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Sample records for highly charged stored

  1. Precision Experiments With Stored And Cooled Highly Charged Ions

    NASA Astrophysics Data System (ADS)

    Kluge, H.-Jürgen

    2006-11-01

    Accumulation, storing and cooling techniques play an increasingly important role in many areas of science. These procedures can be applied in Penning traps and storage rings to ions. In this way, quantum electrodynamics can be tested in extreme electromagnetic fields by measuring hyperfine structure splittings. Lamb shifts, or g-factors in hydrogen-like heavy systems such as U91+ or Pb81+. In addition, fundamental constants or nuclear properties like the atomic mass can be determined. In the case of a radioactive ion, the fate of an individual ion, undergoing a nuclear decay, can be studied in detail by observing the disappearance of the signal of the mother and the appearance of that of the daughter isotope. Presently, the Highly-charged Ion TRAP (HITRAP) facility is being built up at GSI. Stable or radioactive highly charged ions are produced by colliding relativistic ions with a target. After electron cooling and deceleration in the storage ring ESR at GSI, these ions are ejected, decelerated further, and injected into a Penning trap where cooling to 4 K takes place. From there, the cooled highly charged ions such as hydrogen-like uranium are transferred at low energy to different experimental set-ups which are being built up by the international HITRAP Collaboration.

  2. Nuclear astrophysics experiments with stored, highly-charged ions at FRS-ESR at GSI

    SciTech Connect

    Scheidenberger, Christoph

    2010-08-12

    At the FRS-ESR complex of GSI a nuclear physics program with exotic nuclei has been established in last 18 years, which also addresses key questions and nuclear properties relevant in nuclear astrophysics. The paper summarizes production of exotic nuclei, lifetime studies of highly-charged ions, direct mass measurements and reactions at internal targets. A few comments on the analysis of two-body weak decays are given.

  3. Traps for storing charged particles and antiparticles in high-precision experiments

    NASA Astrophysics Data System (ADS)

    Eseev, M. K.; Meshkov, I. N.

    2016-03-01

    The storage and confinement of charged particles and antiparticles (electrons, positrons, ions) in open traps and storage rings of various designs are considered. Experiments on positron storage in the Penning - Malmberg - Surko trap in the Low-Energy Particle Toroidal Accumulator (LEPTA) are described in detail.

  4. Charge and Energy Stored in a Capacitor

    ERIC Educational Resources Information Center

    Kraftmakher, Yaakov

    2012-01-01

    Using a data-acquisition system, the charge and energy stored in a capacitor are measured and displayed during the charging/discharging process. The experiment is usable as a laboratory work and/or a lecture demonstration. (Contains 3 figures.)

  5. Modeling of stored charge in metallized biaxially oriented polypropylene film capacitors based on charging current measurement

    NASA Astrophysics Data System (ADS)

    Li, Hua; Wang, Bowen; Li, Zhiwei; Liu, De; Lin, Fuchang; Dai, Ling; Zhang, Qin; Chen, Yaohong

    2013-10-01

    Metallized biaxially oriented polypropylene film (BOPP) capacitors are widely used in pulsed power systems. When the capacitor is used as the energy storage equipment under high electric field, more charges should be provided to maintain the voltage of the capacitor. This should be ascribed to the completion of the slow polarization which may take several hours or even longer. This paper focuses on the stored charge in metallized BOPP film capacitors. The modeling of the stored charge by the equivalent conversion of circuits is conducted to analyse the slow polarization in the BOPP film. The 3-RC network is proposed to represent the time-dependent charge stored in the capacitor. A charging current measurement system is established to investigate the charge storage property of the capacitor. The measurement system can measure the long time charging current with a sampling rate of 300Hz. The total charge calculated by the charging current indicates that the stored charge in the capacitor under the electric field of 400 V/μm is 13.5% larger than the product of the voltage and the capacitance measured by the AC bridge. The nonlinear effect of the electric field on the slow polarization charge is also demonstrated. And the simulation of charge storage based on the 3-RC network can match well with the trend of the stored charge increasing with the time.

  6. Modeling of stored charge in metallized biaxially oriented polypropylene film capacitors based on charging current measurement.

    PubMed

    Li, Hua; Wang, Bowen; Li, Zhiwei; Liu, De; Lin, Fuchang; Dai, Ling; Zhang, Qin; Chen, Yaohong

    2013-10-01

    Metallized biaxially oriented polypropylene film (BOPP) capacitors are widely used in pulsed power systems. When the capacitor is used as the energy storage equipment under high electric field, more charges should be provided to maintain the voltage of the capacitor. This should be ascribed to the completion of the slow polarization which may take several hours or even longer. This paper focuses on the stored charge in metallized BOPP film capacitors. The modeling of the stored charge by the equivalent conversion of circuits is conducted to analyse the slow polarization in the BOPP film. The 3-RC network is proposed to represent the time-dependent charge stored in the capacitor. A charging current measurement system is established to investigate the charge storage property of the capacitor. The measurement system can measure the long time charging current with a sampling rate of 300 Hz. The total charge calculated by the charging current indicates that the stored charge in the capacitor under the electric field of 400 V/μm is 13.5% larger than the product of the voltage and the capacitance measured by the AC bridge. The nonlinear effect of the electric field on the slow polarization charge is also demonstrated. And the simulation of charge storage based on the 3-RC network can match well with the trend of the stored charge increasing with the time. PMID:24182144

  7. Taming Highly Charged Radioisotopes

    NASA Astrophysics Data System (ADS)

    Chowdhury, Usman; Eberhardt, Benjamin; Jang, Fuluni; Schultz, Brad; Simon, Vanessa; Delheij, Paul; Dilling, Jens; Gwinner, Gerald

    2012-10-01

    The precise and accurate mass of short-lived radioisotopes is a very important parameter in physics. Contribution to the improvement of nuclear models, metrological standard fixing and tests of the unitarity of the Caibbibo-Kobayashi-Maskawa (CKM) matrix are a few examples where the mass value plays a major role. TRIUMF's ion trap for atomic and nuclear physics (TITAN) is a unique facility of three online ion traps that enables the mass measurement of short-lived isotopes with high precision (˜10-8). At present TITAN's electron beam ion trap (EBIT) increases the charge state to increase the precision, but there is no facility to significantly reduce the energy spread introduced by the charge breeding process. The precision of the measured mass of radioisotopes is linearly dependent on the charge state while the energy spread of the charged radioisotopes affects the precision adversely. To boost the precision level of mass measurement at TITAN without loosing too many ions, a cooler Penning trap (CPET) is being developed. CPET is designed to use either positively (proton) or negatively (electron) charged particles to reduce the energy spread via sympathetic cooling. Off-line setup of CPET is complete. Details of the working principles and updates are presented

  8. 143. MOBILE HIGH PRESSURE NITROGEN CART STORED IN CONTROL ROOM ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    143. MOBILE HIGH PRESSURE NITROGEN CART STORED IN CONTROL ROOM (214), LSB (BLDG. 751) - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 East, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

  9. Manipulation of stored charge in anodic aluminium oxide/SiO2 dielectric stacks by the use of pulsed anodisation

    NASA Astrophysics Data System (ADS)

    Lu, Zhong; Ouyang, Zi; Grant, Nicholas; Wan, Yimao; Yan, Di; Lennon, Alison

    2016-02-01

    A method of fabricating anodic aluminium oxide (AAO) with the capability of manipulating its stored charge is reported. This method involves the use of a pulsed current source to anodise aluminium layers instead of the typically used constant current/voltage source, with the test structures experiencing positive and negative cycles periodically. By tuning the positive cycle percentage, it is demonstrated that the effective stored charge density can be manipulated in a range from -5.2 × 1011 to 2.5 × 1012 q/cm2 when the AAO is formed over a 12 nm SiO2 layer. An investigation of the stored charge distribution in the dielectric stacks indicates a positive fixed charge at the SiO2/Si interface, a negative fixed charge at the AAO/SiO2 interface and a positive bulk charge within the AAO layer. The effective stored charge density and interface states were found to be affected by annealing conditions and it is suggested that oxygen annealing can reduce the bulk positive charge while post-metallisation anneal is most effective in reducing silicon interface defects. Charge manipulation using pulsed anodisation is shown to reduce carrier recombination on boron-diffused silicon surfaces highlighting the potential of the process to be used to tune the electrical properties of dielectric layers so that they can reduce surface recombination on silicon surfaces having different dopant polarity and concentrations.

  10. Radioactive decays of highly-charged ions

    NASA Astrophysics Data System (ADS)

    Gao, B. S.; Najafi, M. A.; Atanasov, D. R.; Blaum, K.; Bosch, F.; Brandau, C.; Chen, X. C.; Dillmann, I.; Dimopoulou, Ch.; Faestermann, Th.; Geissel, H.; Gernhäuser, R.; Hillenbrand, P.-M.; Kovalenko, O.; Kozhuharov, C.; Litvinov, S. A.; Litvinov, Yu. A.; Maier, L.; Nolden, F.; Piotrowski, J.; Sanjari, M. S.; Scheidenberger, C.; Spillmann, U.; Steck, M.; Stöhlker, Th.; Trageser, Ch.; Tu, X. L.; Weick, H.; Winckler, N.; Xu, H. S.; Yamaguchi, T.; Yan, X. L.; Zhang, Y. H.; Zhou, X. H.

    2015-05-01

    Access to stored and cooled highly-charged radionuclides offers unprecedented opportunities to perform high-precision investigations of their decays. Since the few-electron ions, e.g. hydrogen- or helium-like ions, are quantum mechanical systems with clear electronic ground state configurations, the decay studies of such ions are performed under well-defined conditions and allow for addressing fundamental aspects of the decay process. Presented here is a compact review of the relevant experiments conducted at the Experimental Storage Ring ESR of GSI. A particular emphasis is given to the investigations of the two-body beta decay, namely the bound-state β-decay and its time-mirrored counterpart, orbital electron-capture.

  11. Adsorption of highly charged Gaussian polyelectrolytes onto oppositely charged surfaces

    NASA Astrophysics Data System (ADS)

    Dutta, Sandipan; Jho, Y. S.

    2016-03-01

    In many biological processes highly charged biopolymers are adsorbed onto oppositely charged surfaces of macroions and membranes. They form strongly correlated structures close to the surface which cannot be explained by the conventional Poisson-Boltzmann theory. In this work strong coupling theory is used to study the adsorption of highly charged Gaussian polyelectrolytes. Two cases of adsorptions are considered, when the Gaussian polyelectrolytes are confined (a) by one charged wall, and (b) between two charged walls. The effects of salt and the geometry of the polymers on their adsorption-depletion transitions in the strong coupling regime are discussed.

  12. High-charge-state ion sources

    SciTech Connect

    Clark, D.J.

    1983-06-01

    Sources of high charge state positive ions have uses in a variety of research fields. For heavy ion particle accelerators higher charge state particles give greater acceleration per gap and greater bending strength in a magnet. Thus higher energies can be obtained from circular accelerators of a given size, and linear accelerators can be designed with higher energy gain per length using higher charge state ions. In atomic physics the many atomic transitions in highly charged ions supplies a wealth of spectroscopy data. High charge state ion beams are also used for charge exchange and crossed beam experiments. High charge state ion sources are reviewed. (WHK)

  13. TOPICAL REVIEW: Highly charged ions

    NASA Astrophysics Data System (ADS)

    Gillaspy, J. D.

    2001-10-01

    This paper reviews some of the fundamental properties of highly charged ions, the methods of producing them (with particular emphasis on table-top devices), and their use as a tool for both basic science and applied technology. Topics discussed include: charge dependence and scaling laws along isoelectronic or isonuclear sequences (for wavefunction size or Bohr radius, ionization energy, dipole transition energy, relativistic fine structure, hyperfine structure, Zeeman effect, Stark effect, line intensities, linewidths, strength of parity violation, etc), changes in angular momentum coupling schemes, selection rules, interactions with surfaces, electron-impact ionization, the electron beam ion trap (EBIT), ion accelerators, atomic reference data, cosmic chronometers, laboratory x-ray astrophysics, vacuum polarization, solar flares, ion implantation, ion lithography, ion microprobes (SIMS and x-ray microscope), nuclear fusion diagnostics, nanotechnology, quantum computing, cancer therapy and biotechnology.

  14. Charged polymers in high dimensions

    NASA Technical Reports Server (NTRS)

    Kantor, Yacov

    1990-01-01

    A Monte Carlo study of charged polymers with either homogeneously distributed frozen charges or with mobile charges has been performed in four and five space dimensions. The results are consistent with the renormalization-group predictions and contradict the predictions of Flory-type theory. Introduction of charge mobility does not modify the behavior of the polymers.

  15. Surface charge compensation for a highly charged Ion emissionmicroscope

    SciTech Connect

    McDonald, J.W.; Hamza, A.V.; Newman, M.W.; Holder, J.P.; Schneider, D.H.G.; Schenkel, T.

    2003-04-01

    A surface charge compensation electron flood gun has been added to the Lawrence Livermore National Laboratory (LLNL) highly charged ion (HCI) emission microscope. HCI surface interaction results in a significant charge residue being left on the surface of insulators and semiconductors. This residual charge causes undesirable aberrations in the microscope images and a reduction of the Time-Of-Flight (TOF) mass resolution when studying the surfaces of insulators and semiconductors. The benefits and problems associated with HCI microscopy and recent results of the electron flood gun enhanced HCI microscope are discussed.

  16. Highly Charged Clusters of Fullerenes: Charge Mobility and Appearance Sizes

    NASA Astrophysics Data System (ADS)

    Manil, B.; Maunoury, L.; Huber, B. A.; Jensen, J.; Schmidt, H. T.; Zettergren, H.; Cederquist, H.; Tomita, S.; Hvelplund, P.

    2003-11-01

    Clusters of fullerenes (C60,C70)n are produced in a gas aggregation source and are multiply ionized in collisions with highly charged Xe20+,30+ ions. Their stabilities and decay processes are analyzed with high-resolution time-of-flight mass spectrometry. Fullerene clusters in charge states up to q=5 have been observed and appearance sizes are found to be as small as napp=5, 10, 21, and 33 for q=2, 3, 4, and 5, respectively. The analysis of the multicoincident fragmentation spectra indicates a high charge mobility. This is in contrast to charge localization effects which have been reported for Arq+n rare gas clusters. Clusters of fullerenes are found to be conducting when multiply charged.

  17. Highly charged clusters of fullerenes: charge mobility and appearance sizes.

    PubMed

    Manil, B; Maunoury, L; Huber, B A; Jensen, J; Schmidt, H T; Zettergren, H; Cederquist, H; Tomita, S; Hvelplund, P

    2003-11-21

    Clusters of fullerenes (C60,C70)(n) are produced in a gas aggregation source and are multiply ionized in collisions with highly charged Xe(20+,30+) ions. Their stabilities and decay processes are analyzed with high-resolution time-of-flight mass spectrometry. Fullerene clusters in charge states up to q=5 have been observed and appearance sizes are found to be as small as n(app)=5, 10, 21, and 33 for q=2, 3, 4, and 5, respectively. The analysis of the multicoincident fragmentation spectra indicates a high charge mobility. This is in contrast to charge localization effects which have been reported for Ar(q+)(n) rare gas clusters. Clusters of fullerenes are found to be conducting when multiply charged. PMID:14683315

  18. High resolution printing of charge

    SciTech Connect

    Rogers, John; Park, Jang-Ung

    2015-06-16

    Provided are methods of printing a pattern of charge on a substrate surface, such as by electrohydrodynamic (e-jet) printing. The methods relate to providing a nozzle containing a printable fluid, providing a substrate having a substrate surface and generating from the nozzle an ejected printable fluid containing net charge. The ejected printable fluid containing net charge is directed to the substrate surface, wherein the net charge does not substantially degrade and the net charge retained on the substrate surface. Also provided are functional devices made by any of the disclosed methods.

  19. High dynamic range charge measurements

    DOEpatents

    De Geronimo, Gianluigi

    2012-09-04

    A charge amplifier for use in radiation sensing includes an amplifier, at least one switch, and at least one capacitor. The switch selectively couples the input of the switch to one of at least two voltages. The capacitor is electrically coupled in series between the input of the amplifier and the input of the switch. The capacitor is electrically coupled to the input of the amplifier without a switch coupled therebetween. A method of measuring charge in radiation sensing includes selectively diverting charge from an input of an amplifier to an input of at least one capacitor by selectively coupling an output of the at least one capacitor to one of at least two voltages. The input of the at least one capacitor is operatively coupled to the input of the amplifier without a switch coupled therebetween. The method also includes calculating a total charge based on a sum of the amplified charge and the diverted charge.

  20. Thermal Analysis of ZPPR High Pu Content Stored Fuel

    DOE PAGESBeta

    Solbrig, Charles W.; Pope, Chad L.; Andrus, Jason P.

    2014-01-01

    The Zero Power Physics Reactor (ZPPR) operated from April 18, 1969, until 1990. ZPPR operated at low power for testing nuclear reactor designs. This paper examines the temperature of Pu content ZPPR fuel while it is in storage. Heat is generated in the fuel due to Pu and Am decay and is a concern for possible cladding damage. Damage to the cladding could lead to fuel hydriding and oxidizing. A series of computer simulations were made to determine the range of temperatures potentially occuring in the ZPPR fuel. The maximum calculated fuel temperature is 292°C (558°F). Conservative assumptions in themore » model intentionally overestimate temperatures. The stored fuel temperatures are dependent on the distribution of fuel in the surrounding storage compartments, the heat generation rate of the fuel, and the orientation of fuel. Direct fuel temperatures could not be measured but storage bin doors, storage sleeve doors, and storage canister temperatures were measured. Comparison of these three temperatures to the calculations indicates that the temperatures calculated with conservative assumptions are, as expected, higher than the actual temperatures. The maximum calculated fuel temperature with the most conservative assumptions is significantly below the fuel failure criterion of 600°C (1,112°F).« less

  1. Polyvinylidene fluoride/nickel composite materials for charge storing, electromagnetic interference absorption, and shielding applications

    NASA Astrophysics Data System (ADS)

    Gargama, H.; Thakur, A. K.; Chaturvedi, S. K.

    2015-06-01

    In this paper, the composites of polyvinylidene fluoride (PVDF)/nickel (Ni) prepared through simple blending and hot-molding process have been investigated for dielectric, electromagnetic shielding, and radar absorbing properties. In order to study complex permittivity of the composites in 40 Hz-20 MHz frequency range, impedance spectroscopy (IS) technique is used. Besides, the complex permittivity and permeability in addition to shielding effectiveness (SE), reflection coefficient (backed by air), and loss factor are calculated using scattering parameters measured in X-band (8.2-12.4 GHz) by waveguide method. Further, in X-band, a theoretical analysis of single layer absorbing structure backed by perfect electrical conductor is then performed. A flanged coaxial holder has also been designed, fabricated, calibrated, and tested for electromagnetic interference SE measurement in the broad frequency range (50 MHz-18 GHz). The IS results indicate large enhancement in dielectric constant as a function of Ni loading in the polymer-metal composite (PMC) phase. This result has been explained using interfacial polarization and percolation theory. The frequency dependent response of ac conductivity has been analyzed by fitting the experimental data to the "Johnscher's universal dielectric response law" model. The results obtained for SE (in X-band over broad frequency range) and reflection coefficient indicate that PVDF/Ni composites give better electromagnetic interference shielding and radar absorption properties at filler concentration (fcon) ≥ fc in the PMC, whereas at fc < fcon, the charge storage mechanism dominates in the insulator regime of the composite phase. Therefore, the range of PMC compositions below and above percolation threshold has been observed to have different variety of applications.

  2. Highly charged ion secondary ion mass spectroscopy

    DOEpatents

    Hamza, Alex V.; Schenkel, Thomas; Barnes, Alan V.; Schneider, Dieter H.

    2001-01-01

    A secondary ion mass spectrometer using slow, highly charged ions produced in an electron beam ion trap permits ultra-sensitive surface analysis and high spatial resolution simultaneously. The spectrometer comprises an ion source producing a primary ion beam of highly charged ions that are directed at a target surface, a mass analyzer, and a microchannel plate detector of secondary ions that are sputtered from the target surface after interaction with the primary beam. The unusually high secondary ion yield permits the use of coincidence counting, in which the secondary ion stops are detected in coincidence with a particular secondary ion. The association of specific molecular species can be correlated. The unique multiple secondary nature of the highly charged ion interaction enables this new analytical technique.

  3. Information stored in high-Q space: Role of high energy scattering

    SciTech Connect

    Egami, T.; Dmowski, W.; Billinge, S. J. L.; Kycia, S.; Eberhardt, A. S.

    1997-07-01

    Much of crystallographic diffraction measurements are focused on obtaining information with Q (=4{pi} sin {theta}/{lambda}) below 17 A{sup -1} or d>0.35 A, with the implicit assumption that no useful information is stored in the Q space above. However, this assumption is valid only with respect to the periodic lattice structure. Actually, high-Q space is full of information on the local atomic structure that could be of major importance in some cases. We discuss high energy x-ray or neutron scattering as the methods of obtaining the data from the high-Q space, and the atomic pair-distribution function (PDF) analysis as the means of extracting information from such data. Preliminary data of our recent high-energy x-ray scattering measurement on a MX compound are shown for which this type of analysis is likely to play a significant role in understanding the properties.

  4. Relaxation of stored charge carriers in a Zn sub 0. 3 Cd sub 0. 7 Se mixed crystal

    SciTech Connect

    Lin, J.Y.; Jiang, H.X. )

    1990-03-15

    Persistent photoconductivity (PPC) has been investigated in detail in a Zn{sub 0.3}Cd{sub 0.7}Se mixed crystal. Two different temperature conductivity states have been observed. Relaxation of stored charge carriers, which contribute to PPC, has been studied at different conditions. We find that the decay of PPC follows the stretched-exponential'' function that is usually observed in a wide class of disordered materials. At {ital T}{lt}220 K, the relaxation time increases with increase of temperature. At a constant temperature, the relaxation time increases with increase of excitation photon dose, which is a consequence of the presence of the two different conductivity states. However, at a constant temperature, the decay exponent is excitation-photon-dose independent, while the characteristic decay time constant depends on excitation photon dose. The PPC observed here thus exhibits characteristic phenomena of disordered systems, which suggests that the random local-potential fluctuations, which arise from the compositional fluctuations, are responsible for PPC. PPC-decay behavior is also analyzed for some of the previously published data on other materials. We find that the stretched-exponential function describes the PPC decay in various materials at low temperatures.

  5. Validation: A highly charged concept.

    PubMed

    Koëter, H B

    1995-12-01

    In order that a proposal for an alternative to an animal test be developed as an internationally accepted guideline, there needs to be consensus on the validity of the method proposed. Over the years, considerable attempts have been made to 'validate' promising alternatives. Probably without exception, these validation programmes demanded considerable budgets whereas the high expectations as to the output, which would justify the costs involved, were hardly ever met. What went wrong? Obviously, as for each new animal test, each new alternative to an animal test should be subjected to a critical appraisal procedure involving its scientific justification, its sensitivity and its reproducibility, before it could be internationally acceptable. Although there may be differences of opinion on the extent of this exercise, there is considerable agreement that validation in one way or another is essential. None the less, validation programmes so far have not resulted in the broad acceptance of any alternative test method. There may be two reasons for this failure. First, the results of the validation studies may have been unsatisfactory, which could mean that either the method subjected to validation failed to show the desired relevance and reliability, or the validation study as such yielded inconclusive results. Secondly, despite clear-cut (supporting) results from the validation exercise, toxicologists/regulators appear reluctant actually to use the data provided for hazard and risk assessment procedures because of a lack of confidence with the (types of) endpoints of the new test. The latter in particular can be considered a major hurdle in the process of acceptance of alternative tests. Therefore, an independent and objective review of any new test, with a view to its usefulness as a contribution to the set of data essential for hazard characterization and risk assessment, should be considered the first step of any comprehensive validation project. Further, the

  6. Electronic Structure Calculations of Highly Charged Ions

    NASA Astrophysics Data System (ADS)

    Bromley, Steve; Ziolkowski, Marcin; Marler, Joan

    2016-05-01

    Exotic systems like Highly Charged Ions (HCIs) are attracting more attention based on their properties and possible interactions. Abundance of HCIs in the solar wind and their interaction with the upper atmosphere puts them in the attention of astro- and atmospheric physicists. Also, their unique properties originating in the high charge make them an excellent candidate for precision measurements and the next generation of atomic clocks. For a better understanding of the dynamics of processes involving HCIs a combined theoretical and experimental effort is needed to study their basic properties and interactions. Both theory and experiment need to be combined due to the extreme nature of these systems. We present preliminary insight into electronic structure of light HCIs, their interactions with neutral atoms and dynamics of charge transfer processes.

  7. Atomic physics with highly charged ions

    NASA Astrophysics Data System (ADS)

    Richard, P.

    1993-10-01

    The past year has been a busy one for all three accelerators: the LINAC, EBIS, and the tandem. The EBIS continues to deliver beams of highly charged ions around the clock for the study of low energy collisions with gases and surfaces. The electron beam energy was upgraded to 10 keV, and intensities of highly charged species such as Xe(44+) were greatly increased. The tandem, the traditional source of highly charged binary encounter electron production at zero degrees were studied for medium Z (Si,Cl,Cu) projectiles. Recoil momentum spectroscopy has been used to separate the contributions to collisional ionization of one-electron ions (C(5+), O(7+), F(8+)) from the nucleus and the electrons of a He target. Marked structure in the binary encounter electron spectra for Cu(sup q+) on H2 targets was measured for moderate velocity projectiles. Electron capture by slow multiply charged (EBIS) projectiles from laser excited targets has been carried out. Cross sections for capture from Na(3s) and Na*(3p) were measured for velocities between 0.1 and 1 au. The extension of these experiments to laser excited Rydberg targets is proceeding. Electron capture cross sections and average Q values for Ar(16+) on He at velocities between 0.23 and 1.67 au were measured. The charge state distribution of the He recoils following large angle scattering of C(4+) and C(6+) ions at 7.5 keV/u has been measured. Cross sections have been measured for up to sextuple capture from C60 (buckminsterfullerene) by highly charged slow projectiles. Coupled channel calculations for double capture from He by slow multicharge ions were carried out.

  8. Information stored in high-Q space: Role of high energy scattering

    SciTech Connect

    Egami, T.; Dmowski, W. Billinge, S.J.L. Kycia, S. Eberhardt, A.S.

    1997-07-01

    Much of crystallographic diffraction measurements are focused on obtaining information with Q(=4{pi}sin{theta}/{lambda}) below 17{Angstrom}{sup {minus}1} or d{gt}0.35{Angstrom}, with the implicit assumption that no useful information is stored in the Q space above. However, this assumption is valid only with respect to the periodic lattice structure. Actually, high-Q space is full of information on the local atomic structure that could be of major importance in some cases. We discuss high energy x-ray or neutron scattering as the methods of obtaining the data from the high-Q space, and the atomic pair-distribution function (PDF) analysis as the means of extracting information from such data. Preliminary data of our recent high-energy x-ray scattering measurement on a MX compound are shown for which this type of analysis is likely to play a significant role in understanding the properties. {copyright} {ital 1997 American Institute of Physics.}

  9. Simulation studies and fabrication of microtraps with long aspect ratio to store high density of positrons

    NASA Astrophysics Data System (ADS)

    Narimannezhad, Alireza

    Conventionally, non-neutral antimatter is stored using a Penning-Malmberg trap, a single tube with aspect ratios being of the order of less than 10:1. Parallel microtubes with aspect ratios of 1000:1 have the potential to store many orders of magnitude more with substantially lower end electrode potential than conventional traps. In this study, the charged particles storage capacity of these microtraps (micro-Penning-Malmberg traps) with radii of the order of tens of microns was explored. Simulation studies of the motions of charged particles were conducted with particle-in-cell plasma code WARP and the Charged Particle Optics (CPO) program. It was presented how to evaluate and lower the numerical noise by controlling the modeling parameters so the simulated plasma evolves toward computational equilibrium. The local equilibrium distribution, where longitudinal force balance is satisfied along each magnetic field line, was attained in 10 μs for plasmas initialized with a uniform density and Boltzmann energy distribution. To reach global equilibrium longer runs were performed using a fast particle mover code. Charge clouds developed the expected radial density distribution (that of a soft edge) and rigid rotation evolved to some extent. The plasma confinement time and its thermalization were independent of the length showing the length-dependency, reported in experiments, is due to fabrication and field asymmetries. Simulation demonstrated each microtrap with 50 microm radius immersed in a 7 T magnetic field could store positrons indefinitely with a density of 1.6x1011 cm-3 while the confinement voltage was only 10 V. For microtraps with radii between 100 μm and 3 μm, the particle density scaled as radius-2. Plasma confinement time was also independent of trap length. A unique approach for the fabrication of long-aspect ratio microtubes was presented for 100 μm microtraps. Standard processes such as photolithography, deep reactive ion etching, sputtering and

  10. High-LET charged particle radiotherapy

    SciTech Connect

    Castro, J.R. . Research Medicine and Radiation Biophysics Div. California Univ., San Francisco, CA . Dept. of Radiation Oncology)

    1991-07-01

    The Department of Radiation Oncology at UCSF Medical Center and the Radiation Oncology Department at UC Lawrence Berkeley Laboratory have been evaluating the use of high LET charged particle radiotherapy in a Phase 1--2 research trial ongoing since 1979. In this clinical trail, 239 patients have received at least 10 Gy (physical) minimum tumor dose with neon ions, meaning that at least one-half of their total treatment was given with high-LET charged particle therapy. Ninety-one patients received all of their therapy with neon ions. Of the 239 patients irradiated, target sites included lesions in the skin, subcutaneous tissues, head and neck such as paranasal sinuses, nasopharynx and salivary glands (major and minor), skull base and juxtaspinal area, GI tract including esophagus, pancreas and biliary tract, prostate, lung, soft tissue and bone. Analysis of these patients has been carried out with a minimum followup period of 2 years.

  11. Spectroscopy with trapped highly charged ions

    SciTech Connect

    Beiersdorfer, P

    2008-01-23

    We give an overview of atomic spectroscopy performed on electron beam ion traps at various locations throughout the world. Spectroscopy at these facilities contributes to various areas of science and engineering, including but not limited to basic atomic physics, astrophysics, extreme ultraviolet lithography, and the development of density and temperature diagnostics of fusion plasmas. These contributions are accomplished by generating, for example, spectral surveys, making precise radiative lifetime measurements, accounting for radiative power emitted in a given wavelength band, illucidating isotopic effects, and testing collisional-radiative models. While spectroscopy with electron beam ion traps had originally focused on the x-ray emission from highly charged ions interacting with the electron beam, the operating modes of such devices have expanded to study radiation in almost all wavelength bands from the visible to the hard x-ray region; and at several facilities the ions can be studied even in the absence of an electron beam. Photon emission after charge exchange or laser excitation has been observed, and the work is no longer restricted to highly charged ions. Much of the experimental capabilities are unique to electron beam ion traps, and the work performed with these devices cannot be undertaken elsewhere. However, in other areas the work on electron beam ion traps rivals the spectroscopy performed with conventional ion traps or heavy-ion storage rings. The examples we present highlight many of the capabilities of the existing electron beam ion traps and their contributions to physics.

  12. High gradient lens for charged particle beam

    SciTech Connect

    Chen, Yu-Jiuan

    2014-04-29

    Methods and devices enable shaping of a charged particle beam. A dynamically adjustable electric lens includes a series of alternating a series of alternating layers of insulators and conductors with a hollow center. The series of alternating layers when stacked together form a high gradient insulator (HGI) tube to allow propagation of the charged particle beam through the hollow center of the HGI tube. A plurality of transmission lines are connected to a plurality of sections of the HGI tube, and one or more voltage sources are provided to supply an adjustable voltage value to each transmission line of the plurality of transmission lines. By changing the voltage values supplied to each section of the HGI tube, any desired electric field can be established across the HGI tube. This way various functionalities including focusing, defocusing, acceleration, deceleration, intensity modulation and others can be effectuated on a time varying basis.

  13. EXTRACTOR FOR HIGH ENERGY CHARGED PARTICLES

    DOEpatents

    Lambertson, G.R.

    1964-04-01

    A particle-extracting apparatus for use with a beam of high-energy charged particles such as travel in an evacuated chamber along a circular equilibrium axis is described. A magnetized target is impacted relatively against the beam whereby the beam particles are deflected from the beam by the magnetic induction in the target. To this end the target may be moved into the beam or the beam may coast into the target and achieve high angular particle deflection and slow extraction. A deflecting septum magnet may additionally be used for deflection at even sharper angles. (AEC)

  14. High-speed two-dimensional laser scanner based on Bragg gratings stored in photothermorefractive glass.

    PubMed

    Yaqoob, Zahid; Arain, Muzammil A; Riza, Nabeel A

    2003-09-10

    A high-speed free-space wavelength-multiplexed optical scanner with high-speed wavelength selection coupled with narrowband volume Bragg gratings stored in photothermorefractive (PTR) glass is reported. The proposed scanner with no moving parts has a modular design with a wide angular scan range, accurate beam pointing, low scanner insertion loss, and two-dimensional beam scan capabilities. We present a complete analysis and design procedure for storing multiple tilted Bragg-grating structures in a single PTR glass volume (for normal incidence) in an optimal fashion. Because the scanner design is modular, many PTR glass volumes (each having multiple tilted Bragg-grating structures) can be stacked together, providing an efficient throughput with operations in both the visible and the infrared (IR) regions. A proof-of-concept experimental study is conducted with four Bragg gratings in independent PTR glass plates, and both visible and IR region scanner operations are demonstrated. PMID:14503693

  15. Apparatus for storing high magnetic fields having reduced mechanical forces and reduced magnetic pollution

    DOEpatents

    Prueitt, Melvin L.; Mueller, Fred M.; Smith, James L.

    1991-01-01

    The present invention identifies several configurations of conducting elements capable of storing extremely high magnetic fields for the purpose of energy storage or for other uses, wherein forces experienced by the conducting elements and the magnetic field pollution produced at locations away from the configuration are both significantly reduced over those which are present as a result of the generation of such high fields by currently proposed techniques. It is anticipated that the use of superconducting materials will both permit the attainment of such high fields and further permit such fields to be generated with vastly improved efficiency.

  16. Apparatus for storing high magnetic fields having reduced mechanical forces and reduced magnetic pollution

    DOEpatents

    Prueitt, M.L.; Mueller, F.M.; Smith, J.L.

    1991-04-09

    The present invention identifies several configurations of conducting elements capable of storing extremely high magnetic fields for the purpose of energy storage or for other uses, wherein forces experienced by the conducting elements and the magnetic field pollution produced at locations away from the configuration are both significantly reduced over those which are present as a result of the generation of such high fields by currently proposed techniques. It is anticipated that the use of superconducting materials will both permit the attainment of such high fields and further permit such fields to be generated with vastly improved efficiency. 15 figures.

  17. Low-fat milk and high-fiber bread availability in food stores in urban and rural communities.

    PubMed

    Hosler, Akiko S; Varadarajulu, Deepa; Ronsani, Adrienne E; Fredrick, Bonnie L; Fisher, Brian D

    2006-01-01

    As part of the Albany Prevention Research Center's Core Project to understand environmental influences on a healthy lifestyle, all food stores in downtown Albany (N=79) and rural Columbia and Greene counties (N=177) in New York State were visited and surveyed for their availability of low-fat milk and high-fiber bread. Stores in the rural community were significantly (P < .01) more likely to stock low-fat milk (71%) and high-fiber bread (55%) than stores in Albany (40% and 33%, respectively). The rural community also had a significantly higher population ratio of "healthy milk & bread (M&B) stores" (carrying both items) than Albany (7.6 vs 3.9 per 10,000 residents). Urban healthy M&B stores were more likely to be a convenience store and accept food stamps, whereas rural healthy M&B stores were more likely to be a gas station store and offer off-street parking. Multiple logistic regression analysis found that healthy M&B stores were inversely associated with proportions of ethnic/racial minorities in the census block group (CBG). More than 80 percent of minorities in Albany resided in a CBG without a healthy M&B store. Urban residents in predominantly minority neighborhoods were most likely to encounter environmental barriers to obtain healthy staple food, and intervention should be tailored to aid this population. PMID:17041304

  18. Coulomb crystallization of highly charged ions

    NASA Astrophysics Data System (ADS)

    Schmöger, L.; Versolato, O. O.; Schwarz, M.; Kohnen, M.; Windberger, A.; Piest, B.; Feuchtenbeiner, S.; Pedregosa-Gutierrez, J.; Leopold, T.; Micke, P.; Hansen, A. K.; Baumann, T. M.; Drewsen, M.; Ullrich, J.; Schmidt, P. O.; López-Urrutia, J. R. Crespo

    2015-03-01

    Control over the motional degrees of freedom of atoms, ions, and molecules in a field-free environment enables unrivalled measurement accuracies but has yet to be applied to highly charged ions (HCIs), which are of particular interest to future atomic clock designs and searches for physics beyond the Standard Model. Here, we report on the Coulomb crystallization of HCIs (specifically 40Ar13+) produced in an electron beam ion trap and retrapped in a cryogenic linear radiofrequency trap by means of sympathetic motional cooling through Coulomb interaction with a directly laser-cooled ensemble of Be+ ions. We also demonstrate cooling of a single Ar13+ ion by a single Be+ ion—the prerequisite for quantum logic spectroscopy with a potential 10-19 accuracy level. Achieving a seven-orders-of-magnitude decrease in HCI temperature starting at megakelvin down to the millikelvin range removes the major obstacle for HCI investigation with high-precision laser spectroscopy.

  19. Interaction of highly charged ions with carbon nano membranes

    NASA Astrophysics Data System (ADS)

    Gruber, Elisabeth; Wilhelm, Richard A.; Smejkal, Valerie; Heller, René; Facsko, Stefan; Aumayr, Friedrich

    2015-09-01

    Charge state and energy loss measurements of slow highly charged ions (HCIs) after transmission through nanometer and sub-nanometer thin membranes are presented. Direct transmission measurements through carbon nano membranes (CNMs) show an unexpected bimodal exit charge state distribution, accompanied by charge exchange dependent energy loss. The energy loss of ions in CNMs with large charge loss shows a quadratic dependency on the incident charge state, indicating charge state dependent stopping force values. Another access to the exit charge state distribution is given by irradiating stacks of CNMs and investigating each layer of the stack with high resolution imaging techniques like transmission electron microscopy (TEM) and helium ion microscopy (HIM) independently. The observation of pores created in all of the layers confirms the assumption derived from the transmission measurements that the two separated charge state distributions reflect two different impact parameter regimes, i.e. close collision with large charge exchange and distant collisions with weak ion-target interaction.

  20. HIGH-INTENSITY, HIGH CHARGE-STATE HEAVY ION SOURCES

    SciTech Connect

    ALESSI,J.G.

    2004-08-16

    There are many accelerator applications for high intensity heavy ion sources, with recent needs including dc beams for RIA, and pulsed beams for injection into synchrotrons such as RHIC and LHC. The present status of sources producing high currents of high charge state heavy ions is reviewed. These sources include ECR, EBIS, and Laser ion sources. Benefits and limitations for these type sources are described. Possible future improvements in these sources are also mentioned.

  1. Precision mass measurements of highly charged ions

    NASA Astrophysics Data System (ADS)

    Kwiatkowski, A. A.; Bale, J. C.; Brunner, T.; Chaudhuri, A.; Chowdhury, U.; Ettenauer, S.; Frekers, D.; Gallant, A. T.; Grossheim, A.; Lennarz, A.; Mane, E.; MacDonald, T. D.; Schultz, B. E.; Simon, M. C.; Simon, V. V.; Dilling, J.

    2012-10-01

    The reputation of Penning trap mass spectrometry for accuracy and precision was established with singly charged ions (SCI); however, the achievable precision and resolving power can be extended by using highly charged ions (HCI). The TITAN facility has demonstrated these enhancements for long-lived (T1/2>=50 ms) isobars and low-lying isomers, including ^71Ge^21+, ^74Rb^8+, ^78Rb^8+, and ^98Rb^15+. The Q-value of ^71Ge enters into the neutrino cross section, and the use of HCI reduced the resolving power required to distinguish the isobars from 3 x 10^5 to 20. The precision achieved in the measurement of ^74Rb^8+, a superallowed β-emitter and candidate to test the CVC hypothesis, rivaled earlier measurements with SCI in a fraction of the time. The 111.19(22) keV isomeric state in ^78Rb was resolved from the ground state. Mass measurements of neutron-rich Rb and Sr isotopes near A = 100 aid in determining the r-process pathway. Advanced ion manipulation techniques and recent results will be presented.

  2. Parallel sort with a ranged, partitioned key-value store in a high perfomance computing environment

    DOEpatents

    Bent, John M.; Faibish, Sorin; Grider, Gary; Torres, Aaron; Poole, Stephen W.

    2016-01-26

    Improved sorting techniques are provided that perform a parallel sort using a ranged, partitioned key-value store in a high performance computing (HPC) environment. A plurality of input data files comprising unsorted key-value data in a partitioned key-value store are sorted. The partitioned key-value store comprises a range server for each of a plurality of ranges. Each input data file has an associated reader thread. Each reader thread reads the unsorted key-value data in the corresponding input data file and performs a local sort of the unsorted key-value data to generate sorted key-value data. A plurality of sorted, ranged subsets of each of the sorted key-value data are generated based on the plurality of ranges. Each sorted, ranged subset corresponds to a given one of the ranges and is provided to one of the range servers corresponding to the range of the sorted, ranged subset. Each range server sorts the received sorted, ranged subsets and provides a sorted range. A plurality of the sorted ranges are concatenated to obtain a globally sorted result.

  3. 10 CFR 73.51 - Requirements for the physical protection of stored spent nuclear fuel and high-level radioactive...

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 2 2011-01-01 2011-01-01 false Requirements for the physical protection of stored spent... (CONTINUED) PHYSICAL PROTECTION OF PLANTS AND MATERIALS Physical Protection Requirements at Fixed Sites § 73.51 Requirements for the physical protection of stored spent nuclear fuel and high-level...

  4. 10 CFR 73.51 - Requirements for the physical protection of stored spent nuclear fuel and high-level radioactive...

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 2 2012-01-01 2012-01-01 false Requirements for the physical protection of stored spent... (CONTINUED) PHYSICAL PROTECTION OF PLANTS AND MATERIALS Physical Protection Requirements at Fixed Sites § 73.51 Requirements for the physical protection of stored spent nuclear fuel and high-level...

  5. 10 CFR 73.51 - Requirements for the physical protection of stored spent nuclear fuel and high-level radioactive...

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 2 2010-01-01 2010-01-01 false Requirements for the physical protection of stored spent... (CONTINUED) PHYSICAL PROTECTION OF PLANTS AND MATERIALS Physical Protection Requirements at Fixed Sites § 73.51 Requirements for the physical protection of stored spent nuclear fuel and high-level...

  6. 10 CFR 73.51 - Requirements for the physical protection of stored spent nuclear fuel and high-level radioactive...

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 2 2014-01-01 2014-01-01 false Requirements for the physical protection of stored spent... (CONTINUED) PHYSICAL PROTECTION OF PLANTS AND MATERIALS Physical Protection Requirements at Fixed Sites § 73.51 Requirements for the physical protection of stored spent nuclear fuel and high-level...

  7. 10 CFR 73.51 - Requirements for the physical protection of stored spent nuclear fuel and high-level radioactive...

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 2 2013-01-01 2013-01-01 false Requirements for the physical protection of stored spent... (CONTINUED) PHYSICAL PROTECTION OF PLANTS AND MATERIALS Physical Protection Requirements at Fixed Sites § 73.51 Requirements for the physical protection of stored spent nuclear fuel and high-level...

  8. LMO dielectronic resonances in highly charged bismuth

    NASA Astrophysics Data System (ADS)

    Smiga, Joseph; Gillaspy, John; Podpaly, Yuri; Ralchenko, Yuri

    2016-05-01

    Dielectronic resonances from high-Z elements are important for the analysis of high temperature plasmas. Thus, the extreme ultraviolet spectra of highly charged bismuth were measured using the NIST electron beam ion trap (EBIT) at beam energies ranging from 8.7 keV to 9.2 keV. The measured intensity ratios between forbidden magnetic-dipole lines in Bi64+ and Bi63+ show strong resonance features. The experimental data were compared to theoretical predictions from a large-scale collisional-radiative model with the code NOMAD, and good agreement was found that allowed the identification of observed resonance features as the LMO inner-shell dielectronic resonances. It is common practice in EBIT experiments that ions are periodically dumped from the trap and replaced. However, in this particular experiment, the contents of the trap were not dumped for the duration of each 10 minute sampling. The effects of trap stability were studied and a small but noticeable shift in beam energy over time was observed. Potential explanations for this are considered.

  9. High 5-hydroxymethylfurfural concentrations are found in Malaysian honey samples stored for more than one year.

    PubMed

    Khalil, M I; Sulaiman, S A; Gan, S H

    2010-01-01

    5-Hydroxymethylfurfural (HMF) content is an indicator of the purity of honey. High concentrations of HMF in honey indicate overheating, poor storage conditions and old honey. This study investigated the HMF content of nine Malaysian honey samples, as well as the correlation of HMF formation with physicochemical properties of honey. Based on the recommendation by the International Honey Commission, three methods for the determination of HMF were used: (1) high performance liquid chromatography (HPLC), (2) White spectrophotometry and (3) Winkler spectrophotometry methods. HPLC and White spectrophotometric results yielded almost similar values, whereas the Winkler method showed higher readings. The physicochemical properties of honey (pH, free acids, lactones and total acids) showed significant correlation with HMF content and may provide parameters that could be used to make quick assessments of honey quality. The HMF content of fresh Malaysian honey samples stored for 3-6 months (at 2.80-24.87 mg/kg) was within the internationally recommended value (80 mg/kg for tropical honeys), while honey samples stored for longer periods (12-24 months) contained much higher HMF concentrations (128.19-1131.76 mg/kg). Therefore, it is recommended that honey should generally be consumed within one year, regardless of the type. PMID:20595027

  10. Frequency metrology using highly charged ions

    NASA Astrophysics Data System (ADS)

    Crespo López-Urrutia, J. R.

    2016-06-01

    Due to the scaling laws of relativistic fine structure splitting, many forbidden optical transitions appear within the ground state configurations of highly charged ions (HCI). In some hydrogen-like ions, even the hyperfine splitting of the 1s ground state gives rise to optical transitions. Given the very low polarizability of HCI, such laser-accessible transitions are extremely impervious to external perturbations and systematics that limit optical clock performance and arise from AC and DC Stark effects, such as black-body radiation and light shifts. Moreover, AC and DC Zeeman splitting are symmetric due to the much larger relativistic spin-orbit coupling and corresponding fine-structure splitting. Appropriate choice of states or magnetic sub-states with suitable total angular momentum and magnetic quantum numbers can lead to a cancellation of residual quadrupolar shifts. All these properties are very advantageous for the proposed use of HCI forbidden lines as optical frequency standards. Extremely magnified relativistic, quantum electrodynamic, and nuclear size contributions to the binding energies of the optically active electrons make HCI ideal tools for fundamental research, as in proposed studies of a possible time variation of the fine structure constant. Beyond this, HCI that cannot be photoionized by vacuum-ultraviolet photons could also provide frequency standards for future lasers operating in that range.

  11. Crystal cookery – using high-throughput technologies and the grocery store as a teaching tool

    PubMed Central

    Luft, Joseph R.; Furlani, Nicholas M.; NeMoyer, Rachel E.; Penna, Elliott J.; Wolfley, Jennifer R.; Snell, M. Elizabeth; Potter, Stephen A.; Snell, Edward H.

    2010-01-01

    Crystallography is a multidisciplinary field that links divergent areas of mathematics, science and engineering to provide knowledge of life on an atomic scale. Crystal growth, a key component of the field, is an ideal vehicle for education. Crystallization has been used with a ‘grocery store chemistry’ approach and linked to high-throughput remote-access screening technologies. This approach provides an educational opportunity that can effectively teach the scientific method, readily accommodate different levels of educational experience, and reach any student with access to a grocery store, a post office and the internet. This paper describes the formation of the program through the students who helped develop and prototype the procedures. A summary is presented of the analysis and preliminary results and a description given of how the program could be linked with other aspects of crystallography. This approach has the potential to bridge the gap between students in remote locations and with limited funding, and access to scientific resources, providing students with an international-level research experience. PMID:22184476

  12. High temperature charge amplifier for geothermal applications

    DOEpatents

    Lindblom, Scott C.; Maldonado, Frank J.; Henfling, Joseph A.

    2015-12-08

    An amplifier circuit in a multi-chip module includes a charge to voltage converter circuit, a voltage amplifier a low pass filter and a voltage to current converter. The charge to voltage converter receives a signal representing an electrical charge and generates a voltage signal proportional to the input signal. The voltage amplifier receives the voltage signal from the charge to voltage converter, then amplifies the voltage signal by the gain factor to output an amplified voltage signal. The lowpass filter passes low frequency components of the amplified voltage signal and attenuates frequency components greater than a cutoff frequency. The voltage to current converter receives the output signal of the lowpass filter and converts the output signal to a current output signal; wherein an amplifier circuit output is selectable between the output signal of the lowpass filter and the current output signal.

  13. High-speed electret charging using vacuum UV photoionization

    SciTech Connect

    Honzumi, Makoto; Suzuki, Yuji; Hagiwara, Kei; Iguchi, Yoshinori

    2011-01-31

    We propose a high-speed charging method of electrets using vacuum ultraviolet irradiation. Due to a large amount of the ionization current at reduced pressure, it takes only a few seconds to charge 15-{mu}m-thick polymer electret film to the surface potential of -900 V. This charging rate is two orders of magnitudes larger than corona/soft-x-ray charging methods. The purity of N{sub 2} gas depends on the charging rate since the O{sub 2} quenching mechanisms of exited N{sub 2} molecule would exist. No charge decay is observed for 3000 h, which indicates charged electrets are as stable as those by other charging methods.

  14. Cloud object store for archive storage of high performance computing data using decoupling middleware

    SciTech Connect

    Bent, John M.; Faibish, Sorin; Grider, Gary

    2015-06-30

    Cloud object storage is enabled for archived data, such as checkpoints and results, of high performance computing applications using a middleware process. A plurality of archived files, such as checkpoint files and results, generated by a plurality of processes in a parallel computing system are stored by obtaining the plurality of archived files from the parallel computing system; converting the plurality of archived files to objects using a log structured file system middleware process; and providing the objects for storage in a cloud object storage system. The plurality of processes may run, for example, on a plurality of compute nodes. The log structured file system middleware process may be embodied, for example, as a Parallel Log-Structured File System (PLFS). The log structured file system middleware process optionally executes on a burst buffer node.

  15. Cloud object store for checkpoints of high performance computing applications using decoupling middleware

    DOEpatents

    Bent, John M.; Faibish, Sorin; Grider, Gary

    2016-04-19

    Cloud object storage is enabled for checkpoints of high performance computing applications using a middleware process. A plurality of files, such as checkpoint files, generated by a plurality of processes in a parallel computing system are stored by obtaining said plurality of files from said parallel computing system; converting said plurality of files to objects using a log structured file system middleware process; and providing said objects for storage in a cloud object storage system. The plurality of processes may run, for example, on a plurality of compute nodes. The log structured file system middleware process may be embodied, for example, as a Parallel Log-Structured File System (PLFS). The log structured file system middleware process optionally executes on a burst buffer node.

  16. HybridStore: A Cost-Efficient, High-Performance Storage System Combining SSDs and HDDs

    SciTech Connect

    Kim, Youngjae; Gupta, Aayush; Urgaonkar, Bhuvan; Piotr, Berman; Sivasubramaniam, Anand

    2011-01-01

    Unlike the use of DRAM for caching or buffering, certain idiosyncrasies of NAND Flash-based solid-state drives (SSDs) make their integration into existing systems non-trivial. Flash memory suffers from limits on its reliability, is an order of magnitude more expensive than the magnetic hard disk drives (HDDs), and can sometimes be as slow as the HDD (due to excessive garbage collection (GC) induced by high intensity of random writes). Given these trade-offs between HDDs and SSDs in terms of cost, performance, and lifetime, the current consensus among several storage experts is to view SSDs not as a replacement for HDD but rather as a complementary device within the high-performance storage hierarchy. We design and evaluate such a hybrid system called HybridStore to provide: (a) HybridPlan: improved capacity planning technique to administrators with the overall goal of operating within cost-budgets and (b) HybridDyn: improved performance/lifetime guarantees during episodes of deviations from expected workloads through two novel mechanisms: write-regulation and fragmentation busting. As an illustrative example of HybridStore s ef cacy, HybridPlan is able to nd the most cost-effective storage con guration for a large scale workload of Microsoft Research and suggest one MLC SSD with ten 7.2K RPM HDDs instead of fourteen 7.2K RPM HDDs only. HybridDyn is able to reduce the average response time for an enterprise scale random-write dominant workload by about 71% as compared to a HDD-based system.

  17. Beam charge and current neutralization of high-charge-state heavy ions

    SciTech Connect

    Logan, B.G.; Callahan, D.A.

    1997-10-29

    High-charge-state heavy-ions may reduce the accelerator voltage and cost of heavy-ion inertial fusion drivers, if ways can be found to neutralize the space charge of the highly charged beam ions as they are focused to a target in a fusion chamber. Using 2-D Particle-In- Cell simulations, we have evaluated the effectiveness of two different methods of beam neutralization: (1) by redistribution of beam charge in a larger diameter, preformed plasma in the chamber, and (2), by introducing a cold-electron-emitting source within the beam channel at the beam entrance into the chamber. We find the latter method to be much more effective for high-charge-state ions.

  18. Electrophoretic Mobility of a Dilute, Highly Charged "Soft" Spherical Particle in a Charged Hydrogel.

    PubMed

    Allison, Stuart; Li, Fei; Le, Melinda

    2016-08-25

    In this paper, numerical modeling studies are carried out on the electrophoretic mobility of a dilute, highly charged "soft" spherical particle in a hard hydrogel subjected to a weak, constant, external electric field. The particle contains a solid core with either a uniform charge density or "zeta" potential on its surface. Outside of this lies a charged gel layer of uniform thickness, composition, and charge density. The present work extends previous studies by accounting for the "relaxation effect", or distortion of the charge distribution in the vicinity of the model particle due to the imposition of an external electric and/or flow field. The particle gel layer and ambient hydrogel are modeled as porous Brinkman media. The (steady state) electrodynamic problem is solved at the level of the Poisson equation. Applications emphasize the influence of the relaxation effect and hydrogel charge density on the electrophoretic mobility. PMID:26815300

  19. Stability of highly-charged Reissner-Nordström black holes to charged scalar perturbations

    NASA Astrophysics Data System (ADS)

    Hod, Shahar

    2015-02-01

    The stability of Reissner-Nordström black holes under the influence of neutral perturbation fields was proved by Moncrief four decades ago. However, the superradiant scattering phenomenon, which characterizes the dynamics of charged bosonic fields in these charged black-hole spacetimes, imposes a greater and nontrivial threat on their stability. According to this well-known phenomenon, integer-spin charged fields interacting with a Reissner-Nordström black hole can be amplified (gain energy) by extracting some of the black-hole Coulomb energy. If, in addition to being electrically charged, the incident bosonic fields also possess nonzero rest masses, then the mutual gravitational attraction between the central black hole and the fields may prevent the extracted energy and electric charge from escaping to infinity. One may suspect that the physical mechanism of superradiant amplification of charged bosonic fields in the charged Reissner-Nordström black-hole spacetime, when combined with the confinement mechanism provided by the mutual gravitational attraction between the black hole and the massive fields, may lead to a superradiant instability of the Reissner-Nordström black-hole spacetime. (This suspicion is mainly based on our experience with rotating Kerr black holes, which are known to be characterized by an analogous superradiant instability when coupled to massive bosonic fields.) However, in this paper we show that, for highly-charged Reissner-Nordström black holes in the charge interval 8 /9 <(Q/M ) 2<1 , the two physical mechanisms which are required in order to trigger the superradiant instability phenomenon in the black-hole spacetime [namely: (1) the superradiant amplification of incident charged scalar fields by the charged black hole, and (2) the existence of a binding potential well in the black-hole exterior region which prevents the extracted energy and electric charge from escaping to infinity] cannot operate simultaneously. In particular, we

  20. Assessing temporal flux of plant hormones in stored processing potatoes using high definition accurate mass spectrometry

    PubMed Central

    Ordaz-Ortiz, José Juan; Foukaraki, Sofia; Terry, Leon Alexander

    2015-01-01

    Plant hormones are important molecules which at low concentration can regulate various physiological processes. Mass spectrometry has become a powerful technique for the quantification of multiple classes of plant hormones because of its high sensitivity and selectivity. We developed a new ultrahigh pressure liquid chromatography–full-scan high-definition accurate mass spectrometry method, for simultaneous determination of abscisic acid and four metabolites phaseic acid, dihydrophaseic acid, 7′-hydroxy-abscisic acid and abscisic acid glucose ester, cytokinins zeatin, zeatin riboside, gibberellins (GA1, GA3, GA4 and GA7) and indole-3-acetyl-L-aspartic acid. We measured the amount of plant hormones in the flesh and skin of two processing potato cvs. Sylvana and Russet Burbank stored for up to 30 weeks at 6 °C under ambient air conditions. Herein, we report for the first time that abscisic acid glucose ester seems to accumulate in the skin of potato tubers throughout storage time. The method achieved a lowest limit of detection of 0.22 ng g−1 of dry weight and a limit of quantification of 0.74 ng g−1 dry weight (zeatin riboside), and was able to recover, detect and quantify a total of 12 plant hormones spiked on flesh and skin of potato tubers. In addition, the mass accuracy for all compounds (<5 ppm) was evaluated. PMID:26504563

  1. Cooling of highly charged ions in a Penning trap

    SciTech Connect

    Gruber, L

    2000-03-31

    Highly charged ions are extracted from an electron beam ion trap and guided to Retrap, a cryogenic Penning trap, where they are merged with laser cooled Be{sup +} ions. The Be{sup +} ions act as a coolant for the hot highly charged ions and their temperature is dropped by about 8 orders of magnitude in a few seconds. Such cold highly charged ions form a strongly coupled nonneutral plasma exhibiting, under such conditions, the aggregation of clusters and crystals. Given the right mixture, these plasmas can be studied as analogues of high density plasmas like white dwarf interiors, and potentially can lead to the development of cold highly charged ion beams for applications in nanotechnology. Due to the virtually non existent Doppler broadening, spectroscopy on highly charged ions can be performed to an unprecedented precision. The density and the temperature of the Be{sup +} plasma were measured and highly charged ions were sympathetically cooled to similar temperatures. Molecular dynamics simulations confirmed the shape, temperature and density of the highly charged ions. Ordered structures were observed in the simulations.

  2. Store-operated channels in the pulmonary circulation of high- and low-altitude neonatal lambs.

    PubMed

    Parrau, Daniela; Ebensperger, Germán; Herrera, Emilio A; Moraga, Fernando; Riquelme, Raquel A; Ulloa, César E; Rojas, Rodrigo T; Silva, Pablo; Hernandez, Ismael; Ferrada, Javiera; Diaz, Marcela; Parer, Julian T; Cabello, Gertrudis; Llanos, Aníbal J; Reyes, Roberto V

    2013-04-15

    We determined whether store-operated channels (SOC) are involved in neonatal pulmonary artery function under conditions of acute and chronic hypoxia, using newborn sheep gestated and born either at high altitude (HA, 3,600 m) or low altitude (LA, 520 m). Cardiopulmonary variables were recorded in vivo, with and without SOC blockade by 2-aminoethyldiphenylborinate (2-APB), during basal or acute hypoxic conditions. 2-APB did not have effects on basal mean pulmonary arterial pressure (mPAP), cardiac output, systemic arterial blood pressure, or systemic vascular resistance in both groups of neonates. During acute hypoxia 2-APB reduced mPAP and pulmonary vascular resistance in LA and HA, but this reduction was greater in HA. In addition, isolated pulmonary arteries mounted in a wire myograph were assessed for vascular reactivity. HA arteries showed a greater relaxation and sensitivity to SOC blockers than LA arteries. The pulmonary expression of two SOC-forming subunits, TRPC4 and STIM1, was upregulated in HA. Taken together, our results show that SOC contribute to hypoxic pulmonary vasoconstriction in newborn sheep and that SOC are upregulated by chronic hypoxia. Therefore, SOC may contribute to the development of neonatal pulmonary hypertension. We propose SOC channels could be potential targets to treat neonatal pulmonary hypertension. PMID:23418093

  3. Contrasting vulnerability of drained tropical and high-latitude peatlands to fluvial loss of stored carbon

    NASA Astrophysics Data System (ADS)

    Evans, Chris D.; Page, Susan E.; Jones, Tim; Moore, Sam; Gauci, Vincent; Laiho, Raija; Hruška, Jakub; Allott, Tim E. H.; Billett, Michael F.; Tipping, Ed; Freeman, Chris; Garnett, Mark H.

    2014-11-01

    Carbon sequestration and storage in peatlands rely on consistently high water tables. Anthropogenic pressures including drainage, burning, land conversion for agriculture, timber, and biofuel production, cause loss of pressures including drainage, burning, land conversion for agriculture, timber, and biofuel production, cause loss of peat-forming vegetation and exposure of previously anaerobic peat to aerobic decomposition. This can shift peatlands from net CO2 sinks to large CO2 sources, releasing carbon held for millennia. Peatlands also export significant quantities of carbon via fluvial pathways, mainly as dissolved organic carbon (DOC). We analyzed radiocarbon (14C) levels of DOC in drainage water from multiple peatlands in Europe and Southeast Asia, to infer differences in the age of carbon lost from intact and drained systems. In most cases, drainage led to increased release of older carbon from the peat profile but with marked differences related to peat type. Very low DOC-14C levels in runoff from drained tropical peatlands indicate loss of very old (centuries to millennia) stored peat carbon. High-latitude peatlands appear more resilient to drainage; 14C measurements from UK blanket bogs suggest that exported DOC remains young (<50 years) despite drainage. Boreal and temperate fens and raised bogs in Finland and the Czech Republic showed intermediate sensitivity. We attribute observed differences to physical and climatic differences between peatlands, in particular, hydraulic conductivity and temperature, as well as the extent of disturbance associated with drainage, notably land use changes in the tropics. Data from the UK Peak District, an area where air pollution and intensive land management have triggered Sphagnum loss and peat erosion, suggest that additional anthropogenic pressures may trigger fluvial loss of much older (>500 year) carbon in high-latitude systems. Rewetting at least partially offsets drainage effects on DOC age.

  4. Collision phenomena involving highly-charged ions in astronomical objects

    NASA Technical Reports Server (NTRS)

    Chutjian, A.

    2001-01-01

    A description of the role of highly charged ions in various astronomical objects; includes the use of critical quantities such as cross sections for excitation, charge-exchange, X-ray emission, radiative recombination (RR) and dielectronic recombination (DR); and lifetimes, branching ratios, and A-values.

  5. High lying N* studies in electromagnetic double charged pion production

    SciTech Connect

    V. I. Mokeev; M. Ripani; M. Anghinolfi; M. Battaglieri; R. De Vita; G. V. Fedotov; E. N. Golovach; B. S. Ishkhanov; M. V. Osipenko; G. Ricco; V. Sapunenko; M. Taiuti

    2002-06-07

    A phenomenological model for double charged pion production is presented, aimed to exact N* electromagnetic form factors from measured observables (differential cross-sections, asymmetries). The preliminary results of CLAS data analysis on double charged pion production by virtual photons are discussed, focusing on high lying N* electromagnetic excitation and signals from possible ''missing'' baryon states.

  6. Location of Food Stores Near Schools Does Not Predict the Weight Status of Maine High School Students

    ERIC Educational Resources Information Center

    Harris, David E.; Blum, Janet Whatley; Bampton, Matthew; O'Brien, Liam M.; Beaudoin, Christina M.; Polacsek, Michele; O'Rourke, Karen A.

    2011-01-01

    Objective: To examine the relationship between stores selling calorie-dense food near schools and student obesity risk, with the hypothesis that high availability predicts increased risk. Methods: Mail surveys determined height, weight, and calorie-dense food consumption for 552 students at 11 Maine high schools. Driving distance from all food…

  7. Charged dust in planetary magnetospheres: Hamiltonian dynamics and numerical simulations for highly charged grains

    NASA Technical Reports Server (NTRS)

    Schaffer, L.; Burns, J. A.

    1994-01-01

    We use a combination of analytical and numerical methods to investigate the dynamics of charged dust grains in planetary magnetospheres. Our emphasis is on obtaining results valid for particles that are not necessarily dominated either by gravitational or electromagnetic forces. A Hamiltonian formulation of the problem yields exact results, for all values of charge-to-mass ratio, when we introduce two constraints: particles remain in the equatorial plane and the magnetic field is taken as axially symmetric. In particular, we obtain locations of equilibrium points, the frequencies of stable periodic orbits, the topology of separatrices in phase space, and the rate of longitudinal drift. These results are significant for specific applications: motion in the nearly aligned dipolar field of Saturn, and the trajectories of arbitrarily charged particles in complex magnetic fields for limited periods of time after ejection from parent bodies. Since the model is restrictive, we also use numerical integrations of the full three-dimensional equations of motion and illustrate under what conditions the constrained problem yields reasonable results. We show that a large fraction of the intermediately charged and highly charged (gyrating) particles will always be lost to a planet's atmosphere within a few hundred hours, for motion through tilted-dipole magnetic fields. We find that grains must have a very high charge-to-mass ratio in order to be mirrored back to the ring plane. Thus, except perhaps at Saturn where the dipole tilt is very small, the likely inhabitants of the dusty ring systems are those particles that are either nearly Keplerian (weakly charged) grains or grains whose charges place them in the lower end of the intermediate charge zone. Fianlly, we demonstrate the effect of plasma drag on the orbits of gyrating particles to be a rapid decrease in gyroradius followed by a slow radial evolution of the guiding center.

  8. Studying and applying channeling at extremely high bunch charges

    SciTech Connect

    Carrigan, R.A.; /Fermilab

    2005-01-01

    The potentially high plasma densities possible in solids might produce extremely high acceleration gradients. However solid-state plasmas could pose daunting challenges. Crystal channeling has been suggested as a mechanism to ameliorate these problems. A high-density plasma in a crystal lattice could quench the channeling process. There is no experimental or theoretical guidance on channeling for intense charged particle beams. An experiment has been carried out at the Fermilab A0 photoinjector to observe electron channeling radiation at high bunch charges. An electron beam with up to 8 nC per electron bunch was used to investigate the electron-crystal interaction. No evidence was found of quenching of channeling at charge densities two orders of magnitude larger than in earlier experiments. Possible new channeling experiments are discussed for the much higher bunch charge densities and shorter times required to probe channeling breakdown and plasma behavior.

  9. Surface erosion and modification by highly charged ions.

    SciTech Connect

    Insepov, Z.; Terasawa, M.; Takayama, K.; Mathematics and Computer Science; KEK, Japan; Univ. of Hyogo

    2008-06-01

    Analyses were conducted of various models and mechanisms of highly charged ion (HCI) and swift-heavy ion energy transfer into a solid target, such as hollow atom formation, charge screening, neutralization, shock wave generation, crater formation, and sputtering. A plasma model of space charge neutralization based on impact ionization of semiconductors at high electric fields was developed and applied to analyze HCI impacts on Si and W. Surface erosions of semiconductor and metal surfaces caused by HCI bombardments were studied by using a molecular dynamics simulation method, and the results were compared with experimental sputtering data.

  10. Highly charged ion based time of flight emission microscope

    DOEpatents

    Barnes, Alan V.; Schenkel, Thomas; Hamza, Alex V.; Schneider, Dieter H.; Doyle, Barney

    2001-01-01

    A highly charged ion based time-of-flight emission microscope has been designed, which improves the surface sensitivity of static SIMS measurements because of the higher ionization probability of highly charged ions. Slow, highly charged ions are produced in an electron beam ion trap and are directed to the sample surface. The sputtered secondary ions and electrons pass through a specially designed objective lens to a microchannel plate detector. This new instrument permits high surface sensitivity (10.sup.10 atoms/cm.sup.2), high spatial resolution (100 nm), and chemical structural information due to the high molecular ion yields. The high secondary ion yield permits coincidence counting, which can be used to enhance determination of chemical and topological structure and to correlate specific molecular species.

  11. Highly charged hollow latex particles prepared via seeded emulsion polymerization.

    PubMed

    Nuasaen, Sukanya; Tangboriboonrat, Pramuan

    2013-04-15

    The carboxylated hollow latex (HL) particles possessing high surface charge density were conveniently prepared by using poly(styrene-co-acrylic acid) (P(St/AA)) as seed particles and methyl methacrylate (MMA)/divinylbenzene (DVB)/AA as monomers. Without seed removal, the hollow structure was simply tuned by adjusting the monomer/seed ratio and the monomer content. The monodisperse, spherical, and non-collapsed HL particles with double shell having the void of 280 nm were obtained from P(St/AA) seeds of 300 nm. The conductimetric back titration, SEM, TEM, and dynamic light scattering measurement revealed that the surface charge density, surface roughness, and size of HL particles significantly increased when applying the stepwise charging monomers/initiator. The highly charged HL particles would be well dispersed in coating film providing good optical properties, for example, opacity and whiteness. PMID:23428072

  12. Atomic structure of highly-charged ions. Final report

    SciTech Connect

    Livingston, A. Eugene

    2002-05-23

    Atomic properties of multiply charged ions have been investigated using excitation of energetic heavy ion beams. Spectroscopy of excited atomic transitions has been applied from the visible to the extreme ultraviolet wavelength regions to provide accurate atomic structure and transition rate data in selected highly ionized atoms. High-resolution position-sensitive photon detection has been introduced for measurements in the ultraviolet region. The detailed structures of Rydberg states in highly charged beryllium-like ions have been measured as a test of long-range electron-ion interactions. The measurements are supported by multiconfiguration Dirac-Fock calculations and by many-body perturbation theory. The high-angular-momentum Rydberg transitions may be used to establish reference wavelengths and improve the accuracy of ionization energies in highly charged systems. Precision wavelength measurements in highly charged few-electron ions have been performed to test the most accurate relativistic atomic structure calculations for prominent low-lying excited states. Lifetime measurements for allowed and forbidden transitions in highly charged few-electron ions have been made to test theoretical transition matrix elements for simple atomic systems. Precision lifetime measurements in laser-excited alkali atoms have been initiated to establish the accuracy of relativistic atomic many-body theory in many-electron systems.

  13. Atomic physics with highly charged ions

    SciTech Connect

    Richard, P.

    1991-08-01

    This report discusses: One electron outer shell processes in fast ion-atom collisions; role of electron-electron interaction in two-electron processes; multi-electron processes at low energy; multi-electron processes at high energy; inner shell processes; molecular fragmentation studies; theory; and, JRM laboratory operations.

  14. Physicochemical and functional property changes in soy protein isolates stored under high relative humidity and temperature.

    PubMed

    Shih, Ming-Chih; Hwang, Tzann-Shun; Chou, Hong-Yen

    2016-01-01

    The effects of water activity (aw) and temperature during storage on the physicochemical characteristics and functional properties of soy protein isolate (SPI) were investigated. SPI was stored with two different temperatures (25, 45 °C) and two levels of water activity (0.25, 0.75) for 224 days. During the 224-day storage period, all the samples showed decreases in gel hardness, emulsifying stability, foaming properties, viscosity, solubility, and color alteration, but increased in surface hydrophobicity (RSo). These alterations were stronger when stored at 45 °C than at 25 °C and in 0.75 aw than 0.25 aw, and most pronounced at 45 °C and 0.75 aw. Our results revealed that storage conditions - temperature and water activity - will indeed affect the functional properties of soy protein isolates. PMID:26788014

  15. Blockade of store-operated calcium entry alleviates high glucose-induced neurotoxicity via inhibiting apoptosis in rat neurons.

    PubMed

    Xu, Zhenkuan; Xu, Wenzhe; Song, Yan; Zhang, Bin; Li, Feng; Liu, Yuguang

    2016-07-25

    Altered store-operated calcium entry (SOCE) has been suggested to be involved in many diabetic complications. However, the association of altered SOCE and diabetic neuronal damage remains unclear. This study aimed to investigate the effects of altered SOCE on primary cultured rat neuron injury induced by high glucose. Our data demonstrated that high glucose increased rat neuron injury and upregulated the expression of store-operated calcium channel (SOC). Inhibition of SOCE by a pharmacological inhibitor and siRNA knockdown of stromal interaction molecule 1 weakened the intracellular calcium overload, restored mitochondrial membrane potential, downregulated cytochrome C release and inhibited cell apoptosis. As well, treatment with the calcium chelator BAPTA-AM prevented cell apoptosis by ameliorating the high glucose-increased intracellular calcium level. These findings suggest that SOCE blockade may alleviate high glucose-induced neuronal damage by inhibiting apoptosis. SOCE might be a promising therapeutic target in diabetic neurotoxicity. PMID:27234048

  16. Charge collection and charge pulse formation in highly irradiated silicon planar detectors

    SciTech Connect

    Dezillie, B.; Li, Z.; Eremin, V.

    1998-06-01

    The interpretation of experimental data and predictions for future experiments for high-energy physics have been based on conventional methods like capacitance versus voltage (C-V) measurements. Experiments carried out on highly irradiated detectors show that the kinetics of the charge collection and the dependence of the charge pulse amplitude on the applied bias are deviated too far from those predicted by the conventional methods. The described results show that in highly irradiated detectors, at a bias lower than the real full depletion voltage (V{sub fd}), the kinetics of the charge collection (Q) contains a fast and a slow component. At V = V{sub fd}*, which is the full depletion voltage traditionally determined by the extrapolation of the fast comopnent amplitude of q versus bias to the maximum value or from the standard C-V measurements, the pulse has a slow component with significant amplitude. This slow component can only be eliminated by applying additional bias that amounts to the real full depletion voltage (V{sub fd}) or more. The above mentioned regularities are explained in this paper in terms of a model of an irradiated detector with multiple regions. This model allows one to use C-V, in a modified way, as well as TChT (transient charge technique) measurements to determine the V{sub fd} for highly irradiated detectors.

  17. Charged particle beam scanning using deformed high gradient insulator

    SciTech Connect

    Chen, Yu -Jiuan

    2015-10-06

    Devices and methods are provided to allow rapid deflection of a charged particle beam. The disclosed devices can, for example, be used as part of a hadron therapy system to allow scanning of a target area within a patient's body. The disclosed charged particle beam deflectors include a dielectric wall accelerator (DWA) with a hollow center and a dielectric wall that is substantially parallel to a z-axis that runs through the hollow center. The dielectric wall includes one or more deformed high gradient insulators (HGIs) that are configured to produce an electric field with an component in a direction perpendicular to the z-axis. A control component is also provided to establish the electric field component in the direction perpendicular to the z-axis and to control deflection of a charged particle beam in the direction perpendicular to the z-axis as the charged particle beam travels through the hollow center of the DWA.

  18. Charged fullerenes as high-capacity hydrogen storage media.

    PubMed

    Yoon, Mina; Yang, Shenyuan; Wang, Enge; Zhang, Zhenyu

    2007-09-01

    Using first-principles calculations within density functional theory, we explore systematically the capacity of charged carbon fullerenes Cn (20 charged fullerenes can be dramatically enhanced to 0.18-0.32 eV, a desirable range for potential room-temperature, near ambient applications. The enhanced binding is delocalized in nature, surrounding the whole surface of a charged fullerene, and is attributed to the polarization of the hydrogen molecules by the high electric field generated near the surface of the charged fullerene. At full hydrogen coverage, these charged fullerenes can gain storage capacities of up to approximately 8.0 wt %. We also find that, contrary to intuitive expectation, fullerenes containing encapsulated metal atoms only exhibit negligible enhancement in the hydrogen binding strength, because the charge donated by the metal atoms is primarily confined inside the fullerene cages. These predictions may prove to be instrumental in searching for a new class of high-capacity hydrogen storage media. PMID:17718530

  19. Charged Fullerenes as High Capacity Hydrogen Storage Media

    SciTech Connect

    Yoon, Mina; Yang, Shenyuan; Wang, Enge; Zhang, Zhenyu

    2007-01-01

    Using first-principles calculations within density functional theory, we explore systematically the capacity of charged carbon fullerenes Cn (20≤n≤84) as hydrogen storage media. We find that the binding strength of molecular hydrogen on either positively or negatively charged fullerenes can be dramatically enhanced to 0.18-0.32 eV, a desirable range for potential room-temperature, near ambient applications. The enhanced binding is delocalized in nature, surrounding the whole surface of a charged fullerene, and is attributed to the polarization of the hydrogen molecules by the high electric field generated near the surface of the charged fullerene. At full hydrogen coverage, these charged fullerenes can gain storage capacities of up to ~8.0wt%. We also find that, contrary to intuitive expectation, fullerenes containing intercalated metal atoms only exhibit negligible enhancement in the hydrogen binding strength, because the charge donated by the metal atoms is primarily confined inside the fullerene cages. These predictions may prove to be instrumental in searching for a new class of high capacity hydrogen storage media.

  20. Diffusion of highly charged cations in olivine

    NASA Astrophysics Data System (ADS)

    Cherniak, D. J.; Watson, E. B.; Liang, Y.

    2012-12-01

    Diffusion of tungsten, titanium and phosphorus have been measured in natural iron-bearing olivine (~Fo90) and synthetic forsterite. Experiments were run under buffered conditions (with iron-wustite or Ni-NiO buffers) in 1-atm furnaces. The sources of diffusant for experiments were MgWO4 for tungsten diffusion, Mg2TiO4 for Ti diffusion, and AlPO4 for P diffusion; in all cases these compounds were pre-reacted at high temperature with Mg2SiO4 or Fe-bearing olivine prior to diffusion anneals. Samples were placed with the source materials in noble metal or silica capsules, which were sealed under vacuum in silica glass ampoules with solid buffers. Rutherford backscattering spectrometry (RBS) was used to measure depth profiles for all sets of experiments; measurements of P were also made with Nuclear Reaction Analysis using the 31P(α,p)34S reaction. These new data suggest marked differences among diffusivities of these cations, with titanium diffusion faster than diffusion of tungsten, but slower than diffusion of phosphorus over the conditions investigated. Diffusivities of all of these elements appear significantly slower than those of divalent cations in olivine. These results will be discussed in context with extant diffusion data for major, trace and minor elements in olivine. The effects of oxygen fugacity and olivine composition on diffusion, and potential implications for diffusion mechanisms will also be considered.

  1. Solar Wind Charge Exchange Studies Of Highly Charged Ions On Atomic Hydrogen

    NASA Astrophysics Data System (ADS)

    Draganić, I. N.; Seely, D. G.; McCammon, D.; Havener, C. C.

    2011-06-01

    Accurate studies of low-energy charge exchange (CX) are critical to understanding underlying soft X-ray radiation processes in the interaction of highly charged ions from the solar wind with the neutral atoms and molecules in the heliosphere, cometary comas, planetary atmospheres, interstellar winds, etc.. Particularly important are the CX cross sections for bare, H-like, and He-like ions of C, N, O and Ne, which are the dominant charge states for these heavier elements in the solar wind. Absolute total cross sections for single electron capture by H-like ions of C, N, O and fully-stripped O ions from atomic hydrogen have been measured in an expanded range of relative collision energies (5 eV/u-20 keV/u) and compared to previous H-oven measurements. The present measurements are performed using a merged-beams technique with intense highly charged ion beams extracted from a 14.5 GHz ECR ion source installed on a high voltage platform at the Oak Ridge National Laboratory. For the collision energy range of 0.3 keV/u-3.3 keV/u, which corresponds to typical ion velocities in the solar wind, the new measurements are in good agreement with previous H-oven measurements. The experimental results are discussed in detail and compared with theoretical calculations where available.

  2. Solar Wind Charge Exchange Studies of Highly Charged Ions on Atomic Hydrogen

    SciTech Connect

    Draganic, Ilija N; Seely, D. G.; McCammon, D; Havener, Charles C

    2011-01-01

    Accurate studies of low energy charge exchange (CX) are critical to understanding underlying soft X ray radiation processes in the interaction of highly charged ions from the solar wind with the neutral atoms and molecules in the heliosphere, cometary comas, planetary atmospheres, interstellar winds, etc.. Particularly important are the CX cross sections for bare, H like, and He like ions of C, N, O and Ne, which are the dominant charge states for these heavier elements in the solar wind. Absolute total cross sections for single electron capture by H like ions of C, N, O and fully stripped O ions from atomic hydrogen have been measured in an expanded range of relative collision energies (5 eV u 20 keV u) and compared to previous H oven measurements. The present measurements are performed using a merged beams technique with intense highly charged ion beams extracted from a 14.5 GHz ECR ion source installed on a high voltage platform at the Oak Ridge National Laboratory. For the collision energy range of 0.3 keV u 3.3 keV u, which corresponds to typical ion velocities in the solar wind, the new measurements are in good agreement with previous H oven measurements. The experimental results are discussed in detail and compared with theoretical calculations where available.

  3. Investigations on Cooling Mechanisms of Highly Charged Ions at HITRAP

    NASA Astrophysics Data System (ADS)

    Maero, Giancarlo; Herfurth, Frank; Kester, Oliver; Kluge, H.-Jürgen; Koszudowski, Stephen; Quint, Wolfgang; Schwarz, Stefan

    2009-03-01

    The upcoming facility HITRAP (Highly Charged Ion TRAP) at GSI will enable high-precision atomic-physics investigations on heavy, highly charged ions at extremely low energies. Species up to U92+ will be produced at the GSI accelerator complex by stripping of relativistic ions and injected into the Experimental Storage Ring (ESR) where they are electron-cooled and decelerated to 4 MeV/u. After ejection out of the ESR and further deceleration in a linear decelerator bunches of 105 ions will be injected into a Penning trap and cooled to 4 K via electron and resistive cooling. Simulations with a Particle-In-Cell (PIC) code have been carried out to study the dynamics of the ion cloud in the Cooler Trap with focus on resistive cooling in presence of space charge.

  4. Electrochemical cell with high discharge/charge rate capability

    DOEpatents

    Redey, Laszlo

    1988-01-01

    A fully charged positive electrode composition for an electrochemical cell includes FeS.sub.2 and NiS.sub.2 in about equal molar amounts along with about 2-20 mole percent of the reaction product Li.sub.2 S. Through selection of appropriate electrolyte compositions, high power output or low operating temperatures can be obtained. The cell includes a substantially constant electrode impedance through most of its charge and discharge range. Exceptionally high discharge rates and overcharge protection are obtainable through use of the inventive electrode composition.

  5. An acoustic charge transport imager for high definition television applications

    NASA Technical Reports Server (NTRS)

    Hunt, W. D.; Brennan, Kevin F.

    1994-01-01

    The primary goal of this research is to develop a solid-state high definition television (HDTV) imager chip operating at a frame rate of about 170 frames/sec at 2 Megapixels per frame. This imager offers an order of magnitude improvement in speed over CCD designs and will allow for monolithic imagers operating from the IR to the UV. The technical approach of the project focuses on the development of the three basic components of the imager and their integration. The imager chip can be divided into three distinct components: (1) image capture via an array of avalanche photodiodes (APD's), (2) charge collection, storage and overflow control via a charge transfer transistor device (CTD), and (3) charge readout via an array of acoustic charge transport (ACT) channels. The use of APD's allows for front end gain at low noise and low operating voltages while the ACT readout enables concomitant high speed and high charge transfer efficiency. Currently work is progressing towards the development of manufacturable designs for each of these component devices. In addition to the development of each of the three distinct components, work towards their integration is also progressing. The component designs are considered not only to meet individual specifications but to provide overall system level performance suitable for HDTV operation upon integration. The ultimate manufacturability and reliability of the chip constrains the design as well. The progress made during this period is described in detail in Sections 2-4.

  6. Molecular Dynamics Simulations of Highly Charged Green Fluorescent Proteins

    SciTech Connect

    Lau, E Y; Phillips, J L; Colvin, M E

    2009-03-26

    A recent experimental study showed that green fluorescent protein (GFP) that has been mutated to have ultra-high positive or negative net charges, retain their native structure and fluorescent properties while gaining resistance to aggregation under denaturing conditions. These proteins also provide an ideal test case for studying the effects of surface charge on protein structure and dynamics. They have performed classical molecular dynamics (MD) simulations on the near-neutral wildtype GFP and mutants with net charges of -29 and +35. They analyzed the resulting trajectories to quantify differences in structure and dynamics between the three GFPs. This analyses shows that all three proteins are stable over the MD trajectory, with the near-neutral wild type GFP exhibiting somewhat more flexibility than the positive or negative GFP mutants, as measured by the order parameter and changes in phi-psi angles. There are more dramatic differences in the properties of the water and counter ions surrounding the proteins. The water diffusion constant near the protein surface is closer to the value for bulk water in the positively charged GFP than in the other two proteins. Additionally, the positively charged GFP shows a much greater clustering of the counter ions (CL-) near its surface than corresponding counter ions (Na+) near the negatively charged mutant.

  7. Charged-particle mutagenesis II. Mutagenic effects of high energy charged particles in normal human fibroblasts

    NASA Astrophysics Data System (ADS)

    Chen, D. J.; Tsuboi, K.; Nguyen, T.; Yang, T. C.

    1994-10-01

    The biological effects of high LET charged particles are a subject of great concern with regard to the prediction of radiation risk in space. In this report, mutagenic effects of high LET charged particles are quantitatively measured using primary cultures of human skin fibroblasts, and the spectrum of induced mutations are analyzed. The LET of the charged particles ranged from 25 KeV/μm to 975 KeV/gmm with particle energy (on the cells) between 94 - 603 MeV/u. The X-chromosome linked hypoxanthine guanine phosphoribosyl transferase (hprt) locus was used as the target gene. Exposure to these high LET charged particles resulted in exponential survival curves; whereas, mutation induction was fitted by a linear model. The Relative Biological Effect (RBE) for cell-killing ranged from 3.73 to 1.25, while that for mutant induction ranged from 5.74 to 0.48. Maximum RBE values were obtained at the LET of 150 keV/μm. The inactivation cross-section (αi) and the action-section for mutant induction (αm) ranged from 2.2 to 92.0 μm2 and 0.09 to 5.56 × 10-3 μm2, respectively. The maximum values were obtained by 56Fe with an LET of 200 keV/μm. The mutagenicity (αm/αi) ranged from 2.05 to 7.99 × 10-5 with the maximum value at 150 keV/μm. Furthermore, molecular analysis of mutants induced by charged particles indicates that higher LET beams are more likely to cause larger deletions in the hprt locus.

  8. Charged-particle mutagenesis II. Mutagenic effects of high energy charged particles in normal human fibroblasts

    NASA Technical Reports Server (NTRS)

    Chen, D. J.; Tsuboi, K.; Nguyen, T.; Yang, T. C.

    1994-01-01

    The biological effects of high LET charged particles are a subject of great concern with regard to the prediction of radiation risk in space. In this report, mutagenic effects of high LET charged particles are quantitatively measured using primary cultures of human skin fibroblasts, and the spectrum of induced mutations are analyzed. The LET of the charged particles ranged from 25 KeV/micrometer to 975 KeV/micrometer with particle energy (on the cells) between 94-603 MeV/u. The X-chromosome linked hypoxanthine guanine phosphoribosyl transferase (hprt) locus was used as the target gene. Exposure to these high LET charged particles resulted in exponential survival curves; whereas, mutation induction was fitted by a linear model. The Relative Biological Effect (RBE) for cell-killing ranged from 3.73 to 1.25, while that for mutant induction ranged from 5.74 to 0.48. Maximum RBE values were obtained at the LET of 150 keV/micrometer. The inactivation cross-section (alpha i) and the action cross-section for mutant induction (alpha m) ranged from 2.2 to 92.0 micrometer2 and 0.09 to 5.56 x 10(-3) micrometer2, respectively. The maximum values were obtained by 56Fe with an LET of 200 keV/micrometer. The mutagenicity (alpha m/alpha i) ranged from 2.05 to 7.99 x 10(-5) with the maximum value at 150 keV/micrometer. Furthermore, molecular analysis of mutants induced by charged particles indicates that higher LET beams are more likely to cause larger deletions in the hprt locus.

  9. Charged-particle mutagenesis 2. Mutagenic effects of high energy charged particles in normal human fibroblasts

    NASA Technical Reports Server (NTRS)

    Chen, D. J.; Tsuboi, K.; Nguyen, T.; Yang, T. C.

    1994-01-01

    The biological effects of high Linear Energy Transfer (LET) charged particles are a subject of great concern with regard to the prediction of radiation risk in space. In this report, mutagenic effects of high LET charged particles are quantitatively measured using primary cultures of human skin fibroblasts, and the spectrum of induced mutations are analyzed. The LET of the charged particles ranged from 25 KeV/micrometer to 975 KeV/micrometer with particle energy (on the cells) between 94-603 MeV/u. The X-chromosome linked hypoxanthine guanine phosphoribosyl transferase (hprt) locus was used as the target gene. Exposure to these high LET charged particles resulted in exponential survival curves; whereas, mutation induction was fitted by a linear model. The Relative Biological Effect (RBE) for cell-killing ranged from 3.73 to 1.25, while that for mutant induction ranged from 5.74 to 0.48. Maximum RBE values were obtained at the LET of 150 keV/micrometer. The inactivation cross-section (alpha i) and the action cross-section for mutant induction (alpha m) ranged from 2.2 to 92.0 sq micrometer and 0.09 to 5.56 x 10(exp -3) sq micrometer respectively. The maximum values were obtained by Fe-56 with an LET of 200 keV/micrometer. The mutagenicity (alpha m/alpha i) ranged from 2.05 to 7.99 x 10(exp -5) with the maximum value at 150 keV/micrometer. Furthermore, molecular analysis of mutants induced by charged particles indicates that higher LET beams are more likely to cause larger deletions in the hprt locus.

  10. High Resolution Diagnostics of a Linear Shaped Charge Jet

    SciTech Connect

    Chase, J.B.; Kuklo, R.M.; Shaw, L.L.; Carter, D.L.; Baum, D.W.

    1999-08-10

    The linear shaped charge is designed to produce a knife blade-like flat jet, which will perforate and sever one side of a modestly hard target from the other. This charge is approximately plane wave initiated and used a water pipe quality circular copper liner. To establish the quality of this jet we report about an experiment using several of the Lawrence Livermore National Laboratory high-resolution diagnostics previously published in this meeting [1]. Image converter tube camera stereo image pairs were obtained early in the jet formation process. Individual IC images were taken just after the perforation of a thin steel plate. These pictures are augmented with 70 mm format rotating mirror framing images, orthogonal 450 KeV flash radiograph pairs, and arrival time switches (velocity traps) positioned along the length of the jet edge. We have confirmed that linear shaped charges are subject to the same need for high quality copper as any other metal jetting device.

  11. Photoionizing Trapped Highly Charged Ions with Synchrotron Radiation

    SciTech Connect

    Crespo, J R; Simon, M; Beilmann, C; Rudolph, J; Steinbruegge, R; Eberle, S; Schwarz, M; Baumann, T; Schmitt, B; Brunner, F; Ginzel, R; Klawitter, R; Kubicek, K; Epp, S; Mokler, P; Maeckel, V; Ullrich, J; Brown, G V; Graf, A; Leutenegger, M; Beiersdorfer, P; Behar, E; Follath, R; Reichardt, G; Schwarzkopf, O

    2011-09-12

    Photoabsorption by highly charged ions plays an essential role in astrophysical plasmas. Diagnostics of photoionized plasmas surrounding binary systems rely heavily on precise identification of absorption lines and on the knowledge of their cross sections and widths. Novel experiments using an electron beam ion trap, FLASH EBIT, in combination with monochromatic synchrotron radiation allow us to investigate ions in charge states hitherto out of reach. Trapped ions can be prepared in any charge state at target densities sufficient to measure absorption cross sections below 0.1 Mb. The results benchmark state-of-the-art predictions of the transitions wavelengths, widths, and absolute cross sections. Recent high resolution results on Fe{sup 14+}, Fe{sup 15+}, and Ar{sup 12+} at photon energies up to 1 keV are presented.

  12. Survival of charged ρ condensation at high temperature and density

    NASA Astrophysics Data System (ADS)

    Liu, Hao; Yu, Lang; Huang, Mei

    2016-02-01

    The charged vector ρ mesons in the presence of external magnetic fields at finite temperature T and chemical potential μ have been investigated in the framework of the Nambu-Jona-Lasinio model. We compute the masses of charged ρ mesons numerically as a function of the magnetic field for different values of temperature and chemical potential. The self-energy of the ρ meson contains the quark-loop contribution, i.e. the leading order contribution in 1/Nc expansion. The charged ρ meson mass decreases with the magnetic field and drops to zero at a critical magnetic field eBc, which indicates that the charged vector meson condensation, i.e. the electromagnetic superconductor can be induced above the critical magnetic field. Surprisingly, it is found that the charged ρ condensation can even survive at high temperature and density. At zero temperature, the critical magnetic field just increases slightly with the chemical potential, which indicates that charged ρ condensation might occur inside compact stars. At zero density, in the temperature range 0.2-0.5 GeV, the critical magnetic field for charged ρ condensation is in the range of 0.2-0.6 GeV2, which indicates that a high temperature electromagnetic superconductor might be created at LHC. Supported by the NSFC (11275213, 11261130311) (CRC 110 by DFG and NSFC), CAS Key Project (KJCX2-EW-N01), and Youth Innovation Promotion Association of CAS. L.Yu is Partially Supported by China Postdoctoral Science Foundation (2014M550841)

  13. An acoustic charge transport imager for high definition television applications

    NASA Technical Reports Server (NTRS)

    Hunt, W. D.; Brennan, K. F.; Summers, C. J.

    1994-01-01

    The primary goal of this research is to develop a solid-state television (HDTV) imager chip operating at a frame rate of about 170 frames/sec at 2 Megapixels/frame. This imager will offer an order of magnitude improvements in speed over CCD designs and will allow for monolithic imagers operating from the IR to UV. The technical approach of the project focuses on the development of the three basic components of the imager and their subsequent integration. The camera chip can be divided into three distinct functions: (1) image capture via an array of avalanche photodiodes (APD's); (2) charge collection, storage, and overflow control via a charge transfer transistor device (CTD); and (3) charge readout via an array of acoustic charge transport (ACT) channels. The use of APD's allows for front end gain at low noise and low operating voltages while the ACT readout enables concomitant high speed and high charge transfer efficiency. Currently work is progressing towards the optimization of each of these component devices. In addition to the development of each of the three distinct components, work towards their integration and manufacturability is also progressing. The component designs are considered not only to meet individual specifications but to provide overall system level performance suitable for HDTV operation upon integration. The ultimate manufacturability and reliability of the chip constrains the design as well. The progress made during this period is described in detail.

  14. Production of highly charged ion beams from ECR ion sources

    SciTech Connect

    Xie, Z.Q.

    1997-09-01

    Electron Cyclotron Resonance (ECR) ion source development has progressed with multiple-frequency plasma heating, higher mirror magnetic fields and better technique to provide extra cold electrons. Such techniques greatly enhance the production of highly charged ions from ECR ion sources. So far at cw mode operation, up to 300 e{mu}A of O{sup 7+} and 1.15 emA of O{sup 6+}, more than 100 e{mu}A of intermediate heavy ions for charge states up to Ar{sup 13+}, Ca{sup 13+}, Fe{sup 13+}, Co{sup 14+} and Kr{sup 18+}, and tens of e{mu}A of heavy ions with charge states to Kr{sup 26+}, Xe{sup 28+}, Au{sup 35+}, Bi{sup 34+} and U{sup 34+} have been produced from ECR ion sources. At an intensity of at least 1 e{mu}A, the maximum charge state available for the heavy ions are Xe{sup 36+}, Au{sup 46+}, Bi{sup 47+} and U{sup 48+}. An order of magnitude enhancement for fully stripped argon ions (I {ge} 60 enA) also has been achieved. This article will review the ECR ion source progress and discuss key requirement for ECR ion sources to produce the highly charged ion beams.

  15. Diffraction efficiency improvement in high spatial frequency holographic gratings stored in PVA/AA photopolymers: several ACPA concentrations

    NASA Astrophysics Data System (ADS)

    Fernandez, Elena; Fuentes, Rosa; Ortuño, Manuel; Beléndez, Augusto; Pascual, Inmaculada

    2015-01-01

    High spatial frequency in holographic gratings is difficult to obtain due to limitations of the recording material. In this paper, the results obtained after storing holographic transmission gratings with a spatial frequency of 2656 lines/mm in a material based on polyvinyl alcohol and acrylamide (PVA/AA) are presented. A chain transfer agent, 4, 4‧-azobis (4-cyanopentanoic acid) (ACPA) was incorporated in the composition of the material to improve the response of the material at a high spatial frequency. Different concentrations of ACPA were used in order to find the optimal concentration giving maximum diffraction efficiency for high spatial frequencies.

  16. Functions and requirements document for interim store solidified high-level and transuranic waste

    SciTech Connect

    Smith-Fewell, M.A., Westinghouse Hanford

    1996-05-17

    The functions, requirements, interfaces, and architectures contained within the Functions and Requirements (F{ampersand}R) Document are based on the information currently contained within the TWRS Functions and Requirements database. The database also documents the set of technically defensible functions and requirements associated with the solidified waste interim storage mission.The F{ampersand}R Document provides a snapshot in time of the technical baseline for the project. The F{ampersand}R document is the product of functional analysis, requirements allocation and architectural structure definition. The technical baseline described in this document is traceable to the TWRS function 4.2.4.1, Interim Store Solidified Waste, and its related requirements, architecture, and interfaces.

  17. More Than Charged Base Loss — Revisiting the Fragmentation of Highly Charged Oligonucleotides

    NASA Astrophysics Data System (ADS)

    Nyakas, Adrien; Eberle, Rahel P.; Stucki, Silvan R.; Schürch, Stefan

    2014-07-01

    Tandem mass spectrometry is a well-established analytical tool for rapid and reliable characterization of oligonucleotides (ONs) and their gas-phase dissociation channels. The fragmentation mechanisms of native and modified nucleic acids upon different mass spectrometric activation techniques have been studied extensively, resulting in a comprehensive catalogue of backbone fragments. In this study, the fragmentation behavior of highly charged oligodeoxynucleotides (ODNs) comprising up to 15 nucleobases was investigated. It was found that ODNs exhibiting a charge level (ratio of the actual to the total possible charge) of 100% follow significantly altered dissociation pathways compared with low or medium charge levels if a terminal pyrimidine base (3' or 5') is present. The corresponding product ion spectra gave evidence for the extensive loss of a cyanate anion (NCO-), which frequently coincided with the abstraction of water from the 3'- and 5'-end in the presence of a 3'- and 5'-terminal pyrimidine nucleobase, respectively. Subsequent fragmentation of the M-NCO- ion by MS3 revealed a so far unreported consecutive excision of a metaphosphate (PO3 -)-ion for the investigated sequences. Introduction of a phosphorothioate group allowed pinpointing of PO3 - loss to the ultimate phosphate group. Several dissociation mechanisms for the release of NCO- and a metaphosphate ion were proposed and the validity of each mechanism was evaluated by the analysis of backbone- or sugar-modified ONs.

  18. Charge Trapping Flash Memory With High-k Dielectrics

    NASA Astrophysics Data System (ADS)

    Eun, Dong Seog

    2011-12-01

    High capacity and affordable price of flash memory make portable electronic devices popular, which in turn stimulates the further scaling down effort of the flash memory cells. Indeed the flash memory cells have been scaling down aggressively and face several crucial challenges. As a result, the technology trend is shifting from the floating-gate cell to the charge-trap cell in order to overcome fatal interference problems between cells. There are critical problems in the charge-trap memory cell which will become main-stream in the near future. The first potential problem is related to the memory retention which is degraded by the charge leakage through thin tunnel dielectrics. The second is the reduction of charge-storage capacity in the scaled down SiN trapping layer. The third is the low operation-efficiency resulting from the methods used to solve the first two problems. Using high-k tunnel dielectrics can solve the first problem. The second problem can be overcome by adopting a high-k trapping dielectric. The dielectric constant of the blocking layer must be higher than those of the tunnel dielectric and the trapping dielectric in order to maintain operation efficiency. This dissertation study is focused on adopting high-k dielectrics in all three of the aforementioned layers for figure generations of flash memory technology. For the high-k tunnel dielectric, the MAD Si3N4 and the MAD Al2O3 are used to fabricate the MANNS structure and the MANAS structure. The MANNS structure has the advantage of reducing the erase voltage due to its low barrier height for holes. In addition, the retention characteristic of the MANAS structure is not sensitive to temperature. The reason is that the carrier transport in MAD Al2O3 is dominated by F-N tunneling, which is nearly independent of temperature. Adopting TiOx as the trapping dielectric forms the MATAS structure. Although the charge capacity of TiOx is not very high, the operating voltage can be reduced to less than 10V

  19. Electron channeling radiation experiments at very high electron bunch charges

    SciTech Connect

    Carrigan, R.A. Jr.; Freudenberger, J.; Fritzler, S.; Genz, H.; Richter, A.; Ushakov, A.; Zilges, A.; Sellschop, J.P.F.

    2003-12-01

    Plasmas offer the possibility of high acceleration gradients. An intriguing suggestion is to use the higher plasma densities possible in solids to get extremely high gradients. Although solid-state plasmas might produce high gradients they would pose daunting problems. Crystal channeling has been suggested as one mechanism to address these challenges. There is no experimental or theoretical guidance on channeling for intense electron beams. A high-density plasma in a crystal lattice could quench the channeling process. An experiment has been carried out at the Fermilab NICADD Photoinjector Laboratory to observe electron channeling radiation at high bunch charges. An electron beam with up to 8 nC per electron bunch was used to investigate the electron-crystal interaction. No evidence was found of quenching of channeling at charge densities two orders of magnitude larger than that in earlier experiments.

  20. X-Ray Diagnostics of CUEBIT Highly Charged Ion Plasma

    NASA Astrophysics Data System (ADS)

    Silwal, Roshani; Gall, Amy; Sosolik, Chad; Harriss, James; Takacs, Endre

    2015-05-01

    Clemson University Electron Beam Ion Trap (CUEBIT) is one of the few EBIT facilities around the globe that produces highly charged ions by successive electron impact ionization. Ions are confined in the machine by the space-charge of the electron beam, a 6 T magnetic field generated by a superconducting magnet, and the voltages applied to axial electrodes. The device is a small laboratory scale instrument for the study of the structure and emission of highly charged ions and the collisions of these ions with external targets. Along with the introduction of the facility including its structure and capabilities, we present an overview of various spectroscopic and imaging tools that allow the diagnosis of the high temperature ion cloud of the CUEBIT. Instruments include a crystal spectrometer, solid-state detectors, and pin-hole imaging setup equipped with an x-ray CCD camera. Measurements of x-ray radiation from CUEBIT are used to investigate the fundamental properties of the highly charged ions and their interaction with the energetic electron beam.

  1. Production of highly charged ion beams with SECRALa)

    NASA Astrophysics Data System (ADS)

    Sun, L. T.; Zhao, H. W.; Lu, W.; Zhang, X. Z.; Feng, Y. C.; Li, J. Y.; Cao, Y.; Guo, X. H.; Ma, H. Y.; Zhao, H. Y.; Shang, Y.; Ma, B. H.; Wang, H.; Li, X. X.; Jin, T.; Xie, D. Z.

    2010-02-01

    Superconducting electron cyclotron resonance ion source with advanced design in Lanzhou (SECRAL) is an all-superconducting-magnet electron cyclotron resonance ion source (ECRIS) for the production of intense highly charged ion beams to meet the requirements of the Heavy Ion Research Facility in Lanzhou (HIRFL). To further enhance the performance of SECRAL, an aluminum chamber has been installed inside a 1.5 mm thick Ta liner used for the reduction of x-ray irradiation at the high voltage insulator. With double-frequency (18+14.5 GHz) heating and at maximum total microwave power of 2.0 kW, SECRAL has successfully produced quite a few very highly charged Xe ion beams, such as 10 e μA of Xe37+, 1 e μA of Xe43+, and 0.16 e μA of Ne-like Xe44+. To further explore the capability of the SECRAL in the production of highly charged heavy metal ion beams, a first test run on bismuth has been carried out recently. The main goal is to produce an intense Bi31+ beam for HIRFL accelerator and to have a feel how well the SECRAL can do in the production of very highly charged Bi beams. During the test, though at microwave power less than 3 kW, more than 150 e μA of Bi31+, 22 e μA of Bi41+, and 1.5 e μA of Bi50+ have been produced. All of these results have again demonstrated the great capability of the SECRAL source. This article will present the detailed results and brief discussions to the production of highly charged ion beams with SECRAL.

  2. Production of highly charged ion beams with SECRAL.

    PubMed

    Sun, L T; Zhao, H W; Lu, W; Zhang, X Z; Feng, Y C; Li, J Y; Cao, Y; Guo, X H; Ma, H Y; Zhao, H Y; Shang, Y; Ma, B H; Wang, H; Li, X X; Jin, T; Xie, D Z

    2010-02-01

    Superconducting electron cyclotron resonance ion source with advanced design in Lanzhou (SECRAL) is an all-superconducting-magnet electron cyclotron resonance ion source (ECRIS) for the production of intense highly charged ion beams to meet the requirements of the Heavy Ion Research Facility in Lanzhou (HIRFL). To further enhance the performance of SECRAL, an aluminum chamber has been installed inside a 1.5 mm thick Ta liner used for the reduction of x-ray irradiation at the high voltage insulator. With double-frequency (18+14.5 GHz) heating and at maximum total microwave power of 2.0 kW, SECRAL has successfully produced quite a few very highly charged Xe ion beams, such as 10 e microA of Xe(37+), 1 e microA of Xe(43+), and 0.16 e microA of Ne-like Xe(44+). To further explore the capability of the SECRAL in the production of highly charged heavy metal ion beams, a first test run on bismuth has been carried out recently. The main goal is to produce an intense Bi(31+) beam for HIRFL accelerator and to have a feel how well the SECRAL can do in the production of very highly charged Bi beams. During the test, though at microwave power less than 3 kW, more than 150 e microA of Bi(31+), 22 e microA of Bi(41+), and 1.5 e microA of Bi(50+) have been produced. All of these results have again demonstrated the great capability of the SECRAL source. This article will present the detailed results and brief discussions to the production of highly charged ion beams with SECRAL. PMID:20192339

  3. High charge short electron bunches for wakefield accelerator structures development.

    SciTech Connect

    Conde, M. E.

    1998-09-25

    The Argonne Wakefield Accelerator group develops accelerating structures based on dielectric loaded waveguides. We use high charge short electron bunches to excite wakefields in dielectric loaded structures, and a second (low charge) beam to probe the wakefields left behind by the drive beam. We report measurements of beam parameters and also initial results of the dielectric loaded accelerating structures. We have studied acceleration of the probe beam in these structures and we have also made measurements on the RF pulses that are generated by the drive beam. Single drive bunches, as well as multiple bunches separated by an integer number of RF periods have been used to generate the accelerating wakefields.

  4. Measurement of Metastable Lifetimes of Highly-Charged Ions

    NASA Technical Reports Server (NTRS)

    Smith, Steven J.; Chutjian, A.; Lozano, J.

    2002-01-01

    The present work is part of a series of measurements of metastable lifetimes of highly-charged ions (HCIs) which contribute to optical absorption, emission and energy balance in the Interstellar Medium (ISM), stellar atmospheres, etc. Measurements were carried out using the 14-GHz electron cyclotron resonance ion source (ECRIS) at the JPL HCI facility. The ECR provides useful currents of charge states such as C(sup(1-6)+), Mg(sup(1-6)+) and Fe(sup(1-17)+). In this work the HCI beam is focused into a Kingdon electrostatic ion trap for measuring lifetimes via optical decays.

  5. Vortices and charge order in high-Tc superconductors

    NASA Astrophysics Data System (ADS)

    Einenkel, Matthias; Meier, Hendrik; Pépin, Catherine; Efetov, Konstantin B.

    2015-03-01

    We theoretically investigate the vortex state of the cuprate high-temperature superconductors in the presence of magnetic fields. Assuming the recently derived nonlinear σ-model for fluctuations in the pseudogap phase, we find that the vortex cores consist of two crossed regions of elliptic shape, in which a static charge order emerges. Charge density wave order manifests itself as satellites to the ordinary Bragg peaks directed along the axes of the reciprocal copper lattice. Quadrupole density wave (bond order) satellites, if seen, are predicted to be along the diagonals. The intensity of the satellites should grow linearly with the magnetic field, in agreement with the result of recent experiments.

  6. Vortices and charge order in high-Tc superconductors

    NASA Astrophysics Data System (ADS)

    Einenkel, M.; Meier, H.; Pépin, C.; Efetov, K. B.

    2014-08-01

    We theoretically investigate the vortex state of the cuprate high-temperature superconductors in the presence of magnetic fields. Assuming the recently derived nonlinear σ-model for fluctuations in the pseudogap phase, we find that the vortex cores consist of two crossed regions of elliptic shape, in which a static charge order emerges. Charge density wave order manifests itself as satellites to the ordinary Bragg peaks directed along the axes of the reciprocal copper lattice. Quadrupole density wave (bond order) satellites, if seen, are predicted to be along the diagonals. The intensity of the satellites should grow linearly with the magnetic field, in agreement with the result of recent experiments.

  7. High sensitivity charge amplifier for ion beam uniformity monitor

    DOEpatents

    Johnson, Gary W.

    2001-01-01

    An ion beam uniformity monitor for very low beam currents using a high-sensitivity charge amplifier with bias compensation. The ion beam monitor is used to assess the uniformity of a raster-scanned ion beam, such as used in an ion implanter, and utilizes four Faraday cups placed in the geometric corners of the target area. Current from each cup is integrated with respect to time, thus measuring accumulated dose, or charge, in Coulombs. By comparing the dose at each corner, a qualitative assessment of ion beam uniformity is made possible. With knowledge of the relative area of the Faraday cups, the ion flux and areal dose can also be obtained.

  8. Transfer ionization in collisions with a fast highly charged ion.

    PubMed

    Voitkiv, A B

    2013-07-26

    Transfer ionization in fast collisions between a bare ion and an atom, in which one of the atomic electrons is captured by the ion whereas another one is emitted, crucially depends on dynamic electron-electron correlations. We show that in collisions with a highly charged ion a strong field of the ion has a very profound effect on the correlated channels of transfer ionization. In particular, this field weakens (strongly suppresses) electron emission into the direction opposite (perpendicular) to the motion of the ion. Instead, electron emission is redirected into those parts of the momentum space which are very weakly populated in fast collisions with low charged ions. PMID:23931364

  9. Space charge templates for high-current beam modeling

    SciTech Connect

    Vorobiev, Leonid G.; /Fermilab

    2008-07-01

    A computational method to evaluate space charge potential and gradients of charged particle beam in the presence of conducting boundaries, has been introduced. The three-dimensional (3D) field of the beam can be derived as a convolution of macro Green's functions (template fields), satisfying the same boundary conditions, as the original beam. Numerical experiments gave a confidence that space charge effects can be modeled by templates with enough accuracy and generality within dramatically faster computational times than standard combination: a grid density + Poisson solvers, realized in the most of Particle in Cell codes. The achieved rapidity may significantly broaden the high-current beam design space, making the optimization in automatic mode possible, which so far was only feasible for simplest self-field formulations such as rms envelope equations. The template technique may be used as a standalone program, or as an optional field solver in existing beam dynamics codes both in one-passage structures and in rings.

  10. Genesis of charge orders in high temperature superconductors

    NASA Astrophysics Data System (ADS)

    Tu, Wei-Lin; Lee, Ting-Kuo

    2016-01-01

    One of the most puzzling facts about cuprate high-temperature superconductors in the lightly doped regime is the coexistence of uniform superconductivity and/or antiferromagnetism with many low-energy charge-ordered states in a unidirectional charge density wave or a bidirectional checkerboard structure. Recent experiments have discovered that these charge density waves exhibit different symmetries in their intra-unit-cell form factors for different cuprate families. Using a renormalized mean-field theory for a well-known, strongly correlated model of cuprates, we obtain a number of charge-ordered states with nearly degenerate energies without invoking special features of the Fermi surface. All of these self-consistent solutions have a pair density wave intertwined with a charge density wave and sometimes a spin density wave. Most of these states vanish in the underdoped regime, except for one with a large d-form factor that vanishes at approximately 19% doping of the holes, as reported by experiments. Furthermore, these states could be modified to have a global superconducting order, with a nodal-like density of states at low energy.

  11. Genesis of charge orders in high temperature superconductors

    PubMed Central

    Tu, Wei-Lin; Lee, Ting-Kuo

    2016-01-01

    One of the most puzzling facts about cuprate high-temperature superconductors in the lightly doped regime is the coexistence of uniform superconductivity and/or antiferromagnetism with many low-energy charge-ordered states in a unidirectional charge density wave or a bidirectional checkerboard structure. Recent experiments have discovered that these charge density waves exhibit different symmetries in their intra-unit-cell form factors for different cuprate families. Using a renormalized mean-field theory for a well-known, strongly correlated model of cuprates, we obtain a number of charge-ordered states with nearly degenerate energies without invoking special features of the Fermi surface. All of these self-consistent solutions have a pair density wave intertwined with a charge density wave and sometimes a spin density wave. Most of these states vanish in the underdoped regime, except for one with a large d-form factor that vanishes at approximately 19% doping of the holes, as reported by experiments. Furthermore, these states could be modified to have a global superconducting order, with a nodal-like density of states at low energy. PMID:26732076

  12. X-ray And EUV Spectroscopy Of Highly Charged Tungsten Ions

    NASA Astrophysics Data System (ADS)

    Biedermann, Christoph; Radtke, Rainer

    2009-09-01

    The Berlin EBIT has been established by the Max-Planck-Institut für Plasmaphysik to generate atomic physics data in support of research in the field of controlled nuclear fusion, by measuring the radiation from highly charged ions in the x-ray, extreme ultraviolet and visible spectral ranges and providing valuable diagnostics for high temperature plasmas [1]. In future fusion devices, for example ITER, currently being constructed at Cadarache, France, the plasma facing components will be armored with high-Z materials, most likely tungsten, due to the favorable properties of this element [2]. At the same time the tremendous radiation cooling of these high-Z materials represents a threat to fusion and obliges one to monitor carefully the radiation. With EBIT a selected ensemble of ions in specific charge states can be produced, stored and excited for spectroscopic investigations. Employing this technique, we have for example resolved the wide structure observed around 5 nm at the ASDEX Upgrade tokamak as originating from E1-transitions into the open 4d shell of tungsten ions in charge states 25+ to 37+ producing a band-like emission pattern [3]. Further, these ions emit well-separated M1 lines in the EUV range around 65 nm suitable for plasma diagnostics [4]. Kr-like to Cr-like tungsten ions (38+ to 50+) show strong soft-x-ray lines in the range 0.5 to 2 and 5 to 15 nm. Lines of even higher charged tungsten ions, up to Ne-like W64+, abundant in the core plasma of present and future fusion test devices, have been investigated with high resolution Bragg-crystal spectroscopy at 0.13 nm [5]. Recently, x-ray spectroscopic measurements of the dielectronic recombination LMn resonances of W60+ to W67+ ions have been preformed and compare well with atomic structure calculations.

  13. Charge Strippers of Heavy Ions for High Intensity Accelerators

    NASA Astrophysics Data System (ADS)

    Nolen, Jerry A.; Marti, Felix

    2014-02-01

    Charge strippers play a critical role in many high intensity heavy ion accelerators. Here we present some history of recent stripper technology development and indicate the capabilities and limitations of the various approaches. The properties of solid, gaseous, and liquid strippers are covered. In particular, the limitations of solid strippers for high intensity, high atomic number heavy ions and the unique features of helium gas and liquid lithium for high intensity applications are covered. The need for high quality simulation of stripper performance as important input for system optimization is explained and examples of the current simulation codes are given.

  14. The effect of high ascorbic acid supplementation on body iron stores

    SciTech Connect

    Cook, J.D.; Watson, S.S.; Simpson, K.M.; Lipschitz, D.A.; Skikne, B.S.

    1984-09-01

    The level of assimilation of dietary iron is believed to have an important influence on iron status. To examine the effect of enhancing the availability of dietary iron on iron balance, 17 adult volunteer subjects were given 2 g of ascorbic acid daily with meals for 16 weeks. Serum ferritin levels before and after the study averaged 46 and 43 micrograms/L, respectively, indicating a negligible effect on iron stores. When vitamin C supplementation was continued for an additional 20 months in five iron-replete and four iron-deficient subjects, serum ferritin determinations again failed to indicate any significant effect of the vitamin C on iron reserves. These findings were not explained by intestinal adaptation to the enhancing effect of the vitamin, because radioisotopic measurements of nonheme iron absorption showed no reduction in the enhancing effect of 1 g of ascorbic acid after four months of megadoses of vitamin C. It is concluded that altering the availability of nonheme dietary iron has little effect on iron status when the diet contains substantial amounts of meat.

  15. Electron impact ionization of highly charged lithiumlike ions

    SciTech Connect

    Wong, K L

    1992-10-01

    Electron impact ionization cross sections can provide valuable information about the charge-state and power balance of highly charged ions in laboratory and astrophysical plasmas. In the present work, a novel technique based on x-ray measurements has been used to infer the ionization cross section of highly charged lithiumlike ions on the Livermore electron beam ion trap. In particular, a correspondence is established between an observed x ray and an ionization event. The measurements are made at one energy corresponding to approximately 2.3 times the threshold energy for ionization of lithiumlike ions. The technique is applied to the transition metals between Z=22 (titanium, Ti[sup 19+]) and Z=26 (iron, Fe[sup 23+]) and to Z=56 (barium, Ba[sup 53+]). The results for the transition metals, which have an estimated 17-33% uncertainty, are in good overall agreement with a relativistic distorted-wave calculation. However, less good agreement is found for barium, which has a larger uncertainty. Methods for properly accounting for the polarization in the x-ray intensities and for inferring the charge-state abundances from x-ray observations, which were developed for the ionization measurements, as well as an x-ray model that assists in the proper interpretation of the data are also presented.

  16. Highly Charged Proteins: The Achilles' Heel of Aging Proteomes.

    PubMed

    de Graff, Adam M R; Hazoglou, Michael J; Dill, Ken A

    2016-02-01

    As cells and organisms age, their proteins sustain increasing amounts of oxidative damage. It is estimated that half of all proteins are damaged in old organisms, yet the dominant mechanisms by which damage affects proteins and cellular phenotypes are not known. Here, we show that random modification of side chain charge induced by oxidative damage is likely to be a dominant source of protein stability loss in aging cells. Using an established model of protein electrostatics, we find that short, highly charged proteins are particularly susceptible to large destabilization from even a single side chain oxidation event. This mechanism identifies 20 proteins previously established to be important in aging that are at particularly high risk for oxidative destabilization, including transcription factors, histone and histone-modifying proteins, ribosomal and telomeric proteins, and proteins essential for homeostasis. Cellular processes enriched in high-risk proteins are shown to be particularly abundant in the aggregates of old organisms. PMID:26724998

  17. Graphene quantum dots as a highly efficient solution-processed charge trapping medium for organic nano-floating gate memory.

    PubMed

    Ji, Yongsung; Kim, Juhan; Cha, An-Na; Lee, Sang-A; Lee, Myung Woo; Suh, Jung Sang; Bae, Sukang; Moon, Byung Joon; Lee, Sang Hyun; Lee, Dong Su; Wang, Gunuk; Kim, Tae-Wook

    2016-04-01

    A highly efficient solution-processible charge trapping medium is a prerequisite to developing high-performance organic nano-floating gate memory (NFGM) devices. Although several candidates for the charge trapping layer have been proposed for organic memory, a method for significantly increasing the density of stored charges in nanoscale layers remains a considerable challenge. Here, solution-processible graphene quantum dots (GQDs) were prepared by a modified thermal plasma jet method; the GQDs were mostly composed of carbon without any serious oxidation, which was confirmed by x-ray photoelectron spectroscopy. These GQDs have multiple energy levels because of their size distribution, and they can be effectively utilized as charge trapping media for organic NFGM applications. The NFGM device exhibited excellent reversible switching characteristics, with an on/off current ratio greater than 10(6), a stable retention time of 10(4) s and reliable cycling endurance over 100 cycles. In particular, we estimated that the GQDs layer trapped ∼7.2 × 10(12) cm(-2) charges per unit area, which is a much higher density than those of other solution-processible nanomaterials, suggesting that the GQDs layer holds promise as a highly efficient nanoscale charge trapping material. PMID:26905768

  18. To what extent can highly charged ions keep captured electrons

    SciTech Connect

    Morgenstern, R. )

    1993-06-05

    In collisions between highly charged ions and atomic or molecular targets three phases can be distinguished: an initial capture into nonstationary states, a rearrangement of the captured electrons, and finally a decay by means of photon or electron emission. To understand the final result of such collisions one has to understand the processes in each phase. Several examples of recent investigations are discussed which shed light on the processes during these phases.

  19. Storing Hydrogen

    SciTech Connect

    Kim, Hyun Jeong; Karkamkar, Abhijeet J.; Autrey, Thomas; Chupas, Peter; Proffen, Thomas E.

    2010-05-31

    Researchers have been studying mesoporous materials for almost two decades with a view to using them as hosts for small molecules and scaffolds for molding organic compounds into new hybrid materials and nanoparticles. Their use as potential storage systems for large quantities of hydrogen has also been mooted. Such systems that might hold large quantities of hydrogen safely and in a very compact volume would have enormous potential for powering fuel cell vehicles, for instance. A sponge-like form of silicon dioxide, the stuff of sand particles and computer chips, can soak up and store other compounds including hydrogen. Studies carried out at the XOR/BESSRC 11-ID-B beamline at the APS have revealed that the nanoscopic properties of the hydrogenrich compound ammonia borane help it store hydrogen more efficiently than usual. The material may have potential for addressing the storage issues associated with a future hydrogen economy. Pacific Northwest National Laboratory is operated by Battelle for the US Department of Energy.

  20. Charge/discharge characteristics of high-capacity methane adsorption storage systems

    SciTech Connect

    Blazek, C.F.; Jasionowski, W.J.; Tiller, A.J. ); Gauthier, S.W. )

    1990-01-01

    The physical and economic barriers restricting a broad acceptance of natural gas as an alternative fuel in the transportation market have proven to be formidable. In order to succeed in the marketplace, systems for storing, dispensing, and utilizing natural gas which are low-cost, lightweight, compact, and efficient must be developed and evaluated. Experiments and numerical modeling indicate that methane storage and delivery are enhanced by low flow rates, high pressures, and designs with low adsorbent-to-cylinder mass ratios. When the adsorbent-to-cylinder mass ratio is greater than 0.3, systems behavior changes from near isothermal to adiabatic. Incorporation and utilization of in-situ thermal energy storage (TES) aids heat management, maintains near isothermal conditions and improves overall performance. TES thermally buffers the charging and discharging of an adsorbent system at or near the phase change temperature of the TES media thereby, enhancing storage and delivery of methane. 1 ref., 7 figs., 3 tabs.

  1. Status of Charge Exchange Cross Section Measurements for Highly Charged Ions on Atomic Hydrogen

    NASA Astrophysics Data System (ADS)

    Draganic, I. N.; Havener, C. C.; Schultz, D. R.; Seely, D. G.; Schultz, P. C.

    2011-05-01

    Total cross sections of charge exchange (CX) for C5+, N6+, and O7+ ions on ground state atomic hydrogen are measured in an extended collision energy range of 1 - 20,000 eV/u. Absolute CX measurements are performed using an improved merged-beams technique with intense highly charged ion beams extracted from a 14.5 GHz ECR ion source mounted on a high voltage platform. In order to improve the problematic H+ signal collection for these exoergic CX collisions at low relative energies, a new double focusing electrostatic analyzer was installed. Experimental CX data are in good agreement with all previous H-oven relative measurements at higher collision energies. We compare our results with the most recent molecular orbital close-coupling (MOCC) and atomic orbital close-coupling (AOCC) theoretical calculations. Work supported by the NASA Solar & Heliospheric Physics Program NNH07ZDA001N, the Office of Fusion Energy Sciences and the Division of Chemical Sciences, Geosciences, and Biosciences, and the Office of Basic Energy Sciences of the U.S. DoE.

  2. Electron impact collision strengths for excitation of highly charged ions

    SciTech Connect

    Sampson, D.H. . Dept. of Astronomy and Astrophysics)

    1990-08-20

    The principle task given us by the Lawrence Livermore National Laboratory (LLNL) to perform under Subcontract 6181405 was to develop a method and corresponding computer programs to make very rapid, yet accurate, fully relativistic and quasirelativistic calculations of cross sections or collision strengths for electron impact excitation of highly charged ions with any value for the nuclear charge number Z. Also while this major code development was being done we were asked to calculate cross sections of interest using our previous rapid, more approximate codes, which used hydrogenic basis functions and screening constants with both the electron-electron Coulomb interaction and relativistic interactions included by perturbation theory. We were also asked to determine the branching ratio for ionization to various final states in complex cases, where two or more states corresponding to the final configuration of the ion were possible.

  3. Creating, Storing, and Dumping Low and High Resolution Graphics on the Apple IIe Microcomputer System.

    ERIC Educational Resources Information Center

    Fletcher, Richard K., Jr.

    This description of procedures for dumping high and low resolution graphics using the Apple IIe microcomputer system focuses on two special hardware configurations that are commonly used in schools--the Apple Dot Matrix Printer with the Apple Parallel Interface Card, and the Imagewriter Printer with the Apple Super Serial Interface Card. Special…

  4. Generation and interferometric analysis of high charge optical vortices

    NASA Astrophysics Data System (ADS)

    Shen, Yong; Campbell, Geoff T.; Hage, Boris; Zou, Hongxin; Buchler, Benjamin C.; Lam, Ping Koy

    2013-04-01

    We report on the generation of optical vortex beams using spatial phase modulation with spiral phase mirrors. The spiral phase mirrors are manufactured by direct machining with an ultra-precision single point diamond turning lathe. The imperfection of the machined phase mirrors and its impact on the generated vortex beams are analyzed with interferometric measurements. Our phase mirror has a surface roughness of 3 nm and a maximum peak-valley deviation of λ/30. The vortex charges of our light beams are directly verified by counting the fringes of their corresponding interferograms. We directly observed the successful generation of an optical vortex beam with a charge as high as 5050. We study the Fourier images of the vortex beams to characterize the quality of the beams. We obtained a conversion efficiency of 92.8% from a TEM00 beam to a vortex beam with charge 1020. This technique of generating optical singularities can potentially be used to produce more complex optical wavefronts, such as optical knots.

  5. Charge-state-dependent energy loss of slow ions. I. Experimental results on the transmission of highly charged ions

    NASA Astrophysics Data System (ADS)

    Wilhelm, Richard A.; Gruber, Elisabeth; Smejkal, Valerie; Facsko, Stefan; Aumayr, Friedrich

    2016-05-01

    We report on energy loss measurements of slow (v ≪v0 ), highly charged (Q >10 ) ions upon transmission through a 1-nm-thick carbon nanomembrane. We emphasize here the scaling of the energy loss with the velocity and charge exchange or loss. We show that a weak linear velocity dependence exists, whereas charge exchange dominates the kinetic energy loss, especially in the case of a large charge capture. A universal scaling of the energy loss with the charge exchange and velocity is found and discussed in this paper. A model for charge-state-dependent energy loss for slow ions is presented in paper II in this series [R. A. Wilhelm and W. Möller, Phys. Rev. A 93, 052709 (2016), 10.1103/PhysRevA.93.052709].

  6. High stored-energy breakdown tests on electrodes made of stainless steel, copper, titanium and molybdenum

    SciTech Connect

    Esch, H. P. L. de Simonin, A.; Grand, C.

    2015-04-08

    IRFM have conducted resilience tests on electrodes made of Cu, stainless steel 304L, Ti and Mo against breakdowns up to 170 kV and 300 J. The tests of the 10×10 cm{sup 2} electrodes have been performed at an electrode distance d=11 mm under vacuum (P∼5×10{sup −6} mbar). No great difference in voltage holding between the materials could be identified; all materials could reach a voltage holding between 140 and 170 kV over the 11 mm gap, i.e. results scatter within a ±10% band. After exposure to ∼10000 seconds of high-voltage (HV) on-time, having accumulated ∼1000 breakdowns, the electrodes were inspected. The anodes were covered with large and small craters. The rugosity of the anodes had increased substantially, that of the cathodes to a lesser extent. The molybdenum electrodes are least affected, but this does not show in their voltage holding capability. It is hypothesized that penetrating high-energy electrons from the breakdown project heat below the surface of the anode and cause a micro-explosion of material when melting point is exceeded. Polished electrodes have also been tested. The polishing results in a substantially reduced breakdown rate in the beginning, but after having suffered a relatively small number (∼100) of breakdowns, the polished electrodes behaved the same as the unpolished ones.

  7. High stored-energy breakdown tests on electrodes made of stainless steel, copper, titanium and molybdenum

    NASA Astrophysics Data System (ADS)

    de Esch, H. P. L.; Simonin, A.; Grand, C.

    2015-04-01

    IRFM have conducted resilience tests on electrodes made of Cu, stainless steel 304L, Ti and Mo against breakdowns up to 170 kV and 300 J. The tests of the 10×10 cm2 electrodes have been performed at an electrode distance d=11 mm under vacuum (P˜5×10-6 mbar). No great difference in voltage holding between the materials could be identified; all materials could reach a voltage holding between 140 and 170 kV over the 11 mm gap, i.e. results scatter within a ±10% band. After exposure to ˜10000 seconds of high-voltage (HV) on-time, having accumulated ˜1000 breakdowns, the electrodes were inspected. The anodes were covered with large and small craters. The rugosity of the anodes had increased substantially, that of the cathodes to a lesser extent. The molybdenum electrodes are least affected, but this does not show in their voltage holding capability. It is hypothesized that penetrating high-energy electrons from the breakdown project heat below the surface of the anode and cause a micro-explosion of material when melting point is exceeded. Polished electrodes have also been tested. The polishing results in a substantially reduced breakdown rate in the beginning, but after having suffered a relatively small number (˜100) of breakdowns, the polished electrodes behaved the same as the unpolished ones.

  8. Energy dissipation of highly charged ions on Al oxide films.

    PubMed

    Lake, R E; Pomeroy, J M; Sosolik, C E

    2010-03-01

    Slow highly charged ions (HCIs) carry a large amount of potential energy that can be dissipated within femtoseconds upon interaction with a surface. HCI-insulator collisions result in high sputter yields and surface nanofeature creation due to strong coupling between the solid's electronic system and lattice. For HCIs interacting with Al oxide, combined experiments and theory indicate that defect mediated desorption can explain reasonably well preferential O atom removal and an observed threshold for sputtering due to potential energy. These studies have relied on measuring mass loss on the target substrate or probing craters left after desorption. Our approach is to extract highly charged ions onto the Al oxide barriers of metal-insulator-metal tunnel junctions and measure the increased conductance in a finished device after the irradiated interface is buried under the top metal layer. Such transport measurements constrain dynamic surface processes and provide large sets of statistics concerning the way individual HCI projectiles dissipate their potential energy. Results for Xe(q +) for q = 32, 40, 44 extracted onto Al oxide films are discussed in terms of postirradiation electrical device characteristics. Future work will elucidate the relationship between potential energy dissipation and tunneling phenomena through HCI modified oxides. PMID:21389384

  9. Atomic physics with highly charged ions. Progress report

    SciTech Connect

    Richard, P.

    1994-08-01

    The study of inelastic collision phenomena with highly charged projectile ions and the interpretation of spectral features resulting from these collisions remain as the major focal points in the atomic physics research at the J.R. Macdonald Laboratory, Kansas State University, Manhattan, Kansas. The title of the research project, ``Atomic Physics with Highly Charged Ions,`` speaks to these points. The experimental work in the past few years has divided into collisions at high velocity using the primary beams from the tandem and LINAC accelerators and collisions at low velocity using the CRYEBIS facility. Theoretical calculations have been performed to accurately describe inelastic scattering processes of the one-electron and many-electron type, and to accurately predict atomic transition energies and intensities for x rays and Auger electrons. Brief research summaries are given for the following: (1) electron production in ion-atom collisions; (2) role of electron-electron interactions in two-electron processes; (3) multi-electron processes; (4) collisions with excited, aligned, Rydberg targets; (5) ion-ion collisions; (6) ion-molecule collisions; (7) ion-atom collision theory; and (8) ion-surface interactions.

  10. Energy dissipation of highly charged ions on Al oxide films

    NASA Astrophysics Data System (ADS)

    Lake, R. E.; Pomeroy, J. M.; Sosolik, C. E.

    2010-03-01

    Slow highly charged ions (HCIs) carry a large amount of potential energy that can be dissipated within femtoseconds upon interaction with a surface. HCI-insulator collisions result in high sputter yields and surface nanofeature creation due to strong coupling between the solid's electronic system and lattice. For HCIs interacting with Al oxide, combined experiments and theory indicate that defect mediated desorption can explain reasonably well preferential O atom removal and an observed threshold for sputtering due to potential energy. These studies have relied on measuring mass loss on the target substrate or probing craters left after desorption. Our approach is to extract highly charged ions onto the Al oxide barriers of metal-insulator-metal tunnel junctions and measure the increased conductance in a finished device after the irradiated interface is buried under the top metal layer. Such transport measurements constrain dynamic surface processes and provide large sets of statistics concerning the way individual HCI projectiles dissipate their potential energy. Results for Xeq + for q = 32, 40, 44 extracted onto Al oxide films are discussed in terms of postirradiation electrical device characteristics. Future work will elucidate the relationship between potential energy dissipation and tunneling phenomena through HCI modified oxides.

  11. Expression of the high capacity calcium-binding domain of calreticulin increases bioavailable calcium stores in plants

    NASA Technical Reports Server (NTRS)

    Wyatt, Sarah E.; Tsou, Pei-Lan; Robertson, Dominique; Brown, C. S. (Principal Investigator)

    2002-01-01

    Modulation of cytosolic calcium levels in both plants and animals is achieved by a system of Ca2+-transport and storage pathways that include Ca2+ buffering proteins in the lumen of intracellular compartments. To date, most research has focused on the role of transporters in regulating cytosolic calcium. We used a reverse genetics approach to modulate calcium stores in the lumen of the endoplasmic reticulum. Our goals were two-fold: to use the low affinity, high capacity Ca2+ binding characteristics of the C-domain of calreticulin to selectively increase Ca2+ storage in the endoplasmic reticulum, and to determine if those alterations affected plant physiological responses to stress. The C-domain of calreticulin is a highly acidic region that binds 20-50 moles of Ca2+ per mole of protein and has been shown to be the major site of Ca2+ storage within the endoplasmic reticulum of plant cells. A 377-bp fragment encoding the C-domain and ER retention signal from the maize calreticulin gene was fused to a gene for the green fluorescent protein and expressed in Arabidopsis under the control of a heat shock promoter. Following induction on normal medium, the C-domain transformants showed delayed loss of chlorophyll after transfer to calcium depleted medium when compared to seedlings transformed with green fluorescent protein alone. Total calcium measurements showed a 9-35% increase for induced C-domain transformants compared to controls. The data suggest that ectopic expression of the calreticulin C-domain increases Ca2+ stores, and that this Ca2+ reserve can be used by the plant in times of stress.

  12. SCATHA survey of high-level spacecraft charging in sunlight

    NASA Technical Reports Server (NTRS)

    Mullen, E. G.; Gussenhoven, M. S.; Hardy, D. A.; Aggson, T. A.; Ledley, B. G.

    1986-01-01

    The statistical occurrence of spacecraft charging at near-geosynchronous orbit in daylight is studied with reference to results of an experiment conducted on the SCATHA satellite. In particular, it is found that: (1) the external current that creates high negative satellite frame potentials is the high-energy electron current from the electron population with energies greater than about 30 keV; (2) the electron current to the satellite from particles with energies less than about 30 keV neither drives the frame potential nor provides the current to balance the high-energy populations; and (3) the ion current provided from the entire range of measured ions is also not the primary source of the balancing current.

  13. High-throughput charge exchange recombination spectroscopy system on MAST

    SciTech Connect

    Conway, N. J.; Carolan, P. G.; McCone, J.; Walsh, M. J.; Wisse, M.

    2006-10-15

    A major upgrade to the charge exchange recombination spectroscopy system on MAST has recently been implemented. The new system consists of a high-throughput spectrometer coupled to a total of 224 spatial channels, including toroidal and poloidal views of both neutral heating beams on MAST. Radial resolution is {approx}1 cm, comparable to the ion Larmor radius. The toroidal views are configured with 64 channels per beam, while the poloidal views have 32 channels per beam. Background channels for both poloidal and toroidal views are also provided. A large transmission grating is at the heart of the new spectrometer, with high quality single lens reflex lenses providing excellent imaging performance and permitting the full exploitation of the available etendue of the camera sensor. The charge-coupled device camera chosen has four-tap readout at a maximum aggregate speed of 8.8 MHz, and it is capable of reading out the full set of 224 channels in less than 4 ms. The system normally operates at 529 nm, viewing the C{sup 5+} emission line, but can operate at any wavelength in the range of 400-700 nm. Results from operating the system on MAST are shown, including impurity ion temperature and velocity profiles. The system's excellent spatial resolution is ideal for the study of transport barrier phenomena on MAST, an activity which has already been advanced significantly by data from the new diagnostic.

  14. A comparison of the nutritional quality of food products advertised in grocery store circulars of high- versus low-income New York City zip codes.

    PubMed

    Ethan, Danna; Basch, Corey H; Rajan, Sonali; Samuel, Lalitha; Hammond, Rodney N

    2014-01-01

    Grocery stores can be an important resource for health and nutrition with the variety and economic value of foods offered. Weekly circulars are a means of promoting foods at a sale price. To date, little is known about the extent that nutritious foods are advertised and prominently placed in circulars. This study's aim was to compare the nutritional quality of products advertised on the front page of online circulars from grocery stores in high- versus low-income neighborhoods in New York City (NYC). Circulars from grocery stores in the five highest and five lowest median household income NYC zip codes were analyzed. Nutrition information for food products was collected over a two-month period with a total of 805 products coded. The study found no significant difference between the nutritional quality of products advertised on the front page of online circulars from grocery stores in high- versus low-income neighborhoods in New York City (NYC). In both groups, almost two-thirds of the products advertised were processed, one-quarter were high in carbohydrates, and few to no products were low-sodium, high-fiber, or reduced-, low- or zero fat. Through innovative partnerships with health professionals, grocery stores are increasingly implementing in-store and online health promotion strategies. Weekly circulars can be used as a means to regularly advertise and prominently place more healthful and seasonal foods at an affordable price, particularly for populations at higher risk for nutrition-related chronic disease. PMID:24384775

  15. Designing of electrode for high energy charged particle acceleration

    NASA Astrophysics Data System (ADS)

    Das, Basanta Kumar; Shyam, A.

    2010-02-01

    Vacuum insulation plays an important role in charged particle acceleration. We are making one compact size neutron generator in our lab. For this purpose the deuterium ions are formed in a penning ion source and extracted along the axis of the electrode arrangement. For neutron generation from D-T reaction, the deuterium ions are to be accelerated up to ~ 100KeV to the tritium target. After extraction of the ions from the ion source, the ions pass through the acceleration electrode. For high acceleration voltage, selecting the shape of the electrode is important. The plane geometry leads to high electric field at the edge whereas a curved geometry reduces this effect. The study of the physical processes at the electrode surface due to ion interaction is crucial. In this presentation, we will present the designing of the electrode for our purpose and discuss the issues related to the physical process at the surface of the electrode

  16. X-ray emission from charge exchange of highly-charged ions in atoms and molecules

    NASA Technical Reports Server (NTRS)

    Greenwood, J. B.; Williams, I. D.; Smith, S. J.; Chutjian, A.

    2000-01-01

    Charge exchange followed by radiative stabilization are the main processes responsible for the recent observations of X-ray emission from comets in their approach to the Sun. A new apparatus was constructed to measure, in collisions of HCIs with atoms and molecules, (a) absolute cross sections for single and multiple charge exchange, and (b) normalized X-ray emission cross sections.

  17. Applied Electric Fields and the Aggregation of Highly Charged Proteins

    NASA Astrophysics Data System (ADS)

    Nemzer, Louis; Flanders, Bret; Sorensen, Christopher

    2011-03-01

    The abnormal aggregation of misfolded proteins is associated with the onset of Alzheimer's disease, along with other neurodegenerative disorders, and there is increasing evidence that prefibrillar clusters, rather than fully-formed amyloid plaques, are primarily responsible. Therefore, weakly invasive methods, such as dynamic light scattering, which can probe the size distribution and structure factor of early nuclei and proto-aggregate clusters, can serve an important role in understanding this process, and may lead to insights regarding future therapeutic interventions. Here we study a highly charged model protein, lysozyme, under the influence of applied AC and DC fields in an effort to evaluate general models of protein aggregation, including the coarse-grained ``patchy protein'' method of visualizing charge heterogeneity. This anisotropy in the interprotein interaction can lead to frustrated crystalline order, resulting in low density phases. Dynamic measurements of the size distribution and structure factor can reveal local ordering, hierarchical clustering, and fractal properties of the aggregates. Early results show that applied fields affect early cluster growth by modulating local protein and counterion concentrations, in addition to their influence on protein alignment.

  18. X-ray Measurements of Highly Charged Europium

    NASA Astrophysics Data System (ADS)

    Widmann, K.; Beiersdorfer, P.; Brown, G. V.; Hell, N.; Magee, E. W.; Träbert, E.

    2015-01-01

    We present spectroscopic measurements of the M-shell emission of highly charged europium performed at the Livermore SuperEBIT electron beam ion trap facility using the EBIT Calorimeter Spectrometer (ECS). There is significant blending among the emission lines from the different charge states but despite the complexity of the observed spectra we have successfully identified the ten brightest n = 4 → 3 transitions from sodium-like Eu52+ utilizing the Flexible Atomic Code (FAC). We find that the difference between the calculated and measured transition energies for these ten Eu52+ lines does not exceed 3 eV. In fact, for four of the identified lines we find agreement within the measured uncertainties. Additional comparison with semi-empirical transition-energy predictions for sodium-like ions from laser-generated plasmas is included and shows that overall the semi-empirical predicted values for the transition energies are slightly higher than the measured values, while the FAC values that didnt agree with the measured transition energies are almost 1 eV lower than the measured values.

  19. Highly Twisted Triarylamines for Photoinduced Intramoleculer ChargeTransfer

    SciTech Connect

    Chudomel, J. M.; Yang, B. Q.; Barnes, M. D.; Achermann, M.; Mague, J. T.; Lahti, P. M.

    2011-08-04

    9-(N,N-Dianisylamino)anthracene (9DAAA), 9-(N,N-dianisylamino)dinaphth([1,2-a:2'-1'-j]-anthracene (9DAAH), and 9,10-bis(N,N-dianisylamino)anthracene (910BAA) were synthesized as highly twisted triarylamines with potential for photoexcited internal charge transfer. Crystallography of 9DAAA shows its dianisylamino group to be twisted nearly perpendicular to its anthracene unit, similar to a report for 910BAA. The solution fluorescence spectra show strong bathochromic shifts for each of the three molecular systems with strongly decreased quantum efficiency in higher polarity solvents. Solution-phase (ensemble) time-resolved photoluminescence measurements show up to 4-fold decreases in fluorescence lifetime in acetonitrile compared to hexane. The combined results are consistent with photoinduced, transient intramolecular charge-transfer from the bis-anisylamine unit to the polycyclic aromatic unit. Computational modeling is in accord with intramolecular transfer of electron density from the bis-anisylamino unit to the anthracene, based on in comparisons of HOMO and LUMO.

  20. High energy implantation with high-charge-state ions in a vacuum arc ion implanter

    SciTech Connect

    Oks, E.M. |; Anders, A.; Brown, I.G.; Dickinson, M.R.; MacGill, R.A.

    1996-08-01

    Ion implantation energy can in principal be increased by increasing the charge states of the ions produced by the ion source rather than by increasing the implanter operating voltage, providing an important savings in cost and size of the implanter. In some recent work the authors have shown that the charge states of metal ions produced in a vacuum arc ion source can be elevated by a strong magnetic field. In general, the effect of both high arc current and high magnetic field is to push the distribution to higher charge states--the mean ion charge state is increased and new high charge states are formed. The effect is significant for implantation application--the mean ion energy can be about doubled without change in extraction voltage. Here they describe the ion source modifications, the results of time-of-flight measurements of ion charge state distributions, and discuss the use and implications of this technique as a means for doing metal iron implantation in the multi-hundreds of keV ion energy range.

  1. Transport of intense beams of highly charged ions

    NASA Astrophysics Data System (ADS)

    Winkler, M.; Gammino, S.; Ciavola, G.; Celona, L.; Spadtke, P.; Tinschert, K.

    2005-10-01

    The new generation of ion sources delivers beams with intensities of several mA. This requires a careful design of the analysing system and the low-energy beam transport (LEBT) from the source to the subsequent systems. At INFN-LNS, high intensity proton sources (TRIPS [L. Celona, G. Ciavola, S. Gammino et al ., Rev. Sci. Instrum. 75(5) 1423 (2004)], PM-TRIPS [G. Ciavola, L. Celona, S. Gammino et al ., Rev. Sci. Instrum. 75(5) 1453 (2004)]) as well as ECR ion sources for the production of highly charged high-intensity heavy ion beams are developed (SERSE [S. Gammino, G. Ciavola, L. Celona et al ., Rev. Sci. Instrum. 72(11) 4090 (2001), and references therein], GyroSERSE [S. Gammino et al ., Rev. Sci. Instrum. 75(5) 1637 (2004)], MS-ECRIS [G. Ciavola et al ., (2005), 11th Int. Conf. on Ion Sources, Caen, (in press)]). In this paper, we present ion-optical design studies of various LEBT systems for ion-sources devoted to the production of intense beams. Calculations were performed using the computer codes GIOS [H. Wollnik, J. Brezina and M. Berz, NIM A 258 (1987)], GICO [M. Berz, H.C. Hoffmann, and H. Wollnik, NIM A 258 (1987)], and TRANSPORT [K.L. Brown, F. Rothacker and D.C. Carey, SLAC-R-95-462, Fermilab-Pub-95/069, UC-414 (1995)]. Simulations take into account the expected phase space growth of the beam emittance due to space-charge effects and image aberrations introduced by the magnetic elements.

  2. Experimental investigation on the use of highly charged nanoparticles to improve the stability of weakly charged colloidal system.

    PubMed

    Zubir, Mohd Nashrul Mohd; Badarudin, A; Kazi, S N; Misran, Misni; Amiri, Ahmad; Sadri, Rad; Khalid, Solangi

    2015-09-15

    The present work highlighted on the implementation of a unique concept for stabilizing colloids at their incipiently low charge potential. A highly charged nanoparticle was introduced within a coagulated prone colloidal system, serving as stabilizer to resist otherwise rapid flocculation and sedimentation process. A low size asymmetry of nanoparticle/colloid serves as the new topic of investigation in addition to the well-established large size ratio nanoparticle/microparticle study. Highly charged Al2O3 nanoparticles were used within the present research context to stabilize TiO2 and Fe3O4 based colloids via the formation of composite structures. It was believed, based on the experimental evidence, that Al2O3 nanoparticle interact with the weakly charged TiO2 and Fe3O4 colloids within the binary system via absorption and/or haloing modes to increase the overall charge potential of the respective colloids, thus preventing further surface contact via van der Waal's attraction. Series of experimental results strongly suggest the presence of weakly charged colloids in the studied bimodal system where, in the absence of highly charged nanoparticle, experience rapid instability. Absorbance measurement indicated that the colloidal stability drops in accordance to the highly charged nanoparticle sedimentation rate, suggesting the dominant influence of nanoparticles to attain a well-dispersed binary system. Further, it was found that the level of colloidal stability was enhanced with increasing nanoparticle fraction within the mixture. Rheological observation revealed that each hybrid complexes demonstrated behavior reminiscence to water with negligible increase in viscosity which serves as highly favorable condition particularly in thermal transport applications. PMID:26048724

  3. X-ray radiography with highly charged ions

    DOEpatents

    Marrs, Roscoe E.

    2000-01-01

    An extremely small (1-250 micron FWHM) beam of slow highly charged ions deexciting on an x-ray production target generates x-ray monochromatic radiation that is passed through a specimen and detected for imaging. The resolution of the x-ray radiograms is improved and such detection is achieved with relatively low dosages of radiation passing through the specimen. An apparatus containing an electron beam ion trap (and modifications thereof) equipped with a focusing column serves as a source of ions that generate radiation projected onto an image detector. Electronic and other detectors are able to detect an increased amount of radiation per pixel than achieved by previous methods and apparati.

  4. The HITRAP facility for slow highly charged ions

    NASA Astrophysics Data System (ADS)

    Herfurth, F.; Andelkovic, Z.; Barth, W.; Chen, W.; Dahl, L. A.; Fedotova, S.; Gerhard, P.; Kaiser, M.; Kester, O. K.; Kluge, H.-J.; Kotovskiy, N.; Maier, M.; Maaß, B.; Neidherr, D.; Quint, W.; Ratzinger, U.; Reiter, A.; Schempp, A.; Stöhlker, Th; Vormann, H.; Vorobjev, G.; Yaramyshev, S.; the HITRAP Collaboration

    2015-11-01

    At the GSI accelerator complex, behind the universal linear accelerator UNILAC and the synchrotron SIS, highly charged ions up to {{{U}}}73+ are produced at 400 MeV/nucleon. When this beam is sent through a copper foil all or nearly all remaining electrons are stripped. The HITRAP facility, a combination of a linear decelerator and a cryogenic Penning trap, is built to decelerate those ions to almost rest and to provide them for the experiments. In a number of commissioning beam times, the deceleration in the ESR, the extraction, bunching and, finally, deceleration to 6 keV/nucleon has been shown. The remaining steps, being capture and cooling in a cryogenic Penning trap, are presently tested off-line.

  5. Special issue on the spectroscopy of highly-charged ions

    NASA Astrophysics Data System (ADS)

    Nakamura, Nobuyuki; Ralchenko, Yuri; Stöhlker, Thomas

    2014-07-01

    Journal of Physics B: Atomic, Molecular and Optical Physics is delighted to announce a forthcoming special issue on the spectroscopy of highly-charged ions, to appear in the early summer of 2015, and invites you to submit a paper. From fusion to astrophysics to EUV lithography, highly-charged ions (HCI) are used to diagnose plasma properties, create new powerful sources of light and even verify the most fundamental theories. Since the mere creation of such multiply-stripped atoms requires extreme temperature or energies, their radiation is frequently the only physical data available to researchers. Even so, the HCI spectra provide a variety of rich and detailed information on ion properties and environment conditions. Over the last couple of decades, spectroscopy of HCI has been given a strong impetus through the development of both compact (e.g. electron beam ion traps) and large-scale (e.g. tokamaks, stellarators, storage rings) machines capable of efficiently producing atoms that are ionized fifty, sixty, or even ninety times. This, in turn, triggered the development of new experimental and theoretical techniques to measure and analyze HCI spectra and to use this radiation for plasma diagnostics. The purpose of this special issue will be to provide an extensive account of the state of the art in this thriving area of atomic physics. The covered topics, in particular, will include (but not be limited to): New experimental methods for the production and recording of HCI spectra Identification of HCI spectra Measurement of transition lifetimes Relativistic, QED and nuclear effects in HCI spectra Polarization and angular distribution of radiation Effects of external fields on HCI spectra Tests of fundamental theories Plasma spectroscopy and spectra modeling with HCI Please submit your article by 1 December 2014 using our website http://mc04.manuscriptcentral.com/jphysb-iop. Submissions received after this date will be considered for the journal, but may not be

  6. Design and performance of an instrument for electron impact tandem mass spectrometry and action spectroscopy of mass/charge selected macromolecular ions stored in RF ion trap*

    NASA Astrophysics Data System (ADS)

    Ranković, Milos Lj.; Giuliani, Alexandre; Milosavljević, Aleksandar R.

    2016-06-01

    A new apparatus was designed, coupling an electron gun with a linear quadrupole ion trap mass spectrometer, to perform m/ z (mass over charge) selected ion activation by electron impact for tandem mass spectrometry and action spectroscopy. We present in detail electron tracing simulations of a 300 eV electron beam inside the ion trap, design of the mechanical parts, electron optics and electronic circuits used in the experiment. We also report examples of electron impact activation tandem mass spectra for Ubiquitin protein, Substance P and Melittin peptides, at incident electron energies in the range from 280 eV to 300 eV.

  7. Recent Excitation, Charge Exchange, and Lifetime Results in Highly Charged Ions Relevant to Stellar, Interstellar, Solar and Comet Phenomena

    NASA Technical Reports Server (NTRS)

    Chutjian, A.; Hossain, S.; Mawhorter, R. J.; Smith, S. J.

    2006-01-01

    Recent JPL absolute excitation and charge exchange cross sections, and measurements of lifetimes of metastable levels in highly-charged ions (HCIs) are reported. These data provide benchmark comparisons to results of theoretical calculations. Theoretical approaches can then be used to calculate the vast array of data which cannot be measured due to experimental constraints. Applications to the X-ray emission from comets are given.

  8. Electrically actuated multiple store launcher

    NASA Astrophysics Data System (ADS)

    Marshall, Frank P.; Travor, Bruce W.

    1991-12-01

    This invention comprises a multi-store, electrical pulse initiated launcher that fits into, and is electrically connected with a transporting vehicle and that contains sequentially stacked assemblies. An electrical pulse from the transporting vehicle causes a resistor with the least value to transfer the electric sufficient gas pressure to force the store out of the launcher. The present invention discloses an electrically-actuated, multi-store dispenser wherein an initial electrical charge ignites gas cartridges causing sequential launching of stores from their tandem position inside a launch container. In some environments, it is desirable to dispense multiple stores from a launch vehicle, for instance sonobuoys, in dense patterns. Due to physical limitations of space in the dispensing vehicle, an effort was made to miniaturize the active components inside the store and therefore reduce the overall outer dimensions thereof. Once the size of the store was reduced, in order to meet the demands of the denser patterns, the inside of the individual launch containers were modified to allow each to hold and dispense more than one store. This new type of launch container, in addition to maintaining the size requirement dictated by the transporting vehicle, is operated by the vehicle's electrical system.

  9. Length-dependent charge generation from vertical arrays of high-aspect-ratio ZnO nanowires.

    PubMed

    Rivera, Vivian Farías; Auras, Florian; Motto, Paolo; Stassi, Stefano; Canavese, Giancarlo; Celasco, Edvige; Bein, Thomas; Onida, Barbara; Cauda, Valentina

    2013-10-18

    Aqueous chemical growth of zinc oxide nanowires is a flexible and effective approach to obtain dense arrays of vertically oriented nanostructures with high aspect ratio. Herein we present a systematic study of the different synthesis parameters that influence the ZnO seed layer and thus the resulting morphological features of the free-standing vertically oriented ZnO nanowires. We obtained a homogeneous coverage of transparent conductive substrates with high-aspect-ratio nanowire arrays (length/diameter ratio of up to 52). Such nanostructured vertical arrays were examined to assess their electric and piezoelectric properties, and showed an electric charge generation upon mechanical compressive stress. The principle of energy harvesting with these nanostructured ZnO arrays was demonstrated by connecting them to an electronic charge amplifier and storing the generated charge in a series of capacitors. We found that the generated charge and the electrical behavior of the ZnO nanowires are strictly dependent on the nanowire length. We have shown the importance of controlling the morphological properties of such ZnO nanostructures for optimizing a nanogenerator device. PMID:24027171

  10. Spacecraft charging at high altitudes - The SCATHA satellite program

    NASA Technical Reports Server (NTRS)

    Mcpherson, D. A.; Cauffman, D. P.; Schober, W.

    1975-01-01

    Satellites at synchronous altitude exhibit unexplained behavior in the operation of electronic circuits and in the performance of thermal controls. A possible explanation for this behavior is the fact that satellites can be charged to large negative voltages by energetic electrons in the space environment. A space measurements program entitled SCATHA has been formulated to determine the characteristics of the charging process, to measure the response of the satellite when charging occurs, and to evaluate the utility of various corrective techniques which can minimize differential charging on the satellite. The instrumentation will measure charging levels and rates of twenty samples of satellite materials, some of which will be modified to prevent buildup of electrostatic charge. The electromagnetic interference background on the satellite will be measured for comparison with MIL STD 461, Electromagnetic Interference Characteristics Requirements for Equipment.

  11. Photoionization of Highly Charged Argon Ions and Their Diagnostic Lines

    NASA Astrophysics Data System (ADS)

    Nahar, Sultana N.

    2012-06-01

    %TEXT OF YOUR ABSTRACT Lines of highly charged He-like and Li-like ions in the ultraviolet and X-ray regions provide useful diagnostics for the physical and chemical conditions of the astrophysical as well as fusion plasmas. For example, Ar XVII lines in a Syfert galaxy have been measured by the X-ray space observatory Chandra. Results on photoionization of Ar XVI and Ar XVII obtained from relativistic Breit-Pauli R-matrix method and close-coupling approximation will be presented. Important features for level-specific photoionization for the diagnostic w, x, y, z lines of He-like Ar XVII in the ultraviolet region will be illustrated. Although monotonous decay dominates the low energy photoionization for these ions, strong resonances appear in the high energy region indicating higher recombination, inverse process of photoionization, at high temperature. The spectra of the well known 22 diagnostics dielectronic satellite lines of Li-like Ar XVI will be shown produced from the the KLL resonances in photoionization. Acknowledgement: Partially supported by DOE, NSF; Computational work was carried out at the Ohio Supercomputer Center

  12. Taxonomic analysis of the microbial community in stored sugar beets using high-throughput sequencing of different marker genes.

    PubMed

    Liebe, Sebastian; Wibberg, Daniel; Winkler, Anika; Pühler, Alfred; Schlüter, Andreas; Varrelmann, Mark

    2016-02-01

    Post-harvest colonization of sugar beets accompanied by rot development is a serious problem due to sugar losses and negative impact on processing quality. Studies on the microbial community associated with rot development and factors shaping their structure are missing. Therefore, high-throughput sequencing was applied to describe the influence of environment, plant genotype and storage temperature (8°C and 20°C) on three different communities in stored sugar beets, namely fungi (internal transcribed spacers 1 and 2), Fusarium spp. (elongation factor-1α gene fragment) and oomycetes (internal transcribed spacers 1). The composition of the fungal community changed during storage mostly influenced by the storage temperature followed by a weak environmental effect. Botrytis cinerea was the prevalent species at 8°C whereas members of the fungal genera Fusarium and Penicillium became dominant at 20°C. This shift was independent of the plant genotype. Species richness within the genus Fusarium also increased during storage at both temperatures whereas the oomycetes community did not change. Moreover, oomycetes species were absent after storage at 20°C. The results of the present study clearly show that rot development during sugar beet storage is associated with pathogens well known as causal agents of post-harvest diseases in many other crops. PMID:26738557

  13. SPM observation of slow highly charged ion induced nanodots on highly orientated pyrolytic graphite

    NASA Astrophysics Data System (ADS)

    Mitsuda, Y.; Nakamura, B. E. O'Rourke1 N.; Kanai, Y.; Ohtani, S.; Yamazaki, Y.

    2007-03-01

    We have observed nanodots on a highly orientated pyrolytic graphite (HOPG) surface produced by highly charged ion impacts using a scanning tunneling microscope. Previous measurements have con.rmed the dominant role of the potential energy or the incident ion charge state on the size and height of the observed nanodots. The present results extend these previous measurements to much lower kinetic energy. It appears that there is no observable influence on the lateral size of the nanodots due to the incident ion kinetic energy down to approximately 200 eV. In contrast some slight reduction in the nanodot height was observed as the kinetic energy was reduced.

  14. Design and performance of an instrument for electron impact tandem mass spectrometry and action spectroscopy of mass/charge selected macromolecular ions stored in RF ion trap*

    NASA Astrophysics Data System (ADS)

    Ranković, Milos Lj.; Giuliani, Alexandre; Milosavljević, Aleksandar R.

    2016-05-01

    A new apparatus was designed, coupling an electron gun with a linear quadrupole ion trap mass spectrometer, to perform m/z (mass over charge) selected ion activation by electron impact for tandem mass spectrometry and action spectroscopy. We present in detail electron tracing simulations of a 300 eV electron beam inside the ion trap, design of the mechanical parts, electron optics and electronic circuits used in the experiment. We also report examples of electron impact activation tandem mass spectra for Ubiquitin protein, Substance P and Melittin peptides, at incident electron energies in the range from 280 eV to 300 eV. Contribution to the Topical Issue "Advances in Positron and Electron Scattering", edited by Paulo Limao-Vieira, Gustavo Garcia, E. Krishnakumar, James Sullivan, Hajime Tanuma and Zoran Petrovic.

  15. STUDIES OF X-RAY PRODUCTION FOLLOWING CHARGE EXCHANGE RECOMBINATION BETWEEN HIGHLY CHARGED IONS AND NEUTRAL ATOMS AND MOLECULES

    SciTech Connect

    Brown, G V; Beiersdorfer, P; Chen, H; Clementson, J; Frankel, M; Gu, M F; Kelley, R L; Kilbourne, C A; Porter, F S; Thorn, D B; Wargelin, B J

    2008-08-28

    We have used microcalorimeters built by the NASA/Goddard Space Flight Center and the Lawrence Livermore National Laboratory Electron Beam Ion Trap to measure X-ray emission produced by charge exchange reactions between highly charged ions colliding with neutral helium, hydrogen, and nitrogen gas. Our measurements show the spectral dependence on neutral species and also show the distinct differences between spectra produced by charge exchange reactions and those produced by direct impact excitation. These results are part of an ongoing experimental investigation at the LLNL EBIT facility of charge exchange spectral signatures and can be used to interpret X-ray spectra produced by a variety of laboratory and celestial sources including cometary and planetary atmospheres, the Earth's magnetosheath, the heliosphere, and tokamaks.

  16. Polyimide Nanocomposites Prepared from High-Temperature, Reduced Charge Organoclays

    NASA Technical Reports Server (NTRS)

    Delozier, D. M.; Orwoll, R. A.; Cahoon, J. F.; Ladislaw, J. S.; Smith, J. G., Jr.; Connell, J. W.

    2003-01-01

    Montmorillonite clays modified with the dihydrochloride salt of 1,3-bis(3-aminophenoxy)benzene (APB) were used in the preparation of polyimide/organoclay hybrid films. Organoclays with varying surface charge based upon APB were prepared and examined for their dispersion behavior in the polymer matrix. High molecular weight poly(amide acid) solutions were prepared in the presence of the organoclays. Films were cast and subsequently heated to 300C to cause imidization. The resulting nanocomposite films, containing 3 wt% of organoclay, were characterized by transmission electron microscopy and X-ray diffraction. The clay's cation exchange capacity (CEC) played a key role in determining the extent of dispersion in the polyimide matrix. Considerable dispersion was observed in some of the nanocomposite films. The most effective organoclay was found to have a CEC of 0.70 meq/g. Nanocomposite films prepared with 3-8 wt% of this organoclay were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), and thin-film tensile testing. High levels of clay dispersion could be achieved even at the higher clay loadings. Results from mechanical testing revealed that while the moduli of the nanocomposites increased with increasing clay loadings, both strength and elongation decreased.

  17. A high-frequency electrospray driven by gas volume charges

    SciTech Connect

    Lastochkin, Dmitri; Chang, H.-C.

    2005-06-15

    High-frequency (>10 kHz) ac electrospray is shown to eject volatile dielectric liquid drops by an entirely different mechanism from dc sprays. The steady dc Taylor conic tip is absent and continuous spraying of submicron drops is replaced by individual dynamic pinchoff events involving the entire drop. We attribute this spraying mechanism to a normal Maxwell force produced by an undispersed plasma cloud in front of the meniscus that produces a visible glow at the spherical tip. The volume charge within the cloud is formed by electron-induced gas ionization of the evaporated liquid and produces a large normal field that is much higher than the nominal applied field such that drop ejection occurs at a voltage (at high frequencies) that is as much as ten times lower than that for dc sprays. The ejection force is sensitive to the liquid properties (but not its electrolyte composition), the ac frequency and trace amounts of inert gases, which are believed to catalyze the ionization reactions. As electroneutral drops are ejected, due to the large (>100) ratio between individual drop ejection time and the ac frequency, this mechanism can produce large (microns) electroneutral drops at relatively low voltages.

  18. An acoustic charge transport imager for high definition television applications

    NASA Technical Reports Server (NTRS)

    Hunt, William D.; Brennan, Kevin F.; Summers, Chris J.

    1992-01-01

    In this report we present the progress during the second six month period of the project. This includes both experimental and theoretical work on the acoustic charge transport (ACT) portion of the chip, the theoretical program modelling of both the avalanche photodiode (APD) and the charge transfer and overflow transistor and the materials growth and fabrication part of the program.

  19. Electron-ion plasma dynamics in the presence of highly charged dust-clusters

    SciTech Connect

    Djebli, Mourad Benkhelifa, El-Amine

    2015-05-15

    Electron-ion plasma expansion is studied in the presence of positively (negatively) highly charged uniformly distributed dust particles, considered as impurities. For that purpose, a multi-fluid model is used, where the charged impurities characteristics are included in Poisson's equation. We found that ion acceleration is enhanced by the presence of positively charged dust. The latter leads to spiky structures in the ion front which have a higher amplitude as the charge increases. The charged impurities have a significant effect when the combination of their charge and density is greater than a critical value which depends on ion to electron temperature ratio.

  20. High-Resolution Field Effect Sensing of Ferroelectric Charges

    SciTech Connect

    Ko, Hyoungsoo; Ryu, Kyunghee; Park, Hongsik; Park, Chulmin; Jeon, Daeyoung; Kim, Yong Kwan; Jung, Juhwan; Min, Dong-Ki; Kim, Yunseok; Lee, Ho Nyung; Park, Yoondong; Shin, Hyunjung; Hong, Seungbum

    2011-01-01

    Nanoscale manipulation of surface charges and their imaging are essential for understanding local electronic behaviors of polar materials and advanced electronic devices. Electrostatic force microscopy and Kelvin probe force microscopy have been extensively used to probe and image local surface charges responsible for electrodynamics and transport phenomena. However, they rely on the weak electric force modulation of cantilever that limits both spatial and temporal resolutions. Here we present a field effect transistor embedded probe that can directly image surface charges on a length scale of 25 nm and a time scale of less than 125 {micro}s. On the basis of the calculation of net surface charges in a 25 nm diameter ferroelectric domain, we could estimate the charge density resolution to be as low as 0.08 {micro}C/cm{sup 2}, which is equivalent to 1/20 electron per nanometer square at room temperature.

  1. High resolution field effect sensing of ferroelectric charges.

    SciTech Connect

    Ko, H.; Ryu, K.; Park, H.; Park, C.; Jeon, D.; Kim, Y. K.; Jung, J.; Min, D.-K.; Kim, Y.; Lee, H. N.; Park, Y.; Shin, H.; Hong, S.

    2011-03-04

    Nanoscale manipulation of surface charges and their imaging are essential for understanding local electronic behaviors of polar materials and advanced electronic devices. Electrostatic force microscopy and Kelvin probe force microscopy have been extensively used to probe and image local surface charges responsible for electrodynamics and transport phenomena. However, they rely on the weak electric force modulation of cantilever that limits both spatial and temporal resolutions. Here we present a field effect transistor embedded probe that can directly image surface charges on a length scale of 25 nm and a time scale of less than 125 {micro}s. On the basis of the calculation of net surface charges in a 25 nm diameter ferroelectric domain, we could estimate the charge density resolution to be as low as 0.08 {micro}C/cm{sup 2}, which is equivalent to 1/20 electron per nanometer square at room temperature.

  2. High-resolution field effect sensing of ferroelectric charges.

    PubMed

    Ko, Hyoungsoo; Ryu, Kyunghee; Park, Hongsik; Park, Chulmin; Jeon, Daeyoung; Kim, Yong Kwan; Jung, Juhwan; Min, Dong-Ki; Kim, Yunseok; Lee, Ho Nyung; Park, Yoondong; Shin, Hyunjung; Hong, Seungbum

    2011-04-13

    Nanoscale manipulation of surface charges and their imaging are essential for understanding local electronic behaviors of polar materials and advanced electronic devices. Electrostatic force microscopy and Kelvin probe force microscopy have been extensively used to probe and image local surface charges responsible for electrodynamics and transport phenomena. However, they rely on the weak electric force modulation of cantilever that limits both spatial and temporal resolutions. Here we present a field effect transistor embedded probe that can directly image surface charges on a length scale of 25 nm and a time scale of less than 125 μs. On the basis of the calculation of net surface charges in a 25 nm diameter ferroelectric domain, we could estimate the charge density resolution to be as low as 0.08 μC/cm(2), which is equivalent to 1/20 electron per nanometer square at room temperature. PMID:21375284

  3. Electron, photons, and molecules: Storing energy from light

    SciTech Connect

    Miller, J.R.

    1996-09-01

    Molecular charge separation has important potential for photochemical energy storage. Its efficiency can be enhanced by principals which maximize the rates of the electron transfer steps which separate charge and minimize those which recombine high-energy charge pairs to lose stored energy. Dramatic scientific progress in understanding these principals has occurred since the founding of DOE and its predecessor agency ERDA. While additional knowledge in needed in broad areas of molecular electron transfer, some key areas of knowledge hold particular promise for the possibility of moving this area from science toward technology capable of contributing to the nation`s energy economy.

  4. Excitation and ionization of highly charged ions by electron impact

    SciTech Connect

    Sampson, D.H.

    1989-11-15

    Two approaches for very rapid calculation of atomic data for high temperature plasma modeling have been developed. The first uses hydrogenic basis states and has been developed and applied in many papers discussed in previous progress reports. Hence, it is only briefly discussed here. The second is a very rapid, yet accurate, fully relativistic approach that has been developed over the past two or three years. It is described in more detail. Recently it has been applied to large scale production of atomic data. Specifically, it has been used to calculate relativistic distorted wave collision strengths and oscillator strengths for the following: all transitions from the ground level to the n=3 and 4 excited levels in the 71 Neon-like ions with nuclear charge number Z in the range 22 {le} Z {le} 92; all transitions among the 2s{sub {1/2}}, 2p{sub {1/2}} and 2p{sub 3/2} levels and from them to all nlj levels with n=3,4 and 5 in the 85 Li-like ions with 8 {le} Z {le} 92; all transitions among the 3s{sub {1/2}}, 3p{sub 3/2}, 3d{sub 3/2} and 3d{sub 5/2} levels and from them to all nlj levels with n=4 and 5 in the 71 Na-like ions with 22 {le} Z {le} 92; and all transitions among 4s{sub {1/2}}, 4p{sub {1/2}}, 4p{sub 3/2}, 4d{sub 3/2}, 4d{sub 5/2}, 4f{sub 5/2} and 4f{sub 7/2} levels and from them to all nlj levels with n=5 in the 33 Cu-like ions with 60 {le} Z {le} 92. Also the program has been extended to give cross-sections for excitation to specific magnetic sublevels of the target ion by an electron beam and very recently it has been extended to give relativistic distorted wave cross sections for ionization of highly charged ions by electron impact.

  5. Tiny Turtles Purchased at Pet Stores are a Potential High Risk for Salmonella Human Infection in the Valencian Region, Eastern Spain.

    PubMed

    Marin, Clara; Vega, Santiago; Marco-Jiménez, Francisco

    2016-07-01

    Turtles may be considered unsafe pets, particularly in households with children. This study aimed to assess Salmonella carriage by turtles in pet stores and in private ownership to inform the public of the potential health risk, enabling informed choices around pet selection. During the period between September and October 2013, 24 pet stores and 96 private owners were sampled in the Valencian Region (Eastern Spain). Salmonella identification procedure was based on ISO 6579: 2002 recommendations (Annex D). Salmonella strains were serotyped in accordance with Kauffman-White-Le-Minor technique. The rate of isolation of Salmonella was very high from pet store samples (75.0% ± 8.8%) and moderate for private owners (29.0% ± 4.6%). Serotyping revealed 18 different serotypes among two Salmonella enterica subspecies: S. enterica subsp. enterica and S. enterica subsp. diarizonae. Most frequently isolated serotypes were Salmonella Typhimurium (39.5%, 17/43) and Salmonella Pomona (9.3%, 4/43). Serotypes identified have previously been reported in turtles, and child Salmonella infections associate with pet turtle exposure. The present study clearly demonstrates that turtles in pet stores, as well as in private owners, could be a direct or indirect source of a high risk of human Salmonella infections. In addition, pet stores should advise their customers of the potential risks associated with reptile ownership. PMID:27228194

  6. Honey bee lines selected for high propolis production also have superior hygienic behavior and increased honey and pollen stores.

    PubMed

    Nicodemo, D; De Jong, D; Couto, R H N; Malheiros, E B

    2013-01-01

    Honey bees use propolis to defend against invaders and disease organisms. As some colonies produce much more propolis than others, we investigated whether propolis collecting is associated with disease resistance traits, including hygienic behavior and resistance to the parasitic bee mite, Varroa destructor. The three highest (HP) and three lowest propolis-producing (LP) colonies among 36 Africanized honey bee colonies were initially selected. Queens and drones from these colonies were crossed through artificial insemination to produce five colonies of each of the following crosses: HP♀ X HP♂, LP♀ X HP♂, HP♀ X LP♂, and LP♀ X LP♂. Colonies headed by HP♀ X HP♂ queens produced significantly more propolis than those with HP♀ X LP♂ and LP♀ X HP♂ queens and these in turn produced significantly more propolis than those headed by LP♀ X LP♂ queens. The brood cell uncapping rate of the high-propolis-producing colonies in the hygienic behavior test was significantly superior to that of the other groups. The LP X LP group was significantly less hygienic than the two HP X LP crosses, based on the evaluation of the rate of removal of pin-killed pupae. The HP X HP colonies were significantly more hygienic than the other crosses. No significant differences were found in mite infestation rates among the groups of colonies; although overall, colony infestation rates were quite low (1.0 to 3.2 mites per 100 brood cells), which could have masked such effects. Honey and pollen stores were significantly and positively correlated with propolis production. PMID:24391041

  7. The interactions of high-energy, highly charged Xe ions with buckyballs

    SciTech Connect

    Ali, R.; Berry, H.G.; Cheng, S.

    1994-12-31

    Ionization and fragmentation have been measured for C{sub 60} molecules bombarded by highly charged (up to 35+) xenon ions with energies ranging up to 625 MeV. The observed mass distribution of positively charged fragments is explained in terms of a theoretical model indicating that the total interaction cross section contains roughly equal contributions from (a) excitation of the giant plasmon resonance, and (b) large-energy-transfer processes that lead to multiple fragmentation of the molecule. Preliminary results of measurements on VUV photons emitted in these interactions are also presented.

  8. Spectroscopic Measurements of Photo Pumped Highly Charged Ions

    NASA Astrophysics Data System (ADS)

    Graf, A.; Beiersdorfer, P.; Brown, G. V.; Crespo Lopez Urrutia, J. R.

    2011-11-01

    We report on recent x-ray laser spectroscopic measurements of line emission from photo-excited highly charged ions. The ion cloud of the HI-LIGHT portable electron beam ion trap (EBIT) was used as a target for the Linac Coherent Light Source (LCLS) free electron laser in the Soft X-Ray (SXR) end station. The SXR monochromator allowed a precision investigation of transition energies and oscillator strength ratios of emission lines from Na-like Fe^15+ and Ne-like Fe^16+ important for astrophysical diagnostics. We have demonstrated a technique for calibration of the SXR monochromator photon energy scale using photo-excited resonant fluorescence spectra of very well known lines from H-like and He-like F and O. Numerous instruments were used to diagnose the fluorescent and autoionizing decay channels of the trapped plasma including an Iglet-X broadband germanium detector, a variable line spacing reflection grating soft x-ray/VUV spectrometer and a Wien filter based ion extraction system. An overview of the experiment as well as preliminary results will be presented.

  9. Multiple ionization of atoms by highly charged ions

    NASA Astrophysics Data System (ADS)

    Tolstikhina, Inga Yu; Shevelko, V. P.

    2015-06-01

    A method is suggested for quickly and easily estimating multiple ionization (MI) cross sections of heavy atoms colliding with highly charged ions, using the independent-particle model (IPM). One-electron ionization probabilities p(b) are calculated using the geometrical model for p(0) values at zero impact parameter b and the relativistic Born approximation for one-electron ionization cross sections. Numerical results of MI cross sections are presented for Ne and Ar atoms colliding with Ar8+, Fe20+, Au24+, Bi67+ and U90+ ions at energies 1 MeV u{}-1-10 GeV u{}-1and compared with available experimental data and CTMC (classical trajectory Monte Carlo) calculations. The present method of calculation describes experimental dependencies of MI cross sections on the number of ejected electrons m within a factor of two to three. Numerical calculations show that at intermediate ion energies E = 1 - 10 MeV u{}-1, the contribution of MI cross sections to the total, i.e. summed over all m values, is quite large ˜35% and decreases with increasing energy.

  10. The study towards high intensity high charge state laser ion sources.

    PubMed

    Zhao, H Y; Jin, Q Y; Sha, S; Zhang, J J; Li, Z M; Liu, W; Sun, L T; Zhang, X Z; Zhao, H W

    2014-02-01

    As one of the candidate ion sources for a planned project, the High Intensity heavy-ion Accelerator Facility, a laser ion source has been being intensively studied at the Institute of Modern Physics in the past two years. The charge state distributions of ions produced by irradiating a pulsed 3 J/8 ns Nd:YAG laser on solid targets of a wide range of elements (C, Al, Ti, Ni, Ag, Ta, and Pb) were measured with an electrostatic ion analyzer spectrometer, which indicates that highly charged ions could be generated from low-to-medium mass elements with the present laser system, while the charge state distributions for high mass elements were relatively low. The shot-to-shot stability of ion pulses was monitored with a Faraday cup for carbon target. The fluctuations within ±2.5% for the peak current and total charge and ±6% for pulse duration were demonstrated with the present setup of the laser ion source, the suppression of which is still possible. PMID:24593615

  11. Highly transverse velocity distribution of convoy electrons emitted by highly charged ions

    NASA Astrophysics Data System (ADS)

    Seliger, M.; Tőkési, K.; Reinhold, C. O.; Burgdörfer, J.

    2003-05-01

    We present a theoretical study of convoy electron emission resulting from highly charged ion (HCI) transport through carbon foils. Employing a classical transport theory we analyze the angular and energy distribution formed by multiple scattering of electrons in the solid. We find that the convoy electron distribution becomes highly transverse at intermediate foil thicknesses representing an oblate spheroidal distribution due to the stepwise excitation of the HCI. The calculated convoy electron spectra are found to be in good agreement with recent measurements.

  12. Highly-correlated Charges in Block Copolyelectrolytes: Charge as a Tool for Morphology Manipulation

    NASA Astrophysics Data System (ADS)

    Sing, Charles; Zwanikken, Jos; Olvera de La Cruz, Monica

    2014-03-01

    Block copolymers that include at least one charged block have been of great technological interest due to their use in materials for battery membranes. These materials are difficult to understand theoretically, however, due to the disparate length scale effects of charge correlation and chain conformation driving the microphase separation of these systems. Using a new theoretical approach that can account for both of these effects that is based of hybrid liquid state integral equation-self consistent field theory (LS-SCFT) calculations, we elucidate the fundamental physics underpinning the thermodynamics of these materials. In particular, we demonstrate four main effects that drive the phase behavior of block copolyelectrolytes: Coulombic cohesion, counterion entropy, excluded volume, and ion self energy effects. Tuning parameters such as charge fraction and dielectric constant can be used to explore different microphase-separated morphologies on an axis orthogonal to traditional routes of manipulating block copolymers (i.e. χ N and block fraction). This expands the palette of tools that can be used to tune this important class of polymeric materials.

  13. Bed Topography of Store Glacier and Fjord, Greenland from High-Resolution Gravity Data and Multi-Beam Echo Sounding

    NASA Astrophysics Data System (ADS)

    An, L.; Rignot, E. J.; Muto, A.; Morlighem, M.; Kemp, C.

    2014-12-01

    Store Glacier is a major west Greenland outlet tidewater glacier draining an area of 30,000 square km into Uummannaq Fjord, and flowing at a speed of 4.8 km per year at its terminus. The bed topography of the glacier is poorly known and the fjord bathymetry was partially surveyed for the first time in August 2012. In this study, we present a new approach for the inference of the glacier bed topography, ice thickness and sea floor bathymetry using high-resolution airborne gravity data combined with other data. In August 2012, we acquired a 250 m spacing grid of free-air gravity data at a speed of 50 knots with accuracy at sub-milligal level much higher accuracy than NASA Operation IceBridge (OIB) gravity campaign with approximate 5.2 km resolution at 290 knots flying speed. In August 2012 and 2013, we used multi-beam echo sounding to survey the sea floor bathymetry in front of the glacier, extending to the calving face of the glacier. Inland, we combined radar-derived ice thickness with ice motion vectors to reconstruct the bed topography at a high resolution. Using a 3D inversion of the gravity data, we reconstruct seamless bed topography across the ice front boundary that matches interior data and sea floor bathymetry, and provides information about sediment thickness beneath and in front of the glacier. Comparison of the results with prior maps reveals vast differences. IBCAO3 bathymetry suggests an ice front grounded at sea level while the measured ice front is grounded 550 m below sea level. The seamless topography obtained across the grounding line reveals the presence of a previously unknown sill, which explains why the glacier has been so stable in the last 50 years. The results have important impacts on the interpretation of the glacier stability, and sensitivity to thermal forcing from the ocean and surface melt. This work was conducted at UCI under a contract with the Gordon and Betty More Foundation and with NASA.

  14. Highly charged ions as a basis of optical atomic clockwork of exceptional accuracy.

    PubMed

    Derevianko, Andrei; Dzuba, V A; Flambaum, V V

    2012-11-01

    We propose a novel class of atomic clocks based on highly charged ions. We consider highly forbidden laser-accessible transitions within the 4f(12) ground-state configurations of highly charged ions. Our evaluation of systematic effects demonstrates that these transitions may be used for building exceptionally accurate atomic clocks which may compete in accuracy with recently proposed nuclear clocks. PMID:23215265

  15. Secondary ion coincidence in highly charged ion based secondary ion mass spectroscopy for process characterization

    SciTech Connect

    Hamza, A.V.; Schenkel, T.; Barnes, A.V.; Schneider, D.H.

    1999-01-01

    Coincidence counting in highly charged ion based secondary ion mass spectroscopy has been applied to the characterization of selective tungsten deposition via disilane reduction of tungsten hexafluoride on a patterned SiO{sub 2}/Si wafer. The high secondary ion yield and the secondary ion emission from a small area produced by highly charged ions make the coincidence technique very powerful.

  16. An Acoustic Charge Transport Imager for High Definition Television

    NASA Technical Reports Server (NTRS)

    Hunt, William D.; Brennan, Kevin; May, Gary; Glenn, William E.; Richardson, Mike; Solomon, Richard

    1999-01-01

    This project, over its term, included funding to a variety of companies and organizations. In addition to Georgia Tech these included Florida Atlantic University with Dr. William E. Glenn as the P.I., Kodak with Mr. Mike Richardson as the P.I. and M.I.T./Polaroid with Dr. Richard Solomon as the P.I. The focus of the work conducted by these organizations was the development of camera hardware for High Definition Television (HDTV). The focus of the research at Georgia Tech was the development of new semiconductor technology to achieve a next generation solid state imager chip that would operate at a high frame rate (I 70 frames per second), operate at low light levels (via the use of avalanche photodiodes as the detector element) and contain 2 million pixels. The actual cost required to create this new semiconductor technology was probably at least 5 or 6 times the investment made under this program and hence we fell short of achieving this rather grand goal. We did, however, produce a number of spin-off technologies as a result of our efforts. These include, among others, improved avalanche photodiode structures, significant advancement of the state of understanding of ZnO/GaAs structures and significant contributions to the analysis of general GaAs semiconductor devices and the design of Surface Acoustic Wave resonator filters for wireless communication. More of these will be described in the report. The work conducted at the partner sites resulted in the development of 4 prototype HDTV cameras. The HDTV camera developed by Kodak uses the Kodak KAI-2091M high- definition monochrome image sensor. This progressively-scanned charge-coupled device (CCD) can operate at video frame rates and has 9 gm square pixels. The photosensitive area has a 16:9 aspect ratio and is consistent with the "Common Image Format" (CIF). It features an active image area of 1928 horizontal by 1084 vertical pixels and has a 55% fill factor. The camera is designed to operate in continuous mode

  17. Depth profile of halide anions under highly charged biological membrane

    NASA Astrophysics Data System (ADS)

    Sung, Woongmo; Wang, Wenjie; Lee, Jonggwan; Vaknin, David; Kim, Doseok

    2015-03-01

    Halide ion (Cl- and I-) distribution under a cationic Langmuir monolayer consisting of 1,2-dipalmitoyl-3 trimethylammonium-propane (DPTAP) molecules was investigated by vibrational sum-frequency generation (VSFG) and X-ray spectroscopy. From VSFG spectra, it was observed that large halide anions (I-) screen surface charge more efficiently so that interfacial water alignment becomes more randomized. On the other hand, number density of ions directly measured by X-ray fluorescence spectroscopy at grazing incidence angle reveals that the ion densities within 6 ~ 8 nm are the same for both I- and Cl-. Since the observed ion densities in both cases are almost equal to the charge density of the DPTAP monolayer, we propose that larger halide anions are attracted closer to the surface making direct binding with the charged headgroups of the molecules in the monolayer, accomplishing charge neutrality in short distance. This direct adsorption of anions also disturbs the monolayer structure both in terms of the conformation of alkyl chains and the vertical configuration of the monolayer, with iodine having the stronger effect. Our study shows that the length scale that ions neutralize a charged interface varies significantly and specifically even between monovalent ions.

  18. High-charge energetic ions generated by intersecting laser pulses

    NASA Astrophysics Data System (ADS)

    Yang, L.; Deng, Z. G.; Yu, M. Y.; Wang, X. G.

    2016-08-01

    Ion acceleration from the interaction of two intersecting intense laser pulses with an overdense plasma is investigated using a three-dimensional particle-in-cell simulation. It is found that, comparing with the single-pulse case, the charge of the resulting energetic ion bunch can be increased by more than an order of magnitude without much loss of quality. Dependence of the ion charge on the interaction parameters, including separation distance and incidence angles of the lasers, is considered. It is shown that the charge of the accelerated ion bunch can be optimized by controlling the degree of laser overlapping. The improved performance can be attributed to the enhanced laser intensity as well as stochastic heating of the accelerated electrons. Since at present the intensity of readily available lasers is limited, the two pulse scheme should be useful for realizing higher laser intensity in order to achieve higher-energy target normal sheath acceleration ions.

  19. High Efficiency, Low Emissions Homogeneous Charge Compression Ignition (HCCI) Engines

    SciTech Connect

    2011-01-31

    This is the final report of the High Efficiency Clean Combustion (HECC) Research Program for the U.S. Department of Energy. Work under this co-funded program began in August 2005 and finished in July 2010. The objective of this program was to develop and demonstrate a low emission, high thermal efficiency engine system that met 2010 EPA heavy-duty on-highway truck emissions requirements (0.2g/bhp-hr NOx, 0.14g/bhp-hr HC and 0.01g/bhp-hr PM) with a thermal efficiency of 46%. To achieve this goal, development of diesel homogenous charge compression ignition (HCCI) combustion was the chosen approach. This report summarizes the development of diesel HCCI combustion and associated enabling technologies that occurred during the HECC program between August 2005 and July 2010. This program showed that although diesel HCCI with conventional US diesel fuel was not a feasible means to achieve the program objectives, the HCCI load range could be increased with a higher volatility, lower cetane number fuel, such as gasoline, if the combustion rate could be moderated to avoid excessive cylinder pressure rise rates. Given the potential efficiency and emissions benefits, continued research of combustion with low cetane number fuels and the effects of fuel distillation are recommended. The operation of diesel HCCI was only feasible at part-load due to a limited fuel injection window. A 4% fuel consumption benefit versus conventional, low-temperature combustion was realized over the achievable operating range. Several enabling technologies were developed under this program that also benefited non-HCCI combustion. The development of a 300MPa fuel injector enabled the development of extended lifted flame combustion. A design methodology for minimizing the heat transfer to jacket water, known as precision cooling, will benefit conventional combustion engines, as well as HCCI engines. An advanced combustion control system based on cylinder pressure measurements was developed. A Well

  20. Space-charge compensation in high-intensity proton rings

    SciTech Connect

    A. Burov, G.W. Foster and V.D. Shiltsev

    2000-09-21

    Recently, it was proposed to use negatively charged electron beams for compensation of beam-beam effects due to protons in the Tevatron collider. The authors show that a similar compensation is possible in space-charge dominated low energy proton beams. The idea has a potential of several-fold increase of the FNAL Booster beam brightness. Best results will be obtained using three electron lenses around the machine circumference, using co-moving electron beam with time structure and profile approximately matched to the proton beam. This technique, if feasible, will be more cost effective than the straightforward alternative of increasing the energy of the injection linac.

  1. Work Towards Experimental Evidence Of Hard X-Ray Photoionization In Highly Charged Krypton

    SciTech Connect

    Silver, E.; Brickhouse, N. S.; Kirby, K.; Lin, T.; Gillaspy, J. D.; Gokhale, P.; Kanter, E. P.; Dunford, R. W.; Seifert, S.; Young, L.; McDonald, J.; Schneider, D.

    2011-06-01

    Ions of almost any charge state can be produced through electron-impact ionization. Here we describe our first experiments designed to photoionize these highly charged ions with hard x-rays by pairing an electron and photon beam. A spectral line at 12.7(1) keV with an intensity corroborated by theory may be the first evidence of hard x-ray photoionization of a highly charged ion.

  2. Work toward experimental evidence of hard x-ray photoionization in highly charged krypton.

    SciTech Connect

    Silver, E.; Gillaspy, J.D.; Gokhale, P.; Kanter, E.P.; Brickhouse, N.S.; Dunford, R.W.; Kirby, K.; Lin, T.; McDonald, J.; Schneider, D.; Seifert, S.; Young, L.

    2011-06-01

    Ions of almost any charge state can be produced through electron-impact ionization. Here we describe our first experiments designed to photoionize these highly charged ions with hard x-rays by pairing an electron and photon beam. A spectral line at 12.7(1) keV with an intensity corroborated by theory may be the first evidence of hard x-ray photoionization of a highly charged ion.

  3. EUV spectroscopy of highly charged high Z ions in the Large Helical Device plasmas

    NASA Astrophysics Data System (ADS)

    Suzuki, C.; Koike, F.; Murakami, I.; Tamura, N.; Sudo, S.; Sakaue, H. A.; Nakamura, N.; Morita, S.; Goto, M.; Kato, D.; Nakano, T.; Higashiguchi, T.; Harte, C. S.; OʼSullivan, G.

    2014-11-01

    We present recent results on the extreme ultraviolet (EUV) spectroscopy of highly charged high Z ions in plasmas produced in the Large Helical Device (LHD) at the National Institute for Fusion Science. Tungsten, bismuth and lanthanide elements have recently been studied in the LHD in terms of their importance in fusion research and EUV light source development. In relatively low temperature plasmas, quasicontinuum emissions from open 4d or 4f subshell ions are predominant in the EUV region, while the spectra tend to be dominated by discrete lines from open 4s or 4p subshell ions in higher temperature plasmas. Comparative analyses using theoretical calculations and charge-separated spectra observed in an electron beam ion trap have been performed to achieve better agreement with the spectra measured in the LHD. As a result, databases on Z dependence of EUV spectra in plasmas have been widely extended.

  4. The interactions of high-energy, highly-charged ions with fullerenes

    SciTech Connect

    Ali, R.; Berry, H.G.; Cheng, S.

    1996-03-01

    In 1985, Robert Curl and Richard Smalley discovered a new form of carbon, the fullerene, C{sub 60}, which consists of 60 carbon atoms in a closed cage resembling a soccer ball. In 1990, Kritschmer et al. were able to make macroscopic quantities of fullerenes. This has generated intense activity to study the properties of fullerenes. One area of research involves collisions between fullerenes and atoms, ions or electrons. In this paper we describe experiments involving interactions between fullerenes and highly charged ions in which the center-of-mass energies exceed those used in other work by several orders of magnitude. The high values of projectile velocity and charge state result in excitation and decay processes differing significantly from those seen in studies 3 at lower energies. Our results are discussed in terms of theoretical models analogous to those used in nuclear physics and this provides an interesting demonstration of the unity of physics.

  5. HIGH CURRENT D- PRODUCTION BY CHARGE EXCHANGE IN SODIUM

    SciTech Connect

    Hooper, E.B.; Poulsen, P.; Pincosy, P.A.

    1981-02-01

    A beam of D{sup -} ions has been produced at 7-13 keV, with currents up to 2.2 {angstrom}, using charge exchange in sodium vapor. The beam profile is bi-Gaussian with angular divergence 0.7{sup o} x 2.8{sup o} and peak current density 15 mA/cm{sup 2}. The characteristics of the beam are in excellent agreement with predictions based on atomic cross sections. The sodium vapor target is formed by a jet directed across the beam. The sodium density drops rapidly in the beamline downstream from the charge exchange region, decreasing three orders of magnitude in 15 cm. Measurement and analysis of the plasma accompanying the beam demonstrate that plasma densities nearly equal to the beam density are obtained 1 m from the charge exchange medium. The plasma produced in the sodium is thus well confined to the charge exchange region and does not propagate along the beam.

  6. Miniaturized high-resolution mass/charge spectrograph /design study/

    NASA Technical Reports Server (NTRS)

    Taylor, L. H.

    1969-01-01

    Use of a double-focusing mass/charge spectrograph weighing less than 25 pounds is feasible for solar wind experiments. Instrument has a parallel-plate energy filter between the ion source and the double focusing units which alleviates the problem of designing an ion source of small energy spread.

  7. A compact, high-voltage pulsed charging system based on an air-core pulse transformer.

    PubMed

    Zhang, Tianyang; Chen, Dongqun; Liu, Jinliang; Liu, Chebo; Yin, Yi

    2015-09-01

    Charging systems of pulsed power generators on mobile platforms are expected to be compact and provide high pulsed power, high voltage output, and high repetition rate. In this paper, a high-voltage pulsed charging system with the aforementioned characteristics is introduced, which can be applied to charge a high-voltage load capacitor. The operating principle of the system and the technical details of the components in the system are described in this paper. The experimental results show that a 600 nF load capacitor can be charged to 60 kV at 10 Hz by the high-voltage pulsed charging system for a burst of 0.5 s. The weight and volume of the system are 60 kg and 600 × 500 × 380 mm(3), respectively. PMID:26429466

  8. Charge Identification of Highly Ionizing Particles in Desensitized Nuclear Emulsion Using High Speed Read-Out System

    SciTech Connect

    Toshito, T.; Kodama, K.; Yusa, K.; Ozaki, M.; Amako, K.; Kameoka, S.; Murakami, K.; Sasaki, T.; Aoki, S.; Ban, T.; Fukuda, T.; Naganawa, N.; Nakamura, T.; Natsume, M.; Niwa, K.; Takahashi, S.; Kanazawa, M.; Kanematsu, N.; Komori, M.; Sato, S.; Asai, M.; /Nagoya U. /Aichi U. of Education /Gunma U., Maebashi /JAXA, Sagamihara /KEK, Tsukuba /Kobe U. /Chiba, Natl. Inst. Rad. Sci. /SLAC /Toho U.

    2006-05-10

    We performed an experimental study of charge identification of heavy ions from helium to carbon having energy of about 290 MeV/u using an emulsion chamber. Emulsion was desensitized by means of forced fading (refreshing) to expand a dynamic range of response to highly charged particles. For the track reconstruction and charge identification, the fully automated high speed emulsion read-out system, which was originally developed for identifying minimum ionizing particles, was used without any modification. Clear track by track charge identification up to Z=6 was demonstrated. The refreshing technique has proved to be a powerful technique to expand response of emulsion film to highly ionizing particles.

  9. Surface modification on highly oriented pyrolytic graphite by slow highly charged ions

    NASA Astrophysics Data System (ADS)

    Baba, Yukari; Nagata, Kazuo; Takahashi, Satoshi; Nakamura, Nobuyuki; Yoshiyasu, Nobuo; Sakurai, Makoto; Yamada, Chikashi; Ohtani, Shunsuke; Tona, Masahide

    2005-12-01

    We have investigated surface modification by highly charged ions (HCIs) on highly oriented pyrolytic graphite (HOPG) surfaces with Raman spectroscopy and scanning tunneling microscopy. The xenon-HCIs having various charges up to 48+ were incident on HOPG samples with an identical collision velocity (5 × 10 5 m/s). In Raman spectra, disorder induced peaks (D peak) appeared around 1355 cm -1 in addition to narrower, persistent peaks (G peak) at 1580 cm -1 which are characteristic of unirradiated HOPG. The intensity ratio of the D peak to the G peak is much larger than that of HOPG irradiated with singly charged ions (SCIs) at the same fluence. By the annealing treatment, the intensity of the D peak decreased as small as practically unobservable. In the microscopic observation, on the other hand, protrusion nanostructures induced by HCI impacts did not disappear completely although their volume decreased drastically. From such relaxation dynamics, it is made clear that not only point and dimmer vacancies which is created in common with SCI irradiation, but also "cluster vacancies" are formed at the surface and subsurface.

  10. Ionization of highly charged iodine ions near the Bohr velocity

    NASA Astrophysics Data System (ADS)

    Zhou, Xianming; Cheng, Rui; Lei, Yu; Sun, Yuanbo; Ren, Jieru; Liu, Shidong; Deng, Jiachuan; Zhao, Yongtao; Xiao, Guoqing

    2015-01-01

    We have measured the L-shell X-rays of iodine from the collisions of 3 MeV Iq+(q=15,20,22,25,26) ions with an iron target. It is found that the X-ray yield decreases with the increasing initial charge state. The energy of the subshell X-ray has a blue shift, which is independent of the projectile charge state. In addition, the relative intensity ratios of Lβ1,3,4 and Lβ2,15 to Lα1,2 X-ray are obtained and compared with the theoretical calculations. That they are larger than for a singly ionized atom can be understood by the multiple ionization effect of the outer-shell electrons.

  11. High load operation in a homogeneous charge compression ignition engine

    SciTech Connect

    Duffy, Kevin P.; Kieser, Andrew J.; Liechty, Michael P.; Hardy, William L.; Rodman, Anthony; Hergart, Carl-Anders

    2008-12-23

    A homogeneous charge compression ignition engine is set up by first identifying combinations of compression ratio and exhaust gas percentages for each speed and load across the engines operating range. These identified ratios and exhaust gas percentages can then be converted into geometric compression ratio controller settings and exhaust gas recirculation rate controller settings that are mapped against speed and load, and made available to the electronic

  12. HIGH CHARGE EFFECTS IN SILICON DRIFT DETECTORS WITH LATERAL CONFINEMENT OF ELECTRONS.

    SciTech Connect

    CASTOLDI,A.; REHAK,P.

    1995-10-21

    A new drift detector prototype which provides suppression of the lateral diffusion of electrons has been tested as a function of the signal charge up to high charge levels, when electrostatic repulsion is not negligible. The lateral diffusion of the electron cloud has been measured for injected charges up to 2 {center_dot} 10{sup 5} electrons. The maximum number of electrons for which the suppression of the lateral spread is effective is obtained.

  13. Treatment of long-term stored DNA--comparison between different methods to obtain high-quality material.

    PubMed

    de Almeida, Máira Pedroso; do Nascimento, Carlos Souza; Périssé, Iuri Viotti; de Souza Duarte, Marcio; Veroneze, Renata; Facioni Guimarães, Simone E

    2013-11-01

    Long-term stored DNA can be sometimes the only source of genetic material of an organism that does not exist anymore, but a research interest still persists. However, there is a lack of information about useful methods to improve quality from such type of material. In this study, we compared four different protocols using DNA samples collected in 1998. Fresh DNA was also tested aiming to check the differences between these two material types. Sixteen samples of each DNA type treated with phenol-chloroform with PEG 5.0%, silica-gel membrane spin column, PEG 7.5%, and glass-fiber matrix spin column were submitted to spectrophotometer measurements, electrophoresis, PCR, and RFLP-PCR to assess the best method concerning yield, quality, and purity. Based on the results, purification with PEG 7.5% was considered the best method to treat aged DNA samples. In addition to the efficiency, this protocol has low cost. Analyzing the data, we also conclude that long-term stored DNA may be considered a reliable and potential resource for future molecular studies. PMID:23893799

  14. Highly charged ion induced nanostructures at surfaces by strong electronic excitations

    NASA Astrophysics Data System (ADS)

    Wilhelm, Richard A.; El-Said, Ayman S.; Krok, Franciszek; Heller, René; Gruber, Elisabeth; Aumayr, Friedrich; Facsko, Stefan

    2015-08-01

    Nanostructure formation by single slow highly charged ion impacts can be associated with high density of electronic excitations at the impact points of the ions. Experimental results show that depending on the target material these electronic excitations may lead to very large desorption yields in the order of a few 1000 atoms per ion or the formation of nanohillocks at the impact site. Even in ultra-thin insulating membranes the formation of nanometer sized pores is observed after ion impact. In this paper, we show recent results on nanostructure formation by highly charged ions and compare them to structures and defects observed after intense electron and light ion irradiation of ionic crystals and graphene. Additional data on energy loss, charge exchange and secondary electron emission of highly charged ions clearly show that the ion charge dominates the defect formation at the surface.

  15. High Charge State Ions Extracted from Metal Plasmas in the Transition Regime from Vacuum Spark to High Current Vacuum Arc

    SciTech Connect

    Yushkov, Georgy Yu.; Anders, A.

    2008-06-19

    Metal ions were extracted from pulsed discharge plasmas operating in the transition region between vacuum spark (transient high voltage of kV) and vacuum arc (arc voltage ~;; 20 V). At a peak current of about 4 kA, and with a pulse duration of 8 ?s, we observed mean ion charges states of about 6 for several cathode materials. In the case of platinum, the highest average charge state was 6.74 with ions of charge states as high as 10 present. For gold we found traces of charge state 11, with the highest average charge state of 7.25. At currents higher than 5 kA, non-metallic contaminations started to dominate the ion beam, preventing further enhancement of the metal charge states.

  16. High charged red pigment nanoparticles for electrophoretic displays

    NASA Astrophysics Data System (ADS)

    Hou, Xin-Yan; Bian, Shu-Guang; Chen, Jian-Feng; Le, Yuan

    2012-12-01

    Organic pigment permanent red F2R nanoparticles were prepared via surface modification to improve the surface charge and dispersion ability in organic medium. Their large surface chargeability is confirmed by ζ-potential value of -49.8 mV. The prepared particles exhibited average size of 105 nm and showed very narrow distribution with polydispersity index of 0.068. The sedimentation ratio of the prepared particles in tetrachloroethylene was less than 5% within 12 days. The electrophoretic inks consisting of the prepared red particles with white particles as contrast showed good electrophoretic display, its refresh time was 200 ms.

  17. Numerical calculations of high-altitude differential charging: Preliminary results

    NASA Technical Reports Server (NTRS)

    Laframboise, J. G.; Godard, R.; Prokopenko, S. M. L.

    1979-01-01

    A two dimensional simulation program was constructed in order to obtain theoretical predictions of floating potential distributions on geostationary spacecraft. The geometry was infinite-cylindrical with angle dependence. Effects of finite spacecraft length on sheath potential profiles can be included in an approximate way. The program can treat either steady-state conditions or slowly time-varying situations, involving external time scales much larger than particle transit times. Approximate, locally dependent expressions were used to provide space charge, density profiles, but numerical orbit-following is used to calculate surface currents. Ambient velocity distributions were assumed to be isotropic, beam-like, or some superposition of these.

  18. Generation of Initial Kinetic Distributions for Simulation of Long-Pulse Charged Particle Beams with High Space-Charge intensity

    SciTech Connect

    Lund, Steven M.; Kikuchi, Takashi; Davidson, Ronald C.

    2007-04-03

    Self-consistent Vlasov-Poisson simulations of beams with high space-charge intensity often require specification of initial phase-space distributions that reflect properties of a beam that is well adapted to the transport channel--both in terms of low-order rms (envelope) properties as well as the higher-order phase-space structure. Here, we first review broad classes of kinetic distributions commonly in use as initial Vlasov distributions in simulations of unbunched or weakly bunched beams with intense space-charge fields including: the Kapchinskij-Vladimirskij (KV) equilibrium, continuous-focusing equilibria with specific detailed examples, and various non-equilibrium distributions, such as the semi-Gaussian distribution and distributions formed from specified functions of linear-field Courant-Snyder invariants. Important practical details necessary to specify these distributions in terms of usual accelerator inputs are presented in a unified format. Building on this presentation, a new class of approximate initial kinetic distributions are constructed using transformations that preserve linear-focusing single-particle Courant-Snyder invariants to map initial continuous-focusing equilibrium distributions to a form more appropriate for non-continuous focusing channels. Self-consistent particle-in-cell simulations are employed to show that the approximate initial distributions generated in this manner are better adapted to the focusing channels for beams with high space-charge intensity. This improved capability enables simulation applications that more precisely probe intrinsic stability properties and machine performance.

  19. Generation of initial Vlasov distributions for simulation of charged particle beams with high space-charge intensity

    SciTech Connect

    Lund, S M; Kikuchi, T; Davidson, R C

    2007-04-12

    Self-consistent Vlasov simulations of beams with high space-charge intensity often require specification of initial phase-space distributions that reflect properties of a beam that is well adapted to the transport channel, both in terms of low-order rms (envelope) properties as well as the higher-order phase-space structure. Here, we first review broad classes of distributions commonly in use as initial Vlasov distributions in simulations of beams with intense space-charge fields including: the Kapchinskij-Vladimirskij (KV) equilibrium, continuous-focusing equilibria with specific detailed examples, and various non-equilibrium distributions, such as the semi-Gaussian distribution and distributions formed from specified functions of linear-field Courant-Snyder invariants. Important practical details necessary to specify these distributions in terms of usual accelerator inputs are presented in a unified format. Building on this presentation, a new class of approximate initial distributions are constructed using transformations that preserve linear-focusing single-particle Courant-Snyder invariants to map initial continuous-focusing equilibrium distributions to a form more appropriate for non-continuous focusing channels. Self-consistent particle-in-cell simulations are employed to show that the approximate initial distributions generated in this manner are better adapted to the focusing channels for beams with high space-charge intensity. This improved capability enables simulation applications that more precisely probe intrinsic stability properties and machine performance.

  20. The explicit token store

    SciTech Connect

    Culler, D.E. ); Papadopoulos, G.M. )

    1990-12-01

    This paper presents an unusually simple approach to dynamic dataflow execution, called the Explicit Token Store (ETS) architecture, and its current realization in Monsoon. The essence of dynamic dataflow execution is captured by a simple transition on state bits associated with storage local to a processor. Low-level storage management is performed by the compiler in assigning nodes to slots in an activation frame, rather than dynamically in hardware. The processor is simple, highly pipelined, and quite general. There is exactly one instruction executed for each action on the dataflow graph. Thus, the machine-oriented ETS model provides new insight into the real cost of direct execution of dataflow graphs.

  1. Kinetic-energy transfer in highly-charged-ion collisions with carbon

    NASA Astrophysics Data System (ADS)

    Lake, R. E.; Arista, N. R.

    2015-11-01

    We present an accurate theoretical model for the charge dependence of kinetic energy transferred in collisions between slow highly charged ions (HCIs) and the atoms in a carbon solid. The model is in excellent agreement with experimental kinetic-energy-loss data for carbon nanomembrane and thin carbon foil targets. This study fills a notable gap in the literature of charged-particle energy loss in the regime of low incident velocity (vp≲2.188 ×106 m/s) where charge states greatly exceed the equilibrium values.

  2. Physical limits for high ion charge states in pulsed discharges in vacuum

    SciTech Connect

    Yushkov, Georgy; Anders, Andre

    2008-12-23

    Short-pulse, high-current discharges in vacuum were investigated with the goal to maximize the ion charge state number. In a direct extension of previous work [Appl. Phys. Lett. 92, 041502 (2008)], the role of pulse length, rate of current rise, and current amplitude was studied. For all experimental conditions, the usable (extractable) mean ion charge state could not be pushed beyond 7+. Instead, a maximum of the mean ion charge state (about 6+ to 7+ for most cathode materials) was found for a power of 2-3 MW dissipated in the discharge gap. The maximum is the result of two opposing processes that occur when the power is increased: (i) the formation of higher ion charge states, and (ii) a greater production of neutrals (both metal and non-metal), which reduces the charge state via charge exchange collisions.

  3. Physical limits for high ion charge states in pulsed discharges in vacuum

    SciTech Connect

    Yushkov, Georgy Yu.; Anders, Andre

    2009-02-15

    Short-pulse high-current discharges in vacuum were investigated with the goal to maximize the ion charge state number. In a direct extension of previous work [G. Y. Yushkov and A. Anders, Appl. Phys. Lett. 92, 041502 (2008)], the role of pulse length, rate of current rise, and current amplitude was studied. For all experimental conditions, the usable (extractable) mean ion charge state could not be pushed beyond 7+. Instead, a maximum of the mean ion charge state (about 6+ to 7+ for most cathode materials) was found for a power of 2-3 MW dissipated in the discharge gap. The maximum is the result of two opposing processes that occur when the power is increased: (i) the formation of higher ion charge states and (ii) a greater production of neutrals (both metal and nonmetal), which reduces the charge state via charge exchange collisions.

  4. Solar photovoltaic charging of high voltage nickel metal hydride batteries using DC power conversion

    NASA Astrophysics Data System (ADS)

    Kelly, Nelson A.; Gibson, Thomas L.

    There are an increasing number of vehicle choices available that utilize batteries and electric motors to reduce tailpipe emissions and increase fuel economy. The eventual production of electricity and hydrogen in a renewable fashion, such as using solar energy, can achieve the long-term vision of having no tailpipe environmental impact, as well as eliminating the dependence of the transportation sector on dwindling supplies of petroleum for its energy. In this report we will demonstrate the solar-powered charging of the high-voltage nickel-metal hydride (NiMH) battery used in the GM 2-mode hybrid system. In previous studies we have used low-voltage solar modules to produce hydrogen via the electrolysis of water and to directly charge lithium-ion battery modules. Our strategy in the present work was to boost low-voltage PV voltage to over 300 V using DC-DC converters in order to charge the high-voltage NiMH battery, and to regulate the battery charging using software to program the electronic control unit supplied with the battery pack. A protocol for high-voltage battery charging was developed, and the solar to battery charging efficiency was measured under a variety of conditions. We believe this is the first time such high-voltage batteries have been charged using solar energy in order to prove the concept of efficient, solar-powered charging for battery-electric vehicles.

  5. Production of Highly Charged Pharmaceutical Aerosols Using a New Aerosol Induction Charger

    PubMed Central

    Golshahi, Laleh; Longest, P. Worth; Holbrook, Landon; Snead, Jessica; Hindle, Michael

    2015-01-01

    Purpose Properly charged particles can be used for effective lung targeting of pharmaceutical aerosols. The objective of this study was to characterize the performance of a new induction charger that operates with a mesh nebulizer for the production of highly charged submicrometer aerosols to bypass the mouth-throat and deliver clinically relevant doses of medications to the lungs. Methods Variables of interest included combinations of model drug (i.e. albuterol sulfate) and charging excipient (NaCl) as well as strength of the charging field (1–5 kV/cm). Aerosol charge and size were measured using a modified electrical low pressure impactor system combined with high performance liquid chromatography. Results At the approximate mass median aerodynamic diameter (MMAD) of the aerosol (~ 0.4 μm), the induction charge on the particles was an order of magnitude above the field and diffusion charge limit. The nebulization rate was 439.3 ± 42.9 μl/min, which with a 0.1 % w/v solution delivered 419.5 ± 34.2 μg of medication per minute. A new correlation was developed to predict particle charge produced by the induction charger. Conclusions The combination of the aerosol induction charger and predictive correlations will allow for the practical generation and control of charged submicrometer aerosols for targeting deposition within the lungs. PMID:25823649

  6. Detection of charge storage on molecular thin films of tris(8-hydroxyquinoline) aluminum (Alq3) by Kelvin force microscopy: a candidate system for high storage capacity memory cells.

    PubMed

    Paydavosi, Sarah; Aidala, Katherine E; Brown, Patrick R; Hashemi, Pouya; Supran, Geoffrey J; Osedach, Timothy P; Hoyt, Judy L; Bulović, Vladimir

    2012-03-14

    Retention and diffusion of charge in tris(8-hydroxyquinoline) aluminum (Alq(3)) molecular thin films are investigated by injecting electrons and holes via a biased conductive atomic force microscopy tip into the Alq(3) films. After the charge injection, Kelvin force microscopy measurements reveal minimal changes with time in the spatial extent of the trapped charge domains within Alq(3) films, even for high hole and electron densities of >10(12) cm(-2). We show that this finding is consistent with the very low mobility of charge carriers in Alq(3) thin films (<10(-7) cm(2)/(Vs)) and that it can benefit from the use of Alq(3) films as nanosegmented floating gates in flash memory cells. Memory capacitors using Alq(3) molecules as the floating gate are fabricated and measured, showing durability over more than 10(4) program/erase cycles and the hysteresis window of up to 7.8 V, corresponding to stored charge densities as high as 5.4 × 10(13) cm(-2). These results demonstrate the potential for use of molecular films in high storage capacity nonvolatile memory cells. PMID:22332966

  7. Effects of high CO₂ levels on fermentation, peroxidation, and cellular water stress in Fragaria vesca stored at low temperature in conditions of unlimited O₂.

    PubMed

    Blanch, Maria; Rosales, Raquel; Mateos, Raquel; Perez-Gago, María B; Sanchez-Ballesta, Maria T; Escribano, María I; Merodio, Carmen

    2015-01-28

    To better understand the tolerance of strawberries (Fragaria vesca L.) to high CO2 in storage atmospheres, fermentation and cellular damage were investigated. Fruits were stored for 3 and 6 days at 0 °C in the presence of different CO2 levels (0, 20, or 40%) with 20% O2. Changes in pyruvate decarboxylase (PDC) and alcohol dehydrogenase (ADH) gene expression and in fermentative metabolites, as well as in bound water and malondialdehyde (MDA) concentrations, were analyzed. In strawberries stored without added CO2, up-regulation of PDC and ADH was not associated with an increase in fermentative metabolites. By contrast, moderate ethanol fermentation in fruits exposed to 20% CO2 seems to be essential to maintain fruit metabolism, reducing both lipid peroxidation and cellular water stress. However, if the CO2 concentration increases (40%), the excess acetaldehyde and ethanol produced were closely correlated with a decrease in bound water and production of MDA. PMID:25568930

  8. Coulomb crystals in a cryogenic Paul trap for sympathetic cooling of molecular ions and highly charged ions

    NASA Astrophysics Data System (ADS)

    Windberger, A.; Schwarz, M.; Versolato, O. O.; Baumann, T.; Bekker, H.; Schmöger, L.; Hansen, A. K.; Gingell, A. D.; Klosowski, L.; Kristensen, S.; Schmidt, P. O.; Ullrich, J.; Drewsen, M.; Crespo López-Urrutia, J. R.

    2013-03-01

    Electron beam ion traps used for spectroscopy of highly charged ions (HCI) produce a deep trapping potential leading to high temperatures of the stored ions, and thus limiting the achievable spectral resolution. A novel device at the Max-Planck-Institut für Kernphysik, the Cryogenic linear Paul Trap Experiment (CryPTEx), attached to an electron beam ion trap, provides a new experimental platform to overcome these limitations. The trap assembly operates at a temperature of 4 K and offers optical access for quantum manipulation and imaging of the trapped ions. Since forbidden optical transitions in HCI do not support direct laser cooling, sympathetic cooling with Coulomb crystals of singly charged ions such as Be+ or Mg+ will be applied in order to reach the natural linewidth of optical forbidden transitions in HCI of interest. With the added advantage of long ion trapping times resulting from residual gas pressures of H2 at 4 K below 10-15 mbar, CryPTEx has been commissioned in collaboration with the Ion Trap Group in Århus using rovibrationally cooled MgH+ ions. Strong suppression of the black body radiation at the trap center, ion storage times of about 28 hours, and largely enhanced population of the rovibrational ground state were achieved.

  9. High intensity high charge state ion beam production with an evaporative cooling magnet ECRIS.

    PubMed

    Lu, W; Qian, C; Sun, L T; Zhang, X Z; Fang, X; Guo, J W; Yang, Y; Feng, Y C; Ma, B H; Xiong, B; Ruan, L; Zhao, H W; Zhan, W L; Xie, D

    2016-02-01

    LECR4 (Lanzhou ECR ion source No. 4) is a room temperature electron cyclotron resonance ion source, designed to produce high current, high charge state ion beams for the SSC-LINAC injector (a new injector for sector separated cyclotron) at the Institute of Modern Physics. LECR4 also serves as a PoP machine for the application of evaporative cooling technology in accelerator field. To achieve those goals, LECR4 ECR ion source has been optimized for the operation at 18 GHz. During 2014, LECR4 ion source was commissioned at 18 GHz microwave of 1.6 kW. To further study the influence of injection stage to the production of medium and high charge state ion beams, in March 2015, the injection stage with pumping system was installed, and some optimum results were produced, such as 560 eμA of O(7+), 620 eμA of Ar(11+), 430 eμA of Ar(12+), 430 eμA of Xe(20+), and so on. The comparison will be discussed in the paper. PMID:26931956

  10. High intensity high charge state ion beam production with an evaporative cooling magnet ECRIS

    NASA Astrophysics Data System (ADS)

    Lu, W.; Qian, C.; Sun, L. T.; Zhang, X. Z.; Fang, X.; Guo, J. W.; Yang, Y.; Feng, Y. C.; Ma, B. H.; Xiong, B.; Ruan, L.; Zhao, H. W.; Zhan, W. L.; Xie, D.

    2016-02-01

    LECR4 (Lanzhou ECR ion source No. 4) is a room temperature electron cyclotron resonance ion source, designed to produce high current, high charge state ion beams for the SSC-LINAC injector (a new injector for sector separated cyclotron) at the Institute of Modern Physics. LECR4 also serves as a PoP machine for the application of evaporative cooling technology in accelerator field. To achieve those goals, LECR4 ECR ion source has been optimized for the operation at 18 GHz. During 2014, LECR4 ion source was commissioned at 18 GHz microwave of 1.6 kW. To further study the influence of injection stage to the production of medium and high charge state ion beams, in March 2015, the injection stage with pumping system was installed, and some optimum results were produced, such as 560 eμA of O7+, 620 eμA of Ar11+, 430 eμA of Ar12+, 430 eμA of Xe20+, and so on. The comparison will be discussed in the paper.

  11. Emission Spectroscopy of Highly Charged Ions in Plasma of an Electron Beam Ion Trap

    SciTech Connect

    Draganic, I.; Crespo Lopez-Urrutia, J.R.; Soria Orts, R.; Ullrich, J.; DuBois, R.; Shevelko, V.; Fritzsche, S.; Zou, Y.

    2004-12-01

    The results of experimental study of magnetic dipole (M1) transitions in highly charged ions of argon (Ar9+, Ar10+, Ar13+ and Ar14+) and krypton (Kr18+ and Kr22+) are presented. The forbidden transitions of the highly charged ions in the visible and near UV range of the photon emission spectra have been measured with accuracy better than 1 ppm. Our measurements for the 'coronal lines' are the most accurate yet reported using an EBIT as a spectroscopic source of highly charged ions. These precise wavelength determinations provide a useful test and challenge for atomic structure calculations of many-electron systems.

  12. Effects of Slow Highly Charged Ion Impact Upon Highly Oriented Pyrolytic Graphite

    NASA Astrophysics Data System (ADS)

    Meguro, Takashi

    Nanoscale modification of electronic states of highly oriented pyrotytic graphite (HOPG) surfaces induced by the impact of slow highly charged ion (HCI) is reviewed. The high potential energy of slow Ar8+ induces multiple emission of electrons from the surface, which strongly modifies the electronic states of the local area of HOPG surfaces. The size of created protrusions created by the Ar8+-impact with 400 eV of the kinetic energy was about 1 nm in diameter, and the subsequent surface treatment by electron injection from a scanning tunneling microscope (STM) induced a localized transition from sp2 to sp3 hybridization at the center of the protrusion, which considered to result in the formation of nano-diamond-like structures.

  13. An acoustic charge transport imager for high definition television applications

    NASA Technical Reports Server (NTRS)

    Hunt, William D.; Brennan, Kevin F.; Summers, Christopher J.

    1993-01-01

    This report covers: (1) invention of a new, ultra-low noise, low operating voltage APD which is expected to offer far better performance than the existing volume doped APD device; (2) performance of a comprehensive series of experiments on the acoustic and piezoelectric properties of ZnO films sputtered on GaAs which can possibly lead to a decrease in the required rf drive power for ACT devices by 15dB; (3) development of an advanced, hydrodynamic, macroscopic simulator used for evaluating the performance of ACT and CTD devices and aiding in the development of the next generation of devices; (4) experimental development of CTD devices which utilize a p-doped top barrier demonstrating charge storage capacity and low leakage currents; (5) refinements in materials growth techniques and in situ controls to lower surface defect densities to record levels as well as increase material uniformity and quality.

  14. On the nature of high field charge transport in reinforced silicone dielectrics: Experiment and simulation

    NASA Astrophysics Data System (ADS)

    Huang, Yanhui; Schadler, Linda S.

    2016-08-01

    The high field charge injection and transport properties in reinforced silicone dielectrics were investigated by measuring the time-dependent space charge distribution and the current under dc conditions up to the breakdown field and were compared with the properties of other dielectric polymers. It is argued that the energy and spatial distribution of localized electronic states are crucial in determining these properties for polymer dielectrics. Tunneling to localized states likely dominates the charge injection process. A transient transport regime arises due to the relaxation of charge carriers into deep traps at the energy band tails and is successfully verified by a Monte Carlo simulation using the multiple-hopping model. The charge carrier mobility is found to be highly heterogeneous due to the non-uniform trapping. The slow moving electron packet exhibits a negative field dependent drift velocity possibly due to the spatial disorder of traps.

  15. Highly-charged heavy-ion production with short pulse lasers

    SciTech Connect

    Logan, G.; Bitmire, T.; Perry, M.; Anderson, O.; Kuehl, T.

    1998-01-27

    This MathCAD document describes a possible approach using a PW -class short pulse laser to form a useful number (10{sup 12}) of high and uniform charge state ions with low ion temperature (<< 100 eV) and low momentum spread ({delta}p{sub z}/p, < 10{sup -4} ) for injection into heavy-ion fusion accelerators. As a specific example, we consider here Xenon{sup +26}, which has an ionization energy E{sub i} {approximately} 860 eV for the 26th electron, and a significantly higher ionization potential of 1500 eV for the 27th electron because of the M-shell jump. The approach considered here may be used for other ion species as well. The challenge is not simply to produce high charge states with a laser (the ITEP group [Sharkov] have used long pulse CO{sub 2} lasers to create many charge states of chromium up to helium-like Cr{sup +25} by collisional ionization at high Te), nor just to create such high charge states more selectively by field (tunneling) ionization at higher intensities and shorter pulses. Rather, the challenge is to create a selected uniform high charge state, in useful numbers, while keeping the ion temperature and momentum spread small, and avoiding subsequent loss of ion charge state due to recombination and charge-exchange with background gas atoms during extraction into a useful low emittance beam.

  16. A high-charge-state plasma neutralizer for an energetic H/sup -/ beam

    SciTech Connect

    Schlachter, A.S.; Leung, K.N.; Stearns, J.W.; Olson, R.E.

    1986-10-01

    A high-charge-state plasma neutralizer for a beam of energetic H/sup -/ ions offers the potential of high optimum neutralization efficiency (approx.85%) relative to a gas target (50 to 60%), and considerably reduced target thickness. We have calculated cross sections for charge-changing interactions of fast H/sup -/ and H/sup 0/ in collision with highly charged ions using a semiclassical model for H/sup -/, and the Classical-Trajectory Monte Carlo method plus Born calculations, to obtain correct asymptotic cross sections in the high-energy limit. Charge-state fractions as a function of plasma line density, and f/sub 0//sup max/, the maximum H/sup 0/ fraction, are calculated using these cross sections; we find that f/sub 0//sup mx/ approx. = 85% for ion charge states in the range 1+ to 10+, and that target ion line density for f/sub 0//sup max/ decreases approximately as the square of the plasma ion charge state. The maximum neutral fraction is also high for a partially ionized plasma. We have built a small multicusp plasma generator to use a a plasma neutralizer; preliminary results show that the plasma contains argon ions with an average charge state between 2+ and 3+ for a steady-state discharge.

  17. Isotope-Shift Measurement of High-energy Highly Charged Ion Beams

    NASA Astrophysics Data System (ADS)

    Ozawa, S.; Ariga, T.; Inabe, N.; Kase, M.; Tanihata, I.; Wakasugi, M.; Yano, Y.

    2001-10-01

    Isotope-shift measurement by the laser spectroscopic method was aimed to apply for radioactive isotope beams up to uranium created by projectile fragmentation at RIKEN RI beam factory (T. Katayama, et al.,): Nucl. Phys., A626, 545c (1997).to make a systematic study of the mean square nuclear charge radii. The present work was started to verify the feasibility of the method. Projectile fragments are high-energy highly charged ions and weak currents. Therefore we designed ultralow-background photon-detection system (M. Wakasugi, et al.,): Nucl. Instr. and Meth., A419, 50 (1998).for collinear laser spectroscopy of such ion beams. To demonstrate isotope-shift measurement, we measured precisely the 1s2s ^3S_1-1s2p ^3P_0,1,2 transition energy of He-like ^12C ion accelerated up to 0.9 MeV/u and ^13C ion 0.6 MeV/u. For the precision measurement, the uncertainty coming from the ambiguity in the absolute ion beam velocity was suppressed by means of that the resonance energy was measured by two laser beams which propagate in parallel and anti-parallel directions to the ion beam. As the result, isotope shifts of these transitions were obtained with the accuracy of 10 %. The lower limit of the ion-beam intensity for the measurement is estimated to be 2000 ions/s.

  18. High-speed, high-resolution observations of shaped-charge jets undergoing particulation

    SciTech Connect

    Winer, K.; Breithaupt, D.; Shaw, L.; Muelder, S.; Baum, D.

    1995-02-28

    Image-converter (IC) camera photography has provided spectacular images and quantitative records of liner collapse and early jet formation in shaped charges. We have extended the application of the IC camera to observations of shaped charge jet surfaces undergoing particulation. Sequential, high-resolution photographs were taken following the same 10-cm portion of jet at 2.5-{mu}s intervals. Simultaneous color rotating-mirror framing camera photographs and 450-keV flash x-ray radiographs were also taken of the same region. This combination provides a detailed record of the evolution of surface structure during jet necking and particulation. In the high-resolution photographs, individual features on the jet surfaces as small as {approximately}100 {mu}m can easily be detected and followed as they evolve over time. The jet surface structure is rough with overlapping slip dislocation lines running along the surface at 45{degree} to either side of the jet axis. This is similar to the texture that develops in long rods undergoing static tension. We discuss the implications of these images for increasing jet particulation times.

  19. Detonation performance of high-dense BTF charges

    NASA Astrophysics Data System (ADS)

    Dolgoborodov, Alexander; Brazhnikov, Michael; Makhov, Michael; Gubin, Sergey; Maklasova, Irina

    2013-06-01

    New experimental data on detonation wave parameters and explosive performance for benzotrifuroxan (BTF) are presented. Optical pyrometry was applied in order to measure the temperature and pressure of BTF detonation products. Chapman-Jouguet pressure and temperature were obtained as following: 33.8 GPa and 3990 K; 34.5 GPa and 4170 K (initial charge densities 1.82 and 1.84 g/cc respectively), the polytropic exponent was estimated as 2.8. The heat of explosion and acceleration ability were measured also. The results of calorimetric measurements performed in bomb calorimeter indicate that BTF slightly surpasses HMX in the heat of explosion. However BTF is inferior to HMX in the acceleration ability, measured by the method of copper casing expansion. It is also considered the hypothesis of formation of nanocarbon particles in detonation products directly behind the detonation front and influence of this processes on the temperature-time history in detonation products. The results of calculations with in view of formation of liquid nanocarbon in products of a detonation also are presented.

  20. High Temperature Thermosetting Polyimide Nanocomposites Prepared with Reduced Charge Organoclay

    NASA Technical Reports Server (NTRS)

    Campbell, Sandi; Liang, Margaret I.

    2005-01-01

    The naturally occurring sodium and calcium cations found in bentonite clay galleries were exchanged with lithium cations. Following the cation exchange, a series of reduced charge clays were prepared by heat treatment of the lithium bentonite at 130 C, 150 C, or 170 C. Inductively coupled plasma (ICP) analysis showed that heating the lithium clay at elevated temperatures reduced its cation exchange capacity. Ion exchange of heat-treated clays with either a protonated alkyl amine or a protonated aromatic diamine resulted in decreasing amounts of the organic modifier incorporated into the lithium clay. The level of silicate dispersion in a thermosetting polyimide matrix was dependent upon the temperature of Li-clay heat treatment as well as the organic modification. In general, clays treated at 150 C or 170 C, and exchanged with protonated octadcylamine or protonated 2,2'-dimethlybenzidine (DMBZ) showed a higher degree of dispersion than clays treated at 130 C, or exchanged with protonated dodecylamine. Dynamic mechanical analysis showed little change in the storage modulus or T(sub g) of the nanocomposites compared to the base resin. However, long term isothermal aging of the samples showed a significant decrease in the resin oxidative weight loss. Nanocomposite samples aged in air for 1000 hours at 288 C showed of to a decrease in weight loss compared to that of the base resin. This again was dependent on the temperature at which the Li-clay was heated and the choice of organic modification.

  1. Acceleration of high charge density electron beams in the SLAC linac

    SciTech Connect

    Sheppard, J.C.; Clendenin, J.E.; Jobe, R.K.; Lueth, V.G.; Millich, A.; Ross, M.C.; Seeman, J.T.; Stiening, R.F.

    1984-01-01

    The SLAC Linear Collider (SLC) will require both electron and positron beams of very high charge density and low emittance to be accelerated to about 50 GeV in the SLAC 3-km linac. The linac is in the process of being improved to meet this requirement. The program to accelerate an electron beam of high charge density through the first third of the SLC linac is described and the experimental results are discussed. 7 references, 5 figures.

  2. Hematite-NiO/α-Ni(OH)2 heterostructure photoanodes with high electrocatalytic current density and charge storage capacity.

    PubMed

    Bora, Debajeet K; Braun, Artur; Erni, Rolf; Müller, Ulrich; Döbeli, Max; Constable, Edwin C

    2013-08-14

    Control of the water splitting reaction in the context of natural photosynthesis is considered as a Holy Grail of chemistry, particularly with respect to artificial photosynthesis for a sustainable energy economy. The underlying objective is to build a solar fuel generator which is economically viable and environmentally benign. Hydrogen generation by solar water splitting in photoelectrochemical cells (PEC) is currently experiencing a renaissance, and the search for high performance but low-cost photoelectrode materials is an on-going quest. We present here a photoanode heterostructure of hematite and NiO/α-Ni(OH)2, which is very efficient. We prepared the heterostructure by a "two reactor" hydrothermal modification of a pristine hematite film. The system shows promising current density of 16 mA cm(-2), several times higher than that of the pristine hematite film. In addition, the system shows charge storing capacity once exposed to AM 1.5 simulated sunlight, along with electrochromic behaviour. Interestingly, the water splitting proceeds as a dark reaction after several hours of light exposure. The abrupt increase in current density originates from the oxidized Ni(OH)2 layer which is absent in the case of pn-junction-like devices made by mere deposition of NiO on hematite by thermal annealing. Hematite alone shows no such behaviour. This kind of new PEC electrode offers a low-cost and simple way for the dual purpose applications of water splitting and charge storage. PMID:23788236

  3. Design of a high performance CMOS charge pump for phase-locked loop synthesizers

    NASA Astrophysics Data System (ADS)

    Zhiqun, Li; Shuangshuang, Zheng; Ningbing, Hou

    2011-07-01

    A new high performance charge pump circuit is designed and realized in 0.18 μm CMOS process. A wide input ranged rail-to-rail operational amplifier and self-biasing cascode current mirror are used to enable the charge pump current to be well matched in a wide output voltage range. Furthermore, a method of adding a precharging current source is proposed to increase the initial charge current, which will speed up the settling time of CPPLLs. Test results show that the current mismatching can be less than 0.4% in the output voltage range of 0.4 to 1.7 V, with a charge pump current of 100 μA and a precharging current of 70 μA. The average power consumption of the charge pump in the locked condition is around 0.9 mW under a 1.8 V supply voltage.

  4. Comparison of charged nanoparticle concentrations near busy roads and overhead high-voltage power lines.

    PubMed

    Jayaratne, E R; Ling, X; Morawska, L

    2015-09-01

    Overhead high-voltage power lines are known sources of corona ions. These ions rapidly attach to aerosols to form charged particles in the environment. Although the effect of ions and charged particles on human health is largely unknown, much attention has focused on the increasing exposure as a result of the expanding power network in urban residential areas. However, it is not widely known that a large number of charged particles in urban environments originate from motor vehicle emissions. In this study, for the first time, we compare the concentrations of charged nanoparticles near busy roads and overhead power lines. We show that large concentrations of both positive and negative charged nanoparticles are present near busy roadways and that these concentrations commonly exceed those under high-voltage power lines. We estimate that the concentration of charged nanoparticles found near two freeways carrying around 120 vehicles per minute exceeded the corresponding maximum concentrations under two corona-emitting overhead power lines by as much as a factor of 5. The difference was most pronounced when a significant fraction of traffic consisted of heavy-duty diesel vehicles which typically have high particle and charge emission rates. PMID:25917858

  5. Weakly nonlinear electrophoresis of a highly charged colloidal particle

    NASA Astrophysics Data System (ADS)

    Schnitzer, Ory; Zeyde, Roman; Yavneh, Irad; Yariv, Ehud

    2013-05-01

    At large zeta potentials, surface conduction becomes appreciable in thin-double-layer electrokinetic transport. In the linear weak-field regime, where this effect is quantified by the Dukhin number, it is manifested in non-Smoluchowski electrophoretic mobilities. In this paper we go beyond linear response, employing the recently derived macroscale model of Schnitzer and Yariv ["Macroscale description of electrokinetic flows at large zeta potentials: Nonlinear surface conduction," Phys. Rev. E 86, 021503 (2012), 10.1103/PhysRevE.86.021503] as the infrastructure for a weakly nonlinear analysis of spherical-particle electrophoresis. A straightforward perturbation in the field strength is frustrated by the failure to satisfy the far-field conditions, representing a non-uniformity of the weak-field approximation at large distances away from the particle, where salt advection becomes comparable to diffusion. This is remedied using inner-outer asymptotic expansions in the spirit of Acrivos and Taylor ["Heat and mass transfer from single spheres in Stokes flow," Phys. Fluids 5, 387 (1962), 10.1063/1.1706630], with the inner region representing the particle neighborhood and the outer region corresponding to distances scaling inversely with the field magnitude. This singular scheme furnishes an asymptotic correction to the electrophoretic velocity, proportional to the applied field cubed, which embodies a host of nonlinear mechanisms unfamiliar from linear electrokinetic theories. These include the effect of induced zeta-potential inhomogeneity, animated by concentration polarization, on electro-osmosis and diffuso-osmosis; bulk advection of salt; nonuniform bulk conductivity; Coulomb body forces acting on bulk volumetric charge; and the nonzero electrostatic force exerted upon the otherwise screened particle-layer system. A numerical solution of the macroscale model validates our weakly nonlinear analysis.

  6. Re-creation of aerosol charge state found near HV power lines using a high voltage corona charger

    NASA Astrophysics Data System (ADS)

    Matthews, J. C.; Wright, M. D.; Biddiscombe, M. F.; Underwood, R.; Usmani, O. S.; Shallcross, D. E.; Henshaw, D. L.

    2015-10-01

    Corona ionisation from AC HV power lines (HVPL) can release ions into the environment, which have the potential to electrically charge pollutant aerosol in the atmosphere. It has been hypothesised that these charged particles have an enhanced probability of being deposited in human airways upon inhalation due to electrostatic attraction by image charge within the lung, with implications for human health. Carbonaceous aerosol particles from a Technegas generator were artificially charge-enhanced using a corona charger. Once generated, particles were passed through the charger, which was either on or off, and stored in a 15 litre conducting bag for ∼20 minutes to observe size and charge distribution changes over time. Charge states were estimated using two Sequential Mobility Particle Sizers measuring the size and mobility distributions. Charge-neutral particles were measured 7 times and positive particles 9 times, the average charge-neutral value of x was 1.00 (sd = 0.06) while the average positive value was 4.60 (0.72). The system will be used to generate positive or charge neutral particles for delivery to human volunteers in an inhalation study to assess the impact of charge on ultrafine (size < 100 nm) particle deposition.

  7. Adsorption and stabilizing effects of highly-charged latex nanoparticles in dispersions of weakly-charged silica colloids.

    PubMed

    Herman, David; Walz, John Y

    2015-07-01

    An experimental study was undertaken to determine the effectiveness of using highly-charged nanoparticles as stabilizers for colloidal dispersions. The specific systems used here involved cationic (amidine) and anionic (sulfate) polystyrene latex nanoparticles with an approximate diameter of 20 nm and silica microparticles of diameter 1.0 μm, and experiments were conducted at the isoelectric point of the silica. It was found that while both types of nanoparticles adsorbed to the silica microparticles and increased the zeta potential to values where stability was expected, long term stability was not achieved, even at bulk nanoparticle concentrations as high as 0.5 vol.%. It is theorized that the incomplete coverage of the microparticles by the nanoparticles (i.e., surface coverage never exceeded 50%) allowed either direct contact between bare patches of the underlying microparticles or, alternatively, for nanoparticles adsorbed on one microparticle to bridge to bare spots on a neighboring microparticle. PMID:25498877

  8. High Performance Non-Dispersive X-Ray Spectrometers for Charge Exchange Measurements

    NASA Technical Reports Server (NTRS)

    Porter Frederick; Adams, J.; Beiersdorfer, P.; Brown, G. V.; Karkatoua, D.; Kelley, R. L.; Kilbourne, C. A.; Lautenagger, M.

    2010-01-01

    Currently, the only measurements of cosmological charge exchange have been made using low resolution, non-dispersive spectrometers like the PSPC on ROSAT and the CCD instruments on Chandra and XMM/Newton. However, upcoming cryogenic spectrometers on Astro-H and IXO will add vast new capabilities to investigate charge exchange in local objects such as comets and planetary atmospheres. They may also allow us to observe charge exchange in extra-solar objects such as galactic supernova remnants. With low spectral resolution instruments such as CCDs, x-ray emission due to charge exchange recombination really only provides information on the acceptor species, such as the solar wind. With the new breed of x-ray calorimeter instruments, emission from charge exchange becomes highly diagnostic allowing one to uniquely determine the acceptor species, ionization state, donor species and ionization state, and the relative velocity of the interaction. We will describe x-ray calorimeter instrumentation and its potential for charge exchange measurements in the near term. We will also touch on the instrumentation behind a decade of high resolution measurements of charge exchange using an x-ray calorimeter at the Lawrence Livermore National Laboratory.

  9. Vascular glycocalyx sodium store – determinant of salt sensitivity?

    PubMed

    Oberleithner, Hans; Wilhelmi, Marianne

    2015-01-01

    Smart mechanisms allow frictionless slipping of rather rigid erythrocytes (red blood cells, RBC) through narrow blood vessels. Nature solved this problem in an elegant way coating the moving object (RBC) and the tunnel wall (endothelium) by negative charges (glycocalyx). As long as these surfaces are intact, repulsive forces create a 'security zone' that keeps the respective surfaces separated from each other. However, damage of either one of these surfaces causes loss of negative charges, allowing an unfavorable physical interaction between the RBC and the endothelium. It has been recently shown that any alteration of the endothelial glycocalyx leaves nasty footprints on the RBC glycocalyx. In this scenario, sodium ions hold a prominent role. Plasma sodium is stored in the glycocalyx partially neutralizing the negative surface charges. A 'good' glycocalyx has a high sodium store capacity but still maintains sufficient surface negativity at normal plasma sodium. A 'bad' glycocalyx shows the opposite. This concept was used for the development of the so-called 'salt blood test' (SBT) that quantitatively measures RBC sodium store capacity of the glycocalyx and thus indirectly evaluates the quality of the inner vessel wall. In an initial step, the applicability of the SBT was tested in eight different medical facilities. The study shows that an increased salt sensitivity, as measured by the SBT, is more frequently found in individuals with a hypertensive history, despite antihypertensive medication. Taken together, preservation of the endothelial glycocalyx appears to be of utmost importance for maintaining a well-balanced function of the vascular system. PMID:25659848

  10. Overview on collision processes of highly charged ions with atoms present status and problems

    SciTech Connect

    Janev, R.K.

    1983-05-01

    This paper provides a brief discussion on the present status of the collision physics of highly charged ions with atoms. The emphasis is on the main achievements in understanding and describing the most important collision processes, and as charge transfer, ionization and Auger-type processes, and even more on those open problems which, due either to their scientific or practical importance, represent challenges to current research in this field. The paper concentrates on general ideas and problems whose development and solutions have advanced or will advance our basic understanding of the collision dynamics of multiply charged ions with atoms.

  11. High energetic excitons in carbon nanotubes directly probe charge-carriers

    PubMed Central

    Soavi, Giancarlo; Scotognella, Francesco; Viola, Daniele; Hefner, Timo; Hertel, Tobias; Cerullo, Giulio; Lanzani, Guglielmo

    2015-01-01

    Theory predicts peculiar features for excited-state dynamics in one dimension (1D) that are difficult to be observed experimentally. Single-walled carbon nanotubes (SWNTs) are an excellent approximation to 1D quantum confinement, due to their very high aspect ratio and low density of defects. Here we use ultrafast optical spectroscopy to probe photogenerated charge-carriers in (6,5) semiconducting SWNTs. We identify the transient energy shift of the highly polarizable S33 transition as a sensitive fingerprint of charge-carriers in SWNTs. By measuring the coherent phonon amplitude profile we obtain a precise estimate of the Stark-shift and discuss the binding energy of the S33 excitonic transition. From this, we infer that charge-carriers are formed instantaneously (<50 fs) even upon pumping the first exciton, S11. The decay of the photogenerated charge-carrier population is well described by a model for geminate recombination in 1D. PMID:25959462

  12. Flexible cobalt-phthalocyanine thin films with high charge carrier mobility

    NASA Astrophysics Data System (ADS)

    Singh, Ajay; Kumar, Arvind; Kumar, Ashwini; Samanta, Soumen; Debnath, Anil K.; Jha, Purushottam; Prasad, Rajeshwar; Salmi, Zakaria; Nowak, Sophie; Chehimi, Mohamed M.; Aswal, Dinesh K.; Gupta, Shiv K.

    2012-11-01

    The structural and charge transport characteristics of cobalt phthalocyanine (CoPc) films deposited on flexible bi-axially oriented polyethylene terephthalate (BOPET) substrates are investigated. CoPc films exhibited a preferential (200) orientation with charge carrier mobility of ˜118 cm2 V-1 s-1 (at 300 K). These films exhibited a reversible resistance changes upon bending them to different radius of curvature. The charge transport in CoPc films is governed by a bias dependent crossover from ohmic (J-V) to trap-free space-charge limited conduction (J-V2). These results demonstrate that CoPc films on flexible BOPET having high mobility and high mechanical flexibility are a potential candidate for flexible electronic devices.

  13. Threshold and efficiency for perforation of 1 nm thick carbon nanomembranes with slow highly charged ions

    NASA Astrophysics Data System (ADS)

    Wilhelm, Richard A.; Gruber, Elisabeth; Ritter, Robert; Heller, René; Beyer, André; Turchanin, Andrey; Klingner, Nico; Hübner, René; Stöger-Pollach, Michael; Vieker, Henning; Hlawacek, Gregor; Gölzhäuser, Armin; Facsko, Stefan; Aumayr, Friedrich

    2015-09-01

    Cross-linking of a self-assembled monolayer of 1,1‧-biphenyl-4-thiol by low energy electron irradiation leads to the formation of a carbon nanomembrane, that is only 1 nm thick. Here we study the perforation of these freestanding membranes by slow highly charged ion irradiation with respect to the pore formation yield. It is found that a threshold in potential energy of the highly charged ions of about 10 keV must be exceeded in order to form round pores with tunable diameters in the range of 5-15 nm. Above this energy threshold, the efficiency for a single ion to form a pore increases from 70% to nearly 100% with increasing charge. These findings are verified by two independent methods, namely the analysis of individual membranes stacked together during irradiation and the detailed analysis of exit charge state spectra utilizing an electrostatic analyzer.

  14. Flexible cobalt-phthalocyanine thin films with high charge carrier mobility

    SciTech Connect

    Singh, Ajay; Kumar, Arvind; Kumar, Ashwini; Samanta, Soumen; Debnath, Anil K.; Jha, Purushottam; Prasad, Rajeshwar; Aswal, Dinesh K.; Gupta, Shiv K.; Salmi, Zakaria; Nowak, Sophie; Chehimi, Mohamed M.

    2012-11-26

    The structural and charge transport characteristics of cobalt phthalocyanine (CoPc) films deposited on flexible bi-axially oriented polyethylene terephthalate (BOPET) substrates are investigated. CoPc films exhibited a preferential (200) orientation with charge carrier mobility of {approx}118 cm{sup 2} V{sup -1} s{sup -1} (at 300 K). These films exhibited a reversible resistance changes upon bending them to different radius of curvature. The charge transport in CoPc films is governed by a bias dependent crossover from ohmic (J-V) to trap-free space-charge limited conduction (J-V{sup 2}). These results demonstrate that CoPc films on flexible BOPET having high mobility and high mechanical flexibility are a potential candidate for flexible electronic devices.

  15. Statistical similarity between high energy charged particle fluxes in near-earth space and earthquakes

    NASA Astrophysics Data System (ADS)

    Wang, P.; Chang, Z.; Wang, H.; Lu, H.

    2014-05-01

    It has long been noticed that rapid short-term variations of high energy charged particle fluxes in near-Earth space occur more frequently several hours before the main shock of earthquakes. Physicists wish that this observation supply a possible precursor of strong earthquakes. Based on DEMETER data, we investigate statistical behaviors of flux fluctuations for high energy charged particles in near-Earth space. Long-term clustering, scaling, and universality in the temporal occurrence are found. There is high degree statistical similarity between high energy charged particle fluxes in near-Earth space and earthquakes. Thus, the observations of the high energy particle fluxes in near-Earth space may supply a useful tool in the study of earthquakes.

  16. GaAs series connected photovoltaic converters for high voltage capacitor charging applications

    SciTech Connect

    Rose, B.H.

    1997-09-01

    This report describes the design features of series connected photovoltaic arrays which will be required to charge capacitors to relatively high (400V) voltages in time periods on the order of 1 microsecond. The factors which determine the array voltage and the capacitor charge time are given. Individual element junction designs, along with an interconnect scheme, and a semiconductor process to realize them are presented. Finally, the input laser optical required to meet the requirements is determined.

  17. Generation of Electric and Magnetic Fields During Detonation of High Explosive Charges in Boreholes

    SciTech Connect

    Soloviev, S; Sweeney, J

    2004-06-04

    We present experimental results of a study of electromagnetic field generation during underground detonation of high explosive charges in holes bored in sandy loam and granite. Test conditions and physico-mechanical properties of the soil exert significant influence on the parameters of electromagnetic signals generated by underground TNT charges with masses of 2 - 200 kg. The electric and magnetic field experimental data are satisfactorily described by an electric dipole model with the source embedded in a layered media.

  18. Evaluation of non-volatile metabolites in beer stored at high temperature and utility as an accelerated method to predict flavour stability.

    PubMed

    Heuberger, Adam L; Broeckling, Corey D; Sedin, Dana; Holbrook, Christian; Barr, Lindsay; Kirkpatrick, Kaylyn; Prenni, Jessica E

    2016-06-01

    Flavour stability is vital to the brewing industry as beer is often stored for an extended time under variable conditions. Developing an accelerated model to evaluate brewing techniques that affect flavour stability is an important area of research. Here, we performed metabolomics on non-volatile compounds in beer stored at 37 °C between 1 and 14 days for two beer types: an amber ale and an India pale ale. The experiment determined high temperature to influence non-volatile metabolites, including the purine 5-methylthioadenosine (5-MTA). In a second experiment, three brewing techniques were evaluated for improved flavour stability: use of antioxidant crowns, chelation of pro-oxidants, and varying plant content in hops. Sensory analysis determined the hop method was associated with improved flavour stability, and this was consistent with reduced 5-MTA at both regular and high temperature storage. Future studies are warranted to understand the influence of 5-MTA on flavour and aging within different beer types. PMID:26830592

  19. High throughput on-chip analysis of high-energy charged particle tracks using lensfree imaging

    NASA Astrophysics Data System (ADS)

    Luo, Wei; Shabbir, Faizan; Gong, Chao; Gulec, Cagatay; Pigeon, Jeremy; Shaw, Jessica; Greenbaum, Alon; Tochitsky, Sergei; Joshi, Chandrashekhar; Ozcan, Aydogan

    2015-04-01

    We demonstrate a high-throughput charged particle analysis platform, which is based on lensfree on-chip microscopy for rapid ion track analysis using allyl diglycol carbonate, i.e., CR-39 plastic polymer as the sensing medium. By adopting a wide-area opto-electronic image sensor together with a source-shifting based pixel super-resolution technique, a large CR-39 sample volume (i.e., 4 cm × 4 cm × 0.1 cm) can be imaged in less than 1 min using a compact lensfree on-chip microscope, which detects partially coherent in-line holograms of the ion tracks recorded within the CR-39 detector. After the image capture, using highly parallelized reconstruction and ion track analysis algorithms running on graphics processing units, we reconstruct and analyze the entire volume of a CR-39 detector within ˜1.5 min. This significant reduction in the entire imaging and ion track analysis time not only increases our throughput but also allows us to perform time-resolved analysis of the etching process to monitor and optimize the growth of ion tracks during etching. This computational lensfree imaging platform can provide a much higher throughput and more cost-effective alternative to traditional lens-based scanning optical microscopes for ion track analysis using CR-39 and other passive high energy particle detectors.

  20. High throughput on-chip analysis of high-energy charged particle tracks using lensfree imaging

    SciTech Connect

    Luo, Wei; Shabbir, Faizan; Gong, Chao; Gulec, Cagatay; Pigeon, Jeremy; Shaw, Jessica; Greenbaum, Alon; Tochitsky, Sergei; Joshi, Chandrashekhar; Ozcan, Aydogan

    2015-04-13

    We demonstrate a high-throughput charged particle analysis platform, which is based on lensfree on-chip microscopy for rapid ion track analysis using allyl diglycol carbonate, i.e., CR-39 plastic polymer as the sensing medium. By adopting a wide-area opto-electronic image sensor together with a source-shifting based pixel super-resolution technique, a large CR-39 sample volume (i.e., 4 cm × 4 cm × 0.1 cm) can be imaged in less than 1 min using a compact lensfree on-chip microscope, which detects partially coherent in-line holograms of the ion tracks recorded within the CR-39 detector. After the image capture, using highly parallelized reconstruction and ion track analysis algorithms running on graphics processing units, we reconstruct and analyze the entire volume of a CR-39 detector within ∼1.5 min. This significant reduction in the entire imaging and ion track analysis time not only increases our throughput but also allows us to perform time-resolved analysis of the etching process to monitor and optimize the growth of ion tracks during etching. This computational lensfree imaging platform can provide a much higher throughput and more cost-effective alternative to traditional lens-based scanning optical microscopes for ion track analysis using CR-39 and other passive high energy particle detectors.

  1. Development of a Sweetness Sensor for Aspartame, a Positively Charged High-Potency Sweetener

    PubMed Central

    Yasuura, Masato; Tahara, Yusuke; Ikezaki, Hidekazu; Toko, Kiyoshi

    2014-01-01

    Taste evaluation technology has been developed by several methods, such as sensory tests, electronic tongues and a taste sensor based on lipid/polymer membranes. In particular, the taste sensor can individually quantify five basic tastes without multivariate analysis. However, it has proven difficult to develop a sweetness sensor, because sweeteners are classified into three types according to the electric charges in an aqueous solution; that is, no charge, negative charge and positive charge. Using membrane potential measurements, the taste-sensing system needs three types of sensor membrane for each electric charge type of sweetener. Since the commercially available sweetness sensor was only intended for uncharged sweeteners, a sweetness sensor for positively charged high-potency sweeteners such as aspartame was developed in this study. Using a lipid and plasticizers, we fabricated various lipid/polymer membranes for the sweetness sensor to identify the suitable components of the sensor membranes. As a result, one of the developed sensors showed responses of more than 20 mV to 10 mM aspartame and less than 5 mV to any other taste. The responses of the sensor depended on the concentration of aspartame. These results suggested that the developed sweetness sensor had high sensitivity to and high selectivity for aspartame. PMID:24763213

  2. Atomistic and molecular effects in electric double layers at high surface charges

    SciTech Connect

    Templeton, Jeremy Alan; Lee, Jonathan; Mani, Ali

    2015-06-16

    Here, the Poisson–Boltzmann theory for electrolytes near a charged surface is known to be invalid due to unaccounted physics associated with high ion concentration regimes. In order to investigate this regime, fluids density functional theory (f-DFT) and molecular dynamics (MD) simulations were used to determine electric surface potential as a function of surface charge. Based on these detailed computations, for electrolytes with nonpolar solvent, the surface potential is shown to depend quadratically on the surface charge in the high charge limit. We demonstrate that modified Poisson–Boltzmann theories can model this limit if they are augmented with atomic packing densities provided by MD. However, when the solvent is a highly polar molecule water an intermediate regime is identified in which a constant capacitance is realized. Simulation results demonstrate the mechanism underlying this regime, and for the salt water system studied here, it persists throughout the range of physically realistic surface charge densities so the potential’s quadratic surface charge dependence is not obtained.

  3. Atomistic and molecular effects in electric double layers at high surface charges

    DOE PAGESBeta

    Templeton, Jeremy Alan; Lee, Jonathan; Mani, Ali

    2015-06-16

    Here, the Poisson–Boltzmann theory for electrolytes near a charged surface is known to be invalid due to unaccounted physics associated with high ion concentration regimes. In order to investigate this regime, fluids density functional theory (f-DFT) and molecular dynamics (MD) simulations were used to determine electric surface potential as a function of surface charge. Based on these detailed computations, for electrolytes with nonpolar solvent, the surface potential is shown to depend quadratically on the surface charge in the high charge limit. We demonstrate that modified Poisson–Boltzmann theories can model this limit if they are augmented with atomic packing densities providedmore » by MD. However, when the solvent is a highly polar molecule water an intermediate regime is identified in which a constant capacitance is realized. Simulation results demonstrate the mechanism underlying this regime, and for the salt water system studied here, it persists throughout the range of physically realistic surface charge densities so the potential’s quadratic surface charge dependence is not obtained.« less

  4. Atomistic and Molecular Effects in Electric Double Layers at High Surface Charges

    SciTech Connect

    Templeton, Jeremy Alan; Lee, Jonathan; Mani, Ali

    2015-06-16

    The Poisson–Boltzmann theory for electrolytes near a charged surface is known to be invalid due to unaccounted physics associated with high ion concentration regimes. In order to investigate this regime, fluids density functional theory (f-DFT) and molecular dynamics (MD) simulations were used to determine electric surface potential as a function of surface charge. Based on these detailed computations, for electrolytes with nonpolar solvent, the surface potential is shown to depend quadratically on the surface charge in the high charge limit. We demonstrate that modified Poisson–Boltzmann theories can model this limit if they are augmented with atomic packing densities provided by MD. However, when the solvent is a highly polar molecule water an intermediate regime is identified in which a constant capacitance is realized. Simulation results demonstrate the mechanism underlying this regime, and for the salt water system studied here, it persists throughout the range of physically realistic surface charge densities so the potential’s quadratic surface charge dependence is not obtained.

  5. Inhomogeneity of charge-density-wave order and quenched disorder in a high-Tc superconductor

    NASA Astrophysics Data System (ADS)

    Campi, G.; Bianconi, A.; Poccia, N.; Bianconi, G.; Barba, L.; Arrighetti, G.; Innocenti, D.; Karpinski, J.; Zhigadlo, N. D.; Kazakov, S. M.; Burghammer, M.; Zimmermann, M. V.; Sprung, M.; Ricci, A.

    2015-09-01

    It has recently been established that the high-transition-temperature (high-Tc) superconducting state coexists with short-range charge-density-wave order and quenched disorder arising from dopants and strain. This complex, multiscale phase separation invites the development of theories of high-temperature superconductivity that include complexity. The nature of the spatial interplay between charge and dopant order that provides a basis for nanoscale phase separation remains a key open question, because experiments have yet to probe the unknown spatial distribution at both the nanoscale and mesoscale (between atomic and macroscopic scale). Here we report micro X-ray diffraction imaging of the spatial distribution of both short-range charge-density-wave `puddles' (domains with only a few wavelengths) and quenched disorder in HgBa2CuO4 + y, the single-layer cuprate with the highest Tc, 95 kelvin (refs 26, 27, 28). We found that the charge-density-wave puddles, like the steam bubbles in boiling water, have a fat-tailed size distribution that is typical of self-organization near a critical point. However, the quenched disorder, which arises from oxygen interstitials, has a distribution that is contrary to the usually assumed random, uncorrelated distribution. The interstitial-oxygen-rich domains are spatially anticorrelated with the charge-density-wave domains, because higher doping does not favour the stripy charge-density-wave puddles, leading to a complex emergent geometry of the spatial landscape for superconductivity.

  6. Inhomogeneity of charge-density-wave order and quenched disorder in a high-Tc superconductor.

    PubMed

    Campi, G; Bianconi, A; Poccia, N; Bianconi, G; Barba, L; Arrighetti, G; Innocenti, D; Karpinski, J; Zhigadlo, N D; Kazakov, S M; Burghammer, M; Zimmermann, M v; Sprung, M; Ricci, A

    2015-09-17

    It has recently been established that the high-transition-temperature (high-Tc) superconducting state coexists with short-range charge-density-wave order and quenched disorder arising from dopants and strain. This complex, multiscale phase separation invites the development of theories of high-temperature superconductivity that include complexity. The nature of the spatial interplay between charge and dopant order that provides a basis for nanoscale phase separation remains a key open question, because experiments have yet to probe the unknown spatial distribution at both the nanoscale and mesoscale (between atomic and macroscopic scale). Here we report micro X-ray diffraction imaging of the spatial distribution of both short-range charge-density-wave 'puddles' (domains with only a few wavelengths) and quenched disorder in HgBa2CuO4 + y, the single-layer cuprate with the highest Tc, 95 kelvin (refs 26-28). We found that the charge-density-wave puddles, like the steam bubbles in boiling water, have a fat-tailed size distribution that is typical of self-organization near a critical point. However, the quenched disorder, which arises from oxygen interstitials, has a distribution that is contrary to the usually assumed random, uncorrelated distribution. The interstitial-oxygen-rich domains are spatially anticorrelated with the charge-density-wave domains, because higher doping does not favour the stripy charge-density-wave puddles, leading to a complex emergent geometry of the spatial landscape for superconductivity. PMID:26381983

  7. Lattice and charge effects in high-temperature superconductors

    NASA Astrophysics Data System (ADS)

    Egami, T.; McQueeney, R. J.; Chung, J.-H.; Yethiraj, M.; Mook, H. A.; Arai, M.; Inamura, Y.; Endoh, Y.; Tajima, S.; Frost, C.; Dogan, F.

    We present the results of inelastic neutron-scattering measurements of a twinned crystal of YBa2Cu3O6.95 using the MAPS spectrometer of the ISIS facility of the Rutherford-Appleton Laboratory as well as the HFIR of the Oak Ridge National Laboratory. The dispersion of the Cu-O bond-stretching modes indicates a strong dielectric anisotropy within the plane and associated electronic anisotropy, supporting the dynamic stripe model. The results suggest a possibility that phonons play a major role in the mechanism of high-temperature superconductivity.

  8. Spectroscopic Non-LTE Modeling of Highly Charged Gold Plasma

    NASA Astrophysics Data System (ADS)

    Dasgupta, A.; Ouart, N. D.; Giuliani, J. L.; Obenschain, S. P.; Clark, R. W.; Aglitskiy, Y.

    2013-10-01

    An X-ray spectrometer is under development at the Naval Research Laboratory (NRL) to investigate emissions from gold targets irradiated by the NIKE KrF facility. This effort is in support of the indirect drive campaign on the National Ignition Facility (NIF). To analyze and interpret the NIKE experimental spectra, we are theoretically exploring line emissions from a gold plasma in the M-band, i.e., 1.5 to 3.5 keV. We employ a detailed Non-LTE atomic model for ions near Ni-like gold by including an adequate number of configurations to obtain spectroscopic details in this range. The atomic states are coupled both collisionally and radiatively, including all dominant atomic processes that have significant contributions to the ionization and emitted synthetic spectra. In particular, we will investigate the effect of dielectronic recombination, which can have a dominant effect on level populations for highly ionized high Z plasmas. Since the radiation field can affect level populations through photoionization and photoexcitation, our collisional-radiative model will include non-local radiation transport. The line shapes of the strong overlapping lines will be resolved by a multifrequency radiation transport method. Synthetic spectra with radiation transport, including resonant photo-pumping, will be generated for realistic densities and temperatures to compare with the NIKE data. Work supported by DOE/NNSA.

  9. Uncharted Frontiers in the Spectroscopy of Highly Charged Ions

    SciTech Connect

    Beiersdorfer, P.; Brown, G.; Crespo, J.; Kim, S.-H.; Neill, P.; Utter, S.; Widmann, K.

    2000-01-08

    The development of novel techniques is critical for maintaining a state-of-the-art core competency in atomic physics and readiness for evolving programmatic needs. We have carried out a three-year effort to develop novel spectroscopic instrumentation that added new dimensions to our capabilities for measuring energy levels, radiative transition probabilities, and electron-ion excitation processes. The new capabilities created were in areas that heretofore had been inaccessible to scientific scrutiny and included high-resolution spectroscopy of hard x rays, femtosecond lifetime measurements, measurements of transition probabilities of long-lived metastable levels, polarization spectroscopy, ultra-precise determinations of energy levels, and the establishment of absolute wavelength standards in x-ray spectroscopy. Instrumentation developed during the period included a transmission-type crystal spectrometer, a flat-field EUV spectrometer, and the development and deployment of absolutely calibrated monolithic crystals. The new capabilities enabled very sensitive tests of atomic wave functions, of calculations of magnetic sublevel populations, and of fundamental theories in uncharted regimes, and provided the basis for developing new diagnostic techniques of high-density plasmas.

  10. Physics of high-intensity nanosecond electron source: Charge limit phenomenon in GaAs photocathodes

    SciTech Connect

    Herrera-Gomez, A. |; Vergara, G.; Spicer, W.E.

    1996-05-01

    GaAs negative electron affinity cathodes are used as high-intensity, short-time electron source at the Stanford Linear Accelerator Center. When the cathodes are illuminated with high-intensity laser pulses draw peak currents that are extremely high, typically of tens of Amperes. Because of the high currents, some nonlinear effects are present. Very noticeable is the so-called charge limit (CL) effect, which consists of a limit on the total charge in each pulse; that is, the total bunch charge stops increasing as the light pulse intensity increases. The CL effect is directly related to a photovoltage built up in the surface as a consequence of the photoelectrons coming from the bulk. We discuss possible ways to minimize the formation of the surface photovoltage. {copyright} {ital 1996 American Institute of Physics.}

  11. High-precision digital charge-coupled device TV system

    NASA Astrophysics Data System (ADS)

    Vishnevsky, Grigory I.; Ioffe, S. A.; Berezin, V. Y.; Rybakov, M. I.; Mikhaylov, A. V.; Belyaev, L. V.

    1991-06-01

    In certain test, measurement, and research applications of CCD TV systems, the greater accuracy than usual 8-bit frame-grabbers can provide is demanded without the system being too expensive. The paper presents the concept and features of the high-precision low-cost digital CCD TV system intended for obtaining 12-bit monochrome images of immobile or relatively slow moving objects. The increase in accuracy is achieved by the specific digitization procedure -- one column per frame, which combines the benefits of a slow A/D converter with real-time TV imaging compatibility. To reduce speed restrictions on sample- and-hold circuits, a zoomed pixel read out cycle, corresponding to the pixel to be digitized, is proposed. The system provides great flexibility in choice of integration times and readout rates by means of a programmable readout sequencer, and is easily adaptable to various user demands and CCDs types.

  12. Tapping unsustainable groundwater stores for agricultural production in the High Plains Aquifer of Kansas, projections to 2110

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Groundwater provides a reliable tap to sustain agricultural production, yet persistent aquifer depletion threatens future sustainability. The High Plains Aquifer supplies 30% of the nation’s irrigated groundwater, and the Kansas portion supports the congressional district with the highest market val...

  13. Grocery Store Math.

    ERIC Educational Resources Information Center

    Clark, Deborah

    1997-01-01

    Presents a hands-on activity, adaptable to various grade levels, to reinforce the mathematical concept of rounding by utilizing grocery store advertisements to demonstrate the concept in a real life setting. Describes the activity on a step-by-step basis and includes suggestions for additional grocery store games. (SD)

  14. Strategies for minimizing emittance growth in high charge CW FEL injectors

    SciTech Connect

    Liu, H.

    1995-12-31

    This paper is concerned with the best strategies for designing low emittance, high charge CW FEL injectors. This issue has become more and more critical as today`s interest in FELs is toward UV wavelength high average power operation. The challenge of obtaining the smallest possible emittance is discussed from both the practical point of view and the beam physics point of view. Various mechanisms responsible for beam emittance growth are addressed in detail. Finally, the design of a high charge injector test stand at CEBAF is chosen to help illustrate the design strategies and emittance growth mechanisms discussed in this paper.

  15. Multi-frequency inversion-charge pumping for charge separation and mobility analysis in high-k/InGaAs metal-oxide-semiconductor field-effect transistors

    SciTech Connect

    Djara, V.; Cherkaoui, K.; Negara, M. A.; Hurley, P. K.

    2015-11-28

    An alternative multi-frequency inversion-charge pumping (MFICP) technique was developed to directly separate the inversion charge density (N{sub inv}) from the trapped charge density in high-k/InGaAs metal-oxide-semiconductor field-effect transistors (MOSFETs). This approach relies on the fitting of the frequency response of border traps, obtained from inversion-charge pumping measurements performed over a wide range of frequencies at room temperature on a single MOSFET, using a modified charge trapping model. The obtained model yielded the capture time constant and density of border traps located at energy levels aligned with the InGaAs conduction band. Moreover, the combination of MFICP and pulsed I{sub d}-V{sub g} measurements enabled an accurate effective mobility vs N{sub inv} extraction and analysis. The data obtained using the MFICP approach are consistent with the most recent reports on high-k/InGaAs.

  16. Evaporation and discharge dynamics of highly charged multicomponent droplets generated by electrospray ionization.

    PubMed

    Grimm, Ronald L; Beauchamp, J L

    2010-01-28

    We investigate the Rayleigh discharge and evaporation dynamics of highly charged two-component droplets consisting principally of methanol with 2-methoxyethanol, tert-butanol, or m-nitrobenzyl alcohol. A phase Doppler anemometer (PDA) characterizes droplets generated by electrospray ionization (ESI) according to size, velocity, and charge as they move through a uniform electric field within an ion mobility spectrometer (IMS). Repeated field reversals result in droplet "ping-pong" through the PDA. This generates individual droplet histories of solvent evaporation behavior and the dynamics of charge loss to progeny droplets during Rayleigh discharge events. On average, methanol droplets discharge at 127% their Rayleigh limit of charge, q(R), and release 25% of the net charge. Charge loss from methanol/2-methoxyethanol droplets behaves similarly to pure 2-methoxyethanol droplets which release approximately 28% of their net charge. Binary methanol droplets containing up to 50% tert-butanol discharge at a lower percent q(R) than pure methanol and release a greater fraction of their net charge. Mixed 99% methanol/1% m-nitrobenzyl alcohol droplets possess discharge characteristics similar to those of methanol. However, droplets of methanol containing 2% m-nitrobenzyl evaporate down to a fixed size and charge that remains constant with no observable discharges. Quasi-steady-state evaporation models accurately describe observed evaporation phenomena in which methanol/tert-butanol droplets evaporate at a rate similar to that of pure methanol and methanol/2-methoxyethanol droplets evaporate at a rate similar to that of 2-methoxyethanol. We compare these results to previous Rayleigh discharge experiments and discuss the implications for binary solvents in electrospray mass spectrometry (ESI-MS) and field-induced droplet ionization mass spectrometry (FIDI-MS). PMID:19848399

  17. Waste from grocery stores

    SciTech Connect

    Lieb, K.

    1993-11-01

    The Community Recycling Center, Inc., (CRC, Champaign, Ill.), last year conducted a two-week audit of waste generated at two area grocery stores. The stores surveyed are part of a 10-store chain. For two of the Kirby Foods Stores, old corrugated containers (OCC) accounted for 39-45% of all waste. The summary drew correlations between the amount of OCC and the sum of food and garbage waste. The study suggested that one can reasonably estimate volumes of waste based on the amount of OCC because most things come in a box. Auditors set up a series of containers to make the collection process straightforward. Every day the containers were taken to local recycling centers and weighed. Approximate waste breakdowns for the two stores were as follows: 45% OCC; 35% food waste; 20% nonrecyclable or noncompostable items; and 10% other.

  18. Parameter-free calculation of charge-changing cross sections at high energy

    NASA Astrophysics Data System (ADS)

    Suzuki, Y.; Horiuchi, W.; Terashima, S.; Kanungo, R.; Ameil, F.; Atkinson, J.; Ayyad, Y.; Cortina-Gil, D.; Dillmann, I.; Estradé, A.; Evdokimov, A.; Farinon, F.; Geissel, H.; Guastalla, G.; Janik, R.; Knoebel, R.; Kurcewicz, J.; Litvinov, Yu. A.; Marta, M.; Mostazo, M.; Mukha, I.; Nociforo, C.; Ong, H. J.; Pietri, S.; Prochazka, A.; Scheidenberger, C.; Sitar, B.; Strmen, P.; Takechi, M.; Tanaka, J.; Tanihata, I.; Vargas, J.; Weick, H.; Winfield, J. S.

    2016-07-01

    Charge-changing cross sections at high energies are expected to provide useful information on nuclear charge radii. No reliable theory to calculate the cross section has yet been available. We develop a formula using Glauber and eikonal approximations and test its validity with recent new data on carbon isotopes measured at around 900 A MeV. We first confirm that our theory reproduces the cross sections of 12,13,14C+12C consistently with the known charge radii. Next we show that the cross sections of C-1912 on a proton target are all well reproduced provided the role of neutrons is accounted for. We also discuss the energy dependence of the charge-changing cross sections.

  19. Effects of atamp-charging coke making on strength and high temperature thermal properties of coke.

    PubMed

    Zhang, Yaru; Bai, Jinfeng; Xu, Jun; Zhong, Xiangyun; Zhao, Zhenning; Liu, Hongchun

    2013-12-01

    The stamp-charging coke making process has some advantages of improving the operation environment, decreasing fugitive emission, higher gas collection efficiency as well as less environmental pollution. This article describes the different structure strength and high temperature thermal properties of 4 different types of coke manufactured using a conventional coking process and the stamp-charging coke making process. The 4 kinds of cokes were prepared from the mixture of five feed coals blended by the petrography blending method. The results showed that the structure strength indices of coke prepared using the stamp-charging coke method increase sharply. In contrast with conventional coking process, the stamp-charging process improved the coke strength after reaction but had little impact on the coke reactivity index. PMID:25078828

  20. Non-targeted effects induced by high LET charged particles

    NASA Astrophysics Data System (ADS)

    Hei, Tom K.; Chai, Yunfei; Hamada, Nobuyuki; Kakinuma, Shizuko; Uchihori, Yukio

    Radiation-induced non-targeted response represents a paradigm shift in our understanding of the radiobiological effects of ionizing radiation in that extranuclear and extracellular effects may also contribute to the final biological consequences of exposure to low doses of radiation. Using the gpt delta transgenic mouse model, there is evidence that irradiation of a small area (1 cm by 1 cm) of the lower abdominal area of animals with a 5 Gy dose of X-rays induced cyclooxygenase-2 as well as deletion mutations in the out-of-field lung tissues of the animals. The mutation correlated with an increase in prostaglandin levels in the bystander lung tissues and with an increase in the level of 8-hydroxydeoxyguanosine (8-OHdG), an oxidative DNA damage marker. An increase in COX-2 level was also detected in the out-of-field lung tissues of animals similarly exposed to high LET argon and carbon ions accelerated at the Heavy Ion Medical Accelerator in Chiba (HIMAC) at the National Institute of Radiological Sciences in Japan. These results provide the first evidence that the COX-2 -related pathway, which is essential in mediating cellular inflammatory response, is the critical signaling link for the non-targeted, bystander phenomenon. A better understanding of the cellular and molecular mechanisms of the non-targeted, out of field phenomenon together with evidence of their occurrence in vivo will allow us to formulate a more accurate assessment of radiation risk.

  1. Accessible passively stored highly spin-polarized D in solid HD, with application to inertially confined fusion

    SciTech Connect

    Alexander, N.B.

    1992-01-01

    Highly spin-polarized D in solid HD was produced in a dilution refrigerator-magnet system under conditions whereby the polarization remains high upon removal of the sample to a 1K, modest field ([approximately]0.1 T) environment. This retained polarization remains for many hours to days. The first intended application of this system is for inertially confined fusion (ICF) experiments with spin-polarized D fuel. The actual (vector) polarization attained thus far is P[sup D] = 38%. The maximum D polarization obtainable with the present refrigerator and magnet (8 mK and 13 T) is 61%. The difference is due to the author's reluctance to wait the full time constants in these demonstration experiments and due to the inability to attain full efficiency in radio-frequency dynamic polarization transfer between D and H, the maximum polarizability of the latter in the system equaling about 85%. It was necessary to develop methods for cold (4 K) sample transfer with engagement and disengagement provisions for the dilution-refrigerator apparatus, a storage-transport cryostat, various sample-preparation and diagnostic apparatus, and an interface to an experimental destination facility. The nature of the fusion experiments required designing and constructing a complex mating system with interchange of cold shrouds to ascertain the sample was always shielded from room temperature black body radiation, and still provide means for positioning the target to within a few microns of the intersection of the high power laser beams. Means of filling plastic target shells to high pressure with the special isotopic composition of HD with H[sub 2]and D[sub 2] impurities, and condensing them at cryogenic temperatures, were also perfected.

  2. Accessible Passively Stored Highly Spin-Polarized Deuterium in Solid Hydrogen Deuterium, with Application to Inertially Confined Fusion

    NASA Astrophysics Data System (ADS)

    Alexander, Neil Brooks

    1992-01-01

    Highly spin-polarized D in solid HD was produced in a dilution refrigerator-magnet system under conditions whereby the polarization remains high upon removal of the sample to a 1K, modest field (~0.1 T) environment. This retained polarization remains for many hours to days, sufficient to allow the polarized material to be transported to distant locations and utilized there. The first intended application of this system is for inertially confined fusion (ICF) experiments with spin-polarized D fuel. The actual (vector) polarization attained thus far is P^{rm D} = 38%. The maximum D polarization obtainable with our present refrigerator and magnet (8 mK and 13 T) is 61%. The difference is due to our reluctance to wait the full time constants in these demonstration experiments and due to the inability to attain full efficiency in radio-frequency dynamic polarization transfer between D and H, the maximum polarizability of the latter in our system equaling about 85%. In addition to implementation of the polarization method, it was also necessary to develop methods for cold (4 K) sample transfer with engagement and disengagement provisions for the dilution-refrigerator apparatus, a storage -transport cryostat, various sample-preparation and diagnostic apparatuses, and an interface to an experimental destination facility, in the present case, the OMEGA fusion chamber at the University of Rochester's Laboratory for Laser Energetics. The nature of the fusion experiments required designing and constructing a complex mating system with interchange of cold shrouds to ascertain the sample was always shielded from room temperature black body radiation, and still provide means for positioning the target to within a few microns of the intersection of the high power laser beams. Means of filling plastic target shells to high pressure (at room temperature) with our special isotopic composition of HD with H_2 and D_2 impurities, and condensing them at cryogenic temperatures, were also

  3. EXTRACTION COMPRESSION AND ACCELERATION OF HIGH LINE CHARGE DENSITY ION BEAMS

    SciTech Connect

    Henestroza, Enrique; Henestroza, E.; Peters, C.; Yu, S.S.; Grote, D.P.; Briggs, R.J.

    2005-05-20

    High Energy Density Physics (HEDP) applications require high line charge density ion beams. An efficient method to obtain this type of beams is to extract a long pulse, high current beam from a gun at high energy, and let the beam pass through a decelerating field to compress it. The low energy beam-bunch is loaded into a solenoid and matched to a Brillouin flow. The Brillouin equilibrium is independent of the energy if the relationship between the beam size (a), solenoid magnetic field strength (B) and line charge density is such that (Ba){sup 2} is proportional to the line charge density. Thus it is possible to accelerate a matched beam at constant line charge density. An experiment, NDCX-1c is being designed to test the feasibility of this type of injectors, where we will extract a 1 microsecond, 100 mA, potassium beam at 160 keV, decelerate it to 55 keV (density {approx}0.2 {micro}C/m), and load it into a 2.5 T solenoid where it will be accelerated to 100-150 keV (head to tail) at constant line charge density. The head-to-tail velocity tilt can be used to increase bunch compression and to control longitudinal beam expansion. We will present the physics design and numerical simulations of the proposed experiment.

  4. Gram-scale, high-yield synthesis of a robust metal-organic framework for storing methane and other gases

    SciTech Connect

    Wilmer, CE; Farha, OK; Yildirim, T; Eryazici, I; Krungleviciute, V; Sarjeant, AA; Snurr, RQ; Hupp, JT

    2013-04-01

    We have synthesized and characterized a new metal-organic framework (MOF) material, NU-125, that, in the single-crystal limit, achieves a methane storage density at 58 bar (840 psi) and 298 K corresponding to 86% of that obtained with compressed natural gas tanks (CNG) used in vehicles today, when the latter are pressurized to 248 bar (3600 psi). More importantly, the deliverable capacity (58 bar to 5.8 bar) for NU-125 is 67% of the deliverable capacity of a CNG tank that starts at 248 bar. (For crystalline granules or powders, particle packing inefficiencies will yield densities and deliverable capacities lower than 86% and 67% of high-pressure CNG.) This material was synthesized in high yield on a gram-scale in a single-batch synthesis. Methane adsorption isotherms were measured over a wide pressure range (0.1-58 bar) and repeated over twelve cycles on the same sample, which showed no detectable degradation. Adsorption of CO2 and H-2 over a broad range of pressures and temperatures are also reported and agree with our computational findings.

  5. An Approach for the Analysis of Regulatory Analytes in High Level Radioactive Waste Stored at Hanford, Richland, Washington

    SciTech Connect

    Wiemers, K.D.; Miller, M.; Lerchen, M.E.

    1999-01-04

    Radiation levels, salt concentration, and the oxidizing nature of the waste dictates modifications to the SW-846 methods. Modified methods will be used to meet target EQLs and QC currently in SW-846. Method modifications will be validated per SW-846 and HASQARD and will be documented consistent with WAC 173-303-910. The affect of modifications to holding times and storage conditions will be evaluated using techniques developed by Maskarinec and Bayne (1996). After validating the methods and performing the holding time study on a minimum of two Phase 1 candidate feed source tank wastes, DOE and Ecology will assess: whether different methods are needed, whether holding time/storage conditions should be altered, whether the high priority analyte list should be refined, and which additional tank waste needs to be characterized.

  6. High-intensity, high-brightness polarized and unpolarized beam production in charge-exchange collisions

    SciTech Connect

    Zelenski, A.; Ritter, J.; Zubets, V.; Steski, D.; Atoian, G.; Davydenko, V.; Ivanov, A.; Kolmogorov, A.

    2011-03-28

    Basic limitations on the high-intensity H{sup -} ion beam production were experimentally studied in charge-exchange collisions of the neutral atomic hydrogen beam in the Na-vapour jet ionizer cell. These studies are the part of the polarized source upgrade (to 10 mA peak current and 85% polarization) project for RHIC. In the source the atomic hydrogen beam of a 5-10 keV energy and total (equivalent) current up to 5 A is produced by neutralization of proton beam in pulsed hydrogen gas target. Formation of the proton beam (from the surface of the plasma emitter with a low transverse ion temperature {approx}0.2 eV) is produced by four-electrode spherical multi-aperture ion-optical system with geometrical focusing. The hydrogen atomic beam intensity up to 1.0 A/cm{sup 2} (equivalent) was obtained in the Na-jet ionizer aperture of a 2.0 cm diameter. At the first stage of the experiment H-beam with 36 mA current, 5 keV energy and {approx}1.0 cm {center_dot} mrad normalized emittance was obtained using the flat grids and magnetic focusing.

  7. Generation of annular, high-charge electron beams at the Argonne wakefield accelerator

    NASA Astrophysics Data System (ADS)

    Wisniewski, E. E.; Li, C.; Gai, W.; Power, J.

    2012-12-01

    We present and discuss the results from the experimental generation of high-charge annular(ring-shaped)electron beams at the Argonne Wakefield Accelerator (AWA). These beams were produced by using laser masks to project annular laser profiles of various inner and outer diameters onto the photocathode of an RF gun. The ring beam is accelerated to 15 MeV, then it is imaged by means of solenoid lenses. Transverse profiles are compared for different solenoid settings. Discussion includes a comparison with Parmela simulations, some applications of high-charge ring beams,and an outline of a planned extension of this study.

  8. Generation of annular, high-charge electron beams at the Argonne wakefield accelerator

    NASA Astrophysics Data System (ADS)

    Wisniewski, E. E.; Li, C.; Gai, W.; Power, J.

    2013-01-01

    We present and discuss the results from the experimental generation of high-charge annular(ring-shaped)electron beams at the Argonne Wakefield Accelerator (AWA). These beams were produced by using laser masks to project annular laser profiles of various inner and outer diameters onto the photocathode of an RF gun. The ring beam is accelerated to 15 MeV, then it is imaged by means of solenoid lenses. Transverse profiles are compared for different solenoid settings. Discussion includes a comparison with Parmela simulations, some applications of high-charge ring beams,and an outline of a planned extension of this study.

  9. Possible Diamond-Like Nanoscale Structures Induced by Slow Highly-Charged Ions on Graphite (HOPG)

    SciTech Connect

    Sideras-Haddad, E.; Schenkel, T.; Shrivastava, S.; Makgato, T.; Batra, A.; Weis, C. D.; Persaud, A.; Erasmus, R.; Mwakikunga, B.

    2009-01-06

    The interaction between slow highly-charged ions (SHCI) of different charge states from an electron-beam ion trap and highly oriented pyrolytic graphite (HOPG) surfaces is studied in terms of modification of electronic states at single-ion impact nanosizeareas. Results are presented from AFM/STM analysis of the induced-surface topological features combined with Raman spectroscopy. I-V characteristics for a number of different impact regions were measured with STM and the results argue for possible formation of diamond-like nanoscale structures at the impact sites.

  10. X-ray resonant photoexcitation: linewidths and energies of Kα transitions in highly charged Fe ions.

    PubMed

    Rudolph, J K; Bernitt, S; Epp, S W; Steinbrügge, R; Beilmann, C; Brown, G V; Eberle, S; Graf, A; Harman, Z; Hell, N; Leutenegger, M; Müller, A; Schlage, K; Wille, H-C; Yavaş, H; Ullrich, J; Crespo López-Urrutia, J R

    2013-09-01

    Photoabsorption by and fluorescence of the Kα transitions in highly charged iron ions are essential mechanisms for x-ray radiation transfer in astrophysical environments. We study photoabsorption due to the main Kα transitions in highly charged iron ions from heliumlike to fluorinelike (Fe24+ to Fe17+) using monochromatic x rays around 6.6 keV at the PETRA III synchrotron photon source. Natural linewidths were determined with hitherto unattained accuracy. The observed transitions are of particular interest for the understanding of photoexcited plasmas found in x-ray binary stars and active galactic nuclei. PMID:25166661

  11. Use of CMOS imagers to measure high fluxes of charged particles

    NASA Astrophysics Data System (ADS)

    Servoli, L.; Tucceri, P.

    2016-03-01

    The measurement of high flux charged particle beams, specifically at medical accelerators and with small fields, poses several challenges. In this work we propose a single particle counting method based on CMOS imagers optimized for visible light collection, exploiting their very high spatial segmentation (> 3 106 pixels/cm2) and almost full efficiency detection capability. An algorithm to measure the charged particle flux with a precision of ~ 1% for fluxes up to 40 MHz/cm2 has been developed, using a non-linear calibration algorithm, and several CMOS imagers with different characteristics have been compared to find their limits on flux measurement.

  12. A vacuum spark ion source: High charge state metal ion beams

    NASA Astrophysics Data System (ADS)

    Yushkov, G. Yu.; Nikolaev, A. G.; Oks, E. M.; Frolova, V. P.

    2016-02-01

    High ion charge state is often important in ion beam physics, among other reasons for the very practical purpose that it leads to proportionately higher ion beam energy for fixed accelerating voltage. The ion charge state of metal ion beams can be increased by replacing a vacuum arc ion source by a vacuum spark ion source. Since the voltage between anode and cathode remains high in a spark discharge compared to the vacuum arc, higher metal ion charge states are generated which can then be extracted as an ion beam. The use of a spark of pulse duration less than 10 μs and with current up to 10 kA allows the production of ion beams with current of several amperes at a pulse repetition rate of up to 5 pps. We have demonstrated the formation of high charge state heavy ions (bismuth) of up to 15 + and a mean ion charge state of more than 10 +. The physics and techniques of our vacuum spark ion source are described.

  13. A vacuum spark ion source: High charge state metal ion beams.

    PubMed

    Yushkov, G Yu; Nikolaev, A G; Oks, E M; Frolova, V P

    2016-02-01

    High ion charge state is often important in ion beam physics, among other reasons for the very practical purpose that it leads to proportionately higher ion beam energy for fixed accelerating voltage. The ion charge state of metal ion beams can be increased by replacing a vacuum arc ion source by a vacuum spark ion source. Since the voltage between anode and cathode remains high in a spark discharge compared to the vacuum arc, higher metal ion charge states are generated which can then be extracted as an ion beam. The use of a spark of pulse duration less than 10 μs and with current up to 10 kA allows the production of ion beams with current of several amperes at a pulse repetition rate of up to 5 pps. We have demonstrated the formation of high charge state heavy ions (bismuth) of up to 15 + and a mean ion charge state of more than 10 +. The physics and techniques of our vacuum spark ion source are described. PMID:26931966

  14. High precision measurement of the proton charge radius: The PRad experiment

    SciTech Connect

    Meziane, Mehdi

    2013-11-01

    The recent high precision measurements of the proton charge radius performed at PSI from muonic hydrogen Lamb shift puzzled the hadronic physics community. A value of 0.8418 {+-} 0.0007 fm was extracted which is 7{sigma} smaller than the previous determinations obtained from electron-proton scattering experiments and based on precision spectroscopy of electronic hydrogen. An additional extraction of the proton charge radius from electron scattering at Mainz is also in good agreement with these "electronic" determinations. An independent measurement of the proton charge radius from unpolarized elastic ep scattering using a magnetic spectrometer free method was proposed and fully approved at Jefferson Laboratory in June 2012. This novel technique uses the high precision calorimeter HyCal and a windowless hydrogen gas target which makes possible the extraction of the charge radius at very forward angles and thus very low momentum transfer Q{sup 2} up to 10{sup -4} (GeV/c){sup 2} with an unprecedented sub-percent precision for this type of experiment. In this paper, after a review of the recent progress on the proton charge radius extraction and the new high precision experiment PRad will be presented.

  15. A high efficiency all-PMOS charge pump for 3D NAND flash memory

    NASA Astrophysics Data System (ADS)

    Liyin, Fu; Yu, Wang; Qi, Wang; Zongliang, Huo

    2016-07-01

    For 3D vertical NAND flash memory, the charge pump output load is much larger than that of the planar NAND, resulting in the performance degradation of the conventional Dickson charge pump. Therefore, a novel all PMOS charge pump with high voltage boosting efficiency, large driving capability and high power efficiency for 3D V-NAND has been proposed. In this circuit, the Pelliconi structure is used to enhance the driving capability, two auxiliary substrate bias PMOS transistors are added to mitigate the body effect, and the degradation of the output voltage and boost efficiency caused by the threshold voltage drop is eliminated by dynamic gate control structure. Simulated results show that the proposed charge pump circuit can achieve the maximum boost efficiency of 86% and power efficiency of 50%. The output voltage of the proposed 9 stages charge pump can exceed 2 V under 2 MHz clock frequency in 2X nm 3D V-NAND technology. Our results provide guidance for the peripheral circuit design of high density 3D V-NAND integration.

  16. Characterization of the surface charge distribution on kaolinite particles using high resolution atomic force microscopy

    NASA Astrophysics Data System (ADS)

    Kumar, Naveen; Zhao, Cunlu; Klaassen, Aram; van den Ende, Dirk; Mugele, Frieder; Siretanu, Igor

    2016-02-01

    Most solid surfaces, in particular clay minerals and rock surfaces, acquire a surface charge upon exposure to an aqueous environment due to adsorption and/or desorption of ionic species. Macroscopic techniques such as titration and electrokinetic measurements are commonly used to determine the surface charge and ζ -potential of these surfaces. However, because of the macroscopic averaging character these techniques cannot do justice to the role of local heterogeneities on the surfaces. In this work, we use dynamic atomic force microscopy (AFM) to determine the distribution of surface charge on the two (gibbsite-like and silica-like) basal planes of kaolinite nanoparticles immersed in aqueous electrolyte with a lateral resolution of approximately 30 nm. The surface charge density is extracted from force-distance curves using DLVO theory in combination with surface complexation modeling. While the gibbsite-like and the silica-like facet display on average positive and negative surface charge values as expected, our measurements reveal lateral variations of more than a factor of two on seemingly atomically smooth terraces, even if high resolution AFM images clearly reveal the atomic lattice on the surface. These results suggest that simple surface complexation models of clays that attribute a unique surface chemistry and hence homogeneous surface charge densities to basal planes may miss important aspects of real clay surfaces.

  17. Ionic Behavior in Highly Concentrated Aqueous Solutions Nanoconfined between Discretely Charged Silicon Surfaces.

    PubMed

    Qiu, Yinghua; Ma, Jian; Chen, Yunfei

    2016-05-17

    Through molecular dynamics simulations considering thermal vibration of surface atoms, ionic behaviors in concentrated NaCl solutions confined between discretely charged silicon surfaces have been investigated. The electric double layer structure was found to be sensitive to the density and distribution of surface charges. Due to the discreteness of the surface charge, a slight charge inversion appeared which depended on the surface charge density, bulk concentration, and confinement. In the nanoconfined NaCl solutions concentrated from 0.2 to 4.0 M, the locations of accumulation layers for Na(+) and Cl(-) ions remained stable, but their peak values increased. The higher the concentration was, the more obvious the charge inversion appeared. In 4.0 M NaCl solution, Na(+) and Cl(-) ions show obvious alternating layered distributions which may correspond to the solidification found in experiments. By changing surface separation, the confinement had a large effect on the ionic distribution. As both surfaces approached each other, many ions and water molecules were squeezed out of the confined space. Two adjacent layers in ion or water distribution profiles can be forced closer to each other and merge together. From ionic hydration analysis, the coordination number of Na(+) ions in highly confined space was much lower than that in the bulk. PMID:27137990

  18. Tapping unsustainable groundwater stores for agricultural production in the High Plains Aquifer of Kansas, projections to 2110.

    PubMed

    Steward, David R; Bruss, Paul J; Yang, Xiaoying; Staggenborg, Scott A; Welch, Stephen M; Apley, Michael D

    2013-09-10

    Groundwater provides a reliable tap to sustain agricultural production, yet persistent aquifer depletion threatens future sustainability. The High Plains Aquifer supplies 30% of the nation's irrigated groundwater, and the Kansas portion supports the congressional district with the highest market value for agriculture in the nation. We project groundwater declines to assess when the study area might run out of water, and comprehensively forecast the impacts of reduced pumping on corn and cattle production. So far, 30% of the groundwater has been pumped and another 39% will be depleted over the next 50 y given existing trends. Recharge supplies 15% of current pumping and would take an average of 500-1,300 y to completely refill a depleted aquifer. Significant declines in the region's pumping rates will occur over the next 15-20 y given current trends, yet irrigated agricultural production might increase through 2040 because of projected increases in water use efficiencies in corn production. Water use reductions of 20% today would cut agricultural production to the levels of 15-20 y ago, the time of peak agricultural production would extend to the 2070s, and production beyond 2070 would significantly exceed that projected without reduced pumping. Scenarios evaluate incremental reductions of current pumping by 20-80%, the latter rate approaching natural recharge. Findings substantiate that saving more water today would result in increased net production due to projected future increases in crop water use efficiencies. Society has an opportunity now to make changes with tremendous implications for future sustainability and livability. PMID:23980153

  19. Tapping unsustainable groundwater stores for agricultural production in the High Plains Aquifer of Kansas, projections to 2110

    PubMed Central

    Steward, David R.; Bruss, Paul J.; Yang, Xiaoying; Staggenborg, Scott A.; Welch, Stephen M.; Apley, Michael D.

    2013-01-01

    Groundwater provides a reliable tap to sustain agricultural production, yet persistent aquifer depletion threatens future sustainability. The High Plains Aquifer supplies 30% of the nation’s irrigated groundwater, and the Kansas portion supports the congressional district with the highest market value for agriculture in the nation. We project groundwater declines to assess when the study area might run out of water, and comprehensively forecast the impacts of reduced pumping on corn and cattle production. So far, 30% of the groundwater has been pumped and another 39% will be depleted over the next 50 y given existing trends. Recharge supplies 15% of current pumping and would take an average of 500–1,300 y to completely refill a depleted aquifer. Significant declines in the region’s pumping rates will occur over the next 15–20 y given current trends, yet irrigated agricultural production might increase through 2040 because of projected increases in water use efficiencies in corn production. Water use reductions of 20% today would cut agricultural production to the levels of 15–20 y ago, the time of peak agricultural production would extend to the 2070s, and production beyond 2070 would significantly exceed that projected without reduced pumping. Scenarios evaluate incremental reductions of current pumping by 20–80%, the latter rate approaching natural recharge. Findings substantiate that saving more water today would result in increased net production due to projected future increases in crop water use efficiencies. Society has an opportunity now to make changes with tremendous implications for future sustainability and livability. PMID:23980153

  20. PREFACE: 8th International Conference on the Physics of Highly Charged Ions (HCI-96)

    NASA Astrophysics Data System (ADS)

    Awaya, Yohko; Kambara, Tadashi

    1997-01-01

    These proceedings contain the papers presented at the Eighth International Conference on the Physics of Highly Charged Ions (HCI-96) which was held on September 23-26, 1996 in Omiya, Saitama, Japan, hosted by the Institute of Physical and Chemical Research (RIKEN). The first conference of this series was held in Stockholm, Sweden in 1982. The subject was the "Production and Physics of Highly Charged Ions". The conference has since been held every other year; in Oxford, UK (1984), Groningen, the Netherlands (1986), Grenoble, France (1988), Giessen, Germany (1990), Manhattan, Kansas, USA (1992) and Vienna, Austria (1994). When the first conference of this series was held, various highly charged ions were available from many heavy ion accelerators, which had been constructed since the 1960's, and ion sources such as EBIS and ECRIS, which were then new facilities. Subsequently, many other experimental techniques have been developed to study or to control highly charged ions, such as ion traps, EBIT's, storage rings, high-brilliance synchrotron radiation, and so forth. Now the properties of highly charged ions themselves and their interactions with various kinds of materials can be studied systematically using ions of any element at various collision energies. These studies will result in a deeper insight into their nature as well as giving us important basic data for use in the fields closely related to atomic physics. About 190 scientists from 18 countries registered at the HCI-96. The number of invited talks was 21 and that of contrib- uted papers 215. In these proceedings, 20 papers of invited talks and 116 papers on contributions are included. They are classified into categories of "Structure and Spectroscopy of Highly Charged Ions and Fundamental Aspects", "Highly Charged Ions in Plasmas and Strong Fields", "Interactions of Highly Charged Ions with Atoms and Ions", "Dynamic Processes Related to Molecules and Clusters", "Interactions of Highly Charged Ions with

  1. Preparation of Nano-Composite Ca2-αZnα(OH)4 with High Thermal Storage Capacity and Improved Recovery of Stored Heat Energy

    NASA Astrophysics Data System (ADS)

    Zheng, M.; Sun, S. M.; Hu, J.; Zhao, Y.; Yu, L. J.

    2014-11-01

    Thermal energy storage has very important prospects in many applications related to the use of renewable energies (solar energy, etc.) or other energy sources, such as waste heat from industrial processes. Thermochemical storage is very attractive for long-term storage, since it could be conducted at room temperature without energy losses. In the present paper, a novel nanocomposite material, Ca2-αZnα(OH)4, is prepared using coprecipitation methodology and is characterized by XRD and DSC tests. The XRD result shows that the grain size of the nano-composite ranges from 40 nm to 95 nm. The DSC test result shows that the nano-composite exhibits high thermal storage capacity: 764.5 J/g at α = 0.8555. Its thermal decomposition temperature was found to be approximately 180º. Itwas found possible to recover 63.25% of the stored heat energy.

  2. Long-term management of liquid high-level radioactive wastes stored at the Western New York Nuclear Service Center, West Valley

    NASA Astrophysics Data System (ADS)

    1981-07-01

    Environmental implications of possible alternatives for long-term management of the liquid high-level radioactive wastes stored in underground tanks in West Valley, New York were assessed and compared. Four basic alternatives, as well as options within these alternatives, considered in the EIS: (1) onsite processing to a terminal waste form for shipment and disposal in a federa repository; (2) onsite conversion to a solid interim form for shipment to a federal waste facility for later processing to a terminal form and shipment and subsequent disposal in a federal repository; (3) mixing the liquid wastes with cement and other additives, pouring it back into the existing tanks, and leaving onsite; and (4) no action (continued storage of the wastes in liquid form in the underground tanks at West Valley). Mitigative measures for environmental impacts were be required.

  3. The mechanism of charge generation in charge generation units containing HATCN for high-luminance tandem OLED display

    NASA Astrophysics Data System (ADS)

    Lee, Sunghun; Lee, Jeong-Hwan; Lee, Jae-Hyun; Kim, Jang-Joo

    2012-09-01

    We report the rate limiting step of charge generation in the charge generation units (CGUs) composed of a p-HTL, HATCN and n-doped electron transporting layer (n-ETL) where TAPC was used as the HTL. Energy level alignment determined by the capacitance-voltage (C-V) measurements and the current density-voltage characteristics of the structure clearly showed that the electron injection at the HATCN/n-ETL junction limits the charge generation in the CGUs rather than charge generation itself at the p-HTL/HATCN junction. Consequently, the CGUs with 30 mol% Rb2CO3 doped BPhen formed with the HATCN layer generates charges very efficiently and the excess voltage required to generate the current density of +/-10 mA/cm2 was around 0.17 V, which is extremely small compared with the literature values reported up to now.

  4. Apolipoprotein E expression and behavioral toxicity of high charge, high energy (HZE) particle radiation

    NASA Technical Reports Server (NTRS)

    Higuchi, Yoshinori; Nelson, Gregory A.; Vazquez, Marcelo; Laskowitz, Daniel T.; Slater, James M.; Pearlstein, Robert D.

    2002-01-01

    Apolipoprotein E (apoE) is a lipid binding protein that plays an important role in tissue repair following brain injury. In the present studies, we have investigated whether apoE affects the behavioral toxicity of high charge, high energy (HZE) particle radiation. METHODS: Sixteen male apoE knockout (KO) mice and sixteen genetically matched wild-type (WT) C57BL mice were used in this experiment. Half of the KO and half of the WT animals were irradiated with 600 MeV/amu iron particles (2 Gy whole body). The effect of irradiation on motor coordination and stamina (Rotarod test), exploratory behavior (open field test), and spatial working and reference memory (Morris water maze) was assessed. ROTAROD TEST: Performance was adversely affected by radiation exposure in both KO and WT groups at 30 d after irradiation. By 60 d after radiation, the radiation effect was lost in WT, but still apparent in irradiated KO mice. OPEN FIELD TEST: Radiation reduced open field exploratory activity 14, 28, 56, 84, and 168 d after irradiation of KO mice, but had no effect on WT mice. MORRIS WATER MAZE: Radiation adversely affected spatial working memory in the KO mice, but had no discernible effect in the WT mice as assessed 180 d after irradiation. In contrast, irradiated WT mice showed marked impairment of spatial reference memory in comparison to non-irradiated mice, while no effect of radiation was observed in KO mice. CONCLUSIONS: These studies show that apoE expression influences the behavioral toxicity of HZE particle radiation and suggest that apoE plays a role in the repair/recovery from radiation injury of the CNS. ApoE deficiency may exacerbate the previously reported effects of HZE particle radiation in accelerating the brain aging process.

  5. Key elements of space charge compensation on a low energy high intensity beam injector

    SciTech Connect

    Peng Shixiang; Lu Pengnan; Ren Haitao; Zhao Jie; Chen Jia; Xu Yuan; Guo Zhiyu; Chen Jia'er; Zhao Hongwei; Sun Liangting

    2013-03-15

    Space charge effect (SCE) along the beam line will decrease beam quality. Space charge compensation (SCC) with extra gas injection is a high-efficiency method to reduce SCE. In this paper, we will report the experimental results on the beam profile, potential distribution, beam emittance, and beam transmission efficiency of a 35 keV/90 mA H{sup +} beam and a 40 keV/10 mA He{sup +} beam compensated by Ar/Kr. The influence of gas type, gas flow, and injection location will be discussed. Emphasis is laid on the consideration of SCC when designing and commissioning a high intensity ion beam injector. Based on measured data, a new definition of space charge compensation degree is proposed.

  6. Key elements of space charge compensation on a low energy high intensity beam injector.

    PubMed

    Peng, Shixiang; Lu, Pengnan; Ren, Haitao; Zhao, Jie; Chen, Jia; Xu, Yuan; Guo, Zhiyu; Chen, Jia'er; Zhao, Hongwei; Sun, Liangting

    2013-03-01

    Space charge effect (SCE) along the beam line will decrease beam quality. Space charge compensation (SCC) with extra gas injection is a high-efficiency method to reduce SCE. In this paper, we will report the experimental results on the beam profile, potential distribution, beam emittance, and beam transmission efficiency of a 35 keV∕90 mA H(+) beam and a 40 keV∕10 mA He(+) beam compensated by Ar∕Kr. The influence of gas type, gas flow, and injection location will be discussed. Emphasis is laid on the consideration of SCC when designing and commissioning a high intensity ion beam injector. Based on measured data, a new definition of space charge compensation degree is proposed. PMID:23556812

  7. A miniature EBIT with ion extraction for isolating highly charged ions

    NASA Astrophysics Data System (ADS)

    Fogwell Hoogerheide, S.; Tan, J. N.

    2015-01-01

    A room-temperature miniature electron beam ion trap (EBIT) is being developed for the production of charge states with a relatively low ionization threshold. A unitary Penning trap is modified slightly to provide the magnetic field and electric potential necessary for ion production via electron impact in this compact EBIT. This design allows radial access for in- EBIT spectroscopy as well as extraction of highly-charged ions for isolation at low energy to investigate proposed experiments. A fast micro-channel plate is used as a time-of-flight detector to study the initial production of helium and neon ions. Planned work would also involve the use of a Wien filter to select a single charge state to be isolated in a secondary ion trap for various studies. For instance, fully stripped ions can be captured for recombination experiments to form one-electron ions in high-angular momentum Rydberg states.

  8. Electric field and space charge distribution measurement in transformer oil struck by impulsive high voltage

    NASA Astrophysics Data System (ADS)

    Sima, Wenxia; Guo, Hongda; Yang, Qing; Song, He; Yang, Ming; Yu, Fei

    2015-08-01

    Transformer oil is widely used in power systems because of its excellent insulation properties. The accurate measurement of electric field and space charge distribution in transformer oil under high voltage impulse has important theoretical and practical significance, but still remains challenging to date because of its low Kerr constant. In this study, the continuous electric field and space charge distribution over time between parallel-plate electrodes in high-voltage pulsed transformer oil based on the Kerr effect is directly measured using a linear array photoelectrical detector. Experimental results demonstrate the applicability and reliability of this method. This study provides a feasible approach to further study the space charge effects and breakdown mechanisms in transformer oil.

  9. Storing your medicines

    MedlinePlus

    ... medlineplus.gov/ency/patientinstructions/000534.htm Storing your medicines To use the sharing features on this page, ... child latch or lock. Do not use Damaged Medicine Damaged medicine may make you sick. DO NOT ...

  10. Battery materials for ultrafast charging and discharging.

    PubMed

    Kang, Byoungwoo; Ceder, Gerbrand

    2009-03-12

    The storage of electrical energy at high charge and discharge rate is an important technology in today's society, and can enable hybrid and plug-in hybrid electric vehicles and provide back-up for wind and solar energy. It is typically believed that in electrochemical systems very high power rates can only be achieved with supercapacitors, which trade high power for low energy density as they only store energy by surface adsorption reactions of charged species on an electrode material. Here we show that batteries which obtain high energy density by storing charge in the bulk of a material can also achieve ultrahigh discharge rates, comparable to those of supercapacitors. We realize this in LiFePO(4) (ref. 6), a material with high lithium bulk mobility, by creating a fast ion-conducting surface phase through controlled off-stoichiometry. A rate capability equivalent to full battery discharge in 10-20 s can be achieved. PMID:19279634

  11. Optical Transitions in Highly Charged Californium Ions with High Sensitivity to Variation of the Fine-Structure Constant

    NASA Astrophysics Data System (ADS)

    Berengut, J. C.; Dzuba, V. A.; Flambaum, V. V.; Ong, A.

    2012-08-01

    We study electronic transitions in highly charged Cf ions that are within the frequency range of optical lasers and have very high sensitivity to potential variations in the fine-structure constant, α. The transitions are in the optical range despite the large ionization energies because they lie on the level crossing of the 5f and 6p valence orbitals in the thallium isoelectronic sequence. Cf16+ is a particularly rich ion, having several narrow lines with properties that minimize certain systematic effects. Cf16+ has very large nuclear charge and large ionization energy, resulting in the largest α sensitivity seen in atomic systems. The lines include positive and negative shifters.

  12. Provenance Store Evaluation

    SciTech Connect

    Paulson, Patrick R.; Gibson, Tara D.; Schuchardt, Karen L.; Stephan, Eric G.

    2008-03-01

    Requirements for the provenance store and access API are developed. Existing RDF stores and APIs are evaluated against the requirements and performance benchmarks. The team’s conclusion is to use MySQL as a database backend, with a possible move to Oracle in the near-term future. Both Jena and Sesame’s APIs will be supported, but new code will use the Jena API

  13. Electrospray Charging of Minerals: Surface Chemistry and Applications to High-Velocity Microparticle Impacts

    NASA Astrophysics Data System (ADS)

    Daly, T.; Call, S.; Austin, D. E.

    2010-12-01

    Electrospray is a soft ionization technique commonly used to charge large biomolecules; it has, however, also been applied to inorganic compounds. We are extending this technique to mineral microparticles. Electrospray-charged mineral microparticles are interesting in the context of surface science because surface chemistry dictates where and how charge carriers can bond to mineral surfaces. In addition, using electrospray to charge mineral particles allows these particles to be electrostatically accelerated as projectiles in high- and hyper-velocity impacts. Since current techniques for producing high- and hyper-velocity microparticle impacts are largely limited to metal or metal-coated projectiles, using minerals as projectiles is a significant innovation. Electrospray involves three steps: creation of charged droplets containing solute/particles, evaporation and bifurcation of droplets, and desolvation of the solute/particles. An acidified solution is slowly pumped through a needle in a strong DC field, which causes the solution to break into tiny, charged droplets laden with protons. Solvent evaporates from the electrosprayed droplets as they move through the electric field toward a grounded plate, causing the charge on the droplet to increase relative to its mass. When the electrosprayed droplet’s charge becomes such that the droplet is no longer stable, it bifurcates, and each of the resulting droplets carries some of the original droplet’s charge. Evaporation and bifurcation continues until the solute particle is completely desolvated. The result is a protonated solute molecule or particle. We built an instrument that electrosprays particles into vacuum and measures them using an image charge detector. Mineral microparticles were prepared by grinding natural mineral samples to ~2 µm diameter. These microparticles are then added to a 4:1 methanol:water solution to create a 0.005% w/v suspension. The suspension is electrosprayed into vacuum, where the

  14. Space-charge perturbation effects in photonic tubes under high irradiation

    SciTech Connect

    Kalibjian, R.; Peterson, G.G.

    1982-06-01

    Potential perturbation effects at the cathode region of a photonic tube can occur at high intensity due to space-charge. Using appropriate photoelectron energy distribution functions, the electric field at the cathode is calculated and its effect upon the spatial/temporal resolution is examined.

  15. Dust particle injector for hypervelocity accelerators provides high charge-to-mass ratio

    NASA Technical Reports Server (NTRS)

    Berg, O. E.

    1966-01-01

    Injector imparts a high charge-to-mass ratio to microparticles and injects them into an electrostatic accelerator so that the particles are accelerated to meteoric speeds. It employs relatively large masses in the anode and cathode structures with a relatively wide separation, thus permitting a large increase in the allowable injection voltages.

  16. Theory of Bound-Electron g Factor in Highly Charged Ions

    SciTech Connect

    Shabaev, V. M.; Glazov, D. A.; Plunien, G.; Volotka, A. V.

    2015-09-15

    The paper presents the current status of the theory of bound-electron g factor in highly charged ions. The calculations of the relativistic, quantum electrodynamics (QED), nuclear recoil, nuclear structure, and interelectronic-interaction corrections to the g factor are reviewed. Special attention is paid to tests of QED effects at strong coupling regime and determinations of the fundamental constants.

  17. Generating free charges by carrier multiplication in quantum dots for highly efficient photovoltaics.

    PubMed

    Ten Cate, Sybren; Sandeep, C S Suchand; Liu, Yao; Law, Matt; Kinge, Sachin; Houtepen, Arjan J; Schins, Juleon M; Siebbeles, Laurens D A

    2015-02-17

    CONSPECTUS: In a conventional photovoltaic device (solar cell or photodiode) photons are absorbed in a bulk semiconductor layer, leading to excitation of an electron from a valence band to a conduction band. Directly after photoexcitation, the hole in the valence band and the electron in the conduction band have excess energy given by the difference between the photon energy and the semiconductor band gap. In a bulk semiconductor, the initially hot charges rapidly lose their excess energy as heat. This heat loss is the main reason that the theoretical efficiency of a conventional solar cell is limited to the Shockley-Queisser limit of ∼33%. The efficiency of a photovoltaic device can be increased if the excess energy is utilized to excite additional electrons across the band gap. A sufficiently hot charge can produce an electron-hole pair by Coulomb scattering on a valence electron. This process of carrier multiplication (CM) leads to formation of two or more electron-hole pairs for the absorption of one photon. In bulk semiconductors such as silicon, the energetic threshold for CM is too high to be of practical use. However, CM in nanometer sized semiconductor quantum dots (QDs) offers prospects for exploitation in photovoltaics. CM leads to formation of two or more electron-hole pairs that are initially in close proximity. For photovoltaic applications, these charges must escape from recombination. This Account outlines our recent progress in the generation of free mobile charges that result from CM in QDs. Studies of charge carrier photogeneration and mobility were carried out using (ultrafast) time-resolved laser techniques with optical or ac conductivity detection. We found that charges can be extracted from photoexcited PbS QDs by bringing them into contact with organic electron and hole accepting materials. However, charge localization on the QD produces a strong Coulomb attraction to its counter charge in the organic material. This limits the production

  18. High pressure study of charge transfer complexes and radical ion salts: A review

    NASA Astrophysics Data System (ADS)

    Singh, Yadunath

    2016-05-01

    High pressure is an important tool to study of material in respect of variation in interatomic distances, phase transitions and other physical properties. The pressure study of charge transfer complexes and radical ion salts provide us a better understanding about the effect of charge transfer forces, structural changes, formation of new ground states, suppression ofPeierls distortions occurs particularly at low temperatures and the intra-molecular overlapping etc. in these materials. The pressure plays a significant role in bringing superconducting transitions in the organic materials.

  19. Highly charged ion impact on uracil: Cross sections measurements and scaling

    NASA Astrophysics Data System (ADS)

    Agnihotri, A. N.; Kasthurirangan, S.; Champion, C.; Rivarola, R. D.; Tribedi, L. C.

    2014-04-01

    Absolute total ionization cross sections (TCS) of uracil in collisions with highly charge C, O and F ions are measured. The scaling properties of cross sections are obtained as a function of projectile charge state and energy. The measurements are compared with the CDW-EIS, CB1 and CTMC calculations. The absolute double differential cross sections (DDCS) of secondary electron emission from uracil in collisions with bare MeV energy C and O ions are also measured. Large enhancement in forward emission is observed.

  20. Ablation of GaAs by Intense, Ultrafast Electronic Excitation from Highly Charged Ions

    SciTech Connect

    Schenkel, T.; Hamza, A.V.; Barnes, A.V.; Schneider, D.H.; Banks, J.C.; Doyle, B.L.

    1998-09-01

    We have measured total ablation rates and secondary ion yields from undoped GaAs(100) interacting with slow (v=6.6{times}10{sup 5} m /s) , very highly charged ions. Ablation rates increase strongly as a function of projectile charge. Some 1400thinspthinsptarget atoms are removed when a single Th{sup 70+} ion deposits a potential energy of 152.6thinspthinspkeV within a few femtoseconds into a nanometer-sized target volume. We discuss models for ablation of semiconductors by intense, ultrafast electronic excitation. {copyright} {ital 1998} {ital The American Physical Society}

  1. Fragmentation of amino acids induced by collisions with low-energy highly charged ions

    NASA Astrophysics Data System (ADS)

    Piekarski, D. G.; Maclot, S.; Domaracka, A.; Adoui, L.; Alcamí, M.; Rousseau, P.; Díaz-Tendero, S.; Huber, B. A.; Martín, F.

    2014-04-01

    Fragmentation of amino acids NH2-(CH2)n-COOH (n=1 glycine; n=2 β-alanine and n=3 γ-aminobutyric acid GABA) following collisions with slow highly charged ions has been studied in the gas phase by a combined experimental and theoretical approach. In the experiments, a multi-coincidence detection method was used to deduce the charge state of the molecules before fragmentation. Quantum chemistry calculations have been carried out in the basis of the density functional theory and ab initio molecular dynamics. The combination of both methodologies is essential to unambiguously unravel the different fragmentation pathways.

  2. Charge Transfer and Triplet States in High Efficiency OPV Materials and Devices

    NASA Astrophysics Data System (ADS)

    Dyakonov, Vladimir

    2013-03-01

    The advantage of using polymers and molecules in electronic devices, such as light-emitting diodes (LED), field-effect transistors (FET) and, more recently, solar cells (SC) is justified by the unique combination of high device performance and processing of the semiconductors used. Power conversion efficiency of nanostructured polymer SC is in the range of 10% on lab scale, making them ready for up-scaling. Efficient charge carrier generation and recombination in SC are strongly related to dissociation of the primary singlet excitons. The dissociation (or charge transfer) process should be very efficient in photovoltaics. The mechanisms governing charge carrier generation, recombination and transport in SC based on the so-called bulk-heterojunctions, i.e. blends of two or more semiconductors with different electron affinities, appear to be very complex, as they imply the presence of the intermediate excited states, neutral and charged ones. Charge transfer states, or polaron pairs, are the intermediate states between free electrons/holes and strongly bound excitons. Interestingly, the mostly efficient OLEDs to date are based on the so-called triplet emitters, which utilize the triplet-triplet annihilation process. In SC, recent investigations indicated that on illumination of the device active layer, not only mobile charges but also triplet states were formed. With respect to triplets, it is unclear how these excited states are generated, via inter-system crossing or via back transfer of the electron from acceptor to donor. Triplet formation may be considered as charge carrier loss channel; however, the fusion of two triplets may lead to a formation of singlet excitons instead. In such case, a generation of charges by utilizing of the so far unused photons will be possible. The fundamental understanding of the processes involving the charge transfer and triplet states and their relation to nanoscale morphology and/or energetics of blends is essential for the

  3. A modified QM/MM Hamiltonian with the Self-Consistent-Charge Density-Functional-Tight-Binding Theory for highly charged QM regions

    PubMed Central

    Hou, Guanhua; Zhu, Xiao; Elstner, Marcus; Cui, Qiang

    2012-01-01

    To improve the description of electrostatic interaction between QM and MM atoms when the QM is SCC-DFTB, we adopt a Klopman-Ohno (KO) functional form which considers the finite size of the QM and MM charge distributions. Compared to the original implementation that used a simple Coulombic interaction between QM Mulliken and MM point charges, the KO based QM/MM scheme takes charge penetration effect into consideration and therefore significantly improves the description of QM/MM interaction at short range, especially when the QM region is highly charged. To be consistent with the third-order formulation of SCC-DFTB, the Hubbard parameter in the KO functional is dependent on the QM charge. As a result, the effective size of the QM charge distribution naturally adjusts as the QM region undergoes chemical transformations, making the KO based QM/MM scheme particularly attractive for describing chemical reactions in the condensed phase. Together with the van der Waals parameters for the QM atom, the KO based QM/MM model introduces four parameters for each element type. They are fitted here based on microsolvation models of small solutes, focusing on negatively charged molecular ions, for elements O, C, H and P with a specific version of SCC-DFTB (SCC-DFTBPR). Test calculations confirm that the KO based QM/MM scheme significantly improves the interactions between QM and MM atoms over the original point charge based model and it is transferable due to the small number of parameters. The new form of QM/MM Hamiltonian will greatly improve the applicability of SCC-DFTB based QM/MM methods to problems that involve highly charged QM regions, such as enzyme catalyzed phosphoryl transfers. PMID:23275762

  4. Angular and charge state distributions of highly charged ions scattered during low energy surface-channeling interactions with Au(110)

    SciTech Connect

    Meyer, F.W.; Folkerts, L.; Schippers, S.

    1994-10-01

    The authors have measured scattered projectile angular and charge state distributions for 3.75 keV/amu O{sup q+} (3 {le} q {le} 8) and 1.2 keV/amu Ar{sup 1+} (3 {le} q {le} 14) ions grazingly incident along the [110] and [100] directions of a Au(110) single crystal target. Scattered projectile angular distribution characteristic of surface channeling are observed. For both incident species, the dominant scattered charge fraction is neutral, which varies only by a few percent as a function of incident charge state. Significant O{sup {minus}} formation is observed, which manifests a distinct velocity threshold. For incident Ar projectiles with open L-shells, the positive scattered charge fractions, while always less than about 10%, increase linearly with increasing number of initial L-shell vacancies.

  5. The Use of Ionization Electron Columns for Space-Charge Compensation in High Intensity Proton Accelerators

    SciTech Connect

    Shiltsev, V.; Alexahin, Y.; Kamerdzhiev, V.; Kapin, V.; Kuznetsov, G.

    2009-01-22

    We discuss a recent proposal to use strongly magnetized electron columns created by beam ionization of the residual gas for compensation of space charge forces of high intensity proton beams in synchrotrons and linacs. The electron columns formed by trapped ionization electrons in a longitudinal magnetic field that assures transverse distribution of electron space charge in the column is the same as in the proton beam. Electrostatic electrodes are used to control the accumulation and release of the electrons. Ions are not magnetized and drift away without affecting the compensation. Possible technical solution for the electron columns is presented. We also discuss the first numerical simulation results for space-charge compensation in the FNAL Booster and results of relevant beam studies in the Tevatron.

  6. The use of ionization electron columns for space-charge compensation in high intensity proton accelerators

    SciTech Connect

    Shiltsev, V.; Alexahin, Y.; Kamerdzhiev, V.; Kapin, V.; Kuznetsov, G.; /Fermilab

    2009-01-01

    We discuss a recent proposal to use strongly magnetized electron columns created by beam ionization of the residual gas for compensation of space charge forces of high intensity proton beams in synchrotrons and linacs. The electron columns formed by trapped ionization electrons in a longitudinal magnetic field that assures transverse distribution of electron space charge in the column is the same as in the proton beam. Electrostatic electrodes are used to control the accumulation and release of the electrons. Ions are not magnetized and drift away without affecting the compensation. Possible technical solution for the electron columns is presented. We also discuss the first numerical simulation results for space-charge compensation in the FNAL Booster and results of relevant beam studies in the Tevatron.

  7. Charge-distribution effect of imaging molecular structure by high-order above-threshold ionization

    SciTech Connect

    Wang Bingbing; Fu Panming; Guo Yingchun; Zhang Bin; Zhao Zengxiu; Yan Zongchao

    2010-10-15

    Using a triatomic molecular model, we show that the interference pattern in the high-order above-threshold ionization (HATI) spectrum depends dramatically on the charge distribution of the molecular ion. Therefore the charge distribution can be considered a crucial factor for imaging a molecular geometric structure. Based on this study, a general destructive interference formula for each above-threshold ionization channel is obtained for a polyatomic molecule concerning the positions and charge values of each nuclei. Comparisons are made for the HATI spectra of CO{sub 2}, O{sub 2}, NO{sub 2}, and N{sub 2}. These results may shed light on imaging complex molecular structure by the HATI spectrum.

  8. High-voltage sheaths and charge neutralization in space power systems

    NASA Technical Reports Server (NTRS)

    Satyanarayana, P.; Chang, Chia-Lie; Drobot, Adam; Papadopoulos, Dennis

    1991-01-01

    The authors examine the electrodynamics of charged platforms in the ionosphere with a variety of analytical and numerical models. These models have been specifically designed to study the tethered satellite system (TSS-1) due to be launched in early 1992. One of the objectives of TSS-1 is to determine the potential of tethers for electrical power generation from orbital motion across the earth's magnetic field. The author identifies and explores important aspects of the interaction between the ambient ionospheric plasma and moving charged orbital platforms: (1) the formation of energetic particles in the wake of a nominally neutral satellite, (2) transient current collection by a highly charged platform, (3) the current closure paths in the ionosphere between multiple polarized platforms, and (4) the conditions for rapid neutralization by enhanced plasma formation in the presence of effluent gases.

  9. Demonstration of cathode emittance dominated high bunch charge beams in a DC gun-based photoinjector

    SciTech Connect

    Gulliford, Colwyn Bartnik, Adam Bazarov, Ivan; Dunham, Bruce; Cultrera, Luca

    2015-03-02

    We present the results of transverse emittance and longitudinal current profile measurements of high bunch charge (≥100 pC) beams produced in the DC gun-based Cornell energy recovery linac photoinjector. In particular, we show that the cathode thermal and core beam emittances dominate the final 95% and core emittances measured at 9–9.5 MeV. Additionally, we demonstrate excellent agreement between optimized 3D space charge simulations and measurement, and show that the quality of the transverse laser distribution limits the optimal simulated and measured emittances. These results, previously thought achievable only with RF guns, demonstrate that DC gun based photoinjectors are capable of delivering beams with sufficient single bunch charge and beam quality suitable for many current and next generation accelerator projects such as Energy Recovery Linacs and Free Electron Lasers.

  10. Demonstration of cathode emittance dominated high bunch charge beams in a DC gun-based photoinjector

    NASA Astrophysics Data System (ADS)

    Gulliford, Colwyn; Bartnik, Adam; Bazarov, Ivan; Dunham, Bruce; Cultrera, Luca

    2015-03-01

    We present the results of transverse emittance and longitudinal current profile measurements of high bunch charge (≥100 pC) beams produced in the DC gun-based Cornell energy recovery linac photoinjector. In particular, we show that the cathode thermal and core beam emittances dominate the final 95% and core emittances measured at 9-9.5 MeV. Additionally, we demonstrate excellent agreement between optimized 3D space charge simulations and measurement, and show that the quality of the transverse laser distribution limits the optimal simulated and measured emittances. These results, previously thought achievable only with RF guns, demonstrate that DC gun based photoinjectors are capable of delivering beams with sufficient single bunch charge and beam quality suitable for many current and next generation accelerator projects such as Energy Recovery Linacs and Free Electron Lasers.

  11. Space Charge Formation and Electrical Breakdown at High Temperature Region in PVC for Electrical Wiring Assembly

    NASA Astrophysics Data System (ADS)

    Miura, Masakazu; Fukuma, Masumi; Kishida, Satoru

    The Polyvinyl chloride (PVC), the most popular insulating material, is used as an insulating material of various electric products. When using an electrical wiring assembly code over the power capacity, PVC could melt by the joule heating and cause an electrical breakdown. Therefore, it is necessary to clarify the electrical breakdown phenomena near the melting point (170°C) in PVC. In this paper, space charge distribution and conduction current have been measured in PVC sheets up to the electrical breakdown in the range from room temperature to 200°C under DC electric field. The breakdown strength decreases with temperature in PVC. Small hetero-space charges are accumulated near both of the electrodes at room temperature region. At high temperature region above 100°C, it is observed that positive charges are injected from anode and move toward the cathode; the electric field is emphasized near the cathode due to the packet-like positive charge in PVC. It shows a thermal breakdown process of the electric fields due to positive charge behavior and conduction current increase with temperature near the melting point in PVC.

  12. Unconventional charge order in a co-doped high-Tc superconductor.

    PubMed

    Pelc, D; Vučković, M; Grafe, H-J; Baek, S-H; Požek, M

    2016-01-01

    Charge-stripe order has recently been established as an important aspect of cuprate high-Tc superconductors. However, owing to the complex interplay between competing phases and the influence of disorder, it is unclear how it emerges from the parent high-temperature state. Here we report on the discovery of an unconventional ordered phase between charge-stripe order and (pseudogapped) metal in the cuprate La1.8-xEu0.2SrxCuO4. We use three complementary experiments-nuclear quadrupole resonance, nonlinear conductivity and specific heat-to demonstrate that the order appears through a sharp phase transition and exists in a dome-shaped region of the phase diagram. Our results imply that the new phase is a state, which preserves translational symmetry: a charge nematic. We thus resolve the process of charge-stripe development in cuprates, show that this nematic phase is distinct from high-temperature pseudogap and establish a link with other strongly correlated electronic materials with prominent nematic order. PMID:27605152

  13. Observation of visible forbidden lines from highly charged tungsten ions at the large helical device

    NASA Astrophysics Data System (ADS)

    Kato, D.; Goto, M.; Morita, S.; Murakami, I.; Sakaue, H. A.; Ding, X. B.; Sudo, S.; Suzuki, C.; Tamura, N.; Nakamura, N.; Watanabe, H.; Koike, F.

    2013-09-01

    Visible line emission from highly charged tungsten ions has been observed at the large helical device (LHD) using a tracer encapsulated solid pellet. One of the measured lines is assigned to a magnetic-dipole (M1) line of the ground-term fine-structure transition of W26+. The other line is unidentified but probably due to a highly charged tungsten ion. Photon emission was observed at 40 lines of sight divided along the vertical direction of a horizontally elongated poloidal cross section of the LHD plasma. The line-integrated intensity of the M1 line along each line of sight indicates a peaked profile at the plasma center where the electron temperatures are high enough so that tungsten ions are highly ionized.

  14. School Store Operation and Control.

    ERIC Educational Resources Information Center

    Barger, Bill J.

    Written to assist the teacher-sponsor responsible for operating a school store, this book offers a system developed specifically for the operation and control of such a store. It also shows ways in which a school store can be used for training students. Chapter 1 discusses a successful school store operated by students and a store record system…

  15. Calculation of dose, dose equivalent, and relative biological effectiveness for high charge and energy ion beams

    NASA Technical Reports Server (NTRS)

    Wilson, J. W.; Chun, S. Y.; Reginatto, M.; Hajnal, F.

    1995-01-01

    The Green's function for the transport of ions of high charge and energy is utilized with a nuclear fragmentation database to evaluate dose, dose equivalent, and RBE for C3H10T1/2 cell survival and neo-plastic transformation as function of depth in soft tissue. Such evaluations are useful to estimates of biological risk for high altitude aircraft, space operations, accelerator operations, and biomedical application.

  16. High Speed Multichannel Charge Sensitive Data Acquisition System with Self-Triggered Event Timing

    PubMed Central

    Tremsin, Anton S.; Siegmund, Oswald H.W.; Vallerga, John V.; Raffanti, Rick; Weiss, Shimon; Michalet, Xavier

    2010-01-01

    A number of modern experiments require simultaneous measurement of charges on multiple channels at > MHz event rates with an accuracy of 100-1000 e− rms. One widely used data processing scheme relies on application of specific integrated circuits enabling multichannel analog peak detection asserted by an external trigger followed by a serial/sparsified readout. Although this configuration minimizes the back end electronics, its counting rate capability is limited by the speed of the serial readout. Recent advances in analog to digital converters and FPGA devices enable fully parallel high speed multichannel data processing with digital peak detection enhanced by finite impulse response filtering. Not only can accurate charge values be obtained at high event rates, but the timing of the event on each channel can also be determined with high accuracy. We present the concept and first experimental tests of fully parallel 128-channel charge sensitive data processing electronics capable of measuring charges with accuracy of ~1000 e- rms. Our system does not require an external trigger and, in addition to charge values, it provides the event timing with an accuracy of ~1 ns FWHM. One of the possible applications of this system is high resolution position sensitive event counting detectors with microchannel plates combined with cross strip readout. Implementation of fast data acquisition electronics increases the counting rates of those detectors to multi-MHz level, preserving their unique capability of virtually noiseless detection of both position (with accuracy of ~10 μm FWHM) and timing (~1 ns FWHM) of individual particles, including photons, electrons, ions, neutrals, and neutrons. PMID:20174482

  17. Neutron-induced reaction studies using stored ions

    NASA Astrophysics Data System (ADS)

    Glorius, Jan; Litvinov, Yuri A.; Reifarth, René

    2015-11-01

    Storage rings provide unique possibilities for investigations of nuclear reactions. Radioactive ions can be stored if the ring is connected to an appropriate facility and reaction studies are feasible at low beam intensities because of the recycling of beam particles. Using gas jet or droplet targets, charged particle-induced reactions on short-lived isotopes can be studied in inverse kinematics. In such a system a high-flux reactor could serve as a neutron target extending the experimental spectrum to neutron-induced reactions. Those could be studied over a wide energy range covering the research fields of nuclear astrophysics and reactor safety, transmutation of nuclear waste and fusion.

  18. SPARC: The Stored Particle Atomic Research Collaboration At FAIR

    SciTech Connect

    Stoehlker, Th.; Beyer, H. F.; Braeuning-Demian, A.; Brandau, C.; Herfurth, F.; Kozhuharov, Ch.; Kuehl, Th.; Liesen, D.; Litvinov, Yu.; Noertershaeuser, W.; Kester, O.; Quint, W.; Spillmann, U.; Winters, D.; Gumberidze, A.; Grisenti, R. E.; Petridis, N.; Hagmann, S.; Maertin, R.; Schramm, U.

    2011-06-01

    The future international accelerator Facility for Antiproton and Ion Research (FAIR) encompasses 4 scientific pillars containing at this time 14 approved technical proposals worked out by more than 2000 scientists from all over the world. They offer a wide range of new and challenging opportunities for atomic physics research in the realm of highly-charged heavy ions and exotic nuclei. As one of the backbones of the Atomic, Plasma Physics and Applications (APPA) pillar, the Stored Particle Atomic Physics Research Collaboration (SPARC) has organized tasks and activities in various working groups for which we will present a concise survey on their current status.

  19. High-k shallow traps observed by charge pumping with varying discharging times

    SciTech Connect

    Ho, Szu-Han; Chen, Ching-En; Tseng, Tseung-Yuen; Chang, Ting-Chang; Lu, Ying-Hsin; Lo, Wen-Hung; Tsai, Jyun-Yu; Liu, Kuan-Ju; Wang, Bin-Wei; Cao, Xi-Xin; Chen, Hua-Mao; Cheng, Osbert; Huang, Cheng-Tung; Chen, Tsai-Fu

    2013-11-07

    In this paper, we investigate the influence of falling time and base level time on high-k bulk shallow traps measured by charge pumping technique in n-channel metal-oxide-semiconductor field-effect transistors with HfO{sub 2}/metal gate stacks. N{sub T}-V{sub high} {sub level} characteristic curves with different duty ratios indicate that the electron detrapping time dominates the value of N{sub T} for extra contribution of I{sub cp} traps. N{sub T} is the number of traps, and I{sub cp} is charge pumping current. By fitting discharge formula at different temperatures, the results show that extra contribution of I{sub cp} traps at high voltage are in fact high-k bulk shallow traps. This is also verified through a comparison of different interlayer thicknesses and different Ti{sub x}N{sub 1−x} metal gate concentrations. Next, N{sub T}-V{sub high} {sub level} characteristic curves with different falling times (t{sub falling} {sub time}) and base level times (t{sub base} {sub level}) show that extra contribution of I{sub cp} traps decrease with an increase in t{sub falling} {sub time}. By fitting discharge formula for different t{sub falling} {sub time}, the results show that electrons trapped in high-k bulk shallow traps first discharge to the channel and then to source and drain during t{sub falling} {sub time}. This current cannot be measured by the charge pumping technique. Subsequent measurements of N{sub T} by charge pumping technique at t{sub base} {sub level} reveal a remainder of electrons trapped in high-k bulk shallow traps.

  20. One Hundred Twenty-One Dystrophin Point Mutations Detected from Stored DNA Samples by Combinatorial Denaturing High-Performance Liquid Chromatography

    PubMed Central

    Torella, Annalaura; Trimarco, Amelia; Del Vecchio Blanco, Francesca; Cuomo, Anna; Aurino, Stefania; Piluso, Giulio; Minetti, Carlo; Politano, Luisa; Nigro, Vincenzo

    2010-01-01

    Duchenne and Becker muscular dystrophies are caused by a large number of different mutations in the dystrophin gene. Outside of the deletion/duplication “hot spots,” small mutations occur at unpredictable positions. These account for about 15 to 20% of cases, with the major group being premature stop codons. When the affected male is deceased, carrier testing for family members and prenatal diagnosis become difficult and expensive. We tailored a cost-effective and reliable strategy to discover point mutations from stored DNA samples in the absence of a muscle biopsy. Samples were amplified in combinatorial pools and tested by denaturing high-performance liquid chromatography analysis. An anomalous elution profile belonging to two different pools univocally addressed the allelic variation to an unambiguous sample. Mutations were then detected by sequencing. We identified 121 mutations of 99 different types. Fifty-six patients show stop codons that represent the 46.3% of all cases. Three non-obvious single amino acid mutations were considered as causative. Our data support combinatorial denaturing high-performance liquid chromatography analysis as a clear-cut strategy for time and cost-effective identification of small mutations when only DNA is available. PMID:19959795

  1. Initial performance assessment of the disposal of spent nuclear fuel and high-level waste stored at Idaho National Engineering Laboratory. Volume 2: Appendices

    SciTech Connect

    Rechard, R.P.

    1993-12-01

    This performance assessment characterized plausible treatment options conceived by the Idaho National Engineering Laboratory (INEL) for its spent fuel and high-level radioactive waste and then modeled the performance of the resulting waste forms in two hypothetical, deep, geologic repositories: one in bedded salt and the other in granite. The results of the performance assessment are intended to help guide INEL in its study of how to prepare wastes and spent fuel for eventual permanent disposal. This assessment was part of the Waste Management Technology Development Program designed to help the US Department of Energy develop and demonstrate the capability to dispose of its nuclear waste, as mandated by the Nuclear Waste Policy Act of 1982. The waste forms comprised about 700 metric tons of initial heavy metal (or equivalent units) stored at the INEL: graphite spent fuel, experimental low enriched and highly enriched spent fuel, and high-level waste generated during reprocessing of some spent fuel. Five different waste treatment options were studied; in the analysis, the options and resulting waste forms were analyzed separately and in combination as five waste disposal groups. When the waste forms were studied in combination, the repository was assumed to also contain vitrified high-level waste from three DOE sites for a common basis of comparison and to simulate the impact of the INEL waste forms on a moderate-sized repository, The performance of the waste form was assessed within the context of a whole disposal system, using the U.S. Environmental Protection Agency`s Environmental Radiation Protection Standards for Management and Disposal of Spent Nuclear Fuel, High-Level and Transuranic Radioactive Wastes, 40 CFR 191, promulgated in 1985. Though the waste form behavior depended upon the repository type, all current and proposed waste forms provided acceptable behavior in the salt and granite repositories.

  2. Ultra-high-mass mass spectrometry with charge discrimination using cryogenic detectors

    DOEpatents

    Frank, Matthias; Mears, Carl A.; Labov, Simon E.; Benner, W. Henry

    1999-01-01

    An ultra-high-mass time-of-flight mass spectrometer using a cryogenic particle detector as an ion detector with charge discriminating capabilities. Cryogenic detectors have the potential for significantly improving the performance and sensitivity of time-of-flight mass spectrometers, and compared to ion multipliers they exhibit superior sensitivity for high-mass, slow-moving macromolecular ions and can be used as "stop" detectors in time-of-flight applications. In addition, their energy resolving capability can be used to measure the charge state of the ions. Charge discrimination is very valuable in all time-of-flight mass spectrometers. Using a cryogenically-cooled Nb-Al.sub.2 O.sub.3 -Nb superconductor-insulator-superconductor (SIS) tunnel junction (STJ) detector operating at 1.3 K as an ion detector in a time-of-flight mass spectrometer for large biomolecules it was found that the STJ detector has charge discrimination capabilities. Since the cryogenic STJ detector responds to ion energy and does not rely on secondary electron production, as in the conventionally used microchannel plate (MCP) detectors, the cryogenic detector therefore detects large molecular ions with a velocity-independent efficiency approaching 100%.

  3. Modeling of direct beam extraction for a high-charge-state fusion driver

    NASA Astrophysics Data System (ADS)

    Anderson, O. A.; Grant Logan, B.

    A newly proposed type of multicharged ion source offers the possibility of an economically advantageous high-charge-state fusion driver. Multiphoton absorption in an intense uniform laser focus can give multiple charge states of high purity, simplifying or eliminating the need for charge-state separation downstream. Very large currents (hundreds of amperes) can be extracted from this type of source. Several arrangements are possible. For example, the laser plasma could be tailored for storage in a magnetic bucket, with beam extracted from the bucket. A different approach, described in this report, is direct beam extraction from the expanding laser plasma. We discuss extraction and focusing for the particular case of a 4.1 MV beam of Xe 16+ ions. The maximum duration of the beam pulse is limited by the total charge in the plasma, while the practical pulse length is determined by the range of plasma radii over which good beam optics can be achieved. The extraction electrode contains a solenoid for beam focusing. Our design studies were carried out first with an envelope code and then with a self-consistent particle code. Results from our initial model showed that hundreds of amperes could be extracted, but that most of this current missed the solenoid entrance or was intercepted by the wall and that only a few amperes were able to pass through. We conclude with an improved design which increases the surviving beam to more than 70 A.

  4. Ultra-high-mass mass spectrometry with charge discrimination using cryogenic detectors

    SciTech Connect

    Frank, M.; Mears, C.A.; Labov, S.E.; Benner, W.H.

    1999-11-30

    An ultra-high-mass time-of-flight mass spectrometer is described which uses a cryogenic particle detector as an ion detector with charge discriminating capabilities. Cryogenic detectors have the potential for significantly improving the performance and sensitivity of time-of-flight mass spectrometers, and compared to ion multipliers they exhibit superior sensitivity for high-mass, slow-moving macromolecular ions and can be used as ``stop'' detectors in time-of-flight applications. In addition, their energy resolving capability can be used to measure the charge state of the ions. Charge discrimination is very valuable in all time-of-flight mass spectrometers. Using a cryogenically-cooled Nb-Al{sub 2}O{sub 3}-Nb superconductor-insulator-superconductor (SIS) tunnel junction (STJ) detector operating at 1.3 K as an ion detector in a time-of-flight mass spectrometer for large biomolecules it was found that the STJ detector has charge discrimination capabilities. Since the cryogenic STJ detector responds to ion energy and does not rely on secondary electron production, as in the conventionally used microchannel plate (MCP) detectors, the cryogenic detector therefore detects large molecular ions with a velocity-independent efficiency approaching 100%.

  5. The Store Challenge

    ERIC Educational Resources Information Center

    Roman, Harry T.

    2014-01-01

    Biomedical and robotic technologies are merging to present a wonderful opportunity to develop artificial limbs and prosthetic devices for humans injured on the job, in the military, or due to disease. In this challenge, students will have the opportunity to design a store or online service that specifically dedicates itself to amputees. Described…

  6. Storing and transporting energy

    DOEpatents

    McClaine, Andrew W.; Brown, Kenneth

    2010-09-07

    Among other things, hydrogen is released from water at a first location using energy from a first energy source; the released hydrogen is stored in a metal hydride slurry; and the metal hydride slurry is transported to a second location remote from the first location.

  7. Charging system using solar panels and a highly resonant wireless power transfer model for small UAS applications

    NASA Astrophysics Data System (ADS)

    Hallman, Sydney N.; Huck, Robert C.; Sluss, James J.

    2016-05-01

    The use of a wireless charging system for small, unmanned aircraft system applications is useful for both military and commercial consumers. An efficient way to keep the aircraft's batteries charged without interrupting flight would be highly marketable. While the general concepts behind highly resonant wireless power transfer are discussed in a few publications, the details behind the system designs are not available even in academic journals, especially in relation to avionics. Combining a highly resonant charging system with a solar panel charging system can produce enough power to extend the flight time of a small, unmanned aircraft system without interruption. This paper provides an overview of a few of the wireless-charging technologies currently available and outlines a preliminary design for an aircraft-mounted battery charging system.

  8. High charge state carbon and oxygen ions in Earth's equatorial quasi-trapping region

    NASA Technical Reports Server (NTRS)

    Christon, S. P.; Hamilton, D. C.; Gloeckler, G.; Eastmann, T. E.

    1994-01-01

    Observations of energetic (1.5 - 300 keV/e) medium-to-high charge state (+3 less than or equal to Q less than or equal to +7) solar wind origin C and O ions made in the quasi-trapping region (QTR) of Earth's magnetosphere are compared to ion trajectories calculated in model equatorial magnetospheric magnetic and electric fields. These comparisons indicate that solar wind ions entering the QTR on the nightside as an energetic component of the plasma sheet exit the region on the dayside, experiencing little or no charge exchange on the way. Measurements made by the CHarge Energy Mass (CHEM) ion spectrometer on board the Active Magnetospheric Particle Tracer Explorer/Charge Composition Explorer (AMPTE/CCE) spacecraft at 7 less than L less than 9 from September 1984 to January 1989 are the source of the new results contained herein: quantitative long-term determination of number densities, average energies, energy spectra, local time distributions, and their variation with geomagnetic disturbance level as indexed by Kp. Solar wind primaries (ions with charge states unchanged) and their secondaries (ions with generally lower charge states produced from primaries in the magnetosphere via charge exchange)are observed throughout the QTR and have distinctly different local time variations that persist over the entire 4-year analysis interval. During Kp larger than or equal to 3 deg intervals, primary ion (e.g., O(+6)) densities exhibit a pronounced predawn maximum with average energy minimum and a broad near-local-noon density minimum with average energy maximum. Secondary ion (e.g., O(+5)) densities do not have an identifiable predawn peak, rather they have a broad dayside maximum peaked in local morning and a nightside minimum. During Kp less than or equal to 2(-) intervals, primary ion density peaks are less intense, broader in local time extent, and centered near midnight, while secondary ion density local time variations diminish. The long-time-interval baseline helps

  9. Interactions of high-energy, highly-charged XE ions with C{sub 60}

    SciTech Connect

    Ali, R.; Berry, H.G.; Dunford, R.W.

    1995-08-01

    Ionization and fragmentation were measured for C{sub 60} molecules bombarded in the vapor phase by Xe{sup 35+} and Xe{sup 18+} ions with energies in the range 420-625 MeV. The CM energies exceeded those used in previous studies by several orders of magnitude. The mass distribution for the resulting positively charged fragments was determined and we studied the dependence of the fragment yields on the energy and charge of the projectiles. We developed a theoretical model that indicates the total interaction cross section contains roughly equal contributions from (1) excitation of the giant plasmon resonance, and (2) large-energy-transfer processes leading to multiple fragmentation of the molecule.

  10. Numerical Simulation of High-Voltage Spacecraft Charging at High Altitudes: Comparison of NASCAP and ECO-M

    NASA Astrophysics Data System (ADS)

    Danilov, V. V.; Dvoryashin, V. M.; Elgin, B. A.; Drolshagen, G.

    1998-11-01

    Computer simulation of spacecraft (SC) charging is one of the main means for the analysis of SC interaction with the hot plasma space environment. Results of two computer codes are presented: NASCAP and ECO-M. Both were applied to the simulation of high-voltage charging of a rotating SC. The analysed SC model is a conducting cylinder covered by thin dielectric material. The plasma environment, solar irradiation, secondary emission and other parameters correspond to realistic conditions for SC in geostationary orbit during a magnetic substorm. Two cases were analysed by both codes: 1) a continuously rotating cylinder; b) rotation starts after equilibrium charging was reached for a fixed orientation. In the first case the potential of illuminated SC surfaces increases steadily from 0 up to a steady-state level with oscillations resulting from the SC rotation frequency. In the second case a rapid potential jump after the beginning of rotation is observed. The potential of initially illuminated surface is changed from -3kV up to +3kV relative the space. A physical explanation of this effect is suggested. The main results of the computer simulations are: (a) a good agreement between ECO-M and NASCAP results, (b) SC rotation has a large influence on the high-voltage charging processes, (c) transition from eclipse to sunlight conditions could lead to sudden jumps of surface potentials.

  11. Numerical Simulation of High-Voltage Charging at High Altitudes; Comparison of NASCAP and ECO-M

    NASA Astrophysics Data System (ADS)

    Danilov, V. V.; Dvoryashin, V. M.; Kramarenko, A. M.; Sokolov, V. S.; Vasilyev, Yu. V.

    1996-12-01

    Computer simulation of spacecraft (SC) charging is one of the main means for the analysis of SC interaction with the hot plasma space environment. Results of two computer codes are presented: NASCAP and ECO-M. Both were applied to the simulation of high-voltage charging of a rotating SC. The analysed SC model is a conducting cylinder covered by thin dielectric material. The plasma environment, solar irradiation, secondary emission and other parameters correspond to realistic conditions for SC in geostationary orbit during a magnetic substorm. Two cases were analysed by both codes: 1) a continuously rotating cylinder; b) rotation starts after equilibrium charging was reached for a fixed orientation. In the first case the potential of illuminated SC surfaces increases steadily from O up to a steady-state level with oscillations resulting from the SC rotation frequency. In the second case a rapid potential jump after the beginning of rotation is observed. The potential of initially illuminated surface is changed from -3kV up to +3kV relative to space. A physical explanation of this effect is suggested. The main results of the computer simulations are: (a) a good agreement between ECO-M and NASCAP results, (b) SC rotation has a large influence on the high-voltage charging processes, (c) transition from eclipse to sunlight conditions could lead to sudden jumps of surface potentials.

  12. High precision computing with charge domain devices and a pseudo-spectral method therefor

    NASA Technical Reports Server (NTRS)

    Barhen, Jacob (Inventor); Toomarian, Nikzad (Inventor); Fijany, Amir (Inventor); Zak, Michail (Inventor)

    1997-01-01

    The present invention enhances the bit resolution of a CCD/CID MVM processor by storing each bit of each matrix element as a separate CCD charge packet. The bits of each input vector are separately multiplied by each bit of each matrix element in massive parallelism and the resulting products are combined appropriately to synthesize the correct product. In another aspect of the invention, such arrays are employed in a pseudo-spectral method of the invention, in which partial differential equations are solved by expressing each derivative analytically as matrices, and the state function is updated at each computation cycle by multiplying it by the matrices. The matrices are treated as synaptic arrays of a neural network and the state function vector elements are treated as neurons. In a further aspect of the invention, moving target detection is performed by driving the soliton equation with a vector of detector outputs. The neural architecture consists of two synaptic arrays corresponding to the two differential terms of the soliton-equation and an adder connected to the output thereof and to the output of the detector array to drive the soliton equation.

  13. Self-Assembling of Tetradecylammonium Chain on Swelling High Charge Micas (Na-Mica-3 and Na-Mica-2): Effect of Alkylammonium Concentration and Mica Layer Charge.

    PubMed

    Pazos, M Carolina; Cota, Agustín; Osuna, Francisco J; Pavón, Esperanza; Alba, María D

    2015-04-21

    A family of tetradecylammonium micas is synthesized using synthetic swelling micas with high layer charge (Na(n)Si(8-n)Al(n)Mg6F4O20·XH2O, where n = 2 and 3) exchanged with tetradecylammonium cations. The molecular arrangement of the surfactant is elucidated on the basis of XRD patterns and DTA. The ordering conformation of the surfactant molecules into the interlayer space of micas is investigated by IR/FT, (13)C, (27)Al, and (29)Si MAS NMR. The structural arrangement of the tetradecylammonium cation in the interlayer space of high-charge micas is more sensitive to the effect of the mica layer charge at high concentration. The surfactant arrangement is found to follow the bilayer-paraffin model for all values of layer charge and surfactant concentration. However, at initial concentration below the mica CEC, a lateral monolayer is also observed. The amount of ordered conformation all-trans is directly proportional to the layer charge and surfactant concentration. PMID:25822908

  14. EBIT in the Magnetic Trapping Mode: Mass Spectrometry, Atomic Lifetime Measurements, and Charge Transfer Reactions of Highly Charged Atomic Ions

    SciTech Connect

    Schweikhard, L; Beiersdorfer, P; Trabert, E

    2001-07-10

    Although it may sound like a contradiction in terms, the electron beam ion trap (EBIT) works as an ion trap even when the electron beam is switched off. We present various experiments that exploit the ''magnetic trapping mode'' for investigations of ion confinement, charge exchange processes, atomic lifetime and ion mass measurements.

  15. Design of a fast gated charge integrating front end for use in high density CAMAC and fastbus modules

    NASA Astrophysics Data System (ADS)

    Beer, A.; Critin, G.; Schuler, G.

    1985-02-01

    This paper describes the design principles of two versions of a gated charge integrating front end for use with high energy physics particle detectors. The current integration, gate and clear problems are discussed. A high slew rate design and its implementation on a very small printed circuit board is presented. The design of a 32 channel, 12 bit CAMAC charge integrating ADC is outlined.

  16. Elevated levels of iron in groundwater in Prey Veng province in Cambodia: a possible factor contributing to high iron stores in women.

    PubMed

    Karakochuk, Crystal D; Murphy, Heather M; Whitfield, Kyly C; Barr, Susan I; Vercauteren, Suzanne M; Talukder, Aminuzzaman; Porter, Keith; Kroeun, Hou; Eath, Many; McLean, Judy; Green, Timothy J

    2015-06-01

    Iron is a natural element found in food, water and soil and is essential for human health. Our aim was to determine the levels of iron and 25 other metals and trace elements in groundwater from 22 households in Prey Veng, Cambodia. Water analyses were conducted using inductively coupled plasma-mass spectrometry and optical emission spectrometry. Compared to the 2011 World Health Organization guidelines for drinking water quality, aluminum, iron and manganese exceeded maximum levels (in 4.5, 72.7 and 40.9% of samples, respectively). Compared to the 2004 Cambodian drinking water quality standards, iron and manganese exceeded maximum levels (in 59.1 and 36.4% of samples, respectively). We found no evidence of arsenic contamination. Guidelines for iron were established primarily for esthetic reasons (e.g. taste), whereas other metals and elements have adverse effects associated with toxicity. Iron in groundwater ranged from 134 to 5,200 μg/L (mean ∼1,422 μg/L). Based on a daily consumption of 3 L groundwater, this equates to ∼0.4-15.6 mg iron (mean ∼4.3 mg/day), which may be contributing to high iron stores and the low prevalence of iron deficiency anemia in Prey Veng women. Elevated levels of manganese in groundwater are a concern and warrant further investigation. PMID:26042988

  17. 2D coherent charge transport in highly ordered conducting polymers doped by solid state diffusion

    NASA Astrophysics Data System (ADS)

    Kang, Keehoon; Watanabe, Shun; Broch, Katharina; Sepe, Alessandro; Brown, Adam; Nasrallah, Iyad; Nikolka, Mark; Fei, Zhuping; Heeney, Martin; Matsumoto, Daisuke; Marumoto, Kazuhiro; Tanaka, Hisaaki; Kuroda, Shin-Ichi; Sirringhaus, Henning

    2016-08-01

    Doping is one of the most important methods to control charge carrier concentration in semiconductors. Ideally, the introduction of dopants should not perturb the ordered microstructure of the semiconducting host. In some systems, such as modulation-doped inorganic semiconductors or molecular charge transfer crystals, this can be achieved by spatially separating the dopants from the charge transport pathways. However, in conducting polymers, dopants tend to be randomly distributed within the conjugated polymer, and as a result the transport properties are strongly affected by the resulting structural and electronic disorder. Here, we show that in the highly ordered lamellar microstructure of a regioregular thiophene-based conjugated polymer, a small-molecule p-type dopant can be incorporated by solid state diffusion into the layers of solubilizing side chains without disrupting the conjugated layers. In contrast to more disordered systems, this allows us to observe coherent, free-electron-like charge transport properties, including a nearly ideal Hall effect in a wide temperature range, a positive magnetoconductance due to weak localization and the Pauli paramagnetic spin susceptibility.

  18. High charge-carrier mobility enables exploitation of carrier multiplication in quantum-dot films

    PubMed Central

    Sandeep, C. S. Suchand; Cate, Sybren ten; Schins, Juleon M.; Savenije, Tom J.; Liu, Yao; Law, Matt; Kinge, Sachin; Houtepen, Arjan J.; Siebbeles, Laurens D. A.

    2013-01-01

    Carrier multiplication, the generation of multiple electron–hole pairs by a single photon, is of great interest for solar cells as it may enhance their photocurrent. This process has been shown to occur efficiently in colloidal quantum dots, however, harvesting of the generated multiple charges has proved difficult. Here we show that by tuning the charge-carrier mobility in quantum-dot films, carrier multiplication can be optimized and may show an efficiency as high as in colloidal dispersion. Our results are explained quantitatively by the competition between dissociation of multiple electron–hole pairs and Auger recombination. Above a mobility of ~1 cm2 V−1 s−1, all charges escape Auger recombination and are quantitatively converted to free charges, offering the prospect of cheap quantum-dot solar cells with efficiencies in excess of the Shockley–Queisser limit. In addition, we show that the threshold energy for carrier multiplication is reduced to twice the band gap of the quantum dots. PMID:23974282

  19. Fragile charge order in the nonsuperconducting ground state of the underdoped high-temperature superconductors

    PubMed Central

    Tan, B. S.; Harrison, N.; Zhu, Z.; Balakirev, F.; Ramshaw, B. J.; Srivastava, A.; Sabok-Sayr, S. A.; Dabrowski, B.; Lonzarich, G. G.; Sebastian, Suchitra E.

    2015-01-01

    The normal state in the hole underdoped copper oxide superconductors has proven to be a source of mystery for decades. The measurement of a small Fermi surface by quantum oscillations on suppression of superconductivity by high applied magnetic fields, together with complementary spectroscopic measurements in the hole underdoped copper oxide superconductors, point to a nodal electron pocket from charge order in YBa2Cu3O6+δ. Here, we report quantum oscillation measurements in the closely related stoichiometric material YBa2Cu4O8, which reveals similar Fermi surface properties to YBa2Cu3O6+δ, despite the nonobservation of charge order signatures in the same spectroscopic techniques, such as X-ray diffraction, that revealed signatures of charge order in YBa2Cu3O6+δ. Fermi surface reconstruction in YBa2Cu4O8 is suggested to occur from magnetic field enhancement of charge order that is rendered fragile in zero magnetic fields because of its potential unconventional nature and/or its occurrence as a subsidiary to more robust underlying electronic correlations. PMID:26199413

  20. Fragile charge order in the nonsuperconducting ground state of the underdoped high-temperature superconductors.

    PubMed

    Tan, B S; Harrison, N; Zhu, Z; Balakirev, F; Ramshaw, B J; Srivastava, A; Sabok-Sayr, S A; Sabok, S A; Dabrowski, B; Lonzarich, G G; Sebastian, Suchitra E

    2015-08-01

    The normal state in the hole underdoped copper oxide superconductors has proven to be a source of mystery for decades. The measurement of a small Fermi surface by quantum oscillations on suppression of superconductivity by high applied magnetic fields, together with complementary spectroscopic measurements in the hole underdoped copper oxide superconductors, point to a nodal electron pocket from charge order in YBa2Cu3(6+δ). Here, we report quantum oscillation measurements in the closely related stoichiometric material YBa2Cu4O8, which reveals similar Fermi surface properties to YBa2Cu3(6+δ), despite the nonobservation of charge order signatures in the same spectroscopic techniques, such as X-ray diffraction, that revealed signatures of charge order in YBa2Cu3(6+δ). Fermi surface reconstruction in YBa2Cu4O8 is suggested to occur from magnetic field enhancement of charge order that is rendered fragile in zero magnetic fields because of its potential unconventional nature and/or its occurrence as a subsidiary to more robust underlying electronic correlations. PMID:26199413

  1. High charge density conducting polymer/graphite fiber composite electrodes for battery applications

    SciTech Connect

    Coffey, B.; Madsen, P.V.; Poehler, T.O.; Searson, P.C.

    1995-02-01

    Novel composite electrode structures have been fabricated by single-step electropolymerization of polypyrrole onto a porous graphite fiber matrix. The graphite substrate provides a lightweight structure with high surface area. The available charge capacity of the composite electrodes was proportional to the electropolymerization time and the mass of electroactive polymer with reversible charge capacities in excess of 4.0 C/cm{sup 2} and a specific capacity of 90 mAh/g, independent of polymer mass. The rate of charge extraction was dependent on the polymer mass and the morphology of the polymer electrode. In test cells using a polypyrrole/graphite fiber anode and a polypyrrole-polystyrene sulfonate/graphite fiber cathode, the authors have demonstrated a capacity of more than 40 mAh/g based on the active mass of the undoped polymer on discharging the cell to 0.1 V over a 10 k{Omega} load. More than 70% of the available charge was extracted from the cell over 50 cycles with no degradation of cell performance.

  2. Inductively-Charged High-Temperature Superconductors And Methods Of Use

    DOEpatents

    Bromberg, Leslie

    2003-09-16

    The invention provides methods of charging superconducting materials and, in particular, methods of charging high-temperature superconducting materials. The methods generally involve cooling a superconducting material to a temperature below its critical temperature. Then, an external magnetic field is applied to charge the material at a nearly constant temperature. The external magnetic field first drives the superconducting material to a critical state and then penetrates into the material. When in the critical state, the superconducting material loses all the pinning ability and therefore is in the flux-flow regime. In some embodiments, a first magnetic field may be used to drive the superconducting material to the critical state and then a second magnetic field may be used to penetrate the superconducting material. When the external field or combination of external fields are removed, the magnetic field that has penetrated into the material remains trapped. The charged superconducting material may be used as solenoidal magnets, dipole magnets, or other higher order multipole magnets in many applications.

  3. Magnetic-dipole transitions in highly charged ions as a basis of ultraprecise optical clocks.

    PubMed

    Yudin, V I; Taichenachev, A V; Derevianko, A

    2014-12-01

    We evaluate the feasibility of using magnetic-dipole (M1) transitions in highly charged ions as a basis of an optical atomic clockwork of exceptional accuracy. We consider a range of possibilities, including M1 transitions between clock levels of the same fine-structure and hyperfine-structure manifolds. In highly charged ions these transitions lie in the optical part of the spectra and can be probed with lasers. The most direct advantage of our proposal comes from the low degeneracy of clock levels and the simplicity of atomic structure in combination with negligible quadrupolar shift. We demonstrate that such clocks can have projected fractional accuracies below the 10^{-20}-10^{-21} level for all common systematic effects, such as blackbody radiation, Zeeman, ac-Stark, and quadrupolar shifts. PMID:25526127

  4. Relativity: X-ray and auger transitions of highly charged ions

    SciTech Connect

    Chen, Mau Hsiung

    1989-03-06

    Many-electron QED correction is one of the unsolved problems in relativistic atomic structure calculations for many-electron systems. The accuracy of the effective-charged screening approach frequently used in the MCDF model to estimate the many-electron QED corrections is examined. The effects of relativity and configuration interaction are simultaneously important in the treatment of highly-charged ions. These effects can sometimes change the transition rates by orders of magnitude; numerous irregularities present in Auger rates and oscillator strengths along the isoelectronic sequence due to the level crossings. The spin-orbit mixing and Breit interaction are responsible for the decay of most of the high-spin metastable autoionizing states. 29 refs., 8 figs.

  5. Charge exchange as a recombination mechanism in high-temperature plasmas

    SciTech Connect

    Hulse, R.A.; Post, D.E.; Mikkelsen, D.R.

    1980-03-01

    Charge exchange with neutral hydrogen is examined as a recombination mechanism for multi-charged impurity ions present in high-temperature fusion plasmas. At sufficiently low electron densities, fluxes of atomic hydrogen produced by either the injection of neutral heating beams or the background of thermal neutrals can yield an important or even dominant recombination process for such ions. Equilibrium results are given for selected impurity elements showing the altered ionization balance and radiative cooling rate produced by the presence of various neutral populations. A notable result is that the stripping of impurities to relatively non-radiative ionization states with increasing electron temperature can be postponed or entirely prevented by the application of intense neutral beam heating power. A time dependent calculation modelling the behavior of iron in recent PLT tokamak high power neutral beam heating experiments is also presented.

  6. High-performing nonlinear visualization of terahertz radiation on a silicon charge-coupled device

    PubMed Central

    Shalaby, Mostafa; Vicario, Carlo; Hauri, Christoph P.

    2015-01-01

    Photoinduced electron transitions can lead to significant changes of the macroscopic electronic properties in semiconductors. This principle is responsible for the detection of light with charge-coupled devices. Their spectral sensitivity is limited by the semiconductor bandgap which has restricted their visualization capabilities to the optical, ultraviolet, and X-ray regimes. The absence of an imaging device in the low frequency terahertz range has severely hampered the advance of terahertz imaging applications in the past. Here we introduce a high-performing imaging concept to the terahertz range. On the basis of a silicon charge-coupled device we visualize 5–13 THz radiation with photon energy under 2% of the sensor's band-gap energy. The unprecedented small pitch and large number of pixels allow the visualization of complex terahertz radiation patterns in real time and with high spatial detail. This advance will have a great impact on a wide range of terahertz imaging disciplines. PMID:26496973

  7. HITRAP - Heavy, highly charged Ions at Rest: Status and experimental Opportunities

    NASA Astrophysics Data System (ADS)

    Herfurth, F.; Barth, W.; Clemente, G.; Dahl, L. A.; Gerhard, P.; Kaiser, M.; Kester, O. K.; Kluge, H.-J.; Krantz, C.; Kotovskiy, N.; Kozhuharov, C.; Maier, M.; Pfister, J.; Quint, W.; Ratzinger, U.; Schempp, A.; Sokolov, A.; Stöhlker, Th; Vormann, H.; Vorobjev, G.; Wolf, A.; Yaramishev, S.; Hitrap Collaboration

    2012-11-01

    HITRAP, the facility for heavy, highly-charged ions at rest, is being commissioned at GSI in Darmstadt. The highly-charged ions are produced by stripping all electrons at 400 MeV/u and then decelerating the beam of bare, heavy nuclei in a storage ring, the ESR, and a linear decelerator. The first steps have been taken into operation successfully; about 105 ions have been decelerated to 0.5 MeV/u. The remaining deceleration and cooling in a RFQ decelerator structure and a Penning trap is prepared. For off-line tests of the experiments as well as the cooler Penning trap, a compact room-temperature EBIT has been installed and delivers beam already.

  8. Enhanced Laboratory Sensitivity to Variation of the Fine-Structure Constant using Highly Charged Ions

    SciTech Connect

    Berengut, J. C.; Dzuba, V. A.; Flambaum, V. V.

    2010-09-17

    We study atomic systems that are in the frequency range of optical atomic clocks and have enhanced sensitivity to potential time variation of the fine-structure constant {alpha}. The high sensitivity is due to coherent contributions from three factors: high nuclear charge Z, high ionization degree, and significant differences in the configuration composition of the states involved. Configuration crossing keeps the frequencies in the optical range despite the large ionization energies. We discuss a few promising examples that have the largest {alpha} sensitivities seen in atomic systems.

  9. Surface potential due to charge accumulation during vacuum ultraviolet exposure for high-k and low-k dielectrics

    SciTech Connect

    Ren, H.; Sinha, H.; Sehgal, A.; Nichols, M. T.; Shohet, J. L.; Antonelli, G. A.; Nishi, Y.

    2010-08-16

    The surface potential due to charge accumulation during vacuum ultraviolet irradiation of high-k and low-k thin dielectric films is measured. Measurement of the substrate current, which is the sum of the charge-accumulation and photoinjection currents, allows an in situ monitoring of the charge accumulation during irradiation. The relationship between the substrate current and the calculated in situ surface potential is also found, eliminating the need for a separate surface-potential measurement. With a high photon dose, the surface potential and substrate current reach a steady-state value with no further net charge accumulation.

  10. In-situ Studies of Highly Charged Ions at the LLNL EBIT

    SciTech Connect

    Beiersdorfer, P

    2001-08-16

    The properties of highly charged ions and their interaction with electrons and atoms is being studied in-situ at the LLNL electron beam ion traps, EBIT-II and SuperEBIT. Spectroscopic measurements provide data on electron-ion and ion-atom interactions as well as accurate transition energies of lines relevant for understanding QED, nuclear magnetization, and the effects of relativity on complex, state-of-the-art atomic calculations.

  11. Atomic physics with highly charged ions. Progress report for FY 1995

    SciTech Connect

    Richard, P.

    1995-09-01

    This report describes progress made during the previous year in experimental and theoretical investigations of high- and low-energy collisions involving multiply charged ions. The work from previous years has resulted in publication of 27 papers in refereed journals during the last twelve months. This report includes a list of published manuscripts as well as lists of abstracts for five different conferences/workshops during the grant period.

  12. Relativistic calculations of the nuclear recoil effect in highly charged Li-like ions

    NASA Astrophysics Data System (ADS)

    Zubova, N. A.; Shabaev, V. M.; Tupitsyn, I. I.; Plunien, G.

    2013-09-01

    Relativistic theory of the nuclear recoil effect in highly charged Li-like ions is considered within the Breit approximation. The normal mass shift (NMS) and the relativistic NMS (RNMS) are calculated by perturbation theory to zeroth and first orders in the parameter 1/Z. The calculations are performed using the dual kinetic balance method with the basis functions constructed from B-splines. The results of the calculations are compared with the theoretical values obtained by other methods.

  13. Advancement of highly charged ion beam production by superconducting ECR ion source SECRAL (invited)

    NASA Astrophysics Data System (ADS)

    Sun, L.; Guo, J. W.; Lu, W.; Zhang, W. H.; Feng, Y. C.; Yang, Y.; Qian, C.; Fang, X.; Ma, H. Y.; Zhang, X. Z.; Zhao, H. W.

    2016-02-01

    At Institute of Modern Physics (IMP), Chinese Academy of Sciences (CAS), the superconducting Electron Cyclotron Resonance (ECR) ion source SECRAL (Superconducting ECR ion source with Advanced design in Lanzhou) has been put into operation for about 10 years now. It has been the main working horse to deliver intense highly charged heavy ion beams for the accelerators. Since its first plasma at 18 GHz, R&D work towards more intense highly charged ion beam production as well as the beam quality investigation has never been stopped. When SECRAL was upgraded to its typical operation frequency 24 GHz, it had already showed its promising capacity of very intense highly charged ion beam production. And it has also provided the strong experimental support for the so called scaling laws of microwave frequency effect. However, compared to the microwave power heating efficiency at 18 GHz, 24 GHz microwave heating does not show the ω2 scale at the same power level, which indicates that microwave power coupling at gyrotron frequency needs better understanding. In this paper, after a review of the operation status of SECRAL with regard to the beam availability and stability, the recent study of the extracted ion beam transverse coupling issues will be discussed, and the test results of the both TE01 and HE11 modes will be presented. A general comparison of the performance working with the two injection modes will be given, and a preliminary analysis will be introduced. The latest results of the production of very intense highly charged ion beams, such as 1.42 emA Ar12+, 0.92 emA Xe27+, and so on, will be presented.

  14. Measurement of L-shell electron-impact ionization cross sections for highly charged uranium ions

    SciTech Connect

    Stoehlker, T.; Kraemer, A. |; Elliott, S.R.; Marrs, R.E.; Scofield, J.H.

    1997-10-01

    L-shell electron-impact ionization cross sections for highly charged uranium ions from fluorinelike U{sup 83+} through lithiumlike U{sup 89+} have been measured at 45-, 60-, and 75-keV electron energy. The cross sections were obtained from x-ray measurements of the equilibrium ionization balance in an electron beam ion trap. The measured cross sections agree with recent relativistic distorted wave calculations. {copyright} {ital 1997} {ital The American Physical Society}

  15. Advancement of highly charged ion beam production by superconducting ECR ion source SECRAL (invited).

    PubMed

    Sun, L; Guo, J W; Lu, W; Zhang, W H; Feng, Y C; Yang, Y; Qian, C; Fang, X; Ma, H Y; Zhang, X Z; Zhao, H W

    2016-02-01

    At Institute of Modern Physics (IMP), Chinese Academy of Sciences (CAS), the superconducting Electron Cyclotron Resonance (ECR) ion source SECRAL (Superconducting ECR ion source with Advanced design in Lanzhou) has been put into operation for about 10 years now. It has been the main working horse to deliver intense highly charged heavy ion beams for the accelerators. Since its first plasma at 18 GHz, R&D work towards more intense highly charged ion beam production as well as the beam quality investigation has never been stopped. When SECRAL was upgraded to its typical operation frequency 24 GHz, it had already showed its promising capacity of very intense highly charged ion beam production. And it has also provided the strong experimental support for the so called scaling laws of microwave frequency effect. However, compared to the microwave power heating efficiency at 18 GHz, 24 GHz microwave heating does not show the ω(2) scale at the same power level, which indicates that microwave power coupling at gyrotron frequency needs better understanding. In this paper, after a review of the operation status of SECRAL with regard to the beam availability and stability, the recent study of the extracted ion beam transverse coupling issues will be discussed, and the test results of the both TE01 and HE11 modes will be presented. A general comparison of the performance working with the two injection modes will be given, and a preliminary analysis will be introduced. The latest results of the production of very intense highly charged ion beams, such as 1.42 emA Ar(12+), 0.92 emA Xe(27+), and so on, will be presented. PMID:26931925

  16. Proceedings of the workshop on opportunities for atomic physics using slow, highly-charged ions

    SciTech Connect

    Not Available

    1987-01-01

    The study of atomic physics with highly-charged ions is an area of intense activity at the present time because of a convergence of theoretical interest and advances in experimental techniques. The purpose of the Argonne ''Workshop on Opportunities for Atomic Physics Using Slow, Highly-Charged Ions'' was to bring together atomic, nuclear, and accelerator physicists in order to identify what new facilities would be most useful for the atomic physics community. The program included discussion of existing once-through machines, advanced ion sources, recoil ion techniques, ion traps, and cooler rings. One of the topics of the Workshop was to discuss possible improvement to the ANL Tandem-Linac facility (ATLAS) to enhance the capability for slowing down ions after they are stripped to a high-charge state (the Accel/Decel technique). Another topic was the opportunity for atomic physics provided by the ECR ion source which is being built for the Uranium Upgrade of ATLAS. 18 analytics were prepared for the individual papers in this volume.

  17. Single ion induced surface nanostructures: a comparison between slow highly charged and swift heavy ions.

    PubMed

    Aumayr, Friedrich; Facsko, Stefan; El-Said, Ayman S; Trautmann, Christina; Schleberger, Marika

    2011-10-01

    This topical review focuses on recent advances in the understanding of the formation of surface nanostructures, an intriguing phenomenon in ion-surface interaction due to the impact of individual ions. In many solid targets, swift heavy ions produce narrow cylindrical tracks accompanied by the formation of a surface nanostructure. More recently, a similar nanometric surface effect has been revealed for the impact of individual, very slow but highly charged ions. While swift ions transfer their large kinetic energy to the target via ionization and electronic excitation processes (electronic stopping), slow highly charged ions produce surface structures due to potential energy deposited at the top surface layers. Despite the differences in primary excitation, the similarity between the nanostructures is striking and strongly points to a common mechanism related to the energy transfer from the electronic to the lattice system of the target. A comparison of surface structures induced by swift heavy ions and slow highly charged ions provides a valuable insight to better understand the formation mechanisms. PMID:21900733

  18. Calculations of differential spacecraft charging in high and low Earth orbits using COULOMB-2 code

    NASA Astrophysics Data System (ADS)

    Novikov, Lev; Makletsov, Andrei; Sinolits, Vadim

    2016-07-01

    In the paper, we discuss the main physical quantities determining the principle features of spacecraft charging in high and low Earth orbits: characteristic values of magnetosphere plasma particle primary currents, peculiarities of the various particle current angular distributions, typical values of secondary emission currents for a number of spacecraft constructional materials. Methods for computation of electrostatic potential distribution over the spacecraft non-uniform complex shape surface which are used in COULOMB-2 program package for high (GEO) and low orbits (LEO) are described. The physical approximations necessary for calculation of the plasma particles primary currents which enable to use the analytical expressions in the case of high spacecraft surface charging similar to formulas for Langmuir currents, are discussed for GEO and for LEO. Distribution of the electrostatic potential over the spacecraft surface is determined as result of numerical solution of nonlinear algebraic equations system corresponding to the established balance of currents on each of discrete elements (2-5 thousands of elements) of the spacecraft surface. The analytical approach noted above enable to obtain the stationary distribution of the potential for rather small computation time that enables to obtain the results for a large number of the influencing factors orientations in reasonable computation time. Typical electric potential distributions over surfaces of the modern GEO and LEO spacecraft are presented. The principle features of these potential distributions determined by specific conditions of charging in GEO and in LEO are discussed.

  19. Charge trapping properties of alternative high-kappa dielectrics in MOS devices

    NASA Astrophysics Data System (ADS)

    Zhou, Xing

    High-kappa dielectrics are promising candidates to replace SiO 2 in advanced integrated circuits in future space systems. Studies of the effects of ionizing radiation and bias-temperature stress (BTS) on high-kappa dielectrics were performed. Trapped charge densities are evaluated as functions of temperature and stress time. Prior radiation exposure enhances BTS-induced degradation in these devices. Worst-case responses in combined effects are positive (or zero) bias irradiation followed by NBTS for HfO2-based devices. Degradation due to oxide or interface trap-charge changes in magnitude with the bias polarity during switched-bias annealing either after irradiation or constant voltage stress (CVS). This demonstrates that metastable electron trapping (dominant during post-rad annealing) and hydrogen transport and reactions (dominant during post-CVS annealing) in the near-interfacial dielectric layers play significant roles in the defect formation process. Additional defect growth with time was observed as a result of additional charge injection through the gate stacks during the annealing process. These results provide insights into fundamental trapping properties of high-kappa dielectrics and can be used to help predict long-term reliability of these devices.

  20. Atomic physics and synchrotron radiation: The production and accumulation of highly charged ions

    NASA Astrophysics Data System (ADS)

    Johnson, B. M.; Meron, M.; Agagu, A.; Jones, K. W.

    1987-04-01

    Synchrotron radiation can be used to produce highly-charged ions, and to study photoexcitation and photoionization for ions of virtually any element in the periodic table. To date, with few exceptions, atomic physics studies have been limited to rare gases and a few metal vapors, and to photoexcitation energies in the VUV region of the electromagnetic spectrum. These limitations can now be overcome using photons produced by high-brightness synchrotron storage rings, such as the X-ray ring at the National Synchrotron Light Source (NSLS) at Brookhaven. Furthermore, calculations indicate that irradiation of an ion trap with an intense energetic photon beam will result in a viable source of highly-charged ions that can be given the name PHOBIS: the photon beam ion source. Promising results, which encourage the wider systematic use of synchrotron radiation in atomic physics research, have been obtained in recent experiments on VUV photoemission and the production and storage of multiply-charged ions. An overview of the field, current plans, and future possibilities will be presented.

  1. Supercharging with m-nitrobenzyl alcohol and propylene carbonate: forming highly charged ions with extended, near-linear conformations.

    PubMed

    Going, Catherine C; Williams, Evan R

    2015-04-01

    The effectiveness of the supercharging reagents m-nitrobenzyl alcohol (m-NBA) and propylene carbonate at producing highly charged protein ions in electrospray ionization is compared. Addition of 5% m-NBA or 15% propylene carbonate increases the average charge of three proteins by ∼21% or ∼23%, respectively, when these ions are formed from denaturing solutions (water/methanol/acetic acid). These results indicate that both reagents are nearly equally effective at supercharging when used at their optimum concentrations. A narrowing of the charge state distribution occurs with both reagents, although this effect is greater for propylene carbonate. Focusing the ion signal into fewer charge states has the advantage of improving sensitivity. The maximum charge state of ubiquitin formed with propylene carbonate is 21+, four charges higher than previously reported. Up to nearly 30% of all residues in a protein can be charged, and the collisional cross sections of the most highly charged ions of both ubiquitin and cytochrome c formed with these supercharging reagents were measured for the first time and found to be similar to those calculated for theoretical highly extended, linear or near-linear conformations. Under native supercharging conditions, m-NBA is significantly more effective at producing high charge states than propylene carbonate. PMID:25719488

  2. Optical transitions in highly charged californium ions with high sensitivity to variation of the fine-structure constant.

    PubMed

    Berengut, J C; Dzuba, V A; Flambaum, V V; Ong, A

    2012-08-17

    We study electronic transitions in highly charged Cf ions that are within the frequency range of optical lasers and have very high sensitivity to potential variations in the fine-structure constant, α. The transitions are in the optical range despite the large ionization energies because they lie on the level crossing of the 5f and 6p valence orbitals in the thallium isoelectronic sequence. Cf(16+) is a particularly rich ion, having several narrow lines with properties that minimize certain systematic effects. Cf(16+) has very large nuclear charge and large ionization energy, resulting in the largest α sensitivity seen in atomic systems. The lines include positive and negative shifters. PMID:23006353

  3. New Supercharging Reagents Produce Highly Charged Protein Ions in Native Mass Spectrometry

    PubMed Central

    Going, Catherine C.; Xia, Zijie; Williams, Evan R.

    2015-01-01

    The effectiveness of two new supercharging reagents for producing highly charged ions by electrospray ionization (ESI) from aqueous solutions in which proteins have native structures and reactivities were investigated. In aqueous solution, 2-thiophenone and 4-hydroxymethyl-1,3-dioxolan-2-one (HD) at a concentration of 2% by volume can increase the average charge of cytochrome c and myoglobin by up to 163%, resulting in even higher charge states than those that are produced from water/methanol/acid solutions in which proteins are denatured. The greatest extent of supercharging occurs in pure water, but these supercharging reagents are also highly effective in aqueous solutions containing 200 mM ammonium acetate buffer commonly used in native mass spectrometry (MS). These reagents are less effective supercharging reagents than m-nitrobenzyl alcohol (m-NBA) and propylene carbonate (PC) when ions are formed from water/methanol/acid. The extent to which loss of the heme group from myoglobin occurs is related to the extent of supercharging. Results from guanidine melts of cytochrome c monitored with tryptophan fluorescence show that the supercharging reagents PC, sulfolane and HD are effective chemical denaturants in solution. These results provide additional evidence for the role of protein structural changes in the electrospray droplet as the primary mechanism for supercharging with these reagents in native MS. These results also demonstrate that for at least some proteins, the formation of highly charged ions from native MS is no longer a significant barrier for obtaining structural information using conventional tandem MS methods. PMID:26421324

  4. New supercharging reagents produce highly charged protein ions in native mass spectrometry.

    PubMed

    Going, Catherine C; Xia, Zijie; Williams, Evan R

    2015-11-01

    The effectiveness of two new supercharging reagents for producing highly charged ions by electrospray ionization (ESI) from aqueous solutions in which proteins have native structures and reactivities were investigated. In aqueous solution, 2-thiophenone and 4-hydroxymethyl-1,3-dioxolan-2-one (HD) at a concentration of 2% by volume can increase the average charge of cytochrome c and myoglobin by up to 163%, resulting in even higher charge states than those that are produced from water/methanol/acid solutions in which these proteins are denatured. The greatest extent of supercharging occurs in pure water, but these supercharging reagents are also highly effective in aqueous solutions containing 200 mM ammonium acetate buffer commonly used in native mass spectrometry (MS). These reagents are less effective supercharging reagents than m-nitrobenzyl alcohol (m-NBA) and propylene carbonate (PC) when ions are formed from water/methanol/acid. The extent to which loss of the heme group from myoglobin occurs is related to the extent of supercharging. Results from guanidine melts of cytochrome c monitored with tryptophan fluorescence show that the supercharging reagents PC, sulfolane and HD are effective chemical denaturants in solution. These results provide additional evidence for the role of protein structural changes in the electrospray droplet as the primary mechanism for supercharging with these reagents in native MS. These results also demonstrate that for at least some proteins, the formation of highly charged ions from native MS is no longer a significant barrier for obtaining structural information using conventional tandem MS methods. PMID:26421324

  5. Stored luminescence computed tomography.

    PubMed

    Cong, Wenxiang; Wang, Chao; Wang, Ge

    2014-09-01

    Phosphor nanoparticles made of doped semiconductors and pre-excited by x-ray radiation were recently reported for their luminescence emission in the range of 650-770 nm upon near-infrared (NIR) light stimulation. These nanophosphors can be functionalized as optical probes for molecular imaging. In this paper, we present stored luminescence computed tomography to reconstruct a nanophosphor distribution in an object. The propagation of x rays in a biological object allows significantly better localization and deeper penetration. Moreover, the nanophosphors, which are pre-excited with collimated x-ray beams or focused x-ray waves, can be successively stimulated for stored luminescence emissions by variable NIR stimulation patterns. The sequentially detected luminescence signals provide more information of a nanophosphor spatial distribution for more accurate image reconstruction and higher image resolution. A realistic numerical study is performed to demonstrate the feasibility and merits of the proposed approach. PMID:25321362

  6. Storing Blood Cells

    NASA Technical Reports Server (NTRS)

    1976-01-01

    The National Cancer Institute worked with Goddard Space Flight Center to propose a solution to the blood-cell freezing problem. White blood cells and bone marrow are stored for future use by leukemia patients as a result of Goddard and Jet Propulsion Laboratory expertise in electronics and cryogenics. White blood cell and bone marrow bank established using freezing unit. Freezing unit monitors temperature of cells themselves. Thermocouple placed against polyethylene container relays temperature signals to an electronic system which controls small heaters located outside container. Heaters allow liquid nitrogen to circulate at constant temperature and maintain consistent freezing rate. Ability to freeze, store, and thaw white cells and bone marrow without damage is important in leukemia treatment.

  7. Process for storing calories

    SciTech Connect

    Perrut, M.; Ronc, M.; Valentin, P.

    1980-09-09

    A process is described for storing heat in the form of fusion/solidification latent heat which comprises passing a thermo-conductive fluid into a thermally insulated storage element containing a substance having a melting point that corresponds to the supply and heat consumption temperatures, characterized in that said fusible substance is absorbed on a microporous carrier which forms a granular bed in which the thermo-conductive fluid circulates.

  8. Spectroscopic investigations of highly charged ions using x-ray calorimeter spectrometers

    NASA Astrophysics Data System (ADS)

    Thorn, Daniel Bristol

    Spectroscopy of K-shell transitions in highly charged heavy ions, like hydrogenlike uranium, has the potential to yield information about quantum electrodynamics (QED) in extremely strong nuclear fields as well as tests of the standard model, specifically parity violation in atomic systems. These measurements would represent the 'holy grail' in high-Z atomic spectroscopy. However, the current state-of-the-art detection schemes used for recording the K-shell spectra from highly charged heavy ions does not yet have the resolving power to be able to attain this goal. As such, to push the field of high-Z spectroscopy forward, new detectors must be found. Recently, x-ray calorimeter spectrometers have been developed that promise to make such measurements. In an effort to make the first steps towards attaining the 'holy grail', measurements have been performed with two x-ray calorimeter spectrometers (the XRS/EBIT and the ECS) designed and built at Goddard Space Flight Center in Greenbelt, MD. The calorimeter spectrometers have been used to record the K-shell spectra of highly charged ions produced in the SuperEBIT electron beam ion trap at Lawrence Livermore National Laboratory in Livermore, CA. Measurements performed with the XRS/EBIT calorimeter array found that the theoretical description of well-above threshold electron-impact excitation cross sections for hydrogenlike iron and nickel ions are correct. Furthermore, the first high-resolution spectrum of hydrogenlike through carbonlike praseodymium ions was recorded with a calorimeter. In addition, the new high-energy array on the EBIT Calorimeter Spectrometer (ECS) was used to resolve the K-shell x-ray emission spectrum of highly charged xenon ions, where a 40 ppm measurement of the energy of the K-shell resonance transition in heliumlike xenon was achieved. This is the highest precision result, ever, for an element with such high atomic number. In addition, a first-of-its-kind measurement of the effect of the

  9. Spectroscopic Investigations of Highly Charged Ions using X-Ray Calorimeter Spectrometers

    SciTech Connect

    Thorn, Daniel Bristol

    2008-11-19

    Spectroscopy of K-shell transitions in highly charged heavy ions, like hydrogen-like uranium, has the potential to yield information about quantum electrodynamics (QED) in extremely strong nuclear fields as well as tests of the standard model, specifically parity violation in atomic systems. These measurements would represent the 'holy grail' in high-Z atomic spectroscopy. However, the current state-of-the-art detection schemes used for recording the K-shell spectra from highly charged heavy ions does not yet have the resolving power to be able to attain this goal. As such, to push the field of high-Z spectroscopy forward, new detectors must be found. Recently, x-ray calorimeter spectrometers have been developed that promise to make such measurements. In an effort to make the first steps towards attaining the 'holy grail', measurements have been performed with two x-ray calorimeter spectrometers (the XRS/EBIT and the ECS) designed and built at Goddard Space Flight Center in Greenbelt, MD. The calorimeter spectrometers have been used to record the K-shell spectra of highly charged ions produced in the SuperEBIT electron beam ion trap at Lawrence Livermore National Laboratory in Livermore, CA. Measurements performed with the XRS/EBIT calorimeter array found that the theoretical description of well-above threshold electron-impact excitation cross sections for hydrogen-like iron and nickel ions are correct. Furthermore, the first high-resolution spectrum of hydrogen-like through carbon-like praseodymium ions was recorded with a calorimeter. In addition, the new high-energy array on the EBIT Calorimeter Spectrometer (ECS) was used to resolve the K-shell x-ray emission spectrum of highly charged xenon ions, where a 40 ppm measurement of the energy of the K-shell resonance transition in helium-like xenon was achieved. This is the highest precision result, ever, for an element with such high atomic number. In addition, a first-of-its-kind measurement of the effect of the

  10. Studies on low energy beam transport for high intensity high charged ions at IMP

    SciTech Connect

    Yang, Y. Lu, W.; Fang, X.; University of Chinese Academy of Sciences, Beijing 100039 ; Sun, L. T.; Hu, Q.; Cao, Y.; Feng, Y. C.; Zhang, X. Z.; Zhao, H. W.; Xie, D. Z.

    2014-02-15

    Superconducting Electron Cyclotron Resonance ion source with Advanced design in Lanzhou (SECRAL) is an advanced fully superconducting ECR ion source at IMP designed to be operational at the microwave frequency of 18–24 GHz. The existing SECRAL beam transmission line is composed of a solenoid lens and a 110° analyzing magnet. Simulations of particle tracking with 3D space charge effect and realistic 3D magnetic fields through the line were performed using particle-in-cell code. The results of the beam dynamics show that such a low energy beam is very sensitive to the space charge effect and significantly suffers from the second-order aberration of the analyzing magnet resulting in large emittance. However, the second-order aberration could be reduced by adding compensating sextupole components in the beam line. On this basis, a new 110° analyzing magnet with relatively larger acceptance and smaller aberration is designed and will be used in the design of low energy beam transport line for a new superconducting ECR ion source SECRAL-II. The features of the analyzer and the corresponding beam trajectory calculation will be detailed and discussed in this paper.

  11. Studies on low energy beam transport for high intensity high charged ions at IMP.

    PubMed

    Yang, Y; Sun, L T; Hu, Q; Cao, Y; Lu, W; Feng, Y C; Fang, X; Zhang, X Z; Zhao, H W; Xie, D Z

    2014-02-01

    Superconducting Electron Cyclotron Resonance ion source with Advanced design in Lanzhou (SECRAL) is an advanced fully superconducting ECR ion source at IMP designed to be operational at the microwave frequency of 18-24 GHz. The existing SECRAL beam transmission line is composed of a solenoid lens and a 110° analyzing magnet. Simulations of particle tracking with 3D space charge effect and realistic 3D magnetic fields through the line were performed using particle-in-cell code. The results of the beam dynamics show that such a low energy beam is very sensitive to the space charge effect and significantly suffers from the second-order aberration of the analyzing magnet resulting in large emittance. However, the second-order aberration could be reduced by adding compensating sextupole components in the beam line. On this basis, a new 110° analyzing magnet with relatively larger acceptance and smaller aberration is designed and will be used in the design of low energy beam transport line for a new superconducting ECR ion source SECRAL-II. The features of the analyzer and the corresponding beam trajectory calculation will be detailed and discussed in this paper. PMID:24593453

  12. Birkeland currents and charged particles in the high-latitude prenoon region - A new interpretation

    NASA Technical Reports Server (NTRS)

    Bythrow, P. F.; Potemra, T. A.; Erlandson, R. E.; Zanetti, L. J.; Klumpar, D. M.

    1988-01-01

    The relationship between Birkeland currents and charged particles in the ionosphere was investigated for the period between the late morning through early afternoon, using data on simultaneous conjugate measurements of magnetic fields and charged particles at low altitude in the high-latitude prenoon sector, acquired on November 1, 1984 by four spacecraft, IMP 8, AMPTE CCE, DMSP F7, and HILAT. The results of these observations indicate that, for both northward and southward IMF, the traditional 'cusp Birkeland currents' lie poleward of the most intense sheathlike particle precipitation, and it is likely that these currents map to the plasma mantle and are associated with divergent flow of ionospheric plasma near noon. It is suggested that the traditional 'cusp' current system might be more appropriately named the 'mantle' Birkeland current system.

  13. Charge transport dependent high open circuit voltage tandem organic photovoltaic cells with low temperature deposited HATCN-based charge recombination layers.

    PubMed

    Wei, Huai-Xin; Zu, Feng-Shuo; Li, Yan-Qing; Chen, Wen-Cheng; Yuan, Yi; Tang, Jian-Xin; Fung, Man-Keung; Lee, Chun-Sing; Noh, Yong-Young

    2016-02-01

    Mechanisms of charge transport between the interconnector and its neighboring layers in tandem organic photovoltaic cells have been systematically investigated by studying electronic properties of the involving interfaces with photoelectron spectroscopies and performance of the corresponding devices. The results show that charge recombination occurs at HATCN and its neighboring hole transport layers which can be deposited at low temperature. The hole transport layer plays an equal role to the interconnector itself. These insights provide guidance for the identification of new materials and the device architecture for high performance devices. PMID:26775613

  14. Highly charged ions for atomic clocks, quantum information, and search for α variation.

    PubMed

    Safronova, M S; Dzuba, V A; Flambaum, V V; Safronova, U I; Porsev, S G; Kozlov, M G

    2014-07-18

    We propose 10 highly charged ions as candidates for the development of next generation atomic clocks, quantum information, and search for α variation. They have long-lived metastable states with transition wavelengths to the ground state between 170-3000 nm, relatively simple electronic structure, stable isotopes, and high sensitivity to α variation (e.g., Sm(14+), Pr(10+), Sm(13+), Nd(10+)). We predict their properties crucial for the experimental exploration and highlight particularly attractive systems for these applications. PMID:25083627

  15. In Pursuit of Highly Accurate Atomic Lifetime Measurements of Multiply Charged Ions

    SciTech Connect

    Trabert, E

    2009-06-01

    Accurate atomic lifetime data are useful for terrestrial and astrophysical plasma diagnostics. At accuracies higher than those required for these applications, lifetime measurements test atomic structure theory in ways complementary to spectroscopic energy determinations. At the highest level of accuracy, the question arises whether such tests reach the limits of modern theory, a combination of quantum mechanics and QED, adn possibly point to physics beyond the Standard Model. If high-precision atomic lifetime measurements, especially on multiply charged ions, have not quite reached this high accuracy yet, then what is necessary to attain this goal?

  16. Characteristics of the soft X-ray emission from laser-produced highly charged platinum plasmas

    NASA Astrophysics Data System (ADS)

    Hara, Hiroyuki; Arai, Goki; Kondo, Yoshiki; Dinh, Thanh-Hung; Dunne, Padraig; O’Sullivan, Gerry; Ejima, Takeo; Hatano, Tadashi; Jiang, Weihua; Nishikino, Masaharu; Sasaki, Akira; Sunahara, Atsushi; Higashiguchi, Takeshi

    2016-06-01

    We characterized the spectral structure of the soft X-ray emission and determined the plasma parameters in laser-produced highly charged platinum plasmas. The spectral structure observed originated from Pt21+ to Pt34+ ions, emissions from which overlapped to produce a high output flux in the carbon-window soft X-ray spectral region. Using dual laser pulse irradiation, we observed the maximum output flux, which was 20% larger than that obtained under single-laser irradiation, and the evolution of a strongly absorbed spectral structure, which was attributed to the effects of both opacity and long-scale length of the expanding pre-plasma.

  17. High Current Ionic Diode Using Homogeneously Charged Asymmetric Nanochannel Network Membrane.

    PubMed

    Choi, Eunpyo; Wang, Cong; Chang, Gyu Tae; Park, Jungyul

    2016-04-13

    A high current ionic diode is achieved using an asymmetric nanochannel network membrane (NCNM) constructed by soft lithography and in situ self-assembly of nanoparticles with uniform surface charge. The asymmetric NCNM exhibits high rectified currents without losing a rectification ratio because of its ionic selectivity gradient and differentiated electrical conductance. Asymmetric ionic transport is analyzed with diode-like I-V curves and visualized via fluorescent dyes, which is closely correlated with ionic selectivity and ion distribution according to variation of NCNM geometries. PMID:26990504

  18. Low stored energy 100 kV regulator for ion sources at LANSCE

    SciTech Connect

    Jacobson, E.G.; Haffner, R.L.; Ingalls, W.B.; Meyer, B.J.; Stelzer, J.E.

    1998-12-31

    To minimize accelerating column damage caused by uncontrolled energy release during arc-downs, it is desirable to minimize the available stored electrical energy. For the Los Alamos Neutron Science Center (LANSCE) H{sup {minus}} ion sources, the stored energy includes, in addition to the charge in the power supply output capacitance, the charge on the electronics racks. They are supported and insulated from ground by PVC pipe and have a capacitance to ground of approximately 900 pf. In 1988 (LANSCE) personnel designed a high-voltage current source using a low-stored-energy power supply and planar triode with the goal of eliminating uncontrolled release of charge stored in the power supply. Construction and testing were performed intermittently as resources permitted until 1993. When work on the Short Pulse Spallation Source (SPSS) started on the LANSCE Ion Source Test Stand (ISTS) it was recognized that a higher current power supply would be needed and work resumed on the regulator circuitry. A 120 kV power supply having low output capacitance, and a planar triode have been used to supply 40 mA, 120 Hz, 12% duty-factor current for the ISTS beam. The triode`s cathode current is controlled by circuitry operating both at power-supply voltage level and at ground level via a fiber optic link. Voltage droop is approximately 600 V during the 1 ms beam pulse. The authors present the status of the regulator and its special challenges.

  19. Determination of Surface Charge of Titanium Dioxide (Anatase) at High Ionic Strength

    NASA Astrophysics Data System (ADS)

    Schoonen, M. A.; Strongin, D. R.

    2014-12-01

    Charge development on mineral surfaces is an important control on the fate of minor and trace elements in a wide range of environments, including in possible radioactive waste repositories. Formation waters have often a high ionic strength. In this study, we determined the zeta potential (ζ) of anatase in potassium chloride solutions with concentrations up to 3M (25°C). The zeta potential is the potential at the hydrodynamic shear plane. In this study, we made use of the electro-acoustic effect. This effect is based on the development of a measureable potential/current when the electrical double layer outside the shearplane is separated from a charged particle through rapid oscillation induced by a sound wave. The advantage of this type of measurement is that the particles are not subjected to a high electric field (common to typical zeta potential measurements), which leads to electrode reactions and a shift of solution pH. Measurements were collected by subtracting the ion vibration current (IVI) due to the presence of potassium and chloride ions from the CVI. The correction is necessary for measurements in solutions with I > 0.25 M. This subtraction was done at each of the measurement conditions by centrifuging the slurrly, measuring the IVI of the supernatant, reconstituting the slurry, and then measuring CVI of the slurry. Subtraction of IVI at each condition is critical because IVI changes with pH and accounts for most of raw signal. The results show that the anatase isoelectric point shifts from a pH ~6.5 to a value of ~4.5 at 1M KCl. At ionic strength in excess of 1 M KCl, the surface appears to be slightly negatively charged accross the pH range accessible by this technique (pH 2.5-10). The loss of an isoelectric point suggests that KCl is no longer an indifferent electrolyte at 1 M KCl and higher. The results are in disagreement with earlier measurements in which anatase was shown to have a positive charge at high ionic strength across the pH scale. The

  20. BRONZE FOUNDRY SCRAP STORED IN THE BINS TO THE RIGHT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    BRONZE FOUNDRY SCRAP STORED IN THE BINS TO THE RIGHT ARE LOADED INTO THE BOTTOM DROPPING CHARGE BUCKET IN THE BACKGROUND BEFORE BEING CHARGED INTO ONE OF THE ELECTRIC ARC FURNACES. - Stockham Pipe & Fittings Company, Brass Foundry, 4000 Tenth Avenue North, Birmingham, Jefferson County, AL

  1. High performance charge breeder for HIE-ISOLDE and TSR@ISOLDE applications

    SciTech Connect

    Shornikov, Andrey Mertzig, Robert C.; Wenander, Fredrik J. C.; Beebe, Edward N.; Pikin, Alexander

    2015-01-09

    We report on the development of the HEC{sup 2} (High Energy Compression and Current) charge breeder, a possible high performance successor to REXEBIS at ISOLDE. The new breeder would match the performance of the HIE-ISOLDE linac upgrade and make full use of the possible installation of a storage ring at ISOLDE (the TSR@ISOLDE initiative [1]). Dictated by ion beam acceptance and capacity requirements, the breeder features a 2–3.5 A electron beam. In many cases very high charge states, including bare ions up to Z=70 and Li/Na-like up to Z=92 could be requested for experiments in the storage ring, therefore, electron beam energies up to 150 keV are required. The electron-beam current density needed for producing ions with such high charge states at an injection rate into TSR of 0.5–1 Hz is between 10 and 20 kA/cm{sup 2}, which agrees with the current density needed to produce A/q<4.5 ions for the HIE-ISOLDE linac with a maximum repetition rate of 100 Hz. The first operation of a prototype electron gun with a pulsed electron beam of 1.5 A and 30 keV was demonstrated in a joint experiment with BNL [2]. In addition, we report on further development aiming to achieve CW operation of an electron beam having a geometrical transverse ion-acceptance matching the injection of 1{sup +} ions (11.5 μm), and an emittance/energy spread of the extracted ion beam matching the downstream mass separator and RFQ (0.08 μm normalized / ± 1%)

  2. Induced charging of shuttle orbiter by high electron-beam currents

    NASA Technical Reports Server (NTRS)

    Liemohn, H. B.

    1977-01-01

    Emission of high-current electron beams that was proposed for some Spacelab payloads required substantial return currents to the orbiter skin in order to neutralize the beam charge. Since the outer skin of the vehicle was covered with approximately 1200 sq m of thermal insulation which has the dielectric quality of air and an electrical conductivity that was estimated by NASA at 10 to the -9 power to 10 to the -10 power mhos/m, considerable transient charging and local potential differences were anticipated across the insulation. The theory for induced charging of spacecraft due to operation of electron guns was only developed for spherical metal vehicles and constant emission currents, which were not directly applicable to the orbiter situation. Field-aligned collection of electron return current from the ambient ionosphere at orbiter altitudes provides up to approximately 150 mA on the conducting surfaces and approximately 2.4 A on the dielectric thermal insulation. Local ionization of the neutral atmosphere by energetic electron bombardment or electrical breakdown may provide somewhat more return current.

  3. Development of highly accurate approximate scheme for computing the charge transfer integral.

    PubMed

    Pershin, Anton; Szalay, Péter G

    2015-08-21

    The charge transfer integral is a key parameter required by various theoretical models to describe charge transport properties, e.g., in organic semiconductors. The accuracy of this important property depends on several factors, which include the level of electronic structure theory and internal simplifications of the applied formalism. The goal of this paper is to identify the performance of various approximate approaches of the latter category, while using the high level equation-of-motion coupled cluster theory for the electronic structure. The calculations have been performed on the ethylene dimer as one of the simplest model systems. By studying different spatial perturbations, it was shown that while both energy split in dimer and fragment charge difference methods are equivalent with the exact formulation for symmetrical displacements, they are less efficient when describing transfer integral along the asymmetric alteration coordinate. Since the "exact" scheme was found computationally expensive, we examine the possibility to obtain the asymmetric fluctuation of the transfer integral by a Taylor expansion along the coordinate space. By exploring the efficiency of this novel approach, we show that the Taylor expansion scheme represents an attractive alternative to the "exact" calculations due to a substantial reduction of computational costs, when a considerably large region of the potential energy surface is of interest. Moreover, we show that the Taylor expansion scheme, irrespective of the dimer symmetry, is very accurate for the entire range of geometry fluctuations that cover the space the molecule accesses at room temperature. PMID:26298117

  4. Low-energy/high-charge-state ions in the polar ionosphere observed by AKEBONO/SMS

    NASA Astrophysics Data System (ADS)

    Sagawa, E.; Watanabe, Shigeaki; Watanabe, Shigeto

    The suprathermal ion mass spectrometer (SMS) onboard the AKEBONO satellite has occasionally observed a broad mass peak in the ion mass spectrum at amu/ q ˜ 2.7. SMS is capable of measuring a wide range of ion mass (1-64 amu/ q) at low energy ( E < ˜100 eV) with good mass resolution (Δ M/ M ˜ 0.1). The events were observed at about 1 Re altitude, and mostly at the polar cusp region as identified by the on-board low-energy particle (LEP) instrument. The broad mass peak is consistent with high-charge state ions commonly seen in the solar wind such as C 6+, O 7+, and O 6+. Although it is difficult to identify the charge state of these ions definitively using SMS, which is a mass-per-charge analyzer, decomposition of the broad mass peak results in a reasonable ratio of O 7+/O 6+ to that in the solar wind. Statistical study shows that this type of events has been observed with an occurrence rate of about 10% near the dayside cusp region. Also, the occurrence rate is slightly higher when IMF Bz is positive, suggesting the entry of the solar wind plasma into the polar ionosphere with weaker acceleration during northward IMF compared with southward IMF.

  5. Opposite counter-ion effects on condensed bundles of highly charged supramolecular nanotubes in water.

    PubMed

    Wei, Shenghui; Chen, Mingming; Wei, Chengsha; Huang, Ningdong; Li, Liangbin

    2016-07-20

    Although ion specificity in aqueous solutions is well known, its manifestation in unconventional strong electrostatic interactions remains implicit. Herein, the ionic effects in dense packing of highly charged polyelectrolytes are investigated in supramolecular nanotube prototypes. Distinctive behaviors of the orthorhombic arrays composed of supramolecular nanotubes in various aqueous solutions were observed by Small Angle X-ray Scattering (SAXS), depending on the counter-ions' size and affiliation to the surface -COO(-) groups. Bigger tetra-alkyl ammonium (TAA(+)) cations weakly bonding to -COO(-) will compress the orthorhombic arrays, while expansion is induced by smaller alkaline metal (M(+)) ions with strong affiliation to -COO(-). Careful analysis of the changes in the SAXS peaks with different counter/co-ion combinations indicates dissimilar mechanisms underlying the two explicit types of ionic effects. The pH measurements are in line with the ion specificity by SAXS and reveal the strong electrostatic character of the system. It is proposed that the small distances between the charged surfaces, in addition to the selective adsorption of counter-ions by the surface charge, bring out the observed distinctive ionic effects. Our results manifest the diverse mechanisms and critical roles of counter-ion effects in strong electrostatic interactions. PMID:27373802

  6. Development of highly accurate approximate scheme for computing the charge transfer integral

    SciTech Connect

    Pershin, Anton; Szalay, Péter G.

    2015-08-21

    The charge transfer integral is a key parameter required by various theoretical models to describe charge transport properties, e.g., in organic semiconductors. The accuracy of this important property depends on several factors, which include the level of electronic structure theory and internal simplifications of the applied formalism. The goal of this paper is to identify the performance of various approximate approaches of the latter category, while using the high level equation-of-motion coupled cluster theory for the electronic structure. The calculations have been performed on the ethylene dimer as one of the simplest model systems. By studying different spatial perturbations, it was shown that while both energy split in dimer and fragment charge difference methods are equivalent with the exact formulation for symmetrical displacements, they are less efficient when describing transfer integral along the asymmetric alteration coordinate. Since the “exact” scheme was found computationally expensive, we examine the possibility to obtain the asymmetric fluctuation of the transfer integral by a Taylor expansion along the coordinate space. By exploring the efficiency of this novel approach, we show that the Taylor expansion scheme represents an attractive alternative to the “exact” calculations due to a substantial reduction of computational costs, when a considerably large region of the potential energy surface is of interest. Moreover, we show that the Taylor expansion scheme, irrespective of the dimer symmetry, is very accurate for the entire range of geometry fluctuations that cover the space the molecule accesses at room temperature.

  7. High prevalence and genotypes of Toxoplasma gondii isolated from goats from a retail meat store destined for human consumption in the USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Little information is available concerning the presence of viable Toxoplasma gondii in tissues of goats worldwide. In the present study, the prevalence of T. gondii was determined in 234 goats from Maryland, Virginia and Pennsylvania, USA. Hearts of 234 goats were obtained from a local grocery store...

  8. Ultrafast Charge Dynamics Initiated by High-Intensity, Ultrashort Laser-Matter Interaction

    SciTech Connect

    Borghesi, Marco; Romagnani, Lorenzo; Kar, Satyabrata; Cecchetti, Carlo A.; Toncian, Toma; Jung, Ralph; Osterholtz, Jens; Willi, Oswald; Antici, Patrizio; Audebert, Patrick; Brambrink, Erik; Fuchs, Julien; Ceccherini, Francesco; Macchi, Andrea; Galimberti, Marco; Gizzi, Leonida A.; Grismayer, Thomas; Mora, Patrick; Schiavi, Angelo

    2006-04-07

    The interaction of high-intensity laser pulses with matter releases instantaneously ultra-large currents of highly energetic electrons, leading to the generation of highly-transient, large-amplitude electric and magnetic fields. We report results of recent experiment in which such charge dynamics have been studied by using proton probing techniques able to provide maps of the electrostatic fields with high spatial and temporal resolution. The dynamics of ponderomotive channelling in underdense plasmas have been studied in this way, as also the processes of Debye sheath formation and MeV ion front expansion at the rear of laser-irradiated thin metallic foils. An application employing laser-driven impulsive fields for energy-selective ion beam focusing is also presented.

  9. Ultrafast Charge Dynamics Initiated by High-Intensity, Ultrashort Laser-Matter Interaction

    NASA Astrophysics Data System (ADS)

    Borghesi, Marco; Romagnani, Lorenzo; Kar, Satyabrata; Toncian, Toma; Antici, Patrizio; Audebert, Patrick; Brambrink, Erik; Ceccherini, Francesco; Cecchetti, Carlo A.; Fuchs, Julien; Galimberti, Marco; Gizzi, Leonida A.; Grismayer, Thomas; Jung, Ralph; Macchi, Andrea; Mora, Patrick; Osterholtz, Jens; Schiavi, Angelo; Willi, Oswald

    2006-04-01

    The interaction of high-intensity laser pulses with matter releases instantaneously ultra-large currents of highly energetic electrons, leading to the generation of highly-transient, large-amplitude electric and magnetic fields. We report results of recent experiment in which such charge dynamics have been studied by using proton probing techniques able to provide maps of the electrostatic fields with high spatial and temporal resolution. The dynamics of ponderomotive channelling in underdense plasmas have been studied in this way, as also the processes of Debye sheath formation and MeV ion front expansion at the rear of laser-irradiated thin metallic foils. An application employing laser-driven impulsive fields for energy-selective ion beam focusing is also presented.

  10. Surface and structure modification induced by high energy and highly charged uranium ion irradiation in monocrystal spinel

    NASA Astrophysics Data System (ADS)

    Yang, Yitao; Zhang, Chonghong; Song, Yin; Gou, Jie; Zhang, Liqing; Meng, Yancheng; Zhang, Hengqing; Ma, Yizhun

    2014-05-01

    Due to its high temperature properties and relatively good behavior under irradiation, magnesium aluminate spinel (MgAl2O4) is considered as a possible material to be used as inert matrix for the minor actinides burning. In this case, irradiation damage is an unavoidable problem. In this study, high energy and highly charged uranium ions (290 MeV U32+) were used to irradiate monocrystal spinel to the fluence of 1.0 × 1013 ions/cm2 to study the modification of surface and structure. Highly charged ions carry large potential energy, when they interact with a surface, the release of potential energy results in the modification of surface. Atomic force microscopy (AFM) results showed the occurrence of etching on surface after uranium ion irradiation. The etching depth reached 540 nm. The surprising efficiency of etching is considered to be induced by the deposition of potential energy with high density. The X-ray diffraction results showed that the (4 4 0) diffraction peak obviously broadened after irradiation, which indicated that the distortion of lattice has occurred. After multi-peak Gaussian fitting, four Gaussian peaks were separated, which implied that a structure with different damage layers could be formed after irradiation.

  11. VRLA Ultrabattery for high-rate partial-state-of-charge operation

    NASA Astrophysics Data System (ADS)

    Lam, L. T.; Louey, R.; Haigh, N. P.; Lim, O. V.; Vella, D. G.; Phyland, C. G.; Vu, L. H.; Furukawa, J.; Takada, T.; Monma, D.; Kano, T.

    The objective of this study is to produce and test the hybrid valve-regulated Ultrabattery designed specifically for hybrid-electric vehicle duty, i.e., high-rate partial-state-of-charge operation. The Ultrabattery developed by CSIRO Energy Technology is a hybrid energy-storage device, which combines an asymmetric supercapacitor, and a lead-acid battery in one unit cells, taking the best from both technologies without the need for extra, expensive electronic controls. The capacitor will enhance the power and lifespan of the lead-acid battery as it acts as a buffer during high-rate discharging and charging. Consequently, this hybrid technology is able to provide and absorb charge rapidly during vehicle acceleration and braking. The work programme of this study is divided into two main parts, namely, field trial of prototype Ultrabatteries in a Honda Insight HEV and laboratory tests of prototype batteries. In this paper, the performance of prototype Ultrabatteries under different laboratory tests is reported. The evaluation of Ultrabatteries in terms of initial performance and cycling performance has been conducted at both CSIRO and Furukawa laboratories. The initial performance of prototype Ultrabatteries, such as capacity, power, cold cranking and self-discharge has been evaluated based upon the US FreedomCAR Battery Test Manual (DOE/ID-11069, October 2003). Results show that the Ultrabatteries meet, or exceed, respective targets of power, available energy, cold cranking and self-discharge set for both minimum and maximum power-assist HEVs. The cycling performance of prototype Ultrabatteries has been evaluated using: (i) simplified discharge and charge profile to simulate the driving conditions of micro-HEV; (ii) 42-V profile to simulate the driving conditions of mild-HEV and (iii) EUCAR and RHOLAB profiles to simulate the driving conditions of medium-HEV. For comparison purposes, nickel-metal-hydride (Ni-MH) cells, which are presently used in the Honda Insight HEV

  12. Surface charging and x-ray emission from insulator surfaces induced by collisions with highly charged ions : relevance to cometary and planetary sp

    NASA Technical Reports Server (NTRS)

    Djuric, N.; Lozano, J. A.; Smith, S. J.; Chutjian, A.

    2005-01-01

    Characteristic X-ray emission lines are detected from simulants of comet surfaces as they undergo collisions with highly charged ions (HCIs). The HCI projectiles are O+2-O+7. Ion energies are varied in the range (2-7)q keV, where q is the ion charge state. The targets are the insulator minerals olivine, augite, and quartz. It is found that the emission of characteristic K-L, K-M X-rays appears to proceed during positive charging of the surface by the HCI beam. When one uses low-energy, flood-gun electrons to neutralize the surface charge, the X-ray emission is eliminated or greatly reduced, depending on the flood-gun current. Acceleration of background electrons onto the charged surface results in excitation of elemental transitions, including the K-L2 and K-L3 target X-ray emission lines of Mg and Si located spectroscopically at 1253.6 and 1739.4 eV, respectively. Also observed are emission lines from O, Na, Ca, Al, and Fe atoms in the target and charge-exchange lines via surface extraction of electrons by the O+q electric field. Good agreement is found in the ratio of the measured X-ray yields for Mg and Si relative to the ratio of their electron-impact K-shell ionization cross sections. The present study may serve as a guide to astronomers as to specific observing X-ray energies indicative of solar/stellar wind or magnetospheric ion interactions with a comet, planetary surface, or circumstellar dust.

  13. Consumers' quality perception of national branded, national store branded, and imported store branded beef.

    PubMed

    Banović, Marija; Grunert, Klaus G; Barreira, Maria Madalena; Fontes, Magda Aguiar

    2010-01-01

    This study investigated the differences in the consumers' quality perception of national branded, national store branded, and imported store branded beef. Partial Least Squares analysis is used for modelling the quality perception process. Results show that consumers perceived national branded Carnalentejana beef, as better on all quality cues and quality aspects than the other two store branded beefs. Preference for Carnalentejana beef stayed highly consistent even after the blind test, where consumers differentiated this beef from the other two beef brands on all sensory dimensions: taste, tenderness, and juiciness, and chose it as the preferred one. Consumers utilized more perceived intrinsic cues to infer expected eating quality of store branded beefs. PMID:20374754

  14. Experimental study of interactions of highly charged ions with atoms at keV energies

    SciTech Connect

    Kostroun, V.O.

    1992-07-05

    This Progress Report describes the experimental work carried out, and the work in progress, at the Cornell EBIS Laboratory during the period 7/1/1991 to 6/30/1992. During this period, a number of experiments were carried out. The absolute values of the total, one, two and three electron transfer cross sections for highly charged argon ions (8{le}q{le}16) colliding with argon at 2.3 qkev laboratory energy were measured. The distribution of recoil ions and molecular fragments formed in highly charged ion atom and molecule collisions was measured in order to help the interpretation of electron spectra in the 40--320 eV energy range emitted in Ar{sup q+}+Ar(8{le}q{le}16) collisions at 2.3 qkeV that were measured in our laboratory. The interpretation of the electron spectra is still under way. A new collision chamber was built which contains an ion decelerating lens system and a high resolution monochromator-analyzer combination. Ions extracted from the Cornell Electron Beam Ion Source were successfully decelerated from 2.3 qkeV down to 30 qeV Preliminary 0{degree} translational energy spectra for Ar{sup l2+} on Ar at a collision energy of 38.6 qeV show a 0.56 qeV resolution. Work is in progress to extend measurements of cross sections and recoil ion charge state distributions down to collision energies in the 10 eV/amu range.

  15. First Use of High Charge States for Mass Measurements of Short-Lived Nuclides in a Penning Trap

    SciTech Connect

    Ettenauer, S.; Gallant, A. T.; Dilling, J.; Simon, M. C.; Chaudhuri, A.; Mane, E.; Delheij, P.; Pearson, M. R.; Brunner, T.; Chowdhury, U.; Simon, V. V.; Brodeur, M.; Andreoiu, C.; Audi, G.; Lopez-Urrutia, J. R. Crespo; Ullrich, J.; Gwinner, G.; Lapierre, A.; Lunney, D.; Ringle, R.

    2011-12-30

    Penning trap mass measurements of short-lived nuclides have been performed for the first time with highly charged ions, using the TITAN facility at TRIUMF. Compared to singly charged ions, this provides an improvement in experimental precision that scales with the charge state q. Neutron-deficient Rb isotopes have been charge bred in an electron beam ion trap to q=8-12+ prior to injection into the Penning trap. In combination with the Ramsey excitation scheme, this unique setup creating low energy, highly charged ions at a radioactive beam facility opens the door to unrivaled precision with gains of 1-2 orders of magnitude. The method is particularly suited for short-lived nuclides such as the superallowed {beta} emitter {sup 74}Rb (T{sub 1/2}=65 ms). The determination of its atomic mass and an improved Q{sub EC} value are presented.

  16. First use of high charge states for mass measurements of short-lived nuclides in a Penning trap.

    PubMed

    Ettenauer, S; Simon, M C; Gallant, A T; Brunner, T; Chowdhury, U; Simon, V V; Brodeur, M; Chaudhuri, A; Mané, E; Andreoiu, C; Audi, G; López-Urrutia, J R Crespo; Delheij, P; Gwinner, G; Lapierre, A; Lunney, D; Pearson, M R; Ringle, R; Ullrich, J; Dilling, J

    2011-12-30

    Penning trap mass measurements of short-lived nuclides have been performed for the first time with highly charged ions, using the TITAN facility at TRIUMF. Compared to singly charged ions, this provides an improvement in experimental precision that scales with the charge state q. Neutron-deficient Rb isotopes have been charge bred in an electron beam ion trap to q=8-12+ prior to injection into the Penning trap. In combination with the Ramsey excitation scheme, this unique setup creating low energy, highly charged ions at a radioactive beam facility opens the door to unrivaled precision with gains of 1-2 orders of magnitude. The method is particularly suited for short-lived nuclides such as the superallowed β emitter 74Rb (T(1/2)=65  ms). The determination of its atomic mass and an improved Q(EC) value are presented. PMID:22243307

  17. Preparation of highly charged cellulose nanofibrils using high-pressure homogenization coupled with strong acid hydrolysis pretreatments.

    PubMed

    Tian, Cuihua; Yi, Jianan; Wu, Yiqiang; Wu, Qinglin; Qing, Yan; Wang, Lijun

    2016-01-20

    Cellulose nanofibrils (CNFs) are attracting much attention for the advantages of excellent mechanical strength, good optical transparency, and high surface area. An eco-friendly and energy-saving method was created in this work to produce highly negative charged CNFs using high-pressure mechanical defibrillation coupled with strong acid hydrolysis pretreatments. The morphological development, zeta potential, crystal structure, chemical composition and thermal degradation behavior of the resultant materials were evaluated by transmission electron microscopy (TEM), zeta potential analysis, X-ray diffraction (XRD), Fourier transform infrared spectrometry (FTIR), and thermogravimetric analysis (TGA). These CNFs were fully separated, surface-charged, and highly entangled. They showed a large fiber aspect ratio compared to traditional cellulose nanocrystrals that are produced by strong acid hydrolysis. Compared to hydrochloric acid hydrolysis, the CNFs produced by sulfuric acid pretreatments were completely defibrillated and presented stable suspensions (or gels) even at low fiber content. On the other hand, CNFs pretreated by hydrochloric acid hydrolysis trended to aggregate because of the absence of surface charge. The crystallinity index (CI) of CNFs decreased because of mechanical defibrillation, and then increased dramatically with increased sulfuric acid concentration and reaction time. FTIR analysis showed that the C-O-SO3 group was introduced on the surfaces of CNFs during sulfuric acid hydrolysis. These sulfate groups accelerated the thermal degradation of CNFs, which occurred at lower temperature than wood pulp, indicating that the thermal stability of sulfuric acid hydrolyzed CNFs was decreased. The temperature of the maximum decomposition rate (Tmax) and the maximum weight-loss rates (MWLRmax) were much lower than for wood pulp because of the retardant effect of sulfuric acid during the combustion of CNFs. By contrast, the CNFs treated with hydrochloric acid

  18. Testing the relevance of effective interaction potentials between highly-charged colloids in suspension

    NASA Astrophysics Data System (ADS)

    Dobnikar, J.; Castañeda-Priego, R.; von Grünberg, H. H.; Trizac, E.

    2006-11-01

    Combining cell and Jellium model mean-field approaches, Monte Carlo together with integral equation techniques, and finally more demanding many-colloid mean-field computations, we investigate the thermodynamic behaviour, pressure and compressibility of highly-charged colloidal dispersions, and at a more microscopic level, the force distribution acting on the colloids. The Kirkwood Buff identity provides a useful probe to challenge the self-consistency of an approximate effective screened Coulomb (Yukawa) potential between colloids. Two effective parameter models are put to the test: cell against renormalized Jellium models.

  19. Design of a high-performance rotary stratified-charge research aircraft engine

    NASA Technical Reports Server (NTRS)

    Jones, C.; Mount, R. E.

    1984-01-01

    The power section for an advanced rotary stratified-charge general aviation engine has been designed under contract to NASA. The single-rotor research engine of 40 cubic-inches displacement (RCI-40), now being procured for test initiation this summer, is targeted for 320 T.O. horse-power in a two-rotor production engine. The research engine is designed for operating on jet-fuel, gasoline or diesel fuel and will be used to explore applicable advanced technologies and to optimize high output performance variables. Design of major components of the engine is described in this paper.

  20. Examination of charge transfer in Au/YSZ for high-temperature optical gas sensing

    SciTech Connect

    Baltrus, John P.; Ohodnicki, Paul R.

    2014-01-01

    Au-nanoparticle incorporated oxide thin film materials demonstrate significant promise as functionalsensor materials for high temperature optical gas sensing in severe environments relevant for fossil andnuclear based power generation. The Au/yttria-stabilized zirconia (YSZ) system has been extensivelystudied in the literature and serves as a model system for fundamental investigations that seek to betterunderstand the mechanistic origin of the plasmonic gas sensing response. In this work, X-ray photoelec-tron spectroscopy techniques are applied to Au/YSZ films in an attempt to provide further experimentalevidence for a proposed sensing mechanism involving a change in free carrier density of Au nanoparticles due to charge transfer.

  1. Fully-depleted, back-illuminated charge-coupled devices fabricated on high-resistivity silicon

    SciTech Connect

    Holland, Stephen E.; Groom, Donald E.; Palaio, Nick P.; Stover, Richard J.; Wei, Mingzhi

    2002-03-28

    Charge-coupled devices (CCD's) have been fabricated on high-resistivity silicon. The resistivity, on the order of 10,000 {Omega}-cm, allows for depletion depths of several hundred microns. Fully-depleted, back-illuminated operation is achieved by the application of a bias voltage to a ohmic contact on the wafer back side consisting of a thin in-situ doped polycrystalline silicon layer capped by indium tin oxide and silicon dioxide. This thin contact allows for good short wavelength response, while the relatively large depleted thickness results in good near-infrared response.

  2. Convoy electron emission following ionization of highly-charged ions excited by resonant coherent excitation

    NASA Astrophysics Data System (ADS)

    Suda, S.; Nakano, Y.; Metoki, K.; Shindo, T.; Ohtsuki, S.; Azuma, T.; Hatakeyama, A.; Komaki, K.; Nakai, Y.; Takada, E.; Murakami, T.

    2012-11-01

    Projectile ionization of highly-charged Ar and Fe ions in the excited states passing relativistically fast through a thin crystalline foil was experimentally studied. We selectively controlled the population of the excited states of the projectiles, and their alignment by choosing a specific m-state through three-dimensional resonant coherent excitation technique by periodical electric fields in a crystalline. We measured energy-differential spectra of electron emission released from projectiles at zero degree. Under the resonance condition, we found an evident enhancement of the convoy electron yield, which reflects the electron momentum distribution of the initial bound state of the excited ions.

  3. Relativistic calculations of the isotope shifts in highly charged Li-like ions

    NASA Astrophysics Data System (ADS)

    Zubova, N. A.; Kozhedub, Y. S.; Shabaev, V. M.; Tupitsyn, I. I.; Volotka, A. V.; Plunien, G.; Brandau, C.; Stöhlker, Th.

    2014-12-01

    Relativistic calculations of the isotope shifts of energy levels in highly charged Li-like ions are performed. The nuclear recoil (mass shift) contributions are calculated by merging the perturbative and large-scale configuration-interaction Dirac-Fock-Sturm (CI-DFS) methods. The nuclear size (field shift) contributions are evaluated by the CI-DFS method including the electron-correlation, Breit, and QED corrections. The nuclear deformation and nuclear polarization corrections to the isotope shifts in Li-like neodymium, thorium, and uranium are also considered. The results of the calculations are compared with the theoretical values obtained with other methods.

  4. Production of a highly charged uranium ion beam with RIKEN superconducting electron cyclotron resonance ion source

    SciTech Connect

    Higurashi, Y.; Ohnishi, J.; Nakagawa, T.; Haba, H.; Fujimaki, M.; Komiyama, M.; Kamigaito, O.; Tamura, M.; Aihara, T.; Uchiyama, A.

    2012-02-15

    A highly charged uranium (U) ion beam is produced from the RIKEN superconducting electron cyclotron resonance ion source using 18 and 28 GHz microwaves. The sputtering method is used to produce this U ion beam. The beam intensity is strongly dependent on the rod position and sputtering voltage. We observe that the emittance of U{sup 35+} for 28 GHz microwaves is almost the same as that for 18 GHz microwaves. It seems that the beam intensity of U ions produced using 28 GHz microwaves is higher than that produced using 18 GHz microwaves at the same Radio Frequency (RF) power.

  5. Formation of surface nano-structures by plasma expansion induced by highly charged ions

    SciTech Connect

    Moslem, W. M.; El-Said, A. S.

    2012-12-15

    Slow highly charged ions (HCIs) create surface nano-structures (nano-hillocks) on the quartz surface. The formation of hillocks was only possible by surpassing a potential energy threshold. By using the plasma expansion approach with suitable hydrodynamic equations, the creation mechanism of the nano-hillocks induced by HCIs is explained. Numerical analysis reveal that within the nanoscale created plasma region, the increase of the temperature causes an increase of the self-similar solution validity domain, and consequently the surface nano-hillocks become taller. Furthermore, the presence of the negative (positive) nano-dust particles would lead to increase (decrease) the nano-hillocks height.

  6. Effects of structural properties of the Stern layer on the electrophoretic migration of a highly charged spherical macroion.

    PubMed

    Rezaei, Majid; Azimian, Ahmad Reza

    2015-12-01

    The electrophoretic migration of a highly charged spherical macroion suspended in an aqueous solution of NaCl is studied using the molecular dynamic method. The objective is to examine the effects of the colloidal surface charge density on the electrophoretic mobility (μ) of the spherical macroion. The bare charge and the size of the macroion are varied separately to induce changes in the colloidal surface charge density. Our results indicate that μ depends on colloidal surface charge density in a nonmonotonic manner, but that this relationship is independent of the way the surface charge density is varied. It is found that an increase in colloidal surface charge density may lead to the formation of new sublayers in the Stern layer. The μ profile is also found to have a local maximum for a bare charge at which a new sublayer is formed in the Stern layer, and a local minimum for a bare charge at which the outer sublayer becomes relatively dense. Finally, the electrophoretic flow caused by the migration of the spherical macroion is studied to find that one decisive factor causing the electrophoretic flow is the ability of the macroion to carry anions in the electrolyte solution. PMID:26456026

  7. Nonlinear Delta-f Particle Simulations of Collective Effects in High Intensity Charged Particle Beams

    NASA Astrophysics Data System (ADS)

    Qin, Hong; Davidson, Ronald C.; Startsev, Edward A.

    2004-11-01

    A wide range of collective effects in high intensity charged particle beams have been numerically studied using the nonlinear delta-f particle simulation method implemented in the Beam Equilibrium Stability and Transport (BEST) code. For the electron-ion two-stream instability in high intensity accelerators and storage rings, the secondary electron yield effects are self-consistently studied by coupling the secondary electron yield library CMEE with the instability simulations. Progress has also been made in applying the delta-f particle simulation method to bunched beams, and a three-dimensional equilibrium solver has been implemented. With the help of recently developed parallel diagnostic techniques, we are able to characterize the chaotic particle dynamics under the influences of collective instabilities as well as three-dimensional equilibrium fields. To further extend the application areas of the delta-f particle simulation method, 2D domain decomposition is being developed using the Message Passing Interface, and three-dimensional equilibria with anisotropic temperature in the transverse and longitudinal directions are being investigated. References: [1] R. C. Davidson and H. Qin, An Introduction to the Physics of Intense Charged Particle Beams in High Energy Accelerators, World Scientific (2001). [2] H. Qin, Physics of Plasmas 10, 2078 (2003). [3] H. Qin, E. A. Startsev, and R. C. Davidson, Physical Review Special Topics on Accelerators and Beams 6, 014401 (2003).

  8. Tuning charge balance in PHOLEDs with ambipolar host materials to achieve high efficiency

    SciTech Connect

    Padmaperuma, Asanga B.; Koech, Phillip K.; Cosimbescu, Lelia; Polikarpov, Evgueni; Swensen, James S.; Chopra, Neetu; So, Franky; Sapochak, Linda S.; Gaspar, Daniel J.

    2009-08-27

    The efficiency and stability of blue organic light emitting devices (OLEDs) continue to be a primary roadblock to developing organic solid state white lighting. For OLEDs to meet the high power conversion efficiency goal, they will require both close to 100% internal quantum efficiency and low operating voltage in a white light emitting device.1 It is generally accepted that such high quantum efficiency, can only be achieved with the use of organometallic phosphor doped OLEDs. Blue OLEDs are particularly important for solid state lighting. The simplest (and therefore likely the lowest cost) method of generating white light is to down convert part of the emission from a blue light source with a system of external phosphors.2 A second method of generating white light requires the superposition of the light from red, green and blue OLEDs in the correct ratio. Either of these two methods (and indeed any method of generating white light with a high color rendering index) critically depends on a high efficiency blue light component.3 A simple OLED generally consists of a hole-injecting anode, a preferentially hole transporting organic layer (HTL), an emissive layer that contains the recombination zone and ideally transports both holes and electrons, a preferentially electron-transporting layer (ETL) and an electron-injecting cathode. Color in state-of-the-art OLEDs is generated by an organometallic phosphor incorporated by co-sublimation into the emissive layer (EML).4 New materials functioning as hosts, emitters, charge transporting, and charge blocking layers have been developed along with device architectures leading to electrophosphorescent based OLEDs with high quantum efficiencies near the theoretical limit. However, the layers added to the device architecture to enable high quantum efficiencies lead to higher operating voltages and correspondingly lower power efficiencies. Achievement of target luminance power efficiencies will require new strategies for lowering

  9. High-Resolution Size-Discrimination of Single Nonionic Synthetic Polymers with a Highly Charged Biological Nanopore.

    PubMed

    Baaken, Gerhard; Halimeh, Ibrahim; Bacri, Laurent; Pelta, Juan; Oukhaled, Abdelghani; Behrends, Jan C

    2015-06-23

    Electrophysiological studies of the interaction of polymers with pores formed by bacterial toxins (1) provide a window on single molecule interaction with proteins in real time, (2) report on the behavior of macromolecules in confinement, and (3) enable label-free single molecule sensing. Using pores formed by the staphylococcal toxin α-hemolysin (aHL), a particularly pertinent observation was that, under high salt conditions (3-4 M KCl), the current through the pore is blocked for periods of hundreds of microseconds to milliseconds by poly(ethylene glycol) (PEG) oligomers (degree of polymerization approximately 10-60). Notably, this block showed monomeric sensitivity on the degree of polymerization of individual oligomers, allowing the construction of size or mass spectra from the residual current values. Here, we show that the current through the pore formed by aerolysin (AeL) from Aeromonas hydrophila is also blocked by PEG but with drastic differences in the voltage-dependence of the interaction. In contrast to aHL, AeL strongly binds PEG at high transmembrane voltages. This fact, which is likely related to AeL's highly charged pore wall, allows discrimination of polymer sizes with particularly high resolution. Multiple applications are now conceivable with this pore to screen various nonionic or charged polymers. PMID:26028280

  10. Soft X-Ray Laser Spectroscopy on Trapped Highly Charged Ions at FLASH

    SciTech Connect

    Epp, S. W.; Lopez-Urrutia, J. R. Crespo; Brenner, G.; Maeckel, V.; Mokler, P. H.; Ullrich, J.; Treusch, R.; Kuhlmann, M.; Yurkov, M. V.; Feldhaus, J.; Schneider, J. R.; Wellhoefer, M.; Martins, M.; Wurth, W.

    2007-05-04

    In a proof-of-principle experiment, we demonstrate high-resolution resonant laser excitation in the soft x-ray region at 48.6 eV of the 2 {sup 2}S{sub 1/2} to 2 {sup 2}P{sub 1/2} transition of Li-like Fe{sup 23+} ions trapped in an electron beam ion trap by using ultrabrilliant light from Free Electron Laser in Hamburg (FLASH). High precision spectroscopic studies of highly charged ions at this and upcoming x-ray lasers with an expected accuracy gain up to a factor of a thousand, become possible with our technique, thus potentially yielding fundamental insights, e.g., into basic aspects of QED.

  11. The Stopping Power of Asteroidal Materials as High-Energy Charged Particle Shielding

    NASA Astrophysics Data System (ADS)

    Pohl, Leos; Johnson, Daniel; Britt, Daniel

    2014-11-01

    Extended human missions in deep space face a challenging radiation environment from high-energy galactic cosmic rays and solar energetic particles generated by solar flares and related coronal mass ejections. Shielding to attenuate these high-energy particles will require significant mass and volume, and would be extremely expensive launch from the surface of the earth. One possible solution could be the use of asteroidal resources as shielding for these high-energy particles. The effectiveness of shielding material for moderately relativistic charged particles is a function of the mean rate of energy loss, primarily to ionization and atomic excitation and is termed stopping power. In general, low atomic number elements are more effective per unit volume. We have calculated the stopping power for the average compositions of all major meteorite groups and will compare these data with typical spacecraft materials.

  12. Confinement physics for thermal, neutral, high-charge-state plasmas in nested-well solenoidal traps.

    PubMed

    Dolliver, D D; Ordonez, C A

    1999-06-01

    A theoretical study is presented which indicates that it is possible to confine a neutral plasma using static electric and solenoidal magnetic fields. The plasma consists of equal temperature electrons and highly stripped ions. The solenoidal magnetic field provides radial confinement, while the electric field, which produces an axial nested-well potential profile, provides axial confinement. A self-consistent, multidimensional numerical solution for the electric potential is obtained, and a fully kinetic theoretical treatment on axial transport is used to determine an axial confinement time scale. The effect on confinement of the presence of a radial electric field is explored with the use of ion trajectory calculations. A thermal, neutral, high-charge-state plasma confined in a nested-well trap opens new possibilities for fundamental studies on plasma recombination and cross-field transport processes under highly controlled conditions. PMID:11969700

  13. Store manager performance and satisfaction: effects on store employee performance and satisfaction, store customer satisfaction, and store customer spending growth.

    PubMed

    Netemeyer, Richard G; Maxham, James G; Lichtenstein, Donald R

    2010-05-01

    Based on emotional contagion theory and the value-profit chain literatures, the present study posits a number of hypotheses that show how managers in the small store, small number of employees retail context may affect store employees, customers, and potentially store performance. With data from 306 store managers, 1,615 store customer-contact employees, and 57,656 customers of a single retail chain, the authors examined relationships among store manager job satisfaction and job performance, store customer-contact employee job satisfaction and job performance, customer satisfaction with the retailer, and a customer-spending-based store performance metric (customer spending growth over a 2-year period). Via path analysis, several hypothesized direct and interaction relations among these constructs are supported. The results suggest implications for academic researchers and retail managers. PMID:20476831

  14. The Subglacial Access and Fast Ice Research Experiment (SAFIRE): 2. High magnitude englacial strain detected with autonomous phase-sensitive FMCW radar on Store Glacier, West Greenland

    NASA Astrophysics Data System (ADS)

    Young, Tun Jan; Christoffersen, Poul; Nicholls, Keith; Bun Lok, Lai; Doyle, Samuel; Hubbard, Bryn; Stewart, Craig; Hofstede, Coen; Bougamont, Marion; Todd, Joseph; Brennan, Paul; Hubbard, Alun

    2016-04-01

    Fast-flowing outlet glaciers terminating in the sea drain 90% of the Greenland Ice Sheet. It is well-known that these glaciers flow rapidly due to fast basal motion, but its contributing processes and mechanisms are, however, poorly understood. In particular, there is a paucity of data to quantify the extent to which basal sliding and internal ice deformation by viscous creep contribute to the fast motion of Greenland outlet glaciers. To study these processes, we installed a network of global positioning system (GPS) receivers around an autonomous phase-sensitive radio-echo sounder (ApRES) capable of imaging internal reflectors and the glacier bed. The ApRES system, including antennas, were custom-designed to monitor and image ice sheets and ice shelves in monostatic and multiple-input multiple-output (MIMO) modes. Specifically, the system transmits a frequency-modulated continuous-wave (FMCW) that increases linearly from 200 to 400 MHz over a period of 1 second. We installed this system 30 km up-flow of the tidewater terminus of Store Glacier, which flows into Uummannaq Fjord in West Greenland, and data were recorded every hour from 06 May to 16 July 2014 and every 4 hours from 26 July to 11 December 2014. The same site was used to instrument 600 m deep boreholes drilled to the bed as part of the SAFIRE research programme. With range and reflector distances captured at high temporal (hourly) and spatial (millimetre) resolutions, we obtained a unique, 6-month-long time series of strain through the vertical ice column at the drill site where tilt was independently recorded in a borehole. Our results show variable, but persistently high vertical strain. In the upper three-fourths of the ice column, we have calculated strain rates on the order of a few percent per year, and the strain regime curiously shifts from vertical thinning in winter to vertical thickening at the onset of summer melt. In the basal ice layer we observed high-magnitude vertical strain rates on

  15. Internal Charging

    NASA Technical Reports Server (NTRS)

    Minow, Joseph I.

    2014-01-01

    (1) High energy (>100keV) electrons penetrate spacecraft walls and accumulate in dielectrics or isolated conductors; (2) Threat environment is energetic electrons with sufficient flux to charge circuit boards, cable insulation, and ungrounded metal faster than charge can dissipate; (3) Accumulating charge density generates electric fields in excess of material breakdown strenght resulting in electrostatic discharge; and (4) System impact is material damage, discharge currents inside of spacecraft Faraday cage on or near critical circuitry, and RF noise.

  16. X-ray emission in collisions of highly charged I, Pr, Ho, and Bi ions with a W surface

    SciTech Connect

    Watanabe, H.; Tona, M.; Ohtani, S.; Sun, J.; Nakamura, N.; Yamada, C.; Yoshiyasu, N.; Sakurai, M.

    2007-06-15

    X-ray emission yields, which are defined as the total number of emitted x-ray photons per incident ion, and dissipated fractions of potential energies through x-ray emission have been measured for slow highly charged ions of I, Pr, Ho, and Bi colliding with a W surface. A larger amount of potential energy was consumed for the x-ray emission with increasing the atomic number and the charge state. The present measurements show that x-ray emission is one of the main decay channels of hollow atoms produced in collisions of very highly charged ions of heavy elements.

  17. FAST TRACK COMMUNICATION: Inhomogeneous charge redistribution in Xe clusters exposed to an intense extreme ultraviolet free electron laser

    NASA Astrophysics Data System (ADS)

    Iwayama, H.; Sugishima, A.; Nagaya, K.; Yao, M.; Fukuzawa, H.; Motomura, K.; Liu, X.-J.; Yamada, A.; Wang, C.; Ueda, K.; Saito, N.; Nagasono, M.; Tono, K.; Yabashi, M.; Ishikawa, T.; Ohashi, H.; Kimura, H.; Togashi, T.

    2010-08-01

    The emission of highly charged ions from Xe clusters exposed to intense extreme ultraviolet laser pulses (λ ~ 52 nm) from the free electron laser in Japan was investigated using ion momentum spectroscopy. With increasing average cluster size, we observed multiply charged ions Xez + up to z = 3. From kinetic energy distributions, we found that multiply charged ions were generated near the cluster surface. Our results suggest that charges are inhomogeneously redistributed in the cluster to lower the total energy stored in the clusters.

  18. Charge-density analysis of an iron-sulfur protein at an ultra-high resolution of 0.48 Å.

    PubMed

    Hirano, Yu; Takeda, Kazuki; Miki, Kunio

    2016-06-01

    The fine structures of proteins, such as the positions of hydrogen atoms, distributions of valence electrons and orientations of bound waters, are critical factors for determining the dynamic and chemical properties of proteins. Such information cannot be obtained by conventional protein X-ray analyses at 3.0-1.5 Å resolution, in which amino acids are fitted into atomically unresolved electron-density maps and refinement calculations are performed under strong restraints. Therefore, we usually supplement the information on hydrogen atoms and valence electrons in proteins with pre-existing common knowledge obtained by chemistry in small molecules. However, even now, computational calculation of such information with quantum chemistry also tends to be difficult, especially for polynuclear metalloproteins. Here we report a charge-density analysis of the high-potential iron-sulfur protein from the thermophilic purple bacterium Thermochromatium tepidum using X-ray data at an ultra-high resolution of 0.48 Å. Residual electron densities in the conventional refinement are assigned as valence electrons in the multipolar refinement. Iron 3d and sulfur 3p electron densities of the Fe4S4 cluster are visualized around the atoms. Such information provides the most detailed view of the valence electrons of the metal complex in the protein. The asymmetry of the iron-sulfur cluster and the protein environment suggests the structural basis of charge storing on electron transfer. Our charge-density analysis reveals many fine features around the metal complex for the first time, and will enable further theoretical and experimental studies of metalloproteins. PMID:27279229

  19. High spatial and temporal resolution charge exchange recombination spectroscopy on the HL-2A tokamak

    NASA Astrophysics Data System (ADS)

    Wei, Y. L.; Yu, D. L.; Liu, L.; Ida, K.; von Hellermann, M.; Cao, J. Y.; Sun, A. P.; Ma, Q.; Chen, W. J.; Liu, Yi; Yan, L. W.; Yang, Q. W.; Duan, X. R.; Liu, Yong

    2014-10-01

    A 32/64-channel charge exchange recombination spectroscopy (CXRS) diagnostic system is developed on the HL-2A tokamak (R = 1.65 m, a = 0.4 m), monitoring plasma ion temperature and toroidal rotation velocity simultaneously. A high throughput spectrometer (F/2.8) and a pitch-controlled fiber bundle enable the temporal resolution of the system up to 400 Hz. The observation geometry and an optimized optic system enable the highest radial resolution up to ˜1 cm at the plasma edge. The CXRS system monitors the carbon line emission (C VI, n = 8-7, 529.06 nm) whose Doppler broadening and Doppler shift provide ion temperature and plasma rotation velocity during the neutral beam injection. The composite CX spectral data are analyzed by the atomic data and analysis structure charge exchange spectroscopy fitting (ADAS CXSFIT) code. First experimental results are shown for the case of HL-2A plasmas with sawtooth oscillations, electron cyclotron resonance heating, and edge transport barrier during the high-confinement mode (H-mode).

  20. Electrohydrodynamic pressure enhanced by free space charge for electrically induced structure formation with high aspect ratio.

    PubMed

    Tian, Hongmiao; Wang, Chunhui; Shao, Jinyou; Ding, Yucheng; Li, Xiangming

    2014-10-28

    Electrically induced structure formation (EISF) is an interesting and unique approach for generating a microstructured duplicate from a rheological polymer by a spatially modulated electric field induced by a patterned template. Most of the research on EISF have so far used various dielectric polymers (with an electrical conductivity smaller than 10(-10) S/m that can be considered a perfect dielectric), on which the electric field induces a Maxwell stress only due to the dipoles (or bounded charges) in the polymer molecules, leading to a structure with a small aspect ratio. This paper presents a different approach for improving the aspect ratio allowed in EISF by doping organic salt into the perfect dielectric polymer, i.e., turning the perfect dielectric into a leaky dielectric, considering the fact that the free space charges enriched in the leaky dielectric polymer can make an additional contribution to the Maxwell stress, i.e., electrohydrodynamic pressure, which is desirable for high aspect ratio structuring. Our numerical simulations and experimental tests have shown that a leaky dielectric polymer, with a small conductivity comparable to that of deionized water, can be much more effective at being electrohydrodynamically deformed into a high aspect ratio in comparison with a perfect dielectric polymer when both of them have roughly the same dielectric constant. PMID:25268463

  1. High spatial and temporal resolution charge exchange recombination spectroscopy on the HL-2A tokamak

    SciTech Connect

    Wei, Y. L.; Yu, D. L. Liu, L.; Cao, J. Y.; Sun, A. P.; Ma, Q.; Chen, W. J.; Liu, Yi; Yan, L. W.; Yang, Q. W.; Duan, X. R.; Liu, Yong; Ida, K.; Hellermann, M. von

    2014-10-01

    A 32/64-channel charge exchange recombination spectroscopy (CXRS) diagnostic system is developed on the HL-2A tokamak (R = 1.65 m, a = 0.4 m), monitoring plasma ion temperature and toroidal rotation velocity simultaneously. A high throughput spectrometer (F/2.8) and a pitch-controlled fiber bundle enable the temporal resolution of the system up to 400 Hz. The observation geometry and an optimized optic system enable the highest radial resolution up to ~1 cm at the plasma edge. The CXRS system monitors the carbon line emission (C VI, n = 8–7, 529.06 nm) whose Doppler broadening and Doppler shift provide ion temperature and plasma rotation velocity during the neutral beam injection. The composite CX spectral data are analyzed by the atomic data and analysis structure charge exchange spectroscopy fitting (ADAS CXSFIT) code. First experimental results are shown for the case of HL-2A plasmas with sawtooth oscillations, electron cyclotron resonance heating, and edge transport barrier during the high-confinement mode (H-mode)

  2. Status of deceleration and laser spectroscopy of highly charged ions at HITRAP

    NASA Astrophysics Data System (ADS)

    Andelkovic, Zoran; Birkl, Gerhard; Fedotova, Svetlana; Hannen, Volker; Herfurth, Frank; König, Kristian; Kotovskiy, Nikita; Maaß, Bernhard; Vollbrecht, Jonas; Murböck, Tobias; Neidherr, Dennis; Nörtershäuser, Wilfried; Schmidt, Stefan; Vogel, Manuel; Vorobjev, Gleb; Weinheimer, Christian

    2015-11-01

    Heavy few-electron ions are relatively simple systems in terms of electron structure and offer unique opportunities to conduct experiments under extremely large electromagnetic fields that exist around their nuclei. However, the preparation of highly charged ions (HCI) has remained the major challenge for experiments. As an extension of the existing GSI accelerator facility, the HITRAP facility was conceived as a multi-stage decelerator for HCI produced at high velocity. It is designed to prepare bunches of around 105 HCI and to deliver them at low energies to various experiments. One of these experiments is SpecTrap, aiming for laser spectroscopy of trapped, cold HCI. We present the latest results on deceleration of ions in a radio-frequency quadrupole, synchrotron cooling of electrons in a trap as a preparation step for the prospective electron cooling of the HCI decelerated in HITRAP, as well as laser cooling of singly charged Mg ions for sympathetic cooling of HCI in SpecTrap.

  3. High-confidence de novo peptide sequencing using positive charge derivatization and tandem MS spectra merging.

    PubMed

    An, Mingrui; Zou, Xiao; Wang, Qingsong; Zhao, Xuyang; Wu, Jing; Xu, Li-Ming; Shen, Hong-Yan; Xiao, Xueyuan; He, Dacheng; Ji, Jianguo

    2013-05-01

    De novo peptide sequencing holds great promise in discovering new protein sequences and modifications but has often been hindered by low success rate of mass spectra interpretation, mainly due to the diversity of fragment ion types and insufficient information for each ion series. Here, we describe a novel methodology that combines highly efficient on-tip charge derivatization and tandem MS spectra merging, which greatly boosts the performance of interpretation. TMPP-Ac-OSu (succinimidyloxycarbonylmethyl tris(2,4,6-trimethoxyphenyl)phosphonium bromide) was used to derivatize peptides at N-termini on tips to reduce mass spectra complexity. Then, a novel approach of spectra merging was adopted to combine the benefits of collision-induced dissociation (CID) and electron transfer dissociation (ETD) fragmentation. We applied this methodology to rat C6 glioma cells and the Cyprinus carpio and searched the resulting peptide sequences against the protein database. Then, we achieved thousands of high-confidence peptide sequences, a level that conventional de novo sequencing methods could not reach. Next, we identified dozens of novel peptide sequences by homology searching of sequences that were fully backbone covered but unmatched during the database search. Furthermore, we randomly chose 34 sequences discovered in rat C6 cells and verified them. Finally, we conclude that this novel methodology that combines on-tip positive charge derivatization and tandem MS spectra merging will greatly facilitate the discovery of novel proteins and the proteome analysis of nonmodel organisms. PMID:23536960

  4. Charging Graphene for Energy Storage

    SciTech Connect

    Liu, Jun

    2014-10-06

    Since 2004, graphene, including single atomic layer graphite sheet, and chemically derived graphene sheets, has captured the imagination of researchers for energy storage because of the extremely high surface area (2630 m2/g) compared to traditional activated carbon (typically below 1500 m2/g), excellent electrical conductivity, high mechanical strength, and potential for low cost manufacturing. These properties are very desirable for achieving high activity, high capacity and energy density, and fast charge and discharge. Chemically derived graphene sheets are prepared by oxidation and reduction of graphite1 and are more suitable for energy storage because they can be made in large quantities. They still contain multiply stacked graphene sheets, structural defects such as vacancies, and oxygen containing functional groups. In the literature they are also called reduced graphene oxide, or functionalized graphene sheets, but in this article they are all referred to as graphene for easy of discussion. Two important applications, batteries and electrochemical capacitors, have been widely investigated. In a battery material, the redox reaction occurs at a constant potential (voltage) and the energy is stored in the bulk. Therefore, the energy density is high (more than 100 Wh/kg), but it is difficult to rapidly charge or discharge (low power, less than 1 kW/kg)2. In an electrochemical capacitor (also called supercapacitors or ultracapacitor in the literature), the energy is stored as absorbed ionic species at the interface between the high surface area carbon and the electrolyte, and the potential is a continuous function of the state-of-charge. The charge and discharge can happen rapidly (high power, up to 10 kW/kg) but the energy density is low, less than 10 Wh/kg2. A device that can have both high energy and high power would be ideal.

  5. Substituent and Solvent Effects on Excited State Charge Transfer Behavior of Highly Fluorescent Dyes Containing Thiophenylimidazole-Based Aldehydes

    NASA Technical Reports Server (NTRS)

    Santos, Javier; Bu, Xiu R.; Mintz, Eric A.

    2001-01-01

    The excited state charge transfer for a series of highly fluorescent dyes containing thiophenylimidazole moiety was investigated. These systems follow the Twisted Intramolecular Charge Transfer (TICT) model. Dual fluorescence was observed for each substituted dye. X-ray structures analysis reveals a twisted ground state geometry for the donor substituted aryl on the 4 and 5 position at the imidazole ring. The excited state charge transfer was modeled by a linear solvation energy relationship using Taft's pi and Dimroth's E(sub T)(30) as solvent parameters. There is linear relation between the energy of the fluorescence transition and solvent polarity. The degree of stabilization of the excited state charge transfer was found to be consistent with the intramolecular molecular charge transfer. Excited dipole moment was studied by utilizing the solvatochromic shift method.

  6. Nanofabrication on a Si surface by slow highly charged ion impact

    NASA Astrophysics Data System (ADS)

    Tona, Masahide; Watanabe, Hirofumi; Takahashi, Satoshi; Nakamura, Nobuyuki; Yoshiyasu, Nobuo; Sakurai, Makoto; Terui, Toshifumi; Mashiko, Shinro; Yamada, Chikashi; Ohtani, Shunsuke

    2007-03-01

    We have observed surface chemical reactions which occur at the impact sites on a Si(1 1 1)-(7 × 7) surface and a highly oriented pyrolytic graphite (HOPG) surface bombarded by highly charged ions (HCIs) by using a scanning tunneling microscope (STM). Crater structures are formed on the Si(1 1 1)-(7 × 7) surface by single I50+-impacts. STM-observation for the early step of oxidation on the surface suggests that the impact site is so active that dangling bonds created by HCI impacts are immediately quenched by reaction with residual gas molecules. We show also the selective adsorption of organic molecules at a HCI-induced impact site on the HOPG surface.

  7. High electrokinetic energy conversion efficiency in charged nanoporous nitrocellulose/sulfonated polystyrene membranes.

    PubMed

    Haldrup, Sofie; Catalano, Jacopo; Hansen, Michael Ryan; Wagner, Manfred; Jensen, Grethe Vestergaard; Pedersen, Jan Skov; Bentien, Anders

    2015-02-11

    The synthesis, characterization, and electrokinetic energy conversion performance have been investigated experimentally in a charged polymeric membrane based on a blend of nitrocellulose and sulfonated polystyrene. The membrane is characterized by a moderate ion exchange capacity and a relatively porous structure with average pore diameter of 11 nm. With electrokinetic energy conversion, pressure can be converted directly into electric energy and vice versa. From the electrokinetic transport properties, a remarkably large intrinsic maximum efficiency of 46% is found. It is anticipated that the results are an experimental verification of theoretical models that predict high electrokinetic energy conversion efficiency in pores with high permselectivity and hydrodynamic slip flow. Furthermore, the result is a promising step for obtaining efficient low-cost electrokinetic generators and pumps for small or microscale applications. PMID:25555128

  8. Polarization spectroscopy of x-ray transitions from beam-excited highly charged ions

    SciTech Connect

    Beiersdorfer, P.; Lopez-Urrutia, J.C.; Decaux, V.; Widmann, K.; Neill, P.

    1997-01-01

    Polarization spectroscopy of x-ray lines represents a diagnostic tool to ascertain the presence of electron beams in high-temperature plasmas. Making use of the Livermore electron beam ion trap, which optimizes the linear x-ray line polarization by exciting highly charged ions with a monoenergetic electron beam, we have begun to develop polarization diagnostics and test theoretical models. Our measurement relies on the sensitivity of crystal spectrometers to the linear polarization of x-ray lines which depends on the value of the Bragg angle. We employed two spectrometers with differing analyzing crystals and simultaneously recorded the K-shell emission from heliumlike Fe{sup 24+} and lithiumlike Fe{sup 23+} ions at two different Bragg angles. A clear difference in the relative intensities of the dominant transitions is observed, which is attributed to the amount of linear polarization of the individual lines. {copyright} {ital 1997 American Institute of Physics.}

  9. Space-Charge Structural Instabilities and Resonances in High-Intensity Beams

    NASA Astrophysics Data System (ADS)

    Hofmann, Ingo; Boine-Frankenheim, Oliver

    2015-11-01

    The existence of a structural resonance stop band caused by space charge in high-current beams, where the resonance frequency is associated with 90° phase advance per focusing period, is well known and alternatively referred to in the literature as envelope instability or as fourth-order resonance. We show, however, that this stop band is actually a coincidence of a structural fourth-order resonance and the much stronger envelope instability as competing mechanisms—depending on the time scale and initial matching. A similar complexity of behavior—dependent on the distribution function—is also found between a third-order instability and a sixth-order resonance in a 60° stop band. We claim that these findings are a generic property of high-intensity beams in periodic focusing; they also allow a reinterpretation of the 90° linear accelerator stop band previously observed experimentally at the UNILAC accelerator.

  10. Precision spectroscopy of trapped highly charged heavy elements: pushing the limits of theory and experiment

    NASA Astrophysics Data System (ADS)

    Gillaspy, J. D.

    2014-11-01

    Atomic spectroscopy results from the electron beam ion trap at the National Institute of Standards and Technology have generally agreed with the predictions of theory extremely well. An interesting exception is our recent result on the helium isoelectronic sequence at Z = 22, which agrees instead with a meta-analysis of all prior measurements above Z = 15, but disagrees with both theory and a contemporaneous report of an independent measurement at Z = 18 which claims to validate theory to high accuracy. Here, a potential systematic shift involving high-n satellite lines induced by double charge exchange is quantitatively estimated and shown to be potentially significant in experiments involving gasses. Suggestions for further refinements in estimating the magnitude of this systematic shift are given.

  11. Ionisation from the 3s sub-level of highly charged ions

    NASA Technical Reports Server (NTRS)

    Golden, L. B.; Sampson, D. H.; Omidvar, K.

    1978-01-01

    Scaled electron-impact cross sections are calculated for ionization from the 3s sublevel of hydrogenic ions with Z equal infinity by use of the Born exchange or the Coulomb-Born Oppenheimer approximation (which is exact, apart from relativistic corrections, in this limit). The results are fitted to an analytic expression which goes into the correct Bethe approximation result at high energies and which can readily be integrated over a Maxwellian electron velocity distribution to obtain collision rates. These results permit calculation of the approximate cross section and collision rate for ionization from the 3s sublevel of any highly charged ion with Z/N larger than approximately 2. Results obtained by the described procedure for Fe-14(+) and Fe-15(+) are compared with results obtained by other procedures.

  12. Wavelength measurement of n = 3 - n' = 3 transitions in highly charged tungsten ions

    SciTech Connect

    Clementson, J; Beiersdorfer, P

    2010-03-10

    3s{sub 1/2} - 3p{sub 3/2} and 3p{sub 1/2} - 3d{sub 3/2} transitions have been studied in potassium-like W{sup 55+} through neon-like W{sup 64}+ ions at the electron-beam ion trap facility in Livermore. The wavelengths of the lines have been measured in high resolution relative to well known reference lines from oxygen and nitrogen ions. Using the high-energy SuperEBIT electron-beam ion trap and an R = 44.3 m grazing-incidence soft x-ray spectrometer, the lines were observed with a cryogenic charge-coupled device camera. The wavelength data for the sodium-like and magnesium-like tungsten lines are compared with theoretical predictions for ions along the isoelectronic sequences.

  13. Generation of high charge state platinum ions on vacuum arc plasma heated by gyrotron radiation.

    PubMed

    Yushkov, G Yu; Vodopyanov, A V; Nikolaev, A G; Izotov, I V; Savkin, K P; Golubev, S V; Oks, E M

    2014-02-01

    The hybrid high charge metal ion source based on vacuum arc plasma heated by gyrotron radiation into simple magnetic trap has been developed. Two types of magnetic traps were used: a mirror configuration and a cusp one with inherent "minimum-B" structure. Pulsed high power (>100 kW) gyrotrons with frequency 37.5 GHz and 75 GHz were used for heating the vacuum arc plasma injected into the traps. Two different ways were used for injecting the metal plasma-axial injection by a miniature arc source located on-axis near the microwave window, and simultaneous radial injection by a number of sources mounted radially at the midplane of the traps. This article represents all data gathered for platinum ions, thus making comparison of the experimental results obtained with different traps and injections convenient and accurate. PMID:24593607

  14. Charge trapping at Pt/high- k dielectric (Ta 2O 5) interface

    NASA Astrophysics Data System (ADS)

    Stojanovska-Georgievska, L.; Novkovski, N.; Atanassova, E.

    2011-09-01

    A detailed analysis of the effects of constant low current injection was done, both in accumulation ( J=0.001-0.2 mA cm -2) and in inversion ( J=0.001-0.04 mA/cm 2). The samples under investigation were metal-insulator-silicon structures containing high- k dielectric Ta 2O 5 radio frequency sputtered on p-type Si wafers, with Pt metal gate electrodes. The obtained results were compared with the ones obtained for Al gate samples. This experiment confirms the occurrence of charge trapping in the case of high-work-function Pt as metal. The effect has been attributed to emitting of electrons into the Pt conduction band during which creation of empty traps in the dielectric occurs, which then attract electrons injected in the dielectric. In order to examine the reversibility of the process, successive short runs as well as long runs (up to 10000 s) were performed.

  15. Visible emission spectroscopy of highly charged tungsten ions in LHD: II. Evaluation of tungsten ion temperature

    NASA Astrophysics Data System (ADS)

    Fujii, K.; Takahashi, Y.; Nakai, Y.; Kato, D.; Goto, M.; Morita, S.; Hasuo, M.; Experiment Group2, LHD

    2015-12-01

    We demonstrated a polarization-resolved high resolution spectroscopy of a visible emission line of highly charged tungsten ions (λ0 = 668.899 nm, Shinohara et al Phys. Scr. 90 125402) for the large helical device (LHD) plasma, where the tungsten ions were introduced by a pellet injection. Its spectral profile shows broadening and polarization dependence, which are attributed to the Doppler and Zeeman effects, respectively. The tungsten ion temperature was evaluated for the first time from the broadening of visible the emission line, with its emission location determined by the Abel inversion of the chord-integrated emission intensities observed with multiple chords. The tungsten ion temperature was found to be close to the helium-like argon ion temperature, which is used as an ion temperature monitor in LHD.

  16. The Impact of Surface Charge on the Mechanical Behavior of High-Porosity Chalk

    NASA Astrophysics Data System (ADS)

    Megawati, M.; Hiorth, A.; Madland, M. V.

    2013-09-01

    We present rock mechanical test results and analytical calculations which demonstrate that a negative surface charge, resulting from sulfate adsorption from the pore water, impacts the rock mechanical behavior of high-porosity chalk. Na2SO4 brine flooded into chalk cores at 130 °C results in significantly reduced bulk modulus and yield point compared with that of NaCl brine at the same conditions. The experimental results have been interpreted using a surface complexation model combined with the Gouy-Chapman theory to describe the double layer. The calculated sulfate adsorption agrees well with the measured data. A sulfate adsorption of about 0.3 μmol/m2 and 0.7-1 μmol/m2 was measured at 50 and 130 °C, respectively. Relative to a total sites of 5 sites/nm2 these values correspond to an occupation of 4 % and 8-13 % which sufficiently explains the negative charging of the calcite surfaces. The interaction between charged surfaces specifically in the weak overlaps of electrical double layer gives rise to the total disjoining pressure in granular contacts. The net repulsive forces act as normal forces in the grains vicinity, counteracting the cohesive forces and enhance pore collapse failure during isotropic loading, which we argue to account for the reduced yield and bulk modulus of chalk cores. The effect of disjoining pressure is also assessed at different sulfate concentrations in aqueous solution, temperatures, as well as ionic strength of solution; all together remarkably reproduce similar trends as observed in the mechanical properties.

  17. Production of high brightness H- beam by charge exchange of hydrogen atom beam in sodium jet

    SciTech Connect

    Davydenko, V.; Zelenski, A.; Ivanov, A.; Kolmogorov, A.

    2010-11-16

    Production of H{sup -} beam for accelerators applications by charge exchange of high brightness hydrogen neutral beam in a sodium jet cell is experimentally studied in joint BNL-BINP experiment. In the experiment, a hydrogen-neutral beam with 3-6 keV energy, equivalent current up to 5 A and 200 microsecond pulse duration is used. The atomic beam is produced by charge exchange of a proton beam in a pulsed hydrogen target. Formation of the proton beam is performed in an ion source by four-electrode multiaperture ion-optical system. To achieve small beam emittance, the apertures in the ion-optical system have small enough size, and the extraction of ions is carried out from the surface of plasma emitter with a low transverse ion temperature of {approx}0.2 eV formed as a result of plasma jet expansion from the arc plasma generator. Developed for the BNL optically pumped polarized ion source, the sodium jet target with recirculation and aperture diameter of 2 cm is used in the experiment. At the first stage of the experiment H{sup -} beam with 36 mA current, 5 keV energy and {approx}0.15 cm {center_dot} mrad normalized emittance was obtained. To increase H{sup -} beam current ballistically focused hydrogen neutral beam will be applied. The effects of H{sup -} beam space-charge and sodium-jet stability will be studied to determine the basic limitations of this approach.

  18. On the Interaction Between Highly Energetic Charged Particles and the Lunar Regolith

    NASA Astrophysics Data System (ADS)

    Jordan, A. P.; Stubbs, T. J.; Zeitlin, C.; Spence, H. E.; Schwadron, N. A.; Zimmerman, M. I.; Farrell, W. M.

    2012-03-01

    In this study we explore how galactic cosmic rays and solar energetic particles contribute to deep dielectric charging within the lunar regolith and how these particles affect lunar surface charging in tenuous plasma environments.

  19. Fast charging technique for high power LiFePO4 batteries: A mechanistic analysis of aging

    NASA Astrophysics Data System (ADS)

    Anseán, D.; Dubarry, M.; Devie, A.; Liaw, B. Y.; García, V. M.; Viera, J. C.; González, M.

    2016-07-01

    One of the major issues hampering the acceptance of electric vehicles (EVs) is the anxiety associated with long charging time. Hence, the ability to fast charging lithium-ion battery (LIB) systems is gaining notable interest. However, fast charging is not tolerated by all LIB chemistries because it affects battery functionality and accelerates its aging processes. Here, we investigate the long-term effects of multistage fast charging on a commercial high power LiFePO4-based cell and compare it to another cell tested under standard charging. Coupling incremental capacity (IC) and IC peak area analysis together with mechanistic model simulations ('Alawa' toolbox with harvested half-cell data), we quantify the degradation modes that cause aging of the tested cells. The results show that the proposed fast charging technique caused similar aging effects as standard charging. The degradation is caused by a linear loss of lithium inventory, coupled with a less degree of linear loss of active material on the negative electrode. This study validates fast charging as a feasible mean of operation for this particular LIB chemistry and cell architecture. It also illustrates the benefits of a mechanistic approach to understand cell degradation on commercial cells.

  20. Multiple stage multiple filter hydrate store

    DOEpatents

    Bjorkman, H.K. Jr.

    1983-05-31

    An improved hydrate store for a metal halogen battery system is disclosed which employs a multiple stage, multiple filter means for separating the halogen hydrate from the liquid used in forming the hydrate. The filter means is constructed in the form of three separate sections which combine to substantially cover the interior surface of the store container. Exit conduit means is provided in association with the filter means for transmitting liquid passing through the filter means to a hydrate former subsystem. The hydrate former subsystem combines the halogen gas generated during the charging of the battery system with the liquid to form the hydrate in association with the store. Relief valve means is interposed in the exit conduit means for controlling the operation of the separate sections of the filter means, such that the liquid flow through the exit conduit means from each of the separate sections is controlled in a predetermined sequence. The three separate sections of the filter means operate in three discrete stages to provide a substantially uniform liquid flow to the hydrate former subsystem during the charging of the battery system. The separation of the liquid from the hydrate causes an increase in the density of the hydrate by concentrating the hydrate along the filter means. 7 figs.

  1. Multiple stage multiple filter hydrate store

    DOEpatents

    Bjorkman, Jr., Harry K.

    1983-05-31

    An improved hydrate store for a metal halogen battery system is disclosed which employs a multiple stage, multiple filter means or separating the halogen hydrate from the liquid used in forming the hydrate. The filter means is constructed in the form of three separate sections which combine to substantially cover the interior surface of the store container. Exit conduit means is provided in association with the filter means for transmitting liquid passing through the filter means to a hydrate former subsystem. The hydrate former subsystem combines the halogen gas generated during the charging of the battery system with the liquid to form the hydrate in association with the store. Relief valve means is interposed in the exit conduit means for controlling the operation of the separate sections of the filter means, such that the liquid flow through the exit conduit means from each of the separate sections is controlled in a predetermined sequence. The three separate sections of the filter means operate in three discrete stages to provide a substantially uniform liquid flow to the hydrate former subsystem during the charging of the battery system. The separation of the liquid from the hydrate causes an increase in the density of the hydrate by concentrating the hydrate along the filter means.

  2. Saccharification of natural lignocellulose biomass and polysaccharides by highly negatively charged heteropolyacids in concentrated aqueous solution.

    PubMed

    Ogasawara, Yoshiyuki; Itagaki, Shintaro; Yamaguchi, Kazuya; Mizuno, Noritaka

    2011-04-18

    Highly negatively charged heteropolyacids (HPAs), in particular H(5) BW(12) O(40) , efficiently promoted saccharification of crystalline cellulose into water-soluble saccharides in concentrated aqueous solutions (e.g., 82 % total yield and 77 % glucose yield, based on cellulose with a 0.7 M H(5) BW(12) O(40) solution); the performance was much better than those of previously reported systems with commonly utilized mineral acids (e.g., H(2) SO(4) and HCl) and HPAs (e.g., H(3) PW(12) O(40) and H(4) SiW(12) O(40)). Besides crystalline cellulose, the present system was applicable to the selective transformation of cellobiose, starch, and xylan to the corresponding monosaccharides such as glucose and xylose. In addition, one-pot synthesis of levulinic acid and sorbitol directly from cellulose was realized by using concentrated HPA solutions. The present system, concentrated aqueous solutions of highly negatively charged HPAs, was further applicable to saccharification of natural (non-purified) lignocellulose biomass, such as "rice plant straw", "oil palm empty fruit bunch (palm EFB) fiber", and "Japanese cedar sawdust", giving a mixture of the corresponding water-soluble saccharides, such as glucose (main product), galactose, mannose, xylose, arabinose, and cellobiose, in high yields (≥77 % total yields of saccharides based on holocellulose). Separation of the saccharides and H(5) BW(12) O(40) was easy, and the retrieved H(5) BW(12) O(40) could repeatedly be used without appreciable loss of the high performance. PMID:21404445

  3. Low-Charge State AMS for High Throughput 14C Quantification

    SciTech Connect

    Ognibene, T.J.; Roberts, M.L.; Southon, J.R.; Vogel, J.S.

    2000-06-16

    Accelerator mass spectrometry (AMS) quantifies attomole (10{sup -18}) amounts of {sup 14}C in milligram sized samples. This sensitivity is used to trace nutrients, toxins and therapeutics in humans and animals at less than {micro}g/kg doses containing 1-100 nCi of {sup 14}C. Widespread use of AMS in pharmaceutical development and biochemical science has been hampered by the size and expense of the typical spectrometer that has been developed for high precision radiocarbon dating. The precision of AMS can be relaxed for biochemical tracing, but sensitivity, accuracy and throughput are important properties that must be maintained in spectrometers designed for routine quantification. We are completing installation of a spectrometer that will maintain the high throughput of our primary spectrometer but which requires less than 20% of the floor space and of the cost. Sensitivity and throughput are kept high by using the LLNL intense cesium sputter ion source with solid graphitic samples. Resultant space-charge effects are minimized by careful modeling to find optimal ion transport in the spectrometer. A long charge-changing ''stripper gas'' volume removes molecular isobars at potentials of a few hundred kiloVolts, reducing the size of the accelerating component. Fast ion detectors count at high rates to keep a wide dynamic range for 14 C concentrations. Solid sample presentation eliminates the sample cross contamination that degrades accuracy and the effects of ''memory'' in the ion source. Automated processes are under development for conversion of liquid and solid biological samples to the preferred graphitic form for the ion source.

  4. Stored energy in irradiated silicon carbide

    SciTech Connect

    Snead, L.L.; Burchell, T.D.

    1997-04-01

    This report presents a short review of the phenomenon of Wigner stored energy release from irradiated graphite and discusses it in relation to neutron irradiation of silicon carbide. A single published work in the area of stored energy release in SiC is reviewed and the results are discussed. It appears from this previous work that because the combination of the comparatively high specific heat of SiC and distribution in activation energies for recombining defects, the stored energy release of SiC should only be a problem at temperatures lower than those considered for fusion devices. The conclusion of this preliminary review is that the stored energy release in SiC will not be sufficient to cause catastrophic heating in fusion reactor components, though further study would be desirable.

  5. The Heidelberg CSR: Stored Ion Beams in a Cryogenic Environment

    SciTech Connect

    Wolf, A.; Hahn, R. von; Grieser, M.; Orlov, D. A.; Fadil, H.; Welsch, C. P.; Andrianarijaona, V.; Diehl, A.; Schroeter, C. D.; Crespo Lopez-Urrutia, J. R.; Weber, T.; Mallinger, V.; Schwalm, D.; Ullrich, J.; Rappaport, M.; Urbain, X.; Haberstroh, Ch.; Quack, H.; Zajfman, D.

    2006-03-20

    A cryogenic electrostatic ion storage ring CSR is under development at the Max-Planck Institute for Nuclear Physics in Heidelberg, Germany. Cooling of the ultrahigh vacuum chamber is envisaged to lead to extremely low pressures as demonstrated by cryogenic ion traps. The ring will apply electron cooling with electron beams of a few eV up to 200 eV. Through long storage times of 1000 s as well as through the low wall temperature, internal cooling of infrared-active molecular ions to their rotational ground state will be possible and their collisions with merged collinear beams of electrons and neutral atoms can be detected with high energy resolution. In addition storage of slow highly charged ions is foreseen. Using a fixed in-ring gas target and a reaction microscope, collisions of the stored ions at a speed of the order of the atomic unit can be kinematically reconstructed. The layout and the cryogenic concept are introduced.

  6. Taking charge of high-risk and high-cost patients in the public healthcare system.

    PubMed

    Denis, Jean-Louis; Cambourieu, Caroline; Roy, Denis A

    2014-01-01

    Many healthcare systems are struggling with the issue of providing high-quality care to high-needs patients at lower costs. Our comments in this paper draw on insights that we have gained from the development and implementation of integrated models of care in Québec. This experience highlights the importance of developing a clear clinical approach to the delivery and coordination of care and to support providers in new roles. Our second insight is that system-level policy guidelines may help to focus the attention of organizations and providers on key priorities, but they need to take into account differing needs in various contexts. Third, a crucial factor for success over the longer term is the ability of local networks to reshape the allocation and use of resources to bring about change in day-to-day operations. We conclude by highlighting key characteristics of high-performing health systems and with the final observation that politicians and policymakers need to allow enough time to harness the full benefit of change initiatives. PMID:25880863

  7. Mucus permeating carriers: formulation and characterization of highly densely charged nanoparticles.

    PubMed

    Pereira de Sousa, Irene; Steiner, Corinna; Schmutzler, Matthias; Wilcox, Matthew D; Veldhuis, Gert J; Pearson, Jeffrey P; Huck, Christian W; Salvenmoser, Willi; Bernkop-Schnürch, Andreas

    2015-11-01

    The GI mucus layer represents a significant block to drug carriers absorption. Taking an example from nature, virus-mimicking nanoparticles (NPs) with highly densely charged surface were designed with the aim to improve their mucus permeation ability. NPs were formulated by combining chitosan with chondroitin sulfate and were characterized by particle size, ζ-potential and hydrophobicity. The interaction occurring between NPs and diluted porcine intestinal mucus was investigated by a new method. Furthermore, the rotating tube technique was exploited to evaluate the NPs permeation ability in fresh undiluted porcine intestinal mucus. NPs (400-500 nm) presenting a slightly positive (4.02 mV) and slightly negative (-3.55 mV) ζ-potential resulted to be hydrophobic and hydrophilic, respectively. On the one hand the hydrophobic NPs undergo physico-chemical changes when incubated with mucus, namely the size increased and the ζ-potential decreased. On the other hand, the hydrophilic NPs did not significantly change size and net charge during incubation with mucus. Both types of NPs showed a 3-fold higher diffusion ability compared to the reference 50/50 DL-lactide/glycolide copolymer NPs (136 nm, -23 mV, hydrophilic). Based on these results, this work gives valuable information for the further design of mucus-penetrating NPs. PMID:25576256

  8. A charge transfer complex nematic liquid crystalline gel with high electrical conductivity

    NASA Astrophysics Data System (ADS)

    Bhargavi, R.; Nair, Geetha G.; Krishna Prasad, S.; Majumdar, R.; Bag, Braja G.

    2014-10-01

    We describe the rheological, dielectric and elastic properties of a nematic liquid crystal gel created using an anthrylidene derivative of arjunolic acid, a chiral triterpenoid, obtained from the extracts of the wood of Terminalia arjuna. In this novel gel, having the electron-donor and acceptor components as minority constituents, the gelation and strengthening of charge-transfer complex (CTC) formation are seen to be occurring concomitantly. In addition to being mechanically strong with a large storage modulus, the gel with the maximized CTC exhibits Frank bend elastic constant values that approach nanonewton levels. The highlight of the study is the observation of 4-5 orders of magnitude increase in electrical conductivity for this gel, a value that is higher than even in the CT complexes of 2-d ordered columnar structures. A further important advantage of the present system over the columnar complex is that the high conductivity is seen for ac probing also, and owing to the nematic nature can be switched between its anisotropic limits. Some of these features are ascribed to a specific molecular packing architecture, which reduces the trapping of the charge carriers.

  9. Fragmentation of positively-charged biological ions activated with a beam of high-energy cations.

    PubMed

    Chingin, Konstantin; Makarov, Alexander; Denisov, Eduard; Rebrov, Oleksii; Zubarev, Roman A

    2014-01-01

    First results are reported on the fragmentation of multiply protonated polypeptide ions produced in electrospray ionization mass spectrometry (ESI-MS) with a beam of high-energy cations as a source of activation. The ion beam is generated with a microwave plasma gun installed on a benchtop Q Exactive mass spectrometer. Precursor polypeptide ions are activated when trapped inside the collision cell of the instrument (HCD cell), and product species are detected in the Orbitrap analyzer. Upon exposure to the beam of air plasma cations (∼100 μA, 5 s), model precursor species such as multiply protonated angiotensin I and ubiquitin dissociated across a variety of pathways. Those pathways include the cleavages of C-CO, C-N as well as N-Cα backbone bonds, accordingly manifested as b/y, a, and c/z fragment ion series in tandem mass spectra. The fragmentation pattern observed includes characteristic fragments of collision-induced dissociation (CID) (b/y/a fragments) as well as electron capture/transfer dissociation (ECD, ETD) (c/z fragments), suggesting substantial contribution of both vibrational and electronic excitation in our experiments. Besides backbone cleavages, notable amounts of nondissociated precursor species were observed with reduced net charge, formed via electron or proton transfer between the colliding partners. Peaks corresponding to increased charge states of the precursor ions were also detected, which is the major distinctive feature of ion beam activation. PMID:24236851

  10. An ultrarobust high-performance triboelectric nanogenerator based on charge replenishment.

    PubMed

    Guo, Hengyu; Chen, Jun; Yeh, Min-Hsin; Fan, Xing; Wen, Zhen; Li, Zhaoling; Hu, Chenguo; Wang, Zhong Lin

    2015-05-26

    Harvesting ambient mechanical energy is a green route in obtaining clean and sustainable electric energy. Here, we report an ultrarobust high-performance triboelectric nanogenerator (TENG) on the basis of charge replenishment by creatively introducing a rod rolling friction in the structure design. With a grating number of 30 and a free-standing gap of 0.5 mm, the fabricated TENG can deliver an output power of 250 mW/m(2) at a rotating rate of 1000 r/min. And it is capable of charging a 200 μF commercial capacitor to 120 V in 170 s, lighting up a G16 globe light as well as 16 spot lights connected in parallel. Moreover, the reported TENG holds an unprecedented robustness in harvesting rotational kinetic energy. After a continuous rotation of more than 14.4 million cycles, there is no observable electric output degradation. Given the superior output performance together with the unprecedented device robustness resulting from distinctive mechanism and novel structure design, the reported TENG renders an effective and sustainable technology for ambient mechanical energy harvesting. This work is a solid step in the development toward TENG-based self-sustained electronics and systems. PMID:25965297

  11. High Precision Three-body Variational Method for Critical Nuclear Charge

    NASA Astrophysics Data System (ADS)

    Busuttil, Michael A.

    For an atom there exists a critical nuclear charge Zc that is just sufficient to bind the nucleus and its electrons into a stable configuration. A study of the critical charge for two-electron atoms is presented with the purpose of improving accuracy for Zc. To this end, high precision techniques involving the variational method with multiple basis sets in Hylleraas coordinates are employed. The method is particularly well adapted to the case where one electron is strongly bound and the other is at the limit of becoming unbound. The results are analysed in terms of fractional powers of (Z -- Zc) related to the analytic structure of the energy E( Z) and a 1/Z expansion for the energy. This results in a Zc of 0.91102808(5). Future work prompted by this study includes development of direct techniques to determine Zc utilizing the low-Z stability of the method; developing the framework and mathematical justification for a novel bootstrap analysis method used in curve-fitting; and investigating the inclusion of finite nuclear mass, relativistic effects, and other higher order corrections in the determination of Zc.

  12. Charge-Reversal APTES-Modified Mesoporous Silica Nanoparticles with High Drug Loading and Release Controllability.

    PubMed

    Wang, Yifeng; Sun, Yi; Wang, Jine; Yang, Yang; Li, Yulin; Yuan, Yuan; Liu, Changsheng

    2016-07-13

    In this study, we demonstrate a facile strategy (DL-SF) for developing MSN-based nanosystems through drug loading (DL, using doxorubicin as a model drug) followed by surface functionalization (SF) of mesoporous silica nanoparticles (MSNs) via aqueous (3-aminopropyl)triethoxysilane (APTES) silylation. For comparison, a reverse functionalization process (i.e., SF-DL) was also studied. The pre-DL process allows for an efficient encapsulation (encapsulation efficiency of ∼75%) of an anticancer drug [doxorubicin (DOX)] inside MSNs, and post-SF allows in situ formation of an APTES outer layer to restrict DOX leakage under physiological conditions. This method makes it possible to tune the DOX release rate by increasing the APTES decoration density through variation of the APTES concentration. However, the SF-DL approach results in a rapid decrease in drug loading capacity with an increase in APTES concentration because of the formation of the APTES outer layer hampers the inner permeability of the DOX drug, resulting in a burst release similar to that of undecorated MSNs. The resulting DOX-loaded DL-SF MSNs present a slightly negatively charged surface under physiological conditions and become positively charged in and extracellular microenvironment of solid tumor due to the protonation effect under acidic conditions. These merits aid their maintenance of long-term stability in blood circulation, high cellular uptake by a kind of skin carcinoma cells, and an enhanced intracellular drug release behavior, showing their potential in the delivery of many drugs beyond anticancer chemotherapeutics. PMID:27314423

  13. A charge transfer complex nematic liquid crystalline gel with high electrical conductivity

    SciTech Connect

    Bhargavi, R.; Nair, Geetha G. E-mail: skpras@gmail.com; Krishna Prasad, S. E-mail: skpras@gmail.com; Majumdar, R.; Bag, Braja G.

    2014-10-21

    We describe the rheological, dielectric and elastic properties of a nematic liquid crystal gel created using an anthrylidene derivative of arjunolic acid, a chiral triterpenoid, obtained from the extracts of the wood of Terminalia arjuna. In this novel gel, having the electron-donor and acceptor components as minority constituents, the gelation and strengthening of charge-transfer complex (CTC) formation are seen to be occurring concomitantly. In addition to being mechanically strong with a large storage modulus, the gel with the maximized CTC exhibits Frank bend elastic constant values that approach nanonewton levels. The highlight of the study is the observation of 4–5 orders of magnitude increase in electrical conductivity for this gel, a value that is higher than even in the CT complexes of 2-d ordered columnar structures. A further important advantage of the present system over the columnar complex is that the high conductivity is seen for ac probing also, and owing to the nematic nature can be switched between its anisotropic limits. Some of these features are ascribed to a specific molecular packing architecture, which reduces the trapping of the charge carriers.

  14. Development of a Kingdon ion trap system for trapping externally injected highly charged ions.

    PubMed

    Numadate, Naoki; Okada, Kunihiro; Nakamura, Nobuyuki; Tanuma, Hajime

    2014-10-01

    We have developed a Kingdon ion trap system for the purpose of the laboratory observation of the x-ray forbidden transitions of highly charged ions (HCIs). Externally injected Ar(q+) (q = 5-7) with kinetic energies of 6q keV were successfully trapped in the ion trap. The energy distribution of trapped ions is discussed in detail on the basis of numerical simulations. The combination of the Kingdon ion trap and the time-of-flight mass spectrometer enabled us to measure precise trapping lifetimes of HCIs. As a performance test of the instrument, we measured trapping lifetimes of Ar(q+) (q = 5-7) under a constant number density of H2 and determined the charge-transfer cross sections of Ar(q+)(q = 5, 6)-H2 collision systems at binary collision energies of a few eV. It was confirmed that the present cross section data are consistent with previous data and the values estimated by some scaling formula. PMID:25362383

  15. Development of a Kingdon ion trap system for trapping externally injected highly charged ions

    SciTech Connect

    Numadate, Naoki; Okada, Kunihiro; Nakamura, Nobuyuki; Tanuma, Hajime

    2014-10-01

    We have developed a Kingdon ion trap system for the purpose of the laboratory observation of the x-ray forbidden transitions of highly charged ions (HCIs). Externally injected Ar{sup q+} (q = 5–7) with kinetic energies of 6q keV were successfully trapped in the ion trap. The energy distribution of trapped ions is discussed in detail on the basis of numerical simulations. The combination of the Kingdon ion trap and the time-of-flight mass spectrometer enabled us to measure precise trapping lifetimes of HCIs. As a performance test of the instrument, we measured trapping lifetimes of Ar{sup q+} (q = 5–7) under a constant number density of H₂ and determined the charge-transfer cross sections of Ar{sup q+}(q = 5, 6)-H₂ collision systems at binary collision energies of a few eV. It was confirmed that the present cross section data are consistent with previous data and the values estimated by some scaling formula.

  16. Thin Static Charged Dust Majumdar-Papapetrou Shells with High Symmetry in D≥4

    NASA Astrophysics Data System (ADS)

    Čermák, Martin; Zouhar, Martin

    2012-08-01

    We present a systematical study of static D≥4 space-times of high symmetry with the matter source being a thin charged dust hypersurface shell. The shell manifold is assumed to have the following structure {S}_{β}×{R}^{D-2-β}, β∈{0,…, D-2} is dimension of a sphere {S}_{β}. In case of β=0, we assume that there are two parallel hyper-plane shells instead of only one. The space-time has Majumdar-Papapetrou form and it inherits the symmetries of the shell manifold—it is invariant under both rotations of the {S}_{β} and translations along ℝ D-2- β . We find a general solution to the Einstein-Maxwell equations with a given shell. Then, we examine some flat interior solutions with special attention paid to D=4. A connection to D=4 non-relativistic theory is pointed out. We also comment on a straightforward generalisation to the case of Kastor-Traschen space-time, i.e. adding a non-negative cosmological constant to the charged dust matter source.

  17. Impact of synthetic antioxidants on lipid peroxidation of distiller's dried grains with solubles and distiller's corn oil stored under high temperature and humidity conditions.

    PubMed

    Hanson, A R; Urriola, P E; Johnston, L J; Shurson, G C

    2015-08-01

    This experiment evaluated the effect of antioxidants, oil content in distiller's dried grains with solubles (DDGS), quality of distiller's corn oil, and storage time on lipid peroxidation. A source of low-oil DDGS (LO-DDGS; 5.0% ether extract [EE], as-fed basis), high-oil DDGS (HO-DDGS; 13.0% EE, as-fed basis), and 2 sources of distiller's corn oil (DCO; 1.20, 0.08, and 0.48% moisture, insoluble impurities, and unsaponifiables [MIU], respectively [DCO-1], and 1.20, 0.01, and 0.10% MIU, respectively [DCO-2]) were obtained. Each of the 4 ingredients was divided into 18 representative subsamples (approximately 908 g for DDGS or 2 kg of DCO). Six subsamples of each ingredient were mixed with either no supplemental antioxidants (CON), Rendox-CQ (REN; 1,000 mg/kg EE; Kemin, Industries, Des Moines, IA), or Santoquin-Q4T (SAN; 1,500 mg/kg EE; Novus International, St. Louis, MO). Each mixture ( = 72) was split into thirds, and 1 portion was immediately frozen at -20°C (d 0). Two portions were stored under hot (38.6 ± 0.1°C) and humid conditions (94.0 ± 0.3% relative humidity) for 14 or 28 d. The MIXED procedure of SAS was used to evaluate the effects of ingredient, antioxidant, storage time, and interactions, with d-0 values used as a covariate. From d 14 to 28, peroxide value (PV), -anisidine value (AnV), and thiobarbituric acid reactive substances (TBARS) of DCO and DDGS increased by 3- to 4-fold ( < 0.05). Over the entire storage period, PV of DCO-1 and HO-DDGS (12.3 ± 0.3 and 12.6 ± 0.3 mEq O/kg oil, respectively) exceeded ( < 0.05) that of DCO-2 and LO-DDGS (9.6 ± 0.3 and 9.3 ± 0.3 mEq O/kg oil, respectively). Adding REN or SAN ( < 0.05) reduced TBARS and AnV relative to CON (TBARS = 11.0 ± 0.2 mg malondialdehyde Eq/kg oil and AnV = 6.5 ± 0.2) over the entire period (mean of d 14 and 28), but TBARS and AnV did not differ ( > 0.05) between antioxidants (TBARS = 6.1 ± 0.2 and 5.9 ± 0.2 mg malondialdehyde Eq/kg oil, respectively, and AnV = 1.9 ± 0.2 and 1.8

  18. K(alpha) X-ray Emission Spectra from Highly Charged Fe Ions in EBIT

    SciTech Connect

    Jacobs, V; Beiersdorfer, P

    2007-03-29

    A detailed spectral model has been developed for the computer simulation of the 2p {yields} 1s K{alpha} X-ray emission from highly charged Fe ions in the Electron Beam Ion Trap (EBIT). The spectral features of interest occur in the range from 1.84 {angstrom} to 1.94 {angstrom}. The fundamental radiative emission processes associated with radiationless electron capture or dielectronic recombination, inner-shell electron collisional excitation, and inner-shell electron collisional ionization are taken in account. For comparison, spectral observations and simulations for high-temperature magnetic-fusion (Tokamak) plasmas are reviewed. In these plasmas, small departures from steady-state corona-model charge-state distributions can occur due to ion transport processes, while the assumption of equilibrium (Maxwellian) electron energy distributions is expected to be valid. Our investigations for EBIT have been directed at the identification of spectral features that can serve as diagnostics of extreme non-equilibrium or transient-ionization conditions, and allowance has been made for general (non-Maxwellian) electron energy distributions. For the precise interpretation of the high-resolution X-ray observations, which may involve the analysis of blended spectral features composed of many lines, it has been necessary to take into account the multitude of individual fine-structure components of the K{alpha} radiative transitions in the ions from Fe XVIII to Fe XXV. At electron densities higher than the validity range of the corona-model approximation, collisionally induced transitions among low-lying excited states can play an important role. It is found that inner-shell electron excitation and ionization processes involving the complex intermediate ions from Fe XVIII to Fe XXI produce spectral features, in the wavelength range from 1.89 {angstrom} to 1.94 {angstrom}, which are particularly sensitive to density variations and transient ionization conditions.

  19. High-precision comparison of the antiproton-to-proton charge-to-mass ratio.

    PubMed

    Ulmer, S; Smorra, C; Mooser, A; Franke, K; Nagahama, H; Schneider, G; Higuchi, T; Van Gorp, S; Blaum, K; Matsuda, Y; Quint, W; Walz, J; Yamazaki, Y

    2015-08-13

    Invariance under the charge, parity, time-reversal (CPT) transformation is one of the fundamental symmetries of the standard model of particle physics. This CPT invariance implies that the fundamental properties of antiparticles and their matter-conjugates are identical, apart from signs. There is a deep link between CPT invariance and Lorentz symmetry--that is, the laws of nature seem to be invariant under the symmetry transformation of spacetime--although it is model dependent. A number of high-precision CPT and Lorentz invariance tests--using a co-magnetometer, a torsion pendulum and a maser, among others--have been performed, but only a few direct high-precision CPT tests that compare the fundamental properties of matter and antimatter are available. Here we report high-precision cyclotron frequency comparisons of a single antiproton and a negatively charged hydrogen ion (H(-)) carried out in a Penning trap system. From 13,000 frequency measurements we compare the charge-to-mass ratio for the antiproton (q/m)p- to that for the proton (q/m)p and obtain (q/m)p-/(q/m)p − 1 =1(69) × 10(-12). The measurements were performed at cyclotron frequencies of 29.6 megahertz, so our result shows that the CPT theorem holds at the atto-electronvolt scale. Our precision of 69 parts per trillion exceeds the energy resolution of previous antiproton-to-proton mass comparisons as well as the respective figure of merit of the standard model extension by a factor of four. In addition, we give a limit on sidereal variations in the measured ratio of <720 parts per trillion. By following the arguments of ref. 11, our result can be interpreted as a stringent test of the weak equivalence principle of general relativity using baryonic antimatter, and it sets a new limit on the gravitational anomaly parameter of |α − 1| < 8.7 × 10(-7). PMID:26268189

  20. Two-Step Suppression of Charge Disproportionation in CaCu3Fe4O12 under High Pressure

    NASA Astrophysics Data System (ADS)

    Kawakami, Takateru; Sekiya, Yoshihiro; Mimura, Ayano; Kobayashi, Kana; Tokumichi, Keita; Yamada, Ikuya; Mizumaki, Masaichiro; Kawamura, Naomi; Shimakawa, Yuichi; Ohishi, Yasuo; Hirao, Naohisa; Ishimatsu, Naoki; Hayashi, Naoaki; Takano, Mikio

    2016-03-01

    The electronic properties of a perovskite Fe4+ oxide, CaCu3Fe4O12, pressurized in a diamond anvil cell at pressures up to 50 GPa, were investigated by X-ray diffraction, electrical resistance measurements, X-ray absorption spectroscopy, and 57Fe Mössbauer spectroscopy. The first transformation from a charge-disproportionated (Fe3+ and Fe5+) semiconducting high-spin state to an approximately charge-uniform (Fe(4-δ)+ and Fe(4+δ)+) metallic high-spin state occurred at ˜15 GPa. This was followed by a second transformation to a completely charge-uniform (Fe4+) metallic low-spin state at ˜30 GPa. This is the first observation of pressure-induced two-step suppression of charge disproportionation in perovskite iron oxides.

  1. Synergistic High Charge-Storage Capacity for Multi-level Flexible Organic Flash Memory

    NASA Astrophysics Data System (ADS)

    Kang, Minji; Khim, Dongyoon; Park, Won-Tae; Kim, Jihong; Kim, Juhwan; Noh, Yong-Young; Baeg, Kang-Jun; Kim, Dong-Yu

    2015-07-01

    Electret and organic floating-gate memories are next-generation flash storage mediums for printed organic complementary circuits. While each flash memory can be easily fabricated using solution processes on flexible plastic substrates, promising their potential for on-chip memory organization is limited by unreliable bit operation and high write loads. We here report that new architecture could improve the overall performance of organic memory, and especially meet high storage for multi-level operation. Our concept depends on synergistic effect of electrical characterization in combination with a polymer electret (poly(2-vinyl naphthalene) (PVN)) and metal nanoparticles (Copper). It is distinguished from mostly organic nano-floating-gate memories by using the electret dielectric instead of general tunneling dielectric for additional charge storage. The uniform stacking of organic layers including various dielectrics and poly(3-hexylthiophene) (P3HT) as an organic semiconductor, followed by thin-film coating using orthogonal solvents, greatly improve device precision despite easy and fast manufacture. Poly(vinylidene fluoride-trifluoroethylene) [P(VDF-TrFE)] as high-k blocking dielectric also allows reduction of programming voltage. The reported synergistic organic memory devices represent low power consumption, high cycle endurance, high thermal stability and suitable retention time, compared to electret and organic nano-floating-gate memory devices.

  2. Synergistic High Charge-Storage Capacity for Multi-level Flexible Organic Flash Memory

    PubMed Central

    Kang, Minji; Khim, Dongyoon; Park, Won-Tae; Kim, Jihong; Kim, Juhwan; Noh, Yong-Young; Baeg, Kang-Jun; Kim, Dong-Yu

    2015-01-01

    Electret and organic floating-gate memories are next-generation flash storage mediums for printed organic complementary circuits. While each flash memory can be easily fabricated using solution processes on flexible plastic substrates, promising their potential for on-chip memory organization is limited by unreliable bit operation and high write loads. We here report that new architecture could improve the overall performance of organic memory, and especially meet high storage for multi-level operation. Our concept depends on synergistic effect of electrical characterization in combination with a polymer electret (poly(2-vinyl naphthalene) (PVN)) and metal nanoparticles (Copper). It is distinguished from mostly organic nano-floating-gate memories by using the electret dielectric instead of general tunneling dielectric for additional charge storage. The uniform stacking of organic layers including various dielectrics and poly(3-hexylthiophene) (P3HT) as an organic semiconductor, followed by thin-film coating using orthogonal solvents, greatly improve device precision despite easy and fast manufacture. Poly(vinylidene fluoride-trifluoroethylene) [P(VDF-TrFE)] as high-k blocking dielectric also allows reduction of programming voltage. The reported synergistic organic memory devices represent low power consumption, high cycle endurance, high thermal stability and suitable retention time, compared to electret and organic nano-floating-gate memory devices. PMID:26201747

  3. Open questions in electronic sputtering of solids by slow highly charged ions with respect to applications in single ion implantation

    SciTech Connect

    Schenkel, T.; Rangelow, I.W.; Keller, R.; Park, S.J.; Nilsson, J.; Persaud, A.; Radmilivitc, V.R.; Liddle, J.A.; Grabiec, P.; Bokor, J.; Schneider, D.H.

    2003-07-16

    In this article we discuss open questions in electronic sputtering of solids by slow, highly charged ions in the context of their application in a single ion implantation scheme. High yields of secondary electrons emitted when highly charged dopant ions impinge on silicon wafers allow for formation of non-Poissonian implant structures such as single atom arrays. Control of high spatial resolution and implant alignment require the use of nanometer scale apertures. We discuss electronic sputtering issues on mask lifetimes, and damage to silicon wafers.

  4. Beam manipulation techniques, nonlinear beam dynamics, and space charge effect in high energy high power accelerators

    SciTech Connect

    Lee, S. Y.

    2014-04-07

    We had carried out a design of an ultimate storage ring with beam emittance less than 10 picometer for the feasibility of coherent light source at X-ray wavelength. The accelerator has an inherent small dynamic aperture. We study method to improve the dynamic aperture and collective instability for an ultimate storage ring. Beam measurement and accelerator modeling are an integral part of accelerator physics. We develop the independent component analysis (ICA) and the orbit response matrix method for improving accelerator reliability and performance. In collaboration with scientists in National Laboratories, we also carry out experimental and theoretical studies on beam dynamics. Our proposed research topics are relevant to nuclear and particle physics using high brightness particle and photon beams.

  5. Highly charged ions for atomic clocks and search for variation of the fine structure constant

    NASA Astrophysics Data System (ADS)

    Dzuba, V. A.; Flambaum, V. V.

    2015-11-01

    We review a number of highly charged ions which have optical transitions suitable for building extremely accurate atomic clocks. This includes ions from Hf 12+ to U 34+, which have the 4 f 12 configuration of valence electrons, the Ir 17+ ion, which has a hole in almost filled 4 f subshell, the Ho 14+, Cf 15+, Es 17+ and Es 16+ ions. Clock transitions in most of these ions are sensitive to variation of the fine structure constant, α (α = e2/hbar c). E.g., californium and einsteinium ions have largest known sensitivity to α-variation while holmium ion looks as the most suitable ion for experimental study. We study the spectra of the ions and their features relevant to the use as frequency standards.

  6. A high-charge and short-pulse RF photocathode gun for wake-field acceleration

    NASA Astrophysics Data System (ADS)

    Gai, W.; Li, X.; Conde, M.; Power, J.; Schoessow, P.

    1998-02-01

    In this paper we present a design report on 1-1/2 cell, L-Band RF photocathode gun which is capable of generating and accelerating electron beams with peak currents >10 kA. We address several critical issues of high-current RF photoinjectors such as longitudinal space charge effect, and transverse emittance growth. Unlike conventional short electron pulse generation, this design does not require magnetic pulse compression. Based on numerical simulations using SUPERFISH and PARMELA, this design will produce 100 nC beam at 18 MeV with r.m.s. bunch length 1.25 mm and normalized transverse emittance 108 mm mrad. Applications of this source beam for wake-field acceleration are also discussed.

  7. EBIT spectroscopy of highly charged heavy ions relevant to hot plasmas

    SciTech Connect

    Nakamura, Nobuyuki; Ding Xiaobin; Dong Chenzhong; Hara, Hirohisa; Watanabe, Tetsuya; Kato, Daiji; Murakami, Izumi; Sakaue, Hiroyuki A.; Koike, Fumihiro; Nakano, Tomohide; Ohashi, Hayato; Watanabe, Hirofumi; Yamamoto, Norimasa

    2013-07-11

    We present spectra of highly charged iron, gadolinium, and tungsten ions obtained with electron beam ion traps. Spectroscopic studies of these ions are important to diagnose and control hot plasmas in several areas. For iron ions, the electron density dependence of the line intensity ratio in extreme ultraviolet spectra is investigated for testing the model calculation used in solar corona diagnostics. Soft x-ray spectra of gadolinium are studied to obtain atomic data required in light source development for future lithography. Tungsten is considered to be the main impurity in the ITER plasma, and thus visible and soft x-ray spectra of tungsten have been observed to explore the emission lines useful for the spectroscopic diagnostics of the ITER plasma.

  8. A highly sensitive and selective fluorescent probe for fluoride anions based on intramolecular charge transfer.

    PubMed

    Liu, Jingkai; Xu, Zhenghe; Liu, Caiyun; Xu, Lirong; Wang, Zhongpeng; Zhu, Baocun

    2016-08-01

    Currently, there is a great need to develop methods for the selective detection of fluoride anions (F(-) ) owing to their toxicity in the environment and biological function in living systems. In this study, we developed a new fluorescent probe (probe 1) employing a Si-O bond as a highly selective recognition receptor for detecting F(-) via intramolecular charge transfer. Probe 1 could detect F(-) quantitatively using the turn-on fluorescence spectroscopy method with excellent sensitivity in the range of 4-38 μM and a detection limit of 0.26 μM; the detection time was < 17 min. We anticipate that probe 1 would be used widely to monitor F(-) in the environment. Copyright © 2015 John Wiley & Sons, Ltd. PMID:26467672

  9. High-frequency, 'quantum' and electromechanical effects in quasi-one-dimensional charge density wave conductors

    NASA Astrophysics Data System (ADS)

    Pokrovskii, Vadim Ya; Zybtsev, Sergey G.; Nikitin, Maksim V.; Gorlova, Irina G.; Nasretdinova, Venera F.; Zaitsev-Zotov, Sergei V.

    2013-01-01

    Recent results (some previously unpublished) on the physics of charge density waves (CDWs) are reviewed. The synthesis conditions and unique properties of the quasi-one-dimensional compound {NbS_3}, with highly coherent room temperature CDWs, are described. A peculiar type of 'quantization' is discussed, which is observed in micro- and nanosamples of {K_{0.3}MoO_3} and {NbSe_3} due to the discrete nature of CDW wave vector values. The electric-field-induced torsional strain (TS) in quasi-one-dimensional conductors is considered. Research results on the TS of a noise character induced by sliding CDWs are presented, along with those on the inverse effect, the modulation of the voltage induced by externally driven TS. Results on the nonlinear conduction of {TiS_3}, a quasi-one-dimensional compound not belonging to the family of classical Peierls conductors, are also described.

  10. Three dimensional space charge model for large high voltage satellites. [plasma sheath

    NASA Technical Reports Server (NTRS)

    Cooks, D.; Parker, L. W.; Mccoy, J. E.

    1980-01-01

    High power solar arrays for satellite power systems with dimensions of kilometers, and with tens of kilovolts distributed over their surface face many plasma interaction problems that must be properly anticipated. In most cases, the effects cannot be adequately modeled without detailed knowledge of the plasma sheath structure and space charge effects. Two computer programs were developed to provide fully self consistent plasma sheath models in three dimensions as a result of efforts to model the experimental plasma sheath studies at NASA/JSC. Preliminary results indicate that for the conditions considered, the Child-Langmuir diode theory can provide a useful estimate of the plasma sheath thickness. The limitations of this conclusion are discussed. Some of the models presented exhibit the strong ion focusing observed in the JSC experiments.

  11. A fully relativistic approach for calculating atomic data for highly charged ions

    SciTech Connect

    Zhang, Hong Lin; Fontes, Christopher J; Sampson, Douglas H

    2009-01-01

    We present a review of our fully relativistic approach to calculating atomic data for highly charged ions, highlighting a research effort that spans twenty years. Detailed discussions of both theoretical and numerical techniques are provided. Our basic approach is expected to provide accurate results for ions that range from approximately half ionized to fully stripped. Options for improving the accuracy and range of validity of this approach are also discussed. In developing numerical methods for calculating data within this framework, considerable emphasis is placed on techniques that are robust and efficient. A variety of fundamental processes are considered including: photoexcitation, electron-impact excitation, electron-impact ionization, autoionization, electron capture, photoionization and photorecombination. Resonance contributions to a variety of these processes are also considered, including discussions of autoionization, electron capture and dielectronic recombination. Ample numerical examples are provided in order to illustrate the approach and to demonstrate its usefulness in providing data for large-scale plasma modeling.

  12. Spin dynamics in relativistic ionization with highly charged ions in super-strong laser fields

    NASA Astrophysics Data System (ADS)

    Klaiber, Michael; Yakaboylu, Enderalp; Müller, Carsten; Bauke, Heiko; Paulus, Gerhard G.; Hatsagortsyan, Karen Z.

    2014-03-01

    Spin dynamics and induced spin effects in above-threshold ionization of hydrogenlike highly charged ions in super-strong laser fields are investigated. Spin-resolved ionization rates in the tunnelling regime are calculated by employing two versions of a relativistic Coulomb-corrected strong-field approximation (SFA). An intuitive simpleman model is developed which explains the derived scaling laws for spin flip and spin asymmetry effects. The intuitive model as well as our ab initio numerical simulations support the analytical results for the spin effects obtained in the dressed SFA where the impact of the laser field on the electron spin evolution in the bound state is taken into account. In contrast, the standard SFA is shown to fail in reproducing spin effects in ionization even at a qualitative level. The anticipated spin-effects are expected to be measurable with modern laser techniques combined with an ion storage facility.

  13. Diagnostic of charge balance in high-temperature tungsten plasmas using LLNL EBIT

    SciTech Connect

    Osborne, G. C.; Safronova, A. S.; Kantsyrev, V. L.; Safronova, U. I.; Yilmaz, M. F.; Williamson, K. M.; Shrestha, I.; Beiersdorfer, P.

    2008-10-15

    Diagnostic of high-temperature M-shell W plasmas is challenging because of contribution of numerous ionization stages in a relatively narrow x-ray spectral region. A method using LLNL EBIT data generated at different electron beam energies has been established for the identification of prominent spectral features and for the determination of charge balance in x-ray M-shell W spectra between 3.5 and 8.5 A . It extends previous work [A. S. Safronova et al., Can. J. Phys. 86, 267 (2008)] which used only Ni-like lines to include the neighboring ionization stages. This diagnostic procedure was tested with results from Z-pinch plasmas produced on the 1 MA pulse power generator Zebra at UNR. These results are of particular importance for fusion research.

  14. Highly charged cellulose-based nanocrystals as flocculants for harvesting Chlorella vulgaris.

    PubMed

    Vandamme, Dries; Eyley, Samuel; Van den Mooter, Guy; Muylaert, Koenraad; Thielemans, Wim

    2015-10-01

    This study presents a novel flocculant for harvesting Chlorella vulgaris as model species for freshwater microalgae based on cellulose nanocrystals (CNCs), thus synthesized from a renewable and biodegradable resource. Cationic pyridinium groups were grafted onto CNCs by two separate one-pot simultaneous esterification and nucleophilic substitution reactions. Both types of modified CNCs were positively charged in the pH range 4-11. Both reactions yielded CNCs with a high degree of substitution (up to 0.38). A maximum flocculation efficiency of 100% was achieved at a dosage of 0.1 g g(-1) biomass. In contrast to conventional polymer flocculants, cationic CNCs were relatively insensitive to inhibition of flocculation by algal organic matter. The present results highlight the potential of these new type of nanocellulose-based flocculants for microalgae harvesting. PMID:26210139

  15. Atomic Spectral Data for Highly Charged Ions of Hf, Ta, W, and Au

    NASA Astrophysics Data System (ADS)

    Gillaspy, John; Reader, Joseph; Osin, Dmitry; Ralchenko, Yuri

    2011-10-01

    We have used an Electron Beam Ion Trap (EBIT) to study the extreme ultraviolet (soft x-ray) spectrum of a variety of heavy elements under electron collision energies in the range 2-24 keV. We have focused on tungsten and elements of similar nuclear charge (Z = 72, 73, 74, 79). The observed wavelengths range from 1.8 nm to 21 nm. Using a collisional-radiative model, we simulated the observed spectra and identified over 100 allowed and forbidden spectral lines which have not been previously reported. Values for the wavelengths are reported to an accuracy of 0.003 nm. The intensity ratios for some of these lines are highly sensitive to the electron density for typical conditions of fusion plasmas. Supported in part by the Office of Fusion Energy Sciences of the U.S. Department of Energy.

  16. Electron emission in collisions of fast highly charged bare ions with helium atoms

    NASA Astrophysics Data System (ADS)

    Mondal, Abhoy; Mandal, Chittranjan; Purkait, Malay

    2016-01-01

    We have studied the electron emission from ground state helium atom in collision with fast bare heavy ions at intermediate and high incident energies. In the present study, we have applied the present three-body formalism of the three Coulomb wave (3C-3B) model and the previously adopted four-body formalism of the three Coulomb wave (3C-4B). To represent the active electron in the helium atom in the 3C-3B model, the initial bound state wavefunction is chosen to be hydrogenic with an effective nuclear charge. The wavefunction for the ejected electron in the exit channel has been approximated to be a Coulomb continuum wavefunction with same effective nuclear charge. Effectively the continuum-continuum correlation effect has been considered in the present investigation. Here we have calculated the energy and angular distribution of double differential cross sections (DDCS) at low and high energy electron emission from helium atom. The large forward-backward asymmetry is observed in the angular distribution which is explained in terms of the two-center effect (TCE). Our theoretical results are compared with available experimental results as well as other theoretical calculations based on the plain wave Born approximation (PWBA), continuum-distorted wave (CDW) approximation, continuum-distorted wave eikonal-initial state (CDW-EIS) approximation, and the corresponding values obtained from the 3C-4B model [S. Jana, R. Samanta, M. Purkait, Phys. Scr. 88, 055301 (2013)] respectively. It is observed that the four-body version of the present investigation produces results which are in better agreement with experimental observations for all cases.

  17. An exact solution to the Einstein-Maxwell equations representing a nonspherical, highly charged object

    NASA Astrophysics Data System (ADS)

    Menon, Govind K.

    The Reissner-Nordstrom solution possesses a naked singularity when e2 > m2, where m is the mass and e is the net charge of the system. Also, the singularity at r = 0 is repulsive (i.e., no timelike geodesics (neutral particles) can reach the singularity). These unusual properties of the Reissner-Nordstrom geometry are considered as an accident resulting from the highly symmetric nature of the space-time. Here we wish to generalize the condition of spherical symmetry to axial symmetry and to probe into the issues of naked singularity and gravitational repulsion. To do this, we must construct a nonspherical solution to the Einstein-Maxwell set of equations in the event that e2 > m2. The Erez-Rosen extension of the vacuum Schwarzschild solution to the non-spherical case gave one of the first physically significant solutions of the Einstein field equations. Nonvacuum extensions of the Erez-Rosen solution representing a non-spherical mass containing a very high net charge (i.e., when e2 > m2) will be discussed. The special case of spherical symmetry, as would be expected, results in the Reissner-Nordstrom solution. The search for the physical singularities involves the calculation of a nontrivial scalar constructed from the Riemann curvature tensor. As it turns out, the resulting geometry does indeed possess a naked singularity. In addition, the space-time also entertains gravitational repulsion. However, unlike the Reissner-Nordstrom solution, it has been found that all timelike geodesics are not necessarily repelled from the origin.

  18. Measurement of short lifetimes in highly-charged ions using a two-foil target

    SciTech Connect

    Berry, H.G.; Dunford, R.W.; Gemmell, D.S.

    1995-08-01

    One of the frontiers in the study of the atomic physics of highly-charged ions is the measurement of lifetimes in the 100 fs to 10 ps regime. The standard technique for measuring lifetimes of states in highly-charged ions is the beam-foil time-of-flight method in which the intensity of an emission line is monitored as a function of the separation between the exciting foil and the portion of the beam being viewed by the detector. This method becomes increasingly difficult as the decay lengths of the states of interest become shorter. At a typical beam velocity of 10% of the speed of light, the beam travels 30 microns in a picosecond. The standard beam-foil time-of-flight method necessitates observation of the decay radiation within one or two decay lengths from the foil while preventing the detectors from observing the beam spot at the foil. For short-lived states this requires tight collimation of the detector with a resulting loss in solid angle. We are developing a method for measuring ultrashort atomic lifetimes utilizing a two-foil target. As a specific case to demonstrate the feasibility of our method, we are studying the decay of the 2 {sup 3}P{sub 2} level in helium-like Kr{sup 34+}. This level has a calculated lifetime of 9.5 ps which corresponds to a decay length of 380 {mu}m. For krypton, theory predicts that 90% of the 2 {sup 3}P{sub 2} states decay via M2 radiation to the ground state. A measurement of the lifetime of this state would contribute to an important current problem which concerns the understanding of atomic structure when both electron correlations and relativistic effects are simultaneously important.

  19. Performance characteristics of high-resolution charge-coupled device film digitizers

    NASA Astrophysics Data System (ADS)

    Lo, Shih-Chung B.; Butson, Philip D.; Lin, Jyh-Shyan; Li, Huai; Freedman, Matthew T.; Mun, Seong K.

    1995-05-01

    This paper describes the performance characteristics of two high resolution charged-coupled device (CCD) film scanners for radiological imaging. The two models of recently developed CCD film scanners made by DBA Systems have been available on the market for ultra high resolution film digitization. One model of the scanner digitizes the film at 21 micrometers and the other one at 42 micrometers . Both systems can be interfaced to a PC. Line-pair, star-pattern and single edge on films were used to test the spatial resolution in the directions perpendicular and parallel to the CCD scan line. Step wedges generated on films through a mammographic system and print transparencies were employed to test the gray value versus the optical density response and variations on a `uniform area.' Geometric distortion of the digitized images was determined to be negligible at less than 1%. This gray value versus optical density response was linearly plotted from optical density (OD) 0 to 2.8. Depending upon optical density regions, gray value fluctuations varied. Both ultra high resolution CCD scanners showed reasonable performance. However, some digital noises were shown in the high OD range.

  20. Tobacco advertising in retail stores.

    PubMed

    Cummings, K M; Sciandra, R; Lawrence, J

    1991-01-01

    Recent studies have described tobacco advertising in the print media, on billboards, and through sponsorship of cultural and sporting events. However, little attention has been given to another common and unavoidable source of tobacco advertising, that which is encountered in retail stores. In July 1987, we conducted a survey of 61 packaged goods retail stores in Buffalo, NY, to assess the prevalence and type of point-of-sale tobacco advertising. In addition, store owners or managers were surveyed to determine their store's policy regarding tobacco advertising, receipt of monetary incentives from distributors for displaying tobacco ads, and willingness to display antitobacco ads. Six types of stores were involved in the study: 10 supermarkets, 10 privately owned grocery stores, 9 chain convenience food stores that do not sell gasoline, 11 chain convenience food stores that sell gasoline, 11 chain pharmacies, and 10 private pharmacies. Two-thirds of the stores displayed tobacco posters, and 87 percent had promotional items advertising tobacco products, primarily cigarettes. Larger stores, and those that were privately owned, tended to display more posters and promotional items. Eighty percent of tobacco product displays were for cigarettes, 16 percent for smokeless tobacco products, and 4 percent for cigars and pipe tobacco. Convenience stores selling gasoline had the most separate tobacco product displays. Of tobacco product displays, 24 percent were located adjacent to candy and snack displays. Twenty-nine of the 61 store owners or managers indicated that their store had a policy regulating the display of tobacco ads and tobacco product displays. Policies dealt primarily with the location of tobacco posters (for example, no ads in the window) and number of product displays. Only 14 shop owners or managers indicated that they had previously displayed antitobacco information; more than half (31 of 61) said that they would be willing to display antitobaccoads.In many

  1. Single polarity charge sensing in high pressure xenon using a coplanar anode configuration

    NASA Astrophysics Data System (ADS)

    Sullivan, Clair Julia

    A new design of a high pressure xenon ionization chamber has been fabricated in an attempt to eliminate the problems associated with acoustical vibrations of the Frisch grid. The function of the traditional Frisch grid has been accomplished by employing a coplanar anode system capable of single polarity charge sensing by means of the Shockley-Ramo theorem. Two different detectors have been built in order to determine if the operation of a high pressure xenon detector in coplanar anode mode is possible. The first is the helical detector comprised of two anode wires wound about a central ceramic core. Through calculation, it is shown that for a cathode bias of -5 kV a potential of 363 V is necessary to collect all of the electrons on the collecting anode, however this is contradicted by the observed pulse waveforms. The results of several experiments are presented that demonstrate the helical detector should work, however in the interest in determining if a coplanar high pressure xenon detector is viable, emphasis was placed on the second detector design. The second design is a parallel plate detector, more analogous to the coplanar semiconductor devices. This detector has demonstrated that it is possible to operate a high pressure xenon detector in coplanar anode mode. However, it is shown that the performance of this detector is limited by high surface leakage current and detector capacitance. Additionally, since the leakage current increases with potential between the two anodes, it is not possible to obtain very high resolution gamma-ray spectroscopy since the required potential between the two anodes for coplanar operation is so high that the detector is already dominated by surface leakage current as this value.

  2. High resolution biomedical imaging system with direct detection of x-rays via a charge coupled device

    DOEpatents

    Atac, M.; McKay, T.A.

    1998-04-21

    An imaging system is provided for direct detection of x-rays from an irradiated biological tissue. The imaging system includes an energy source for emitting x-rays toward the biological tissue and a charge coupled device (CCD) located immediately adjacent the biological tissue and arranged transverse to the direction of irradiation along which the x-rays travel. The CCD directly receives and detects the x-rays after passing through the biological tissue. The CCD is divided into a matrix of cells, each of which individually stores a count of x-rays directly detected by the cell. The imaging system further includes a pattern generator electrically coupled to the CCD for reading a count from each cell. A display device is provided for displaying an image representative of the count read by the pattern generator from the cells of the CCD. 13 figs.

  3. High resolution biomedical imaging system with direct detection of x-rays via a charge coupled device

    DOEpatents

    Atac, Muzaffer; McKay, Timothy A.

    1998-01-01

    An imaging system is provided for direct detection of x-rays from an irradiated biological tissue. The imaging system includes an energy source for emitting x-rays toward the biological tissue and a charge coupled device (CCD) located immediately adjacent the biological tissue and arranged transverse to the direction of irradiation along which the x-rays travel. The CCD directly receives and detects the x-rays after passing through the biological tissue. The CCD is divided into a matrix of cells, each of which individually stores a count of x-rays directly detected by the cell. The imaging system further includes a pattern generator electrically coupled to the CCD for reading a count from each cell. A display device is provided for displaying an image representative of the count read by the pattern generator from the cells of the CCD.

  4. Enhanced Coherence and High Figure of Merit in a Silicon Charge qubit

    NASA Astrophysics Data System (ADS)

    Shi, Zhan; Simmons, Christie; Ward, Daniel; Prance, Jonathan; Koh, Teck Seng; Gamble, John; Wu, Xian; Savage, Donald; Lagally, Max; Friesen, Mark; Coppersmith, Susan; Eriksson, Mark

    2013-03-01

    Coherent manipulation of a charge qubit is an essential step in the use of pulsed gate voltages to manipulate a quantum dot hybrid spin qubit. Here, we demonstrate coherent manipulation of a charge qubit in Si/SiGe double quantum dot. We perform Larmor oscillations (x-rotations on the Bloch sphere) between the (2,1) and (1,2) charge states, measuring a T2* time of 2.1 ns at the charge degeneracy point. We find an increased coherence time (3.7 ns) and higher figure of merit (37) away from the charge degeneracy point, arising from a second charge anti-crossing involving a low lying excited state in the right dot - the desired structure for a hybrid spin qubit. We also observe Ramsey fringes (z-rotations on the Bloch sphere) and measure a T2* of 179 ps at detunings away from any protective energy level structures. Now work at Massachusetts Institute of Technology

  5. Failure mode of valve-regulated lead-acid batteries under high-rate partial-state-of-charge operation

    NASA Astrophysics Data System (ADS)

    Lam, L. T.; Haigh, N. P.; Phyland, C. G.; Urban, A. J.

    Within the next decade, there will be major changes in automotive technology with the introduction of several new features which will increase significantly the on-board power requirements. This high power demand is beyond the capability of present 14 V alternators and thus a 42 V power network is to be adopted. The new 'PowerNet' requires the lead-acid battery to be capable of providing a large number of shallow discharge-charge cycles at a high rate. High-rate discharge is necessary for engine cranking and power assist, while high-rate charge is associated with regenerative braking. The battery will operate at these high rates in a partial-state-of-charge condition, so-called HRPSoC duty. Under simulated HRPSoC duty, it is found that the valve-regulated lead-acid (VRLA) battery fails prematurely due to the progressive accumulation of lead sulfate mainly on the surfaces of the negative plates. This is because the lead sulfate cannot be converted efficiently back to sponge lead during charging either from the engine or from regenerative braking. Eventually, the layer of lead sulfate develops to such extent that the effective surface area of the plate is reduced markedly and the plate can no longer deliver the high cranking-current demanded by the automobile. A mechanistic analysis of battery operation during HRPSoC duty shows that high-rate discharge is the key factor responsible for the build-up of the lead sulfate layer. Such discharge causes a compact layer of tiny lead sulfate crystals to form on the surface of the negative plate and subsequent charging gives rise to an early evolution of hydrogen. Hydrogen evolution is further exacerbated when a high charging current is used.

  6. Atomic collision experiments utilizing low-velocity, highly-charged ion beams

    SciTech Connect

    Johnson, B.M.; Jones, K.W.; Meron, M.

    1982-01-01

    Intense beams of highly-stripped ions are now routinely produced at low velocities using the Brookhaven dual MP-tandens in a unique four-stage accel/decel mode. This mode of operation combines three stages of acceleration, stripping at high energy, and one stage of deceleration to near-zero velocity. To date, experiments have used 10-100 nA beams of bare and few-electron heavy ions at energies as low as 0.2 MeV/amu, and upgrades of the facility should push the lower limit below 0.1 MeV/amu. Recent experiments, such as measurements of charge transfer and x-ray production for S/sup 6-16+/ on He and Ar at 6 to 20 MeV and P(b) measurements for MO x-rays produced in Cl/sup 16 +/ + Ar collisions at 20, 10, and 5 MeV have demonstrated the usefulness of highly-stripped, low-velocity projectiles. These experiments and a few possibilities for future experiments are discussed.

  7. Ultrafast high harmonics for probing the fastest spin and charge dynamics in magnetic materials

    NASA Astrophysics Data System (ADS)

    Grychtol, Patrick

    2015-03-01

    Ultrafast light based on the high-harmonic up-conversion of femtosecond laser pulses have been successfully employed to access resonantly enhanced magnetic contrast at the Mabsorption edges of the 3d ferromagnets Fe, Co and Ni in a table-top setup. Thus, it has been possible to study element-specific dynamics in magnetic materials at femtosecond time scales in a laboratory environment, providing a wealth of opportunities for a greater fundamental understanding of correlated phenomena in solid-state matter. However, these investigations have so far been limited to linear polarized harmonics, since most techniques by which circular soft x-rays can be generated are highly inefficient reducing the photon flux to a level unfit for scientific applications. Besides presenting key findings of our ultrafast studies on charge and spin dynamics, we introduce a simple setup which allows for the efficient generation of circular harmonics bright enough for XMCD experiments. Our work thus represents a critical advance that enables element-specific imaging and spectroscopy of multiple elements simultaneously in magnetic and other chiral media with very high spatial and temporal resolution on the tabletop. In collboration with Ronny Knut, Emrah Turgut, Dmitriy Zusin, Christian Gentry, Henry Kapteyn, Margaret Murnane, JILA, University of Colorado, Boulder; Justin Shaw, Hans Nembach, Tom Silva, Electromagnetics Division, NIST, Boulder, CO; and Ofer Kfir, Avner Fleischer, Oren Cohen, Extreme Nonlinear Optics Group, Solid State Institute, Technion, Israel.

  8. High-Fidelity Rapid Initialization and Read-Out of an Electron Spin via the Single Donor D- Charge State

    NASA Astrophysics Data System (ADS)

    Watson, T. F.; Weber, B.; House, M. G.; Büch, H.; Simmons, M. Y.

    2015-10-01

    We demonstrate high-fidelity electron spin read-out of a precision placed single donor in silicon via spin selective tunneling to either the D+ or D- charge state of the donor. By performing read-out at the stable two electron D0↔D- charge transition we can increase the tunnel rates to a nearby single electron transistor charge sensor by nearly 2 orders of magnitude, allowing faster qubit read-out (1 ms) with minimum loss in read-out fidelity (98.4%) compared to read-out at the D+↔D0 transition (99.6%). Furthermore, we show that read-out via the D- charge state can be used to rapidly initialize the electron spin qubit in its ground state with a fidelity of FI=99.8 %.

  9. Variation of Surface Charge along the Surface of Wool Fibers Assessed by High-Resolution Force Spectroscopy

    PubMed Central

    Zimmerman, Bonnie; Chow, James; Abbott, Albert G.; Ellison, Michael S.; Kennedy, Marian S.; Dean, Delphine

    2011-01-01

    In this study, we have mapped the surface charge of wool fibers using chemically specific high-resolution force spectroscopy in order to better understand the dispersion of amino acids in relation to fiber morphology. The inter-surface forces between standard atomic force microscopy (AFM) probe tips (tip radius ~ 50 nm) functionalized with COOH and NH3 terminated alkanethiol self assembling monolayers and the wool surface were used to estimate the surface charge per unit area using linear Poisson-Boltzmann-based electrostatic double layer theory. The positional measurement of nano-scale surface charge showed a correlation between the surface charge and fiber morphology, indicated that basic amino acids are located near the scale edges. PMID:21866220

  10. Highly Charged Ions from Laser-Cluster Interactions: Local-Field-Enhanced Impact Ionization and Frustrated Electron-Ion Recombination

    SciTech Connect

    Fennel, Thomas; Ramunno, Lora; Brabec, Thomas

    2007-12-07

    Our molecular dynamics analysis of Xe{sub 147-5083} clusters identifies two mechanisms that contribute to the yet unexplained observation of extremely highly charged ions in intense laser cluster experiments. First, electron impact ionization is enhanced by the local cluster electric field, increasing the highest charge states by up to 40%; a corresponding theoretical method is developed. Second, electron-ion recombination after the laser pulse is frustrated by acceleration electric fields typically used in ion detectors. This increases the highest charge states by up to 90%, as compared to the usual assumption of total recombination of all cluster-bound electrons. Both effects together augment the highest charge states by up to 120%, in reasonable agreement with experiments.

  11. Hydrogen Absorption into Austenitic Stainless Steels Under High-Pressure Gaseous Hydrogen and Cathodic Charge in Aqueous Solution

    NASA Astrophysics Data System (ADS)

    Enomoto, Masato; Cheng, Lin; Mizuno, Hiroyuki; Watanabe, Yoshinori; Omura, Tomohiko; Sakai, Jun'ichi; Yokoyama, Ken'ichi; Suzuki, Hiroshi; Okuma, Ryuji

    2014-12-01

    Type 316L and Type 304 austenitic stainless steels, both deformed and non-deformed, were hydrogen charged cathodically in an aqueous solution as well as by exposure to high-pressure gaseous hydrogen in an attempt to identify suitable conditions of cathodic charge for simulating hydrogen absorption from gaseous hydrogen environments. Thermal desorption analysis (TDA) was conducted, and the amount of absorbed hydrogen and the spectrum shape were compared between the two charging methods. Simulations were performed by means of the McNabb-Foster model to analyze the spectrum shape and peak temperature, and understand the effects of deformation on the spectra. It was revealed that the spectrum shape and peak temperature were dependent directly upon the initial distribution of hydrogen within the specimen, which varied widely according to the hydrogen charge condition. Deformation also had a marked effect on the amount of absorbed hydrogen in Type 304 steel due to the strain-induced martensitic transformation.

  12. Charge and fluence lifetime measurements of a dc high voltage GaAs photogun at high average current

    SciTech Connect

    J. Grames, R. Suleiman, P.A. Adderley, J. Clark, J. Hansknecht, D. Machie, M. Poelker, M.L. Stutzman

    2011-04-01

    GaAs-based dc high voltage photoguns used at accelerators with extensive user programs must exhibit long photocathode operating lifetime. Achieving this goal represents a significant challenge for proposed high average current facilities that must operate at tens of milliamperes or more. This paper describes techniques to maintain good vacuum while delivering beam, and techniques that minimize the ill effects of ion bombardment, the dominant mechanism that reduces photocathode yield of a GaAs-based dc high voltage photogun. Experimental results presented here demonstrate enhanced lifetime at high beam currents by: (a) operating with the drive laser beam positioned away from the electrostatic center of the photocathode, (b) limiting the photocathode active area to eliminate photoemission from regions of the photocathode that do not support efficient beam delivery, (c) using a large drive laser beam to distribute ion damage over a larger area, and (d) by applying a relatively low bias voltage to the anode to repel ions created within the downstream beam line. A combination of these techniques provided the best total charge extracted lifetimes in excess of 1000 C at dc beam currents up to 9.5 mA, using green light illumination of bulk GaAs inside a 100 kV photogun.

  13. Development of a Bulk-Format System to Harvest, Handle, Store, and Deliver High-Tonnage Low-Moisture Switchgrass Feedstock

    SciTech Connect

    Womac, Alvin; Groothuis, Mitch; Westover, Tyler; Phanphanich, Manunya; Webb, Erin; Sokhansanj, Shahab; Turhollow, Anthony

    2013-09-24

    This project evaluates and compares comprehensive feedstock logistics systems (FLS), where a FLS is defined to comprehensively span from biomass material standing in a field to conveyance of a uniform, industrial-milled product into the throat of a biomass conversion facility (BCF). Elements of the bulk-format FLS evaluated in this project include: field-standing switchgrass dry chopped into bulk format on the farm, hauled (either loose or bulk compacted) to storage, stored with confining overburden in a protective facility, reclaimed and conveyed to bulk-format discharge, bulk compacted into an ejector trailer, and conveyed as bulk flow into the BCF. In this FLS evaluation, bulk storage bins served as a controlled and sensored proxy for large commercial stacks protected from moisture with a membrane cover.

  14. High throughput ab initio modeling of charge transport for bio-molecular-electronics

    NASA Astrophysics Data System (ADS)

    Bruque, Nicolas Alexander

    2009-12-01

    Self-assembled nanostructures, composed of inorganic and organic materials, have multiple applications in the fields of engineering and nanotechnology. Experimental research using nanoscaled materials, such as semiconductor/metallic nanocrystals, nanowires (NW), and carbon nanotube (CNT)-molecular systems have potential applications in next generation nano electronic devices. Many of these molecular systems exhibit electronic device functionality. However, experimental analytical techniques to determine how the chemistry and geometry affects electron transport through these devices does not yet exist. Using theory and modeling, one can approximate the chemistry and geometry at the atomic level and also determine how the chemistry and geometry governs electron current. Nanoelectronic devices however, contain several thousand atoms which makes quantum modeling difficult. Popular atomistic modeling approaches are capable of handling small molecular systems, which are of scientific interest, but have little engineering value. The lack of large scale modeling tools has left the scientific and engineering community with a limited ability to understand, explore, and design complex systems of engineering interest. To address these issues, I have developed a high performance general quantum charge transport model based on the non-equilibrium Green function (NEGF) formalism using density functional theory (DFT) as implemented in the FIREBALL software. FIREBALL is a quantum molecular dynamics code which has demonstrated the ability to model large molecular systems. This dissertation project of integrating NEGF into FIREBALL provides researchers with a modeling tool capable of simulating charge current in large inorganic/organic systems. To provide theoretical support for experimental efforts, this project focused on CNT-molecular systems, which includes the discovery of a CNT-molecular resonant tunneling diode (RTD) for electronic circuit applications. This research also

  15. Isoindigo-based polymer field-effect transistors: effects of selenophene-substitution on high charge carrier mobility.

    PubMed

    Park, Kwang Hun; Cheon, Kwang Hee; Lee, Yun-Ji; Chung, Dae Sung; Kwon, Soon-Ki; Kim, Yun-Hi

    2015-05-11

    We show that selenophene-substitution can be an efficient synthetic strategy toward high charge carrier mobility of isoindigo (IID)-based copolymers when their side chains are optimized. A high mobility of 5.8 cm(2) V(-1) s(-1) is demonstrated by a strategically designed IID-based polymer, with both side-chain adjustment and selenophene-substitution. PMID:25871952

  16. Highly efficient bioinspired molecular Ru water oxidation catalysts with negatively charged backbone ligands.

    PubMed

    Duan, Lele; Wang, Lei; Li, Fusheng; Li, Fei; Sun, Licheng

    2015-07-21

    The oxygen evolving complex (OEC) of the natural photosynthesis system II (PSII) oxidizes water to produce oxygen and reducing equivalents (protons and electrons). The oxygen released from PSII provides the oxygen source of our atmosphere; the reducing equivalents are used to reduce carbon dioxide to organic products, which support almost all organisms on the Earth planet. The first photosynthetic organisms able to split water were proposed to be cyanobacteria-like ones appearing ca. 2.5 billion years ago. Since then, nature has chosen a sustainable way by using solar energy to develop itself. Inspired by nature, human beings started to mimic the functions of the natural photosynthesis system and proposed the concept of artificial photosynthesis (AP) with the view to creating energy-sustainable societies and reducing the impact on the Earth environments. Water oxidation is a highly energy demanding reaction and essential to produce reducing equivalents for fuel production, and thereby effective water oxidation catalysts (WOCs) are required to catalyze water oxidation and reduce the energy loss. X-ray crystallographic studies on PSII have revealed that the OEC consists of a Mn4CaO5 cluster surrounded by oxygen rich ligands, such as oxyl, oxo, and carboxylate ligands. These negatively charged, oxygen rich ligands strongly stabilize the high valent states of the Mn cluster and play vital roles in effective water oxidation catalysis with low overpotential. This Account describes our endeavors to design effective Ru WOCs with low overpotential, large turnover number, and high turnover frequency by introducing negatively charged ligands, such as carboxylate. Negatively charged ligands stabilized the high valent states of Ru catalysts, as evidenced by the low oxidation potentials. Meanwhile, the oxygen production rates of our Ru catalysts were improved dramatically as well. Thanks to the strong electron donation ability of carboxylate containing ligands, a seven

  17. Electron emission and defect formation in the interaction of slow,highly charged ions with diamond surfaces

    SciTech Connect

    Sideras-Haddad, E.; Shrivastava, S.; Rebuli, D.B.; Persaud, A.; Schneider, D.H.; Schenkel, T.

    2006-05-31

    We report on electron emission and defect formation in theinteraction between slow (v~;0.3 vBohr) highly charged ions (SHCI) withinsulating (type IIa) and semiconducting (type IIb) diamonds. Electronemission induced by 31Pq+ (q=5 to 13), and 136Xeq+ (q=34 to 44) withkinetic energies of 9 kVxq increase linearly with the ion charge states,reaching over 100 electrons per ion for high xenon charge states withoutsurface passivation of the diamond with hydrogen. Yields from bothdiamond types are up to a factor of two higher then from reference metalsurfaces. Crater like defects with diameters of 25 to 40 nm are formed bythe impact of single Xe44+ ions. High secondary electron yields andsingle ion induced defects enable the formation of single dopant arrayson diamond surfaces.

  18. Charge versus Energy Transfer Effects in High-Performance Perylene Diimide Photovoltaic Blend Films.

    PubMed

    Singh, Ranbir; Shivanna, Ravichandran; Iosifidis, Agathaggelos; Butt, Hans-Jürgen; Floudas, George; Narayan, K S; Keivanidis, Panagiotis E

    2015-11-11

    Perylene diimide (PDI)-based organic photovoltaic devices can potentially deliver high power conversion efficiency values provided the photon energy absorbed is utilized efficiently in charge transfer (CT) reactions instead of being consumed in nonradiative energy transfer (ET) steps. Hitherto, it remains unclear whether ET or CT primarily drives the photoluminescence (PL) quenching of the PDI excimer state in PDI-based blend films. Here, we affirm the key role of the thermally assisted PDI excimer diffusion and subsequent CT reaction in the process of PDI excimer PL deactivation. For our study we perform PL quenching experiments in the model PDI-based composite made of poly[4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-b;4,5-b']dithiophene-2,6-diyl-alt-(4-(2-ethylhexanoyl)-thieno[3,4-b]thiophene)-2-6-diyl] (PBDTTT-CT) polymeric donor mixed with the N,N'-bis(1-ethylpropyl)-perylene-3,4,9,10-tetracarboxylic diimide (PDI) acceptor. Despite the strong spectral overlap between the PDI excimer PL emission and UV-vis absorption of PBDTTT-CT, two main observations indicate that no significant ET component operates in the overall PL quenching: the PL intensity of the PDI excimer (i) increases with decreasing temperature and (ii) remains unaffected even in the presence of 10 wt % content of the PBDTTT-CT quencher. Temperature-dependent wide-angle X-ray scattering experiments further indicate that nonradiative resonance ET is highly improbable due to the large size of PDI domains. The dominance of the CT over the ET process is verified by the high performance of devices with an optimum composition of 30:70 PBDTTT-CT:PDI. By adding 0.4 vol % of 1,8-diiodooctane we verify the plasticization of the polymer side chains that balances the charge transport properties of the PBDTTT-CT:PDI composite and results in additional improvement in the device efficiency. The temperature-dependent spectral width of the PDI excimer PL band suggests the presence of energetic disorder in the

  19. Prospects for laser spectroscopy of highly charged ions with high-harmonic XUV and soft x-ray sources

    NASA Astrophysics Data System (ADS)

    Rothhardt, J.; Hädrich, S.; Demmler, S.; Krebs, M.; Winters, D. F. A.; Kühl, Th; Stöhlker, Th; Limpert, J.; Tünnermann, A.

    2015-11-01

    We present novel high photon flux XUV and soft x-ray sources based on high harmonic generation (HHG). The sources employ femtosecond fiber lasers, which can be operated at very high (MHz) repetition rate and average power (>100 W). HHG with such lasers results in ˜1013 photons s-1 within a single harmonic line at ˜40 nm (˜30 eV) wavelength, a photon flux comparable to what is typically available at synchrotron beam lines. In addition, resonant enhancement of HHG can result in narrow-band harmonics with high spectral purity—well suited for precision spectroscopy. These novel light sources will enable seminal studies on electronic transitions in highly-charged ions. For example, at the experimental storage ring 2s1/2-2p1/2 transitions in Li-like ions can be excited up to Z = 47 (˜100 eV transition energy), which provides unique sensitivity to quantum electro-dynamical effects and nuclear corrections. We estimate fluorescence count rates of the order of tens per second, which would enable studies on short-lived isotopes as well. In combination with the Doppler up-shift available in head-on excitation at future heavy-ion storage rings, such as the high energy storage ring, even multi-keV transitions can potentially be excited. Pump-probe experiments with femtosecond resolution could also be feasible and access the lifetime of short-lived excited states, thus providing novel benchmarks for atomic structure theory.

  20. Enhanced charge transport in highly conducting PEDOT-PSS films after acid treatment

    NASA Astrophysics Data System (ADS)

    Shiva, V. Akshaya; Bhatia, Ravi; Menon, Reghu

    The high electrical conductivity, good stability, high strength, flexibility and good transparency of poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT-PSS), make it useful for many applications including polymeric anodes for organic photovoltaics, light-emitting diodes, flexible electrodes, supercapacitors, electrochromic devices, field-effect transistors and antistatic-coatings. However, the electrical conductivity of PEDOT-PSS has to be increased significantly for replacement of indium tin oxide (ITO) as the transparent electrode in optoelectronic devices. The as prepared (pristine) PEDOT-PSS film prepared from the PEDOT-PSS aqueous solution usually has conductivity below 1Scm-1, remarkably lower than ITO. Significant conductivity enhancement has been observed on transparent and conductive PEDOT-PSS films after a treatment with inorganic acids. Our study investigates the charge transport in pristine and H2SO4, HNO3, HCl treated PEDOT-PSS films. We have treated the films with various concentrations of acids to probe the effect of the acid treatment on the conduction mechanism. The study includes the measurement of dc and electric field dependent conductivity of films in the temperature range of 4.2K-300K. We have also performed magneto-resistance measurements in the range of 0-5T. An enhancement by a factor of~103 has been observed in the room temperature conductivity. The detailed magneto-transport studies explain the various mechanisms for the conductivity enhancement observed.