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Sample records for beam energy civa

  1. Low electron beam energy CIVA analysis of passivated ICs

    SciTech Connect

    Cole, E.I. Jr.; Soden, J.M.; Dodd, B.A.; Henderson, C.L.

    1994-08-01

    Low Energy Charge-Induced Voltage Alteration (LECIVA) is a new scanning electron microscopy technique developed to localize open conductors in passivated ICs. LECIVA takes advantage of recent experimental work showing that the dielectric surface equilibrium voltage has an electron flux density dependence at low electron beam energies ({le}1.0 keV). The equilibrium voltage changes from positive to negative as the electron flux density is increased. Like Charge-Induced Voltage Alteration (CIVA), LECIVA images are produced from the voltage fluctuations of a constant current power supply as an electron beam is scanned over the IC surface. LECIVA image contrast is generated only by the electrically open part of a conductor, yielding, the same high selectivity demonstrated by CIVA. Because LECIVA is performed at low beam energies, radiation damage by the primary electrons and x-rays to MOS structures is far less than that caused by CIVA. LECIVA may also be performed on commercial electron beam test systems that do not have high primary electron beam energy capabilities. The physics of LECIVA signal generation are described. LECIVA imaging examples illustrate its utility on both a standard scanning electron microscope (SEM) and a commercial electron beam test system.

  2. Civa

    NASA Astrophysics Data System (ADS)

    Bibring, J.-P.; Lamy, P.; Langevin, Y.; Soufflot, A.; Berthé, M.; Borg, J.; Poulet, F.; Mottola, S.

    2007-02-01

    CIVA ( Comet Infrared and Visible Analyser) is an integrated set of imaging instruments, designed to characterize the 360∘ panorama (CIVA-P) as seen from the Rosetta Lander Philae, and to study surface and subsurface samples (CIVA-M). CIVA-P is a panoramic stereo camera, while CIVA-M is an optical microscope coupled to a near infrared microscopic hyperspectral imager. CIVA shares a common Imaging Main Electronics (IME) with ROLIS. CIVA-P will characterize the landing site, with an angular sampling (IFOV) of 1.1 mrad: each pixel will image a 1 mm size feature at the distance of the landing legs, and a few metres at the local horizon. The panorama will be mapped by 6 identical miniaturized micro-cameras covering contiguous FOV, with their optical axis 60∘ apart. Stereoscopic capability will be provided by an additional micro-camera, identical to and co-aligned with one of the panoramic micro-camera, with its optical axis displaced by 10 cm. CIVA-M combines two ultra-compact and miniaturised microscopes, one operating in the visible and one constituting an IR hyperspectral imaging spectrometer: they will characterize, by non-destructive analyses, the texture, the albedo, the molecular and the mineralogical composition of each of the samples provided by the Sample Drill and Distribution (SD2) system. For the optical microscope, the spatial sampling is 7 μm; for the IR, the spectral range (1 4 μm) and the spectral sampling (5 nm) have been chosen to allow identification of most minerals, ices and organics, on each pixel, 40 μm in size. After being studied by CIVA, the sample could be analysed by a subsequent experiment (PTOLEMY and/or COSAC). The process would be repeated for each sample obtained at different depths and/or locations.

  3. Electron and optical beam testing of integrated circuits using CIVA, LIVA, and LECIVA

    SciTech Connect

    Cole, E.I. Jr.

    1995-09-01

    Charge-Induced Voltage Alteration (CIVA), Light-Induced Voltage Alteration, (LIVA), and Low Energy CIVA (LECIVA) are three new failure analysis imaging techniques developed to quickly localize defects on ICs. All three techniques utilize the voltage fluctuations of a constant current power supply as an electron or photon beam is scanned across an IC. CIVA and LECIVA yield rapid localization of open interconnections on ICs. LIVA allows quick localization of open-circuited and damaged semiconductor junctions. LIVA can also be used to image transistor logic states and can be performed from the backside of ICs with an infrared laser source. The physics of signal generation for each technique and examples of their use in failure analysis are described.

  4. Experiment vs simulation RT WFNDEC 2014 benchmark: CIVA results

    SciTech Connect

    Tisseur, D. Costin, M. Rattoni, B. Vienne, C. Vabre, A. Cattiaux, G.; Sollier, T.

    2015-03-31

    The French Atomic Energy Commission and Alternative Energies (CEA) has developed for years the CIVA software dedicated to simulation of NDE techniques such as Radiographic Testing (RT). RT modelling is achieved in CIVA using combination of a determinist approach based on ray tracing for transmission beam simulation and a Monte Carlo model for the scattered beam computation. Furthermore, CIVA includes various detectors models, in particular common x-ray films and a photostimulable phosphor plates. This communication presents the results obtained with the configurations proposed in the World Federation of NDEC 2014 RT modelling benchmark with the RT models implemented in the CIVA software.

  5. Experiment vs simulation RT WFNDEC 2014 benchmark: CIVA results

    NASA Astrophysics Data System (ADS)

    Tisseur, D.; Costin, M.; Rattoni, B.; Vienne, C.; Vabre, A.; Cattiaux, G.; Sollier, T.

    2015-03-01

    The French Atomic Energy Commission and Alternative Energies (CEA) has developed for years the CIVA software dedicated to simulation of NDE techniques such as Radiographic Testing (RT). RT modelling is achieved in CIVA using combination of a determinist approach based on ray tracing for transmission beam simulation and a Monte Carlo model for the scattered beam computation. Furthermore, CIVA includes various detectors models, in particular common x-ray films and a photostimulable phosphor plates. This communication presents the results obtained with the configurations proposed in the World Federation of NDEC 2014 RT modelling benchmark with the RT models implemented in the CIVA software.

  6. High energy beam lines

    NASA Astrophysics Data System (ADS)

    Marchetto, M.; Laxdal, R. E.

    2014-01-01

    The ISAC post accelerator comprises an RFQ, DTL and SC-linac. The high energy beam lines connect the linear accelerators as well as deliver the accelerated beams to two different experimental areas. The medium energy beam transport (MEBT) line connects the RFQ to the DTL. The high energy beam transport (HEBT) line connects the DTL to the ISAC-I experimental stations (DRAGON, TUDA-I, GPS). The DTL to superconducting beam (DSB) transport line connects the ISAC-I and ISAC-II linacs. The superconducting energy beam transport (SEBT) line connects the SC linac to the ISAC-II experimental station (TUDA-II, HERACLES, TIGRESS, EMMA and GPS). All these lines have the function of transporting and matching the beams to the downstream sections by manipulating the transverse and longitudinal phase space. They also contain diagnostic devices to measure the beam properties.

  7. Civa 10 RX module: Preliminary validation in a nuclear context

    SciTech Connect

    Tisseur, D.; Buyens, F.; Rattoni, B.; Cattiaux, G.; Sollier, T.

    2012-05-17

    The French Institute for Radioprotection and Nuclear Safety (IRSN) in partnership with CEA, has started in 2009 a program over several years for the validation of CIVA RX module. The aim of this paper is to present preliminary results of CIVA RX tools validation. The study consists in a cross comparison between experimental and simulation results. These have been carried out on different objects (step wedge, dissimilar metal weld mock up, IQI, notches) with different sources (Co{sup 60} and 450 kV X-ray tube) and radiographic film. Simulation and experimental data are compared in term of optical density, IQI perceptivity and flaws detectability. This study shows a good agreement between experiment and simulation.

  8. Beamed energy propulsion

    NASA Technical Reports Server (NTRS)

    Shoji, James M.

    1992-01-01

    Beamed energy concepts offer an alternative for an advanced propulsion system. The use of a remote power source reduces the weight of the propulsion system in flight and this, combined with the high performance, provides significant payload gains. Within the context of this study's baseline scenario, two beamed energy propulsion concepts are potentially attractive: solar thermal propulsion and laser thermal propulsion. The conceived beamed energy propulsion devices generally provide low thrust (tens of pounds to hundreds of pounds); therefore, they are typically suggested for cargo transportation. For the baseline scenario, these propulsion system can provide propulsion between the following nodes: (1) low Earth orbit to geosynchronous Earth orbit; (2) low Earth orbit to low lunar orbit; (3) low lunar orbit to low Mars orbit--only solar thermal; and (4) lunar surface to low lunar orbit--only laser thermal.

  9. Low energy antiproton beams

    NASA Astrophysics Data System (ADS)

    Klapisch, R.

    1992-04-01

    It was the invention of stochastic cooling by S. Van Meer that has allowed antiproton beams to become a powerful tool for the physicist. As a byproduct of the high energy proton-antiproton collider, a versatile low-energy facility, LEAR has been operating at CERN since 1984. The facility and its characteristics will be described as well as examples of its use for studying fundamental properties of the antiproton and for topics in atomic, nuclear and particle Physics.

  10. CRYSTALLINE BEAMS AT HIGH ENERGIES.

    SciTech Connect

    WEI, J.; OKAMOTO, H.; YURI, Y.; SESSLER, A.; MACHIDA, S.

    2006-06-23

    Previously it was shown that by crystallizing each of the two counter-circulating beams, a much larger beam-beam tune shift can be tolerated during the beam-beam collisions; thus a higher luminosity can be reached for colliding beams [1]. On the other hand, crystalline beams can only be formed at energies below the transition energy ({gamma}{sub T}) of the accelerators [2]. In this paper, we investigate the formation of crystals in a high-{gamma}{sub T} lattice that also satisfies the maintenance condition for a crystalline beam [3].

  11. Implementation and evaluation of two helical CT reconstruction algorithms in CIVA

    NASA Astrophysics Data System (ADS)

    Banjak, H.; Costin, M.; Vienne, C.; Kaftandjian, V.

    2016-02-01

    The large majority of industrial CT systems reconstruct the 3D volume by using an acquisition on a circular trajec-tory. However, when inspecting long objects which are highly anisotropic, this scanning geometry creates severe artifacts in the reconstruction. For this reason, the use of an advanced CT scanning method like helical data acquisition is an efficient way to address this aspect known as the long-object problem. Recently, several analytically exact and quasi-exact inversion formulas for helical cone-beam reconstruction have been proposed. Among them, we identified two algorithms of interest for our case. These algorithms are exact and of filtered back-projection structure. In this work we implemented the filtered-backprojection (FBP) and backprojection-filtration (BPF) algorithms of Zou and Pan (2004). For performance evaluation, we present a numerical compari-son of the two selected algorithms with the helical FDK algorithm using both complete (noiseless and noisy) and truncated data generated by CIVA (the simulation platform for non-destructive testing techniques developed at CEA).

  12. Integrated circuit failure analysis by low-energy charge-induced voltage alteration

    DOEpatents

    Cole, Jr., Edward I.

    1996-01-01

    A scanning electron microscope apparatus and method are described for detecting and imaging open-circuit defects in an integrated circuit (IC). The invention uses a low-energy high-current focused electron beam that is scanned over a device surface of the IC to generate a charge-induced voltage alteration (CIVA) signal at the location of any open-circuit defects. The low-energy CIVA signal may be used to generate an image of the IC showing the location of any open-circuit defects. A low electron beam energy is used to prevent electrical breakdown in any passivation layers in the IC and to minimize radiation damage to the IC. The invention has uses for IC failure analysis, for production-line inspection of ICs, and for qualification of ICs.

  13. Integrated circuit failure analysis by low-energy charge-induced voltage alteration

    DOEpatents

    Cole, E.I. Jr.

    1996-06-04

    A scanning electron microscope apparatus and method are described for detecting and imaging open-circuit defects in an integrated circuit (IC). The invention uses a low-energy high-current focused electron beam that is scanned over a device surface of the IC to generate a charge-induced voltage alteration (CIVA) signal at the location of any open-circuit defects. The low-energy CIVA signal may be used to generate an image of the IC showing the location of any open-circuit defects. A low electron beam energy is used to prevent electrical breakdown in any passivation layers in the IC and to minimize radiation damage to the IC. The invention has uses for IC failure analysis, for production-line inspection of ICs, and for qualification of ICs. 5 figs.

  14. Energy Focusability of Annular Beams

    NASA Astrophysics Data System (ADS)

    Astadjov, Dimo N.

    2010-01-01

    A simulation of coherent annular flat two-level beams by two-dimensional Fast Fourier Transform is presented. After parameterization of the source beam (the `input') we examined the influence of its parameters on the shape and proportions of the output beam profile. The output pattern has a prominent central peak and faint rings concentrically surrounding it. The fraction of the central peak energy to the whole energy of beam, PF0 gives a notion of energy spread within the focal spot: PF0 is a function of beam annularity, k (i.e. `inside diameter/outside diameter' ratio) and the intensity dip, Idip of annulus central area (i.e. ring intensity minus central-bottom intensity, normalized). Up to k = 0.8 and Idip = 0.75, PF0 does not change too much—it is ⩾0.7 which is ⩾90% of PF0 maximum (0.778 at k = 0 and Idip = 0). Simulations revealed that even great changes in the shape of input beam annulus lead to small variations in the energy spread of output beam profile in the range of practical use of coherent annular beams.

  15. Intense low energy positron beams

    SciTech Connect

    Lynn, K.G.; Jacobsen, F.M.

    1993-12-31

    Intense positron beams are under development or being considered at several laboratories. Already today a few accelerator based high intensity, low brightness e{sup +} beams exist producing of the order of 10{sup 8} {minus} 10{sup 9} e{sup +}/sec. Several laboratories are aiming at high intensity, high brightness e{sup +} beams with intensities greater than 10{sup 9} e{sup +}/sec and current densities of the order of 10{sup 13} {minus} 10{sup 14} e{sup +} sec{sup {minus}} {sup 1}cm{sup {minus}2}. Intense e{sup +} beams can be realized in two ways (or in a combination thereof) either through a development of more efficient B{sup +} moderators or by increasing the available activity of B{sup +} particles. In this review we shall mainly concentrate on the latter approach. In atomic physics the main trust for these developments is to be able to measure differential and high energy cross-sections in e{sup +} collisions with atoms and molecules. Within solid state physics high intensity, high brightness e{sup +} beams are in demand in areas such as the re-emission e{sup +} microscope, two dimensional angular correlation of annihilation radiation, low energy e{sup +} diffraction and other fields. Intense e{sup +} beams are also important for the development of positronium beams, as well as exotic experiments such as Bose condensation and Ps liquid studies.

  16. Beam characteristics of energy-matched flattening filter free beams

    SciTech Connect

    Paynter, D.; Weston, S. J.; Cosgrove, V. P.; Evans, J. A.; Thwaites, D. I.

    2014-05-15

    Purpose: Flattening filter free (FFF) linear accelerators can increase treatment efficiency and plan quality. There are multiple methods of defining a FFF beam. The Elekta control system supports tuning of the delivered FFF beam energy to enable matching of the percentage depth-dose (PDD) of the flattened beam at 10 cm depth. This is compared to FFF beams where the linac control parameters are identical to those for the flattened beam. All beams were delivered on an Elekta Synergy accelerator with an Agility multi-leaf collimator installed and compared to the standard, flattened beam. The aim of this study is to compare “matched” FFF beams to both “unmatched” FFF beams and flattened beams to determine the benefits of matching beams. Methods: For the three modes of operation 6 MV flattened, 6 MV matched FFF, 6 MV unmatched FFF, 10 MV flattened, 10 MV matched FFF, and 10 MV unmatched FFF beam profiles were obtained using a plotting tank and were measured in steps of 0.1 mm in the penumbral region. Beam penumbra was defined as the distance between the 80% and 20% of the normalized dose when the inflection points of the unflattened and flattened profiles were normalized with the central axis dose of the flattened field set as 100%. PDD data was obtained at field sizes ranging from 3 cm × 3 cm to 40 cm × 40 cm. Radiation protection measurements were additionally performed to determine the head leakage and environmental monitoring through the maze and primary barriers. Results: No significant change is made to the beam penumbra for FFF beams with and without PDD matching, the maximum change in penumbra for a 10 cm × 10 cm field was within the experimental error of the study. The changes in the profile shape with increasing field size are most significant for the matched FFF beam, and both FFF beams showed less profile shape variation with increasing depth when compared to flattened beams, due to consistency in beam energy spectra across the radiation field

  17. 67P/Churyumov-Gerasimenko surface properties as derived from CIVA panoramic images

    NASA Astrophysics Data System (ADS)

    Bibring, J.-P.; Langevin, Y.; Carter, J.; Eng, P.; Gondet, B.; Jorda, L.; Le Mouélic, S.; Mottola, S.; Pilorget, C.; Poulet, F.; Vincendon, M.

    2015-07-01

    The structure and composition of cometary constituents, down to their microscopic scale, are critical witnesses of the processes and ingredients that drove the formation and evolution of planetary bodies toward their present diversity. On board Rosetta’s lander Philae, the Comet Infrared and Visible Analyser (CIVA) experiment took a series of images to characterize the surface materials surrounding the lander on comet 67P/Churyumov-Gerasimenko. Images were collected twice: just after touchdown, and after Philae finally came to rest, where it acquired a full panorama. These images reveal a fractured surface with complex structure and a variety of grain scales and albedos, possibly constituting pristine cometary material.

  18. COMETARY SCIENCE. 67P/Churyumov-Gerasimenko surface properties as derived from CIVA panoramic images.

    PubMed

    Bibring, J-P; Langevin, Y; Carter, J; Eng, P; Gondet, B; Jorda, L; Le Mouélic, S; Mottola, S; Pilorget, C; Poulet, F; Vincendon, M

    2015-07-31

    The structure and composition of cometary constituents, down to their microscopic scale, are critical witnesses of the processes and ingredients that drove the formation and evolution of planetary bodies toward their present diversity. On board Rosetta's lander Philae, the Comet Infrared and Visible Analyser (CIVA) experiment took a series of images to characterize the surface materials surrounding the lander on comet 67P/Churyumov-Gerasimenko. Images were collected twice: just after touchdown, and after Philae finally came to rest, where it acquired a full panorama. These images reveal a fractured surface with complex structure and a variety of grain scales and albedos, possibly constituting pristine cometary material. PMID:26228154

  19. Results of the 2013 UT modeling benchmark obtained with models implemented in CIVA

    SciTech Connect

    Toullelan, Gwénaël; Raillon, Raphaële; Chatillon, Sylvain; Lonne, Sébastien

    2014-02-18

    The 2013 Ultrasonic Testing (UT) modeling benchmark concerns direct echoes from side drilled holes (SDH), flat bottom holes (FBH) and corner echoes from backwall breaking artificial notches inspected with a matrix phased array probe. This communication presents the results obtained with the models implemented in the CIVA software: the pencilmodel is used to compute the field radiated by the probe, the Kirchhoff approximation is applied to predict the response of FBH and notches and the SOV (Separation Of Variables) model is used for the SDH responses. The comparison between simulated and experimental results are presented and discussed.

  20. Results of the 2013 UT modeling benchmark obtained with models implemented in CIVA

    NASA Astrophysics Data System (ADS)

    Toullelan, Gwénaël; Raillon, Raphaële; Chatillon, Sylvain; Lonne, Sébastien

    2014-02-01

    The 2013 Ultrasonic Testing (UT) modeling benchmark concerns direct echoes from side drilled holes (SDH), flat bottom holes (FBH) and corner echoes from backwall breaking artificial notches inspected with a matrix phased array probe. This communication presents the results obtained with the models implemented in the CIVA software: the pencilmodel is used to compute the field radiated by the probe, the Kirchhoff approximation is applied to predict the response of FBH and notches and the SOV (Separation Of Variables) model is used for the SDH responses. The comparison between simulated and experimental results are presented and discussed.

  1. Confined energy distribution for charged particle beams

    DOEpatents

    Jason, Andrew J.; Blind, Barbara

    1990-01-01

    A charged particle beam is formed to a relatively larger area beam which is well-contained and has a beam area which relatively uniformly deposits energy over a beam target. Linear optics receive an accelerator beam and output a first beam with a first waist defined by a relatively small size in a first dimension normal to a second dimension. Nonlinear optics, such as an octupole magnet, are located about the first waist and output a second beam having a phase-space distribution which folds the beam edges along the second dimension toward the beam core to develop a well-contained beam and a relatively uniform particle intensity across the beam core. The beam may then be expanded along the second dimension to form the uniform ribbon beam at a selected distance from the nonlinear optics. Alternately, the beam may be passed through a second set of nonlinear optics to fold the beam edges in the first dimension. The beam may then be uniformly expanded along the first and second dimensions to form a well-contained, two-dimensional beam for illuminating a two-dimensional target with a relatively uniform energy deposition.

  2. Characterization of the Abydos region through OSIRIS high-resolution images in support of CIVA measurements

    NASA Astrophysics Data System (ADS)

    Lucchetti, A.; Cremonese, G.; Jorda, L.; Poulet, F.; Bibring, J.-P.; Pajola, M.; La Forgia, F.; Massironi, M.; El-Maarry, M. R.; Oklay, N.; Sierks, H.; Barbieri, C.; Lamy, P.; Rodrigo, R.; Koschny, D.; Rickman, H.; Keller, H. U.; Agarwal, J.; A'Hearn, M. F.; Barucci, M. A.; Bertaux, J.-L.; Bertini, I.; Da Deppo, V.; Davidsson, B.; Debei, S.; De Cecco, M.; Fornasier, S.; Fulle, M.; Groussin, O.; Gutierrez, P. J.; Güttler, C.; Hviid, S. F.; Ip, W.-H.; Knollenberg, J.; Kramm, J.-R.; Kührt, E.; Küppers, M.; Lara, L. M.; Lazzarin, M.; Lopez Moreno, J. J.; Marzari, F.; Mottola, S.; Naletto, G.; Preusker, F.; Scholten, F.; Thomas, N.; Tubiana, C.; Vincent, J.-B.

    2016-01-01

    Context. On 12 November 2014, the European mission Rosetta delivered the Philae lander on the nucleus of comet 67P/Churyumov-Gerasimenko (67P). After the first touchdown, the lander bounced three times before finally landing at a site named Abydos. Aims: We provide a morphologically detailed analysis of the Abydos landing site to support Philae's measurements and to give context for the interpretation of the images coming from the Comet Infrared and Visible Analyser (CIVA) camera system onboard the lander. Methods: We used images acquired by the OSIRIS Narrow Angle Camera (NAC) on 6 December 2014 to perform the analysis of the Abydos landing site, which provided the geomorphological map, the gravitational slope map, the size-frequency distribution of the boulders. We also computed the albedo and spectral reddening maps. Results: The morphological analysis of the region could suggest that Philae is located on a primordial terrain. The Abydos site is surrounded by two layered and fractured outcrops and presents a 0.02 km2 talus deposit rich in boulders. The boulder size frequency distribution gives a cumulative power-law index of -4.0 + 0.3/-0.4, which is correlated with gravitational events triggered by sublimation and/or thermal fracturing causing regressive erosion. The average value of the albedo is 5.8% at λ1 = 480.7 nm and 7.4% at λ2 = 649.2 nm, which is similar to the global albedos derived by OSIRIS and CIVA, respectively.

  3. Definition of the Active Cooling System for the Space Instrument CIVA/Mars

    NASA Astrophysics Data System (ADS)

    Lamartinie, Sujit; Bibring, Jean-Pierre; Soufflot, Alain

    2003-03-01

    CIVA/Mars is a space miniaturized spectral imaging microscope. It is designed to in-situ analyze samples on Mars surface. It requires the use of a double cooling system : a passive cooling for the global instrument which will be maintained at a temperature higher than 160 K and an active cooling system for the IR MCT detector matrix which must be maintained at a temperature lower than 140 K. Taking into account the mission constraints, a trade-off analysis of available active cooling systems led to the choice of a thermoelectrical cooler (TEC). Space validation tests of standard multi-stage TECs were performed. Performances did not meet the technical specifications of the instrument. Two types of customized TEC modules were then designed and manufactured : mechanical prototypes from RMT Ltd. and optimized modules from Marlow Ind. A first RMT prototype passed the vibration &shock qualification tests and a second passed the low temperatures vacuum qualification tests with few margins. A Marlow optimized module passed the low temperatures vacuum qualification tests; its characteristics and performances make it compatible with CIVA/Mars. In this paper, the instrument mission and characteristics are first presented. Then TEC design studies are discussed. Finally, optimized TEC space qualification tests are detailed, and the performances analyzed.

  4. High energy polarized beams from hyperon decays

    SciTech Connect

    Underwood, D.G.

    1986-01-01

    The use of various ways to utilize lambda decays to obtain polarized beams of protons and antiprotons is emphasized. Examples described are the Fermilab polarized beam, now under construction, and the use of similar techniques at other energies. Beam transport, spin precession and reversal systems, and polarimeters are also discussed. 8 refs., 4 figs.

  5. TPX/TFTR Neutral Beam energy absorbers

    SciTech Connect

    Dahlgren, F.; Wright, K.; Kamperschroer, J.; Grisham, L.; Lontai, L.; Peters, C.; VonHalle, A.

    1993-11-01

    The present beam energy absorbing surfaces on the TFTR Neutral Beams such as Ion Dumps, Calorimeters, beam defining apertures, and scrapers, are simple water cooled copper plates which wee designed to absorb (via their thermal inertia) the incident beam power for two seconds with a five minute coal down interval between pulses. These components are not capable of absorbing the anticipated beam power loading for 1000 second TPX pulses and will have to be replaced with an actively cooled design. While several actively cooled energy absorbing designs were considered,, the hypervapotron elements currently being used on the JET beamlines were chosen due to their lower cooling water demands and reliable performance on JET.

  6. Intermediate energy neutron beams from the MURR

    SciTech Connect

    Brugger, R.M.; Herleth, W.H. )

    1990-01-01

    Several reactors in the United States are potential candidates to deli1ver beams of intermediate energy neutrons for NCT. At this time, moderators, as compared to filters, appear to be the more effective means of tailoring the flux of these reactors. The objective is to sufficiently reduce the flux of fast neutrons while producing enough intermediate energy neutrons for treatments. At the University of Missouri Research Reactor (MURR), the code MCNP has recently been used to calculate doses in a phantom. First, ideal beams of 1, 35, and 1000 eV neutrons were analyzed to determine doses and advantage depths in the phantom. Second, a high quality beam that had been designed to fit in the thermal column of the MURR, was reanalyzed. MCNP calculations of the dose in phantom in this beam confirmed previous calculations and showed that this beam would be a nearly ideal one with neutrons of the desired energy and also a high neutron current. However, installation of this beam will require a significant modification of the thermal column of the MURR. Therefore, a second beam that is less difficult to build and install, but of lower neutron current, has been designed to fit in MURR port F. This beam is designed using inexpensive A1, S, and Pb. The doses calculated in the phantom placed in this beam show that it will be satisfactory for sample tests, animal tests, and possible initial patient trials. Producing this beam will require only modest modifications of the existing tube.

  7. Effective Electron Beam Injection With Broad Energy Initial Beam

    SciTech Connect

    Cooley, J.H.; Hubbard, R.F.; Gordon, D.F.; Ting, A.; Sprangle, P.; Zigler, A.

    2004-12-07

    Laser Wakefield Accelerators (LWFA), in the resonant regime, require use of an injected electron beam. Several optical methods for generating electron bunches exist e.g., Laser Ionization and Ponderomotive Acceleration (LIPA) and Self-Modulated LWFA among others. Each of these schemes produces an electron bunch with a characteristic energy distribution. We examine the trapping characteristics in a resonant LWFA for an injection electron beam with a broad energy spread that can be characterized using a Boltzmann distribution with an 'effective temperature'. We present results of both analytic calculations and simulations which provide a methodology for optimizing the resulting accelerated electron bunch characteristics i.e., energy and energy spread, for a given LWFA configuration.

  8. Energy-beam-driven rapid fabrication system

    DOEpatents

    Keicher, David M.; Atwood, Clinton L.; Greene, Donald L.; Griffith, Michelle L.; Harwell, Lane D.; Jeantette, Francisco P.; Romero, Joseph A.; Schanwald, Lee P.; Schmale, David T.

    2002-01-01

    An energy beam driven rapid fabrication system, in which an energy beam strikes a growth surface to form a molten puddle thereon. Feed powder is then injected into the molten puddle from a converging flow of feed powder. A portion of the feed powder becomes incorporated into the molten puddle, forcing some of the puddle contents to freeze on the growth surface, thereby adding an additional layer of material. By scanning the energy beam and the converging flow of feed powder across the growth surface, complex three-dimensional shapes can be formed, ready or nearly ready for use. Nearly any class of material can be fabricated using this system.

  9. Low energy beam transport system developments

    NASA Astrophysics Data System (ADS)

    Dudnikov, V.; Han, B.; Stockli, M.; Welton, R.; Dudnikova, G.

    2015-04-01

    For high brightness beam production it is important to preserve the brightness in the low energy beam transport system (LEBT) used to transport and match the ion beams to the next stage of acceleration, usually an RFQ. While electrostatic focusing can be problematic for high current beam transport, reliable electrostatic LEBT operation has been demonstrated with H- beams up to 60 mA. Now, however, it is commonly accepted that an optimal LEBT for high current accelerator applications consists of focusing solenoids with space charge compensation. Two-solenoid LEBTs are successfully used for high current (>100 mA) proton beam transport. Preservation of low emittances (~0.15 π mm-mrad) requires the addition of a heavy gas (Xe, Kr), which causes ~5% of proton loss in a 1 m long LEBT. Similar Xe densities would be required to preserve low emittances of H- beams, but such gas densities cause unacceptably high H- beam losses. A short LEBT with only one short solenoid, movable for RFQ matching, can be used for reduced negative ion stripping. A strong electrostatic-focusing LEBT has been successfully adopted for transport of high current H- beams in the SNS Front End. Some modifications of such electrostatic LEBTs are expected to improve the reliable transport of intense positive and negative ion beams without greatly degrading their low emittances. We concentrate on processes that determine the beam brightness degradation and on their prevention. Proposed improvements to the SNS electrostatic LEBT are discussed.

  10. Calibration of a proton beam energy monitor

    SciTech Connect

    Moyers, M. F.; Coutrakon, G. B.; Ghebremedhin, A.; Shahnazi, K.; Koss, P.; Sanders, E.

    2007-06-15

    Delivery of therapeutic proton beams requires an absolute energy accuracy of {+-}0.64 to 0.27 MeV for patch fields and a relative energy accuracy of {+-}0.10 to 0.25 MeV for tailoring the depth dose distribution using the energy stacking technique. Achromatic switchyard tunes, which lead to better stability of the beam incident onto the patient, unfortunately limit the ability of switchyard magnet tesla meters to verify the correct beam energy within the tolerances listed above. A new monitor to measure the proton energy before each pulse is transported through the switchyard has been installed into a proton synchrotron. The purpose of this monitor is to correct and/or inhibit beam delivery when the measured beam energy is outside of the tolerances for treatment. The monitor calculates the beam energy using data from two frequency and eight beam position monitors that measure the revolution frequency of the proton bunches and the effective offset of the orbit from the nominal radius of the synchrotron. The new energy monitor has been calibrated by measuring the range of the beam through water and comparing with published range-energy tables for various energies. A relationship between depth dose curves and range-energy tables was first determined using Monte Carlo simulations of particle transport and energy deposition. To reduce the uncertainties associated with typical scanning water phantoms, a new technique was devised in which the beam energy was scanned while fixed thickness water tanks were sandwiched between two fixed parallel plate ionization chambers. Using a multitude of tank sizes, several energies were tested to determine the nominal accelerator orbit radius. After calibration, the energy reported by the control system matched the energy derived by range measurements to better than 0.72 MeV for all nine energies tested between 40 and 255 MeV with an average difference of -0.33 MeV. A study of different combinations of revolution frequency and radial

  11. Calibration of a proton beam energy monitor.

    PubMed

    Moyers, M F; Coutrakon, G B; Ghebremedhin, A; Shahnazi, K; Koss, P; Sanders, E

    2007-06-01

    Delivery of therapeutic proton beams requires an absolute energy accuracy of +/-0.64 to 0.27 MeV for patch fields and a relative energy accuracy of +/-0.10 to 0.25 MeV for tailoring the depth dose distribution using the energy stacking technique. Achromatic switchyard tunes, which lead to better stability of the beam incident onto the patient, unfortunately limit the ability of switchyard magnet tesla meters to verify the correct beam energy within the tolerances listed above. A new monitor to measure the proton energy before each pulse is transported through the switchyard has been installed into a proton synchrotron. The purpose of this monitor is to correct and/or inhibit beam delivery when the measured beam energy is outside of the tolerances for treatment. The monitor calculates the beam energy using data from two frequency and eight beam position monitors that measure the revolution frequency of the proton bunches and the effective offset of the orbit from the nominal radius of the synchrotron. The new energy monitor has been calibrated by measuring the range of the beam through water and comparing with published range-energy tables for various energies. A relationship between depth dose curves and range-energy tables was first determined using Monte Carlo simulations of particle transport and energy deposition. To reduce the uncertainties associated with typical scanning water phantoms, a new technique was devised in which the beam energy was scanned while fixed thickness water tanks were sandwiched between two fixed parallel plate ionization chambers. Using a multitude of tank sizes, several energies were tested to determine the nominal accelerator orbit radius. After calibration, the energy reported by the control system matched the energy derived by range measurements to better than 0.72 MeV for all nine energies tested between 40 and 255 MeV with an average difference of -0.33 MeV. A study of different combinations of revolution frequency and radial

  12. Straight low energy beam transport for intense uranium beams

    NASA Astrophysics Data System (ADS)

    Xiao, C.; Groening, L.; Vormann, H.; Mickat, S.; Hollinger, R.; Adonin, A.; Orzhekhovskaya, A.; Maier, M.; Al-Omari, H.; Barth, W.; Kester, O. K.; Yaramyshev, S.

    2015-07-01

    A new high current uranium ion source and dedicated Low Energy Beam Transport (LEBT) will be built at the GSI High Current Injector (HSI). This LEBT will be integrated into the existing complex which already comprises two branches. The paper presents the design and dynamics simulation using the TRACE-3D and TRACK code. The simulation results illustrate that this straight LEBT can transport uranium beams over a wide range of space-charge compensation, and can provide 15.4 (14.2) mA U4+ inside of the effective acceptance of the subsequent RFQ assuming the space-charge is compensated to 100% (95%).

  13. Fundamentals of high energy electron beam generation

    NASA Astrophysics Data System (ADS)

    Turman, B. N.; Mazarakis, M. G.; Neau, E. L.

    High energy electron beam accelerator technology has been developed over the past three decades in response to military and energy-related requirements for weapons simulators, directed-energy weapons, and inertially-confined fusion. These applications required high instantaneous power, large beam energy, high accelerated particle energy, and high current. These accelerators are generally referred to as 'pulsed power' devices, and are typified by accelerating potential of millions of volts (MV), beam current in thousands of amperes (KA), pulse duration of tens to hundreds of nanoseconds, kilojoules of beam energy, and instantaneous power of gigawatts to teffawatts (10(exp 9) to 10(exp 12) watts). Much of the early development work was directed toward single pulse machines, but recent work has extended these pulsed power devices to continuously repetitive applications. These relativistic beams penetrate deeply into materials, with stopping range on the order of a centimeter. Such high instantaneous power deposited in depth offers possibilities for new material fabrication and processing capabilities that can only now be explored. Fundamental techniques of pulse compression, high voltage requirements, beam generation and transport under space-charge-dominated conditions will be discussed in this paper.

  14. Energy spectrum control for modulated proton beams.

    PubMed

    Hsi, Wen C; Moyers, Michael F; Nichiporov, Dmitri; Anferov, Vladimir; Wolanski, Mark; Allgower, Chris E; Farr, Jonathan B; Mascia, Anthony E; Schreuder, Andries N

    2009-06-01

    In proton therapy delivered with range modulated beams, the energy spectrum of protons entering the delivery nozzle can affect the dose uniformity within the target region and the dose gradient around its periphery. For a cyclotron with a fixed extraction energy, a rangeshifter is used to change the energy but this produces increasing energy spreads for decreasing energies. This study investigated the magnitude of the effects of different energy spreads on dose uniformity and distal edge dose gradient and determined the limits for controlling the incident spectrum. A multilayer Faraday cup (MLFC) was calibrated against depth dose curves measured in water for nonmodulated beams with various incident spectra. Depth dose curves were measured in a water phantom and in a multilayer ionization chamber detector for modulated beams using different incident energy spreads. Some nozzle entrance energy spectra can produce unacceptable dose nonuniformities of up to +/-21% over the modulated region. For modulated beams and small beam ranges, the width of the distal penumbra can vary by a factor of 2.5. When the energy spread was controlled within the defined limits, the dose nonuniformity was less than +/-3%. To facilitate understanding of the results, the data were compared to the measured and Monte Carlo calculated data from a variable extraction energy synchrotron which has a narrow spectrum for all energies. Dose uniformity is only maintained within prescription limits when the energy spread is controlled. At low energies, a large spread can be beneficial for extending the energy range at which a single range modulator device can be used. An MLFC can be used as part of a feedback to provide specified energy spreads for different energies. PMID:19610318

  15. Energy spectrum control for modulated proton beams

    SciTech Connect

    Hsi, Wen C.; Moyers, Michael F.; Nichiporov, Dmitri; Anferov, Vladimir; Wolanski, Mark; Allgower, Chris E.; Farr, Jonathan B.; Mascia, Anthony E.; Schreuder, Andries N.

    2009-06-15

    In proton therapy delivered with range modulated beams, the energy spectrum of protons entering the delivery nozzle can affect the dose uniformity within the target region and the dose gradient around its periphery. For a cyclotron with a fixed extraction energy, a rangeshifter is used to change the energy but this produces increasing energy spreads for decreasing energies. This study investigated the magnitude of the effects of different energy spreads on dose uniformity and distal edge dose gradient and determined the limits for controlling the incident spectrum. A multilayer Faraday cup (MLFC) was calibrated against depth dose curves measured in water for nonmodulated beams with various incident spectra. Depth dose curves were measured in a water phantom and in a multilayer ionization chamber detector for modulated beams using different incident energy spreads. Some nozzle entrance energy spectra can produce unacceptable dose nonuniformities of up to {+-}21% over the modulated region. For modulated beams and small beam ranges, the width of the distal penumbra can vary by a factor of 2.5. When the energy spread was controlled within the defined limits, the dose nonuniformity was less than {+-}3%. To facilitate understanding of the results, the data were compared to the measured and Monte Carlo calculated data from a variable extraction energy synchrotron which has a narrow spectrum for all energies. Dose uniformity is only maintained within prescription limits when the energy spread is controlled. At low energies, a large spread can be beneficial for extending the energy range at which a single range modulator device can be used. An MLFC can be used as part of a feedback to provide specified energy spreads for different energies.

  16. High energy laser beam dump

    SciTech Connect

    Halpin, John

    2004-09-14

    The laser beam dump is positioned in a housing. An absorbing glass plate means is operatively connected to the housing. A heat sync means for extracting heat from the absorbing glass plate means is operatively connected to the housing and operatively connected to the absorbing glass plate means.

  17. Beam simulation studies of ECR beam extraction and low energy beam transport for FRIB

    NASA Astrophysics Data System (ADS)

    Ren, Haitao; Pozdeyev, Eduard; Lund, Steven M.; Machicoane, Guillaume; Wu, Xiaoyu; Morgan, Glenn

    2016-02-01

    To meet the beam power requirements of 400 kW at the fragmentation target for facility for Rare Isotope Beams (FRIB), simultaneous acceleration of two-charge states should be used for heavier ions. These intense multi-charged ion beams will be produced by a 28 GHz electron cyclotron resonance (ECR) ion source at a high voltage of 35 kV. After extraction, the ion beam will be pre-accelerated to 12 keV/u with a 50 kV platform, transported down to an achromatic charge state selection (CSS) system followed by a vertical transport line, and then injected into a radio frequency quadrupole accelerator. The TRACK code developed at ANL is used to perform the simulations of the ECR beam extraction and low energy beam transport for FRIB. In this study, we include the magnetic field of ECR ion source into simulations. Different initial beam conditions as well as different space charge neutralization levels are tested for the ECR beamline. The beam loss in CSS system and the corresponding protective measures are discussed. The detailed results about the beam dynamic simulation and beam loss in CSS system will be presented in this paper.

  18. RHIC low energy beam loss projections

    SciTech Connect

    Satogata,T.

    2009-08-01

    For RHIC low-energy operations, we plan to collide Au beams with energies of E = 2:5-10 GeV/u in RHIC. Beams are injected into collision optics, and RHIC runs as a storage ring with no acceleration. At these low energies, observed beam lifetimes are minutes, with measured beam lifetimes of 3.5 min (fast) and 50 min (slow) at E=4.6 GeV/u in the March 2008 test run. With these lifetimes we can operate RHIC as a storage ring to produce reasonable integrated luminosity. This note estimates beam losses and collimator/dump energy deposition in normal injection modes of low energy operation. The main question is whether a normal injection run is feasible for an FY10 10-15 week operations run from a radiation safety perspective. A peripheral question is whether continuous injection operations is feasible from a radiation safety perspective. In continuous injection mode, we fill both rings, then continuously extract and reinject the oldest bunches that have suffered the most beam loss to increase the overall integrated luminosity. We expect to gain a factor of 2-3 in integrated luminosity from continuous injection at lowest energies if implemented[1]. Continuous injection is feasible by FY11 from an engineering perspective given enough effort, but the required extra safety controls and hardware dose risk make it unappealing for the projected luminosity improvement. Low-energy electron cooling will reduce beam losses by at least an order of magnitude vs normal low-energy operations, but low energy cooling is only feasible in the FY13 timescale and therefore beyond the scope of this note. For normal injection low energy estimates we assume the following: (1) RHIC beam total energies are E=2.5-10 GeV/u. (Continuous injection mode is probably unnecessary above total energies of E=7-8 GeV/u.); (2) RHIC operates only as a storage ring, with no acceleration; (3) 110 bunches of about 0.5-1.0 x 10{sup 9} initial bunch intensities (50-100% injection efficiency, likely conservative

  19. Beam-energy and laser beam-profile monitor at the BNL LINAC

    SciTech Connect

    Connolly, R.; Briscoe, B.; Degen, C.; DeSanto, L.; Meng, W.; Minty, M.; Nayak, S.; Raparia, D.; Russo, T.

    2010-05-02

    We are developing a non-interceptive beam profile and energy monitor for H{sup -} beams in the high energy beam transport (HEBT) line at the Brookhaven National Lab linac. Electrons that are removed from the beam ions either by laser photodetachment or stripping by background gas are deflected into a Faraday cup. The beam profile is measured by stepping a narrow laser beam across the ion beam and measuring the electron charge vs. transverse laser position. There is a grid in front of the collector that can be biased up to 125kV. The beam energy spectrum is determined by measuring the electron charge vs. grid voltage. Beam electrons have the same velocity as the beam and so have an energy of 1/1836 of the beam protons. A 200MeV H{sup -} beam yields 109keV electrons. Energy measurements can be made with either laser-stripped or gas-stripped electrons.

  20. Low energy beam transport system developments

    SciTech Connect

    Dudnikov, V.; Han, B.; Stockli, M.; Welton, R.; Dudnikova, G.

    2015-04-08

    For high brightness beam production it is important to preserve the brightness in the low energy beam transport system (LEBT) used to transport and match the ion beams to the next stage of acceleration, usually an RFQ. While electrostatic focusing can be problematic for high current beam transport, reliable electrostatic LEBT operation has been demonstrated with H{sup −} beams up to 60 mA. Now, however, it is commonly accepted that an optimal LEBT for high current accelerator applications consists of focusing solenoids with space charge compensation. Two-solenoid LEBTs are successfully used for high current (>100 mA) proton beam transport. Preservation of low emittances (~0.15 π mm-mrad) requires the addition of a heavy gas (Xe, Kr), which causes ~5% of proton loss in a 1 m long LEBT. Similar Xe densities would be required to preserve low emittances of H{sup −} beams, but such gas densities cause unacceptably high H{sup −} beam losses. A short LEBT with only one short solenoid, movable for RFQ matching, can be used for reduced negative ion stripping. A strong electrostatic-focusing LEBT has been successfully adopted for transport of high current H{sup −} beams in the SNS Front End. Some modifications of such electrostatic LEBTs are expected to improve the reliable transport of intense positive and negative ion beams without greatly degrading their low emittances. We concentrate on processes that determine the beam brightness degradation and on their prevention. Proposed improvements to the SNS electrostatic LEBT are discussed.

  1. Moving core beam energy absorber and converter

    DOEpatents

    Degtiarenko, Pavel V.

    2012-12-18

    A method and apparatus for the prevention of overheating of laser or particle beam impact zones through the use of a moving-in-the-coolant-flow arrangement for the energy absorbing core of the device. Moving of the core spreads the energy deposition in it in 1, 2, or 3 dimensions, thus increasing the effective cooling area of the device.

  2. TLD linearity vs. beam energy and modality

    SciTech Connect

    Troncalli, Andrew J.; Chapman, Jane

    2002-12-31

    Thermoluminescent dosimetry (TLD) is considered to be a valuable dosimetric tool in determining patient dose. Lithium fluoride doped with magnesium and titanium (TLD-100) is widely used, as it does not display widely divergent energy dependence. For many years, we have known that TLD-100 shows supralinearity to dose. In a radiotherapy clinic, there are multiple energies and modality beams. This work investigates whether individual linearity corrections must be used for each beam or whether a single correction can be applied to all beams. The response of TLD as a function of dose was measured from 25 cGy to 1000 cGy on both electrons and photons from 6 to 18 MeV. This work shows that, within our measurement uncertainty, TLD-100 exhibits supralinearity at all megavoltage energies and modalities.

  3. SU-E-T-635: Quantitative Study On Beam Flatness Variation with Beam Energy Change

    SciTech Connect

    Li, J S; Eldib, A; Ma, C; Lin, M

    2014-06-15

    Purpose: Beam flatness check has been proposed for beam energy check for photon beams with flattering filters. In this work, beam flatness change with beam energy was investigated quantitatively using the Monte Carlo method and its significance was compared with depth dose curve change. Methods: Monte Carlo simulations for a linear accelerator with flattering filter were performed with different initial electron energies for photon beams of 6MV and 10MV. Dose calculations in a water phantom were then perform with the phase space files obtained from the simulations. The beam flatness was calculated based on the dose profile at 10 cm depth for all the beams with different initial electron energies. The percentage depth dose (PDD) curves were also analyzed. The dose at 10cm depth (D10) and the ratio of the dose at 10cm and 20cm depth (D10/D20) and their change with the beam energy were calculated and compared with the beam flatness variation. Results: It was found that the beam flatness variation with beam energy change was more significant than the change of D10 and the ratio between D10 and D20 for both 6MV and 10MV beams. Half MeV difference on the initial electron beam energy brought in at least 20% variation on the beam flatness but only half percent change on the ratio of D10 and D20. The change of D10 or D20 alone is even less significant. Conclusion: The beam energy impact on PDD is less significant than that on the beam flatness. If the PDD is used for checking the beam energy, uncertainties of the measurement could possibly disguise its change. Beam flatness changes more significantly with beam energy and therefore it can be used for monitoring the energy change for photon beams with flattering filters. However, other factors which may affect the beam flatness should be watched as well.

  4. Superintense ion beam with high energy density

    NASA Astrophysics Data System (ADS)

    Dudnikov, Vadim; Dudnikova, Galina

    2008-04-01

    The energy density of ion beam accumulated in a storage ring can be increased dramatically with using of space charge compensation as was demonstrated in experiments [1]. The intensity of said superintense beam can be far greater than a space charge limit without space charge compensation. The model of secondary plasma build up with secondary ion-electron emission as a source of delayed electrons has been presented and discussed. This model can be used for explanation of bunched beam instability with electron surviving after gap, for prediction of e-cloud generation in coasting and long bunches beam, and can be important for pressure rise in worm and cold sections of storage rings. A fast desorption by ion of physically adsorbed molecules can explain a ``first pulse Instability''. Application of this model for e-p instability selfstabilization and superintense circulating beam accumulation is considered. Importance of secondary plasma for high perveance ion beam stabilization in ion implantation will be considered. Preliminary results of simulation of electron and ion accumulation will be presented. [1]. Belchenko et al., Xth International Particle Accelerator Conference, Protvino, 1977, Vol. 2, p. 287.

  5. Individual Beam Size And Length Measurements at the SLC Interaction Point Derived From the Beam Energy Loss During a Beam Beam Deflection Scan

    SciTech Connect

    Raimondi, P.; Field, R.Clive; Phinney, N.; Ross, M.C.; Slaton, T.; Traller, R.; /SLAC

    2011-08-26

    At the Interaction Point (IP) of the SLC Final Focus, beam-beam deflection scans routinely provide a measurement of the sum in quadrature of the electron and positron transverse beam sizes, but no information on the individual beam sizes. During the 1996 SLC run, an upgrade to the Final Focus beam position monitor system allowed a first measurement of the absolute beam energy loss of both beams on each step of the deflection scan. A fit to the energy loss distributions of the two beams provides a measurement not only of the individual transverse beam sizes at the IP but also of the individual bunch lengths.

  6. Energy Production Demonstrator for Megawatt Proton Beams

    SciTech Connect

    Pronskikh, Vitaly S.; Mokhov, Nikolai V.; Novitski, Igor; Tyutyunnikov, Sergey I.

    2014-07-16

    A preliminary study of the Energy Production Demonstrator (EPD) concept - a solid heavy metal target irradiated by GeV-range intense proton beams and producing more energy than consuming - is carried out. Neutron production, fission, energy deposition, energy gain, testing volume and helium production are simulated with the MARS15 code for tungsten, thorium, and natural uranium targets in the proton energy range 0.5 to 120 GeV. This study shows that the proton energy range of 2 to 4 GeV is optimal for both a natU EPD and the tungsten-based testing station that would be the most suitable for proton accelerator facilities. Conservative estimates, not including breeding and fission of plutonium, based on the simulations suggest that the proton beam current of 1 mA will be sufficient to produce 1 GW of thermal output power with the natU EPD while supplying < 8% of that power to operate the accelerator. The thermal analysis shows that the concept considered has a problem due to a possible core meltdown; however, a number of approaches (a beam rastering, in first place) are suggested to mitigate the issue. The efficiency of the considered EPD as a Materials Test Station (MTS) is also evaluated in this study.

  7. Beamed-Energy Propulsion (BEP) Study

    NASA Technical Reports Server (NTRS)

    George, Patrick; Beach, Raymond

    2012-01-01

    The scope of this study was to (1) review and analyze the state-of-art in beamed-energy propulsion (BEP) by identifying potential game-changing applications, (2) formulate a roadmap of technology development, and (3) identify key near-term technology demonstrations to rapidly advance elements of BEP technology to Technology Readiness Level (TRL) 6. The two major areas of interest were launching payloads and space propulsion. More generally, the study was requested and structured to address basic mission feasibility. The attraction of beamed-energy propulsion (BEP) is the potential for high specific impulse while removing the power-generation mass. The rapid advancements in high-energy beamed-power systems and optics over the past 20 years warranted a fresh look at the technology. For launching payloads, the study concluded that using BEP to propel vehicles into space is technically feasible if a commitment to develop new technologies and large investments can be made over long periods of time. From a commercial competitive standpoint, if an advantage of beamed energy for Earth-to-orbit (ETO) is to be found, it will rest with smaller, frequently launched payloads. For space propulsion, the study concluded that using beamed energy to propel vehicles from low Earth orbit to geosynchronous Earth orbit (LEO-GEO) and into deep space is definitely feasible and showed distinct advantages and greater potential over current propulsion technologies. However, this conclusion also assumes that upfront infrastructure investments and commitments to critical technologies will be made over long periods of time. The chief issue, similar to that for payloads, is high infrastructure costs.

  8. Multipass Beam Breakup in Energy Recovery Linacs

    SciTech Connect

    Eduard Pozdeyev; Christopher Tennant; Joseph Bisognano; M Sawamura; R. Hajima; T.I. Smith

    2005-03-19

    This paper is a compilation of several presentations on multipass beam breakup (BBU) in energy recovery linacs (ERL) given at the 32nd Advanced ICFA Beam Workshop on ERLs. The goal of this paper is to summarize the progress achieved in analytical, numerical, and experimental studies of the instability and outline available and proposed BBU mitigation techniques. In this paper, a simplified theory of multipass BBU in recirculating linacs is presented. Several BBU suppression techniques and their working principles are discussed. The paper presents an overview of available BBU codes. Results of experimental studies of multipass BBU at the Jefferson Laboratory (JLab) FEL Upgrade are described.

  9. Overview of the APT high-energy beam transport and beam expanders

    SciTech Connect

    Shafer, R.E.; Blind, B.; Gray, E.R.

    1997-08-01

    The APT high energy beam transport (HEBT) and beam expanders convey the 1700-MeV, 100-mA cw proton beam from the linac to the tritium target/blanket assembly, or a tuning beam stop. The HEBT includes extensive beam diagnostics, collimators, and beam jitter correction, to monitor and control the 170-MW beam prior to expansion. A zero-degree beamline conveys the beam to the beam stop, and an achromatic bend conveys the beam to the tritium production target. Nonlinear beam expanders make use of higher-order multipole magnets and dithering dipoles to expand the beam to a uniform-density, 16-cm wide by 160-cm high rectangular profile on the tritium-production target. The overall optics design will be reviewed, and beam simulations will be presented.

  10. Inspection applications with higher electron beam energies

    NASA Astrophysics Data System (ADS)

    Norman, D. R.; Jones, J. L.; Yoon, W. Y.; Haskell, K. J.; Sterbentz, J. W.; Zabriskie, J. M.; Hunt, A. W.; Harmon, F.; Kinlaw, M. T.

    2005-12-01

    The Idaho National Laboratory has developed prototype shielded nuclear material detection systems based on pulsed photonuclear assessment (PPA) techniques for the inspection of cargo containers. During this work, increased nuclear material detection capabilities have been demonstrated at higher electron beam energies than those allowed by federal regulations for cargo inspection. This paper gives a general overview of a nuclear material detection system, the PPA technique and discusses the benefits of using these higher energies. This paper also includes a summary of the numerical and test results from LINAC operations up to 24 MeV and discusses some of the federal energy limitations associated with cargo inspection.

  11. Space Experiments to Advance Beamed Energy Propulsion

    NASA Astrophysics Data System (ADS)

    Johansen, Donald G.

    2010-05-01

    High power microwave sources are now available and usable, with modification, or beamed energy propulsion experiments in space. As output windows and vacuum seals are not needed space is a natural environment for high power vacuum tubes. Application to space therefore improves reliability and performance but complicates testing and qualification. Low power communications satellite devices (TWT, etc) have already been through the adapt-to-space design cycle and this history is a useful pathway for high power devices such as gyrotrons. In this paper, space experiments are described for low earth orbit (LEO) and lunar environment. These experiments are precursors to space application for beamed energy propulsion using high power microwaves. Power generation and storage using cryogenic systems are important elements of BEP systems and also have an important role as part of BEP experiments in the space environment.

  12. An Exploration Perspective of Beamed Energy Propulsion

    NASA Technical Reports Server (NTRS)

    Cole, John W.

    2007-01-01

    The Vision for Exploration is currently focused on flying the Space Shuttle safely to complete our Space Station obligations, retiring the Shuttle in 2010, then returning humans to the Moon and learning how to proceed to Mars and beyond. The NASA budget still includes funds for science and aeronautics but the primary focus is on human exploration. Fiscal constraints have led to pursuing exploration vehicles that use heritage hardware, particularly existing boosters and engines, with the minimum modifications necessary to satisfy mission requirements. So, pursuit of immature technologies is not currently affordable by NASA. Beamed energy is one example of an immature technology, from a human exploration perspective, that may eventually provide significant benefits for human exploration of space, but likely not in the near future. Looking to the more distant future, this paper will examine some of the criteria that must be achieved by beamed energy propulsion to eventually contribute to human exploration of the solar system. The analysis focuses on some of the implications of increasing the payload fraction of a launch vehicle, with a quick look at trans-lunar injection. As one would expect, there is potential for benefit, and there are concerns. The analysis concludes with an assessment of the Technology Readiness Level (TRL) for some beamed energy propulsion components, indicating that TRL 2 is close to being completed.

  13. An Exploration Perspective of Beamed Energy Propulsion

    SciTech Connect

    Cole, John

    2008-04-28

    The Vision for Exploration is currently focused on flying the Space Shuttle safely to complete our Space Station obligations, retiring the Shuttle in 2010, then returning humans to the Moon and learning how to proceed to Mars and beyond. The NASA budget still includes funds for science and aeronautics but the primary focus is on human exploration. Fiscal constraints have led to pursuing exploration vehicles that use heritage hardware, particularly existing boosters and engines, with the minimum modifications necessary to satisfy mission requirements. So, pursuit of immature technologies is not currently affordable by NASA. Beamed energy is one example of an immature technology, from a human exploration perspective, that may eventually provide significant benefits for human exploration of space, but likely not in the near future. Looking to the more distant future, this paper will examine some of the criteria that must be achieved by beamed energy propulsion to eventually contribute to human exploration of the solar system. The analysis focuses on some of the implications of increasing the payload fraction of a launch vehicle, with a quick look at trans-lunar injection. As one would expect, there is potential for benefit, and there are concerns. The analysis concludes with an assessment of the Technology Readiness Level (TRL) for some beamed energy propulsion components, indicating that TRL 2 is close to being completed.

  14. An Exploration Perspective of Beamed Energy Propulsion

    NASA Astrophysics Data System (ADS)

    Cole, John

    2008-04-01

    The Vision for Exploration is currently focused on flying the Space Shuttle safely to complete our Space Station obligations, retiring the Shuttle in 2010, then returning humans to the Moon and learning how to proceed to Mars and beyond. The NASA budget still includes funds for science and aeronautics but the primary focus is on human exploration. Fiscal constraints have led to pursuing exploration vehicles that use heritage hardware, particularly existing boosters and engines, with the minimum modifications necessary to satisfy mission requirements. So, pursuit of immature technologies is not currently affordable by NASA. Beamed energy is one example of an immature technology, from a human exploration perspective, that may eventually provide significant benefits for human exploration of space, but likely not in the near future. Looking to the more distant future, this paper will examine some of the criteria that must be achieved by beamed energy propulsion to eventually contribute to human exploration of the solar system. The analysis focuses on some of the implications of increasing the payload fraction of a launch vehicle, with a quick look at trans-lunar injection. As one would expect, there is potential for benefit, and there are concerns. The analysis concludes with an assessment of the Technology Readiness Level (TRL) for some beamed energy propulsion components, indicating that TRL 2 is close to being completed.

  15. Overview of the APT High-Energy Beam Transport and Beam Expanders

    NASA Astrophysics Data System (ADS)

    Shafer, R. E.; Blind, B.; Gray, E. R.; Gilpatrick, J. D.; Barlow, D.; Lawrence, G. P.

    1997-05-01

    The APT high energy beam transport (HEBT) and beam expanders transport the 1700-MeV, 100-mA cw proton beam from the linac to any of three end stations. The HEBT includes extensive beam diagnostics, collimators, and dejitter correction, to monitor and control the 170-MW proton beam prior to expansion. One zero-degree beam line and two achromatic bends transport the beam to one of three beam expanders. These nonlinear beam expanders, making use of higher order multipole magnets and dithering dipoles, expand the beam to a uniform density, 16-cm wide by 160-cm high rectangular profile on the tritium-production targets. The overall optics design will be reviewed, and beam simulations will be presented.

  16. Energy compensation of slow extracted beams with RF acceleration

    NASA Astrophysics Data System (ADS)

    Fujimoto, Tetsuya; Souda, Hikaru; Torikoshi, Masami; Kanai, Tatsuaki; Yamada, Satoru; Noda, Koji

    2016-03-01

    In a conventional carbon-ion radiotherapy facility, a carbon-ion beam is typically accelerated up to an optimum energy, slowly extracted from a synchrotron ring by a resonant slow extraction method, and ultimately delivered to a patient through a beam-delivery system. At Japan's Gunma University, a method employing slow-beam extraction along with beam-acceleration has been adopted. This method slightly alters the extracted-beam's energy owing to the acceleration component of the process, which subsequently results in a residual-range variation of approximately 2 mm in water-equivalent length. However, this range variation does not disturb a distal dose distribution with broad-beam methods such as the single beam-wobbling method. With the pencil-beam 3D scanning method, however, such a range variation disturbs a distal dose distribution because the variation is comparable to slice thickness. Therefore, for pencil-beam 3D scanning, an energy compensation method for a slow extracted beam is proposed in this paper. This method can compensate for the aforementioned energy variances by controlling net energy losses through a rotatable energy absorber set fixed between the synchrotron exit channel and the isocenter. Experimental results demonstrate that beam energies can be maintained constant, as originally hypothesized. Moreover, energy-absorber positions were found to be significantly enhanced by optimizing beam optics for reducing beam-size growth by implementation of the multiple-scattering effect option.

  17. Low-energy beam transport studies supporting the Spallation Neutron Source 1-MW beam operationa

    SciTech Connect

    Han, Baoxi; Kalvas, T.; Tarvainen, O.; Welton, Robert F; Murray Jr, S N; Pennisi, Terry R; Santana, Manuel; Stockli, Martin P

    2012-01-01

    The H- injector consisting of a cesium enhanced RF-driven ion source and a 2-lens electrostatic low-energy beam transport (LEBT) system supports the Spallation Neutron Source 1-MW beam operation with ~38 mA beam current in the linac at 60 Hz with a pulse length of up to ~1.0 ms. In this work, two important issues associated with the low-energy beam transport are discussed: 1) inconsistent dependence of the post-RFQ beam current on the ion source tilt angle, and 2) high power beam losses on the LEBT electrodes under some off-nominal conditions compromising their reliability.

  18. Beam lifetime and limitations during low-energy RHIC operation

    SciTech Connect

    Fedotov, A.V.; Bai, M.; Blaskiewicz, M.; Fischer, W.; Kayran, D.; Montag, C.; Satogata, T.; Tepikian, S.; Wang, G.

    2011-03-28

    The low-energy physics program at the Relativistic Heavy Ion Collider (RHIC), motivated by a search for the QCD phase transition critical point, requires operation at low energies. At these energies, large nonlinear magnetic field errors and large beam sizes produce low beam lifetimes. A variety of beam dynamics effects such as Intrabeam Scattering (IBS), space charge and beam-beam forces also contribute. All these effects are important to understand beam lifetime limitations in RHIC at low energies. During the low-energy RHIC physics run in May-June 2010 at beam {gamma} = 6.1 and {gamma} = 4.1, gold beam lifetimes were measured for various values of space-charge tune shifts, transverse acceptance limitation by collimators, synchrotron tunes and RF voltage. This paper summarizes our observations and initial findings.

  19. Ion beam energy spectrum calculation via dosimetry data deconvolution.

    SciTech Connect

    Harper-Slaboszewicz, Victor Jozef; Sharp, Andrew Clinton

    2010-10-01

    The energy spectrum of a H{sup +} beam generated within the HERMES III accelerator is calculated from dosimetry data to refine future experiments. Multiple layers of radiochromic film are exposed to the beam. A graphic user interface was written in MATLAB to align the film images and calculate the beam's dose depth profile. Singular value regularization is used to stabilize the unfolding and provide the H{sup +} beam's energy spectrum. The beam was found to have major contributions from 1 MeV and 8.5 MeV protons. The HERMES III accelerator is typically used as a pulsed photon source to experimentally obtain photon impulse response of systems due to high energy photons. A series of experiments were performed to explore the use of Hermes III to generate an intense pulsed proton beam. Knowing the beam energy spectrum allows for greater precision in experiment predictions and beam model verification.

  20. Longitudinal Density Modulation and Energy Conversion in Intense Beams

    SciTech Connect

    Harris, J; Neumann, J; Tian, K; O'Shea, P

    2006-02-17

    Density modulation of charged particle beams may occur as a consequence of deliberate action, or may occur inadvertently because of imperfections in the particle source or acceleration method. In the case of intense beams, where space charge and external focusing govern the beam dynamics, density modulation may under some circumstances be converted to velocity modulation, with a corresponding conversion of potential energy to kinetic energy. Whether this will occur depends on the properties of the beam and the initial modulation. This paper describes the evolution of discrete and continuous density modulations on intense beams, and discusses three recent experiments related to the dynamics of density-modulated electron beams.

  1. High Energy Polarized e+e‑ Beams

    NASA Astrophysics Data System (ADS)

    Shatunov, Yu.; Koop, I.; Otboev, A.; Mane, S.

    2016-02-01

    Recently, the wide discussion about Higgs-factory design again returns to problem of high energy polarized electrons and positrons. It’s good known the radiative beam polarization at LEP-collider. It was obtained after spin resonance suppression at Z0 pick, but didn’t appear at energies above 70 GeV due to an enhancement of unavoidable depolarization effects. We examine in this paper various ideas for radiative polarization at TLEP/FCC-ee and formulate some estimates for the polarization buildup time and the asymptotic polarization. Using wigglers, a useful degree of polarization (for energy calibration), with a time constant of about 1 h, may be possible up to the threshold of W pair production. At higher energies such as the threshold of Higgs production, attaining a useful level of polarization may be difficult in a planar ring. With Siberian Snakes, wigglers and some imagination, polarization of reasonable magnitude, with a reasonable time constant (of not more than about 1 h), may be achievable at very high energies.

  2. Advanced energy conversion concept for beamed-energy propulsion

    NASA Astrophysics Data System (ADS)

    Myrabo, Leik N.

    1987-08-01

    Basic research was performed on an innovative power conversion concept for trans atmospheric, beamed energy propulsion: a new class of External Surface Impulse (ESI) thrusters. This advanced thruster principle could be used for atmospheric VTOL, high acceleration, and lateral flight (e.g., short-term cruise) propulsion of Single-Stage-To-Orbit (SSTO) beam-powered shuttlecraft of the next century. Three classes of ESI thrusters were initially examined: (1) simple thermal, (2) electrostatic, and (3) electromagnetic. Beam power wavelengths from 10 cm (microwave) to 0.3 micron (laser) were considered. The subsequent effort concentrated on the simple thermal repetitively-pulsed ESI thrusters, energized with laser power and using air as the working fluid. Laser frequencies were selected because of the relative wealth of experimental data and theoretical research on laser impulse coupling existing in the literature. The first year analytical effort has proven conclusively that such an engine can deliver high levels of thrust-to-beam-power at liftoff (e.g., at least an order of magnitude greater than beam-powered hydrogen-fueled rockets), with infinite specific impulse (decreased only, perhaps, by ablation of the thruster surface). Later along an orbital trajectory, the primary propulsion function would transition to other modes; upon leaving the atmosphere, the SSTO vehicle would continue in a pure rocket mode.

  3. Energy Beam Highways Through the Skies

    NASA Technical Reports Server (NTRS)

    Myrabo, Leik N.

    1996-01-01

    The emergence of Energy Beam Flight Transportation Systems could dramatically change the way we travel in the 21st Century. A framework for formulating 'Highways of Light' and the top level architectures that invoke radically new Space Power Grid infrastructure, are introduced. Basically, such flight systems, hereafter called Lightcraft, would employ off-board energy beam sources (either laser or microwave) to energize on-board dependent 'motors' -- instead of the traditional autonomous 'engines' with their on-board energy sources (e.g., chemical fuels). Extreme reductions in vehicle dry mass appear feasible with the use of off-board power and a high degree of on-board artificial intelligence. Such vehicles may no longer need airports for refueling (since they require no propellant), and could possibly pick up travelers at their homes -- before motoring over to one of many local boost stations, for the flight out. With off-board power, hyper-energetic acceleration performance and boost-glide trajectories become feasible. Hypersonic MS airbreathing propulsion can enable boosts up to twice escape velocity, which will cut trip times to the moon down to 5.5 hours. The predominant technological, environmental and social factors that will result from such transportation systems will be stressed. This presentation first introduces the remote source siting options for the space power system infrastructure, and then provides three representative laser/microwave Lightcraft options (derived from historical Case Studies): i.e., 'Acorn', 'Toy Top', and 'Disc.' Next the gamut of combined-cycle engine options developed for these Lightcraft are examined -- to illuminate the 'emerging technologies' that must be harnessed to produce flight hardware. Needed proof-of concept experiments are identified, along with the Macro-Level Issues that can springboard these revolutionary concepts into hardware reality.

  4. Exact and geometrical optics energy trajectories in twisted beams

    NASA Astrophysics Data System (ADS)

    Berry, M. V.; McDonald, K. T.

    2008-03-01

    Energy trajectories, that is, integral curves of the Poynting (current) vector, are calculated for scalar Bessel and Laguerre-Gauss beams carrying orbital angular momentum. The trajectories for the exact waves are helices, winding on cylinders for Bessel beams and hyperboloidal surfaces for Laguerre-Gauss beams. In the geometrical optics approximations, the trajectories for both types of beam are overlapping families of straight skew rays lying on hyperboloidal surfaces; the envelopes of the hyperboloids are the caustics: a cylinder for Bessel beams and two hyperboloids for Laguerre-Gauss beams.

  5. Use of incomplete energy recovery for the energy compression of large energy spread charged particle beams

    DOEpatents

    Douglas, David R.; Benson, Stephen V.

    2007-01-23

    A method of energy recovery for RF-base linear charged particle accelerators that allows energy recovery without large relative momentum spread of the particle beam involving first accelerating a waveform particle beam having a crest and a centroid with an injection energy E.sub.o with the centroid of the particle beam at a phase offset f.sub.o from the crest of the accelerating waveform to an energy E.sub.full and then recovering the beam energy centroid a phase f.sub.o+Df relative to the crest of the waveform particle beam such that (E.sub.full-E.sub.o)(1+cos(f.sub.o+Df))>dE/2 wherein dE=the full energy spread, dE/2=the full energy half spread and Df=the wave form phase distance.

  6. Electron beam energy QA - a note on measurement tolerances.

    PubMed

    Meyer, Juergen; Nyflot, Matthew J; Smith, Wade P; Wottoon, Landon S; Young, Lori; Yang, Fei; Kim, Minsun; Hendrickson, Kristi R G; Ford, Eric; Kalet, Alan M; Cao, Ning; Dempsey, Claire; Sandison, George A

    2016-01-01

    Monthly QA is recommended to verify the constancy of high-energy electron beams generated for clinical use by linear accelerators. The tolerances are defined as 2%/2 mm in beam penetration according to AAPM task group report 142. The practical implementation is typically achieved by measuring the ratio of readings at two different depths, preferably near the depth of maximum dose and at the depth corresponding to half the dose maximum. Based on beam commissioning data, we show that the relationship between the ranges of energy ratios for different electron energies is highly nonlinear. We provide a formalism that translates measurement deviations in the reference ratios into change in beam penetration for electron energies for six Elekta (6-18 MeV) and eight Varian (6-22 MeV) electron beams. Experimental checks were conducted for each Elekta energy to compare calcu-lated values with measurements, and it was shown that they are in agreement. For example, for a 6 MeV beam a deviation in the measured ionization ratio of ± 15% might still be acceptable (i.e., be within ± 2 mm), whereas for an 18 MeV beam the corresponding tolerance might be ± 6%. These values strongly depend on the initial ratio chosen. In summary, the relationship between differences of the ionization ratio and the corresponding beam energy are derived. The findings can be translated into acceptable tolerance values for monthly QA of electron beam energies. PMID:27074488

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

    NASA Astrophysics Data System (ADS)

    Kumar, Sarvesh; Mandal, A.

    2016-04-01

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

  8. Acoustical problems in high energy pulsed E-beams lasers

    NASA Technical Reports Server (NTRS)

    Horton, T. E.; Wylie, K. F.

    1976-01-01

    During the pulsing of high energy, CO2, electron beam lasers, a significant fraction of input energy ultimately appears as acoustical disturbances. The magnitudes of these disturbances were quantified by computer analysis. Acoustical and shock impedance data are presented on materials (Rayleigh type) which show promise in controlling acoustical disturbance in E-beam systems.

  9. Electron beam directed energy device and methods of using same

    DOEpatents

    Retsky, Michael W.

    2007-10-16

    A method and apparatus is disclosed for an electron beam directed energy device. The device consists of an electron gun with one or more electron beams. The device includes one or more accelerating plates with holes aligned for beam passage. The plates may be flat or preferably shaped to direct each electron beam to exit the electron gun at a predetermined orientation. In one preferred application, the device is located in outer space with individual beams that are directed to focus at a distant target to be used to impact and destroy missiles. The aimings of the separate beams are designed to overcome Coulomb repulsion. A method is also presented for directing the beams to a target considering the variable terrestrial magnetic field. In another preferred application, the electron beam is directed into the ground to produce a subsurface x-ray source to locate and/or destroy buried or otherwise hidden objects including explosive devices.

  10. Absolute beam energy measurements in e+e- storage rings

    NASA Astrophysics Data System (ADS)

    Placidi, M.

    1997-01-01

    The CERN Large Electron Positron collider (LEP) was dedicated to the measurement of the mass Mz and the width Γz of the Z0 resonance during the LEP1 phase which terminated in September 1995. The Storage Ring operated in Energy Scan mode during the 1993 and 1995 physics runs by choosing the beam energy Ebeam to correspond to a center-of-mass (CM) energy at the interaction points (IPs) ECMpeak±1762 MeV. After a short review of the techniques usually adopted to set and control the beam energy, this paper describes in more detail two methods adopted at LEP for precise beam energy determination that are essential to reduce the contribution to the systematic error on Mz and Γz. The positron beam momentum was initially determined at the 20-GeV injection energy by measuring the speed of a less relativistic proton beam circulating on the same orbit, taking advantage of the unique opportunity to inject two beams into the LEP at short time intervals. The positron energy at the Z0 peak was in this case derived by extrapolation. Once transverse polarization became reproducible, the Resonant Depolarization (RD) technique was implemented at the Z0 operating energies, providing a ⩽2×10-5 instantaneous accuracy. RD Beam Energy Calibration has been adopted during the LEP Energy Scan campaigns as well as in Accelerator Physics runs for accurate measurement of machine parameters.

  11. Laser-beam zooming to mitigate crossed-beam energy losses in direct-drive implosions.

    PubMed

    Igumenshchev, I V; Froula, D H; Edgell, D H; Goncharov, V N; Kessler, T J; Marshall, F J; McCrory, R L; McKenty, P W; Meyerhofer, D D; Michel, D T; Sangster, T C; Seka, W; Skupsky, S

    2013-04-01

    Spherically symmetric direct-drive-ignition designs driven by laser beams with a focal-spot size nearly equal to the target diameter suffer from energy losses due to crossed-beam energy transfer (CBET). Significant reduction of CBET and improvements in implosion hydrodynamic efficiency can be achieved by reducing the beam diameter. Narrow beams increase low-mode perturbations of the targets because of decreased illumination uniformity that degrades implosion performance. Initiating an implosion with nominal beams (equal in size to the target diameter) and reducing the beam diameter by ∼ 30%-40% after developing a sufficiently thick target corona, which smooths the perturbations, mitigate CBET while maintaining low-mode target uniformity in ignition designs with a fusion gain ≫ 1. PMID:25166997

  12. Prototyping of beam position monitor for medium energy beam transport section of RAON heavy ion accelerator

    NASA Astrophysics Data System (ADS)

    Jang, Hyojae; Jin, Hyunchang; Jang, Ji-Ho; Hong, In-Seok

    2016-02-01

    A heavy ion accelerator, RAON is going to be built by Rare Isotope Science Project in Korea. Its target is to accelerate various stable ions such as uranium, proton, and xenon from electron cyclotron resonance ion source and some rare isotopes from isotope separation on-line. The beam shaping, charge selection, and modulation should be applied to the ions from these ion sources because RAON adopts a superconducting linear accelerator structure for beam acceleration. For such treatment, low energy beam transport, radio frequency quadrupole, and medium energy beam transport (MEBT) will be installed in injector part of RAON accelerator. Recently, development of a prototype of stripline beam position monitor (BPM) to measure the position of ion beams in MEBT section is under way. In this presentation, design of stripline, electromagnetic (EM) simulation results, and RF measurement test results obtained from the prototyped BPM will be described.

  13. Low-energy beam transport studies supporting the spallation neutron source 1-MW beam operation

    SciTech Connect

    Han, B. X.; Welton, R. F.; Murray, S. N. Jr.; Pennisi, T. R.; Santana, M.; Stockli, M. P.; Kalvas, T.; Tarvainen, O.

    2012-02-15

    The H{sup -} injector consisting of a cesium enhanced RF-driven ion source and a 2-lens electrostatic low-energy beam transport (LEBT) system supports the spallation neutron source 1 MW beam operation with {approx}38 mA beam current in the linac at 60 Hz with a pulse length of up to {approx}1.0 ms. In this work, two important issues associated with the low-energy beam transport are discussed: (1) inconsistent dependence of the post-radio frequency quadrupole accelerator beam current on the ion source tilt angle and (2) high power beam losses on the LEBT electrodes under some off-nominal conditions compromising their reliability.

  14. Low-energy beam transport studies supporting the spallation neutron source 1-MW beam operation

    SciTech Connect

    Kalvas, T.; Welton, Robert F; Pennisi, Terry R

    2012-01-01

    The H{sup -} injector consisting of a cesium enhanced RF-driven ion source and a 2-lens electrostatic low-energy beam transport (LEBT) system supports the spallation neutron source 1 MW beam operation with {approx}38 mA beam current in the linac at 60 Hz with a pulse length of up to {approx}1.0 ms. In this work, two important issues associated with the low-energy beam transport are discussed: (1) inconsistent dependence of the post-radio frequency quadrupole accelerator beam current on the ion source tilt angle and (2) high power beam losses on the LEBT electrodes under some off-nominal conditions compromising their reliability.

  15. Prototyping of beam position monitor for medium energy beam transport section of RAON heavy ion accelerator.

    PubMed

    Jang, Hyojae; Jin, Hyunchang; Jang, Ji-Ho; Hong, In-Seok

    2016-02-01

    A heavy ion accelerator, RAON is going to be built by Rare Isotope Science Project in Korea. Its target is to accelerate various stable ions such as uranium, proton, and xenon from electron cyclotron resonance ion source and some rare isotopes from isotope separation on-line. The beam shaping, charge selection, and modulation should be applied to the ions from these ion sources because RAON adopts a superconducting linear accelerator structure for beam acceleration. For such treatment, low energy beam transport, radio frequency quadrupole, and medium energy beam transport (MEBT) will be installed in injector part of RAON accelerator. Recently, development of a prototype of stripline beam position monitor (BPM) to measure the position of ion beams in MEBT section is under way. In this presentation, design of stripline, electromagnetic (EM) simulation results, and RF measurement test results obtained from the prototyped BPM will be described. PMID:26932088

  16. H{sup -} beam transport experiments in a solenoid low energy beam transport

    SciTech Connect

    Gabor, C.; Back, J. J.; Faircloth, D. C.; Lawrie, S. R.; Letchford, A. P.; Izaola, Z.

    2012-02-15

    The Front End Test Stand (FETS) is located at Rutherford Appleton Laboratory and aims for a high current, fast chopped 3 MeV H{sup -} ion beam suitable for future high power proton accelerators like ISIS upgrade. The main components of the front end are the Penning ion source, a low energy beam transport line, an radio-frequency quadrupole (RFQ) and a medium energy beam transport (MEBT) providing also a chopper section and rebuncher. FETS is in the stage of commissioning its low energy beam transport (LEBT) line consisting of three solenoids. The LEBT has to transport an H{sup -} high current beam (up to 60 mA) at 65 keV. This is the injection energy of the beam into the RFQ. The main diagnostics are slit-slit emittance scanners for each transversal plane. For optimizing the matching to the RFQ, experiments have been performed with a variety of solenoid settings to better understand the actual beam transport. Occasionally, source parameters such as extractor slit width and beam energy were varied as well. The paper also discusses simulations based on these measurements.

  17. Energy transfer between laser beams crossing in ignition hohlraums

    SciTech Connect

    Michel, P; Divol, L; Williams, E A; Thomas, C A; Callahan, D A; Weber, S; Haan, S W; Salmonson, J D; Dixit, S; Hinkel, D E; Edwards, M J; MacGowan, B J; Lindl, J D; Glenzer, S H; Suter, L J

    2008-10-03

    The full scale modeling of power transfer between laser beams crossing in plasmas is presented. A new model was developed, allowing calculation of the propagation and coupling of pairs of laser beams with their associated plasma wave in three dimensions. The full laser beam smoothing techniques used in ignition experiments are modeled, and their effects on crossed-beam energy transfer is investigated. A shift in wavelength between the beams can move the instability off resonance and reduce the transfer, hence preserving the symmetry of the capsule implosion.

  18. Ion Beam Energy Dependant Study of Nanopore Sculpting

    NASA Astrophysics Data System (ADS)

    Ledden, Brad

    2005-03-01

    Experiments show that ion beams of various energies (1keV, 3keV, and 5keV) can be used to controllably ``sculpt'' nanoscale features in silicon nitride films using a feedback controlled ion beam sculpting apparatus. We report on nanopore ion beam sculpting effects that depend on inert gas ion beam energy. We show that: (1) all ion beam energies enable single nanometer control of structural dimensions in nanopores; (2) the ion beam energies above show similar ion beam flux dependence of nanopore formation; (3) the thickness of nanopores differs depending on ion beam energy. Computer simulations (with SRIM and TRIM) and an ``adatom'' surface diffusion model are employed to explain the dynamics of nanoscale dimension change by competing sputtering and surface mass transport processes induced by different ion beam irradiation. These experiments and theoretical work reveal the surface atomic transport phenomena in a quantitative way that allows the extraction of parameters such as the adatom surface diffusion coefficients and average travel distances.

  19. Study on electron beam in a low energy plasma focus

    SciTech Connect

    Khan, Muhammad Zubair; Ling, Yap Seong; San, Wong Chiow

    2014-03-05

    Electron beam emission was investigated in a low energy plasma focus device (2.2 kJ) using copper hollow anode. Faraday cup was used to estimate the energy of the electron beam. XR100CR X-ray spectrometer was used to explore the impact of the electron beam on the target observed from top-on and side-on position. Experiments were carried out at optimized pressure of argon gas. The impact of electron beam is exceptionally notable with two different approaches using lead target inside hollow anode in our plasma focus device.

  20. The energy stabilization for the SLC scavenger beam

    SciTech Connect

    Hsu, Ian; Browne, M.; Himel, T.; Humphrey, R.; Jobe, K.; Ross, M.; Pellegrin, J.L.; Seeman, J.

    1990-08-01

    The energy of the SLC scavenger beam which is used to produce positrons must be carefully maintained so that the beam can be transported through the collimators in the dispersive region of the extraction line which leads from the Linac to the positron target. A feedforward control loop has been developed to compensate the energy fluctuations due to the beam intensity fluctuations. The loop detects the beam intensities in the damping rings and then calculates how much energy needs to be compensated due to beam loading effects. The energy is corrected by adjusting the acceleration phases of two sets of klystrons right before the extraction. Because there is feedback loop using the same controls, their interaction needs to be carefully treated. This paper presents an overview of the feedforward algorithms. 3 figs.

  1. Linac4 low energy beam measurements with negative hydrogen ions

    SciTech Connect

    Scrivens, R. Bellodi, G.; Crettiez, O.; Dimov, V.; Gerard, D.; Granemann Souza, E.; Guida, R.; Hansen, J.; Lallement, J.-B.; Lettry, J.; Lombardi, A.; Midttun, Ø.; Pasquino, C.; Raich, U.; Riffaud, B.; Roncarolo, F.; Valerio-Lizarraga, C. A.; Wallner, J.; Yarmohammadi Satri, M.; Zickler, T.

    2014-02-15

    Linac4, a 160 MeV normal-conducting H{sup −} linear accelerator, is the first step in the upgrade of the beam intensity available from the LHC proton injectors at CERN. The Linac4 Low Energy Beam Transport (LEBT) line from the pulsed 2 MHz RF driven ion source, to the 352 MHz RFQ (Radiofrequency Quadrupole) has been built and installed at a test stand, and has been used to transport and match to the RFQ a pulsed 14 mA H{sup −} beam at 45 keV. A temporary slit-and-grid emittance measurement system has been put in place to characterize the beam delivered to the RFQ. In this paper a description of the LEBT and its beam diagnostics is given, and the results of beam emittance measurements and beam transmission measurements through the RFQ are compared with the expectation from simulations.

  2. Piezoelectric energy harvester having planform-tapered interdigitated beams

    DOEpatents

    Kellogg, Rick A.; Sumali, Hartono

    2011-05-24

    Embodiments of energy harvesters have a plurality of piezoelectric planform-tapered, interdigitated cantilevered beams anchored to a common frame. The plurality of beams can be arranged as two or more sets of beams with each set sharing a common sense mass affixed to their free ends. Each set thus defined being capable of motion independent of any other set of beams. Each beam can comprise a unimorph or bimorph piezoelectric configuration bonded to a conductive or non-conductive supporting layer and provided with electrical contacts to the active piezoelectric elements for collecting strain induced charge (i.e. energy). The beams are planform tapered along the entirety or a portion of their length thereby increasing the effective stress level and power output of each piezoelectric element, and are interdigitated by sets to increase the power output per unit volume of a harvester thus produced.

  3. Precision measurements of the SLC (Stanford Linear Collider) beam energy

    SciTech Connect

    Kent, J.; King, M.; Von Zanthier, C.; Watson, S.; Levi, M.; Rouse, F.; Bambade, P.; Erickson, R.; Jung, C.K.; Nash, J.

    1989-03-01

    A method of precisely determining the beam energy in high energy linear colliders has been developed using dipole spectrometers and synchrotron radiation detectors. Beam lines implementing this method have been installed on the Stanford Linear Collider. An absolute energy measurement with an accuracy of better than deltaE/E = 5 /times/ 10/sup /minus/4/ can be achieved on a pulse-to-pulse basis. The operation of this system will be described. 4 refs., 3 figs., 1 tab.

  4. Propagation of high-energy laser beams through metallic aerosols

    SciTech Connect

    Zardecki, A.; Armstrong, R.L.

    1988-08-01

    By combining the results of the hydrodynamic code CON1D and the beam propagation code LASER, we investigate the propagation of high-energy laser beams through vaporizing metallic aerosols in the regime for which the plasma generation becomes important. An effective plasma absorption coefficient allows us to set up a coupled system of equations describing the system consisting of the beam and vapor. 14 refs., 5 figs.

  5. STAR results on strangeness production in beam energy scan program

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaoping

    2016-01-01

    We present the recent STAR results on the production of strange hadrons (K0s, ϕ, Λ, Ξ and Ω) in √sNN= 7.7 — 39 GeV Au+Au collisions in the RHIC beam energy scan program. We investigate the strangeness enhancement and strangeness equilibration as a function of beam energy and system size at RHIC. Nuclear modification factors and particle ratios will be highlighted. Implications on partonic vs. hadronic dynamics as a function of the beam energy will be discussed.

  6. Australian Science and Technology with Relevance to Beamed Energy Propulsion

    SciTech Connect

    Froning, H. David Jr

    2008-04-28

    Although Australia has no Beamed Energy Propulsion programs at the present time, it is accomplishing significant scientific and technological activity that is of potential relevance to Beamed Energy Propulsion (BEP). These activities include: continual upgrading and enhancement of the Woomera Test Facility, Which is ideal for development and test of high power laser or microwave systems and the flight vehicles they would propel; collaborative development and test, with the US and UK of hypersonic missiles that embody many features needed by beam-propelled flight vehicles; hypersonic air breathing propulsion systems that embody inlet-engine-nozzle features needed for beam-riding agility by air breathing craft; and research on specially conditioned EM fields that could reduce beamed energy lost during atmospheric propagation.

  7. Magnetic Stoppers on Single Beam Piezoelectric Energy Harvesting

    NASA Astrophysics Data System (ADS)

    Shih, Y. S.; Vasic, D.; Costa, F.; Wu, W. J.

    The single beam structure has been long used in piezoelectric energy harvesting to harvest the vibrations of the circumstances. One of the critical defects of the structure is its narrow band of operating frequency. Many propose mechanical stoppers, rigid or non-rigid, such as another beam, to create a non-linear broadband effect. Moreover, with a piecewise linear PEG (Piezoelectric Energy Generator), or a simple cantilever beam with one or two mechanical stoppers laid on its sides, the constant driven amplitude of the beam displacement can be enlarged by a perturbation. It is also proposed that the stoppers prevent the piezoelectric pad from cracking due to over deformation. However, from a long-term point of view, the impact of the beam on the stoppers can also cause faster fatigue of the beam body, not to mention the noise that will hinder its practical application which maybe apparatuses nearby human. Therefore, this paper proposes a magnetic pair to serve as the stoppers for piezoelectric beam, so as to perform similar effects of bandwidth enlargement and also the amplification using perturbation. With no actual contacts, the single beam can be well protected, but also eliminated from over bending by the magnets. By placing the magnets on a beam on each side of the main beam. The magnetic force, which is distance dependent, can provide a smoother feedback to the beam, giving a greater displacement in comparison to the mechanical stopper. Moreover, the characteristic of the beam output is altered so that there exists two peaking frequencies, depending on the design of the stopper beams.

  8. Beam energy tracking system on Optima XEx high energy ion implanter

    SciTech Connect

    David, Jonathan; Satoh, Shu; Wu Xiangyang; Geary, Cindy; Deluca, James

    2012-11-06

    The Axcelis Optima XEx high energy implanter is an RF linac-based implanter with 12 RF resonators for beam acceleration. Even though each acceleration field is an alternating, sinusoidal RF field, the well known phase-focusing principle produces a beam with a sharp quasi-monoenergetic energy spectrum. A magnetic energy filter after the linac further attenuates the low energy continuum in the energy spectrum often associated with RF acceleration. The final beam energy is a function of the phase and amplitude of the 12 resonators in the linac. When tuning a beam, the magnetic energy filter is set to the desired energy, and each linac parameter is tuned to maximize the transmission through the filter. Once a beam is set up, all the parameters are stored in a recipe, which can be easily tuned and has proven to be quite repeatable. The magnetic field setting of the energy filter selects the beam energy from the RF Linac accelerator, and in-situ verification of beam energy in addition to the magnetic energy filter setting has long been desired. An independent energy tracking system was developed for this purpose, using the existing electrostatic beam scanner as a deflector to construct an in-situ electrostatic energy analyzer. This paper will describe the system and performance of the beam energy tracking system.

  9. Cross-Beam Energy Transfer Driven by Incoherent Laser Beams with Frequency Detuning

    NASA Astrophysics Data System (ADS)

    Maximov, A.; Myatt, J. F.; Short, R. W.; Igumenshchev, I. V.; Seka, W.

    2015-11-01

    In the direct-drive method of the inertial confinement fusion (ICF), the coupling of laser energy to target plasmas is strongly influenced by the effect of cross-beam energy transfer (CBET) between multiple driving laser beams. The laser -plasma interaction (LPI) model of CBET is based on the nonparaxial laser light propagation coupled with the low-frequency ion-acoustic-domain plasma response. Common ion waves driven by multiple laser beams play a very important role in CBET. The effect of the frequency detuning (colors) in the driving laser beams is studied and it is shown to significantly reduce the level of common ion waves and therefore the level of CBET. The differences between the LPI-based CBET model and the ray-based CBET model used in hydrocodes are discussed. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.

  10. An online, energy-resolving beam profile detector for laser-driven proton beams.

    PubMed

    Metzkes, J; Zeil, K; Kraft, S D; Karsch, L; Sobiella, M; Rehwald, M; Obst, L; Schlenvoigt, H-P; Schramm, U

    2016-08-01

    In this paper, a scintillator-based online beam profile detector for the characterization of laser-driven proton beams is presented. Using a pixelated matrix with varying absorber thicknesses, the proton beam is spatially resolved in two dimensions and simultaneously energy-resolved. A thin plastic scintillator placed behind the absorber and read out by a CCD camera is used as the active detector material. The spatial detector resolution reaches down to ∼4 mm and the detector can resolve proton beam profiles for up to 9 proton threshold energies. With these detector design parameters, the spatial characteristics of the proton distribution and its cut-off energy can be analyzed online and on-shot under vacuum conditions. The paper discusses the detector design, its characterization and calibration at a conventional proton source, as well as the first detector application at a laser-driven proton source. PMID:27587116

  11. Micro-beam friction liner and method of transferring energy

    DOEpatents

    Mentesana, Charles

    2007-07-17

    A micro-beam friction liner adapted to increase performance and efficiency and reduce wear in a piezoelectric motor or actuator or other device using a traveling or standing wave to transfer energy in the form of torque and momentum. The micro-beam friction liner comprises a dense array of micro-beam projections having first ends fixed relative to a rotor and second ends projecting substantially toward a plurality of teeth of a stator, wherein the micro-beam projections are compressed and bent during piezoelectric movement of the stator teeth, thereby storing the energy, and then react against the stator teeth to convert the stored energy stored to rotational energy in the rotor.

  12. Method and apparatus for varying accelerator beam output energy

    DOEpatents

    Young, Lloyd M.

    1998-01-01

    A coupled cavity accelerator (CCA) accelerates a charged particle beam with rf energy from a rf source. An input accelerating cavity receives the charged particle beam and an output accelerating cavity outputs the charged particle beam at an increased energy. Intermediate accelerating cavities connect the input and the output accelerating cavities to accelerate the charged particle beam. A plurality of tunable coupling cavities are arranged so that each one of the tunable coupling cavities respectively connect an adjacent pair of the input, output, and intermediate accelerating cavities to transfer the rf energy along the accelerating cavities. An output tunable coupling cavity can be detuned to variably change the phase of the rf energy reflected from the output coupling cavity so that regions of the accelerator can be selectively turned off when one of the intermediate tunable coupling cavities is also detuned.

  13. Design study of low-energy beam transport for multi-charge beams at RAON

    NASA Astrophysics Data System (ADS)

    Bahng, Jungbae; Qiang, Ji; Kim, Eun-San

    2015-12-01

    The Rare isotope Accelerator Of Newness (RAON) at the Rare Isotope Science Project (RISP) is being designed to simultaneously accelerate beams with multiple charge states. It includes a driver superconducting (SC) linac for producing 200 MeV/u and 400 kW continuous wave (CW) heavy ion beams from protons to uranium. The RAON consists of a few electron cyclotron resonance ion sources, a low-energy beam transport (LEBT) system, a CW 81.25 MHz, 500 keV/u radio frequency quadrupole (RFQ) accelerator, a medium-energy beam transport system, the SC linac, and a charge-stripper system. The LEBT system for the RISP accelerator facility consists of a high-voltage platform, two 90° dipoles, a multi-harmonic buncher (MHB), solenoids, electrostatic quadrupoles, a velocity equalizer, and a diagnostic system. The ECR ion sources are located on a high-voltage platform to reach an initial beam energy of 10 keV/u. After extraction, the ion beam is transported through the LEBT system to the RFQ accelerator. The generated charge states are selected by an achromatic bending system and then bunched by the MHB in the LEBT system. The MHB is used to achieve a small longitudinal emittance in the RFQ by generating a sawtooth wave with three harmonics. In this paper, we present the results and issues of the beam dynamics of the LEBT system.

  14. Molecular Ion Beam Transportation for Low Energy Ion Implantation

    SciTech Connect

    Kulevoy, T. V.; Kropachev, G. N.; Seleznev, D. N.; Yakushin, P. E.; Kuibeda, R. P.; Kozlov, A. V.; Koshelev, V. A.; Hershcovitch, A.; Johnson, B. M.; Gushenets, V. I.; Oks, E. M.; Polozov, S. M.; Poole, H. J.

    2011-01-07

    A joint research and development of steady state intense boron ion sources for 100's of electron-volt ion implanters has been in progress for the past five years. Current density limitation associated with extracting and transporting low energy ion beams result in lower beam currents that in turn adversely affects the process throughput. The transport channel with electrostatic lenses for decaborane (B{sub 10}H{sub 14}) and carborane (C{sub 2}B{sub 10}H{sub 12}) ion beams transportation was developed and investigated. The significant increase of ion beam intensity at the beam transport channel output is demonstrated. The transport channel simulation, construction and experimental results of ion beam transportation are presented.

  15. Experimental investigation of fatigue in a cantilever energy harvesting beam

    NASA Astrophysics Data System (ADS)

    Avvari, Panduranga Vittal; Yang, Yaowen; Liu, Peiwen; Soh, Chee Kiong

    2015-03-01

    Over the last decade, cantilever energy harvesters gained immense popularity owing to the simplicity of the design and piezoelectric energy harvesting (PEH) using the cantilever design has undergone considerable evolution. The major drawback of a vibrating cantilever beam is its vulnerability to fatigue over a period of time. This article brings forth an experimental investigation into the phenomenon of fatigue of a PEH cantilever beam. As there has been very little literature reported in this area, an effort has been made to scrutinize the damage due to fatigue in a linear vibrating cantilever PEH beam consisting of an aluminum substrate with a piezoelectric macro-fiber composite (MFC) patch attached near the root of the beam and a tip mass attached to the beam. The beam was subjected to transverse vibrations and the behavior of the open circuit voltage was recorded with passing time. Moreover, electro-mechanical admittance readings were obtained periodically using the same MFC patch as a Structural health monitoring (SHM) sensor to assess the health of the PEH beam. The results show that with passing time the PEH beam underwent fatigue in both the substrate and MFC, which is observed in a complimentary trend in the voltage and admittance readings. The claim is further supported using the variation of root mean square deviation (RMSD) of the real part of admittance (conductance) readings. Thus, this study concludes that the fatigue issue should be addressed in the design of PEH for long term vibration energy harvesting.

  16. High energy laser testbed for accurate beam pointing control

    NASA Astrophysics Data System (ADS)

    Kim, Dojong; Kim, Jae Jun; Frist, Duane; Nagashima, Masaki; Agrawal, Brij

    2010-02-01

    Precision laser beam pointing is a key technology in High Energy Laser systems. In this paper, a laboratory High Energy Laser testbed developed at the Naval Postgraduate School is introduced. System identification is performed and a mathematical model is constructed to estimate system performance. New beam pointing control algorithms are designed based on this mathematical model. It is shown in both computer simulation and experiment that the adaptive filter algorithm can improve the pointing performance of the system.

  17. MCNPX benchmark of in-beam proton energy deposition

    SciTech Connect

    Corzine, K.; Ferguson, P.; Morgan, G.; Quintana, D.; Waters, L.; Cooper, R.; Liljestrand, R.; Whiteson, A.

    2000-07-01

    The MCNPX code is being used to calculate energy deposition in the accelerator production of tritium (APT) target/blanket system components. To ensure that these components are properly designed, the code must be validated. An energy deposition experiment was designed to aid in the code validation using thermocouple sensors in-beam and thermistor-type sensors in decoupler- and blanketlike regions. This paper focuses on the in-beam thermocouple sensors.

  18. Energy Spread of the Proton Beam in the Fermilab Booster at its Injection Energy

    SciTech Connect

    Bhat, C. M.; Chase, B. E.; Chaurize, S. J.; Garcia, F. G.; Seiya, K.; Pellico, W. A.; Sullivan, T. M.; Triplett, A. K.

    2015-04-27

    We have measured the energy spread of the Booster beam at its injection energy of 400 MeV by three different methods: (1) creating a notch of about 40 nsec wide in the beam immediately after multiple turn injection and measuring the slippage time required for high and low momentum particles for a grazing touch in line-charge distribution, (2) injecting partial turn beam and letting it to debunch, and (3) comparing the beam profile monitor data with predictions from MAD simulations for the 400 MeV injection beam line. The measurements are repeated under varieties of conditions of rf systems in the ring and in the beam transfer line.

  19. Beam dynamics simulations of post low energy beam transport section in RAON heavy ion accelerator

    NASA Astrophysics Data System (ADS)

    Jin, Hyunchang; Jang, Ji-Ho; Jang, Hyojae; Hong, In-Seok

    2016-02-01

    RAON (Rare isotope Accelerator Of Newness) heavy ion accelerator of the rare isotope science project in Daejeon, Korea, has been designed to accelerate multiple-charge-state beams to be used for various science programs. In the RAON accelerator, the rare isotope beams which are generated by an isotope separation on-line system with a wide range of nuclei and charges will be transported through the post Low Energy Beam Transport (LEBT) section to the Radio Frequency Quadrupole (RFQ). In order to transport many kinds of rare isotope beams stably to the RFQ, the post LEBT should be devised to satisfy the requirement of the RFQ at the end of post LEBT, simultaneously with the twiss parameters small. We will present the recent lattice design of the post LEBT in the RAON accelerator and the results of the beam dynamics simulations from it. In addition, the error analysis and correction in the post LEBT will be also described.

  20. Uncorrelated Energy Spread and Longitudinal Emittance of a Photoinjector Beam

    SciTech Connect

    Huang, Z; Dowell, D.; Emma, P.; Limborg-Deprey, C.; Stupakov, G.; Wu, J.; /SLAC

    2005-05-25

    Longitudinal phase space properties of a photoinjector beam are important in many areas of high-brightness beam applications such as bunch compression, transverse-to-longitudinal emittance exchange, and high-gain free-electron lasers. In this paper, we discuss both the rf and the space charge contributions to the uncorrelated energy spread of the beam generated from a laser-driven rf gun. We compare analytical expressions for the uncorrelated energy spread and the longitudinal emittance with numerical simulations and recent experimental results.

  1. Anomalous broadening of energy distributions in photoemitted electron beams

    NASA Astrophysics Data System (ADS)

    Guidi, Vincenzo

    1996-06-01

    Photoemission is widely used to generate electron beams with an energy spread lower than by thermoemission. However, when a photocathode is illuminated by a multimode laser this feature is lost and an electron beam with several eV of energy spread is produced. We have developed an explanation for this anomalous behavior pointing out its origin in the combined effect of charge relaxation, taking place within the beam, together with the modulation of the laser power imposed by laser modes. The model permits a correct interpretation overall experimental evidences.

  2. Laser-based profile and energy monitor for H beams

    SciTech Connect

    Connolly,R.; Alessi, J.; Bellavia, S.; Dawson, C.; Degen, C.; Meng, W.; Raparia, D.; Russo, T.; Tsoupas, N.

    2008-09-29

    A beam profile and energy monitor for H{sup -} beams based on laser photoneutralization was built at Brookhaven National Laboratory (BNL)* for use on the High Intensity Neutrino Source (HMS) at Fermilab. An H{sup -} ion has a first ionization potential of 0.75eV and can be neutralized by light from a Nd:YAG laser ({lambda}=1064nm). To measure beam profiles, a narrow laser beam is stepped across the ion beam, removing electrons from the portion of the H{sup -} beam intercepted by the laser. These electrons are channeled into a Faraday cup by a curved axial magnetic field. To measure the energy distribution of the electrons, the laser position is fixed and the voltage on a screen in front of the Faraday cup is raised in small steps. We present a model which reproduces the measured energy spectrum from calculated beam energy and space-charge fields. Measurements are reported from experiments in the BNL linac MEBT at 750keV.

  3. Coherent parasitic energy loss of the recycler beam

    SciTech Connect

    K.Y. Ng

    2004-07-14

    Parasitic energy loss of the particle beam in the Recycler Ring is discussed. The long beam confined between two barrier waves has a spectrum that falls off rapidly with frequency. Discrete summation over the revolution harmonics must be made to obtain the correct energy loss per particle per turn, because only a few lower revolution harmonics of real part of the longitudinal impedance contribute to the parasitic energy loss. The longitudinal impedances of the broadband rf cavities, the broadband resistive-wall monitors, and the resistive wall of the vacuum chamber are discussed. They are the main sources of the parasitic energy loss.

  4. Transport of intense ion beams and space charge compensation issues in low energy beam lines (invited)

    SciTech Connect

    Chauvin, N.; Delferriere, O.; Duperrier, R.; Gobin, R.; Nghiem, P. A. P.; Uriot, D.

    2012-02-15

    Over the last few years, the interest of the international scientific community for high power accelerators in the megawatt range has been increasing. For such machines, the ion source has to deliver a beam intensity that ranges from several tens up to a hundred of mA. One of the major challenges is to extract and transport the beam while minimizing the emittance growth and optimizing its injection into the radio frequency quadrupole. Consequently, it is crucial to perform precise simulations and cautious design of the low energy beam transport (LEBT) line. In particular, the beam dynamics calculations have to take into account not only the space charge effects but also the space charge compensation of the beam induced by ionization of the residual gas. The physical phenomena occurring in a high intensity LEBT and their possible effects on the beam are presented, with a particular emphasis on space charge compensation. Then, beam transport issues in different kind of LEBTs are briefly reviewed. The SOLMAXP particle-in-cell code dedicated to the modeling of the transport of charge particles under a space charge compensation regime is described. Finally, beam dynamics simulations results obtained with SOLMAXP are presented in the case of international fusion materials irradiation facility injector.

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

    SciTech Connect

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

    2010-05-15

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

  6. Energy harvesting from controlled buckling of piezoelectric beams

    NASA Astrophysics Data System (ADS)

    Ansari, M. H.; Karami, M. Amin

    2015-11-01

    A piezoelectric vibration energy harvester is presented that can generate electricity from the weight of passing cars or crowds. The energy harvester consists of a piezoelectric beam, which buckles when the device is stepped on. The energy harvester can have a horizontal or vertical configuration. In the vertical (direct) configuration, the piezoelectric beam is vertical and directly sustains the weight of the vehicles or people. In the horizontal (indirect) configuration, the vertical weight is transferred to a horizontal axial force through a scissor-like mechanism. Buckling of the beam results in significant stresses and, thus, large power production. However, if the beam’s buckling is not controlled, the beam will fracture. To prevent this, the axial deformation is constrained to limit the deformations of the beam. In this paper, the energy harvester is analytically modeled. The considered piezoelectric beam is a general non-uniform beam. The natural frequencies, mode shapes, and the critical buckling force corresponding to each mode shape are calculated. The electro-mechanical coupling and the geometric nonlinearities are included in the model. The design criteria for the device are discussed. It is demonstrated that a device, realized with commonly used piezoelectric patches, can generate tens of milliwatts of power from passing car traffic. The proposed device could also be implemented in the sidewalks or integrated in shoe soles for energy generation. One of the key features of the device is its frequency up-conversion characteristics. The piezoelectric beam undergoes free vibrations each time the weight is applied to or removed from the energy harvester. The frequency of the free vibrations is orders of magnitude larger than the frequency of the load. The device is, thus, both efficient and insensitive to the frequency of the force excitations.

  7. Cross-Beam Energy Transfer Driven by Incoherent Laser Beams with Colors

    NASA Astrophysics Data System (ADS)

    Maximov, A. V.; Myatt, J. F.; Short, R. W.; Igumenshchev, I. V.; Seka, W.

    2014-10-01

    Recently, the effect of cross-beam energy transfer (CBET) has become one of the most important challenges for the effective coupling of laser energy to the target in inertial confinement fusion (ICF) (see, e.g., Ref. 1). CBET is based on the process of stimulated Brillouin scattering (SBS) driven by multiple crossing laser beams in the regime of moderate SBS amplification gains, and is consequently sensitive to the frequency characteristics of the laser beams driving the ICF targets: smoothing by spectral dispersion or frequency shifts between the beams (colors). Different from reduced ray-type models used in large-scale hydrodynamic simulations with CBET, we have developed a laser-plasma interaction (LPI)-type model of CBET that is capable of capturing the effects of laser speckles and the non-paraxial propagation of multiple laser beams. The LPI-type CBET model has been applied to the interaction between incoherent laser beams with different colors and the differences from the ray-type CBET model have been shown. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.

  8. Using Polarimetry to Determine the CEBAF Beam Energy

    SciTech Connect

    Higinbotham, Douglas W.

    2014-06-01

    As Jefferson Lab begins operations with its upgraded CEBAF a ccelerator, the lab once again needs to experimentally determine the absolute beam energy of the machine. Previously, the CE- BAF beam energy was determined using precision measurement s of the bending magnet integral fields along with beam position information. The result obta ined from this technique was cross- checked with elastic scattering from hydrogen where knowle dge of the scattering angles of the electron and proton allow the beam energy to be determined. Wh ile the field integral method will still work with the upgraded machine, the elastic cross sect ion becomes too small to make preci- sion measurements at angles that are large enough to be easil y accessible; thus a new technique for energy determination has been sought. It will be shown th at by making use of polarimetry, one can use CEBAF’s polarized electrons’ g-2 spin precessio n to determine the absolute beam energy. This can be done in a single hall if the parameters of t he machine, such as the injector energy and linac imbalance, are known or with two halls witho ut any knowledge of the machine parameters

  9. Electron beam pumping of CdZnSe quantum well laser structures using a variable energy electron beam

    NASA Astrophysics Data System (ADS)

    Trager-Cowan, C.; Bagnall, D. M.; McGow, F.; McCallum, W.; O'Donnell, K. P.; Smith, P. C.; Wright, P. J.; Cockayne, B.; Prior, K. A.; Mullins, J. T.; Horsburgh, G.; Cavenett, B. C.

    1996-02-01

    In this paper we present experimental results on electron beam pumping of MBE and MOVPE lasers with CdZnSe single quantum wells. Laser emission in the gree and blue occurs under pulsed excitation, with threshold power densities typically less than 2 kW/cm 2 at low temperatures. Threshold curves obtained at different electron beam energies show that there is an optimum electron beam energy for wells at a given depth below the surface. This suggests that it is possible to match the electron beam energy to a given structure. Results are broadly consistent with Monte Carlo calculations of the depth dependence of the energy deposition of the electron beam.

  10. Crossed-beam energy transfer in direct-drive implosions

    SciTech Connect

    Seka, W; Edgell, D H; Michel, D T; Froula, D H; Goncharov, V N; Craxton, R S; Divol, L; Epstein, R; Follett, R; Kelly, J H; Kosc, T Z; Maximov, A V; McCrory, R L; Meyerhofer, D D; Michel, P; Myatt, J F; Sangster, T C; Shvydky, A; Skupsky, S; Stoeckl, C

    2012-05-22

    Direct-drive-implosion experiments on the OMEGA laser [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)] have showed discrepancies between simulations of the scattered (non-absorbed) light levels and measured ones that indicate the presence of a mechanism that reduces laser coupling efficiency by 10%-20%. This appears to be due to crossed-beam energy transfer (CBET) that involves electromagnetic-seeded, low-gain stimulated Brillouin scattering. CBET scatters energy from the central portion of the incoming light beam to outgoing light, reducing the laser absorption and hydrodynamic efficiency of implosions. One-dimensional hydrodynamic simulations including CBET show good agreement with all observables in implosion experiments on OMEGA. Three strategies to mitigate CBET and improve laser coupling are considered: the use of narrow beams, multicolor lasers, and higher-Z ablators. Experiments on OMEGA using narrow beams have demonstrated improvements in implosion performance.

  11. Energy gain and spectral tailoring of ion beams using ultra-high intensity laser beams

    NASA Astrophysics Data System (ADS)

    Prasad, Rajendra; Swantusch, Marco; Cerchez, Mirela; Spickermann, Sven; Auorand, Bastian; Wowra, Thomas; Boeker, Juergen; Willi, Oswald

    2015-11-01

    The field of laser driven ion acceleration over the past decade has produced a huge amount of research. Nowadays, several multi-beam facilities with high rep rate system, e.g. ELI, are being developed across the world for different kinds of experiments. The study of interaction dynamics of multiple beams possessing ultra-high intensity and ultra-short pulse duration is of vital importance. Here, we present the first experimental results on ion acceleration using two ultra-high intensity beams. Thanks to the unique capability of Arcturus laser at HHU Düsseldorf, two almost identical, independent beams in laser parameters such as intensity (>1020 W/cm2), pulse duration (30 fs) and contrast (>1010), could be accessed. Both beams are focused onto a 5 μm thin Ti target. While ensuring spatial overlap of the two beams, at relative temporal delay of ~ 50 ps (optimum delay), the proton and carbon ion energies were enhanced by factor of 1.5. Moreover, strong modulation in C4+ions near the high energy cut-off is observed later than the optimum delay for the proton enhancement. This offers controlled tailoring of the spectral content of heavy ions.

  12. High energy density plasma science with an ultrarelativistic electron beam

    NASA Astrophysics Data System (ADS)

    Joshi, C.; Blue, B.; Clayton, C. E.; Dodd, E.; Huang, C.; Marsh, K. A.; Mori, W. B.; Wang, S.; Hogan, M. J.; O'Connell, C.; Siemann, R.; Watz, D.; Muggli, P.; Katsouleas, T.; Lee, S.

    2002-05-01

    An intense, high-energy electron or positron beam can have focused intensities rivaling those of today's most powerful laser beams. For example, the 5 ps (full-width, half-maximum), 50 GeV beam at the Stanford Linear Accelerator Center (SLAC) at 1 kA and focused to a 3 micron rms spot size gives intensities of >1020 W/cm-2 at a repetition rate of >10 Hz. Unlike a ps or fs laser pulse which interacts with the surface of a solid target, the particle beam can readily tunnel through tens of cm of steel. However, the same particle beam can be manipulated quite effectively by a plasma that is a million times less dense than air! This is because of the incredibly strong collective fields induced in the plasma by the Coulomb force of the beam. The collective fields in turn react back onto the beam leading to many clearly observable phenomena. The beam paraticles can be: (1) Deflected leading to focusing, defocusing, or even steering of the beam; (2) undulated causing the emission of spontaneous betatron x-ray radiation and; (3) accelerated or decelerated by the plasma fields. Using the 28.5 GeV electron beam from the SLAC linac a series of experiments have been carried out that demonstrate clearly many of the above mentioned effects. The results can be compared with theoretical predictions and with two-dimensional and three-dimensional, one-to-one, particle-in-cell code simulations. These phenomena may have practical applications in future technologies including optical elements in particle beam lines, synchrotron light sources, and ultrahigh gradient accelerators.

  13. Coulomb repulsion and the electron beam directed energy weapon

    NASA Astrophysics Data System (ADS)

    Retsky, Michael W.

    2004-09-01

    Mutual repulsion of discrete charged particles or Coulomb repulsion is widely considered to be an ultimate hard limit in charged particle optics. It prevents the ability to finely focus high current beams into small spots at large distances from defining apertures. A classic example is the 1970s era "Star Wars" study of an electron beam directed energy weapon as an orbiting antiballistic missile device. After much analysis, it was considered physically impossible to focus a 1000-amp 1-GeV beam into a 1-cm diameter spot 1000-km from the beam generator. The main reason was that a 1-cm diameter beam would spread to 5-m diameter at 1000-km due to Coulomb repulsion. Since this could not be overcome, the idea was abandoned. But is this true? What if the rays were reversed? That is, start with a 5-m beam converging slightly with the same nonuniform angular and energy distribution as the electrons from the original problem were spreading at 1000-km distance. Could Coulomb repulsion be overcome? Looking at the terms in computational studies, some are reversible while others are not. Based on estimates, the nonreversible terms should be small - of the order of 0.1 mm. If this is true, it is possible to design a practical electron beam directed weapon not limited by Coulomb repulsion.

  14. Low energy, high power hydrogen neutral beam for plasma heating

    NASA Astrophysics Data System (ADS)

    Deichuli, P.; Davydenko, V.; Ivanov, A.; Korepanov, S.; Mishagin, V.; Smirnov, A.; Sorokin, A.; Stupishin, N.

    2015-11-01

    A high power, relatively low energy neutral beam injector was developed to upgrade of the neutral beam system of the gas dynamic trap device and C2-U experiment. The ion source of the injector produces a proton beam with the particle energy of 15 keV, current of up to 175 A, and pulse duration of a few milliseconds. The plasma emitter of the ion source is produced by superimposing highly ionized plasma jets from an array of four arc-discharge plasma generators. A multipole magnetic field produced with permanent magnets at the periphery of the plasma box is used to increase the efficiency and improve the uniformity of the plasma emitter. Multi-slit grids with 48% transparency are fabricated from bronze plates, which are spherically shaped to provide geometrical beam focusing. The focal length of the Ion Optical System (IOS) is 3.5 m and the initial beam diameter is 34 cm. The IOS geometry and grid potentials were optimized numerically to ensure accurate beam formation. The measured angular divergences of the beam are ±0.01 rad parallel to the slits and ±0.03 rad in the transverse direction.

  15. Low energy, high power hydrogen neutral beam for plasma heating.

    PubMed

    Deichuli, P; Davydenko, V; Ivanov, A; Korepanov, S; Mishagin, V; Smirnov, A; Sorokin, A; Stupishin, N

    2015-11-01

    A high power, relatively low energy neutral beam injector was developed to upgrade of the neutral beam system of the gas dynamic trap device and C2-U experiment. The ion source of the injector produces a proton beam with the particle energy of 15 keV, current of up to 175 A, and pulse duration of a few milliseconds. The plasma emitter of the ion source is produced by superimposing highly ionized plasma jets from an array of four arc-discharge plasma generators. A multipole magnetic field produced with permanent magnets at the periphery of the plasma box is used to increase the efficiency and improve the uniformity of the plasma emitter. Multi-slit grids with 48% transparency are fabricated from bronze plates, which are spherically shaped to provide geometrical beam focusing. The focal length of the Ion Optical System (IOS) is 3.5 m and the initial beam diameter is 34 cm. The IOS geometry and grid potentials were optimized numerically to ensure accurate beam formation. The measured angular divergences of the beam are ±0.01 rad parallel to the slits and ±0.03 rad in the transverse direction. PMID:26628137

  16. Low energy, high power hydrogen neutral beam for plasma heating

    SciTech Connect

    Deichuli, P.; Davydenko, V.; Ivanov, A. Mishagin, V.; Sorokin, A.; Stupishin, N.; Korepanov, S.; Smirnov, A.

    2015-11-15

    A high power, relatively low energy neutral beam injector was developed to upgrade of the neutral beam system of the gas dynamic trap device and C2-U experiment. The ion source of the injector produces a proton beam with the particle energy of 15 keV, current of up to 175 A, and pulse duration of a few milliseconds. The plasma emitter of the ion source is produced by superimposing highly ionized plasma jets from an array of four arc-discharge plasma generators. A multipole magnetic field produced with permanent magnets at the periphery of the plasma box is used to increase the efficiency and improve the uniformity of the plasma emitter. Multi-slit grids with 48% transparency are fabricated from bronze plates, which are spherically shaped to provide geometrical beam focusing. The focal length of the Ion Optical System (IOS) is 3.5 m and the initial beam diameter is 34 cm. The IOS geometry and grid potentials were optimized numerically to ensure accurate beam formation. The measured angular divergences of the beam are ±0.01 rad parallel to the slits and ±0.03 rad in the transverse direction.

  17. Ion energy distribution functions of low energy beams formed by wire extraction electrodes

    SciTech Connect

    Tokumura, S.; Kasuya, T.; Vasquez, M. Jr.; Maeno, S.; Wada, M.

    2012-02-15

    The two-electrode extractor system made of 0.1 mm diameter tungsten wires separated by 0.7 mm has formed an argon ion beam with 50 V extraction potential. Energy spreads of the extracted beams were typically less than 2 eV when the beam current density was low. The beam intensity rapidly decreased as the distance between the extractor and the beam detector increased, indicating space charge limited transport of the beam. Problems associated with the emittance measurements are also discussed.

  18. Optical system design for high-energy particle beam diagnostics.

    SciTech Connect

    Yang, B. X. Y.

    2002-08-29

    Radiation generated by high-energy particle beams is widely used to characterize the beam properties. While the wavelengths of radiation may vary from visible to x-rays, the physics underlying the engineering designs are similar. In this tutorial, we discuss the basic considerations for the optical system design in the context of beam instrumentation and the constraints applied by high-radiation environments. We cover commonly used optical diagnostics: fluorescence flags, visible and x-ray synchrotron radiation imaging. Emphases will be on achieving desired resolution, accuracy, and reproducibility.

  19. Pin diode calibration - beam overlap monitoring for low energy cooling

    SciTech Connect

    Drees, A.; Montag, C.; Thieberger, P.

    2015-09-30

    We were trying to address the question whether or not the Pin Diodes, currently installed approximately 1 meter downstream of the RHIC primary collimators, are suitable to monitor a recombination signal from the future RHIC low energy cooling section. A maximized recombination signal, with the Au+78 ions being lost on the collimator, will indicate optimal Au-electron beam overlap as well as velocity matching of the electron beam in the cooling section.

  20. A fast chopper for medium energy beams

    NASA Astrophysics Data System (ADS)

    Madrak, R.; Wildman, D.

    2014-10-01

    The key elements have been constructed for a fast chopper system capable of removing single 2.5 MeV proton bunches spaced at 325 MHz. The average chopping rate is ~ 1 MHz. The components include a pulse delaying microstrip structure for deflecting the beam, high voltage (1.2 kV) fast (ns rise time) pulsers, and an associated wideband combiner. Various designs for the deflecting structures have been studied. Measurements of the microstrip structures' coverage factors and pulse shapes are presented.

  1. Beamed-Energy Propulsion (BEP): Considerations for Beaming High Energy-Density Electromagnetic Waves Through the Atmosphere

    NASA Technical Reports Server (NTRS)

    Manning, Robert M.

    2015-01-01

    A study to determine the feasibility of employing beamed electromagnetic energy for vehicle propulsion within and outside the Earth's atmosphere was co-funded by NASA and the Defense Advanced Research Projects Agency that began in June 2010 and culminated in a Summary Presentation in April 2011. A detailed report entitled "Beamed-Energy Propulsion (BEP) Study" appeared in February 2012 as NASA/TM-2012-217014. Of the very many nuances of this subject that were addressed in this report, the effects of transferring the required high energy-density electromagnetic fields through the atmosphere were discussed. However, due to the limitations of the length of the report, only a summary of the results of the detailed analyses were able to be included. It is the intent of the present work to make available the complete analytical modeling work that was done for the BEP project with regard to electromagnetic wave propagation issues. In particular, the present technical memorandum contains two documents that were prepared in 2011. The first one, entitled "Effects of Beaming Energy Through the Atmosphere" contains an overview of the analysis of the nonlinear problem inherent with the transfer of large amounts of energy through the atmosphere that gives rise to thermally-induced changes in the refractive index; application is then made to specific beamed propulsion scenarios. A brief portion of this report appeared as Appendix G of the 2012 Technical Memorandum. The second report, entitled "An Analytical Assessment of the Thermal Blooming Effects on the Propagation of Optical and Millimeter- Wave Focused Beam Waves For Power Beaming Applications" was written in October 2010 (not previously published), provides a more detailed treatment of the propagation problem and its effect on the overall characteristics of the beam such as its deflection as well as its radius. Comparisons are then made for power beaming using the disparate electromagnetic wavelengths of 1.06 microns and 2

  2. Polarimeters and Energy Spectrometers for the ILC Beam Delivery System

    SciTech Connect

    Boogert, S.; Hildreth, M.; Kafer, D.; List, J.; Monig, K.; Moffeit, K.C.; Moortgat-Pick, G.; Riemann, S.; Schreiber, H.J.; Schuler, P.; Torrence, E.; Woods, M.; /SLAC

    2009-02-24

    This article gives an overview of current plans and issues for polarimeters and energy spectrometers in the Beam Delivery System of the ILC. It is meant to serve as a useful reference for the Detector Letter of Intent documents currently being prepared. Concepts for high precision polarization and energy measurements exist. These concepts have resulted in detailed system layouts that are included in the RDR description for the Beam Delivery System. The RDR includes both upstream and downstream polarimeters and energy spectrometers for both beams. This provides needed complementarity and redundancy for achieving the precision required, with adequate control and demonstration of systematic errors. The BDS polarimeters and energy spectrometers need to be a joint effort of the ILC BDS team and the Detector collaborations, with collaboration members responsible for the performance and accuracy of the measurements. Details for this collaboration and assigning of responsibilities remain to be worked out. There is also a demonstrated need for Detector physicists to play an active role in the design and evaluation of accelerator components that impact beam polarization and beam energy capabilities, including the polarized source and spin rotator systems. A workshop was held in 2008 on ILC Polarization and Energy measurements, which resulted in a set of recommendations for the ILC design and operation. Additional input and action is needed on these from the Detector collaborations, the Research Director and the GDE. Work is continuing during the ILC engineering design phase to further optimize the polarimeter and energy spectrometer concepts and fully implement them in the ILC. This includes consideration for alternative methods, detailed design and cost estimates, and prototype and test beam activities.

  3. Fast IMRT with narrow high energy scanned photon beams

    SciTech Connect

    Andreassen, Bjoern; Straaring t, Sara Janek; Holmberg, Rickard; Naefstadius, Peder; Brahme, Anders

    2011-08-15

    Purpose: Since the first publications on intensity modulated radiation therapy (IMRT) in the early 1980s almost all efforts have been focused on fairly time consuming dynamic or segmental multileaf collimation. With narrow fast scanned photon beams, the flexibility and accuracy in beam shaping increases, not least in combination with fast penumbra trimming multileaf collimators. Previously, experiments have been performed with full range targets, generating a broad bremsstrahlung beam, in combination with multileaf collimators or material compensators. In the present publication, the first measurements with fast narrow high energy (50 MV) scanned photon beams are presented indicating an interesting performance increase even though some of the hardware used were suboptimal. Methods: Inverse therapy planning was used to calculate optimal scanning patterns to generate dose distributions with interesting properties for fast IMRT. To fully utilize the dose distributional advantages with scanned beams, it is necessary to use narrow high energy beams from a thin bremsstrahlung target and a powerful purging magnet capable of deflecting the transmitted electron beam away from the generated photons onto a dedicated electron collector. During the present measurements the scanning system, purging magnet, and electron collimator in the treatment head of the MM50 racetrack accelerator was used with 3-6 mm thick bremsstrahlung targets of beryllium. The dose distributions were measured with diodes in water and with EDR2 film in PMMA. Monte Carlo simulations with geant4 were used to study the influence of the electrons transmitted through the target on the photon pencil beam kernel. Results: The full width at half-maximum (FWHM) of the scanned photon beam was 34 mm measured at isocenter, below 9.5 cm of water, 1 m from the 3 mm Be bremsstrahlung target. To generate a homogeneous dose distribution in a 10 x 10 cm{sup 2} field, the authors used a spot matrix of 100 equal intensity

  4. HIGH ENERGY DENSITY PHYSICS EXPERIMENTS WITH INTENSE HEAVY ION BEAMS

    SciTech Connect

    Henestroza, E.; Leitner, M.; Logan, B.G.; More, R.M.; Roy, P.K.; Ni, P.; Seidl, P.A.; Waldron, W.L.; Barnard, J.J.

    2010-03-16

    The US heavy ion fusion science program has developed techniques for heating ion-beam-driven warm dense matter (WDM) targets. The WDM conditions are to be achieved by combined longitudinal and transverse space-charge neutralized drift compression of the ion beam to provide a hot spot on the target with a beam spot size of about 1 mm, and pulse length about 1-2 ns. As a technique for heating volumetric samples of matter to high energy density, intense beams of heavy ions are capable of delivering precise and uniform beam energy deposition dE/dx, in a relatively large sample size, and the ability to heat any solid-phase target material. Initial experiments use a 0.3 MeV K+ beam (below the Bragg peak) from the NDCX-I accelerator. Future plans include target experiments using the NDCX-II accelerator, which is designed to heat targets at the Bragg peak using a 3-6 MeV lithium ion beam. The range of the beams in solid matter targets is about 1 micron, which can be lengthened by using porous targets at reduced density. We have completed the fabrication of a new experimental target chamber facility for WDM experiments, and implemented initial target diagnostics to be used for the first target experiments in NDCX-1. The target chamber has been installed on the NDCX-I beamline. The target diagnostics include a fast multi-channel optical pyrometer, optical streak camera, VISAR, and high-speed gated cameras. Initial WDM experiments will heat targets by compressed NDCX-I beams and will explore measurement of temperature and other target parameters. Experiments are planned in areas such as dense electronegative targets, porous target homogenization and two-phase equation of state.

  5. HIGH ENERGY DENSITY PHYSICS EXPERIMENTS WITH INTENSE HEAVY ION BEAMS

    SciTech Connect

    Bieniosek, F.M.; Henestroza, E.; Leitner, M.; Logan, B.G.; More, R.M.; Roy, P.K.; Ni, P.; Seidl, P.A.; Waldron, W.L.; Barnard, J.J.

    2008-08-01

    The US heavy ion fusion science program has developed techniques for heating ion-beam-driven warm dense matter (WDM) targets. The WDM conditions are to be achieved by combined longitudinal and transverse space-charge neutralized drift compression of the ion beam to provide a hot spot on the target with a beam spot size of about 1 mm, and pulse length about 1-2 ns. As a technique for heating volumetric samples of matter to high energy density, intense beams of heavy ions are capable of delivering precise and uniform beam energy deposition dE/dx, in a relatively large sample size, and the ability to heat any solid-phase target material. Initial experiments use a 0.3 MeV K+ beam (below the Bragg peak) from the NDCX-I accelerator. Future plans include target experiments using the NDCX-II accelerator, which is designed to heat targets at the Bragg peak using a 3-6 MeV lithium ion beam. The range of the beams in solid matter targets is about 1 micron, which can be lengthened by using porous targets at reduced density. We have completed the fabrication of a new experimental target chamber facility for WDM experiments, and implemented initial target diagnostics to be used for the first target experiments in NDCX-1. The target chamber has been installed on the NDCX-I beamline. The target diagnostics include a fast multi-channel optical pyrometer, optical streak camera, VISAR, and high-speed gated cameras. Initial WDM experiments will heat targets by compressed NDCX-I beams and will explore measurement of temperature and other target parameters. Experiments are planned in areas such as dense electronegative targets, porous target homogenization and two-phase equation of state.

  6. High Energy Density Science with Ultrarelativistic Electron Beams

    NASA Astrophysics Data System (ADS)

    Joshi, Chan

    2001-10-01

    An intense, high-energy electron or positron beam can have focused intensities rivaling those of today's most powerful lasers. For example, the 5 ps (FWHM), 50 GeV beam at the Stanford Linear Accelerator Center at 1 kA and focused to a 3 micron rms spot size gives intensities of > 10^20 W/cm^2 at a repetition rate of 10 Hz. Unlike a ps or fs laser pulse, the particle beam can readily bore through several mm of steel due to the rigidity of its flux component. However, the same particle beam can be manipulated quite strongly by a plasma that is a million times less dense than air! This is because of the incredibly strong collective fields induced in the plasma by the Coulomb force of the beam. The collective fields in turn react back onto the beam leading to many clearly-observable phenomena. The beam can be: (1) deflected leading focusing, defocusing, or even steering of the beam; (2) undulated causing the emission of spontaneous betatron x-ray radiation and; (3) accelerated or de-accelerated by the plasma fields. Using the 28.5 GeV electron and positron beams from the SLAC linac we have carried out a series of experiments that demonstrate clearly the above mentioned effects. The results are compared with theoretical predictions and 3D, one-to-one PIC code simulations using the code OSIRIS. These phenomena may have practical application in future technologies including optical elements in particle beam lines, synchrotron light sources, and ultra-high gradient accelerators.

  7. Advanced beamed-energy and field propulsion concepts

    NASA Technical Reports Server (NTRS)

    Myrabo, L. N.

    1983-01-01

    Specific phenomena which might lead to major advances in payload, range and terminal velocity of very advanced vehicle propulsion are studied. The effort focuses heavily on advanced propulsion spinoffs enabled by current government-funded investigations in directed-energy technology: i.e., laser, microwave, and relativistic charged particle beams. Futuristic (post-year 2000) beamed-energy propulsion concepts which indicate exceptional promise are identified and analytically investigated. The concepts must be sufficiently developed to permit technical understanding of the physical processes involved, assessment of the enabling technologies, and evaluation of their merits over conventional systems. Propulsion concepts that can be used for manned and/or unmanned missions for purposes of solar system exploration, planetary landing, suborbital flight, transport to orbit, and escape are presented. Speculations are made on the chronology of milestones in beamed-energy propulsion development, such as in systems applications of defense, satellite orbit-raising, global aerospace transportation, and manned interplanetary carriers.

  8. American Institute of Beamed Energy Propulsion: An Introduction

    NASA Astrophysics Data System (ADS)

    Pakhomov, Andrew V.

    2008-04-01

    To date ISBEP remains the main forum addressing the science and engineering of beamed energy propulsion. Hopefully, it will continue to serve BEP community in this capacity for years to come. The need for organization acting beyond ISBEP was discussed since the second symposium. This paper will address the following question: if our community is ready for having its own organization, a BEP institute, what new it should bring comparing to already existing conference. Such organization, an American Institute on Beamed Energy Propulsion (AIBEP) was recently established. The institute is designed as a nonprofit corporation serving the purpose "to promote the ideas, concepts and benefits of beamed-energy propulsion to research community, industry and society at large". The goals of the institute, expected outcomes and benefits of the organization and its membership will be discussed.

  9. Staging laser plasma accelerators for increased beam energy

    SciTech Connect

    Panasenko, Dmitriy; Shu, Anthony; Schroeder, Carl; Gonsalves, Anthony; Nakamura, Kei; Matlis, Nicholas; Cormier-Michel, Estelle; Plateau, Guillaume; Lin, Chen; Toth, Csaba; Geddes, Cameron; Esarey, Eric; Leemans, Wim

    2008-09-29

    Staging laser plasma accelerators is an efficient way of mitigating laser pump depletion in laser driven accelerators and necessary for reaching high energies with compact laser systems. The concept of staging includes coupling of additional laser energy and transporting the electron beam from one accelerating module to another. Due to laser damage threshold constraints, in-coupling laser energy with conventional optics requires distances between the accelerating modules of the order of 10m, resulting in decreased average accelerating gradient and complicated e-beam transport. In this paper we use basic scaling laws to show that the total length of future laser plasma accelerators will be determined by staging technology. We also propose using a liquid jet plasma mirror for in-coupling the laser beam and show that it has the potential to reduce distance between stages to the cm-scale.

  10. Staging Laser Plasma Accelerators for Increased Beam Energy

    SciTech Connect

    Panasenko, D.; Shu, A. J.; Schroeder, C. B.; Gonsalves, A. J.; Nakamura, K.; Matlis, N. H.; Cormier-Michel, E.; Plateau, G.; Lin, C.; Toth, C.; Geddes, C. G. R.; Esarey, E.; Leemans, W. P.

    2009-01-22

    Staging laser plasma accelerators is an efficient way of mitigating laser pump depletion in laser driven accelerators and necessary for reaching high energies with compact laser systems. The concept of staging includes coupling of additional laser energy and transporting the electron beam from one accelerating module to another. Due to laser damage threshold constraints, in-coupling laser energy with conventional optics requires distances between the accelerating modules of the order of 10 m, resulting in decreased average accelerating gradient and complicated e-beam transport. In this paper we use basic scaling laws to show that the total length of future laser plasma accelerators will be determined by staging technology. We also propose using a liquid jet plasma mirror for in-coupling the laser beam and show that it has the potential to reduce distance between stages to the cm-scale.

  11. Surface modification using low energy ground state ion beams

    NASA Technical Reports Server (NTRS)

    Chutjian, Ara (Inventor); Hecht, Michael H. (Inventor); Orient, Otto J. (Inventor)

    1990-01-01

    A method of effecting modifications at the surfaces of materials using low energy ion beams of known quantum state, purity, flux, and energy is presented. The ion beam is obtained by bombarding ion-generating molecules with electrons which are also at low energy. The electrons used to bombard the ion generating molecules are separated from the ions thus obtained and the ion beam is directed at the material surface to be modified. Depending on the type of ion generating molecules used, different ions can be obtained for different types of surface modifications such as oxidation and diamond film formation. One area of application is in the manufacture of semiconductor devices from semiconductor wafers.

  12. Field energy and RMS emittance in intense particle beams

    SciTech Connect

    Wangler, T.P.; Crandall, K.R.; Mills, R.S.; Reiser, M.

    1986-04-25

    An equation is presented for continuous beam with azimuthal symmetry and continuous linear focusing; the equation expresses a relationship between the rate of change for squared rms emittance and the rate of change for a quantity we call the nonlinear field energy. The nonlinear field energy depends on the shape of the charge distribution and corresponds to the residual field energy possessed by beams with nonuniform charge distributions. The equation can be integrated for the case of an rms matched beam to yield a formula for space-charge-induced emittance growth that we have tested numerically for a variety of initial distributions. The results provide a framework for discussing the scaling of rms emittance growth and an explanation for the well-established lower limit on output emittance.

  13. Modeling crossed-beam energy transfer for inertial confinement fusion

    NASA Astrophysics Data System (ADS)

    Marion, D. J. Y.; Debayle, A.; Masson-Laborde, P.-E.; Loiseau, P.; Casanova, M.

    2016-05-01

    We developed a numerical code that describes both the energy transfer occurring when two or more laser beams overlap in a weakly non-homogeneous plasma, and the beam energy losses associated with the electron-ion collisions. The numerical solutions are validated with both the exact analytical solutions in homogeneous plasmas, and with new approximate analytical solutions in non-homogeneous plasmas that include the aforementioned inverse bremsstrahlung effect. Comparisons with kinetic particle-in-cell simulations are satisfactory, provided the acoustic wave-breaking limit and the self-focusing regime are not reached. An application of the Cross-Beam Energy Transfer model is shown for a typical case of indirect-drive implosion in a gold hohlraum.

  14. Energy harvesting of two cantilever beams structure: interfacing circuit discussion

    NASA Astrophysics Data System (ADS)

    Chen, Yu-Yin; Vasic, Dejan

    2015-03-01

    Today research on supplying of low power consumption device is highly focused on piezoelectric energy harvesting from ambient vibration. The most popular structure is a cantilever beam with piezoelectric patch to convert mechanical energy into electric energy. In the past researches, the theoretical analysis and interfacing circuit design of single cantilever beam structure is highly developed. In this study, the electrical interfacing circuit of two (or more) piezoelectric generators connected to only one load is proposed and discussed. The nonlinear synchronized switching technique SSHI (Synchronized Switching Harvesting in Inductor) is examined to increase the power efficiency effectively of each piezoelectric generator. In the multiple cantilever beam or flag structure application, the structure may be composed of many piezoelectric patches and the interfacing circuit becomes more complicated and important. From the theoretical analysis and the governing equation, the equivalent circuit of two cantilever beam will be proposed and simulated with the optimized synchronous electric charge extraction (OSECE) nonlinear technique to optimize the interfacing circuit and increase the power efficiency by using the Matlab and PSIM software. The experiments will also show the good agreement with the theoretical analysis. The interfacing circuit design concept in the two cantilever beams structure can be further used in the multi-piezoelectric patches energy harvesting system such as piezoelectric flag to optimize the circuit and increase the power efficiency.

  15. High-energy accelerator for beams of heavy ions

    DOEpatents

    Martin, Ronald L.; Arnold, Richard C.

    1978-01-01

    An apparatus for accelerating heavy ions to high energies and directing the accelerated ions at a target comprises a source of singly ionized heavy ions of an element or compound of greater than 100 atomic mass units, means for accelerating the heavy ions, a storage ring for accumulating the accelerated heavy ions and switching means for switching the heavy ions from the storage ring to strike a target substantially simultaneously from a plurality of directions. In a particular embodiment the heavy ion that is accelerated is singly ionized hydrogen iodide. After acceleration, if the beam is of molecular ions, the ions are dissociated to leave an accelerated singly ionized atomic ion in a beam. Extraction of the beam may be accomplished by stripping all the electrons from the atomic ion to switch the beam from the storage ring by bending it in magnetic field of the storage ring.

  16. Range and Energy Straggling in Ion Beam Transport

    NASA Technical Reports Server (NTRS)

    Wilson, John W.; Tai, Hsiang

    2000-01-01

    A first-order approximation to the range and energy straggling of ion beams is given as a normal distribution for which the standard deviation is estimated from the fluctuations in energy loss events. The standard deviation is calculated by assuming scattering from free electrons with a long range cutoff parameter that depends on the mean excitation energy of the medium. The present formalism is derived by extrapolating Payne's formalism to low energy by systematic energy scaling and to greater depths of penetration by a second-order perturbation. Limited comparisons are made with experimental data.

  17. Beamed Energy Propulsion: Research Status And Needs--Part 1

    SciTech Connect

    Birkan, Mitat

    2008-04-28

    One promising solution to the operationally responsive space is the application of remote electromagnetic energy to propel a launch vehicle into orbit. With beamed energy propulsion, one can leave the power source stationary on the ground or space, and direct heat propellant on the spacecraft with a beam from a fixed station. This permits the spacecraft to leave its power source at home, saving significant amounts of mass, greatly improving performance. This concept, which removes the mass penalty of carrying the propulsion energy source on board the vehicle, was first proposed by Arthur Kantrowitz in 1972; he invoked an extremely powerful ground based laser. The same year Michael Minovich suggested a conceptually similar 'in-space' laser rocket system utilizing a remote laser power station. In the late 1980's, Air Force Office of Scientific Research (AFOSR) funded continuous, double pulse laser and microwave propulsion while Strategic Defense Initiative Office (SDIO) funded ablative laser rocket propulsion. Currently AFOSR has been funding the concept initiated by Leik Myrabo, repetitively pulsed laser propulsion, which has been universally perceived, arguably, to be the closest for mid-term applications. This 2-part paper examines the investment strategies in beamed energy propulsion and technical challenges to be overcome. Part 1 presents a world-wide review of beamed energy propulsion research, including both laser and microwave arenas.

  18. SU-F-19A-05: Experimental and Monte Carlo Characterization of the 1 Cm CivaString 103Pd Brachytherapy Source

    SciTech Connect

    Reed, J; Micka, J; Culberson, W; DeWerd, L; Rivard, M

    2014-06-15

    Purpose: To determine the in-air azimuthal anisotropy and in-water dose distribution for the 1 cm length of the CivaString {sup 103}Pd brachytherapy source through measurements and Monte Carlo (MC) simulations. American Association of Physicists in Medicine Task Group No. 43 (TG-43) dosimetry parameters were also determined for this source. Methods: The in-air azimuthal anisotropy of the source was measured with a NaI scintillation detector and simulated with the MCNP5 radiation transport code. Measured and simulated results were normalized to their respective mean values and compared. The TG-43 dose-rate constant, line-source radial dose function, and 2D anisotropy function for this source were determined from LiF:Mg,Ti thermoluminescent dosimeter (TLD) measurements and MC simulations. The impact of {sup 103}Pd well-loading variability on the in-water dose distribution was investigated using MC simulations by comparing the dose distribution for a source model with four wells of equal strength to that for a source model with strengths increased by 1% for two of the four wells. Results: NaI scintillation detector measurements and MC simulations of the in-air azimuthal anisotropy showed that ≥95% of the normalized data were within 1.2% of the mean value. TLD measurements and MC simulations of the TG-43 dose-rate constant, line-source radial dose function, and 2D anisotropy function agreed to within the experimental TLD uncertainties (k=2). MC simulations showed that a 1% variability in {sup 103}Pd well-loading resulted in changes of <0.1%, <0.1%, and <0.3% in the TG-43 dose-rate constant, radial dose distribution, and polar dose distribution, respectively. Conclusion: The CivaString source has a high degree of azimuthal symmetry as indicated by the NaI scintillation detector measurements and MC simulations of the in-air azimuthal anisotropy. TG-43 dosimetry parameters for this source were determined from TLD measurements and MC simulations. {sup 103}Pd well

  19. Energy Spread Reduction of Electron Beams Produced via Laser Wake

    SciTech Connect

    Pollock, Bradley Bolt

    2012-01-01

    Laser wakefield acceleration of electrons holds great promise for producing ultra-compact stages of GeV scale, high quality electron beams for applications such as x-ray free electron lasers and high energy colliders. Ultra-high intensity laser pulses can be self-guided by relativistic plasma waves over tens of vacuum diffraction lengths, to give >1 GeV energy in cm-scale low density plasma using ionization-induced injection to inject charge into the wake at low densities. This thesis describes a series of experiments which investigates the physics of LWFA in the self-guided blowout regime. Beginning with high density gas jet experiments the scaling of the LWFA-produced electron beam energy with plasma electron density is found to be in excellent agreement with both phenomenological theory and with 3-D PIC simulations. It is also determined that self-trapping of background electrons into the wake exhibits a threshold as a function of the electron density, and at the densities required to produce electron beams with energies exceeding 1 GeV a different mechanism is required to trap charge into low density wakes. By introducing small concentrations of high-Z gas to the nominal He background the ionization-induced injection mechanism is enabled. Electron trapping is observed at densities as low as 1.3 x 1018 cm-3 in a gas cell target, and 1.45 GeV electrons are demonstrated for the first time from LWFA. This is currently the highest electron energy ever produced from LWFA. The ionization-induced trapping mechanism is also shown to generate quasi-continuous electron beam energies, which is undesirable for accelerator applications. By limiting the region over which ionization-induced trapping occurs, the energy spread of the electron beams can be controlled. The development of a novel two-stage gas cell target provides the capability to tailor the gas composition in the longitudinal direction, and confine the trapping process to occur only in a

  20. Optics and beam transport in energy recovery linacs

    NASA Astrophysics Data System (ADS)

    Hoffstaetter, Georg H.; Litvinenko, Vladimir; Owen, Hywel

    2006-02-01

    Here, we report on the working group "Optics and Beam Transport" of the 2005 Energy-Recovery-Linac Workshop. This workshop also had working groups on "Electron Guns and Injector Designs", "Superconducting RF and RF Control", and "Synchronization and Diagnostics/Instrumentation". Here, we are concerned with the many different ERL proposals that international laboratories have been working on. Subjects of concern are optics, accelerator design and modeling, stability requirements, designs of the merger that connects the conventional injector linac with the Energy Recovery Linac, longitudinal phase space manipulations to produce short pulses, beam dynamics and limitations by beam instabilities, and computational aspects of space-charge and synchrotron radiation effects. A coarse grain overview is given and reference is made to more detailed articles that were presented in this working group. Subjects are identified where collaborations should be encouraged and areas of future R&D are prioritized.

  1. Large energy-spread beam diagnostics through quadrupole scans

    SciTech Connect

    Frederico, Joel; Adli, Erik; Hogan, Mark; Raubenheimer, Tor

    2012-12-21

    The Facility for Advanced Accelerator and Experimental Tests (FACET) is a new user facility at the SLAC National Accelerator Laboratory, servicing next-generation accelerator experiments. The 1.5% RMS energy spread of the FACET beam causes large chromatic aberrations in optics. These aberrations necessitate updated quadrupole scan fits to remain accurate.

  2. Solar Power Satellites: Creating the Market for Beamed Energy Propulsion

    SciTech Connect

    Coopersmith, Jonathan

    2010-05-06

    Beamed energy advocates must investigate the potential of major markets like space based solar satellites and space-based nuclear waste disposal. For BEP to succeed, its proponents must work with these possible users to generate interest and resources needed to develop BEP.

  3. MEIC Proton Beam Formation with a Low Energy Linac

    SciTech Connect

    Zhang, Yuhong

    2015-09-01

    The MEIC proton and ion beams are generated, accumulated, accelerated and cooled in a new green-field ion injector complex designed specifically to support its high luminosity goal. This injector consists of sources, a linac and a small booster ring. In this paper we explore feasibility of a short ion linac that injects low-energy protons and ions into the booster ring.

  4. Solar Power Satellites: Creating the Market for Beamed Energy Propulsion

    NASA Astrophysics Data System (ADS)

    Coopersmith, Jonathan

    2010-05-01

    Beamed energy advocates must investigate the potential of major markets like space based solar satellites and space-based nuclear waste disposal. For BEP to succeed, its proponents must work with these possible users to generate interest and resources needed to develop BEP.

  5. Spiral design and beam dynamics for a variable energy cyclotron

    SciTech Connect

    Baltz, A.J.; Chasman, C.; Thorn, C.E.

    1981-01-01

    Beam-orbit studies were performed for the conversion of the SREL synchrocyclotron magnet for use as a room temperature, multiparticle, isochronous cyclotron. Based on model magnet measurements of field profiles for 8 to 23/sup 0/K gauss hill fields, a four sector spiral pole tip design has been realized which allows all isotope species of heavy ion beams to be accelerated to required final energies. The total spiral angle of 38/sup 0/ allows injection of the beams from the MP tandem into the cyclotron through a valley. The two valey RF system of 140 kV peak accelerates beams on harmonic numbers 2, 3, 4, 6 and 10 at 14 to 21 MHz. Computer calculations indicated acceptable ..nu../sub z/, ..nu../sub r/ and phase space beam characteristics and passing of resonances for typical beams considered: /sup 16/O at 8 and 150 MeV/amu, /sup 60/Ni at 100 MeV/amu and /sup 238/U at 2.5 and 16 MeV/amu. Single turn extraction is achieved with electrostatic deflection.

  6. Vibration piezoelectric energy harvester with multi-beam

    SciTech Connect

    Cui, Yan Zhang, Qunying Yao, Minglei; Dong, Weijie; Gao, Shiqiao

    2015-04-15

    This work presents a novel vibration piezoelectric energy harvester, which is a micro piezoelectric cantilever with multi-beam. The characteristics of the PZT (Pb(Zr{sub 0.53}Ti{sub 0.47})O{sub 3}) thin film were measured; XRD (X-ray diffraction) pattern and AFM (Atomic Force Microscope) image of the PZT thin film were measured, and show that the PZT (Pb(Zr{sub 0.53}Ti{sub 0.47})O{sub 3}) thin film is highly (110) crystal oriented; the leakage current is maintained in nA magnitude, the residual polarisation Pr is 37.037 μC/cm{sup 2}, the coercive field voltage Ec is 27.083 kV/cm, and the piezoelectric constant d{sub 33} is 28 pC/N. In order to test the dynamic performance of the energy harvester, a new measuring system was set up. The maximum output voltage of the single beam of the multi-beam can achieve 80.78 mV under an acceleration of 1 g at 260 Hz of frequency; the maximum output voltage of the single beam of the multi-beam is almost 20 mV at 1400 Hz frequency. .

  7. Determination of the beam quality index of high-energy photon beams under nonstandard reference conditions

    SciTech Connect

    Palmans, Hugo

    2012-09-15

    Purpose: At some modern radiotherapy machines it is not possible to achieve reference conditions for the measurement of beam quality indices used in dosimetry codes of practice, such as IAEA TRS-398 and AAPM TG-51. This work aims at providing self-consistent and simpler expressions and more accurate fits for a limited range of beams of interest than have been proposed previously for deriving these beam quality indices from measurements. Methods: The starting point is a formula proposed by Sauer [Med. Phys. 36, 4168-4172 (2009)] for deriving the beam quality index used in IAEA TRS-398, TPR{sub 20,10}, from a measurement of the tissue phantom ratio at depths of 20 cm and 10 cm in water for an s Multiplication-Sign s cm{sup 2} (equivalent) square field, TPR{sub 20,10}(s). First, a self-consistent version of this formula is established followed by a simpler version by making a linear approximation. A similar approach is proposed to derive the beam quality index used in AAPM TG-51, %dd(10){sub X}, from a measurement of PDD{sub 10}(s), the percentage depth dose at 10 cm for a square field with size s. All models were fitted to subsets of relevant data from BJR supplement 25. Results: The linear models for TPR{sub 20,10}(s) and exponential models for PDD{sub 10}(s) as a function of the (equivalent) square field size can reproduce the beam quality within 0.3% and beam quality correction factors within 0.05% for square field sizes ranging from 4 cm to 12 cm and nominal photon energies from 4 MV to 12 MV. For higher energy beams the errors are only slightly worse but for %dd(10){sub X}, an additional uncertainty component has to be considered for the electron contamination correction. Conclusions: The models proposed here can be used in practical recommendations for the dosimetry of small and nonstandard fields.

  8. Energy harvesting under excitation of clamped-clamped beam

    NASA Astrophysics Data System (ADS)

    Batra, Ashok; Alomari, Almuatasim; Aggarwal, Mohan; Bandyopadhyay, Alak

    2016-04-01

    In this article, a piezoelectric energy harvesting has been developed experimentally and theoretically based on Euler- Bernoulli Theory. A PVDF piezoelectric thick film has attached along of clamped-clamped beam under sinusoidal base excitation of shaker. The results showed a good agreement between the experimental and simulation of suggested model. The voltage output frequency response function (FRF), current FRF, and output power has been studied under short and open circuit conditions at first vibration mode. The mode shape of the clamped-clamped beam for first three resonance frequency has been modeled and investigated using COMSOL Multiphysics and MATLAB.

  9. The production and use of ultralow energy ion beams

    NASA Astrophysics Data System (ADS)

    Goldberg, R. D.; Armour, D. G.; van den Berg, J. A.; Cook, C. E. A.; Whelan, S.; Zhang, S.; Knorr, N.; Foad, M. A.; Ohno, H.

    2000-02-01

    An ion accelerator, purpose built to produce beams at energies down to 10 eV with current densities in the 10-100 μA cm-2 range, is described. Fitted with dual ion source assemblies, the machine enables ultralow energy ion implantation and the growth of films and multilayers to be carried out under highly controlled conditions. The accelerator delivers ion beams into an ultrahigh vacuum chamber, containing a temperature controlled target stage (range -120 to +1350 °C), where they are used to study the fundamental physics relating to the interaction of ultralow energy ions with surfaces. This knowledge underlies a wide range of ion-beam and plasma-based technologies and, to illustrate its importance, results are presented from investigations designed to determine the optimum conditions for the growth of diamond-like and aluminum films by ion-beam deposition and the formation of ultrashallow junctions in semiconductors by 2.5 keV As+ implantation. The later investigation shows how transient arsenic diffusion, which occurs during post-implant thermal processing, can be controlled by manipulating the substrate temperature during implantation.

  10. In-situ determination of energy species yields of intense particle beams

    DOEpatents

    Kugel, Henry W.; Kaita, Robert

    1987-01-01

    An arrangement is provided for the in-situ determination of energy species yields of intense particle beams. The beam is directed onto a target surface of known composition, such that Rutherford backscattering of the beam occurs. The yield-energy characteristic response of the beam to backscattering from the target is analyzed using Rutherford backscattering techniques to determine the yields of energy species components of the beam.

  11. High-energy tritium beams as current drivers in tokamak reactors

    SciTech Connect

    Mikkelsen, D.R.; Grisham, L.R.

    1983-04-01

    The effect on neutral-beam design and reactor performance of using high-energy (approx. 3-10 MeV) tritium neutral beams to drive steady-state tokamak reactors is considered. The lower current of such beams leads to several advantages over lower-energy neutral beams. The major disadvantage is the reduction of the reactor output caused by the lower current-drive efficiency of the high-energy beams.

  12. Noninterceptive beam energy measurements in line D of the Los Alamos Meson Physics Facility

    SciTech Connect

    Gilpatrick, J.D.; Carter, H.; Plum, M.; Power, J.F.; Rose, C.R.; Shurter, R.B.

    1995-12-31

    Several members of the Accelerator and Operations Technology (AOT) division beam-diagnostics team performed time-of-flight (TOF) beam-energy measurements in line D of the Los Alamos Meson Physics Facility (LAMPF) using developmental beam time. These measurements provided information for a final design of an on-line beam energy measurement. The following paper discusses these measurements and how they apply to the final beam energy measurement design.

  13. Noninterceptive beam energy measurements in line D of the Los Alamos Meson Physics Facility

    SciTech Connect

    Gilpatrick, J.D.; Carter, H.; Plum, M.; Power, J.F.; Rose, C.R.; Shurter, R.B.

    1995-05-05

    Several members of the Accelerator and Operations Technology (AOT) division beam-diagnostics team performed time-of-flight (TOF) beam-energy measurements in line D of the Los Alamos Meson Physics Facility (LAMPF) using developmental beam time. These measurements provided information for a final design of an on-line beam energy measurement. The following paper discusses these measurements and how they apply to the final beam energy measurement design. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

  14. In-situ determination of energy species yields of intense particle beams

    DOEpatents

    Kugel, Henry W.; Kaita, Robert

    1987-03-03

    An arrangement is provided for the in-situ determination of energy species yields of intense particle beams. The beam is directed onto a target surface of known composition, such that Rutherford backscattering of the beam occurs. The yield-energy characteristic response of the beam to backscattering from the target is analyzed using Rutherford backscattering techniques to determine the yields of energy species components of the beam.

  15. Spacecraft Power Beaming Using High-Energy Lasers, Experimental Validation

    SciTech Connect

    Michael, Sherif

    2008-04-28

    The lifetime of many spacecrafts are often limited by degradation of their electrical power subsystem, e.g. radiation-damaged solar arrays or failed batteries. Being able to beam power from terrestrial sites using high energy lasers, could alleviate this limitation, extending the lifetime of billions of dollars of satellite assets, as well as providing additional energy for electric propulsion that can be used for stationkeeping and orbital changes. In addition, extensive research at the Naval Postgraduate School (NPS) has shown the potential for annealing damaged solar cells using lasers. This paper describes that research and a proposed experiment to demonstrate the relevant concepts of high energy laser power beaming to an NPS-built and operated satellite. Preliminary results of ground experiment of laser illuminations of some of the solar panels of one of the spacecrafts are also presented.

  16. Spacecraft Power Beaming Using High-Energy Lasers, Experimental Validation

    NASA Astrophysics Data System (ADS)

    Michael, Sherif

    2008-04-01

    The lifetime of many spacecrafts are often limited by degradation of their electrical power subsystem, e.g. radiation-damaged solar arrays or failed batteries. Being able to beam power from terrestrial sites using high energy lasers, could alleviate this limitation, extending the lifetime of billions of dollars of satellite assets, as well as providing additional energy for electric propulsion that can be used for stationkeeping and orbital changes. In addition, extensive research at the Naval Postgraduate School (NPS) has shown the potential for annealing damaged solar cells using lasers. This paper describes that research and a proposed experiment to demonstrate the relevant concepts of high energy laser power beaming to an NPS-built and operated satellite. Preliminary results of ground experiment of laser illuminations of some of the solar panels of one of the spacecrafts are also presented.

  17. Highly Compressed Ion Beam for High Energy Density Science

    SciTech Connect

    Friedman, A.; Barnard, J.J.; Briggs, R.J.; Callahan, D.A.; Caporaso, G.J.; Celata, C.M.; Davidson, R.C.; Faltens, A.; Grisham, L.; Grote, D.P.; Henestroza, E.; Kaganovich I.; Lee, E.P.; Lee, R.W.; Leitner, M.; Logan, B.G.; Nelson, S.D.; Olson, C.L.; Penn, G.; Reginato,L.R.; Renk, T.; Rose, D.; Seessler, A.; Staples, J.W.; Tabak, M.; Thoma,C.; Waldron, W.; Welch, D.R.; Wurtele, J.; Yu, S.S.

    2005-05-16

    The Heavy Ion Fusion Virtual National Laboratory is developing the intense ion beams needed to drive matter to the High Energy Density regimes required for Inertial Fusion Energy and other applications. An interim goal is a facility for Warm Dense Matter studies, wherein a target is heated volumetrically without being shocked, so that well-defined states of matter at 1 to 10 eV are generated within a diagnosable region. In the approach they are pursuing, low to medium mass ions with energies just above the Bragg peak are directed onto thin target ''foils,'' which may in fact be foams with mean densities 1% to 10% of solid. This approach complements that being pursued at GSI Darmstadt, wherein high-energy ion beams deposit a small fraction of their energy in a cylindrically target. They present the beam requirements for Warm Dense Matter experiments. The authors discuss neutralized drift compression and final focus experiments and modeling. They describe suitable accelerator architectures based on Drift-Tube Linac, RF, single-gap, Ionization-Front Accelerator, and Pulse-Line Ion Accelerator concepts. The last of these is being pursued experimentally. Finally, they discuss plans toward a user facility for target experiments.

  18. Beam-energy-spread minimization using cell-timing optimization

    NASA Astrophysics Data System (ADS)

    Rose, C. R.; Ekdahl, C.; Schulze, M.

    2012-04-01

    Beam energy spread, and related beam motion, increase the difficulty in tuning for multipulse radiographic experiments at the dual-axis radiographic hydrodynamic test facility’s axis-II linear induction accelerator (LIA). In this article, we describe an optimization method to reduce the energy spread by adjusting the timing of the cell voltages (both unloaded and loaded), either advancing or retarding, such that the injector voltage and summed cell voltages in the LIA result in a flatter energy profile. We developed a nonlinear optimization routine which accepts as inputs the 74 cell-voltage, injector voltage, and beam current waveforms. It optimizes cell timing per user-selected groups of cells and outputs timing adjustments, one for each of the selected groups. To verify the theory, we acquired and present data for both unloaded and loaded cell-timing optimizations. For the unloaded cells, the preoptimization baseline energy spread was reduced by 34% and 31% for two shots as compared to baseline. For the loaded-cell case, the measured energy spread was reduced by 49% compared to baseline.

  19. Dual energy scanning beam laminographic x-radiography

    DOEpatents

    Majewski, Stanislaw; Wojcik, Randolph F.

    1998-01-01

    A multiple x-ray energy level imaging system includes a scanning x-ray beam and two detector design having a first low x-ray energy sensitive detector and a second high x-ray energy sensitive detector. The low x-ray energy detector is placed next to or in front of the high x-ray energy detector. The low energy sensitive detector has small stopping power for x-rays. The lower energy x-rays are absorbed and converted into electrical signals while the majority of the higher energy x-rays pass through undetected. The high energy sensitive detector has a large stopping power for x-rays as well as it having a filter placed between it and the object to absorb the lower energy x-rays. In a second embodiment; a single energy sensitive detector is provided which provides an output signal proportional to the amount of energy in each individual x-ray it absorbed. It can then have an electronic threshold or thresholds set to select two or more energy ranges for the images. By having multiple detectors located at different positions, a dual energy laminography system is possible.

  20. Dual energy scanning beam laminographic x-radiography

    DOEpatents

    Majewski, S.; Wojcik, R.F.

    1998-04-21

    A multiple x-ray energy level imaging system includes a scanning x-ray beam and two detector design having a first low x-ray energy sensitive detector and a second high x-ray energy sensitive detector. The low x-ray energy detector is placed next to or in front of the high x-ray energy detector. The low energy sensitive detector has small stopping power for x-rays. The lower energy x-rays are absorbed and converted into electrical signals while the majority of the higher energy x-rays pass through undetected. The high energy sensitive detector has a large stopping power for x-rays as well as it having a filter placed between it and the object to absorb the lower energy x-rays. In a second embodiment; a single energy sensitive detector is provided which provides an output signal proportional to the amount of energy in each individual x-ray it absorbed. It can then have an electronic threshold or thresholds set to select two or more energy ranges for the images. By having multiple detectors located at different positions, a dual energy laminography system is possible. 6 figs.

  1. Curing Composite Materials Using Lower-Energy Electron Beams

    NASA Technical Reports Server (NTRS)

    Byrne, Catherine A.; Bykanov, Alexander

    2004-01-01

    In an improved method of fabricating composite-material structures by laying up prepreg tapes (tapes of fiber reinforcement impregnated by uncured matrix materials) and then curing them, one cures the layups by use of beams of electrons having kinetic energies in the range of 200 to 300 keV. In contrast, in a prior method, one used electron beams characterized by kinetic energies up to 20 MeV. The improved method was first suggested by an Italian group in 1993, but had not been demonstrated until recently. With respect to both the prior method and the present improved method, the impetus for the use of electron- beam curing is a desire to avoid the high costs of autoclaves large enough to effect thermal curing of large composite-material structures. Unfortunately, in the prior method, the advantages of electron-beam curing are offset by the need for special walls and ceilings on curing chambers to shield personnel from x rays generated by impacts of energetic electrons. These shields must be thick [typically 2 to 3 ft (about 0.6 to 0.9 m) if made of concrete] and are therefore expensive. They also make it difficult to bring large structures into and out of the curing chambers. Currently, all major companies that fabricate composite-material spacecraft and aircraft structures form their layups by use of automated tape placement (ATP) machines. In the present improved method, an electron-beam gun is attached to an ATP head and used to irradiate the tape as it is pressed onto the workpiece. The electron kinetic energy between 200 and 300 keV is sufficient for penetration of the ply being laid plus one or two of the plies underneath it. Provided that the electron-beam gun is properly positioned, it is possible to administer the required electron dose and, at the same time, to protect personnel with less shielding than is needed in the prior method. Adequate shielding can be provided by concrete walls 6 ft (approximately equal to 1.8 m) high and 16 in. (approximately

  2. Exotic X-ray Sources from Intermediate Energy Electron Beams

    SciTech Connect

    Chouffani, K.; Wells, D.; Harmon, F.; Jones, J.L.; Lancaster, G.

    2003-08-26

    High intensity x-ray beams are used in a wide variety of applications in solid-state physics, medicine, biology and material sciences. Synchrotron radiation (SR) is currently the primary, high-quality x-ray source that satisfies both brilliance and tunability. The high cost, large size and low x-ray energies of SR facilities, however, are serious limitations. Alternatively, 'novel' x-ray sources are now possible due to new small linear accelerator (LINAC) technology, such as improved beam emittance, low background, sub-Picosecond beam pulses, high beam stability and higher repetition rate. These sources all stem from processes that produce Radiation from relativistic Electron beams in (crystalline) Periodic Structures (REPS), or the periodic 'structure' of laser light. REPS x-ray sources are serious candidates for bright, compact, portable, monochromatic, and tunable x-ray sources with varying degrees of polarization and coherence. Despite the discovery and early research into these sources over the past 25 years, these sources are still in their infancy. Experimental and theoretical research are still urgently needed to answer fundamental questions about the practical and ultimate limits of their brightness, mono-chromaticity etc. We present experimental results and theoretical comparisons for three exotic REPS sources. These are Laser-Compton Scattering (LCS), Channeling Radiation (CR) and Parametric X-Radiation (PXR)

  3. Feasibility of ceramic joining with high energy electron beams

    SciTech Connect

    Turman, B.N.; Glass, S.J.; Halbleib, J.A.; Helmich, D.R.; Loehman, R.E.; Clifford, J.R.

    1995-01-01

    Joining structural ceramics is possible using high melting point metals such as Mo and Pt that are heated with a high energy electron beam, with the potential for producing joints with high temperature capability. A 10 MeV electron beam can penetrate through 1 cm of ceramic, offering the possibility of buried interface joining. Because of transient heating and the lower heat capacity of the metal relative to the ceramic, a pulsed high power beam has the potential for melting the metal without decomposing or melting the adjacent ceramic. The authors have demonstrated the feasibility of the process with a series of 10 MeV, 1 kW electron beam experiments. Shear strengths up to 28 NTa have been measured for Si{sub 3}N{sub 4}-Mo-Si{sub 3}N{sub 4}. These modest strengths are due to beam non-uniformity and the limited area of bonding. The bonding mechanism appears to be a thin silicide reaction layer. Si{sub 3}N{sub 4}-Si{sub 3}N{sub 4} joints with no metal layer were also produced, apparently bonded an yttrium apatite grain boundary phase.

  4. Low energy beam transport in the NSLS UV-FEL

    SciTech Connect

    Zhang, X.; Gallardo, J.C.

    1993-06-01

    A design of the injection low energy transport line for the proposed NSLS UV-FEL is presented. The main concern is to control the beam transverse emittance dilution due to space charge, energy spread and non-linear forces introduced by magnetic elements. The design considerations to optimize the transport line are discussed including the deleterious effects of space charge and energy spread as modeled by the particle code PARMELA. The results from PARMELA are analyzed, and the concept of slice emittance is used to examine the causes of emittance growth.

  5. Low energy beam transport in the NSLS UV-FEL

    SciTech Connect

    Zhang, X.; Gallardo, J.C.

    1993-01-01

    A design of the injection low energy transport line for the proposed NSLS UV-FEL is presented. The main concern is to control the beam transverse emittance dilution due to space charge, energy spread and non-linear forces introduced by magnetic elements. The design considerations to optimize the transport line are discussed including the deleterious effects of space charge and energy spread as modeled by the particle code PARMELA. The results from PARMELA are analyzed, and the concept of slice emittance is used to examine the causes of emittance growth.

  6. Interaction of turbulence with flexible beams in fluidic energy harvesting

    NASA Astrophysics Data System (ADS)

    Danesh Yazdi, Amir Hossein

    Advances in the development and fabrication of microelectronics have enhanced the energy efficiency of these devices to such an extent that they can now operate at very low power levels, typically on the order of a few microwatts or less. Batteries are primarily thought of as the most convenient source of power for electronic devices, but in instances where a device needs to be deployed in a difficult-to-access location such as under water, the added weight and especially maintenance of such a power source becomes costly. A solution that avoids this problem and is particularly attractive in a "deploy & forget" setting involves designing a device that continuously harvests energy from the surrounding environment. Piezoelectric energy harvesters, which employ the direct piezoelectric effect to convert mechanical strain into electrical energy, have garnered a great deal of attention in the literature. This work presents an overview of the experimental and analytical results related to fluidic energy extraction from vortex and turbulent flow using piezoelectric cantilever beams. In particular, the development of the FTGF (Fourier Transform-Green's Function) solution approach to the coupled, continuous electromechanical equations governing piezoelectric cantilever beams and the associated TFB (Train of Frozen Boxcars) method, which models the flow of vortices and turbulent eddies over the beams, is discussed. In addition, the behavior of fluidic energy harvesters in decaying isotropic, homogeneous grid turbulence generated by passive, semi-passive and active grids is examined and a novel grid-turbulence forcing model is introduced. An expression for the expected power output of the piezoelectric beam is obtained by utilizing this forcing function model in the single degree-of-freedom electromechanical equations. Furthermore, approximate, closed-form solutions to the theoretical expected power are derived from deterministic turbulence forcing models and are compared with

  7. Losses of ion energy in the multicomponent beam

    NASA Astrophysics Data System (ADS)

    Gasanov, Ilkham S.; Gurbanov, Ilgar I.; Akbarov, Elchin M.

    2015-03-01

    Energy losses of near axis ions and decreases in ion current density in the center of a beam were observed in a liquid metal source operating under a charged nanodroplets (In, Sn, Au, Ge) generation regime. In experiments, nanodroplets with the sizes of 2-20 nanometers and a characteristic specific charge of 5 × 104 C/kg were revealed. Energy spectra of ions were defined by means of the filter of speeds with cross-section static electromagnetic fields. A reduction of 4% of the In+ ions energy was observed under the conditions of the curried out measurements. The stream of nanoparticles, in contrast to an ion beam, has a small radial divergence; outside of this stream, change of ion speeds is not observed. Energy losses of ions occur during their flight through small nanoparticles. Penetration depth of the accelerated ions in liquid indium is estimated within the framework of the Lindhard-Scharff-Schiott model. Similar interaction between components occurs in ion-beam systems of complex composition where there is a relative movement of various charged particles.

  8. Beamed Energy Propulsion: Research Status And Needs--Part 2

    SciTech Connect

    Birkan, Mitat

    2008-04-28

    One promising solution to the operationally responsive space is the application of remote electromagnetic energy to propel a launch vehicle into orbit. With beamed energy propulsion, one can leave the power source stationary on the ground or space, and direct heat propellant on the spacecraft with a beam from a fixed station. This permits the spacecraft to leave its power source at home, saving significant amounts of mass, greatly improving performance. This concept, which removes the mass penalty of carrying the propulsion energy source on board the vehicle, was first proposed by Arthur Kantrowitz in 1972; he invoked an extremely powerful ground based laser. The same year Michael Minovich suggested a conceptually similar 'in-space' laser rocket system utilizing a remote laser power station. In the late 1980's, Air Force Office of Scientific Research (AFOSR) funded continuous, double pulse laser and microwave propulsion while Strategic Defense Initiative Office (SDIO) funded ablative laser rocket propulsion. Currently AFOSR has been funding the concept initiated by Leik Myrabo, repetitively pulsed laser propulsion, which has been universally perceived, arguably, to be the closest for mid-term applications. This 2-part paper examines the investment strategies in beamed energy propulsion and technical challenges to be covers Part 2 covers the present research status and needs.

  9. High energy electron beam irradiation of water, wastewater and sludge

    SciTech Connect

    Kurucz, C.N.; Waite, T.D.; Cooper, W.J.; Nickelsen, M.J.

    1991-12-31

    Research on the use of high energy electrons for treating water, wastewater and wastewater sludge has been under way for approximately twenty years. Much of this work has been supported by the National Science Foundation and an overview of that support has been reported on by Bryan. The results of recent work, especially the most recent project at the Miami Electron Beam Research Facility (EBRF), has stimulated great interest in the area of utilizing this technology for treating environmental problems. This facility is located at the Miami Dade Central District (Virginia Key) Wastewater Treatment Plant in Miami, Florida, and is unique in that it is the only electron beam system set up for large scale treatment of wastewater. High energy electron beam irradiation as a treatment process has potential application in many areas of water, wastewater and industrial waste treatment and in the area of toxic/hazardous waste disposal. This chapter will discuss these applications and present selected results to date. Electron beam technology is described and the underlying chemistry is reviewed to provide a basis for interpretation of results obtained so far, and to point out the necessary information on water quality that is required to quantitatively describe the effectiveness of the process. 55 refs., 10 figs., 5 tabs.

  10. A method for calculating strain energy release rate based on beam theory

    NASA Technical Reports Server (NTRS)

    Sun, C. T.; Pandey, R. K.

    1993-01-01

    The Timoshenko beam theory was used to model cracked beams and to calculate the total strain energy release rate. The root rotation of the beam segments at the crack tip were estimated based on an approximate 2D elasticity solution. By including the strain energy released due to the root rotations of the beams during crack extension, the strain energy release rate obtained using beam theory agrees very well with the 2D finite element solution. Numerical examples were given for various beam geometries and loading conditions. Comparisons with existing beam models were also given.

  11. Radiation damage in zircon by high-energy electron beams

    SciTech Connect

    Jiang Nan; Spence, John C. H.

    2009-06-15

    Radiation damage induced by high-energy (200 keV) electron irradiation in zircon has been studied thoroughly using imaging, diffraction, and electron energy-loss spectroscopy techniques in transmission electron microscopy. Both structural and compositional changes during the damage were measured using the above techniques in real time. It was found that the damage was mainly caused by the preferential sputtering of O. The loss of O occurred initially within small sporadic regions with dimension of several nanometers, resulting in the direct transformation of zircon into Zr{sub x}Si{sub y}. These isolated patches gradually connect each other and eventually cover the whole area of the electron beam. These differ from the previous observations either in the self-irradiated natural and synthetic zircon or in ion-beam irradiated thin zircon specimen.

  12. Developments in low energy electron beam machinery and processes

    NASA Astrophysics Data System (ADS)

    Nablo, S. V.; Chrusciel, J.; Cleghorn, D. A.; Rangwalla, I.

    2003-08-01

    The engineering and development of a new generation of low energy, high power electron beam equipment is presented. Operating voltages range from 80 to 125 kV at widths to 1.65 m. At 110 kV these systems deliver 1000 Mrad m min -1 at 110 kV. Equipment operating power levels and their impact on reducing equipment size and cost are reviewed. The advantages of electron curing at these reduced operating voltages are described. The principles of the electron beam fluidized bed process for the treatment of powders and particulates in high-speed pneumatic transport are discussed. Typical system performances for polymer dissociation and crosslinking, or for agroproduct disinfestation and disinfection are presented. A process for the sterilization of polymer food containers employing the injection of low energy electrons through the open mouth has been developed. Some of its sterilization capabilities for bottles up to 2 l capacity are described.

  13. Enhanced aeroelastic energy harvesting with a beam stiffener

    NASA Astrophysics Data System (ADS)

    Zhao, Liya; Yang, Yaowen

    2015-03-01

    In this article, we propose an easy but quite effective method to significantly enhance the power generation capability of an aeroelastic energy harvester. The method is to attach a beam stiffener to the substrate of the harvester, which works as an electromechanical coupling magnifier. It is shown to be effective for all three considered types of harvesters based on galloping, vortex-induced vibration and flutter, leading to a superior performance over the conventional designs without the beam stiffener, with dozens of times the increase in power and an almost 100% increase in the power extraction efficiency yet with comparable or even smaller transverse displacement. Choice guidelines of optimal types of energy harvesters are also suggested based on the given wind situations where the electronic device is located.

  14. Lattice design and beam dynamics studies of the high energy beam transport line in the RAON heavy ion accelerator

    NASA Astrophysics Data System (ADS)

    Jin, Hyunchang; Jang, Ji-Ho; Jang, Hyojae; Jeon, Dong-O.

    2015-12-01

    In RAON heavy ion accelerator, beams generated by superconducting electron cyclotron resonance ion source (ECR-IS) or Isotope Separation On-Line (ISOL) system are accelerated by lower energy superconducting linac and high energy superconducting linac. The accelerated beams are used in the high energy experimental hall which includes bio-medical and muon-SR facilities, after passing through the high energy beam transport lines. At the targets of those two facilities, the stable and small beams meeting the requirements rigorously are required in the transverse plane. Therefore the beams must be safely sent to the targets and simultaneously satisfy the two requirements, the achromatic condition and the mid-plane symmetric condition, of the targets. For this reason, the lattice design of the high energy beam transport lines in which the long deflecting sections are included is considered as a significant issue in the RAON accelerator. In this paper, we will describe the calculated beam optics satisfying the conditions and present the result of particle tracking simulations with the designed lattice of the high energy beam transport lines in the RAON accelerator. Also, the orbit distortion caused by the machine imperfections and the orbit correction with correctors will be discussed.

  15. Trap-Based Beam Formation Mechanisms and the Development of an Ultra-High-Energy-Resolution Cryogenic Positron Beam

    NASA Astrophysics Data System (ADS)

    Natisin, Michael Ryan

    The focus of this dissertation is the development of a positron beam with significantly improved energy resolution over any beam resolution previously available. While positron interactions with matter are important in a variety of contexts, the range of experimental data available regarding fundamental positron-matter interactions is severely limited as compared to analogous electron-matter processes. This difference is due largely to the difficulties encountered in creating positron beams with narrow energy spreads. Described here is a detailed investigation into the physical processes operative during positron cooling and beam formation in state-of-the-art, trap-based beam systems. These beams rely on buffer gas traps (BGTs), in which positrons are trapped and cooled to the ambient temperature (300 K) through interactions with a molecular gas, and subsequently ejected as a high resolution pulsed beam. Experimental measurements, analytic models, and simulation results are used to understand the creation and characterization of these beams, with a focus on the mechanisms responsible for setting beam energy resolution. The information gained from these experimental and theoretical studies was then used to design, construct, and operate a next-generation high-energy-resolution beam system. In this new system, the pulsed beam from the BGT is magnetically guided into a new apparatus which re-traps the positrons, cools them to 50 K, and re-emits them as a pulsed beam with superior beam characteristics. Using these techniques, positron beams with total energy spreads as low as 6.9 meV FWHM are produced. This represents a factor of ˜ 5 improvement over the previous state-of-the-art, making it the largest increase in positron beam energy resolution since the development of advanced moderator techniques in the early 1980's. These beams also have temporal spreads of 0.9 mus FWHM and radial spreads of 1 mm FWHM. This represents improvements by factors of ˜2 and 10

  16. Measurement of ultra-low ion energy of decelerated ion beam using a deflecting electric field

    NASA Astrophysics Data System (ADS)

    Thopan, P.; Suwannakachorn, D.; Tippawan, U.; Yu, L. D.

    2015-12-01

    In investigation on ultra-low-energy ion bombardment effect on DNA, an ion beam deceleration lens was developed for high-quality ultra-low-energy ion beam. Measurement of the ion energy after deceleration was necessary to confirm the ion beam really decelerated as theoretically predicted. In contrast to conventional methods, this work used a simple deflecting electrostatic field after the deceleration lens to bend the ion beam. The beam bending distance depended on the ion energy and was described and simulated. A system for the measurement of the ion beam energy was constructed. It consisted of a pair of parallel electrode plates to generate the deflecting electrical field, a copper rod measurement piece to detect ion beam current, a vernier caliper to mark the beam position, a stepping motor to translate the measurement rod, and a webcam-camera to read the beam bending distance. The entire system was installed after the ion-beam deceleration lens inside the large chamber of the bioengineering vertical ion beam line. Moving the measurement rod across the decelerated ion beam enabled to obtain beam profiles, from which the beam bending distance could be known and the ion beam energy could be calculated. The measurement results were in good agreement with theoretical and simulated results.

  17. Design of a multiresonant beam for broadband piezoelectric energy harvesting

    NASA Astrophysics Data System (ADS)

    Qi, Shaofan; Shuttleworth, Roger; Olutunde Oyadiji, S.; Wright, Jan

    2010-09-01

    This paper describes initial investigations into the behavior of a mechanical system for a proposed novel energy harvesting device. The device comprises a clamped-clamped beam piezoelectric fiber composite generator with side mounted cantilevers. These side mounted cantilevers are tuned by added masses to be resonant at different frequencies. A Rayleigh-Ritz model has been developed to predict the vibration response of the device and results from this model and from the real system are compared. The mechanical aspects of the device show a wide band energy harvesting characteristic in comparison to a single cantilever piezoelectric harvester.

  18. Upgrade of beam energy measurement system at BEPC-II

    NASA Astrophysics Data System (ADS)

    Zhang, Jian-Yong; Cai, Xiao; Mo, Xiao-Hu; Guo, Di-Zhou; Wang, Jian-Li; Liu, Bai-Qi; Achasov, M. N.; Krasnov, A. A.; Muchnoi, N. Yu.; Pyata, E. E.; Mamoshkina, E. V.; Harris, F. A.

    2016-07-01

    The beam energy measurement system is of great importance for both BEPC-II accelerator and BES-III detector. The system is based on measuring the energies of Compton back-scattered photons. In order to meet the requirements of data taking and improve the measurement accuracy, the system has continued to be upgraded, which involves the updating of laser and optics subsystems, replacement of a view-port of the laser to the vacuum insertion subsystem, the use of an electric cooling system for a high purity germanium detector, and improvement of the data acquisition and processing subsystem. The upgrade system guarantees the smooth and efficient measurement of beam energy at BEPC-II and enables accurate offline energy values for further physics analysis at BES-III. Supported in part by National Natural Science Foundation of China (NSFC)(11375206, 10775142, 10825524, 11125525, 11235011), the Ministry of Science and Technology of China (2015CB856700, 2015CB856705), State key laboratory of particle and detection and electronics; and the CAS Center for Excellence in Particle Physics (CCEPP); the RFBR grant(14-02-00129-a), U.S. Department of Energy (DE-FG02-04ER41291, DE-FG02-05ER41374, DE-FG02-94ER40823, DESC0010118), U.S. National Science Foundation, part of this work related to the design of ZnSe viewports is supported by the Russian Science Foundation (14-50-00080)

  19. Study on astrophysical reactions using low-energy RI beams

    NASA Astrophysics Data System (ADS)

    Yamaguchi, Hidetoshi

    2009-10-01

    In recent years, low-energy RI beams can be produced in a good intensity and they have been used for studying many astrophysical reactions. One of the facilities producing low-energy RI beams is CRIB (CNS Radio-Isotope Beam separator) [1,2], an RI-beam separator of Center for Nuclear Study, University of Tokyo. Taking CRIB as an example, recent improvements on the RI-beam production and experimental results on astrophysical studies are presented. Several experimental approaches have been taken for the studies on astrophysical reactions.The feature of each method are discussed based on real measurements performed at CRIB. One is the direct method, applied for measurements of reactions such as (α,p) [3]. Another is the measurement of proton/alpha resonance scattering using the thick target method in inverse kinematics, by which we can obtain information on the resonances relevant in astrophysical reactions [4,5]. A recent fruitful result was from a measurement of proton resonance scattering using a ^7Be beam [5]. The energy level structure of ^8B, revealed by the experiment, is especially of interest as it is related with the ^7Be(p,γ) ^8B reaction, responsible for the production of ^8B neutrinos in the sun. We successfully determined parameters of resonances in ^8B below 6.7 MeV, which may affect the ^7Be(p,γ)^8B reaction rate at the solar temparature. Indirect methods, such as ANC and the Trojan Horse Method, were also used in some of the measurements.[4pt] [1] S. Kubono et al., Eur. Phys. J. A13 (2002) 217.[0pt] [2] Y. Yanagisawa et al., Nucl. Instrum. Meth. Phys. Res., Sect. A 539 (2005) 74.[0pt] [3] M. Notani et al., Nucl. Phys. A 764 (2004) 113c.[0pt] [4] T. Teranishi et al., Phys. Lett. B 650 (2007) 129.[0pt] [5] H. Yamaguchi et al., Phys. Lett. B 672 (2009) 230.

  20. Effective parameters in beam acoustic metamaterials based on energy band structures

    NASA Astrophysics Data System (ADS)

    Jing, Li; Wu, Jiu Hui; Guan, Dong; Hou, Mingming; Kuan, Lu; Shen, Li

    2016-07-01

    We present a method to calculate the effective material parameters of beam acoustic metamaterials. The effective material parameters of a periodic beam are calculated as an example. The dispersion relations and energy band structures of this beam are calculated. Subsequently, the effective material parameters of the beam are investigated by using the energy band structures. Then, the modal analysis and transmission properties of the beams with finite cells are simulated in order to confirm the correctness of effective approximation. The results show that the periodic beam can be equivalent to the homogeneous beam with dynamic effective material parameters in passband.

  1. Equipment for Beam Current and Electron Energy Monitoring During Industry Irradiation.

    NASA Astrophysics Data System (ADS)

    Zavadtsev, A. A.

    1997-05-01

    The electron beam irradiation sterilization is placed first among all types of medical items sterilization. The quality of sterilization is determined by value of dose, which is in one's turn determined by beam current, electron energy and beam scanning system parameters. Therefore this parameters have to be controlled during the irradiation process. The equipment for beam current and electron energy monitoring allows to control beam current, electron energy spectrum and nominal deflection of electron beam when scanning during the irradiation process each scanning period or, for example, each tenth period by request.

  2. Energy-selective filtration of dental x-ray beams

    SciTech Connect

    Gelskey, D.E.; Baker, C.G.

    1981-11-01

    Samarium is known for its ability to filter simultaneously low- and high-energy x-ray photons from an x-ray beam that are not useful in producing a diagnostic radiograph. This study was undertaken to determine the optimum thickness of samarium required to minimize patient exposure and exposure time. The results indicate that use of a filter thickness of 0.16 mm. minimized patient radiation exposure and permitted the use of an exposure time sufficiently short to minimize motion unsharpness. The incorporation of a 0.16 mm. samarium filter in the x-ray beam reduced exposure by about 40 percent as compared to a 2.5 mm. aluminum filter; the exposure time must be increased approximately twice to obtain optical densities equivalent to those produced with aluminum filtration.

  3. Producing titanium-niobium alloy by high energy beam

    NASA Astrophysics Data System (ADS)

    Sharkeev, Yu. P.; Golkovski, M. G.; Glukhov, I. A.; Eroshenko, A. Yu.; Bataev, V. A.; Fortuna, S. V.

    2016-01-01

    The research is involved in producing a Ti-Nb alloy surface layer on titanium substrate by high energy beam method, as well as in examining their structures and mechanical properties. Applying electron-beam cladding it was possible to produce a Ti-Nb alloy surface layer of several millimeters, where the niobium concentration was up to 40% at. and the structure itself could be related to martensite quenching structure. At the same time, a significant microhardness increase of 3200-3400 MPa was observed, which, in its turn, is connected with the formation of martensite structure. Cladding material of Ti-Nb composition could be the source in producing alloys of homogeneous microhardness and desired concentration of alloying niobium element.

  4. An Energy Saving System for a Beam Pumping Unit.

    PubMed

    Lv, Hongqiang; Liu, Jun; Han, Jiuqiang; Jiang, An

    2016-01-01

    Beam pumping units are widely used in the oil production industry, but the energy efficiency of this artificial lift machinery is generally low, especially for the low-production well and high-production well in the later stage. There are a number of ways for energy savings in pumping units, with the periodic adjustment of stroke speed and rectification of balance deviation being two important methods. In the paper, an energy saving system for a beam pumping unit (ESS-BPU) based on the Internet of Things (IoT) was proposed. A total of four types of sensors, including load sensor, angle sensor, voltage sensor, and current sensor, were used to detect the operating conditions of the pumping unit. Data from these sensors was fed into a controller installed in an oilfield to adjust the stroke speed automatically and estimate the degree of balance in real-time. Additionally, remote supervision could be fulfilled using a browser on a computer or smartphone. Furthermore, the data from a practical application was recorded and analyzed, and it can be seen that ESS-BPU is helpful in reducing energy loss caused by unnecessarily high stroke speed and a poor degree of balance. PMID:27187402

  5. An Energy Saving System for a Beam Pumping Unit

    PubMed Central

    Lv, Hongqiang; Liu, Jun; Han, Jiuqiang; Jiang, An

    2016-01-01

    Beam pumping units are widely used in the oil production industry, but the energy efficiency of this artificial lift machinery is generally low, especially for the low-production well and high-production well in the later stage. There are a number of ways for energy savings in pumping units, with the periodic adjustment of stroke speed and rectification of balance deviation being two important methods. In the paper, an energy saving system for a beam pumping unit (ESS-BPU) based on the Internet of Things (IoT) was proposed. A total of four types of sensors, including load sensor, angle sensor, voltage sensor, and current sensor, were used to detect the operating conditions of the pumping unit. Data from these sensors was fed into a controller installed in an oilfield to adjust the stroke speed automatically and estimate the degree of balance in real-time. Additionally, remote supervision could be fulfilled using a browser on a computer or smartphone. Furthermore, the data from a practical application was recorded and analyzed, and it can be seen that ESS-BPU is helpful in reducing energy loss caused by unnecessarily high stroke speed and a poor degree of balance. PMID:27187402

  6. Beamed energy for space craft propulsion - Conceptual status and development potential

    NASA Technical Reports Server (NTRS)

    Sercel, Joel C.; Frisbee, Robert H.

    1987-01-01

    This paper outlines the results of a brief study that sought to identify and characterize beamed energy spacecraft propulsion concepts that may have positive impact on the economics of space industrialization. It is argued that the technology of beamed energy propulsion systems may significantly improve the prospects for near-term colonization of outer space. It is tentatively concluded that, for space industrialization purposes, the most attractive near-term beamed energy propulsion systems are based on microwave technology. This conclusion is reached based on consideration of the common features that exist between beamed microwave propulsion and the Solar Power Satellite (SPS) concept. Laser power beaming also continues to be an attractive option for spacecraft propulsion due to the reduced diffraction-induced beam spread afforded by laser radiation wavelengths. The conceptual status and development potential of a variety of beamed energy propulsion concepts are presented. Several alternative space transportation system concepts based on beamed energy propulsion are described.

  7. Energy characteristics of beam-plasma interaction in a closed volume

    NASA Astrophysics Data System (ADS)

    Klykov, I. L.; Tarakanov, V. P.; Shustin, E. G.

    2012-03-01

    Energy exchange between an electron beam and plasma during a beam-plasma discharge in a closed cavity excited by the electron beam is analyzed using computer simulations by the KARAT code. A method allowing one to analyze the beam-plasma interaction in the quasi-steady stage of the discharge is proposed. Qualitative characteristics of energy exchange (such as beam energy losses and the energy distributions of beam electrons and plasma particles leaving the discharge) both during spontaneous discharge excitation and in the presence of initial beam modulation by regular or noiselike signals are determined. The results obtained enable one to estimate the energy characteristics of a plasma processing reactor based on a beam-plasma discharge.

  8. Remote Electric Power Transfer Between Spacecrafts by Infrared Beamed Energy

    NASA Astrophysics Data System (ADS)

    Chertok, Boris E.; Evdokimov, Roman A.; Legostaev, Victor P.; Lopota, Vitaliy A.; Sokolov, Boris A.; Tugaenko, Vjacheslav Yu.

    2011-11-01

    High efficient wireless electric energy transmission (WET) technology between spacecrafts by laser channel is proposed. WET systems could be used for remote power supplying of different consumers in space. First of all, there are autonomous technology modules for microgravity experiments, micro and nano satellites, different equipment for explorations of planetary surfaces, space transport vehicles with electric rocket propulsion systems. The main components of the WET technology consist of radiation sources on the base of semiconductor IR laser diodes; systems for narrow laser beam creation; special photovoltaic receivers for conversion of monochromatic IR radiation with high energy density to electric power. The multistage space experiment for WET technology testing is described. During this experiment energy will be transmitted from International Space Station to another spacecrafts like cargo transport vehicles (Progress or/and ATV) and micro satellites.

  9. Strain energy release rate distributions for double cantilever beam specimens

    NASA Technical Reports Server (NTRS)

    Crews, J. H., Jr.; Shivakumar, K. N.; Raju, I. S.

    1991-01-01

    A 24-ply composite double cantilever-beam specimen under mode I (opening) loading has been analyzed by a 3D FEM code that calculated along a straight delamination starter for several different specimen materials. An isotropic specimen was found to have a strain-energy release rate distribution which varied along its delamination front due to the boundary-layer effect and another effect associated with the anticlastic curvature of the bent specimen arms. A 0-deg graphite-reinforced epoxy specimen had a nearly-uniform strain-energy release rate distribution which dropped only near the edge, due to the boundary-layer effect, and a +/- 45-deg graphite/epoxy specimen exhibited a pronounced strain-energy release rate variation across the specimen width.

  10. Beam collimation and energy spectrum compression of laser-accelerated proton beams using solenoid field and RF cavity

    NASA Astrophysics Data System (ADS)

    Teng, J.; Gu, Y. Q.; Zhu, B.; Hong, W.; Zhao, Z. Q.; Zhou, W. M.; Cao, L. F.

    2013-11-01

    This paper presents a new method of laser produced proton beam collimation and spectrum compression using a combination of a solenoid field and a RF cavity. The solenoid collects laser-driven protons efficiently within an angle that is smaller than 12 degrees because it is mounted few millimeters from the target, and collimates protons with energies around 2.3 MeV. The collimated proton beam then passes through a RF cavity to allow compression of the spectrum. Particle-in-cell (PIC) simulations demonstrate the proton beam transport in the solenoid and RF electric fields. Excellent energy compression and collection efficiency of protons are presented. This method for proton beam optimization is suitable for high repetition-rate laser acceleration proton beams, which could be used as an injector for a conventional proton accelerator.

  11. Review of Recent Results from the Rhic Beam Energy Scan

    NASA Astrophysics Data System (ADS)

    Kumar, Lokesh

    2013-10-01

    We review recent results from the RHIC beam energy scan (BES) program, aimed to study the Quantum Chromodynamics (QCD) phase diagram. The main goals are to search for the possible phase boundary, softening of equation of state or first order phase transition, and possible critical point. Phase-I of the BES program has recently concluded with data collection for Au+Au collisions at center-of-mass energies (√ {sNN}) of 7.7, 11.5, 19.6, 27 and 39 GeV. Several interesting results are observed for these lower energies where the net-baryon density is high at the mid-rapidity. These results indicate that the matter formed at lower energies (7.7 and 11.5 GeV) is hadron dominated and might not have undergone a phase transition. In addition, a centrality dependence of freeze-out parameters is observed for the first time at lower energies, slope of directed flow for (net)-protons measured versus rapidity shows an interesting behavior at lower energies, and higher moments of net-proton show deviation from Skellam expectations at lower energies. An outlook for the future BES Phase-II program is presented and efforts for the detailed study of QCD phase diagram are discussed.

  12. Stable topological insulators achieved using high energy electron beams

    PubMed Central

    Zhao, Lukas; Konczykowski, Marcin; Deng, Haiming; Korzhovska, Inna; Begliarbekov, Milan; Chen, Zhiyi; Papalazarou, Evangelos; Marsi, Marino; Perfetti, Luca; Hruban, Andrzej; Wołoś, Agnieszka; Krusin-Elbaum, Lia

    2016-01-01

    Topological insulators are potentially transformative quantum solids with metallic surface states which have Dirac band structure and are immune to disorder. Ubiquitous charged bulk defects, however, pull the Fermi energy into the bulk bands, denying access to surface charge transport. Here we demonstrate that irradiation with swift (∼2.5 MeV energy) electron beams allows to compensate these defects, bring the Fermi level back into the bulk gap and reach the charge neutrality point (CNP). Controlling the beam fluence, we tune bulk conductivity from p- (hole-like) to n-type (electron-like), crossing the Dirac point and back, while preserving the Dirac energy dispersion. The CNP conductance has a two-dimensional character on the order of ten conductance quanta and reveals, both in Bi2Te3 and Bi2Se3, the presence of only two quantum channels corresponding to two topological surfaces. The intrinsic quantum transport of the topological states is accessible disregarding the bulk size. PMID:26961901

  13. Stable topological insulators achieved using high energy electron beams

    NASA Astrophysics Data System (ADS)

    Zhao, Lukas; Konczykowski, Marcin; Deng, Haiming; Korzhovska, Inna; Begliarbekov, Milan; Chen, Zhiyi; Papalazarou, Evangelos; Marsi, Marino; Perfetti, Luca; Hruban, Andrzej; Wołoś, Agnieszka; Krusin-Elbaum, Lia

    2016-03-01

    Topological insulators are potentially transformative quantum solids with metallic surface states which have Dirac band structure and are immune to disorder. Ubiquitous charged bulk defects, however, pull the Fermi energy into the bulk bands, denying access to surface charge transport. Here we demonstrate that irradiation with swift (~2.5 MeV energy) electron beams allows to compensate these defects, bring the Fermi level back into the bulk gap and reach the charge neutrality point (CNP). Controlling the beam fluence, we tune bulk conductivity from p- (hole-like) to n-type (electron-like), crossing the Dirac point and back, while preserving the Dirac energy dispersion. The CNP conductance has a two-dimensional character on the order of ten conductance quanta and reveals, both in Bi2Te3 and Bi2Se3, the presence of only two quantum channels corresponding to two topological surfaces. The intrinsic quantum transport of the topological states is accessible disregarding the bulk size.

  14. Stable topological insulators achieved using high energy electron beams.

    PubMed

    Zhao, Lukas; Konczykowski, Marcin; Deng, Haiming; Korzhovska, Inna; Begliarbekov, Milan; Chen, Zhiyi; Papalazarou, Evangelos; Marsi, Marino; Perfetti, Luca; Hruban, Andrzej; Wołoś, Agnieszka; Krusin-Elbaum, Lia

    2016-01-01

    Topological insulators are potentially transformative quantum solids with metallic surface states which have Dirac band structure and are immune to disorder. Ubiquitous charged bulk defects, however, pull the Fermi energy into the bulk bands, denying access to surface charge transport. Here we demonstrate that irradiation with swift (∼2.5 MeV energy) electron beams allows to compensate these defects, bring the Fermi level back into the bulk gap and reach the charge neutrality point (CNP). Controlling the beam fluence, we tune bulk conductivity from p- (hole-like) to n-type (electron-like), crossing the Dirac point and back, while preserving the Dirac energy dispersion. The CNP conductance has a two-dimensional character on the order of ten conductance quanta and reveals, both in Bi2Te3 and Bi2Se3, the presence of only two quantum channels corresponding to two topological surfaces. The intrinsic quantum transport of the topological states is accessible disregarding the bulk size. PMID:26961901

  15. Measuring pion beta decay with high-energy pion beams

    SciTech Connect

    McFarlane, W.K. Temple Univ., Philadelphia, PA ); Hoffman, C.M. )

    1993-01-01

    Improved measurements of the pion beta decay rate are possible with an intense high-energy pion beam. The rate for the decay [pi][sup +] [yields] [pi][sup 0]e[sup +]v[epsilon] is predicted by the Standard Model (SM) to be R([pi][sup +] [yields] [pi][sup 0]e[sup +]v[epsilon]) = 0.3999[plus minus]0.0005 s[sup [minus]1]. The best experimental number, obtained using in-flight decays, is R([pi][sup +] [yields] [pi][sup 0]e[sup +]v[epsilon]) = 0.394 [plus minus] 0.015 s[sup [minus]1]. A precise measurement would test the SM by testing the unitarity of the Cabibbo-Kobayashi-Maskawa matrix for which one analysis of the nuclear beta decay data has shown a 0.4% discrepancy. Several nuclear correction factors, needed for nuclear decay, are not present for pion beta decay, so that an experiment at the 0.2% level would be a significant one. Detailed study of possible designs will be needed, as well as extensive testing of components. The reduction of systematic errors to the 0.1% level can only be done over a period of years with a highly stable apparatus and beam. At a minimum, three years of occupancy of a beam line, with 800 hours per year, would be required.

  16. Measuring pion beta decay with high-energy pion beams

    SciTech Connect

    McFarlane, W.K. |; Hoffman, C.M.

    1993-02-01

    Improved measurements of the pion beta decay rate are possible with an intense high-energy pion beam. The rate for the decay {pi}{sup +} {yields} {pi}{sup 0}e{sup +}v{epsilon} is predicted by the Standard Model (SM) to be R({pi}{sup +} {yields} {pi}{sup 0}e{sup +}v{epsilon}) = 0.3999{plus_minus}0.0005 s{sup {minus}1}. The best experimental number, obtained using in-flight decays, is R({pi}{sup +} {yields} {pi}{sup 0}e{sup +}v{epsilon}) = 0.394 {plus_minus} 0.015 s{sup {minus}1}. A precise measurement would test the SM by testing the unitarity of the Cabibbo-Kobayashi-Maskawa matrix for which one analysis of the nuclear beta decay data has shown a 0.4% discrepancy. Several nuclear correction factors, needed for nuclear decay, are not present for pion beta decay, so that an experiment at the 0.2% level would be a significant one. Detailed study of possible designs will be needed, as well as extensive testing of components. The reduction of systematic errors to the 0.1% level can only be done over a period of years with a highly stable apparatus and beam. At a minimum, three years of occupancy of a beam line, with 800 hours per year, would be required.

  17. Replacement of chemical rocket launchers by beamed energy propulsion.

    PubMed

    Fukunari, Masafumi; Arnault, Anthony; Yamaguchi, Toshikazu; Komurasaki, Kimiya

    2014-11-01

    Microwave Rocket is a beamed energy propulsion system that is expected to reach space at drastically lower cost. This cost reduction is estimated by replacing the first-stage engine and solid rocket boosters of the Japanese H-IIB rocket with Microwave Rocket, using a recently developed thrust model in which thrust is generated through repetitively pulsed microwave detonation with a reed-valve air-breathing system. Results show that Microwave Rocket trajectory, in terms of velocity versus altitude, can be designed similarly to the current H-IIB first stage trajectory. Moreover, the payload ratio can be increased by 450%, resulting in launch-cost reduction of 74%. PMID:25402933

  18. Beamed Energy Propulsion by Means of Target Ablation

    NASA Astrophysics Data System (ADS)

    Rosenberg, Benjamin A.

    2004-03-01

    This paper describes hundreds of pendulum tests examining the beamed energy conversion efficiency of different metal targets coated with multiple liquid enhancers. Preliminary testing used a local laser with photographic paper targets, with no liquid, water, canola oil, or methanol additives. Laboratory experimentation was completed at Wright-Patterson AFB using a high-powered laser, and ballistic pendulums of aluminum, titanium, or copper. Dry targets, and those coated with water, methanol and oil were repeatedly tested in laboratory conditions. Results were recorded on several high-speed digital video cameras, and the conversion efficiency was calculated. Paper airplanes successfully launched using BEP were likewise recorded.

  19. Vacuum Chamber for the Measurement System of the Beam Energy

    NASA Astrophysics Data System (ADS)

    Abakumova, E.; Achasov, M.; Dong, HaiYi; Qu, HuaMin; Krasnov, A.; Kosarev, A.; Muchnoi, N.; Pyata, E.; Xiao, Qiong; Mo, XiaoHu; Wang, YiFang; Zhukov, A.

    Vacuum chamber for the beam energy measurement system based on the Compton backscattering method is presented. The main elements of the chamber are GaAs entrance viewport and a copper mirror. The viewport design provides baking out of the vacuum chamber up to 250 °C. To produce the viewport, an original technology based on brazing GaAs plate by lead has been developed. The vacuum chambers were installed at the BEPC-II and VEPP-4 M colliders. After installation the residual gas pressure is about 10-10 Torr.

  20. Beamed Energy Propulsion by Means of Target Ablation

    SciTech Connect

    Rosenberg, Benjamin A.

    2004-03-30

    This paper describes hundreds of pendulum tests examining the beamed energy conversion efficiency of different metal targets coated with multiple liquid enhancers. Preliminary testing used a local laser with photographic paper targets, with no liquid, water, canola oil, or methanol additives. Laboratory experimentation was completed at Wright-Patterson AFB using a high-powered laser, and ballistic pendulums of aluminum, titanium, or copper. Dry targets, and those coated with water, methanol and oil were repeatedly tested in laboratory conditions. Results were recorded on several high-speed digital video cameras, and the conversion efficiency was calculated. Paper airplanes successfully launched using BEP were likewise recorded.

  1. Beam Line Design and Beam Physics Study of Energy Recovery Linac Free Electron Laser at Peking University

    SciTech Connect

    Wang, Guimei

    2011-12-31

    Energy recovering linac (ERL) offers an attractive alternative for generating intense beams of charged particles by approaching the operational efficiency of a storage ring while maintaining the superior beam quality typical of a linear accelerator. In ERLs, the decelerated beam cancels the beam loading effects of the accelerated beam with high repetition rate. Therefore, ERLs can, in principle, accelerate very high average currents with only modest amounts of RF power. So the efficiency of RF power to beam is much higher. Furthermore, the energy of beam to dump is lower, so it will reduce dump radiation. With the successful experiments in large maximum-to-injection energy ratio up to 51:1 and high power FEL up to 14kW, the use of ERL, especially combining with superconducting RF technology, provides a potentially powerful new paradigm for generation of the charged particle beams used in MW FEL, synchrotron radiation sources, high-energy electron cooling devices and so on. The 3+1/2 DC-SC photo injector and two 9cell TESLA superconducting cavity for IR SASE FEL in PKU provides a good platform to achieve high average FEL with Energy Recovery. The work of this thesis is on Beam line design and Beam dynamics study of Energy Recovery Linac Free Electron Laser for Peking University. It is the upgrade of PKU facility, which is under construction. With ERL, this facility can work in CW mode, so it can operate high average beam current without RF power constraint in main linac and generate high average FEL power. Moreover, it provides a test facility to study the key technology in ERL. System parameters are optimized for PKU ERL-FEL. The oscillation FEL output power is studied with different bunch charge, transverse emittance, bunch length and energy spread. The theory of optimal RF power and Q{sub ext} with ERL and without ERL is analyzed and applied to PKU injector and linac including microphonic effect. pace charge effect in the injector and merger is studied for beam

  2. Tuning the implosion symmetry of ICF targets via controlled crossed-beam energy transfer

    SciTech Connect

    Michel, P; Divol, L; Williams, E; Weber, S; Thomas, C A; Callahan, D A; Haan, S W; Salmonson, J D; Dixit, S; Hinkel, D E; Edwards, M J; MacGowan, B J; Lindl, J D; Glenzer, S H; Suter, L

    2008-07-29

    Radiative hydrodynamics simulations of ignition experiments show that energy transfer between crossing laser beams allows tuning of the implosion symmetry. A new full-scale, three dimensional quantitative model has been developed for crossed-beam energy transfer, allowing calculations of the propagation and coupling of multiple laser beams and their associated plasma waves in ignition hohlraums. This model has been implemented in a radiative-hydrodynamics code, demonstrating control of the implosion symmetry by a wavelength separation between cones of laser beams.

  3. Feasibility of a 90° electric sector energy analyzer for low energy ion beam characterization

    SciTech Connect

    Mahinay, C. L. S. Ramos, H. J.; Wada, M.

    2015-02-15

    A simple formula to calculate refocusing by locating the output slit at a specific distance away from the exit of 90° ion deflecting electric sector is given. Numerical analysis is also performed to calculate the ion beam trajectories for different values of the initial angular deviation of the beam. To validate the theory, a compact (90 mm × 5.5 mm × 32 mm) 90° sector ESA is fabricated which can fit through the inner diameter of a conflat 70 vacuum flange. Experimental results show that the dependence of resolution upon the distance between the sector exit and the Faraday cup agrees with the theory. The fabricated 90° sector electrostatic energy analyzer was then used to measure the space resolved ion energy distribution functions of an ion beam with the energy as low as 600 eV.

  4. Feasibility of a 90° electric sector energy analyzer for low energy ion beam characterization.

    PubMed

    Mahinay, C L S; Wada, M; Ramos, H J

    2015-02-01

    A simple formula to calculate refocusing by locating the output slit at a specific distance away from the exit of 90° ion deflecting electric sector is given. Numerical analysis is also performed to calculate the ion beam trajectories for different values of the initial angular deviation of the beam. To validate the theory, a compact (90 mm × 5.5 mm × 32 mm) 90° sector ESA is fabricated which can fit through the inner diameter of a conflat 70 vacuum flange. Experimental results show that the dependence of resolution upon the distance between the sector exit and the Faraday cup agrees with the theory. The fabricated 90° sector electrostatic energy analyzer was then used to measure the space resolved ion energy distribution functions of an ion beam with the energy as low as 600 eV. PMID:25725835

  5. Transport of intense proton beam in the presence of subdominant species in a low energy beam transport system

    NASA Astrophysics Data System (ADS)

    Babu, P. Sing; Goswami, A.; Pandit, V. S.

    2016-04-01

    The dynamics of space-charge-dominated low energy proton beam in the presence of H2+ and H3+ beams has been studied in a solenoid based transport system using particle-in-cell (PIC) simulation method. Multispecies envelope equation and random search technique have been used to transport and match the primary beam considering two options. The PIC simulation shows the formation of hollow distribution of H2+ and H3+ beams around the proton beam in the first case where the waist of the proton beam is formed in between the solenoids and it is absent in the second case where the beam size is kept large in between the solenoids. Separation of hollow distribution appears more distinct as the proton fraction is increased and is almost independent of the combination of H2+ and H3+ beams for a given proton fraction. This effect helps to reject the unwanted species more effectively. The evolution of rms size and emittance of the proton beam has been studied in the presence of a circular aperture using KV and Gaussian distributions for the species in both the cases.

  6. A parallel particle-in-cell model for beam-beam interaction in high energy ring colliders

    NASA Astrophysics Data System (ADS)

    Qiang, Ji; Furman, Miguel A.; Ryne, Robert D.

    2004-07-01

    In this paper we present a self-consistent simulation model of colliding beams in high energy ring colliders. The model, which is based on a particle-in-cell method, uses a new developed shifted effective Green function algorithm for the efficient calculation of the beam-beam interaction with arbitrary separation and large aspect ratio. The model uses transfer maps to treat the external focusing elements and a stochastic map to treat radiation damping and quantum excitation of the beams. In the parallel implementation we studied various strategies to deal with the particular nature of the colliding beam system - a system in which there can be significant particle movement between beam-beam collisions. We chose a particle-field decomposition approach instead of the conventional domain decomposition or particle decomposition approach. The particle-field approach leads to good load balance, reduced communication cost, and shows the best scalability on an IBM SP3 among the three parallel implementations we studied. A performance test of the beam-beam model on a Cray T3E, IBM SP3, and a PC cluster is presented. As an application, we studied the flip-flop instability in an electron-positron collider.

  7. Measuring the photon energy scale through test beam data

    NASA Astrophysics Data System (ADS)

    Loureiro, Karina Flavia

    This dissertation aims at measuring the photon energy scale combining specialized Monte Carlo simulation with data taken during the combined ATLAS test beam in 2004. This work explains the steps taken to arrive at the photon energy scale, starting from the knowledge acquired for electrons. The chapters are structured as follows: Chapters 1 and 2 briefly introduce this work and the motivation behind it. Chapter 3 gives an overview of the LHC experiment and the ATLAS detector as a whole. Chapters 4 and 5 address in detail the ATLAS electromagnetic calorimeter and signal reconstruction at the cell level. Chapter 6 concentrates on the setup for the combined test beam with emphasis on the photon run. Chapter 7 details the event selection strategy used for the photon run analysis. Chapter 8 describes the generation and tuning of the special Monte Carlo for the photon run. Chapter 9 focuses on the highly specialized Monte Carlo studies that employed special calibration objects known as calibration hits. Chapter 10 details the methodology behind the measurement of the photon scale and evaluates it in terms of the electromagnetic calorimeter resolution. Chapters 11 and 12 present a summary of the results and the conclusions, respectively.

  8. BEAM INDUCED ENERGY DEPOSITION IN MUON STORAGE RINGS.

    SciTech Connect

    MOKHOV,N.V.; JOHNSTONE,C.J.; PARKER,B.L.

    2001-06-18

    Beam-induced radiation effects have been simulated for 20 and 50 GeV muon storage rings designed for a Neutrino Factory. It is shown that by appropriately shielding the superconducting magnets, quench stability, acceptable dynamic heat loads, and low residual dose rates can be achieved. Alternatively, if a specially-designed skew focusing magnet without superconducting coils on the magnet's mid-plane is used, then the energy is deposited preferentially in the warm iron yoke or outer cryostat layers and internal shielding may not be required. In addition to the component irradiation analysis, shielding studies have been performed. Calculations of the external radiation were done for both designs but the internal energy deposition calculations for the 20 GeV Study-2 lattice are still in progress.

  9. Beam-induced energy deposition in muon storage rings

    SciTech Connect

    Nikolai V. Mokhov; Carol J. Johnstone; Brett Parker

    2001-06-22

    Beam-induced radiation effects have been simulated for 20 and 50 GeV muon storage rings designed for a Neutrino Factory. It is shown that by appropriately shielding the superconducting magnets, quench stability, acceptable dynamic heat loads, and low residual dose rates can be achieved. Alternatively, if a specially-designed skew focusing magnet without superconducting coils on the magnet's mid-plane is used, then the energy is deposited preferentially in the warm iron yoke or outer cryostat layers and internal shielding may not be required. In addition to the component irradiation analysis, shielding studies have been performed. Calculations of the external radiation were done for both designs but the internal energy deposition calculations for the 20 GeV Study-2 lattice are still in progress.

  10. Online beam energy measurement of Beijing electron positron collider II linear accelerator.

    PubMed

    Wang, S; Iqbal, M; Liu, R; Chi, Y

    2016-02-01

    This paper describes online beam energy measurement of Beijing Electron Positron Collider upgraded version II linear accelerator (linac) adequately. It presents the calculation formula, gives the error analysis in detail, discusses the realization in practice, and makes some verification. The method mentioned here measures the beam energy by acquiring the horizontal beam position with three beam position monitors (BPMs), which eliminates the effect of orbit fluctuation, and is much better than the one using the single BPM. The error analysis indicates that this online measurement has further potential usage such as a part of beam energy feedback system. The reliability of this method is also discussed and demonstrated in this paper. PMID:26931839

  11. Generalized energy-aperture product limit for multi-beam and spotlight SARs

    SciTech Connect

    Karr, T.J.

    1995-12-21

    The SAR energy-aperture product limit is extended to multi-beam SARS, Spotlight and moving spotlight SARS. This fundamental limit bounds the tradeoff between energy and antenna size. The kinematic relations between design variables such as platform speed, pulse repetition frequency, beam width and area rate are analyzed in a unified framework applicable to a wide variety of SARs including strip maps, spotlights, vermer arrays and multi-beam SARS, both scanning and swept-beam. Then the energy-aperture product limit is derived from the signal-to noise requirement and the kinematic constraints. The derivation clarifies impact of multiple beams and spotlighting on SAR performance.

  12. Online beam energy measurement of Beijing electron positron collider II linear accelerator

    NASA Astrophysics Data System (ADS)

    Wang, S.; Iqbal, M.; Liu, R.; Chi, Y.

    2016-02-01

    This paper describes online beam energy measurement of Beijing Electron Positron Collider upgraded version II linear accelerator (linac) adequately. It presents the calculation formula, gives the error analysis in detail, discusses the realization in practice, and makes some verification. The method mentioned here measures the beam energy by acquiring the horizontal beam position with three beam position monitors (BPMs), which eliminates the effect of orbit fluctuation, and is much better than the one using the single BPM. The error analysis indicates that this online measurement has further potential usage such as a part of beam energy feedback system. The reliability of this method is also discussed and demonstrated in this paper.

  13. Future Physics Opportunities in Beam Energy Scan at RHIC

    NASA Astrophysics Data System (ADS)

    Xu, Nu

    2015-10-01

    In the first phase of the beam energy scan program (BES-I) at RHIC, we have collected data from Au +Au collisions at the center of mass energy range from 7.7 GeV to 39 GeV, corresponding to the baryonic chemical potential of 420 MeV to 120 MeV, respectively. We have observed the disappearance of the suppression of leading hadrons at large pT, break down of the quark scaling in the identified particle elliptic flow, the net-proton directed flow slope dv1/dy shows a minimum with negative sign, and a non-monotonical behavior of the net-proton correlation function (the fourth order) at the energy less than 20 GeV. All of these observations indicate that the property of the medium at high baryon density is dramatically different from that created at the RHIC top energy where the baryon density is small and partonic interactions are dominant. In this talk I will first review what we have learned in RHIC BES-I. Then I will discuss the opportunities in the future bean energy scan program in order to address key questions regarding the QCD phase structure including the illusive critical point. I will stress that adequate detector upgrades, focused at the large baryon density region, are essential for the physics program.

  14. The RHIC Beam Energy Scan: Present Challenges and Coming Opportunities

    NASA Astrophysics Data System (ADS)

    Rajagopal, Krishna

    2015-10-01

    The RHIC Beam Energy Scan is mapping the phase diagram of QCD, creating and probing quark-gluon plasma ``doped'' to varying degrees with an excess of quarks over antiquarks. Recent data from the first phase of the scan challenge us to understand intriguing non-monotonic collision energy dependence (and therefore doping dependence) of various observables. They hint at a reduction in the QGP pressure, long anticipated in collisions that form QGP at temperatures not far above the crossover region. As the collision energy is lowered, possible signs of the turning off of effects driven by the chiral anomaly, signaling the approximate restoration of chiral symmetry, have been seen. And, there are tantalizing indications of a substantial drop and a subsequent substantial rise in a fluctuation observable that is particularly sensitive to critical fluctuations and that has been predicted to do exactly that the doping increases if a critical point on the phase diagram is approached. Each of these points to opportunities for discovery in the second phase of the scan (BES-II), coming in 2019-20, with much higher statistics data at the low energies where the most tantalizing effects reside. Today, though, the ball is squarely in the theorists' court: the data demand a concerted, multifaceted, theoretical response, building a quantitative framework for modeling the salient features of lower energy heavy ion collisions. If we respond well to this present challenge, BES-II can turn today's trends and features into discoveries, conclusions, and new understanding.

  15. Use of off-axis injection as an alternative to geometrically merging beams in an energy-recovering linac

    DOEpatents

    Douglas, David R.

    2012-01-10

    A method of using off-axis particle beam injection in energy-recovering linear accelerators that increases operational efficiency while eliminating the need to merge the high energy re-circulating beam with an injected low energy beam. In this arrangement, the high energy re-circulating beam and the low energy beam are manipulated such that they are within a predetermined distance from one another and then the two immerged beams are injected into the linac and propagated through the system. The configuration permits injection without geometric beam merging as well as decelerated beam extraction without the use of typical beamline elements.

  16. Beam Fields and Energy Dissipation Inside the the BE Beam Pipe of the Super-B Detector

    SciTech Connect

    Novokhatski, Alexander; Sullivan, Michael; /SLAC

    2010-09-10

    We study the bunch field diffusion and energy dissipation in the beam pipe of the Super-B detector, which consists of two coaxial Be thin pipes (half a millimeter). Cooling water will run between these two pipes. Gold and nickel will be sputtered (several microns) onto the beryllium pipe at different sides. The Maxwell equations for the beam fields in these thin layers are solved numerically for the case of infinite pipes. We also calculate the amplitude of the electromagnetic fields outside the beam pipe, which may be noticeable as the beam current can reach 4 A in each beam. Results of simulations are used for the design of this central part of the Super-B detector.

  17. Beam structure and transverse emittance studies of high-energy ion beams

    NASA Astrophysics Data System (ADS)

    Saadatmand, K.; Johnson, K. F.; Schneider, J. D.

    1991-05-01

    A visual diagnostic technique was developed to monitor and study ion beam structure shape and size along a transport line. In this technique, a commercially available fluorescent screen is utilized in conjunction with a video camera. This visual representation of the beam structure is digitized and enhanced through use of false color coding and displayed on a TV monitor for on-line viewing. Digitized information is stored for further off-line processing (e.g., extraction of beam profiles). An optional wire grid placed upstream of the fluor screen adds the capability of transverse emittance (or angular spread) measurement to this technique. This diagnostic allows real time observation of the beam response to parameter changes (e.g., evolution of the beam structure, shifts in the beam intensity at various spatial locations within the beam perimeter, and shifts in the beam center and position).

  18. Implementation of a compact magnetic electron energy spectrometer for intense relativistic electron beams. Interim report

    SciTech Connect

    Gregor, J.A.; Antoniades, J.A.

    1993-11-05

    A diagnostic used for measuring the energy of 1 to 5 MEV pulsed electron beams by means independent of the beam generating device is investigated. The method employed is capable of collecting the required data optically in a single pulse. The beam energy is measured using a magnetic electron spectrometer coupled with a scintillating material. Using a polaroid camera to collect data, the energy of electron beams from two field emission diode accelerators is measured. The first is a nominal 1 MEV, 16 kA, 25 ns FWHM electron beam and the second is a nominal 5 MEV, 20 kA, 50 ns FWHM electron beam. A detailed study of measurement accuracy and possible sources of error was accomplished. Energy, Relativistic, Electron beam. Electron, Spectrometer.

  19. Inverse planning of energy-modulated electron beams in radiotherapy

    SciTech Connect

    Gentry, John R. . E-mail: gentryj@gmh.org; Steeves, Richard; Paliwal, Bhudatt A.

    2006-01-01

    The use of megavoltage electron beams often poses a clinical challenge in that the planning target volume (PTV) is anterior to other radiosensitive structures and has variable depth. To ensure that skin as well as the deepest extent of the PTV receives the prescribed dose entails prescribing to a point beyond the depth of peak dose for a single electron energy. This causes dose inhomogeneities and heightened potential for tissue fibrosis, scarring, and possible soft tissue necrosis. Use of bolus on the skin improves the entrant dose at the cost of decreasing the therapeutic depth that can be treated. Selection of a higher energy to improve dose homogeneity results in increased dose to structures beyond the PTV, as well as enlargement of the volume receiving heightened dose. Measured electron data from a linear accelerator was used as input to create an inverse planning tool employing energy and intensity modulation using bolus (e-IMRT{sup TM}). Using tools readily available in a radiotherapy department, the applications of energy and intensity modulation on the central axis makes it possible to remove hot spots of 115% or more over the depths clinically encountered. The e-IMRT{sup TM} algorithm enables the development of patient-specific dose distributions with user-defined positions of peak dose, range, and reduced dose to points beyond the prescription point.

  20. Future of the Beam Energy Scan program at RHIC

    SciTech Connect

    Odyniec, Grazyna; Bravina, L.; Foka, Y.; Kabana, S.

    2015-05-29

    The first exploratory phase of a very successful Beam Energy Scan Program at RHIC was completed in 2014 with Au+Au collisions at energies ranging from 7 to 39 GeV. Data sets taken earlier extended the upper limit of energy range to the √sNN of 200 GeV. This provided an initial look into the uncharted territory of the QCD phase diagram, which is considered to be the single most important graph of our field. The main results from BES phase I, although effected by large statistical errors (steeply increasing with decreasing energy), suggest that the highest potential for discovery of the QCD Critical Point lies bellow √sNN 20 GeV. Here, we discuss the plans and the preparation for phase II of the BES program, with an order of magnitude larger statistics, which is planned for 2018-2019. The BES II will focus on Au+Au collisions at √sNN from 20 to 7 GeV in collider mode, and from √sNN 7 to 3.5 GeV in the fixed target mode, which will be run concurrently with the collider mode operation.

  1. Future of the beam energy scan program at RHIC

    NASA Astrophysics Data System (ADS)

    Odyniec, Grazyna

    2015-05-01

    The first exploratory phase of a very successful Beam Energy Scan Program at RHIC was completed in 2014 with Au+Au collisions at energies ranging from 7 to 39 GeV. Data sets taken earlier extended the upper limit of energy range to the √sNN of 200 GeV. This provided an initial look into the uncharted territory of the QCD phase diagram, which is considered to be the single most important graph of our field. The main results from BES phase I, although effected by large statistical errors (steeply increasing with decreasing energy), suggest that the highest potential for discovery of the QCD Critical Point lies bellow √sNN 20 GeV. Here, we discuss the plans and the preparation for phase II of the BES program, with an order of magnitude larger statistics, which is planned for 2018-2019. The BES II will focus on Au+Au collisions at √sNN from 20 to 7 GeV in collider mode, and from √sNN 7 to 3.5 GeV in the fixed target mode, which will be run concurrently with the collider mode operation.

  2. Future of the Beam Energy Scan program at RHIC

    DOE PAGESBeta

    Odyniec, Grazyna; Bravina, L.; Foka, Y.; Kabana, S.

    2015-05-29

    The first exploratory phase of a very successful Beam Energy Scan Program at RHIC was completed in 2014 with Au+Au collisions at energies ranging from 7 to 39 GeV. Data sets taken earlier extended the upper limit of energy range to the √sNN of 200 GeV. This provided an initial look into the uncharted territory of the QCD phase diagram, which is considered to be the single most important graph of our field. The main results from BES phase I, although effected by large statistical errors (steeply increasing with decreasing energy), suggest that the highest potential for discovery of themore » QCD Critical Point lies bellow √sNN 20 GeV. Here, we discuss the plans and the preparation for phase II of the BES program, with an order of magnitude larger statistics, which is planned for 2018-2019. The BES II will focus on Au+Au collisions at √sNN from 20 to 7 GeV in collider mode, and from √sNN 7 to 3.5 GeV in the fixed target mode, which will be run concurrently with the collider mode operation.« less

  3. The angular and energy distribution of the primary electron beam.

    PubMed

    Keall, P J; Hoban, P W

    1994-09-01

    The angular distribution for electron beams produced by the Siemens KD-2 linear accelerator has been found by simulating electron transport through the scattering foils and air using two methods: Fermi-Eyges multiple Coulomb scattering calculations, and EGS4 Monte Carlo simulations. Fermi-Eyges theory gives solutions where both the angular and spatial fluence distributions are Gaussian, with the angular standard deviation being invariant with off-axis distance. The EGS4 results show slightly non-Gaussian angular and lateral distributions as a result of the use of Moliére theory rather than Fermi-Eyges multiple scattering theory, as well as the simulation of discrete bremsstrahlung and Møller interactions. However, the results from both methods are very similar. The angular standard deviations obtained by these methods agree very closely with those found experimentally. The similar shape of the Monte Carlo and Fermi-Eyges results indicate that a Gaussian approximation to the incident angular distribution will be adequate for use in treatment planning algorithms. Furthermore, the angular standard deviation may be determined using Fermi-Eyges theory as an alternative to experimental methods. Both Monte Carlo simulations, and Fermi-Eyges theory predict that the mean electron angle is proportional to off axis distance for all useful field sizes. For a 15 MeV electron beam, an effective source position of 99 cm and 98 cm from the nominal 100 SSD plane was obtained from Fermi-Eyges and Monte Carlo results respectively for a 15 MeV beam. The effective source position found experimentally for this energy was 98 cm.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7980200

  4. Beam measurements on the H- source and Low Energy Beam Transport system for the Spallation Neutron Source

    SciTech Connect

    Thomae, R.; Gough, R.; Keller, R.; Leung, K.N.; Schenkel, T.; Aleksandrov, A.; Stockli, M.; Welton, R.

    2001-09-01

    The ion source and Low Energy Beam Transport section of the front-end systems presently being built by Berkeley Lab are required to provide 50 mA of H - beam current at 6% duty factor (1 ms pulses at 60 Hz) with a normalized rms emittance of less than 0.20 p-mm-mrad. Experimental results, including emittance, chopping, and steering measurements, on the performance of the ion source and LEBT system operated at the demanded beam parameters will be discussed.

  5. Experimental study of magnetically confined hollow electron beams in the Tevatron as collimators for intense high-energy hadron beams

    SciTech Connect

    Stancari, G.; Annala, G.; Shiltsev, V.; Still, D.; Valishev, A.; Vorobiev, L.; /Fermilab

    2011-03-01

    Magnetically confined hollow electron beams for controlled halo removal in high-energy colliders such as the Tevatron or the LHC may extend traditional collimation systems beyond the intensity limits imposed by tolerable losses. They may also improve collimation performance by suppressing loss spikes due to beam jitter and by increasing capture efficiency. A hollow electron gun was designed and tested at Fermilab for this purpose. It was installed in one of the Tevatron electron lenses in the summer of 2010. We present the results of the first experimental tests of the hollow-beam collimation concept on 980-GeV antiproton bunches in the Tevatron.

  6. A new Bernoulli-Euler beam model incorporating microstructure and surface energy effects

    NASA Astrophysics Data System (ADS)

    Gao, X.-L.; Mahmoud, F. F.

    2014-04-01

    A new Bernoulli-Euler beam model is developed using a modified couple stress theory and a surface elasticity theory. A variational formulation based on the principle of minimum total potential energy is employed, which leads to the simultaneous determination of the equilibrium equation and complete boundary conditions for a Bernoulli-Euler beam. The new model contains a material length scale parameter accounting for the microstructure effect in the bulk of the beam and three surface elasticity constants describing the mechanical behavior of the beam surface layer. The inclusion of these additional material constants enables the new model to capture the microstructure- and surface energy-dependent size effect. In addition, Poisson's effect is incorporated in the current model, unlike existing beam models. The new beam model includes the models considering only the microstructure dependence or the surface energy effect as special cases. The current model reduces to the classical Bernoulli-Euler beam model when the microstructure dependence, surface energy, and Poisson's effect are all suppressed. To demonstrate the new model, a cantilever beam problem is solved by directly applying the general formulas derived. Numerical results reveal that the beam deflection predicted by the new model is smaller than that by the classical beam model. Also, it is found that the difference between the deflections predicted by the two models is very significant when the beam thickness is small but is diminishing with the increase of the beam thickness.

  7. Scheme for Low Energy Beam Transport with a Non-Neutralized Section

    SciTech Connect

    Shemyakin, A.; Prost, L.

    2015-04-23

    A typical Low Energy Beam Transport (LEBT) design relies on dynamics with nearly complete beam space charge neutralization over the entire length of the LEBT. This paper argues that, for a beam with modest perveance and uniform current density distribution when generated at the source, a downstream portion of the LEBT can be un-neutralized without significant emittance growth.

  8. Energy deposition studies for the LBNE beam absorber

    SciTech Connect

    Rakhno, Igor L.; Mokhov, Nikolai V.; Tropin, Igor S.

    2015-01-29

    Results of detailed Monte Carlo energy deposition studies performed for the LBNE absorber core and the surrounding shielding with the MARS15 code are described. The model of the entire facility, that includes a pion-production target, focusing horns, target chase, decay channel, hadron absorber system – all with corresponding radiation shielding – was developed using the recently implemented ROOT-based geometry option in the MARS15 code. This option provides substantial flexibility and automation when developing complex geometry models. Both normal operation and accidental conditions were studied. Various design options were considered, in particular the following: (i) filling the decay pipe with air or helium; (ii) the absorber mask material and shape; (iii) the beam spoiler material and size. Results of detailed thermal calculations with the ANSYS code helped to select the most viable absorber design options.

  9. Low-Energy Run of Fermilab Electron Cooler's Beam Generation System

    SciTech Connect

    Prost, L.R.; Shemyakin, A.; Fedotov, A.; Kewisch, J.; /Brookhaven

    2011-03-14

    In the context of the evaluation of possibly using the Fermilab Electron Cooler for the proposed low-energy RHIC run at BNL, operating the cooler at 1.6 MeV electron beam energy was tested in a short beam line configuration. The main conclusion of this feasibility study is that the cooler's beam generation system is suitable for BNL needs. The beam recirculation was stable for all tested parameters. In particular, a beam current of 0.38 A was achieved with the cathode magnetic field up to the maximum value presently available of 250 G. The energy ripple was measured to be 40 eV. A striking difference with running the 4.3 MeV beam (nominal for operation at FNAL) is that no unprovoked beam recirculation interruptions were observed. Electron cooling proposed to increase the luminosity of the RHIC collider for heavy ion beam energies below 10 GeV/nucleon [1] needs a good quality, 0.9-5 MeV electron beam. Preliminary design studies indicate that the scheme of the Recycler's electron cooler at FNAL is suitable for low-energy RHIC cooling and most parts of the cooler can be re-used after the end of the Tevatron Run II. To analyze issues related to the generation of the electron beam in the energy recovery mode and to gain experience with the beam transport at lower beam energy, a dedicated study was performed at FNAL with a beam run through a short beam line (so called U-bend). This report summarizes our findings and observations in the course of the measurements.

  10. Superharp: A wire scanner with absolute position readout for beam energy measurement at CEBAF

    SciTech Connect

    Yan, C.

    1994-09-07

    Superharp is an upgrade CEBAF wire scanner with absolute position readout from shaft encoder. As high precision absolute beam position probe ({Delta}x {approximately} 10{mu}m), three pairs of superharps are installed at the entrance, the mid-point, and the exit of Hall C arc beamline in beam switch yard, which will be tuned in dispersive mode as energy spectrometer performing 10{sup {minus}3} beam energy measurement. With dual sensor system: the direct current pickup and the bremsstrahlung detection electronics, beam profile can be obtained by superharp at wide beam current range from 1 {mu}A to 100 {mu}A.

  11. Development of Ultra Small Shock Tube for High Energy Molecular Beam Source

    SciTech Connect

    Miyoshi, Nobuya; Nagata, Shuhei; Kinefuchi, Ikuya; Shimizu, Kazuya; Matsumoto, Yoichiro; Takagi, Shu

    2008-12-31

    A molecular beam source exploiting a small shock tube is described for potential generation of high energy beam in a range of 1-5 eV without any undesirable impurities. The performance of a non-diaphragm type shock tube with an inner diameter of 2 mm was evaluated by measuring the acceleration and attenuation process of shock waves. With this shock tube installed in a molecular beam source, we measured the time-of-flight distributions of shock-heated beams, which demonstrated the ability of controlling the beam energy with the initial pressure ratio of the shock tube.

  12. Development of Ultra Small Shock Tube for High Energy Molecular Beam Source

    NASA Astrophysics Data System (ADS)

    Miyoshi, Nobuya; Nagata, Shuhei; Kinefuchi, Ikuya; Shimizu, Kazuya; Takagi, Shu; Matsumoto, Yoichiro

    2008-12-01

    A molecular beam source exploiting a small shock tube is described for potential generation of high energy beam in a range of 1-5 eV without any undesirable impurities. The performance of a non-diaphragm type shock tube with an inner diameter of 2 mm was evaluated by measuring the acceleration and attenuation process of shock waves. With this shock tube installed in a molecular beam source, we measured the time-of-flight distributions of shock-heated beams, which demonstrated the ability of controlling the beam energy with the initial pressure ratio of the shock tube.

  13. Low-energy run of Fermilab Electron Cooler's beam generation system

    SciTech Connect

    Prost, Lionel; Shemyakin, Alexander; Fedotov, Alexei; Kewisch, Jorg; /Brookhaven

    2010-08-01

    As a part of a feasibility study of using the Fermilab Electron Cooler for a low-energy Relativistic Heavy Ion Collider (RHIC) run at Brookhaven National Laboratory (BNL), the cooler operation at 1.6 MeV electron beam energy was tested in a short beam line configuration. The main result of the study is that the cooler beam generation system is suitable for BNL needs. In a striking difference with running 4.3 MeV beam, no unprovoked beam recirculation interruptions were observed.

  14. Beam energy dependence of the viscous damping of anisotropic flow

    NASA Astrophysics Data System (ADS)

    Lacey, Roy

    2013-10-01

    The flow harmonics v2 , 3 for charged hadrons, are studied for a broad range of centrality selections and beam collision energies in Au+Au (√{sNN} = 7 . 7 - 200 GeV) and Pb+Pb (√{sNN} = 2 . 76 TeV) collisions. They validate the characteristic signature expected for the system size dependence of viscous damping at each collision energy studied. The extracted viscous coefficients, that encode the magnitude of the ratio of shear viscosity to entropy density η / s , are observed to decrease to an apparent minimum as the collision energy is increased from √{sNN} = 7 . 7 to approximately 62.4 GeV; thereafter, they show a slow increase with √{sNN} up to 2.76 TeV. This pattern of viscous damping provides the first experimental constraint for η / s in the temperature-baryon chemical potential (T ,μB) plane, and could be an initial indication for decay trajectories which lie close to the critical end point in the phase diagram for nuclear matter. This research is supported by the US DOE under contract DE-FG02-87ER40331.A008.

  15. Chaotic control of a piezomagnetoelastic beam for improved energy harvesting

    NASA Astrophysics Data System (ADS)

    Geiyer, Daniel; Kauffman, Jeffrey L.

    2015-04-01

    Linear cantilevered piezoelectric energy harvesters do not typically operate efficiently through a large span of excitation frequencies. Beam theory dictates optimum displacement at resonance excitation; however, typical environments evolve and vary over time with no clear dominant frequency. Nonlinear, non-resonant harvesting techniques have been implemented, but none so far have embraced chaotic behavior as a desirable property of the system. This work aims to benefit from chaotic phenomena by stabilizing high energy periodic orbits located within a chaotic attractor to improve operating bandwidth. Delay coordinate embedding is used to reconstruct the system states from a single time series measurement of displacement. Orbit selection, local linearization, and control perturbation are all computed from the single time series independent of an explicit system model. Although chaos in non-autonomous systems is typically associated with harmonic inputs, chaotic attractor motion can also exist throughout other excitation sources. Accelerometer data from inside a commercial vehicle and a stochastic excitation signal are used to illustrate the existence of chaos in dynamic environments, allowing such environments to be likely candidates for the proposed bandwidth improving energy harvesting technique.

  16. Transferring the Energy of Hadron Beams to Lepton Beams via Plasma Wakes

    NASA Astrophysics Data System (ADS)

    Mori, W. B.; Lu, W.; An, W.; Joshi, C.; Huang, C.; Vieira, J.; Fonseca, R. A.; Silva, L. O.

    2010-11-01

    Hadron beams (p^- & p^+) exist at Fermilab and CERN could be used to drive high gradient plasma wakefields for accelerating trailing lepton (e^- & e^+) beams. We consider what would be possible if the existing hadron beams could be compressed and if existing beams excite wakes via self-modulation instabilities. A compressed p^- beam drives an identical wake as an electron beam [1] with the same current. However, for this case dephasing (not pump depletion) limits the acceleration length. Simulation results show that a witness electron bunch can gain more than 600 GeV in a 1 TeV p^- beam driven PWFA during 50 meters acceleration. For the p^+ beam, driving a similar wake by using a short p^+ beam for accelerating electrons has been proposed recently [2]. Although p^+ beam available at CERN is much longer, a train of short bunches may be generated through self-modulation as the long bunch propagates in the plasma [3]. Preliminary simulation results for such interactions will be presented. [1] I. Blumenfeld et al., Nature 445, 741 (2007) [2] A. Caldwell et al., Nature Phys. 5, 363 (2009) [3] N. Kumar et al., Phys. Rev. Lett. 104, 255003 (2010)

  17. Increasing beam power and energy with the SBS forward energy transfer instability

    NASA Astrophysics Data System (ADS)

    Kirkwood, R. K.; London, R. A.; Dunlop, W. H.; Michel, P. A.; Williams, E. A.; Fournier, K. B.; Landen, O. L.; MacGowan, B. J.

    2012-10-01

    The understanding of the exchange of forward going power and energy between two crossing beams in a plasma [1] is now sufficiently developed that it can be used to enable access to new experimental configurations. The existing models of the process allow the design of beam combiners that will produce higher energy in individual beams for new applications in ignition and HED physics. For example the Energy Partitioning and Energy Coupling (EPEC) [2] program is simulating nuclear events in various environments by delivering energy to the center of a chamber through a narrow tube that allows minimal perturbation of the surrounding region. We will describe the design of gas filled targets that will allow a 2x to 5x increase in the energy in a single NIF quad to enable higher yield events to be simulated in EPEC. These designs as well as advanced ignition target designs will require models with improved precision to predict their performance accurately. We will also compare the predictions of existing and emerging models of wave saturation [3] with the existing experimental data to determine the uncertainty in the models.[4pt] [1] P. Michel Physics of Plasmas 2010.[0pt] [2] K. Fournier, these proceedings[0pt] [3] P. Michel, E. Williams, these proceedings.

  18. Adventures in Gaseous Positronics - An Ultra-High-Energy-Resolution Cryogenic Beam

    NASA Astrophysics Data System (ADS)

    Natisin, Mike

    2016-05-01

    While positron interactions with matter are important in a variety of contexts, many important experiments have been inhibited due to the difficulties encountered in creating beams with narrow energy spreads. This talk focuses on the development of a pulsed positron beam with a total energy spread of 7 meV FWHM; this represents a factor of five improvement over the previous state-of-the-art. Current positron atomic physics experiments rely on high quality beams from buffer gas traps. Although widely used, the physical phenomena operative in beam formation had not previously been fully investigated, and understanding these processes proved crucial to improving beam quality. Experimental measurements and simulation results of positron cooling and beam formation are discussed, with an emphasis on beam energy resolution. Using these results, a new cryogenic, trap-based beam system was built. Positrons are cooled to 50 K using a CO buffer gas, resulting in beams with total energy spreads as low as 6.9 meV FWHM, sub-microsecond temporal spreads and beam diameters as small as 1 mm. Details of this beam system, as well as new experiments that will be enabled by it, will be discussed. Work supported by NSF Grant PHY-1401794.

  19. Focusing dynamics of high-energy density, laser-driven ion beams.

    PubMed

    Chen, S N; d'Humières, E; Lefebvre, E; Romagnani, L; Toncian, T; Antici, P; Audebert, P; Brambrink, E; Cecchetti, C A; Kudyakov, T; Pipahl, A; Sentoku, Y; Borghesi, M; Willi, O; Fuchs, J

    2012-02-01

    The dynamics of the focusing of laser-driven ion beams produced from concave solid targets was studied. Most of the ion beam energy is observed to converge at the center of the cylindrical targets with a spot diameter of 30  μm, which can be very beneficial for applications requiring high beam energy densities. Also, unbalanced laser irradiation does not compromise the focusability of the beam. However, significant filamentation occurs during the focusing, potentially limiting the localization of the energy deposition region by these beams at focus. These effects could impact the applicability of such high-energy density beams for applications, e.g., in proton-driven fast ignition. PMID:22400936

  20. A Compact 2 Degree-of-Freedom Energy Harvester with Cut-Out Cantilever Beam

    NASA Astrophysics Data System (ADS)

    Wu, Hao; Tang, Lihua; Yang, Yaowen; Kiong Soh, Chee

    2012-04-01

    In this work, a novel 2 degree-of-freedom (DOF) vibration energy harvester is proposed. The harvester comprises one main cantilever beam and one secondary cantilever beam cut out within the main beam. By varying the proof masses, the first two resonances can be tuned close to each other, while maintaining significant magnitudes, thus providing a useful wide bandwidth for energy harvesting. Unlike previous 2-DOF harvesters, the proposed harvester is compact and utilizes the beam more efficiently by generating energy from both the main and secondary cantilevers. Therefore, the proposed harvester is more adaptive and functional in practical random or frequency-variant vibrational circumstances.

  1. Characterization of the NEPOMUC primary and remoderated positron beams at different energies

    NASA Astrophysics Data System (ADS)

    Stanja, J.; Hergenhahn, U.; Niemann, H.; Paschkowski, N.; Sunn Pedersen, T.; Saitoh, H.; Stenson, E. V.; Stoneking, M. R.; Hugenschmidt, C.; Piochacz, C.

    2016-08-01

    We report on the characterization of the positron beam provided at the open beam port of the NEPOMUC facility at the Heinz Maier-Leibnitz Zentrum (MLZ) Garching. The absolute positron flux of the primary beam at 400 eV and 1 keV kinetic energy and of the remoderated beam at 5, 12 and 22 eV were determined. Energy-dependent intensities in the range of (1 - 5) ·108e+ / s and (2 - 6) ·107e+ / s have been observed for the primary and remoderated beam, respectively. We attribute the significant losses for the primary beam, in comparison with the expected value, to the non-adiabatic positron guiding in the beam line. We also measured the longitudinal energy distribution of the remoderated beam, yielding an energy spread below 3.3 eV. The mean transverse energy of the remoderated beam, determined from measurements in different final magnetic fields, was found to be below 1.3 eV. These results are likely to apply to the NEPOMUC beam delivered to other user stations.

  2. Experimental studies using a low-energy RI beam separator at CNS

    NASA Astrophysics Data System (ADS)

    Teranishi, T.; Kubono, S.; Shimoura, S.; Notani, M.; Yanagisawa, Y.; Michimasa, S.; Ue, K.; Iwasaki, H.; Kurokawa, M.; Satou, Y.; Morikawa, T.; Saito, A.; Baba, H.; Lee, J. H.; Lee, C. S.; Fülöp, Zs.; Kato, S.

    2003-05-01

    Radioactive-ion (RI) beams of 10C, 14O, 12N and 11C with energies low 10 A MeV were produced by using a low-energy in-flight RI beam separator newly constructed by CNS, University of Tokyo. Using the 12N and 11C beams, some resonance states were identified in the proton elastic scattering 12N+p and 11C+p, respectively.

  3. Surface modification of structural materials by low-energy high-current pulsed electron beam treatment

    SciTech Connect

    Panin, A. V. E-mail: kms@ms.tsc.ru; Kazachenok, M. S. E-mail: kms@ms.tsc.ru; Sinyakova, E. A.; Borodovitsina, O. M.; Ivanov, Yu. F.; Leontieva-Smirnova, M. V.

    2014-11-14

    Microstructure formation in surface layers of pure titanium and ferritic-martensitic steel subjected to electron beam treatment is studied. It is shown that low energy high-current pulsed electron beam irradiation leads to the martensite structure within the surface layer of pure titanium. Contrary, the columnar ferrite grains grow during solidification of ferritic-martensitic steel. The effect of electron beam energy density on the surface morphology and microstructure of the irradiated metals is demonstrated.

  4. Energy-absorbing-beam design for composite aircraft subfloors

    NASA Technical Reports Server (NTRS)

    Carden, Huey D.; Kellas, Sotiris

    1993-01-01

    Data have been presented from the design support testing of composite energy absorbing (EA) aircraft subfloor structures. The focus of the current study is the design and testing of subfloor structural concepts that would limit the loads transmitted to occupants to less than 20 g at crush speeds of approximately 30 fps. The EA composite subfloor is being designed to replace an existing noncrashworthy metallic subfloor in a composite aircraft prior to a full-scale crash test. A sandwich spar construction of a sine wave beam was chosen for evaluation and was found to have excellent energy absorbing characteristics. The design objective of obtaining sustained crushing loads of the spar between 200-300 lbf/inch were achieved for potentially limiting occupants loads to around 20 g's. Stroke efficiency of up to 79 percent of the initial spar height under desired sustained crushing loads was obtained which is far greater than the level provided by metal structure. Additionally, a substantial residual spar stiffness was retained after impact, and the flange integrity, which is critical for seat retention, was maintained after crushing of the spars.

  5. Characteristics of low-energy ion beams extracted from a wire electrode geometry

    SciTech Connect

    Vasquez, M. Jr.; Tokumura, S.; Kasuya, T.; Maeno, S.; Wada, M.

    2012-02-15

    Beams of argon ions with energies less than 50 eV were extracted from an ion source through a wire electrode extractor geometry. A retarding potential energy analyzer (RPEA) was constructed in order to characterize the extracted ion beams. The single aperture RPEA was used to determine the ion energy distribution function, the mean ion energy and the ion beam energy spread. The multi-cusp hot cathode ion source was capable of producing a low electron temperature gas discharge to form quiescent plasmas from which ion beam energy as low as 5 eV was realized. At 50 V extraction potential and 0.1 A discharge current, the ion beam current density was around 0.37 mA/cm{sup 2} with an energy spread of 3.6 V or 6.5% of the mean ion energy. The maximum ion beam current density extracted from the source was 0.57 mA/cm{sup 2} for a 50 eV ion beam and 1.78 mA/cm{sup 2} for a 100 eV ion beam.

  6. Beam-induced energy deposition issues in the Very Large Hadron Collider

    SciTech Connect

    Nikolai V. Mokhov; Alexandr I. Drozhdin; G. William Foster

    2001-06-26

    Energy deposition issues are extremely important in the Very Large Hadron Collider (VLHC) with huge energy stored in its 20 TeV (Stage-1) and 87.5 TeV (Stage-2) beams. The status of the VLHC design on these topics, and possible solutions of the problems are discussed. Protective measures are determined based on the operational and accidental beam loss limits for the prompt radiation dose at the surface, residual radiation dose, ground water activation, accelerator components radiation damage and quench stability. The beam abort and beam collimation systems are designed to protect accelerator from accidental and operational beam losses, IP region quadrupoles from irradiation by the products of beam-beam collisions, and to reduce the accelerator-induced backgrounds in the detectors.

  7. Design study of the Low Energy Beam Transport system at RISP

    NASA Astrophysics Data System (ADS)

    Bahng, Jungbae; Kim, Eunsan; Kim, Yonghwan; Hong, In-Seok

    2013-03-01

    We present the design status of LEBT for the RISP that consists of two 90 degree dipoles, a multi-harmonic buncher, pair solenoids, electrostatic quadrupoles and a high voltage platform. After ECR-IS with an energy of 10 keV/u, heavy-ion beams are selected by achromatic bending systems and then be bunched in the LEBT. A multi-harmonic buncher is used to achieve a small longitudinal emittance in the RFQ. We show the results on the optics design by using the TRANSPORT code and the beam tracking of two-charge beams by using the code IMPACT. We present the results and issues on beam dynamics simulaitons in the designed LEBT system. For heavy ion beams in the low energy system, we have to separate and select desire beam. we also transport beam from ECR to RFQ with high transmission.

  8. Space charge compensation in the Linac4 low energy beam transport line with negative hydrogen ions

    SciTech Connect

    Valerio-Lizarraga, Cristhian A.; Lallement, Jean-Baptiste; Lettry, Jacques; Scrivens, Richard; Leon-Monzon, Ildefonso; Midttun, Øystein

    2014-02-15

    The space charge effect of low energy, unbunched ion beams can be compensated by the trapping of ions or electrons into the beam potential. This has been studied for the 45 keV negative hydrogen ion beam in the CERN Linac4 Low Energy Beam Transport using the package IBSimu [T. Kalvas et al., Rev. Sci. Instrum. 81, 02B703 (2010)], which allows the space charge calculation of the particle trajectories. The results of the beam simulations will be compared to emittance measurements of an H{sup −} beam at the CERN Linac4 3 MeV test stand, where the injection of hydrogen gas directly into the beam transport region has been used to modify the space charge compensation degree.

  9. Beam losses and beam halos in accelerators for new energy sources

    SciTech Connect

    Jameson, R.A.

    1995-12-31

    Large particle accelerators are proposed as drivers for new ways to produce electricity from nuclear fusion and fission reactions. The accelerators must be designed to deliver large particle beam currents to a target facility with very little beam spill along the accelerator itself, in order that accelerator maintenance can be accomplished without remote manipulators. Typically, particle loss is preceded by the formation of a tenuous halo of particles around the central beam core, caused by beam dynamics effects, often coupled with the slight imperfections inevitable in a practical design. If the halo becomes large enough, particles may be scraped off along the accelerator. The tolerance for beam spill in different applications is discussed, halo mechanisms and recent work to explore and understand their dynamics are reviewed, and possible directions for future investigation are outlined. 17 refs., 10 figs.

  10. Uncertainty of the beam energy measurement in the e+e- collision using Compton backscattering

    NASA Astrophysics Data System (ADS)

    Mo, Xiao-Hu

    2014-10-01

    The beam energy is measured in the e+e- collision by using Compton backscattering. The uncertainty of this measurement process is studied by virtue of analytical formulas, and the special effects of variant energy spread and energy drift on the systematic uncertainty estimation are also studied with the Monte Carlo sampling technique. These quantitative conclusions are especially important for understanding the uncertainty of the beam energy measurement system.