collection of outstanding and original research articles from the leading experimental groups and from some of the theorists who seek to interpret the hard-won data and to speculate on the origin of the highest energy cosmic rays. This focus issue in New Journal of Physics on the topic of high energy cosmic rays, contains a comprehensive account of the work of the Yakutsk group (A A Ivanov, S P Knurenko and I Ye Sleptsov) who have used Cerenkov radiation produced by shower particles in the air to provide the basis for energy calibration. This technique contrasts with that of detecting fluorescence radiation from space that is proposed for the JEM-EUSO instrument to be placed on the International Space Station in 2013, described by Y Takahashi. Supplementing this is an article by A Santangelo and A Petrolini describing the scientific goals, requirements and main instrument features of the Super Extreme Universe Space Observatory mission (S-EUSO). The use of fluorescence light to measure energies was the key component of the HiRes instrument and is also used extensively by the Pierre Auger Collaboration so an article, by F Arqueros, F Blanco and J Rosado, summarizing the properties of fluorescence emission, still not fully understood, is timely. M Nagano, one of the architects of the AGASA Observatory, has provided an overview of the experimental situation with

  9. Proton Acceleration: New Developments in Energy Increase, Focusing and Energy Selection

    SciTech Connect

    D'Humieres, Emmanuel; Fuchs, Julien; Antici, Patrizio; Audebert, Patrick; Brambrink, Erik; Romagnani, Lorenzo; Borghesi, Marco; Cecchetti, Carlo Alberto; Kaluza, Malte; Schreiber, Joerg; Lefebvre, Erik; Malka, Victor; Manclossi, Mauro; Meyroneinc, Samuel; Mora, Patrick; Pepin, Henri; Pipahl, Ariane; Toncian, Toma; Willi, Oswald; Sentoku, Yasuhiko

    2006-11-27

    In the last few years, intense research has been conducted on laser-accelerated ion sources and their applications. These sources have exceptional properties, i.e. high brightness and high spectral cut-oft high directionality and laminarity, short burst duration. These proton sources open new opportunities for ion beam generation and control, and could stimulate development of compact ion accelerators for many applications. We have studied the variations of the proton acceleration characteristic time with target and laser parameters. We used these variations to correct one of the model recently developed to predict maximum energies of laser-accelerated protons for low energy, short duration laser pulses. We have also developed an ultra-fast laser-triggered micro-lens that allows tunable control of the beam divergence as well as energy selection, therefore solving two of the major problems that these proton beams were facing. We used PIC simulations to explain the focusing and energy selection mechanisms, and to study the symmetry of the expanding plasma inside the cylinder.

  10. Deflection of high-intensity pulsed ion beam in focusing magnetically insulated ion diode with a passive anode

    NASA Astrophysics Data System (ADS)

    Zhu, X. P.; Zhang, Q.; Ding, L.; Zhang, Z. C.; Yu, N.; Pushkarev, A.; Lei, M. K.

    2016-12-01

    The focused high-intensity pulsed ion beam (HIPIB) of 100 ns order pulse is generated with respect to its spatial stability in two types of magnetically insulated ion diodes (MIDs) with geometrical focusing configuration using the passive anode, i.e., insulation of electrons with an external magnetic-field and a self-magnetic field, respectively. Anode plasma formation for the ion beam generation is based on different processes in the two types of MIDs, as the surface breakdown on the polymer-coated anode operated in the unipolar pulse mode for the external-magnetic field MID and the explosive electron emission on the graphite anode in the bipolar-pulse mode for the self-magnetic field MID. Typical energy density per pulse is in the range of 3-6 J/cm2, at an accelerating voltage of 200-300 kV with a pulse duration of 120-150 ns. The spatial deviations of the HIPIB is evaluated by measuring the energy density distribution by using an infrared diagnostic method considering neutralizing during the ion beam propagation to the focal plane with a spatial resolution of 1 mm. The ion beam deviation is about ±1.5 mm for the external-magnetic field MID and ±2.5 mm for the self-magnetic field MID, leading to a fluctuation in the energy density of 1%-12%, and 9%-27% within a 10 mm range at the focal point, respectively. It is revealed that the displacement of different parts of a beam spot occurs nonsynchronously, mainly attributable to the intrinsic diode processes of plasma generation and expansion, and ion beam extraction from the anode-cathode gap, while the influence of magnetic field in the transportation region is negligible. The ion beam spatial deviation has a major influence on the shot-to-shot stability of ion beam, and it is suggested that the stability can be enhanced via diode process improvement.

  11. Focused ion beam fabrication of boron-doped diamond ultramicroelectrodes.

    PubMed

    Hu, Jingping; Holt, Katherine B; Foord, John S

    2009-07-15

    The fabrication of ultramicroelectrodes (UMEs) for analytical electrochemical applications has been explored, using boron-doped diamond as the active electrode material in an insulating coating formed by deposition of electrophoretic paint. Because of the rough nature of the diamond film, the property of such coatings that is normally exploited in the fabrication of UMEs, namely the tendency to retract automatically from sharp protrusions, cannot be used in the present instance. Instead focused ion beam (FIB) sputtering was employed to controllably produce UMEs with well-defined geometry, critical dimension of a few micrometers, and very thin insulating coatings. If the FIB machining is carried out at normal incidence to the diamond electrode surface, significant ion beam damage reduces the yield of successful electrodes. However, if a parallel machining geometry is employed, high yields of ultramicroelectrodes with a flat disk geometry can be obtained very reliably. The electrochemical properties of diamond UMEs are characterized. They show much lower background currents than the equivalent Pt or carbon fiber electrodes but more varied electrochemical response than macroscopic diamond electrodes.

  12. Electromigration in focused ion beam deposited tungsten single nanowires

    NASA Astrophysics Data System (ADS)

    Mandal, Pabitra; Das, Bipul; Raychaudhuri, A. K.

    As the focused ion beam induced deposited (FIBID) nanowires (NWs) of W, Pt are being used in nanoelectronic technology to connect individual nanodevices, repairing damaged interconnects in integrated circuit (IC), electromigration study in FIBID-NWs has become essential. Briefly, when a thin conductor, like metallic Al, Cu interconnects in an IC chip carry quite high current density ~1012 A/m2, ions or atoms start migrating. Such migration causes void and hillock formation leading to interconnect discontinuity, short circuit and ultimately IC failure. Our electromigration study in single FIBID-NWs of W reveals that failure in NWs of width and thickness ~100 nm occurs typically at 1011 A/m2. Most notably, void and hillock always form in opposite polarity compared to typical metallic NWs. Such distinctly new outcome is explained via electromigration driven by direct force (ionic charge*electric field) opposed to wind force driven migration observed in metallic NWs. As FIBID-NWs are composite in nature, different species (e.g., Ga, W and C) migrate with different degree and direction depending on their oxidation state, leading to redistribution of species across NW length and formation of a Ga rich hillock. S. N. Bose National Centre for Basic Sciences, Block-JD, Sector-III, Salt Lake, Kolkata-98, India.

  13. Magnetic strip patterns induced by focused ion beam irradiation

    SciTech Connect

    Makarov, D.; Tibus, S.; Rettner, C. T.; Thomson, T.; Terris, B. D.; Schrefl, T.; Albrecht, M.

    2008-03-15

    Focused ion beam exposure was used to locally alter the magnetic properties of a continuous Co/Pd multilayer film with perpendicular magnetic anisotropy. The saturation magnetization, coercivity, and magnetic anisotropy of the films can be tuned by Ga irradiation depending on exposure dose. As a result, a periodic strip pattern consisting of 80 nm wide exposed strips which are magnetically soft, separated by 170 nm wide magnetically hard, unexposed areas was created. Due to strong magnetostatic coupling between the strips, a number of magnetic domain configurations could be stabilized and these have been observed by magnetic force microscopy and magneto-optic Kerr effect measurements. The magnetic domain configurations and their reversal behavior were investigated by micromagnetic simulations as a function of exposure dose and strip period.

  14. Energy-banded ions in Saturn's magnetosphere

    NASA Astrophysics Data System (ADS)

    Thomsen, M. F.; Badman, S. V.; Jackman, C. M.; Jia, X.; Kivelson, M. G.; Kurth, W. S.

    2017-05-01

    Using data from the Cassini Plasma Spectrometer ion mass spectrometer, we report the first observation of energy-banded ions at Saturn. Observed near midnight at relatively high magnetic latitudes, the banded ions are dominantly H+, and they occupy the range of energies typically associated with the thermal pickup distribution in the inner magnetosphere (L < 10), but their energies decline monotonically with increasing radial distance (or time or decreasing latitude). Their pitch angle distribution suggests a source at low (or slightly southern) latitudes. The band energies, including their pitch angle dependence, are consistent with a bounce-resonant interaction between thermal H+ ions and the standing wave structure of a field line resonance. There is additional evidence in the pitch angle dependence of the band energies that the particles in each band may have a common time of flight from their most recent interaction with the wave, which may have been at slightly southern latitudes. Thus, while the particles are basically bounce resonant, their energization may be dominated by their most recent encounter with the standing wave.Plain Language SummaryDuring an outbound passage by the Cassini spacecraft through Saturn's inner magnetosphere, <span class="hlt">ion</span> <span class="hlt">energy</span> distributions were observed that featured discrete flux peaks at regularly spaced <span class="hlt">energies</span>. The peaks persisted over several hours and several Saturn radii of distance away from the planet. We show that these "bands" of <span class="hlt">ions</span> are plausibly the result of an interaction between the Saturnian plasma and standing waves that form along the magnetospheric magnetic field lines. These observations are the first reported evidence that such standing waves may be present in the inner magnetosphere, where they could contribute to the radial transport of Saturn's radiation belt particles.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011JPhCS.282a2018R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011JPhCS.282a2018R"><span>Symmetry <span class="hlt">Energy</span> Effects on Low <span class="hlt">Energy</span> Dissipative Heavy <span class="hlt">Ion</span> Collisions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rizzo, C.; Baran, V.; Colonna, M.; Di Toro, M.; Odsuren, M.</p> <p>2011-02-01</p> <p>We investigate the reaction path followed by Heavy <span class="hlt">Ion</span> Collisions with exotic nuclear beams at low <span class="hlt">energies</span>. We <span class="hlt">focus</span> on the interplay between reaction mechanisms, fusion vs. break-up (fast-fission, deep-inelastic), that in exotic systems is expected to be influenced by the symmetry <span class="hlt">energy</span> term at densities around the normal value. The method described here, based on the event by event evolution of phase space quadrupole collective modes, will nicely allow to extract the fusion probability at relatively early times, when the transport results are reliable. Fusion probabilities for reactions induced by 132Sn on 64,58Ni targets at 10 AMeV are evaluated. We obtain larger fusion cross sections for the more n-rich composite system, and, for a given reaction, with a soft symmetry term above saturation. A collective charge equilibration mechanism (the Dynamical Dipole Resonance, DDR) is revealed in both fusion and break-up events, depending on the stiffness of the symmetry term just below saturation. Finally we investigate the effect of the mass asymmetry in the entrance channel for systems with the same overall isospin content and similar initial charge asymmetry. As expected we find reduced fusion probabilities for the more mass symmetric case, while the DDR strength appears not much affected. This is a nice confirmation of the prompt nature of such collective isovector mode.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/861022','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/861022"><span>Highly Compressed <span class="hlt">Ion</span> Beam for High <span class="hlt">Energy</span> Density Science</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Friedman, A.; Barnard, J.J.; Briggs, R.J.; Callahan, D.A.; Caporaso, G.J.; Celata, C.M.; Davidson, R.C.; Faltens, A.; Grisham, L.; Grote, D.P.; Henestroza, E.; Kaganovich I.; Lee, E.P.; Lee, R.W.; Leitner, M.; Logan, B.G.; Nelson, S.D.; Olson, C.L.; Penn, G.; Reginato,L.R.; Renk, T.; Rose, D.; Seessler, A.; Staples, J.W.; Tabak, M.; Thoma,C.; Waldron, W.; Welch, D.R.; Wurtele, J.; Yu, S.S.</p> <p>2005-05-16</p> <p>The Heavy <span class="hlt">Ion</span> Fusion Virtual National Laboratory is developing the intense <span class="hlt">ion</span> beams needed to drive matter to the High <span class="hlt">Energy</span> Density regimes required for Inertial Fusion <span class="hlt">Energy</span> and other applications. An interim goal is a facility for Warm Dense Matter studies, wherein a target is heated volumetrically without being shocked, so that well-defined states of matter at 1 to 10 eV are generated within a diagnosable region. In the approach they are pursuing, low to medium mass <span class="hlt">ions</span> with <span class="hlt">energies</span> just above the Bragg peak are directed onto thin target ''foils,'' which may in fact be foams with mean densities 1% to 10% of solid. This approach complements that being pursued at GSI Darmstadt, wherein high-<span class="hlt">energy</span> <span class="hlt">ion</span> beams deposit a small fraction of their <span class="hlt">energy</span> in a cylindrically target. They present the beam requirements for Warm Dense Matter experiments. The authors discuss neutralized drift compression and final <span class="hlt">focus</span> experiments and modeling. They describe suitable accelerator architectures based on Drift-Tube Linac, RF, single-gap, Ionization-Front Accelerator, and Pulse-Line <span class="hlt">Ion</span> Accelerator concepts. The last of these is being pursued experimentally. Finally, they discuss plans toward a user facility for target experiments.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1271869-situ-mitigation-subsurface-peripheral-focused-ion-beam-damage-via-simultaneous-pulsed-laser-heating','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1271869-situ-mitigation-subsurface-peripheral-focused-ion-beam-damage-via-simultaneous-pulsed-laser-heating"><span>In situ mitigation of subsurface and peripheral <span class="hlt">focused</span> <span class="hlt">ion</span> beam damage via simultaneous pulsed laser heating</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Stanford, Michael G.; Lewis, Brett B.; Iberi, Vighter O.; ...</p> <p>2016-02-16</p> <p><span class="hlt">Focused</span> helium and neon <span class="hlt">ion</span> (He(+)/Ne(+) ) beam processing has recently been used to push resolution limits of direct-write nanoscale synthesis. The ubiquitous insertion of <span class="hlt">focused</span> He(+) /Ne(+) beams as the next-generation nanofabrication tool-of-choice is currently limited by deleterious subsurface and peripheral damage induced by the energetic <span class="hlt">ions</span> in the underlying substrate. The in situ mitigation of subsurface damage induced by He(+)/Ne(+) <span class="hlt">ion</span> exposures in silicon via a synchronized infrared pulsed laser-assisted process is demonstrated. The pulsed laser assist provides highly localized in situ photothermal <span class="hlt">energy</span> which reduces the implantation and defect concentration by greater than 90%. The laser-assisted exposuremore » process is also shown to reduce peripheral defects in He(+) patterned graphene, which makes this process an attractive candidate for direct-write patterning of 2D materials. In conclusion, these results offer a necessary solution for the applicability of high-resolution direct-write nanoscale material processing via <span class="hlt">focused</span> <span class="hlt">ion</span> beams.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1271869','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1271869"><span>In situ mitigation of subsurface and peripheral <span class="hlt">focused</span> <span class="hlt">ion</span> beam damage via simultaneous pulsed laser heating</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Stanford, Michael G.; Lewis, Brett B.; Iberi, Vighter O.; Fowlkes, Jason Davidson; Tan, Shida; Livengood, Rick; Rack, Philip D.</p> <p>2016-02-16</p> <p><span class="hlt">Focused</span> helium and neon <span class="hlt">ion</span> (He(+)/Ne(+) ) beam processing has recently been used to push resolution limits of direct-write nanoscale synthesis. The ubiquitous insertion of <span class="hlt">focused</span> He(+) /Ne(+) beams as the next-generation nanofabrication tool-of-choice is currently limited by deleterious subsurface and peripheral damage induced by the energetic <span class="hlt">ions</span> in the underlying substrate. The in situ mitigation of subsurface damage induced by He(+)/Ne(+) <span class="hlt">ion</span> exposures in silicon via a synchronized infrared pulsed laser-assisted process is demonstrated. The pulsed laser assist provides highly localized in situ photothermal <span class="hlt">energy</span> which reduces the implantation and defect concentration by greater than 90%. The laser-assisted exposure process is also shown to reduce peripheral defects in He(+) patterned graphene, which makes this process an attractive candidate for direct-write patterning of 2D materials. In conclusion, these results offer a necessary solution for the applicability of high-resolution direct-write nanoscale material processing via <span class="hlt">focused</span> <span class="hlt">ion</span> beams.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22025426','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22025426"><span>Mechanisms of nanorod growth on <span class="hlt">focused-ion</span>-beam-irradiated semiconductor surfaces: Role of redeposition</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Wu, J. H.; Goldman, R. S.</p> <p>2012-01-30</p> <p>We have examined the formation and evolution of irradiation-induced nanorod (NR) growth through a comparison of <span class="hlt">focused-ion</span>-beam irradiation of InSb wafers and InSb/GaAs heterostructures. Above a critical <span class="hlt">ion</span> dose, cone-shaped NRs capped with In islands form on both InSb surfaces. For InSb wafers, the NR base diameter increases with <span class="hlt">ion</span> <span class="hlt">energy</span>. In the case of InSb/GaAs heterostructures, as the milled depth approaches the InSb/GaAs interface, the cone-shaped NRs transition to capless NRs with a truncated cone shape. These results suggest a growth mechanism in which both the NR cap and body are supplied by redeposition of atoms sputtered from InSb.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/910205','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/910205"><span>Simulating Electron Effects in Heavy-<span class="hlt">Ion</span> Accelerators with Solenoid <span class="hlt">Focusing</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Sharp, W M; Grote, D P; Cohen, R H; Friedman, A; Molvik, A W; Vay, J; Seidl, P; Roy, P K; Coleman, J E; Haber, I</p> <p>2007-06-29</p> <p>Contamination from electrons is a concern for solenoid-<span class="hlt">focused</span> <span class="hlt">ion</span> accelerators being developed for experiments in high-<span class="hlt">energy</span>-density physics. These electrons, produced directly by beam <span class="hlt">ions</span> hitting lattice elements or indirectly by ionization of desorbed neutral gas, can potentially alter the beam dynamics, leading to a time-varying focal spot, increased emittance, halo, and possibly electron-<span class="hlt">ion</span> instabilities. The electrostatic particle-in-cell code WARP is used to simulate electron-cloud studies on the solenoid-transport experiment (STX) at Lawrence Berkeley National Laboratory. We present self-consistent simulations of several STX configurations and compare the results with experimental data in order to calibrate physics parameters in the model.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li class="active"><span>8</span></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_8 --> <div id="page_9" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li class="active"><span>9</span></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="161"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/894003','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/894003"><span>Simulating Electron Clouds in High-Current <span class="hlt">Ion</span> Accelerators with Solenoid <span class="hlt">Focusing</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Sharp, W; Grote, D; Cohen, R; Friedman, A; Vay, J; Seidl, P; Roy, P; Coleman, J; Armijo, J; Haber, I</p> <p>2006-08-15</p> <p>Contamination from electrons is a concern for the solenoid-<span class="hlt">focused</span> <span class="hlt">ion</span> accelerators being developed for experiments in high-<span class="hlt">energy</span>-density physics (HEDP). These electrons are produced directly by beam <span class="hlt">ions</span> hitting lattice elements and intercepting diagnostics, or indirectly by ionization of desorbed neutral gas, and they are believed responsible for time dependence of the beam radius, emittance, and focal distance seen on the Solenoid Transport Experiment (STX) at Lawrence Berkeley National Laboratory. The electrostatic particle-in-cell code WARP has been upgraded to included the physics needed to simulate electron-cloud phenomena. We present preliminary self-consistent simulations of STX experiments suggesting that the observed time dependence of the beam stems from a complicated interaction of beam <span class="hlt">ions</span>, desorbed neutrals, and electrons.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/918120','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/918120"><span>Simulating Electron Clouds in High-Current <span class="hlt">Ion</span> Accelerators withSolenoid <span class="hlt">Focusing</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Sharp, W.M.; Grote, D.P.; Cohen, R.H.; Friedman, A.; Vay, J.-L.; Seidl, P.A.; Roy, P.K.; Coleman, J.E.; Armijo, J.; Haber, I.</p> <p>2006-09-20</p> <p>Contamination from electrons is a concern for the solenoid-<span class="hlt">focused</span> <span class="hlt">ion</span> accelerators being developed for experiments in high-<span class="hlt">energy</span>-density physics (HEDP). These electrons are produced directly by beam <span class="hlt">ions</span> hitting lattice elements and intercepting diagnostics, or indirectly by ionization of desorbed neutral gas, and they are believed responsible for time dependence of the beam radius, emittance, and focal distance seen on the Solenoid Transport Experiment (STX) at Lawrence Berkeley National Laboratory. The electrostatic particle-in-cell code WARP has been upgraded to included the physics needed to simulate electron-cloud phenomena. We present preliminary self-consistent simulations of STX experiments suggesting that the observed time dependence of the beam stems from a complicated interaction of beam <span class="hlt">ions</span>, desorbed neutrals, and electrons.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/929695','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/929695"><span>Simulating Electron Effects in Heavy-<span class="hlt">Ion</span> Accelerators with Solenoid <span class="hlt">Focusing</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Sharp, W. M.; Grote, D. P.; Cohen, R. H.; Friedman, A.; Molvik, A. W.; Vay, J.-L.; Seidl, P. A.; Roy, P. K.; Coleman, J. E.; Haber, I.</p> <p>2007-06-20</p> <p>Contamination from electrons is a concern for solenoid-<span class="hlt">focused</span> <span class="hlt">ion</span> accelerators being developed for experiments in high-<span class="hlt">energy</span>-density physics. These electrons, produced directly by beam <span class="hlt">ions</span> hitting lattice elements or indirectly by ionization of desorbed neutral gas, can potentially alter the beam dynamics, leading to a time-varying focal spot, increased emittance, halo, and possibly electron-<span class="hlt">ion</span> instabilities. The electrostatic particle-in-cell code WARP is used to simulate electron-cloud studies on the solenoid-transport experiment (STX) at Lawrence Berkeley National Laboratory. We present self-consistent simulations of several STX configurations and compare the results with experimental data in order to calibrate physics parameters in the model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1379314-radiation-pressure-acceleration-factors-limiting-maximum-attainable-ion-energy','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1379314-radiation-pressure-acceleration-factors-limiting-maximum-attainable-ion-energy"><span>Radiation pressure acceleration: The factors limiting maximum attainable <span class="hlt">ion</span> <span class="hlt">energy</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Bulanov, S. S.; Esarey, E.; Schroeder, C. B.; ...</p> <p>2016-04-15</p> <p>Radiation pressure acceleration (RPA) is a highly efficient mechanism of laser-driven <span class="hlt">ion</span> acceleration, with near complete transfer of the laser <span class="hlt">energy</span> to the <span class="hlt">ions</span> in the relativistic regime. However, there is a fundamental limit on the maximum attainable <span class="hlt">ion</span> <span class="hlt">energy</span>, which is determined by the group velocity of the laser. The tightly <span class="hlt">focused</span> laser pulses have group velocities smaller than the vacuum light speed, and, since they offer the high intensity needed for the RPA regime, it is plausible that group velocity effects would manifest themselves in the experiments involving tightly <span class="hlt">focused</span> pulses and thin foils. However, in this case,more » finite spot size effects are important, and another limiting factor, the transverse expansion of the target, may dominate over the group velocity effect. As the laser pulse diffracts after passing the <span class="hlt">focus</span>, the target expands accordingly due to the transverse intensity profile of the laser. Due to this expansion, the areal density of the target decreases, making it transparent for radiation and effectively terminating the acceleration. The off-normal incidence of the laser on the target, due either to the experimental setup, or to the deformation of the target, will also lead to establishing a limit on maximum <span class="hlt">ion</span> <span class="hlt">energy</span>.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1379314','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1379314"><span>Radiation pressure acceleration: The factors limiting maximum attainable <span class="hlt">ion</span> <span class="hlt">energy</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Bulanov, S. S.; Esarey, E.; Schroeder, C. B.; Bulanov, S. V.; Esirkepov, T. Zh.; Kando, M.; Pegoraro, F.; Leemans, W. P.</p> <p>2016-04-15</p> <p>Radiation pressure acceleration (RPA) is a highly efficient mechanism of laser-driven <span class="hlt">ion</span> acceleration, with near complete transfer of the laser <span class="hlt">energy</span> to the <span class="hlt">ions</span> in the relativistic regime. However, there is a fundamental limit on the maximum attainable <span class="hlt">ion</span> <span class="hlt">energy</span>, which is determined by the group velocity of the laser. The tightly <span class="hlt">focused</span> laser pulses have group velocities smaller than the vacuum light speed, and, since they offer the high intensity needed for the RPA regime, it is plausible that group velocity effects would manifest themselves in the experiments involving tightly <span class="hlt">focused</span> pulses and thin foils. However, in this case, finite spot size effects are important, and another limiting factor, the transverse expansion of the target, may dominate over the group velocity effect. As the laser pulse diffracts after passing the <span class="hlt">focus</span>, the target expands accordingly due to the transverse intensity profile of the laser. Due to this expansion, the areal density of the target decreases, making it transparent for radiation and effectively terminating the acceleration. The off-normal incidence of the laser on the target, due either to the experimental setup, or to the deformation of the target, will also lead to establishing a limit on maximum <span class="hlt">ion</span> <span class="hlt">energy</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22600253','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22600253"><span>Radiation pressure acceleration: The factors limiting maximum attainable <span class="hlt">ion</span> <span class="hlt">energy</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Bulanov, S. S.; Esarey, E.; Schroeder, C. B.; Bulanov, S. V.; Esirkepov, T. Zh.; Kando, M.; Pegoraro, F.; Leemans, W. P.</p> <p>2016-05-15</p> <p>Radiation pressure acceleration (RPA) is a highly efficient mechanism of laser-driven <span class="hlt">ion</span> acceleration, with near complete transfer of the laser <span class="hlt">energy</span> to the <span class="hlt">ions</span> in the relativistic regime. However, there is a fundamental limit on the maximum attainable <span class="hlt">ion</span> <span class="hlt">energy</span>, which is determined by the group velocity of the laser. The tightly <span class="hlt">focused</span> laser pulses have group velocities smaller than the vacuum light speed, and, since they offer the high intensity needed for the RPA regime, it is plausible that group velocity effects would manifest themselves in the experiments involving tightly <span class="hlt">focused</span> pulses and thin foils. However, in this case, finite spot size effects are important, and another limiting factor, the transverse expansion of the target, may dominate over the group velocity effect. As the laser pulse diffracts after passing the <span class="hlt">focus</span>, the target expands accordingly due to the transverse intensity profile of the laser. Due to this expansion, the areal density of the target decreases, making it transparent for radiation and effectively terminating the acceleration. The off-normal incidence of the laser on the target, due either to the experimental setup, or to the deformation of the target, will also lead to establishing a limit on maximum <span class="hlt">ion</span> <span class="hlt">energy</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21251677','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21251677"><span>Sources for Low <span class="hlt">Energy</span> Extreme of <span class="hlt">Ion</span> Implantation</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Hershcovitch, A.; Johnson, B. M.; Batalin, V. A.; Kolomiets, A. A.; Kropachev, G. N.; Kuibeda, R. P.; Kulevoy, T. V.; Pershin, V. I.; Petrenko, S. V.; Rudskoy, I.; Seleznev, D. N.; Bugaev, A. S.; Gushenets, V. I.; Oks, E. M.; Yushkov, G. Yu.; Masunov, E. S.; Polozov, S. M.; Poole, H. J.; Storozhenko, P. A.; Svarovski, A. Ya.</p> <p>2008-11-03</p> <p>A joint research and development effort <span class="hlt">focusing</span> on the design of steady state, intense <span class="hlt">ion</span> sources has been in progress for the past four and a half years. The ultimate goal is to meet the two, <span class="hlt">energy</span> extreme range needs of mega-electron-volt and 100's of electron-volt <span class="hlt">ion</span> implanters. This endeavor has resulted in record steady state output currents of higher charge state Antimony and Phosphorous <span class="hlt">ions</span>: P{sup 2+}(8.6 pmA), P{sup 3+}(1.9 pmA), and P{sup 4+}(0.12 pmA) and 16.2, 7.6, 3.3, and 2.2 pmA of Sb{sup 3+} Sb{sup 4+}, Sb{sup 5+}, and Sb{sup 6+} respectively. During the past year the effort was channeled towards low <span class="hlt">energy</span> implantation, for which the effort involved molecular <span class="hlt">ions</span> and a novel plasmaless/gasless deceleration method. To date, 3 emA of positive Decaborane <span class="hlt">ions</span> were extracted at 14 keV and a smaller current of negative Decaborane <span class="hlt">ions</span> were also extracted. Additionally, a Boron fraction of over 70% was extracted from a Bernas-Calutron <span class="hlt">ion</span> source.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/6720925','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/6720925"><span>Edge envelope equation for a ballistically <span class="hlt">focused</span> neutralized <span class="hlt">ion</span> beam</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Lemons, D.S.; Thode, L.E.</p> <p>1980-11-01</p> <p>An envelope equation for a cold <span class="hlt">ion</span> beam with overall charge and current neutralization provided by a coflowing electron gas obeying an adiabatic equation of state is derived. The derivation assumes the beam evolves self-similarly with the <span class="hlt">ion</span> at the edge of a uniform density <span class="hlt">ion</span> profile. Numerical and approximate analytical solutions are calculated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18401041','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18401041"><span><span class="hlt">Ion</span> optical evaluation of a miniature double-<span class="hlt">focusing</span> mass spectrograph.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Nishiguchi, Masaru; Ishihara, Morio; Katakuse, Itsuo; Toyoda, Michisato</p> <p>2008-01-01</p> <p>A new miniature double-<span class="hlt">focusing</span> mass spectrograph has been designed and constructed. The <span class="hlt">ion</span> optical system was designed based on Mattauch-Herzog geometry. The mass spectrograph employs a focal plane detector consisting of a microchannel plate, a phosphor layer, a fiber-optic plate and a charge-coupled device. For the evaluation of the <span class="hlt">ion</span> optics of the instrument, the <span class="hlt">energy</span> and angular focal planes were investigated both experimentally and by simulation. Double <span class="hlt">focusing</span> was satisfactorily achieved along a straight line over a wide mass range, and the experimental and simulated results were mutually consistent. A second-order element of the transfer matrix was also measured experimentally and proved to be in good agreement with the simulated result.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003APS..DPPGP1044Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003APS..DPPGP1044Y"><span>Development of a Fast <span class="hlt">Ion</span> <span class="hlt">Energy</span> Analyzer</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Young, W. C.; Bellan, P. M.</p> <p>2003-10-01</p> <p>In an effort to measure the <span class="hlt">ion</span> <span class="hlt">energy</span> spectra of short duration plasmas, two different analyzers are being compared for usability on short time scales. A traditional <span class="hlt">energy</span> analyzer, the retarding field <span class="hlt">energy</span> analyzer (RFEA), is being compared to a design using an electric field to deflect <span class="hlt">ions</span> onto multiple collectors. The use of multiple collectors allows for simultaneous measurement of several <span class="hlt">energies</span> overcoming the major limitation of the RFEA is measuring only a single <span class="hlt">energy</span> per plasma shot. The tradeoff is that the <span class="hlt">energy</span> resolution of the new design is limited by the number of collectors. These methods are being tested on both a single <span class="hlt">energy</span> electron gun and also on a spheromak with a plasma duration of 20-30 μs and <span class="hlt">ion</span> temperature of 20 eV. Both designs have been demonstrated to work under simplified conditions using an electron gun. Currently the RFEA is being tested on the spheromak and efforts are being made to increase the resolution and lower the noise of the new analyzer.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/6287961','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/6287961"><span><span class="hlt">Ion-ion</span> interaction and <span class="hlt">energy</span> transfer of 4+ transuranium <span class="hlt">ions</span> in cerium tetrafluoride</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Liu, G.K.; Beitz, J.V.</p> <p>1990-01-01</p> <p>Dynamics of excited 5f electron states of the transuranium <span class="hlt">ions</span> Cm{sup 4+} and Bk{sup 4+} in CeF{sub 4} are compared. Based on time- and wavelength-resolved laser-induced fluorescence, excitation <span class="hlt">energy</span> transfer processes have been probed. Depending on concentration and electronic <span class="hlt">energy</span> level structure of the studied 4+ transuranium <span class="hlt">ion</span>, the dominant <span class="hlt">energy</span> transfer mechanisms were identified as cross relaxation, exciton-exciton annihilation, and trapping. <span class="hlt">Energy</span> transfer rates derived from the fitting of the observed fluorescence decays to theoretical models, based on electric multipolar <span class="hlt">ion-ion</span> interactions, are contrasted with prior studies of 4f states of 3+ lanthanide and 3d states of transition metal <span class="hlt">ions</span>. 16 refs., 1 tab.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/20643775','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/20643775"><span><span class="hlt">Energy</span> loss of helium <span class="hlt">ions</span> in zinc</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Lantschner, G.H.; Eckardt, J.C.; Lifschitz, A.F.; Arista, N.R.; Araujo, L.L.; Duarte, P.F.; Santos, J.H.R. dos; Behar, M.; Dias, J.F.; Grande, P.L.; Montanari, C.C.; Miraglia, J.E.</p> <p>2004-06-01</p> <p>The <span class="hlt">energy</span> loss of helium <span class="hlt">ions</span> in zinc has been measured in the <span class="hlt">energy</span> range from 37.5 to 1750 keV/amu using the transmission technique and the Rutherford backscattering method. In addition, calculations using the extended Friedel sum rule, the unitary convolution approximation, and the local plasma approximation have been performed. The contributions of the inner-shell and valence electrons to the total <span class="hlt">energy</span> loss are separately evaluated. The measurements and calculations are in good agreement over an extended range of <span class="hlt">energies</span>, and both of them yield stopping values higher than those provided by SRIM 2003.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3311327','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3311327"><span><span class="hlt">Focused</span> <span class="hlt">ion</span> beam micromachining of eukaryotic cells for cryoelectron tomography</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Rigort, Alexander; Bäuerlein, Felix J. B.; Villa, Elizabeth; Eibauer, Matthias; Laugks, Tim; Baumeister, Wolfgang; Plitzko, Jürgen M.</p> <p>2012-01-01</p> <p>Cryoelectron tomography provides unprecedented insights into the macromolecular and supramolecular organization of cells in a close-to-living state. However because of the limited thickness range (< 0.5–1 μm) that is accessible with today’s intermediate voltage electron microscopes only small prokaryotic cells or peripheral regions of eukaryotic cells can be examined directly. Key to overcoming this limitation is the ability to prepare sufficiently thin samples. Cryosectioning can be used to prepare thin enough sections but suffers from severe artefacts, such as substantial compression. Here we describe a procedure, based upon <span class="hlt">focused</span> <span class="hlt">ion</span> beam (FIB) milling for the preparation of thin (200–500 nm) lamellae from vitrified cells grown on electron microscopy (EM) grids. The self-supporting lamellae are apparently free of distortions or other artefacts and open up large windows into the cell’s interior allowing tomographic studies to be performed on any chosen part of the cell. We illustrate the quality of sample preservation with a structure of the nuclear pore complex obtained from a single tomogram. PMID:22392984</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22392984','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22392984"><span><span class="hlt">Focused</span> <span class="hlt">ion</span> beam micromachining of eukaryotic cells for cryoelectron tomography.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Rigort, Alexander; Bäuerlein, Felix J B; Villa, Elizabeth; Eibauer, Matthias; Laugks, Tim; Baumeister, Wolfgang; Plitzko, Jürgen M</p> <p>2012-03-20</p> <p>Cryoelectron tomography provides unprecedented insights into the macromolecular and supramolecular organization of cells in a close-to-living state. However because of the limited thickness range (< 0.5-1 μm) that is accessible with today's intermediate voltage electron microscopes only small prokaryotic cells or peripheral regions of eukaryotic cells can be examined directly. Key to overcoming this limitation is the ability to prepare sufficiently thin samples. Cryosectioning can be used to prepare thin enough sections but suffers from severe artefacts, such as substantial compression. Here we describe a procedure, based upon <span class="hlt">focused</span> <span class="hlt">ion</span> beam (FIB) milling for the preparation of thin (200-500 nm) lamellae from vitrified cells grown on electron microscopy (EM) grids. The self-supporting lamellae are apparently free of distortions or other artefacts and open up large windows into the cell's interior allowing tomographic studies to be performed on any chosen part of the cell. We illustrate the quality of sample preservation with a structure of the nuclear pore complex obtained from a single tomogram.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26531887','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26531887"><span>Optical fiber tip templating using direct <span class="hlt">focused</span> <span class="hlt">ion</span> beam milling.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Micco, A; Ricciardi, A; Pisco, M; La Ferrara, V; Cusano, A</p> <p>2015-11-04</p> <p>We report on a method for integrating sub-wavelength resonant structures on top of optical fiber tip. Our fabrication technique is based on direct milling of the glass on the fiber facet by means of <span class="hlt">focused</span> <span class="hlt">ion</span> beam. The patterned fiber tip acts as a structured template for successive depositions of any responsive or functional overlay. The proposed method is validated by depositing on the patterned fiber a high refractive index material layer, to obtain a 'double-layer' photonic crystal slab supporting guided resonances, appearing as peaks in the reflection spectrum. Morphological and optical characterizations are performed to investigate the effects of the fabrication process. Our results show how undesired effects, intrinsic to the fabrication procedure should be taken into account in order to guarantee a successful development of the device. Moreover, to demonstrate the flexibility of our approach and the possibility to engineering the resonances, a thin layer of gold is also deposited on the fiber tip, giving rise to a hybrid photonic-plasmonic structure with a complementary spectral response and different optical field distribution at the resonant wavelengths. Overall, this work represents a significant step forward the consolidation of Lab-on-Fiber Technology.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4632123','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4632123"><span>Optical fiber tip templating using direct <span class="hlt">focused</span> <span class="hlt">ion</span> beam milling</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Micco, A.; Ricciardi, A.; Pisco, M.; La Ferrara, V.; Cusano, A.</p> <p>2015-01-01</p> <p>We report on a method for integrating sub-wavelength resonant structures on top of optical fiber tip. Our fabrication technique is based on direct milling of the glass on the fiber facet by means of <span class="hlt">focused</span> <span class="hlt">ion</span> beam. The patterned fiber tip acts as a structured template for successive depositions of any responsive or functional overlay. The proposed method is validated by depositing on the patterned fiber a high refractive index material layer, to obtain a ‘double-layer’ photonic crystal slab supporting guided resonances, appearing as peaks in the reflection spectrum. Morphological and optical characterizations are performed to investigate the effects of the fabrication process. Our results show how undesired effects, intrinsic to the fabrication procedure should be taken into account in order to guarantee a successful development of the device. Moreover, to demonstrate the flexibility of our approach and the possibility to engineering the resonances, a thin layer of gold is also deposited on the fiber tip, giving rise to a hybrid photonic-plasmonic structure with a complementary spectral response and different optical field distribution at the resonant wavelengths. Overall, this work represents a significant step forward the consolidation of Lab-on-Fiber Technology. PMID:26531887</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22728463','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22728463"><span>Atomic force microscope cantilever calibration using a <span class="hlt">focused</span> <span class="hlt">ion</span> beam.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Slattery, Ashley D; Quinton, Jamie S; Gibson, Christopher T</p> <p>2012-07-20</p> <p>A calibration method is presented for determining the spring constant of atomic force microscope (AFM) cantilevers, which is a modification of the established Cleveland added mass technique. A <span class="hlt">focused</span> <span class="hlt">ion</span> beam (FIB) is used to remove a well-defined volume from a cantilever with known density, substantially reducing the uncertainty usually present in the added mass method. The technique can be applied to any type of AFM cantilever; but for the lowest uncertainty it is best applied to silicon cantilevers with spring constants above 0.7 N m(-1), where uncertainty is demonstrated to be typically between 7 and 10%. Despite the removal of mass from the cantilever, the calibration method presented does not impair the probes' ability to acquire data. The technique has been extensively tested in order to verify the underlying assumptions in the method. This method was compared to a number of other calibration methods and practical improvements to some of these techniques were developed, as well as important insights into the behavior of FIB modified cantilevers. These results will prove useful to research groups concerned with the application of microcantilevers to nanoscience, in particular for cases where maintaining pristine AFM tip condition is critical.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009NJPh...11e5003O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009NJPh...11e5003O"><span>EDITORIAL: <span class="hlt">Focus</span> on High <span class="hlt">Energy</span> Particle Astronomy <span class="hlt">FOCUS</span> ON HIGH <span class="hlt">ENERGY</span> PARTICLE ASTRONOMY</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ong, Rene A.; Covault, Corbin E.</p> <p>2009-05-01</p> <p> another clue to understanding the nature of high-<span class="hlt">energy</span> objects both within and outside our galaxy. And yet, along with new understandings, we are also faced with new puzzles. Each of the papers in this <span class="hlt">focus</span> issue presents the field of high-<span class="hlt">energy</span> particle astronomy from the perspective of a given instrumental approach, corresponding to the current state-of-the-art for a particular class of messenger particle in a given <span class="hlt">energy</span> range. For gamma-ray astronomy, we have a excellent report by R Johnson and R Mukherjee on results from space-borne telescopes, first from the Compton Gamma Ray Observatory and then from the recently commissioned Fermi Gamma-Ray Space Telescope. The detailed paper by J Hinton describes a wealth of results from several ground-based gamma-ray telescopes using the atmospheric Cherenokov technique. Gamma-ray results and the prospects from air-shower detectors which can provide all-sky monitoring are very well described in a paper by G Sinnis. Larger plans for the future of ground-based gamma-ray astronomy are summarized in a paper by F Krennrich (in preparation). We also include two papers for 'non-photon' particle detection, a summary of the exciting new results for cosmic ray physics by P Sommers and S Westerhoff and an article by K Hoffman describing the astrophysics and capabilities of truly remarkable, large-volume neutrino detectors. For both cosmic rays and neutrinos, the fields seem to be on the threshold of doing astronomy—that is, associating specific detected particles with particular astrophysical objects. Together, the fully operational space- and ground-based gamma-ray observatories and the new large-area experiments for cosmic ray and neutrino detection represent a new era in astronomy. We can be confident that the field of high-<span class="hlt">energy</span> particle astronomy will continue to rapidly develop as more exciting results from these instruments are reported in the future. <span class="hlt">Focus</span> on High <span class="hlt">Energy</span> Particle Astronomy Contents Gamma ray astronomy with</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21316376','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21316376"><span>Quantum <span class="hlt">energy</span> teleportation with trapped <span class="hlt">ions</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Hotta, Masahiro</p> <p>2009-10-15</p> <p>We analyze a protocol of quantum <span class="hlt">energy</span> teleportation that transports <span class="hlt">energy</span> from the left edge of a linear <span class="hlt">ion</span> crystal to the right edge by local operations and classical communication at a speed considerably greater than the speed of a phonon in the crystal. A probe qubit is strongly coupled with phonon fluctuation in the ground state for a short time and it is projectively measured in order to obtain information about this phonon fluctuation. During the measurement process, phonons are excited by the time-dependent measurement interaction and the <span class="hlt">energy</span> of the excited phonons must be infused from outside the system. The obtained information is transferred to the right edge of the crystal through a classical channel. Even though the phonons excited at the left edge do not arrive at the right edge at the same time as when the information arrives at the right edge, we are able to soon extract <span class="hlt">energy</span> from the <span class="hlt">ions</span> at the right edge by using the transferred information. Because the intermediate <span class="hlt">ions</span> of the crystal are not excited during the execution of the protocol, <span class="hlt">energy</span> is transmitted in the <span class="hlt">energy</span>-transfer channel without heat generation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015ApSS..328..577H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015ApSS..328..577H"><span>Effective implantation of light emitting centers by plasma immersion <span class="hlt">ion</span> implantation and <span class="hlt">focused</span> <span class="hlt">ion</span> beam methods into nanosized diamond</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Himics, L.; Tóth, S.; Veres, M.; Tóth, A.; Koós, M.</p> <p>2015-02-01</p> <p>Two different implantation techniques, plasma immersion <span class="hlt">ion</span> implantation and <span class="hlt">focused</span> <span class="hlt">ion</span> beam, were used to introduce nitrogen <span class="hlt">ions</span> into detonation nanodiamond crystals with the aim to create nitrogen-vacancy related optically active centers of light emission in near UV region. Previously samples were subjected to a defect creation process by helium irradiation in both cases. Heat treatments at different temperatures (750 °C, 450 °C) were applied in order to initiate the formation of nitrogen-vacancy related complex centers and to decrease the sp2 carbon content formed under different treatments. As a result, a relatively narrow and intensive emission band with fine structure at 2.98, 2.83 and 2.71 eV photon <span class="hlt">energies</span> was observed in the light emission spectrum. It was assigned to the N3 complex defect center. The formation of this defect center can be expected by taking into account the relatively high dose of implanted nitrogen <span class="hlt">ions</span> and the overlapped depth distribution of vacancies and nitrogen. The calculated depth profiles distribution for both implanted nitrogen and helium by SRIM simulation support this expectation.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li class="active"><span>9</span></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_9 --> <div id="page_10" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active"><span>10</span></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="181"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21796647','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21796647"><span>The prospects of a subnanometer <span class="hlt">focused</span> neon <span class="hlt">ion</span> beam.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Rahman, F H M; McVey, Shawn; Farkas, Louis; Notte, John A; Tan, Shida; Livengood, Richard H</p> <p>2012-01-01</p> <p>The success of the helium <span class="hlt">ion</span> microscope has encouraged extensions of this technology to produce beams of other <span class="hlt">ion</span> species. A review of the various candidate <span class="hlt">ion</span> beams and their technical prospects suggest that a neon beam might be the most readily achieved. Such a neon beam would provide a sputtering yield that exceeds helium by an order of magnitude while still offering a theoretical probe size less than 1-nm. This article outlines the motivation for a neon gas field <span class="hlt">ion</span> source, the expected performance through simulations, and provides an update of our experimental progress. © Wiley Periodicals, Inc.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22390819','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22390819"><span><span class="hlt">Ion</span> probe beam experiments and kinetic modeling in a dense plasma <span class="hlt">focus</span> Z-pinch</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Schmidt, A. Ellsworth, J. Falabella, S. Link, A. McLean, H. Rusnak, B. Sears, J. Tang, V.; Welch, D.</p> <p>2014-12-15</p> <p>The Z-pinch phase of a dense plasma <span class="hlt">focus</span> (DPF) emits multiple-MeV <span class="hlt">ions</span> in a ∼cm length. The mechanisms through which these physically simple devices generate such high <span class="hlt">energy</span> beams in a relatively short distance are not fully understood. We are exploring the origins of these large gradients using measurements of an <span class="hlt">ion</span> probe beam injected into a DPF during the pinch phase and the first kinetic simulations of a DPF Z-pinch. To probe the accelerating fields in our table top experiment, we inject a 4 MeV deuteron beam along the z-axis and then sample the beam <span class="hlt">energy</span> distribution after it passes through the pinch region. Using this technique, we have directly measured for the first time the acceleration of an injected <span class="hlt">ion</span> beam. Our particle-in-cell simulations have been benchmarked on both a kJ-scale DPF and a MJ-scale DPF. They have reproduced experimentally measured neutron yields as well as <span class="hlt">ion</span> beams and EM oscillations which fluid simulations do not exhibit. Direct comparisons between the experiment and simulations enhance our understanding of these plasmas and provide predictive design capability for accelerator and neutron source applications.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28062041','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28062041"><span>Improved Force Spectroscopy Using <span class="hlt">Focused-Ion</span>-Beam-Modified Cantilevers.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Faulk, J K; Edwards, D T; Bull, M S; Perkins, T T</p> <p>2017-01-01</p> <p>Atomic force microscopy (AFM) is widely used in biophysics, including force-spectroscopy studies of protein folding and protein-ligand interactions. The precision of such studies increases with improvements in the underlying quality of the data. Currently, data quality is limited by the mechanical properties of the cantilever when using a modern commercial AFM. The key tradeoff is force stability vs short-term force precision and temporal resolution. Here, we present a method that avoids this compromise: efficient <span class="hlt">focused-ion</span>-beam (FIB) modification of commercially available cantilevers. Force precision is improved by reducing the cantilever's hydrodynamic drag, and force stability is improved by reducing the cantilever stiffness and by retaining a cantilever's gold coating only at its free end. When applied to a commonly used short cantilever (L=40μm), we achieved sub-pN force precision over 5 decades of bandwidth (0.01-1000Hz) without significantly sacrificing temporal resolution (~75μs). Extending FIB modification to an ultrashort cantilever (L=9μm) also improved force precision and stability, while maintaining 1-μs-scale temporal resolution. Moreover, modifying ultrashort cantilevers also eliminated their inherent underdamped high-frequency motion and thereby avoided applying a rapidly oscillating force across the stretched molecule. Importantly, fabrication of FIB-modified cantilevers is accessible after an initial investment in training. Indeed, undergraduate researchers routinely modify 2-4 cantilevers per hour with the protocol detailed here. Furthermore, this protocol offers the individual user the ability to optimize a cantilever for a particular application. Hence, we expect FIB-modified cantilevers to improve AFM-based studies over broad areas of biophysical research. © 2017 Elsevier Inc. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/15016856','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/15016856"><span>A Final <span class="hlt">Focus</span> Model for Heavy <span class="hlt">Ion</span> Fusion Driver System Codes</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Barnard, J J; Bangerter, R O; Henestroza, E; Kaganovich, I D; Logan, B G; Meier, W R; Rose, D V; Santhanam, P; Sharp, W M; Welch, D R; Yu, S S</p> <p>2004-12-15</p> <p>The need to reach high temperatures in an inertial fusion <span class="hlt">energy</span> (IFE) target (or a target for the study of High <span class="hlt">Energy</span> Density Physics, HEDP) requires the ability to <span class="hlt">focus</span> <span class="hlt">ion</span> beams down to a small spot. System models indicate that within the accelerator, the beam radius will be of order centimeters, whereas at the final focal spot on the target, a beam radius of order millimeters is required, so radial compression factors of order ten are required. The IFE target gain (and hence the overall cost of electricity) and the HEDP target temperature are sensitive functions of the final spot radius on target. Because of this sensitivity, careful attention needs to be paid to the spot radius calculation. We review our current understanding of the elements that enter into a systems model (such as emittance growth from chromatic, geometric, and non-linear space charge forces) for the final <span class="hlt">focus</span> based on a quadrupolar magnet system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22085915','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22085915"><span>Electrostatic <span class="hlt">energy</span> analyzer measurements of low <span class="hlt">energy</span> zirconium beam parameters in a plasma sputter-type negative <span class="hlt">ion</span> source</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Malapit, Giovanni M.; Mahinay, Christian Lorenz S.; Poral, Matthew D.; Ramos, Henry J.</p> <p>2012-02-15</p> <p>A plasma sputter-type negative <span class="hlt">ion</span> source is utilized to produce and detect negative Zr <span class="hlt">ions</span> with <span class="hlt">energies</span> between 150 and 450 eV via a retarding potential-type electrostatic <span class="hlt">energy</span> analyzer. Traditional and modified semi-cylindrical Faraday cups (FC) inside the analyzer are employed to sample negative Zr <span class="hlt">ions</span> and measure corresponding <span class="hlt">ion</span> currents. The traditional FC registered indistinct <span class="hlt">ion</span> current readings which are attributed to backscattering of <span class="hlt">ions</span> and secondary electron emissions. The modified Faraday cup with biased repeller guard ring, cut out these signal distortions leaving only ringings as issues which are theoretically compensated by fitting a sigmoidal function into the data. The mean <span class="hlt">energy</span> and <span class="hlt">energy</span> spread are calculated using the <span class="hlt">ion</span> current versus retarding potential data while the beam width values are determined from the data of the transverse measurement of <span class="hlt">ion</span> current. The most energetic negative Zr <span class="hlt">ions</span> yield tighter <span class="hlt">energy</span> spread at 4.11 eV compared to the least energetic negative Zr <span class="hlt">ions</span> at 4.79 eV. The smallest calculated beam width is 1.04 cm for the negative Zr <span class="hlt">ions</span> with the highest mean <span class="hlt">energy</span> indicating a more <span class="hlt">focused</span> beam in contrast to the less energetic negative Zr <span class="hlt">ions</span> due to space charge forces.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22380309','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22380309"><span>Electrostatic <span class="hlt">energy</span> analyzer measurements of low <span class="hlt">energy</span> zirconium beam parameters in a plasma sputter-type negative <span class="hlt">ion</span> source.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Malapit, Giovanni M; Mahinay, Christian Lorenz S; Poral, Matthew D; Ramos, Henry J</p> <p>2012-02-01</p> <p>A plasma sputter-type negative <span class="hlt">ion</span> source is utilized to produce and detect negative Zr <span class="hlt">ions</span> with <span class="hlt">energies</span> between 150 and 450 eV via a retarding potential-type electrostatic <span class="hlt">energy</span> analyzer. Traditional and modified semi-cylindrical Faraday cups (FC) inside the analyzer are employed to sample negative Zr <span class="hlt">ions</span> and measure corresponding <span class="hlt">ion</span> currents. The traditional FC registered indistinct <span class="hlt">ion</span> current readings which are attributed to backscattering of <span class="hlt">ions</span> and secondary electron emissions. The modified Faraday cup with biased repeller guard ring, cut out these signal distortions leaving only ringings as issues which are theoretically compensated by fitting a sigmoidal function into the data. The mean <span class="hlt">energy</span> and <span class="hlt">energy</span> spread are calculated using the <span class="hlt">ion</span> current versus retarding potential data while the beam width values are determined from the data of the transverse measurement of <span class="hlt">ion</span> current. The most energetic negative Zr <span class="hlt">ions</span> yield tighter <span class="hlt">energy</span> spread at 4.11 eV compared to the least energetic negative Zr <span class="hlt">ions</span> at 4.79 eV. The smallest calculated beam width is 1.04 cm for the negative Zr <span class="hlt">ions</span> with the highest mean <span class="hlt">energy</span> indicating a more <span class="hlt">focused</span> beam in contrast to the less energetic negative Zr <span class="hlt">ions</span> due to space charge forces.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25387461','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25387461"><span>Monte Carlo simulations of nanoscale <span class="hlt">focused</span> neon <span class="hlt">ion</span> beam sputtering of copper: elucidating resolution limits and sub-surface damage.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Timilsina, R; Tan, S; Livengood, R; Rack, P D</p> <p>2014-12-05</p> <p>A three dimensional Monte Carlo simulation program was developed to model physical sputtering and to emulate vias nanomachined by the gas field <span class="hlt">ion</span> microscope. Experimental and simulation results of <span class="hlt">focused</span> neon <span class="hlt">ion</span> beam induced sputtering of copper are presented and compared to previously published experiments. The simulation elucidates the nanostructure evolution during the physical sputtering of high aspect ratio nanoscale features. Quantitative information such as the <span class="hlt">energy</span>-dependent sputtering yields, dose dependent aspect ratios, and resolution-limiting effects are discussed. Furthermore, the nuclear <span class="hlt">energy</span> loss and implant concentration beneath the etch front is correlated with the sub-surface damage revealed by transmission electron microscopy at different beam <span class="hlt">energies</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=aves&pg=4&id=EJ112473','ERIC'); return false;" href="https://eric.ed.gov/?q=aves&pg=4&id=EJ112473"><span><span class="hlt">Focus</span> on <span class="hlt">Energy</span>: Schools Asked for Help in <span class="hlt">Energy</span> Study</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Anderson, Carl R.; Stanley, Preston O.</p> <p>1975-01-01</p> <p>Describes procedures to be followed in a national survey of <span class="hlt">energy</span> use and conservation in the public schools. A series of policy options will be developed from the information acquired from the survey. (Published by Association of School Business Officers, 2424 W. Lawrence Ave., Chicago, Illinois 60625) (Author/DN)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=aves&pg=4&id=EJ112473','ERIC'); return false;" href="http://eric.ed.gov/?q=aves&pg=4&id=EJ112473"><span><span class="hlt">Focus</span> on <span class="hlt">Energy</span>: Schools Asked for Help in <span class="hlt">Energy</span> Study</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Anderson, Carl R.; Stanley, Preston O.</p> <p>1975-01-01</p> <p>Describes procedures to be followed in a national survey of <span class="hlt">energy</span> use and conservation in the public schools. A series of policy options will be developed from the information acquired from the survey. (Published by Association of School Business Officers, 2424 W. Lawrence Ave., Chicago, Illinois 60625) (Author/DN)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011PMagL..91..530C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011PMagL..91..530C"><span>Interface failure and adhesion measured by <span class="hlt">focused</span> <span class="hlt">ion</span> beam cutting of metal-polymer interfaces</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cordill, M. J.; Schmidegg, K.; Dehm, G.</p> <p>2011-08-01</p> <p>New developments in flexible electronics require metal films to adhere to polymer substrates. Measuring the interfacial adhesion of these systems is challenging, requiring the formulation of new techniques and models. A strategy to measure the adhesion of Cr-polyethylene terephthalate (PET) interfaces using tensile straining and buckle formation is presented in this article. <span class="hlt">Focused</span> <span class="hlt">ion</span> beam cross-sectioning of the buckles reveals that the polymer substrate can locally fail, which may lead to an overestimate of adhesion. Cr-PET adhesion <span class="hlt">energy</span> of 9.4 ± 1.6 J/m2 is determined with the present approach.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21294365','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21294365"><span>Formation and coarsening of Ga droplets on <span class="hlt">focused-ion</span>-beam irradiated GaAs surfaces</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Wu, J. H.; Ye, W.; Cardozo, B. L.; Saltzman, D.; Sun, K.; Sun, H.; Mansfield, J. F.; Goldman, R. S.</p> <p>2009-10-12</p> <p>We have investigated the formation and coarsening of Ga droplets on <span class="hlt">focused-ion</span>-beam (FIB) irradiated GaAs surfaces. To separately examine formation and coarsening, Ga droplets were fabricated by Ga{sup +} FIB irradiation of GaAs substrates with and without pre-patterned holes. We determined the droplet growth rate and size distribution as a function of FIB <span class="hlt">energy</span> following irradiation. The data suggest a droplet formation mechanism that involves Ga precipitation from a Ga-rich layer, followed by droplet coarsening via a combination of diffusion and Ostwald ripening or coalescence via droplet migration (dynamic coalescence)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007JAP...102b4316K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007JAP...102b4316K"><span>Room temperature operational single electron transistor fabricated by <span class="hlt">focused</span> <span class="hlt">ion</span> beam deposition</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Karre, P. Santosh Kumar; Bergstrom, Paul L.; Mallick, Govind; Karna, Shashi P.</p> <p>2007-07-01</p> <p>We present the fabrication and room temperature operation of single electron transistors using 8nm tungsten islands deposited by <span class="hlt">focused</span> <span class="hlt">ion</span> beam deposition technique. The tunnel junctions are fabricated using oxidation of tungsten in peracetic acid. Clear Coulomb oscillations, showing charging and discharging of the nanoislands, are seen at room temperature. The device consists of an array of tunnel junctions; the tunnel resistance of individual tunnel junction of the device is calculated to be as high as 25.13GΩ. The effective capacitance of the array of tunnel junctions was found to be 0.499aF, giving a charging <span class="hlt">energy</span> of 160.6meV.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24104430','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24104430"><span><span class="hlt">Focus</span> issue introduction: renewable <span class="hlt">energy</span> and the environment.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Seassal, Christian; Koshel, John</p> <p>2013-05-06</p> <p>This <span class="hlt">focus</span> issue highlights selected contributions from authors who presented promising concepts at OSA's Renewable <span class="hlt">Energy</span> and the Environment Optics and Photonics Congress held 11-15 November 2012 in Eindhoven, The Netherlands.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhyE...75..235M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhyE...75..235M"><span>Superconductivity of In/Mo narrow wires fabricated using <span class="hlt">focused</span> Ga-<span class="hlt">ion</span> beam</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Makise, K.; Matsubara, Y.; Tasaki, S.; Mitsuishi, K.; Shinozaki, B.</p> <p>2016-01-01</p> <p>By using a <span class="hlt">focused-ion</span>-beam (FIB) method with Ga <span class="hlt">ions</span>, we prepared quasi-one-dimensional (q-1D) In/Mo specimens with widths of ≈ 200 nm and ≈ 500 nm from two dimensional (2D) films deposited on a SiO2/Si substrate. We observed the superconducting transition of q-1D In/Mo, whose transition temperature Tc is higher than Tc ≈ 3.6 K of a 2D In/Mo specimen on a glass substrate. For specimens fabricated using the FIB method, the element distributions analyzed by <span class="hlt">energy</span> dispersive x-ray spectroscopy reveal Ga invasion into the q-1D In/Mo region. The gradually changing resistance of q-1D In/Mo at temperatures below Tc can be well explained by the thermal activation phase-slip model with Tc = 5.1 K and coherence length ξ(0) ≈ 9.5 nm .</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012JPhCS.390a2004T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012JPhCS.390a2004T"><span>ECR Based Low <span class="hlt">Energy</span> <span class="hlt">Ion</span> Beam Facility at VECC, Kolkata</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Taki, G. S.; Chakraborty, D. K.; Ghosh, Subhash; Majhi, S.; Pal, Gautam; Mallik, C.; Bhandari, R. K.; Krishna, J. B. M.; Dey, K.; Sinha, A. K.</p> <p>2012-11-01</p> <p>A low <span class="hlt">energy</span> heavy <span class="hlt">ion</span> irradiation/implantation facility has been developed at VECC, Kolkata for materials science and atomic physics research, utilizing indigenously developed 6.4 GHz ECR <span class="hlt">ion</span> source. The facility provides high charge state <span class="hlt">ion</span> beams of N, O, Ne, Ar, S, Kr, Xe, Fe, Ti, Hf etc. up to a few micro amperes to an <span class="hlt">energy</span> of 10 keV per charge state.The beam <span class="hlt">energy</span> can be further enhanced by floating the target at a negative potential (up to 25 kV). The <span class="hlt">ion</span> beam is <span class="hlt">focused</span> to a spot of about 2 mm diameter on the target using a set of glaser lenses. A x-y scanner is used to scan the beam over a target area of 10 mm x 10 mm to obtain uniform implantation. The recently commissioned multi facility sample chamber has provision for mounting multiple samples on indigenously developed disposable beam viewers for insitu beam viewing during implantation. The ionization chamber of ECR source is mainly pumped by ECR plasma. An additional pumping speed has been provided through extraction hole and pumping slots to obtain low base pressure. In the <span class="hlt">ion</span> source, base pressure of 1x10-7 Torr in injector stage and ~5x10-8 Torr in extraction chamber have been routinely obtained. The ultra-high vacuum multi facility experimental chamber is generally kept at ~ 1x10-7 Torr during implantation on the targets. This facility is a unique tool for studying fundamental and technologically important problems of materials science and atomic physics research. High <span class="hlt">ion</span> flux available from this machine is suitable for generating high defect densities i.e. high value of displacement-per-atom (dpa). Recently this facility has been used for studies like "Tunability of dielectric constant of conducting polymer Polyaniline (PANI) by low <span class="hlt">energy</span> Ar9+ irradiation" and "Fe10+ implantation in ZnO for synthesis of dilute magnetic semiconductor".</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhRvP...7e4006Q','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhRvP...7e4006Q"><span>Acoustic <span class="hlt">Focusing</span> and <span class="hlt">Energy</span> Confinement Based on Multilateral Metasurfaces</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Qi, Shuibao; Li, Yong; Assouar, Badreddine</p> <p>2017-05-01</p> <p>Metamaterial-based acoustic wave manipulation shows great potential in effective acoustic <span class="hlt">energy</span> confinement and low-frequency acoustic isolation. We numerically and theoretically propose here a concept based on multilateral metasurfaces for reflected acoustic <span class="hlt">focusing</span> and <span class="hlt">energy</span> confinement. The theoretical phase-shift profile required for reflected wave <span class="hlt">focusing</span> and governed by the generalized Snell's law can be discretely realized by appropriately arraying the labyrinthine units in the right sequences. Based on this design, multilateral metasurfaces for acoustic wave <span class="hlt">focusing</span> and <span class="hlt">energy</span> confinement under point-source incidence are considered and sufficiently investigated. The coupling effects and multiple reflections between or among metasurfaces, which play a significant role in the <span class="hlt">energy</span> confinement, are initially analyzed and discussed. We show that the acoustic <span class="hlt">focusing</span> and confinement increase with the sides of the multilateral metasurfaces as anticipated. In addition to the contribution of the first reflection, multiple reflections also contribute to the acoustic <span class="hlt">focusing</span> and <span class="hlt">energy</span> confinement, especially when the metasurfaces are configured in parallel. The proposed multilateral metasurfaces should have excellent performance in acoustic <span class="hlt">energy</span> confinement in various situations due to the variable designs and strong acoustic <span class="hlt">focusing</span> capabilities.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/784719','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/784719"><span>Plasma <span class="hlt">Focusing</span> of High <span class="hlt">Energy</span> Density Electron and Positron Beams</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Ng, Johnny S.T.</p> <p>2000-10-09</p> <p>We present results from the SLAC E-150 experiment on plasma <span class="hlt">focusing</span> of high <span class="hlt">energy</span> density electron and, for the first time, positron beams. We also present results on plasma lens-induced synchrotron radiation, longitudinal dynamics of plasma <span class="hlt">focusing</span>, and laser- and beam-plasma interactions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21386621','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21386621"><span>Desorption of cluster <span class="hlt">ions</span> from solid Ne by low-<span class="hlt">energy</span> <span class="hlt">ion</span> impact.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Tachibana, T; Fukai, K; Koizumi, T; Hirayama, T</p> <p>2010-12-01</p> <p>We investigated Ne(+) <span class="hlt">ions</span> and Ne(n)(+) (n = 2-20) cluster <span class="hlt">ions</span> desorbed from the surface of solid Ne by 1.0 keV Ar(+) <span class="hlt">ion</span> impact. Kinetic <span class="hlt">energy</span> analysis shows a considerably narrower <span class="hlt">energy</span> distribution for Ne(n)(+) (n ≥ 3) <span class="hlt">ions</span> than for Ne(n)(+) (n = 1, 2) <span class="hlt">ions</span>. The dependence of <span class="hlt">ion</span> yields on Ne film thickness indicates that cluster <span class="hlt">ions</span> (n ≥ 3) are desorbed only from relatively thick films. We conclude that desorbed <span class="hlt">ions</span> grow into large cluster <span class="hlt">ions</span> during the outflow of deep bulk atoms to the vacuum.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28440227','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28440227"><span>3D silicon shapes through bulk nano structuration by <span class="hlt">focused</span> <span class="hlt">ion</span> beam implantation and wet etching.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Salhi, Billel; Troadec, David; Boukherroub, Rabah</p> <p>2017-05-19</p> <p>The work presented in this paper concerns the synthesis of silicon (Si) 2D and 3D nanostructures using the delayed effect, caused by implanted Ga <span class="hlt">ions</span>, on the dissolution of Si in aqueous solutions of tetramethylammonium hydroxide (TMAH). The crystalline silicon substrates (100) are first cleaned and then hydrogenated by immersion in an aqueous solution of hydrofluoric acid. The <span class="hlt">ion</span> implantation is then carried out by a <span class="hlt">focused</span> <span class="hlt">ion</span> beam by varying the dose and the exposure time. Chemical etching in aqueous solutions of TMAH at 80 °C leads to the selective dissolution of the Si planes not exposed to the <span class="hlt">ions</span>. The preliminary results obtained in the laboratory made it possible to optimize the experimental conditions for the synthesis of 2D and 3D nanoobjects of controlled shape and size. Analysis by transmission electron microscopy and <span class="hlt">energy</span> dispersive x-ray showed the amorphous nature of the nanostructures obtained and the presence of 5%-20% Ga in these nanoobjects. The first experiments of recrystallization by rapid thermal annealing allowed to reconstitute the crystal structure of these nanoobjects.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/823670','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/823670"><span>Low <span class="hlt">Energy</span> <span class="hlt">Ion</span>-Molecule Reactions</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>James M. Farrar</p> <p>2004-05-01</p> <p>This objective of this project is to study the dynamics of the interactions of low <span class="hlt">energy</span> <span class="hlt">ions</span> important in combustion with small molecules in the gas phase and with liquid hydrocarbon surfaces. The first of these topics is a long-standing project in our laboratory devoted to probing the key features of potential <span class="hlt">energy</span> surfaces that control chemical reactivity. The project provides detailed information on the utilization of specific forms of incident <span class="hlt">energy</span>, the role of preferred reagent geometries, and the disposal of total reaction <span class="hlt">energy</span> into product degrees of freedom. We employ crossed molecular beam methods under single collision conditions, at collision <span class="hlt">energies</span> from below one eV to several eV, to probe potential surfaces over a broad range of distances and interaction <span class="hlt">energies</span>. These studies allow us to test and validate dynamical models describing chemical reactivity. Measurements of <span class="hlt">energy</span> and angular distributions of the reaction products with vibrational state resolution provide the key data for these studies. We employ the crossed beam low <span class="hlt">energy</span> mass spectrometry methods that we have developed over the last several years.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active"><span>10</span></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_10 --> <div id="page_11" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="201"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1013495','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1013495"><span>Sources and transport systems for low <span class="hlt">energy</span> extreme of <span class="hlt">ion</span> implantation</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Hershcovitch, A.; Batalin, V.A.; Bugaev, A.S.; Gushenets, V.I.; Alexeyenko, O.; Gurkova, E.; Johnson, B.M.; Kolomiets, A.A.; Kropachev, G.N.; Kuibeda, R.P.; Kulevoy, T.V.; Masunov, E.S.; Oks, E.M.; Pershin, V.I.; Polozov, S.M.; Poole, H.J.; Seleznev, D.N.; Storozhenko, P.A.; Vizir, A.; Svarovski, A.Ya.; Yakushin, P.; Yushkov, G.Yu.</p> <p>2010-06-06</p> <p>For the past seven years a joint research and development effort <span class="hlt">focusing</span> on the design of steady state, intense <span class="hlt">ion</span> sources has been in progress with the ultimate goal being to meet the two, <span class="hlt">energy</span> extreme range needs of mega-electron-volt and 100's of electron-volt <span class="hlt">ion</span> implanters. However, since the last Fortier is low <span class="hlt">energy</span> <span class="hlt">ion</span> implantation, <span class="hlt">focus</span> of the endeavor has shifted to low <span class="hlt">energy</span> <span class="hlt">ion</span> implantation. For boron cluster source development, we started with molecular <span class="hlt">ions</span> of decaborane (B{sub 10}H{sub 14}), octadecaborane (B{sub 18}H{sub 22}), and presently our <span class="hlt">focus</span> is on carborane (C{sub 2}B{sub 10}H{sub 12}) <span class="hlt">ions</span> developing methods for mitigating graphite deposition. Simultaneously, we are developing a pure boron <span class="hlt">ion</span> source (without a working gas) that can form the basis for a novel, more efficient, plasma immersion source. Our Calutron-Berna <span class="hlt">ion</span> source was converted into a universal source capable of switching between generating molecular phosphorous P{sub 4}{sup +}, high charge state <span class="hlt">ions</span>, as well as other types of <span class="hlt">ions</span>. Additionally, we have developed transport systems capable of transporting a very large variety of <span class="hlt">ion</span> species, and simulations of a novel gasless/plasmaless <span class="hlt">ion</span> beam deceleration method were also performed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016APS..DPPN10109L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APS..DPPN10109L"><span>Kinetic Modeling of <span class="hlt">Ion</span> Beams in Dense Plasma <span class="hlt">Focus</span> Z-Pinches</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Link, A.; Bennett, N.; Falabella, S.; Higginson, D. P.; Olsen, R.; Podpaly, Y. A.; Povilus, A.; Shaw, B.; Sipes, N.; Welch, D. R.; Schmidt, A.</p> <p>2016-10-01</p> <p>Dense plasma <span class="hlt">focus</span> (DPF) Z-pinches are compact devices capable of producing MeV <span class="hlt">ion</span> beams, x-rays, and (for D or DT gas fill) neutrons. We report on predictions of <span class="hlt">ion</span> beam generation using the particle-in-cell code LSP. These simulations include full-scale electrodes, an external pulse power circuit and model through the run-down phase as a fluid, transitioning to a fully kinetic simulation during the run-in phase and through the pinch. Simulations of a deuterium filled DPF predict a substantial number of <span class="hlt">ions</span> accelerated to <span class="hlt">energies</span> greater than 50 keV escape the dense plasma in the pinch region and could be used to enhance total neutron yield by employing a solid target. Results of the simulations will be presented and compared to experimental observations. LLNL-ABS-697617 This work performed under the auspices of the U.S. Department of <span class="hlt">Energy</span> by Lawrence Livermore National Laboratory (LLNL) under Contract DE-AC52-07NA27344 and with support from the Computing Grand Challenge program at LLNL.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1999PlST....1...79Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1999PlST....1...79Y"><span>Interaction between Low <span class="hlt">Energy</span> <span class="hlt">Ions</span> and the Complicated Organism</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yu, Zeng-liang</p> <p>1999-12-01</p> <p>Low <span class="hlt">energy</span> <span class="hlt">ions</span> exist widely in natural world, but people pay a little attention on the interaction between low <span class="hlt">energy</span> <span class="hlt">ions</span> and matter, it is even more out of the question of studying on the relation of low <span class="hlt">energy</span> <span class="hlt">ions</span> and the complicated organism. The discovery of bioeffect induced by <span class="hlt">ion</span> implantation has, however, opened a new branch in the field of <span class="hlt">ion</span> beam application in life sciences. This paper reports recent advances in research on the role of low <span class="hlt">energy</span> <span class="hlt">ions</span> in chemical synthesis of the biomolecules and application in genetic modification.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19910070447&hterms=negative+energy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dnegative%2Benergy','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19910070447&hterms=negative+energy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dnegative%2Benergy"><span><span class="hlt">Ion</span> acceleration to cosmic ray <span class="hlt">energies</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lee, Martin A.</p> <p>1990-01-01</p> <p>The acceleration and transport environment of the outer heliosphere is described schematically. Acceleration occurs where the divergence of the solar-wind flow is negative, that is at shocks, and where second-order Fermi acceleration is possible in the solar-wind turbulence. Acceleration at the solar-wind termination shock is presented by reviewing the spherically-symmetric calculation of Webb et al. (1985). Reacceleration of galactic cosmic rays at the termination shock is not expected to be important in modifying the cosmic ray spectrum, but acceleration of <span class="hlt">ions</span> injected at the shock up to <span class="hlt">energies</span> not greater than 300 MeV/charge is expected to occur and to create the anomalous cosmic ray component. Acceleration of energetic particles by solar wind turbulence is expected to play almost no role in the outer heliosphere. The one exception is the energization of interstellar pickup <span class="hlt">ions</span> beyond the threshold for acceleration at the quasi-perpendicular termination shock.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA597233','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA597233"><span>Exploring Cryogenic <span class="hlt">Focused</span> <span class="hlt">Ion</span> Beam Milling as a Group III-V Device Fabrication Tool</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2013-09-01</p> <p><span class="hlt">focused</span> <span class="hlt">ion</span> beam (cryo-FIB) milling as a Group III-V device fabrication tool. Cryogenic cooling of III-V semiconductor material during Ga + FIB irradiation...potential applications of cryogenic <span class="hlt">focused</span> <span class="hlt">ion</span> beam (cryo-FIB) milling as a Group III-V device fabrication tool. Cryogenic cooling of III-V semiconductor...sensitivity to the Ga <span class="hlt">ion</span> beam . This sensitivity is manifested as changes in the structure and chemical composition of the starting material upon exposure to</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22152301','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22152301"><span>Brain <span class="hlt">energy</span> metabolism: <span class="hlt">focus</span> on astrocyte-neuron metabolic cooperation.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bélanger, Mireille; Allaman, Igor; Magistretti, Pierre J</p> <p>2011-12-07</p> <p>The <span class="hlt">energy</span> requirements of the brain are very high, and tight regulatory mechanisms operate to ensure adequate spatial and temporal delivery of <span class="hlt">energy</span> substrates in register with neuronal activity. Astrocytes-a type of glial cell-have emerged as active players in brain <span class="hlt">energy</span> delivery, production, utilization, and storage. Our understanding of neuroenergetics is rapidly evolving from a "neurocentric" view to a more integrated picture involving an intense cooperativity between astrocytes and neurons. This review <span class="hlt">focuses</span> on the cellular aspects of brain <span class="hlt">energy</span> metabolism, with a particular emphasis on the metabolic interactions between neurons and astrocytes. Copyright © 2011 Elsevier Inc. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA216905','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA216905"><span><span class="hlt">Ion</span> and Electron Interactions at Thermal and Suprathermal <span class="hlt">Energies</span></span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>1989-09-30</p> <p>has allowed the <span class="hlt">ion</span> <span class="hlt">energy</span> to be elevated above that appropriate to the carer -gas temperature by impressing an electric field along the axis of a...classified according to the observed products; when the negative <span class="hlt">ion</span> products are the parent molecular negative tons (e.g., SF,- from SF and CF from CF... parent negative <span class="hlt">ion</span>. M -. or modify the product <span class="hlt">ion</span> distribution (i.e., as between parent <span class="hlt">ions</span> or fragment <span class="hlt">ions</span>, see below). For such reactions it is to</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013APS..GECHW1068L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013APS..GECHW1068L"><span>Measurement of <span class="hlt">Ion</span> <span class="hlt">Energy</span> Distribution in Magnetized ICP using Multi-channel <span class="hlt">Ion</span> <span class="hlt">Energy</span> Analyzer</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lee, Woohyun; Kim, Hyuk; Kim, Jiwon; Cheong, Hee Woon; Koo, Il Gyo; Lee, Soojin; Seong, Hyo-Seong; Whang, Ki-Woong</p> <p>2013-09-01</p> <p>In plasma etch processes, the flux and <span class="hlt">energy</span> of <span class="hlt">ions</span> incident on the substrate are the important parameters that control the etch profile and the etch rate. In this regard, retarding field <span class="hlt">Ion</span> <span class="hlt">Energy</span> Analyzer (IEA) has been developed and applied to plasma etch. As the size of wafer and etch chamber increase, simultaneous measurement at multi points in radial and poloidal direction becomes important. For this purpose, Plasma lab in Seoul National University and SEMES jointly developed an IEA that can measure the <span class="hlt">ion</span> <span class="hlt">energy</span> distributions at five positions in 6-inch wafer at the same time. The IEA is composed of 4 mesh grids (floating, electron repelling, discriminator, secondary electron retarding) and one metal layer (<span class="hlt">Ion</span> collector). We used a remote controllable voltage source and DAC to supply the stepwise wave form to discriminator voltage source. We used the developed IEA to measure the radial and polodial uniformity of <span class="hlt">energy</span> distribution of <span class="hlt">ions</span> incident on the substrate with the change of bias power, gas pressure and bias power frequency. This was supported by SEMES cooperative research project.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhRvA..94b2712W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhRvA..94b2712W"><span>Water fragmentation by bare and dressed light <span class="hlt">ions</span> with MeV <span class="hlt">energies</span>: Fragment-<span class="hlt">ion-energy</span> and time-of-flight distributions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wolff, W.; Luna, H.; Schuch, R.; Cariatore, N. D.; Otranto, S.; Turco, F.; Fregenal, D.; Bernardi, G.; Suárez, S.</p> <p>2016-08-01</p> <p>The <span class="hlt">energy</span> and time-of-flight distributions of water ionic fragments produced by impact of fast atoms and bare and dressed <span class="hlt">ions</span>; namely, H+, Li0 -3 +, C1 +, and C2 + are reported in this work. Fragment species as a function of emission <span class="hlt">energy</span> and time-of-flight were recorded by using an electrostatic spectrometer and a time-of-flight mass spectrometer, respectively. An improved Coulomb explosion model coupled to a classical trajectory Monte Carlo (CTMC) simulation gave the <span class="hlt">energy</span> centroids of the fragments for the dissociation channels resulting from the removal of two to five electrons from the water molecule. For the <span class="hlt">energy</span> distribution ranging up to 50 eV, both the experiment and model reveal an isotropic production of multiple charged oxygen <span class="hlt">ions</span>, as well as hydrogen <span class="hlt">ions</span>. From the <span class="hlt">ion</span> <span class="hlt">energy</span> distribution, relative yields of the dissociation resulting from multiple ionization were obtained as a function of the charge state, as well as for several projectile <span class="hlt">energies</span>. Multiple-ionization yields with charge state up to 4+, were extracted from the measurements of the time-of-flight spectra, <span class="hlt">focused</span> on the production of single and multiple charged oxygen <span class="hlt">ions</span>. The measurements were compared to <span class="hlt">ion</span>-water collision experiments investigated at the keV <span class="hlt">energy</span> range available in the literature, revealing differences and similarities in the fragment-<span class="hlt">ion</span> <span class="hlt">energy</span> distribution.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22267801','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22267801"><span>Study on electron beam in a low <span class="hlt">energy</span> plasma <span class="hlt">focus</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Khan, Muhammad Zubair; Ling, Yap Seong; San, Wong Chiow</p> <p>2014-03-05</p> <p>Electron beam emission was investigated in a low <span class="hlt">energy</span> plasma <span class="hlt">focus</span> device (2.2 kJ) using copper hollow anode. Faraday cup was used to estimate the <span class="hlt">energy</span> of the electron beam. XR100CR X-ray spectrometer was used to explore the impact of the electron beam on the target observed from top-on and side-on position. Experiments were carried out at optimized pressure of argon gas. The impact of electron beam is exceptionally notable with two different approaches using lead target inside hollow anode in our plasma <span class="hlt">focus</span> device.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017OptEL..13..309L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017OptEL..13..309L"><span>A robust auto-<span class="hlt">focus</span> measure based on inner <span class="hlt">energy</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Li, Yang; Tang, Ting-long; Huang, Wei</p> <p>2017-07-01</p> <p>This paper proposes a robust auto-<span class="hlt">focus</span> (AF) measure based on inner <span class="hlt">energy</span>. In general, the inner <span class="hlt">energy</span> of noise pixels is close to zero because the magnitude of gradient and the direction of the noise pixels are random. Therefore, the inner <span class="hlt">energy</span> can effectively eliminate the influence of noise on image quality assessment. But the gradients of near edge points are consistent with those of edge points, so the inner <span class="hlt">energy</span> of edge pixels is relatively large, and the detail information of the image can be highlighted. Experimental results indicate that compared with traditional methods, the proposed method has higher accuracy, fewer local peaks, stronger robustness and better practicability. In particular, the evaluation results are close to the subjective evaluation of the human eyes. These results illustrate that the proposed method can be applied in automatic <span class="hlt">focusing</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1984AIPC..111..463N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1984AIPC..111..463N"><span>The plasma <span class="hlt">focus</span> as a source of collimated beams of negative <span class="hlt">ion</span> clusters and of neutral deuterium atoms</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nardi, V.; Powell, C.</p> <p>1984-03-01</p> <p>We report the space anisotropy and brightness B4 (i.e., the momentum normalized density in four dimensional transverse phase space) of a high-intensity pulsed source of neutral-atom and negative-<span class="hlt">ion</span>-cluster beams with <span class="hlt">energy</span>/atom E≳0.2 Mev, <span class="hlt">ion</span> clusters with m/Z (a.u.) ≳200. The source is formed in an 0.5 MA plasma <span class="hlt">focus</span>-PF-discharge. The <span class="hlt">energy</span> spectrum of different particle species is obtained from a 12.2 kG magnetic analyzer, <span class="hlt">energy</span> filters and time resolved detectors. Collimated particle beams are ejected within a <6° cone along the discharge axis inside a ≳3 mm diameter plasma channel (neutral atoms, <span class="hlt">ion</span> clusters, impurity heavy <span class="hlt">ions</span> at 0°, electron beams, clusters and negatively-charged <span class="hlt">ion</span> clumps at 180°). Pulsed kA currents of <span class="hlt">ions</span> (and neutral fluence of comparable intensity at 180°) are detected in the 6° cone at 0° with B4˜107 (mA/cm2rad2) for particle <span class="hlt">energies</span> E≳200 KeV. In the 180° direction the soruce ejects multiple pulses of electron and <span class="hlt">ion</span> beams in alternating sequency (typical pulse duration ˜10 ns) with a net negative charge which provide charge neutralization for <span class="hlt">ion</span> and <span class="hlt">ion</span> cluster beams. The source which can operate—in principle—at a high repetition rate has a scaling law in which the particle-intensity increases without a detectable increase of the angular dispersion.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014PhDT.......255P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014PhDT.......255P"><span>A new route to nanoscale tomographic chemical analysis: <span class="hlt">Focused</span> <span class="hlt">ion</span> beam-induced auger electron spectrosocpy</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Parvaneh, Hamed</p> <p></p> <p>This research project is aimed to study the application of <span class="hlt">ion</span>-induced Auger electron spectroscopy (IAES) in combination with the characteristics of <span class="hlt">focused</span> <span class="hlt">ion</span> beam (FIB) microscopy for performing chemical spectroscopy and further evaluate its potential for 3-dimensional chemical tomography applications. The mechanism for generation of Auger electrons by bombarding <span class="hlt">ions</span> is very different from its electron induced counterpart. In the conventional electron-induced Auger electron spectroscopy (EAES), an electron beam with <span class="hlt">energy</span> typically in the range 1-10kV is used to excite inner-shell (core) electrons of the solid. An electron from a higher electron <span class="hlt">energy</span> state then de-excites to fill the hole and the extra <span class="hlt">energy</span> is then transferred to either another electron, i.e. the Auger electron, or generation of an X-ray (photon). In both cases the emitting particles have charac-teristic <span class="hlt">energies</span> and could be used to identify the excited target atoms. In IAES, however, large excitation cross sections can occur by promotion of in-ner shell electrons through crossing of molecular orbitals. Originally such phenomenological excitation processes were first proposed [3] for bi-particle gas phase collision systems to explain the generation of inner shell vacancies in violent collisions. In addition to excitation of incident or target atoms, due to a much heavier mass of <span class="hlt">ions</span> compared to electrons, there would also be a substantial momentum transfer from the incident to the target atoms. This may cause the excited target atom to recoil from the lattice site or alternatively sputter off the surface with the possibility of de-excitation while the atom is either in motion in the matrix or traveling in vacuum. As a result, one could expect differences between the spectra induced by incident electrons and <span class="hlt">ions</span> and interpretation of the IAE spectra requires separate consideration of both excitation and decay processes. In the first stage of the project, a state-of-the-art mass</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/5950039','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/5950039"><span>Theory and simulations of neutralization and <span class="hlt">focusing</span> of ICF <span class="hlt">ion</span> beams</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Lemons, D.S.; Jones, M.E.</p> <p>1985-10-01</p> <p>Inertial Confinement Fusion (ICF) <span class="hlt">ion</span> beams must be <span class="hlt">focused</span> to a small spot during final propagation to the target. In general, both beam emittance and space charge limit the achievable spot size. Here we consider the latter and how its effect can be eliminated by injecting into the target chamber electrons which are comoving and coexstensive with the <span class="hlt">ions</span>. Unlike <span class="hlt">focusing</span> an <span class="hlt">ion</span> beam through a neutralizing plasma channel, the present propagation mode requires a hard vacuum (10/sup -4/ to 10/sup -5/ Torr) target chamber into which both <span class="hlt">ions</span> and electrons are injected, and thus avoids possibly deleterious beam plasma interactions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1248303','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1248303"><span>Enhanced collective <span class="hlt">focusing</span> of intense neutralized <span class="hlt">ion</span> beam pulses in the presence of weak solenoidal magnetic fields</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Dorf, Mikhail A.; Davidson, Ronald C.; Kaganovich, Igor D.; Startsev, Edward A.</p> <p>2012-05-31</p> <p>In this study, the design of <span class="hlt">ion</span> drivers for warm dense matter and high <span class="hlt">energy</span> density physics applications and heavy <span class="hlt">ion</span> fusion involves transverse <span class="hlt">focusing</span> and longitudinal compression of intense <span class="hlt">ion</span> beams to a small spot size on the target. To facilitate the process, the compression occurs in a long drift section filled with a dense background plasma, which neutralizes the intense beam self-fields. Typically, the <span class="hlt">ion</span> bunch charge is better neutralized than its current, and as a result a net self-pinching (magnetic) force is produced. The self-pinching effect is of particular practical importance, and is used in various <span class="hlt">ion</span> driver designs in order to control the transverse beam envelope. In the present work we demonstrate that this radial self-<span class="hlt">focusing</span> force can be significantly enhanced if a weak (B~100 G) solenoidal magnetic field is applied inside the neutralized drift section, thus allowing for substantially improved transport. It is shown that in contrast to magnetic self-pinching, the enhanced collective self-<span class="hlt">focusing</span> has a radial electric field component and occurs as a result of the overcompensation of the beam charge by plasmaelectrons, whereas the beam current becomes well-neutralized. As the beam leaves the neutralizing drift section, additional transverse <span class="hlt">focusing</span> can be applied. For instance, in the neutralized drift compression experiments (NDCX) a strong (several Tesla) final <span class="hlt">focus</span> solenoid is used for this purpose. In the present analysis we propose that the tight final <span class="hlt">focus</span> in the NDCX experiments may possibly be achieved by using a much weaker (few hundred Gauss) magnetic lens, provided the <span class="hlt">ion</span> beam carries an equal amount of co-moving neutralizing electrons from the preceding drift section into the lens. In this case the enhanced <span class="hlt">focusing</span> is provided by the collective electrondynamics strongly affected by a weak applied magnetic field.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/432688','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/432688"><span>Summary of the tandem <span class="hlt">energy</span> <span class="hlt">focusing</span> explosive warhead technologies</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Zhou, T.S.</p> <p>1996-09-26</p> <p>In this paper, on the basis of a great amount of the analysis of the tandem <span class="hlt">energy</span> <span class="hlt">focusing</span> explosive warhead in our country and other countries, we summarize the design demand of the tandem warhead, the delayed ignition controlling technique between the explosives, the isolating explosion protection technique and the detonator technique.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016NIMPB.370...32O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016NIMPB.370...32O"><span>Main magnetic <span class="hlt">focus</span> <span class="hlt">ion</span> source: Basic principles, theoretical predictions and experimental confirmations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ovsyannikov, V. P.; Nefiodov, A. V.</p> <p>2016-03-01</p> <p>It is proposed to produce highly charged <span class="hlt">ions</span> in the local potential traps formed by the rippled electron beam in a <span class="hlt">focusing</span> magnetic field. In this method, extremely high electron current densities can be attained on short length of the <span class="hlt">ion</span> trap. The design of very compact <span class="hlt">ion</span> sources of the new generation is presented. The computer simulations predict that for such <span class="hlt">ions</span> as, for example, Ne8+ and Xe44+, the intensities of about 109 and 106 <span class="hlt">ions</span> per second, respectively, can be obtained. The experiments with pilot example of the <span class="hlt">ion</span> source confirm efficiency of the suggested method. The X-ray emission from Ir59+, Xe44+ and Ar16+ <span class="hlt">ions</span> was detected. The control over depth of the local <span class="hlt">ion</span> trap is shown to be feasible.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017ApPhB.123...70W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ApPhB.123...70W"><span>Directional <span class="hlt">energy</span> <span class="hlt">focusing</span> on monolayer graphene coupling system</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wei, Buzheng; Yang, Yuguang; Yao, Shuzhi; Xiao, Han; Jian, Shuisheng</p> <p>2017-03-01</p> <p>A directional <span class="hlt">energy</span> <span class="hlt">focusing</span> system based on parallel-monolayer graphene sheets is proposed and is analytically and numerically investigated in this paper. By properly designing the chemical potential distributions, we obtain a ˜0.8-nm-size <span class="hlt">focusing</span> point at desired positions with <span class="hlt">energy</span> enhancement factor of over 2410. The flexible tunability of the transmission properties enables us to shut one parallel pair propagation down and guide the waves to the other branch. The light signal at the focal point is efficiently slowed down to over 10,000 times the speed in vacuum as well. The proposed structure may find potential applications in integrated circuits, on-chip systems or <span class="hlt">energy</span> storage.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22408128','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22408128"><span>Angular distribution of energetic argon <span class="hlt">ions</span> emitted by a 90 kJ Filippov-type plasma <span class="hlt">focus</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Pestehe, S. J.; Mohammadnejad, M.</p> <p>2015-02-15</p> <p>Characteristics of the energetic argon <span class="hlt">ions</span> emitted by a 90 kJ Filippov-type plasma <span class="hlt">focus</span> are studied by employing an array of Faraday cups. The Faraday cups are designed to minimize the secondary electron emission effects on their response. Angular distribution of the <span class="hlt">ions</span> is measured, and the results indicate a highly anisotropic emission with a dip at the device axis and a local maximum at the angle of 7° with respect to the axis. It has been argued that this kind of anisotropic emission may be related to the surfatron acceleration mechanism and shown that this behavior is independent of the working gas pressure. It has been also demonstrated that this mechanism is responsible for the generation of MeV <span class="hlt">ions</span>. Measuring the total <span class="hlt">ion</span> number at different working gas pressures gives an optimum pressure of 0.3 Torr. In addition, the <span class="hlt">energy</span> spectrum of <span class="hlt">ions</span> is measured by taking into account of the ambient gas effects on the <span class="hlt">energy</span> and charge of the <span class="hlt">ions</span>. The current neutralization effect of electrons trapped in the <span class="hlt">ion</span> beam as well as the effect of conducting boundaries surrounding the beam, on the detected signals are investigated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20060050282&hterms=Neutralization&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DNeutralization','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20060050282&hterms=Neutralization&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DNeutralization"><span>Production of High <span class="hlt">Energy</span> <span class="hlt">Ions</span> Near an <span class="hlt">Ion</span> Thruster Discharge Hollow Cathode</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Katz, Ira; Mikellides, I. G.; Goebel, D. M.; Jameson, K. K.; Wirz, R.; Polk, James E.</p> <p>2006-01-01</p> <p>Several researchers have measured <span class="hlt">ions</span> leaving <span class="hlt">ion</span> thruster discharge chambers with <span class="hlt">energies</span> far greater than measured discharge chamber potentials. Presented in this paper is a new mechanism for the generation of high <span class="hlt">energy</span> <span class="hlt">ions</span> and a comparison with measured <span class="hlt">ion</span> spectra. The source of high <span class="hlt">energy</span> <span class="hlt">ions</span> has been a puzzle because they not only have <span class="hlt">energies</span> in excess of measured steady state potentials, but as reported by Goebel et. al. [1], their flux is independent of the amplitude of time dependent plasma fluctuations. The mechanism relies on the charge exchange neutralization of xenon <span class="hlt">ions</span> accelerated radially into the potential trough in front of the discharge cathode. Previous researchers [2] have identified the importance of charge exchange in this region as a mechanism for protecting discharge cathode surfaces from <span class="hlt">ion</span> bombardment. This paper is the first to identify how charge exchange in this region can lead to <span class="hlt">ion</span> <span class="hlt">energy</span> enhancement.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_11 --> <div id="page_12" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="221"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20060050282&hterms=Neutralization&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DNeutralization','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20060050282&hterms=Neutralization&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DNeutralization"><span>Production of High <span class="hlt">Energy</span> <span class="hlt">Ions</span> Near an <span class="hlt">Ion</span> Thruster Discharge Hollow Cathode</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Katz, Ira; Mikellides, I. G.; Goebel, D. M.; Jameson, K. K.; Wirz, R.; Polk, James E.</p> <p>2006-01-01</p> <p>Several researchers have measured <span class="hlt">ions</span> leaving <span class="hlt">ion</span> thruster discharge chambers with <span class="hlt">energies</span> far greater than measured discharge chamber potentials. Presented in this paper is a new mechanism for the generation of high <span class="hlt">energy</span> <span class="hlt">ions</span> and a comparison with measured <span class="hlt">ion</span> spectra. The source of high <span class="hlt">energy</span> <span class="hlt">ions</span> has been a puzzle because they not only have <span class="hlt">energies</span> in excess of measured steady state potentials, but as reported by Goebel et. al. [1], their flux is independent of the amplitude of time dependent plasma fluctuations. The mechanism relies on the charge exchange neutralization of xenon <span class="hlt">ions</span> accelerated radially into the potential trough in front of the discharge cathode. Previous researchers [2] have identified the importance of charge exchange in this region as a mechanism for protecting discharge cathode surfaces from <span class="hlt">ion</span> bombardment. This paper is the first to identify how charge exchange in this region can lead to <span class="hlt">ion</span> <span class="hlt">energy</span> enhancement.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/15013675','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/15013675"><span>Development and testing of the improved <span class="hlt">focusing</span> quadrupole for heavy <span class="hlt">ion</span> fusion accelerators</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Manahan, R R; Martovetsky, N N; Meinke, R B; Chiesa, L; Lietzke, A F; Sabbi, G L; Seidl, P A</p> <p>2003-10-23</p> <p>An improved version of the <span class="hlt">focusing</span> magnet for a Heavy <span class="hlt">Ion</span> Fusion (HIF) accelerator was designed, built and tested in 2002-2003. This quadrupole has higher <span class="hlt">focusing</span> power and lower error field than the previous version of the <span class="hlt">focusing</span> quadrupoles successfully built and tested in 2001. We discuss the features of the new design, selected fabrication issues and test results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/7067698','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/biblio/7067698"><span>Electron <span class="hlt">energy</span> recovery system for negative <span class="hlt">ion</span> sources</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Dagenhart, W.K.; Stirling, W.L.</p> <p>1979-10-25</p> <p>An electron <span class="hlt">energy</span> recovery system for negative <span class="hlt">ion</span> sources is provided. The system, employing crossed electric and magnetic fields, separates the electrons from the <span class="hlt">ions</span> as they are extracted from the <span class="hlt">ion</span> source plasma generator and before the <span class="hlt">ions</span> are accelerated to their full <span class="hlt">energy</span>. With the electric and magnetic fields oriented 90/sup 0/ to each other, the electrons remain at approximately the electrical potential at which they were generated. The electromagnetic forces cause the <span class="hlt">ions</span> to be accelerated to the full accelerating supply voltage <span class="hlt">energy</span> while being deflected through an angle of less than 90/sup 0/. The electrons precess out of the accelerating field region into an electron recovery region where they are collected at a small fraction of the full accelerating supply <span class="hlt">energy</span>. It is possible, by this method, to collect > 90% of the electrons extracted along with the negative <span class="hlt">ions</span> from a negative <span class="hlt">ion</span> source beam at < 4% of full <span class="hlt">energy</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18268637','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18268637"><span><span class="hlt">Focusing</span> high-<span class="hlt">energy</span> x rays by compound refractive lenses.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Snigirev, A; Kohn, V; Snigireva, I; Souvorov, A; Lengeler, B</p> <p>1998-02-01</p> <p>Compound lenses made from low-Z materials (e.g., Be, B, C, and Al) set up as a linear array of refractive lenses are proposed for submicrometer <span class="hlt">focusing</span> of high-<span class="hlt">energy</span> x rays (>5 keV) in one or two dimensions. A theory of <span class="hlt">focusing</span> based on Maxwell's equation and the Fresnel-Kirchhoff approach is presented. Compound refractive lenses were manufactured by drilling into an Al block a linear array of 200 closely spaced holes 0.5 mm in diameter for linear <span class="hlt">focusing</span> and two crossed arrays of 100 holes each for point <span class="hlt">focusing</span>. Focal spots of 3.7 mum and 8 mum x 18 mum were obtained at 30 keV for linear and two-dimensional lenses, respectively. Different technologies of manufacturing and possible applications of the proposed lenses are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011JAP...109d3501V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011JAP...109d3501V"><span>Topography evolution mechanism on fused silica during low-<span class="hlt">energy</span> <span class="hlt">ion</span> beam sputtering</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Völlner, J.; Ziberi, B.; Frost, F.; Rauschenbach, B.</p> <p>2011-02-01</p> <p>In this study, the topography evolution of fused silica surfaces during low-<span class="hlt">energy</span> <span class="hlt">ion</span> beam erosion has been investigated depending on the <span class="hlt">ion</span> incidence angle and with <span class="hlt">focus</span> on the importance of the initial surface topography. Ripple prepattern, also prepared by <span class="hlt">ion</span> beam erosion, that exhibits an anisotropic surface with adjustable surface amplitudes and gradients was utilized. Based on experimental results that confirm smoothing and patterning behavior, gradient-dependent sputtering is identified being the dominant topography evolution mechanism.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19770014074','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19770014074"><span>Analysis of the theory of high <span class="hlt">energy</span> <span class="hlt">ion</span> transport</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wilson, J. W.</p> <p>1977-01-01</p> <p>Procedures for the approximation of the transport of high-<span class="hlt">energy</span> <span class="hlt">ions</span> are discussed on the basis of available data on <span class="hlt">ion</span> nuclear reactions. A straightahead approximation appears appropriate for space applications. The assumption that the secondary-<span class="hlt">ion</span>-fragment velocity is equal to that of the fragmenting nucleus is inferior to straightahead theory but is of sufficient accuracy if the primary <span class="hlt">ions</span> display a broad <span class="hlt">energy</span> spectrum. An iterative scheme for the solution of the inhomogenous integral transport equations holds promise for practical calculation. A model calculation shows that multiple charged <span class="hlt">ion</span> fragments penetrate to greater depths in comparison with the free path of a primary heavy <span class="hlt">ion</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22392493','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22392493"><span>Magnetized retarding field <span class="hlt">energy</span> analyzer measuring the particle flux and <span class="hlt">ion</span> <span class="hlt">energy</span> distribution of both positive and negative <span class="hlt">ions</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Rafalskyi, Dmytro; Aanesland, Ane; Dudin, Stanislav</p> <p>2015-05-15</p> <p>This paper presents the development of a magnetized retarding field <span class="hlt">energy</span> analyzer (MRFEA) used for positive and negative <span class="hlt">ion</span> analysis. The two-stage analyzer combines a magnetic electron barrier and an electrostatic <span class="hlt">ion</span> <span class="hlt">energy</span> barrier allowing both positive and negative <span class="hlt">ions</span> to be analyzed without the influence of electrons (co-extracted or created downstream). An optimal design of the MRFEA for <span class="hlt">ion-ion</span> beams has been achieved by a comparative study of three different MRFEA configurations, and from this, scaling laws of an optimal magnetic field strength and topology have been deduced. The optimal design consists of a uniform magnetic field barrier created in a rectangular channel and an electrostatic barrier consisting of a single grid and a collector placed behind the magnetic field. The magnetic barrier alone provides an electron suppression ratio inside the analyzer of up to 6000, while keeping the <span class="hlt">ion</span> <span class="hlt">energy</span> resolution below 5 eV. The effective <span class="hlt">ion</span> transparency combining the magnetic and electrostatic sections of the MRFEA is measured as a function of the <span class="hlt">ion</span> <span class="hlt">energy</span>. It is found that the <span class="hlt">ion</span> transparency of the magnetic barrier increases almost linearly with increasing <span class="hlt">ion</span> <span class="hlt">energy</span> in the low-<span class="hlt">energy</span> range (below 200 eV) and saturates at high <span class="hlt">ion</span> <span class="hlt">energies</span>. The <span class="hlt">ion</span> transparency of the electrostatic section is almost constant and close to the optical transparency of the entrance grid. We show here that the MRFEA can provide both accurate <span class="hlt">ion</span> flux and <span class="hlt">ion</span> <span class="hlt">energy</span> distribution measurements in various experimental setups with <span class="hlt">ion</span> beams or plasmas run at low pressure and with <span class="hlt">ion</span> <span class="hlt">energies</span> above 10 eV.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26026517','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26026517"><span>Magnetized retarding field <span class="hlt">energy</span> analyzer measuring the particle flux and <span class="hlt">ion</span> <span class="hlt">energy</span> distribution of both positive and negative <span class="hlt">ions</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Rafalskyi, Dmytro; Dudin, Stanislav; Aanesland, Ane</p> <p>2015-05-01</p> <p>This paper presents the development of a magnetized retarding field <span class="hlt">energy</span> analyzer (MRFEA) used for positive and negative <span class="hlt">ion</span> analysis. The two-stage analyzer combines a magnetic electron barrier and an electrostatic <span class="hlt">ion</span> <span class="hlt">energy</span> barrier allowing both positive and negative <span class="hlt">ions</span> to be analyzed without the influence of electrons (co-extracted or created downstream). An optimal design of the MRFEA for <span class="hlt">ion-ion</span> beams has been achieved by a comparative study of three different MRFEA configurations, and from this, scaling laws of an optimal magnetic field strength and topology have been deduced. The optimal design consists of a uniform magnetic field barrier created in a rectangular channel and an electrostatic barrier consisting of a single grid and a collector placed behind the magnetic field. The magnetic barrier alone provides an electron suppression ratio inside the analyzer of up to 6000, while keeping the <span class="hlt">ion</span> <span class="hlt">energy</span> resolution below 5 eV. The effective <span class="hlt">ion</span> transparency combining the magnetic and electrostatic sections of the MRFEA is measured as a function of the <span class="hlt">ion</span> <span class="hlt">energy</span>. It is found that the <span class="hlt">ion</span> transparency of the magnetic barrier increases almost linearly with increasing <span class="hlt">ion</span> <span class="hlt">energy</span> in the low-<span class="hlt">energy</span> range (below 200 eV) and saturates at high <span class="hlt">ion</span> <span class="hlt">energies</span>. The <span class="hlt">ion</span> transparency of the electrostatic section is almost constant and close to the optical transparency of the entrance grid. We show here that the MRFEA can provide both accurate <span class="hlt">ion</span> flux and <span class="hlt">ion</span> <span class="hlt">energy</span> distribution measurements in various experimental setups with <span class="hlt">ion</span> beams or plasmas run at low pressure and with <span class="hlt">ion</span> <span class="hlt">energies</span> above 10 eV.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1012384','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1012384"><span>H-mode accelerating structures with PMQ <span class="hlt">focusing</span> for low-beta <span class="hlt">ion</span> beams</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Kurennoy, Sergey S; O' Hara, James F; Olivas, Eric R; Rybarcyk, Lawrence J</p> <p>2010-01-01</p> <p>We are developing high-efficiency normal-conducting RF accelerating structures based on inter-digital H-mode (IH) cavities and the transverse beam <span class="hlt">focusing</span> with permanent-magnet quadrupoles (PMQ), for beam velocities in the range of a few percent of the speed of light. Such IH-PMQ accelerating structures following a short RFQ can be used in the front end of <span class="hlt">ion</span> linacs or in stand-alone applications, e.g. a compact deuteron-beam accelerator up to the <span class="hlt">energy</span> of several MeV. Results of combined 3-D modeling for a full IH-PMQ accelerator tank - electromagnetic computations, beam-dynamics simulations with high currents, and thermal-stress analysis - are presented. The accelerating field profile in the tank is tuned to provide the best beam propagation using coupled iterations of electromagnetic and beam-dynamics modeling. A cold model of the IH-PMQ tank is being manufactured.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4650821','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4650821"><span><span class="hlt">Focused-Ion</span>-Beam Induced Rayleigh-Plateau Instability for Diversiform Suspended Nanostructure Fabrication</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Li, Can; Zhao, Lurui; Mao, Yifei; Wu, Wengang; Xu, Jun</p> <p>2015-01-01</p> <p>A novel method for fabricating diversiform suspended nanostructures is reported. The method utilizes <span class="hlt">focused-ion</span>-beam (FIB) induced material redistribution and Rayleigh-Plateau instability, which determine the resulting shapes of formed nanostructures. By choosing target materials, their predefined patterns as well as FIB settings, we have achieved parallel nanofabrication of various kinds including nanostrings, nanobead chains and nanopore membranes with smooth surfaces due to the self-perfection effect of the material redistribution upon the minimization of system free <span class="hlt">energy</span>. The diameters of the nanostrings and nanopores reach about 10 nm and 200 nm, respectively. The average period of the nanobead chains is 250 nm. PMID:25649055</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/862996','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/862996"><span>High-<span class="hlt">energy</span> accelerator for beams of heavy <span class="hlt">ions</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Martin, Ronald L.; Arnold, Richard C.</p> <p>1978-01-01</p> <p>An apparatus for accelerating heavy <span class="hlt">ions</span> to high <span class="hlt">energies</span> and directing the accelerated <span class="hlt">ions</span> at a target comprises a source of singly ionized heavy <span class="hlt">ions</span> of an element or compound of greater than 100 atomic mass units, means for accelerating the heavy <span class="hlt">ions</span>, a storage ring for accumulating the accelerated heavy <span class="hlt">ions</span> and switching means for switching the heavy <span class="hlt">ions</span> from the storage ring to strike a target substantially simultaneously from a plurality of directions. In a particular embodiment the heavy <span class="hlt">ion</span> that is accelerated is singly ionized hydrogen iodide. After acceleration, if the beam is of molecular <span class="hlt">ions</span>, the <span class="hlt">ions</span> are dissociated to leave an accelerated singly ionized atomic <span class="hlt">ion</span> in a beam. Extraction of the beam may be accomplished by stripping all the electrons from the atomic <span class="hlt">ion</span> to switch the beam from the storage ring by bending it in magnetic field of the storage ring.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015NIMPB.365..394T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015NIMPB.365..394T"><span>Measurement of ultra-low <span class="hlt">ion</span> <span class="hlt">energy</span> of decelerated <span class="hlt">ion</span> beam using a deflecting electric field</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Thopan, P.; Suwannakachorn, D.; Tippawan, U.; Yu, L. D.</p> <p>2015-12-01</p> <p>In investigation on ultra-low-<span class="hlt">energy</span> <span class="hlt">ion</span> bombardment effect on DNA, an <span class="hlt">ion</span> beam deceleration lens was developed for high-quality ultra-low-<span class="hlt">energy</span> <span class="hlt">ion</span> beam. Measurement of the <span class="hlt">ion</span> <span class="hlt">energy</span> after deceleration was necessary to confirm the <span class="hlt">ion</span> beam really decelerated as theoretically predicted. In contrast to conventional methods, this work used a simple deflecting electrostatic field after the deceleration lens to bend the <span class="hlt">ion</span> beam. The beam bending distance depended on the <span class="hlt">ion</span> <span class="hlt">energy</span> and was described and simulated. A system for the measurement of the <span class="hlt">ion</span> beam <span class="hlt">energy</span> was constructed. It consisted of a pair of parallel electrode plates to generate the deflecting electrical field, a copper rod measurement piece to detect <span class="hlt">ion</span> beam current, a vernier caliper to mark the beam position, a stepping motor to translate the measurement rod, and a webcam-camera to read the beam bending distance. The entire system was installed after the <span class="hlt">ion</span>-beam deceleration lens inside the large chamber of the bioengineering vertical <span class="hlt">ion</span> beam line. Moving the measurement rod across the decelerated <span class="hlt">ion</span> beam enabled to obtain beam profiles, from which the beam bending distance could be known and the <span class="hlt">ion</span> beam <span class="hlt">energy</span> could be calculated. The measurement results were in good agreement with theoretical and simulated results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/5815487','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/5815487"><span>Reorganization at Oryx <span class="hlt">Energy</span> <span class="hlt">focuses</span> on teamwork, technology</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Box, J.W. )</p> <p>1993-11-08</p> <p>As one of the largest independent oil and gas companies in the world, Oryx <span class="hlt">Energy</span> Co. has become a strong international player, In an increasingly global business, they are competing with some very tough international companies. This competition calls for their continued <span class="hlt">focus</span> on technology and innovative ways of conducting business, not only on the international scene but also in the U.S. Here the author <span class="hlt">focuses</span> on ways his company is approaching U.S. activities, both onshore and in the Gulf of Mexico.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23449320','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23449320"><span>Effect of using stencil masks made by <span class="hlt">focused</span> <span class="hlt">ion</span> beam milling on permalloy (Ni81Fe19) nanostructures.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bates, J R; Miyahara, Y; Burgess, J A J; Iglesias-Freire, O; Grütter, P</p> <p>2013-03-22</p> <p><span class="hlt">Focused</span> <span class="hlt">ion</span> beam (FIB) milling is a common fabrication technique to make nanostencil masks which has the unintended consequence of gallium <span class="hlt">ion</span> implantation surrounding milled features in silicon nitride membranes. We observe major changes in film structure, chemical composition, and magnetic behaviour of permalloy nanostructures deposited by electron beam evaporation using silicon nitride stencil masks made by a FIB as compared to stencil masks made by regular lithography techniques. We characterize the stenciled structures and both types of masks using transmission electron microscopy, electron <span class="hlt">energy</span> loss spectroscopy, <span class="hlt">energy</span> dispersive x-ray spectroscopy, magnetic force microscopy and kelvin probe force microscopy. All these techniques demonstrate distinct differences at a length scale of a 1-100 nm for the structures made using stencil mask fabricated using a FIB. The origin of these differences seems to be related to the presence of implanted <span class="hlt">ions</span>, a detailed understanding of the mechanism however remains to be developed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009NIMPB.267.1332S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009NIMPB.267.1332S"><span>Er + medium <span class="hlt">energy</span> <span class="hlt">ion</span> implantation into lithium niobate</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Svecova, B.; Nekvindova, P.; Mackova, A.; Oswald, J.; Vacik, J.; Grötzschel, R.; Spirkova, J.</p> <p>2009-05-01</p> <p>Erbium-doped lithium niobate (Er:LiNbO3) is a prospective photonics component, operating at 1.5 μm, which could find its use chiefly as an optical amplifier or waveguide laser. In this study, we have <span class="hlt">focused</span> on the properties of the optically active Er:LiNbO3 layers, which are fabricated by medium <span class="hlt">energy</span> <span class="hlt">ion</span> implantation under various experimental conditions. Erbium <span class="hlt">ions</span> were implanted at <span class="hlt">energies</span> of 330 and 500 keV with fluences of 1.0 × 1015, 2.5 × 1015 and 1.0 × 1016 cm-2 into LiNbO3 single-crystalline cuts of various orientations. The as-implanted samples were annealed in air at 350 °C for 5 h. The depth distribution and diffusion profiles of the implanted Er were measured by Rutherford Backscattering Spectroscopy (RBS) using 2 MeV He+ <span class="hlt">ions</span>. The projected range RP and projected range straggling ΔRP were calculated employing the SRIM code. The damage distribution and structural changes were described using the RBS/channelling method. Changes of the lithium concentration depth distribution were studied by Neutron Depth Profiling (NDP). The photoluminescence spectra of the samples were measured to determine whether the emission was in the desired region of 1.5 μm. The obtained data made it possible to reveal the relations between the structural changes of erbium-implanted lithium niobate and its luminescence properties important for photonics applications.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19910005500','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19910005500"><span>Surface modification using low <span class="hlt">energy</span> ground state <span class="hlt">ion</span> beams</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Chutjian, Ara (Inventor); Hecht, Michael H. (Inventor); Orient, Otto J. (Inventor)</p> <p>1990-01-01</p> <p>A method of effecting modifications at the surfaces of materials using low <span class="hlt">energy</span> <span class="hlt">ion</span> beams of known quantum state, purity, flux, and <span class="hlt">energy</span> is presented. The <span class="hlt">ion</span> beam is obtained by bombarding <span class="hlt">ion</span>-generating molecules with electrons which are also at low <span class="hlt">energy</span>. The electrons used to bombard the <span class="hlt">ion</span> generating molecules are separated from the <span class="hlt">ions</span> thus obtained and the <span class="hlt">ion</span> beam is directed at the material surface to be modified. Depending on the type of <span class="hlt">ion</span> generating molecules used, different <span class="hlt">ions</span> can be obtained for different types of surface modifications such as oxidation and diamond film formation. One area of application is in the manufacture of semiconductor devices from semiconductor wafers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1248303-enhanced-collective-focusing-intense-neutralized-ion-beam-pulses-presence-weak-solenoidal-magnetic-fields','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1248303-enhanced-collective-focusing-intense-neutralized-ion-beam-pulses-presence-weak-solenoidal-magnetic-fields"><span>Enhanced collective <span class="hlt">focusing</span> of intense neutralized <span class="hlt">ion</span> beam pulses in the presence of weak solenoidal magnetic fields</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Dorf, Mikhail A.; Davidson, Ronald C.; Kaganovich, Igor D.; ...</p> <p>2012-05-31</p> <p>In this study, the design of <span class="hlt">ion</span> drivers for warm dense matter and high <span class="hlt">energy</span> density physics applications and heavy <span class="hlt">ion</span> fusion involves transverse <span class="hlt">focusing</span> and longitudinal compression of intense <span class="hlt">ion</span> beams to a small spot size on the target. To facilitate the process, the compression occurs in a long drift section filled with a dense background plasma, which neutralizes the intense beam self-fields. Typically, the <span class="hlt">ion</span> bunch charge is better neutralized than its current, and as a result a net self-pinching (magnetic) force is produced. The self-pinching effect is of particular practical importance, and is used in various ionmore » driver designs in order to control the transverse beam envelope. In the present work we demonstrate that this radial self-<span class="hlt">focusing</span> force can be significantly enhanced if a weak (B~100 G) solenoidal magnetic field is applied inside the neutralized drift section, thus allowing for substantially improved transport. It is shown that in contrast to magnetic self-pinching, the enhanced collective self-<span class="hlt">focusing</span> has a radial electric field component and occurs as a result of the overcompensation of the beam charge by plasmaelectrons, whereas the beam current becomes well-neutralized. As the beam leaves the neutralizing drift section, additional transverse <span class="hlt">focusing</span> can be applied. For instance, in the neutralized drift compression experiments (NDCX) a strong (several Tesla) final <span class="hlt">focus</span> solenoid is used for this purpose. In the present analysis we propose that the tight final <span class="hlt">focus</span> in the NDCX experiments may possibly be achieved by using a much weaker (few hundred Gauss) magnetic lens, provided the <span class="hlt">ion</span> beam carries an equal amount of co-moving neutralizing electrons from the preceding drift section into the lens. In this case the enhanced <span class="hlt">focusing</span> is provided by the collective electrondynamics strongly affected by a weak applied magnetic field.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26457668','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26457668"><span>Post-thinning using Ar <span class="hlt">ion</span>-milling system for transmission electron microscopy specimens prepared by <span class="hlt">focused</span> <span class="hlt">ion</span> beam system.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lee, Min-Hee; Kim, Kyou-Hyun</p> <p>2016-03-01</p> <p>We investigate Ar <span class="hlt">ion</span>-milling rates and Ga-<span class="hlt">ion</span> induced damage on sample surfaces of Si and GaAs single crystals prepared by <span class="hlt">focused</span> <span class="hlt">ion</span> beam (FIB) method for transmission electron microscopy observation. The convergent beam electron diffraction technique with Bloch simulation is used to measure the thickness of the Ar-<span class="hlt">ion</span> milled samples to calculate the milling rates of Si and GaAs single crystals. The measurement shows that an amorphous layer is formed on the sample surface and can be removed by further Ar-<span class="hlt">ion</span> milling. In addition, the local symmetry breaking induced by FIB is investigated using quantitative symmetry measurement. The FIBed-GaAs sample shows local symmetry breaking after FIB milling, although the FIBed-Si sample has no considerable symmetry breaking. © 2015 The Authors Journal of Microscopy © 2015 Royal Microscopical Society.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/5472371','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/5472371"><span>Neutral beamline with improved <span class="hlt">ion-energy</span> recovery</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Dagenhart, W.K.; Haselton, H.H.; Stirling, W.L.; Whealton, J.H.</p> <p>1981-04-13</p> <p>A neutral beamline generator with unneutralized <span class="hlt">ion</span> <span class="hlt">energy</span> recovery is provided which enhances the <span class="hlt">energy</span> recovery of the full <span class="hlt">energy</span> <span class="hlt">ion</span> component of the beam exiting the neutralizer cell of the beamline. The unneutralized full <span class="hlt">energy</span> <span class="hlt">ions</span> exiting the neutralizer are deflected from the beam path and the electrons in the cell are blocked by a magnetic field applied transverse to the beamline in the cell exit region. The <span class="hlt">ions</span>, which are generated at essentially ground potential and accelerated through the neutralizer cell by a negative acceleration voltage, are collected at ground potential. A neutralizer cell exit end region is provided which allows the magnetic and electric fields acting on the exiting <span class="hlt">ions</span> to be closely coupled. As a result, the fractional <span class="hlt">energy</span> <span class="hlt">ions</span> exiting the cell with the full <span class="hlt">energy</span> <span class="hlt">ions</span> are reflected back into the gas cell. Thus, the fractional <span class="hlt">energy</span> <span class="hlt">ions</span> do not detract from the <span class="hlt">energy</span> recovery efficiency of full <span class="hlt">energy</span> <span class="hlt">ions</span> exiting the cell which can reach the ground potential interior surfaces of the beamline housing.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhDT.......109Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhDT.......109Z"><span>Fabrication of Amorphous Indium Gallium Zinc Oxide Thin Film Transistor by using <span class="hlt">Focused</span> <span class="hlt">Ion</span> Beam</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhu, Wencong</p> <p></p> <p>Compared with other transparent semiconductors, amorphous indium gallium zinc oxide (a-IGZO) has both good uniformity and high electron mobility, which make it as a good candidate for displays or large-scale transparent circuit. The goal of this research is to fabricate alpha-IGZO thin film transistor (TFT) with channel milled by <span class="hlt">focused</span> <span class="hlt">ion</span> beam (FIB). TFTs with different channel geometries can be achieved by applying different milling strategies, which facilitate modifying complex circuit. Technology Computer-Aided Design (TCAD) was also introduced to understand the effect of trapped charges on the device performance. The investigation of the trapped charge at IGZO/SiO2 interface was performed on the IGZO TFT on p-Silicon substrate with thermally grown SiO2 as dielectric. The subgap density-of-state model was used for the simulation, which includes conduction band-tail trap states and donor-like state in the subgap. The result shows that the de-trapping and donor-state ionization determine the interface trapped charge density at various gate biases. Simulation of IGZO TFT with FIB defined channel on the same substrate was also applied. The drain and source were connected intentionally during metal deposition and separated by FIB milling. Based on the simulation, the Ga <span class="hlt">ions</span> in SiO2 introduced by the <span class="hlt">ion</span> beam was drifted by gate bias and affects the saturation drain current. Both side channel and direct channel transparent IGZO TFTs were fabricated on the glass substrate with coated ITO. Higher <span class="hlt">ion</span> <span class="hlt">energy</span> (30 keV) was used to etch through the substrate between drain and source and form side channels at the corner of milled trench. Lower <span class="hlt">ion</span> <span class="hlt">energy</span> (16 keV) was applied to stop the milling inside IGZO thin film and direct channel between drain and source was created. Annealing after FIB milling removed the residual Ga <span class="hlt">ions</span> and the devices show switch feature. Direct channel shows higher saturation drain current (~10-6 A) compared with side channel (~10-7 A) because</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_12 --> <div id="page_13" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="241"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26467120','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26467120"><span>Peptide fragmentation caused by Ar cluster <span class="hlt">ions</span> depending on primary <span class="hlt">ion</span> <span class="hlt">energy</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Aoyagi, Satoka; Kawashima, Tomoko; Yokoyama, Yuta</p> <p>2015-09-30</p> <p>Time-of-flight secondary <span class="hlt">ion</span> mass spectrometry (TOF-SIMS) with an Ar cluster <span class="hlt">ion</span> beam as a primary <span class="hlt">ion</span> source provides useful information in terms of peptide analysis. It is, however, difficult to interpret the spectra. The ToF-SIMS peptide spectra obtained with Ar clusters having different <span class="hlt">energies</span> have been investigated in order to classify the secondary <span class="hlt">ions</span> into the peptide fragment <span class="hlt">ions</span> and those related to contaminants or the substrate. Three peptides having different molecular weights from 600 to 1300 u were measured with Ar cluster beams having different <span class="hlt">energies</span> per atom from 4 to 40 eV/atom. In the spectra normalized to a geometric average of all the spectra, the amino acid fragment <span class="hlt">ions</span> are distinguished from other secondary <span class="hlt">ions</span>. In the mass range above 600 u, the peptide fragment <span class="hlt">ions</span> increase with mass while those not related to the peptide decrease with mass. <span class="hlt">Energy</span>-dependence fragmentation helps in understanding the peptide spectra. Specific peptide fragment <span class="hlt">ions</span> of the larger peptides are likely to be detected under lower <span class="hlt">energy</span> than <span class="hlt">energy</span> higher than 10 eV/atom. Although it is difficult to interpret the TOF-SIMS spectra of a peptide obtained with an Ar cluster <span class="hlt">ion</span> beam, the secondary <span class="hlt">ions</span> can be classified by comparing those obtained with different <span class="hlt">energy</span> Ar cluster <span class="hlt">ion</span> beams. Copyright © 2015 John Wiley & Sons, Ltd.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JPhCS.798a2170O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JPhCS.798a2170O"><span>Universal main magnetic <span class="hlt">focus</span> <span class="hlt">ion</span> source: A new tool for laboratory research of astrophysics and Tokamak microplasma</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ovsyannikov, V. P.; Nefiodov, A. V.; Levin, A. A.</p> <p>2017-01-01</p> <p>A novel room-temperature <span class="hlt">ion</span> source for the production of atomic <span class="hlt">ions</span> in electron beam within wide ranges of electron <span class="hlt">energy</span> and current density is developed. The device can operate both as conventional Electron Beam <span class="hlt">Ion</span> Source/Trap (EBIS/T) and novel Main Magnetic <span class="hlt">Focus</span> <span class="hlt">Ion</span> Source. The <span class="hlt">ion</span> source is suitable for generation of the low-, medium- and high-density microplasma in steady state, which can be employed for investigation of a wide range of physical problems in ordinary university laboratory, in particular, for microplasma simulations relevant to astrophysics and ITER reactor. For the electron beam characterized by the incident <span class="hlt">energy</span> Ee = 10 keV, the current density je ∼ 20 kA/cm2 and the number density ne ∼ 2 × 1013 cm‑3 were achieved experimentally. For Ee ∼ 60 keV, the value of electron number density ne ∼ 1014 cm‑3 is feasible. The efficiency of the novel <span class="hlt">ion</span> source for laboratory astrophysics significantly exceeds that of other existing warm and superconducting EBITs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20080026198','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20080026198"><span><span class="hlt">Focused</span> <span class="hlt">Ion</span> Beam Recovery of Hypervelocity Impact Residue in Experimental Craters on Metallic Foils</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Graham, G. A.; Teslich, N.; Dai, Z. R.; Bradley, J. P.; Kearsley, A. T.; Horz, F.</p> <p>2006-01-01</p> <p>The Stardust sample return capsule will return to Earth in January 2006 with primitive debris collected from Comet 81P/Wild-2 during the fly-by encounter in 2004. In addition to the cometary particles embedded in low-density silica aerogel, there will be microcraters preserved in the Al foils (1100 series; 100 micrometers thick) that are wrapped around the sample tray assembly. Soda lime spheres (approximately 49 m in diameter) have been accelerated with a light-gas-gun into flight-grade Al foils at 6.35 km s(sup -1) to simulate the potential capture of cometary debris. The preserved crater penetrations have been analyzed using scanning electron microscopy (SEM) and x-ray <span class="hlt">energy</span> dispersive spectroscopy (EDX) to locate and characterize remnants of the projectile material remaining within the craters. In addition, <span class="hlt">ion</span> beam induced secondary electron imaging has proven particularly useful in identifying areas within the craters that contain residue material. Finally, high-precision <span class="hlt">focused</span> <span class="hlt">ion</span> beam (FIB) milling has been used to isolate and then extract an individual melt residue droplet from the interior wall of an impact penetration. This enabled further detailed elemental characterization, free from the background contamination of the Al foil substrate. The ability to recover pure melt residues using FIB will significantly extend the interpretations of the residue chemistry preserved in the Al foils returned by Stardust.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23763344','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23763344"><span>Internal composition of atmospheric dust particles from <span class="hlt">focused</span> <span class="hlt">ion</span>-beam scanning electron microscopy.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Conny, Joseph M</p> <p>2013-08-06</p> <p>Use of <span class="hlt">focused</span> <span class="hlt">ion</span>-beam scanning electron microscopy (FIB-SEM) to investigate the internal composition of atmospheric particles is demonstrated for assessing particle optical properties. In the FIB-SEM instrument equipped with an X-ray detector, a gallium-<span class="hlt">ion</span> beam mills the particle, while the electron beam images the slice faces and <span class="hlt">energy</span>-dispersive X-ray spectroscopy provides element maps of the particle. Differences in assessments of optical behavior based on FIB-SEM and conventional SEM were shown for five selected urban dust particles. The benefit of FIB-SEM for accurately determining the depth and size of optically important phases within particles was shown. FIB-SEM revealed that iron oxide grains left undetected by conventional SEM could potentially shift the single-scattering albedo of the particle from negative to positive radiative forcing. Analysis of a coke-like particle showed that 73% of the light-scattering inclusion went undetected with conventional SEM, causing the bulk absorption coefficient to vary by as much as 25%. Optical property calculations for particles as volume-equivalent spheres and as spheroids that approximated actual particle shapes revealed that the largest effect between conventional SEM and FIB-SEM analyses was on backscattering efficiency, in some cases varying several-fold.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/887281','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/887281"><span><span class="hlt">Focused</span> <span class="hlt">Ion</span> Beam Recovery of Hypervelocity Impact Residue in Experimental Craters on Metallic Foils.</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Graham, G A; Teslich, N; Dai, Z R; Bradley, J P; Kearsley, A T; Horz, F</p> <p>2005-11-04</p> <p>The Stardust sample return capsule will return to Earth in January 2006 with primitive debris collected from Comet 81P/Wild-2 during the fly-by encounter in 2004. In addition to the cometary particles embedded in low-density silica aerogel, there will be microcraters preserved in the Al foils (1100 series; 100 {micro}m thick) that are wrapped around the sample tray assembly. Soda lime spheres ({approx}49 {micro}m in diameter) have been accelerated with a Light Gas Gun into flight-grade Al foils at 6.35 km s{sup -1} to simulate the capture of cometary debris. The experimental craters have been analyzed using scanning electron microscopy (SEM) and x-ray <span class="hlt">energy</span> dispersive spectroscopy (EDX) to locate and characterize remnants of the projectile material remaining within the craters. In addition, <span class="hlt">ion</span> beam induced secondary electron imaging has proven particularly useful in identifying areas within the craters that contain residue material. Finally, high-precision <span class="hlt">focused</span> <span class="hlt">ion</span> beam (FIB) milling has been used to isolate and then extract an individual melt residue droplet from the interior wall of an impact. This enabled further detailed elemental characterization, free from the background contamination of the Al foil substrate. The ability to recover ''pure'' melt residues using FIB will significantly extend the interpretations of the residue chemistry preserved in the Al foils returned by Stardust.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009JAP...105d4305B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009JAP...105d4305B"><span>Producing metastable nanophase with sharp interface by means of <span class="hlt">focused</span> <span class="hlt">ion</span> beam irradiation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Barna, Árpád; Kotis, László; Lábár, János; Osváth, Zoltán; Tóth, Attila L.; Menyhárd, Miklós; Zalar, Anton; Panjan, Peter</p> <p>2009-02-01</p> <p>Amorphous carbon/nickel double layers were irradiated by 30 keV Ga+ <span class="hlt">ions</span> via <span class="hlt">focused</span> <span class="hlt">ion</span> beam. The effect of irradiation on the concentration distribution of all constituents was studied by Auger electron spectroscopy depth profiling and cross sectional transmission electron microscopy, while the morphology change of the sample was determined by atomic force microscopy. The Ga+ <span class="hlt">ion</span> irradiation results in the formation of metastable Ni3C layer with a uniform thickness. The C/Ni3C and Ni3C/Ni interfaces were found to be sharp up to a fluence of 200 Ga+ <span class="hlt">ions</span>/nm2.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/10196790','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/10196790"><span>Axial <span class="hlt">focusing</span> of <span class="hlt">energy</span> from a hypervelocity impact on earth</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Boslough, M.B.; Chael, E.P.; Trucano, T.G.; Crawford, D.A.</p> <p>1994-12-01</p> <p>We have performed computational simulations to determine how <span class="hlt">energy</span> from a large hypervelocity impact on the Earth`s surface would couple to its interior. Because of the first-order axial symmetry of both the impact <span class="hlt">energy</span> source and the stress-wave velocity structure of the Earth, a disproportionate amount of <span class="hlt">energy</span> is dissipated along the axis defined by the impact point and its antipode (point opposite the impact). For a symmetric and homogeneous Earth model, all the impact <span class="hlt">energy</span> that is radiated as seismic waves into the Earth at a given takeoff angle (ray parameter), independent of azimuthal direction, is refocused (minus attenuation) on the axis of symmetry, regardless of the number of reflections and refractions it has experienced. Material on or near the axis of symmetry experiences more strain cycles with much greater amplitude than elsewhere, and therefore experiences more irreversible heating. The <span class="hlt">focusing</span> is most intense in the upper mantle, within the asthenosphere, where seismic <span class="hlt">energy</span> is most effectively converted to heat. For a sufficiently energetic impact, this mechanism might generate enough local heating to create an isostatic instability leading to uplift, possibly resulting in rifting, volcanism, or other rearrangement of the interior dynamics of the planet. These simulations demonstrate how hypervelocity impact <span class="hlt">energy</span> can be transported to the Earth`s interior, supporting the possibility of a causal link between large impacts on Earth and major internally-driven geophysical processes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016NatSR...638843S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016NatSR...638843S"><span>Breakthrough in 4π <span class="hlt">ion</span> emission mechanism understanding in plasma <span class="hlt">focus</span> devices</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sohrabi, Mehdi; Zarinshad, Arefe; Habibi, Morteza</p> <p>2016-12-01</p> <p><span class="hlt">Ion</span> emission angular distribution mechanisms in plasma <span class="hlt">focus</span> devices (PFD) have not yet been well developed and understood being due to the lack of an efficient wide-angle <span class="hlt">ion</span> distribution image detection system to characterize a PFD space in detail. Present belief is that the acceleration of <span class="hlt">ions</span> points from “anode top” upwards in forward direction within a small solid angle. A breakthrough is reported in this study, by mega-size position-sensitive polycarbonate <span class="hlt">ion</span> image detection systems invented, on discovery of 4π <span class="hlt">ion</span> emission from the “anode top” in a PFD space after plasma pinch instability and radial run-away of <span class="hlt">ions</span> from the “anode cathodes array” during axial acceleration of plasma sheaths before the radial phase. These two <span class="hlt">ion</span> emission source mechanisms behave respectively as a “Point <span class="hlt">Ion</span> Source” and a “Line <span class="hlt">Ion</span> Source” forming “<span class="hlt">Ion</span> Cathode Shadows” on mega-size detectors. We believe that the inventions and discoveries made here will open new horizons for advanced <span class="hlt">ion</span> emission studies towards better mechanisms understanding and in particular will promote efficient applications of PFDs in medicine, science and technology.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5150579','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5150579"><span>Breakthrough in 4π <span class="hlt">ion</span> emission mechanism understanding in plasma <span class="hlt">focus</span> devices</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Sohrabi, Mehdi; Zarinshad, Arefe; Habibi, Morteza</p> <p>2016-01-01</p> <p><span class="hlt">Ion</span> emission angular distribution mechanisms in plasma <span class="hlt">focus</span> devices (PFD) have not yet been well developed and understood being due to the lack of an efficient wide-angle <span class="hlt">ion</span> distribution image detection system to characterize a PFD space in detail. Present belief is that the acceleration of <span class="hlt">ions</span> points from “anode top” upwards in forward direction within a small solid angle. A breakthrough is reported in this study, by mega-size position-sensitive polycarbonate <span class="hlt">ion</span> image detection systems invented, on discovery of 4π <span class="hlt">ion</span> emission from the “anode top” in a PFD space after plasma pinch instability and radial run-away of <span class="hlt">ions</span> from the “anode cathodes array” during axial acceleration of plasma sheaths before the radial phase. These two <span class="hlt">ion</span> emission source mechanisms behave respectively as a “Point <span class="hlt">Ion</span> Source” and a “Line <span class="hlt">Ion</span> Source” forming “<span class="hlt">Ion</span> Cathode Shadows” on mega-size detectors. We believe that the inventions and discoveries made here will open new horizons for advanced <span class="hlt">ion</span> emission studies towards better mechanisms understanding and in particular will promote efficient applications of PFDs in medicine, science and technology. PMID:27941832</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/918768','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/918768"><span><span class="hlt">Focused</span> <span class="hlt">ion</span> beam techniques for fabricating geometrically-complex components and devices.</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Mayer, Thomas Michael; Adams, David Price; Hodges, V. Carter; Vasile, Michael J.</p> <p>2004-03-01</p> <p>We have researched several new <span class="hlt">focused</span> <span class="hlt">ion</span> beam (FIB) micro-fabrication techniques that offer control of feature shape and the ability to accurately define features onto nonplanar substrates. These FIB-based processes are considered useful for prototyping, reverse engineering, and small-lot manufacturing. <span class="hlt">Ion</span> beam-based techniques have been developed for defining features in miniature, nonplanar substrates. We demonstrate helices in cylindrical substrates having diameters from 100 {micro}m to 3 mm. <span class="hlt">Ion</span> beam lathe processes sputter-define 10-{micro}m wide features in cylindrical substrates and tubes. For larger substrates, we combine <span class="hlt">focused</span> <span class="hlt">ion</span> beam milling with ultra-precision lathe turning techniques to accurately define 25-100 {micro}m features over many meters of path length. In several cases, we combine the feature defining capability of <span class="hlt">focused</span> <span class="hlt">ion</span> beam bombardment with additive techniques such as evaporation, sputter deposition and electroplating in order to build geometrically-complex, functionally-simple devices. Damascene methods that fabricate bound, metal microcoils have been developed for cylindrical substrates. Effects of <span class="hlt">focused</span> <span class="hlt">ion</span> milling on surface morphology are also highlighted in a study of <span class="hlt">ion</span>-milled diamond.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28767313','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28767313"><span>Low-<span class="hlt">Energy</span> <span class="hlt">Ion</span>-Species-Dependent Induction of DNA Double-Strand Breaks: <span class="hlt">Ion</span> <span class="hlt">Energy</span> and Fluence Thresholds.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Thopan, Prutchayawoot; Yu, Liangdeng; Brown, Ian G; Tippawan, Udomrat</p> <p>2017-10-01</p> <p>The goal of this study was to determine the critical <span class="hlt">ion</span>-radiation conditions under which heavy <span class="hlt">ion</span> beams can induce DNA double-strand breaks. Helium, nitrogen and argon-<span class="hlt">ion</span> beams in the <span class="hlt">energy</span> range of 20 eV to 2 keV were used to irradiate naked DNA plasmid pGFP to fluences of 1, 2 and 4 × 10(15) <span class="hlt">ions</span>/cm(2). The topological forms of DNA were subsequently analyzed using gel electrophoresis. The DNA forms were changed from the original supercoiled to damaged relaxed and linear forms, depending on the <span class="hlt">ion</span> mass, <span class="hlt">energy</span>, fluence and inertia. We found <span class="hlt">ion</span> <span class="hlt">energy</span> and fluence thresholds above which direct double-strand breaks can occur. The threshold is discussed in terms of the areal <span class="hlt">ion-energy</span> density and the cross-section.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014APS..MARW32003R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014APS..MARW32003R"><span>Free <span class="hlt">Energy</span> Wells and Barriers to <span class="hlt">Ion</span> Transport Across Membranes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rempe, Susan</p> <p>2014-03-01</p> <p>The flow of <span class="hlt">ions</span> across cellular membranes is essential to many biological processes. <span class="hlt">Ion</span> transport is also important in synthetic materials used as battery electrolytes. Transport often involves specific <span class="hlt">ions</span> and fast conduction. To achieve those properties, <span class="hlt">ion</span> conduction pathways must solvate specific <span class="hlt">ions</span> by just the ``right amount.'' The right amount of solvation avoids <span class="hlt">ion</span> traps due to deep free <span class="hlt">energy</span> wells, and avoids <span class="hlt">ion</span> block due to high free <span class="hlt">energy</span> barriers. <span class="hlt">Ion</span> channel proteins in cellular membranes demonstrate this subtle balance in solvation of specific <span class="hlt">ions</span>. Using ab initio molecular simulations, we have interrogated the link between binding site structure and <span class="hlt">ion</span> solvation free <span class="hlt">energies</span> in biological <span class="hlt">ion</span> binding sites. Our results emphasize the surprisingly important role of the environment that surrounds <span class="hlt">ion</span>-binding sites for fast transport of specific <span class="hlt">ions</span>. We acknowledge support from Sandia's LDRD program. Sandia National Labs is a multi-program laboratory operated by Sandia Corp., a wholly owned subsidiary of Lockheed Martin Corp., for the US DOE's NNSA under contract DE-AC04-94AL85000.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19810002855','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19810002855"><span>Determination of optimum voltages of <span class="hlt">ion</span> <span class="hlt">focusing</span> devices using computer techniques</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Eckstein, B. A.</p> <p>1980-01-01</p> <p>Electric potentials for two dimensional cross sections of <span class="hlt">ion</span> <span class="hlt">focusing</span> devices used in a mass spectrometer are calculated via a series of computer programs designed to compute potentials between areas of fixed voltages. <span class="hlt">Ion</span> trajectories within these devices may be determined by computer and a histogram obtained which plots <span class="hlt">ion</span> density against <span class="hlt">ion</span> position along a plate of the <span class="hlt">focusing</span> device. For each lens system, a plate voltage may be changed, the electric potentials recalculated, and a new histogram calculated in order to determine if the new voltage configuration has increased the device's efficiency. This process may be repeated until the optimum voltage values have been found for maximum particle transmission in each <span class="hlt">focusing</span> device.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25074238','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25074238"><span><span class="hlt">Focused</span> <span class="hlt">ion</span> beam lithography for fabrication of suspended nanostructures on highly corrugated surfaces.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Erdmanis, M; Sievilä, P; Shah, A; Chekurov, N; Ovchinnikov, V; Tittonen, I</p> <p>2014-08-22</p> <p>We propose a nanofabrication method that allows for patterning on extremely corrugated surfaces with micrometer-size features. The technique employs <span class="hlt">focused</span> <span class="hlt">ion</span> beam nanopatterning of <span class="hlt">ion</span>-sensitive inorganic resists formed by atomic layer deposition at low temperature. The nanoscale resolution on corrugated surfaces is ensured by inherently large depth of <span class="hlt">focus</span> of a <span class="hlt">focused</span> <span class="hlt">ion</span> beam system and very uniform resist coating. The utilized TiO₂ and Al₂O₃ resists show high selectivity in deep reactive <span class="hlt">ion</span> etching and enable the release of suspended nanostructures by dry etching. We demonstrate the great flexibility of the process by fabricating suspended nanostructures on flat surfaces, inclined walls, and on the bottom of deep grooves.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/950723','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/950723"><span>Comparative Review of a Dozen National <span class="hlt">Energy</span> Plans: <span class="hlt">Focus</span> on Renewable and Efficient <span class="hlt">Energy</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Logan, J.; James, T. L.</p> <p>2009-03-01</p> <p>Dozens of groups have submitted <span class="hlt">energy</span>, environmental, and economic recovery plans for consideration by the Obama administration and the 111th Congress. This report provides a comparative analysis of 12 national proposals, <span class="hlt">focusing</span> especially on <span class="hlt">energy</span> efficiency (EE) and renewable <span class="hlt">energy</span> (RE) market and policy issues.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1219287','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1219287"><span>A Comparative Review of a Dozen National <span class="hlt">Energy</span> Plans. <span class="hlt">Focus</span> on Renewable and Efficient <span class="hlt">Energy</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Logan, Jeffrey; James, Ted L.</p> <p>2009-03-01</p> <p>Dozens of groups have submitted <span class="hlt">energy</span>, environmental, and economic recovery plans for consideration by the Obama administration and the 111th Congress. This report provides a comparative analysis of 12 national proposals, <span class="hlt">focusing</span> especially on <span class="hlt">energy</span> efficiency (EE) and renewable <span class="hlt">energy</span> (RE) market and policy issues.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20140001969&hterms=Hwang&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DHwang','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20140001969&hterms=Hwang&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DHwang"><span>Electrolytes with Improved Safety Characteristics for High Voltage, High Specific <span class="hlt">Energy</span> Li-<span class="hlt">ion</span> Cells</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Smart, M. C.; Krause, F. C.; Hwang, C.; West, W. C.; Soler, J.; Whitcanack, L. W.; Prakash, G. K. S.; Ratnakumar, B. V.</p> <p>2012-01-01</p> <p>(1) NASA is actively pursuing the development of advanced electrochemical <span class="hlt">energy</span> storage and conversion devices for future lunar and Mars missions; (2) The Exploration Technology Development Program, <span class="hlt">Energy</span> Storage Project is sponsoring the development of advanced Li-<span class="hlt">ion</span> batteries and PEM fuel cell and regenerative fuel cell systems for the Altair Lunar Lander, Extravehicular Activities (EVA), and rovers and as the primary <span class="hlt">energy</span> storage system for Lunar Surface Systems; (3) At JPL, in collaboration with NASA-GRC, NASA-JSC and industry, we are actively developing advanced Li-<span class="hlt">ion</span> batteries with improved specific <span class="hlt">energy</span>, <span class="hlt">energy</span> density and safety. One effort is <span class="hlt">focused</span> upon developing Li-<span class="hlt">ion</span> battery electrolyte with enhanced safety characteristics (i.e., low flammability); and (4) A number of commercial applications also require Li-<span class="hlt">ion</span> batteries with enhanced safety, especially for automotive applications.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20140001969&hterms=li-ion+production&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dli-ion%2Bproduction','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20140001969&hterms=li-ion+production&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dli-ion%2Bproduction"><span>Electrolytes with Improved Safety Characteristics for High Voltage, High Specific <span class="hlt">Energy</span> Li-<span class="hlt">ion</span> Cells</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Smart, M. C.; Krause, F. C.; Hwang, C.; West, W. C.; Soler, J.; Whitcanack, L. W.; Prakash, G. K. S.; Ratnakumar, B. V.</p> <p>2012-01-01</p> <p>(1) NASA is actively pursuing the development of advanced electrochemical <span class="hlt">energy</span> storage and conversion devices for future lunar and Mars missions; (2) The Exploration Technology Development Program, <span class="hlt">Energy</span> Storage Project is sponsoring the development of advanced Li-<span class="hlt">ion</span> batteries and PEM fuel cell and regenerative fuel cell systems for the Altair Lunar Lander, Extravehicular Activities (EVA), and rovers and as the primary <span class="hlt">energy</span> storage system for Lunar Surface Systems; (3) At JPL, in collaboration with NASA-GRC, NASA-JSC and industry, we are actively developing advanced Li-<span class="hlt">ion</span> batteries with improved specific <span class="hlt">energy</span>, <span class="hlt">energy</span> density and safety. One effort is <span class="hlt">focused</span> upon developing Li-<span class="hlt">ion</span> battery electrolyte with enhanced safety characteristics (i.e., low flammability); and (4) A number of commercial applications also require Li-<span class="hlt">ion</span> batteries with enhanced safety, especially for automotive applications.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17764322','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17764322"><span>Measurement of <span class="hlt">ion</span> <span class="hlt">energy</span> distributions using a combined <span class="hlt">energy</span> and mass analyzer.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Walton, S G; Fernsler, R F; Leonhardt, D</p> <p>2007-08-01</p> <p>A method is described for measuring <span class="hlt">ion</span> <span class="hlt">energy</span> distributions using a commercially available, combined <span class="hlt">energy</span> analyzer/mass spectrometer. The distributions were measured at an electrode located adjacent to pulsed, electron beam-generated plasmas produced in argon. The method uses <span class="hlt">energy</span>-dependent tuning and was tested for various plasma conditions. The results indicate an improved collection efficiency of low-<span class="hlt">energy</span> <span class="hlt">ions</span> when compared to conventional approaches in measuring <span class="hlt">ion</span> <span class="hlt">energy</span> distributions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19740029720&hterms=Exchange+rate&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DExchange%2Brate','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19740029720&hterms=Exchange+rate&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DExchange%2Brate"><span><span class="hlt">Ion</span> momentum and <span class="hlt">energy</span> transfer rates for charge exchange collisions</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Horwitz, J.; Banks, P. M.</p> <p>1973-01-01</p> <p>The rates of momentum and <span class="hlt">energy</span> transfer have been obtained for charge exchange collisions between <span class="hlt">ion</span> and neutral gases having arbitrary Maxwellian temperatures and bulk transport velocities. The results are directly applicable to the F-region of the ionosphere where 0+ - 0 charge is the dominant mechanism affecting <span class="hlt">ion</span> momentum and <span class="hlt">energy</span> transfer.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_13 --> <div id="page_14" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="261"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1985DoSSR.283.1355N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1985DoSSR.283.1355N"><span>Calculation of the <span class="hlt">energy</span> levels of lithium-like <span class="hlt">ions</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nadykto, B. A.</p> <p></p> <p>An attempt is made to develop a straightforward and sufficiently accurate method for calculating the <span class="hlt">energies</span> of complex <span class="hlt">ion</span> states. The method is based on Bohr's computational model and Sommerfeld's model in relativistic form (for circular orbits only). The method proposed here makes it possible to calculate excited <span class="hlt">ion</span> states having different atomic and quantum numbers. A similar method can be used for calculating the <span class="hlt">energies</span> of <span class="hlt">ion</span> states with the number of electrons exceeding three.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24593445','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24593445"><span>A 2D Particle in Cell model for <span class="hlt">ion</span> extraction and <span class="hlt">focusing</span> in electrostatic accelerators.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Veltri, P; Cavenago, M; Serianni, G</p> <p>2014-02-01</p> <p>Negative <span class="hlt">ions</span> are fundamental to produce intense and high <span class="hlt">energy</span> neutral beams used to heat the plasma in fusion devices. The processes regulating the <span class="hlt">ion</span> extraction involve the formation of a sheath on a scale comparable to the Debye length of the plasma. On the other hand, the <span class="hlt">ion</span> acceleration as a beam is obtained on distances greater than λD. The paper presents a model for both the phases of <span class="hlt">ion</span> extraction and acceleration of the <span class="hlt">ions</span> and its implementation in a numerical code. The space charge of particles is deposited following usual Particle in Cell codes technique, while the field is solved with finite element methods. Some hypotheses on the beam plasma transition are described, allowing to model both regions at the same time. The code was tested with the geometry of the NIO1 negative <span class="hlt">ions</span> source, and the results are compared with existing ray tracing codes and discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22254100','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22254100"><span>A 2D Particle in Cell model for <span class="hlt">ion</span> extraction and <span class="hlt">focusing</span> in electrostatic accelerators</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Veltri, P. Serianni, G.; Cavenago, M.</p> <p>2014-02-15</p> <p>Negative <span class="hlt">ions</span> are fundamental to produce intense and high <span class="hlt">energy</span> neutral beams used to heat the plasma in fusion devices. The processes regulating the <span class="hlt">ion</span> extraction involve the formation of a sheath on a scale comparable to the Debye length of the plasma. On the other hand, the <span class="hlt">ion</span> acceleration as a beam is obtained on distances greater than λ{sub D}. The paper presents a model for both the phases of <span class="hlt">ion</span> extraction and acceleration of the <span class="hlt">ions</span> and its implementation in a numerical code. The space charge of particles is deposited following usual Particle in Cell codes technique, while the field is solved with finite element methods. Some hypotheses on the beam plasma transition are described, allowing to model both regions at the same time. The code was tested with the geometry of the NIO1 negative <span class="hlt">ions</span> source, and the results are compared with existing ray tracing codes and discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24784684','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24784684"><span>Note: application of UF-4 emulsion films to detect low-<span class="hlt">energy</span> <span class="hlt">ions</span> from plasmas produced by laser ablation.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Nishio, M; Shrestha, I; Kantsyrev, V L; Tooth, M; Takasugi, K</p> <p>2014-04-01</p> <p>Detection of low-<span class="hlt">energy</span> <span class="hlt">ions</span> via Thomson parabola mass analyzer in the absence of any additional electrical systems is examined. Numerous low-<span class="hlt">energy</span> <span class="hlt">ions</span> were recorded on UF-4 solid state emulsion films. Kinetic <span class="hlt">energies</span> between 1 and 4 keV of <span class="hlt">ions</span> generated by YAG laser <span class="hlt">focused</span> on Al and Ti targets were obtained using Thomson parabola measurements. Characteristics of <span class="hlt">ion</span> tracks on the UF-4 detector are discussed in terms of pressure ranges of vacuum chamber. Moreover, differences in charges of <span class="hlt">ions</span> between this study and previous spectroscopic measurements are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017RScI...88f3306G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017RScI...88f3306G"><span><span class="hlt">Ion</span> mass and <span class="hlt">energy</span> selective hyperthermal <span class="hlt">ion</span>-beam assisted deposition setup</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gerlach, J. W.; Schumacher, P.; Mensing, M.; Rauschenbach, S.; Cermak, I.; Rauschenbach, B.</p> <p>2017-06-01</p> <p>For the synthesis of high-quality thin films, <span class="hlt">ion</span>-beam assisted deposition (IBAD) is a frequently used technique providing precise control over several substantial film properties. IBAD typically relies on the use of a broad-beam <span class="hlt">ion</span> source. Such <span class="hlt">ion</span> sources suffer from the limitation that they deliver a blend of <span class="hlt">ions</span> with different <span class="hlt">ion</span> masses, each of them possessing a certain distribution of kinetic <span class="hlt">energy</span>. In this paper, a compact experimental setup is presented that enables the separate control of <span class="hlt">ion</span> mass and <span class="hlt">ion</span> kinetic <span class="hlt">energy</span> in the region of hyperthermal <span class="hlt">energies</span> (few 1 eV - few 100 eV). This <span class="hlt">ion</span> <span class="hlt">energy</span> region is of increasing interest not only for <span class="hlt">ion</span>-assisted film growth but also for the wide field of preparative mass spectrometry. The setup consists of a constricted glow-discharge plasma beam source and a tailor-made, compact quadrupole system equipped with entry and exit <span class="hlt">ion</span> optics. It is demonstrated that the separation of monoatomic and polyatomic nitrogen <span class="hlt">ions</span> (N+ and N2+) is accomplished. For both <span class="hlt">ion</span> species, the kinetic <span class="hlt">energy</span> is shown to be selectable in the region of hyperthermal <span class="hlt">energies</span>. At the sample position, <span class="hlt">ion</span> current densities are found to be in the order of 1 μA/cm2 and the full width at half maximum of the <span class="hlt">ion</span> beam profile is in the order of 10 mm. Thus, the requirements for homogeneous deposition processes in sufficiently short periods of time are fulfilled. Finally, employing the described setup, for the first time in practice epitaxial GaN films were deposited. This opens up the opportunity to fundamentally study the influence of the simultaneous irradiation with hyperthermal <span class="hlt">ions</span> on the thin film growth in IBAD processes and to increase the flexibility of the technique.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008NIMPB.266.1846B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008NIMPB.266.1846B"><span>Application of mass-separated <span class="hlt">focused</span> <span class="hlt">ion</span> beams in nano-technology</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bischoff, L.</p> <p>2008-04-01</p> <p>FIB applications like writing <span class="hlt">ion</span> implantation, <span class="hlt">ion</span> beam mixing or <span class="hlt">ion</span> beam synthesis in the μm- or nm range often require <span class="hlt">ion</span> species other than gallium. Therefore alloy liquid metal <span class="hlt">ion</span> sources (LMIS) have to be developed and applied in FIB tools. The <span class="hlt">energy</span> distribution of <span class="hlt">ions</span> emitted from an alloy LMIS is one of the crucial parameters for the performance of a FIB column. Different source materials like AuGe, AuSi, AuGeSi, CoNd, ErNi, ErFeNiCr, MnGe, GaBi, GaBiLi, SnPb, … were investigated with respect to the <span class="hlt">energy</span> spread of the different <span class="hlt">ion</span> species as a function of emission current, <span class="hlt">ion</span> mass and emitter temperature. Different alloy LMIS's have been developed and used in the FZD - FIB system especially for writing implantation to fabricate sub-μm pattern without any lithographic steps. Co and various other <span class="hlt">ion</span> species were applied to generate CoSi2 nano-structures, like dots and wires by <span class="hlt">ion</span> beam synthesis or to manipulate the properties of magnetic films. Additionally, the possibility of varying the flux in the FIB by changing the pixel dwell-time can be used for the investigation of the radiation damage and dynamic annealing in Si, Ge and SiC at elevated implantation temperatures. Furthermore, a broad spectrum of <span class="hlt">ions</span> was employed to study in a fast manner the sputtering process depending on temperature, angle of incidence and <span class="hlt">ion</span> mass on a couple of target materials. These studies are important for the 3D-fabrication of various kinds of micro-tools by FIB milling.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20160004098','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20160004098"><span>Nustar: Bringing the High-<span class="hlt">Energy</span> Universe into <span class="hlt">Focus</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Fineberg, Larry</p> <p>2016-01-01</p> <p>This is a presentation to students at the University of Florida in the Small Satellite Design Club. The subject matter is the NuSTAR mission and covers topics about the spacecraft itself and the launch campaign. NASA's Nuclear Spectroscopic Telescope Array (NuSTAR) is the first <span class="hlt">focusing</span> high-<span class="hlt">energy</span> X-ray mission. Studies the hottest, densest, most energetic phenomena in the Universe. Purpose is to search for black holes, map the remnants of stellar explosions, and study the most extreme active galaxies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25177991','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25177991"><span>Spectromicroscopy and coherent diffraction imaging: <span class="hlt">focus</span> on <span class="hlt">energy</span> materials applications.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hitchcock, Adam P; Toney, Michael F</p> <p>2014-09-01</p> <p>Current and future capabilities of X-ray spectromicroscopy are discussed based on coherence-limited imaging methods which will benefit from the dramatic increase in brightness expected from a diffraction-limited storage ring (DLSR). The methods discussed include advanced coherent diffraction techniques and nanoprobe-based real-space imaging using Fresnel zone plates or other diffractive optics whose performance is affected by the degree of coherence. The capabilities of current systems, improvements which can be expected, and some of the important scientific themes which will be impacted are described, with <span class="hlt">focus</span> on <span class="hlt">energy</span> materials applications. Potential performance improvements of these techniques based on anticipated DLSR performance are estimated. Several examples of <span class="hlt">energy</span> sciences research problems which are out of reach of current instrumentation, but which might be solved with the enhanced DLSR performance, are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011PhRvS..14c1304H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011PhRvS..14c1304H"><span>Collection and <span class="hlt">focusing</span> of laser accelerated <span class="hlt">ion</span> beams for therapy applications</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hofmann, Ingo; Meyer-Ter-Vehn, Jürgen; Yan, Xueqing; Orzhekhovskaya, Anna; Yaramyshev, Stepan</p> <p>2011-03-01</p> <p>Experimental results in laser acceleration of protons and <span class="hlt">ions</span> and theoretical predictions that the currently achieved <span class="hlt">energies</span> might be raised by factors 5-10 in the next few years have stimulated research exploring this new technology for oncology as a compact alternative to conventional synchrotron based accelerator technology. The emphasis of this paper is on collection and <span class="hlt">focusing</span> of the laser produced particles by using simulation data from a specific laser acceleration model. We present a scaling law for the “chromatic emittance” of the collector—here assumed as a solenoid lens—and apply it to the particle <span class="hlt">energy</span> and angular spectra of the simulation output. For a 10 Hz laser system we find that particle collection by a solenoid magnet well satisfies requirements of intensity and beam quality as needed for depth scanning irradiation. This includes a sufficiently large safety margin for intensity, whereas a scheme without collection—by using mere aperture collimation—hardly reaches the needed intensities.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005JAP....98l4102A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005JAP....98l4102A"><span>Artificial domain structures realized by local gallium <span class="hlt">focused</span> <span class="hlt">Ion</span>-beam modification of Pt /Co/Pt trilayer transport structure</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Aziz, A.; Bending, S. J.; Roberts, H.; Crampin, S.; Heard, P. J.; Marrows, C. H.</p> <p>2005-12-01</p> <p>We demonstrate that a high-resolution Ga <span class="hlt">focused</span> <span class="hlt">ion</span> beam can be used to introduce artificial domain structures in Pt(1.6nm )/Co(0.5nm)/Pt(3.5nm) trilayer transport structures. We have used thin SiO2 overlayers to control the effective <span class="hlt">energy</span> and dose of Ga <span class="hlt">ions</span> at the Pt /Co interface. The extraordinary Hall effect (EHE) was used to characterize the magnetic properties of the patterned films. Using 30keV Ga <span class="hlt">ions</span> and SiO2 overlayer thicknesses in the range of 0-24nm, we achieve complete control of the coercive field of our Pt /Co/Pt trilayer structures. The magnetization reversal mechanism for an artificial domain of size of 3×0.5μm2 is investigated using EHE.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19730045444&hterms=electric+energy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Delectric%2Benergy','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19730045444&hterms=electric+energy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Delectric%2Benergy"><span><span class="hlt">Energy</span> partitioning of gaseous <span class="hlt">ions</span> in an electric field.</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hahn, H.-S.; Mason, E. A.</p> <p>1973-01-01</p> <p>The partitioning of <span class="hlt">ion</span> <span class="hlt">energy</span> among thermal <span class="hlt">energy</span>, drift <span class="hlt">energy</span>, and random-field <span class="hlt">energy</span> is studied by solution of the Boltzmann equation. An expansion in powers of the square of the electric field strength is obtained by Kihara's method. Numerical calculations for several <span class="hlt">ion</span>-neutral force laws show that Wannier's constant mean-free-time model gives a reasonable first approximation. The formal extension to multicomponent mixtures is also given. The matrix elements obtained are tabulated, and can be used to study the field dependence of other moments of the <span class="hlt">ion</span>-distribution function.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19730045444&hterms=energy+fields&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Denergy%2Bfields','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19730045444&hterms=energy+fields&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Denergy%2Bfields"><span><span class="hlt">Energy</span> partitioning of gaseous <span class="hlt">ions</span> in an electric field.</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hahn, H.-S.; Mason, E. A.</p> <p>1973-01-01</p> <p>The partitioning of <span class="hlt">ion</span> <span class="hlt">energy</span> among thermal <span class="hlt">energy</span>, drift <span class="hlt">energy</span>, and random-field <span class="hlt">energy</span> is studied by solution of the Boltzmann equation. An expansion in powers of the square of the electric field strength is obtained by Kihara's method. Numerical calculations for several <span class="hlt">ion</span>-neutral force laws show that Wannier's constant mean-free-time model gives a reasonable first approximation. The formal extension to multicomponent mixtures is also given. The matrix elements obtained are tabulated, and can be used to study the field dependence of other moments of the <span class="hlt">ion</span>-distribution function.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014NIMPB.332..326S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014NIMPB.332..326S"><span>Biomaterial imaging with MeV-<span class="hlt">energy</span> heavy <span class="hlt">ion</span> beams</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Seki, Toshio; Wakamatsu, Yoshinobu; Nakagawa, Shunichiro; Aoki, Takaaki; Ishihara, Akihiko; Matsuo, Jiro</p> <p>2014-08-01</p> <p>The spatial distribution of several chemical compounds in biological tissues and cells can be obtained with mass spectrometry imaging (MSI). In conventional secondary <span class="hlt">ion</span> mass spectrometry (SIMS) with keV-<span class="hlt">energy</span> <span class="hlt">ion</span> beams, elastic collisions occur between projectiles and atoms of constituent molecules. The collisions produce fragments, making the acquisition of molecular information difficult. In contrast, <span class="hlt">ion</span> beams with MeV-<span class="hlt">energy</span> excite near-surface electrons and enhance the ionization of high-mass molecules; hence, SIMS spectra of fragment-suppressed ionized molecules can be obtained with MeV-SIMS. To compare between MeV and conventional SIMS, we used the two methods based on MeV and Bi3-keV <span class="hlt">ions</span>, respectively, to obtain molecular images of rat cerebellum. Conventional SIMS images of m/z 184 were clearly observed, but with the Bi3 <span class="hlt">ion</span>, the distribution of the molecule with m/z 772.5 could be observed with much difficulty. This effect was attributed to the low secondary <span class="hlt">ion</span> yields and we could not get many signal counts with keV-<span class="hlt">energy</span> beam. On the other hand, intact molecular <span class="hlt">ion</span> distributions of lipids were clearly observed with MeV-SIMS, although the mass of all lipid molecules was higher than 500 Da. The peaks of intact molecular <span class="hlt">ions</span> in MeV-SIMS spectra allowed us to assign the mass. The high secondary <span class="hlt">ion</span> sensitivity with MeV-<span class="hlt">energy</span> heavy <span class="hlt">ions</span> is very useful in biomaterial analysis.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017SPIE10145E..1VO','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017SPIE10145E..1VO"><span>Molecular dynamics and dynamic Monte-Carlo simulation of irradiation damage with <span class="hlt">focused</span> <span class="hlt">ion</span> beams</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ohya, Kaoru</p> <p>2017-03-01</p> <p>The <span class="hlt">focused</span> <span class="hlt">ion</span> beam (FIB) has become an important tool for micro- and nanostructuring of samples such as milling, deposition and imaging. However, this leads to damage of the surface on the nanometer scale from implanted projectile <span class="hlt">ions</span> and recoiled material atoms. It is therefore important to investigate each kind of damage quantitatively. We present a dynamic Monte-Carlo (MC) simulation code to simulate the morphological and compositional changes of a multilayered sample under <span class="hlt">ion</span> irradiation and a molecular dynamics (MD) simulation code to simulate dose-dependent changes in the backscattering-<span class="hlt">ion</span> (BSI)/secondary-electron (SE) yields of a crystalline sample. Recent progress in the codes for research to simulate the surface morphology and Mo/Si layers intermixing in an EUV lithography mask irradiated with FIBs, and the crystalline orientation effect on BSI and SE yields relating to the channeling contrast in scanning <span class="hlt">ion</span> microscopes, is also presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015APS..DPPC12044C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015APS..DPPC12044C"><span>Recent <span class="hlt">Ion</span> <span class="hlt">Energy</span> Distribution Observations on MST RFP Plasmas</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Clark, Jerry; Titus, J. B.; Mezonlin, E. D.; Johnson, J. A., III; Almagri, A. F.; Andeson, J. A.</p> <p>2015-11-01</p> <p><span class="hlt">Ion</span> <span class="hlt">energy</span> distribution and temperature measurements have been made on the Madison Symmetric Torus (MST) using the Florida A&M University compact neutral particle analyzer (CNPA). The CNPA is a low <span class="hlt">energy</span> (0.34-5.2 keV), high <span class="hlt">energy</span> resolution (25 channels) neutral particle analyzer, with a radial view on MST. Recently, a retarding potential system was built to allow CNPA measurements to ensemble a complete <span class="hlt">ion</span> <span class="hlt">energy</span> distribution with high-<span class="hlt">energy</span> resolution, providing insight into the dynamics of the bulk and fast <span class="hlt">ion</span> populations. Recent work has also been done to improve the analysis techniques used to infer the <span class="hlt">ion</span> temperature measurements, allowing us to understand temperature dynamics better during global magnetic reconnection events. Work supported in part by grants to FAMU and to UW from NSF and from Fusion <span class="hlt">Energy</span> Sciences at DOE.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23902053','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23902053"><span>The <span class="hlt">energy</span> transfer in the TEMP-4M pulsed <span class="hlt">ion</span> beam accelerator.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Isakova, Y I; Pushkarev, A I; Khaylov, I P</p> <p>2013-07-01</p> <p>The results of a study of the <span class="hlt">energy</span> transfer in the TEMP-4M pulsed <span class="hlt">ion</span> beam accelerator are presented. The <span class="hlt">energy</span> transfer efficiency in the Blumlein and a self-magnetically insulated <span class="hlt">ion</span> diode was analyzed. Optimization of the design of the accelerator allows for 85% of <span class="hlt">energy</span> transferred from Blumlein to the diode (including after-pulses), which indicates that the <span class="hlt">energy</span> loss in Blumlein and spark gaps is insignificant and not exceeds 10%-12%. Most losses occur in the diode. The efficiency of <span class="hlt">energy</span> supplied to the diode to the <span class="hlt">energy</span> of accelerated <span class="hlt">ions</span> is 8%-9% for a planar strip self-magnetic MID, 12%-15% for <span class="hlt">focusing</span> diode and 20% for a spiral self-magnetic MID.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22220540','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22220540"><span>The <span class="hlt">energy</span> transfer in the TEMP-4M pulsed <span class="hlt">ion</span> beam accelerator</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Isakova, Y. I.; Pushkarev, A. I.; Khaylov, I. P.</p> <p>2013-07-15</p> <p>The results of a study of the <span class="hlt">energy</span> transfer in the TEMP-4M pulsed <span class="hlt">ion</span> beam accelerator are presented. The <span class="hlt">energy</span> transfer efficiency in the Blumlein and a self-magnetically insulated <span class="hlt">ion</span> diode was analyzed. Optimization of the design of the accelerator allows for 85% of <span class="hlt">energy</span> transferred from Blumlein to the diode (including after-pulses), which indicates that the <span class="hlt">energy</span> loss in Blumlein and spark gaps is insignificant and not exceeds 10%–12%. Most losses occur in the diode. The efficiency of <span class="hlt">energy</span> supplied to the diode to the <span class="hlt">energy</span> of accelerated <span class="hlt">ions</span> is 8%–9% for a planar strip self-magnetic MID, 12%–15% for <span class="hlt">focusing</span> diode and 20% for a spiral self-magnetic MID.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SPIE.9908E..8DD','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SPIE.9908E..8DD"><span>The prime <span class="hlt">focus</span> corrector for dark <span class="hlt">energy</span> spectroscopic instrument</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Doel, Peter; Besuner, Robert; Brooks, David; Flaugher, Brenna; Gallo, Giuseppe; Gutierrez, Gaston; Kent, Stephen; Lampton, Michael; Levi, Michael; Liang, Ming; Miller, Timothy; Sprayberry, David</p> <p>2016-08-01</p> <p>The Dark <span class="hlt">Energy</span> Spectroscopic Instrument (DESI), currently under construction, is designed to measure the expansion history of the Universe using the Baryon Acoustic Oscillation technique. The spectra of 40 million galaxies over 14000 sq deg will be measured during the life of the experiment. A new prime <span class="hlt">focus</span> corrector for the KPNO Mayall telescope will deliver light to 5000 fiber optic positioners. The fibers in turn feed ten broad-band spectrographs. This paper describes the overall design and construction status of the prime <span class="hlt">focus</span> corrector. The size and complexity of the system poses significant design and production challenges. The optics of the corrector consists of six lenses, ranging from 0.8 - 1.14m in diameter, two of which can be rotated to act as an atmospheric dispersion corrector. These lenses are mounted in custom cells that themselves are mounted in a barrel assembly the alignment of which can be actively controlled by a hexapod system to micrometer precision. The whole assembly will be mounted at the prime <span class="hlt">focus</span> of the Mayall 4m telescope at Kitt Peak observatory and will be one of the largest lens systems ever built for an optical telescope. Construction of the corrector began in 2014 and is well advanced. The system is due to be delivered to the telescope for installation in early 2018.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/5747581','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/5747581"><span>Kinetic <span class="hlt">energy</span> distributions of <span class="hlt">ions</span> after surface collisions</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Short, R.T.; Todd, P.J.; Grimm, C.C.</p> <p>1991-01-01</p> <p>As a part of the development of an organic <span class="hlt">ion</span> microprobe, to be used for imaging of particular organic compounds in biological tissue, various methods of quadrupole-based tandem mass spectroscopy (MS/MS) have been investigated. High transmission efficiency is essential for the success of the organic <span class="hlt">ion</span> microprobe, due to expected low analyte concentrations in biological tissue and the potential for sample damage from prolonged exposure to the primary <span class="hlt">ion</span> beam. MS/MS is necessary for organic <span class="hlt">ion</span> imaging because of the complex nature of the biological matrices. The goal of these studies of was to optimize the efficiency of daughter <span class="hlt">ion</span> production and transmission by first determining daughter <span class="hlt">ion</span> properties and then designing <span class="hlt">ion</span> optics based on those properties. The properties of main interest are daughter <span class="hlt">ion</span> kinetic <span class="hlt">energy</span> and angular distribution. 1 fig.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/1032410','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/1032410"><span>Large Area Microcorrals and Cavity Formation on Cantilevers using a <span class="hlt">Focused</span> <span class="hlt">Ion</span> Beam</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Saraf, Laxmikant V.; Britt, David W.</p> <p>2011-09-14</p> <p>We utilize <span class="hlt">focused</span> <span class="hlt">ion</span> beam (FIB) to explore various sputtering parameters to form large area microcorrals and cavities on cantilevers. Microcorrals were rapidly created by modifying <span class="hlt">ion</span> beam blur and overlaps. Modification in FIB sputtering parameters affects the periodicity and shape of corral microstructure. Cantilever deflections show <span class="hlt">ion</span> beam amorphization effects as a function of sputtered area and cantilever base cavities with or without side walls. The FIB sputtering parameters address a method for rapid creation of a cantilever tensiometer with integrated fluid storage and delivery.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_14 --> <div id="page_15" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="281"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22299825','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22299825"><span>Interaction of the high <span class="hlt">energy</span> deuterons with the graphite target in the plasma <span class="hlt">focus</span> devices based on Lee model</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Akel, M. Alsheikh Salo, S.; Ismael, Sh.; Saw, S. H.; Lee, S.</p> <p>2014-07-15</p> <p>Numerical experiments are systematically carried out using the Lee model code extended to compute the <span class="hlt">ion</span> beams on various plasma <span class="hlt">focus</span> devices operated with Deuterium gas. The deuteron beam properties of the plasma <span class="hlt">focus</span> are studied for low and high <span class="hlt">energy</span> plasma <span class="hlt">focus</span> device. The <span class="hlt">energy</span> spectral distribution for deuteron <span class="hlt">ions</span> ejected from the pinch plasma is calculated and the <span class="hlt">ion</span> numbers with <span class="hlt">energy</span> around 1 MeV is then determined. The deuteron–graphite target interaction is studied for different conditions. The yield of the reaction {sup 12}C(d,n){sup 13}N and the induced radioactivity for one and multi shots plasma <span class="hlt">focus</span> devices in the graphite solid target is investigated. Our results present the optimized high <span class="hlt">energy</span> repetitive plasma <span class="hlt">focus</span> devices as an alternative to accelerators for the production of {sup 13}N short lived radioisotopes. However, technical challenges await solutions on two fronts: (a) operation of plasma <span class="hlt">focus</span> machines at high rep rates for a sufficient period of time (b) design of durable targets that can take the thermal load.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/15006432','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/15006432"><span>Terascale simulations for heavy <span class="hlt">ion</span> inertial fusion <span class="hlt">energy</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Friedman, A; Cohen, R H; Grote, D P; Sharp, W M; Celata, C M; Lee, E P; Vay, J-L; Davidson, R C; Kaganovich, I; Lee, W W; Qin, H; Welch, D R; Haber, I; Kishek, R A</p> <p>2000-06-08</p> <p>The intense <span class="hlt">ion</span> beams in a heavy <span class="hlt">ion</span> Inertial Fusion <span class="hlt">Energy</span> (IFE) driver and fusion chamber are non-neutral plasmas whose dynamics are largely dominated by space charge. We propose to develop a ''source-to-target'' Heavy <span class="hlt">Ion</span> Fusion (HIF) beam simulation capability: a description of the kinetic behavior of this complex, nonlinear system which is both integrated and detailed. We will apply this new capability to further our understanding of key scientific issues in the physics of <span class="hlt">ion</span> beams for IFE. The simulations will entail self-consistent field descriptions that require interprocessor communication, but are scalable and will run efficiently on terascale architectures. This new capability will be based on the integration of three types of simulations, each requiring terascale computing: (1) simulations of acceleration and confinement of the space-charge-dominated <span class="hlt">ion</span> beams through the driver (accelerator, pulse compression line, and final <span class="hlt">focusing</span> system) which accurately describe their dynamics, including emittance growth (phase-space dilution) effects; these are particle-in-cell (PIC) models; (2) electromagnetic (EM) and magnetoinductive (Darwin) simulations which describe the beam and the fusion chamber environment, including multibeam, neutralization, stripping, beam and plasma ionization processes, and return current effects; and (3) highly detailed simulations (6f, multispecies PIC, continuum Vlasov), which can examine electron effects and collective modes in the driver and chamber, and can study halo generation with excellent statistics, to ensure that these effects do not disrupt the <span class="hlt">focusability</span> of the beams. The code development will involve: (i) adaptation of existing codes to run efficiently on multi-SMP computers that use a hybrid of shared and distributed memory; (ii) development of new and improved numerical algorithms, e.g., averaging techniques that will afford larger timesteps; and (iii) incorporation of improved physics models (e.g., for self</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014APS..DPPNP8112M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014APS..DPPNP8112M"><span><span class="hlt">Energy</span> Loss of High Intensity <span class="hlt">Focused</span> Proton Beams Penetrating Metal Foils</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>McGuffey, C.; Qiao, B.; Kim, J.; Beg, F. N.; Wei, M. S.; Evans, M.; Fitzsimmons, P.; Stephens, R. B.; Chen, S. N.; Fuchs, J.; Nilson, P. M.; Canning, D.; Mastrosimone, D.; Foord, M. E.</p> <p>2014-10-01</p> <p>Shortpulse-laser-driven intense <span class="hlt">ion</span> beams are appealing for applications in probing and creating high <span class="hlt">energy</span> density plasmas. Such a beam isochorically heats and rapidly ionizes any target it enters into warm dense matter with uncertain transport and stopping properties. Here we present experimental measurements taken with the 1.25 kJ, 10 ps OMEGA EP BL shortpulse laser of the proton and carbon spectra after passing through metal foils. The laser irradiated spherically curved C targets with intensity 4×1018 W/cm2, producing proton beams with 3 MeV slope temperature and a sharp low <span class="hlt">energy</span> cutoff at 5 MeV which has not been observed on lower <span class="hlt">energy</span>, shorter pulse intense lasers. The beam either diverged freely or was <span class="hlt">focused</span> to estimated 1016 p +/cm2 ps by a surrounding structure before entering the metal foils (Al or Ag and a Cu tracer layer). The proton and <span class="hlt">ion</span> spectra were altered by the foil depending on material and whether or not the beam was <span class="hlt">focused</span>. Transverse proton radiography probed the target with ps temporal and 10 micron spatial resolution, indicating an electrostatic field on the foil may also have affected the beam. We present complementary particle-in-cell simulations of the beam generation and transport to the foils. This work was supported by the DOE/NNSA National Laser User Facility program, Contract DE-SC0001265.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24921506','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24921506"><span><span class="hlt">Focused</span> <span class="hlt">ion</span> beam post-processing of optical fiber Fabry-Perot cavities for sensing applications.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>André, Ricardo M; Pevec, Simon; Becker, Martin; Dellith, Jan; Rothhardt, Manfred; Marques, Manuel B; Donlagic, Denis; Bartelt, Hartmut; Frazão, Orlando</p> <p>2014-06-02</p> <p><span class="hlt">Focused</span> <span class="hlt">ion</span> beam technology is combined with chemical etching of specifically designed fibers to create Fabry-Perot interferometers. Hydrofluoric acid is used to etch special fibers and create microwires with diameters of 15 μm. These microwires are then milled with a <span class="hlt">focused</span> <span class="hlt">ion</span> beam to create two different structures: an indented Fabry-Perot structure and a cantilever Fabry-Perot structure that are characterized in terms of temperature. The cantilever structure is also sensitive to vibrations and is capable of measuring frequencies in the range 1 Hz - 40 kHz.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27176945','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27176945"><span>Direct patterning of vortex generators on a fiber tip using a <span class="hlt">focused</span> <span class="hlt">ion</span> beam.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Vayalamkuzhi, Pramitha; Bhattacharya, Shanti; Eigenthaler, Ulrike; Keskinbora, Kahraman; Samlan, C T; Hirscher, Michael; Spatz, Joachim P; Viswanathan, Nirmal K</p> <p>2016-05-15</p> <p>The realization of spiral phase optical elements on the cleaved end of an optical fiber by <span class="hlt">focused</span> <span class="hlt">ion</span> beam milling is presented. A <span class="hlt">focused</span> Ga<sup>+</sup> <span class="hlt">ion</span> beam with an acceleration voltage of 30 keV is used to etch continuous spiral phase plates and fork gratings directly on the tip of the fiber. The phase characteristics of the output beam generated by the fabricated structures measured via an interference experiment confirmed the presence of phase singularity in the output beam. The devices are expected to be promising candidates for all-fiber beam shaping and optical trapping applications.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26365600','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26365600"><span>Secondary batteries with multivalent <span class="hlt">ions</span> for <span class="hlt">energy</span> storage.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Xu, Chengjun; Chen, Yanyi; Shi, Shan; Li, Jia; Kang, Feiyu; Su, Dangsheng</p> <p>2015-09-14</p> <p>The use of electricity generated from clean and renewable sources, such as water, wind, or sunlight, requires efficiently distributed electrical <span class="hlt">energy</span> storage by high-power and high-<span class="hlt">energy</span> secondary batteries using abundant, low-cost materials in sustainable processes. American Science Policy Reports state that the next-generation "beyond-lithium" battery chemistry is one feasible solution for such goals. Here we discover new "multivalent <span class="hlt">ion</span>" battery chemistry beyond lithium battery chemistry. Through theoretic calculation and experiment confirmation, stable thermodynamics and fast kinetics are presented during the storage of multivalent <span class="hlt">ions</span> (Ni(2+), Zn(2+), Mg(2+), Ca(2+), Ba(2+), or La(3+) <span class="hlt">ions</span>) in alpha type manganese dioxide. Apart from zinc <span class="hlt">ion</span> battery, we further use multivalent Ni(2+) <span class="hlt">ion</span> to invent another rechargeable battery, named as nickel <span class="hlt">ion</span> battery for the first time. The nickel <span class="hlt">ion</span> battery generally uses an alpha type manganese dioxide cathode, an electrolyte containing Ni(2+) <span class="hlt">ions</span>, and Ni anode. The nickel <span class="hlt">ion</span> battery delivers a high <span class="hlt">energy</span> density (340 Wh kg(-1), close to lithium <span class="hlt">ion</span> batteries), fast charge ability (1 minute), and long cycle life (over 2200 times).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/873116','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/873116"><span>Low <span class="hlt">energy</span> spread <span class="hlt">ion</span> source with a coaxial magnetic filter</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Leung, Ka-Ngo; Lee, Yung-Hee Yvette</p> <p>2000-01-01</p> <p>Multicusp <span class="hlt">ion</span> sources are capable of producing <span class="hlt">ions</span> with low axial <span class="hlt">energy</span> spread which are necessary in applications such as <span class="hlt">ion</span> projection lithography (IPL) and radioactive <span class="hlt">ion</span> beam production. The addition of a radially extending magnetic filter consisting of a pair of permanent magnets to the multicusp source reduces the <span class="hlt">energy</span> spread considerably due to the improvement in the uniformity of the axial plasma potential distribution in the discharge region. A coaxial multicusp <span class="hlt">ion</span> source designed to further reduce the <span class="hlt">energy</span> spread utilizes a cylindrical magnetic filter to achieve a more uniform axial plasma potential distribution. The coaxial magnetic filter divides the source chamber into an outer annular discharge region in which the plasma is produced and a coaxial inner <span class="hlt">ion</span> extraction region into which the <span class="hlt">ions</span> radially diffuse but from which ionizing electrons are excluded. The <span class="hlt">energy</span> spread in the coaxial source has been measured to be 0.6 eV. Unlike other <span class="hlt">ion</span> sources, the coaxial source has the capability of adjusting the radial plasma potential distribution and therefore the transverse <span class="hlt">ion</span> temperature (or beam emittance).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27979588','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27979588"><span>The 2nd order <span class="hlt">focusing</span> sector field type TOF mass analyzer with an orthogonal <span class="hlt">ion</span> acceleration for LC-IMS-MS.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Poteshin, S S; Zarakovsky, A I</p> <p>2017-03-15</p> <p>Original orthogonal acceleration (OA) electrostatic sector time of flight (TOF) mass analyzer is proposed those allows the second order <span class="hlt">focusing</span> of time of flight by initial <span class="hlt">ions</span> position. Resolving power aberration limit exceeding 80,000 FW (full width mass peak) was shown to be obtainable for mass analyzer with the total length of flight L=133.2cm, the average <span class="hlt">ion</span> <span class="hlt">energy</span> 3700V and the <span class="hlt">ion</span> <span class="hlt">energy</span> spread of 2.5% on the entrance of sector field. Copyright © 2016 Elsevier B.V. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120003591','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120003591"><span>Solar <span class="hlt">Ion</span> Sputter Deposition in the Lunar Regolith: Experimental Simulation Using <span class="hlt">Focused-Ion</span> Beam Techniques</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Christoffersen, R.; Rahman, Z.; Keller, L. P.</p> <p>2012-01-01</p> <p>As regions of the lunar regolith undergo space weathering, their component grains develop compositionally and microstructurally complex outer coatings or "rims" ranging in thickness from a few 10 s to a few 100's of nm. Rims on grains in the finest size fractions (e.g., <20 m) of mature lunar regoliths contain optically-active concentrations of nm size metallic Fe spherules, or "nanophase Fe(sup o)" that redden and attenuate optical reflectance spectral features important in lunar remote sensing. Understanding the mechanisms for rim formation is therefore a key part of connecting the drivers of mineralogical and chemical changes in the lunar regolith with how lunar terrains are observed to become space weathered from a remotely-sensed point of view. As interpreted based on analytical transmission electron microscope (TEM) studies, rims are produced from varying relative contributions from: 1) direct solar <span class="hlt">ion</span> irradiation effects that amorphize or otherwise modify the outer surface of the original host grain, and 2) nanoscale, layer-like, deposition of extrinsic material processed from the surrounding soil. This extrinsic/deposited material is the dominant physical host for nanophase Fe(sup o) in the rims. An important lingering uncertainty is whether this deposited material condensed from regolith components locally vaporized in micrometeorite or larger impacts, or whether it formed as solar wind <span class="hlt">ions</span> sputtered exposed soil and re-deposited the sputtered <span class="hlt">ions</span> on less exposed areas. Deciding which of these mechanisms is dominant, or possibility exclusive, has been hampered because there is an insufficient library of chemical and microstructural "fingerprints" to distinguish deposits produced by the two processes. Experimental sputter deposition / characterization studies relevant to rim formation have particularly lagged since the early post-Apollo experiments of Hapke and others, especially with regard to application of TEM-based characterization techniques. Here</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/5024773','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/5024773"><span>High <span class="hlt">energy</span> heavy <span class="hlt">ions</span>: techniques and applications</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Alonso, J.R.</p> <p>1985-04-01</p> <p>Pioneering work at the Bevalac has given significant insight into the field of relativistic heavy <span class="hlt">ions</span>, both in the development of techniques for acceleration and delivery of these beams as well as in many novel areas of applications. This paper will outline our experiences at the Bevalac; <span class="hlt">ion</span> sources, low velocity acceleration, matching to the synchrotron booster, and beam delivery. Applications discussed will include the observation of new effects in central nuclear collisions, production of beams of exotic short-lived (down to 1 ..mu..sec) isotopes through peripheral nuclear collisions, atomic physics with hydrogen-like uranium <span class="hlt">ions</span>, effects of heavy ''cosmic rays'' on satellite equipment, and an ongoing cancer radiotherapy program with heavy <span class="hlt">ions</span>. 39 refs., 6 figs., 1 tab.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/AD1029705','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/AD1029705"><span>High <span class="hlt">Energy</span> <span class="hlt">Ion</span> Acceleration by Extreme Laser Radiation Pressure</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2017-03-14</p> <p>AFRL-AFOSR-UK-TR-2017-0015 High <span class="hlt">energy</span> <span class="hlt">ion</span> acceleration by extreme laser radiation pressure Paul McKenna UNIVERSITY OF STRATHCLYDE VIZ ROYAL COLLEGE...MM-YYYY)   14-03-2017 2. REPORT TYPE  Final 3. DATES COVERED (From - To)  01 May 2013 to 31 Dec 2016 4. TITLE AND SUBTITLE High <span class="hlt">energy</span> <span class="hlt">ion</span> acceleration...Prescribed by ANSI Std. Z39.18 Page 1 of 1FORM SF 298 3/15/2017https://livelink.ebs.afrl.af.mil/livelink/llisapi.dll 1 HIGH <span class="hlt">ENERGY</span> <span class="hlt">ION</span> ACCELERATION BY</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24985812','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24985812"><span>A low <span class="hlt">energy</span> <span class="hlt">ion</span> source for electron capture spectroscopy.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Tusche, C; Kirschner, J</p> <p>2014-06-01</p> <p>We report on the design of an <span class="hlt">ion</span> source for the production of single and double charged Helium <span class="hlt">ions</span> with kinetic <span class="hlt">energies</span> in the range from 300 eV down to 5 eV. The construction is based on a commercial sputter <span class="hlt">ion</span> gun equipped with a Wien-filter for mass/charge separation. Retardation of the <span class="hlt">ions</span> from the ionizer potential (2 keV) takes place completely within the lens system of the sputter gun, without modification of original parts. For 15 eV He(+) <span class="hlt">ions</span>, the design allows for beam currents up to 30 nA, limited by the space charge repulsion in the beam. For He(2 +) operation, we obtain a beam current of 320 pA at 30 eV, and 46 pA at 5 eV beam <span class="hlt">energy</span>, respectively. In addition, operating parameters can be optimized for a significant contribution of metastable He*(+) (2s) <span class="hlt">ions</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23526167','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23526167"><span>How constant momentum acceleration decouples <span class="hlt">energy</span> and space <span class="hlt">focusing</span> in distance-of-flight and time-of-flight mass spectrometries.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Dennis, Elise A; Gundlach-Graham, Alexander W; Enke, Christie G; Ray, Steven J; Carado, Anthony J; Barinaga, Charles J; Koppenaal, David W; Hieftje, Gary M</p> <p>2013-05-01</p> <p>Resolution in time-of-flight mass spectrometry (TOFMS) is ordinarily limited by the initial <span class="hlt">energy</span> and space distributions within an instrument's acceleration region and by the length of the field-free flight zone. With gaseous <span class="hlt">ion</span> sources, these distributions lead to systematic flight-time errors that cannot be simultaneously corrected with conventional static-field <span class="hlt">ion-focusing</span> devices (i.e., an <span class="hlt">ion</span> mirror). It is known that initial <span class="hlt">energy</span> and space distributions produce non-linearly correlated errors in both <span class="hlt">ion</span> velocity and exit time from the acceleration region. Here we reinvestigate an old acceleration technique, constant-momentum acceleration (CMA), to decouple the effects of initial <span class="hlt">energy</span> and space distributions. In CMA, only initial <span class="hlt">ion</span> <span class="hlt">energies</span> (and not their positions) affect the velocity <span class="hlt">ions</span> gain. Therefore, with CMA, the spatial distribution within the acceleration region can be manipulated without creating <span class="hlt">ion</span>-velocity error. The velocity differences caused by a spread in initial <span class="hlt">ion</span> <span class="hlt">energy</span> can be corrected with an <span class="hlt">ion</span> mirror. We discuss here the use of CMA and independent <span class="hlt">focusing</span> of <span class="hlt">energy</span> and space distributions for both distance-of-flight mass spectrometry (DOFMS) and TOFMS. Performance characteristics of our CMA-DOFMS and CMA-TOFMS instrument, fitted with a glow-discharge ionization source, are described. In CMA-DOFMS, resolving powers (FWHM) of greater than 1000 are achieved for atomic <span class="hlt">ions</span> with a flight length of 285 mm. In CMA-TOFMS, only <span class="hlt">ions</span> over a narrow range of m/z values can be <span class="hlt">energy-focused</span>; however, the technique offers improved resolution for these <span class="hlt">focused</span> <span class="hlt">ions</span>, with resolving powers of greater than 2000 for a separation distance of 350 mm.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010IJTFM.130..331N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010IJTFM.130..331N"><span>Dependence of <span class="hlt">Ion</span> <span class="hlt">Energy</span> on PTFE Surface Modification Effect by Nitrogen <span class="hlt">Ion</span> Irradiation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nakayama, Akihiko; Iwao, Toru; Yumoto, Motoshige</p> <p></p> <p>PTFE (Poly-tetra-fluoro-ethylene) has superior characteristic. But, it has low adhesion force. In order to improve adhesion force, we have studied on surface modification of PTFE by using discharge under high E/n (E:electric field, n:particle density) condition in nitrogen. From the results, it was deduced that <span class="hlt">ion</span> <span class="hlt">energy</span> around 40 eV is effective for polar groups introduction. In addition, treated surface unevenness did not increase compared with the untreated one. Then, we performed nitrogen <span class="hlt">ion</span> irradiation by changing <span class="hlt">ion</span> <span class="hlt">energy</span>. From the results, it is shown that low <span class="hlt">ion</span> <span class="hlt">energy</span> is effective for polar groups introduction. It is also shown that high <span class="hlt">energy</span> <span class="hlt">ion</span> suppresses surface roughness. Thus, we measured surface <span class="hlt">energy</span> and composition of samples irradiated by high and low <span class="hlt">energy</span> <span class="hlt">ions</span>. When <span class="hlt">ion</span> with 30 eV was irradiated for 5 minute and following it <span class="hlt">ion</span> with 1060 eV was irradiated for 10 second, many polar groups were introduced and surface unevenness was kept at the untreatment level. From the results by XPS (X-ray Photoelectron Spectroscopy) analysis and FT-IR (Fourier transform Infrared Spectroscopy) analysis by using the ATR (Attenuated Total Reflection) method, it was confirmed that polar groups of oxygen component and cross-linked structure via nitrogen or carbon was introduced at the surface.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/171306','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/171306"><span>Mixed Waste <span class="hlt">Focus</span> Area: Department of <span class="hlt">Energy</span> complex needs report</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Roach, J.A.</p> <p>1995-11-16</p> <p>The Assistant Secretary for the Office of Environmental Management (EM) at the US Department of <span class="hlt">Energy</span> (DOE) initiated a new approach in August of 1993 to environmental research and technology development. A key feature of this new approach included establishment of the Mixed Waste Characterization, Treatment, and Disposal <span class="hlt">Focus</span> Area (MWFA). The mission of the MWFA is to identify, develop, and implement needed technologies such that the major environmental management problems related to meeting DOE`s commitments for treatment of mixed wastes under the Federal Facility Compliance Act (FFCA), and in accordance with the Land Disposal Restrictions (LDR) of the Resource Conservation and Recovery Act (RCRA), can be addressed, while cost-effectively expending the funding resources. To define the deficiencies or needs of the EM customers, the MWFA analyzed Proposed Site Treatment Plans (PSTPs), as well as other applicable documents, and conducted site visits throughout the summer of 1995. Representatives from the Office of Waste Management (EM-30), the Office of Environmental Restoration (EM-40), and the Office of Facility Transition and Management (EM-60) at each site visited were requested to consult with the <span class="hlt">Focus</span> Area to collaboratively define their technology needs. This report documents the needs, deficiencies, technology gaps, and opportunities for expedited treatment activities that were identified during the site visit process. The defined deficiencies and needs are categorized by waste type, namely Wastewaters, Combustible Organics, Sludges/Soils, Debris/Solids, and Unique Wastes, and will be prioritized based on the relative affect the deficiency has on the DOE Complex.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19780052134&hterms=energy+clean&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Denergy%2Bclean','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19780052134&hterms=energy+clean&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Denergy%2Bclean"><span><span class="hlt">Energy</span> distributions of sputtered copper neutrals and <span class="hlt">ions</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lundquist, T. R.</p> <p>1978-01-01</p> <p>Direct quantitative analysis of surfaces by secondary <span class="hlt">ion</span> mass spectrometry will depend on an understanding of the yield ratio of <span class="hlt">ions</span> to neutrals. This ratio as a function of the <span class="hlt">energy</span> of the sputtered particles has been obtained for a clean polycrystalline copper surface sputtered by 1000-3000 eV Ar(+). The <span class="hlt">energy</span> distributions of both neutral and ionized copper were measured with a retarding potential analyzer using potential modulation differentiation and signal averaging. The maximum for both distributions is identical and occurs near 2.5 eV. The <span class="hlt">energy</span> distributions of neutrals is more sharply peaked than that of the <span class="hlt">ions</span>, presumably as a consequence of more efficient nutralization of slow escaping <span class="hlt">ions</span> by the mobile electrons of copper. The <span class="hlt">ion</span>-neutral ratio is compared with results from various ionization models.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/527672','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/527672"><span><span class="hlt">Ion</span> <span class="hlt">energy</span> distributions in silane-hydrogen plasmas</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Hamers, E.A.G.; Sark, W.G.J.H.M. van; Bezemer, J.; Weg, W.F. van der; Goedheer, W.J.</p> <p>1996-12-31</p> <p>For the first time <span class="hlt">ion</span> <span class="hlt">energy</span> distributions (IED) of different <span class="hlt">ions</span> from silane-hydrogen (SiH{sub 4}-H{sub 2}) RF plasmas are presented, i.e., the distributions of SiH{sub 3}{sup +}, SiH{sub 2}{sup +} and Si{sub 2}H{sub 4}{sup +}. The <span class="hlt">energy</span> distributions of SiH{sub 3}{sup +} and SiH{sub 2}{sup +} <span class="hlt">ions</span> show peaks, which are caused by a charge exchange process in the sheath. A method is presented by which the net charge density in the sheath is determined from the plasma potential and the <span class="hlt">energy</span> positions of the charge exchange peaks. Knowing the net charge density in the sheath and the plasma potential, the sheath thickness can be determined and an estimation of the absolute <span class="hlt">ion</span> fluxes can be made. The flux of <span class="hlt">ions</span> can, at maximum, account for 10% of the observed deposition rate.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19890000267&hterms=negative+energy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dnegative%2Benergy','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19890000267&hterms=negative+energy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dnegative%2Benergy"><span>Variable-<span class="hlt">Energy</span> <span class="hlt">Ion</span> Beams For Modification Of Surfaces</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Chutjian, Ara; Hecht, Michael H.; Orient, Otto J.</p> <p>1989-01-01</p> <p>Beam of low-<span class="hlt">energy</span> negative oxygen <span class="hlt">ions</span> used to grow layer of silicon dioxide on silicon. Beam unique both in purity, contains no molecular oxygen or other charged species, and in low <span class="hlt">energy</span>, which is insufficient to damage silicon by physically displacing atoms. Low-<span class="hlt">energy</span> growth accomplished with help of <span class="hlt">ion</span>-beam apparatus. Directs electrons into crosswise stream of gas, generating stream of negative <span class="hlt">ions</span>. Pair of charged plates separates <span class="hlt">ions</span> from accompanying electrons and diverts <span class="hlt">ion</span> beam to target - silicon substrate. Diameter of beam at target 0.5 to 0.75 cm. Promises useful device to study oxidation of semiconductors and, in certain applications, to replace conventional oxidation processes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19780052134&hterms=clean+energy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dclean%2Benergy','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19780052134&hterms=clean+energy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dclean%2Benergy"><span><span class="hlt">Energy</span> distributions of sputtered copper neutrals and <span class="hlt">ions</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lundquist, T. R.</p> <p>1978-01-01</p> <p>Direct quantitative analysis of surfaces by secondary <span class="hlt">ion</span> mass spectrometry will depend on an understanding of the yield ratio of <span class="hlt">ions</span> to neutrals. This ratio as a function of the <span class="hlt">energy</span> of the sputtered particles has been obtained for a clean polycrystalline copper surface sputtered by 1000-3000 eV Ar(+). The <span class="hlt">energy</span> distributions of both neutral and ionized copper were measured with a retarding potential analyzer using potential modulation differentiation and signal averaging. The maximum for both distributions is identical and occurs near 2.5 eV. The <span class="hlt">energy</span> distributions of neutrals is more sharply peaked than that of the <span class="hlt">ions</span>, presumably as a consequence of more efficient nutralization of slow escaping <span class="hlt">ions</span> by the mobile electrons of copper. The <span class="hlt">ion</span>-neutral ratio is compared with results from various ionization models.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/6752245','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/6752245"><span>Negative <span class="hlt">ions</span> as a source of low <span class="hlt">energy</span> neutral beams</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Fink, J.H.</p> <p>1980-01-01</p> <p>Little consideration has been given to the impact of recent developments in negative <span class="hlt">ion</span> source technology on the design of low <span class="hlt">energy</span> neutral beam injectors. However, negative <span class="hlt">ion</span> sources of improved operating efficiency, higher gas efficiency, and smaller beam divergence will lead to neutral deuterium injectors, operating at less than 100 keV, with better operating efficiencies and more compact layouts than can be obtained from positive <span class="hlt">ion</span> systems.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_15 --> <div id="page_16" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="301"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SPIE.9916E..1NR','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SPIE.9916E..1NR"><span>Special diffractive elements for optical trapping fabricated on optical fiber tips using the <span class="hlt">focused</span> <span class="hlt">ion</span> beam</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rodrigues Ribeiro, R. S.; Guerreiro, A.; Viegas, J.; Jorge, P. A. S.</p> <p>2016-05-01</p> <p>In this work, spiral phase lenses and Fresnel zone lenses for beam tailoring, fabricated on the tip of optical fibers, are reported. The spiral phase lenses allow tailoring the fundamental guided mode, a Gaussian beam, into a Laguerre - Gaussian profile without using additional optical elements. Whereas, the Fresnel lenses are used as <span class="hlt">focusing</span> systems. The lenses are fabricated using <span class="hlt">Focused</span> <span class="hlt">Ion</span> Beam milling, enabling high resolution in the manufacturing process. The output optical intensity profiles matching the numerical simulations are presented and analyzed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26822900','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26822900"><span>Site-selective local fluorination of graphene induced by <span class="hlt">focused</span> <span class="hlt">ion</span> beam irradiation.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Li, Hu; Daukiya, Lakshya; Haldar, Soumyajyoti; Lindblad, Andreas; Sanyal, Biplab; Eriksson, Olle; Aubel, Dominique; Hajjar-Garreau, Samar; Simon, Laurent; Leifer, Klaus</p> <p>2016-01-29</p> <p>The functionalization of graphene remains an important challenge for numerous applications expected by this fascinating material. To keep advantageous properties of graphene after modification or functionalization of its structure, local approaches are a promising road. A novel technique is reported here that allows precise site-selective fluorination of graphene. The basic idea of this approach consists in the local radicalization of graphene by <span class="hlt">focused</span> <span class="hlt">ion</span> beam (FIB) irradiation and simultaneous introduction of XeF2 gas. A systematic series of experiments were carried out to outline the relation between inserted defect creation and the fluorination process. Based on a subsequent X-ray photoelectron spectroscopy (XPS) analysis, a 6-fold increase of the fluorine concentration on graphene under simultaneous irradiation was observed when compared to fluorination under normal conditions. The fluorine atoms are predominately localized at the defects as indicated from scanning tunneling microscopy (STM). The experimental findings are confirmed by density functional theory which predicts a strong increase of the binding <span class="hlt">energy</span> of fluorine atoms when bound to the defect sites. The developed technique allows for local fluorination of graphene without using resists and has potential to be a general enabler of site-selective functionalization of graphene using a wide range of gases.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4731758','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4731758"><span>Site-selective local fluorination of graphene induced by <span class="hlt">focused</span> <span class="hlt">ion</span> beam irradiation</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Li, Hu; Daukiya, Lakshya; Haldar, Soumyajyoti; Lindblad, Andreas; Sanyal, Biplab; Eriksson, Olle; Aubel, Dominique; Hajjar-Garreau, Samar; Simon, Laurent; Leifer, Klaus</p> <p>2016-01-01</p> <p>The functionalization of graphene remains an important challenge for numerous applications expected by this fascinating material. To keep advantageous properties of graphene after modification or functionalization of its structure, local approaches are a promising road. A novel technique is reported here that allows precise site-selective fluorination of graphene. The basic idea of this approach consists in the local radicalization of graphene by <span class="hlt">focused</span> <span class="hlt">ion</span> beam (FIB) irradiation and simultaneous introduction of XeF2 gas. A systematic series of experiments were carried out to outline the relation between inserted defect creation and the fluorination process. Based on a subsequent X-ray photoelectron spectroscopy (XPS) analysis, a 6-fold increase of the fluorine concentration on graphene under simultaneous irradiation was observed when compared to fluorination under normal conditions. The fluorine atoms are predominately localized at the defects as indicated from scanning tunneling microscopy (STM). The experimental findings are confirmed by density functional theory which predicts a strong increase of the binding <span class="hlt">energy</span> of fluorine atoms when bound to the defect sites. The developed technique allows for local fluorination of graphene without using resists and has potential to be a general enabler of site-selective functionalization of graphene using a wide range of gases. PMID:26822900</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1999NIMPB.153..410Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1999NIMPB.153..410Y"><span>Dynamic MC simulation of low-<span class="hlt">energy</span> <span class="hlt">ion</span> implantation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yamamura, Y.</p> <p>1999-06-01</p> <p>In order to investigate the <span class="hlt">ion</span> fluence effect in the depth profiles of the dynamic Monte Carlo code, ACAT-DIFFUSE, is applied to the calculation of depth profiles due to low-<span class="hlt">energy</span> B <span class="hlt">ion</span> implantation, where 1 and 5 keV B <span class="hlt">ions</span> are implanted into an amorphized silicon target. As the <span class="hlt">ion</span> fluence increases, the dopant B atoms are accumulated in solids and the target must be considered as a two-component material composed of the original target atoms and trapped implanted <span class="hlt">ions</span>. This results in the radiation-induced-diffusion and the self-sputtering of trapped implanted <span class="hlt">ions</span>. It is found that the peak locations of the dopant B depth profiles at 1 keV B <span class="hlt">ion</span> bombardment shifted to the surface due to radiation-induced diffusion as <span class="hlt">ion</span> increased and we observe the near-the-surface enhancement in the dopant B depth profiles due to 5 keV B <span class="hlt">ion</span> bombardment. The self-sputtering also becomes important with increasing <span class="hlt">ion</span> fluence. The retention ratios of the implanted B atoms are about 0.89 and 0.94 for 1 and 5 keV B <span class="hlt">ions</span>, respectively, at 3.0 × 10 13 B <span class="hlt">ions</span>/cm 2.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26650068','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26650068"><span>Development of Functional Surfaces on High-Density Polyethylene (HDPE) via Gas-Assisted Etching (GAE) Using <span class="hlt">Focused</span> <span class="hlt">Ion</span> Beams.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sezen, Meltem; Bakan, Feray</p> <p>2015-12-01</p> <p>Irradiation damage, caused by the use of beams in electron and <span class="hlt">ion</span> microscopes, leads to undesired physical/chemical material property changes or uncontrollable modification of structures. Particularly, soft matter such as polymers or biological materials is highly susceptible and very much prone to react on electron/<span class="hlt">ion</span> beam irradiation. Nevertheless, it is possible to turn degradation-dependent physical/chemical changes from negative to positive use when materials are intentionally exposed to beams. Especially, controllable surface modification allows tuning of surface properties for targeted purposes and thus provides the use of ultimate materials and their systems at the micro/nanoscale for creating functional surfaces. In this work, XeF2 and I2 gases were used in the <span class="hlt">focused</span> <span class="hlt">ion</span> beam scanning electron microscope instrument in combination with gallium <span class="hlt">ion</span> etching of high-density polyethylene surfaces with different beam currents and accordingly different gas exposure times resulting at the same <span class="hlt">ion</span> dose to optimize and develop new polymer surface properties and to create functional polymer surfaces. Alterations in the surface morphologies and surface chemistry due to gas-assisted etching-based nanostructuring with various processing parameters were tracked using high-resolution SEM imaging, complementary <span class="hlt">energy</span>-dispersive spectroscopic analyses, and atomic force microscopic investigations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015NatSR...514120X','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015NatSR...514120X"><span>Secondary batteries with multivalent <span class="hlt">ions</span> for <span class="hlt">energy</span> storage</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Xu, Chengjun; Chen, Yanyi; Shi, Shan; Li, Jia; Kang, Feiyu; Su, Dangsheng</p> <p>2015-09-01</p> <p>The use of electricity generated from clean and renewable sources, such as water, wind, or sunlight, requires efficiently distributed electrical <span class="hlt">energy</span> storage by high-power and high-<span class="hlt">energy</span> secondary batteries using abundant, low-cost materials in sustainable processes. American Science Policy Reports state that the next-generation “beyond-lithium” battery chemistry is one feasible solution for such goals. Here we discover new “multivalent ion” battery chemistry beyond lithium battery chemistry. Through theoretic calculation and experiment confirmation, stable thermodynamics and fast kinetics are presented during the storage of multivalent <span class="hlt">ions</span> (Ni2+, Zn2+, Mg2+, Ca2+, Ba2+, or La3+ <span class="hlt">ions</span>) in alpha type manganese dioxide. Apart from zinc <span class="hlt">ion</span> battery, we further use multivalent Ni2+ <span class="hlt">ion</span> to invent another rechargeable battery, named as nickel <span class="hlt">ion</span> battery for the first time. The nickel <span class="hlt">ion</span> battery generally uses an alpha type manganese dioxide cathode, an electrolyte containing Ni2+ <span class="hlt">ions</span>, and Ni anode. The nickel <span class="hlt">ion</span> battery delivers a high <span class="hlt">energy</span> density (340 Wh kg-1, close to lithium <span class="hlt">ion</span> batteries), fast charge ability (1 minute), and long cycle life (over 2200 times).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4568479','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4568479"><span>Secondary batteries with multivalent <span class="hlt">ions</span> for <span class="hlt">energy</span> storage</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Xu, Chengjun; Chen, Yanyi; Shi, Shan; Li, Jia; Kang, Feiyu; Su, Dangsheng</p> <p>2015-01-01</p> <p>The use of electricity generated from clean and renewable sources, such as water, wind, or sunlight, requires efficiently distributed electrical <span class="hlt">energy</span> storage by high-power and high-<span class="hlt">energy</span> secondary batteries using abundant, low-cost materials in sustainable processes. American Science Policy Reports state that the next-generation “beyond-lithium” battery chemistry is one feasible solution for such goals. Here we discover new “multivalent ion” battery chemistry beyond lithium battery chemistry. Through theoretic calculation and experiment confirmation, stable thermodynamics and fast kinetics are presented during the storage of multivalent <span class="hlt">ions</span> (Ni2+, Zn2+, Mg2+, Ca2+, Ba2+, or La3+ <span class="hlt">ions</span>) in alpha type manganese dioxide. Apart from zinc <span class="hlt">ion</span> battery, we further use multivalent Ni2+ <span class="hlt">ion</span> to invent another rechargeable battery, named as nickel <span class="hlt">ion</span> battery for the first time. The nickel <span class="hlt">ion</span> battery generally uses an alpha type manganese dioxide cathode, an electrolyte containing Ni2+ <span class="hlt">ions</span>, and Ni anode. The nickel <span class="hlt">ion</span> battery delivers a high <span class="hlt">energy</span> density (340 Wh kg−1, close to lithium <span class="hlt">ion</span> batteries), fast charge ability (1 minute), and long cycle life (over 2200 times). PMID:26365600</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/7192524','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/7192524"><span>Flute instability of an <span class="hlt">ion-focused</span> slab electron beam in a broad plasma</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Whittum, D.H. , 1-1 Oho, Tsukuba, Ibaraki 305 ); Lampe, M.; Joyce, G.; Slinker, S.P. ); Yu, S.S.; Sharp, W.M. )</p> <p>1992-11-15</p> <p>An intense relativistic electron beam with an elongated cross section, propagating in the <span class="hlt">ion-focused</span> regime through a broad, uniform, unmagnetized plasma, is shown to suffer a transverse flute instability. This instability arises from the electrostatic coupling between the beam and the plasma electrons at the <span class="hlt">ion</span>-channel edge. The instability is found to be absolute and the asymptotic growth of the flute amplitude is computed in the frozen-field'' approximation and the large skin-depth limit. The minimum growth length is shown to be much less than the betatron period, with the consequence that <span class="hlt">focusing</span> is rendered ineffective. It is further shown that growth is much reduced when the beam propagates through a narrow channel where the <span class="hlt">ion</span> density greatly exceeds that of the surrounding plasma. In this limit, a modest spread in betatron frequency produces rapid saturation. The effect of plasma electron collisions is also considered. Results of beam breakup simulations are noted.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013ApPhL.103p3105O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013ApPhL.103p3105O"><span>Micro/nanofabrication of poly(L-lactic acid) using <span class="hlt">focused</span> <span class="hlt">ion</span> beam direct etching</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Oyama, Tomoko Gowa; Hinata, Toru; Nagasawa, Naotsugu; Oshima, Akihiro; Washio, Masakazu; Tagawa, Seiichi; Taguchi, Mitsumasa</p> <p>2013-10-01</p> <p>Micro/nanofabrication of biocompatible and biodegradable poly(L-lactic acid) (PLLA) using <span class="hlt">focused</span> Ga <span class="hlt">ion</span> beam direct etching was evaluated for future bio-device applications. The fabrication performance was determined with different <span class="hlt">ion</span> fluences and fluxes (beam currents), and it was found that the etching speed and fabrication accuracy were affected by irradiation-induced heat. <span class="hlt">Focused</span> <span class="hlt">ion</span> beam (FIB)-irradiated surfaces were analyzed using micro-area X-ray photoelectron spectroscopy. Owing to reactions such as the physical sputtering of atoms and radiation-induced decomposition, PLLA was gradually carbonized with increasing C=C bonds. Controlled micro/nanostructures of PLLA were fabricated with C=C bond-rich surfaces expected to have good cell attachment properties.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013NIMPB.315..356S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013NIMPB.315..356S"><span>An electrostatic quadrupole doublet <span class="hlt">focusing</span> system for MeV heavy <span class="hlt">ions</span> in MeV-SIMS</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Seki, T.; Shitomoto, S.; Nakagawa, S.; Aoki, T.; Matsuo, J.</p> <p>2013-11-01</p> <p>The importance of imaging mass spectrometry (MS) for visualizing the spatial distribution of molecular species in biological tissues and cells is growing. In conventional SIMS with keV-<span class="hlt">energy</span> <span class="hlt">ion</span> beams, elastic collisions occur between projectiles and atoms in constituent molecules. The collisions produce fragments, making acquisition of molecular information difficult. In contrast, MeV-<span class="hlt">energy</span> <span class="hlt">ion</span> beams excite electrons near the surface and enhance the ionization of high-mass molecules, hence, fragment suppressed SIMS spectrum of ionized molecules can be obtained. This work is a further step on our previous report on the successful development of a MeV secondary <span class="hlt">ion</span> mass spectrometry (MeV-SIMS) for biological samples. We have developed an electrostatic quadrupole doublet (EQ doublet) <span class="hlt">focusing</span> system, made of two separate lenses, Q1 and Q2, to <span class="hlt">focus</span> the MeV heavy <span class="hlt">ion</span> beam and reduce measurement time. A primary beam of 6 MeV Cu4+ was <span class="hlt">focused</span> with this EQ doublet. We applied 1120 V to the Q1 lens and 1430 V to the Q2 lens, and the current density increased by a factor of about 60. Using this arrangement, we obtained an MeV-SIMS image of 100 × 100 pixels of cholesterol-OH+ of cerebellum (m/z = 369.3) over a 4 mm × 4 mm field of view, with a pixel size of 40 μm within 5 min, showing that our EQ doublet reduces the measurement time of current imaging by a factor of about 30.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1234540-enhancement-maximum-attainable-ion-energy-radiation-pressure-acceleration-regime-using-guiding-structure','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1234540-enhancement-maximum-attainable-ion-energy-radiation-pressure-acceleration-regime-using-guiding-structure"><span>Enhancement of maximum attainable <span class="hlt">ion</span> <span class="hlt">energy</span> in the radiation pressure acceleration regime using a guiding structure</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Bulanov, S. S.; Esarey, E.; Schroeder, C. B.; ...</p> <p>2015-03-13</p> <p>Radiation Pressure Acceleration is a highly efficient mechanism of laser driven <span class="hlt">ion</span> acceleration, with the laser <span class="hlt">energy</span> almost totally transferrable to the <span class="hlt">ions</span> in the relativistic regime. There is a fundamental limit on the maximum attainable <span class="hlt">ion</span> <span class="hlt">energy</span>, which is determined by the group velocity of the laser. In the case of a tightly <span class="hlt">focused</span> laser pulses, which are utilized to get the highest intensity, another factor limiting the maximum <span class="hlt">ion</span> <span class="hlt">energy</span> comes into play, the transverse expansion of the target. Transverse expansion makes the target transparent for radiation, thus reducing the effectiveness of acceleration. Utilization of an external guidingmore » structure for the accelerating laser pulse may provide a way of compensating for the group velocity and transverse expansion effects.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1234540','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1234540"><span>Enhancement of maximum attainable <span class="hlt">ion</span> <span class="hlt">energy</span> in the radiation pressure acceleration regime using a guiding structure</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Bulanov, S. S.; Esarey, E.; Schroeder, C. B.; Bulanov, S. V.; Esirkepov, T. Zh.; Kando, M.; Pegoraro, F.; Leemans, W. P.</p> <p>2015-03-13</p> <p>Radiation Pressure Acceleration is a highly efficient mechanism of laser driven <span class="hlt">ion</span> acceleration, with the laser <span class="hlt">energy</span> almost totally transferrable to the <span class="hlt">ions</span> in the relativistic regime. There is a fundamental limit on the maximum attainable <span class="hlt">ion</span> <span class="hlt">energy</span>, which is determined by the group velocity of the laser. In the case of a tightly <span class="hlt">focused</span> laser pulses, which are utilized to get the highest intensity, another factor limiting the maximum <span class="hlt">ion</span> <span class="hlt">energy</span> comes into play, the transverse expansion of the target. Transverse expansion makes the target transparent for radiation, thus reducing the effectiveness of acceleration. Utilization of an external guiding structure for the accelerating laser pulse may provide a way of compensating for the group velocity and transverse expansion effects.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ars.usda.gov/research/publications/publication/?seqNo115=260013','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/publication/?seqNo115=260013"><span>Subsurface examination of a foliar biofilm using scanning electron- and <span class="hlt">focused-ion</span>-beam microscopy</span></a></p> <p><a target="_blank" href="https://www.ars.usda.gov/research/publications/find-a-publication/">USDA-ARS?s Scientific Manuscript database</a></p> <p></p> <p></p> <p>The dual beam scanning electron microscope, equipped with both a <span class="hlt">focused</span> <span class="hlt">ion</span>- and scanning electron- beam (FIB SEM) is a novel tool for the exploration of the subsurface structure of biological tissues. The FIB is capable of removing small cross sections to view the subsurface features and may be s...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23548767','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23548767"><span>Synthesis of nanowires via helium and neon <span class="hlt">focused</span> <span class="hlt">ion</span> beam induced deposition with the gas field <span class="hlt">ion</span> microscope.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wu, H M; Stern, L A; Chen, J H; Huth, M; Schwalb, C H; Winhold, M; Porrati, F; Gonzalez, C M; Timilsina, R; Rack, P D</p> <p>2013-05-03</p> <p>The <span class="hlt">ion</span> beam induced nanoscale synthesis of platinum nanowires using the trimethyl (methylcyclopentadienyl)platinum(IV) (MeCpPt(IV)Me3) precursor is investigated using helium and neon <span class="hlt">ion</span> beams in the gas field <span class="hlt">ion</span> microscope. The He(+) beam induced deposition resembles material deposited by electron beam induced deposition with very small platinum nanocrystallites suspended in a carbonaceous matrix. The He(+) deposited material composition was estimated to be 16% Pt in a matrix of amorphous carbon with a large room-temperature resistivity (∼3.5 × 10(4)-2.2 × 10(5) μΩ cm) and temperature-dependent transport behavior consistent with a granular material in the weak intergrain tunnel coupling regime. The Ne(+) deposited material has comparable composition (17%), however a much lower room-temperature resistivity (∼600-3.0 × 10(3) μΩ cm) and temperature-dependent electrical behavior representative of strong intergrain coupling. The Ne(+) deposited nanostructure has larger platinum nanoparticles and is rationalized via Monte Carlo <span class="hlt">ion</span>-solid simulations which show that the neon <span class="hlt">energy</span> density deposited during growth is much larger due to the smaller <span class="hlt">ion</span> range and is dominated by nuclear stopping relative to helium which has a larger range and is dominated by electronic stopping.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA149992','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA149992"><span>New High Resolution Scanning <span class="hlt">Ion</span> Microprobe and <span class="hlt">Focused</span> <span class="hlt">Ion</span> Beam Applications.</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>1984-08-31</p> <p>toward a number of practical applications. Somewhat paradoxically , the structure of intercalated graphite is better known at the atomic level, through x...Timothy R. Fox, Ph.D. Thesis, The University of Chicago, December 1980. 2. <span class="hlt">Energy</span> Loss of Diproton Clusters in Carbon Below the Fermi Velocity. Kin</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1992PhRvA..46.5497P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1992PhRvA..46.5497P"><span>Semiclassical <span class="hlt">energy</span> levels and the corresponding potentials in nonhydrogenic <span class="hlt">ions</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pankratov, P.; Meyer-Ter-Vehn, J.</p> <p>1992-11-01</p> <p>A semiclassical expression is derived for the potential seen by an nl-shell electron in a nonhydrogenic <span class="hlt">ion</span>. Corresponding <span class="hlt">energies</span> Enl are compared with experimental values and with results of self-consistent-field calculations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19870012678','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19870012678"><span><span class="hlt">IONS</span> (ANURADHA): Ionization states of low <span class="hlt">energy</span> cosmic rays</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Biswas, S.; Chakraborti, R.; Cowsik, R.; Durgaprasad, N.; Kajarekar, P. J.; Singh, R. K.; Vahia, M. N.; Yadav, J. S.; Dutt, N.; Goswami, J. N.</p> <p>1987-01-01</p> <p><span class="hlt">IONS</span> (ANURADHA), the experimental payload designed specifically to determine the ionization states, flux, composition, <span class="hlt">energy</span> spectra and arrival directions of low <span class="hlt">energy</span> (10 to 100 MeV/amu) anomalous cosmic ray <span class="hlt">ions</span> of helium to iron in near-Earth space, had a highly successful flight and operation Spacelab-3 mission. The experiment combines the accuracy of a highly sensitive CR-39 nuclear track detector with active components included in the payload to achieve the experimental objectives. Post-flight analysis of detector calibration pieces placed within the payload indicated no measurable changes in detector response due to its exposure in spacelab environment. Nuclear tracks produced by alpha-particles, oxygen group and Fe <span class="hlt">ions</span> in low <span class="hlt">energy</span> anomalous cosmic rays were identified. It is calculated that the main detector has recorded high quality events of about 10,000 alpha-particles and similar number of oxygen group and heavier <span class="hlt">ions</span> of low <span class="hlt">energy</span> cosmic rays.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/674707','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/674707"><span>Production of low axial <span class="hlt">energy</span> spread <span class="hlt">ion</span> beams with multicusp sources</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Lee, Yung -Hee Y.</p> <p>1998-05-01</p> <p>Multicusp <span class="hlt">ion</span> sources are capable of producing <span class="hlt">ions</span> with low axial <span class="hlt">energy</span> spread which are necessary in applications such as: <span class="hlt">ion</span> projection lithography (IPL) and <span class="hlt">focused</span> <span class="hlt">ion</span> beams for the next generation lithographic tools and nuclear science experiments such as radioactive <span class="hlt">ion</span> beam production. The axial <span class="hlt">ion</span> <span class="hlt">energy</span> spread for multicusp source is approximately 6 eV which is too large for IPL and radioactive <span class="hlt">ion</span> beam applications. The addition of a magnetic filter which consists of a pair of permanent magnets to the multicusp source reduces the <span class="hlt">energy</span> spread considerably. The reduction is due to the improvement in the uniformity of the axial plasma potential distribution in the discharge region. Axial <span class="hlt">ion</span> <span class="hlt">energy</span> spread of the filament driven <span class="hlt">ion</span> source has been measured using three different techniques. In all cases, it was found to be less than 2 eV. <span class="hlt">Energy</span> spread of the radio frequency (RF) driven source has also been explored, and it was found to be less than 3 eV with the proper RF-shielding. A new multicusp source configuration has been designed and constructed to further reduce the <span class="hlt">energy</span> spread. To achieve a more uniform axial plasma potential distribution, a cylindrical magnetic filter has been designed and constructed for a 2-cm-diameter source. This new source configuration, the co-axial source, is new in its kind. The <span class="hlt">energy</span> spread in this source has been measured to be a record low of 0.6 eV. Because of the novelty of this device, some plasma parameters inside the source have been studied. Langmuir probe has been used to measure the plasma potential, the electron temperature and the density distribution.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/7273318','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/7273318"><span>BNL high <span class="hlt">energy</span> heavy <span class="hlt">ion</span> experiments</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Miake, Yasuo.</p> <p>1989-01-01</p> <p>This paper discusses the measurement of particle spectra and correlations with good particle identification and with various triggers, such as selection of charged multiplicity, neutral <span class="hlt">energy</span> and forward <span class="hlt">energy</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014PhDT.......249S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014PhDT.......249S"><span><span class="hlt">Energy</span> loss of <span class="hlt">ions</span> implanted in MOS dielectric films</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shyam, Radhey</p> <p></p> <p><span class="hlt">Energy</span> loss measurements of <span class="hlt">ions</span> in the low kinetic <span class="hlt">energy</span> regime have been made on as-grown SiO2(170-190nm) targets. Singly charged Na + <span class="hlt">ions</span> with kinetic <span class="hlt">energies</span> of 2-5 keV and highly charged <span class="hlt">ions</span> Ar +Q (Q=4, 8 and 11) with a kinetic <span class="hlt">energy</span> of 1 keV were used. Excitations produced by the <span class="hlt">ion</span> <span class="hlt">energy</span> loss in the oxides were captured by encapsulating the irradiated oxide under a top metallic contact. The resulting Metal-Oxide-Semiconductor (MOS) devices were probed with Capacitance-Voltage (C V) measurements and extracted the flatband voltages from the C-V curves. The C-V results for singly charged <span class="hlt">ion</span> experiments reveal that the changes in the flatband voltage and slope for implanted devices relative to the pristine devices can be used to delineate effects due to implanted <span class="hlt">ions</span> only and <span class="hlt">ion</span> induced damage. The data shows that the flatband voltage shifts and C-V slope changes are <span class="hlt">energy</span> dependent. The observed changes in flatband voltage which are greater than those predicted by calculations scaled for the <span class="hlt">ion</span> dose and implantation range (SRIM). These results, however, are consistent with a columnar recombination model, where electron-hole pairs are created due to the <span class="hlt">energy</span> deposited by the implanted <span class="hlt">ions</span> within the oxide. The remaining holes left after recombination losses are diffused through the oxide at the room temperature and remain present as trapped charges. Comparison of the data with the total number of the holes generated gives a fractional yield of 0.0124 which is of the same order as prior published high <span class="hlt">energy</span> irradiation experiments. Additionally, the interface trap density, extracted from high and low frequency C-V measurements is observed to increase by one order of magnitude over our incident beam <span class="hlt">energy</span>. These results confirm that dose- and kinetic <span class="hlt">energy</span> -dependent effects can be recorded for singly charged <span class="hlt">ion</span> irradiation on oxides using this method. Highly charged <span class="hlt">ion</span> results also confirm that dose as well as and charge-dependent effects can</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_16 --> <div id="page_17" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="321"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22254148','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22254148"><span>A compact, versatile low-<span class="hlt">energy</span> electron beam <span class="hlt">ion</span> source</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Zschornack, G.; König, J.; Schmidt, M.; Thorn, A.</p> <p>2014-02-15</p> <p>A new compact Electron Beam <span class="hlt">Ion</span> Source, the Dresden EBIT-LE, is introduced as an <span class="hlt">ion</span> source working at low electron beam <span class="hlt">energies</span>. The EBIT-LE operates at an electron <span class="hlt">energy</span> ranging from 100 eV to some keV and can easily be modified to an EBIT also working at higher electron beam <span class="hlt">energies</span> of up to 15 keV. We show that, depending on the electron beam <span class="hlt">energy</span>, electron beam currents from a few mA in the low-<span class="hlt">energy</span> regime up to about 40 mA in the high-<span class="hlt">energy</span> regime are possible. Technical solutions as well as first experimental results of the EBIT-LE are presented. In <span class="hlt">ion</span> extraction experiments, a stable production of low and intermediate charged <span class="hlt">ions</span> at electron beam <span class="hlt">energies</span> below 2 keV is demonstrated. Furthermore, X-ray spectroscopy measurements confirm the possibility of using the machine as a source of X-rays from <span class="hlt">ions</span> excited at low electron <span class="hlt">energies</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24593602','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24593602"><span>A compact, versatile low-<span class="hlt">energy</span> electron beam <span class="hlt">ion</span> source.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zschornack, G; König, J; Schmidt, M; Thorn, A</p> <p>2014-02-01</p> <p>A new compact Electron Beam <span class="hlt">Ion</span> Source, the Dresden EBIT-LE, is introduced as an <span class="hlt">ion</span> source working at low electron beam <span class="hlt">energies</span>. The EBIT-LE operates at an electron <span class="hlt">energy</span> ranging from 100 eV to some keV and can easily be modified to an EBIT also working at higher electron beam <span class="hlt">energies</span> of up to 15 keV. We show that, depending on the electron beam <span class="hlt">energy</span>, electron beam currents from a few mA in the low-<span class="hlt">energy</span> regime up to about 40 mA in the high-<span class="hlt">energy</span> regime are possible. Technical solutions as well as first experimental results of the EBIT-LE are presented. In <span class="hlt">ion</span> extraction experiments, a stable production of low and intermediate charged <span class="hlt">ions</span> at electron beam <span class="hlt">energies</span> below 2 keV is demonstrated. Furthermore, X-ray spectroscopy measurements confirm the possibility of using the machine as a source of X-rays from <span class="hlt">ions</span> excited at low electron <span class="hlt">energies</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/6268436','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/6268436"><span>Measurement of parallel <span class="hlt">ion</span> <span class="hlt">energy</span> distribution function in PISCES plasma</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Tynan, G.R.; Goebel, D.M.; Conn, R.W.</p> <p>1987-08-01</p> <p>The PISCES facility is used to conduct controlled plasma-surface interaction experiments. Plasma parameters typical of those found in the edge plasmas of major fusion confinement experiments are produced. In this work, the <span class="hlt">energy</span> distribution of the <span class="hlt">ion</span> flux incident on a material surface is measured using a gridded <span class="hlt">energy</span> analyzer in place of a material sample. The full width at half maximum <span class="hlt">energy</span> distribution of the <span class="hlt">ion</span> flux is found to vary from 10 eV to 30 eV both hydrogen and deuterium plasmas. Helium plasmas have a much lower FWHM <span class="hlt">energy</span> spread than hydrogen and deuterium plasmas. The FWHM <span class="hlt">ion</span> <span class="hlt">energy</span> spread is found to be linearly related to the electron temperature. The most probable <span class="hlt">ion</span> <span class="hlt">energy</span> is found to be linearly related to the bias applied to the <span class="hlt">energy</span> analyzer. Other plasma parameters have a weak influence upon the <span class="hlt">energy</span> distribution of the <span class="hlt">ion</span> flux. Two possible physical mechanisms for producing the observed results are introduced and suggestions for further work are made. The impact of the reported measurements on the materials experiments conducted in the PISCES facility are discussed and recommendations for future experiments are made. 11 refs., 13 figs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/5390087','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/5390087"><span>Super high <span class="hlt">energy</span> heavy <span class="hlt">ion</span> collisions</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Geist, W.M.</p> <p>1987-12-01</p> <p>Basic theoretical ideas on a phase transition to a plasma of free quarks and gluons in heavy <span class="hlt">ion</span> collisions are outlined. First results from experiments with oxygen beams at 14.5 GeV/c/N (BNL), 60 and 200 GeV/c/N (CERN) are discussed. 30 refs., 9 figs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22053905','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22053905"><span>Emittance estimation by an <span class="hlt">ion</span> optical element with variable <span class="hlt">focusing</span> strength and a viewing target</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Maeder, J.; Rossbach, J.; Maimone, F.; Spaedtke, P.; Tinschert, K.; Lang, R.; Sun, L.; Cao, Y.; Zhao, H.</p> <p>2010-02-15</p> <p>The emittance of an extracted <span class="hlt">ion</span> beam can be estimated to first order by a series of three linear independent profile measurements. This estimation is restricted to the evaluation of an upper limit of the emittance value for a homogeneous, nonfilamented beam. The beam is assumed to be round, respectively elliptical, without any structure of the intensity distribution, no space charge has been assumed for the drifting beam, and the optics is assumed to be linear. Instead of using three different drift sections, a linear <span class="hlt">focusing</span> element with three different <span class="hlt">focusing</span> strengths can be used. Plotting the beam radius as function of <span class="hlt">focusing</span> strength, three independent solutions can be used to calculate the Twiss parameters {alpha}, {beta}, and {gamma} and furthermore the emittance {epsilon}. Here we describe the measurements which have been performed with the SECRAL <span class="hlt">ion</span> source at Institute of Modern Physics Lanzhou.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014PhPl...21c3504P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014PhPl...21c3504P"><span>Dynamic Faraday cup signal analysis and the measurement of energetic <span class="hlt">ions</span> emitted by plasma <span class="hlt">focus</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pestehe, S. J.; Mohammadnejad, M.; Irani Mobaraki, S.</p> <p>2014-03-01</p> <p>A theoretical model is developed to study the signals from a typical dynamic Faraday cup, and using this model the output signals from this structure are obtained. A detailed discussion on the signal structure, using different experimental conditions, is also given. It is argued that there is a possibility of determining the total charge of the generated <span class="hlt">ion</span> pulse, the maximum velocity of the <span class="hlt">ions</span>, <span class="hlt">ion</span> velocity distribution, and the number of <span class="hlt">ion</span> species for mixed working gases, under certain conditions. In addition, the number of different ionization stages, the number of different pinches in one shot, and the number of different existing acceleration mechanisms can also be determined provided that the mentioned conditions being satisfied. An experiment is carried out on the Filippov type 90 kJ Sahand plasma <span class="hlt">focus</span> using Ar as the working gas at the pressure of 0.25 Torr. The data from a typical shot are fitted to a signal from the model and the total charge of the related energetic <span class="hlt">ion</span> pulse is deduced using the values of the obtained fit parameters. Good agreement between the obtained amount of the total charge and the values obtained during other experiments on the same plasma <span class="hlt">focus</span> device is observed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21825787','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21825787"><span>Controlled fabrication of nanopores using a direct <span class="hlt">focused</span> <span class="hlt">ion</span> beam approach with back face particle detection.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Patterson, N; Adams, D P; Hodges, V C; Vasile, M J; Michael, J R; Kotula, P G</p> <p>2008-06-11</p> <p>We report a direct, <span class="hlt">ion</span> drilling technique that enables the reproducible fabrication and placement of nanopores in membranes of different thickness. Using a 30 keV <span class="hlt">focused</span> Ga <span class="hlt">ion</span> beam column combined with an in situ, back face, multi-channelplate particle detector, nanopores are sputtered in Si(3)N(4) and W/Si(3)N(4) to have diameters as small as 12 nm. Transmission electron microscopy shows that <span class="hlt">focused</span> <span class="hlt">ion</span> beam-drilled holes are near-conical with the diameter decreasing from entry to exit side. By monitoring the detector signal during <span class="hlt">ion</span> exposure, the drilled hole width can be minimized such that the exit-side diameter is smaller than the full width at half-maximum of the nominally Gaussian-shaped incident beam. Judicious choice of the beam defining aperture combined with back face particle detection allows for reproducible exit-side hole diameters between 18 and 100 nm. The nanopore direct drilling technique does not require potentially damaging broad area exposure to tailor hole sizes. Moreover, this technique successfully achieves breakthrough despite the effects of varying membrane thickness, redeposition, polycrystalline grain structure, and slight <span class="hlt">ion</span> beam current fluctuations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22251981','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22251981"><span>Dynamic Faraday cup signal analysis and the measurement of energetic <span class="hlt">ions</span> emitted by plasma <span class="hlt">focus</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Pestehe, S. J. Mohammadnejad, M.; Irani Mobaraki, S.</p> <p>2014-03-15</p> <p>A theoretical model is developed to study the signals from a typical dynamic Faraday cup, and using this model the output signals from this structure are obtained. A detailed discussion on the signal structure, using different experimental conditions, is also given. It is argued that there is a possibility of determining the total charge of the generated <span class="hlt">ion</span> pulse, the maximum velocity of the <span class="hlt">ions</span>, <span class="hlt">ion</span> velocity distribution, and the number of <span class="hlt">ion</span> species for mixed working gases, under certain conditions. In addition, the number of different ionization stages, the number of different pinches in one shot, and the number of different existing acceleration mechanisms can also be determined provided that the mentioned conditions being satisfied. An experiment is carried out on the Filippov type 90 kJ Sahand plasma <span class="hlt">focus</span> using Ar as the working gas at the pressure of 0.25 Torr. The data from a typical shot are fitted to a signal from the model and the total charge of the related energetic <span class="hlt">ion</span> pulse is deduced using the values of the obtained fit parameters. Good agreement between the obtained amount of the total charge and the values obtained during other experiments on the same plasma <span class="hlt">focus</span> device is observed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/864205','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/864205"><span>Electron <span class="hlt">energy</span> recovery system for negative <span class="hlt">ion</span> sources</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Dagenhart, William K.; Stirling, William L.</p> <p>1982-01-01</p> <p>An electron <span class="hlt">energy</span> recovery system for negative <span class="hlt">ion</span> sources is provided. The system, employs crossed electric and magnetic fields to separate the electrons from <span class="hlt">ions</span> as they are extracted from a negative <span class="hlt">ion</span> source plasma generator and before the <span class="hlt">ions</span> are accelerated to their full kinetic <span class="hlt">energy</span>. With the electric and magnetic fields oriented 90.degree. to each other, the electrons are separated from the plasma and remain at approximately the electrical potential of the generator in which they were generated. The electrons migrate from the <span class="hlt">ion</span> beam path in a precessing motion out of the <span class="hlt">ion</span> accelerating field region into an electron recovery region provided by a specially designed electron collector electrode. The electron collector electrode is uniformly spaced from a surface of the <span class="hlt">ion</span> generator which is transverse to the direction of migration of the electrons and the two surfaces are contoured in a matching relationship which departs from a planar configuration to provide an electric field component in the recovery region which is parallel to the magnetic field thereby forcing the electrons to be directed into and collected by the electron collector electrode. The collector electrode is maintained at a potential slightly positive with respect to the <span class="hlt">ion</span> generator so that the electrons are collected at a small fraction of the full accelerating supply voltage <span class="hlt">energy</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19910018810','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19910018810"><span>Low <span class="hlt">energy</span> sputtering of cobalt by cesium <span class="hlt">ions</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Handoo, A.; Ray, Pradosh K.</p> <p>1989-01-01</p> <p>An experimental facility to investigate low <span class="hlt">energy</span> (less than 500 eV) sputtering of metal surfaces with <span class="hlt">ions</span> produced by an <span class="hlt">ion</span> gun is described. Results are reported on the sputtering yield of cobalt by cesium <span class="hlt">ions</span> in the 100 to 500 eV <span class="hlt">energy</span> range at a pressure of 1 times 10(exp -6) Torr. The target was electroplated on a copper substrate. The sputtered atoms were collected on a cobalt foil surrounding the target. Co-57 was used as a tracer to determine the sputtering yield.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20080041055','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20080041055"><span>Model for Cumulative Solar Heavy <span class="hlt">Ion</span> <span class="hlt">Energy</span> and LET Spectra</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Xapsos, Mike; Barth, Janet; Stauffer, Craig; Jordan, Tom; Mewaldt, Richard</p> <p>2007-01-01</p> <p>A probabilistic model of cumulative solar heavy <span class="hlt">ion</span> <span class="hlt">energy</span> and lineary <span class="hlt">energy</span> transfer (LET) spectra is developed for spacecraft design applications. Spectra are given as a function of confidence level, mission time period during solar maximum and shielding thickness. It is shown that long-term solar heavy <span class="hlt">ion</span> fluxes exceed galactic cosmic ray fluxes during solar maximum for shielding levels of interest. Cumulative solar heavy <span class="hlt">ion</span> fluences should therefore be accounted for in single event effects rate calculations and in the planning of space missions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28653242','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28653242"><span>Variables Affecting the Internal <span class="hlt">Energy</span> of Peptide <span class="hlt">Ions</span> During Separation by Differential <span class="hlt">Ion</span> Mobility Spectrometry.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Santiago, Brandon G; Campbell, Matthew T; Glish, Gary L</p> <p>2017-06-26</p> <p>Differential <span class="hlt">ion</span> mobility spectrometry (DIMS) devices separate <span class="hlt">ions</span> on the basis of differences in <span class="hlt">ion</span> mobility in low and high electric fields, and can be used as a stand-alone analytical method or as a separation step before further analysis. As with other <span class="hlt">ion</span> mobility separation techniques, the ability of DIMS separations to retain the structural characteristics of analytes has been of concern. For DIMS separations, this potential loss of <span class="hlt">ion</span> structure originates from the fact that the separations occur at atmospheric pressure and the <span class="hlt">ions</span>, during their transit through the device, undergo repeated collisions with the DIMS carrier gas while being accelerated by the electric field. These collisions have the ability to increase the internal <span class="hlt">energy</span> distribution of the <span class="hlt">ions</span>, which can cause isomerization or fragmentation. The increase in internal <span class="hlt">energy</span> of the <span class="hlt">ions</span> is based on a number of variables, including the dispersion field and characteristics of the carrier gas such as temperature and composition. The effects of these parameters on the intra-DIMS fragmentation of multiply charged <span class="hlt">ions</span> of the peptides bradykinin (RPPGFSPFR) and GLISH are discussed herein. Furthermore, similarities and differences in the internal <span class="hlt">energy</span> deposition that occur during collisional activation in tandem mass spectrometry experiments are discussed, as the fragmentation pathways accessed by both are similar. Graphical Abstract ᅟ.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JASMS..28.2160S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JASMS..28.2160S"><span>Variables Affecting the Internal <span class="hlt">Energy</span> of Peptide <span class="hlt">Ions</span> During Separation by Differential <span class="hlt">Ion</span> Mobility Spectrometry</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Santiago, Brandon G.; Campbell, Matthew T.; Glish, Gary L.</p> <p>2017-10-01</p> <p>Differential <span class="hlt">ion</span> mobility spectrometry (DIMS) devices separate <span class="hlt">ions</span> on the basis of differences in <span class="hlt">ion</span> mobility in low and high electric fields, and can be used as a stand-alone analytical method or as a separation step before further analysis. As with other <span class="hlt">ion</span> mobility separation techniques, the ability of DIMS separations to retain the structural characteristics of analytes has been of concern. For DIMS separations, this potential loss of <span class="hlt">ion</span> structure originates from the fact that the separations occur at atmospheric pressure and the <span class="hlt">ions</span>, during their transit through the device, undergo repeated collisions with the DIMS carrier gas while being accelerated by the electric field. These collisions have the ability to increase the internal <span class="hlt">energy</span> distribution of the <span class="hlt">ions</span>, which can cause isomerization or fragmentation. The increase in internal <span class="hlt">energy</span> of the <span class="hlt">ions</span> is based on a number of variables, including the dispersion field and characteristics of the carrier gas such as temperature and composition. The effects of these parameters on the intra-DIMS fragmentation of multiply charged <span class="hlt">ions</span> of the peptides bradykinin (RPPGFSPFR) and GLISH are discussed herein. Furthermore, similarities and differences in the internal <span class="hlt">energy</span> deposition that occur during collisional activation in tandem mass spectrometry experiments are discussed, as the fragmentation pathways accessed by both are similar. [Figure not available: see fulltext.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19990045892&hterms=springer&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26Nf%3DPublication-Date%257CBTWN%2B19970101%2B20031231%26N%3D0%26No%3D50%26Ntt%3Dspringer','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19990045892&hterms=springer&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26Nf%3DPublication-Date%257CBTWN%2B19970101%2B20031231%26N%3D0%26No%3D50%26Ntt%3Dspringer"><span>Radial Distribution of Electron Spectra from High-<span class="hlt">Energy</span> <span class="hlt">Ions</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Cucinotta, Francis A.; Katz, Robert; Wilson, John W.</p> <p>1998-01-01</p> <p>The average track model describes the response of physical and biological systems using radial dose distribution as the key physical descriptor. We report on an extension of this model to describe the average distribution of electron spectra as a function of radial distance from an <span class="hlt">ion</span>. We present calculations of these spectra for <span class="hlt">ions</span> of identical linear <span class="hlt">energy</span> transfer (LET), but dissimilar charge and velocity to evaluate the differences in electron spectra from these <span class="hlt">ions</span>. To illustrate the usefulness of the radial electron spectra for describing effects that are not described by electron dose, we consider the evaluation of the indirect events in microdosimetric distributions for <span class="hlt">ions</span>. We show that folding our average electron spectra model with experimentally determined frequency distributions for photons or electrons provides a good representation of radial event spectra from high-<span class="hlt">energy</span> <span class="hlt">ions</span> in 0.5-2 micrometer sites.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19990045892&hterms=Electron+Transfer&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3DElectron%2BTransfer','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19990045892&hterms=Electron+Transfer&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3DElectron%2BTransfer"><span>Radial Distribution of Electron Spectra from High-<span class="hlt">Energy</span> <span class="hlt">Ions</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Cucinotta, Francis A.; Katz, Robert; Wilson, John W.</p> <p>1998-01-01</p> <p>The average track model describes the response of physical and biological systems using radial dose distribution as the key physical descriptor. We report on an extension of this model to describe the average distribution of electron spectra as a function of radial distance from an <span class="hlt">ion</span>. We present calculations of these spectra for <span class="hlt">ions</span> of identical linear <span class="hlt">energy</span> transfer (LET), but dissimilar charge and velocity to evaluate the differences in electron spectra from these <span class="hlt">ions</span>. To illustrate the usefulness of the radial electron spectra for describing effects that are not described by electron dose, we consider the evaluation of the indirect events in microdosimetric distributions for <span class="hlt">ions</span>. We show that folding our average electron spectra model with experimentally determined frequency distributions for photons or electrons provides a good representation of radial event spectra from high-<span class="hlt">energy</span> <span class="hlt">ions</span> in 0.5-2 micrometer sites.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011JPhD...44g5205D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011JPhD...44g5205D"><span>Retarding field <span class="hlt">energy</span> analyser <span class="hlt">ion</span> current calibration and transmission</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Denieffe, K.; Mahony, C. M. O.; Maguire, P. D.; Gahan, D.; Hopkins, M. B.</p> <p>2011-02-01</p> <p>Accurate measurement of <span class="hlt">ion</span> current density and <span class="hlt">ion</span> <span class="hlt">energy</span> distributions (IEDs) is often critical for plasma processes in both industrial and research settings. Retarding field <span class="hlt">energy</span> analysers (RFEAs) have been used to measure IEDs because they are considered accurate, relatively simple and cost effective. However, their usage for critical measurement of <span class="hlt">ion</span> current density is less common due to difficulties in estimating the proportion of incident <span class="hlt">ion</span> current reaching the current collector through the RFEA retarding grids. In this paper an RFEA has been calibrated to measure <span class="hlt">ion</span> current density from an <span class="hlt">ion</span> beam at pressures ranging from 0.5 to 50.0 mTorr. A unique method is presented where the currents generated at each of the retarding grids and the RFEA upper face are measured separately, allowing the reduction in <span class="hlt">ion</span> current to be monitored and accounted for at each stage of <span class="hlt">ion</span> transit to the collector. From these I-V measurements a physical model is described. Subsequently, a mathematical description is extracted which includes parameters to account for grid transmissions, upper face secondary electron emission and collisionality. Pressure-dependent calibration factors can be calculated from least mean square best fits of the collector current to the model allowing quantitative measurement of <span class="hlt">ion</span> current density.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/940478','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/940478"><span>Applied <span class="hlt">Focused</span> <span class="hlt">Ion</span> Beam Techniques for Sample Preparation of Astromaterials for Integrated Nano-Analysis</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Graham, G A; Teslich, N E; Kearsley, A T; Stadermann, F J; Stroud, R M; Dai, Z R; Ishii, H A; Hutcheon, I D; Bajt, S; Snead, C J; Weber, P K; Bradley, J P</p> <p>2007-02-20</p> <p>Sample preparation is always a critical step in study of micrometer sized astromaterials available for study in the laboratory, whether their subsequent analysis is by electron microscopy or secondary <span class="hlt">ion</span> mass spectrometry. A <span class="hlt">focused</span> beam of gallium <span class="hlt">ions</span> has been used to prepare electron transparent sections from an interplanetary dust particle, as part of an integrated analysis protocol to maximize the mineralogical, elemental, isotopic and spectroscopic information extracted from one individual particle. In addition, <span class="hlt">focused</span> <span class="hlt">ion</span> beam techniques have been employed to extract cometary residue preserved on the rims and walls of micro-craters in 1100 series aluminum foils that were wrapped around the sample tray assembly on the Stardust cometary sample collector. Non-ideal surface geometries and inconveniently located regions of interest required creative solutions. These include support pillar construction and relocation of a significant portion of sample to access a region of interest. Serial sectioning, in a manner similar to ultramicrotomy, is a significant development and further demonstrates the unique capabilities of <span class="hlt">focused</span> <span class="hlt">ion</span> beam microscopy for sample preparation of astromaterials.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008M%26PS...43..561G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008M%26PS...43..561G"><span>Applied <span class="hlt">focused</span> <span class="hlt">ion</span> beam techniques for sample preparation of astromaterials for integrated nanoanalysis</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Graham, Giles A.; Teslich, Nick E.; Kearsley, Anton T.; Stadermann, Frank J.; Stroud, Rhonda M.; Dai, Zurong; Ishii, Hope A.; Hutcheon, Ian D.; Bajt, SašA.; Snead, Christopher J.; Weber, Peter K.; Bradley, John P.</p> <p>2008-03-01</p> <p>Sample preparation is always a critical step in the study of micrometer-sized astromaterials available for study in the laboratory, whether their subsequent analysis is by electron microscopy or secondary <span class="hlt">ion</span> mass spectrometry. A <span class="hlt">focused</span> beam of gallium <span class="hlt">ions</span> has been used to prepare electron transparent sections from an interplanetary dust particle (IDP), as part of an integrated analysis protocol to maximize the mineralogical, elemental, isotopic, and spectroscopic information extracted from one individual particle. In addition, <span class="hlt">focused</span> <span class="hlt">ion</span> beam (FIB) techniques have been employed to extract cometary residue preserved on the rims and walls of microcraters in 1100 series aluminum foils that were wrapped around the sample tray assembly on the Stardust cometary sample collector. Non-ideal surface geometries and inconveniently located regions of interest required creative solutions. These include support pillar construction and relocation of a significant portion of sample to access a region of interest. Serial sectioning, in a manner similar to ultramicrotomy, is a significant development and further demonstrates the unique capabilities of <span class="hlt">focused</span> <span class="hlt">ion</span> beam microscopy for sample preparation of astromaterials.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011PhRvS..14h2801Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011PhRvS..14h2801Z"><span>Back-streaming <span class="hlt">ion</span> emission and beam <span class="hlt">focusing</span> on high power linear induction accelerator</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhu, Jun; Chen, Nan; Yu, Haijun; Jiang, Xiaoguo; Wang, Yuan; Dai, Wenhua; Gao, Feng; Wang, Minhong; Li, Jin; Shi, Jinshui</p> <p>2011-08-01</p> <p><span class="hlt">Ions</span> released from target surfaces by impact of a high intensity and current electron beam can be accelerated and trapped in the beam potential, and further destroy the beam <span class="hlt">focus</span>. By solving the 2D Poisson equation, we found that the charge neutralization factor of the <span class="hlt">ions</span> to the beam under space charge limited condition is 1/3, which is large enough to disrupt the spot size. Therefore, the <span class="hlt">ion</span> emission at the target in a single-pulse beam/target system must be source limited. Experimental results on the time-resolved beam profile measurement have also proven that. A new <span class="hlt">focus</span> scheme is proposed in this paper to <span class="hlt">focus</span> the beam to a small spot size with the existence of back-streaming <span class="hlt">ions</span>. We found that the focal spot will move upstream as the charge neutralization factor increases. By comparing the theoretical and experimental focal length of the Dragon-I accelerator (20 MeV, 2.5 kA, 60 ns flattop), we found that the average neutralization factor is about 5% in the beam/target system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16853872','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16853872"><span>Ultralow <span class="hlt">energy</span> <span class="hlt">ion</span> beam surface modification of low density polyethylene.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Shenton, Martyn J; Bradley, James W; van den Berg, Jaap A; Armour, David G; Stevens, Gary C</p> <p>2005-12-01</p> <p>Ultralow <span class="hlt">energy</span> Ar+ and O+ <span class="hlt">ion</span> beam irradiation of low density polyethylene has been carried out under controlled dose and monoenergetic conditions. XPS of Ar+-treated surfaces exposed to ambient atmosphere show that the bombardment of 50 eV Ar+ <span class="hlt">ions</span> at a total dose of 10(16) cm(-2) gives rise to very reactive surfaces with oxygen incorporation at about 50% of the species present in the upper surface layer. Using pure O+ beam irradiation, comparatively low O incorporation is achieved without exposure to atmosphere (approximately 13% O in the upper surface). However, if the surface is activated by Ar+ pretreatment, then large oxygen contents can be achieved under subsequent O+ irradiation (up to 48% O). The results show that for very low <span class="hlt">energy</span> (20 eV) oxygen <span class="hlt">ions</span> there is a dose threshold of about 5 x 10(15) cm(-2) before surface oxygen incorporation is observed. It appears that, for both Ar+ and O+ <span class="hlt">ions</span> in this regime, the degree of surface modification is only very weakly dependent on the <span class="hlt">ion</span> <span class="hlt">energy</span>. The results suggest that in the nonequilibrium plasma treatment of polymers, where the <span class="hlt">ion</span> flux is typically 10(18) m(-2) s(-1), low <span class="hlt">energy</span> <span class="hlt">ions</span> (<50 eV) may be responsible for surface chemical modification.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_17 --> <div id="page_18" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="341"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1984PhDT........82D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1984PhDT........82D"><span><span class="hlt">Ion</span>-Molecule Reaction Studies at Low <span class="hlt">Energies</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dheandhanoo, Seksan</p> <p></p> <p>A variable temperature drift tube-mass spectrometer apparatus has been used to determine the forward rate coefficients for the association reactions of NO('+) <span class="hlt">ions</span> with N(,2) and CO(,2), O(,2)('+) with N(,2), N('+) and N(,2)('+) with N(,2), and CH(,5)('+) and C(,2)H(,5)('+) with CH(,4) as a function of gas temperature. The measured rate coefficients were fitted to power laws of the form k(,+) = C(T/300)(' -x), where the exponents ranged from 2.0 to 4.3, i.e. a strong temperature dependence was observed in most of these three-body (clustering) reactions. The equilibrium constants K = k(,+)/k(,-) for the association reactions of CH(,5)('+) and C(,2)H(,5)('+) with CH(,4) were also measured as a function of gas temperature, allowing the reverse rate coefficients k(,-) for these two reactions to be determined. In a second set of measurements, rate coefficients for several two-body <span class="hlt">ion</span>-molecule reactions involving hydrocarbons have been determined at thermal <span class="hlt">energies</span> and above using a selected <span class="hlt">ion</span> drift tube-mass spectrometer apparatus. The results indicate that the product yields of several of the fast <span class="hlt">ion</span>-molecule reactions depend on <span class="hlt">ion</span> <span class="hlt">energy</span> (temperature), even though the total rate coefficients are independent of <span class="hlt">energy</span>. The oxidation reaction of the metal <span class="hlt">ion</span> Zr('+) has been found to be a fast reaction and the rate coefficient has been found to be independent of <span class="hlt">ion</span> <span class="hlt">energy</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/6689136','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/6689136"><span>Cathode spot <span class="hlt">energy</span> transfer simulated by a <span class="hlt">focused</span> laser beam</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Vogel, N.; Hoft, H. )</p> <p>1989-10-01</p> <p>Minimum conditions for the formation of surface craters by laser irradiation have been studied experimentally and theoretically for various metals. The critical power density for crater formation within 20 ns was about 10{sup 11}W/m{sup 2}. It is therefore concluded that crater formation by <span class="hlt">ion</span> bombardment will require an <span class="hlt">ion</span> current density of the order of 10{sup 10}A/m{sup 2}.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003JChEd..80...22S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003JChEd..80...22S"><span>An Environmental <span class="hlt">Focus</span> Using Inductively Coupled Plasma Optical Emission Spectrometry and <span class="hlt">Ion</span> Chromatography</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Salido, Arthur; Atterholt, Cynthia; Bacon, J. Roger; Butcher, David J.</p> <p>2003-01-01</p> <p>The Western Carolina University chemistry faculty have developed an environmental <span class="hlt">focus</span> to their curriculum. Inductively coupled plasma-optical emission spectrometry (ICP-OES) and <span class="hlt">ion</span> chromatography (IC) have been shown to be useful tools for the determination of elements and <span class="hlt">ions</span>, respectively. Several novel experiments have been developed monitoring these analytes in environmental samples, including water, pressure-treated wood, and nutritional supplements. In addition, ICP-OES and IC have been used to teach seniors the principles of analytical method development. Lastly, this equipment has been employed extensively in a vigorous research program.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22267714','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22267714"><span>Percolation of gallium dominates the electrical resistance of <span class="hlt">focused</span> <span class="hlt">ion</span> beam deposited metals</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Faraby, H.; DiBattista, M.; Bandaru, P. R.</p> <p>2014-04-28</p> <p>Metal deposition through <span class="hlt">focused</span> <span class="hlt">ion</span> beam (FIB) based systems is thought to result in material composed of the primary metal from the metallo-organic precursor in addition to carbon, oxygen, and gallium. We determined, through electrical resistance and chemical composition measurements on a wide range of FIB deposited platinum and tungsten lines, that the gallium <span class="hlt">ion</span> (Ga{sup +}) concentration in the metal lines plays the dominant role in controlling the electrical resistivity. Effective medium theory, based on McLachlan's formalisms, was used to describe the relationship between the Ga{sup +} concentration and the corresponding resistivity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017MS%26E..167a2071Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017MS%26E..167a2071Z"><span>Preparation of MgB2 superconducting microbridges by <span class="hlt">focused</span> <span class="hlt">ion</span> beam direct milling</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Xuena; Li, Yanli; Xu, Zhuang; Kong, Xiangdong; Han, Li</p> <p>2017-01-01</p> <p>MgB2 superconducting microbridges were prepared by <span class="hlt">focused</span> <span class="hlt">ion</span> beam (FIB) direct milling on MgB2 films. The surface topography of the microbridges were observed using SEM and AFM and the superconductivity was measured in this paper. Lots of cracks and holes were found near the milled area. And the superconducting transition temperature was decreased a lot and the bridges prepared were not superconducting due to <span class="hlt">ion</span> damage after milled with large dose. Through these works, we explored the effect regular of FIB milling and experimental parameters on the performance of microbridges.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014APS..DPPJP8129S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014APS..DPPJP8129S"><span>Dense Plasma <span class="hlt">Focus</span> With High <span class="hlt">Energy</span> Helium Beams for Radiological Source Replacement</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schmidt, Andrea; Ellsworth, Jennifer; Falabella, Steve; Link, Anthony; Rusnak, Brian; Sears, Jason; Tang, Vincent</p> <p>2014-10-01</p> <p>A dense plasma <span class="hlt">focus</span> (DPF) is a compact accelerator that can produce intense high <span class="hlt">energy</span> <span class="hlt">ion</span> beams (multiple MeV). It could be used in place of americium-beryllium (AmBe) neutron sources in applications such as oil well logging if optimized to produce high <span class="hlt">energy</span> helium beams. AmBe sources produce neutrons when 5.5 MeV alphas emitted from the Am interact with the Be. However, due to the very small alpha-Be cross section for alphas <2 MeV, an AmBe source replacement would have to accelerate ~0.15 μC of He to 2 + MeV in order to produce 107 neutrons per pulse. We are using our particle in cell (PIC) model in LSP of a 4 kJ dense plasma <span class="hlt">focus</span> discharge to guide the optimization of a compact DPF for the production of high-<span class="hlt">energy</span> helium beam. This model is fluid for the run-down phase, and then transitions to fully kinetic prior to the pinch in order to include kinetic effects such as <span class="hlt">ion</span> beam formation and anomalous resistivity. An external pulsed-power driver circuit is used at the anode-cathode boundary. Simulations will be benchmarked to He beam measurements using filtered and time-of-flight Faraday cup diagnostics. This work performed under the auspices of the U.S. Department of <span class="hlt">Energy</span> by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. This work supported by US DOE/NA-22 Office of Non-proliferation Research and Development. Computing support for this work came from the LLNL Institutional Computing Grand Challenge program.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19920068569&hterms=Free+energy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DFree%2Benergy','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19920068569&hterms=Free+energy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DFree%2Benergy"><span>Relationship between wave <span class="hlt">energy</span> and free <span class="hlt">energy</span> from pickup <span class="hlt">ions</span> in the Comet Halley environment</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Huddleston, D. E.; Johnstone, A. D.</p> <p>1992-01-01</p> <p>The free <span class="hlt">energy</span> available from the implanted heavy <span class="hlt">ion</span> population at Comet Halley is calculated by assuming that the initial unstable velocity space ring distribution of the <span class="hlt">ions</span> evolves toward a bispherical shell. Ultimately this free <span class="hlt">energy</span> adds to the turbulence in the solar wind. Upstream and downstream free <span class="hlt">energies</span> are obtained separately for the conditions observed along the Giotto spacecraft trajectory. The results indicate that the waves are mostly upstream propagating in the solar wind frame. The total free <span class="hlt">energy</span> density always exceeds the measured wave <span class="hlt">energy</span> density because, as expected in the nonlinear process of <span class="hlt">ion</span> scattering, the available <span class="hlt">energy</span> is not all immediately released. An estimate of the amount which has been released can be obtained from the measured oxygen <span class="hlt">ion</span> distributions and again it exceeds that observed. The theoretical analysis is extended to calculate the k spectrum of the cometary-<span class="hlt">ion</span>-generated turbulence.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19920068569&hterms=Johnstone&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAuthor-Name%26N%3D0%26No%3D40%26Ntt%3DJohnstone','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19920068569&hterms=Johnstone&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAuthor-Name%26N%3D0%26No%3D40%26Ntt%3DJohnstone"><span>Relationship between wave <span class="hlt">energy</span> and free <span class="hlt">energy</span> from pickup <span class="hlt">ions</span> in the Comet Halley environment</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Huddleston, D. E.; Johnstone, A. D.</p> <p>1992-01-01</p> <p>The free <span class="hlt">energy</span> available from the implanted heavy <span class="hlt">ion</span> population at Comet Halley is calculated by assuming that the initial unstable velocity space ring distribution of the <span class="hlt">ions</span> evolves toward a bispherical shell. Ultimately this free <span class="hlt">energy</span> adds to the turbulence in the solar wind. Upstream and downstream free <span class="hlt">energies</span> are obtained separately for the conditions observed along the Giotto spacecraft trajectory. The results indicate that the waves are mostly upstream propagating in the solar wind frame. The total free <span class="hlt">energy</span> density always exceeds the measured wave <span class="hlt">energy</span> density because, as expected in the nonlinear process of <span class="hlt">ion</span> scattering, the available <span class="hlt">energy</span> is not all immediately released. An estimate of the amount which has been released can be obtained from the measured oxygen <span class="hlt">ion</span> distributions and again it exceeds that observed. The theoretical analysis is extended to calculate the k spectrum of the cometary-<span class="hlt">ion</span>-generated turbulence.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22258603','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22258603"><span>Structural and composition investigations at delayered locations of low k integrated circuit device by gas-assisted <span class="hlt">focused</span> <span class="hlt">ion</span> beam</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Wang, Dandan Kee Tan, Pik; Yamin Huang, Maggie; Lam, Jeffrey; Mai, Zhihong</p> <p>2014-05-15</p> <p>The authors report a new delayering technique – gas-assisted <span class="hlt">focused</span> <span class="hlt">ion</span> beam (FIB) method and its effects on the top layer materials of integrated circuit (IC) device. It demonstrates a highly efficient failure analysis with investigations on the precise location. After removing the dielectric layers under the bombardment of an <span class="hlt">ion</span> beam, the chemical composition of the top layer was altered with the reduced oxygen content. Further <span class="hlt">energy</span>-dispersive x-ray spectroscopy and Fourier transform infrared analysis revealed that the oxygen reduction lead to appreciable silicon suboxide formation. Our findings with structural and composition alteration of dielectric layer after FIB delayering open up a new insight avenue for the failure analysis in IC devices.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1326053','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1326053"><span>The role of cross-shock potential on pickup <span class="hlt">ion</span> shock acceleration in the framework of <span class="hlt">focused</span> transport theory</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Zuo, Pingbing; Zhang, Ming; Rassoul, Hamid K.</p> <p>2013-10-03</p> <p>The <span class="hlt">focused</span> transport theory is appropriate to describe the injection and acceleration of low-<span class="hlt">energy</span> particles at shocks as an extension of diffusive shock acceleration (DSA). In this investigation, we aim to characterize the role of cross-shock potential (CSP) originated in the charge separation across the shock ramp on pickup <span class="hlt">ion</span> (PUI) acceleration at various types of shocks with a <span class="hlt">focused</span> transport model. The simulation results of <span class="hlt">energy</span> spectrum and spatial density distribution for the cases with and without CSP added in the model are compared. With sufficient acceleration time, the <span class="hlt">focused</span> transport acceleration finally falls into the DSA regime with the power-law spectral index equal to the solution of the DSA theory. The CSP can affect the shape of the spectrum segment at lower <span class="hlt">energies</span>, but it does not change the spectral index of the final power-law spectrum at high <span class="hlt">energies</span>. It is found that the CSP controls the injection efficiency which is the fraction of PUIs reaching the DSA regime. A stronger CSP jump results in a dramatically improved injection efficiency. Our simulation results also show that the injection efficiency of PUIs is mass-dependent, which is lower for species with a higher mass. Additionally, the CSP is able to enhance the particle reflection upstream to produce a stronger intensity spike at the shock front. Lastly, we conclude that the CSP is a non-negligible factor that affects the dynamics of PUIs at shocks.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1326053-role-cross-shock-potential-pickup-ion-shock-acceleration-framework-focused-transport-theory','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1326053-role-cross-shock-potential-pickup-ion-shock-acceleration-framework-focused-transport-theory"><span>The role of cross-shock potential on pickup <span class="hlt">ion</span> shock acceleration in the framework of <span class="hlt">focused</span> transport theory</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Zuo, Pingbing; Zhang, Ming; Rassoul, Hamid K.</p> <p>2013-10-03</p> <p>The <span class="hlt">focused</span> transport theory is appropriate to describe the injection and acceleration of low-<span class="hlt">energy</span> particles at shocks as an extension of diffusive shock acceleration (DSA). In this investigation, we aim to characterize the role of cross-shock potential (CSP) originated in the charge separation across the shock ramp on pickup <span class="hlt">ion</span> (PUI) acceleration at various types of shocks with a <span class="hlt">focused</span> transport model. The simulation results of <span class="hlt">energy</span> spectrum and spatial density distribution for the cases with and without CSP added in the model are compared. With sufficient acceleration time, the <span class="hlt">focused</span> transport acceleration finally falls into the DSA regime withmore » the power-law spectral index equal to the solution of the DSA theory. The CSP can affect the shape of the spectrum segment at lower <span class="hlt">energies</span>, but it does not change the spectral index of the final power-law spectrum at high <span class="hlt">energies</span>. It is found that the CSP controls the injection efficiency which is the fraction of PUIs reaching the DSA regime. A stronger CSP jump results in a dramatically improved injection efficiency. Our simulation results also show that the injection efficiency of PUIs is mass-dependent, which is lower for species with a higher mass. Additionally, the CSP is able to enhance the particle reflection upstream to produce a stronger intensity spike at the shock front. Lastly, we conclude that the CSP is a non-negligible factor that affects the dynamics of PUIs at shocks.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFMSA11A1574F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFMSA11A1574F"><span>A New <span class="hlt">Focus</span> Lens for Improved <span class="hlt">Energy</span> Resolution in the Wind and Temperature Spectrometer</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fenn, D.; Herrero, F.; Syrstad, E. A.</p> <p>2010-12-01</p> <p>The Wind and Temperature Spectrometer (WATS) is a novel neutral particle sensor capable of simultaneously measuring neutral winds, temperature, composition, and density in the upper atmosphere. This compact, low-power instrument is ideally suited for in situ thermospheric measurements on small-satellite platforms. Building on work previously performed, we detail here endeavors to more fully characterize the effects of proposed instrument modifications, leading to a greater understanding of their impact on overall sensor performance. Additionally, laboratory testing of the WATS seeks to confirm theoretical data previously gathered. WATS utilizes electron impact ionization, a crossed Small Deflection <span class="hlt">Energy</span> Analyzer (SDEA) pair, and a microchannel plate (MCP) detector with linear spatial readout to measure the full 3-D velocity distribution of an incoming neutral stream. A minor weakness in the original WATS design was that a large <span class="hlt">ion</span> beam divergence at the SDEA entrance led to degraded <span class="hlt">energy</span> resolution. To address this problem, a simple <span class="hlt">focusing</span> lens system with a large acceptance angle range, dubbed the Tapered Quad Deflector (TQD), was designed and previously presented. Here, the results of <span class="hlt">ion</span> trajectory calculations (Simion 3D) and Monte Carlo simulations (Matlab) are used to explore various aspects of the TQD’s functionality. With no modifications to the instrument aside from the addition of the TQD, simulations show an increase in the <span class="hlt">energy</span> resolution by a factor of two. Further simulations reveal that reducing the width of the instrument’s collimator slit decreases the beam divergence (with a corresponding increase in instrument <span class="hlt">energy</span> resolution) for both the original and modified WATS. However, this effect is markedly more pronounced in the latter, meaning that the TQD could enable a significant reduction in beam divergence while minimizing the loss of signal that would result from narrowing the collimator slit. Also presented are the results of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JTePh..62..341K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JTePh..62..341K"><span>Dependence of the beam-channel interaction force on the radial profiles of a relativistic electron beam and an <span class="hlt">ion</span> channel in the <span class="hlt">ion-focusing</span> regime</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kolesnikov, E. K.; Manuilov, A. S.</p> <p>2017-02-01</p> <p>We have derived the formulas for calculating the force of the interaction of a relativistic electron beam with an <span class="hlt">ion</span> plasma channel in the case of the beam transportation during <span class="hlt">ion</span> <span class="hlt">focusing</span>. The dependence of the difference in radial profiles of the beam and the <span class="hlt">ion</span> channel on this force for different amplitudes of beam deviations from the channel symmetry axis has been studied.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1473444','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1473444"><span>Electrostatic calculations for an <span class="hlt">ion</span> channel. I. <span class="hlt">Energy</span> and potential profiles and interactions between <span class="hlt">ions</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Levitt, D G</p> <p>1978-01-01</p> <p>The electrostatic <span class="hlt">energy</span> profile of one, two, or three <span class="hlt">ions</span> in an aqueous channel through a lipid membrane is calculated. It is shown that the previous solution to this problem (based on the assumption that the channel is infinitely long) significantly overestimates the electrostatic <span class="hlt">energy</span> barrier. For example, for a 3-A radius pore, the <span class="hlt">energy</span> is 16 kT for the infinite channel and 6.7 kT for an <span class="hlt">ion</span> in the center of a channel 25 A long. The <span class="hlt">energy</span> as a function of the position of the <span class="hlt">ion</span> is also determined. With this <span class="hlt">energy</span> profile, the rate of crossing the membrane (using the Nernst-Planck equation) was estimated and found to be compatible with the maximum conductance observed for the gramicidin A channel. The total electrostatic <span class="hlt">energy</span> (as a function of position) required to place two or three <span class="hlt">ions</span> in the channel is also calculated. The electrostatic interaction is small for two <span class="hlt">ions</span> at opposite ends of the channel and large for any positioning of the three <span class="hlt">ions</span>. Finally, the gradient through the channel of an applied potential is calculated. The solution to these problems is based on solving an equivalent problem in which an appropriate surface charge is placed on the boundary between the lipid and aqueous regions. The magnitude of the surface charge is obtained from the numerical solution for a system of coupled integral equations. PMID:656542</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1999JPCM...11.8739L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1999JPCM...11.8739L"><span><span class="hlt">Energy</span> transfer between Eu3+ <span class="hlt">ions</span> in calcium diborate glasses</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lavín, V.; Martín, I. R.; Rodríguez-Mendoza, U. R.; Rodríguez, V. D.</p> <p>1999-11-01</p> <p>The evolution of the 5D0icons/Journals/Common/to" ALT="to" ALIGN="TOP"/> 7F0 emission of Eu3+ <span class="hlt">ions</span> in calcium diborate glasses has been analysed using time resolved fluorescence line narrowing measurements in order to give a complete view of the <span class="hlt">energy</span> transfer processes between these <span class="hlt">ions</span>. At low concentration (2.5 mol% of Eu2O3) and exciting within the high <span class="hlt">energy</span> side of the inhomogeneous 7F0icons/Journals/Common/to" ALT="to" ALIGN="TOP"/> 5D0 absorption band, the luminescence spectrum mainly consists of a narrow resonant peak that repeats the exciting profile, indicating that the migration processes between Eu3+ <span class="hlt">ions</span> within the 5D0 level is not important. However, at higher concentrations (5 to 11.5 mol% of Eu2O3) the luminescence spectrum contains not only a narrow emission but also a broad band due to <span class="hlt">ions</span> excited by <span class="hlt">energy</span> transfer (background fluorescence), which for long times well reproduces the inhomogeneous profile. The temporal evolution of the narrow band fluorescence and the shape of the background fluorescence have been analysed using a previously proposed model. The purpose is to understand the dynamics involved in the <span class="hlt">energy</span> transfer processes caused by the interaction between Eu3+ <span class="hlt">ions</span> and the implications in their luminescence. A very good agreement with the experimental results is found taking into account an <span class="hlt">energy</span> dependent quadrupole-quadrupole (S = 10) non-radiative <span class="hlt">energy</span> transfer process assisted by a phonon from Eu3+ <span class="hlt">ions</span> at high crystal field sites to <span class="hlt">ions</span> at low crystal field sites. The temperature dependence of the <span class="hlt">energy</span> transfer processes is analysed in the range from 13 to 60 K.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017ApPRv...4a1302B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ApPRv...4a1302B"><span>Comparison of technologies for nano device prototyping with a special <span class="hlt">focus</span> on <span class="hlt">ion</span> beams: A review</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bruchhaus, L.; Mazarov, P.; Bischoff, L.; Gierak, J.; Wieck, A. D.; Hövel, H.</p> <p>2017-03-01</p> <p>Nano device prototyping (NDP) is essential for realizing and assessing ideas as well as theories in the form of nano devices, before they can be made available in or as commercial products. In this review, application results patterned similarly to those in the semiconductor industry (for cell phone, computer processors, or memory) will be presented. For NDP, some requirements are different: thus, other technologies are employed. Currently, in NDP, for many applications direct write Gaussian vector scan electron beam lithography (EBL) is used to define the required features in organic resists on this scale. We will take a look at many application results carried out by EBL, self-organized 3D epitaxy, atomic probe microscopy (scanning tunneling microscope/atomic force microscope), and in more detail <span class="hlt">ion</span> beam techniques. For <span class="hlt">ion</span> beam techniques, there is a special <span class="hlt">focus</span> on those based upon liquid metal (alloy) <span class="hlt">ion</span> sources, as recent developments have significantly increased their applicability for NDP.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27056544','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27056544"><span>Preparation and Analysis of Atom Probe Tips by Xenon <span class="hlt">Focused</span> <span class="hlt">Ion</span> Beam Milling.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Estivill, Robert; Audoit, Guillaume; Barnes, Jean-Paul; Grenier, Adeline; Blavette, Didier</p> <p>2016-06-01</p> <p>The damage and <span class="hlt">ion</span> distribution induced in Si by an inductively coupled plasma Xe <span class="hlt">focused</span> <span class="hlt">ion</span> beam was investigated by atom probe tomography. By using predefined patterns it was possible to prepare the atom probe tips with a sub 50 nm end radius in the <span class="hlt">ion</span> beam microscope. The atom probe reconstruction shows good agreement with simulated implantation profiles and interplanar distances extracted from spatial distribution maps. The elemental profiles of O and C indicate co-implantation during the milling process. The presence of small disc-shaped Xe clusters are also found in the three-dimensional reconstruction. These are attributed to the presence of Xe nanocrystals or bubbles that open during the evaporation process. The expected accumulated dose points to a loss of >95% of the Xe during analysis, which escapes undetected.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017Nanot..28h5303L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017Nanot..28h5303L"><span>Silicon dioxide mask by plasma enhanced atomic layer deposition in <span class="hlt">focused</span> <span class="hlt">ion</span> beam lithography</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liu, Zhengjun; Shah, Ali; Alasaarela, Tapani; Chekurov, Nikolai; Savin, Hele; Tittonen, Ilkka</p> <p>2017-02-01</p> <p>In this work, <span class="hlt">focused</span> <span class="hlt">ion</span> beam (FIB) lithography was developed for plasma enhanced atomic layer deposited (PEALD) silicon dioxide SiO2 hard mask. The PEALD process greatly decreases the deposition temperature of the SiO2 hard mask. FIB Ga+ <span class="hlt">ion</span> implantation on the deposited SiO2 layer increases the wet etch resistivity of the irradiated region. A programmed exposure in FIB followed by development in a wet etchant enables the precisely defined nanoscale patterning. The combination of FIB exposure parameters and the development time provides greater freedom for optimization. The developed process provides high pattern dimension accuracy over the tested range of 90-210 nm. Utilizing the SiO2 mask developed in this work, silicon nanopillars with 40 nm diameter were successfully fabricated with cryogenic deep reactive <span class="hlt">ion</span> etching and the aspect ratio reached 16:1. The fabricated mask is suitable for sub-100 nm high aspect ratio silicon structure fabrication.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28045005','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28045005"><span>Silicon dioxide mask by plasma enhanced atomic layer deposition in <span class="hlt">focused</span> <span class="hlt">ion</span> beam lithography.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Liu, Zhengjun; Shah, Ali; Alasaarela, Tapani; Chekurov, Nikolai; Savin, Hele; Tittonen, Ilkka</p> <p>2017-02-24</p> <p>In this work, <span class="hlt">focused</span> <span class="hlt">ion</span> beam (FIB) lithography was developed for plasma enhanced atomic layer deposited (PEALD) silicon dioxide SiO2 hard mask. The PEALD process greatly decreases the deposition temperature of the SiO2 hard mask. FIB Ga(+) <span class="hlt">ion</span> implantation on the deposited SiO2 layer increases the wet etch resistivity of the irradiated region. A programmed exposure in FIB followed by development in a wet etchant enables the precisely defined nanoscale patterning. The combination of FIB exposure parameters and the development time provides greater freedom for optimization. The developed process provides high pattern dimension accuracy over the tested range of 90-210 nm. Utilizing the SiO2 mask developed in this work, silicon nanopillars with 40 nm diameter were successfully fabricated with cryogenic deep reactive <span class="hlt">ion</span> etching and the aspect ratio reached 16:1. The fabricated mask is suitable for sub-100 nm high aspect ratio silicon structure fabrication.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22283107','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22283107"><span><span class="hlt">Focused</span> <span class="hlt">ion</span> beam high resolution grayscale lithography for silicon-based nanostructures</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Erdmanis, M. Tittonen, I.</p> <p>2014-02-17</p> <p>Nanofabrication techniques providing a fine control over the profile of silicon structures are of great importance for nanophotonics, plasmonics, sensing, micro- and nano fluidics, and biomedical applications. We report on the applicability of <span class="hlt">focused</span> <span class="hlt">ion</span> beam for the fine grayscale lithography, which yields surface profiles that are customized at nanoscale. The approach is based on a correlation between the <span class="hlt">ion</span> beam irradiation dose of inorganic resist and the mask etching rate in the reactive <span class="hlt">ion</span> etching. An exceptional property of this method is the number of gray tones that are not limited by the resist characteristics. We apply the process to fabricate unique periodic nanostructures with a slope angle varying across the structure and a period as small as 200 nm.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_18 --> <div id="page_19" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="361"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22390822','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22390822"><span><span class="hlt">Ion</span> beam and neutron output from a sub-kilojoule dense plasma <span class="hlt">focus</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Ellsworth, J. L. Falabella, S. Schmidt, A. Tang, V.</p> <p>2014-12-15</p> <p>We are seeking to gain a better fundamental understanding of the <span class="hlt">ion</span> beam acceleration and neutron production dense plasma <span class="hlt">focus</span> (DPF) device. Experiments were performed on a kilojoule level, fast rise time DPF located at LLNL. <span class="hlt">Ion</span> beam spectra and neutron yield were measured for deuterium pinches. Visible light images of the pinch are used to determine the pinch length. In addition, an RF probe was placed just outside the cathode to measure fluctuations in E{sub z} up to 6 GHz, which is within the range of the lower hybrid frequencies. We find these oscillations arise at a characteristic frequency near 4 GHz during the pinch. Comparisons of the neutron yield and <span class="hlt">ion</span> beam characteristics are presented. The neutron yield is also compared to scaling laws.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/15317019','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/15317019"><span>Internal <span class="hlt">energy</span> and fragmentation of <span class="hlt">ions</span> produced in electrospray sources.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gabelica, Valérie; De Pauw, Edwin</p> <p>2005-01-01</p> <p>This review addresses the determination of the internal <span class="hlt">energy</span> of <span class="hlt">ions</span> produced by electrospray ionization (ESI) sources, and the influence of the internal <span class="hlt">energy</span> on analyte fragmentation. A control of the analyte internal <span class="hlt">energy</span> is crucial for several applications of electrospray mass spectrometry, like structural studies, construction of reproducible and exportable spectral libraries, analysis of non-covalent complexes. Sections II and III summarize the Electrospray mechanisms and source design considerations which are relevant to the problem of internal <span class="hlt">energy</span>, and Section IV gives an overview of the inter-relationships between <span class="hlt">ion</span> internal <span class="hlt">energy</span>, reaction time scale, and analyte fragmentation. In these three sections we tried to make the most important theoretical elements understandable by all ESI users, and their understanding requires a minimal background in physical chemistry. We then present the different approaches used to experimentally determine the <span class="hlt">ion</span> internal <span class="hlt">energy</span>, as well as various attempts in modeling the internal <span class="hlt">energy</span> uptake in electrospray sources. Finally, a tentative comparison between electrospray and other ionization sources is made. As the reader will see, although many reports appeared on the subject, the knowledge in the field of internal <span class="hlt">energy</span> of <span class="hlt">ions</span> produced by soft ionization sources is still scarce, because of the complexity of the system, and this is what makes this area of research so interesting. The last section presents some perspectives for future research.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1996NIMPA.374....1Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1996NIMPA.374....1Y"><span>Production of low <span class="hlt">energy</span> spread <span class="hlt">ion</span> beams with multicusp sources</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Y., Lee; Perkins, L. T.; Gough, R. A.; Hoffmann, M.; Kunkel, W. B.; N. Leung, K.; Sarstedt, M.; Vujic, J.; Weber, M.; Williams, M. D.</p> <p>1996-02-01</p> <p>The use of multicusp sources to generate <span class="hlt">ion</span> beams with narrow <span class="hlt">energy</span> spread has been investigated. It is found that the presence of a magnetic filter can reduce the longitudinal <span class="hlt">energy</span> spread significantly. This is achieved by creating a uniform plasma potential distribution in the discharge chamber region, eliminating <span class="hlt">ion</span> production in the extraction chamber and in the sheath of the exit aperture and by minimizing the probability of charge exchange processes in the extraction chamber. An <span class="hlt">energy</span> spread as low as 1 eV has been measured.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016APS..DPPJ10073C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APS..DPPJ10073C"><span>Enabling High Fidelity Measurements of <span class="hlt">Energy</span> and Pitch Angle for Escaping Energetic <span class="hlt">Ions</span> with a Fast <span class="hlt">Ion</span> Loss Detector</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chaban, R.; Pace, D. C.; Marcy, G. R.; Taussig, D.</p> <p>2016-10-01</p> <p>Energetic <span class="hlt">ion</span> losses must be minimized in burning plasmas to maintain fusion power, and existing tokamaks provide access to energetic <span class="hlt">ion</span> parameter regimes that are relevant to burning machines. A new Fast <span class="hlt">Ion</span> Loss Detector (FILD) probe on the DIII-D tokamak has been optimized to resolve beam <span class="hlt">ion</span> losses across a range of 30 - 90 keV in <span class="hlt">energy</span> and 40° to 80° in pitch angle, thereby providing valuable measurements during many different experiments. The FILD is a magnetic spectrometer; once inserted into the tokamak, the magnetic field allows energetic <span class="hlt">ions</span> to pass through a collimating aperture and strike a scintillator plate that is imaged by a wide view camera and narrow view photomultiplier tubes (PMTs). The design involves calculating scintillator strike patterns while varying probe geometry. Calculated scintillator patterns are then used to design an optical system that allows adjustment of the <span class="hlt">focus</span> regions for the 1 MS/s resolved PMTs. A synthetic diagnostic will be used to determine the <span class="hlt">energy</span> and pitch angle resolution that can be attained in DIII-D experiments. Work supported in part by US DOE under the Science Undergraduate Laboratory Internship (SULI) program and under DE-FC02-04ER54698.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/973582','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/973582"><span>Carbon <span class="hlt">ion</span> beam <span class="hlt">focusing</span> using laser irradiated heated diamond hemispherical shells</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Offermann, Dustin T; Flippo, Kirk A; Gaillard, Sandrine A</p> <p>2009-01-01</p> <p>Experiments preformed at the Los Alamos National Laboratory's Trident Laser Facility were conducted to observe the acceleration and <span class="hlt">focusing</span> of carbon <span class="hlt">ions</span> via the TNSA mechanism using hemispherical diamond targets. Trident is a 200TW class laser system with 80J of 1 {micro}m, short-pulse light delivered in 0.5ps, with a peak intensity of 5 x 10{sup 20} W/cm{sup 2}. Targets where Chemical Vapor Deposition (CVD) diamonds formed into hemispheres with a radius of curvature of 400{micro}m and a thickness of 5{micro}m. The accelerated <span class="hlt">ions</span> from the hemisphere were diagnosed by imaging the shadow of a witness copper mesh grid located 2mm behind the target onto a film pack located 5cm behind the target. Ray tracing was used to determine the location of the <span class="hlt">ion</span> focal spot. The TNSA mechanism favorably accelerates hydrogen found in and on the targets. To make the carbon beam detectable, targets were first heated to several hundred degrees Celsius using a CW, 532nm, 8W laser. Imaging of the carbon beam was accomplished via an auto-radiograph of a nuclear activated lithium fluoride window in the first layer of the film pack. The <span class="hlt">focus</span> of the carbon <span class="hlt">ion</span> beam was determined to be located 630 {+-} 110 {micro}m from the vertex of the hemisphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017NIMPB.396...61A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017NIMPB.396...61A"><span>Study of the thermal effect on silicon surface induced by <span class="hlt">ion</span> beam from plasma <span class="hlt">focus</span> device</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ahmad, Z.; Ahmad, M.; Al-Hawat, Sh.; Akel, M.</p> <p>2017-04-01</p> <p>Structural modifications in form of ripples and cracks are induced by nitrogen <span class="hlt">ions</span> from plasma <span class="hlt">focus</span> on silicon surface. The investigation of such structures reveals correlation between ripples and cracks formation in peripheral region of the melt spot. The reason of such correlation and structure formation is explained as result of thermal effect. Melting and resolidification of the center of irradiated area occur within one micro second of time. This is supported by a numerical simulation used to investigate the thermal effect induced by the plasma <span class="hlt">focus</span> <span class="hlt">ion</span> beams on the silicon surface. This simulation provides information about the temperature profile as well as the dynamic of the thermal propagation in depth and lateral directions. In accordance with the experimental observations, that ripples are formed in latter stage after the arrival of last <span class="hlt">ion</span>, the simulation shows that the thermal relaxation takes place in few microseconds after the end of the <span class="hlt">ion</span> beam arrival. Additionally, the dependency of thermal propagation and relaxation on the distance of the silicon surface from the anode is presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/7045056','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/7045056"><span>Optical characterization of locally and compositionally mixed superlattices using conventional and <span class="hlt">focused</span> <span class="hlt">ion</span> beam implantation</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Choo, A.G.</p> <p>1992-01-01</p> <p>Spatially resolved Raman scattering and low temperature photoluminescence have been utilized to investigate implantation-induced lattice damage and compositional disordering in multiple quantum well (MQW) structures prepared using by <span class="hlt">ion</span> beam (conventional and <span class="hlt">focused</span>) implantation and subsequent rapid thermal annealing (RTA). The RTA of 10 sec at 950[degrees] for short period MQW and 10 sec at 1000[degrees]C for long period MQW are appropriate thermal annealing condition. <span class="hlt">Focused</span> on beam (FIB) implantation induces more damage than conventional <span class="hlt">ion</span> beam (CIB) implantation for the whole dose range. The highest dose FIB induces significant damage compared to the CIB. The degree of FIB implantation-induced intermixing increases with increasing <span class="hlt">ion</span> dose. As RTA time increases, additional enhanced intermixing does not occur in MQW channel waveguide structure. The donor-to-acceptor transition from PL is dominant in the <span class="hlt">ion</span>-implanted samples. The multiple scan FIB and the CIB shows more compensation than the single scan FIB. The spatial scanning of Raman scattering is demonstrated to characterize MQW channel waveguide structure.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26832268','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26832268"><span>Direct core structuring of microstructured optical fibers using <span class="hlt">focused</span> <span class="hlt">ion</span> beam milling.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Warren-Smith, Stephen C; André, Ricardo M; Perrella, Christopher; Dellith, Jan; Bartelt, Hartmut</p> <p>2016-01-11</p> <p>We demonstrate the use of <span class="hlt">focused</span> <span class="hlt">ion</span> beam milling to machine optical structures directly into the core of microstructured optical fibers. The particular fiber used was exposed-core microstructured optical fiber, which allowed direct access to the optically guiding core. Two different designs of Fabry-Perot cavity were fabricated and optically characterized. The first cavity was formed by completely removing a section of the fiber core, while the second cavity consisted of a shallow slot milled into the core, leaving the majority of the core intact. This work highlights the possibility of machining complex optical devices directly onto the core of microstructured optical fibers using <span class="hlt">focused</span> <span class="hlt">ion</span> beam milling for applications including environmental, chemical, and biological sensing.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24332462','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24332462"><span>Coordinate transformation based cryo-correlative methods for electron tomography and <span class="hlt">focused</span> <span class="hlt">ion</span> beam milling.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Fukuda, Yoshiyuki; Schrod, Nikolas; Schaffer, Miroslava; Feng, Li Rebekah; Baumeister, Wolfgang; Lucic, Vladan</p> <p>2014-08-01</p> <p>Correlative microscopy allows imaging of the same feature over multiple length scales, combining light microscopy with high resolution information provided by electron microscopy. We demonstrate two procedures for coordinate transformation based correlative microscopy of vitrified biological samples applicable to different imaging modes. The first procedure aims at navigating cryo-electron tomography to cellular regions identified by fluorescent labels. The second procedure, allowing navigation of <span class="hlt">focused</span> <span class="hlt">ion</span> beam milling to fluorescently labeled molecules, is based on the introduction of an intermediate scanning electron microscopy imaging step to overcome the large difference between cryo-light microscopy and <span class="hlt">focused</span> <span class="hlt">ion</span> beam imaging modes. These methods make it possible to image fluorescently labeled macromolecular complexes in their natural environments by cryo-electron tomography, while minimizing exposure to the electron beam during the search for features of interest. Copyright © 2013 Elsevier B.V. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28863693','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28863693"><span>Kinetic <span class="hlt">energy</span> offsets for multicharged <span class="hlt">ions</span> from an electron beam <span class="hlt">ion</span> source.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kulkarni, D D; Ahl, C D; Shore, A M; Miller, A J; Harriss, J E; Sosolik, C E; Marler, J P</p> <p>2017-08-01</p> <p>Using a retarding field analyzer, we have measured offsets between the nominal and measured kinetic <span class="hlt">energy</span> of multicharged <span class="hlt">ions</span> extracted from an electron beam <span class="hlt">ion</span> source (EBIS). By varying source parameters, a shift in <span class="hlt">ion</span> kinetic <span class="hlt">energy</span> was attributed to the trapping potential produced by the space charge of the electron beam within the EBIS. The space charge of the electron beam depends on its charge density, which in turn depends on the amount of negative charge (electron beam current) and its velocity (electron beam <span class="hlt">energy</span>). The electron beam current and electron beam <span class="hlt">energy</span> were both varied to obtain electron beams of varying space charge and these were related to the observed kinetic <span class="hlt">energy</span> offsets for Ar(4+) and Ar(8+) <span class="hlt">ion</span> beams. Knowledge of these offsets is important for studies that seek to utilize slow, i.e., low kinetic <span class="hlt">energy</span>, multicharged <span class="hlt">ions</span> to exploit their high potential <span class="hlt">energies</span> for processes such as surface modification. In addition, we show that these offsets can be utilized to estimate the effective radius of the electron beam inside the trap.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017RScI...88h3306K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017RScI...88h3306K"><span>Kinetic <span class="hlt">energy</span> offsets for multicharged <span class="hlt">ions</span> from an electron beam <span class="hlt">ion</span> source</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kulkarni, D. D.; Ahl, C. D.; Shore, A. M.; Miller, A. J.; Harriss, J. E.; Sosolik, C. E.; Marler, J. P.</p> <p>2017-08-01</p> <p>Using a retarding field analyzer, we have measured offsets between the nominal and measured kinetic <span class="hlt">energy</span> of multicharged <span class="hlt">ions</span> extracted from an electron beam <span class="hlt">ion</span> source (EBIS). By varying source parameters, a shift in <span class="hlt">ion</span> kinetic <span class="hlt">energy</span> was attributed to the trapping potential produced by the space charge of the electron beam within the EBIS. The space charge of the electron beam depends on its charge density, which in turn depends on the amount of negative charge (electron beam current) and its velocity (electron beam <span class="hlt">energy</span>). The electron beam current and electron beam <span class="hlt">energy</span> were both varied to obtain electron beams of varying space charge and these were related to the observed kinetic <span class="hlt">energy</span> offsets for Ar4+ and Ar8+ <span class="hlt">ion</span> beams. Knowledge of these offsets is important for studies that seek to utilize slow, i.e., low kinetic <span class="hlt">energy</span>, multicharged <span class="hlt">ions</span> to exploit their high potential <span class="hlt">energies</span> for processes such as surface modification. In addition, we show that these offsets can be utilized to estimate the effective radius of the electron beam inside the trap.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013PhRvS..16d1302H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013PhRvS..16d1302H"><span>Performance of solenoids versus quadrupoles in <span class="hlt">focusing</span> and <span class="hlt">energy</span> selection of laser accelerated protons</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hofmann, Ingo</p> <p>2013-04-01</p> <p>Using laser accelerated protons or <span class="hlt">ions</span> for various applications—for example in particle therapy or short-pulse radiographic diagnostics—requires an effective method of <span class="hlt">focusing</span> and <span class="hlt">energy</span> selection. We derive an analytical scaling for the performance of a solenoid compared with a doublet/triplet as function of the <span class="hlt">energy</span>, which is confirmed by TRACEWIN simulations. Generally speaking, the two approaches are equivalent in <span class="hlt">focusing</span> capability, if parameters are such that the solenoid length approximately equals its diameter. The scaling also shows that this is usually not the case above a few MeV; consequently, a solenoid needs to be pulsed or superconducting, whereas the quadrupoles can remain conventional. It is also important that the transmission of the triplet is found only 25% lower than that of the equivalent solenoid. Both systems are equally suitable for <span class="hlt">energy</span> selection based on their chromatic effect as is shown using an initial distribution following the RPA simulation model by Yan et al. [Phys. Rev. Lett. 103, 135001 (2009PRLTAO0031-900710.1103/PhysRevLett.103.135001].</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006JVSJ...48..339K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006JVSJ...48..339K"><span>Estimation of Nitrogen <span class="hlt">Ion</span> <span class="hlt">Energy</span> in Sterilization Technology by Plasma Based <span class="hlt">Ion</span> Implantation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kondou, Youhei; Nakashima, Takeru; Tanaka, Takeshi; Takagi, Toshinori; Watanabe, Satoshi; Ohkura, Kensaku; Shibahara, Kentaro; Yokoyama, Shin</p> <p></p> <p>Plasma based <span class="hlt">ion</span> implantation (PBII) with negative voltage pulses to the test specimen has been applied to the sterilization process as a technique suitable for three-dimensional work pieces. Pulsed high negative voltage (5 μs pulse width, 300 pulses/s, -800 V to -15 kV) was applied to the electrode in this process at a gas pressure of 2.4 Pa of N2. We found that the PBII process, in which N2 gas self-ignitted plasma generated by only pulsed voltages is used, reduces the number of active Bacillus pumilus cell. The number of bacteria survivors was reduced by 10-5 x with 5 min exposure. Since the <span class="hlt">ion</span> <span class="hlt">energy</span> is the most important processing parameter, a simple method to estimate the nitrogen <span class="hlt">ion</span> <span class="hlt">energy</span> from distribution of nitrogen atoms in Si implanted by PBII was developed. The implanted <span class="hlt">ion</span> <span class="hlt">energy</span> is discussed from the SIMS in depth profiles.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22075726','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22075726"><span>Comparison between single- and dual-electrode <span class="hlt">ion</span> source systems for low-<span class="hlt">energy</span> <span class="hlt">ion</span> transport</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Vasquez, M. Jr.; Tokumura, S.; Kasuya, T.; Maeno, S.; Wada, M.</p> <p>2012-11-06</p> <p>Extraction of <span class="hlt">ions</span> with <span class="hlt">energies</span> below 100 eV has been demonstrated using a hot-cathode multi-cusp <span class="hlt">ion</span> source equipped with extraction electrodes made of thin wires. Two electrode geometries, a single-electrode system, and a dual-electrode system were built and tested. The single-electrode configuration showed high <span class="hlt">ion</span> beam current densities at shorter distances from the electrode but exhibited rapid attenuation as the distance from the electrode increased. Beam angular spread measurements showed similar beam divergence for both electrode configurations at low plasma densities. At high plasma densities and low extraction potentials, the single-electrode system showed the angular spread twice as large as that of the dual-electrode system. <span class="hlt">Energy</span> distribution analyses showed a broader <span class="hlt">energy</span> spread for <span class="hlt">ion</span> beams extracted from a single-electrode set-up.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=alternate+AND+energy&pg=2&id=ED195408','ERIC'); return false;" href="https://eric.ed.gov/?q=alternate+AND+energy&pg=2&id=ED195408"><span><span class="hlt">Focus</span> On: Classroom <span class="hlt">Energy</span> Materials. Publication Number 11895.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Kocsis, Mitzie</p> <p></p> <p>The Massachusetts Dissemination Project presents this compendium of <span class="hlt">energy</span>-related educational resources as a reference guide for persons interested in exploring <span class="hlt">energy</span> problems, conservation techniques, and alternate <span class="hlt">energy</span> sources with their students. Provided are brief descriptions of available bibliographies, classroom materials, publications,…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=coloring+AND+books&pg=4&id=ED195408','ERIC'); return false;" href="http://eric.ed.gov/?q=coloring+AND+books&pg=4&id=ED195408"><span><span class="hlt">Focus</span> On: Classroom <span class="hlt">Energy</span> Materials. Publication Number 11895.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Kocsis, Mitzie</p> <p></p> <p>The Massachusetts Dissemination Project presents this compendium of <span class="hlt">energy</span>-related educational resources as a reference guide for persons interested in exploring <span class="hlt">energy</span> problems, conservation techniques, and alternate <span class="hlt">energy</span> sources with their students. Provided are brief descriptions of available bibliographies, classroom materials, publications,…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA513618','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA513618"><span><span class="hlt">Focused</span> <span class="hlt">Ion</span> Beam Milling Applied in Future Tunable-Wavelength Nano-LED’s Fabrication</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2010-01-07</p> <p>When this method was applied in light emitting diodes (LED) devices, a single pillar or arrays of pillars comprising InGaN /GaN multiple quantum wells...milling in different depth, which may contribute to light extraction enhancement of the InGaN /GaN MQW LED surface. Figure 3 shows a scanning...<span class="hlt">Focused</span> <span class="hlt">ion</span> beam milling followed by KOH wet etching method in fabricating future tunable-wavelength nano-light emitting diode (LED) comprised of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20215654','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20215654"><span><span class="hlt">Focused</span> <span class="hlt">ion</span> beam fabrication of spintronic nanostructures: an optimization of the milling process.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Urbánek, M; Uhlír, V; Bábor, P; Kolíbalová, E; Hrncír, T; Spousta, J; Sikola, T</p> <p>2010-04-09</p> <p><span class="hlt">Focused</span> <span class="hlt">ion</span> beam (FIB) milling has been used to fabricate magnetic nanostructures (wires, squares, discs) from single magnetic layers (Co, permalloy) and spin-valve (permalloy/Cu/Co) multilayers (thicknesses 5-50 nm) prepared by <span class="hlt">ion</span> beam sputtering deposition. Milled surfaces of metallic thin films typically exhibit residual roughness, which is also transferred onto the edges of the milled patterns. This can lead to domain wall pinning and influence the magnetization behaviour of the nanostructures. We have investigated the milling process and the influence of the FIB parameters (incidence angle, dwell time, overlap and <span class="hlt">ion</span> beam current) on the roughness of the milled surface. It has been found that the main reasons for increased roughness are different sputter yields for various crystallographic orientations of the grains in polycrystalline magnetic thin films. We have found that the oblique <span class="hlt">ion</span> beam angle, long dwell time and overlap < 1 are favourable parameters for suppression of this intrinsic roughness. Finally, we have shown how to determine the <span class="hlt">ion</span> dose necessary to mill through the whole thin film up to the silicon substrate from scanning electron microscopy (SEM) images only.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22066165','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22066165"><span>Effects of <span class="hlt">focused</span> <span class="hlt">ion</span> beam milling on austenite stability in ferrous alloys</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Knipling, K.E.; Rowenhorst, D.J.; Fonda, R.W.; Spanos, G.</p> <p>2010-01-15</p> <p>The susceptibility of fcc austenite to transform to bcc during <span class="hlt">focused</span> <span class="hlt">ion</span> beam milling was studied in three commercial stainless steels. The alloys investigated, in order of increasing austenite stability, were: (i) a model maraging steel, Sandvik 1RK91; (ii) an AISI 304 austenitic stainless steel; and (iii) AL-6XN, a super-austenitic stainless steel. Small trenches were milled across multiple austenite grains in each alloy using a 30 kV Ga{sup +} <span class="hlt">ion</span> beam at normal incidence to the specimen surface. The <span class="hlt">ion</span> beam dose was controlled by varying the trench depth and the beam current. The factors influencing the transformation of fcc austenite to bcc (listed in order of decreasing influence) were found to be: (i) alloy composition (i.e., austenite stability), (ii) <span class="hlt">ion</span> beam dose (or trench depth), and (iii) crystallographic orientation of the austenite grains. The <span class="hlt">ion</span> beam current had a negligible influence on the FIB-induced transformation of austenite in these alloys.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19498893','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19498893"><span>Diffraction grating couplers milled in Si3N4 rib waveguides with a <span class="hlt">focused</span> <span class="hlt">ion</span> beam.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zinoviev, Kirill; Dominguez, Carlos; Vilà, Anna</p> <p>2005-10-17</p> <p><span class="hlt">Focused</span> <span class="hlt">ion</span> beam milling is a processing technology which allows flexible direct writing of nanometer scale features efficiently substituting electron beam lithography. No mask need results in ability for patterns writing even on fragile micromechanical devices. In this work we studied the abilities of the tool for fabrication of diffraction grating couplers in silicon nitride waveguides. The gratings were fabricated on a chip with extra fragile cantilevers of sub micron thickness. Optical characterization of the couplers was done using excitation of the waveguides in visible range by <span class="hlt">focused</span> Gaussian beams of different waist sizes. Influence of Ga+ implantation on the device performance was studied.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_19 --> <div id="page_20" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="381"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1986SPIE..632...76P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1986SPIE..632...76P"><span>The Nanofab-150-A Versatile New <span class="hlt">Focused-Ion</span>-Beam System</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Parker, N. William; Robinson, William P.; Snyder, Joseph M.</p> <p>1986-06-01</p> <p>MicroBeam developed a new <span class="hlt">focused-ion</span>-beam system, the NanoFab-150, for the fabrication of submicron structures with fully integrated imaging and analysis capabilities for inspection and endpoint detection. The system can operate in a manual mode, but is fully automated to reduce operating costs and enhance application reproducibility. The <span class="hlt">ion</span> probe for the NanoFab-150 is changeable from 50 nanometers to 500 nanometers, with voltages variable from 3 kV to 150 kV at current densities up to 5 A/cm2. Elec-tronic selection of specific <span class="hlt">ion</span> species from alloy sources is possible using the system's mass filter. An automated dual loadlock allows for rapid sample throughput. The stage has x-y travel to accommodate 6-in. wafers or masks, with the capability to use laser inter-ferometric positioning. High speed cryopumping is used for both the optical chamber (housing the <span class="hlt">ion</span> source, lenses, mass filter and deflectors) and the target chamber (housing the x-y-theta stage, position sensors and probe monitors). The target and optical chambers are differentially pumped, allowing pressure differences of several orders of magnitude. This feature allows the use of <span class="hlt">ion</span>-assisted chemical vapor deposition and gas-enhanced sputter etching. The differential pumping maintains a very low pressure in the optical chamber, increasing source lifetimes. In microfabrication and other applications, the NanoFab-150 functions as a scanning <span class="hlt">ion</span> microscope in imaging and analysis of nanometer structures. The system uses a channel electron multiplier (CEM) with operating modes for collecting secondary electrons and/or secondary <span class="hlt">ions</span>. The integral high collection efficiency SIMS optics is used for process endpoint detection and can also provide high spatial resolution maps with isotopic sensitivity in gray scale or color. The system configuration, results of early performance testing, and goals for the final performance specifications are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1999PhDT.......119W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1999PhDT.......119W"><span>Control of <span class="hlt">ion</span> <span class="hlt">energy</span> at the substrates during plasma processing</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Shiang-Bau</p> <p>1999-11-01</p> <p><span class="hlt">Ion</span> bombardment plays a significant role in many aspects of plasma processing in integrated circuit manufacturing, including etch rate, etch selectivity, etched feature profiles, differential charging, deposited film quality, damage, etc. Some of these have emerged as new challenges as device sizes continue shrinking. Since those challenges are somewhat related to the <span class="hlt">ion</span> trajectory (or <span class="hlt">ion</span> <span class="hlt">energy</span>), more precise control of <span class="hlt">ion</span> bombarding <span class="hlt">energy</span> is critical and necessary. This study combined plasma model simulation and experimental implementation to develop an <span class="hlt">ion</span> <span class="hlt">energy</span> distribution function (IEDF) control technique by carefully tailoring the bias voltage waveform applied to the substrate. A time-dependent, spherical-shell, whole-region plasma fluid model was constructed first to investigate the factors that affect the <span class="hlt">ion</span> <span class="hlt">energy</span> distribution. The simulation results show that a greatly narrowed IEDF can be obtained by applying a specially tailored bias voltage waveform composed of a series of pulses and a slow negative linear slope between pulses. The simulation also demonstrates that the IEDF produced with this technique is independent of <span class="hlt">ion</span> mass, the technique does not induce a non-uniform substrate potential, and does produce a more precisely controllable <span class="hlt">ion</span> <span class="hlt">energy</span> compared to the conventional sinusoidal bias voltage power supply design. Experiments in a helicon argon plasma show good agreement with simulation results. Not limited to electropositive plasmas, this technique also demonstrates similar performance in an electronegative SF6 plasma. Experiments related to the applications of this technique in a real-time non-intrusive <span class="hlt">ion</span> bombarding flux measurement as well as to SiO2/Si etching selectivity improvement have also been performed. The real-time non-intrusive <span class="hlt">ion</span> bombarding flux measurements show more accurate results than are obtainable with Langmuir probes and the output can serve as a meaningful control variable for etching processes. This technique</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1986NIMPB..13..393Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1986NIMPB..13..393Y"><span>Angular distributions of sputtered atoms for low-<span class="hlt">energy</span> heavy <span class="hlt">ions</span>, medium <span class="hlt">ions</span> and light <span class="hlt">ions</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yamamura, Yasunori; Mizuno, Yoshiyuki; Kimura, Hidetoshi</p> <p>1986-03-01</p> <p>The angular distributions of sputtered atoms for the near-threshold sputtering of heavy <span class="hlt">ions</span>, medium <span class="hlt">ions</span>, and light <span class="hlt">ions</span> have been investigated by a few-collision model and the ACAT computer simulation code. For heavy-<span class="hlt">ion</span> sputtering the preferential angle of sputtered atoms is about 50° which is measured from the surface normal, while in the case of the near-threshold light-<span class="hlt">ion</span> sputtering the preferential angles are nearly equal to the surface normal and do not depend on angle of incidence. It is found that the agreement between the ACAT preferential angles and theoretical values due to a few-collision model is very good.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JAP...116x4301T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JAP...116x4301T"><span>Performance predictions of a <span class="hlt">focused</span> <span class="hlt">ion</span> beam from a laser cooled and compressed atomic beam</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>ten Haaf, G.; Wouters, S. H. W.; van der Geer, S. B.; Vredenbregt, E. J. D.; Mutsaers, P. H. A.</p> <p>2014-12-01</p> <p><span class="hlt">Focused</span> <span class="hlt">ion</span> beams are indispensable tools in the semiconductor industry because of their ability to image and modify structures at the nanometer length scale. Here, we report on performance predictions of a new type of <span class="hlt">focused</span> <span class="hlt">ion</span> beam based on photo-ionization of a laser cooled and compressed atomic beam. Particle tracing simulations are performed to investigate the effects of disorder-induced heating after ionization in a large electric field. They lead to a constraint on this electric field strength which is used as input for an analytical model which predicts the minimum attainable spot size as a function of, amongst others, the flux density of the atomic beam, the temperature of this beam, and the total current. At low currents (I < 10 pA), the spot size will be limited by a combination of spherical aberration and brightness, while at higher currents, this is a combination of chromatic aberration and brightness. It is expected that a nanometer size spot is possible at a current of 1 pA. The analytical model was verified with particle tracing simulations of a complete <span class="hlt">focused</span> <span class="hlt">ion</span> beam setup. A genetic algorithm was used to find the optimum acceleration electric field as a function of the current. At low currents, the result agrees well with the analytical model, while at higher currents, the spot sizes found are even lower due to effects that are not taken into account in the analytical model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/20778553','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/20778553"><span>Conical octopole <span class="hlt">ion</span> guide: Design, <span class="hlt">focusing</span>, and its application to the deposition of low energetic clusters</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Roettgen, Martin A.; Judai, Ken; Antonietti, Jean-Marie; Heiz, Ueli; Rauschenbach, Stephan; Kern, Klaus</p> <p>2006-01-15</p> <p>A design of a radio-frequency (rf) octopole <span class="hlt">ion</span> guide with truncated conical rods arranged in a conical geometry is presented. The performance is tested in a cluster deposition apparatus used for the soft-landing of size-selected clusters on well-characterized substrates used as a model system in heterogeneous catalysis in ultrahigh vacuum. This device allows us to <span class="hlt">focus</span> 500 pA of a mass-selected Ni{sub 20}{sup +} cluster <span class="hlt">ion</span> beam from 9 mm down to a spot size of 2 mm in diameter. The transmittance is 70%{+-}5% at a rf voltage of 420 V{sub pp} applied over an amateur radio transceiver with an interposed homemade amplifier-transformer circuit. An increase of the cluster density by a factor of 15 has been achieved. Three <span class="hlt">ion</span> trajectories are simulated by using SIMION6, which are relevant for this <span class="hlt">focusing</span> device: transmitted, reflected, and absorbed. The observed effects in the simulations can be successfully explained by the adiabatic approximation. The <span class="hlt">focusing</span> behavior of the conical octopole lens is demonstrated by experiment and simulations to be a very useful technique for increasing molecule or cluster densities on a substrate and thus reducing deposition time.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17204060','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17204060"><span>Application of the <span class="hlt">focused</span> <span class="hlt">ion</span> beam technique in aerosol science: detailed investigation of selected, airborne particles.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kaegi, R; Gasser, Ph</p> <p>2006-11-01</p> <p>The <span class="hlt">focused</span> <span class="hlt">ion</span> beam technique was used to fabricate transmission electron microscope lamellas of selected, micrometre-sized airborne particles. Particles were sampled from ambient air on Nuclepore polycarbonate filters and analysed with an environmental scanning electron microscope. A large number of particles between 0.6 and 10 microm in diameter (projected optical equivalent diameter) were detected and analysed using computer-controlled scanning electron microscopy. From the resulting dataset, where the chemistry, morphology and position of each individual particle are stored, two particles were selected for a more detailed investigation. For that purpose, the particle-loaded filter was transferred from the environmental scanning electron microscope to the <span class="hlt">focused</span> <span class="hlt">ion</span> beam, where lamellas of the selected particles were fabricated. The definition of a custom coordinate system enabled the relocation of the particles after the transfer. The lamellas were finally analysed with an analytical transmission electron microscope. Internal structure and elemental distribution maps of the interior of the particles provided additional information about the particles, which helped to assign the particles to their sources. The combination of computer-controlled scanning electron microscopy, <span class="hlt">focused</span> <span class="hlt">ion</span> beam and transmission electron microscopy offers new possibilities for characterizing airborne particles in great detail, eventually enabling a detailed source apportionment of specific particles. The particle of interest can be selected from a large dataset (e.g. based on chemistry and/or morphology) and then investigated in more detail in the transmission electron microscope.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20170003087&hterms=Energy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DEnergy','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20170003087&hterms=Energy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DEnergy"><span>Inverse <span class="hlt">Energy</span> Dispersion of Energetic <span class="hlt">Ions</span> Observed in the Magnetosheath</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lee, S. H.; Sibeck, D. G.; Hwang, K.-J.; Wang, Y.; Silveira, M. V. D.; Fok, M.-C.; Mauk, B. H.; Cohen, I. J.; Ruohoniemi, J. M.; Kitamura, N.; Burch, J. L.; Giles, B. L.; Torbert, R. B.; Russell, C. T.; Lester, M.</p> <p>2016-01-01</p> <p>We present a case study of energetic <span class="hlt">ions</span> observed by the Energetic Particle Detector (EPD) on the Magnetospheric Multiscale spacecraft in the magnetosheath just outside the subsolar magnetopause that occurred at 1000 UT on 8 December 2015. As the magnetopause receded inward, the EPD observed a burst of energetic (approximately 50-1000 keV) proton, helium, and oxygen <span class="hlt">ions</span> that exhibited an inverse dispersion, with the lowest <span class="hlt">energy</span> <span class="hlt">ions</span> appearing first. The prolonged interval of fast antisunward flow observed in the magnetosheath and transient increases in the H components of global ground magnetograms demonstrate that the burst appeared at a time when the magnetosphere was rapidly compressed. We attribute the inverse <span class="hlt">energy</span> dispersion to the leakage along reconnected magnetic field lines of betatron-accelerated energetic <span class="hlt">ions</span> in the magnetosheath, and a burst of reconnection has an extent of about 1.5 R(sub E) using combined Super Dual Auroral Radar Network radar and EPD observations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMSM12A..04L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMSM12A..04L"><span>Inverse <span class="hlt">Energy</span> Dispersion of Energetic <span class="hlt">Ions</span> Observed in the Magnetosheath</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lee, S. H.; Sibeck, D. G.; Hwang, K. J.; Wang, Y.; Silveira, M. D.; Fok, M. C. H.; Mauk, B.; Cohen, I. J.; Ruohoniemi, J. M.; Kitamura, N.; Burch, J. L.; Giles, B. L.; Torbert, R. B.; Russell, C. T.; Lester, M.</p> <p>2016-12-01</p> <p>We present a case study of energetic <span class="hlt">ions</span> observed by the Energetic Particle Detector (EPD) on the Magnetospheric Multiscale (MMS) spacecraft in the magnetosheath just outside the subsolar magnetopause that occurred at 1000 UT on December 8, 2015. As the magnetopause receded inward, the EPD observed a burst of energetic ( 50-1000 keV) proton, helium, and oxygen <span class="hlt">ions</span> that exhibited an inverse dispersion, with the lowest <span class="hlt">energy</span> <span class="hlt">ions</span> appearing first. The prolonged interval of fast antisunward flow observed in the magnetosheath and transient increases in the H components of global ground magnetograms demonstrate that the burst appeared at a time when the magnetosphere was rapidly compressed. We attribute the inverse <span class="hlt">energy</span> dispersion to the leakage along reconnected magnetic field lines of betatron-accelerated energetic <span class="hlt">ions</span> in the magnetosheath and a burst of reconnection has an extent of about 1.5 RE using combined Super Dual Auroral Radar Network (SuperDARN) radar and EPD observations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3064342','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3064342"><span><span class="hlt">Ion</span> clustering in aqueous solutions probed with vibrational <span class="hlt">energy</span> transfer</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Bian, Hongtao; Wen, Xiewen; Li, Jiebo; Chen, Hailong; Han, Suzee; Sun, Xiuquan; Song, Jian; Zhuang, Wei; Zheng, Junrong</p> <p>2011-01-01</p> <p>Despite prolonged scientific efforts to unravel the hydration structures of <span class="hlt">ions</span> in water, many open questions remain, in particular concerning the existences and structures of <span class="hlt">ion</span> clusters in 1∶1 strong electrolyte aqueous solutions. A combined ultrafast 2D IR and pump/probe study through vibrational <span class="hlt">energy</span> transfers directly observes <span class="hlt">ion</span> clustering in aqueous solutions of LiSCN, NaSCN, KSCN and CsSCN. In a near saturated KSCN aqueous solution (water/KSCN molar ratio = 2.4/1), 95% of the anions form <span class="hlt">ion</span> clusters. Diluting the solution results in fewer, smaller, and tighter clusters. Cations have significant effects on cluster formation. A small cation results in smaller and fewer clusters. The vibrational <span class="hlt">energy</span> transfer method holds promise for studying a wide variety of other fast short-range molecular interactions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20170003087&hterms=Energy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DEnergy','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20170003087&hterms=Energy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DEnergy"><span>Inverse <span class="hlt">Energy</span> Dispersion of Energetic <span class="hlt">Ions</span> Observed in the Magnetosheath</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lee, S. H.; Sibeck, D. G.; Hwang, K.-J.; Wang, Y.; Silveira, M. V. D.; Fok, M.-C.; Mauk, B. H.; Cohen, I. J.; Ruohoniemi, J. M.; Kitamura, N.; <a style="text-decoration: none; " href="javascript:void(0); " onClick="displayelement('author_20170003087'); toggleEditAbsImage('author_20170003087_show'); toggleEditAbsImage('author_20170003087_hide'); "> <img style="display:inline; width:12px; height:12px; " src="images/arrow-up.gif" width="12" height="12" border="0" alt="hide" id="author_20170003087_show"> <img style="width:12px; height:12px; display:none; " src="images/arrow-down.gif" width="12" height="12" border="0" alt="hide" id="author_20170003087_hide"></p> <p>2016-01-01</p> <p>We present a case study of energetic <span class="hlt">ions</span> observed by the Energetic Particle Detector (EPD) on the Magnetospheric Multiscale spacecraft in the magnetosheath just outside the subsolar magnetopause that occurred at 1000 UT on 8 December 2015. As the magnetopause receded inward, the EPD observed a burst of energetic (approximately 50-1000 keV) proton, helium, and oxygen <span class="hlt">ions</span> that exhibited an inverse dispersion, with the lowest <span class="hlt">energy</span> <span class="hlt">ions</span> appearing first. The prolonged interval of fast antisunward flow observed in the magnetosheath and transient increases in the H components of global ground magnetograms demonstrate that the burst appeared at a time when the magnetosphere was rapidly compressed. We attribute the inverse <span class="hlt">energy</span> dispersion to the leakage along reconnected magnetic field lines of betatron-accelerated energetic <span class="hlt">ions</span> in the magnetosheath, and a burst of reconnection has an extent of about 1.5 R(sub E) using combined Super Dual Auroral Radar Network radar and EPD observations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1050030','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1050030"><span>Science Requirements and Conceptual Design for a Polarized Medium <span class="hlt">Energy</span> Electron-<span class="hlt">Ion</span> Collider at Jlab</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Abeyratne, S; Ahmed, S; Barber, D; Bisognano, J; Bogacz, A; Castilla, A; Chevtsov, P; Corneliussen, S; Deconinck, W; Degtiarenko, P; Delayen, J; Derbenev, Ya; DeSilva, S; Douglas, D; Dudnikov, V; Ent, R; Erdelyi, B; Evtushenko, P; Fujii, Yu; Filatov, Yury; Gaskell, D; Geng, R; Guzey, V; Horn, T; Hutton, A; Hyde, C; Johnson, R; Kim, Y; Klein, F; Kondratenko, A; Kondratenko, M; Krafft, G; Li, R; Lin, F; Manikonda, S; Marhauser, F; McKeown, R; Morozov, V; Dadel-Turonski, P; Nissen, E; Ostroumov, P; Pivi, M; Pilat, F; Poelker, M; Prokudin, A; Rimmer, R; Satogata, T; Sayed, H; Spata, M; Sullivan, M; Tennant, C; Terzic, B; Tiefenback, M; Wang, M; Wang, S; Weiss, C; Yunn, B; Zhang, Y</p> <p>2012-08-01</p> <p> beginning, the design studies at Jefferson Lab have <span class="hlt">focused</span> on achieving high collider performance, particularly ultrahigh luminosities up to 10{sup 34} cm{sup -2}s{sup -1} per detector with large acceptance, while maintaining high polarization for both the electron and light-<span class="hlt">ion</span> beams. These are the two key performance requirements of a future electron-<span class="hlt">ion</span> collider facility as articulated by the NSAC Long Range Plan. In MEIC, a new <span class="hlt">ion</span> complex is designed specifically to deliver <span class="hlt">ion</span> beams that match the high bunch repetition and highly polarized electron beam from CEBAF. During the last two years, both development of the science case and optimization of the machine design point toward a medium-<span class="hlt">energy</span> electron-<span class="hlt">ion</span> collider as the topmost goal for Jefferson Lab. The MEIC, with relatively compact collider rings, can deliver a luminosity above 10{sup 34} cm{sup -2}s{sup -1} at a center-of-mass <span class="hlt">energy</span> up to 65 GeV. It offers an electron <span class="hlt">energy</span> up to 11 GeV, a proton <span class="hlt">energy</span> up to 100 GeV, and corresponding <span class="hlt">energies</span> per nucleon for heavy <span class="hlt">ions</span> with the same magnetic rigidity. This design choice balances the scope of the science program, collider capabilities, accelerator technology innovation, and total project cost. An <span class="hlt">energy</span> upgrade could be implemented in the future by adding two large collider rings housed in another large tunnel to push the center-of-mass <span class="hlt">energy</span> up to or exceeding 140 GeV. After careful consideration of an alternative electron <span class="hlt">energy</span> recovery linac on <span class="hlt">ion</span> storage ring approach, a ring-ring collider scenario at high bunch repetition frequency was found to offer fully competitive performance while eliminating the uncertainties of challenging R&D on ampere-class polarized electron sources and many-pass <span class="hlt">energy</span>-recovery linacs (ERLs). The essential new elements of an MEIC facility at Jefferson Lab are an electron storage ring and an entirely new, modern <span class="hlt">ion</span> acceleration and storage complex. For the high-current electron collider ring, the upgraded 12 GeV CEBAF SRF</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009APS..MAR.A5003W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009APS..MAR.A5003W"><span>Direct writing of electronic circuits and micromachining by <span class="hlt">focused</span> <span class="hlt">ion</span> beam (FIB) implantation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wieck, Andreas Dirk</p> <p>2009-03-01</p> <p>The maskless implantation of FIBs in semiconductors creates a local doping. In n-type conducting sheets, p-lines are written to insulate n-regions laterally from each other or vice versa. In this way, conducting areas can be biased with respect to each other. Narrow paths are easily driven into depletion, creating lateral transistor channels. The advent of multi-focussed-<span class="hlt">ion</span>-beams allows a more parallel writing of such integrated circuits. For <span class="hlt">ion</span> beam milling, a new long-life Bismuth (Bi) source is developed and employed [1]. Bi is the heaviest, non-radioactive element and has thus a maximal impact on the material to be sputtered locally. It is non-toxic, well available, mono-isotopic, and inexpensive, has a low melting temperature, and comes even in clusters and the single charged particles make up 95% of the whole FIB-beam. This means that the chromatic errors of the electrostatic Einzel-lenses in the FIB system are not important. Since heavy <span class="hlt">ions</span> are slower than light ones at the same <span class="hlt">energy</span>, Bi penetrates to a minimal depth into the target, leaving minimal contaminations. The sputter rate is about 5 times higher than the one of the usual Ga. Since Bi is the only element in this source, it is not necessary to separate it from other <span class="hlt">ions</span> by a mass filter. Bi is thus a good candidate to improve the performance of sputter-FIBs ultimately, up to replacing Ga. We developed FIB - liquid metal <span class="hlt">ion</span> sources of nearly all metallic elements in the periodic table. In this way, practically all dopants can be introduced into semiconductors after epitaxial growth in a full ultra-high vacuum process, which enhances the flexibility of the material choice enormously. [4pt] [1] P. Mazarov, A. Melnikov, R. Wernhardt, and A.D. Wieck, Long-life bismuth liquid metal <span class="hlt">ion</span> source for focussed <span class="hlt">ion</span> beam micromachining application, Appl. Surf. Sci. 254, 7401 (2008).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhPro..72..266P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhPro..72..266P"><span>The 2nd Order <span class="hlt">Focusing</span> by <span class="hlt">Energy</span> for TOF Sector Field Mass Analyzer with an Orthogonal Acceleration: Theory, Modeling, Experiment</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Poteshin, S. S.; Chernyshev, D. M.; Sysoev, Alexey A.; Sysoev, Alexander A.</p> <p></p> <p>Currently axially symmetric type of analyzer with an electrostatic sector fields (AESF) is rarely used to construct time-of-flight mass spectrometers. The main drawback, hindering the wider use of the analyzers of this type, is the lack of chromatic second-order <span class="hlt">focusing</span> by <span class="hlt">energy</span>. However, the configuration of AESF in combination with orthogonal accelerator (OA) allows to achieved it through compensation of <span class="hlt">energy</span> aberrations of the analyzer in the system of orthogonal input of the <span class="hlt">ion</span> beam. In the presented work the results of theoretical calculation, simulation and experimentally obtained data are compared. Characteristics of the analyzer with OA in a large extent depend on the parameters of the incoming <span class="hlt">ion</span> beam. Data of modeling the 2nd stage of gas-dynamic interface, which have the greatest influence on the parameters of the <span class="hlt">ion</span> beam, is provided.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19850025258','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19850025258"><span>Use of low <span class="hlt">energy</span> hydrogen <span class="hlt">ion</span> implants in high efficiency crystalline silicon solar cells</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Fonash, S. J.; Singh, R.</p> <p>1985-01-01</p> <p>This program is a study of the use of low <span class="hlt">energy</span> hydrogen <span class="hlt">ion</span> implantation for high efficiency crystalline silicon solar cells. The first quarterly report <span class="hlt">focuses</span> on two tasks of this program: (1) an examination of the effects of low <span class="hlt">energy</span> hydrogen implants on surface recombination speed; and (2) an examination of the effects of hydrogen on silicon regrowth and diffusion in silicon. The first part of the project focussed on the measurement of surface properties of hydrogen implanted silicon. Low <span class="hlt">energy</span> hydrogen <span class="hlt">ions</span> when bombarded on the silicon surface will create structural damage at the surface, deactivate dopants and introduce recombination centers. At the same time the electrically active centers such as dangling bonds will be passivated by these hydrogen <span class="hlt">ions</span>. Thus hydrogen is expected to alter properties such as the surface recombination velocity, dopant profiles on the emitter, etc. In this report the surface recombination velocity of a hydrogen emplanted emitter was measured.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/6214734','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/6214734"><span><span class="hlt">Ion</span> composition and <span class="hlt">energy</span> distribution during 10 magnetic storms</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Lennartsson, W.; Sharp, R.D.; Shelley, E.G.; Johnson, R.G.; Balsiger, H.</p> <p>1981-06-01</p> <p>Data from the plasma composition experiment on ISEE 1 were used to investigate the relative quantities and <span class="hlt">energy</span> characteristics of H/sup +/, He/sup + +/, and O/sup +/ in the near-equatorial magnetosphere at R< or =15 R/sub E/ during magnetic storms, principally during the early main phase. The <span class="hlt">ions</span> included in this study had <span class="hlt">energies</span> in the range of 0.1< or =E/Q< or =17 keV/e. The number densities were characterized by a large to dominant fraction of terrestrial <span class="hlt">ions</span> through this <span class="hlt">energy</span> window. Terrestrial O/sup +/ <span class="hlt">ions</span> were most clearly identified, but strong evidence for a significant contribution of terrestrial H/sup +/ <span class="hlt">ions</span> was also found. On occasions, the O/sup +/ alone contributed 50% or more of the integral number density, as well as the <span class="hlt">energy</span> density, over distances of several earth radii along the orbit. The largest fractions of O/sup +/ (< or approx. =75%) and He/sup +/ (< or =25%) were found at R<3 R/sub E/(L<5). In general, the He/sup +/ only represented a few percent, however. Small fractions of O/sup +/ (<10%) and He/sup +/ (<1%) were mostly found in the 0100--0600 LT sector, at R> or approx. = 7 R/sub E/. The He/sup + +/ was often obscured by background and rarely exceeded 2%, except in the 0100--0600 LT sector, at R> or approx. =7 R/sub E/, where it reached several percent relatively frequently, suggesting a larger solar wind component here. It is argued, based on certain signatures in the <span class="hlt">energy</span> spectra, that solar wind <span class="hlt">ions</span> may enter the inner magnetosphere through this region and thereby contribute a larger portion of the high-<span class="hlt">energy</span> ring current population (50--100 keV). The data do not suggest, however, that the solar wind is always the dominant source of <span class="hlt">ions</span> for the high-<span class="hlt">energy</span> ring current.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/6838622','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/6838622"><span>Electron capture in <span class="hlt">ion</span>-molecule collisions at intermediate <span class="hlt">energy</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Kumura, M.</p> <p>1986-01-01</p> <p>Recent progress of theoretical charge transfer study in <span class="hlt">ion</span>-molecule collisions at the intermediate <span class="hlt">energy</span> is reviewed. Concept of close and distant collisions obtained from extensive <span class="hlt">ion</span>-atom collision studies is identified so that it can be utilized to model two distinct collision processes. For a close collision, explicit representation of the whole collision complex is necessary to describe collision dynamics correctly, while a model potential approach for molecule is appropriate for a distant collision. It is shown that these two distinct models are indeed capable of reproducing experimental charge transfer cross sections. Some remarks for further theoretical study of <span class="hlt">ion</span>-molecule collisions are also given. 21 refs., 8 figs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/933067','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/933067"><span><span class="hlt">Energy</span> loss of coasting gold <span class="hlt">ions</span> and deuterons in RHIC.</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Abreu,N.; Blaskiewicz, M.; Brown, K.A.; Butler, J.J.; FischW; Harvey, M.; Tepikian, S.</p> <p>2008-06-23</p> <p>The total <span class="hlt">energy</span> loss of coasting gold <span class="hlt">ion</span> beams was measured at RHIC at two <span class="hlt">energies</span>, corresponding to a gamma of 75.2 and 107.4. We describe the experiment and observations and compare the measured total <span class="hlt">energy</span> loss with expectations from ionization losses at the residual gas, the <span class="hlt">energy</span> loss due to impedance and synchrotron radiation. We find that the measured <span class="hlt">energy</span> losses are below what is expected from free space synchrotron radiation. We believe that this shows evidence for suppression of synchrotron radiation which is cut off at long wavelength by the presence of the conducting beam pipe.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20000032536','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20000032536"><span>Range and <span class="hlt">Energy</span> Straggling in <span class="hlt">Ion</span> Beam Transport</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wilson, John W.; Tai, Hsiang</p> <p>2000-01-01</p> <p>A first-order approximation to the range and <span class="hlt">energy</span> straggling of <span class="hlt">ion</span> beams is given as a normal distribution for which the standard deviation is estimated from the fluctuations in <span class="hlt">energy</span> loss events. The standard deviation is calculated by assuming scattering from free electrons with a long range cutoff parameter that depends on the mean excitation <span class="hlt">energy</span> of the medium. The present formalism is derived by extrapolating Payne's formalism to low <span class="hlt">energy</span> by systematic <span class="hlt">energy</span> scaling and to greater depths of penetration by a second-order perturbation. Limited comparisons are made with experimental data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/812456','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/812456"><span><span class="hlt">Focused</span> <span class="hlt">ion</span> beam assisted three-dimensional rock imaging at submicron scale</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Tomutsa, Liviu; Radmilovic, Velimir</p> <p>2003-05-09</p> <p>Computation of effective flow properties of fluids in porous media based on three dimensional (3D) pore structure information has become more successful in the last few years, due to both improvements in the input data and the network models. Computed X-ray microtomography has been successful in 3D pore imaging at micron scale, which is adequate for many sandstones. For other rocks of economic interest, such as chalk and diatomite, submicron resolution is needed in order to resolve the 3D-pore structure. To achieve submicron resolution, a new method of sample serial sectioning and imaging using <span class="hlt">Focused</span> <span class="hlt">Ion</span> Beam (FIB) technology has been developed and 3D pore images of the pore system for diatomite and chalk have been obtained. FIB was used in the milling of layers as wide as 50 micrometers and as thin as 100 nanometers by sputtering of atoms from the sample surface. The <span class="hlt">focused</span> <span class="hlt">ion</span> beam, consisting of gallium <span class="hlt">ions</span> (Ga+) accelerated by potentials of up to 30 kV and currents up to 20,000 pA, yields very clean, flat surfaces in which the pore-grain boundaries appear in high contrast. No distortion of the pore boundaries due to the <span class="hlt">ion</span> milling is apparent. After each milling step, as a new surface is exposed, an image of the surface is generated. Using secondary electrons or <span class="hlt">ions</span>, resolutions as high as 10 nm can be obtained. Afterwards, the series of 2D images can be stacked in the computer and, using appropriate interpolation and surface rendering algorithms, the 3D pore structure is reconstructed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21978256','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21978256"><span>Mining the ChEMBL database: an efficient chemoinformatics workflow for assembling an <span class="hlt">ion</span> channel-<span class="hlt">focused</span> screening library.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mok, N Yi; Brenk, Ruth</p> <p>2011-10-24</p> <p>The ChEMBL database was mined to efficiently assemble an <span class="hlt">ion</span> channel-<span class="hlt">focused</span> screening library. The compiled library consists of 3241 compounds representing 123 templates across nine <span class="hlt">ion</span> channel categories. Compounds in the screening library are annotated with their respective <span class="hlt">ion</span> channel category to facilitate back-tracing of prospective molecular targets from phenotypic screening results. The established workflow is adaptable to the construction of <span class="hlt">focused</span> screening libraries for other therapeutic target classes with diverse recognition motifs.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_20 --> <div id="page_21" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="401"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhDT.......518S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhDT.......518S"><span>Locally Appropriate <span class="hlt">Energy</span> Strategies for the Developing World: A <span class="hlt">focus</span> on Clean <span class="hlt">Energy</span> Opportunities in Borneo</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shirley, Rebekah Grace</p> <p></p> <p>This dissertation <span class="hlt">focuses</span> on an integration of <span class="hlt">energy</span> modeling tools to explore <span class="hlt">energy</span> transition pathways for emerging economies. The spate of growth in the global South has led to a global <span class="hlt">energy</span> transition, evidenced in part by a surge in the development of large scale <span class="hlt">energy</span> infrastructure projects for the provision of reliable electricity service. The rational of <span class="hlt">energy</span> security and exigency often usher these large scale projects through to implementation with minimal analysis of costs: social and environmental impact, ecological risk, or opportunity costs of alternative <span class="hlt">energy</span> transition pathways foregone. Furthermore, development of <span class="hlt">energy</span> infrastructure is inherently characterized by the involvement of a number of state and non-state actors, with varying interests, objectives and access to authority. Being woven through and into social institutions necessarily impacts the design, control and functionality of infrastructure. In this dissertation I therefore conceptualize <span class="hlt">energy</span> infrastructure as lying at the intersection, or nexus, of people, the environment and <span class="hlt">energy</span> security. I argue that <span class="hlt">energy</span> infrastructure plans and policy should, and can, be informed by each of these fields of influence in order to appropriately satisfy local development needs. This case study explores the socio-techno-environmental context of contemporary mega-dam development in northern Borneo. I describe the key actors of an ongoing mega-dam debate and the constellation of their interaction. This highlights the role that information may play in public discourse and lends insight into how inertia in the established system may stymie technological evolution. I then use a combination of power system simulation, ecological modeling and spatial analysis to analyze the potential for, and costs and tradeoffs of, future <span class="hlt">energy</span> scenarios. In this way I demonstrate reproducible methods that can support <span class="hlt">energy</span> infrastructure decision making by directly addressing data limitation barriers. I</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1999JPhB...32.4261A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1999JPhB...32.4261A"><span>Bremsstrahlung spectra from atoms and <span class="hlt">ions</span> at low relativistic <span class="hlt">energies</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Avdonina, N. B.; Pratt, R. H.</p> <p>1999-09-01</p> <p>Analytic expressions for bremsstrahlung spectra from neutral atoms and <span class="hlt">ions</span>, including the polarizational bremsstrahlung contribution in a stripped atom approximation, are developed for electron scattering at <span class="hlt">energies</span> of 10-2000 keV. A modified Elwert factor and a simple higher Born correction are used for the Coulomb spectrum, with ordinary bremsstrahlung screening effects in <span class="hlt">ions</span> and atoms adequately characterized in the non-relativistic Born approximation. In parallel with the development of this analytic description, new numerical results are obtained for ordinary bremsstrahlung from <span class="hlt">ions</span> and from bare nuclei, appreciably extending the available data set which can be used to study dependences on element, ionicity, <span class="hlt">energy</span> and the fraction of incident <span class="hlt">energy</span> radiated. The accuracy of predictions with the analytic expressions is then determined by comparison with the full numerical relativistic partial-wave results for ordinary bremsstrahlung and with non-relativistic numerical results in the Born approximation or in partial waves for the polarizational amplitude.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20481616','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20481616"><span>Dissociation of <span class="hlt">energy</span>-selected 1,1-dimethylhydrazine <span class="hlt">ions</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gengeliczki, Zsolt; Borkar, Sampada N; Sztáray, Bálint</p> <p>2010-05-27</p> <p>The unimolecular dissociation of 1,1-dimethylhydrazine <span class="hlt">ions</span> was studied by threshold photoelectron photoion coincidence spectroscopy (TPEPICO). Time-of-flight distributions and breakdown curves were recorded in the photon <span class="hlt">energy</span> range of 9.5-10.4 eV. The 0 K appearance <span class="hlt">energies</span> of the fragment <span class="hlt">ions</span> were extracted by modeling the experimental data with rigid activated complex (RAC-) RRKM theory. It was found that the data could be well-reproduced with a single TS for each dissociation channel if two different H-loss channels were assumed, one corresponding to a C-H and the other to a N-H bond dissociation. Once the appearance <span class="hlt">energies</span> were established, heats of formation of the fragment <span class="hlt">ions</span> could be derived. The heat of formation of the neutral molecule was computed by applying composite ab initio methods (G3, CBS-APNO, W1U) on a series of isodesmic reactions between methyl hydrazines and methyl amines.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19790064331&hterms=wave+energy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dwave%2Benergy','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19790064331&hterms=wave+energy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dwave%2Benergy"><span>Heating of <span class="hlt">ions</span> to superthermal <span class="hlt">energies</span> in the topside ionosphere by electrostatic <span class="hlt">ion</span> cyclotron waves</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ungstrup, E.; Klumpar, D. M.; Heikkila, W. J.</p> <p>1979-01-01</p> <p>The soft particle spectrometer on the Isis 2 spacecraft occasionally observes fluxes of <span class="hlt">ions</span> moving upward out of the ionosphere in the vicinity of the auroral oval. These <span class="hlt">ion</span> fluxes are characterized by a sharp pitch angle distribution usually peaked at an angle somewhat greater than 90 deg, indicative of particles heated to a large transverse temperature in a narrow range below the spacecraft. The observations are interpreted in terms of electrostatic <span class="hlt">ion</span> cyclotron waves, which heat the <span class="hlt">ions</span> to superthermal <span class="hlt">energies</span> transverse to the earth's magnetic field. When the transverse <span class="hlt">energy</span> increases, the repulsive force of the earth's magnetic field, proportional to the particle magnetic moment, repels the particles away from the earth.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19790064331&hterms=wave+energy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dwave%2Benergy','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19790064331&hterms=wave+energy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dwave%2Benergy"><span>Heating of <span class="hlt">ions</span> to superthermal <span class="hlt">energies</span> in the topside ionosphere by electrostatic <span class="hlt">ion</span> cyclotron waves</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ungstrup, E.; Klumpar, D. M.; Heikkila, W. J.</p> <p>1979-01-01</p> <p>The soft particle spectrometer on the Isis 2 spacecraft occasionally observes fluxes of <span class="hlt">ions</span> moving upward out of the ionosphere in the vicinity of the auroral oval. These <span class="hlt">ion</span> fluxes are characterized by a sharp pitch angle distribution usually peaked at an angle somewhat greater than 90 deg, indicative of particles heated to a large transverse temperature in a narrow range below the spacecraft. The observations are interpreted in terms of electrostatic <span class="hlt">ion</span> cyclotron waves, which heat the <span class="hlt">ions</span> to superthermal <span class="hlt">energies</span> transverse to the earth's magnetic field. When the transverse <span class="hlt">energy</span> increases, the repulsive force of the earth's magnetic field, proportional to the particle magnetic moment, repels the particles away from the earth.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007PhDT.........5Q','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007PhDT.........5Q"><span>Low <span class="hlt">energy</span> <span class="hlt">ion</span> beam assisted growth of metal multilayers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Quan, Junjie</p> <p></p> <p>Vapor deposited metal multilayers have attracted a great deal of interest in recent years because they offer extraordinary strength, hardness, heat resistance, and unexpected new properties like high reflectivity and spin-dependent conductivity. The giant magnetoresistance effects discovered in Fe/Cr artificial superstructures in 1988 stimulated a large number of studies on the electronic transport properties of spintronic materials because of their important applications in highly sensitive magnetic sensors, nonvolatile random access memories, and the data storage industry in general. Magnetic multilayers allow exploitation of unique micromagnetic, magnetooptic, and magnetoelectronic phenomena that cannot be realized using conventional materials. For example, if ferromagnetic layers (such as CoFe) with a thicknesses of 5-7 nm are separated by a non-magnetic spacer (such as Cu or AlOx) of an appropriate thickness (1-3 nm), they can exhibit large changes in their electrical resistance when a magnetic field is applied. These changes are caused mainly by spin-dependent conduction electron scattering at magnetic multilayer interfaces. Many experimental and theoretical works have sought to promote a basic understanding of the effect of atomic structure in thin film multilayers upon spin dependent transport. It has been found that interfacial imperfections, such as interfacial roughness and interlayer mixing, dramatically reduce the properties exploited for spintronic applications. A combination of computer modeling and experiments has been used to discover more effective ways to control the interfacial structures of metal multilayers. Earlier atomic simulations had indicated that it is very important to control adatom <span class="hlt">energy</span> during deposition in order to improve interface properties. Based on these ideas, this dissertation has investigated the effects of low <span class="hlt">energy</span> <span class="hlt">ion</span> assistance during metal multilayer deposition. Using molecular dynamics modeling, the effects of <span class="hlt">ion</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/1079105','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/1079105"><span>How Constant Momentum Acceleration Decouples <span class="hlt">Energy</span> and Space <span class="hlt">Focusing</span> in Distance-of-Flight and Time-of-Flight Mass Spectrometries</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Dennis, Elise; Gundlach-Graham, Alexander W.; Enke, Chris; Ray, Steven J.; Carado, Anthony J.; Barinaga, Charles J.; Koppenaal, David W.; Hieftje, Gary M.</p> <p>2013-05-01</p> <p>Time-of-flight (TOF) and distance-of-flight (DOF) mass spectrometers require means for <span class="hlt">focusing</span> <span class="hlt">ions</span> at the detector(s) because of initial dispersions of position and <span class="hlt">energy</span> at the time of their acceleration. Time-of-flight mass spectrometers ordinarily employ constant <span class="hlt">energy</span> acceleration (CEA), which creates a space-<span class="hlt">focus</span> plane at which the initial spatial dispersion is corrected. In contrast, constant-momentum acceleration (CMA), in conjunction with an <span class="hlt">ion</span> mirror, provides <span class="hlt">focus</span> of the initial <span class="hlt">energy</span> dispersion at the <span class="hlt">energy</span> <span class="hlt">focus</span> time for <span class="hlt">ions</span> of all m/z at their respective positions along the flight path. With CEA, the initial <span class="hlt">energy</span> dispersion is not simultaneously correctable as its effect on <span class="hlt">ion</span> velocity is convoluted with that of the spatial dispersion. The initial spatial dispersion with CMA remains unchanged throughout the field-free region of the flight path, so spatial dispersion can be reduced before acceleration. Improved <span class="hlt">focus</span> is possible when each dispersion can be addressed independently. With minor modification, a TOF mass spectrometer can be operated in CMA mode by treating the TOF detector as though it were a single element in the array of detectors that would be used in a DOF mass spectrometer. Significant improvement in mass resolution is thereby achieved, albeit over a narrow range of m/z values. In this paper, experimental and theoretical results are presented that illustrate the <span class="hlt">energy-focusing</span> capabilities of both DOF and TOF mass spectrometry.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21637203','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21637203"><span>Imaging three-dimensional tissue architectures by <span class="hlt">focused</span> <span class="hlt">ion</span> beam scanning electron microscopy.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bushby, Andrew J; P'ng, Kenneth M Y; Young, Robert D; Pinali, Christian; Knupp, Carlo; Quantock, Andrew J</p> <p>2011-06-01</p> <p>In this protocol, we describe a 3D imaging technique known as 'volume electron microscopy' or '<span class="hlt">focused</span> <span class="hlt">ion</span> beam scanning electron microscopy (FIB/SEM)' applied to biological tissues. A scanning electron microscope equipped with a <span class="hlt">focused</span> gallium <span class="hlt">ion</span> beam, used to sequentially mill away the sample surface, and a backscattered electron (BSE) detector, used to image the milled surfaces, generates a large series of images that can be combined into a 3D rendered image of stained and embedded biological tissue. Structural information over volumes of tens of thousands of cubic micrometers is possible, revealing complex microanatomy with subcellular resolution. Methods are presented for tissue processing, for the enhancement of contrast with osmium tetroxide/potassium ferricyanide, for BSE imaging, for the preparation and platinum deposition over a selected site in the embedded tissue block, and for sequential data collection with <span class="hlt">ion</span> beam milling; all this takes approximately 90 h. The imaging conditions, procedures for alternate milling and data acquisition and techniques for processing and partitioning the 3D data set are also described; these processes take approxiamtely 30 h. The protocol is illustrated by application to developing chick cornea, in which cells organize collagen fibril bundles into complex, multilamellar structures essential for transparency in the mature connective tissue matrix. The techniques described could have wide application in a range of fields, including pathology, developmental biology, microstructural anatomy and regenerative medicine.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1995SPIE.2512..398S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1995SPIE.2512..398S"><span>State of the art in <span class="hlt">focused</span> <span class="hlt">ion</span>-beam mask repair systems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Stewart, Diane K.; Doherty, John A.; Doyle, Andrew F.; Morgan, John C.</p> <p>1995-07-01</p> <p><span class="hlt">Focused</span> <span class="hlt">ion</span> beam (FIB) systems are commonly used to repair lithographic masks with features below one micron. We will summarize the development of <span class="hlt">focused</span> <span class="hlt">ion</span> beam mask repair systems starting from the original tools developed for photomasks approximately 10 years ago. The present state of the art in FIB mask repair systems is incorporated in two types of tools-one for repair of proximity print X-ray masks, and the other for repair of photomasks and some phase shift masks. Similarities of the two styles of systems include the gallium <span class="hlt">ion</span> optics, the lithographic stage for accurate positioning, a thermal enclosure to minimize system drift, deflection and scanning electronics, and an interface to inspection data. The differences include the process chemistries, repair strategies, and imaging techniques. Examples of a variety of repaired defects on both X-ray and phase shift masks will be shown. Advanced masks such as those for EUV (Extreme Ultraviolet), DUV (Deep Ultraviolet), and SCALPEL (Scattering with Angular Limitation in Projection Electron Lithography) will have to be repaired should those technologies mature, and presumably with FIB tools. Preliminary research and development of advanced mask repair problems will be described and possible approaches will be suggested.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/943519','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/943519"><span>Soft X-Ray Magnetic Imaging of <span class="hlt">Focused</span> <span class="hlt">Ion</span> Beam Lithographically Patterned Fe Thin Films</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Cook, Paul J.; Shen, Tichan H.; Grundy, PhilJ.; Im, Mi Young; Fischer, Peter; Morton, Simon A.; Kilcoyne, Arthur D.L.</p> <p>2008-11-09</p> <p>We illustrate the potential of modifying the magnetic behavior and structural properties of ferromagnetic thin films using <span class="hlt">focused</span> <span class="hlt">ion</span> beam 'direct-write' lithography. Patterns inspired by the split-ring resonators often used as components in meta-materials were defined upon 15 nm Fe films using a 30 keV Ga{sup +} <span class="hlt">focused</span> <span class="hlt">ion</span> beam at a dose of 2 x 10{sup 16} <span class="hlt">ions</span> cm{sup -2}. Structural, chemical and magnetic changes to the Fe were studied using transmission soft X-ray microscopy at the ALS, Berkeley CA. X-ray absorption spectra showed a 23% reduction in the thickness of the film in the Ga irradiated areas, but no change to the chemical environment of Fe was evident. X-ray images of the magnetic reversal process show domain wall pinning around the implanted areas, resulting in an overall increase in the coercivity of the film. Transmission electron microscopy showed significant grain growth in the implanted regions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016APS..MARH17009P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APS..MARH17009P"><span><span class="hlt">Focused</span> helium-<span class="hlt">ion</span> beam irradiation effects on electrical properties of multi-layer WSe2</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pudasaini, Pushpa Raj; Stanford, Michael; Cross, Nick; Duscher, Gerd; Mandrus, David; Rack, Philip</p> <p></p> <p>Atomically thin transition metal dichalcogenides (TMDs) are currently receiving great attention due to their excellent opto-electronic properties. Tuning optical and electrical properties of mono and few layers TMDs, such as Tungsten diselenide (WSe2), by controlling the defects, is an intriguing opportunity to fabricate the next generation opto-electronic devices. Here, we report the effects of <span class="hlt">focused</span> helium <span class="hlt">ion</span> beam irradiation on structural, optical and electrical properties of few layer WSe2, via high resolution scanning transmission electron microscopy, Raman spectroscopy and electrical measurements. By controlling the <span class="hlt">ion</span> irradiation dose, we selectively introduced precise defects in few layer WSe2 thereby locally tuning the electrically resistivity of the material. Hole transport in the few layer WSe2 is severely affected compared to electron transport for the same dose of helium <span class="hlt">ion</span> beam irradiation studied. Furthermore, by selectively exposing the <span class="hlt">ion</span> beams, we demonstrate the lateral p-n junction in few layer WSe2 flakes, which constitute an important advance towards two dimensional opto-electronic devices. Materials Science and Technology Division, ORNL, Oak Ridge, TN 37831, USA.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1994NIMPA.353..568A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1994NIMPA.353..568A"><span>Density and composition analysis using <span class="hlt">focused</span> MeV <span class="hlt">ion</span> mubeam techniques</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Antolak, A. J.; Bench, G. S.; Pontau, A. E.; Morse, D. H.; Heikkinen, D. W.; Weirup, D. L.</p> <p>1994-12-01</p> <p>Nuclear muscopy uses <span class="hlt">focused</span> MeV <span class="hlt">ion</span> mubeams to non-destructively characterize materials and components with mun scale spatial resolution. Although a number of accelerator-based mubeam methods are available for materials analysis, this paper centers on the techniques of <span class="hlt">Ion</span> mutomography (IMT) and Particle-Induced X-ray Emission (PIXE). IMT provides quantitative three-dimensional density information with mun-scale spatial resolution and 1% density variation sensitivity. Recently, IMT has become more versatile because greater emphasis has been placed on understanding the effects of reconstruction artifacts, beam spatial broadening, and limited projection data sets. PIXE provides quantitative elemental information with detection sensitivities to 1 μg/g or below in some instances. By scanning the beam, two-dimensional maps of elemental concentration can also be recorded. However, since X-rays are produced along the entire path of the <span class="hlt">ion</span> beam as it penetrates the sample, these measurements only give depth-averaged information in general. PIXE tomography (PIXET) is the natural extension from conventional PIXE analysis to the full three-dimensional measurement and forms the bridge linking the complementary techniques of PIXE and IMT. This paper presents recent developments and applications of these <span class="hlt">ion</span> beam techniques in a diverse range of fields including characterizing metal-matrix composites, biological specimens and inertial confinement fusion targets.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009JNuM..389..248C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009JNuM..389..248C"><span>Characterization of high <span class="hlt">energy</span> <span class="hlt">ion</span> implantation into Ti-6Al-4V</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Carroll, M. P.; Stephenson, K.; Findley, K. O.</p> <p>2009-06-01</p> <p><span class="hlt">Ion</span> implantation is a surface modification process that can improve the wear, fatigue, and corrosion resistance for several metals and alloys. Much of the research to date has <span class="hlt">focused</span> on <span class="hlt">ion</span> <span class="hlt">energies</span> less than 1 MeV. With this in mind, Ti-6Al-4V was implanted with Al 2+, Au 3+, and N + <span class="hlt">ions</span> at <span class="hlt">energies</span> of 1.5 and 5 MeV and various doses to determine the effects on strengthening of a high <span class="hlt">energy</span> beam. A post heat treatment on the specimens implanted with Al 2+ samples was conducted to precipitate Ti xAl type intermetallics near the surface. Novel techniques, such as nanoindentation, are available now to determine structure-mechanical property relationships in near-surface regions of the implanted samples. Thus, nanoindentation was performed on pre-implanted, as-implanted, and post heat treated samples to detect differences in elastic modulus and hardness at the sub-micron scale. In addition, sliding wear tests were performed to qualitatively determine the changes in wear performance. The effect of this processing was significant for samples implanted with Al 2+ <span class="hlt">ions</span> at 1.5 MeV with a dose higher than 1 × 10 16 <span class="hlt">ions</span>/cm 2 where precipitation hardening likely occurs and with N + <span class="hlt">ions</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1999AIPC..475..583B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1999AIPC..475..583B"><span>Influence of planar oscillations on scattered <span class="hlt">ion</span> <span class="hlt">energy</span> distributions in transmission <span class="hlt">ion</span> channeling</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bailes, A. A.; Seiberling, L. E.</p> <p>1999-06-01</p> <p>Utilizing the transmission <span class="hlt">ion</span> channeling technique and a Monte Carlo simulation of the channeling of He <span class="hlt">ions</span> in Si, we have been able to determine surface structure by comparing experimental to simulated scattered <span class="hlt">ion</span> <span class="hlt">energy</span> distributions. In analyzing data for {110} beam incidence, we have found that planar oscillations persist well past 2000 Å in our Monte Carlo simulations. These oscillations yield no benefit to this method of data analysis but can make analysis more difficult by the requirement for more accurate Si thickness determination.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/5607893','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/5607893"><span>Theory and simulation of emittance, space charge and electron pressure effects on <span class="hlt">focusing</span> of neutralized <span class="hlt">ion</span> beams</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Lemons, D.S.; Jones, M.E.</p> <p>1986-01-01</p> <p>We investigate the final <span class="hlt">focus</span> mode characterized by warm comoving electrons and vacuum propagation. In particular, we extend a previous envelope equation analysis of <span class="hlt">ion</span> <span class="hlt">focusing</span> in this mode to include the effects of <span class="hlt">ion</span> emittance as well as <span class="hlt">ion</span> space charge and initial electron temperature. Our major result is a simple equation relating initial R/sub o/ and final R/sub f/ beam radii to <span class="hlt">ion</span> emittance epsilon and perveance K and electron Debye length lambda/sub D/ which is supported by one dimensional, electrostatic, particle-in-cell simulations of radial <span class="hlt">ion</span> <span class="hlt">focusing</span>. Finally, we use this equation to find the allowed temperature of neutralizing electrons for typical Heavy <span class="hlt">Ion</span> Fusion reactor and High Temperature Experiment scenarios.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20000086611','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20000086611"><span>Fracture Tests of Etched Components Using a <span class="hlt">Focused</span> <span class="hlt">Ion</span> Beam Machine</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kuhn, Jonathan, L.; Fettig, Rainer K.; Moseley, S. Harvey; Kutyrev, Alexander S.; Orloff, Jon; Powers, Edward I. (Technical Monitor)</p> <p>2000-01-01</p> <p>Many optical MEMS device designs involve large arrays of thin (0.5 to 1 micron components subjected to high stresses due to cyclic loading. These devices are fabricated from a variety of materials, and the properties strongly depend on size and processing. Our objective is to develop standard and convenient test methods that can be used to measure the properties of large numbers of witness samples, for every device we build. In this work we explore a variety of fracture test configurations for 0.5 micron thick silicon nitride membranes machined using the Reactive <span class="hlt">Ion</span> Etching (RIE) process. Testing was completed using an FEI 620 dual <span class="hlt">focused</span> <span class="hlt">ion</span> beam milling machine. Static loads were applied using a probe. and dynamic loads were applied through a piezo-electric stack mounted at the base of the probe. Results from the tests are presented and compared, and application for predicting fracture probability of large arrays of devices are considered.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4063082','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4063082"><span>Membrane Thickness Dependence of Nanopore Formation with a <span class="hlt">Focused</span> Helium <span class="hlt">Ion</span> Beam</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Sawafta, Furat; Carlsen, Autumn T.; Hall, Adam R.</p> <p>2014-01-01</p> <p>Solid-state nanopores are emerging as a valuable tool for the detection and characterization of individual biomolecules. Central to their success is the realization of fabrication strategies that are both rapid and flexible in their ability to achieve diverse device dimensions. In this paper, we demonstrate the membrane thickness dependence of solid-state nanopore formation with a <span class="hlt">focused</span> helium <span class="hlt">ion</span> beam. We vary membrane thickness in situ and show that the rate of pore expansion follows a reproducible trend under all investigated membrane conditions. We show that this trend shifts to lower <span class="hlt">ion</span> dose for thin membranes in a manner that can be described quantitatively, allowing devices of arbitrary dimension to be realized. Finally, we demonstrate that thin, small-diameter nanopores formed with our approach can be utilized for high signal-to-noise ratio resistive pulse sensing of DNA. PMID:24806739</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24806739','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24806739"><span>Membrane thickness dependence of nanopore formation with a <span class="hlt">focused</span> helium <span class="hlt">ion</span> beam.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sawafta, Furat; Carlsen, Autumn T; Hall, Adam R</p> <p>2014-05-06</p> <p>Solid-state nanopores are emerging as a valuable tool for the detection and characterization of individual biomolecules. Central to their success is the realization of fabrication strategies that are both rapid and flexible in their ability to achieve diverse device dimensions. In this paper, we demonstrate the membrane thickness dependence of solid-state nanopore formation with a <span class="hlt">focused</span> helium <span class="hlt">ion</span> beam. We vary membrane thickness in situ and show that the rate of pore expansion follows a reproducible trend under all investigated membrane conditions. We show that this trend shifts to lower <span class="hlt">ion</span> dose for thin membranes in a manner that can be described quantitatively, allowing devices of arbitrary dimension to be realized. Finally, we demonstrate that thin, small-diameter nanopores formed with our approach can be utilized for high signal-to-noise ratio resistive pulse sensing of DNA.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008JAP...104i3913L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008JAP...104i3913L"><span>Tunability of the superconductivity of tungsten films grown by <span class="hlt">focused-ion</span>-beam direct writing</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Li, Wuxia; Fenton, J. C.; Wang, Yiqian; McComb, D. W.; Warburton, P. A.</p> <p>2008-11-01</p> <p>We have grown tungsten-containing films by <span class="hlt">focused-ion</span>-beam (FIB)-induced chemical vapor deposition. The films lie close to the metal-insulator transition with an electrical conductivity which changes by less than 5% between room temperature and 7 K. The superconducting transition temperature Tc of the films can be controlled between 5.0 and 6.2 K by varying the <span class="hlt">ion</span>-beam deposition current. The Tc can be correlated with how far the films are from the metal-insulator transition, showing a nonmonotonic dependence, which is well described by the heuristic model of [Osofsky et al., Phys. Rev. Lett. 87, 197004 (2001)]. Our results suggest that FIB direct-writing of W composites might be a potential approach to fabricate mask-free superconducting devices as well as to explore the role of reduced dimensionality on superconductivity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2000SPIE.4180...40K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2000SPIE.4180...40K"><span>Fracture tests of etched components using a <span class="hlt">focused</span> <span class="hlt">ion</span> beam machine</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kuhn, Jonathan L.; Fettig, Rainer K.; Moseley, Samuel H., Jr.; Kutyrev, Alexander S.; Orloff, Jon</p> <p>2000-08-01</p> <p>Many optical MEMS device designs involve large arrays of thin (0.5 to 1 (mu) m) components subjected to high stresses due to cyclic loading. These devices are fabricated from a variety of materials, and the properties strongly depend on size and processing. Our objective is to develop standard and convenient test methods that can be used to measure the properties of large numbers of witness samples, for every device we build. In this work we explore a variety of fracture tests configurations for 0.5 (mu) m thick silicon nitride membranes machined using the Reactive <span class="hlt">Ion</span> Etching (RIE) process. Testing was completed using an FEI 620 dual <span class="hlt">focused</span> <span class="hlt">ion</span> beam milling machine. Static loads were applied using a probe, and dynamic loads were applied through a piezo-electric stack mounted at the base of the probe. Results from the tests are presented and compared, and application for predicting fracture probability of large arrays of devices are considered.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_21 --> <div id="page_22" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="421"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23038357','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23038357"><span><span class="hlt">Focused</span> <span class="hlt">ion</span> beam engineered whispering gallery mode resonators with open cavity structure.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Aveline, David C; Baumgartel, Lukas; Ahn, Byungmin; Yu, Nan</p> <p>2012-07-30</p> <p>We report the realization of an open cavity whispering gallery mode optical resonator, in which the circulating light traverses a free space gap. We utilize <span class="hlt">focused</span> <span class="hlt">ion</span> beam microfabrication to precisely cut a 10 μm wide notch into the perimeter of a crystalline disc. We have shown that this modified resonator structure supports high quality modes, and demonstrated qualify factor, Q ~/= 10(6), limited by the notch surface roughness due to the <span class="hlt">ion</span> milling process. Furthermore, we investigated the spatial profile of the modes inside the open cavity with a microfabricated probe mechanism. This new type of resonator structure facilitates interaction of the cavity's optical field with mechanical resonators as well as individual atoms or molecules.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26368702','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26368702"><span>Mode selection in InAs quantum dot microdisk lasers using <span class="hlt">focused</span> <span class="hlt">ion</span> beam technique.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bogdanov, A A; Mukhin, I S; Kryzhanovskaya, N V; Maximov, M V; Sadrieva, Z F; Kulagina, M M; Zadiranov, Yu M; Lipovskii, A A; Moiseev, E I; Kudashova, Yu V; Zhukov, A E</p> <p>2015-09-01</p> <p>Optically pumped InAs quantum dot microdisk lasers with grooves etched on their surface by a <span class="hlt">focused</span> <span class="hlt">ion</span> beam are studied. It is shown that the radial grooves, depending on their length, suppress the lasing of specific radial modes of the microdisk. Total suppression of all radial modes, except for the fundamental radial one, is also demonstrated. The comparison of laser spectra measured at 78 K before and after <span class="hlt">ion</span> beam etching for a microdisk of 8 μm in diameter shows a sixfold increase of mode spacing, from 2.5 to 15.5 nm, without a significant decrease of the dominant mode quality factor. Numerical simulations are in good agreement with experimental results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21064439','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21064439"><span>Iodine enhanced <span class="hlt">focused-ion</span>-beam etching of silicon for photonic applications</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Schrauwen, Jonathan; Thourhout, Dries van; Baets, Roel</p> <p>2007-11-15</p> <p><span class="hlt">Focused-ion</span>-beam etching of silicon enables fast and versatile fabrication of micro- and nanophotonic devices. However, large optical losses due to crystal damage and <span class="hlt">ion</span> implantation make the devices impractical when the optical mode is confined near the etched region. These losses are shown to be reduced by the local implantation and etching of silicon waveguides with iodine gas enhancement, followed by baking at 300 deg. C. The excess optical loss in the silicon waveguides drops from 3500 to 1700 dB/cm when iodine gas is used, and is further reduced to 200 dB/cm after baking at 300 deg. C. We present elemental and chemical surface analyses supporting that this is caused by the desorption of iodine from the silicon surface. Finally we present a model to extract the absorption coefficient from the measurements.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22163160','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22163160"><span>Novel EBSD preparation method for Cu/Sn microbumps using a <span class="hlt">focused</span> <span class="hlt">ion</span> beam</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Liu, Tao-Chi; Chen, Chih; Chiu, Kuo-Jung; Lin, Han-Wen; Kuo, Jui-Chao</p> <p>2012-12-15</p> <p>We proposed a novel technique developed from <span class="hlt">focused</span> <span class="hlt">ion</span> beam (FIB) polishing for sample preparation of electron backscatter diffraction (EBSD) measurement. A low-angle incident gallium <span class="hlt">ion</span> beam with a high acceleration voltage of 30 kV was used to eliminate the surface roughness of cross-sectioned microbumps resulting from mechanical polishing. This work demonstrates the application of the FIB polishing technique to solders for a high-quality sample preparation for EBSD measurement after mechanical polishing. - Highlights: Black-Right-Pointing-Pointer The novel FIB technique of sample preparation is fast, effective and low-cost. Black-Right-Pointing-Pointer It can enhance the process precision to the specific area of the sample. Black-Right-Pointing-Pointer It is convenient for analyzing the metallurgy of the microbump in 3DIC packaging. Black-Right-Pointing-Pointer The EBSD image quality can be enhanced by just using a common FIB instrument.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AIPC.1169...38S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AIPC.1169...38S"><span>Development of Lithium-<span class="hlt">ion</span> Battery as <span class="hlt">Energy</span> Storage for Mobile Power Sources Applications</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sulaiman, Mohd Ali; Hasan, Hasimah</p> <p>2009-09-01</p> <p>In view of the need to protect the global environment and save <span class="hlt">energy</span>, there has been strong demand for the development of lithium-<span class="hlt">ion</span> battery technology as a <span class="hlt">energy</span> storage system, especially for Light Electric Vehicle (LEV) and electric vehicles (EV) applications. The R&D trend in the lithium-<span class="hlt">ion</span> battery development is toward the high power and <span class="hlt">energy</span> density, cheaper in price and high safety standard. In our laboratory, the research and development of lithium-<span class="hlt">ion</span> battery technology was mainly <span class="hlt">focus</span> to develop high power density performance of cathode material, which is <span class="hlt">focusing</span> to the Li-metal-oxide system, LiMO2, where M=Co, Ni, Mn and its combination. The nano particle size material, which has irregular particle shape and high specific surface area was successfully synthesized by self propagating combustion technique. As a result the <span class="hlt">energy</span> density and power density of the synthesized materials are significantly improved. In addition, we also developed variety of sizes of lithium-<span class="hlt">ion</span> battery prototype, including (i) small size for electronic gadgets such as mobile phone and PDA applications, (ii) medium size for remote control toys and power tools applications and (iii) battery module for high power application such as electric bicycle and electric scooter applications. The detail performance of R&D in advanced materials and prototype development in AMREC, SIRIM Berhad will be discussed in this paper.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/5462799','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/5462799"><span>Trajectory analysis of low-<span class="hlt">energy</span> and hyperthermal <span class="hlt">ions</span> scattered from Cu(110)</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>McEachern, R.L.; Goodstein, D.M.; Cooper, B.H.</p> <p>1989-05-15</p> <p>Trajectories of Na{sup +} <span class="hlt">ions</span> scattered from the Cu(110) surface in the <1 1bar 0> and <001> azimuths were studied for a range of incident <span class="hlt">energies</span> from 56 eV to 4 keV. The goal is to explain the trends observed in the <span class="hlt">energy</span> spectra and determine what types of trajectories contribute to these spectra. Using the computer program SAFARI, simulations were performed with trajectory analyses for 100-, 200-, and 400-eV scattering. We show results from the 100-eV simulations in both azimuths and compare them with the experimental data. The simulated <span class="hlt">energy</span> spectra are in excellent agreement with the data. <span class="hlt">Ion</span> trajectories and impact parameter plots from the simulations are used to determine the relative importance of different types of <span class="hlt">ion</span>-surface-atom collisions. The simulations have shown that the striking differences observed in comparing the <1 1bar 0> and <001> spectra are mostly due to <span class="hlt">ions</span> which scatter from second-layer atoms. This system exhibits strong <span class="hlt">focusing</span> onto the second-layer atoms by the first-layer rows, and the <span class="hlt">focusing</span> is very sensitive to the spacing between the rows. At the lower beam <span class="hlt">energies</span>, scattering from the second layer dominates the measured spectra.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/20982337','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/20982337"><span>Formation of <span class="hlt">ions</span> by high-<span class="hlt">energy</span> photons</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Drukarev, E. G.; Mikhailov, A. I.; Mikhailov, I. A.; Rakhimov, Kh. Yu.; Scheid, W.</p> <p>2007-03-15</p> <p>We calculate the electron <span class="hlt">energy</span> spectrum of ionization by a high-<span class="hlt">energy</span> photon, accompanied by creation of an e{sup -}e{sup +} pair. The total cross section of the process is also obtained. The asymptotics of the cross section does not depend on the photon <span class="hlt">energy</span>. At the photon <span class="hlt">energies</span> exceeding a certain value {omega}{sub 0} this appears to be the dominant mechanism of formation of the <span class="hlt">ions</span>. The dependence of {omega}{sub 0} on the value of nuclear charge is obtained. Our results are consistent with experimental data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004JPFR...80..406K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004JPFR...80..406K"><span>A New Formula for <span class="hlt">Energy</span> Spectrum of Sputtered Atoms Due to Low-<span class="hlt">Energy</span> Light <span class="hlt">Ions</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kenmotsu, Takahiro; Yamamura, Yasunori; Ono, Tadayoshi; Kawamura, Takaichi</p> <p></p> <p>A new formula has been derived to describe the <span class="hlt">energy</span> spectrum of sputtered atoms from a target material bombarded by light <span class="hlt">ions</span>. We assume that sputtered atoms bombarded by low-<span class="hlt">energy</span> light <span class="hlt">ions</span> are mainly primary knock-on atoms which are created by large-angle backscattered light <span class="hlt">ions</span>. The escape processes of recoil atoms are estimated on the basis of the Falcone-Sigmund model. The new formula has the dependence on the incident <span class="hlt">energy</span> of a projectile. We have compared the new formula with simulation results calculated with ACAT code for a Fe target material bombarded by 50eV, 100eV and 500eV D+ <span class="hlt">ions</span>. Good agreements are found for 50eV and 100eV D+ <span class="hlt">ions</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1325972','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1325972"><span>A Variable <span class="hlt">Energy</span> CW Compact Accelerator for <span class="hlt">Ion</span> Cancer Therapy</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Johnstone, Carol J.; Taylor, J.; Edgecock, R.; Schulte, R.</p> <p>2016-03-10</p> <p>Cancer is the second-largest cause of death in the U.S. and approximately two-thirds of all cancer patients will receive radiation therapy with the majority of the radiation treatments performed using x-rays produced by electron linacs. Charged particle beam radiation therapy, both protons and light <span class="hlt">ions</span>, however, offers advantageous physical-dose distributions over conventional photon radiotherapy, and, for particles heavier than protons, a significant biological advantage. Despite recognition of potential advantages, there is almost no research activity in this field in the U.S. due to the lack of clinical accelerator facilities offering light <span class="hlt">ion</span> therapy in the States. In January, 2013, a joint DOE/NCI workshop was convened to address the challenges of light <span class="hlt">ion</span> therapy [1], inviting more than 60 experts from diverse fields related to radiation therapy. This paper reports on the conclusions of the workshop, then translates the clinical requirements into accelerat or and beam-delivery technical specifications. A comparison of available or feasible accelerator technologies is compared, including a new concept for a compact, CW, and variable <span class="hlt">energy</span> light <span class="hlt">ion</span> accelerator currently under development. This new light <span class="hlt">ion</span> accelerator is based on advances in nonscaling Fixed-Field Alternating gradient (FFAG) accelerator design. The new design concepts combine isochronous orbits with long (up to 4m) straight sections in a compact racetrack format allowing inner circulating orbits to be <span class="hlt">energy</span> selected for low-loss, CW extraction, effectively eliminating the high-loss <span class="hlt">energy</span> degrader in conventional CW cyclotron designs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1021059','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1021059"><span>Heavy <span class="hlt">Ion</span> Inertial Fusion <span class="hlt">Energy</span>: Summaries of Program Elements</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Friedman, A; Barnard, J J; Kaganovich, I; Seidl, P A; Briggs, R J; Faltens, A; Kwan, J W; Lee, E P; Logan, B G</p> <p>2011-02-28</p> <p>The goal of the Heavy <span class="hlt">Ion</span> Fusion (HIF) Program is to apply high-current accelerator technology to IFE power production. <span class="hlt">Ion</span> beams of mass {approx}100 amu and kinetic <span class="hlt">energy</span> {>=} 1 GeV provide efficient <span class="hlt">energy</span> coupling into matter, and HIF enjoys R&D-supported favorable attributes of: (1) the driver, projected to be robust and efficient; see 'Heavy <span class="hlt">Ion</span> Accelerator Drivers.'; (2) the targets, which span a continuum from full direct to full indirect drive (and perhaps fast ignition), and have metal exteriors that enable injection at {approx}10 Hz; see 'IFE Target Designs'; (3) the near-classical <span class="hlt">ion</span> <span class="hlt">energy</span> deposition in the targets; see 'Beam-Plasma Interactions'; (4) the magnetic final lens, robust against damage; see 'Final Optics-Heavy <span class="hlt">Ion</span> Beams'; and (5) the fusion chamber, which may use neutronically-thick liquids; see 'Liquid-Wall Chambers.' Most studies of HIF power plants have assumed indirect drive and thick liquid wall protection, but other options are possible.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1999PhLA..256..205X','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1999PhLA..256..205X"><span><span class="hlt">Energy</span> spectra of He + <span class="hlt">ions</span> penetrating thick biological targets</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Xia, Yueyuan; Tan, Chunyu; Mu, Yuguang; Wang, Ruijin; Zhang, Jianhua; Liu, Xiangdong; Liu, Jitian; Yu, Zhengliang</p> <p>1999-05-01</p> <p><span class="hlt">Energy</span> spectra of 500 keV-1MeV He + <span class="hlt">ion</span> penetrating 50 μ m- 100 μ m thick seed coat of maize, fruit peel of grape and of tomato, are measured. The results indicate that these thick biological targets, as seen by the penetrating <span class="hlt">ions</span>, are inhomogeneous, and there are open paths, along which the incident <span class="hlt">ions</span> can penetrate the targets easily. While most of the incident <span class="hlt">ions</span> are stopped in the targets, some of the penetrating <span class="hlt">ions</span> only lose a small fraction of their initial incident <span class="hlt">energy</span>. The penetration <span class="hlt">energy</span> spectra show a pure electronic stopping feature. Transmission electron microscope (TEM) micrographs taken from these samples with thickness of 30 μ m indicate that 150 keV electron beam from the TEM can penetrate the thick samples to give very good images with clear contrast. The electronic structures of β-1,4 glucosan molecular chains, which is deemed as the most important constituent of the cell walls of seed coats and peels of fruits, are calculated to show the possible open-path directions which exist in biological samples.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/970064','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/970064"><span>Modeling heavy <span class="hlt">ion</span> ionization <span class="hlt">energy</span> loss at low and intermediate <span class="hlt">energies</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Rakhno, I.L.; /Fermilab</p> <p>2009-11-01</p> <p>The needs of contemporary accelerator and space projects led to significant efforts made to include description of heavy <span class="hlt">ion</span> interactions with matter in general-purpose Monte Carlo codes. This paper deals with an updated model of heavy <span class="hlt">ion</span> ionization <span class="hlt">energy</span> loss developed previously for the MARS code. The model agrees well with experimental data for various projectiles and targets including super-heavy <span class="hlt">ions</span> in low-Z media.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003SPIE.5130..496L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003SPIE.5130..496L"><span>New advancements in <span class="hlt">focused</span> <span class="hlt">ion</span> beam repair of alternating phase-shift masks</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lessing, Joshua; Robinson, Tod; Brannen, Rey A.; Morrison, Troy B.; Holtermann, Theresa</p> <p>2003-08-01</p> <p>As advanced photolithography extends the ability to print feature sizes below the 100 nm technology node, various reticle enhancement techniques (RET) are being employed to improve resolution. An example of RET is the alternating phase shift mask (APSM), which currently challenges the ability of conventional repair techniques to repair even the most basic reticle defect. The phase shifting quartz bump is one defect type critical to the performance of APSM technology masks. These defects on the APSM reticle are caused by imperfections in the resist image during processing, resulting in a localized under or over etch of the quartz substrate. The integrated application of gas assisted etch (GAE), <span class="hlt">focused</span> <span class="hlt">ion</span> beam (FIB) reticle repair, and atomic force microscopy (AFM), provide a comprehensive solution for advanced reticle defect repair and characterization. <span class="hlt">Ion</span> beam repair offers superior accuracy and precision for removal without significant damage to the underlying or adjacent quartz. The AFM technique provides quantitative measurement of 3D structures, including those associated with alternating phase shifters etched into quartz as well as embedded shifters. In the work presented in this paper, quartz bum defects were pre-scanned on an AFM tool and proprietary software algorithms were used to generate defect image and height map files for transfer to the FIB reticle repair tool via a network connection. The FIB tool then used these files to control selectively the <span class="hlt">ion</span> dose during the corresponding quartz defect repair. A 193 nm APSM phase shift photomask with programmed defects in 400 nm line and space pattern was repaired using an FEI Stylus NanoProfilometer (SNP) and a FEI Accura 850 <span class="hlt">focus</span> <span class="hlt">ion</span> beam (FIB) tool. Using the APSM FIB repair method, the transmittance evaluated from 193 nm AIMS at the repair area was more than 90% without post-processing.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003SPIE.5256.1208L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003SPIE.5256.1208L"><span>Advancements in <span class="hlt">focused</span> <span class="hlt">ion</span> beam repair of alternating phase-shift masks</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lessing, Joshua; Robinson, Tod; Morrision, Troy; Holtermann, Theresa</p> <p>2003-12-01</p> <p>As advanced photolithography extends the ability to print feature sizes below the 100 nm technology node, various reticle enhancement techniques (RET) are being employed to improve resolution. An example of RET is the alternating phase shift mask (APSM), which currently challenges the ability of conventional repair techniques to repair even the most basic reticle defect. The phase shifting quartz bump is one defect type critical to the performance of APSM technology masks. These defects on the APSM reticle are caused by imperfections in the resist image during processing, resulting in a localized under or over etch of the quartz substrate. The integrated application of gas assisted etch (GAE), <span class="hlt">focused</span> <span class="hlt">ion</span> beam (FIB) reticle repair, and atomic force microscopy (AFM), provides a comprehensive solution for advanced reticle defect repair and characterization. <span class="hlt">Ion</span> beam repair offers superior accuracy and precision for removal without significant damage to the underlying or adjacent quartz. The AFM technique provides quantitative measurement of 3D structures, including those associated with alternating phase shifters etched into quartz as well as embedded shifters. In the work presented in this paper, quartz bump defects were pre-scanned on an AFM tool and proprietary software algorithms were used to generate defect image and height map files for transfer to the FIB reticle repair tool via a network connection. The FIB tool then used these files to selectively control the <span class="hlt">ion</span> dose during the corresponding quartz defect repair. A 193 nm APSM phase shift photomask with programmed defects in 400 nm line and space pattern was repaired using an FEI Stylus NanoProfilometer (SNP) and a FEI Accura 850 <span class="hlt">focus</span> <span class="hlt">ion</span> beam (FIB) tool. Using the APSM FIB repair method, the transmittance evaluated from 193 nm AIMS at the repair area was more than 90% without post-processing.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/918571','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/918571"><span>A core-particle model for periodically <span class="hlt">focused</span> <span class="hlt">ion</span> beams withintense space-charge</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Lund, Steven M.; Barnard, John J.; Bukh, Boris; Chawla, SurgreevR.; Chilton, Sven H.</p> <p>2006-08-28</p> <p>A core-particle model is derived to analyze transverse orbits of test particles evolving in the presence of a core <span class="hlt">ion</span> beam that has uniform density within an elliptical cross-section. The model can be applied to both quadrupole and solenoidal <span class="hlt">focused</span> beams in periodic or aperiodic lattices. Efficient analytical descriptions of electrostatic space-charge fields external to the beam core are derived to simplify model equations. Image charge effects are analyzed for an elliptical beam centered in a round, conducting pipe to estimate model corrections resulting from image charge nonlinearities. Transformations are employed to remove coherent flutter motion associated with oscillations of the <span class="hlt">ion</span> beam core due to rapidly varying, linear applied <span class="hlt">focusing</span> forces. Diagnostics for particle trajectories, Poincare phase-space projections, and single-particle emittances based on these transformations better illustrate the effects of nonlinear forces acting on particles evolving outside the core. A numerical code has been written based on this model. Example applications illustrate model characteristics. The core-particle model described has recently been applied to identify physical processes leading to space-charge transport limits for an rms matched beam in a periodic quadrupole <span class="hlt">focusing</span> channel. Further characteristics of these processes are presented here.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/936679','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/936679"><span>A Core-Particle Model for Periodically <span class="hlt">Focused</span> <span class="hlt">Ion</span> Beams with Intense Space-Charge</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Lund, S M; Barnard, J J; Bukh, B; Chawla, S R; Chilton, S H</p> <p>2006-08-02</p> <p>A core-particle model is derived to analyze transverse orbits of test particles evolving in the presence of a core <span class="hlt">ion</span> beam described by the KV distribution. The core beam has uniform density within an elliptical cross-section and can be applied to model both quadrupole and solenoidal <span class="hlt">focused</span> beams in periodic or aperiodic lattices. Efficient analytical descriptions of electrostatic space-charge fields external to the beam core are derived to simplify model equations. Image charge effects are analyzed for an elliptical beam centered in a round, conducting pipe to estimate model corrections resulting from image charge nonlinearities. Transformations are employed to remove coherent utter motion associated with oscillations of the <span class="hlt">ion</span> beam core due to rapidly varying, linear applied <span class="hlt">focusing</span> forces. Diagnostics for particle trajectories, Poincare phase-space projections, and single-particle emittances based on these transformations better illustrate the effects of nonlinear forces acting on particles evolving outside the core. A numerical code has been written based on this model. Example applications illustrate model characteristics. The core-particle model described has recently been applied to identify physical processes leading to space-charge transport limits for an rms matched beam in a periodic quadrupole <span class="hlt">focusing</span> channel [Lund and Chawla, Nuc. Instr. and Meth. A 561, 203 (2006)]. Further characteristics of these processes are presented here.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/981525','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/981525"><span>ULTRA-LOW-<span class="hlt">ENERGY</span> HIGH-CURRENT <span class="hlt">ION</span> SOURCE</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Anders, Andre; Yushkov, Georgy Yu.; Baldwin, David A.</p> <p>2009-11-20</p> <p>The technical objective of the project was to develop an ultra-low-<span class="hlt">energy</span>, high-intensity <span class="hlt">ion</span> source (ULEHIIS) for materials processing in high-technology fields including semiconductors, micro-magnetics and optics/opto-electronics. In its primary application, this <span class="hlt">ion</span> source can be incorporated into the 4Wave thin-film deposition technique called biased target <span class="hlt">ion</span>-beam deposition (BTIBD), which is a deposition technique based on sputtering (without magnetic field, i.e., not the typical magnetron sputtering). It is a technological challenge because the laws of space charge limited current (Child-Langmuir) set strict limits of how much current can be extracted from a reservoir of <span class="hlt">ions</span>, such as a suitable discharge plasma. The solution to the problem was an innovative dual-discharge system without the use of extraction grids.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009IJTFM.129..281W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009IJTFM.129..281W"><span>Structure Change of PTFE by Low <span class="hlt">Energy</span> <span class="hlt">Ion</span> Irradiation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Watari, Kunio; Iwao, Toru; Yumoto, Motoshige</p> <p></p> <p>The authors irradiate low <span class="hlt">energy</span> nitrogen <span class="hlt">ion</span> (100eV) on PTFE (poly-tetra-fluoro-ethylene) for surface modification. However, PTFE cannot anticipate adhesive strength improvement because it is collapse type polymer and weariness of surface occurs by <span class="hlt">ion</span> irradiation. We paid attention to cross-linked structure to solve this problem. By this study introduce below, PTFE was changed collapse type polymer into cross-linked type polymer by rising temperature above the glass transition in the case of <span class="hlt">ion</span> irradiation. As a result, the formation of the CF3 combination was restrained and collapse phenomenon was prevented by <span class="hlt">ion</span> irradiation above the glass transition. In addition, it was suggested that cross-linked structure is effective for adhesive strength improvement by convolution of C1s spectrum and density profile.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22482970','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22482970"><span><span class="hlt">Ion</span> collector design for an <span class="hlt">energy</span> recovery test proposal with the negative <span class="hlt">ion</span> source NIO1</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Variale, V.; Cavenago, M.; Agostinetti, P.; Sonato, P.; Zanotto, L.</p> <p>2016-02-15</p> <p>Commercial viability of thermonuclear fusion power plants depends also on minimizing the recirculation power used to operate the reactor. The neutral beam injector (NBI) remains one of the most important method for plasma heating and control. For the future fusion power plant project DEMO, a NBI wall plug efficiency at least of 0.45 is required, while efficiency of present NBI project is about 0.25. The D{sup −} beam from a negative <span class="hlt">ion</span> source is partially neutralized by a gas cell, which leaves more than 40% of <span class="hlt">energy</span> in residual beams (D{sup −} and D{sup +}), so that an <span class="hlt">ion</span> beam <span class="hlt">energy</span> recovery system can significantly contribute to optimize efficiency. Recently, the test negative <span class="hlt">ion</span> source NIO1 (60 keV, 9 beamlets with 15 mA H{sup −} each) has been designed and built at RFX (Padua) for negative <span class="hlt">ion</span> production efficiency and the beam quality optimization. In this paper, a study proposal to use the NIO1 source also for a beam <span class="hlt">energy</span> recovery test experiment is presented and a preliminary design of a negative <span class="hlt">ion</span> beam collector with simulations of beam <span class="hlt">energy</span> recovery is discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26932033','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26932033"><span><span class="hlt">Ion</span> collector design for an <span class="hlt">energy</span> recovery test proposal with the negative <span class="hlt">ion</span> source NIO1.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Variale, V; Cavenago, M; Agostinetti, P; Sonato, P; Zanotto, L</p> <p>2016-02-01</p> <p>Commercial viability of thermonuclear fusion power plants depends also on minimizing the recirculation power used to operate the reactor. The neutral beam injector (NBI) remains one of the most important method for plasma heating and control. For the future fusion power plant project DEMO, a NBI wall plug efficiency at least of 0.45 is required, while efficiency of present NBI project is about 0.25. The D(-) beam from a negative <span class="hlt">ion</span> source is partially neutralized by a gas cell, which leaves more than 40% of <span class="hlt">energy</span> in residual beams (D(-) and D(+)), so that an <span class="hlt">ion</span> beam <span class="hlt">energy</span> recovery system can significantly contribute to optimize efficiency. Recently, the test negative <span class="hlt">ion</span> source NIO1 (60 keV, 9 beamlets with 15 mA H(-) each) has been designed and built at RFX (Padua) for negative <span class="hlt">ion</span> production efficiency and the beam quality optimization. In this paper, a study proposal to use the NIO1 source also for a beam <span class="hlt">energy</span> recovery test experiment is presented and a preliminary design of a negative <span class="hlt">ion</span> beam collector with simulations of beam <span class="hlt">energy</span> recovery is discussed.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_22 --> <div id="page_23" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="441"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016RScI...87bB305V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016RScI...87bB305V"><span><span class="hlt">Ion</span> collector design for an <span class="hlt">energy</span> recovery test proposal with the negative <span class="hlt">ion</span> source NIO1</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Variale, V.; Cavenago, M.; Agostinetti, P.; Sonato, P.; Zanotto, L.</p> <p>2016-02-01</p> <p>Commercial viability of thermonuclear fusion power plants depends also on minimizing the recirculation power used to operate the reactor. The neutral beam injector (NBI) remains one of the most important method for plasma heating and control. For the future fusion power plant project DEMO, a NBI wall plug efficiency at least of 0.45 is required, while efficiency of present NBI project is about 0.25. The D- beam from a negative <span class="hlt">ion</span> source is partially neutralized by a gas cell, which leaves more than 40% of <span class="hlt">energy</span> in residual beams (D- and D+), so that an <span class="hlt">ion</span> beam <span class="hlt">energy</span> recovery system can significantly contribute to optimize efficiency. Recently, the test negative <span class="hlt">ion</span> source NIO1 (60 keV, 9 beamlets with 15 mA H- each) has been designed and built at RFX (Padua) for negative <span class="hlt">ion</span> production efficiency and the beam quality optimization. In this paper, a study proposal to use the NIO1 source also for a beam <span class="hlt">energy</span> recovery test experiment is presented and a preliminary design of a negative <span class="hlt">ion</span> beam collector with simulations of beam <span class="hlt">energy</span> recovery is discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25225831','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25225831"><span>Tuning the surface properties of hydrogel at the nanoscale with <span class="hlt">focused</span> <span class="hlt">ion</span> irradiation.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kim, Y; Abuelfilat, A Y; Hoo, S P; Al-Abboodi, A; Liu, B; Ng, Tuck; Chan, P; Fu, J</p> <p>2014-11-14</p> <p>With the site-specific machining capability of <span class="hlt">Focused</span> <span class="hlt">Ion</span> Beam (FIB) irradiation, we aim to tailor the surface morphology and physical attributes of biocompatible hydrogel at the nano/micro scale particularly for tissue engineering and other biomedical studies. Thin films of Gtn-HPA/CMC-Tyr hydrogels were deposited on a gold-coated substrate and were subjected to irradiation with a kiloelectronvolt (keV) gallium <span class="hlt">ion</span> beam. The sputtering yield, surface morphology and mechanical property changes were investigated using Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM) and Monte Carlo simulations. The sputtering yield of the hydrogel was found to be approximately 0.47 μm(3) nC(-1) compared with Monte-Carlo simulation results of 0.09 μm(3) nC(-1). Compared to the surface roughness of the pristine hydrogel at approximately 2 nm, the average surface roughness significantly increased with the increase of <span class="hlt">ion</span> fluence with measurements extended to 20 nm at 100 pC μm(-2). Highly packed submicron porous patterns were also revealed with AFM, while significantly decreased pore sizes and increased porosity were found with <span class="hlt">ion</span> irradiation at oblique incidence. The Young's modulus of irradiated hydrogel determined using AFM force spectroscopy was revealed to be dependent on <span class="hlt">ion</span> fluence. Compared to the original Young's modulus value of 20 MPa, irradiation elevated the value to 250 MPa and 350 MPa at 1 pC μm(-2) and 100 pC μm(-2), respectively. Cell culture studies confirmed that the irradiated hydrogel samples were biocompatible, and the generated nanoscale patterns remained stable under physiological conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26750803','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26750803"><span>Can particle beam therapy be improved using helium <span class="hlt">ions</span>? - a planning study <span class="hlt">focusing</span> on pediatric patients.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Knäusl, Barbara; Fuchs, Hermann; Dieckmann, Karin; Georg, Dietmar</p> <p>2016-06-01</p> <p>Aim To explore the potential of scanned helium <span class="hlt">ion</span> beam therapy ((4)He) compared to proton therapy in a comparative planning study <span class="hlt">focusing</span> on pediatric patients. This was motivated by the superior biological and physical characteristics of (4)He. Material and methods For eleven neuroblastoma (NB), nine Hodgkin lymphoma (HL), five Wilms tumor (WT), five ependymoma (EP) and four Ewing sarcoma (EW) patients, treatment plans were created for protons and (4)He. Dose prescription to the planning target volume (PTV) was 21 Gy [relative biological effectiveness (RBE)] (NB), 19.8 Gy (RBE) (HL), 25.2 Gy (RBE) for the WT boost volume and 54 Gy (RBE) for EP and EW patients. A pencil beam algorithm for protons (constant RBE = 1.1) and (4)He was implemented in the treatment planning system Hyperion. For (4)He the relative biological effectiveness (RBE) was calculated with a 'zonal' model based on different linear <span class="hlt">energy</span> transfer regions. Results Target constraints were fulfilled for all indications. For NB patients differences for kidneys and liver were observed for all dose-volume areas, except the high-dose volume. The body volume receiving up to 12.6 Gy (RBE) was reduced by up to 10% with (4)He. For WT patients the mean and high-dose volume for the liver was improved when using (4)He. For EP normal tissue dose was reduced using (4)He with 12.7% of the voxels receiving higher doses using protons. For HL and EW sarcoma patients the combination of large PTV volumes with the position of the organs at risk (OARs) obliterated the differences between the two particle species, while patients with the heart close to the PTV could benefit from (4)He. Conclusion Treatment plan quality improved with (4)He compared to proton plans, but advantages in OAR sparing were depending on indication and tumor geometries. These first results of scanned (4)He therapy motivate comprehensive research on (4)He, including acquisition of experimental data to improve modeling of (4)He.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1990ZPhyD..16..229D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1990ZPhyD..16..229D"><span><span class="hlt">Energy</span> loss of heavy <span class="hlt">ions</span> in a dense hydrogen plasma</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dietrich, K.-G.; Hoffmann, D. H. H.; Wahl, H.; Haas, C. R.; Kunze, H.; Brandenburg, W.; Noll, R.</p> <p>1990-12-01</p> <p>The <span class="hlt">energy</span> loss of heavy <span class="hlt">ions</span> with an <span class="hlt">energy</span> of 1.4 MeV/u in a hydrogen plasma has been measured. A 20 cm long z-pinch has been used as plasma target. Our data show a strong enhancement of the stopping power of the plasma compared to that of a cold gas with equal density. The results completely confirm the predictions of the standard stopping power model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19840053305&hterms=High+Altitude+Plasma+Instrument&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DHigh%2BAltitude%2BPlasma%2BInstrument','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19840053305&hterms=High+Altitude+Plasma+Instrument&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DHigh%2BAltitude%2BPlasma%2BInstrument"><span>Intense low-<span class="hlt">energy</span> <span class="hlt">ion</span> populations at low equatorial altitudes</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Williams, D. J.; Frank, L. A.</p> <p>1984-01-01</p> <p>The ISEE 1 satellite trajectory often passed through the magnetospheric region during the time from November 1977 to April 1978. On every occasion, the medium <span class="hlt">energy</span> particles instrument (MEPI) of the satellite recorded an intense <span class="hlt">ion</span> population in a region corresponding to low equatorial altitudes. An intensity peak was observed in the lowest MEPI <span class="hlt">energy</span> channel. A comparison of high bit rate MEPI data with simultaneous data from the LEPEDEA plasma instrument on Nov. 29, 1977 1930-2000 UT shows additional peaks in the <span class="hlt">ion</span> population existing in the L of 2 to at least 4. In the present report, data characterizing these <span class="hlt">ion</span> populations are presented, and implications are discussed in terms of source and loss mechanisms.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AIPC.1215..140L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AIPC.1215..140L"><span><span class="hlt">Energy</span>-Based Adaptive <span class="hlt">Focusing</span>: Optimal Ultrasonic <span class="hlt">Focusing</span> Using Magnetic Resonance Guidance</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Larrat, B.; Pernot, M.; Montaldo, G.; Fink, M.; Tanter, M.</p> <p>2010-03-01</p> <p>Adaptive <span class="hlt">focusing</span> of ultrasonic waves is performed under the guidance of a Magnetic Resonance (MR) system. The technique is based on the maximization of the ultrasonic wave intensity at a target point. The wave intensity is indirectly estimated from the local tissue motion induced at the chosen <span class="hlt">focus</span> by the acoustic radiation force of the ultrasonic beam. A motion sensitive MR sequence is used to measure the resulting local tissue displacements. Based on the transmission of a set of spatially coded ultrasonic waves, a non iterative inversion process is used to estimate the phase aberrations induced by the propagation medium and to maximize the acoustical intensity at the target. Both programmable and physical aberrating layers introducing strong distortions (up to 2π radians) are recovered within acceptable errors (<0.8 rad). This non invasive technique is shown to accurately correct the phase aberrations in a phantom gel with negligible heat deposition and limited acquisition time. These refocusing performances demonstrate a major potential in the field of MR-Guided Ultrasound Therapy in particular for transcranial brain HIFU.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1213383-photon-dilepton-production-high-energy-heavy-ion-collisions','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1213383-photon-dilepton-production-high-energy-heavy-ion-collisions"><span>Photon and dilepton production in high <span class="hlt">energy</span> heavy <span class="hlt">ion</span> collisions</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Sakaguchi, Takao</p> <p>2015-05-07</p> <p>The recent results on direct photons and dileptons in high <span class="hlt">energy</span> heavy <span class="hlt">ion</span> collisions, obtained particularly at RHIC and LHC are reviewed. The results are new not only in terms of the probes, but also in terms of the precision. We shall discuss the physics learned from the results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1213383','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1213383"><span>Photon and dilepton production in high <span class="hlt">energy</span> heavy <span class="hlt">ion</span> collisions</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Sakaguchi, Takao</p> <p>2015-05-07</p> <p>The recent results on direct photons and dileptons in high <span class="hlt">energy</span> heavy <span class="hlt">ion</span> collisions, obtained particularly at RHIC and LHC are reviewed. The results are new not only in terms of the probes, but also in terms of the precision. We shall discuss the physics learned from the results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013PhRvL.111w2301E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013PhRvL.111w2301E"><span>Pressure Isotropization in High <span class="hlt">Energy</span> Heavy <span class="hlt">Ion</span> Collisions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Epelbaum, Thomas; Gelis, François</p> <p>2013-12-01</p> <p>The early stages of high <span class="hlt">energy</span> heavy <span class="hlt">ion</span> collisions are studied in the color glass condensate framework, with a real-time classical lattice simulation. When increasing the coupling constant, we observe a rapid increase of the ratio of longitudinal to transverse pressure. The transient regime that precedes this behavior is of the order of 1fm/c.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/895775','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/895775"><span>On final conditions in high <span class="hlt">energy</span> heavy <span class="hlt">ion</span> Collisions</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Sinyukov, Yu.M.; Akkelin, S.V.; Xu, N.</p> <p>1998-06-01</p> <p>Motivated by the recent experimental observations, wediscuss the freeze-out properties of the fireball created in centralheavy <span class="hlt">ion</span> collisions. We find that the freeze-out conditions, liketemperature, velocity gradient near center of the fireball, are similarfor different colliding systems and beam <span class="hlt">energies</span>. This means that thetransverse flow is stronger in the collisions of heavy nuclei than thatof the light ones.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22299891','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22299891"><span>Micro-contacting of single and periodically arrayed columnar silicon structures by <span class="hlt">focused</span> <span class="hlt">ion</span> beam techniques</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Friedrich, F. Herfurth, N.; Teodoreanu, A.-M.; Boit, C.</p> <p>2014-06-16</p> <p>Micron-sized, periodic crystalline Silicon columns on glass substrate were electrically contacted with a transparent conductive oxide front contact and a <span class="hlt">focused</span> <span class="hlt">ion</span> beam processed local back contact. Individual column contacts as well as arrays of >100 contacted columns were processed. Current-voltage characteristics of the devices were determined. By comparison with characteristics obtained from adapted device simulation, the absorber defect density was reconstructed. The contacting scheme allows the fabrication of testing devices in order to evaluate the electronic potential of promising semiconductor microstructures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20588646','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20588646"><span>Fabrication of micro DOE using micro tools shaped with <span class="hlt">focused</span> <span class="hlt">ion</span> beam.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Xu, Z W; Fang, F Z; Zhang, S J; Zhang, X D; Hu, X T; Fu, Y Q; Li, L</p> <p>2010-04-12</p> <p>A novel method is proposed to fabricate micro Diffractive Optical Elements (DOE) using micro cutting tools shaped with <span class="hlt">focused</span> <span class="hlt">ion</span> beam (FIB) milling. Micro tools with nanometric cutting edges and complicated shapes are fabricated by controlling the tool facet's orientation relative to the FIB. The tool edge radius of less than 30 nm is achieved for the nano removal of the work materials. Semi-circular micro tools and DOE-shaped micro tools are developed to fabricate micro-DOE and sinusoidal modulation templates. Experiments show that the proposed method can be a high efficient way in fabricating micro-DOE with nanoscale surface finishes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3585404','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3585404"><span>Correlative In Vivo 2 Photon and <span class="hlt">Focused</span> <span class="hlt">Ion</span> Beam Scanning Electron Microscopy of Cortical Neurons</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Maco, Bohumil; Holtmaat, Anthony; Cantoni, Marco; Kreshuk, Anna; Straehle, Christoph N.; Hamprecht, Fred A.; Knott, Graham W.</p> <p>2013-01-01</p> <p>Correlating in vivo imaging of neurons and their synaptic connections with electron microscopy combines dynamic and ultrastructural information. Here we describe a semi-automated technique whereby volumes of brain tissue containing axons and dendrites, previously studied in vivo, are subsequently imaged in three dimensions with <span class="hlt">focused</span> <span class="hlt">ion</span> beam scanning electron microcopy. These neurites are then identified and reconstructed automatically from the image series using the latest segmentation algorithms. The fast and reliable imaging and reconstruction technique avoids any specific labeling to identify the features of interest in the electron microscope, and optimises their preservation and staining for 3D analysis. PMID:23468982</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20040065912&hterms=floss&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dfloss','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20040065912&hterms=floss&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dfloss"><span><span class="hlt">Focused</span> <span class="hlt">Ion</span> Beam Recovery and Analysis of Interplanetary Dust Particles (IDPs) and Stardust Analogues</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Graham, G. A.; Bradley, J. P.; Bernas, M.; Stroud, R. M.; Dai, Z. R.; Floss, C.; Stadermann, F. J.; Snead, C. J.; Westphal, A. J.</p> <p>2004-01-01</p> <p>Meteoritics research is a major beneficiary of recent developments in analytical instrumentation [1,2]. Integrated studies in which multiple analytical techniques are applied to the same specimen are providing new insight about the nature of IDPs [1]. Such studies are dependent on the ability to prepare specimens that can be analyzed in multiple instruments. <span class="hlt">Focused</span> <span class="hlt">ion</span> beam (FIB) microscopy has revolutionized specimen preparation in materials science [3]. Although FIB has successfully been used for a few IDP and meteorite studies [1,4-6], it has yet to be widely utilized in meteoritics. We are using FIB for integrated TEM/NanoSIMS/synchrotron infrared (IR) studies [1].</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004SPIE.5774..637G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004SPIE.5774..637G"><span>Replication of the nano-scale mold fabricated with <span class="hlt">focused</span> <span class="hlt">ion</span> beam</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gao, J. X.; Chan-Park, M. B.; Xie, D. Z.; Ngoi, Bryan K. A.</p> <p>2004-12-01</p> <p>Silicon mold fabricated with <span class="hlt">Focused</span> <span class="hlt">Ion</span> Beam lithography (FIB) was used to make silicone elastomer molds. The silicon mold is composed of lattice of holes which the diameter and depth are about 200 nm and 60 nm, respectively. The silicone elastomer material was then used to replicate slavery mold. Our study show the replication process with the elastomer mold had been performed successfully and the diameter of humps on the elastomer mold is near to that of holes on the master mold. But the height of humps in the elastomer mold is only 42 nm and it is different from the depth of holes in the master mold.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20040065912&hterms=Analogue&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DAnalogue','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20040065912&hterms=Analogue&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DAnalogue"><span><span class="hlt">Focused</span> <span class="hlt">Ion</span> Beam Recovery and Analysis of Interplanetary Dust Particles (IDPs) and Stardust Analogues</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Graham, G. A.; Bradley, J. P.; Bernas, M.; Stroud, R. M.; Dai, Z. R.; Floss, C.; Stadermann, F. J.; Snead, C. J.; Westphal, A. J.</p> <p>2004-01-01</p> <p>Meteoritics research is a major beneficiary of recent developments in analytical instrumentation [1,2]. Integrated studies in which multiple analytical techniques are applied to the same specimen are providing new insight about the nature of IDPs [1]. Such studies are dependent on the ability to prepare specimens that can be analyzed in multiple instruments. <span class="hlt">Focused</span> <span class="hlt">ion</span> beam (FIB) microscopy has revolutionized specimen preparation in materials science [3]. Although FIB has successfully been used for a few IDP and meteorite studies [1,4-6], it has yet to be widely utilized in meteoritics. We are using FIB for integrated TEM/NanoSIMS/synchrotron infrared (IR) studies [1].</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015SPIE.9634E..3IA','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015SPIE.9634E..3IA"><span>Bragg grating fabrication on tapered fiber tips based on <span class="hlt">focused</span> <span class="hlt">ion</span> beam milling</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>André, Ricardo M.; Becker, Martin; Dellith, Jan; Rothhardt, Manfred; Zibaii, M. I.; Latifi, H.; Marques, Manuel B.; Bartelt, Hartmut; Frazão, Orlando</p> <p>2015-09-01</p> <p><span class="hlt">Focused</span> <span class="hlt">ion</span> beam milling is used on chemically etched tapered fiber tips to create fiber Bragg gratings. These fiber Bragg gratings are based on a modulation of silica and external medium. This leads to a wide and structured spectrum obtained due to imperfections and the inherent structure of the tip. The fiber Bragg gratings presented are very short and have a length of 27 μm and 43 μm and are milled on the tapered fiber tip. They are characterized in the high temperature range 350-850ºC and a sensitivity of 14.4 pm/K is determined.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22392280','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22392280"><span>Microscopic diamond solid-immersion-lenses fabricated around single defect centers by <span class="hlt">focused</span> <span class="hlt">ion</span> beam milling</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Jamali, Mohammad; Rezai, Mohammad; Fedder, Helmut; Gerhardt, Ilja; Wrachtrup, Jörg; Frenner, Karsten</p> <p>2014-12-15</p> <p>Recent efforts to define microscopic solid-immersion-lenses (SIL) by <span class="hlt">focused</span> <span class="hlt">ion</span> beam milling into diamond substrates that are registered to a preselected single photon emitter are summarized. We show how we determine the position of a single emitter with at least 100 nm lateral and 500 nm axial accuracy, and how the milling procedure is optimized. The characteristics of a single emitter, a Nitrogen Vacancy (NV) center in diamond, are measured before and after producing the SIL and compared with each other. A count rate of 1.0 × 10{sup 6} counts/s is achieved with a [111] oriented NV center.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA253352','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA253352"><span>Simulation of Electron Beam Transport in <span class="hlt">Ion-Focused</span> Regime Conditioning Cells</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>1992-07-21</p> <p>leflhron Davis lgharay. Swft, I M. Arlington. VA 22Z02.4302. and to the office of Management and Budget. Paperwork Reduction Protect (07044 1in). Wahngon...nb(r, rz) and nh(r, rz) are the beam and <span class="hlt">ion</span> densities, respectively, and vi is the gas ionization rate. In sir at pressure P, vi =P(torr) nsecŕ . In... Humphries and Ekdah156 and Fernsler, et al.57 FRIEZR employs a variation of Adler’s thin lens approximation to treat foil <span class="hlt">focusing</span>. The impulse has the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28273045','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28273045"><span>Control of tunnel barriers in multi-wall carbon nanotubes using <span class="hlt">focused</span> <span class="hlt">ion</span> beam irradiation.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Tomizawa, H; Suzuki, K; Yamaguchi, T; Akita, S; Ishibashi, K</p> <p>2017-04-21</p> <p>We have formed tunnel barriers in individual multi-wall carbon nanotubes using the Ga <span class="hlt">focused</span> <span class="hlt">ion</span> beam irradiation. The barrier height was estimated by the temperature dependence of the current (Arrhenius plot) and the current-voltage curves (Fowler-Nordheim plot). It is shown that the barrier height has a strong correlation with the barrier resistance that is controlled by the dose. Possible origins for the variation in observed barrier characteristics are discussed. Finally, the single electron transistor with two barriers is demonstrated.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_23 --> <div id="page_24" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="461"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1998PhDT.......169L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1998PhDT.......169L"><span>Production of low axial <span class="hlt">energy</span> spread <span class="hlt">ion</span> beams with multicusp sources</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lee, Yung-Hee Yvette</p> <p></p> <p>Multicusp <span class="hlt">ion</span> sources are capable of producing <span class="hlt">ions</span> with low axial <span class="hlt">energy</span> spread which are necessary in applications such as: <span class="hlt">ion</span> projection lithography (IPL) and <span class="hlt">focused</span> <span class="hlt">ion</span> beams for the next generation lithographic tools and nuclear science experiments such as radioactive <span class="hlt">ion</span> beam production. The axial <span class="hlt">ion</span> <span class="hlt">energy</span> spread for multicusp source is approximately 6 eV which is too large for IPL and radioactive <span class="hlt">ion</span> beam applications. The addition of a magnetic filter which consists of a pair of permanent magnets to the multicusp source reduces the <span class="hlt">energy</span> spread considerably. The reduction is due to the improvement in the uniformity of the axial plasma potential distribution in the discharge region. Axial <span class="hlt">ion</span> <span class="hlt">energy</span> spread of the filament driven <span class="hlt">ion</span> source has been measured using three different techniques. In all cases, it was found to be less than 2 eV. <span class="hlt">Energy</span> spread of the radio frequency (RF) driven source has also been explored, and it was found to be less than 3 eV with the proper RF-shielding. A new multicusp source configuratian has been designed and constructed to further reduce the <span class="hlt">energy</span> spread. To achieve a more uniform axial plasma potential distribution, a cylindrical magnetic filter has been designed and constructed for a 20-cm-diameter source. This new source configuration, the co-axial source, is new in its kind. The <span class="hlt">energy</span> spread in this source has been measured to be a record low of 0.6 eV. Because of the novelty of this device, some plasma parameters inside the source have been studied. Langmuir probe has been used to measure the plasma potential, the electron temperature and the density distribution. Unlike any other source in existence, the co-axial source has been designed to have a capability in adjusting the radial plasma potential distribution and therefore the transverse <span class="hlt">ion</span> temperature (or beam emittance). The effect on the beam emittance has been verified by using a triode accelerator assembly and a Allison type parallel- plate emittance</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19780002611','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19780002611"><span>Portable linear-<span class="hlt">focused</span> solar thermal <span class="hlt">energy</span> collecting system</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Miller, C. G.; Pohl, J. G. (Inventor)</p> <p>1977-01-01</p> <p>A solar heat collection system is provided by utilizing a line-<span class="hlt">focusing</span> device that is effectively a cylindrically curved concentrator within a protected environment formed by a transparent inflatable casing. A target, such as a fluid or gas carrying conduit is positioned within or near the casing containing the concentrator, at the line <span class="hlt">focus</span> of the concentrator. The casing can be inflated at the site of use by a low pressure air supply to form a unitary light weight structure. The collector, including casing, concentrator and target, is readily transportable and can be used either at ground level or on rooftops. The inflatable concentrator can be replaced with a rigid metal or other concentrator while maintaining the novel advantages of the whole solar heat collection system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28831127','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28831127"><span>Spacial <span class="hlt">Energy</span> Distribution Manipulation with Multi-<span class="hlt">focus</span> Huygens Metamirror.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wang, Zhuochao; Ding, Xumin; Zhang, Kuang; Wu, Qun</p> <p>2017-08-22</p> <p>Huygens metasurface is a planar array of crossed electric and magnetic dipoles, which provide specific surface current to tailor the electromagnetic field distribution. By changing the geometrical parameters of the proposed unit cell, the manipulation range of reflection phase can achieve 2π, while the amplitude of the reflection coefficient can keep above 0.993. Based on the designed Huygens meta-atoms, a novel multi-<span class="hlt">focus</span> Huygens metamirror is proposed at microwave range in this paper. Utilizing the meta-atoms with the desired reflection phase distribution as calculated, the incident plane wave can be converged to designated points in any desired fashion including focal number, location and intensity distribution, which exhibits outstanding manipulation capability. Our research on Huygens metamirror provides a fascinating design of multi-<span class="hlt">focus</span> imaging in microwave region, which makes it potential applications in antenna and imaging systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1390418-real-single-ion-solvation-free-energies-quantum-mechanical-simulation','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1390418-real-single-ion-solvation-free-energies-quantum-mechanical-simulation"><span>Real single <span class="hlt">ion</span> solvation free <span class="hlt">energies</span> with quantum mechanical simulation</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Duignan, Timothy TS; Baer, Marcel D.; Schenter, Gregory K.; ...</p> <p>2017-09-01</p> <p>Single <span class="hlt">ion</span> solvation free <span class="hlt">energies</span> are one of the most important properties of electrolyte solution and yet there is ongoing debate about what these values are. Experimental methods can only determine the values for neutral <span class="hlt">ion</span> pairs. Here, we use DFT interaction potentials with molecular dynamics simulation (DFT-MD) combined with a modified version of the quasi chemical theory (QCT) to calculate these <span class="hlt">energies</span> for the lithium and fluoride <span class="hlt">ions</span>. A new method to rigorously correct for the error in the DFT functional is developed and very good agreement with the experimental value for the lithium fluoride pair is obtained. Moreover,more » this method partitions the <span class="hlt">energies</span> into physically intuitive terms such as surface potential, cavity and charging <span class="hlt">energies</span> which are amenable to descriptions with reduced models. Our research suggests that lithium’s solvation <span class="hlt">energy</span> is dominated by the free energetics of a charged hard sphere, whereas fluoride exhibits significant quantum mechanical behavior that cannot be simply described with a reduced model. We would like to thank Thomas Beck, Shawn Kathmann and Sotiris Xantheas for helpful discussions. Computing resources were generously allocated by PNNLs Institutional Computing program. This research also used resources of the National <span class="hlt">Energy</span> Research Scientific Computing Center, a DOE Office of Science User Facility supported by the Office of Science of the U.S. Department of <span class="hlt">Energy</span> under Contract No. DE-AC02-05CH11231. TTD, GKS and CJM were supported by the U.S. Department of <span class="hlt">Energy</span>, Office of Science, Office of Basic <span class="hlt">Energy</span> Sciences, Division of Chemical Sciences, Geosciences, and Biosciences. MDB was supported by MS3 (Materials Synthesis and Simulation Across Scales) Initiative, a Laboratory Directed Research and Development Program at Pacific Northwest National Laboratory (PNNL). PNNL is a multi-program national laboratory operated by Battelle for the U.S. Department of <span class="hlt">Energy</span>.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006JGRA..11112215Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006JGRA..11112215Z"><span>Simulation of the POLAR-observed Geomagnetic <span class="hlt">Ion</span> <span class="hlt">Energy</span> Spectrometer</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zeng, W.; Horwitz, J. L.; Elliott, H. A.; Moore, T. E.</p> <p>2006-12-01</p> <p>Observations by polar-orbiting spacecraft of outward streaming ionospheric O+ <span class="hlt">ions</span> in the polar cap magnetosphere often show decreasing field-aligned streaming <span class="hlt">energy</span> with antisunward distance from their apparent dayside source, the Cleft <span class="hlt">Ion</span> Fountain (CIF). In this paper we use the UT Arlington Dynamic Fluid-Kinetic (DyFK) ionospheric plasma transport model to simulate the transport of CIF generated <span class="hlt">ions</span> along convecting magnetic flux tubes. We compare these simulations to observations by the Thermal <span class="hlt">Ion</span> Dynamics Experiments (TIDE) on board the Polar spacecraft, for periods when the Polar orbit was aligned parallel to the noon-midnight direction. When the Polar spacecraft traversed from high altitudes on the dayside to lower altitudes on the nightside, the peak O+ streaming <span class="hlt">energy</span> decreased from above 100 eV to below 5 eV. For the case in which the Polar satellite traveled from the nightside higher altitude to the dayside lower altitude, the O+ <span class="hlt">energy</span> remained relatively stable, ranging between 20 eV and about 50 eV. Using the DyFK model, we simulate the ionospheric plasma transport and, in particular, the <span class="hlt">energy</span> spectrometer effects under the geophysical circumstances of the observations, and compare the simulated and observed streaming <span class="hlt">energies</span>. The results show that the simulated O+-streaming <span class="hlt">energy</span> variations in the noon-midnight direction were in reasonable agreement with those of the Polar/TIDE observations, independent of whether Polar was moving sunward or antisunward, for realistic choices of geophysical parameters. The altitude and the distance to the CIF are the two primary O+ parameters influencing the O+ <span class="hlt">energy</span> spectrometer variations, with the antisunward distance from the CIF being the principal controlling parameter.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19990014464&hterms=ram&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dram','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19990014464&hterms=ram&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dram"><span>Observations of Reflected <span class="hlt">Ions</span> and Plasma Turbulence for Satellite Potentials Greater than the <span class="hlt">Ion</span> Ram <span class="hlt">Energy</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wright, K. H., Jr.; Stone, N. H.; Sorensen, J.; Winningham, J. D.; Gurgiolo, C.</p> <p>1998-01-01</p> <p>During the TSS-1R mission, the behavior of the <span class="hlt">ions</span> flowing from the forward hemisphere of the Tethered Satellite System (TSS) satellite was examined as the potential of the satellite was changed from below to above 5 V. The ram <span class="hlt">energy</span> of the ambient atomic oxygen <span class="hlt">ions</span> is approximately 5 eV. For satellite potentials less than 5 V, no <span class="hlt">ions</span> were observed on the ram side of the satellite. When the satellite potential was raised greater than 5 V, <span class="hlt">ions</span> were observed to be flowing from the forward region of the satellite. In the region sampled, the <span class="hlt">ion</span> flux was a few percent of the ambient with <span class="hlt">energies</span> of approximately 5 eV. The temperature of the out-flowing <span class="hlt">ions</span> was observed to be enhanced, relative to the ambient ionosphere. The net current to the probe package became much more noisy for satellite potentials greater than 5 V as compared with satellite potentials less than 5 V, indicating a more disturbed plasma environment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19990080070&hterms=ram&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dram','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19990080070&hterms=ram&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dram"><span>Observations of Reflected <span class="hlt">Ions</span> and Plasma Turbulence for Satellite Potentials Greater Than the <span class="hlt">Ion</span> Ram <span class="hlt">Energy</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wright, K. H., Jr.; Stone, N. H.; Sorensen, J.; Winningham, J. D.; Gurgiolo, C.</p> <p>1997-01-01</p> <p>During the TSS-1R mission, the behavior of the <span class="hlt">ions</span> flowing from the forward hemisphere of the Tethered Satellite System (TSS) satellite was examined as the potential on the satellite was changed from below to above 5 Volts. The ram <span class="hlt">energy</span> of the ambient atomic oxygen <span class="hlt">ions</span> is about 5 eV. For satellite potentials less than 5 V, no <span class="hlt">ions</span> were observed on the ram side of the satellite. When the satellite potential was raised above 5 V, <span class="hlt">ions</span> were observed to be flowing from the forward region of the satellite. In the region sampled, the <span class="hlt">ion</span> flux was a few percent of the ambient with <span class="hlt">energies</span> of about 5 eV. The temperature of the outflowing <span class="hlt">ions</span> was observed to be enhanced, relative to the ambient ionosphere, and had a maximum in a plane containing the center of the satellite and normal to the geomagnetic field. The net current to the probe package became much more noisy for satellite potentials above 5 V as compared with satellite potentials below 5 V indicating a more disturbed plasma environment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/881880','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/881880"><span>Optimization of a 3x3 <span class="hlt">focusing</span> array for heavy <span class="hlt">ion</span> drivers</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Martovetsky, N N; Meinke, R B</p> <p>2005-08-08</p> <p>A heavy <span class="hlt">ion</span> driver for inertial fusion will accelerate an array of beams through common induction cores and then direct the beams onto the DT target. An array of quadrupole <span class="hlt">focusing</span> magnets is used to prevent beam expansion from space charge forces. In the array, the magnet fields from the coils embracing the beams are coupled, which reduces the cost of superconductor and increases the <span class="hlt">focusing</span> power. The challenges in designing such an array are meeting the strict requirements for the quadrupole field inside the beam pipes and preventing stray fields outside. We report our optimization effort on designing such an array and show that 3 x 3 or larger arrays are feasible and practical to build with flat racetrack coils.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001NIMPA.464..152L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001NIMPA.464..152L"><span>Final <span class="hlt">focus</span> shielding designs for modern heavy-<span class="hlt">ion</span> fusion power plant designs</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Latkowski, J. F.; Meier, W. R.</p> <p>2001-05-01</p> <p>Recent work in heavy-<span class="hlt">ion</span> fusion accelerators and final <span class="hlt">focusing</span> systems shows a trend towards less current per beam, and thus, a greater number of beams. Final <span class="hlt">focusing</span> magnets are susceptible to nuclear heating, radiation damage, and neutron activation. The trend towards more beams, however, means that there can be less shielding for each magnet. Excessive levels of nuclear heating may lead to magnet quench or to an intolerable recirculating power for magnet cooling. High levels of radiation damage may result in short magnet lifetimes and low reliability. Finally, neutron activation of the magnet components may lead to difficulties in maintenance, recycling, and waste disposal. The present work expands upon previous, three-dimensional magnet shielding calculations for a modified version of the HYLIFE-II IFE power plant design. We present key magnet results as a function of the number of beams.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/15013164','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/15013164"><span>Final <span class="hlt">Focus</span> Shielding Designs for Modern Heavy-<span class="hlt">Ion</span> Fusion Power Plant Designs</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Latkowski, J F; Meier, W R</p> <p>2000-07-05</p> <p>Recent work in heavy-<span class="hlt">ion</span> fusion accelerators and final <span class="hlt">focusing</span> systems shows a trend towards less current per beam, and thus, a greater number of beams. Final <span class="hlt">focusing</span> magnets are susceptible to nuclear heating, radiation damage, and neutron activation. The trend towards more beams, however, means that there can be less shielding for each magnet, Excessive levels of nuclear heating may lead to magnet quench or an intolerable recirculating power for magnet cooling. High levels of radiation damage may result in short magnet lifetimes and low reliability. Finally, neutron activation of the magnet components may lead to difficulties in maintenance, recycling, and waste disposal. The present work expands upon previous, three-dimensional magnet shielding calculations for a modified version of the HYLIFE-I1 IFE power plant design. We present key magnet results as a function of the number of beams.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/793557','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/793557"><span>Improved Final <span class="hlt">Focus</span> Shielding Designs for Modern Heavy-<span class="hlt">Ion</span> Fusion Power Plant Designs</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Latkowski, J.F.; Meier, W.R.</p> <p>2000-03-01</p> <p>Recent work in heavy-<span class="hlt">ion</span> fusion accelerators and final <span class="hlt">focusing</span> systems shows a trend towards less current per beam, and thus, a significantly greater number of beams. Final <span class="hlt">focusing</span> magnets are susceptible to nuclear heating, radiation damage, and neutron activation. The trend towards more beams, however, means that there can be less shielding for each magnet. Excessive levels of nuclear heating may lead to magnet quench or an intolerable recirculating power for magnet cooling. High levels of radiation damage may result in short magnet lifetimes and low reliability. Finally, neutron activation of the magnet components may lead to difficulties in maintenance, recycling, and waste disposal. The present work expands upon previous, three-dimensional magnet shielding calculations for a modified version of the HYLIFE-II IFE power plant design. We present key magnet results as a function of the number of beams.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28262900','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28262900"><span>Influence of lanthanide <span class="hlt">ion</span> <span class="hlt">energy</span> levels on luminescence of corresponding metalloporphyrins.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhao, Huimin; Zang, Lixin; Guo, Chengshan</p> <p>2017-03-15</p> <p>Lanthanide (Ln) porphyrins exhibit diverse luminescence properties that have not been fully explained yet. A series of Ln <span class="hlt">ions</span> (Ln <span class="hlt">ions</span> = La(3+), Ce(3+), Pr(3+), Nd(3+), Sm(3+), Eu(3+), Gd(3+), Tb(3+), Dy(3+), Ho(3+), Er(3+), Tm(3+), Yb(3+), and Lu(3+)) were coordinated with hematoporphyrin monomethyl ether (HMME), and their luminescence properties and related differences were studied. Spectral analysis indicated that all Ln-HMMEs exhibit fluorescence emission. Gd- and Lu-HMMEs were the only lanthanide-HMMEs displaying strong molecular π-π room-temperature phosphorescence (RTP) with quantum yield ΦP > 10(-3). Tb(3+) can also induce RTP from HMME but ΦP of Tb-HMME is much smaller (ΦP ∼ 10(-4)). The observed luminescence property differences were analyzed in detail, <span class="hlt">focusing</span> on the 4f <span class="hlt">energy</span> levels of Ln <span class="hlt">ions</span>. These levels mostly lie below the lowest singlet (S1) and triplet (T1) excited states of HMME, resulting in <span class="hlt">energy</span> transfer from the T1 state in HMME to Ln <span class="hlt">ions</span> and, therefore, in the absence of RTP from the corresponding metalloporphyrins. Gd(3+) and Lu(3+) are the only lanthanide <span class="hlt">ions</span> not possessing such 4f <span class="hlt">energy</span> levels, avoiding T1 quenching in Gd- and Lu-HMMEs. Although Tb(3+) has low-lying 4f <span class="hlt">energy</span> levels, the corresponding transition from the ground state is partly forbidden, resulting in weak <span class="hlt">energy</span> transfer from HMME to Tb(3+) that accounts for the low RTP quantum yield of the corresponding complex. Thus, our results indicate that the luminescence property differences of lanthanide porphyrins are due to the disparate <span class="hlt">energy</span> levels of the Ln <span class="hlt">ions</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002JAP....91.6836C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002JAP....91.6836C"><span>Fabrication and characterization of <span class="hlt">focused-ion</span>-beam trimmed write heads for perpendicular magnetic recording</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Clinton, T. W.; van der Heijden, P. A. A.; Karns, D. C.; Yu, J.; Park, C. M.; Batra, S.</p> <p>2002-05-01</p> <p>A <span class="hlt">focused</span> <span class="hlt">ion</span> beam (FIB) has been used to trim write heads for perpendicular magnetic recording using untrimmed HGA-level longitudinal heads. The <span class="hlt">ion</span>-beam imaging of the write head during FIB processing was minimized to limit exposure of the active magnetic material at the ABS to a 30 keV Ga+ <span class="hlt">ion</span> dose of less than 1014Ga+/cm2 (≈10-13 C/μm2) (the GMR reader was never exposed), which is significantly below levels where magnetic properties have been observed to degrade [W. M. Kaminsky et al., Appl. Phys. Lett. 78, 1589 (2001)]. The corresponding recording characteristics and spatial profiles of written tracks have been measured on a spin stand and a magnetic force microscope (MFM). Recording performance, such as SNR, and pulse shape of transitions, for example, as a function of head design and FIB processing is discussed, which compares very favorably to the performance of untrimmed heads. The MFM images reveal curvature in the magnetic transitions (transition smile) when writing with a single-pole writer with a straight trailing edge. Conversely, we demonstrate straight transitions using a single-pole writer with a curved trailing edge. Our results demonstrate the robustness of FIB-trimmed heads down to sub-100-nm length scales.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24322544','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24322544"><span>Chemical degradation and morphological instabilities during <span class="hlt">focused</span> <span class="hlt">ion</span> beam prototyping of polymers.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Orthacker, A; Schmied, R; Chernev, B; Fröch, J E; Winkler, R; Hobisch, J; Trimmel, G; Plank, H</p> <p>2014-01-28</p> <p><span class="hlt">Focused</span> <span class="hlt">ion</span> beam processing of low melting materials, such as polymers or biological samples, often leads to chemical and morphological instabilities which prevent the straight-forward application of this versatile direct-write structuring method. In this study the behaviour of different polymer classes under <span class="hlt">ion</span> beam exposure is investigated using different patterning parameters and strategies with the aim of (i) correlating local temperatures with the polymers' chemistry and its morphological consequences; and (ii) finding a way of processing sensitive polymers with lowest chemical degradation while maintaining structuring times. It is found that during processing of polymers three temperature regimes can be observed: (1) at low temperatures all polymers investigated show stable chemical and morphological behaviour; (2) very high temperatures lead to strong chemical degradation which entails unpredictable morphologies; and (3) in the intermediate temperature regime the behaviour is found to be strongly material dependent. A detailed look reveals that polymers which rather cross-link in the proximity of the beam show stable morphologies in this intermediate regime, while polymers that rather undergo chain scission show tendencies to develop a creeping phase, where material follows the <span class="hlt">ion</span> beam movement leading to instable and unpredictable morphologies. Finally a simple, alternative patterning strategy is suggested, which allows stable processing conditions with lowest chemical damage even for challenging polymers undergoing chain scission.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23571491','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23571491"><span>Aluminum oxide mask fabrication by <span class="hlt">focused</span> <span class="hlt">ion</span> beam implantation combined with wet etching.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Liu, Zhengjun; Iltanen, Kari; Chekurov, Nikolai; Grigoras, Kestutis; Tittonen, Ilkka</p> <p>2013-05-03</p> <p>A novel aluminum oxide (Al2O3) hard mask fabrication process with nanoscale resolution is introduced. The Al2O3 mask can be used for various purposes, but in this work it was utilized for silicon patterning using cryogenic deep reactive <span class="hlt">ion</span> etching (DRIE). The patterning of Al2O3 is a two-step process utilizing <span class="hlt">focused</span> <span class="hlt">ion</span> beam (FIB) irradiation combined with wet chemical etching. Gallium (Ga(+)) FIB maskless patterning confers wet etch selectivity between the irradiated region and the non-irradiated one on the Al2O3 layer, and mask patterns can easily be revealed by wet etching. This method is a modification of Ga(+) FIB mask patterning for the silicon etch stop, which eliminates the detrimental lattice damage and doping of the silicon substrate in critical devices. The shallow surface gallium FIB irradiated Al2O3 mask protects the underlying silicon from Ga(+) <span class="hlt">ions</span>. The performance of the masking capacity was tested by drawing pairs consisting of a line and an empty space with varying width. The best result was seven such pairs for 1 μm. The smallest half pitch was 59 nm. This method is capable of arbitrary pattern generation. The fabrication of a freestanding single-ended tuning fork resonator utilizing the introduced masking method is demonstrated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/20861165','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/20861165"><span>Development of a low <span class="hlt">energy</span> <span class="hlt">ion</span> source for ROSINA <span class="hlt">ion</span> mode calibration</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Rubin, Martin; Altwegg, Kathrin; Jaeckel, Annette; Balsiger, Hans</p> <p>2006-10-15</p> <p>The European Rosetta mission on its way to comet 67P/Churyumov-Gerasimenko will remain for more than a year in the close vicinity (1 km) of the comet. The two ROSINA mass spectrometers on board Rosetta are designed to analyze the neutral and ionized volatile components of the cometary coma. However, the relative velocity between the comet and the spacecraft will be minimal and also the velocity of the outgassing particles is below 1 km/s. This combination leads to very low <span class="hlt">ion</span> <span class="hlt">energies</span> in the surrounding plasma of the comet, typically below 20 eV. Additionally, the spacecraft may charge up to a few volts in this environment. In order to simulate such plasma and to calibrate the mass spectrometers, a source for <span class="hlt">ions</span> with very low <span class="hlt">energies</span> had to be developed for the use in the laboratory together with the different gases expected at the comet. In this paper we present the design of this <span class="hlt">ion</span> source and we discuss the physical parameters of the <span class="hlt">ion</span> beam like sensitivity, <span class="hlt">energy</span> distribution, and beam shape. Finally, we show the first <span class="hlt">ion</span> measurements that have been performed together with one of the two mass spectrometers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012PhPl...19i2707D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012PhPl...19i2707D"><span>Transition <span class="hlt">energies</span> and polarizabilities of hydrogen like <span class="hlt">ions</span> in plasma</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Das, Madhusmita</p> <p>2012-09-01</p> <p>Effect of plasma screening on various properties like transition <span class="hlt">energy</span>, polarizability (dipole and quadrupole), etc. of hydrogen like <span class="hlt">ions</span> is studied. The bound and free state wave functions and transition matrix elements are obtained by numerically integrating the radial Schrodinger equation for appropriate plasma potential. We have used adaptive step size controlled Runge-Kutta method to perform the numerical integration. Debye-Huckel potential is used to investigate the variation in transition lines and polarizabilities (dipole and quadrupole) with increasing plasma screening. For a strongly coupled plasma, <span class="hlt">ion</span> sphere potential is used to show the variation in excitation <span class="hlt">energy</span> with decreasing <span class="hlt">ion</span> sphere radius. It is observed that plasma screening sets in phenomena like continuum lowering and pressure ionization, which are unique to <span class="hlt">ions</span> in plasma. Of particular interest is the blue (red) shift in transitions conserving (non-conserving) principal quantum number. The plasma environment also affects the dipole and quadrupole polarizability of <span class="hlt">ions</span> in a significant manner. The bound state contribution to polarizabilities decreases with increase in plasma density whereas the continuum contribution is significantly enhanced. This is a result of variation in the behavior of bound and continuum state wave functions in the presence of plasma. We have compared the results with existing theoretical and experimental data wherever present.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008NIMPB.266.4488P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008NIMPB.266.4488P"><span>Cryogenic helium as stopping medium for high-<span class="hlt">energy</span> <span class="hlt">ions</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Purushothaman, S.; Dendooven, P.; Moore, I.; Penttilä, H.; Ronkainen, J.; Saastamoinen, A.; Äystö, J.; Peräjärvi, K.; Takahashi, N.; Gloos, K.</p> <p>2008-10-01</p> <p>We have investigated the survival and transport efficiency of 219Rn <span class="hlt">ions</span> emitted by a 223Ra source in high-density cryogenic helium gas, with ionisation of the gas induced by a proton beam. The combined efficiency of <span class="hlt">ion</span> survival and transport by an applied electric field was measured as a function of ionisation rate density for electric fields up to 160 V/cm and for three temperature and density combinations: 77 K, 0.18 mg/cm3, 10 K, 0.18 mg/cm3 and 10 K, 0.54 mg/cm3. At low beam intensity or high electric field, an efficiency of 30 % is obtained, confirming earlier results. A sharp drop in efficiency is observed at a "threshold" ionisation rate density which increases with the square of the applied electric field. At 160 V/cm, the efficiency stays above 10% up to an ionisation rate density of 1012 <span class="hlt">ion</span>-electron pairs/cm3/s. The observed behaviour is understood as the result of shielding of the applied field by the weak plasma created by the proton beam: it counteracts the effective transport of <span class="hlt">ions</span> and electrons, leading to recombination between the two. We conclude that cryogenic helium gas at high-density and high electric field is a promising medium for the transformation of very high-<span class="hlt">energy</span> <span class="hlt">ions</span> into low-<span class="hlt">energy</span> ones.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22086151','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22086151"><span>Transition <span class="hlt">energies</span> and polarizabilities of hydrogen like <span class="hlt">ions</span> in plasma</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Das, Madhusmita</p> <p>2012-09-15</p> <p>Effect of plasma screening on various properties like transition <span class="hlt">energy</span>, polarizability (dipole and quadrupole), etc. of hydrogen like <span class="hlt">ions</span> is studied. The bound and free state wave functions and transition matrix elements are obtained by numerically integrating the radial Schrodinger equation for appropriate plasma potential. We have used adaptive step size controlled Runge-Kutta method to perform the numerical integration. Debye-Huckel potential is used to investigate the variation in transition lines and polarizabilities (dipole and quadrupole) with increasing plasma screening. For a strongly coupled plasma, <span class="hlt">ion</span> sphere potential is used to show the variation in excitation <span class="hlt">energy</span> with decreasing <span class="hlt">ion</span> sphere radius. It is observed that plasma screening sets in phenomena like continuum lowering and pressure ionization, which are unique to <span class="hlt">ions</span> in plasma. Of particular interest is the blue (red) shift in transitions conserving (non-conserving) principal quantum number. The plasma environment also affects the dipole and quadrupole polarizability of <span class="hlt">ions</span> in a significant manner. The bound state contribution to polarizabilities decreases with increase in plasma density whereas the continuum contribution is significantly enhanced. This is a result of variation in the behavior of bound and continuum state wave functions in the presence of plasma. We have compared the results with existing theoretical and experimental data wherever present.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/930790','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/930790"><span>Secondary Electron Generation by Low <span class="hlt">Energy</span> <span class="hlt">Ion</span> Beams</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Joy, David Charles; Lin, Yinghong; Meyer III, Harry M; Demers, Hendrix; Newbury, Dale</p> <p>2006-01-01</p> <p>Low <span class="hlt">energy</span> <span class="hlt">ion</span> beams are being increasingly viewed as an alternative to, or even as areplacement for, low voltage SEMs. The beam interaction volumes in both cases are comparable in their size and their proximity to the sample surface, and both can produce high quality secondary electron images. However, although a cursory comparison of <span class="hlt">ion</span> generated SE (iSE) and electron generated SE (eSE) images of the same area of a sample shows micrographs that can look very similar this is misleading because the nature of the iSE and eSE images are quite distinct. More experimental data and additional analysis of the beam interactions is therefore required if images are to be properly nterpreted.The yield de of eSE, rises rapidly with incident beam <span class="hlt">energy</span> E reaching a maximum value which is typically in the range 1.5-2 and occurs at an <span class="hlt">energy</span> of a few hundred eV before then falling away as about 1/E.. In the case of <span class="hlt">ion</span> beam irradiation the kinetic production of iSE commences at a particle velocity of about 107cm/sec 30eV for He, (3keV for Ar) producing a yield di of iSE which rises almost linearly with the accelerating voltage and reaches typical values of 1.5 - 2.5 for <span class="hlt">energies</span> of the order of 20- 30kV. Thus while at low <span class="hlt">energies</span> the eSE and iSE yields are comparable in magnitude, at higher <span class="hlt">energies</span> the iSE yield is an order of magnitude or more larger. The iSE yield will eventually each a maximum value and then begin to fall when once the interaction volume lies mostly below the escape depth of the SE. Both eSE and iSE yields also display a marked - although apparently chaotic - dependence on the atomic number of the target (Z2) and, in the <span class="hlt">ion</span> case, on the atomic number of the <span class="hlt">ion</span> (Z1) itself. In the electron case the minima in the SE yield versus Z2 plot correspond to shell filling but there is presently insufficient evidence to confirm if the same is true for the <span class="hlt">ion</span> SE case. Because the stopping powers of <span class="hlt">ion</span> and electrons, and hence their range in a given material, are</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_24 --> <div id="page_25" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="481"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1996APS..MAR.I1608K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1996APS..MAR.I1608K"><span>Large scale self <span class="hlt">energy</span> calculations for <span class="hlt">ion</span>-surface interactions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kürpick, P.; Thumm, U.</p> <p>1996-03-01</p> <p>We present large scale non-perturbative self <span class="hlt">energy</span> calculations for the interaction of an <span class="hlt">ion</span> with a metal surface. Using both the simple jellium potential and more sophisticated ab initio potentials(P. J. Jennings, R. O. Jones and M. Weinert, Phys. Rev. B, 37), 6113 (1988)., we study the complex self <span class="hlt">energy</span> matrix for various n-manifolds allowing for the calculation of diabatic and adiabatic non-perturbative level shifts and widths, and hybrid orbitals(P. Kürpick and U.Thumm, to be published.). Besides this self <span class="hlt">energy</span> calculations a new adiabatic close--coupling calculation is being developed that will be applied to the interaction of <span class="hlt">ions</span> in various charge states with metal surfaces.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22898959','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22898959"><span><span class="hlt">Focused</span> <span class="hlt">ion</span> beam preparation of samples for X-ray nanotomography.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lombardo, Jeffrey J; Ristau, Roger A; Harris, William M; Chiu, Wilson K S</p> <p>2012-09-01</p> <p>The preparation of hard material samples with the necessary size and shape is critical to successful material analysis. X-ray nanotomography requires that samples are sufficiently thin for X-rays to pass through the sample during rotation for tomography. One method for producing samples that fit the criteria for X-ray nanotomography is <span class="hlt">focused</span> <span class="hlt">ion</span> beam/scanning electron microscopy (FIB/SEM) which uses a <span class="hlt">focused</span> beam of <span class="hlt">ions</span> to selectively mill around a region of interest and then utilizes a micromanipulator to remove the milled-out sample from the bulk material and mount it on a sample holder. In this article the process for preparing X-ray nanotomography samples in multiple shapes and sizes is discussed. Additionally, solid-oxide fuel cell anode samples prepared through the FIB/SEM technique underwent volume-independence studies for multiple properties such as volume fraction, average particle size, tortuosity and contiguity to observe the characteristics of FIB/SEM samples in X-ray nanotomography.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26035337','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26035337"><span><span class="hlt">Focused</span> Electron and <span class="hlt">Ion</span> Beam Induced Deposition on Flexible and Transparent Polycarbonate Substrates.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Peinado, Patricia; Sangiao, Soraya; De Teresa, José M</p> <p>2015-06-23</p> <p>The successful application of <span class="hlt">focused</span> electron (and <span class="hlt">ion</span>) beam induced deposition techniques for the growth of nanowires on flexible and transparent polycarbonate films is reported here. After minimization of charging effects in the substrate, sub-100 nm-wide Pt, W, and Co nanowires have been grown and their electrical conduction is similar compared to the use of standard Si-based substrates. Experiments where the substrate is bent in a controlled way indicate that the electrical conduction is stable up to high bending angles, >50°, for low-resistivity Pt nanowires grown by the <span class="hlt">ion</span> beam. On the other hand, the resistance of Pt nanowires grown by the electron beam changes significantly and reversibly with the bending angle. Aided by the substrate transparency, a diffraction grating in transmission mode has been built based on the growth of an array of Pt nanowires that shows sharp diffraction spots. The set of results supports the large potential of <span class="hlt">focused</span> beam deposition as a high-resolution nanolithography technique on transparent and flexible substrates. The most promising applications are expected in flexible nano-optics and nanoplasmonics, flexible electronics, and nanosensing.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SPIE.9927E..0RA','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SPIE.9927E..0RA"><span>Tapered optical fiber tip probes based on <span class="hlt">focused</span> <span class="hlt">ion</span> beam-milled Fabry-Perot microcavities</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>André, Ricardo M.; Warren-Smith, Stephen C.; Becker, Martin; Dellith, Jan; Rothhardt, Manfred; Zibaii, M. I.; Latifi, H.; Marques, Manuel B.; Bartelt, Hartmut; Frazão, Orlando</p> <p>2016-09-01</p> <p><span class="hlt">Focused</span> <span class="hlt">ion</span> beam technology is combined with dynamic chemical etching to create microcavities in tapered optical fiber tips, resulting in fiber probes for temperature and refractive index sensing. Dynamic chemical etching uses hydrofluoric acid and a syringe pump to etch standard optical fibers into cone structures called tapered fiber tips where the length, shape, and cone angle can be precisely controlled. On these tips, <span class="hlt">focused</span> <span class="hlt">ion</span> beam is used to mill several different types of Fabry-Perot microcavities. Two main cavity types are initially compared and then combined to form a third, complex cavity structure. In the first case, a gap is milled on the tapered fiber tip which allows the external medium to penetrate the light guiding region and thus presents sensitivity to external refractive index changes. In the second, two slots that function as mirrors are milled on the tip creating a silica cavity that is only sensitive to temperature changes. Finally, both cavities are combined on a single tapered fiber tip, resulting in a multi-cavity structure capable of discriminating between temperature and refractive index variations. This dual characterization is performed with the aid of a fast Fourier transform method to separate the contributions of each cavity and thus of temperature and refractive index. Ultimately, a tapered optical fiber tip probe with sub-standard dimensions containing a multi-cavity structure is projected, fabricated, characterized and applied as a sensing element for simultaneous temperature and refractive index discrimination.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1997APS..MAR.S1805U','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1997APS..MAR.S1805U"><span>Local correlation <span class="hlt">energies</span> of atoms, <span class="hlt">ions</span> and model systems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Umrigar, Cyrus; Huang, Chien-Jung</p> <p>1997-03-01</p> <p>We present nearly local definitions of the correlation <span class="hlt">energy</span> density, and its potential and kinetic components, and evaluate them for several atoms, <span class="hlt">ions</span> and model systems. This information provides valuable guidance in constructing better correlation functionals than those in common use, such as the local density approximation (LDA) and the various generalized gradient approximations (GGAs). The true local correlation <span class="hlt">energy</span> per electron has oscillations, reflecting the shell-structure, whereas the LDA approximation to it is monotonic. In addition we demonstrate that, for two-electron systems, the quantum chemistry and the density functional definitions of the correlation <span class="hlt">energy</span> approach each other with increasing atomic number as 1/Z^3.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1997RScI...68.1398L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1997RScI...68.1398L"><span><span class="hlt">Ion</span> <span class="hlt">energy</span> spread and current measurements of the rf-driven multicusp <span class="hlt">ion</span> source</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lee, Y.; Gough, R. A.; Kunkel, W. B.; Leung, K. N.; Perkins, L. T.; Pickard, D. S.; Sun, L.; Vujic, J.; Williams, M. D.; Wutte, D.</p> <p>1997-03-01</p> <p>Axial <span class="hlt">energy</span> spread and useful beam current of positive <span class="hlt">ion</span> beams have been carried out using a radio frequency (rf)-driven multicusp <span class="hlt">ion</span> source. Operating the source with a 13.56 MHz induction discharge, the axial <span class="hlt">energy</span> spread is found to be approximately 3.2 eV. The extractable beam current of the rf-driven source is found to be comparable to that of filament-discharge sources. With a 0.6 mm diameter extraction aperture, a positive hydrogen <span class="hlt">ion</span> beam current density of 80 mA/cm2 can be obtained at a rf input power of 2.5 kW. The expected source lifetime is much longer than that of filament discharges.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28327280','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28327280"><span>[Hypothalamic inflammation and <span class="hlt">energy</span> balance deregulations: <span class="hlt">focus</span> on chemokines.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Le Thuc, Ophélia; Rovère, Carole</p> <p>2016-01-01</p> <p>The hypothalamus is a key brain region in the regulation of <span class="hlt">energy</span> balance. It especially controls food intake and both <span class="hlt">energy</span> storage and expenditure through integration of humoral, neural and nutrient-related signals and cues. Hypothalamic neurons and glial cells act jointly to orchestrate, both spatially and temporally, regulated metabolic functions of the hypothalamus. Thus, the existence of a causal link between hypothalamic inflammation and deregulations of feeding behavior, such as involuntary weight-loss or obesity, has been suggested. Among the inflammatory mediators that could induce deregulations of hypothalamic control of the <span class="hlt">energy</span> balance, chemokines represent interesting candidates. Indeed, chemokines, primarily known for their chemoattractant role of immune cells to the inflamed site, have also been suggested capable of neuromodulation. Thus, chemokines could disrupt cellular activity together with synthesis and/or secretion of multiple neurotransmitters/mediators that are involved in the maintenance of <span class="hlt">energy</span> balance. Here, we relate, on one hand, recent results showing the primary role of the central chemokinergic signaling CCL2/CCR2 for metabolic and behavioral adaptation to high-grade inflammation, especially loss of appetite and weight, through its activity on hypothalamic neurons producing the orexigenic peptide Melanin-Concentrating Hormone (MCH) and, on the other hand, results that suggest that chemokines could also deregulate hypothalamic neuropeptidergic circuits to induce an opposite phenotype and eventually participate in the onset/development of obesity. In more details, we will emphasize a study recently showing, in a model of high-grade acute inflammation of LPS injection in mice, that central CCL2/CCR2 signaling is of primary importance for several aspects explaining weight loss associated with inflammation: after LPS injection, animals lose weight, reduce their food intake, increase their fat oxidation (thus <span class="hlt">energy</span> consumption from</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016P%26SS..130...60S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016P%26SS..130...60S"><span><span class="hlt">Ion</span> <span class="hlt">energy</span> distributions and densities in the plume of Enceladus</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sakai, Shotaro; Cravens, Thomas E.; Omidi, Nojan; Perry, Mark E.; Waite, J. Hunter</p> <p>2016-10-01</p> <p>Enceladus has a dynamic plume that is emitting gas, including water vapor, and dust. The gas is ionized by solar EUV radiation, charge exchange, and electron impact and extends throughout the inner magnetosphere of Saturn. The charge exchange collisions alter the plasma composition. Ice grains (dust) escape from the vicinity of Enceladus and form the E ring, including a portion that is negatively charged by the local plasma. The inner magnetosphere within 10 RS (Saturn radii) contains a complex mixture of plasma, neutral gas, and dust that links back to Enceladus. In this paper we investigate the <span class="hlt">energy</span> distributions, <span class="hlt">ion</span> species and densities of water group <span class="hlt">ions</span> in the plume of Enceladus using test particle and Monte Carlo methods that include collisional processes such as charge exchange and <span class="hlt">ion</span>-neutral chemical reactions. <span class="hlt">Ion</span> observations from the Cassini <span class="hlt">Ion</span> and Neutral Mass Spectrometer (INMS) for E07 are presented for the first time. We use the modeling results to interpret observations made by the Cassini Plasma Spectrometer (CAPS) and the INMS. The low <span class="hlt">energy</span> <span class="hlt">ions</span>, as observed by CAPS, appear to be affected by a vertical electric field (EZ=-10 μV/m) in the plume. The EZ field may be associated with the charged dust and/or the pressure gradient of plasma. The model results, along with the results of earlier models, show that H3O+ <span class="hlt">ions</span> created by chemistry are predominant in the plume, which agrees with INMS and CAPS data, but the INMS count rate in the plume for the model is several times greater than the data, which we do not fully understand. This composition and the total <span class="hlt">ion</span> count found in the plume agree with INMS and CAPS data. On the other hand, the Cassini Langmuir Probe measured a maximum plume <span class="hlt">ion</span> density more than 30,000 cm-3, which is far larger than the maximum <span class="hlt">ion</span> density from our model, 900 cm-3. The model results also demonstrate that most of the <span class="hlt">ions</span> in the plume are from the external magnetospheric flow and are not generated by local</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1981JGR....86.4628L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1981JGR....86.4628L"><span><span class="hlt">Ion</span> composition and <span class="hlt">energy</span> distribution during 10 magnetic storms</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lennartsson, W.; Sharp, R. D.; Shelley, E. G.; Johnson, R. G.; Balsiger, H.</p> <p>1981-06-01</p> <p>Data from the plasma composition experiment of ISEE 1 are used to investigate the relative quantities and <span class="hlt">energy</span> characteristics of H(+), He(++), He(+), and O(+) <span class="hlt">ions</span> in the near-equatorial magnetosphere during magnetic storm conditions. The <span class="hlt">ions</span> in the study had <span class="hlt">energies</span> between 0.1 and 17 keV/e and pitch angles between 45 and 135 deg. The data were obtained during 10 storms, for the most part at or immediately following the peak Dst, covering all major local time sectors and geocentric distances between 2 and 15 earth radii. The <span class="hlt">ion</span> fluxes are averaged over the spacecraft spin angle and over time for periods ranging from about 20 min close to the earth to more than an hour in most distant regions. The inferred 'isotropic' number densities are characterized by a large to dominant fraction of terrestrial <span class="hlt">ions</span> throughout the <span class="hlt">energy</span> range covered. The data are found to be consistent with a terrestrial origin for all of the O(+), most of the He(+), and a large but varying fraction of the H(+), whereas the He(++) and part of the H(+) appear to be of solar wind origin.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19810054551&hterms=balsiger&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dbalsiger','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19810054551&hterms=balsiger&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dbalsiger"><span><span class="hlt">Ion</span> composition and <span class="hlt">energy</span> distribution during 10 magnetic storms</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lennartsson, W.; Sharp, R. D.; Shelley, E. G.; Johnson, R. G.; Balsiger, H.</p> <p>1981-01-01</p> <p>Data from the plasma composition experiment of ISEE 1 are used to investigate the relative quantities and <span class="hlt">energy</span> characteristics of H(+), He(++), He(+), and O(+) <span class="hlt">ions</span> in the near-equatorial magnetosphere during magnetic storm conditions. The <span class="hlt">ions</span> in the study had <span class="hlt">energies</span> between 0.1 and 17 keV/e and pitch angles between 45 and 135 deg. The data were obtained during 10 storms, for the most part at or immediately following the peak Dst, covering all major local time sectors and geocentric distances between 2 and 15 earth radii. The <span class="hlt">ion</span> fluxes are averaged over the spacecraft spin angle and over time for periods ranging from about 20 min close to the earth to more than an hour in most distant regions. The inferred 'isotropic' number densities are characterized by a large to dominant fraction of terrestrial <span class="hlt">ions</span> throughout the <span class="hlt">energy</span> range covered. The data are found to be consistent with a terrestrial origin for all of the O(+), most of the He(+), and a large but varying fraction of the H(+), whereas the He(++) and part of the H(+) appear to be of solar wind origin.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22413185','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22413185"><span>Mechanisms of material removal and mass transport in <span class="hlt">focused</span> <span class="hlt">ion</span> beam nanopore formation</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Das, Kallol Johnson, Harley T.; Freund, Jonathan B.</p> <p>2015-02-28</p> <p>Despite the widespread use of <span class="hlt">focused</span> <span class="hlt">ion</span> beam (FIB) processing as a material removal method for applications ranging from electron microscope sample preparation to nanopore processing for DNA sequencing, the basic material removal mechanisms of FIB processing are not well understood. We present the first complete atomistic simulation of high-flux FIB using large-scale parallel molecular dynamics (MD) simulations of nanopore fabrication in freestanding thin films. We <span class="hlt">focus</span> on the root mechanisms of material removal and rearrangement and describe the role of explosive boiling in forming nanopores. FIB nanopore fabrication is typically understood to occur via sputter erosion. This can be shown to be the case in low flux systems, where individual <span class="hlt">ion</span> impacts are sufficiently separated in time that they may be considered as independent events. But our detailed MD simulations show that in high flux FIB processing, above a threshold level at which thermal effects become significant, the primary mechanism of material removal changes to a significantly accelerated, thermally dominated process. Under these conditions, the target is heated by the <span class="hlt">ion</span> beam faster than heat is conducted away by the material, leading quickly to melting, and then continued heating to nearly the material critical temperature. This leads to explosive boiling of the target material with spontaneous bubble formation and coalescence. Mass is rapidly rearranged at the atomistic scale, and material removal occurs orders of magnitude faster than would occur by simple sputtering. While the phenomenology is demonstrated computationally in silicon, it can be expected to occur at lower beam fluxes in other cases where thermal conduction is suppressed due to material properties, geometry, or ambient thermal conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1912011P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1912011P"><span>Structure of High <span class="hlt">Energy</span>, Heavy <span class="hlt">Ions</span> in Venus' Upper Ionosphere</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Persson, Moa; Futaana, Yoshifumi; Nilsson, Hans; Stenberg Wieser, Gabriella; Hamrin, Maria; Fedorov, Andrei; Barabash, Stas</p> <p>2017-04-01</p> <p>The solar wind interacts with the atmosphere of Venus, and can reach directly down to the ionosphere. The interaction has previously been studied using the Pioneer Venus mission (PVO) and is now known to cause variations in the density in the ionosphere [Taylor et al., 1980], a transport of <span class="hlt">ions</span> towards the night side [Knudsen et al., 1980], and an outflow of <span class="hlt">ions</span> from the atmosphere [Barabash et al., 2007]. Measurements made by PVO showed that the main constituents of Venus ionosphere in the altitude range 150-400 km is the O+ and O2+ <span class="hlt">ions</span>, where the former dominates from 180 km and higher, and the latter dominates from 180 km down to 150 km [Taylor et al., 1980]. New measurements, made by the <span class="hlt">Ion</span> Mass Analyzer (IMA) onboard the Venus Express spacecraft, reveal the high-<span class="hlt">energy</span> (10 eV to 15 keV) plasma characteristics in the ionosphere of Venus. Using the data collected during the low altitude (down to 130 km) pericentre passages during the aerobraking time period, we are able to extract the height profile of the total heavy <span class="hlt">ion</span> content (O+ and O2+ <span class="hlt">ions</span>) of Venus ionosphere. The results show two scale heights separated at 200 km; 10 km for <200 km and 100 km for >200 km. We interpret the results as two heavy <span class="hlt">ion</span> components, namely, the O+ <span class="hlt">ions</span> are dominant for >200 km, while the O2+ is dominant for <200 km. This is consistent with previous results from PVO. Furthermore, we attempt several methods of mass separation, to extract the two <span class="hlt">ion</span> components of the scale height profiles, (O+ and O2+). First method is to use the moderate mass separation capabilities of the IMA instrument. The individual mass spectra are fitted by two Gaussian curves, representing O+ and O2+, derived from ground calibration information. The second method uses the <span class="hlt">energy</span> spectrum, which sometimes has two discrete peaks. By assuming the same velocity for different components in the spacecraft reference frame (resulting in different <span class="hlt">energy</span> for different masses), we can separate the composition</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/983210','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/983210"><span>FINAL <span class="hlt">FOCUS</span> <span class="hlt">ION</span> BEAM INTENSITY FROM TUNGSTEN FOIL CALORIMETER AND SCINTILLATOR IN NDCX-I</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Lidia, S.M.; Bieniosek, F.; Henestroza, E.; Ni, P.; Seidl, P.</p> <p>2010-04-30</p> <p>Laboratory high <span class="hlt">energy</span> density experiments using <span class="hlt">ion</span> beam drivers rely upon the delivery of high-current, high-brightness <span class="hlt">ion</span> beams with high peak intensity onto targets. Solid-state scintillators are typically used to measure the <span class="hlt">ion</span> beam spatial profile but they display dose-dependent degradation and aging effects. These effects produce uncertainties and limit the accuracy of measuring peak beam intensities delivered to the target. For beam tuning and characterizing the incident beam intensity, we have developed a cross-calibrating diagnostic suite that extends the upper limit of measurable peak intensity dynamic range. Absolute intensity calibration is obtained with a 3 {micro}m thick tungsten foil calorimeter and streak spectrometer. We present experimental evidence for peak intensity measures in excess of 400 kW/cm{sup 2} using a 0.3 MV, 25 mA, 5-20 {micro}sec K{sup +1} beam. Radiative models and thermal diffusion effects are discussed because they affect temporal and spatial resolution of beam intensity profiles.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/1064985','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/1064985"><span>Comparison of SOFC Cathode Microstructure Quantified using X-ray Nanotomography and <span class="hlt">Focused</span> <span class="hlt">Ion</span> Beam - Scanning Electron Microscopy</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Nelson, George J.; Harris, William H.; Lombardo, Jeffrey J.; Izzo, Jr., John R.; Chiu, W. K. S.; Tanasini, Pietro; Cantoni, Marco; Van herle, Jan; Comninellis, Christos; Andrews, Joy C.; Liu, Yijin; Pianetta, Piero; Chu, Yong</p> <p>2011-03-24</p> <p>X-ray nanotomography and <span class="hlt">focused</span> <span class="hlt">ion</span> beam scanning electron microscopy (FIB-SEM) have been applied to investigate the complex 3D microstructure of solid oxide fuel cell (SOFC) electrodes at spatial resolutions of 45 nm and below. The application of near edge differential absorption for x-ray nanotomography and <span class="hlt">energy</span> selected backscatter detection for FIB–SEM enable elemental mapping within the microstructure. Using these methods, non-destructive 3D x-ray imaging and FIB–SEM serial sectioning have been applied to compare three-dimensional elemental mapping of the LSM, YSZ, and pore phases in the SOFC cathode microstructure. The microstructural characterization of an SOFC cathode is reported based on these measurements. The results presented demonstrate the viability of x-ray nanotomography as a quantitative characterization technique and provide key insights into the SOFC cathode microstructure.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/100253','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/100253"><span>High-<span class="hlt">energy</span> <span class="hlt">ion</span> processing of materials for improved hardcoatings</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Williams, J.M.; Gorbatkin, S.M.; Rhoades, R.L.; Oliver, W.C.; Riester, L.; Tsui, T.Y.</p> <p>1994-02-01</p> <p>Research has been directed toward use of economically viable <span class="hlt">ion</span> processing strategies for production and improvement of hardcoatings. Processing techniques were high-<span class="hlt">energy</span> <span class="hlt">ion</span> implantation and electron cyclotron resonance microwave plasma processing. Subject materials were boron suboxides, Ti-6Al-4V alloy, CoCrMo alloy (a Stellite{trademark}), and electroplated Cr. These materials may be regarded either as coatings themselves (which might be deposited by thermal spraying, plasma processing, etc.) or in some cases, as substrates whose surfaces can be improved. hardness and other properties in relation to process variables are reported.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16906989','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16906989"><span>Laser acceleration of electrons to giga-electron-volt <span class="hlt">energies</span> using highly charged <span class="hlt">ions</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hu, S X; Starace, Anthony F</p> <p>2006-06-01</p> <p>The recent proposal to use highly charged <span class="hlt">ions</span> as sources of electrons for laser acceleration [S. X. Hu and A. F. Starace, Phys. Rev. Lett. 88, 245003 (2002)] is investigated here in detail by means of three-dimensional, relativistic Monte Carlo simulations for a variety of system parameters, such as laser pulse duration, ionic charge state, and laser <span class="hlt">focusing</span> spot size. Realistic laser <span class="hlt">focusing</span> effects--e.g., the existence of longitudinal laser field components-are taken into account. Results of spatial averaging over the laser <span class="hlt">focus</span> are also presented. These numerical simulations show that the proposed scheme for laser acceleration of electrons from highly charged <span class="hlt">ions</span> is feasible with current or near-future experimental conditions and that electrons with GeV <span class="hlt">energies</span> can be obtained in such experiments.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016APS..GECHT6005V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APS..GECHT6005V"><span>Influence of pressure on <span class="hlt">ion</span> <span class="hlt">energy</span> distribution functions in EUV-induced hydrogen plasmas</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>van de Ven, T. H. M.; Reefman, P.; de Meijere, C. A.; Banine, V. Y.; Beckers, J.</p> <p>2016-09-01</p> <p>Next-generation lithography tools currently use Extreme Ultraviolet (EUV) radiation to create even smaller features on computer chips. The high <span class="hlt">energy</span> photons (92 eV) induce a plasma in the low pressure background gas by photoionization. Industries have realized that these plasmas are of significant importance with respect to machine lifetime because impacting <span class="hlt">ions</span> affect exposed surfaces. The mass resolved <span class="hlt">ion</span> <span class="hlt">energy</span> distribution function (IEDF) is therefore one of the main plasma parameters of interest. In this research an <span class="hlt">ion</span> mass spectrometer is used to investigate IEDFs of <span class="hlt">ions</span> impacting on surfaces in EUV-induced plasmas. EUV radiation is <span class="hlt">focused</span> into a vessel with a low pressure hydrogen environment. Here, photoionization creates free electrons with <span class="hlt">energies</span> up to 76 eV, which further ionize the background gas. The influence of the pressure on plasma composition and IEDFs has been investigated in the range 0.1-10 Pa. In general the <span class="hlt">ion</span> fluxes towards the surface increase with pressure. However, above 5 Pa the flux of H2+ is not affected by the increase in pressure due to the balance between the creation of H2+ and the conversion of H2+ to H3+. These results will be used to benchmark plasma scaling models and verify numerical simulations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/106880','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/106880"><span>Design of high-<span class="hlt">energy</span> high-current linac with <span class="hlt">focusing</span> by superconducting solenoids</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Batskikh, G.I.; Belugin, V.M.; Bondarev, B.I.</p> <p>1995-10-01</p> <p>The advancement of MRTI design for 1.5 GeV and 250 mA <span class="hlt">ion</span> CW linac was presented in a previous report. In this new linac version all the way from input to output the <span class="hlt">ions</span> are <span class="hlt">focused</span> by magnetic fields of superconducting solenoids. The <span class="hlt">ion</span> limit current is far beyond the needed value. The linac <span class="hlt">focusing</span> channel offers major advantages over the more conventional ones. The acceptance is 1.7 times as large for such <span class="hlt">focusing</span> channel as for quadrupole one. Concurrently, a random perturbation sensitivity for such channel is one order of magnitude smaller than in quadrupole channel. These <span class="hlt">focusing</span> channel features allow to decrease beam matched radius and increase a linac radiation purity without aperture growth. {open_quotes}Regotron{close_quotes} is used as high power generator in linac main part. But D&W cavities need not be divided into sections connected by RF-bridges which denuded them of high coupling factor.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22392358','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22392358"><span>Feasibility of a 90° electric sector <span class="hlt">energy</span> analyzer for low <span class="hlt">energy</span> <span class="hlt">ion</span> beam characterization</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Mahinay, C. L. S. Ramos, H. J.; Wada, M.</p> <p>2015-02-15</p> <p>A simple formula to calculate refocusing by locating the output slit at a specific distance away from the exit of 90° <span class="hlt">ion</span> deflecting electric sector is given. Numerical analysis is also performed to calculate the <span class="hlt">ion</span> beam trajectories for different values of the initial angular deviation of the beam. To validate the theory, a compact (90 mm × 5.5 mm × 32 mm) 90° sector ESA is fabricated which can fit through the inner diameter of a conflat 70 vacuum flange. Experimental results show that the dependence of resolution upon the distance between the sector exit and the Faraday cup agrees with the theory. The fabricated 90° sector electrostatic <span class="hlt">energy</span> analyzer was then used to measure the space resolved <span class="hlt">ion</span> <span class="hlt">energy</span> distribution functions of an <span class="hlt">ion</span> beam with the <span class="hlt">energy</span> as low as 600 eV.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015RScI...86b3306M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015RScI...86b3306M"><span>Feasibility of a 90° electric sector <span class="hlt">energy</span> analyzer for low <span class="hlt">energy</span> <span class="hlt">ion</span> beam characterization</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mahinay, C. L. S.; Wada, M.; Ramos, H. J.</p> <p>2015-02-01</p> <p>A simple formula to calculate refocusing by locating the output slit at a specific distance away from the exit of 90° <span class="hlt">ion</span> deflecting electric sector is given. Numerical analysis is also performed to calculate the <span class="hlt">ion</span> beam trajectories for different values of the initial angular deviation of the beam. To validate the theory, a compact (90 mm × 5.5 mm × 32 mm) 90° sector ESA is fabricated which can fit through the inner diameter of a conflat 70 vacuum flange. Experimental results show that the dependence of resolution upon the distance between the sector exit and the Faraday cup agrees with the theory. The fabricated 90° sector electrostatic <span class="hlt">energy</span> analyzer was then used to measure the space resolved <span class="hlt">ion</span> <span class="hlt">energy</span> distribution functions of an <span class="hlt">ion</span> beam with the <span class="hlt">energy</span> as low as 600 eV.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_25 --> <center> <div class="footer-extlink text-muted"><small>Some links on this page may take you to non-federal websites. 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