Science.gov

Sample records for accelerated beam intensity

  1. A microsecond-pulsewidth, intense, light-ion beam accelerator

    SciTech Connect

    Rej, D.J.; Bartsch, R.R.; Davis, H.A.; Greenly, J.B.; Waganaar, W.J.

    1993-07-01

    A relatively long-pulsewidth (0.1-1 {mu}s) intense ion beam accelerator has been built for materials processing applications. An applied-B{sub r}, magnetically-insulated extraction ion diode with dielectric flashover ion source is installed directly onto the output of a 1.2-MV, 300-kJ Marx generator. Initial operation of the accelerator at 0.4 MV indicates satisfactory performance without the need for additional pulse-shaping.

  2. Microsecond pulse width, intense, light-ion beam accelerator

    NASA Astrophysics Data System (ADS)

    Rej, D. J.; Bartsch, R. R.; Davis, H. A.; Faehl, R. J.; Greenly, J. B.; Waganaar, W. J.

    1993-10-01

    A relatively long-pulse width (0.1-1 μs) intense ion beam accelerator has been built for materials processing applications. An applied Br, magnetically insulated extraction ion diode with dielectric flashover ion source is installed directly onto the output of a 1.2 MV, 300-kJ Marx generator. The diode is designed with the aid of multidimensional particle-in-cell simulations. Initial operation of the accelerator at 0.4 MV indicates satisfactory performance without the need for additional pulse shaping. The effect of a plasma opening switch on diode behavior is considered.

  3. Selected List of Low Energy Beam Transport Facilities for Light-Ion, High-Intensity Accelerators

    SciTech Connect

    Prost, L. R.

    2016-02-17

    This paper presents a list of Low Energy Beam Transport (LEBT) facilities for light-ion, high-intensity accelerators. It was put together to facilitate comparisons with the PXIE LEBT design choices. A short discussion regarding the importance of the beam perveance in the choice of the transport scheme follows.

  4. Target Material Irradiation Studies for High-Intensity Accelerator Beams

    SciTech Connect

    Simos, N.; Kirk, H.; Ludewig, H.; Thieberger, P.; Weng, W.T.; McDonald, K.; Sheppard, J.; Evangelakis, G.; Yoshimura, K.; /KEK, Tsukuba

    2005-08-16

    This paper presents results of recent experimental studies focusing on the behavior of special materials and composites under irradiation conditions and their potential use as accelerator targets. The paper also discusses the approach and goals of on-going investigations on an expanded material matrix geared toward the neutrino superbeam and muon collider initiatives.

  5. Doubling Beam Intensity Unlocks Rare Opportunities for Discovery at Fermi National Accelerator Laboratory

    SciTech Connect

    Segui, Jennifer A.

    2014-05-01

    Particle accelerators such as the Booster synchrotron at the Fermi National Accelerator Laboratory (FNAL) produce high-intensity proton beams for particle physics experiments that can ultimately reveal the secrets of the universe. High-intensity proton beams are required by experiments at the “intensity frontier” of particle physics research, where the availability of more particles improves the chances of observing extremely rare physical processes. In addition to their central role in particle physics experiments, particle accelerators have found widespread use in industrial, nuclear, environmental, and medical applications. RF cavities are essential components of particle accelerators that, depending on the design, can perform multiple functions, including bunching, focusing, decelerating, and accelerating a beam of charged particles. Engineers are working to model the RF cavities required for upgrading the 40-year old Booster synchrotron. It is a rather complicated process to refurbish, test, and qualify the upgraded RF cavities to sustain an increased repetition rate of the RF field required to produce proton beams at double the current intensity. Both multiphysics simulation and physical measurements are used to evaluate the RF, thermal, and mechanical properties of the Booster RF cavities.

  6. High intensity neutrino beams

    SciTech Connect

    Ichikawa, A. K.

    2015-07-15

    High-intensity proton accelerator complex enabled long baseline neutrino oscillation experiments with a precisely controlled neutrino beam. The beam power so far achieved is a few hundred kW with enourmorous efforts of accelerator physicists and engineers. However, to fully understand the lepton mixing structure, MW-class accelerators are desired. We describe the current intensity-frontier high-energy proton accelerators, their plans to go beyond and technical challenges in the neutrino beamline facilities.

  7. INJECTION ACCELERATION AND EXTRACTION OF HIGH INTENSITY PROTON BEAM FOR THE NEUTRINO FACILITY PROJECT AT BNL.

    SciTech Connect

    Tsoupas, N; Barton, D; Ganetis, G; Jain, A; Lee, Y; Marneris, I; Meng, W; Raparia, D; Roser, T; Ruggiero, A; Tuozzolo, J; Wanderer, P; Weng, W

    2003-05-12

    The proposed ''neutrino-production'' project [1.2] to be built at the Brookhaven National Laboratory (BNL) requires that the neutrino-production target be bombarded by a high intensity proton beam-pulse of {approx} 90 x 10{sup 12} protons of 28 GeV in energy and at a rate of 2.5 Hz, resulting in a 1 MW power of proton beam deposited on the target for the production of the neutrinos. In this paper we investigate the possibility of producing this high intensity proton beam, using as the main accelerator the Alternating Gradient Synchrotron (AGS) at the Brookhaven National Laboratory (BNL). The following aspects of the project are reported in this paper: (a) The beam injection into the AGS synchrotron of 1.2 GeV H{sup -} beam produced by a super-conducting LINAC[3]; (b) The effect of the eddy currents induced on the vacuum chamber of the circulating beam during the ''ramping'' of the main magnets of the AGS; (c) The method of the beam extraction from the AGS and the optics of the 28 GeV beam extracted from the AGS.

  8. Increasing the intensity of an induction accelerator and reduction of the beam breakup instability

    NASA Astrophysics Data System (ADS)

    Coleman, J. E.; Moir, D. C.; Ekdahl, C. A.; Johnson, J. B.; McCuistian, B. T.; Sullivan, G. W.; Crawford, M. T.

    2014-03-01

    A 7 cm cathode has been deployed for use on a 3.8 MV, 80 ns (FWHM) Blumlein, to increase the extracted electron current from the nominal 1.7 to 2.9 kA. The intense relativistic electron bunch is accelerated and transported through a nested solenoid and ferrite induction core lattice consisting of 64 elements, exiting the accelerator with a nominal energy of 19.8 MeV. The principal objective of these experiments is to quantify the space-charge limitations on the beam quality, its coupling with the beam breakup (BBU) instability, and provide an independent validation of the BBU theory in a higher current regime, I >2 kA. Time resolved centroid measurements indicate a reduction in BBU >10× with simply a 50% increase in the average B-field used to transport the beam through the accelerator. A qualitative comparison of experimental and calculated results are presented, which include time resolved current density distributions, radial BBU amplitude relative to the calculated beam envelope, and frequency analyzed BBU amplitude with different accelerator lattice tunes.

  9. Intense laser-driven ion beams in the relativistic-transparency regime: acceleration, control and applications

    NASA Astrophysics Data System (ADS)

    Fernandez, Juan C.

    2016-10-01

    Laser-plasma interactions in the novel regime of relativistically-induced transparency have been harnessed to generate efficiently intense ion beams with average energies exceeding 10 MeV/nucleon (>100 MeV for protons) at ``table-top'' scales. We have discovered and utilized a self-organizing scheme that exploits persisting self-generated plasma electric ( 0.1 TV/m) and magnetic ( 104 Tesla) fields to reduce the ion-energy (Ei) spread after the laser exits the plasma, thus separating acceleration from spread reduction. In this way we routinely generate aluminum and carbon beams with narrow spectral peaks at Ei up to 310 MeV and 220 MeV, respectively, with high efficiency ( 5%). The experimental demonstration has been done at the LANL Trident laser with 0.12 PW, high-contrast, 0.65 ps Gaussian laser pulses irradiating planar foils up to 250 nm thick. In this regime, Ei scales empirically with laser intensity (I) as I 1 / 2. Our progress is enabled by high-fidelity, massive computer simulations of the experiments. This work advances next-generation compact accelerators suitable for new applications. E . g ., a carbon beam with Ei 400 MeV and 10% energy spread is suitable for fast ignition (FI) of compressed DT. The observed scaling suggests that is feasible with existing target fabrication and PW-laser technologies, using a sub-ps laser pulse with I 2.5 ×1021 W/cm2. These beams have been used on Trident to generate warm-dense matter at solid-densities, enabling us to investigate its equation of state and mixing of heterogeneous interfaces purely by plasma effects distinct from hydrodynamics. They also drive an intense neutron-beam source with great promise for important applications such as active interrogation of shielded nuclear materials. Considerations on controlling ion-beam divergence for their increased utility are discussed. Funded by the LANL LDRD program.

  10. Numerical Modelling of Intense Electron Beam Transport in the Spiral Line Induction Accelerator

    DTIC Science & Technology

    1992-08-28

    arising in the context of the spiral line induction accelerator (SLIA), a device in which the beam is transported along an open-ended beam pipe ...field. Because the field coils are wound directly onto the spiral beam pipe , and because each bend is magnetically shielded from its neighbors, each... Spiral Line Induction Accelerator J. KRALL, S. SLINKER, M. LAMPE AND G. JOYCE Beam Physics Branch Plasma Physics Division August 28, 1992 _pw DTIC U)lz E

  11. High-intensity laser-accelerated ion beam produced from cryogenic micro-jet target.

    PubMed

    Gauthier, M; Kim, J B; Curry, C B; Aurand, B; Gamboa, E J; Göde, S; Goyon, C; Hazi, A; Kerr, S; Pak, A; Propp, A; Ramakrishna, B; Ruby, J; Willi, O; Williams, G J; Rödel, C; Glenzer, S H

    2016-11-01

    We report on the successful operation of a newly developed cryogenic jet target at high intensity laser-irradiation. Using the frequency-doubled Titan short pulse laser system at Jupiter Laser Facility, Lawrence Livermore National Laboratory, we demonstrate the generation of a pure proton beam a with maximum energy of 2 MeV. Furthermore, we record a quasi-monoenergetic peak at 1.1 MeV in the proton spectrum emitted in the laser forward direction suggesting an alternative acceleration mechanism. Using a solid-density mixed hydrogen-deuterium target, we are also able to produce pure proton-deuteron ion beams. With its high purity, limited size, near-critical density, and high-repetition rate capability, this target is promising for future applications.

  12. High-intensity laser-accelerated ion beam produced from cryogenic micro-jet target

    NASA Astrophysics Data System (ADS)

    Gauthier, M.; Kim, J. B.; Curry, C. B.; Aurand, B.; Gamboa, E. J.; Göde, S.; Goyon, C.; Hazi, A.; Kerr, S.; Pak, A.; Propp, A.; Ramakrishna, B.; Ruby, J.; Willi, O.; Williams, G. J.; Rödel, C.; Glenzer, S. H.

    2016-11-01

    We report on the successful operation of a newly developed cryogenic jet target at high intensity laser-irradiation. Using the frequency-doubled Titan short pulse laser system at Jupiter Laser Facility, Lawrence Livermore National Laboratory, we demonstrate the generation of a pure proton beam a with maximum energy of 2 MeV. Furthermore, we record a quasi-monoenergetic peak at 1.1 MeV in the proton spectrum emitted in the laser forward direction suggesting an alternative acceleration mechanism. Using a solid-density mixed hydrogen-deuterium target, we are also able to produce pure proton-deuteron ion beams. With its high purity, limited size, near-critical density, and high-repetition rate capability, this target is promising for future applications.

  13. High-intensity laser-accelerated ion beam produced from cryogenic micro-jet target

    DOE PAGES

    Gauthier, M.; Kim, J. B.; Curry, C. B.; ...

    2016-08-24

    Here, we report on the successful operation of a newly developed cryogenic jet target at high intensity laser-irradiation. Using the frequency-doubled Titan short pulse laser system at Jupiter Laser Facility, Lawrence Livermore National Laboratory, we demonstrate the generation of a pure proton beam a with maximum energy of 2 MeV. Furthermore, we record a quasi-monoenergetic peak at 1.1 MeV in the proton spectrum emitted in the laser forward direction suggesting an alternative acceleration mechanism. Using a solid-density mixed hydrogen-deuterium target, we are also able to produce pure proton-deuteron ion beams. With its high purity, limited size, near-critical density, and high-repetitionmore » rate capability, this target is promising for future applications.« less

  14. High-intensity laser-accelerated ion beam produced from cryogenic micro-jet target

    SciTech Connect

    Gauthier, M.; Kim, J. B.; Curry, C. B.; Aurand, B.; Gamboa, E. J.; Göde, S.; Goyon, C.; Hazi, A.; Kerr, S.; Pak, A.; Propp, A.; Ramakrishna, B.; Ruby, J.; Willi, O.; Williams, G. J.; Rödel, C.; Glenzer, S. H.

    2016-08-24

    Here, we report on the successful operation of a newly developed cryogenic jet target at high intensity laser-irradiation. Using the frequency-doubled Titan short pulse laser system at Jupiter Laser Facility, Lawrence Livermore National Laboratory, we demonstrate the generation of a pure proton beam a with maximum energy of 2 MeV. Furthermore, we record a quasi-monoenergetic peak at 1.1 MeV in the proton spectrum emitted in the laser forward direction suggesting an alternative acceleration mechanism. Using a solid-density mixed hydrogen-deuterium target, we are also able to produce pure proton-deuteron ion beams. With its high purity, limited size, near-critical density, and high-repetition rate capability, this target is promising for future applications.

  15. Beam Dynamics Studies and the Design, Fabrication and Testing of Superconducting Radiofrequency Cavity for High Intensity Proton Accelerator

    SciTech Connect

    Saini, Arun

    2012-03-01

    The application horizon of particle accelerators has been widening significantly in recent decades. Where large accelerators have traditionally been the tools of the trade for high-energy nuclear and particle physics, applications in the last decade have grown to include large-scale accelerators like synchrotron light sources and spallation neutron sources. Applications like generation of rare isotopes, transmutation of nuclear reactor waste, sub-critical nuclear power, generation of neutrino beams etc. are next area of investigation for accelerator scientific community all over the world. Such applications require high beam power in the range of few mega-watts (MW). One such high intensity proton beam facility is proposed at Fermilab, Batavia, US, named as Project-X. Project-X facility is based on H- linear accelerator (linac), which will operate in continuous wave (CW) mode and accelerate H- ion beam with average current of 1 mA from kinetic energy of 2.5 MeV to 3 GeV to deliver 3MW beam power. One of the most challenging tasks of the Project-X facility is to have a robust design of the CW linac which can provide high quality beam to several experiments simultaneously. Hence a careful design of linac is important to achieve this objective.

  16. Synchronization of high speed framing camera and intense electron-beam accelerator

    SciTech Connect

    Cheng Xinbing; Liu Jinliang; Hong Zhiqiang; Qian Baoliang

    2012-06-15

    A new trigger program is proposed to realize the synchronization of high speed framing camera (HSFC) and intense electron-beam accelerator (IEBA). The trigger program which include light signal acquisition radiated from main switch of IEBA and signal processing circuit could provide a trigger signal with rise time of 17 ns and amplitude of about 5 V. First, the light signal was collected by an avalanche photodiode (APD) module, and the delay time between the output voltage of APD and load voltage of IEBA was tested, it was about 35 ns. Subsequently, the output voltage of APD was processed further by the signal processing circuit to obtain the trigger signal. At last, by combining the trigger program with an IEBA, the trigger program operated stably, and a delay time of 30 ns between the trigger signal of HSFC and output voltage of IEBA was obtained. Meanwhile, when surface flashover occurred at the high density polyethylene sample, the delay time between the trigger signal of HSFC and flashover current was up to 150 ns, which satisfied the need of synchronization of HSFC and IEBA. So the experiment results proved that the trigger program could compensate the time (called compensated time) of the trigger signal processing time and the inherent delay time of the HSFC.

  17. Intense ion beam generator

    DOEpatents

    Humphries, Jr., Stanley; Sudan, Ravindra N.

    1977-08-30

    Methods and apparatus for producing intense megavolt ion beams are disclosed. In one embodiment, a reflex triode-type pulsed ion accelerator is described which produces ion pulses of more than 5 kiloamperes current with a peak energy of 3 MeV. In other embodiments, the device is constructed so as to focus the beam of ions for high concentration and ease of extraction, and magnetic insulation is provided to increase the efficiency of operation.

  18. Generation of high-quality mega-electron volt proton beams with intense-laser-driven nanotube accelerator

    SciTech Connect

    Murakami, M.; Tanaka, M.

    2013-04-22

    An ion acceleration scheme using carbon nanotubes (CNTs) is proposed, in which embedded fragments of low-Z materials are irradiated by an ultrashort intense laser to eject substantial numbers of electrons. Due to the resultant characteristic electrostatic field, the nanotube and embedded materials play the roles of the barrel and bullets of a gun, respectively, to produce highly collimated and quasimonoenergetic ion beams. Three-dimensional particle simulations, that take all the two-body Coulomb interactions into account, demonstrate generation of quasimonoenergetic MeV-order proton beams using nanometer-size CNT under a super-intense electrostatic field {approx}10{sup 14} V m{sup -1}.

  19. Relativistic electron dynamics in intense crossed laser beams: acceleration and Compton harmonics.

    PubMed

    Salamin, Yousef I; Mocken, Guido R; Keitel, Christoph H

    2003-01-01

    Electron motion and harmonic generation are investigated in the crossed-beam laser-accelerator scheme in a vacuum. Exact solutions of the equations of motion of the electron in plane-wave fields are given, subject to a restricted set of initial conditions. The trajectory solutions corresponding to axial injection are used to calculate precise emission spectra. Guided by hindsight from the analytic investigations, numerical calculations are then performed employing a Gaussian-beam representation of the fields in which terms of order epsilon(5), where epsilon is the diffraction angle, are retained. Present-day laser powers and initial conditions on the electron motion that simulate realistic laboratory conditions are used in the calculations. The analytic plane-wave work shows, and the numerical investigations confirm, that an optimal crossing angle exists, i.e., one that renders the electron energy gain a maximum for a particular set of parameters. Furthermore, the restriction to small crossing angles is not made anywhere. It is also shown that energy gains of a few GeV and energy gradients of several TeV/m may be obtained using petawatt power laser beams.

  20. Neutral particle beam intensity controller

    DOEpatents

    Dagenhart, William K.

    1986-01-01

    A neutral beam intensity controller is provided for a neutral beam generator in which a neutral beam is established by accelerating ions from an ion source into a gas neutralizer. An amplitude modulated, rotating magnetic field is applied to the accelerated ion beam in the gas neutralizer to defocus the resultant neutral beam in a controlled manner to achieve intensity control of the neutral beam along the beam axis at constant beam energy. The rotating magnetic field alters the orbits of ions in the gas neutralizer before they are neutralized, thereby controlling the fraction of neutral particles transmitted out of the neutralizer along the central beam axis to a fusion device or the like. The altered path or defocused neutral particles are sprayed onto an actively cooled beam dump disposed perpendicular to the neutral beam axis and having a central open for passage of the focused beam at the central axis of the beamline. Virtually zero therough 100% intensity control is achieved by varying the magnetic field strength without altering the ion source beam intensity or its species yield.

  1. Ion beam accelerator system

    NASA Technical Reports Server (NTRS)

    Aston, Graeme (Inventor)

    1984-01-01

    A system is described that combines geometrical and electrostatic focusing to provide high ion extraction efficiency and good focusing of an accelerated ion beam. The apparatus includes a pair of curved extraction grids (16, 18) with multiple pairs of aligned holes positioned to direct a group of beamlets (20) along converging paths. The extraction grids are closely spaced and maintained at a moderate potential to efficiently extract beamlets of ions and allow them to combine into a single beam (14). An accelerator electrode device (22) downstream from the extraction grids, is at a much lower potential than the grids to accelerate the combined beam.

  2. Ion beam accelerator system

    NASA Technical Reports Server (NTRS)

    Aston, G. (Inventor)

    1981-01-01

    A system is described that combines geometrical and electrostatic focusing to provide high ion extraction efficiency and good focusing of an accelerated ion beam. The apparatus includes a pair of curved extraction grids with multiple pairs of aligned holes positioned to direct a group of beamlets along converging paths. The extraction grids are closely spaced and maintained at a moderate potential to efficiently extract beamlets of ions and allow them to combine into a single beam. An accelerator electrode device downstream from the extraction grids is at a much lower potential than the grids to accelerate the combined beam. The application of the system to ion implantation is mentioned.

  3. Parallel beam dynamics simulation of linear accelerators

    SciTech Connect

    Qiang, Ji; Ryne, Robert D.

    2002-01-31

    In this paper we describe parallel particle-in-cell methods for the large scale simulation of beam dynamics in linear accelerators. These techniques have been implemented in the IMPACT (Integrated Map and Particle Accelerator Tracking) code. IMPACT is being used to study the behavior of intense charged particle beams and as a tool for the design of next-generation linear accelerators. As examples, we present applications of the code to the study of emittance exchange in high intensity beams and to the study of beam transport in a proposed accelerator for the development of accelerator-driven waste transmutation technologies.

  4. Investigation of Generation, Acceleration, Transport and Final Focusing of High-Intensity Heavy Ion Beams from Sources to Targets

    SciTech Connect

    Chiping Chen

    2006-10-26

    Under the auspices of the research grant, the Intense Beam Theoretical Research Goup at Massachusetts Institute of Technology's Plasma Science and Fusion Center made significant contributions in a number of important areas in the HIF and HEDP research, including: (a) Derivation of rms envelope equations and study of rms envelope dynamics for high-intensity heavy ion beams in a small-aperture AG focusing transport systems; (b) Identification of a new mechanism for chaotic particle motion, halo formation, and beam loss in high-intensity heavy ion beams in a small-aperture AG focusing systems; Development of elliptic beam theory; (d) Study of Physics Issues in the Neutralization Transport Experiment (NTX).

  5. High intensity hadron accelerators

    SciTech Connect

    Teng, L.C.

    1989-05-01

    This rapporteur report consists mainly of two parts. Part I is an abridged review of the status of all High Intensity Hadron Accelerator projects in the world in semi-tabulated form for quick reference and comparison. Part II is a brief discussion of the salient features of the different technologies involved. The discussion is based mainly on my personal experiences and opinions, tempered, I hope, by the discussions I participated in in the various parallel sessions of the workshop. In addition, appended at the end is my evaluation and expression of the merits of high intensity hadron accelerators as research facilities for nuclear and particle physics.

  6. 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.

  7. CLASHING BEAM PARTICLE ACCELERATOR

    DOEpatents

    Burleigh, R.J.

    1961-04-11

    A charged-particle accelerator of the proton synchrotron class having means for simultaneously accelerating two separate contra-rotating particle beams within a single annular magnet structure is reported. The magnet provides two concentric circular field regions of opposite magnetic polarity with one field region being of slightly less diameter than the other. The accelerator includes a deflector means straddling the two particle orbits and acting to collide the two particle beams after each has been accelerated to a desired energy. The deflector has the further property of returning particles which do not undergo collision to the regular orbits whereby the particles recirculate with the possibility of colliding upon subsequent passages through the deflector.

  8. Acceleration of plasma electrons by intense nonrelativistic ion and electron beams propagating in background plasma due to two-stream instability

    NASA Astrophysics Data System (ADS)

    Kaganovich, Igor D.

    2015-11-01

    In this paper we study the effects of the two-stream instability on the propagation of intense nonrelativistic ion and electron beams in background plasma. Development of the two-stream instability between the beam ions and plasma electrons leads to beam breakup, a slowing down of the beam particles, acceleration of the plasma particles, and transfer of the beam energy to the plasma particles and wave excitations. Making use of the particle-in-cell codes EDIPIC and LSP, and analytic theory we have simulated the effects of the two-stream instability on beam propagation over a wide range of beam and plasma parameters. Because of the two-stream instability the plasma electrons can be accelerated to velocities as high as twice the beam velocity. The resulting return current of the accelerated electrons may completely change the structure of the beam self - magnetic field, thereby changing its effect on the beam from focusing to defocusing. Therefore, previous theories of beam self-electromagnetic fields that did not take into account the effects of the two-stream instability must be significantly modified. This effect can be observed on the National Drift Compression Experiment-II (NDCX-II) facility by measuring the spot size of the extracted beamlet propagating through several meters of plasma. Particle-in-cell, fluid simulations, and analytical theory also reveal the rich complexity of beam- plasma interaction phenomena: intermittency and multiple regimes of the two-stream instability in dc discharges; band structure of the growth rate of the two-stream instability of an electron beam propagating in a bounded plasma and repeated acceleration of electrons in a finite system. In collaboration with E. Tokluoglu, D. Sydorenko, E. A. Startsev, J. Carlsson, and R. C. Davidson. Research supported by the U.S. Department of Energy.

  9. Accelerators, Beams And Physical Review Special Topics - Accelerators And Beams

    SciTech Connect

    Siemann, R.H.; /SLAC

    2011-10-24

    Accelerator science and technology have evolved as accelerators became larger and important to a broad range of science. Physical Review Special Topics - Accelerators and Beams was established to serve the accelerator community as a timely, widely circulated, international journal covering the full breadth of accelerators and beams. The history of the journal and the innovations associated with it are reviewed.

  10. Beam intensity expectations for a 200 MeV/u 400 kW radioactive beam driver accelerator.

    SciTech Connect

    Back, B. B.; Jiang, C. L.; Physics

    2006-12-31

    The expected radioactive ion production rate for a 200 MeV/u 400 kW driver linac using four different production methods is discussed. For each isotope the optimum method is identified and the rate is calculated based on different model assumptions, empirical observation and extrapolations. The results are compared to the rates expected for a 550 MeV proton driver machine with a beam power of 50 kW, as well as the full RIA facility with a 400 MeV/u 400 kW production linac.

  11. High-intensity ion sources for accelerators with emphasis on H- beam formation and transport (invited)a)

    NASA Astrophysics Data System (ADS)

    Keller, R.

    2010-02-01

    This paper lays out the fundamental working principles of a variety of high-current ion sources for accelerators in a tutorial manner, and gives examples of specific source types such as dc discharge-driven and rf-driven multicusp sources, Penning-type, and electron cyclotron resonance-based sources while discussing those principles, pointing out general performance limits as well as the performance parameters of specific sources. Laser-based, two-chamber, and surface-ionization sources are briefly mentioned. Main aspects of this review are particle feed, ionization mechanism, beam formation, and beam transport. Issues seen with beam formation and low-energy transport of negative hydrogen-ion beams are treated in detail.

  12. Generation of quasi-monoenergetic heavy ion beams via staged shock wave acceleration driven by intense laser pulses in near-critical plasmas

    NASA Astrophysics Data System (ADS)

    Zhang, W. L.; Qiao, B.; Shen, X. F.; You, W. Y.; Huang, T. W.; Yan, X. Q.; Wu, S. Z.; Zhou, C. T.; He, X. T.

    2016-09-01

    Laser-driven ion acceleration potentially offers a compact, cost-effective alternative to conventional accelerators for scientific, technological, and health-care applications. A novel scheme for heavy ion acceleration in near-critical plasmas via staged shock waves driven by intense laser pulses is proposed, where, in front of the heavy ion target, a light ion layer is used for launching a high-speed electrostatic shock wave. This shock is enhanced at the interface before it is transmitted into the heavy ion plasmas. Monoenergetic heavy ion beam with much higher energy can be generated by the transmitted shock, comparing to the shock wave acceleration in pure heavy ion target. Two-dimensional particle-in-cell simulations show that quasi-monoenergetic {{{C}}}6+ ion beams with peak energy 168 MeV and considerable particle number 2.1 × {10}11 are obtained by laser pulses at intensity of 1.66 × {10}20 {{W}} {{cm}}-2 in such staged shock wave acceleration scheme. Similarly a high-quality {{Al}}10+ ion beam with a well-defined peak with energy 250 MeV and spread δ E/{E}0=30 % can also be obtained in this scheme.

  13. An improved pulse-line accelerator-driven, intense current-density, and high-brightness pseudospark electron beam

    SciTech Connect

    Zhu, J.; Wang, Z.; Zhang, L.; Wang, M.

    1996-02-01

    A high-voltage (200 kV), high current-density, low-emittance (23 {pi}{center_dot}mm mrd), high-brightness (8 {times} 10{sup 10} A/(mrd){sup 2}) electron beam was generated in a pseudospark chamber filled with 15 Pa nitrogen and driven by a modified pulse line accelerator. The beam ejected with {le}1-mm diameter, 2.2-kA beam current, 400-ns pulse length, and about 20 cm propagation distance. Exposure of 10 shots on the same film produced a hole of 1.6-mm diameter at 7 cm downstream of the anode, and showed its good reproducibility. After 60 shots, it was observed that almost no destructive damage traces were left on the surfaces of the various electrodes and insulators of the pseudospark discharge chamber. It was experimentally found that the quality of the pseudospark electron beam remains very high, even at high voltages (of several hundred kilovolts), similar to low voltages, and is much better than the quality of the cold-cathode electron beams.

  14. Dynamics of high-energy proton beam acceleration and focusing from hemisphere-cone targets by high-intensity lasers.

    PubMed

    Qiao, B; Foord, M E; Wei, M S; Stephens, R B; Key, M H; McLean, H; Patel, P K; Beg, F N

    2013-01-01

    Acceleration and focusing of high-energy proton beams from fast-ignition (FI) -related hemisphere-cone assembled targets have been numerically studied by hybrid particle-in-cell simulations and compared with those from planar-foil and open-hemisphere targets. The whole physical process including the laser-plasma interaction has been self-consistently modeled for 15 ps, at which time the protons reach asymptotic motion. It is found that the achievable focus of proton beams is limited by the thermal pressure gradients in the co-moving hot electrons, which induce a transverse defocusing electric field that bends proton trajectories near the axis. For the advanced hemisphere-cone target, the flow of hot electrons along the cone wall induces a local transverse focusing sheath field, resulting in a clear enhancement in proton focusing; however, it leads to a significant loss of longitudinal sheath potential, reducing the total conversion efficiency from laser to protons.

  15. High-powered pulsed-ion-beam acceleration and transport

    SciTech Connect

    Humphries, S. Jr.; Lockner, T.R.

    1981-11-01

    The state of research on intense ion beam acceleration and transport is reviewed. The limitations imposed on ion beam transport by space charge effects and methods available for neutralization are summarized. The general problem of ion beam neutralization in regions free of applied electric fields is treated. The physics of acceleration gaps is described. Finally, experiments on multi-stage ion acceleration are summarized.

  16. Neutral particle beam intensity controller

    DOEpatents

    Dagenhart, W.K.

    1984-05-29

    The neutral beam intensity controller is based on selected magnetic defocusing of the ion beam prior to neutralization. The defocused portion of the beam is dumped onto a beam dump disposed perpendicular to the beam axis. Selective defocusing is accomplished by means of a magnetic field generator disposed about the neutralizer so that the field is transverse to the beam axis. The magnetic field intensity is varied to provide the selected partial beam defocusing of the ions prior to neutralization. The desired focused neutral beam portion passes along the beam path through a defining aperture in the beam dump, thereby controlling the desired fraction of neutral particles transmitted to a utilization device without altering the kinetic energy level of the desired neutral particle fraction. By proper selection of the magnetic field intensity, virtually zero through 100% intensity control of the neutral beam is achieved.

  17. High-Intensity Proton Accelerator

    SciTech Connect

    Jay L. Hirshfield

    2011-12-27

    Analysis is presented for an eight-cavity proton cyclotron accelerator that could have advantages as compared with other accelerators because of its potentially high acceleration gradient. The high gradient is possible since protons orbit in a sequence of TE111 rotating mode cavities of equally diminishing frequencies with path lengths during acceleration that greatly exceed the cavity lengths. As the cavities operate at sequential harmonics of a basic repetition frequency, phase synchronism can be maintained over a relatively wide injection phase window without undue beam emittance growth. It is shown that use of radial vanes can allow cavity designs with significantly smaller radii, as compared with simple cylindrical cavities. Preliminary beam transport studies show that acceptable extraction and focusing of a proton beam after cyclic motion in this accelerator should be possible. Progress is also reported on design and tests of a four-cavity electron counterpart accelerator for experiments to study effects on beam quality arising from variations injection phase window width. This device is powered by four 500-MW pulsed amplifiers at 1500, 1800, 2100, and 2400 MHz that provide phase synchronous outputs, since they are driven from a with harmonics derived from a phase-locked 300 MHz source.

  18. Beam Breakup Effects in Dielectric Based Accelerators

    SciTech Connect

    Schoessow, P.; Kanareykin, A.; Jing, C.; Kustov, A.; Altmark, A.; Power, J. G.; Gai, W.

    2009-01-22

    The dynamics of the beam in structure-based wakefield accelerators leads to beam stability issues not ordinarily found in other machines. In particular, the high current drive beam in an efficient wakefield accelerator loses a large fraction of its energy in the decelerator structure, resulting in physical emittance growth, increased energy spread, and the possibility of head-tail instability for an off axis beam, all of which can lead to severe reduction of beam intensity. Beam breakup (BBU) effects resulting from parasitic wakefields provide a potentially serious limitation to the performance of dielectric structure based wakefield accelerators as well. We report on experimental and numerical investigation of BBU and its mitigation. The experimental program focuses on BBU measurements at the AWA facility in a number of high gradient and high transformer ratio wakefield devices. New pickup-based beam diagnostics will provide methods for studying parasitic wakefields that are currently unavailable. The numerical part of this research is based on a particle-Green's function beam breakup code we are developing that allows rapid, efficient simulation of beam breakup effects in advanced linear accelerators. The goal of this work is to be able to compare the results of detailed experimental measurements with the accurate numerical results and to design an external FODO channel for the control of the beam in the presence of strong transverse wakefields.

  19. Beam Control for Ion Induction Accelerators

    SciTech Connect

    Sangster, T.C.; Ahle, L.

    2000-02-17

    Coordinated bending and acceleration of an intense space-charge-dominated ion beam has been achieved for the first time. This required the development of a variable waveform, precision, bi-polar high voltage pulser and a precision, high repetition rate induction core modulator. Waveforms applied to the induction cores accelerate the beam as the bi-polar high voltage pulser delivers a voltage ramp to electrostatic dipoles which bend the beam through a 90 degree permanent magnet quadrupole lattice. Further work on emittance minimization is also reported.

  20. Accelerators for Intensity Frontier Research

    SciTech Connect

    Derwent, Paul; /Fermilab

    2012-05-11

    In 2008, the Particle Physics Project Prioritization Panel identified three frontiers for research in high energy physics, the Energy Frontier, the Intensity Frontier, and the Cosmic Frontier. In this paper, I will describe how Fermilab is configuring and upgrading the accelerator complex, prior to the development of Project X, in support of the Intensity Frontier.

  1. Strong radiation damping effects in a gamma-ray source generated by the interaction of a high intensity laser with a wakefield accelerated electron beam

    NASA Astrophysics Data System (ADS)

    Thomas, Alexander; Ridgers, Christopher; Bulanov, Stepan; Griffin, Blake; Mangles, Stuart

    2012-10-01

    We present numerical calculations of the angularly resolved radiation spectrum from a relativistic electron beam interacting with an ultrashort laser pulse. These calculations include the effect of semi-classical radiation reaction forces including a Gaunt factor for synchrotron radiation. For a laser of 5x10^21 Wcm-2 intensity interacting with a 200 MeV electron beam with an emittance similar to that in laser wakefield acceleration experiments, radiation reaction does not produce a significant change in the angular and energy distribution of photons. However the effects of radiation reaction are clear when observing the electron beam properties. The result is that near-term experiments using such a counter-propagating beam-laser geometry should be able to measure the effects of quantum effects in radiation reaction. The calculations also show that the brilliance of this source is very high, with a peak spectral brilliance exceeding 10^29 photons,s-1mm-2mrad-2(0.1% bandwidth)-1 with approximately 2% efficiency and with a peak energy of 10 MeV.

  2. Strong Radiation-Damping Effects in a Gamma-Ray Source Generated by the Interaction of a High-Intensity Laser with a Wakefield-Accelerated Electron Beam

    NASA Astrophysics Data System (ADS)

    Thomas, A. G. R.; Ridgers, C. P.; Bulanov, S. S.; Griffin, B. J.; Mangles, S. P. D.

    2012-10-01

    A number of theoretical calculations have studied the effect of radiation-reaction forces on radiation distributions in strong-field counterpropagating electron-beam-laser interactions, but could these effects—including quantum corrections—be observed in interactions with realistic bunches and focusing fields, as is hoped in a number of soon-to-be-proposed experiments? We present numerical calculations of the angularly resolved radiation spectrum from an electron bunch with parameters similar to those produced in laser-wakefield-acceleration experiments, interacting with an intense, ultrashort laser pulse. For our parameters, the effect of radiation damping on the angular distribution and energy distribution of photons is not easily discernible for a realistic moderate-emittance electron beam. However, experiments using such a counterpropagating beam-laser geometry should be able to measure these effects using current laser systems through measurement of the electron-beam properties. In addition, the brilliance of this source is very high, with peak spectral brilliance exceeding 1029photonss-1mm-2mrad-2(0.1%bandwidth)-1 with an approximately 2% conversion efficiency and with a peak energy of 10 MeV.

  3. Theory of laser acceleration of light-ion beams from interaction of ultrahigh-intensity lasers with layered targets.

    PubMed

    Albright, B J; Yin, L; Hegelich, B M; Bowers, Kevin J; Kwan, T J T; Fernández, J C

    2006-09-15

    Experiments at the LANL Trident facility demonstrated the production of monoenergetic ion beams from the interaction of an ultraintense laser with a target comprising a heavy ion substrate and thin layer of light ions. An analytic model is obtained that predicts how the mean energy and quality of monoenergetic ion beams and the energy of substrate ions vary with substrate material and light-ion layer composition and thickness. Dimensionless parameters controlling the dynamics are derived and the model is validated with particle-in-cell simulations and experimental data.

  4. Progress toward a microsecond duration, repetitively pulsed, intense- ion beam

    SciTech Connect

    Davis, H.A.; Olson, J.C.; Reass, W.A.; Coates, D.M.; Hunt, J.W.; Schleinitz, H.M.; Lovberg, R.H.; Greenly, J.B.

    1996-07-01

    A number of intense ion beams applications are emerging requiring repetitive high-average-power beams. These applications include ablative deposition of thin films, rapid melt and resolidification for surface property enhancement, advanced diagnostic neutral beams for the next generation of Tokamaks, and intense pulsed-neutron sources. We are developing a 200-250 keV, 15 kA, 1 {mu}s duration, 1-30 Hz intense ion beam accelerator to address these applications.

  5. Applications of High Intensity Proton Accelerators

    NASA Astrophysics Data System (ADS)

    Raja, Rajendran; Mishra, Shekhar

    2010-06-01

    Superconducting radiofrequency linac development at Fermilab / S. D. Holmes -- Rare muon decay experiments / Y. Kuno -- Rare kaon decays / D. Bryman -- Muon collider / R. B. Palmer -- Neutrino factories / S. Geer -- ADS and its potential / J.-P. Revol -- ADS history in the USA / R. L. Sheffield and E. J. Pitcher -- Accelerator driven transmutation of waste: high power accelerator for the European ADS demonstrator / J. L. Biarrotte and T. Junquera -- Myrrha, technology development for the realisation of ADS in EU: current status & prospects for realisation / R. Fernandez ... [et al.] -- High intensity proton beam production with cyclotrons / J. Grillenberger and M. Seidel -- FFAG for high intensity proton accelerator / Y. Mori -- Kaon yields for 2 to 8 GeV proton beams / K. K. Gudima, N. V. Mokhov and S. I. Striganov -- Pion yield studies for proton driver beams of 2-8 GeV kinetic energy for stopped muon and low-energy muon decay experiments / S. I. Striganov -- J-Parc accelerator status and future plans / H. Kobayashi -- Simulation and verification of DPA in materials / N. V. Mokhov, I. L. Rakhno and S. I. Striganov -- Performance and operational experience of the CNGS facility / E. Gschwendtner -- Particle physics enabled with super-conducting RF technology - summary of working group 1 / D. Jaffe and R. Tschirhart -- Proton beam requirements for a neutrino factory and muon collider / M. S. Zisman -- Proton bunching options / R. B. Palmer -- CW SRF H linac as a proton driver for muon colliders and neutrino factories / M. Popovic, C. M. Ankenbrandt and R. P. Johnson -- Rapid cycling synchrotron option for Project X / W. Chou -- Linac-based proton driver for a neutrino factory / R. Garoby ... [et al.] -- Pion production for neutrino factories and muon colliders / N. V. Mokhov ... [et al.] -- Proton bunch compression strategies / V. Lebedev -- Accelerator test facility for muon collider and neutrino factory R&D / V. Shiltsev -- The superconducting RF linac for muon

  6. Unveiling the propagation dynamics of self-accelerating vector beams

    NASA Astrophysics Data System (ADS)

    Bar-David, Jonathan; Voloch-Bloch, Noa; Mazurski, Noa; Levy, Uriel

    2016-09-01

    We study theoretically and experimentally the varying polarization states and intensity patterns of self-accelerating vector beams. It is shown that as these beams propagate, the main intensity lobe and the polarization singularity gradually drift apart. Furthermore, the propagation dynamics can be manipulated by controlling the beams’ acceleration coefficients. We also demonstrate the self-healing dynamics of these accelerating vector beams for which sections of the vector beam are being blocked by an opaque or polarizing obstacle. Our results indicate that the self-healing process is almost insensitive for the obstacles’ polarization direction. Moreover, the spatial polarization structure also shows self- healing properties, and it is reconstructed as the beam propagates further beyond the perturbation plane. These results open various possibilities for generating, shaping and manipulating the intensity patterns and space variant polarization states of accelerating vector beams.

  7. Unveiling the propagation dynamics of self-accelerating vector beams

    PubMed Central

    Bar-David, Jonathan; Voloch-Bloch, Noa; Mazurski, Noa; Levy, Uriel

    2016-01-01

    We study theoretically and experimentally the varying polarization states and intensity patterns of self-accelerating vector beams. It is shown that as these beams propagate, the main intensity lobe and the polarization singularity gradually drift apart. Furthermore, the propagation dynamics can be manipulated by controlling the beams’ acceleration coefficients. We also demonstrate the self-healing dynamics of these accelerating vector beams for which sections of the vector beam are being blocked by an opaque or polarizing obstacle. Our results indicate that the self-healing process is almost insensitive for the obstacles’ polarization direction. Moreover, the spatial polarization structure also shows self- healing properties, and it is reconstructed as the beam propagates further beyond the perturbation plane. These results open various possibilities for generating, shaping and manipulating the intensity patterns and space variant polarization states of accelerating vector beams. PMID:27671745

  8. Nonparaxial Near-Nondiffracting Accelerating Optical Beams

    NASA Astrophysics Data System (ADS)

    Lai, Ru-Yu; Zhou, Ting

    2017-02-01

    We show that new families of accelerating and almost nondiffracting beams (solutions) for Maxwell's equations can be constructed. These are complex geometrical optics (CGO) solutions to Maxwell's equations with nonlinear limiting Carleman weights. They have the form of wave packets that propagate along circular trajectories while almost preserving a transverse intensity profile. We also show similar waves constructed using the approach combining CGO solutions and the Kelvin transform.

  9. The Two-beam accelerator

    SciTech Connect

    Sessler, A.M.; Hopkins, D.B.

    1986-06-01

    The Two-Beam Accelerator (TBA) consists of a long high-gradient accelerator structure (HGS) adjacent to an equal-length Free Electron Laser (FEL). In the FEL, a beam propagates through a long series of undulators. At regular intervals, waveguides couple microwave power out of the FEL into the HGS. To replenish energy given up by the FEL beam to the microwave field, induction accelerator units are placed periodically along the length of the FEL. In this manner it is expected to achieve gradients of more than 250 MV/m and thus have a serious option for a 1 TeV x 1 TeV linear collider. The state of present theoretical understanding of the TBA is presented with particular emphasis upon operation of the ''steady-state'' FEL, phase and amplitude control of the rf wave, and suppression of sideband instabilities. Experimental work has focused upon the development of a suitable HGS and the testing of this structure using the Electron Laser Facility (ELF). Description is given of a first test at ELF with a seven-cell 2..pi../3 mode structure which without preconditioning and with a not-very-good vacuum nevertheless at 35 GHz yielded an average accelerating gradient of 180 MV/m.

  10. Intense Relativistic Electron Beam Investigations

    DTIC Science & Technology

    1979-04-01

    flashover and other undetermined physical processes which create a plasma at the liner surface . The ions are drawn toward the Uiner axis by the...dielectric wall and causing surface flashover and the liberation of ions. These ions provide sufficient charge neutralization for the beam to propagate a...beam-induced surface flashover process which produces the ions to be accelerated. Alternative methods are proposed in Section III for next year’s

  11. Intense diagnostic neutral beam development for ITER

    SciTech Connect

    Rej, D.J.; Henins, I.; Fonck, R.J.; Kim, Y.J.

    1992-05-01

    For the next-generation, burning tokamak plasmas such as ITER, diagnostic neutral beams and beam spectroscopy will continue to be used to determine a variety of plasma parameters such as ion temperature, rotation, fluctuations, impurity content, current density profile, and confined alpha particle density and energy distribution. Present-day low-current, long-pulse beam technology will be unable to provide the required signal intensities because of higher beam attenuation and background bremsstrahlung radiation in these larger, higher-density plasmas. To address this problem, we are developing a short-pulse, intense diagnostic neutral beam. Protons or deuterons are accelerated using magnetic-insulated ion-diode technology, and neutralized in a transient gas cell. A prototype 25-kA, 100-kV, 1-{mu}s accelerator is under construction at Los Alamos. Initial experiments will focus on ITER-related issues of beam energy distribution, current density, pulse length, divergence, propagation, impurity content, reproducibility, and maintenance.

  12. Intense diagnostic neutral beam development for ITER

    SciTech Connect

    Rej, D.J.; Henins, I. ); Fonck, R.J.; Kim, Y.J. . Dept. of Nuclear Engineering and Engineering Physics)

    1992-01-01

    For the next-generation, burning tokamak plasmas such as ITER, diagnostic neutral beams and beam spectroscopy will continue to be used to determine a variety of plasma parameters such as ion temperature, rotation, fluctuations, impurity content, current density profile, and confined alpha particle density and energy distribution. Present-day low-current, long-pulse beam technology will be unable to provide the required signal intensities because of higher beam attenuation and background bremsstrahlung radiation in these larger, higher-density plasmas. To address this problem, we are developing a short-pulse, intense diagnostic neutral beam. Protons or deuterons are accelerated using magnetic-insulated ion-diode technology, and neutralized in a transient gas cell. A prototype 25-kA, 100-kV, 1-{mu}s accelerator is under construction at Los Alamos. Initial experiments will focus on ITER-related issues of beam energy distribution, current density, pulse length, divergence, propagation, impurity content, reproducibility, and maintenance.

  13. Effect of the change in the load resistance on the high voltage pulse transformer of the intense electron-beam accelerators.

    PubMed

    Cheng, Xin-bing; Liu, Jin-liang; Qian, Bao-liang; Zhang, Yu; Zhang, Hong-bo

    2009-11-01

    A high voltage pulse transformer (HVPT) is usually used as a charging device for the pulse forming line (PFL) of intense electron-beam accelerators (IEBAs). Insulation of the HVPT is one of the important factors that restrict the development of the HVPT. Until now, considerable effort has been focused on minimizing high field regions to avoid insulation breakdown between windings. Characteristics of the HVPT have been widely discussed to achieve these goals, but the effects of the PFL and load resistance on HVPT are usually neglected. In this paper, a HVPT is used as a charging device for the PFL of an IEBA and the effect of the change in the load resistance on the HVPT of the IEBA is presented. When the load resistance does not match the wave impedance of the PFL, a high-frequency bipolar oscillating voltage will occur, and the amplitude of the oscillating voltage will increase with the decrease in the load resistance. The load resistance approximates to zero and the amplitude of the oscillating voltage is much higher. This makes it easier for surface flashover along the insulation materials to form and decrease the lifetime of the HVPT.

  14. Self-Consistent Simulation of Transport and Energy Deposition of Intense Laser-Accelerated Proton Beams in Solid-Density Matter.

    PubMed

    Kim, J; Qiao, B; McGuffey, C; Wei, M S; Grabowski, P E; Beg, F N

    2015-07-31

    The first self-consistent hybrid particle-in-cell (PIC) simulation of intense proton beam transport and energy deposition in solid-density matter is presented. Both the individual proton slowing-down and the collective beam-plasma interaction effects are taken into account with a new dynamic proton stopping power module that has been added to a hybrid PIC code. In this module, the target local stopping power can be updated at each time step based on its thermodynamic state. For intense proton beams, the reduction of target stopping power from the cold condition due to continuous proton heating eventually leads to broadening of the particle range and energy deposition far beyond the Bragg peak. For tightly focused beams, large magnetic field growth in collective interactions results in self-focusing of the beam and much stronger localized heating of the target.

  15. BEAM LOSS MECHANISMS IN HIGH INTENSITY LINACS

    SciTech Connect

    Plum, Michael A

    2012-01-01

    In the present operation of the Oak Ridge Spallation Neutron Source, 60-Hz, 825-us H beam pulses are accelerated to 910 MeV, and then compressed to less than a microsecond in the storage ring, to deliver 1 MW of beam power to the spallation target. The beam loss in the superconducting portion of the linac is higher than expected, and it has shown a surprising counter-intuitive correlation with quadrupole magnetic fields, with a loss minimum occurring when the quadrupoles are set to approximately half their design values. This behavior can now be explained by a recent set of experiments that show the beam loss is primarily due to intra-beam stripping. Beam halo is another important beam loss contributor, and collimation in the 2.5 MeV Medium Energy Beam Transport has proven to be an effective mitigation strategy. In this presentation, we will summarize these and other beam loss mechanisms that are important for high intensity linacs.

  16. Multi-beam linear accelerator EVT

    NASA Astrophysics Data System (ADS)

    Teryaev, Vladimir E.; Kazakov, Sergey Yu.; Hirshfield, Jay L.

    2016-09-01

    A novel electron multi-beam accelerator is presented. The accelerator, short-named EVT (Electron Voltage Transformer) belongs to the class of two-beam accelerators. It combines an RF generator and essentially an accelerator within the same vacuum envelope. Drive beam-lets and an accelerated beam are modulated in RF modulators and then bunches pass into an accelerating structure, comprising uncoupled with each other and inductive tuned cavities, where the energy transfer from the drive beams to the accelerated beam occurs. A phasing of bunches is solved by choice correspond distances between gaps of the adjacent cavities. Preliminary results of numerical simulations and the initial specification of EVT operating in S-band, with a 60 kV gun and generating a 2.7 A, 1.1 MV beam at its output is presented. A relatively high efficiency of 67% and high design average power suggest that EVT can find its use in industrial applications.

  17. Production of an Accelerated Oxygen-14 Beam

    SciTech Connect

    Powell, James; O'Neil, James P.; Cerny, Joseph

    2002-05-03

    BEARS is an ongoing project to provide a light-ion radioactive-beam capability at the 88-Inch Cyclotron at LBNL. Light radioactive isotopes are produced at a 10 MeV proton medical cyclotron, transported 350 m via a high-speed gas transport capillary, cryogenically separated, and injected into the 88-Inch Cyclotron's ion source. The first radioactive beam successfully accelerated was Carbon-11 and beams of intensity more than 108 ions/sec have been utilized for experiments. Development of Oxygen-14 as the second BEARS beam presented considerable technical challenges, both due to its short half-life of 71 seconds and the radiation chemistry of oxygen in the target. The usual techniques developed for medical uses of Oxygen-15 involve the addition of significant amounts of carrier oxygen, something that would overload the ion source. As a solution, Oxygen-14 is produced as water in a carrier-free form, and is chemically converted in two steps to carbon dioxide, a form readily usable by the BEARS. This system has been built and is operational, and initial tests of accelerating an Oxygen-14 beam have been performed.

  18. 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.

  19. Electron acceleration by a tightly focused cylindrical vector Gaussian beam

    NASA Astrophysics Data System (ADS)

    Xu, Jian; Yang, Zhen-Jun; Li, Jian-Xing; Zang, Wei-Ping

    2017-02-01

    We have studied the electron acceleration by a tightly focused cylindrical vector Gaussian beam. Different from the Lax series field, cylindrical vector Gaussian beams are vector-beam solutions of Maxwell’s equations and its focusing property can be numerically analyzed by the Richards-Wolf vectorial diffraction theory. Field differences exist between the cylindrical vector Gaussian beam and the Lax series field. The cylindrical vector Gaussian beam increases the asymmetry of the electromagnetic fields, which is more beneficial to the electron acceleration. When the beam waist falls down to the order of the wavelength, the high laser intensity zone is more proper to define the reflection, capture and transmission conditions of the electrons. The injection energy and the injected angle of the electron and the initial phase of the laser beam play important roles for the electron to enter and be trapped by the high laser intensity zone.

  20. Intense Pulsed Heavy Ion Beam Technology

    NASA Astrophysics Data System (ADS)

    Masugata, Katsumi; Ito, Hiroaki

    Development of intense pulsed heavy ion beam accelerator technology is described for the application of materials processing. Gas puff plasma gun and vacuum arc discharge plasma gun were developed as an active ion source for magnetically insulated pulsed ion diode. Source plasma of nitrogen and aluminum were successfully produced with the gas puff plasma gun and the vacuum arc plasma gun, respectively. The ion diode was successfully operated with gas puff plasma gun at diode voltage 190 kV, diode current 2.2 kA and nitrogen ion beam of ion current density 27 A/cm2 was obtained. The ion composition was evaluated by a Thomson parabola spectrometer and the purity of the nitrogen ion beam was estimated to be 86%. The diode also operated with aluminum ion source of vacuum arc plasma gun. The ion diode was operated at 200 kV, 12 kA, and aluminum ion beam of current density 230 A/cm2 was obtained. The beam consists of aluminum ions (Al(1-3)+) of energy 60-400 keV, and protons (90-130 keV), and the purity was estimated to be 89 %. The development of the bipolar pulse accelerator (BPA) was reported. A double coaxial type bipolar pulse generator was developed as the power supply of the BPA. The generator was tested with dummy load of 7.5 ohm, bipolar pulses of -138 kV, 72 ns (1st pulse) and +130 kV, 70 ns (2nd pulse) were succesively generated. By applying the bipolar pulse to the drift tube of the BPA, nitrogen ion beam of 2 A/cm2 was observed in the cathode, which suggests the bipolar pulse acceleration.

  1. Pulsed laser beam intensity monitor

    SciTech Connect

    Cason, C.M.; Jones, R.W.

    1982-07-13

    A pulsed laser beam intensity monitor measures the peak power within a selectable cross section of a test laser beam and measures integrated energy of the beam during the pulse period of a test laser. A continuous wave laser and a pulsed ruby laser are coaxially arranged for simultaneously transmitting optical output energy through a crystal flat during the time a test laser pulse is transmitted through the flat. Due to stress birefringence in the crystal, the ruby laser pulse transmitted through the flat is recorded and analyzed to provide peak power information about the test laser output pulse, and the continuous wave laser output reflected from the crystal flat provides a measurement of energy during the test laser pulse.

  2. Accelerated iterative beam angle selection in IMRT

    SciTech Connect

    Bangert, Mark; Unkelbach, Jan

    2016-03-15

    Purpose: Iterative methods for beam angle selection (BAS) for intensity-modulated radiation therapy (IMRT) planning sequentially construct a beneficial ensemble of beam directions. In a naïve implementation, the nth beam is selected by adding beam orientations one-by-one from a discrete set of candidates to an existing ensemble of (n − 1) beams. The best beam orientation is identified in a time consuming process by solving the fluence map optimization (FMO) problem for every candidate beam and selecting the beam that yields the largest improvement to the objective function value. This paper evaluates two alternative methods to accelerate iterative BAS based on surrogates for the FMO objective function value. Methods: We suggest to select candidate beams not based on the FMO objective function value after convergence but (1) based on the objective function value after five FMO iterations of a gradient based algorithm and (2) based on a projected gradient of the FMO problem in the first iteration. The performance of the objective function surrogates is evaluated based on the resulting objective function values and dose statistics in a treatment planning study comprising three intracranial, three pancreas, and three prostate cases. Furthermore, iterative BAS is evaluated for an application in which a small number of noncoplanar beams complement a set of coplanar beam orientations. This scenario is of practical interest as noncoplanar setups may require additional attention of the treatment personnel for every couch rotation. Results: Iterative BAS relying on objective function surrogates yields similar results compared to naïve BAS with regard to the objective function values and dose statistics. At the same time, early stopping of the FMO and using the projected gradient during the first iteration enable reductions in computation time by approximately one to two orders of magnitude. With regard to the clinical delivery of noncoplanar IMRT treatments, we could

  3. Laser wakefield acceleration of polarized electron beams

    NASA Astrophysics Data System (ADS)

    Pugacheva, D. V.; Andreev, N. E.; Cros, B.

    2016-11-01

    The acceleration of highly polarized electron beams are widely used in state-of-the-art high-energy physics experiments. In this work, a model for investigation of polarization dynamics of electron beams in the laser-plasma accelerator depending on the initial energy of electrons was developed and tested. To obtain the evolution of the trajectory and momentum of the electron for modeling its acceleration the wakefield structure was determined. The spin precession of the beam electron was described by Thomas-Bargman-Michel-Telegdi equations. The evolution of the electron beam polarization was investigated for zero-emittance beams with zero-energy spread.

  4. Electron beam accelerator with magnetic pulse compression and accelerator switching

    DOEpatents

    Birx, D.L.; Reginato, L.L.

    1984-03-22

    An electron beam accelerator is described comprising an electron beam generator-injector to produce a focused beam of greater than or equal to .1 MeV energy electrons; a plurality of substantially identical, aligned accelerator modules to sequentially receive and increase the kinetic energies of the beam electron by about .1-1 MeV per module. Each accelerator module includes a pulse-forming network that delivers a voltage pulse to the module of substantially .1-1 MeV maximum energy over a time duration of less than or equal to 1 ..mu..sec.

  5. Electron beam accelerator with magnetic pulse compression and accelerator switching

    DOEpatents

    Birx, Daniel L.; Reginato, Louis L.

    1987-01-01

    An electron beam accelerator comprising an electron beam generator-injector to produce a focused beam of .gtoreq.0.1 MeV energy electrons; a plurality of substantially identical, aligned accelerator modules to sequentially receive and increase the kinetic energies of the beam electrons by about 0.1-1 MeV per module. Each accelerator module includes a pulse-forming network that delivers a voltage pulse to the module of substantially 0.1-1 MeV maximum energy over a time duration of .ltoreq.1 .mu.sec.

  6. Electron beam accelerator with magnetic pulse compression and accelerator switching

    DOEpatents

    Birx, Daniel L.; Reginato, Louis L.

    1988-01-01

    An electron beam accelerator comprising an electron beam generator-injector to produce a focused beam of .gtoreq.0.1 MeV energy electrons; a plurality of substantially identical, aligned accelerator modules to sequentially receive and increase the kinetic energies of the beam electrons by about 0.1-1 MeV per module. Each accelerator module includes a pulse-forming network that delivers a voltage pulse to the module of substantially .gtoreq.0.1-1 MeV maximum energy over a time duration of .ltoreq.1 .mu.sec.

  7. Low Intensity Beam Imaging - Position Sensitive Avalanche Counter

    SciTech Connect

    Mas, J.; Shapira, D; T.A. Lewis

    1998-11-04

    Monitors of this type are mostly intended for the lowest intensity beams at the HRIBF at ORNL. They are used to aid the accelerator operator in focusing and steering the beam and by the experimenters at the focal plane of the spectrometers.

  8. Beam break-up in the two beam accelerator

    SciTech Connect

    Whittum, D.H.; Travish, G.A.; Sessler, A.M.; Craig, G.D.; DeFord, J.F.

    1989-03-01

    We have studied numerically beam break-up (BBU) in the drive beam of a Two-Beam Accelerator (TBA), using transverse wakes calculated numerically using the AMOS Code. We examine only cumulative BBU due to the wake of the linear induction accelerator cavities. We do not consider regenerative BBU due to the relativistic klystron (RK) cavities. We find growth lengths of order /approximately/100 m for typical parameters. 14 refs., 2 figs., 1 tab.

  9. Landscape of Future Accelerators at the Energy and Intensity Frontier

    SciTech Connect

    Syphers, M. J.; Chattopadhyay, S.

    2016-11-21

    An overview is provided of the currently envisaged landscape of charged particle accelerators at the energy and intensity frontiers to explore particle physics beyond the standard model via 1-100 TeV-scale lepton and hadron colliders and multi-Megawatt proton accelerators for short- and long- baseline neutrino experiments. The particle beam physics, associated technological challenges and progress to date for these accelerator facilities (LHC, HL-LHC, future 100 TeV p-p colliders, Tev-scale linear and circular electron-positron colliders, high intensity proton accelerator complex PIP-II for DUNE and future upgrade to PIP-III) are outlined. Potential and prospects for advanced “nonlinear dynamic techniques” at the multi-MW level intensity frontier and advanced “plasma- wakefield-based techniques” at the TeV-scale energy frontier and are also described.

  10. Efficient Optical Energy Harvesting in Self-Accelerating Beams

    PubMed Central

    Bongiovanni, Domenico; Hu, Yi; Wetzel, Benjamin; Robles, Raul A.; Mendoza González, Gregorio; Marti-Panameño, Erwin A.; Chen, Zhigang; Morandotti, Roberto

    2015-01-01

    We report the experimental observation of energetically confined self-accelerating optical beams propagating along various convex trajectories. We show that, under an appropriate transverse compression of their spatial spectra, these self-accelerating beams can exhibit a dramatic enhancement of their peak intensity and a significant decrease of their transverse expansion, yet retaining both the expected acceleration profile and the intrinsic self-healing properties. We found our experimental results to be in excellent agreement with the numerical simulations. We expect further applications in such contexts where power budget and optimal spatial confinement can be important limiting factors. PMID:26299360

  11. Survey of proposed high intensity accelerators and their applications

    SciTech Connect

    Schriber, S.O.

    1994-09-01

    Many interesting applications are being considered for high intensity accelerators. Implications of the technology developments that are enhancing these opportunities, or making them possible, will be covered in context of the applications. Applications include those for research (in areas such as material science, biological sciences, nuclear and high energy physics), accelerator-driven transmutation technologies, defense, and medicine. Specific examples will be used to demonstrate the impact that technology development can have and how transfer of this technology to industry can have an impact in the consumer and commercial arenas. Technology Development in rf power, controls, beam optics, rf structures, magnets, injectors, and beam halos will be considered.

  12. Production of accelerating quad Airy beams and their optical characteristics.

    PubMed

    Ren, Zhijun; Wu, Qiong; Shi, Yile; Chen, Chen; Wu, Jiangmiao; Wang, Hui

    2014-06-16

    Based on a geometric caustic argument and diffraction catastrophe theory, we generate a novel form of accelerating beams using a symmetric 3/2 phase-only pattern. Such beams can be called accelerating quad Airy beams (AQABs) because they look very much like four face-to-face combined Airy beams. Optical characteristics of AQABs are subsequently investigated. The research results show that the beams have axial-symmetrical and centrosymmetrical transverse intensity patterns and quasi-diffraction-free propagation features for their four main lobes while undergoing transverse shift along parabolic trajectories. Moreover, we also demonstrate that AQABs possess self-construction ability when local areas are blocked. The unique optical properties of these beams will make them useful tools for future scientific applications.

  13. Beam experiments towards high-intensity beams in RHIC

    SciTech Connect

    Montag C.; Ahrens, L.; Brennan, J.M.; Blaskiewicz, M.; Drees, A.; Fischer, W.; Hayes, T.; Huang, H.; Mernick, K.; Robert-Demolaize, G.; Smith, K.; Than, R.; Thieberger, P.; Yip, K.; Zeno, K.; Zhang, S.Y.

    2012-05-20

    Proton bunch intensities in RHIC are planned to be increased from 2 {center_dot} 10{sup 11} to 3 {center_dot} 10{sup 11} protons per bunch to increase the luminosity, together with head-on beam-beam compensation using electron lenses. To study the feasibility of the intensity increase, beam experiments are being performed. Recent experimental results are presented.

  14. The TRIUMF-ISAC Post-Accelerator for Radioactive Beams

    NASA Astrophysics Data System (ADS)

    Laxdal, R. E.

    1998-04-01

    The ISAC radioactive ion beam facility under construction at TRIUMF comprises a 500 MeV proton beam (I <= 100 μA) from the TRIUMF cyclotron impinging on a thick target, an on-line source to ionize the radioactive products, a mass-separator for mass selection, an accelerator complex and experimental areas. The accelerator chain comprises a 35 MHz RF Quadrupole (RFQ) to accelerate beams of q/A >= 1/30 from 2 keV/u to 150 keV/u and a post stripper, 105 MHz variable energy drift tube linac (DTL) to accelerate ions of q/A >= 1/6 to a final energy between 0.15 MeV/u to 1.5 MeV/u. The accelerators have several noteworthy features. Both linacs are required to operate cw to preserve beam intensity. The RFQ, a four vane split-ring structure, has no bunching section; instead the beam is pre-bunched at 11.7 MHz with a single gap pseudo saw tooth buncher. The variable energy DTL is based on a unique separated function approach. Five independent interdigital H-mode (IH) structures operating at 0^circ synchronous phase provide the acceleration while quadrupole triplets and three gap bunching cavities between tanks provide transverse and longitudinal focussing respectively. Details of the accelerator design as well as the present status will be presented.

  15. ALPI Setup as the SPES Accelerator of Exotic Beams

    NASA Astrophysics Data System (ADS)

    Bisoffi, G.; Bassato, G.; Battistella, A.; Bermudez, J.; Bortolato, D.; Canella, S.; Chalykh, B.; Comunian, M.; Facco, A.; Fagotti, E.; Galatà, A.; Giacchini, M.; Gramegna, F.; Lamy, T.; Modanese, P.; Palmieri, A.; Pengo, R.; Pisent, A.; Poggi, M.; Porcellato, A.; Roncolato, C.; Scarpa, D.

    2014-03-01

    The SPES (Selective Production of Exotic Species) project for a national exotic beam facility in Legnaro includes pivotal upgrades of the existing superconducting linac ALPI (Acceleratore Lineare Per Ioni), to make it appropriate as the RIB (Radioactive Ion Beam) accelerator. The new injector, consisting of an Electron Cyclotron Resonance (ECR)-type charge breeder and a radiofrequency quadrupole (RFQ), will be described. Upgrade measures in ALPI to improve beam transmission and final energy, and handle low-intensity RIB will be explained, with the aim of increasing transmission to T > 90%, Ef by ~ 20%, reaching 10 MeV/u for the reference beam 132Sn.

  16. Tailoring accelerating beams in phase space

    NASA Astrophysics Data System (ADS)

    Wen, Yuanhui; Chen, Yujie; Zhang, Yanfeng; Chen, Hui; Yu, Siyuan

    2017-02-01

    An appropriate wave-front design will enable light fields that propagate along arbitrary trajectories, thus forming accelerating beams in free space. Previous strategies for designing such accelerating beams rely mainly on caustic methods, which start from diffraction integrals and deal only with two-dimensional fields. Here we introduce an alternate perspective to construct accelerating beams in phase space by designing the corresponding Wigner distribution function (WDF). We find that such a WDF-based method is capable of providing both the initial field distribution and the angular spectrum in need by projecting the WDF into the real space and the Fourier space, respectively. Moreover, this approach applies to the construction of both two- and three-dimensional fields, greatly generalizing previous caustic methods. It may therefore open a new route for construction of highly tailored accelerating beams and facilitate applications ranging from particle manipulation and trapping to optical routing as well as material processing.

  17. Laser-driven shock acceleration of monoenergetic ion beams.

    PubMed

    Fiuza, F; Stockem, A; Boella, E; Fonseca, R A; Silva, L O; Haberberger, D; Tochitsky, S; Gong, C; Mori, W B; Joshi, C

    2012-11-21

    We show that monoenergetic ion beams can be accelerated by moderate Mach number collisionless, electrostatic shocks propagating in a long scale-length exponentially decaying plasma profile. Strong plasma heating and density steepening produced by an intense laser pulse near the critical density can launch such shocks that propagate in the extended plasma at high velocities. The generation of a monoenergetic ion beam is possible due to the small and constant sheath electric field associated with the slowly decreasing density profile. The conditions for the acceleration of high-quality, energetic ion beams are identified through theory and multidimensional particle-in-cell simulations. The scaling of the ion energy with laser intensity shows that it is possible to generate ~200 MeV proton beams with state-of-the-art 100 TW class laser systems.

  18. Microwave accelerator E-beam pumped laser

    DOEpatents

    Brau, Charles A.; Stein, William E.; Rockwood, Stephen D.

    1980-01-01

    A device and method for pumping gaseous lasers by means of a microwave accelerator. The microwave accelerator produces a relativistic electron beam which is applied along the longitudinal axis of the laser through an electron beam window. The incident points of the electron beam on the electron beam window are varied by deflection coils to enhance the cooling characteristics of the foil. A thyratron is used to reliably modulate the microwave accelerator to produce electron beam pulses which excite the laser medium to produce laser pulse repetition frequencies not previously obtainable. An aerodynamic window is also disclosed which eliminates foil heating problems, as well as a magnetic bottle for reducing laser cavity length and pressures while maintaining efficient energy deposition.

  19. High efficiency beam splitting for H/sup -/ accelerators

    SciTech Connect

    Kramer, S.L.; Stipp, V.; Krieger, C.; Madsen, J.

    1985-01-01

    Beam splitting for high energy accelerators has typically involved a significant loss of beam and radiation. This paper reports on a new method of splitting beams for H/sup -/ accelerators. This technique uses a high intensity flash of light to strip a fraction of the H/sup -/ beam to H/sup 0/ which are then easily separated by a small bending magnet. A system using a 900-watt (average electrical power) flashlamp and a highly efficient collector will provide 10/sup -3/ to 10/sup -2/ splitting of a 50 MeV H/sup -/ beam. Results on the operation and comparisons with stripping cross sections are presented. Also discussed is the possibility for developing this system to yield a higher stripping fraction.

  20. Laser-Bessel-Beam-Driven Electron Acceleration

    NASA Astrophysics Data System (ADS)

    Li, Dazhi; Imasaki, Kazuo

    2005-08-01

    A vacuum-laser-driven acceleration scheme using a laser Bessel beam is presented. In contrast to the conventional Gaussian beam, the Bessel beam demonstrates diffraction-free propagation, which implies the possibility of extending the effective interaction distance for a laser-electron system. In this method, the Bessel beam is truncated by annular slits to realize a series of nonsuccessive dim regions along the path of laser propagation, where the amplitude of the laser field is reduced, making the electron slightly decelerate as it travels in the decelerating phase. We analyzed the propagation characteristics of the truncated Bessel beam with scalar diffraction theory, and then introduced this approach with careful investigation of a three-stage acceleration model.

  1. Proton shock acceleration using a high contrast high intensity laser

    NASA Astrophysics Data System (ADS)

    Gauthier, Maxence; Roedel, Christian; Kim, Jongjin; Aurand, Bastian; Curry, Chandra; Goede, Sebastian; Propp, Adrienne; Goyon, Clement; Pak, Art; Kerr, Shaun; Ramakrishna, Bhuvanesh; Ruby, John; William, Jackson; Glenzer, Siegfried

    2015-11-01

    Laser-driven proton acceleration is a field of intense research due to the interesting characteristics of this novel particle source including high brightness, high maximum energy, high laminarity, and short duration. Although the ion beam characteristics are promising for many future applications, such as in the medical field or hybrid accelerators, the ion beam generated using TNSA, the acceleration mechanism commonly achieved, still need to be significantly improved. Several new alternative mechanisms have been proposed such as collisionless shock acceleration (CSA) in order to produce a mono-energetic ion beam favorable for those applications. We report the first results of an experiment performed with the TITAN laser system (JLF, LLNL) dedicated to the study of CSA using a high intensity (5x1019W/cm2) high contrast ps laser pulse focused on 55 μm thick CH and CD targets. We show that the proton spectrum generated during the interaction exhibits high-energy mono-energetic features along the laser axis, characteristic of a shock mechanism.

  2. LATTICES FOR HIGH-POWER PROTON BEAM ACCELERATION AND SECONDARY BEAM COLLECTION AND COOLING.

    SciTech Connect

    WANG, S.; WEI, J.; BROWN, K.; GARDNER, C.; LEE, Y.Y.; LOWENSTEIN, D.; PEGGS, S.; SIMOS, N.

    2006-06-23

    Rapid cycling synchrotrons are used to accelerate high-intensity proton beams to energies of tens of GeV for secondary beam production. After primary beam collision with a target, the secondary beam can be collected, cooled, accelerated or decelerated by ancillary synchrotrons for various applications. In this paper, we first present a lattice for the main synchrotron. This lattice has: (a) flexible momentum compaction to avoid transition and to facilitate RF gymnastics (b) long straight sections for low-loss injection, extraction, and high-efficiency collimation (c) dispersion-free straights to avoid longitudinal-transverse coupling, and (d) momentum cleaning at locations of large dispersion with missing dipoles. Then, we present a lattice for a cooler ring for the secondary beam. The momentum compaction across half of this ring is near zero, while for the other half it is normal. Thus, bad mixing is minimized while good mixing is maintained for stochastic beam cooling.

  3. Space-Charge Waves and Instabilities in Intense Beams

    NASA Astrophysics Data System (ADS)

    Wang, J. G.

    1997-11-01

    Advancced accelerator applications, such as drivers for heavy ion inertial fusion, high-intensity synchrotrons for spallation neutron sources, high energy boosters, free electron lasers, high-power microwave generators, etc., require ever-increasing beam intensity. An important beam dynamics issue in such beams is the collective behavior of charged particles due to their space charge effects. This includes the phenomena of space-charge waves and instabilities excited on beams by external perturbations. It is very crucial to fully understand these phenomena in order to develop advanced accelerators for various applications. At the University of Maryland we have been conducting experimental programs to study space-charge waves and longitudinal instabilities by employing low-energy, high-current, space-charge dominated electron beams. Localized perturbations on the beams are generated from a gridded electron gun. In a conducting transport channel focused by short solenoids, these perturbations evolve into space-charge waves propagating on the beams. The wave speed is measured and many beam parameters are determined with this technique. The reflection of space-charge waves at the shoulder of an initially rectangular beam bunch is also observed. In a resistive-wall channel focused by a uniform long solenoid, the space-charge waves suffer longitudinal instability. The properties of the instabilities are studied in detail in the long wavelength range. In this talk we review our experimental results on the waves and instabilities and compare with theory.

  4. Beam Splitter Intensities Are Preselected

    NASA Technical Reports Server (NTRS)

    Campbell, W.; Owen, R. B.

    1982-01-01

    New beam splitter is a block of optically clear material with two parallel polish faces. Some of area of one surface is coated with totally reflecting layer, which may be metal or dielectric. On opposite surface, a metal coating of stepped thickness offers a different reflectivity at each step. Width and spacing of reflecting zones are chosen to accommodate angle of spacing of incidence of input beam and desired spacing of ouput beams.

  5. Intense tera-hertz laser driven proton acceleration in plasmas

    NASA Astrophysics Data System (ADS)

    Sharma, A.; Tibai, Z.; Hebling, J.

    2016-06-01

    We investigate the acceleration of a proton beam driven by intense tera-hertz (THz) laser field from a near critical density hydrogen plasma. Two-dimension-in-space and three-dimension-in-velocity particle-in-cell simulation results show that a relatively long wavelength and an intense THz laser can be employed for proton acceleration to high energies from near critical density plasmas. We adopt here the electromagnetic field in a long wavelength (0.33 THz) regime in contrast to the optical and/or near infrared wavelength regime, which offers distinct advantages due to their long wavelength ( λ = 350 μ m ), such as the λ 2 scaling of the electron ponderomotive energy. Simulation study delineates the evolution of THz laser field in a near critical plasma reflecting the enhancement in the electric field of laser, which can be of high relevance for staged or post ion acceleration.

  6. Auto-focusing accelerating hyper-geometric laser beams

    NASA Astrophysics Data System (ADS)

    Kovalev, A. A.; Kotlyar, V. V.; Porfirev, A. P.

    2016-02-01

    We derive a new solution to the paraxial wave equation that defines a two-parameter family of three-dimensional structurally stable vortex annular auto-focusing hyper-geometric (AH) beams, with their complex amplitude expressed via a degenerate hyper-geometric function. The AH beams are found to carry an orbital angular momentum and be auto-focusing, propagating on an accelerating path toward a focus, where the annular intensity pattern is ‘sharply’ reduced in diameter. An explicit expression for the complex amplitude of vortex annular auto-focusing hyper-geometric-Gaussian beams is derived. The experiment has been shown to be in good agreement with theory.

  7. Electron capture acceleration channel in a slit laser beam

    SciTech Connect

    Wang, P. X.; Scheid, W.; Ho, Y. K.

    2007-03-12

    Using numerical simulations, the authors find that the electrons can be captured and accelerated to high energies (GeV) in a slit laser beam with an intensity of I{lambda}{sup 2}{approx}10{sup 20} W/cm{sup 2} {mu}m{sup 2}, where {lambda} is the laser wavelength in units of {mu}m. The range of the optimum incident energy is very wide, even up to GeV. These results are of interest for experiments because the relatively low intensity can be achieved with present chirped pulse amplification technique and a wide range of incident energies means that a multistage acceleration is possible.

  8. Materials processing with intense pulsed ion beams

    SciTech Connect

    Rej, D.J.; Davis, H.A.; Olson, J.C.

    1996-12-31

    We review research investigating the application of intense pulsed ion beams (IPIBs) for the surface treatment and coating of materials. The short range (0.1-10 {mu}m) and high-energy density (1-50 J/cm{sup 2}) of these short-pulsed ({le} 1 {mu}s) beams (with ion currents I = 5 - 50 kA, and energies E = 100 - 1000 keV) make them ideal to flash-heat a target surface, similar to the more familiar pulsed laser processes. IPIB surface treatment induces rapid melt and solidification at up to 10{sup 10} K/s to cause amorphous layer formation and the production of non-equilibrium microstructures. At higher energy density the target surface is vaporized, and the ablated vapor is condensed as coatings onto adjacent substrates or as nanophase powders. Progress towards the development of robust, high-repetition rate IPIB accelerators is presented along with economic estimates for the cost of ownership of this technology.

  9. Pulsed power accelerators for particle beam fusion

    SciTech Connect

    Martin, T.H.; Barr, G.W.; VanDevender, J.P.; White, R.A.; Johnson, D.L.

    1980-01-01

    Sandia National Laboratories is completing the construction phase of the Particle Beam Fusion Accelerator-I (PBFA-I). Testing of the 36 module, 30 TW, 1 MJ output accelerator is in the initial stages. The 4 MJ, PBFA Marx generator has provided 3.6 MA into water-copper sulfate load resistors with a spread from first to last Marx firing between 15 to 25 ns and an output power of 5.7 TW. This accelerator is a modular, lower voltage, pulsed power device that is capable of scaling to power levels exceeding 100 TW. The elements of the PBFA technology and their integration into an accelerator system for particle beam fusion will be discussed.

  10. Vacuum electron acceleration and bunch compression by a flat-top laser beam.

    PubMed

    Wang, W; Wang, P X; Ho, Y K; Kong, Q; Gu, Y; Wang, S J

    2007-09-01

    The field intensity distribution and phase velocity characteristics of a flat-top laser beam are analyzed and discussed. The dynamics of electron acceleration in this kind of beam are investigated using three-dimensional test particle simulations. Compared with the standard (i.e., TEM(00) mode) Gaussian beam, a flat-top laser beam has a stronger longitudinal electric field and a larger diffraction angle. These characteristics make it easier for electrons to be trapped and accelerated by the beam. With a flat-top shape, the laser beam is also applicable to the acceleration of low energy electron and bunch compression.

  11. Electron Cooling of Intense Ion Beam

    SciTech Connect

    Dietrich, J.; Kamerdjiev, V.; Maier, R.; Prasuhn, D.; Stein, J.; Stockhorst, H.; Korotaev, Yu.; Meshkov, I.; Sidorin, A.; Smirnov, A.

    2006-03-20

    Results of experimental studies of the electron cooling of a proton beam at COSY (Juelich, Germany) are presented. Intensity of the proton beam is limited by two general effects: particle loss directly after the injection and development of instability in a deep cooled ion beam. Results of the instability investigations performed at COSY during last years are presented in this report in comparison with previous results from HIMAC (Chiba, Japan) CELSIUS (Uppsala, Sweden) and LEAR (CERN). Methods of the instability suppression, which allow increasing the cooled beam intensity, are described. This work is supported by RFBR grant no. 05-02-16320 and INTAS grant no. 03-54-5584.

  12. Design Considerations for Plasma Accelerators Driven by Lasers or Particle Beams

    SciTech Connect

    Schroeder, C. B.; Esarey, E.; Benedetti, C.; Toth, Cs.; Geddes, C. G. R.; Leemans, W.P.

    2010-06-01

    Plasma accelerators may be driven by the ponderomotive force of an intense laser or the space-charge force of a charged particle beam. The implications for accelerator design and the different physical mechanisms of laser-driven and beam-driven plasma acceleration are discussed. Driver propagation is examined, as well as the effects of the excited plasma wave phase velocity. The driver coupling to subsequent plasma accelerator stages for high-energy physics applications is addressed.

  13. Neutrino factory and beta beam: accelerator options for future neutrino experiments

    SciTech Connect

    Zisman, Michael S.

    2012-06-03

    Two accelerator options for producing intense neutrino beams a Neutrino Factory based on stored muon beams and a Beta Beam facility based on stored beams of beta unstable ions are described. Technical challenges for each are described and current R&D efforts aimed at mitigating these challenges are indicated. Progress is being made in the design of both types of facility, each of which would extend the state-of-the-art in accelerator science.

  14. Fast wire scanner for intense electron beams

    NASA Astrophysics Data System (ADS)

    Moore, T.; Agladze, N. I.; Bazarov, I. V.; Bartnik, A.; Dobbins, J.; Dunham, B.; Full, S.; Li, Y.; Liu, X.; Savino, J.; Smolenski, K.

    2014-02-01

    We have developed a cost-effective, fast rotating wire scanner for use in accelerators where high beam currents would otherwise melt even carbon wires. This new design uses a simple planetary gear setup to rotate a carbon wire, fixed at one end, through the beam at speeds in excess of 20 m/s. We present results from bench tests, as well as transverse beam profile measurements taken at Cornell's high-brightness energy recovery linac photoinjector, for beam currents up to 35 mA.

  15. The First Observation of Intra Beam Stripping of Negative Hydrogen in a Superconducting Linear Accelerator

    SciTech Connect

    Aleksandrov, Alexander V; Plum, Michael A; Shishlo, Andrei P; Galambos, John D

    2012-01-01

    We report on an experiment in which a negative hydrogen ions beam in the Spallation Neutron Source (SNS) linear accelerator was replaced with a beam of protons with similar size and dynamics. Beam loss in the superconducting part of the SNS accelerator was at least an order of magnitude lower for the proton beam. Also beam loss has a stronger dependence on intensity with H- than with proton beams. These measurements verify a recent theoretical explanation of unexpected beam losses in the SNS superconducting linear accelerator based on an intra beam stripping mechanism for negative hydrogen ions. An identification of the new physics mechanism for beam loss is important for the design of new high current linear ion accelerators and the performance improvement of existing machines

  16. High-intensity laser-induced electron acceleration in vacuum.

    PubMed

    Wang, J X; Ho, Y K; Feng, L; Kong, Q; Wang, P X; Yuan, Z S; Scheid, W

    1999-12-01

    In this paper, an approximate pulsed-laser-beam solution of Maxwell's equation in vacuum is derived. Then with the numerical simulation method, electron acceleration induced by high-intensity [Q(0)=eE(0)/(m(e)omega c)=3] lasers is discussed in connection with the recent experiment of Malka et al. It is found that the maximum energy gain and the relationship between the final energy and the scattering angle can be well reproduced, but the polarization effect of electron-laser interactions is not very prominent. These results show that the ponderomotive potential model is still applicable, which means that the stimulated Compton scattering is the main fundamental mechanism responsible for the electron acceleration at this laser intensity.

  17. High power target approaches for intense radioactive ion beam facilities

    SciTech Connect

    Talbert, W.L. ||; Hodges, T.A.; Hsu, H.; Fikani, M.M.

    1997-02-01

    Development of conceptual approaches for targets to produce intense radioactive ion beams is needed in anticipation of activity for a next-generation, intense ISOL-type radioactive beams facility, strongly recommended in the NSAC 1995 Long Range Plan for Nuclear Science. The production of isotopes in vapor form for subsequent mass separation and acceleration will depend on the ability to control target temperature profiles within the target resulting from interactions of the intense production beams with the target material. A number of earlier studies have identified promising approaches which need, however, to be carefully analyzed for specific target systems. A survey will be made of these earlier concepts employing various cooling techniques, including imposition of thermal barriers between the target materials and cooling systems. Some results of preliminary analyses are summarized. {copyright} {ital 1997 American Institute of Physics.}

  18. Short rise time intense electron beam generator

    DOEpatents

    Olson, Craig L.

    1987-01-01

    A generator for producing an intense relativistic electron beam having a subnanosecond current rise time includes a conventional generator of intense relativistic electrons feeding into a short electrically conductive drift tube including a cavity containing a working gas at a low enough pressure to prevent the input beam from significantly ionizing the working gas. Ionizing means such as a laser simultaneously ionize the entire volume of working gas in the cavity to generate an output beam having a rise time less than one nanosecond.

  19. Short rise time intense electron beam generator

    DOEpatents

    Olson, C.L.

    1984-03-16

    A generator for producing an intense relativisitc electron beam having a subnanosecond current rise time includes a conventional generator of intense relativistic electrons feeding into a short electrically conductive drift tube including a cavity containing a working gas at a low enough pressure to prevent the input beam from significantly ionizing the working gas. Ionizing means such as a laser simultaneously ionize the entire volume of working gas in the cavity to generate an output beam having a rise time less than one nanosecond.

  20. On a theory of two-beam mechanisms of charged particle acceleration in electrodynamic structures

    SciTech Connect

    Ostrovsky, A.O.

    1993-09-01

    This work is devoted to the theoretical studies of two-beam mechanisms of charged particle acceleration in electronic structures. The first section continues the outline of results of theoretical studies commenced in the intermediate report and considers the two-beam scheme of acceleration in the plasma waveguide. According to this scheme the strong current relativistic electron beam (REB) excites the intensive plasma waves accelerating the electrons of the second beam. The driving beam is assumed to be density-modulated. The preliminary modulation of the driving REB is shown to enhance substantially the acceleration efficiency of relativistic electrons of the driven beam. The second section deals with the two-beam acceleration in the vacuum corrugated waveguide. According to this scheme the excitation of electromagnetic waves and acceleration of driven beam electrons by them is accomplished under different Cherenkov resonances between the particles of beams and the corrugated waveguide field. The electromagnetic field in the periodic structure is known to be the superposition of spatial harmonics. With the small depth of the periodic nonuniformity the amplitudes of these harmonics decrease fast with their number increasing. Therefore, if the driving beam is in the Cherenkov resonance with the first spatial harmonic and the driven beam is in resonance with the zero space harmonic then the force accelerating the driven beam would be considerably bigger than the force decelerating the driving beam electrons.

  1. Proton Beam Intensity Upgrades for the Neutrino Program at Fermilab

    SciTech Connect

    Bhat, C. M.

    2016-12-15

    Fermilab is committed to upgrading its accelerator complex towards the intensity frontier to pursue HEP research in the neutrino sector and beyond. The upgrade has two steps: 1) the Proton Improvement Plan (PIP), which is underway, has its primary goal to start providing 700 kW beam power on NOvA target by the end of 2017 and 2) the foreseen PIP–II will replace the existing LINAC, a 400 MeV injector to the Booster, by an 800 MeV superconducting LINAC by the middle of next decade, with output beam intensity from the Booster increased significantly and the beam power on the NOvA target increased to <1.2 MW. In any case, the Fermilab Booster is going to play a very significant role for the next two decades. In this context, we have recently developed and commissioned an innovative beam injection scheme for the Booster called "early injection scheme". This scheme is already in operation and has a potential to increase the Booster beam intensity from the PIP design goal by a considerable amount with a reduced beam emittance and beam loss. In this paper, we will present results from our experience from the new scheme in operation, current status and future plans.

  2. Beam alignment test for therapy accelerators

    SciTech Connect

    Lutz, W.R.; Larsen, R.D.; Bjarngard, B.D.

    1981-12-01

    Beam spot displacement, collimator asymmetry, and movement of either collimator or gantry rotational axis can cause misalignment of the X ray beam from a therapy accelerator. A test method, sensitive to all the above problems, consists of double-exposing a film, located at the isocenter, for two gantry positions, 180/sup o/ apart. Opposite halves of the field are blocked for each exposure. A lateral shift of one half with respect to the other indicates the presence of one of the problems mentioned above. Additional tests are described, each of which is sensitive to only one of the problems and capable of quantifying the error.

  3. Beam alignment tests for therapy accelerators

    SciTech Connect

    Lutz, W.R.; Larsen, R.D.; Bjarngard, B.E.

    1981-12-01

    Beam spot displacement, collimator asymmetry, and movement of either collimator or gantry rotational axis can cause misalignment of the X ray beam from a therapy accelerator. A test method, sensitive to all the above problems, consists of double-exposing a film, located at the isocenter, for two gantry positions, 180/sup 0/ apart. Opposite halves of the field are blocked for each exposure. A lateral shift of one half with respect to the other indicates the presence of one of the problems mentioned above. Additional tests are described, each of which is sensitive to only one of the problems and capable of quantifying the error.

  4. A large distributed digital camera system for accelerator beam diagnostics

    NASA Astrophysics Data System (ADS)

    Catani, L.; Cianchi, A.; Di Pirro, G.; Honkavaara, K.

    2005-07-01

    Optical diagnostics, providing images of accelerated particle beams using radiation emitted by particles impinging a radiator, typically a fluorescent screen, has been extensively used, especially on electron linacs, since the 1970's. Higher intensity beams available in the last decade allow extending the use of beam imaging techniques to perform precise measurements of important beam parameters such as emittance, energy, and energy spread using optical transition radiation (OTR). OTR-based diagnostics systems are extensively used on the superconducting TESLA Test Facility (TTF) linac driving the vacuum ultraviolet free electron laser (VUV-FEL) at the Deutsches Elektronen-Synchrotron facility. Up to 30 optical diagnostic stations have been installed at various positions along the 250-m-long linac, each equipped with a high-performance digital camera. This paper describes the new approach to the design of the hardware and software setups required by the complex topology of such a distributed camera system.

  5. Operation of the intensity monitors in beam transport lines at Fermilab during Run II¹

    DOE PAGES

    Crisp, J.; Fellenz, B.; Fitzgerald, J.; ...

    2011-10-06

    The intensity of charged particle beams at Fermilab must be kept within pre-determined safety and operational envelopes in part by assuring all beam within a few percent has been transported from any source to destination. Beam instensity monitors with toroidial pickups provide such beam intensity measurements in the transport lines between accelerators at FNAL. With Run II, much effort was made to continually improve the resolution and accuracy of the system.

  6. The beam business: Accelerators in industry

    SciTech Connect

    Hamm, Robert W.; Hamm, Marianne E.

    2011-06-15

    Most physicists know that particle accelerators are widely used for treating cancer. But few are acquainted with the depth and breadth of their use in a myriad of applications outside of pure science and medicine. Society benefits from the use of particle beams in the areas of communications, transportation, the environment, security, health, and safety - in terms both of the global economy and quality of life. On the manufacturing level, the use of industrial accelerators has resulted in the faster and cheaper production of better parts for medical devices, automobiles, aircraft, and virtually all modern electronics. Consumers also benefit from the use of accelerators to explore for oil, gas, and minerals; sterilize food, wastewater, and medical supplies; and aid in the development of drugs and biomaterials.

  7. Correcting the beam centroid motion in an induction accelerator and reducing the beam breakup instability

    NASA Astrophysics Data System (ADS)

    Coleman, J. E.; Ekdahl, C. A.; Moir, D. C.; Sullivan, G. W.; Crawford, M. T.

    2014-09-01

    Axial beam centroid and beam breakup (BBU) measurements were conducted on an 80 ns FWHM, intense relativistic electron bunch with an injected energy of 3.8 MV and current of 2.9 kA. The intense relativistic electron bunch is accelerated and transported through a nested solenoid and ferrite induction core lattice consisting of 64 elements, exiting the accelerator with a nominal energy of 19.8 MeV. The principal objective of these experiments is to quantify the coupling of the beam centroid motion to the BBU instability and validate the theory of this coupling for the first time. Time resolved centroid measurements indicate a reduction in the BBU amplitude, ⟨ξ⟩, of 19% and a reduction in the BBU growth rate (Γ) of 4% by reducing beam centroid misalignments ˜50% throughout the accelerator. An investigation into the contribution of the misaligned elements is made. An alignment algorithm is presented in addition to a qualitative comparison of experimental and calculated results which include axial beam centroid oscillations, BBU amplitude, and growth with different dipole steering.

  8. Fast damping in mismatched high intensity beam transportation

    NASA Astrophysics Data System (ADS)

    Variale, V.

    2001-08-01

    A very fast damping of beam envelope oscillation amplitudes was recently observed in simulations of high intensity beam transport, through periodic FODO cells, in mismatched conditions [V. Variale, Nuovo Cimento Soc. Ital. Fis. 112A, 1571-1582 (1999) and T. Clauser et al., in Proceedings of the Particle Accelerator Conference, New York, 1999 (IEEE, Piscataway, NJ, 1999), p. 1779]. A Landau damping mechanism was proposed at the origin of observed effect. In this paper, to further investigate the source of this fast damping, extensive simulations have been carried out. The results presented here support the interpretation of the mechanism at the origin of the fast damping as a Landau damping effect.

  9. Intense steady state electron beam generator

    DOEpatents

    Hershcovitch, Ady; Kovarik, Vincent J.; Prelec, Krsto

    1990-01-01

    An intense, steady state, low emittance electron beam generator is formed by operating a hollow cathode discharge plasma source at critical levels in combination with an extraction electrode and a target electrode that are operable to extract a beam of fast primary electrons from the plasma source through a negatively biased grid that is critically operated to repel bulk electrons toward the plasma source while allowing the fast primary electrons to move toward the target in the desired beam that can be successfully transported for relatively large distances, such as one or more meters away from the plasma source.

  10. 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.

  11. Delivering the world's most intense muon beam

    NASA Astrophysics Data System (ADS)

    Cook, S.; D'Arcy, R.; Edmonds, A.; Fukuda, M.; Hatanaka, K.; Hino, Y.; Kuno, Y.; Lancaster, M.; Mori, Y.; Ogitsu, T.; Sakamoto, H.; Sato, A.; Tran, N. H.; Truong, N. M.; Wing, M.; Yamamoto, A.; Yoshida, M.

    2017-03-01

    A new muon beam line, the muon science innovative channel, was set up at the Research Center for Nuclear Physics, Osaka University, in Osaka, Japan, using the 392 MeV proton beam impinging on a target. The production of an intense muon beam relies on the efficient capture of pions, which subsequently decay to muons, using a novel superconducting solenoid magnet system. After the pion-capture solenoid, the first 36° of the curved muon transport line was commissioned and the muon flux was measured. In order to detect muons, a target of either copper or magnesium was placed to stop muons at the end of the muon beam line. Two stations of plastic scintillators located upstream and downstream from the muon target were used to reconstruct the decay spectrum of muons. In a complementary method to detect negatively charged muons, the x-ray spectrum yielded by muonic atoms in the target was measured in a germanium detector. Measurements, at a proton beam current of 6 pA, yielded (10.4 ±2.7 )×1 05 muons per watt of proton beam power (μ+ and μ-), far in excess of other facilities. At full beam power (400 W), this implies a rate of muons of (4.2 ±1.1 )×1 08 muons s-1 , among the highest in the world. The number of μ- measured was about a factor of 10 lower, again by far the most efficient muon beam produced. The setup is a prototype for future experiments requiring a high-intensity muon beam, such as a muon collider or neutrino factory, or the search for rare muon decays which would be a signature for phenomena beyond the Standard Model of particle physics. Such a muon beam can also be used in other branches of physics, nuclear and condensed matter, as well as other areas of scientific research.

  12. Fan-beam intensity modulated proton therapy

    PubMed Central

    Hill, Patrick; Westerly, David; Mackie, Thomas

    2013-01-01

    Purpose: This paper presents a concept for a proton therapy system capable of delivering intensity modulated proton therapy using a fan beam of protons. This system would allow present and future gantry-based facilities to deliver state-of-the-art proton therapy with the greater normal tissue sparing made possible by intensity modulation techniques. Methods: A method for producing a divergent fan beam of protons using a pair of electromagnetic quadrupoles is described and particle transport through the quadrupole doublet is simulated using a commercially available software package. To manipulate the fan beam of protons, a modulation device is developed. This modulator inserts or retracts acrylic leaves of varying thickness from subsections of the fan beam. Each subsection, or beam channel, creates what effectively becomes a beam spot within the fan area. Each channel is able to provide 0–255 mm of range shift for its associated beam spot, or stop the beam and act as an intensity modulator. Results of particle transport simulations through the quadrupole system are incorporated into the MCNPX Monte Carlo transport code along with a model of the range and intensity modulation device. Several design parameters were investigated and optimized, culminating in the ability to create topotherapy treatment plans using distal-edge tracking on both phantom and patient datasets. Results: Beam transport calculations show that a pair of electromagnetic quadrupoles can be used to create a divergent fan beam of 200 MeV protons over a distance of 2.1 m. The quadrupole lengths were 30 and 48 cm, respectively, with transverse field gradients less than 20 T/m, which is within the range of water-cooled magnets for the quadrupole radii used. MCNPX simulations of topotherapy treatment plans suggest that, when using the distal edge tracking delivery method, many delivery angles are more important than insisting on narrow beam channel widths in order to obtain conformal target coverage

  13. Fan-beam intensity modulated proton therapy

    SciTech Connect

    Hill, Patrick; Westerly, David; Mackie, Thomas

    2013-11-15

    Purpose: This paper presents a concept for a proton therapy system capable of delivering intensity modulated proton therapy using a fan beam of protons. This system would allow present and future gantry-based facilities to deliver state-of-the-art proton therapy with the greater normal tissue sparing made possible by intensity modulation techniques.Methods: A method for producing a divergent fan beam of protons using a pair of electromagnetic quadrupoles is described and particle transport through the quadrupole doublet is simulated using a commercially available software package. To manipulate the fan beam of protons, a modulation device is developed. This modulator inserts or retracts acrylic leaves of varying thickness from subsections of the fan beam. Each subsection, or beam channel, creates what effectively becomes a beam spot within the fan area. Each channel is able to provide 0–255 mm of range shift for its associated beam spot, or stop the beam and act as an intensity modulator. Results of particle transport simulations through the quadrupole system are incorporated into the MCNPX Monte Carlo transport code along with a model of the range and intensity modulation device. Several design parameters were investigated and optimized, culminating in the ability to create topotherapy treatment plans using distal-edge tracking on both phantom and patient datasets.Results: Beam transport calculations show that a pair of electromagnetic quadrupoles can be used to create a divergent fan beam of 200 MeV protons over a distance of 2.1 m. The quadrupole lengths were 30 and 48 cm, respectively, with transverse field gradients less than 20 T/m, which is within the range of water-cooled magnets for the quadrupole radii used. MCNPX simulations of topotherapy treatment plans suggest that, when using the distal edge tracking delivery method, many delivery angles are more important than insisting on narrow beam channel widths in order to obtain conformal target coverage

  14. 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.

  15. 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.

  16. Ion source studies for particle beam accelerators

    SciTech Connect

    Bieg, K.W.; Burns, E.J.T.; Olsen, J.N.; Dorrell, L.R.

    1985-05-01

    High power particle beam accelerators are being developed for use in inertial confinement fusion applications. These pulsed power accelerators require sources of low atomic number ions (e.g., protons, deuterons, carbon, or lithium). The sources must be of high purity for efficient accelerator operation and proper target coupling, must have a rapid ''turn-on,'' and must be compatible with ion diode configurations under development. A particular type of source presently being investigated is the flashover ion source which generates ions by means of the vacuum flashover of an insulating anode material when the high voltage pulse arrives at the diode. We have developed an applied-magnetic-field, extraction ion diode for the 0.03 TW Nereus accelerator specifically to investigate these sources. Extracted ion species are measured by means of a Thomson-parabola ion analyzer, dB/dt current monitors, and Faraday cups. Experiments have been performed to investigate the surface flashover mechanism and the effects of various dielectric source materials, anode preparation methods (including rf glow discharge cleaning), and vacuum conditions on ion species and diode operation.

  17. High power targets for production of intense radioactive ion beams

    SciTech Connect

    Talbert, W. L.; Drake, D. M.; Wilson, M. T.; Walker, J. J.; Lenz, J. W.

    1999-04-26

    Issues are discussed in producing intense Radioactive Ion Beams (RIB) using the Isotope Separator On-Line (ISOL) approach, based on the use of thick targets employed at existing facilities. Some new physics studies may possibly be addressed by improving the performance of these existing targets through improvements in release and effusion properties to optimize the RIB yields. It is, however, acknowledged that many desired physics objectives using RIB can be met only by employing production beams of energetic light ions or protons with currents up to 100 {mu}A. Development of targets that use such intense production beams needs to address the requirement to control operational temperatures derived from internal production beam interactions with the target materials. In addition, issues arise for target materials in terms of their thermal characteristics, such as thermal conductivity and thermo-mechanical properties. A target concept is described for an in-beam test of a prototype target for actual thermal behavior under RIB production conditions. For such a test, a high-power test facility is needed; fortunately, the prototypical production beam currents required exist at the TRIUMF accelerator facility. An experimental proposal has been approved for such a test.

  18. Demonstration of a positron beam-driven hollow channel plasma wakefield accelerator

    SciTech Connect

    Gessner, Spencer; Adli, Erik; Allen, James M.; An, Weiming; Clarke, Christine I.; Clayton, Chris E.; Corde, Sebastien; Delahaye, J. P.; Frederico, Joel; Green, Selina Z.; Hast, Carsten; Hogan, Mark J.; Joshi, Chan; Lindstrøm, Carl A.; Lipkowitz, Nate; Litos, Michael; Lu, Wei; Marsh, Kenneth A.; Mori, Warren B.; O’Shea, Brendan; Vafaei-Najafabadi, Navid; Walz, Dieter; Yakimenko, Vitaly; Yocky, Gerald

    2016-06-02

    Plasma wakefield accelerators have been used to accelerate electron and positron particle beams with gradients that are orders of magnitude larger than those achieved in conventional accelerators. In addition to being accelerated by the plasma wakefield, the beam particles also experience strong transverse forces that may disrupt the beam quality. Hollow plasma channels have been proposed as a technique for generating accelerating fields without transverse forces. In this study, we demonstrate a method for creating an extended hollow plasma channel and measure the wakefields created by an ultrarelativistic positron beam as it propagates through the channel. The plasma channel is created by directing a high-intensity laser pulse with a spatially modulated profile into lithium vapour, which results in an annular region of ionization. A peak decelerating field of 230 MeV m-1 is inferred from changes in the beam energy spectrum, in good agreement with theory and particle-in-cell simulations.

  19. Demonstration of a positron beam-driven hollow channel plasma wakefield accelerator.

    PubMed

    Gessner, Spencer; Adli, Erik; Allen, James M; An, Weiming; Clarke, Christine I; Clayton, Chris E; Corde, Sebastien; Delahaye, J P; Frederico, Joel; Green, Selina Z; Hast, Carsten; Hogan, Mark J; Joshi, Chan; Lindstrøm, Carl A; Lipkowitz, Nate; Litos, Michael; Lu, Wei; Marsh, Kenneth A; Mori, Warren B; O'Shea, Brendan; Vafaei-Najafabadi, Navid; Walz, Dieter; Yakimenko, Vitaly; Yocky, Gerald

    2016-06-02

    Plasma wakefield accelerators have been used to accelerate electron and positron particle beams with gradients that are orders of magnitude larger than those achieved in conventional accelerators. In addition to being accelerated by the plasma wakefield, the beam particles also experience strong transverse forces that may disrupt the beam quality. Hollow plasma channels have been proposed as a technique for generating accelerating fields without transverse forces. Here we demonstrate a method for creating an extended hollow plasma channel and measure the wakefields created by an ultrarelativistic positron beam as it propagates through the channel. The plasma channel is created by directing a high-intensity laser pulse with a spatially modulated profile into lithium vapour, which results in an annular region of ionization. A peak decelerating field of 230 MeV m(-1) is inferred from changes in the beam energy spectrum, in good agreement with theory and particle-in-cell simulations.

  20. Demonstration of a positron beam-driven hollow channel plasma wakefield accelerator

    PubMed Central

    Gessner, Spencer; Adli, Erik; Allen, James M.; An, Weiming; Clarke, Christine I.; Clayton, Chris E.; Corde, Sebastien; Delahaye, J. P.; Frederico, Joel; Green, Selina Z.; Hast, Carsten; Hogan, Mark J.; Joshi, Chan; Lindstrøm, Carl A.; Lipkowitz, Nate; Litos, Michael; Lu, Wei; Marsh, Kenneth A.; Mori, Warren B.; O'Shea, Brendan; Vafaei-Najafabadi, Navid; Walz, Dieter; Yakimenko, Vitaly; Yocky, Gerald

    2016-01-01

    Plasma wakefield accelerators have been used to accelerate electron and positron particle beams with gradients that are orders of magnitude larger than those achieved in conventional accelerators. In addition to being accelerated by the plasma wakefield, the beam particles also experience strong transverse forces that may disrupt the beam quality. Hollow plasma channels have been proposed as a technique for generating accelerating fields without transverse forces. Here we demonstrate a method for creating an extended hollow plasma channel and measure the wakefields created by an ultrarelativistic positron beam as it propagates through the channel. The plasma channel is created by directing a high-intensity laser pulse with a spatially modulated profile into lithium vapour, which results in an annular region of ionization. A peak decelerating field of 230 MeV m−1 is inferred from changes in the beam energy spectrum, in good agreement with theory and particle-in-cell simulations. PMID:27250570

  1. Demonstration of a positron beam-driven hollow channel plasma wakefield accelerator

    DOE PAGES

    Gessner, Spencer; Adli, Erik; Allen, James M.; ...

    2016-06-02

    Plasma wakefield accelerators have been used to accelerate electron and positron particle beams with gradients that are orders of magnitude larger than those achieved in conventional accelerators. In addition to being accelerated by the plasma wakefield, the beam particles also experience strong transverse forces that may disrupt the beam quality. Hollow plasma channels have been proposed as a technique for generating accelerating fields without transverse forces. In this study, we demonstrate a method for creating an extended hollow plasma channel and measure the wakefields created by an ultrarelativistic positron beam as it propagates through the channel. The plasma channel ismore » created by directing a high-intensity laser pulse with a spatially modulated profile into lithium vapour, which results in an annular region of ionization. A peak decelerating field of 230 MeV m-1 is inferred from changes in the beam energy spectrum, in good agreement with theory and particle-in-cell simulations.« less

  2. Irradiation of Materials using Short, Intense Ion Beams

    NASA Astrophysics Data System (ADS)

    Seidl, Peter; Ji, Q.; Persaud, A.; Feinberg, E.; Silverman, M.; Sulyman, A.; Waldron, W. L.; Schenkel, T.; Barnard, J. J.; Friedman, A.; Grote, D. P.; Gilson, E. P.; Kaganovich, I. D.; Stepanov, A.; Zimmer, M.

    2016-10-01

    We present experiments studying material properties created with nanosecond and millimeter-scale ion beam pulses on the Neutralized Drift Compression Experiment-II at Berkeley Lab. The explored scientific topics include the dynamics of ion induced damage in materials, materials synthesis far from equilibrium, warm dense matter and intense beam-plasma physics. We describe the improved accelerator performance, diagnostics and results of beam-induced irradiation of thin samples of, e.g., tin and silicon. Bunches with >3x1010 ions/pulse with 1-mm radius and 2-30 ns FWHM duration and have been created. To achieve the short pulse durations and mm-scale focal spot radii, the 1.2 MeV He+ ion beam is neutralized in a drift compression section which removes the space charge defocusing effect during the final compression and focusing. Quantitative comparison of detailed particle-in-cell simulations with the experiment play an important role in optimizing the accelerator performance and keep pace with the accelerator repetition rate of <1/minute. This work was supported by the Office of Science of the US Department of Energy under contracts DE-AC0205CH11231 (LBNL), DE-AC52-07NA27344 (LLNL) and DE-AC02-09CH11466 (PPPL).

  3. Intense Ion Beam for Warm Dense Matter Physics

    SciTech Connect

    Coleman, Joshua Eugene

    2008-01-01

    The Neutralized Drift Compression Experiment (NDCX) at Lawrence Berkeley National Laboratory is exploring the physical limits of compression and focusing of ion beams for heating material to warm dense matter (WDM) and fusion ignition conditions. The NDCX is a beam transport experiment with several components at a scale comparable to an inertial fusion energy driver. The NDCX is an accelerator which consists of a low-emittance ion source, high-current injector, solenoid matching section, induction bunching module, beam neutralization section, and final focusing system. The principal objectives of the experiment are to control the beam envelope, demonstrate effective neutralization of the beam space-charge, control the velocity tilt on the beam, and understand defocusing effects, field imperfections, and limitations on peak intensity such as emittance and aberrations. Target heating experiments with space-charge dominated ion beams require simultaneous longitudinal bunching and transverse focusing. A four-solenoid lattice is used to tune the beam envelope to the necessary focusing conditions before entering the induction bunching module. The induction bunching module provides a head-to-tail velocity ramp necessary to achieve peak axial compression at the desired focal plane. Downstream of the induction gap a plasma column neutralizes the beam space charge so only emittance limits the focused beam intensity. We present results of beam transport through a solenoid matching section and simultaneous focusing of a singly charged K+ ion bunch at an ion energy of 0.3 MeV. The results include a qualitative comparison of experimental and calculated results after the solenoid matching section, which include time resolved current density, transverse distributions, and phase-space of the beam at different diagnostic planes. Electron cloud and gas measurements in the solenoid lattice and in the vicinity of intercepting diagnostics are also presented. Finally

  4. Characterisation of electron beams from laser-driven particle accelerators

    SciTech Connect

    Brunetti, E.; Manahan, G. G.; Shanks, R. P.; Islam, M. R.; Ersfeld, B.; Anania, M. P.; Cipiccia, S.; Issac, R. C.; Vieux, G.; Welsh, G. H.; Wiggins, S. M.; Jaroszynski, D. A.

    2012-12-21

    The development, understanding and application of laser-driven particle accelerators require accurate measurements of the beam properties, in particular emittance, energy spread and bunch length. Here we report measurements and simulations showing that laser wakefield accelerators can produce beams of quality comparable to conventional linear accelerators.

  5. Plating Processes Utilizing High Intensity Acoustic Beams

    NASA Technical Reports Server (NTRS)

    Oeftering, Richard C. (Inventor); Denofrio, Charles (Inventor)

    2002-01-01

    A system and a method for selective plating processes are disclosed which use directed beams of high intensity acoustic waves to create non-linear effects that alter and improve the plating process. The directed beams are focused on the surface of an object, which in one embodiment is immersed in a plating solution, and in another embodiment is suspended above a plating solution. The plating processes provide precise control of the thickness of the layers of the plating, while at the same time, in at least some incidents, eliminates the need for masking.

  6. A beam-matching concept for medical linear accelerators.

    PubMed

    Sjöström, David; Bjelkengren, Ulf; Ottosson, Wiviann; Behrens, Claus F

    2009-01-01

    The flexibility in radiotherapy can be improved if a patient can be moved between any one of the department's medical linear accelerators without the need to change anything in the patient's treatment plan. For this to be possible, the dosimetric characteristics of the various accelerators must be the same, or nearly the same i.e. the accelerators must be beam-matched. During a period of nine months, eight Varian iX accelerators with 6 and 15 MV photon beams and 6-18 MeV electron beams (only four of the eight) were installed at our clinic. All accelerators fulfilled the vendor-defined "fine beam-match" criteria, and a more extensive set of measurements was carried out during commissioning. The measured absorbed dose data for each accelerator were compared with the first accelerator, chosen as reference, and the TPS calculations. Two of the eight accelerators showed a larger discrepancy for the 15 MV beam not revealed by the vendor-defined acceptance criteria, whereas the other six accelerators were satisfactorily matched. The beam-matching acceptance criteria defined by the vendor are not strict enough to guarantee optimal beam-match. Deviations related to dose calculations and to beam-matched accelerators may add up. The safest and most practical way to ensure that all accelerators are within clinical acceptable accuracy is to include TPS calculations in the evaluation. Further, comparisons between measurements and calculations should be done in absolute dose terms.

  7. Charge-state enhancement for radioactive beam post-acceleration

    SciTech Connect

    Nolen, J.A.; Dooling, J.

    1995-08-01

    A critical question for an ISOL-type radioactive-beam facility, such as that being discussed by the North American Isospin Laboratory Committee, is the efficiency and q/m of the ion source for the radioactive species. ISOLDE at CERN demonstrated that high efficiency is obtained for a wide variety of species in the 1{sup +} charge state. These ion sources also generally have excellent transverse emittances and low energy spreads. One possibility is to use this proven technology plus an ionizer stage to increase the output of such sources to 2, 3, or 4{sup +} with high efficiency. We are currently investigating technical options for such charge-state enhancement. There is a proposal by a Heidelberg/ISOLDE collaboration to build a {open_quotes}charge-state breeder{close_quotes} as part of an experiment called REX-ISOLDE. This concept would deliver batches of radioactive ions with low duty cycle, optimized for relatively low-intensity secondary beams, on the order of 10{sup 6}/sec. We are independently doing simulations of an alternative approach, called the Electron-Beam Charge-State Amplifier (EBQA), which would yield DC beams with improved transverse emittance and would not have the intensity limitation of the batch transfer process. The cost and efficiency of the EBQA will have to be compared with those of a normally-conducting CW RFQ followed by ion stripping, as alternatives for the first stage of a secondary ion accelerator.

  8. Coherent light in intense spatiospectral twin beams

    NASA Astrophysics Data System (ADS)

    Peřina, Jan

    2016-06-01

    Intense spatio-spectral twin beams generated in the regime with pump depletion are analyzed applying a suggested quantum model that treats the signal, idler, and pump fields in the same way. The model assumes the signal and idler fields in the form of the generalized superposition of signal and noise and reveals nonzero signal coherent components in both fields, contrary to the models developed earlier. The influence of coherent components on the properties of intense twin beams is elucidated. The interference pattern formed in the process of sum-frequency generation and that of the Hong-Ou-Mandel interferometer are shown to be able to experimentally confirm the presence of coherent components.

  9. Progress Towards Doubling the Beam Power at Fermilab's Accelerator Complex

    SciTech Connect

    Kourbanis, Ioanis

    2014-07-01

    After a 16 month shutdown to reconfigure the Fermilab Accelerators for high power operations, the Fermilab Accelerator Complex is again providing beams for numerous Physics Experiments. By using the Recycler to slip stack protons while the Main Injector is ramping, the beam power at 120 GeV can reach 700 KW, a factor of 2 increase. The progress towards doubling the Fermilab's Accelerator complex beam power will be presented.

  10. Summary report of working group 4: Beam-driven acceleration

    NASA Astrophysics Data System (ADS)

    Litos, M.; Jing, C.

    2017-03-01

    Despite the urgent need for a TeV-class linear collider in High-Energy Physics (HEP), a clear path to buildable and affordable accelerator technologies has yet to be realized. Clearly, the identification and advancement of next generation accelerator technologies for a linear collider have been one of the main charges since the inception of the Advanced Accelerator Concepts (AAC) workshop. The fundamental requirements of linear colliders for accelerator technologies are to demonstrate high wall-plug efficiency, high beam quality preservation, high effective gradient, scalability, etc. Within the AAC community, beam-driven wakefield acceleration schemes (the central subject of Working Group 4) are always promising and attractive approaches. Since the last AAC workshop, a few high profile experiments related to beam-driven plasma wakefield acceleration have been conducted at the SLAC National Accelerator Laboratory's FACET facility. These experiments have successfully answered questions related to obtaining high beam energy transfer efficiency, demonstrating high gradient positron acceleration, and demonstrating high quality witness beam acceleration. Research on beam-driven structure-based wakefield acceleration has also demonstrated significant results for high gradient acceleration, including longitudinal bunch shaping for high efficiency and beam breakup control. As an important application or a stepping-stone facility, beam-driven plasma or structure-based wakefield accelerators for 5th generation FEL light sources have attracted broad attention. Studies have been undertaken on various aspects, ranging from the overall parameterizations to detailed beam generation and control technologies. Other related applications, such as high power RF and THz generation, beam modulation and energy chirp compensation, are also within the scope of our Working Group. In summary, WG4 examined the advancement of beam-driven wakefield accelerators (plasma and structure-based) in

  11. Positron microanalysis with high intensity beams

    SciTech Connect

    Hulett, L.D. Jr.; Donohue, D.L.

    1990-01-01

    One of the more common applications for a high intensity slow positron facility will be microanalysis of solid materials. In the first section of this paper some examples are given of procedures that can be developed. Since most of the attendees of this workshop are experts in positron spectroscopy, comprehensive descriptions will be omitted. With the exception of positron emission microscopy, most of the procedures will be based on those already in common use with broad beams. The utility of the methods have all been demonstrated, but material scientists use very few of them because positron microbeams are not generally available. A high intensity positron facility will make microbeams easier to obtain and partially alleviate this situation. All microanalysis techniques listed below will have a common requirement, which is the ability to locate the microscopic detail or area of interest and to focus the positron beam exclusively on it. The last section of this paper is a suggestion of how a high intensity positron facility might be designed so as to have this capability built in. The method will involve locating the specimen by scanning it with the microbeam of positrons and inducing a secondary electron image that will immediately reveal whether or not the positron beam is striking the proper portion of the specimen. This scanning positron microscope' will be a somewhat prosaic analog of the conventional SEM. It will, however, be an indispensable utility that will enhance the practicality of positron microanalysis techniques. 6 refs., 1 fig.

  12. Requirements of a proton beam accelerator for an accelerator-driven reactor

    SciTech Connect

    Takahashi, H.; Zhao, Y.; Tsoupas, N.; An, Y.; Yamazaki, Y.

    1997-12-31

    When the authors first proposed an accelerator-driven reactor, the concept was opposed by physicists who had earlier used the accelerator for their physics experiments. This opposition arose because they had nuisance experiences in that the accelerator was not reliable, and very often disrupted their work as the accelerator shut down due to electric tripping. This paper discusses the requirements for the proton beam accelerator. It addresses how to solve the tripping problem and how to shape the proton beam.

  13. Editorial: Focus on Laser- and Beam-Driven Plasma Accelerators

    NASA Astrophysics Data System (ADS)

    Joshi, Chan; Malka, Victor

    2010-04-01

    The ability of short but intense laser pulses to generate high-energy electrons and ions from gaseous and solid targets has been well known since the early days of the laser fusion program. However, during the past decade there has been an explosion of experimental and theoretical activity in this area of laser-matter interaction, driven by the prospect of realizing table-top plasma accelerators for research, medical and industrial uses, and also relatively small and inexpensive plasma accelerators for high-energy physics at the frontier of particle physics. In this focus issue on laser- and beam-driven plasma accelerators, the latest advances in this field are described. Focus on Laser- and Beam-Driven Plasma Accelerators Contents Slow wave plasma structures for direct electron acceleration B D Layer, J P Palastro, A G York, T M Antonsen and H M Milchberg Cold injection for electron wakefield acceleration X Davoine, A Beck, A Lifschitz, V Malka and E Lefebvre Enhanced proton flux in the MeV range by defocused laser irradiation J S Green, D C Carroll, C Brenner, B Dromey, P S Foster, S Kar, Y T Li, K Markey, P McKenna, D Neely, A P L Robinson, M J V Streeter, M Tolley, C-G Wahlström, M H Xu and M Zepf Dose-dependent biological damage of tumour cells by laser-accelerated proton beams S D Kraft, C Richter, K Zeil, M Baumann, E Beyreuther, S Bock, M Bussmann, T E Cowan, Y Dammene, W Enghardt, U Helbig, L Karsch, T Kluge, L Laschinsky, E Lessmann, J Metzkes, D Naumburger, R Sauerbrey, M. Scḧrer, M Sobiella, J Woithe, U Schramm and J Pawelke The optimum plasma density for plasma wakefield excitation in the blowout regime W Lu, W An, M Zhou, C Joshi, C Huang and W B Mori Plasma wakefield acceleration experiments at FACET M J Hogan, T O Raubenheimer, A Seryi, P Muggli, T Katsouleas, C Huang, W Lu, W An, K A Marsh, W B Mori, C E Clayton and C Joshi Electron trapping and acceleration on a downward density ramp: a two-stage approach R M G M Trines, R Bingham, Z Najmudin

  14. FERMILAB ACCELERATOR R&D PROGRAM TOWARDS INTENSITY FRONTIER ACCELERATORS : STATUS AND PROGRESS

    SciTech Connect

    Shiltsev, Vladimir

    2016-11-15

    The 2014 P5 report indicated the accelerator-based neutrino and rare decay physics research as a centrepiece of the US domestic HEP program at Fermilab. Operation, upgrade and development of the accelerators for the near- term and longer-term particle physics program at the Intensity Frontier face formidable challenges. Here we discuss key elements of the accelerator physics and technology R&D program toward future multi-MW proton accelerators and present its status and progress. INTENSITY FRONTIER ACCELERATORS

  15. Electron Beam Charge Diagnostics for Laser Plasma Accelerators

    SciTech Connect

    Nakamura, Kei; Gonsalves, Anthony; Lin, Chen; Smith, Alan; Rodgers, David; Donahue, Rich; Byrne, Warren; Leemans, Wim

    2011-06-27

    A comprehensive study of charge diagnostics is conducted to verify their validity for measuring electron beams produced by laser plasma accelerators (LPAs). First, a scintillating screen (Lanex) was extensively studied using subnanosecond electron beams from the Advanced Light Source booster synchrotron, at the Lawrence Berkeley National Laboratory. The Lanex was cross calibrated with an integrating current transformer (ICT) for up to the electron energy of 1.5 GeV, and the linear response of the screen was confirmed for charge density and intensity up to 160 pC/mm{sup 2} and 0.4 pC/(ps mm{sup 2}), respectively. After the radio-frequency accelerator based cross calibration, a series of measurements was conducted using electron beams from an LPA. Cross calibrations were carried out using an activation-based measurement that is immune to electromagnetic pulse noise, ICT, and Lanex. The diagnostics agreed within {+-}8%, showing that they all can provide accurate charge measurements for LPAs.

  16. 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.

  17. Experimental evidence of space charge driven resonances in high intensity linear accelerators

    NASA Astrophysics Data System (ADS)

    Jeon, Dong-O.

    2016-01-01

    In the construction of high intensity accelerators, it is the utmost goal to minimize the beam loss by avoiding or minimizing contributions of various halo formation mechanisms. As a halo formation mechanism, space charge driven resonances are well known for circular accelerators. However, the recent finding showed that even in linear accelerators the space charge potential can excite the 4 σ =360 ° fourth order resonance [D. Jeon et al., Phys. Rev. ST Accel. Beams 12, 054204 (2009)]. This study increased the interests in space charge driven resonances of linear accelerators. Experimental studies of the space charge driven resonances of high intensity linear accelerators are rare as opposed to the multitude of simulation studies. This paper presents an experimental evidence of the space charge driven 4 σ =360 ° resonance and the 2 σx (y )-2 σz=0 resonance of a high intensity linear accelerator through beam profile measurements from multiple wire-scanners. Measured beam profiles agree well with the characteristics of the space charge driven 4 σ =360 ° resonance and the 2 σx (y )-2 σz=0 resonance that are predicted by the simulation.

  18. Facility for intense diagnostic neutral beam (IDNB) development

    SciTech Connect

    Kasik, R.J.; Hinckley, W.B.; Bartsch, R.R.; Rej, D.J.; Henins, I.; Greenly, J.B.

    1993-08-01

    An intense, pulsed neutral beam source is under development for use as a probe beam on hot, burning plasmas such as in the international thermonuclear experimental reactor (ITER) which is presently in the planning stage. A pulsed, neutral hydrogen beam of 10s of kilo amperes of current can have an alpha particle, charge-exchange-recombination-spectroscopy (alpha-CHERS) signal-to-noise ratio of {approximately} 10. This beam would allow the measurement, on a single pulse of a few hundred nanoseconds duration, of the local alpha particle distribution function as well as other features of the tokamak plasma such as current density profile, impurity density, and microturbulence spectrum. The cross-sections for the CHERS diagnostic dictate operation with proton energies greater than {approximately}50keV. A pulsed neutral hydrogen source of this voltage and intensity can be achieved by neutralizing the ion flux from a magnetized ion-diode. The cross-sections for attachment and stripping, when coupled with scaling from Child-Langmiur, space-charge-limited, ion-current flow imply operation below - 100keV for maximum neutral fluence. The development of a flashover-anode, ion source for forthcoming evaluation of a neutralizing section is described below. This source operates in the accelerator voltage range 70 to 100keV. Eventually, the flashover-anode, magnetized ion-diode will be replaced with a plasma-anode, magnetized ion-diode.

  19. Accelerator systems and instrumentation for the NuMI neutrino beam

    SciTech Connect

    Zwaska, Robert Miles

    2005-12-01

    The neutrinos at the main injector (NuMI) neutrino beam facility began operating at the Fermi National Accelerator Laboratory in 2005. NuMI produces an intense, muon-neutrino beam to a number of experiments. Foremost of these experiments is MINOS-the Main Injector Neutrino Oscillation Search-that uses two neutrino detectors in the beam, one at Fermilab and one in northern Minnesota, to investigate the phenomenon of neutrino oscillations.

  20. Laser ion acceleration toward future ion beam cancer therapy - Numerical simulation study -

    PubMed Central

    Kawata, Shigeo; Izumiyama, Takeshi; Nagashima, Toshihiro; Takano, Masahiro; Barada, Daisuke; Kong, Qing; Gu, Yan Jun; Wang, Ping Xiao; Ma, Yan Yun; Wang, Wei Min

    2013-01-01

    Background: Ion beam has been used in cancer treatment, and has a unique preferable feature to deposit its main energy inside a human body so that cancer cell could be killed by the ion beam. However, conventional ion accelerator tends to be huge in its size and its cost. In this paper a future intense-laser ion accelerator is proposed to make the ion accelerator compact. Subjects and methods: An intense femtosecond pulsed laser was employed to accelerate ions. The issues in the laser ion accelerator include the energy efficiency from the laser to the ions, the ion beam collimation, the ion energy spectrum control, the ion beam bunching and the ion particle energy control. In the study particle computer simulations were performed to solve the issues, and each component was designed to control the ion beam quality. Results: When an intense laser illuminates a target, electrons in the target are accelerated and leave from the target; temporarily a strong electric field is formed between the high-energy electrons and the target ions, and the target ions are accelerated. The energy efficiency from the laser to ions was improved by using a solid target with a fine sub-wavelength structure or by a near-critical density gas plasma. The ion beam collimation was realized by holes behind the solid target. The control of the ion energy spectrum and the ion particle energy, and the ion beam bunching were successfully realized by a multi-stage laser-target interaction. Conclusions: The present study proposed a novel concept for a future compact laser ion accelerator, based on each component study required to control the ion beam quality and parameters. PMID:24155555

  1. Spectrum bandwidth narrowing of Thomson scattering X-rays with energy chirped electron beams from laser wakefield acceleration

    SciTech Connect

    Xu, Tong; Chen, Min Li, Fei-Yu; Yu, Lu-Le; Sheng, Zheng-Ming; Zhang, Jie

    2014-01-06

    We study incoherent Thomson scattering between an ultrashort laser pulse and an electron beam accelerated from a laser wakefield. The energy chirp effects of the accelerated electron beam on the final radiation spectrum bandwidth are investigated. It is found that the scattered X-ray radiation has the minimum spectrum width and highest intensity as electrons are accelerated up to around the dephasing point. Furthermore, it is proposed that the electron acceleration process inside the wakefield can be studied by use of 90° Thomson scattering. The dephasing position and beam energy chirp can be deduced from the intensity and bandwidth of the scattered radiation.

  2. Levy-Student distributions for halos in accelerator beams

    SciTech Connect

    Cufaro Petroni, Nicola; De Martino, Salvatore; De Siena, Silvio; Illuminati, Fabrizio

    2005-12-15

    We describe the transverse beam distribution in particle accelerators within the controlled, stochastic dynamical scheme of stochastic mechanics (SM) which produces time reversal invariant diffusion processes. This leads to a linearized theory summarized in a Schroedinger-like (SL) equation. The space charge effects have been introduced in recent papers by coupling this S-L equation with the Maxwell equations. We analyze the space-charge effects to understand how the dynamics produces the actual beam distributions, and in particular we show how the stationary, self-consistent solutions are related to the (external and space-charge) potentials both when we suppose that the external field is harmonic (constant focusing), and when we a priori prescribe the shape of the stationary solution. We then proceed to discuss a few other ideas by introducing generalized Student distributions, namely, non-Gaussian, Levy infinitely divisible (but not stable) distributions. We will discuss this idea from two different standpoints: (a) first by supposing that the stationary distribution of our (Wiener powered) SM model is a Student distribution; (b) by supposing that our model is based on a (non-Gaussian) Levy process whose increments are Student distributed. We show that in the case (a) the longer tails of the power decay of the Student laws and in the case (b) the discontinuities of the Levy-Student process can well account for the rare escape of particles from the beam core, and hence for the formation of a halo in intense beams.

  3. Adaptive Vlasov Simulations of Intense Beams

    SciTech Connect

    Sonnendruecker, Eric; Gutnic, Michael; Haefele, Matthieu; Lemaire, Jean-Louis

    2005-06-08

    Most simulations of intense particle beams are performed nowadays using Particle In Cell (PIC) techniques. Direct grid based Vlasov methods have also been used but mostly for 1D simulations as they become very costly in higher dimensions when using uniform phase space grids. We have recently introduced adaptive mesh refinement techniques that allow us to automatically concentrate the grid points at places where the distribution function is varying most. In this paper we shall introduce this technique and show how it can be used to improve the efficiency of grid based Vlasov solvers.

  4. Method of enhancing cyclotron beam intensity

    DOEpatents

    Hudson, Ed D.; Mallory, Merrit L.

    1977-01-01

    When an easily ionized support gas such as xenon is added to the cold cathode in sources of the Oak Ridge Isochronous Cyclotron, large beam enhancements are produced. For example, .sup.20 Ne.sup.7+ is increased from 0.05 enA to 27 enA, and .sup.16 O.sup.5+ intensities in excess of 35 e.mu.A have been extracted for periods up to 30 minutes. Approximately 0.15 cc/min of the easily ionized support gas is supplied to the ion source through a separate gas feed line and the primary gas flow is reduced by about 30%.

  5. Relativistic electron beam acceleration by Compton scattering of extraordinary waves

    SciTech Connect

    Sugaya, R.

    2006-05-15

    Relativistic transport equations, which demonstrate that relativistic and nonrelativistic particle acceleration along and across a magnetic field and the generation of an electric field transverse to the magnetic field, are induced by nonlinear wave-particle scattering (nonlinear Landau and cyclotron damping) of almost perpendicularly propagating electromagnetic waves in a relativistic magnetized plasma were derived from the relativistic Vlasov-Maxwell equations. The relativistic transport equations show that electromagnetic waves can accelerate particles in the k{sup ''} direction (k{sup ''}=k-k{sup '}). Simultaneously, an intense cross-field electric field, E{sub 0}=B{sub 0}xv{sub d}/c, is generated via the dynamo effect owing to perpendicular particle drift to satisfy the generalized Ohm's law, which means that this cross-field particle drift is identical to the ExB drift. On the basis of these equations, acceleration and heating of a relativistic electron beam due to nonlinear wave-particle scattering of electromagnetic waves in a magnetized plasma were investigated theoretically and numerically. Two electromagnetic waves interact nonlinearly with the relativistic electron beam, satisfying the resonance condition of {omega}{sub k}-{omega}{sub k{sup '}}-(k{sub perpendicular}-k{sub perpendicula=} r{sup '})v{sub d}-(k{sub parallel}-k{sub parallel}{sup '})v{sub b}{approx_equal}m{omega}{sub ce}, where v{sub b} and v{sub d} are the parallel and perpendicular velocities of the relativistic electron beam, respectively, and {omega}{sub ce} is the relativistic electron cyclotron frequency. The relativistic transport equations using the relativistic drifted Maxwellian momentum distribution function of the relativistic electron beam were derived and analyzed. It was verified numerically that extraordinary waves can accelerate the highly relativistic electron beam efficiently with {beta}m{sub e}c{sup 2} < or approx. 1 GeV, where {beta}=(1-v{sub b}{sup 2}/c{sup 2}){sup -1/2}.

  6. Accelerating Airy beams in the presence of inhomogeneities

    NASA Astrophysics Data System (ADS)

    Besieris, Ioannis M.; Shaarawi, Amr M.; Zamboni-Rached, Michel

    2016-06-01

    Studies have already been made of accelerating Airy beams in the presence of deterministic inhomogeneities, illustrating, in particular, that the inherent self-healing properties of such beams are preserved. The cases of a range-dependent linear transverse potential and a converging GRIN structure (harmonic oscillator) have been examined thoroughly. Examples will be given in this article of novel accelerating Airy beams in the presence of five other types of potential functions. Three of the resulting exact analytical solutions have a common salient characteristic property: they are constructed using the free-space accelerating Airy beam solution as a seed.

  7. Advanced accelerating structures and their interaction with electron beams.

    SciTech Connect

    Gai, W.; High Energy Physics

    2008-01-01

    In this paper, we give a brief description of several advanced accelerating structures, such as dielectric loaded waveguides, photonic band gap, metamaterials and improved iris-loaded cavities. We describe wakefields generated by passing high current electron beams through these structures, and applications of wakefields to advanced accelerator schemes. One of the keys to success for high gradient wakefield acceleration is to develop high current drive beam sources. As an example, the high current RF photo injector at the Argonne Wakefield Accelerator, passed a {approx}80 nC electron beam through a high gradient dielectric loaded structure to achieve a 100 MV/m gradient. We will summarize recent related experiments on beam-structure interactions and also discuss high current electron beam generation and propagation and their applications to wakefield acceleration.

  8. Advanced Accelerating Structures and Their Interaction with Electron Beams

    SciTech Connect

    Gai Wei

    2009-01-22

    In this paper, we give a brief description of several advanced accelerating structures, such as dielectric loaded waveguides, photonic band gap, metamaterials and improved iris-loaded cavities. We describe wakefields generated by passing high current electron beams through these structures, and applications of wakefields to advanced accelerator schemes. One of the keys to success for high gradient wakefield acceleration is to develop high current drive beam sources. As an example, the high current RF photo injector at the Argonne Wakefield Accelerator, passed a {approx}80 nC electron beam through a high gradient dielectric loaded structure to achieve a 100 MV/m gradient. We will summarize recent related experiments on beam-structure interactions and also discuss high current electron beam generation and propagation and their applications to wakefield acceleration.

  9. Accessing defect dynamics using intense, nanosecond pulsed ion beams

    SciTech Connect

    Persaud, A.; Barnard, J. J.; Guo, H.; Hosemann, P.; Lidia, S.; Minor, A. M.; Seidl, P. A.; Schenkel, T.

    2015-06-18

    Gaining in-situ access to relaxation dynamics of radiation induced defects will lead to a better understanding of materials and is important for the verification of theoretical models and simulations. We show preliminary results from experiments at the new Neutralized Drift Compression Experiment (NDCX-II) at Lawrence Berkeley National Laboratory that will enable in-situ access to defect dynamics through pump-probe experiments. Here, the unique capabilities of the NDCX-II accelerator to generate intense, nanosecond pulsed ion beams are utilized. Preliminary data of channeling experiments using lithium and potassium ions and silicon membranes are shown. We compare these data to simulation results using Crystal Trim. Furthermore, we discuss the improvements to the accelerator to higher performance levels and the new diagnostics tools that are being incorporated.

  10. Accessing defect dynamics using intense, nanosecond pulsed ion beams

    DOE PAGES

    Persaud, A.; Barnard, J. J.; Guo, H.; ...

    2015-06-18

    Gaining in-situ access to relaxation dynamics of radiation induced defects will lead to a better understanding of materials and is important for the verification of theoretical models and simulations. We show preliminary results from experiments at the new Neutralized Drift Compression Experiment (NDCX-II) at Lawrence Berkeley National Laboratory that will enable in-situ access to defect dynamics through pump-probe experiments. Here, the unique capabilities of the NDCX-II accelerator to generate intense, nanosecond pulsed ion beams are utilized. Preliminary data of channeling experiments using lithium and potassium ions and silicon membranes are shown. We compare these data to simulation results using Crystalmore » Trim. Furthermore, we discuss the improvements to the accelerator to higher performance levels and the new diagnostics tools that are being incorporated.« less

  11. INERTIAL FUSION DRIVEN BY INTENSE HEAVY-ION BEAMS

    SciTech Connect

    Sharp, W. M.; Friedman, A.; Grote, D. P.; Barnard, J. J.; Cohen, R. H.; Dorf, M. A.; Lund, S. M.; Perkins, L. J.; Terry, M. R.; Logan, B. G.; Bieniosek, F. M.; Faltens, A.; Henestroza, E.; Jung, J. Y.; Kwan, J. W.; Lee, E. P.; Lidia, S. M.; Ni, P. A.; Reginato, L. L.; Roy, P. K.; Seidl, P. A.; Takakuwa, J. H.; Vay, J.-L.; Waldron, W. L.; Davidson, R. C.; Gilson, E. P.; Kaganovich, I. D.; Qin, H.; Startsev, E.; Haber, I.; Kishek, R. A.; Koniges, A. E.

    2011-03-31

    Intense heavy-ion beams have long been considered a promising driver option for inertial-fusion energy production. This paper briefly compares inertial confinement fusion (ICF) to the more-familiar magnetic-confinement approach and presents some advantages of using beams of heavy ions to drive ICF instead of lasers. Key design choices in heavy-ion fusion (HIF) facilities are discussed, particularly the type of accelerator. We then review experiments carried out at Lawrence Berkeley National Laboratory (LBNL) over the past thirty years to understand various aspects of HIF driver physics. A brief review follows of present HIF research in the US and abroad, focusing on a new facility, NDCX-II, being built at LBNL to study the physics of warm dense matter heated by ions, as well as aspects of HIF target physics. Future research directions are briefly summarized.

  12. US Accelerator R&D Program Toward Intensity Frontier Machines

    SciTech Connect

    Shiltsev, Vladimir

    2016-09-15

    The 2014 P5 report indicated the accelerator-based neutrino and rare decay physics research as a centerpiece of the US domestic HEP program. Operation, upgrade and development of the accelerators for the near-term and longer-term particle physics program at the Intensity Frontier face formidable challenges. Here we discuss key elements of the accelerator physics and technology R&D program toward future multi-MW proton accelerators.

  13. Flyer Acceleration by Pulsed Ion Beam Ablation and Application for Space Propulsion

    SciTech Connect

    Harada, Nobuhiro; Buttapeng, Chainarong; Yazawa, Masaru; Kashine, Kenji; Jiang Weihua; Yatsui, Kiyoshi

    2004-02-04

    Flyer acceleration by ablation plasma pressure produced by irradiation of intense pulsed ion beam has been studied. Acceleration process including expansion of ablation plasma was simulated based on fluid model. And interaction between incident pulsed ion beam and a flyer target was considered as accounting stopping power of it. In experiments, we used ETIGO-II intense pulsed ion beam generator with two kinds of diodes; 1) Magnetically Insulated Diode (MID, power densities of <100 J/cm2) and 2) Spherical-focused Plasma Focus Diode (SPFD, power densities of up to 4.3 kJ/cm2). Numerical results of accelerated flyer velocity agreed well with measured one over wide range of incident ion beam energy density. Flyer velocity of 5.6 km/s and ablation plasma pressure of 15 GPa was demonstrated by the present experiments. Acceleration of double-layer target consists of gold/aluminum was studied. For adequate layer thickness, such a flyer target could be much more accelerated than a single layer. Effect of waveform of ion beam was also examined. Parabolic waveform could accelerate more efficiently than rectangular waveform. Applicability of ablation propulsion was discussed. Specific impulse of 7000{approx}8000 seconds and time averaged thrust of up to 5000{approx}6000N can be expected. Their values can be controllable by changing power density of incident ion beam and pulse duration.

  14. Dynamic response of an accelerator driven system to accelerator beam interruptions for criticality

    NASA Astrophysics Data System (ADS)

    Lafuente, A.; Abanades, A.; Leon, P. T.; Sordo, F.; Martinez-Val, J. M.

    2008-06-01

    Subcritical nuclear reactors driven by intense neutron sources can be very suitable tools for nuclear waste transmutation, particularly in the case of minor actinides with very low fractions of delayed neutrons. A proper control of these systems needs to know at every time the absolute value of the reactor subcriticality (negative reactivity), which must be measured by fully reliable methods, usually conveying a short interruption of the accelerator beam in order to assess the neutron flux reduction. Those interruptions should be very short in time, for not disturbing too much the thermal magnitudes of the reactor. Otherwise, the cladding and the fuel would suffer from thermal fatigue produced by those perturbations, and the mechanical integrity of the reactor would be jeopardized. It is shown in this paper that beam interruptions of the order of 400 μs repeated every second would not disturb significantly the reactor thermal features, while enabling for an adequate measurement of the negative reactivity.

  15. Generation of heavy ion beams using high-intensity short pulse lasers

    NASA Astrophysics Data System (ADS)

    Petrov, George; McGuffey, Chris; Thomas, Alec; Krushelnick, Karl; Beg, Farhat

    2016-10-01

    A theoretical study of ion acceleration from high-Z material irradiated by intense sub-picosecond lasers is presented. The underlying physics of beam formation and acceleration is similar for light and heavy ions, however, nuances of the acceleration process make the heavy ions more challenging. At least four technical hurdles have been identified: low charge-to-mass ratio, limited number of ions amenable to acceleration, delayed acceleration and poor energy coupling due to high reflectivity of the plasma. Using two dimensional particle-in-cell (PIC) simulations, we observed transitions from Radiation Pressure Acceleration (RPA) to the Breakout Afterburner regime (BoA) and to Target Normal Sheath Acceleration (TNSA) akin to light ions. The numerical simulations predict gold ions beams with high directionality (<10 degrees half-angle), high fluxes (>1011 ions/sr) and energy (>10 MeV/nucleon) from laser systems delivering >20 J of energy on target.

  16. Low-emittance monoenergetic electron and ion beams from ultra-intense laser-solid interactions

    SciTech Connect

    Cowan, T E; Roth, M; Allen, M M; Johnson, J; Hatchett, S P; Le Sage, G P; Wilks, S C

    2000-03-03

    Recent experiments at the LLNL Petawatt Laser have demonstrated the generation of intense, high energy beams of electrons and ions from the interaction of ultra-intense laser light with solid targets. Focused laser intensities as high as 6 x 10{sup 20} W/cm{sup 2} are achieved, at which point the quiver energies of the target electrons extend to {approx}10 MeV. In this new, fully relativistic regime of laser-plasma interactions, nuclear processes become important and nuclear techniques are required to diagnose the high-energy particle production. In recent experiments we have observed electrons accelerated to 100 MeV, up to 60 MeV brehmsstrahlung generation, photo-nuclear fission and positron-electron pair creation. We also have observed monoenergetic jets of electrons having sufficiently small emittance to be interesting as a laser-accelerated beam, if the production mechanism could be understood and controlled. The huge flux of multi-MeV ponderomotively accelerated electrons produced in the laser-solid interaction is also observed to accelerate contaminant ions from the rear surface of the solid target up to 50 MeV. We describe spectroscopic measurements which reveal intense monoenergetic beam features in the proton energy spectrum. The total spectrum contains >10{sup 13} protons, while the monoenergetic beam pulses contain {approx}1 nC of protons, and exhibits a longitudinal and transverse emittance smaller than conventional RF proton accelerator beams.

  17. Intense ion beam optimization and characterization with thermal imaging

    SciTech Connect

    Davis, H.A.; Bartsch, R.R.; Rej, D.J.; Waganaar, W.J.

    1994-08-01

    The authors have developed thermal imaging of beam targets to optimize and characterize intense ion beams. The technique, which measures the beam energy-density distribution on each machine firing, has been used to rapidly develop and characterize two very different beams--a 400 kV beam used to study materials processing, and an 80 kV beam use for magnetic fusion diagnostics.

  18. Stable long range proton acceleration driven by intense laser pulse with underdense plasmas

    SciTech Connect

    Gu, Y. J.; Zhu, Z.; Li, X. F.; Yu, Q.; Huang, S.; Zhang, F.; Kong, Q.; Kawata, S.

    2014-06-15

    Proton acceleration is investigated by 2.5-dimensional particle-in-cell simulations in an interaction of an ultra intense laser with a near-critical-density plasma. It was found that multi acceleration mechanisms contribute together to a 1.67 GeV collimated proton beam generation. The W-BOA (breakout afterburner based on electrons accelerated by a wakefield) acceleration mechanism plays an important role for the proton energy enhancement in the area far from the target. The stable and continuous acceleration maintains for a long distance and period at least several pico-seconds. Furthermore, the energy scalings are also discussed about the target density and the laser intensity.

  19. Stable long range proton acceleration driven by intense laser pulse with underdense plasmas

    NASA Astrophysics Data System (ADS)

    Gu, Y. J.; Zhu, Z.; Li, X. F.; Yu, Q.; Huang, S.; Zhang, F.; Kong, Q.; Kawata, S.

    2014-06-01

    Proton acceleration is investigated by 2.5-dimensional particle-in-cell simulations in an interaction of an ultra intense laser with a near-critical-density plasma. It was found that multi acceleration mechanisms contribute together to a 1.67 GeV collimated proton beam generation. The W-BOA (breakout afterburner based on electrons accelerated by a wakefield) acceleration mechanism plays an important role for the proton energy enhancement in the area far from the target. The stable and continuous acceleration maintains for a long distance and period at least several pico-seconds. Furthermore, the energy scalings are also discussed about the target density and the laser intensity.

  20. 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.

  1. Heavy ion beam-ionosphere interactions: Electron acceleration

    SciTech Connect

    Kaufmann, R.L.; Arnoldy, R.L.; Moore, T.E.; Kintner, P.M.; Cahill L.J. Jr.; Walker, D.N.

    1985-10-01

    Operation of a divergent 25-eV Ar/sup +/ gun within an auroral arc produced dramatic changes in the flux of electrons with energies between 1 keV and the 88-eV detector cutoff. The observations suggest that intense return currents flowed parallel to B/sub 0/ to neutralize the Ar/sup +/ beam, particularly within a few meters of the rocket. These neutralization currents were carried above and below the rocket by the few-eV electrons which were emitted by the gun and by colder ionospheric electrons. Such low-energy electrons could not be measured directly by detectors on the rocket. We concluded that generation of strong field-aligned return currents was the most important effect of ion gun operation, and that these field aligned currents were responsible for many other observable effects. Downgoing hectovolt electrons appear to have been accelerated because of interactions with waves or quasi-stationary electric fields that were generated by the field-aligned current. This acceleration took place throughout a cylinder centered on the rocket,with a radius of at least several meters. Acceleration of hectovolt electrons depended surprisingly little on the direction in which the Ar/sup +/ gun was pointing.

  2. Plasma Wakefield Acceleration and FACET - Facilities for Accelerator Science and Experimental Test Beams at SLAC

    ScienceCinema

    Andrei Seryi

    2016-07-12

    Plasma wakefield acceleration is one of the most promising approaches to advancing accelerator technology. This approach offers a potential 1,000-fold or more increase in acceleration over a given distance, compared to existing accelerators.  FACET, enabled by the Recovery Act funds, will study plasma acceleration, using short, intense pulses of electrons and positrons. In this lecture, the physics of plasma acceleration and features of FACET will be presented.  

  3. Optimization of accelerated charged particle beam for ADS energy production

    NASA Astrophysics Data System (ADS)

    Baldin, A. A.; Berlev, A. I.; Paraipan, M.; Tyutyunnikov, S. I.

    2017-01-01

    A comparative analysis and optimization of energy efficiency for proton and ion beams in ADS systems is performed via simulation using a GEANT4 code with account for energy consumption for different accelerator types. It is demonstrated that for light nuclei, beginning from 7Li, with energies above 1 GeV/nucleon, ion beams are considerably (several times) more efficient than the 1-3 GeV proton beam. The possibility of achieving energy deposition equivalent to 1 GeV protons in a quasi-infinite uranium target with higher efficiency (and twice as small accelerator size) in the case of acceleration of light ions is substantiated.

  4. High-gradient two-beam electron accelerator

    SciTech Connect

    Hirshfield, Jay L.

    2014-11-04

    The main goal for this project was to design, build, and evaluate a detuned-cavity, collinear, two-beam accelerator structure. Testing was to be at the Yale University Beam Physics Laboratory, under terms of a sub-grant from Omega-P to Yale. Facilities available at Yale for this project include a 6-MeV S-band RF gun and associated beam line for forming and transporting a ~1 A drive beam , a 300 kV beam source for use as a test beam, and a full panoply of laboratory infrastructure and test equipment. During the first year of this project, availability and functionality of the 6-MeV drive beam and 300 kV test beam were confirmed, and the beam line was restored to a layout to be used with the two-beam accelerator project. Major efforts during the first year were also focused on computational design and simulation of the accelerator structure itself, on beam dynamics, and on beam transport. Effort during the second year was focussed on building and preparing to test the structure, including extensive cold testing. Detailed results from work under this project have been published in twelve archival journal articles, listed in Section IV of the technical report.

  5. Intense muon beams and neutrino factories

    SciTech Connect

    Parsa, Z.

    2000-10-05

    High intensity muon sources are needed in exploring neutrino factories, lepton flavor violating muon processes, and lower energy experiments as the stepping phase towards building higher energy {mu}{sup +}{mu}{sup {minus}} colliders. We present a brief overview, sketch of a neutrino source, and an example of a muon storage ring at BNL with detector(s) at Fermilab, Sudan, etc. Physics with low energy neutrino beams based on muon storage rings ({mu}SR) and conventional Horn Facilities are described and compared. CP violation Asymmetries and a new Statistical Figure of Merit to be used for comparison is given. Improvements in the sensitivity of low energy experiments to study Flavor changing neutral currents are also included.

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

    SciTech Connect

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

    2009-10-05

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

  7. Transverse Beam Shape Measurements of Intense Proton Beams Using Optical Transition Radiation

    NASA Astrophysics Data System (ADS)

    Scarpine, Victor E.

    A number of particle physics experiments are being proposed as part of the Department of Energy HEP Intensity Frontier. Many of these experiments will utilize megawatt level proton beams onto targets to form secondary beams of muons, kaons and neutrinos. These experiments require transverse size measurements of the incident proton beam onto target for each beam spill. Because of the high power levels, most beam intercepting profiling techniques will not work at full beam intensity. The possibility of utilizing optical transition radiation (OTR) for high intensity proton beam profiling is discussed. In addition, previous measurements of OTR beam profiles from the NuMI beamline are presented.

  8. Transverse beam shape measurements of intense proton beams using optical transition radiation

    SciTech Connect

    Scarpine, Victor E.; /Fermilab

    2012-03-01

    A number of particle physics experiments are being proposed as part of the Department of Energy HEP Intensity Frontier. Many of these experiments will utilize megawatt level proton beams onto targets to form secondary beams of muons, kaons and neutrinos. These experiments require transverse size measurements of the incident proton beam onto target for each beam spill. Because of the high power levels, most beam intercepting profiling techniques will not work at full beam intensity. The possibility of utilizing optical transition radiation (OTR) for high intensity proton beam profiling is discussed. In addition, previous measurements of OTR beam profiles from the NuMI beamline are presented.

  9. 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.

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

    SciTech Connect

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

    2016-02-15

    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.

  11. Drift tube suspension for high intensity linear accelerators

    DOEpatents

    Liska, D.J.; Schamaun, R.G.; Clark, D.C.; Potter, R.C.; Frank, J.A.

    1980-03-11

    The disclosure relates to a drift tube suspension for high intensity linear accelerators. The system comprises a series of box-sections girders independently adjustably mounted on a linear accelerator. A plurality of drift tube holding stems are individually adjustably mounted on each girder.

  12. Drift tube suspension for high intensity linear accelerators

    DOEpatents

    Liska, Donald J.; Schamaun, Roger G.; Clark, Donald C.; Potter, R. Christopher; Frank, Joseph A.

    1982-01-01

    The disclosure relates to a drift tube suspension for high intensity linear accelerators. The system comprises a series of box-sections girders independently adjustably mounted on a linear accelerator. A plurality of drift tube holding stems are individually adjustably mounted on each girder.

  13. First acceleration of a proton beam in a side coupled drift tube linac

    NASA Astrophysics Data System (ADS)

    Ronsivalle, C.; Picardi, L.; Ampollini, A.; Bazzano, G.; Marracino, F.; Nenzi, P.; Snels, C.; Surrenti, V.; Vadrucci, M.; Ambrosini, F.

    2015-07-01

    We report the first experiment aimed at the demonstration of low-energy protons acceleration by a high-efficiency S-band RF linear accelerator. The proton beam has been accelerated from 7 to 11.6 MeV by a 1 meter long SCDTL (Side Coupled Drift Tube Linac) module powered with 1.3 MW. The experiment has been done in the framework of the Italian TOP-IMPLART (Oncological Therapy with Protons-Intensity Modulated Proton Therapy Linear Accelerator for Radio-Therapy) project devoted to the realization of a proton therapy centre based on a proton linear accelerator for intensity modulated cancer treatments to be installed at IRE-IFO, the largest oncological hospital in Rome. It is the first proton therapy facility employing a full linear accelerator scheme based on high-frequency technology.

  14. Brighter H/sup -/ source for the intense pulsed neutron source accelerator system

    SciTech Connect

    Stipp, V.; DeWitt, A.; Madsen, J.

    1983-01-01

    Further increases in the beam intensity of the Intense Pulsed Neutron Source (IPNS) at Argonne National Laboratory required the replacement of the H/sup -/ source with a higher current source. A magnetron ion source of Fermi National Accelerator Laboratory (FNAL) design was adapted with a grooved cathode to provide a stable 40 to 50 mA of beam operating at 30 Hz for up to a 90 ..mu..s pulse duration. Problems of space charge blowup due to the lack of neutralization of the H/sup -/ beam were solved by injecting additional gs into the 20 keV transport system. The source has recently been installed in the machine and the available input to the accelerator has more than doubled.

  15. A prototype of a beam steering assistant tool for accelerator operations

    SciTech Connect

    M. Bickley; P. Chevtsov

    2006-10-24

    The CEBAF accelerator provides nuclear physics experiments at Jefferson Lab with high quality electron beams. Three experimental end stations can simultaneously receive the beams with different energies and intensities. For each operational mode, the accelerator setup procedures are complicated and require very careful checking of beam spot sizes and positions on multiple beam viewers. To simplify these procedures and make them reproducible, a beam steering assistant GUI tool has been created. The tool is implemented as a multi-window control screen. The screen has an interactive graphical object window, which is an overlay on top of a digitized live video image from a beam viewer. It allows a user to easily create and edit any graphical objects consisting of text, ellipses, and lines, right above the live beam viewer image and then save them in a file that is called a beam steering template. The template can show, for example, the area within which the beam must always be on the viewer. Later, this template can be loaded in the interactive graphical object window to help accelerator operators steer the beam to the specified area on the viewer.

  16. Simulation study of accelerator based quasi-mono-energetic epithermal neutron beams for BNCT.

    PubMed

    Adib, M; Habib, N; Bashter, I I; El-Mesiry, M S; Mansy, M S

    2016-01-01

    Filtered neutron techniques were applied to produce quasi-mono-energetic neutron beams in the energy range of 1.5-7.5 keV at the accelerator port using the generated neutron spectrum from a Li (p, n) Be reaction. A simulation study was performed to characterize the filter components and transmitted beam lines. The feature of the filtered beams is detailed in terms of optimal thickness of the primary and additive components. A computer code named "QMNB-AS" was developed to carry out the required calculations. The filtered neutron beams had high purity and intensity with low contamination from the accompanying thermal, fast neutrons and γ-rays.

  17. The use of radiochromic films to measure and analyze the beam profile of charged particle accelerators.

    PubMed

    Avila-Rodriguez, M A; Wilson, J S; McQuarrie, S A

    2009-11-01

    The use of radiochromic films as a simple and inexpensive tool to accurately measure and analyze the beam profile of charged particle accelerators is described. In this study, metallic foils of different materials and thicknesses were irradiated with 17.8MeV protons and autoradiographic images of the beam strike were acquired by exposing pieces of RCF in direct contact with the irradiated foils. The films were digitalized using a conventional scanner and images were analyzed using DoseLab. Beam intensity distributions, isodose curves and linear beam profiles of the digitalized images were acquired.

  18. Far-field intensity of Lorentz related beams

    NASA Astrophysics Data System (ADS)

    Peng, Xi; Chen, Chidao; Chen, Bo; Peng, Yulian; Zhou, Meiling; Zhang, Liping; Li, Dongdong; Deng, Dongmei

    2016-12-01

    We introduce a sufficient condition under which the Lorentz beam convolution with other beams constitutes valid cross-spectral densities. Two examples are given to show how the Lorentz related beam can be used for generation of a far field being a modulated version of another one. The far-field intensity patterns in the Cartesian symmetries by the convolution operation of the Lorentz beams with multi-sinc beams, and the convolution operation of the Lorentz beams with multi-sinc Gaussian beams, are shown respectively. We find that different beam order can result distinct far field changes.

  19. Progress Towards Doubling the Beam Power at Fermilab's Accelerator Complex

    SciTech Connect

    Kourbanis, ioanis

    2014-06-01

    After a 14 month shutdown accelerator modifications and upgrades are in place to allow us doubling of the Main Injector beam power. We will discuss the past MI high power operation and the current progress towards doubling the power.

  20. Beam polarimetry at the SPASCHARM experiment at IHEP U-70 accelerator

    NASA Astrophysics Data System (ADS)

    Bogdanov, A. A.; Chetvertkov, M. A.; Chetvertkova, V. A.; Garkusha, B. I.; Meshchanin, A. P.; Mochalov, V. V.; Nurusheva, M. B.; Nurushev, S. B.; Rykov, V. L.; Runzo, M. F.; Semenov, P. A.; Strikhanov, M. N.; Vasiliev, A. N.; Zapolsky, V. N.

    2017-01-01

    We describe the absolute polarimeters for the beam channel intended to transport polarized proton and antiproton beam at U70 accelerator. The circulating proton beam of 60 GeV/c and intensity 1013 p/cycle is slowly extracted from accelerator. It strakes the external an aluminum target of one interaction length. The emitted on forward direction Λ and \\bar Λ hyperons by parity violating process serve as the source of the polarized protons and antiprotons. In this case we expect to get the polarized antiproton beams in the momentum range 10-40 GeV/c with intensity, approximately 104 – 4x105 antiprotons/cycle, 106 protons/cycle.

  1. Beam manipulation and acceleration with Dielectric-Lined Waveguides

    SciTech Connect

    Lemery, Francois

    2015-06-01

    The development of next-generation TeV+ electron accelerators will require either immense footprints based on conventional acceleraton techniques or the development of new higher{gradient acceleration methods. One possible alternative is beam-driven acceleration in a high-impedance medium such as a dielectric-lined-waveguide (DLW), where a highcharge bunch passes through a DLW and can excite gradients on the order of GV/m. An important characteristic of this acceleration class is the transformer ratio which characterizes the energy transfer of the scheme. This dissertation discusses alternative methods to improve the transformer ratio for beam-driven acceleration and also considers the use of DLWs for beam manipulation at low energy.

  2. Multiple beam induction accelerators for heavy ion fusion

    NASA Astrophysics Data System (ADS)

    Seidl, Peter A.; Barnard, John J.; Faltens, Andris; Friedman, Alex; Waldron, William L.

    2014-01-01

    Induction accelerators are appealing for heavy-ion driven inertial fusion energy (HIF) because of their high efficiency and their demonstrated capability to accelerate high beam current (≥10 kA in some applications). For the HIF application, accomplishments and challenges are summarized. HIF research and development has demonstrated the production of single ion beams with the required emittance, current, and energy suitable for injection into an induction linear accelerator. Driver scale beams have been transported in quadrupole channels of the order of 10% of the number of quadrupoles of a driver. We review the design and operation of induction accelerators and the relevant aspects of their use as drivers for HIF. We describe intermediate research steps that would provide the basis for a heavy-ion research facility capable of heating matter to fusion relevant temperatures and densities, and also to test and demonstrate an accelerator architecture that scales well to a fusion power plant.

  3. Beam dynamics in a long-pulse linear induction accelerator

    SciTech Connect

    Ekdahl, Carl; Abeyta, Epifanio O; Aragon, Paul; Archuleta, Rita; Cook, Gerald; Dalmas, Dale; Esquibel, Kevin; Gallegos, Robert A; Garnett, Robert; Harrison, James F; Johnson, Jeffrey B; Jacquez, Edward B; Mc Cuistian, Brian T; Montoya, Nicholas A; Nath, Subrato; Nielsen, Kurt; Oro, David; Prichard, Benjamin; Rose, Chris R; Sanchez, Manolito; Schauer, Martin M; Seitz, Gerald; Schulze, Martin; Bender, Howard A; Broste, William B; Carlson, Carl A; Frayer, Daniel K; Johnson, Douglas E; Tom, C Y; Trainham, C; Williams, John; Scarpetti, Raymond; Genoni, Thomas; Hughes, Thomas; Toma, Carsten

    2010-01-01

    The second axis of the Dual Axis Radiography of Hydrodynamic Testing (DARHT) facility produces up to four radiographs within an interval of 1.6 microseconds. It accomplishes this by slicing four micro-pulses out of a long 1.8-kA, 16.5-MeV electron beam pulse and focusing them onto a bremsstrahlung converter target. The long beam pulse is created by a dispenser cathode diode and accelerated by the unique DARHT Axis-II linear induction accelerator (LIA). Beam motion in the accelerator would be a problem for radiography. High frequency motion, such as from beam breakup instability, would blur the individual spots. Low frequency motion, such as produced by pulsed power variation, would produce spot to spot differences. In this article, we describe these sources of beam motion, and the measures we have taken to minimize it.

  4. ISABELLE accelerator software, control system, and beam diagnostic philosophy

    SciTech Connect

    Cornacchia, M.; Humphrey, J.W.; Niederer, J.; Poole, J.H.

    1981-01-01

    The ISABELLE Project combines two large proton accelerators with two storage rings in the same facility using superconducting magnet technology. This combination leads to severe constraints on beam loss in magnets and involves complex treatment of magnetic field imperfections and correction elements. The consequent demands placed upon beam diagnostics, accelerator model programs, and the computer oriented control system are discussed in terms of an illustrative operation scenario.

  5. Lévy-Student distributions for halos in accelerator beams.

    PubMed

    Cufaro Petroni, Nicola; De Martino, Salvatore; De Siena, Silvio; Illuminati, Fabrizio

    2005-12-01

    We describe the transverse beam distribution in particle accelerators within the controlled, stochastic dynamical scheme of stochastic mechanics (SM) which produces time reversal invariant diffusion processes. This leads to a linearized theory summarized in a Schrödinger-like (SL) equation. The space charge effects have been introduced in recent papers by coupling this S-L equation with the Maxwell equations. We analyze the space-charge effects to understand how the dynamics produces the actual beam distributions, and in particular we show how the stationary, self-consistent solutions are related to the (external and space-charge) potentials both when we suppose that the external field is harmonic (constant focusing), and when we a priori prescribe the shape of the stationary solution. We then proceed to discuss a few other ideas by introducing generalized Student distributions, namely, non-Gaussian, Lévy infinitely divisible (but not stable) distributions. We will discuss this idea from two different standpoints: (a) first by supposing that the stationary distribution of our (Wiener powered) SM model is a Student distribution; (b) by supposing that our model is based on a (non-Gaussian) Lévy process whose increments are Student distributed. We show that in the case (a) the longer tails of the power decay of the Student laws and in the case (b) the discontinuities of the Lévy-Student process can well account for the rare escape of particles from the beam core, and hence for the formation of a halo in intense beams.

  6. Intense beams: The past, present, and future

    SciTech Connect

    Yonas, G.; Sweeney, M.A.

    1998-06-01

    Nobody could have predicted the circuitous course of the last 30 years of progress in intense beams and pulsed power. There were many discoveries and twists and turns along the way, but the steady flow of understanding and technological advances has sustained the field. Pulsed power research began in the early 1960s with the development of the technology to test the reliability of nuclear weapons in a pulsed radiation environment. Because of the effort in the 1970s on an electron beam approach to inertial confinement fusion (ICF) at Sandia National Laboratories and at the Kurchatov Institute, simulation codes, diagnostics, and innovative pulsed power techniques such as self-magnetic insulation were developed. The electron approach ended in 1979, and the more promising ion approach continued. At the same time, z pinches, used since the early 1970s to evaluate the response of materials to keV X rays, were considered as an alternative to drive ICF capsules. The use of z pinches for ICF was discontinued in 1984 because of budget cuts and the belief that ions offered a route to the standoff requirement for energy applications. Now, in 1998, because of budget limitations and the 1995 discovery that the soft x-ray power achievable in a z-pinch implosion can be greatly enhanced, the ion approach has been suspended, and a new facility, X-1, proposed to achieve high yield in the laboratory with z pinches. In this paper the authors review the research paths that led to these changes, describe the present status of z pinches, and predict what the future holds. Although nobody can predict the future, the past 30 years have taught us some lessons that can be applied to the next 30 years. The paper concludes with some of these lessons learned.

  7. The upgraded rf system for the AGS and high intensity proton beams

    SciTech Connect

    Brennan, J.M.

    1995-05-01

    The AGS has been upgraded over the past three years to produce a record beam intensity of 6 {times} 10{sup 13} protons per pulse for the fixed-target physics program. The major elements of the upgrade are: the new 1.5 GeV Booster synchrotron, the main magnet power supply, a high frequency longitudinal dilution cavity, a feedback damper for transverse instabilities, a fast gamma transition jump system, and a new high-power rf system. The new rf system and its role in achieving the high intensity goal are the subjects of this report. The rf system is heavily beam loaded, with 7 Amps of rf current in the beam and a peak power of 0.75 MW delivered to the beam by ten cavities. As an example of the scale of beam loading, at one point in the acceleration cycle the cavities are operated at 1.5 kV/gap; whereas, were it not for the new power amplifiers, the beam-induced voltage on the cavities would be over 25 kV/gap. The upgraded rf system, comprising: new power amplifiers, wide band rf feedback, improved cavities, and new low-level beam control electronics, is described. Results of measurements with beam, which characterize the system`s performance, are presented. A typical high intensity acceleration cycle is described with emphasis on the key challenges of beam loading.

  8. Start-to-end simulation with rare isotope beam for post accelerator of the RAON accelerator

    NASA Astrophysics Data System (ADS)

    Jin, Hyunchang; Jang, Ji-Ho

    2016-09-01

    The RAON accelerator for the Rare Isotope Science Project (RISP) has been developed to create and accelerate various kinds of stable heavy ion beams and rare isotope beams for a wide range of science applications. In the RAON accelerator, the rare isotope beams generated by the Isotope Separation On-Line (ISOL) system will be transported through the post accelerator, namely, from the post Low Energy Beam Transport (LEBT) system and the post Radio Frequency Quadrupole (RFQ) to the superconducting linac (SCL3). The accelerated beams will be put to use in the low energy experimental hall or accelerated again by the superconducting linac (SCL2) in order to be used in the high energy experimental hall. In this paper, we will describe the results of the start-toend simulations with the rare isotope beams generated by the ISOL system in the post accelerator of the RAON accelerator. In addition, the error analysis and correction at the superconducting linac SCL3 will be presented.

  9. The ADRIA project for high intensity radioactive beams production

    SciTech Connect

    Bisoffi, G.; Cavenago, M.; Dainelli, A.; Facco, A.; Fortuna, G.; Lombardi, A.; Moisio, M.F.; Pisent, A.; Spolaore, P.; Tiveron, B. ); Ruggiero, A.G. ); Tecchio, L. Istituto Nazionale di Fisica Nucleare, Turin )

    1992-01-01

    A proposal of an accelerator complex (ADRIA) for the Laboratori Nazionali di Legnaro (LNL) is described in this report. The main components of the complex are a Heavy Ion Injection system and two rings, a Booster and a Decelerator, both with a maximum rigidity of 22.25 Tm, connected by a Transfer Line where exotic proposal has two main goals consisting in the isotopes are produced and selected. The proposal has two main goals consisting in the acceleration of stable ion species up to kinetic energies of the order of few GeV/u, at a repetition rate of 10 Hz with intensities of about 10[sup 12] ions per second, for fixed target experiments in nuclear physics and for the production of fully stripped radioactive beams, using particle fragmentation method for nuclear spectroscopy experiments. Fragments are accumulated in the Decelerator, with intensities 10[sup 8] [divided by] 10[sup 9] ions/s, cooled and delivered at the production energies or decelerated down to energies of few MeV/u, in proximity of the Coulomb barrier.

  10. The ADRIA project for high intensity radioactive beams production

    SciTech Connect

    Bisoffi, G.; Cavenago, M.; Dainelli, A.; Facco, A.; Fortuna, G.; Lombardi, A.; Moisio, M.F.; Pisent, A.; Spolaore, P.; Tiveron, B.; Ruggiero, A.G.; Tecchio, L. |

    1992-12-31

    A proposal of an accelerator complex (ADRIA) for the Laboratori Nazionali di Legnaro (LNL) is described in this report. The main components of the complex are a Heavy Ion Injection system and two rings, a Booster and a Decelerator, both with a maximum rigidity of 22.25 Tm, connected by a Transfer Line where exotic proposal has two main goals consisting in the isotopes are produced and selected. The proposal has two main goals consisting in the acceleration of stable ion species up to kinetic energies of the order of few GeV/u, at a repetition rate of 10 Hz with intensities of about 10{sup 12} ions per second, for fixed target experiments in nuclear physics and for the production of fully stripped radioactive beams, using particle fragmentation method for nuclear spectroscopy experiments. Fragments are accumulated in the Decelerator, with intensities 10{sup 8} {divided_by} 10{sup 9} ions/s, cooled and delivered at the production energies or decelerated down to energies of few MeV/u, in proximity of the Coulomb barrier.

  11. Electrostatic quadrupole focused particle accelerating assembly with laminar flow beam

    DOEpatents

    Maschke, Alfred W.

    1985-01-01

    A charged particle accelerating assembly provided with a predetermined ratio of parametric structural characteristics and with related operating voltages applied to each of its linearly spaced focusing and accelerating quadrupoles, thereby to maintain a particle beam traversing the electrostatic fields of the quadrupoles in the assembly in an essentially laminar flow throughout the assembly.

  12. 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.

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

    SciTech Connect

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

    2016-02-15

    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.

  14. Scintillator diagnostics for the detection of laser accelerated ion beams

    NASA Astrophysics Data System (ADS)

    Cook, N.; Tresca, O.; Lefferts, R.

    2014-09-01

    Laser plasma interaction with ultraintense pulses present exciting schemes for accelerating ions. One of the advantages conferred by using a gaseous laser and target is the potential for a fast (several Hz) repetition rate. This requires diagnostics which are not only suited for a single shot configuration, but also for repeated use. We consider several scintillators as candidates for an imaging diagnostic for protons accelerated to MeV energies by a CO2 laser focused on a gas jet target. We have measured the response of chromium-doped alumina (chromox) and polyvinyl toluene (PVT) screens to protons in the 2-8 MeV range. We have calibrated the luminescent yield in terms of photons emitted per incident proton for each scintillator. We also discuss how light scattering and material properties affect detector resolution. Furthermore, we consider material damage and the presence of an afterglow under intense exposures. Our analysis reveals a near order of magnitude greater yield from chromox in response to proton beams at > 8 MeV energies, while scattering effects favor PVT-based scintillators at lower energies.

  15. High transformer ratio drive beams for wakefield accelerator studies

    SciTech Connect

    England, R. J.; Ng, C.-K.; Frederico, J.; Hogan, M. J.; Litos, M.; Muggli, P.; Joshi, C.; An, W.; Andonian, G.; Mori, W.; Lu, W.

    2012-12-21

    For wakefield based acceleration schemes, use of an asymmetric (or linearly ramped) drive bunch current profile has been predicted to enhance the transformer ratio and generate large accelerating wakes. We discuss plans and initial results for producing such bunches using the 20 to 23 GeV electron beam at the FACET facility at SLAC National Accelerator Laboratory and sending them through plasmas and dielectric tubes to generate transformer ratios greater than 2 (the limit for symmetric bunches). The scheme proposed utilizes the final FACET chicane compressor and transverse collimation to shape the longitudinal phase space of the beam.

  16. On the re-acceleration of bunched beams

    SciTech Connect

    Whittum, D.H.; Sessler, A.M.; Craig, G.D.; DeFord, J.F.; Yu, David U.L.

    1989-02-01

    We examine the re-acceleration of a bunched beam through a linear induction accelerator (LIA) cavity, with attention to the energy lost through coupling to the TM modes of the structure. We find that the energy lost at 1 kA peak current is a small fraction of the boost which the LIA is designed to impart. We discuss implications for a Relativistic Klystron or Free Electron Laser (FEL) version of the Two-Beam Accelerator (TBA). 18 refs., 5 figs., 1 tab.

  17. Economics of electron beam accelerator facilities: Concept vs actual

    NASA Astrophysics Data System (ADS)

    Minbiole, Paul R.

    1995-02-01

    Electron beam accelerator facilities continue to demonstrate their ability to "add value" to a wide range of industrial products. The power, energy, and reliability of commercially available accelerators have increased steadily over the past several decades. The high throughput potential of modern electron beam facilities, together with the broad spectrum of commercial applications, result in the concept that an electron beam facility is an effective tool for adding economic value to industrial products. However, the high capital costs of such a facility (including hidden costs), together with practical limitations to high throughput (including several layers of inefficiencies), result in profit-and-loss economics which are more tenuous than expected after first analysis.

  18. Beam Dynamics Design and Simulation in Ion Linear Accelerators (

    SciTech Connect

    Ostroumov, Peter N.; Asseev, Vladislav N.; Mustapha, and Brahim

    2006-08-01

    Orginally, the ray tracing code TRACK has been developed to fulfill the many special requirements for the Rare Isotope Accelerator Facility known as RIA. Since no available beam-dynamics code met all the necessary requirements, modifications to the code TRACK were introduced to allow end-to-end (from the ion souce to the production target) simulations of the RIA machine, TRACK is a general beam-dynamics code and can be applied for the design, commissioning and operation of modern ion linear accelerators and beam transport systems.

  19. Fermilab main injector: High intensity operation and beam loss control

    NASA Astrophysics Data System (ADS)

    Brown, Bruce C.; Adamson, Philip; Capista, David; Chou, Weiren; Kourbanis, Ioanis; Morris, Denton K.; Seiya, Kiyomi; Wu, Guan Hong; Yang, Ming-Jen

    2013-07-01

    From 2005 through 2012, the Fermilab Main Injector provided intense beams of 120 GeV protons to produce neutrino beams and antiprotons. Hardware improvements in conjunction with improved diagnostics allowed the system to reach sustained operation at 400 kW beam power. Transmission was very high except for beam lost at or near the 8 GeV injection energy where 95% beam transmission results in about 1.5 kW of beam loss. By minimizing and localizing loss, residual radiation levels fell while beam power was doubled. Lost beam was directed to either the collimation system or to the beam abort. Critical apertures were increased while improved instrumentation allowed optimal use of available apertures. We will summarize the improvements required to achieve high intensity, the impact of various loss control tools and the status and trends in residual radiation in the Main Injector.

  20. Beam loss studies in high-intensity heavy-ion linacs

    NASA Astrophysics Data System (ADS)

    Ostroumov, P. N.; Aseev, V. N.; Mustapha, B.

    2004-09-01

    The proposed Rare Isotope Accelerator (RIA) Facility, an innovative exotic-beam facility for the production of high-quality beams of short-lived isotopes, consists of a fully superconducting 1.4GV driver linac and a 140MV postaccelerator. To produce sufficient intensities of secondary beams the driver linac will provide 400kW primary beams of any ion from hydrogen to uranium. Because of the high intensity of the primary beams the beam losses must be minimized to avoid radioactivation of the accelerator equipment. To keep the power deposited by the particles lost on the accelerator structures below 1 W/m, the relative beam losses per unit length should be less than 10-5, especially along the high-energy section of the linac. A new beam dynamics simulation code TRACK has been developed and used for beam loss studies in the RIA driver linac. In the TRACK code, ions are tracked through the three-dimensional electromagnetic fields of every element of the linac starting from the electron cyclotron resonance (ECR) ion source to the production target. The simulation starts with a multicomponent dc ion beam extracted from the ECR. The space charge forces are included in the simulations. They are especially important in the front end of the driver linac. Beam losses are studied by tracking a large number of particles (up to 106) through the whole linac considering all sources of error such us element misalignments, rf field errors, and stripper thickness fluctuations. For each configuration of the linac, multiple sets of error values have been randomly generated and used in the calculations. The results are then combined to calculate important beam parameters, estimate beam losses, and characterize the corresponding linac configuration. To track a large number of particles for a comprehensive number of error sets (up to 500), the code TRACK was parallelized and run on the Jazz computer cluster at ANL.

  1. The IFMIF-EVEDA accelerator beam dump design

    NASA Astrophysics Data System (ADS)

    Iglesias, D.; Arranz, F.; Arroyo, J. M.; Barrera, G.; Brañas, B.; Casal, N.; García, M.; López, D.; Martínez, J. I.; Mayoral, A.; Ogando, F.; Parro, M.; Oliver, C.; Rapisarda, D.; Sanz, J.; Sauvan, P.; Ibarra, A.

    2011-10-01

    The IFMIF-EVEDA accelerator will be a 9 MeV, 125 mA cw deuteron accelerator prototype for verifying the validity of the 40 MeV accelerator design for IFMIF. A beam dump designed for maximum power of 1.12 MW will be used to stop the beam at the accelerator exit. The conceptual design for the IFMIF-EVEDA accelerator beam dump is based on a conical beam stop made of OFE copper. The cooling system uses an axial high velocity flow of water pressurized up to 3.4 × 10 5 Pa to avoid boiling. The design has been shown to be compliant with ASME mechanical design rules under nominal full power conditions. A sensitivity analysis has been performed to take into account the possible margin on the beam properties at the beam dump entrance. This analysis together with the study of the maintenance issues and the mounting and dismounting operations has led to the complete design definition.

  2. Transformer ratio improvement for beam based plasma accelerators

    SciTech Connect

    O'Shea, Brendan; Rosenzweig, James; Barber, Samuel; Fukasawa, Atsushi; Williams, Oliver; Muggli, Patric; Yakimenko, Vitaly; Kusche, Karl

    2012-12-21

    Increasing the transformer ratio of wakefield accelerating systems improves the viability of present novel accelerating schemes. The use of asymmetric bunches to improve the transformer ratio of beam based plasma systems has been proposed for some time[1, 2] but suffered from lack appropriate beam creation systems. Recently these impediments have been overcome [3, 4] and the ability now exists to create bunches with current profiles shaped to overcome the symmetric beam limit of R {<=} 2. We present here work towards experiments designed to measure the transformer ratio of such beams, including theoretical models and simulations using VORPAL (a 3D capable PIC code) [5]. Specifically we discuss projects to be carried out in the quasi-nonlinear regime [6] at the UCLA Neptune Laboratory and the Accelerator Test Facility at Brookhaven National Lab.

  3. Accelerator systems and instrumentation for the NuMI neutrino beam

    NASA Astrophysics Data System (ADS)

    Zwaska, Robert Miles

    The Neutrinos at the Main Injector (NuMI) neutrino beam facility began operating at the Fermi National Accelerator Laboratory in 2005. NuMI produces an intense, muon-neutrino beam to a number of experiments. Fore most of these experiments is MINOS---the Main Injector Neutrino Oscillation Search---that uses two neutrino detectors in the beam, one at Fermilab and one in northern Minnesota, to investigate the phenomenon of neutrino oscillations. NuMI is a conventional, horn-focused neutrino beam. It is designed to accept a 400 kW, 120 GeV proton beam from the Fermilab Main Injector accelerator. The proton beam is steered onto a target, producing a secondary beam of mesons which are focused into a long evacuated volume where they decay to muons and neutrinos. Pulsed toroidal magnets (horns) focus an adjustable meson momentum range. Design of the beamline and its components is challenged by the 400 kW average proton beam power. To achieve such high proton power, the Fermilab Main Injector (MI) must store and accelerate ˜ 4x1013 protons per acceleration cycle. This requires the MI to be loaded with 6 or more batches of protons from the 8 GeV Booster accelerator. Such multiple-batch injection involves a synchronization of the two machines not previously required by the Fermilab accelerators. In this dissertation, we investigate timing errors that can arise between the two accelerators, and a feedback system which enables multiple Booster transfers into the Main Injector without significant loss of beam. Using this method of synchronous transfer, the Main Injector has delivered as many as 3x1013 protons per pulse to the NuMI beam. The instrumentation to assess the quality of the neutrino beam includes arrays of radiation-tolerant ionization chambers downstream of the decay volume. These arrays detect the remnant hadrons and tertiary muons produced with the neutrinos. This thesis discusses measurements using the arrays, including diagnostics of potential beam errors and

  4. Final Report for "Modeling Electron Cloud Diagnostics for High-Intensity Proton Accelerators"

    SciTech Connect

    Seth A Veitzer

    2009-09-25

    Electron clouds in accelerators such as the ILC degrade beam quality and limit operating efficiency. The need to mitigate electron clouds has a direct impact on the design and operation of these accelerators, translating into increased cost and reduced performance. Diagnostic techniques for measuring electron clouds in accelerating cavities are needed to provide an assessment of electron cloud evolution and mitigation. Accurate numerical modeling of these diagnostics is needed to validate the experimental techniques. In this Phase I, we developed detailed numerical models of microwave propagation through electron clouds in accelerating cavities with geometries relevant to existing and future high-intensity proton accelerators such as Project X and the ILC. Our numerical techniques and simulation results from the Phase I showed that there was a high probability of success in measuring both the evolution of electron clouds and the effects of non-uniform electron density distributions in Phase II.

  5. A laser-plasma accelerator producing monoenergetic electron beams.

    PubMed

    Faure, J; Glinec, Y; Pukhov, A; Kiselev, S; Gordienko, S; Lefebvre, E; Rousseau, J-P; Burgy, F; Malka, V

    2004-09-30

    Particle accelerators are used in a wide variety of fields, ranging from medicine and biology to high-energy physics. The accelerating fields in conventional accelerators are limited to a few tens of MeV m(-1), owing to material breakdown at the walls of the structure. Thus, the production of energetic particle beams currently requires large-scale accelerators and expensive infrastructures. Laser-plasma accelerators have been proposed as a next generation of compact accelerators because of the huge electric fields they can sustain (>100 GeV m(-1)). However, it has been difficult to use them efficiently for applications because they have produced poor-quality particle beams with large energy spreads, owing to a randomization of electrons in phase space. Here we demonstrate that this randomization can be suppressed and that the quality of the electron beams can be dramatically enhanced. Within a length of 3 mm, the laser drives a plasma bubble that traps and accelerates plasma electrons. The resulting electron beam is extremely collimated and quasi-monoenergetic, with a high charge of 0.5 nC at 170 MeV.

  6. Challenges in plasma and laser wakefield accelerated beams diagnostic

    NASA Astrophysics Data System (ADS)

    Cianchi, A.; Anania, M. P.; Bellaveglia, M.; Castellano, M.; Chiadroni, E.; Ferrario, M.; Gatti, G.; Marchetti, B.; Mostacci, A.; Pompili, R.; Ronsivalle, C.; Rossi, A. R.; Serafini, L.

    2013-08-01

    The new frontier in the particle beam accelerator is the so called plasma acceleration. Using the strong electric field inside a plasma it is possible to achieve accelerating gradients in the order of magnitude larger with respect to the actual technologies. Different schemes have been proposed and several already tested, producing beams of energy of several GeV. Mainly two approaches are followed: either the beam is directly produced by the interaction of a TW/PW class laser with a gas jet or a preexisting particle beam is accelerated in a plasma channel. In both cases a precise determination of the emerging beam parameters is mandatory for the fine tuning of the devices. The measurement of these parameters, in particular the emittance, is not trivial, mainly due to the large energy spread and to the tight focusing of these beams or to the background noise produced in the plasma channel. We show the problems related to the diagnostic of this kind of beams and the proposed or already realized solutions.

  7. High intensity electron cyclotron resonance proton source for low energy high intensity proton accelerator.

    PubMed

    Roychowdhury, P; Chakravarthy, D P

    2009-12-01

    Electron cyclotron resonance (ECR) proton source at 50 keV, 50 mA has been designed, developed, and commissioned for the low energy high intensity proton accelerator (LEHIPA). Plasma characterization of this source has been performed. ECR plasma was generated with 400-1100 W of microwave power at 2.45 GHz, with hydrogen as working gas. Microwave was fed in the plasma chamber through quartz window. Plasma density and temperature was studied under various operating conditions, such as microwave power and gas pressure. Langmuir probe was used for plasma characterization using current voltage variation. The typical hydrogen plasma density and electron temperature measured were 7x10(11) cm(-3) and 6 eV, respectively. The total ion beam current of 42 mA was extracted, with three-electrode extraction geometry, at 40 keV of beam energy. The extracted ion current was studied as a function of microwave power and gas pressure. Depending on source pressure and discharge power, more than 30% total gas efficiency was achieved. The optimization of the source is under progress to meet the requirement of long time operation. The source will be used as an injector for continuous wave radio frequency quadrupole, a part of 20 MeV LEHIPA. The required rms normalized emittance of this source is less than 0.2 pi mm mrad. The simulated value of normalized emittance is well within this limit and will be measured shortly. This paper presents the study of plasma parameters, first beam results, and the status of ECR proton source.

  8. High intensity electron cyclotron resonance proton source for low energy high intensity proton accelerator

    SciTech Connect

    Roychowdhury, P.; Chakravarthy, D. P.

    2009-12-15

    Electron cyclotron resonance (ECR) proton source at 50 keV, 50 mA has been designed, developed, and commissioned for the low energy high intensity proton accelerator (LEHIPA). Plasma characterization of this source has been performed. ECR plasma was generated with 400-1100 W of microwave power at 2.45 GHz, with hydrogen as working gas. Microwave was fed in the plasma chamber through quartz window. Plasma density and temperature was studied under various operating conditions, such as microwave power and gas pressure. Langmuir probe was used for plasma characterization using current voltage variation. The typical hydrogen plasma density and electron temperature measured were 7x10{sup 11} cm{sup -3} and 6 eV, respectively. The total ion beam current of 42 mA was extracted, with three-electrode extraction geometry, at 40 keV of beam energy. The extracted ion current was studied as a function of microwave power and gas pressure. Depending on source pressure and discharge power, more than 30% total gas efficiency was achieved. The optimization of the source is under progress to meet the requirement of long time operation. The source will be used as an injector for continuous wave radio frequency quadrupole, a part of 20 MeV LEHIPA. The required rms normalized emittance of this source is less than 0.2 {pi} mm mrad. The simulated value of normalized emittance is well within this limit and will be measured shortly. This paper presents the study of plasma parameters, first beam results, and the status of ECR proton source.

  9. An Undulator-Based Laser Wakefield Accelerator Electron Beam Diagnostic

    NASA Astrophysics Data System (ADS)

    Bakeman, Michael S.

    Currently particle accelerators such as the Large Hadron Collider use RF cavities with a maximum field gradient of 50-100 MV/m to accelerate particles over long distances. A new type of plasma based accelerator called a Laser Plasma Accelerator (LPA) is being investigated at the LOASIS group at Lawrence Berkeley National Laboratory which can sustain field gradients of 10-100 GV/m. This new type of accelerator offers the potential to create compact high energy accelerators and light sources. In order to investigate the feasibility of producing a compact light source an undulator-based electron beam diagnostic for use on the LOASIS LPA has been built and calibrated. This diagnostic relies on the principal that the spectral analysis of synchrotron radiation from an undulator can reveal properties of the electron beam such as emittance, energy and energy spread. The effects of electron beam energy spread upon the harmonics of undulator produced synchrotron radiation were derived from the equations of motion of the beam and numerically simulated. The diagnostic consists of quadrupole focusing magnets to collimate the electron beam, a 1.5 m long undulator to produce the synchrotron radiation, and a high resolution high gain XUV spectrometer to analyze the radiation. The undulator was aligned and tuned in order to maximize the flux of synchrotron radiation produced. The spectrometer was calibrated at the Advanced Light Source, with the results showing the ability to measure electron beam energy spreads at resolutions as low as 0.1% rms, a major improvement over conventional magnetic spectrometers. Numerical simulations show the ability to measure energy spreads on realistic LPA produced electron beams as well as the improvements in measurements made with the quadrupole magnets. Experimentally the quadrupoles were shown to stabilize and focus the electron beams at specific energies for their insertion into the undulator, with the eventual hope of producing an all optical

  10. Higher order mode beams mitigate halos in high intensity proton linacs

    NASA Astrophysics Data System (ADS)

    Pathak, Abhishek; Krishnagopal, Srinivas

    2017-01-01

    High intensity proton linacs (HIPLs) for applications such as Accelerator Driven Reactor Systems (ADRS) have serious beam dynamics issues related to beam halo formation. This can lead to particle loss and radioactivation of the surroundings which consequently limit the beam current. Beam halos are largely driven by the nonlinear space-charge force of the beam, which depends strongly on the beam distribution and also on the initial beam mismatch. We propose here the use of a higher order mode beam (HOMB), that has a weaker nonlinear force, to mitigate beam halos. We first show how the nonlinear space-charge force can itself be exploited in the presence of nonlinear solenoid fields, to produce a HOMB in the low energy beam transport (LEBT) line. We then study the transport of such a beam through a radio frequency quadrupole (RFQ), and show that the HOMB has a significant advantage in terms of emittance blow-up, halo formation and beam loss, over a Gaussian beam, even with a finite initial mismatch. For example, for the transport of a 30 mA beam through the RFQ, with an initial beam mismatch of 45%, the Gaussian beam sees an emittance blow-up of 125%, while the HOMB sees a blow-up of only 35% (relative to the initial emittance of 0.2 π mm -mrad ). Similarly, the beam halo parameter and beam loss are 0.95 and 25% respectively for a Gaussian beam, but only 0.35 and 15% for a HOMB. The beam dynamics of the HOMB agrees quite well with the particle-core model, because of the more linear space-charge force, while for the Gaussian beam there are additional particle loss mechanisms arising from nonlinear resonances. Therefore, the HOMB suppresses emittance blow-up and halo formation, and can make high current ADRS systems more viable.

  11. Beam diagnostics at high-intensity storage rings

    SciTech Connect

    Plum, M. )

    1994-10-10

    Beam diagnostics at high-intensity facilities feature their own special set of problems and characteristics, issues peculiar to high-intensity storage rings include beam loss, beam halos, extraction efficiency, beam in the gap, clearing electrodes, and beam-profile measurement. The Los Alamos Proton Storage Ring (PSR) is a nice example of a high-intensity storage ring. I will discuss in some detail three diagnostic systems currently in use at the PSR: the beam-loss-monitor system, the electron-clearing system, and the beam-in-the-gap monitor. Much of our discussion is inspired by the problems we have encountered and the useful things we have learned while commissioning and developing the PSR. Another inspiration is our work on the next-generation neutron-spallation source, also known as the National Center for Neutron Research (NCNR).

  12. Beam diagnostics at high-intensity storage rings

    SciTech Connect

    Plum, M.

    1993-11-01

    Beam diagnostics at high-intensity facilities feature their own special set of problems and characteristics. Issues peculiar to high-intensity storage rings include beam loss, beam halos, extraction efficiency, beam in the gap, clearing electrodes, and beam-profile measurement. The Los Alamos Proton Storage Ring (PSR) is a nice example of a high-intensity storage ring. The author discusses in some detail three diagnostic systems currently in use at the PSR: the beam-loss-monitor system, the electron-clearing system, and the beam-in-the-gap monitor. Much of the discussion is inspired by the problems that were encountered and the useful things learned while commissioning and developing the PSR. Another inspiration is the work on the next-generation neutron-spallation source, also known as the National Center for Neutron Research (NCNR).

  13. Michigan state upgrade to produce intense radioactive ion beams by fragmentation technique

    SciTech Connect

    Lubkin, G.B.

    1997-05-01

    This article describes the planned upgrading of accelerator facilities to produce intense radioactive ion beams, by a fragmentation technique, for experimental simulation of nucleosynthesis in novas and supernovas. (AIP) {ital 1997 American Institute of Physics.} {copyright} {ital 1997} {ital American Institute of Physics}

  14. Intrinsic beam emittance of laser-accelerated electrons measured by x-ray spectroscopic imaging

    DOE PAGES

    Golovin, G.; Banerjee, S.; Liu, C.; ...

    2016-04-19

    Here, the recent combination of ultra-intense lasers and laser-accelerated electron beams is enabling the development of a new generation of compact x-ray light sources, the coherence of which depends directly on electron beam emittance. Although the emittance of accelerated electron beams can be low, it can grow due to the effects of space charge during free-space propagation. Direct experimental measurement of this important property is complicated by micron-scale beam sizes, and the presence of intense fields at the location where space charge acts. Reported here is a novel, non-destructive, single-shot method that overcame this problem. It employed an intense lasermore » probe pulse, and spectroscopic imaging of the inverse-Compton scattered x-rays, allowing measurement of an ultra-low value for the normalized transverse emittance, 0.15 (±0.06) π mm mrad, as well as study of its subsequent growth upon exiting the accelerator. The technique and results are critical for designing multi-stage laser-wakefield accelerators, and generating high-brightness, spatially coherent x-rays.« less

  15. Intrinsic beam emittance of laser-accelerated electrons measured by x-ray spectroscopic imaging

    SciTech Connect

    Golovin, G.; Banerjee, S.; Liu, C.; Chen, S.; Zhang, J.; Zhao, B.; Zhang, P.; Veale, M.; Wilson, M.; Seller, P.; Umstadter, D.

    2016-04-19

    Here, the recent combination of ultra-intense lasers and laser-accelerated electron beams is enabling the development of a new generation of compact x-ray light sources, the coherence of which depends directly on electron beam emittance. Although the emittance of accelerated electron beams can be low, it can grow due to the effects of space charge during free-space propagation. Direct experimental measurement of this important property is complicated by micron-scale beam sizes, and the presence of intense fields at the location where space charge acts. Reported here is a novel, non-destructive, single-shot method that overcame this problem. It employed an intense laser probe pulse, and spectroscopic imaging of the inverse-Compton scattered x-rays, allowing measurement of an ultra-low value for the normalized transverse emittance, 0.15 (±0.06) π mm mrad, as well as study of its subsequent growth upon exiting the accelerator. The technique and results are critical for designing multi-stage laser-wakefield accelerators, and generating high-brightness, spatially coherent x-rays.

  16. Intrinsic beam emittance of laser-accelerated electrons measured by x-ray spectroscopic imaging.

    PubMed

    Golovin, G; Banerjee, S; Liu, C; Chen, S; Zhang, J; Zhao, B; Zhang, P; Veale, M; Wilson, M; Seller, P; Umstadter, D

    2016-04-19

    The recent combination of ultra-intense lasers and laser-accelerated electron beams is enabling the development of a new generation of compact x-ray light sources, the coherence of which depends directly on electron beam emittance. Although the emittance of accelerated electron beams can be low, it can grow due to the effects of space charge during free-space propagation. Direct experimental measurement of this important property is complicated by micron-scale beam sizes, and the presence of intense fields at the location where space charge acts. Reported here is a novel, non-destructive, single-shot method that overcame this problem. It employed an intense laser probe pulse, and spectroscopic imaging of the inverse-Compton scattered x-rays, allowing measurement of an ultra-low value for the normalized transverse emittance, 0.15 (±0.06) π mm mrad, as well as study of its subsequent growth upon exiting the accelerator. The technique and results are critical for designing multi-stage laser-wakefield accelerators, and generating high-brightness, spatially coherent x-rays.

  17. Intrinsic beam emittance of laser-accelerated electrons measured by x-ray spectroscopic imaging

    PubMed Central

    Golovin, G.; Banerjee, S.; Liu, C.; Chen, S.; Zhang, J.; Zhao, B.; Zhang, P.; Veale, M.; Wilson, M.; Seller, P.; Umstadter, D.

    2016-01-01

    The recent combination of ultra-intense lasers and laser-accelerated electron beams is enabling the development of a new generation of compact x-ray light sources, the coherence of which depends directly on electron beam emittance. Although the emittance of accelerated electron beams can be low, it can grow due to the effects of space charge during free-space propagation. Direct experimental measurement of this important property is complicated by micron-scale beam sizes, and the presence of intense fields at the location where space charge acts. Reported here is a novel, non-destructive, single-shot method that overcame this problem. It employed an intense laser probe pulse, and spectroscopic imaging of the inverse-Compton scattered x-rays, allowing measurement of an ultra-low value for the normalized transverse emittance, 0.15 (±0.06) π mm mrad, as well as study of its subsequent growth upon exiting the accelerator. The technique and results are critical for designing multi-stage laser-wakefield accelerators, and generating high-brightness, spatially coherent x-rays. PMID:27090440

  18. Emittance growth of an nonequilibrium intense electron beam in a transport channel with discrete focusing

    SciTech Connect

    Carlsten, B.E.

    1997-02-01

    The author analyzes the emittance growth mechanisms for a continuous, intense electron beam in a focusing transport channel, over distances short enough that the beam does not reach equilibrium. The emittance grows from the effect of nonlinear forces arising from (1) current density nonuniformities, (2) energy variations leading to nonlinearities in the space-charge force even if the current density is uniform, (3) axial variations in the radial vector potential, (4) an axial velocity shear along the beam, and (5) an energy redistribution of the beam as the beam compresses or expands. The emittance growth is studied analytically and numerically for the cases of balanced flow, tight focusing, and slight beam scalloping, and is additionally studied numerically for an existing 6-MeV induction linear accelerator. Rules for minimizing the emittance along a beamline are established. Some emittance growth will always occur, both from current density nonuniformities that arise along the transport and from beam radius changes along the transport.

  19. The SPIRAL2 Project and experiments with high-intensity rare isotope beams

    NASA Astrophysics Data System (ADS)

    Lewitowicz, Marek

    2011-09-01

    The SPIRAL2 facility at GANIL, which entered recently in the construction phase consists of a new superconducting linear accelerator delivering high intensity, up to 40 MeV, light (proton, deuteron, 3-4He) beams as well as a large variety of 14.5 MeV/nucleon heavy-ion beams and the associated Rare Isotope Beam facility. Using a dedicated converter and the 5 mA deuteron beam, a neutron-induced fission rate is expected to approach 1014 fissions/s for high-density UCx target. The energies of accelerated RIBs will reach 5-10 MeV/nucleon for fission fragments and 20 MeV/nucleon for neutron-deficient nuclei. The physics case of SPIRAL2 is based on the use of high intensity RIBs & stable-ion beams and on possibilities to perform several experiments simultaneously. A use of these beams at a new low-energy ISOL facility (DESIR) and their acceleration to several MeV/nucleon will open new possibilities in nuclear structure physics, nuclear astrophysics and reaction dynamics studies. The high intensities (up to 1011pps) and a high cost of RIBs impose a use of the most efficient and innovative detection systems like ACTAR, FAZIA, GASPARD, HELIOS, NEDA, PARIS and a new separator/spectrometer S3.

  20. Long-pulse beam acceleration of MeV-class H(-) ion beams for ITER NB accelerator.

    PubMed

    Umeda, N; Kashiwagi, M; Taniguchi, M; Tobari, H; Watanabe, K; Dairaku, M; Yamanaka, H; Inoue, T; Kojima, A; Hanada, M

    2014-02-01

    In order to realize neutral beam systems in International Thermonuclear Experimental Reactor whose target is to produce a 1 MeV, 200 A/m(2) during 3600 s D(-) ion beam, the electrostatic five-stages negative ion accelerator so-called "MeV accelerator" has been developed at Japan Atomic Energy Agency. To extend pulse length, heat load of the acceleration grids was reduced by controlling the ion beam trajectory. Namely, the beam deflection due to the residual magnetic field of filter magnet was suppressed with the newly developed extractor with a 0.5 mm off-set aperture displacement. The new extractor improved the deflection angle from 6 mrad to 1 mrad, resulting in the reduction of direct interception of negative ions from 23% to 15% of the total acceleration power, respectively. As a result, the pulse length of 130 A/m(2), 881 keV H(-) ion beam has been successfully extended from a previous value of 0.4 s to 8.7 s. This is the first long pulse negative ion beam acceleration over 100 MW/m(2).

  1. Accelerator Based Neutron Beams for Neutron Capture Therapy

    SciTech Connect

    Yanch, Jacquelyn C.

    2003-04-11

    The DOE-funded accelerator BNCT program at the Massachusetts Institute of Technology has resulted in the only operating accelerator-based epithermal neutron beam facility capable of generating significant dose rates in the world. With five separate beamlines and two different epithermal neutron beam assemblies installed, we are currently capable of treating patients with rheumatoid arthritis in less than 15 minutes (knee joints) or 4 minutes (finger joints) or irradiating patients with shallow brain tumors to a healthy tissue dose of 12.6 Gy in 3.6 hours. The accelerator, designed by Newton scientific Incorporated, is located in dedicated laboratory space that MIT renovated specifically for this project. The Laboratory for Accelerator Beam Applications consists of an accelerator room, a control room, a shielded radiation vault, and additional laboratory space nearby. In addition to the design, construction and characterization of the tandem electrostatic accelerator, this program also resulted in other significant accomplishments. Assemblies for generating epithermal neutron beams were designed, constructed and experimentally evaluated using mixed-field dosimetry techniques. Strategies for target construction and target cooling were implemented and tested. We demonstrated that the method of submerged jet impingement using water as the coolant is capable of handling power densities of up to 6 x 10(sup 7) W/m(sup 2) with heat transfer coefficients of 10(sup 6)W/m(sup 2)-K. Experiments with the liquid metal gallium demonstrated its superiority compared with water with little effect on the neutronic properties of the epithermal beam. Monoenergetic proton beams generated using the accelerator were used to evaluate proton RBE as a function of LET and demonstrated a maximum RBE at approximately 30-40 keV/um, a finding consistent with results published by other researchers. We also developed an experimental approach to biological intercomparison of epithermal beams and

  2. Particle in cell simulation of laser-accelerated proton beams for radiation therapy.

    PubMed

    Fourkal, E; Shahine, B; Ding, M; Li, J S; Tajima, T; Ma, C M

    2002-12-01

    In this article we present the results of particle in cell (PIC) simulations of laser plasma interaction for proton acceleration for radiation therapy treatments. We show that under optimal interaction conditions protons can be accelerated up to relativistic energies of 300 MeV by a petawatt laser field. The proton acceleration is due to the dragging Coulomb force arising from charge separation induced by the ponderomotive pressure (light pressure) of high-intensity laser. The proton energy and phase space distribution functions obtained from the PIC simulations are used in the calculations of dose distributions using the GEANT Monte Carlo simulation code. Because of the broad energy and angular spectra of the protons, a compact particle selection and beam collimation system will be needed to generate small beams of polyenergetic protons for intensity modulated proton therapy.

  3. Electron Accelerators for Radioactive Ion Beams

    SciTech Connect

    Lia Merminga

    2007-10-10

    The summary of this paper is that to optimize the design of an electron drive, one must: (a) specify carefully the user requirements--beam energy, beam power, duty factor, and longitudinal and transverse emittance; (b) evaluate different machine options including capital cost, 10-year operating cost and delivery time. The author is convinced elegant solutions are available with existing technology. There are several design options and technology choices. Decisions will depend on system optimization, in-house infrastructure and expertise (e.g. cryogenics, SRF, lasers), synergy with other programs.

  4. Beam transport channels and beam injection and extraction systems of the NICA accelerator complex

    NASA Astrophysics Data System (ADS)

    Butenko, A. V.; Volkov, V. I.; Kolesnikov, S. Yu.; Meshkov, I. N.; Mikhaylov, V. A.; Rabtsun, S. V.; Sidorin, A. O.; Sidorov, A. I.; Topilin, N. D.; Trubnikov, G. V.; Tuzikov, A. V.; Fateev, A. A.; Shvetsov, V. S.

    2016-12-01

    A new accelerator complex is being constructed at the Joint Institute for Nuclear Research as a part of the Nuclotron-based Ion Collider fAcility (NICA) project. The goal is to conduct experiments with colliding ion beams (at the first stage of the project) and colliding polarized proton/deuteron beams (at the second stage). Transport beam channels and the systems of beam injection and extraction for synchrotrons and collider rings are an important connecting link for the whole accelerator facility. The design of the primary beam-transport channels and injection/extraction systems are presented. Special attention is paid to various aspects of dynamics of beams in their transfer between the NICA accelerators.

  5. High-quality electron beams from a helical inverse free-electron laser accelerator

    NASA Astrophysics Data System (ADS)

    Duris, J.; Musumeci, P.; Babzien, M.; Fedurin, M.; Kusche, K.; Li, R. K.; Moody, J.; Pogorelsky, I.; Polyanskiy, M.; Rosenzweig, J. B.; Sakai, Y.; Swinson, C.; Threlkeld, E.; Williams, O.; Yakimenko, V.

    2014-09-01

    Compact, table-top sized accelerators are key to improving access to high-quality beams for use in industry, medicine and academic research. Among laser-based accelerating schemes, the inverse free-electron laser (IFEL) enjoys unique advantages. By using an undulator magnetic field in combination with a laser, GeV m-1 gradients may be sustained over metre-scale distances using laser intensities several orders of magnitude less than those used in laser wake-field accelerators. Here we show for the first time the capture and high-gradient acceleration of monoenergetic electron beams from a helical IFEL. Using a modest intensity (~1013 W cm-2) laser pulse and strongly tapered 0.5 m long undulator, we demonstrate >100 MV m-1 accelerating gradient, >50 MeV energy gain and excellent output beam quality. Our results pave the way towards compact, tunable GeV IFEL accelerators for applications such as driving soft X-ray free-electron lasers and producing γ-rays by inverse Compton scattering.

  6. High-quality electron beams from a helical inverse free-electron laser accelerator.

    PubMed

    Duris, J; Musumeci, P; Babzien, M; Fedurin, M; Kusche, K; Li, R K; Moody, J; Pogorelsky, I; Polyanskiy, M; Rosenzweig, J B; Sakai, Y; Swinson, C; Threlkeld, E; Williams, O; Yakimenko, V

    2014-09-15

    Compact, table-top sized accelerators are key to improving access to high-quality beams for use in industry, medicine and academic research. Among laser-based accelerating schemes, the inverse free-electron laser (IFEL) enjoys unique advantages. By using an undulator magnetic field in combination with a laser, GeV m(-1) gradients may be sustained over metre-scale distances using laser intensities several orders of magnitude less than those used in laser wake-field accelerators. Here we show for the first time the capture and high-gradient acceleration of monoenergetic electron beams from a helical IFEL. Using a modest intensity (~10(13) W cm(-2)) laser pulse and strongly tapered 0.5 m long undulator, we demonstrate >100 MV m(-1) accelerating gradient, >50 MeV energy gain and excellent output beam quality. Our results pave the way towards compact, tunable GeV IFEL accelerators for applications such as driving soft X-ray free-electron lasers and producing γ-rays by inverse Compton scattering.

  7. Beam-driven acceleration in ultra-dense plasma media

    SciTech Connect

    Shin, Young-Min

    2014-09-15

    Accelerating parameters of beam-driven wakefield acceleration in an extremely dense plasma column has been analyzed with the dynamic framed particle-in-cell plasma simulator, and compared with analytic calculations. In the model, a witness beam undergoes a TeV/m scale alternating potential gradient excited by a micro-bunched drive beam in a 10{sup 25 }m{sup −3} and 1.6 × 10{sup 28 }m{sup −3} plasma column. The acceleration gradient, energy gain, and transformer ratio have been extensively studied in quasi-linear, linear-, and blowout-regimes. The simulation analysis indicated that in the beam-driven acceleration system a hollow plasma channel offers ∼20% higher acceleration gradient by enlarging the channel radius (r) from 0.2 λ{sub p} to 0.6 λ{sub p} in a blowout regime. This paper suggests a feasibility of TeV/m scale acceleration with a hollow crystalline structure (e.g., nanotubes) of high electron plasma density.

  8. Beam-driven acceleration in ultra-dense plasma media

    SciTech Connect

    Shin, Young-Min

    2014-09-15

    Accelerating parameters of beam-driven wakefield acceleration in an extremely dense plasma column has been analyzed with the dynamic framed particle-in-cell plasma simulator, and compared with analytic calculations. In the model, a witness beam undergoes a TeV/m scale alternating potential gradient excited by a micro-bunched drive beam in a 1025 m-3 and 1.6 x 1028 m-3 plasma column. The acceleration gradient, energy gain, and transformer ratio have been extensively studied in quasi-linear, linear-, and blowout-regimes. The simulation analysis indicated that in the beam-driven acceleration system a hollow plasma channel offers 20 % higher acceleration gradient by enlarging the channel radius (r) from 0.2 Ap to 0.6 .Ap in a blowout regime. This paper suggests a feasibility of TeV/m scale acceleration with a hollow crystalline structure (e.g. nanotubes) of high electron plasma density.

  9. Beam-driven acceleration in ultra-dense plasma media

    DOE PAGES

    Shin, Young-Min

    2014-09-15

    Accelerating parameters of beam-driven wakefield acceleration in an extremely dense plasma column has been analyzed with the dynamic framed particle-in-cell plasma simulator, and compared with analytic calculations. In the model, a witness beam undergoes a TeV/m scale alternating potential gradient excited by a micro-bunched drive beam in a 1025 m-3 and 1.6 x 1028 m-3 plasma column. The acceleration gradient, energy gain, and transformer ratio have been extensively studied in quasi-linear, linear-, and blowout-regimes. The simulation analysis indicated that in the beam-driven acceleration system a hollow plasma channel offers 20 % higher acceleration gradient by enlarging the channel radius (r)more » from 0.2 Ap to 0.6 .Ap in a blowout regime. This paper suggests a feasibility of TeV/m scale acceleration with a hollow crystalline structure (e.g. nanotubes) of high electron plasma density.« less

  10. Beam acceleration by plasma-loaded free-electron devices

    NASA Astrophysics Data System (ADS)

    Tsui, K. H.; Serbeto, A.; D'olival, J. B.

    1998-01-01

    The use of a plasma-filled wiggler free-electron laser device operating near the plasma cutoff to accelerate electron beams is examined. Near the cutoff, the group velocity of the microwave field in the plasma is much less than the beam velocity. This scheme, therefore, operates in the pulse mode to accelerate electron beam bunches much shorter than the wiggler length. Between one bunch and the other, the wiggler is reloaded with microwave field. During the loading period, the laser-wiggler-plasma (SWL) Raman interaction generates a Langmuir mode with the laser and the wiggler as the primary energy sources. When the wiggler plasma is fully loaded with microwave field, a short electron bunch is fired into the device. In this accelerating period, the Langmuir mode is coupled to the laser-wiggler-beam (SWB) free-electron-laser interaction. The condition that the Langmuir phase velocity matches the free-electron-laser resonant beam velocity assures the simultaneous interaction of the SWL and SWB parametric processes. Beam acceleration is accomplished fundamentally via the space charge field of the Langmuir mode and the electron phase in the ponderomotive potential. Linear energy gain regime is accomplished when the phase velocity of the Langmuir mode is exactly equal to the speed of light.

  11. High intensity single bunch operation with heavy periodic transient beam loading in wide band rf cavities

    NASA Astrophysics Data System (ADS)

    Tamura, Fumihiko; Hotchi, Hideaki; Schnase, Alexander; Yoshii, Masahito; Yamamoto, Masanobu; Ohmori, Chihiro; Nomura, Masahiro; Toda, Makoto; Shimada, Taihei; Hasegawa, Katsushi; Hara, Keigo

    2015-09-01

    The rapid cycling synchrotron (RCS) in the Japan Proton Accelerator Research Complex (J-PARC) was originally designed to accelerate two high intensity bunches, while some of neutron experiments in the materials and life science experimental facility and a muon experiment using main ring beams require a single bunch operation mode, in which one of the two rf buckets is filled and the other is empty. The beam intensity in the single bunch operation has been limited by longitudinal beam losses due to the rf bucket distortions by the wake voltage of the odd harmonics (h =1 ,3 ,5 ) in the wide band magnetic alloy cavities. We installed an additional rf feedforward system to compensate the wake voltages of the odd harmonics (h =1 ,3 ,5 ). The additional system has a similar structure as the existing feedforward system for the even harmonics (h =2 ,4 ,6 ). We describe the function of the feedforward system for the odd harmonics, the commissioning methodology, and the commissioning results. The longitudinal beam losses during the single bunch acceleration disappeared with feedforward for the odd harmonics. We also confirmed that the beam quality in the single bunch acceleration are similar to that of the normal operation with two bunches. Thus, high intensity single bunch acceleration at the intensity of 2.3 ×1013 protons per bunch has been achieved in the J-PARC RCS. This article is a follow-up of our previous article, Phys. Rev. ST Accel. Beams 14, 051004 (2011). The feedforward system extension for single bunch operation was successful.

  12. Analytical considerations of beam hardening in medical accelerator photon spectra.

    PubMed

    Kleinschmidt, C

    1999-09-01

    Beam hardening is a well-known phenomenon for therapeutic accelerator beams passing through matter in narrow beam geometry. This study assesses quantitatively the magnitude of beam hardening of therapeutic beams in water. A formal concept of beam hardening is proposed which is based on the decrease of the mean attenuation coefficient with depth. On the basis of this concept calculations of beam hardening effects are easily performed by means of a commercial spreadsheet program. Published accelerator spectra and the tabulated values of attenuation coefficients serve as input for these calculations. It is shown that the mean attenuation coefficient starts at depth zero with an almost linear decrease and then slowly levels off to a limit value. A similar behavior is found for the beam hardening coefficient. A physically reasonable, semianalytical model is given which fits the data better than previously published functions. The energy dependence of the initial attenuation coefficient is evaluated and shown. It fits well to published experimental data. The initial beam hardening coefficient, however, shows no energy dependence. Its mean value (eta0) approximately 0.006 cm(-1)) is also in close agreement to the measured data.

  13. The WARP Code: Modeling High Intensity Ion Beams

    SciTech Connect

    Grote, D P; Friedman, A; Vay, J L; Haber, I

    2004-12-09

    The Warp code, developed for heavy-ion driven inertial fusion energy studies, is used to model high intensity ion (and electron) beams. Significant capability has been incorporated in Warp, allowing nearly all sections of an accelerator to be modeled, beginning with the source. Warp has as its core an explicit, three-dimensional, particle-in-cell model. Alongside this is a rich set of tools for describing the applied fields of the accelerator lattice, and embedded conducting surfaces (which are captured at sub-grid resolution). Also incorporated are models with reduced dimensionality: an axisymmetric model and a transverse ''slice'' model. The code takes advantage of modern programming techniques, including object orientation, parallelism, and scripting (via Python). It is at the forefront in the use of the computational technique of adaptive mesh refinement, which has been particularly successful in the area of diode and injector modeling, both steady-state and time-dependent. In the presentation, some of the major aspects of Warp will be overviewed, especially those that could be useful in modeling ECR sources. Warp has been benchmarked against both theory and experiment. Recent results will be presented showing good agreement of Warp with experimental results from the STS500 injector test stand. Additional information can be found on the web page http://hif.lbl.gov/theory/WARP{_}summary.html.

  14. The WARP Code: Modeling High Intensity Ion Beams

    SciTech Connect

    Grote, David P.; Friedman, Alex; Vay, Jean-Luc; Haber, Irving

    2005-03-15

    The Warp code, developed for heavy-ion driven inertial fusion energy studies, is used to model high intensity ion (and electron) beams. Significant capability has been incorporated in Warp, allowing nearly all sections of an accelerator to be modeled, beginning with the source. Warp has as its core an explicit, three-dimensional, particle-in-cell model. Alongside this is a rich set of tools for describing the applied fields of the accelerator lattice, and embedded conducting surfaces (which are captured at sub-grid resolution). Also incorporated are models with reduced dimensionality: an axisymmetric model and a transverse 'slice' model. The code takes advantage of modern programming techniques, including object orientation, parallelism, and scripting (via Python). It is at the forefront in the use of the computational technique of adaptive mesh refinement, which has been particularly successful in the area of diode and injector modeling, both steady-state and time-dependent. In the presentation, some of the major aspects of Warp will be overviewed, especially those that could be useful in modeling ECR sources. Warp has been benchmarked against both theory and experiment. Recent results will be presented showing good agreement of Warp with experimental results from the STS500 injector test stand. Additional information can be found on the web page http://hif.lbl.gov/theory/WARP{sub s}ummary.html.

  15. Intense non-relativistic cesium ion beam

    SciTech Connect

    Lampel, M.C.

    1984-02-01

    The Heavy Ion Fusion group at Lawrence Berkeley Laboratory has constructed the One Ampere Cesium Injector as a proof of principle source to supply an induction linac with a high charge density and high brightness ion beam. This is studied here. An electron beam probe was developed as the major diagnostic tool for characterizing ion beam space charge. Electron beam probe data inversion is accomplished with the EBEAM code and a parametrically adjusted model radial charge distribution. The longitudinal charge distribution was not derived, although it is possible to do so. The radial charge distribution that is derived reveals an unexpected halo of trapped electrons surrounding the ion beam. A charge fluid theory of the effect of finite electron temperature on the focusing of neutralized ion beams (Nucl. Fus. 21, 529 (1981)) is applied to the problem of the Cesium beam final focus at the end of the injector. It is shown that the theory's predictions and assumptions are consistent with the experimental data, and that it accounts for the observed ion beam radius of approx. 5 cm, and the electron halo, including the determination of an electron Debye length of approx. 10 cm.

  16. Generation of heavy ion beams using femtosecond laser pulses in the target normal sheath acceleration and radiation pressure acceleration regimes

    NASA Astrophysics Data System (ADS)

    Petrov, G. M.; McGuffey, C.; Thomas, A. G. R.; Krushelnick, K.; Beg, F. N.

    2016-06-01

    Theoretical study of heavy ion acceleration from sub-micron gold foils irradiated by a short pulse laser is presented. Using two dimensional particle-in-cell simulations, the time history of the laser pulse is examined in order to get insight into the laser energy deposition and ion acceleration process. For laser pulses with intensity 3 × 10 21 W / cm 2 , duration 32 fs, focal spot size 5 μm, and energy 27 J, the calculated reflection, transmission, and coupling coefficients from a 20 nm foil are 80%, 5%, and 15%, respectively. The conversion efficiency into gold ions is 8%. Two highly collimated counter-propagating ion beams have been identified. The forward accelerated gold ions have average and maximum charge-to-mass ratio of 0.25 and 0.3, respectively, maximum normalized energy 25 MeV/nucleon, and flux 2 × 10 11 ions / sr . An analytical model was used to determine a range of foil thicknesses suitable for acceleration of gold ions in the radiation pressure acceleration regime and the onset of the target normal sheath acceleration regime. The numerical simulations and analytical model point to at least four technical challenges hindering the heavy ion acceleration: low charge-to-mass ratio, limited number of ions amenable to acceleration, delayed acceleration, and high reflectivity of the plasma. Finally, a regime suitable for heavy ion acceleration has been identified in an alternative approach by analyzing the energy absorption and distribution among participating species and scaling of conversion efficiency, maximum energy, and flux with laser intensity.

  17. Medical Isotope Production using High Intensity Accelerator Neutrons

    NASA Astrophysics Data System (ADS)

    Nagai, Yasuki

    We proposed aprototype facility for the generation of radioisotopes with accelerator neutrons by deuterons. The neutrons are producedbynatC(d,n) with 40MeV 2 mA deuteron beams, and about 8.1 TBq/week of 99Mois produced by irradiating an enriched 100Mo sample with the neutrons.High-quality 99mTc can be separatedfrom an irradiated 100MoO3 sample by thermo-chromatographic separation.In this contribution we present the system to produce medical radioisotopes, such as 99Mo, 90Y, and 67Cu, and experimental studies on 99Mo and 67Cu produced by using accelerator neutrons.

  18. Beam breakup in an advanced linear induction accelerator

    SciTech Connect

    Ekdahl, Carl August; Coleman, Joshua Eugene; McCuistian, Brian Trent

    2016-07-01

    Two linear induction accelerators (LIAs) have been in operation for a number of years at the Los Alamos Dual Axis Radiographic Hydrodynamic Test (DARHT) facility. A new multipulse LIA is being developed. We have computationally investigated the beam breakup (BBU) instability in this advanced LIA. In particular, we have explored the consequences of the choice of beam injector energy and the grouping of LIA cells. We find that within the limited range of options presently under consideration for the LIA architecture, there is little adverse effect on the BBU growth. The computational tool that we used for this investigation was the beam dynamics code linear accelerator model for DARHT (LAMDA). In conclusion, to confirm that LAMDA was appropriate for this task, we first validated it through comparisons with the experimental BBU data acquired on the DARHT accelerators.

  19. Two-beam, Multi-mode Detuned Accelerating Structure

    SciTech Connect

    Kazakov, S. Yu.; Kuzikov, S. V.; Yakovlev, V. P.; Hirshfield, J. L.

    2009-01-22

    A two-beam accelerator structure is described having several novel features including all metal construction, no transfer structures required between the drive and accelerator channels, symmetric fields at the axes of each channel, RF micropulse widths on cavity irises that are less than half those for a conventional cavity at the same fundamental frequency by virtue of using several harmonically-related cavity modes, and a transformer ratio much greater than unity by the use of detuned cavities. Detuning is also shown to allow either parallel or anti-parallel directions for the drive and accelerated beams. A preliminary calculation for the dilution of emittance due to short-range wakes for drive beam parameters similar to those for CLIC shows this effect to be acceptably small.

  20. Beam breakup in an advanced linear induction accelerator

    DOE PAGES

    Ekdahl, Carl August; Coleman, Joshua Eugene; McCuistian, Brian Trent

    2016-07-01

    Two linear induction accelerators (LIAs) have been in operation for a number of years at the Los Alamos Dual Axis Radiographic Hydrodynamic Test (DARHT) facility. A new multipulse LIA is being developed. We have computationally investigated the beam breakup (BBU) instability in this advanced LIA. In particular, we have explored the consequences of the choice of beam injector energy and the grouping of LIA cells. We find that within the limited range of options presently under consideration for the LIA architecture, there is little adverse effect on the BBU growth. The computational tool that we used for this investigation wasmore » the beam dynamics code linear accelerator model for DARHT (LAMDA). In conclusion, to confirm that LAMDA was appropriate for this task, we first validated it through comparisons with the experimental BBU data acquired on the DARHT accelerators.« less

  1. Advanced post-acceleration methodology for pseudospark-sourced electron beam

    NASA Astrophysics Data System (ADS)

    Zhao, J.; Yin, H.; Zhang, L.; Shu, G.; He, W.; Zhang, Q.; Phelps, A. D. R.; Cross, A. W.

    2017-02-01

    During its conductive phase, a pseudospark discharge is able to generate a low energy electron beam with a higher combined current density and brightness compared with electron beams formed from any other known type of electron source. In this paper, a configuration is proposed to post-accelerate an electron beam extracted from a single-gap pseudospark discharge cavity in order to achieve high quality high energy intense electron beams. The major advancement is that the triggering of the pseudospark discharge, the pseudospark discharge itself, and the post-accelerating of the electron beam are all driven by a single high voltage pulse. An electron beam with a beam current of ˜20 A, beam voltage of 40 kV, and duration of ˜180 ns has been generated using this structure. The beam energy can be adjusted through adjusting the amplitude of the voltage pulse and the operating voltage of the whole structure, which can be varied from 24 to 50 kV with an efficient triggering method under fixed gas pressure below ˜10 Pa.

  2. Parametric study of transport beam lines for electron beams accelerated by laser-plasma interaction

    NASA Astrophysics Data System (ADS)

    Scisciò, M.; Lancia, L.; Migliorati, M.; Mostacci, A.; Palumbo, L.; Papaphilippou, Y.; Antici, P.

    2016-03-01

    In the last decade, laser-plasma acceleration of high-energy electrons has attracted strong attention in different fields. Electrons with maximum energies in the GeV range can be laser-accelerated within a few cm using multi-hundreds terawatt (TW) lasers, yielding to very high beam currents at the source (electron bunches with up to tens-hundreds of pC in a few fs). While initially the challenge was to increase the maximum achievable electron energy, today strong effort is put in the control and usability of these laser-generated beams that still lack of some features in order to be used for applications where currently conventional, radio-frequency (RF) based, electron beam lines represent the most common and efficient solution. Several improvements have been suggested for this purpose, some of them acting directly on the plasma source, some using beam shaping tools located downstream. Concerning the latter, several studies have suggested the use of conventional accelerator magnetic devices (such as quadrupoles and solenoids) as an easy implementable solution when the laser-plasma accelerated beam requires optimization. In this paper, we report on a parametric study related to the transport of electron beams accelerated by laser-plasma interaction, using conventional accelerator elements and tools. We focus on both, high energy electron beams in the GeV range, as produced on petawatt (PW) class laser systems, and on lower energy electron beams in the hundreds of MeV range, as nowadays routinely obtained on commercially available multi-hundred TW laser systems. For both scenarios, our study allows understanding what are the crucial parameters that enable laser-plasma accelerators to compete with conventional ones and allow for a beam transport. We show that suitable working points require a tradeoff-combination between low beam divergence and narrow energy spread.

  3. Accelerators for E-beam and X-ray processing

    NASA Astrophysics Data System (ADS)

    Auslender, V. L.; Bryazgin, A. A.; Faktorovich, B. L.; Gorbunov, V. A.; Kokin, E. N.; Korobeinikov, M. V.; Krainov, G. S.; Lukin, A. N.; Maximov, S. A.; Nekhaev, V. E.; Panfilov, A. D.; Radchenko, V. N.; Tkachenko, V. O.; Tuvik, A. A.; Voronin, L. A.

    2002-03-01

    During last years the demand for pasteurization and desinsection of various food products (meat, chicken, sea products, vegetables, fruits, etc.) had increased. The treatment of these products in industrial scale requires the usage of powerful electron accelerators with energy 5-10 MeV and beam power at least 50 kW or more. The report describes the ILU accelerators with energy range up to 10 MeV and beam power up to 150 kW.The different irradiation schemes in electron beam and X-ray modes for various products are described. The design of the X-ray converter and 90° beam bending system are also given.

  4. Radiobiological effectiveness of laser accelerated electrons in comparison to electron beams from a conventional linear accelerator.

    PubMed

    Laschinsky, Lydia; Baumann, Michael; Beyreuther, Elke; Enghardt, Wolfgang; Kaluza, Malte; Karsch, Leonhard; Lessmann, Elisabeth; Naumburger, Doreen; Nicolai, Maria; Richter, Christian; Sauerbrey, Roland; Schlenvoigt, Hans-Peter; Pawelke, Jörg

    2012-01-01

    The notable progress in laser particle acceleration technology promises potential medical application in cancer therapy through compact and cost effective laser devices that are suitable for already existing clinics. Previously, consequences on the radiobiological response by laser driven particle beams characterised by an ultra high peak dose rate have to be investigated. Therefore, tumour and non-malignant cells were irradiated with pulsed laser accelerated electrons at the JETI facility for the comparison with continuous electrons of a conventional therapy LINAC. Dose response curves were measured for the biological endpoints clonogenic survival and residual DNA double strand breaks. The overall results show no significant differences in radiobiological response for in vitro cell experiments between laser accelerated pulsed and clinical used electron beams. These first systematic in vitro cell response studies with precise dosimetry to laser driven electron beams represent a first step toward the long term aim of the application of laser accelerated particles in radiotherapy.

  5. Studies of polarized beam acceleration and Siberian Snakes

    SciTech Connect

    Lee, S.Y.

    1992-12-31

    We studied depolarization mechanisms of polarized proton acceleration in high energy accelerators with snakes and found that the perturbed spin tune due to the imperfection resonance plays an important role in beam depolarization at snake resonances. We also found that even order snake resonances exist in the overlapping intrinsic and imperfection resonances. Due to the perturbed spin tune of imperfection resonances, each snake resonance splits into two. Thus the available betatron tune space becomes smaller. Some constraints on polarized beam colliders were also examined.

  6. Beam manipulation techniques, nonlinear beam dynamics, and space charge effect in high energy high power accelerators

    SciTech Connect

    Lee, S. Y.

    2014-04-07

    We had carried out a design of an ultimate storage ring with beam emittance less than 10 picometer for the feasibility of coherent light source at X-ray wavelength. The accelerator has an inherent small dynamic aperture. We study method to improve the dynamic aperture and collective instability for an ultimate storage ring. Beam measurement and accelerator modeling are an integral part of accelerator physics. We develop the independent component analysis (ICA) and the orbit response matrix method for improving accelerator reliability and performance. In collaboration with scientists in National Laboratories, we also carry out experimental and theoretical studies on beam dynamics. Our proposed research topics are relevant to nuclear and particle physics using high brightness particle and photon beams.

  7. Electron Beam/Converter Target Interactions in Radiographic Accelerators

    SciTech Connect

    McCarrick, J; Caporaso, G; Chambers, F; Chen, Y-J; Falabella, S; Goldin, F; Guethlein, G; Ho, D; Richardson, R; Weir, J

    2003-05-27

    Linear induction accelerators used in X-ray radiography have single-pulse parameters of the order 20 MeV of electron beam energy, 2 kA of beam current, pulse lengths of 50-100 ns, and spot sizes of 1-2 mm. The thermal energy deposited in a bremsstrahlung converter target made of tantalum from such a pulse is {approx}80 kJ/cc, more than enough to bring the target material to a partially ionized state. The tail end of a single beam pulse, or any subsequent pulse in a multi-pulse train, undergoes a number of interactions with the target that can affect beam transport and radiographic performance. Positive ions extracted from the target plasma by the electron beam space charge can affect the beam focus and centroid stability. As the target expands on the inter-pulse time scale, the integrated line density of material decreases, eventually affecting the X-ray output of the system. If the target plume becomes sufficiently large, beam transport through it is affected by macroscopic charge and current neutralization effects and microscopic beam/plasma instability mechanisms. We will present a survey of some of these interactions, as well as some results of an extensive experimental and theoretical campaign to understand the practical amelioration of these effects, carried out at the ETA-II accelerator facility at the Lawrence Livermore National Laboratory.

  8. Collective Ion Acceleration and Electron Beam Propagation in Dielectric Guides.

    DTIC Science & Technology

    1980-04-01

    PULSE 600 Under * Typical Experimental Conditions and (b) Transported Beam Current at Positions of 2 cm and 15 cm Down Guide . .3-6 3-4 Beam-Front...of the dielectric guide. A low-temperature plasma is formed at the irradiated surface of the guide by various processes , including volume breakdown...of the dielectric, surface flashover , and ionization and breakdown of desorbed gas. The ions of this plasma are accelerated electrostatically into the

  9. Physics of beam self-modulation in plasma wakefield accelerators

    SciTech Connect

    Lotov, K. V.

    2015-10-15

    The self-modulation instability is a key effect that makes possible the usage of nowadays proton beams as drivers for plasma wakefield acceleration. Development of the instability in uniform plasmas and in plasmas with a small density up-step is numerically studied with the focus at nonlinear stages of beam evolution. The step parameters providing the strongest established wakefield are found, and the mechanism of stable bunch train formation is identified.

  10. Approaches to develop targets for production of intense radioactive ion beams

    SciTech Connect

    Talbert, W. L.; Drake, D. M.; Wilson, M. T.; Walker, J. J.; Lenz, J. W.

    1999-06-10

    Approaches to develop targets for production of intense radioactive ion beams (RIBs) have been evaluated over the past five years. It is acknowledged that many desired physics objectives using RIBs can be met only by using production beams of energetic protons with currents up to 100 {mu}A. Such beams can be made available at future spallation neutron facilities. The production targets will require active cooling to control operational temperatures due to internal heating caused by the production beam. A target concept has been selected, and calculational analyses of the target concept have been performed to guide the design of a prototype target for an in-beam test of the actual thermal behavior. For this test, a high-power test facility is needed; fortunately, the beam currents required exist at the TRIUMF accelerator facility. An experimental proposal has been approved for such a test.

  11. Accelerators for the PS neutrino beam

    NASA Astrophysics Data System (ADS)

    Steerenberg, R.; Calviani, M.; Gschwendtner, E.; Pardons, A.; Vincke, H.

    2013-02-01

    A recent memorandum for an experimental proposal [1] was discussed during the CERN PS and SPS experimental committee (SPSC) of April 2011 and at the Research Board of June 2011. The proposed experiment, with objective to investigate the anomalous νμ → νe oscillations, aims at re-using the discontinued CERN PS Neutrino Facility (PSNF) and experimental zones to install a 150 ton liquid argon time projection chamber (LArTPC) as near detector and a 600 ton LArTPC as far detector. This article will summarize the experimental needs, the proposed facility layout, a primary beam production scheme and the requirements for the reconstruction of the PSNF.

  12. GeV electron acceleration by a Gaussian field laser with effect of beam width parameter in magnetized plasma

    NASA Astrophysics Data System (ADS)

    Ghotra, Harjit Singh; Kant, Niti

    2017-01-01

    Electron acceleration due to a circularly polarized (CP) Gaussian laser field has been investigated theoretically in magnetized plasma. A Gaussian laser beam possesses trapping forces on electrons during its propagation through plasma. A single particle simulation indicates a resonant enhancement of electron acceleration with a Gaussian laser beam. The plasma is magnetized with an axial magnetic field in same direction as that of laser beam propagation. The dependence of laser beam width parameter on electron energy gain with propagation distance has been presented graphically for different values of laser intensity. Electron energy gain is relatively high where the laser beam parameter is at its minimum value. Enhanced energy gain of the order of GeV is reported with magnetic field under 20 MG in plasma. It is also seen that the axial magnetic field maintains the electron acceleration for large propagation distance even with an increasing beam width parameter.

  13. An intense polarized beam by a laser ionization injection

    NASA Astrophysics Data System (ADS)

    Ohmori, Chihiro; Hiramatsu, Shigenori; Nakamura, Takeshi

    1990-12-01

    Accumulation of protons and polarized protons by photo-ionization injection are described. This method consists of: (1) producing the neutral hydrogen beam by Lorentz stripping; (2) excitation of the neutral hydrogen beam with a laser; and (3) ionization of the hydrogen beam in the 2P excited state with another laser. When the laser for the excitation is circularly polarized, we can get a polarized proton beam. An ionization efficiency of 98 percent and a polarization of 80 percent can be expected by an intense laser beam from a free electron laser (FEL).

  14. Gridded Electron Guns and Modulation of Intense Beams

    SciTech Connect

    Harris, J R; O'Shea, P G

    2006-05-02

    Gridded guns are useful for producing modulated electron beams. This modulation is generally limited to simple gating of the beam, but may be used to apply structure to the beam pulse shape. In intense beams, this structure spawns space charge waves whose dynamics depend in part on the relative strengths of the velocity and density variations which comprise the initial current modulation. In this paper, we calculate the strengths of beam current and velocity modulation produced in a gridded electron gun, and show that under normal conditions the initial modulation is dominated by density variation rather than velocity variation.

  15. Theoretical and Computational Investigation of Periodically Focused Intense Charged-Particle Beams

    SciTech Connect

    Chen, Chiping

    2013-06-26

    The purpose of this report is to summarize results of theoretical and computational investigations of periodically focused intense charged-particle beams in parameter regimes relevant to the development of advanced high-brightness, high-power accelerators for high-energy physics research. The breakthroughs and highlights in our research in the period from April 1, 2010 to March 30, 2013 were: a) Theory and simulation of adiabatic thermal Child-Langmuir flow; b) Particle-in-cell simulations of adiabatic thermal beams in periodic solenoidal focusing field; c)Dynamics of charged particles in an adiabatic thermal beam equilibrium in a periodic solenoidal focusing field; d) Training of undergraduate researchers and graduate student in accelerator and beam physics. A brief introduction and summary is presented. Detailed descriptions of research results are provided in an appendix of publications at the end of the report.

  16. Low energy beam transport for facility for rare isotope beams driver linear particle accelerator.

    PubMed

    Sun, L T; Leitner, D; Machicoane, G; Pozdeyev, E; Smirnov, V; Vorozhtsov, S B; Winklehner, D; Zhao, Q

    2012-02-01

    The driver linac for the facility for rare isotope beams (FRIB) will provide a wide range of primary ion beams for nuclear physics research. The linac will be capable of accelerating a uranium beam to an energy of up to 200 Mev∕u and delivering it to a fragmentation target with a maximum power of 400 kW. Stable ion beams will be produced by a high performance electron cyclotron resonance ion source operating at 28 GHz. The ion source will be located on a high voltage platform to reach an initial beam energy of 12 keV∕u. After extraction, the ion beam will be transported vertically down to the linac tunnel in a low energy beam transport (LEBT) system and injected into a radio frequency quadrupole (RFQ) operating at a frequency of 80.5 MHz. To meet the beam power requirements, simultaneous acceleration of two-charge states will be used for heavier ions (≥Xe). This paper presents the layout of the FRIB LEBT and the beam dynamics in the LEBT. In particular, simulation and design of the beam line section before charge state selection will be detailed. The need to use an achromatic design for the charge state selection system and the advantage of an ion beam collimation system to limit the emittance of the beam injected into the RFQ will be discussed in this paper.

  17. Fully vectorial accelerating diffraction-free Helmholtz beams.

    PubMed

    Aleahmad, Parinaz; Miri, Mohammad-Ali; Mills, Matthew S; Kaminer, Ido; Segev, Mordechai; Christodoulides, Demetrios N

    2012-11-16

    We show that new families of diffraction-free nonparaxial accelerating optical beams can be generated by considering the symmetries of the underlying vectorial Helmholtz equation. Both two-dimensional transverse electric and magnetic accelerating wave fronts are possible, capable of moving along elliptic trajectories. Experimental results corroborate these predictions when these waves are launched from either the major or minor axis of the ellipse. In addition, three-dimensional spherical nondiffracting field configurations are presented along with their evolution dynamics. Finally, fully vectorial self-similar accelerating optical wave solutions are obtained via oblate-prolate spheroidal wave functions. In all occasions, these effects are illustrated via pertinent examples.

  18. Back-streaming ion emission and beam focusing on high power linear induction accelerator

    NASA Astrophysics Data System (ADS)

    Zhu, Jun; Chen, Nan; Yu, Haijun; Jiang, Xiaoguo; Wang, Yuan; Dai, Wenhua; Gao, Feng; Wang, Minhong; Li, Jin; Shi, Jinshui

    2011-08-01

    Ions released from target surfaces by impact of a high intensity and current electron beam can be accelerated and trapped in the beam potential, and further destroy the beam focus. By solving the 2D Poisson equation, we found that the charge neutralization factor of the ions to the beam under space charge limited condition is 1/3, which is large enough to disrupt the spot size. Therefore, the ion emission at the target in a single-pulse beam/target system must be source limited. Experimental results on the time-resolved beam profile measurement have also proven that. A new focus scheme is proposed in this paper to focus the beam to a small spot size with the existence of back-streaming ions. We found that the focal spot will move upstream as the charge neutralization factor increases. By comparing the theoretical and experimental focal length of the Dragon-I accelerator (20 MeV, 2.5 kA, 60 ns flattop), we found that the average neutralization factor is about 5% in the beam/target system.

  19. Laser-accelerated ion beam diagnostics with TOF detectors for the ELIMED beam line

    NASA Astrophysics Data System (ADS)

    Milluzzo, G.; Scuderi, V.; Amico, A. G.; Borghesi, M.; Cirrone, G. A. P.; Cuttone, G.; De Napoli, M.; Doria, D.; Dostal, J.; Larosa, G.; Leanza, R.; Margarone, D.; Petringa, G.; Pipek, J.; Romagnani, L.; Romano, F.; Schillaci, F.; Velyhan, A.

    2017-02-01

    Laser-accelerated ion beams could represent the future of particle acceleration in several multidisciplinary applications, as for instance medical physics, hadrontherapy and imaging field, being a concrete alternative to old paradigm of acceleration, characterized by huge and complex machines. In this framework, following on from the ELIMED collaboration, launched in 2012 between INFN-LNS and ELI-Beamlines, in 2014 a three-years contract has been signed between the two institutions for the design and the development of a complete transport beam-line for high-energy ion beams (up to 60 MeV) coupled with innovative diagnostics and in-air dosimetry devices. The beam-line will be installed at the ELI-Beamlines facility and will be available for users. The measurement of the beam characteristics, such as energy spectra, angular distributions and dose-rate is mandatory to optimize the transport as well as the beam delivery at the irradiation point. In order to achieve this purpose, the development of appropriate on-line diagnostics devices capable to detect high-pulsed beams with high accuracy, represents a crucial point in the ELIMED beamline development. The diagnostics solution, based on the use of silicon carbide (SiC) and diamond detectors using TOF technique, will be presented together with the preliminary results obtained with laser-accelerated proton beams.

  20. Indirectly sensing accelerator beam currents for limiting maximum beam current magnitude

    DOEpatents

    Bogaty, J.M.; Clifft, B.E.; Bollinger, L.M.

    1995-08-08

    A beam current limiter is disclosed for sensing and limiting the beam current in a particle accelerator, such as a cyclotron or linear accelerator, used in scientific research and medical treatment. A pair of independently operable capacitive electrodes sense the passage of charged particle bunches to develop an RF signal indicative of the beam current magnitude produced at the output of a bunched beam accelerator. The RF signal produced by each sensing electrode is converted to a variable DC voltage indicative of the beam current magnitude. The variable DC voltages thus developed are compared to each other to verify proper system function and are further compared to known references to detect beam currents in excess of pre-established limits. In the event of a system malfunction, or if the detected beam current exceeds pre-established limits, the beam current limiter automatically inhibits further accelerator operation. A high Q tank circuit associated with each sensing electrode provides a narrow system bandwidth to reduce noise and enhance dynamic range. System linearity is provided by injecting, into each sensing electrode, an RF signal that is offset from the bunching frequency by a pre-determined beat frequency to ensure that subsequent rectifying diodes operate in a linear response region. The system thus provides a large dynamic range in combination with good linearity. 6 figs.

  1. Indirectly sensing accelerator beam currents for limiting maximum beam current magnitude

    DOEpatents

    Bogaty, John M.; Clifft, Benny E.; Bollinger, Lowell M.

    1995-01-01

    A beam current limiter for sensing and limiting the beam current in a particle accelerator, such as a cyclotron or linear accelerator, used in scientific research and medical treatment. A pair of independently operable capacitive electrodes sense the passage of charged particle bunches to develop an RF signal indicative of the beam current magnitude produced at the output of a bunched beam accelerator. The RF signal produced by each sensing electrode is converted to a variable DC voltage indicative of the beam current magnitude. The variable DC voltages thus developed are compared to each other to verify proper system function and are further compared to known references to detect beam currents in excess of pre-established limits. In the event of a system malfunction, or if the detected beam current exceeds pre-established limits, the beam current limiter automatically inhibits further accelerator operation. A high Q tank circuit associated with each sensing electrode provides a narrow system bandwidth to reduce noise and enhance dynamic range. System linearity is provided by injecting, into each sensing electrode, an RF signal that is offset from the bunching frequency by a pre-determined beat frequency to ensure that subsequent rectifying diodes operate in a linear response region. The system thus provides a large dynamic range in combination with good linearity.

  2. Anisotropy-driven collective instability in intense charged particle beams

    NASA Astrophysics Data System (ADS)

    Startsev, Edward A.; Davidson, Ronald C.; Qin, Hong

    2005-12-01

    The classical electrostatic Harris instability is generalized to the case of a one-component intense charged particle beam with anisotropic temperature including the important effects of finite transverse geometry and beam space charge. For a long, coasting beam, the eigenmode code bEASt have been used to determine detailed 3D stability properties over a wide range of temperature anisotropy and beam intensity. A simple theoretical model is developed which describes the essential features of the linear stage of the instability. Both the simulations and the analytical theory clearly show that moderately intense beams are linearly unstable to short-wavelength perturbations provided the ratio of the longitudinal temperature to the transverse temperature is smaller than some threshold value. The delta-f particle-in-cell code BEST has been used to study the detailed nonlinear evolution and saturation of the instability.

  3. Transverse Beam Emittance Measurements of a 16 MeV Linac at the Idaho Accelerator Center

    SciTech Connect

    S. Setiniyaz, T.A. Forest, K. Chouffani, Y. Kim, A. Freyberger

    2012-07-01

    A beam emittance measurement of the 16 MeV S-band High Repetition Rate Linac (HRRL) was performed at Idaho State University's Idaho Accelerator Center (IAC). The HRRL linac structure was upgraded beyond the capabilities of a typical medical linac so it can achieve a repetition rate of 1 kHz. Measurements of the HRRL transverse beam emittance are underway that will be used to optimize the production of positrons using HRRL's intense electron beam on a tungsten converter. In this paper, we describe a beam imaging system using on an OTR screen and a digital CCD camera, a MATLAB tool to extract beamsize and emittance, detailed measurement procedures, and the measured transverse emittances for an arbitrary beam energy of 15 MeV.

  4. Investigating the adiabatic beam grouping at the NICA accelerator complex

    NASA Astrophysics Data System (ADS)

    Brovko, O. I.; Butenko, A. V.; Grebentsov, A. Yu.; Eliseev, A. V.; Meshkov, I. N.; Svetov, A. L.; Sidorin, A. O.; Slepnev, V. M.

    2016-12-01

    The NICA complex comprises the Booster and Nuclotron synchrotrons for accelerating particle beams to the required energy and the Collider machine, in which particle collisions are investigated. The experimental heavy-ion program deals with ions up to Au+79. The light-ion program deals with polarized deuterons and protons. Grouping of a beam coasting in an ion chamber is required in many parts of the complex. Beam grouping may effectively increase the longitudinal emittance and particle losses. To avoid these negative effects, various regimes of adiabatic grouping have been simulated and dedicated experiments with a deuteron beam have been conducted at the Nuclotron machine. As a result, we are able to construct and optimize the beam-grouping equipment, which provides a capture efficiency near 100% either retaining or varying the harmonic multiplicity of the HF system.

  5. Intense electron beam propagation across a magnetic field

    SciTech Connect

    Zhang, X.; Striffler, C.D.; Yao, R.L.; Destler, W.W.; Reiser, M.P.

    1989-01-01

    In this paper we consider the propagation of an intense electron-ion beam across an applied magnetic field. In the absence of the applied field, the beam system is in a Bennett equilibrium state that involves electrons with both large axial and thermal velocities and a cold stationary space-charge neutralizing ion species. Typical parameters under consideration are V{sub o} {approximately} 1 MV, I {approximately} 5 kA, T{sub e} {approximately} 100 keV, and beam radii {approximately} 1 cm. We find that in the intense beam regime, the propagation is limited due to space-charge depression caused by the deflection of the electron beam by the transverse field. This critical field is of the order of the peak self-magnetic field of the electron beam which is substantially higher than the single particle cut-off field. 8 refs., 3 figs.

  6. Reduction of angular divergence of laser-driven ion beams during their acceleration and transport

    NASA Astrophysics Data System (ADS)

    Zakova, M.; Pšikal, Jan; Margarone, Daniele; Maggiore, Mario; Korn, G.

    2015-05-01

    Laser plasma physics is a field of big interest because of its implications in basic science, fast ignition, medicine (i.e. hadrontherapy), astrophysics, material science, particle acceleration etc. 100-MeV class protons accelerated from the interaction of a short laser pulse with a thin target have been demonstrated. With continuing development of laser technology, greater and greater energies are expected, therefore projects focusing on various applications are being formed, e.g. ELIMAIA (ELI Multidisciplinary Applications of laser-Ion Acceleration). One of the main characteristic and crucial disadvantage of ion beams accelerated by ultra-short intense laser pulses is their large divergence, not suitable for the most of applications. In this paper two ways how to decrease beam divergence are proposed. Firstly, impact of different design of targets on beam divergence is studied by using 2D Particlein-cell simulations (PIC). Namely, various types of targets include at foils, curved foil and foils with diverse microstructures. Obtained results show that well-designed microstructures, i.e. a hole in the center of the target, can produce proton beam with the lowest divergence. Moreover, the particle beam accelerated from a curved foil has lower divergence compared to the beam from a flat foil. Secondly, another proposed method for the divergence reduction is using of a magnetic solenoid. The trajectories of the laser accelerated particles passing through the solenoid are modeled in a simple Matlab program. Results from PIC simulations are used as input in the program. The divergence is controlled by optimizing the magnetic field inside the solenoid and installing an aperture in front of the device.

  7. Intense e-beam interaction with matter

    SciTech Connect

    Ritchie, R.H.; Crawford, O.H.

    1984-01-01

    This document describes work done in this period on certain nonlinear processes of potential importance at high energy densities in condensed matter, and on the theory of the electron slowing-down-cascade spectrum engendered in solids by e-beams.

  8. Drift compression of an intense neutralized ion beam

    SciTech Connect

    Roy, P.K.; Yu, S.S.; Henestroza, E.; Anders, A.; Bieniosek, F.M.; Coleman, J.; Eylon, S.; Greenway, W.G.; Leitner, M.; Logan, B.G.; Waldron, W.L.; Welch, D.R.; Thoma, C.; Sefkow, A.B.; Gilson, E.P.; Efthimion, P.C.; Davidson, R.C.

    2004-10-25

    Longitudinal compression of a tailored-velocity, intense neutralized ion beam has been demonstrated. The compression takes place in a 1-2 m drift section filled with plasma to provide space-charge neutralization. An induction cell produces a head-to-tail velocity ramp that longitudinally compresses the neutralized beam, enhancing the beam peak current by a factor of 50 and producing a pulse duration of about 3 ns. this measurement has been confirmed independently with two different diagnostic systems.

  9. Improving Plating by Use of Intense Acoustic Beams

    NASA Technical Reports Server (NTRS)

    Oeftering, Richard C.; Denofrio, Charles

    2003-01-01

    An improved method of selective plating of metals and possibly other materials involves the use of directed high-intensity acoustic beams. The beams, typically in the ultrasonic frequency range, can be generated by fixed-focus transducers (see figure) or by phased arrays of transducers excited, variously, by continuous waves, tone bursts, or single pulses. The nonlinear effects produced by these beams are used to alter plating processes in ways that are advantageous.

  10. Beam collimation and transport of quasineutral laser-accelerated protons by a solenoid field

    NASA Astrophysics Data System (ADS)

    Harres, K.; Alber, I.; Tauschwitz, A.; Bagnoud, V.; Daido, H.; Günther, M.; Nürnberg, F.; Otten, A.; Schollmeier, M.; Schütrumpf, J.; Tampo, M.; Roth, M.

    2010-02-01

    This article reports about controlling laser-accelerated proton beams with respect to beam divergence and energy. The particles are captured by a pulsed high field solenoid with a magnetic field strength of 8.6 T directly behind a flat target foil that is irradiated by a high intensity laser pulse. Proton beams with energies around 2.3 MeV and particle numbers of 1012 could be collimated and transported over a distance of more than 300 mm. In contrast to the protons the comoving electrons are strongly deflected by the solenoid field. They propagate at a submillimeter gyroradius around the solenoid's axis which could be experimentally verified. The originated high flux electron beam produces a high space charge resulting in a stronger focusing of the proton beam than expected by tracking results. Leadoff particle-in-cell simulations show qualitatively that this effect is caused by space charge attraction due to the comoving electrons. The collimation and transport of laser-accelerated protons is the first step to provide these unique beams for further applications such as postacceleration by conventional accelerator structures.

  11. Three electron beams from a laser-plasma wakefield accelerator and the energy apportioning question.

    PubMed

    Yang, X; Brunetti, E; Gil, D Reboredo; Welsh, G H; Li, F Y; Cipiccia, S; Ersfeld, B; Grant, D W; Grant, P A; Islam, M R; Tooley, M P; Vieux, G; Wiggins, S M; Sheng, Z M; Jaroszynski, D A

    2017-03-10

    Laser-wakefield accelerators are compact devices capable of delivering ultra-short electron bunches with pC-level charge and MeV-GeV energy by exploiting the ultra-high electric fields arising from the interaction of intense laser pulses with plasma. We show experimentally and through numerical simulations that a high-energy electron beam is produced simultaneously with two stable lower-energy beams that are ejected in oblique and counter-propagating directions, typically carrying off 5-10% of the initial laser energy. A MeV, 10s nC oblique beam is ejected in a 30°-60° hollow cone, which is filled with more energetic electrons determined by the injection dynamics. A nC-level, 100s keV backward-directed beam is mainly produced at the leading edge of the plasma column. We discuss the apportioning of absorbed laser energy amongst the three beams. Knowledge of the distribution of laser energy and electron beam charge, which determine the overall efficiency, is important for various applications of laser-wakefield accelerators, including the development of staged high-energy accelerators.

  12. Three electron beams from a laser-plasma wakefield accelerator and the energy apportioning question

    PubMed Central

    Yang, X.; Brunetti, E.; Gil, D. Reboredo; Welsh, G. H.; Li, F. Y.; Cipiccia, S.; Ersfeld, B.; Grant, D. W.; Grant, P. A.; Islam, M. R.; Tooley, M. P.; Vieux, G.; Wiggins, S. M.; Sheng, Z. M.; Jaroszynski, D. A.

    2017-01-01

    Laser-wakefield accelerators are compact devices capable of delivering ultra-short electron bunches with pC-level charge and MeV-GeV energy by exploiting the ultra-high electric fields arising from the interaction of intense laser pulses with plasma. We show experimentally and through numerical simulations that a high-energy electron beam is produced simultaneously with two stable lower-energy beams that are ejected in oblique and counter-propagating directions, typically carrying off 5–10% of the initial laser energy. A MeV, 10s nC oblique beam is ejected in a 30°–60° hollow cone, which is filled with more energetic electrons determined by the injection dynamics. A nC-level, 100s keV backward-directed beam is mainly produced at the leading edge of the plasma column. We discuss the apportioning of absorbed laser energy amongst the three beams. Knowledge of the distribution of laser energy and electron beam charge, which determine the overall efficiency, is important for various applications of laser-wakefield accelerators, including the development of staged high-energy accelerators. PMID:28281679

  13. Emittance growth mechanisms for laser-accelerated proton beams.

    PubMed

    Kemp, Andreas J; Fuchs, J; Sentoku, Y; Sotnikov, V; Bakeman, M; Antici, P; Cowan, T E

    2007-05-01

    In recent experiments the transverse normalized rms emittance of laser-accelerated MeV ion beams was found to be < 0.002 mm mrad, which is at least 100 times smaller than the emittance of thermal ion sources used in accelerators [T. E. Cowan, Phys. Rev. Lett. 92, 204801 (2004)]. We investigate the origin for the low emittance of laser-accelerated proton beams by studying several candidates for emittance-growth mechanisms. As our main tools, we use analytical models and one- and two-dimensional particle-in-cell simulations that have been modified to include binary collisions between particles. We find that the dominant source of emittance is filamentation of the laser-generated hot electron jets that drive the ion acceleration. Cold electron-ion collisions that occur before ions are accelerated contribute less than ten percent of the final emittance. Our results are in qualitative agreement with the experiment, for which we present a refined analysis relating emittance to temperature, a better representative of the fundamental beam physics.

  14. A new luminescence beam profile monitor for intense proton and heavy ion beams

    SciTech Connect

    Tsang,T.; Bellavia, S.; Connolly, R.; Gassner, D.; Makdisi, Y.; Russo, T.; Thieberger, P.; Trbojevic, D.; Zelenski, A.

    2008-10-01

    A new luminescence beam profile monitor is realized in the polarized hydrogen gas jet target at the Relativistic Heavy Ion Collider (RHIC) facility. In addition to the spin polarization of the proton beam being routinely measured by the hydrogen gas jet, the luminescence produced by beam-hydrogen excitation leads to a strong Balmer series lines emission. A selected hydrogen Balmer line is spectrally filtered and imaged to produce the transverse RHIC proton beam shape with unprecedented details on the RHIC beam profile. Alternatively, when the passage of the high energy RHIC gold ion beam excited only the residual gas molecules in the beam path, sufficient ion beam induced luminescence is produced and the transverse gold ion beam profile is obtained. The measured transverse beam sizes and the calculated emittances provide an independent confirmation of the RHIC beam characteristics and to verify the emittance conservation along the RHIC accelerator. This optical beam diagnostic technique by making use of the beam induced fluorescence from injected or residual gas offers a truly noninvasive particle beam characterization, and provides a visual observation of proton and heavy ion beams. Combined with a longitudinal bunch measurement system, a 3-dimensional spatial particle beam profile can be reconstructed tomographically.

  15. Compact Dielectric Wall Accelerator Development For Intensity Modulated Proton Therapy And Homeland Security Applications

    SciTech Connect

    Chen, Y -; Caporaso, G J; Guethlein, G; Sampayan, S; Akana, G; Anaya, R; Blackfield, D; Cook, E; Falabella, S; Gower, E; Harris, J; Hawkins, S; Hickman, B; Holmes, C; Horner, A; Nelson, S; Paul, A; Pearson, D; Poole, B; Richardson, R; Sanders, D; Stanley, J; Sullivan, J; Wang, L; Watson, J; Weir, J

    2009-06-17

    Compact dielectric wall (DWA) accelerator technology is being developed at the Lawrence Livermore National Laboratory. The DWA accelerator uses fast switched high voltage transmission lines to generate pulsed electric fields on the inside of a high gradient insulating (HGI) acceleration tube. Its high electric field gradients are achieved by the use of alternating insulators and conductors and short pulse times. The DWA concept can be applied to accelerate charge particle beams with any charge to mass ratio and energy. Based on the DWA system, a novel compact proton therapy accelerator is being developed. This proton therapy system will produce individual pulses that can be varied in intensity, energy and spot width. The system will be capable of being sited in a conventional linac vault and provide intensity modulated rotational therapy. The status of the developmental new technologies that make the compact system possible will be reviewed. These include, high gradient vacuum insulators, solid dielectric materials, SiC photoconductive switches and compact proton sources. Applications of the DWA accelerator to problems in homeland security will also be discussed.

  16. Intra-pulse transition between ion acceleration mechanisms in intense laser-foil interactions

    NASA Astrophysics Data System (ADS)

    Padda, Hersimerjit; King, Martin; Gray, Ross; Powell, Haydn; Gonzalez-Izquierdo, Bruno; Stockhausen, Luca; Wilson, Robbie; Carroll, David; Dance, Rachel; MacLellan, David; Yuan, Xiaohui; Butler, Nick; Capdessus, Remi; Borghesi, Marco; Neely, David; McKenna, Paul

    2016-10-01

    Laser-driven sheath acceleration of ions has been widely studied and the recent move to ultra thin foil interactions enables promising new acceleration mechanisms. However, the acceleration dynamics in this regime are complex and over the course of the laser-foil interaction multiple ion acceleration mechanisms can occur, resulting in the dominant mechanism changing throughout the interaction. Measuring the spatial intensity distribution of the accelerated proton beam we investigate the transition from radiation pressure acceleration to transparency-driven processes. Using PIC simulations, the radiation pressure drives an increased expansion of the target ions, which results in a radial deflection of low MeV protons to form an annular distribution. By varying the thickness of the target, the opening angle of the ring is shown to be correlated to the point in time that transparency occurs and is maximised at the peak of the laser intensity profile. Measurements of the ring size as a function of target thickness are found to be in good agreement with the simulation results.

  17. Acceleration of electrons in strong beam-plasma interactions

    NASA Technical Reports Server (NTRS)

    Wilhelm, K.; Bernstein, W.; Kellogg, P. J.; Whalen, B. A.

    1984-01-01

    The effects of strong beam-plasma interactions on the electron population of the upper atmosphere have been investigated in an electron acceleration experiment performed with a sounding rocket. The rocket carried the Several Complex Experiments (SCEX) payload which included an electron accelerator, three disposable 'throwaway' detectors (TADs), and a stepped electron energy analyzer. The payload was launched in an auroral arc over the rocket at altitudes of 157 and 178 km, respectively. The performance characteristics of the instruments are discussed in detail. The data are combined with the results of laboratory measurements and show that electrons with energies of at least two and probably four times the injection energy of 2 keV were observed during strong beam-plasma interaction events. The interaction events occurred at pitch angles of 54 and 126 degrees. On the basis of the data it is proposed that the superenergization of the electrons is correlated with the length of the beam-plasma interaction region.

  18. HIGH POWER BEAM DUMP AND TARGET / ACCELERATOR INTERFACE PROCEDURES

    SciTech Connect

    Blokland, Willem; Plum, Michael A; Peters, Charles C; Brown, David L; Galambos, John D

    2013-01-01

    Satisfying operational procedures and limits for the beam target interface is a critical concern for high power operation at spallation neutron sources. At the Oak Ridge Spallation Neutron Source (SNS) a number of protective measures are instituted to ensure that the beam position, beam size and peak intensity are within acceptable limits at the target and high power Ring Injection Dump (RID). The high power beam dump typically handles up to 50 100 kW of beam power and its setup is complicated by the fact that there are two separate beam components simultaneously directed to the dump. The beam on target is typically in the 800-1000 kW average power level, delivered in sub- s 60 Hz pulses. Setup techniques using beam measurements to quantify the beam parameters at the target and dump will be described. However, not all the instrumentation used for the setup and initial qualification is available during high power operation. Additional techniques are used to monitor the beam during high power operation to ensure the setup conditions are maintained, and these are also described.

  19. Modeling beam-driven and laser-driven plasma Wakefield accelerators with XOOPIC

    SciTech Connect

    Bruhwiler, David L.; Giacone, Rodolfo; Cary, John R.; Verboncoeur, John P.; Mardahl, Peter; Esarey, Eric; Leemans, Wim

    2000-06-01

    We present 2-D particle-in-cell simulations of both beam-driven and laser-driven plasma wakefield accelerators, using the object-oriented code XOOPIC, which is time explicit, fully electromagnetic, and capable of running on massively parallel supercomputers. Simulations of laser-driven wakefields with low ({approximately} 10{sup 16} W/cm{sup 2}) and high ({approximately} 10{sup 18} W/cm{sup 2}) peak intensity laser pulses are conducted in slab geometry, showing agreement with theory. Simulations of the E-157 beam wakefield experiment at the Stanford Linear Accelerator Center, in which a 30 GeV electron beam passes through 1 m of preionized lithium plasma, are conducted in cylindrical geometry, obtaining good agreement with previous work. We briefly describe some of the more significant modifications to XOOPIC required by this work, and summarize the issues relevant to modeling electron-neutral collisions in a particle-in-cell code.

  20. Intense high-quality medical proton beams via laser fields.

    PubMed

    Galow, Benjamin J; Harman, Zoltán; Keitel, Christoph H

    2010-12-06

    Simulations based on the coupled relativistic equations of motion show that protons stemming from laser-plasma processes can be efficiently post-accelerated employing single and crossed pulsed laser beams focused to spot radii on the order of the laser wavelength. We demonstrate that the crossed beams produce quasi-monoenergetic accelerated protons with kinetic energies exceeding 200 MeV, small energy spreads of about 1% and high densities as required for hadron cancer therapy. To our knowledge, this is the first scheme allowing for this important application based on an all-optical set-up.

  1. Photo-production of (99)Mo/(99m)Tc with electron linear accelerator beam.

    PubMed

    Avagyan, R; Avetisyan, A; Kerobyan, I; Dallakyan, R

    2014-09-01

    We report on the development of a relatively new method for the production of (99)Mo/(99m)Tc. The method involves the irradiation of natural molybdenum using high-intensity bremsstrahlung photons from the electron beam of the LUE50 linear electron accelerator located at the Yerevan Physics Institute (YerPhi). The production method has been developed and shown to be successful. The linear electron accelerator at YerPhi was upgraded to allow for significant increases of the beam intensity and spatial density. The LUE50 was also instrumented by a remote control system for ease of operation. We have developed and tested the (99m)Tc extraction from the irradiation of natural MoO3. This paper reports on the optimal conditions of our method of (99)Mo production. We show the success of this method with the production and separation of the first usable amounts of (99m)Tc.

  2. Radiation-Pressure Acceleration of Ion Beams from Nanofoil Targets: The Leaky Light-Sail Regime

    SciTech Connect

    Qiao, B.; Zepf, M.; Borghesi, M.; Dromey, B.; Geissler, M.; Karmakar, A.; Gibbon, P.

    2010-10-08

    A new ion radiation-pressure acceleration regime, the 'leaky light sail', is proposed which uses sub-skin-depth nanometer foils irradiated by circularly polarized laser pulses. In the regime, the foil is partially transparent, continuously leaking electrons out along with the transmitted laser field. This feature can be exploited by a multispecies nanofoil configuration to stabilize the acceleration of the light ion component, supplementing the latter with an excess of electrons leaked from those associated with the heavy ions to avoid Coulomb explosion. It is shown by 2D particle-in-cell simulations that a monoenergetic proton beam with energy 18 MeV is produced by circularly polarized lasers at intensities of just 10{sup 19} W/cm{sup 2}. 100 MeV proton beams are obtained by increasing the intensities to 2x10{sup 20} W/cm{sup 2}.

  3. Radiation-pressure acceleration of ion beams from nanofoil targets: the leaky light-sail regime.

    PubMed

    Qiao, B; Zepf, M; Borghesi, M; Dromey, B; Geissler, M; Karmakar, A; Gibbon, P

    2010-10-08

    A new ion radiation-pressure acceleration regime, the "leaky light sail," is proposed which uses sub-skin-depth nanometer foils irradiated by circularly polarized laser pulses. In the regime, the foil is partially transparent, continuously leaking electrons out along with the transmitted laser field. This feature can be exploited by a multispecies nanofoil configuration to stabilize the acceleration of the light ion component, supplementing the latter with an excess of electrons leaked from those associated with the heavy ions to avoid Coulomb explosion. It is shown by 2D particle-in-cell simulations that a monoenergetic proton beam with energy 18 MeV is produced by circularly polarized lasers at intensities of just 10¹⁹  W/cm². 100 MeV proton beams are obtained by increasing the intensities to 2 × 10²⁰  W/cm².

  4. ELECTROMAGNETIC SIMULATIONS OF DIELECTRIC WALL ACCELERATOR STRUCTURES FOR ELECTRON BEAM ACCELERATION

    SciTech Connect

    Nelson, S D; Poole, B R

    2005-05-05

    Dielectric Wall Accelerator (DWA) technology incorporates the energy storage mechanism, the switching mechanism, and the acceleration mechanism for electron beams. Electromagnetic simulations of DWA structures includes these effects and also details of the switch configuration and how that switch time affects the electric field pulse which accelerates the particle beam. DWA structures include both bi-linear and bi-spiral configurations with field gradients on the order of 20MV/m and the simulations include the effects of the beampipe, the beampipe walls, the DWA High Gradient Insulator (HGI) insulating stack, wakefield impedance calculations, and test particle trajectories with low emittance gain. Design trade-offs include the transmission line impedance (typically a few ohms), equilibration ring optimization, driving switch inductances, and layer-to-layer coupling effects and the associated affect on the acceleration pulse's peak value.

  5. Raman conversion in intense femtosecond Bessel beams in air

    NASA Astrophysics Data System (ADS)

    Scheller, Maik; Chen, Xi; Ariunbold, Gombojav O.; Born, Norman; Moloney, Jerome; Kolesik, Miroslav; Polynkin, Pavel

    2014-05-01

    We demonstrate experimentally that bright and nearly collimated radiation can be efficiently generated in air pumped by an intense femtosecond Bessel beam. We show that this nonlinear conversion process is driven by the rotational Raman response of air molecules. Under optimum conditions, the conversion efficiency from the Bessel pump into the on-axis propagating beam exceeds 15% and is limited by the onset of intensity clamping and plasma refraction on the beam axis. Our experimental findings are in excellent agreement with numerical simulations based on the standard model for the ultrafast nonlinear response of air.

  6. Beam Dump Design for the Rare Isotope Accelerator Fragmentation Line

    SciTech Connect

    Stein, W; Ahle, L E; Reyes, S

    2006-05-02

    Beam dumps for the heavy ion beams of the fragmentation line of the Rare Isotope Accelerator have been designed. The most severe operational case involves a continuous U beam impacting the beam dump with a power of 295 kW and a nominal spot diameter size of 5 cm. The dump mechanically consists of two rotating barrels with a water cooled outer wall of 2 mm thick aluminum. The barrels are 70 cm in diameter and axially long enough to intercept a variety of other beams. The aluminum wall absorbs approximately 15% of the U beam power with the rest absorbed in the water downstream of the wall. The water acts as an absorber of the beam and as a coolant for the 2 mm aluminum wall. The barrel rotates at less than 400 RPM, maximum aluminum temperatures are less than 100 C and maximum thermal fatigue stresses are low at 3.5 x 10{sup 7} Pa (5 ksi). Rotation of the dump results in relatively low radiation damage levels with an operating lifetime of years for most beams.

  7. GeV electron beams from a cm-scale accelerator

    SciTech Connect

    Leemans, W.P.; Nagler, B.; Gonsalves, A.J.; Toth, C.; Nakamura,K.; Geddes, C.G.R.; Esarey, E.B.; Schroeder, C.; Hooker, S.M.

    2006-05-04

    GeV electron accelerators are essential to synchrotron radiation facilities and free electron lasers, and as modules for high-energy particle physics. Radio frequency based accelerators are limited to relatively low accelerating fields (10-50 MV/m) and hence require tens to hundreds of meters to reach the multi-GeV beam energies needed to drive radiation sources, and many kilometers to generate particle energies of interest to the frontiers of high-energy physics.Laser wakefield accelerators (LWFA) in which particles are accelerated by the field of a plasma wave driven by an intense laser pulse produce electric fields several orders of magnitude stronger (10-100 GV/m) and so offer the potential of very compact devices. However, until now it has not been possible to maintain the required laser intensity, and hence acceleration, over the several centimeters needed to reach GeV energies.For this reason laser-driven accelerators have to date been limited to the 100 MeV scale. Contrary to predictions that PW-class lasers would be needed to reach GeV energies, here we demonstrate production of a high-quality electron beam with 1 GeV energy by channeling a 40 TW peak power laser pulse in a 3.3 cm long gas-filled capillary discharge waveguide. We anticipate that laser-plasma accelerators based on capillary discharge waveguides will have a major impact on the development of future femtosecond radiation sources such as x-ray free electron lasers and become a standard building block for next generation high-energy accelerators.

  8. Stopping intense beams of internally cold molecules via centrifugal forces

    NASA Astrophysics Data System (ADS)

    Wu, Xing; Gantner, Thomas; Zeppenfeld, Martin; Chervenkov, Sotir; Rempe, Gerhard

    2016-05-01

    Cryogenic buffer-gas cooling produces intense beams of internally cold molecules. It offers a versatile source for studying collision dynamics and reaction pathways in the cold regime, and could open new avenues for controlled chemistry, precision spectroscopy, and exploration of fundamental physics. However, an efficient deceleration of these beams still presents a challenge. Here, we demonstrate that intense and continuous beams of electrically guided molecules produced by a cryogenic buffer-gas cell can be brought to a halt by the centrifugal force in a rotating frame. Various molecules (e.g. CH3F and CF3CCH) are decelerated to below 20m /s at a corresponding output intensity of ~ 6 ×109mm-2 .s-1 . In addition, our RF-resonant depletion detection shows that up to 90 % rotational-state purity can be achieved in the so-produced slow molecular beams.

  9. Applications with Intense OTR Images II: Microbunched Electron Beams

    NASA Astrophysics Data System (ADS)

    Lumpkin, A. H.; Dejus, R. J.; Rule, D. W.

    2004-12-01

    In this second application for intense images we take advantage of the coherent enhancement of optical transition radiation (OTR) due to self-amplified spontaneous emission (SASE) free-electron laser (FEL)-induced microbunching of the beam. A much smaller number of total particles is involved, but the microbunched fraction (NB) gives a NB2 enhancement. We report measurements on the z-dependent growth of the coherent OTR (COTR) and the effects of beam size and electron beam/photon beam coalignment in the COTR interferograms.

  10. Diagnostic Tools For Low Intensity Ion Micro-Beams

    SciTech Connect

    Finocchiaro, P.; Cosentino, L.; Pappalardo, A.; Vervaeke, M.; Volckaerts, B.; Vynck, P.; Hermanne, A.; Thienpont, H.

    2003-08-26

    We have developed two techniques for microscopic ion beam imaging and profiling, both based on scintillators, particularly suitable for applications in Deep Lithography with Protons (DLP) or with heavier ions. The first one employs a scintillating fiberoptic plate and a CCD camera with suitable lenses, the second makes use of a small scintillator optically coupled to a compact photomultiplier. We have proved the possibility of spanning from single beam particles counting up to several nA currents. Both devices are successfully being exploited for on-line control of low and very low intensity proton beams, down to a beam size of less than 50{mu}m.

  11. Limiting current of intense electron beams in a decelerating gap

    NASA Astrophysics Data System (ADS)

    Nusinovich, G. S.; Beaudoin, B. L.; Thompson, C.; Karakkad, J. A.; Antonsen, T. M.

    2016-02-01

    For numerous applications, it is desirable to develop electron beam driven efficient sources of electromagnetic radiation that are capable of producing the required power at beam voltages as low as possible. This trend is limited by space charge effects that cause the reduction of electron kinetic energy and can lead to electron reflection. So far, this effect was analyzed for intense beams propagating in uniform metallic pipes. In the present study, the limiting currents of intense electron beams are analyzed for the case of beam propagation in the tubes with gaps. A general treatment is illustrated by an example evaluating the limiting current in a high-power, tunable 1-10 MHz inductive output tube (IOT), which is currently under development for ionospheric modification. Results of the analytical theory are compared to results of numerical simulations. The results obtained allow one to estimate the interaction efficiency of IOTs.

  12. New techniques in hadrontherapy: intensity modulated proton beams.

    PubMed

    Cella, L; Lomax, A; Miralbell, R

    2001-01-01

    Inverse planning and intensity modulated (IM) X-ray beam treatment techniques can achieve significant improvements in dose distributions comparable to those obtained with forward planned proton beams. However, intensity modulation can also be applied to proton beams and further optimization in dose distribution can reasonably be expected. A comparative planning exercise between IM X-rays and IM proton beams was carried out on two different tumor cases: a pediatric rhabdomyosarcoma and a prostate cancer. Both IM X-rays and IM protons achieved equally homogenous coverage of the target volume in the two tumor sites. Predicted NTCPs were equally low for both treatment techniques. Nevertheless, a reduced low-to-medium dose to the organs at risk and a lesser integral non-target mean dose for IM protons in the two cases favored the use of IM proton beams.

  13. Radio Frequency Station - Beam Dynamics Interaction in Circular Accelerators

    SciTech Connect

    Mastoridis, Themistoklis

    2010-08-01

    The longitudinal beam dynamics in circular accelerators is mainly defined by the interaction of the beam current with the accelerating Radio Frequency (RF) stations. For stable operation, Low Level RF (LLRF) feedback systems are employed to reduce coherent instabilities and regulate the accelerating voltage. The LLRF system design has implications for the dynamics and stability of the closed-loop RF systems as well as for the particle beam, and is very sensitive to the operating range of accelerator currents and energies. Stability of the RF loop and the beam are necessary conditions for reliable machine operation. This dissertation describes theoretical formalisms and models that determine the longitudinal beam dynamics based on the LLRF implementation, time domain simulations that capture the dynamic behavior of the RF station-beam interaction, and measurements from the Positron-Electron Project (PEP-II) and the Large Hadron Collider (LHC) that validate the models and simulations. These models and simulations are structured to capture the technical characteristics of the system (noise contributions, non-linear elements, and more). As such, they provide useful results and insight for the development and design of future LLRF feedback systems. They also provide the opportunity to study diverse longitudinal beam dynamics effects such as coupled-bunch impedance driven instabilities and single bunch longitudinal emittance growth. Coupled-bunch instabilities and RF station power were the performance limiting effects for PEP-II. The sensitivity of the instabilities to individual LLRF parameters, the effectiveness of alternative operational algorithms, and the possible tradeoffs between RF loop and beam stability were studied. New algorithms were implemented, with significant performance improvement leading to a world record current during the last PEP-II run of 3212 mA for the Low Energy Ring. Longitudinal beam emittance growth due to RF noise is a major concern for LHC

  14. High intensity copper atom beam - Preliminary results

    NASA Technical Reports Server (NTRS)

    Kelly, A. J.; Santavicca, D.

    1973-01-01

    The development of a nozzle which gas-dynamically accelerates neutral copper atoms at controlled energy levels and flux rates suitable for the investigation of inelastic copper atom collision processes is reported. Preliminary test data demonstrate that vapor-deposited rhenium nozzles do not degrade in the presence of copper vapor at high temperatures. Operation with high purity helium gas at nozzle stagnation temperatures in the range 2650-2700 K and total stagnation pressures from 1/4 to 2 atm with continuous copper atom flux rates of approximately 10 to the 18th power per second has been maintained, for a total time of 8-1/2 h to date.

  15. Superconducting accelerating structures for very low velocity ion beams

    SciTech Connect

    Xu, J.; Shepard, K.W.; Ostroumov, P.N.; Fuerst, J.D.; Waldschmidt, G.; Gonin, I.V.; /Fermilab

    2008-01-01

    This paper presents designs for four types of very-low-velocity superconducting accelerating cavity capable of providing several MV of accelerating potential per cavity, and suitable for particle velocities in the range 0.006 < v/c < 0.06. Superconducting TEM-class cavities have been widely applied to CW acceleration of ion beams. SC linacs can be formed as an array of independently-phased cavities, enabling a variable velocity profile to maximize the output energy for each of a number of different ion species. Several laboratories in the US and Europe are planning exotic beam facilities based on SC linacs. The cavity designs presented here are intended for the front-end of such linacs, particularly for the post-acceleration of rare isotopes of low charge state. Several types of SC cavities have been developed recently to cover particle velocities above 0.06c. Superconducting four-gap quarter-wave resonators for velocities 0.008 < {beta} = v/c < 0.05 were developed about two decades ago and have been successfully operated at the ATLAS SC linac at Argonne National Laboratory. Since that time, progress in simulation tools, cavity fabrication and processing have increased SC cavity gradients by a factor of 3-4. This paper applies these tools to optimize the design of a four-gap quarter-wave resonator for exotic beam facilities and other low-velocity applications.

  16. Undulator radiation driven by laser-wakefield accelerator electron beams

    NASA Astrophysics Data System (ADS)

    Wiggins, S. M.; Anania, M. P.; Welsh, G. H.; Brunetti, E.; Cipiccia, S.; Grant, P. A.; Reboredo, D.; Manahan, G.; Grant, D. W.; Jaroszynski, D. A.

    2015-05-01

    The Advanced Laser-Plasma High-Energy Accelerators towards X-rays (ALPHA-X) programme is developing laserplasma accelerators for the production of ultra-short electron bunches with subsequent generation of coherent, bright, short-wavelength radiation pulses. The new Scottish Centre for the Application of Plasma-based Accelerators (SCAPA) will develop a wide range of applications utilising such light sources. Electron bunches can be propagated through a magnetic undulator with the aim of generating fully coherent free-electron laser (FEL) radiation in the ultra-violet and Xrays spectral ranges. Demonstration experiments producing spontaneous undulator radiation have been conducted at visible and extreme ultra-violet wavelengths but it is an on-going challenge to generate and maintain electron bunches of sufficient quality in order to stimulate FEL behaviour. In the ALPHA-X beam line experiments, a Ti:sapphire femtosecond laser system with peak power 20 TW has been used to generate electron bunches of energy 80-150 MeV in a 2 mm gas jet laser-plasma wakefield accelerator and these bunches have been transported through a 100 period planar undulator. High peak brilliance, narrow band spontaneous radiation pulses in the vacuum ultra-violet wavelength range have been generated. Analysis is provided with respect to the magnetic quadrupole beam transport system and subsequent effect on beam emittance and duration. Requirements for coherent spontaneous emission and FEL operation are presented.

  17. Heavy-ion beam dynamics in the RIA post-accelerator.

    SciTech Connect

    Ostroumov, P. N.; Kolomiets, A. A.; Aseev, V. N.; Physics

    2005-01-01

    The RIA post-accelerator (RIB) includes three main sections: a room temperature injector with design ion charge-to-mass ratio 1/240 and output energy of {approx} 93 keV/u, a superconducting (SC) linac for ions with charge-to-mass ratio 1/66 or higher up to an energy of {approx} 1 MeV/u and a higher energy SC linac including existing ATLAS to produce 10 MeV/u beams up to uranium. Two strippers are installed between the sections. Extensive accelerator design studies and end-to-end beam dynamics simulations have been performed to minimize the cost of the linac while providing high-quality and high-intensity radioactive beams. Specifically, we have found that cost-effective acceleration in the front end can be provided by several hybrid RFQs proposed and developed for acceleration of low-velocity heavy ions. For beam focusing in the second section it is appropriate to use electrostatic lenses and SC quadrupoles inside common cryostats with the resonators.

  18. Emittance Growth in Intense Non-Circular Beams

    NASA Astrophysics Data System (ADS)

    Anderson, O. A.

    1997-05-01

    The electrostatic energy of intense beams in linear uniform focusing channels is minimized when the initial beam configuration is both uniform and round.(In the case of quadrupole focusing, this means round on the average.) Deviations from either uniformity or roundness produce free energy and emittance growth. Over the past 25 years, the consequences of beam nonuniformity have been thoroughly investigated for the case of round beams. Recently, there has been interest in more complex beam configurations such as those that occur in Heavy Ion Fusion (HIF) combiners or splitters. We discuss free energy and emittance growth for a variety of cases: (a) square beams, (b) hexagonal beams, (c) beams bounded by a quadrant or sextant of a circle, (d) rectangular beams, (e) elliptical beams, (f) pairs of beamlets, and (g) arrays of many beamlets. Cases (a) and (b) are approximations for large arrays of beamlets as proposed for HIF combiners or for negative-ion sources. Beam splitting, suggested for a particular HIF final focus scheme, leads to (c). The large emittance growth in cases (d)-(f), calculated by a new method,(O.A. Anderson, Proceedings of EPAC 96 conference.) illustrates the importance of maintaining symmetry. Practical examples are given for several cases.

  19. Optimization of Beam Injection Into the First Accelerating Module at TTF With Cavity Dipole Mode Signals

    SciTech Connect

    Baboi, N.; Kreps, G.; Schlarb, H.; Wendt, M.; Frisch, J.; McCormick, D.; Ross, M.; Smith, T.; Napoly, O.; Paparella, R.G.; /DSM, DAPNIA, Saclay

    2006-04-10

    The TESLA Test Facility (TTF) is a user facility for intense VUV-FEL light. The facility is densely equipped with diagnostics, essential in obtaining the necessary beam parameters, in particular the low emittance. However there is no dedicated component for alignment of the beam in the accelerating modules, each containing eight superconducting cavities. Large beam offsets can lead to an increase of the beam emittance. The centering of the beam in these modules is therefore important, mostly at the low energy end. A misalignment of the first TTF module with respect to the gun axis has already been observed using cavity dipole modes. This paper presents the experimental results of the optimization of the beam injection into the first module, based on the monitoring of dipole modes through the couplers installed for wakefield damping. For this we use a spectrum analyzer together with a multiplexer. By scanning the beam position and tilt with two pairs of steerers, we can find the trajectory which minimizes the dipole modes amplitude. The impact of the beam steering in the module on the beam is discussed. A time domain setup is also being presented.

  20. Beam loading compensation for acceleration of multi-bunch electron beam train

    NASA Astrophysics Data System (ADS)

    Liu, Shengguang; Fukuda, Masafumi; Araki, Sakae; Terunuma, Nobuhiro; Urakawa, Junji; Hirano, Koichiro; Sasao, Noboru

    2008-01-01

    The laser undulator compact X-ray source (LUCX) is a test bench used with the compact, high-brightness X-ray generator at KEK (High Energy Accelerator Research Organization). Our group is conducting experiments with LUCX to demonstrate the possibility of K-edge digital subtraction angiography, based on Compton scattering. One of the challenging problems is to generate high-brightness multi-bunch electron beams to compensate for the energy difference arising from the beam loading effect. In this paper we calculate the transient beam loading voltage and energy gain from the RF field in the gun and accelerating tube for a multi-bunch train. To do so we consider the process by which the RF field builds up in the gun and accelerating tube, and the special shape of the RF pulse. We generate and accelerate 100 bunches with a 50 nC electron bunch train, effectively compensating for the beam loading effect by adjusting the injection timing. Using a beam position monitor (BPM) and optical transition radiation (OTR) system, we measure the electron beam energy bunch by bunch. The average energy of a 100-bunch train is 40.5 MeV and the maximum energy difference from bunch to bunch is 0.26 MeV.

  1. Laser beam-profile impression and target thickness impact on laser-accelerated protons

    NASA Astrophysics Data System (ADS)

    Schollmeier, M.; Harres, K.; Nürnberg, F.; Blažević, A.; Audebert, P.; Brambrink, E.; Fernández, J. C.; Flippo, K. A.; Gautier, D. C.; Geißel, M.; Hegelich, B. M.; Schreiber, J.; Roth, M.

    2008-05-01

    Experimental results on the influence of the laser focal spot shape onto the beam profile of laser-accelerated protons from gold foils are reported. The targets' microgrooved rear side, together with a stack of radiochromic films, allowed us to deduce the energy-dependent proton source-shape and size, respectively. The experiments show, that shape and size of the proton source depend only weakly on target thickness as well as shape of the laser focus, although they strongly influence the proton's intensity distribution. It was shown that the laser creates an electron beam that closely follows the laser beam topology, which is maintained during the propagation through the target. Protons are then accelerated from the rear side with an electron created electric field of a similar shape. Simulations with the Sheath-Accelerated Beam Ray-tracing for IoN Analysis code SABRINA, which calculates the proton distribution in the detector for a given laser-beam profile, show that the electron distribution during the transport through a thick target (50μm Au) is only modified due to multiple small angle scattering. Thin targets (10μm) show large source sizes of over 100μm diameter for 5MeV protons, which cannot be explained by multiple scattering only and are most likely the result of refluxing electrons.

  2. Laser beam-profile impression and target thickness impact on laser-accelerated protons

    SciTech Connect

    Schollmeier, M.; Harres, K.; Nuernberg, F.; Roth, M.; Blazevic, A.; Audebert, P.; Brambrink, E.; Fernandez, J. C.; Flippo, K. A.; Gautier, D. C.; Geissel, M.; Hegelich, B. M.; Schreiber, J.

    2008-05-15

    Experimental results on the influence of the laser focal spot shape onto the beam profile of laser-accelerated protons from gold foils are reported. The targets' microgrooved rear side, together with a stack of radiochromic films, allowed us to deduce the energy-dependent proton source-shape and size, respectively. The experiments show, that shape and size of the proton source depend only weakly on target thickness as well as shape of the laser focus, although they strongly influence the proton's intensity distribution. It was shown that the laser creates an electron beam that closely follows the laser beam topology, which is maintained during the propagation through the target. Protons are then accelerated from the rear side with an electron created electric field of a similar shape. Simulations with the Sheath-Accelerated Beam Ray-tracing for IoN Analysis code SABRINA, which calculates the proton distribution in the detector for a given laser-beam profile, show that the electron distribution during the transport through a thick target (50 {mu}m Au) is only modified due to multiple small angle scattering. Thin targets (10 {mu}m) show large source sizes of over 100 {mu}m diameter for 5 MeV protons, which cannot be explained by multiple scattering only and are most likely the result of refluxing electrons.

  3. ELIMED, future hadrontherapy applications of laser-accelerated beams

    NASA Astrophysics Data System (ADS)

    Cirrone, Giuseppe A. P.; Carpinelli, Massimo; Cuttone, Giacomo; Gammino, Santo; Bijan Jia, S.; Korn, Georg; Maggiore, Mario; Manti, Lorenzo; Margarone, Daniele; Prokupek, Jan; Renis, Marcella; Romano, Francesco; Schillaci, Francesco; Tomasello, Barbara; Torrisi, Lorenzo; Tramontana, Antonella; Velyhan, Andriy

    2013-12-01

    Laser-ion acceleration has recently gained a great interest as an alternative to conventional and more expensive acceleration techniques. These ion beams have desirable qualities such as small source size, high luminosity and small emittance to be used in different fields as Nuclear Physics, Medical Physics, etc. This is very promising specially for the future perspective of a new concept of hadrontherapy based on laser-based devices could be developed, replacing traditional accelerating machines. Before delivering laser-driven beams for treatments they have to be handled, cleaned from unwanted particles and characterized in order to have the clinical requirements. In fact ion energy spectra have exponential trend, almost 100% energy spread and a wide angular divergence which is the biggest issue in the beam transport and, hence, in a wider use of this technology. In order to demonstrate the clinical applicability of laser-driven beams new collaboration between ELI-Beamlines project researchers from Prague (Cz) and a INFN-LNS group from Catania (I) has been already launched and scientists from different countries have already express their will in joining the project. This cooperation has been named ELIMED (MEDical application at ELIBeamlines) and will take place inside the ELI-Beamlines infrastructure located in Prague. This work describes the schedule of the ELIMED project and the design of the energy selector which will be realized at INFN-LNS. The device is an important part of the whole transport beam line which will be realised in order to make the ion beams suitable for medical applications.

  4. Transformer ratio saturation in a beam-driven wakefield accelerator

    SciTech Connect

    Farmer, J. P.; Martorelli, R.; Pukhov, A.

    2015-12-15

    We show that for beam-driven wakefield acceleration, the linearly ramped, equally spaced train of bunches typically considered to optimise the transformer ratio only works for flat-top bunches. Through theory and simulation, we explain that this behaviour is due to the unique properties of the plasma response to a flat-top density profile. Calculations of the optimal scaling for a train of Gaussian bunches show diminishing returns with increasing bunch number, tending towards saturation. For a periodic bunch train, a transformer ratio of 23 was achieved for 50 bunches, rising to 40 for a fully optimised beam.

  5. Development of a synchrotron radiation beam monitor for the Integrable Optics Test Accelerator

    SciTech Connect

    Scarpelli, Andrea

    2016-01-01

    Nonlinear integrable optics applied to beam dynamics may mitigate multi-particle instabilities, but proof of principle experiments have never been carried out. The Integrable Optics Test Accelerator (IOTA) is an electron and proton storage ring currently being built at Fermilab, which addresses tests of nonlinear lattice elements in a real machine in addition to experiments on optical stochastic cooling and on the single-electron wave function. These experiments require an outstanding control over the lattice parameters, achievable with fast and precise beam monitoring systems. This work describes the steps for designing and building a beam monitor for IOTA based on synchrotron radiation, able to measure intensity, position and transverse cross-section beam.

  6. Study of a multi-beam accelerator driven thorium reactor

    SciTech Connect

    Ludewig, H.; Aronson, A.

    2011-03-01

    The primary advantages that accelerator driven systems have over critical reactors are: (1) Greater flexibility regarding the composition and placement of fissile, fertile, or fission product waste within the blanket surrounding the target, and (2) Potentially enhanced safety brought about by operating at a sufficiently low value of the multiplication factor to preclude reactivity induced events. The control of the power production can be achieved by vary the accelerator beam current. Furthermore, once the beam is shut off the system shuts down. The primary difference between the operation of an accelerator driven system and a critical system is the issue of beam interruptions of the accelerator. These beam interruptions impose thermo-mechanical loads on the fuel and mechanical components not found in critical systems. Studies have been performed to estimate an acceptable number of trips, and the value is significantly less stringent than had been previously estimated. The number of acceptable beam interruptions is a function of the length of the interruption and the mission of the system. Thus, for demonstration type systems and interruption durations of 1sec < t < 5mins, and t > 5mins 2500/yr and 50/yr are deemed acceptable. However, for industrial scale power generation without energy storage type systems and interruption durations of t < 1sec., 1sec < t < 10secs., 10secs < t < 5mins, and t > 5mins, the acceptable number of interruptions are 25000, 2500, 250, and 3 respectively. However, it has also been concluded that further development is required to reduce the number of trips. It is with this in mind that the following study was undertaken. The primary focus of this study will be the merit of a multi-beam target system, which allows for multiple spallation sources within the target/blanket assembly. In this manner it is possible to ameliorate the effects of sudden accelerator beam interruption on the surrounding reactor, since the remaining beams will still

  7. Advanced concepts for acceleration

    SciTech Connect

    Keefe, D.

    1986-07-01

    Selected examples of advanced accelerator concepts are reviewed. Such plasma accelerators as plasma beat wave accelerator, plasma wake field accelerator, and plasma grating accelerator are discussed particularly as examples of concepts for accelerating relativistic electrons or positrons. Also covered are the pulsed electron-beam, pulsed laser accelerator, inverse Cherenkov accelerator, inverse free-electron laser, switched radial-line accelerators, and two-beam accelerator. Advanced concepts for ion acceleration discussed include the electron ring accelerator, excitation of waves on intense electron beams, and two-wave combinations. (LEW)

  8. The beat in laser-accelerated ion beams

    SciTech Connect

    Schnürer, M.; Abicht, F.; Bränzel, J.; Koschitzki, Ch.; Andreev, A. A.; Platonov, K. Yu.; Priebe, G.; Sandner, W.

    2013-10-15

    Regular modulation in the ion velocity distribution becomes detectable if intense femtosecond laser pulses with very high temporal contrast are used for target normal sheath acceleration of ions. Analytical and numerical analysis of the experimental observation associates the modulation with the half-cycle of the driving laser field period. In processes like ion acceleration, the collective and laser-frequency determined electron dynamics creates strong fields in plasma to accelerate the ions. Even the oscillatory motion of electrons and its influence on the acceleration field can dominate over smoothing effects in plasma if a high temporal contrast of the driving laser pulse is given. Acceleration parameters can be directly concluded out of the experimentally observed modulation period in ion velocity spectra. The appearance of the phenomenon at a temporal contrast of ten orders between the intensity of the pulse peak and the spontaneous amplified emission background as well as remaining intensity wings at picosecond time-scale might trigger further parameter studies with even higher contrast.

  9. Characterization of intense ion beam energy density and beam induced pressure on the target with acoustic diagnostics

    SciTech Connect

    Pushkarev, A. I.; Isakova, Yu. I.; Khailov, I. P.; Yu, Xiao

    2013-08-15

    We have developed the acoustic diagnostics based on a piezoelectric transducer for characterization of high-intensity pulsed ion beams. The diagnostics was tested using the TEMP-4M accelerator (150 ns, 250–300 kV). The beam is composed of C{sup +} ions (85%) and protons, the beam energy density is 0.5–5 J/cm{sup 2} (depending on diode geometry). A calibration dependence of the signal from a piezoelectric transducer on the ion beam energy density is obtained using thermal imaging diagnostics. It is shown that the acoustic diagnostics allows for measurement of the beam energy density in the range of 0.1–2 J/cm{sup 2}. The dependence of the beam generated pressure on the input energy density is also determined and compared with the data from literature. The developed acoustic diagnostics do not require sophisticated equipment and can be used for operational control of pulsed ion beam parameters with a repetition rate of 10{sup 3} pulses/s.

  10. Laser-driven multicharged heavy ion beam acceleration

    NASA Astrophysics Data System (ADS)

    Nishiuchi, M.; Sakaki, H.; Esirkepov, T. Z.; Nishio, K.; Pikuz, T. A.; Faenov, A. Y.; Pirozhkov, A. S.; Sagisaka, A.; Ogura, K.; Kanasaki, M.; Kiriyama, H.; Fukuda, Y.; Kando, M.; Yamauchi, T.; Watanabe, Y.; Bulanov, S. V.; Kondo, K.; Imai, K.; Nagamiya, S.

    2015-05-01

    Experimental demonstration of multi-charged heavy ion acceleration from the interaction between the ultra-intense short pulse laser system and the metal target is presented. The laser pulse of <10 J laser energy, 36 fs pulse width, and the contrast level of ~1010 from 200 TW class Ti:sapphire J-KAREN laser system at JAEA is used in the experiment. Almost fully stripped Fe ions accelerated up to 0.9 GeV are demonstrated. This is achieved by the high intensity laser field of ˜ 1021Wcm-2 interacting with the solid density target. The demonstrated iron ions with high charge to mass ratio (Q/M) is difficult to be achieved by the conventional heavy ion source technique in the accelerators.

  11. Physics with post-accelerated beams at ISOLDE: nuclear reactions

    NASA Astrophysics Data System (ADS)

    Di Pietro, A.; Riisager, K.; Van Duppen, P.

    2017-04-01

    Nuclear-reaction studies have until now constituted a minor part of the physics program with post-accelerated beams at ISOLDE, mainly due to the maximum energy of REX-ISOLDE of around 3 MeV/u that limits reaction work to the mass region below A = 100. We give an overview of the current experimental status and of the physics results obtained so far. Finally, the improved conditions given by the HIE-ISOLDE upgrade are described.

  12. Intense beams from gases generated by a permanent magnet ECR ion source at PKUa)

    NASA Astrophysics Data System (ADS)

    Ren, H. T.; Peng, S. X.; Lu, P. N.; Yan, S.; Zhou, Q. F.; Zhao, J.; Yuan, Z. X.; Guo, Z. Y.; Chen, J. E.

    2012-02-01

    An electron cyclotron resonance (ECR) ion source is designed for the production of high-current ion beams of various gaseous elements. At the Peking University (PKU), the primary study is focused on developing suitable permanent magnet ECR ion sources (PMECRs) for separated function radio frequency quadrupole (SFRFQ) accelerator and for Peking University Neutron Imaging Facility. Recently, other kinds of high-intensity ion beams are required for new acceleration structure demonstration, simulation of fusion reactor material irradiation, aviation bearing modification, and other applications. So we expanded the ion beam category from O+, H+, and D+ to N+, Ar+, and He+. Up to now, about 120 mA of H+, 83 mA of D+, 50 mA of O+, 63 mA of N+, 70 mA of Ar+, and 65 mA of He+ extracted at 50 kV through a ϕ 6 mm aperture were produced by the PMECRs at PKU. Their rms emittances are less than 0.2 π mm mrad. Tungsten samples were irradiated by H+ or He+ beam extracted from this ion source and H/He holes and bubbles have been observed on the samples. A method to produce a high intensity H/He mixed beam to study synergistic effect is developed for nuclear material irradiation. To design a He+ beam injector for coupled radio frequency quadruple and SFRFQ cavity, He+ beam transmission experiments were carried out on PKU low energy beam transport test bench and the transmission was less than 50%. It indicated that some electrode modifications must be done to decrease the divergence of He+ beam.

  13. Intense beams from gases generated by a permanent magnet ECR ion source at PKU

    SciTech Connect

    Ren, H. T.; Chen, J. E.; Peng, S. X.; Lu, P. N.; Yan, S.; Zhou, Q. F.; Zhao, J.; Yuan, Z. X.; Guo, Z. Y.

    2012-02-15

    An electron cyclotron resonance (ECR) ion source is designed for the production of high-current ion beams of various gaseous elements. At the Peking University (PKU), the primary study is focused on developing suitable permanent magnet ECR ion sources (PMECRs) for separated function radio frequency quadrupole (SFRFQ) accelerator and for Peking University Neutron Imaging Facility. Recently, other kinds of high-intensity ion beams are required for new acceleration structure demonstration, simulation of fusion reactor material irradiation, aviation bearing modification, and other applications. So we expanded the ion beam category from O{sup +}, H{sup +}, and D{sup +} to N{sup +}, Ar{sup +}, and He{sup +}. Up to now, about 120 mA of H{sup +}, 83 mA of D{sup +}, 50 mA of O{sup +}, 63 mA of N{sup +}, 70 mA of Ar{sup +}, and 65 mA of He{sup +} extracted at 50 kV through a {phi} 6 mm aperture were produced by the PMECRs at PKU. Their rms emittances are less than 0.2 {pi} mm mrad. Tungsten samples were irradiated by H{sup +} or He{sup +} beam extracted from this ion source and H/He holes and bubbles have been observed on the samples. A method to produce a high intensity H/He mixed beam to study synergistic effect is developed for nuclear material irradiation. To design a He{sup +} beam injector for coupled radio frequency quadruple and SFRFQ cavity, He{sup +} beam transmission experiments were carried out on PKU low energy beam transport test bench and the transmission was less than 50%. It indicated that some electrode modifications must be done to decrease the divergence of He{sup +} beam.

  14. Optimization and control of two-component radially self-accelerating beams

    SciTech Connect

    Vetter, Christian; Eichelkraut, Toni; Ornigotti, Marco; Szameit, Alexander

    2015-11-23

    We report on the properties of radially self-accelerating intensity distributions consisting of two components in the angular frequency domain. We show how this subset of solutions, in literature also known as helicon beams, possesses peculiar characteristics that enable a better control over its properties. In this work, we present a step-by-step optimization procedure to achieve the best possible intensity contrast, a distinct rotation rate and long propagation lengths. All points are discussed on a theoretical basis and are experimentally verified.

  15. Intense Pulsed Neutron Emission from a Compact Pyroelectric Driven Accelerator

    SciTech Connect

    Tang, V; Meyer, G; Falabella, S; Guethlein, G; Sampayan, S; Kerr, P; Rusnak, B; Morse, J

    2008-10-08

    Intense pulsed D-D neutron emission with rates >10{sup 10} n/s during the pulse, pulse widths of {approx}100's ns, and neutron yields >10 k per pulse are demonstrated in a compact pyroelectric accelerator. The accelerator consists of a small pyroelectric LiTaO{sub 3} crystal which provides the accelerating voltage and an independent compact spark plasma ion source. The crystal voltage versus temperature is characterized and compare well with theory. Results show neutron output per pulse that scales with voltage as V{approx}1.7. These neutron yields match a simple model of the system at low voltages but are lower than predicted at higher voltages due to charge losses not accounted for in the model. Interpretation of the data against modeling provides understanding of the accelerator and in general pyroelectric LiTaO{sub 3} crystals operated as charge limited negative high voltage targets. The findings overall serve as the proof-of-principle and basis for pyroelectric neutron generators that can be pulsed, giving peak neutron rates orders of magnitude greater than previous work, and notably increase the potential applications of pyroelectric based neutron generators.

  16. Trends for Electron Beam Accelerator Applications in Industry

    NASA Astrophysics Data System (ADS)

    Machi, Sueo

    2011-02-01

    Electron beam (EB) accelerators are major pieces of industrial equipment used for many commercial radiation processing applications. The industrial use of EB accelerators has a history of more than 50 years and is still growing in terms of both its economic scale and new applications. Major applications involve the modification of polymeric materials to create value-added products, such as heat-resistant wires, heat-shrinkable sheets, automobile tires, foamed plastics, battery separators and hydrogel wound dressing. The surface curing of coatings and printing inks is a growing application for low energy electron accelerators, resulting in an environmentally friendly and an energy-saving process. Recently there has been the acceptance of the use of EB accelerators in lieu of the radioactive isotope cobalt-60 as a source for sterilizing disposable medical products. Environmental protection by the use of EB accelerators is a new and important field of application. A commercial plant for the cleaning flue gases from a coal-burning power plant is in operation in Poland, employing high power EB accelerators. In Korea, a commercial plant uses EB to clean waste water from a dye factory.

  17. Loss-proof self-accelerating beams and their use in non-paraxial manipulation of particles' trajectories.

    PubMed

    Schley, Ran; Kaminer, Ido; Greenfield, Elad; Bekenstein, Rivka; Lumer, Yaakov; Segev, Mordechai

    2014-10-30

    Self-accelerating beams--shape-preserving bending beams--are attracting great interest, offering applications in many areas such as particle micromanipulation, microscopy, induction of plasma channels, surface plasmons, laser machining, nonlinear frequency conversion and electron beams. Most of these applications involve light-matter interactions, hence their propagation range is limited by absorption. We propose loss-proof accelerating beams that overcome linear and nonlinear losses. These beams, as analytic solutions of Maxwell's equations with losses, propagate in absorbing media while maintaining their peak intensity. While the power such beams carry decays during propagation, the peak intensity and the structure of their main lobe region are maintained over large distances. We use these beams for manipulation of particles in fluids, steering the particles to steeper angles than ever demonstrated. Such beams offer many additional applications, such as loss-proof self-bending plasmons. In transparent media these beams show exponential intensity growth, which facilitates other novel applications in micromanipulation and ignition of nonlinear processes.

  18. Population Inversions in Ablation Plasmas Generated by Intense Electron Beams.

    DTIC Science & Technology

    1988-11-01

    light weight design, and moderate cost. The Soviets have investigated intense proton beam pumped plasma lasers , however, the University of Michigan...interpretations have been verified by moving the position of the probe laser beam away from the surface of the anode (from 0.1 cm to 0.4 cm) and noting the changes...Properties Effects on Ultraviolet Laser induced Flashover of Angled Plastic insulators in Vacuum", C.L. Ensloe and R. M. Gilgenbach, IEEE 3 Trans. on

  19. Nonlinear d--ta-f Simulation Studies of Intense Charged Particle Beams with Large Temperature Anisotropy

    SciTech Connect

    Edward A. Startsev; Ronald C. Davidson; Hong Qin

    2002-05-07

    In this paper, a 3-D nonlinear perturbative particle simulation code (BEST) [H. Qin, R.C. Davidson and W.W. Lee, Physical Review Special Topics on Accelerators and Beams 3 (2000) 084401] is used to systematically study the stability properties of intense nonneutral charged particle beams with large temperature anisotropy (T{sub {perpendicular}b} >> T{sub {parallel}b}). The most unstable modes are identified, and their eigen frequencies, radial mode structure, and nonlinear dynamics are determined for axisymmetric perturbations with {partial_derivative}/{partial_derivative}{theta} = 0.

  20. Laser-driven electron beam acceleration and future application to compact light sources

    SciTech Connect

    Hafz, N.; Jeong, T. M.; Lee, S. K.; Pae, K. H.; Sung, J. H.; Choi, I. W.; Yu, T. J.; Lee, J.; Jeong, Y. U.

    2009-07-25

    Laser-driven plasma accelerators are gaining much attention by the advanced accelerator community due to the potential these accelerators hold in miniaturizing future high-energy and medium-energy machines. In the laser wakefield accelerator (LWFA), the ponderomotive force of an ultrashort high intensity laser pulse excites a longitudinal plasma wave or bubble. Due to huge charge separation, electric fields created in the plasma bubble can be several orders of magnitude higher than those available in conventional microwave and RF-based accelerator facilities which are limited (up to approx100 MV/m) by material breakdown. Therefore, if an electron bunch is injected into the bubble in phase with its field, it will gain relativistic energies within an extremely short distance. Here, in the LWFA we show the generation of high-quality and high-energy electron beams up to the GeV-class within a few millimeters of gas-jet plasmas irradiated by tens of terawatt ultrashort laser pulses. Thus we realize approximately four orders of magnitude acceleration gradients higher than available by conventional technology. As a practical application of the stable high-energy electron beam generation, we are planning on injecting the electron beams into a few-meters long conventional undulator in order to realize compact X-ray synchrotron (immediate) and FEL (future) light sources. Stable laser-driven electron beam and radiation devices will surely open a new era in science, medicine and technology and will benefit a larger number of users in those fields.

  1. Electron Beam Focusing in the Linear Accelerator (linac)

    NASA Astrophysics Data System (ADS)

    Jauregui, Luis

    2015-10-01

    To produce consistent data with an electron accelerator, it is critical to have a well-focused beam. To keep the beam focused, quadrupoles (quads) are employed. Quads are magnets, which focus the beam in one direction (x or y) and defocus in the other. When two or more quads are used in series, a net focusing effect is achieved in both vertical and horizontal directions. At start up there is a 5% calibration error in the linac at Thomas Jefferson National Accelerator Facility. This means that the momentum of particles passing through the quads isn't always what is expected, which affects the focusing of the beam. The objective is to find exactly how sensitive the focusing in the linac is to this 5% error. A linac was simulated, which contained 290 RF Cavities with random electric fields (to simulate the 5% calibration error), and a total momentum kick of 1090 MeV. National Science Foundation, Department of Energy, Jefferson Lab, Old Dominion University.

  2. Electrostatic-accelerator free-electron lasers for power beaming

    SciTech Connect

    Pinhasi, Y.; Yakover, I.M.; Gover, A.

    1995-12-31

    Novel concepts of electrostatic-accelerator free-electron lasers (EA-FELs) for energy transfer through the atmosphere are presented. The high average power attained from an EA-FEL makes it an efficient source of mm-wave for power beaming from a ground stations. General aspects of operating the FEL as a high power oscillator (like acceleration voltage, e-beam. current, gain and efficiency) are studied and design considerations are described. The study takes into account requirements of power beaming application such as characteristic dips in the atmospheric absorption spectrum, sizes of transmitting and receiving antennas and meteorological conditions. We present a conceptual design of a moderate voltage (.5-3 MeV) high current (1-10 Amp) EA-FEL operating at mm-wavelength bands, where the atmospheric attenuation allows efficient power beaming to space. The FEL parameters were calculated, employing analytical and numerical models. The performance parameters of the FEL (power, energy conversion efficiency average power) will be discussed in connection to the proposed application.

  3. A DSP based data acquisition module for colliding beam accelerators

    SciTech Connect

    Mead, J.A.; Shea, T.J.

    1995-10-01

    In 1999, the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory will accelerate and store two beams of gold ions. The ions will then collide head on at a total energy of nearly 40 trillion electron volts. Attaining these conditions necessitates real-time monitoring of beam parameters and for this purpose a flexible data acquisition platform has been developed. By incorporating a floating point digital signal processor (DSP) and standard input/output modules, this system can acquire and process data from a variety of beam diagnostic devices. The DSP performs real time corrections, filtering, and data buffering to greatly reduce control system computation and bandwidth requirements. We will describe the existing hardware and software while emphasizing the compromises required to achieve a flexible yet cost effective system. Applications in several instrumentation systems currently construction will also be presented.

  4. Bayesian Estimations of Peak Ground Acceleration and 5% Damped Spectral Acceleration from Modified Mercalli Intensity Data

    USGS Publications Warehouse

    Ebel, J.E.; Wald, D.J.

    2003-01-01

    We describe a new probabilistic method that uses observations of modified Mercalli intensity (MMI) from past earthquakes to make quantitative estimates of ground shaking parameters (i.e., peak ground acceleration, peak ground velocity, 5% damped spectral acceleration values, etc.). The method uses a Bayesian approach to make quantitative estimates of the probabilities of different levels of ground motions from intensity data given an earthquake of known location and magnitude. The method utilizes probability distributions from an intensity/ground motion data set along with a ground motion attenuation relation to estimate the ground motion from intensity. The ground motions with the highest probabilities are the ones most likely experienced at the site of the MMI observation. We test the method using MMI/ground motion data from California and published ground motion attenuation relations to estimate the ground motions for several earthquakes: 1999 Hector Mine, California (M7.1); 1988 Saguenay, Quebec (M5.9); and 1982 Gaza, New Hampshire (M4.4). In an example where the method is applied to a historic earthquake, we estimate that the peak ground accelerations associated with the 1727 (M???5.2) earthquake at Newbury, Massachusetts, ranged from 0.23 g at Newbury to 0.06 g at Boston.

  5. Simulating Intense Ion Beams for Inertial Fusion Energy

    SciTech Connect

    Friedman, A.

    2001-02-20

    The Heavy Ion Fusion (HIF) program's goal is the development of the body of knowledge needed for Inertial Fusion Energy (IFE) to realize its promise. The intense ion beams that will drive HIF targets are rzonneutral plasmas and exhibit collective, nonlinear dynamics which must be understood using the kinetic models of plasma physics. This beam physics is both rich and subtle: a wide range in spatial and temporal scales is involved, and effects associated with both instabilities and non-ideal processes must be understood. Ion beams have a ''long memory,'' and initialization of a beam at mid-system with an idealized particle distribution introduces uncertainties; thus, it will be crucial to develop, and to extensively use, an integrated and detailed ''source-to-target'' HIF beam simulation capability. We begin with an overview of major issues.

  6. Simulating Intense Ion Beams for Inertial Fusion Energy

    SciTech Connect

    Friedman, A

    2001-02-20

    The Heavy Ion Fusion (HIF) program's goal is the development of the body of knowledge needed for Inertial Fusion Energy (IFE) to realize its promise. The intense ion beams that will drive HIF targets are nonneutral plasmas and exhibit collective, nonlinear dynamics which must be understood using the kinetic models of plasma physics. This beam physics is both rich and subtle: a wide range in spatial and temporal scales is involved, and effects associated with both instabilities and non-ideal processes must be understood. Ion beams have a ''long memory'', and initialization of a beam at mid-system with an idealized particle distribution introduces uncertainties; thus, it will be crucial to develop, and to extensively use, an integrated and detailed ''source-to-target'' HIF beam simulation capability. We begin with an overview of major issues.

  7. A 3 Ghz photoelectron gun for high beam intensity

    SciTech Connect

    Bossart, R.; Braun, H.; Dehler, M.

    1995-12-31

    The CLIC Test Facility (CTF) for new accelerator structures of the proposed Compact Linear Collider (CLIC) is to be equipped with a new RF gun containing a laser driven photocathode. The new 3 GHz gun with photocathode shall produce a bunch train of 48 electron bunches of 25 nC charge each with a bunch length of 8 - 15 ps fwhm. The new RF gun consists of 2{1/2} cells and accelerates the beam to an energy of 7 MeV with a peak field gradient Ez = 100 MV/m. The strong space charge forces at low beam energy caused by the high charge density of the electron bunches must be contained by radial and longitudinal RF focusing in the RF gun. Radial RF focusing is applied by a conical backplane around the photocathode in the first cell where the electrons have a low energy. Longitudinal RF focusing is obtained by varying the length of each of the three cells of the gun. The total electric charge of the bunch train exceeds 1{mu}C and causes strong beam loading to the RF structures so that the stored energy is reduced to half of the unloaded RF energy. The RF gun under construction is being optimized by MAFIA beam simulations for an injector assembly comprising a second accelerating RF structure of 4 cells and an intermediate solenoid magnet correcting the beam divergence of the 2{1/2} cell gun. The scheme with two accelerating RF sections will provide a linear energy increase along the bunch suitable for further compression of the bunch length in a magnetic chicane.

  8. Intense ion beam neutralization using underdense background plasma

    SciTech Connect

    Berdanier, William; Roy, Prabir K.; Kaganovich, Igor

    2015-01-15

    Producing an overdense background plasma for neutralization purposes with a density that is high compared to the beam density is not always experimentally possible. We show that even an underdense background plasma with a small relative density can achieve high neutralization of intense ion beam pulses. Using particle-in-cell simulations, we show that if the total plasma electron charge is not sufficient to neutralize the beam charge, electron emitters are necessary for effective neutralization but are not needed if the plasma volume is so large that the total available charge in the electrons exceeds that of the ion beam. Several regimes of possible underdense/tenuous neutralization plasma densities are investigated with and without electron emitters or dense plasma at periphery regions, including the case of electron emitters without plasma, which does not effectively neutralize the beam. Over 95% neutralization is achieved for even very underdense background plasma with plasma density 1/15th the beam density. We compare results of particle-in-cell simulations with an analytic model of neutralization and find close agreement with the particle-in-cell simulations. Further, we show experimental data from the National Drift Compression experiment-II group that verifies the result that underdense plasma can neutralize intense heavy ion beams effectively.

  9. Enhanced proton beam collimation in the ultra-intense short pulse regime

    NASA Astrophysics Data System (ADS)

    Green, J. S.; Dover, N. P.; Borghesi, M.; Brenner, C. M.; Cameron, F. H.; Carroll, D. C.; Foster, P. S.; Gallegos, P.; Gregori, G.; McKenna, P.; Murphy, C. D.; Najmudin, Z.; Palmer, C. A. J.; Prasad, R.; Romagnani, L.; Quinn, K. E.; Schreiber, J.; Streeter, M. J. V.; Ter-Avetisyan, S.; Tresca, O.; Zepf, M.; Neely, D.

    2014-08-01

    The collimation of proton beams accelerated during ultra-intense laser irradiation of thin aluminum foils was measured experimentally whilst varying laser contrast. Increasing the laser contrast using a double plasma mirror system resulted in a marked decrease in proton beam divergence (20° to <10°), and the enhanced collimation persisted over a wide range of target thicknesses (50 nm-6 µm), with an increased flux towards thinner targets. Supported by numerical simulation, the larger beam divergence at low contrast is attributed to the presence of a significant plasma scale length on the target front surface. This alters the fast electron generation and injection into the target, affecting the resultant sheath distribution and dynamics at the rear target surface. This result demonstrates that careful control of the laser contrast will be important for future laser-driven ion applications in which control of beam divergence is crucial.

  10. The generation and acceleration of low emittance flat beams for future linear colliders

    SciTech Connect

    Raubenheimer, T.O.

    1991-11-01

    Many future linear collider designs call for electron and positron beams with normalized rms horizontal and vertical emittances of {gamma}{epsilon}{sub x} = 3{times}10{sup {minus}6} m-rad and {gamma}{epsilon}{sub y} = 3{times}10{sup {minus}8} m-rad; these are a factor of 10 to 100 below those observed in the Stanford Linear Collider. In this dissertation, we examine the feasibility of achieving beams with these very small vertical emittances. We examine the limitations encountered during both the generation and the subsequent acceleration of such low emittance beams. We consider collective limitations, such as wakefields, space charge effects, scattering processes, and ion trapping; and also how intensity limitations, such as anomalous dispersion, betatron coupling, and pulse-to-pulse beam jitter. In general, the minimum emittance in both the generation and the acceleration stages is limited by the transverse misalignments of the accelerator components. We describe a few techniques of correcting the effect of these errors, thereby easing the alignment tolerances by over an order of magnitude. Finally, we also calculate fundamental'' limitations on the minimum vertical emittance; these do not constrain the current designs but may prove important in the future.

  11. The generation and acceleration of low emittance flat beams for future linear colliders

    SciTech Connect

    Raubenheimer, T.O.

    1991-11-01

    Many future linear collider designs call for electron and positron beams with normalized rms horizontal and vertical emittances of {gamma}{epsilon}{sub x} = 3{times}10{sup {minus}6} m-rad and {gamma}{epsilon}{sub y} = 3{times}10{sup {minus}8} m-rad; these are a factor of 10 to 100 below those observed in the Stanford Linear Collider. In this dissertation, we examine the feasibility of achieving beams with these very small vertical emittances. We examine the limitations encountered during both the generation and the subsequent acceleration of such low emittance beams. We consider collective limitations, such as wakefields, space charge effects, scattering processes, and ion trapping; and also how intensity limitations, such as anomalous dispersion, betatron coupling, and pulse-to-pulse beam jitter. In general, the minimum emittance in both the generation and the acceleration stages is limited by the transverse misalignments of the accelerator components. We describe a few techniques of correcting the effect of these errors, thereby easing the alignment tolerances by over an order of magnitude. Finally, we also calculate ``fundamental`` limitations on the minimum vertical emittance; these do not constrain the current designs but may prove important in the future.

  12. Excitation of Accelerating Plasma Waves by Counter-propagating Laser Beams

    SciTech Connect

    Gennady Shvets; Nathaniel J. Fisch; and Alexander Pukhov

    2001-08-30

    Generation of accelerating plasma waves using two counter-propagating laser beams is considered. Colliding-beam accelerator requires two laser pulses: the long pump and the short timing beam. We emphasize the similarities and differences between the conventional laser wakefield accelerator and the colliding-beam accelerator (CBA). The highly nonlinear nature of the wake excitation is explained using both nonlinear optics and plasma physics concepts. Two regimes of CBA are considered: (i) the short-pulse regime, where the timing beam is shorter than the plasma period, and (ii) the parametric excitation regime, where the timing beam is longer than the plasma period. Possible future experiments are also outlined.

  13. High-efficiency acceleration of an electron beam in a plasma wakefield accelerator.

    PubMed

    Litos, M; Adli, E; An, W; Clarke, C I; Clayton, C E; Corde, S; Delahaye, J P; England, R J; Fisher, A S; Frederico, J; Gessner, S; Green, S Z; Hogan, M J; Joshi, C; Lu, W; Marsh, K A; Mori, W B; Muggli, P; Vafaei-Najafabadi, N; Walz, D; White, G; Wu, Z; Yakimenko, V; Yocky, G

    2014-11-06

    High-efficiency acceleration of charged particle beams at high gradients of energy gain per unit length is necessary to achieve an affordable and compact high-energy collider. The plasma wakefield accelerator is one concept being developed for this purpose. In plasma wakefield acceleration, a charge-density wake with high accelerating fields is driven by the passage of an ultra-relativistic bunch of charged particles (the drive bunch) through a plasma. If a second bunch of relativistic electrons (the trailing bunch) with sufficient charge follows in the wake of the drive bunch at an appropriate distance, it can be efficiently accelerated to high energy. Previous experiments using just a single 42-gigaelectronvolt drive bunch have accelerated electrons with a continuous energy spectrum and a maximum energy of up to 85 gigaelectronvolts from the tail of the same bunch in less than a metre of plasma. However, the total charge of these accelerated electrons was insufficient to extract a substantial amount of energy from the wake. Here we report high-efficiency acceleration of a discrete trailing bunch of electrons that contains sufficient charge to extract a substantial amount of energy from the high-gradient, nonlinear plasma wakefield accelerator. Specifically, we show the acceleration of about 74 picocoulombs of charge contained in the core of the trailing bunch in an accelerating gradient of about 4.4 gigavolts per metre. These core particles gain about 1.6 gigaelectronvolts of energy per particle, with a final energy spread as low as 0.7 per cent (2.0 per cent on average), and an energy-transfer efficiency from the wake to the bunch that can exceed 30 per cent (17.7 per cent on average). This acceleration of a distinct bunch of electrons containing a substantial charge and having a small energy spread with both a high accelerating gradient and a high energy-transfer efficiency represents a milestone in the development of plasma wakefield acceleration into a

  14. Commissioning measurements for photon beam data on three TrueBeam linear accelerators, and comparison with Trilogy and Clinac 2100 linear accelerators.

    PubMed

    Beyer, Gloria P

    2013-01-07

    This study presents the beam data measurement results from the commissioning of three TrueBeam linear accelerators. An additional evaluation of the measured beam data within the TrueBeam linear accelerators contrasted with two other linear accelerators from the same manufacturer (i.e., Clinac and Trilogy) was performed to identify and evaluate any differences in the beam characteristics between the machines and to evaluate the possibility of beam matching for standard photon energies. We performed a comparison of commissioned photon beam data for two standard photon energies (6 MV and 15 MV) and one flattening filter-free ("FFF") photon energy (10 FFF) between three different TrueBeam linear accelerators. An analysis of the beam data was then performed to evaluate the reproducibility of the results and the possibility of "beam matching" between the TrueBeam linear accelerators. Additionally, the data from the TrueBeam linear accelerator was compared with comparable data obtained from one Clinac and one Trilogy linear accelerator models produced by the same manufacturer to evaluate the possibility of "beam matching" between the TrueBeam linear accelerators and the previous models. The energies evaluated between the linear accelerator models are the 6 MV for low energy and the 15 MV for high energy. PDD and output factor data showed less than 1% variation and profile data showed variations within 1% or 2 mm between the three TrueBeam linear accelerators. PDD and profile data between the TrueBeam, the Clinac, and Trilogy linear accelerators were almost identical (less than 1% variation). Small variations were observed in the shape of the profile for 15 MV at shallow depths (< 5 cm) probably due to the differences in the flattening filter design. A difference in the penumbra shape was observed between the TrueBeam and the other linear accelerators; the TrueBeam data resulted in a slightly greater penumbra width. The diagonal scans demonstrated significant differences

  15. Improving the intensity of a focused laser beam

    NASA Astrophysics Data System (ADS)

    Haddadi, Sofiane; Fromager, Michael; Louhibi, Djelloul; Hasnaoui, Abdelkrim; Harfouche, Ali; Cagniot, Emmanuel; ńit-Ameur, Kamel

    2015-03-01

    Let us consider the family of symmetrical Laguerre-Gaus modes of zero azimuthal order which will be denoted as LGp0 . The latter is made up of central lobe surrounded by p concentric rings of light. The fundamental mode LG00 is a Gaussian beam of width W. The focusing of a LGp0 beam of power P by a converging lens of focal length f produces a focal spot keeping the LGp0 -shape and having a central intensity I0= 2PW2/(λf)2 whatever the value of the radial order p. Many applications of lasers (laser marking, laser ablation, …) seek nowadays for a focal laser spot with the highest as possible intensity. For a given power P, increasing intensity I0 can be achieved by increasing W and reducing the focal length f. However, this way of doing is in fact limited because the ratio W/f cannot increase indefinitely at the risk of introducing a huge truncation upon the edge of the lens. In fact, it is possible to produce a single-lobed focal spot with a central intensity of about p times the intensity I0. This result has been obtained by reshaping (rectification) a LGp0 beam thanks to a proper Binary Diffractive Optical Element (BDOE). In addition, forcing a laser cavity to oscillate upon a LGp0 can improve the power extract due to a mode volume increasing with the mode order p. This could allow envisaging an economy of scale in term of laser pumping power for producing a given intensity I0. In addition, we have demonstrated that a rectified LGp0 beam better stand the lens spherical aberration than the usual Gaussian beam.

  16. Advanced treatment planning methods for efficient radiation therapy with laser accelerated proton and ion beams

    SciTech Connect

    Schell, Stefan; Wilkens, Jan J.

    2010-10-15

    Purpose: Laser plasma acceleration can potentially replace large and expensive cyclotrons or synchrotrons for radiotherapy with protons and ions. On the way toward a clinical implementation, various challenges such as the maximum obtainable energy still remain to be solved. In any case, laser accelerated particles exhibit differences compared to particles from conventional accelerators. They typically have a wide energy spread and the beam is extremely pulsed (i.e., quantized) due to the pulsed nature of the employed lasers. The energy spread leads to depth dose curves that do not show a pristine Bragg peak but a wide high dose area, making precise radiotherapy impossible without an additional energy selection system. Problems with the beam quantization include the limited repetition rate and the number of accelerated particles per laser shot. This number might be too low, which requires a high repetition rate, or it might be too high, which requires an additional fluence selection system to reduce the number of particles. Trying to use laser accelerated particles in a conventional way such as spot scanning leads to long treatment times and a high amount of secondary radiation produced when blocking unwanted particles. Methods: The authors present methods of beam delivery and treatment planning that are specifically adapted to laser accelerated particles. In general, it is not necessary to fully utilize the energy selection system to create monoenergetic beams for the whole treatment plan. Instead, within wide parts of the target volume, beams with broader energy spectra can be used to simultaneously cover multiple axially adjacent spots of a conventional dose delivery grid as applied in intensity modulated particle therapy. If one laser shot produces too many particles, they can be distributed over a wider area with the help of a scattering foil and a multileaf collimator to cover multiple lateral spot positions at the same time. These methods are called axial and

  17. Ion Acceleration by Ultra-intense Laser Pulse Interacting with Double-layer Near-critical Density Plasma

    NASA Astrophysics Data System (ADS)

    Gu, Y. J.; Kong, Q.; Kawata, S.; Izumiyama, T.; Nagashima, T.; Takano, M.; Li, X. F.; Yu, Q.; Barada, D.; Ma, Y. Y.; Wang, P. X.

    2016-03-01

    A collimated ion beam is generated through the interaction between ultra-intense laser pulse and a double layer plasma. The maximum energy is above 1GeV and the total charge of high energy protons is about several tens of nC/μm. The double layer plasma is combined with an underdense plasma and a thin overdense one. The wakefield traps and accelerates a bunch of electrons to high energy in the first underdense slab. When the well collimated electron beam accelerated by the wakefield penetrates through the second overdense slab, it enhances target normal sheath acceleration (TNSA) and breakout after-burner (BOA) regimes. The mechanism is simulated and analyzed by 2.5 dimensional Particle-in-cell code. Compared with single target TNSA or BOA, both the acceleration gradient and energy transfer efficiency are higher in the double layer regime.

  18. Laser plasma acceleration of electrons with multi-PW laser beams in the frame of CILEX

    NASA Astrophysics Data System (ADS)

    Cros, B.; Paradkar, B. S.; Davoine, X.; Chancé, A.; Desforges, F. G.; Dobosz-Dufrénoy, S.; Delerue, N.; Ju, J.; Audet, T. L.; Maynard, G.; Lobet, M.; Gremillet, L.; Mora, P.; Schwindling, J.; Delferrière, O.; Bruni, C.; Rimbault, C.; Vinatier, T.; Di Piazza, A.; Grech, M.; Riconda, C.; Marquès, J. R.; Beck, A.; Specka, A.; Martin, Ph.; Monot, P.; Normand, D.; Mathieu, F.; Audebert, P.; Amiranoff, F.

    2014-03-01

    Laser plasma acceleration of electrons has progressed along with advances in laser technology. It is thus expected that the development in the near-future of multi-PW-class laser and facilities will enable a vast range of scientific opportunities for laser plasma acceleration research. On one hand, high peak powers can be used to explore the extremely high intensity regime of laser wakefield acceleration, producing for example large amounts of electrons in the GeV range or generating high energy photons. On the other hand, the available laser energy can be used in the quasi-linear regime to create accelerating fields in large volumes of plasma and study controlled acceleration in a plasma stage of externally injected relativistic particles, either electrons or positrons. In the frame of the Centre Interdisciplinaire de la Lumière EXtrême (CILEX), the Apollon-10P laser will deliver two beams at the 1 PW and 10 PW levels, in ultra-short (> 15 fs) pulses, to a target area dedicated to electron acceleration studies, such as the exploration of the non-linear regimes predicted theoretically, or multi-stage laser plasma acceleration.

  19. Lessons from shielding retrofits at the LAMPF/LANSCE/PSR accelerator, beam lines and target facilities

    SciTech Connect

    Macek, R.J.

    1994-07-01

    The experience in the past 7 years to improve the shielding and radiation control systems at the Los Alamos Meson Physics Facility (LAMPF) and the Manuel Lujan Jr. Neutron Scattering Center (LANSCE) provides important lessons for the design of radiation control systems at future, high beam power proton accelerator facilities. Major issues confronted and insight gained in developing shielding criteria and in the use of radiation interlocks are discussed. For accelerators and beam lines requiring hands-on-maintenance, our experience suggests that shielding criteria based on accident scenarios will be more demanding than criteria based on routinely encountered beam losses. Specification and analysis of the appropriate design basis accident become all important. Mitigation by active protection systems of the consequences of potential, but severe, prompt radiation accidents has been advocated as an alternate choice to shielding retrofits for risk management at both facilities. Acceptance of active protection systems has proven elusive primarily because of the difficulty in providing convincing proof that failure of active systems (to mitigate the accident) is incredible. Results from extensive shielding assessment studies are presented including data from experimental beam spill tests, comparisons with model estimates, and evidence bearing on the limitations of line-of-sight attenuation models in complex geometries. The scope and significant characteristics of major shielding retrofit projects at the LAMPF site are illustrated by the project to improve the shielding beneath a road over a multiuse, high-intensity beam line (Line D).

  20. Laser-driven beam lines for delivering intensity modulated radiation therapy with particle beams

    NASA Astrophysics Data System (ADS)

    Hofmann, K. M.; Schell, S.; Wilkens, J. J.

    2013-07-01

    Laser-accelerated particles can provide a promising opportunity for radiation therapy of cancer. Potential advantages arise from combining a compact, cost-efficient treatment unit with the physical advantages in dose delivery of charged particle beams. We consider different dose delivery schemes and the required devices to design a possible treatment unit. The secondary radiation produced in several beam line elements remains a challenge to be addressed.

  1. Laser-driven beam lines for delivering intensity modulated radiation therapy with particle beams

    SciTech Connect

    Hofmann, K. M.; Schell, S.; Wilkens, J. J.

    2013-07-26

    Laser-accelerated particles can provide a promising opportunity for radiation therapy of cancer. Potential advantages arise from combining a compact, cost-efficient treatment unit with the physical advantages in dose delivery of charged particle beams. We consider different dose delivery schemes and the required devices to design a possible treatment unit. The secondary radiation produced in several beam line elements remains a challenge to be addressed.

  2. Radiation Safety System for SPIDER Neutral Beam Accelerator

    SciTech Connect

    Sandri, S.; Poggi, C.; Coniglio, A.; D'Arienzo, M.

    2011-12-13

    SPIDER (Source for Production of Ion of Deuterium Extracted from RF Plasma only) and MITICA (Megavolt ITER Injector Concept Advanced) are the ITER neutral beam injector (NBI) testing facilities of the PRIMA (Padova Research Injector Megavolt Accelerated) Center. Both injectors accelerate negative deuterium ions with a maximum energy of 1 MeV for MITICA and 100 keV for SPIDER with a maximum beam current of 40 A for both experiments. The SPIDER facility is classified in Italy as a particle accelerator. At present, the design of the radiation safety system for the facility has been completed and the relevant reports have been presented to the Italian regulatory authorities. Before SPIDER can operate, approval must be obtained from the Italian Regulatory Authority Board (IRAB) following a detailed licensing process. In the present work, the main project information and criteria for the SPIDER injector source are reported together with the analysis of hypothetical accidental situations and safety issues considerations. Neutron and photon nuclear analysis is presented, along with special shielding solutions designed to meet Italian regulatory dose limits. The contribution of activated corrosion products (ACP) to external exposure of workers has also been assessed. Nuclear analysis indicates that the photon contribution to worker external exposure is negligible, and the neutron dose can be considered by far the main radiation protection issue. Our results confirm that the injector has no important radiological impact on the population living around the facility.

  3. High energy electron beam processing experiments with induction accelerators

    NASA Astrophysics Data System (ADS)

    Goodman, D. L.; Birx, D. L.; Dave, V. R.

    1995-05-01

    Induction accelerators are capable of producing very high electron beam power for processing at energies of 1-10 MeV. A high energy electron beam (HEEB) material processing system based on all-solid-state induction accelerator technology is in operation at Science Research Laboratory. The system delivers 50 ns 500 A current pulses at 1.5 MeV and is capable of operating at high power (500 kW) and high (˜ 5 kHz) repetition rate. HEEB processing with induction accelerators is useful for a wide variety of applications including the joining of high temperature materials, powder metallurgical fabrication, treatment of organic-contaminated wastewater and the curing of polymer matrix composites. High temperature HEEB experiments at SRL have demonstrated the brazing of carbon-carbon composites to metallic substrates and the melting and sintering of powders for graded-alloy fabrication. Other experiments have demonstrated efficient destruction of low-concentration organic contaminants in water and low temperature free-radical cross-linking of fiber-reinforced composites with acrylated resin matrices.

  4. Internal dynamics of intense twin beams and their coherence

    PubMed Central

    Peřina, Jan; Haderka, Ondřej; Allevi, Alessia; Bondani, Maria

    2016-01-01

    The dynamics of intense twin beams in pump-depleted parametric down-conversion is studied. A generalized parametric approximation is suggested to solve the quantum model. Its comparison with a semiclassical model valid for larger twin-beam intensities confirms its applicability. The experimentally observed maxima in the spectral and spatial intensity auto- and cross- correlation functions depending on pump power are explained in terms of different speeds of the (back-) flow of energy between the individual down-converted modes and the corresponding pump modes. This effect is also responsible for the gradual replacement of the initial exponential growth of the down-converted fields by the linear one. Furthermore, it forms a minimum in the curve giving the effective number of twin-beam modes. These effects manifest a tight relation between the twin-beam coherence and its internal structure, as clearly visible in the model. Multiple maxima in the intensity correlation functions originating in the oscillations of energy flow between the pump and down-converted modes are theoretically predicted. PMID:26924749

  5. Experimental and numerical study of high intensity argon cluster beams

    SciTech Connect

    Korobeishchikov, N. G.; Kalyada, V. V.; Shmakov, A. A.; Zarvin, A. E.; Skovorodko, P. A.

    2014-12-09

    Experimental and numerical investigations of expansion of argon with homogeneous condensation in supersonic conical nozzle and in free jet behind it were carried out. Optimal parameters (stagnation pressure, nozzle-skimmer distance) for the formation of cluster beam with maximum intensity were determined. Two available models for nonequilibrium nucleation were tested. The numerical results are in satisfactory agreement with the measured data.

  6. Deflection of a Reflected Intense Vortex Laser Beam

    NASA Astrophysics Data System (ADS)

    Zhang, Lingang; Shen, Baifei; Zhang, Xiaomei; Huang, Shan; Shi, Yin; Liu, Chen; Wang, Wenpeng; Xu, Jiancai; Pei, Zhikun; Xu, Zhizhan

    2016-09-01

    An interesting deflection effect deviating the optical reflection law is revealed in the relativistic regime of intense vortex laser plasma interaction. When an intense vortex laser obliquely impinges onto an overdense plasma target, the reflected beam deflects out of the plane of incidence with an experimentally observable deflection angle. The mechanism is demonstrated by full three-dimensional particle-in-cell simulation as well as analytical modeling using the Maxwell stress tensor. The deflection results from the rotational symmetry breaking of the foil driven by the unsymmetrical shear stress of the vortex beam. The l -dependent shear stress, where l is the topological charge, as an intrinsic characteristic to the vortex beam, plays an important role as the ponderomotive force in relativistic vortex laser matter interaction.

  7. New methods for high current fast ion beam production by laser-driven acceleration.

    PubMed

    Margarone, D; Krasa, J; Prokupek, J; Velyhan, A; Torrisi, L; Picciotto, A; Giuffrida, L; Gammino, S; Cirrone, P; Cutroneo, M; Romano, F; Serra, E; Mangione, A; Rosinski, M; Parys, P; Ryc, L; Limpouch, J; Laska, L; Jungwirth, K; Ullschmied, J; Mocek, T; Korn, G; Rus, B

    2012-02-01

    An overview of the last experimental campaigns on laser-driven ion acceleration performed at the PALS facility in Prague is given. Both the 2 TW, sub-nanosecond iodine laser system and the 20 TW, femtosecond Ti:sapphire laser, recently installed at PALS, are used along our experiments performed in the intensity range 10(16)-10(19) W∕cm(2). The main goal of our studies was to generate high energy, high current ion streams at relatively low laser intensities. The discussed experimental investigations show promising results in terms of maximum ion energy and current density, which make the laser-accelerated ion beams a candidate for new-generation ion sources to be employed in medicine, nuclear physics, matter physics, and industry.

  8. Stable GeV Ion-Beam Acceleration from Thin Foils by Circularly Polarized Laser Pulses

    SciTech Connect

    Qiao, B.; Zepf, M.; Borghesi, M.; Geissler, M.

    2009-04-10

    A stable relativistic ion acceleration regime for thin foils irradiated by circularly polarized laser pulses is suggested. In this regime, the 'light-sail' stage of radiation pressure acceleration for ions is smoothly connected with the initial relativistic 'hole-boring' stage, and a defined relationship between laser intensity I{sub 0}, foil density n{sub 0}, and thickness l{sub 0} should be satisfied. For foils with a wide range of n{sub 0}, the required I{sub 0} and l{sub 0} for the regime are theoretically estimated and verified with the particle-in-cell code ILLUMINATION. It is shown for the first time by 2D simulations that high-density monoenergetic ion beams with energy above GeV/u and divergence of 10 deg. are produced by circularly polarized lasers at intensities of 10{sup 22} W/cm{sup 2}, which are within reach of current laser systems.0.

  9. Simulation of direct plasma injection for laser ion beam acceleration with a radio frequency quadrupole

    SciTech Connect

    Jin, Q. Y.; Li, Zh. M.; Liu, W.; Zhao, H. Y. Zhang, J. J.; Sha, Sh.; Zhang, Zh. L.; Zhang, X. Zh.; Sun, L. T.; Zhao, H. W.

    2014-07-15

    The direct plasma injection scheme (DPIS) has been being studied at Institute of Modern Physics since several years ago. A C{sup 6+} beam with peak current of 13 mA, energy of 593 keV/u has been successfully achieved after acceleration with DPIS method. To understand the process of DPIS, some simulations have been done as follows. First, with the total current intensity and the relative yields of different charge states for carbon ions measured at the different distance from the target, the absolute current intensities and time-dependences for different charge states are scaled to the exit of the laser ion source in the DPIS. Then with these derived values as the input parameters, the extraction of carbon beam from the laser ion source to the radio frequency quadrupole with DPIS is simulated, which is well agreed with the experiment results.

  10. Simulation of direct plasma injection for laser ion beam acceleration with a radio frequency quadrupole.

    PubMed

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

    2014-07-01

    The direct plasma injection scheme (DPIS) has been being studied at Institute of Modern Physics since several years ago. A C(6+) beam with peak current of 13 mA, energy of 593 keV/u has been successfully achieved after acceleration with DPIS method. To understand the process of DPIS, some simulations have been done as follows. First, with the total current intensity and the relative yields of different charge states for carbon ions measured at the different distance from the target, the absolute current intensities and time-dependences for different charge states are scaled to the exit of the laser ion source in the DPIS. Then with these derived values as the input parameters, the extraction of carbon beam from the laser ion source to the radio frequency quadrupole with DPIS is simulated, which is well agreed with the experiment results.

  11. Positron acceleration by sheath field in ultra-intense laser–solid interactions

    NASA Astrophysics Data System (ADS)

    Yan, Yonghong; Wu, Yuchi; Chen, Jia; Yu, Minghai; Dong, Kegong; Gu, Yuqiu

    2017-04-01

    A positron production experiment was performed by irradiating an ultra-intense picosecond laser on solid tantalum targets. Quasi-monoenergetic positron beams were obtained owing to the sheath field on the back of the target. The experiment shows that the peak energy of the positron spectrum has a linear relation with the reciprocal of the target diameter. A simple analytical model of the sheath field was constructed to explain the experimental data, which predicts the positron peak energy in terms of the target diameter and hot electron parameters. Based on the field model, Monte Carlo simulations were conducted to treat the positron production and acceleration self-consistently. The simulated spectra are in good agreement with most experiment results. The disagreement of the 1 mm diameter data reveals that the hot electron propagation along the target flank surface plays an important role in the sheath field set up. Several aspects involved in the positron acceleration are discussed.

  12. Physics of Neutralization of Intense High-Energy Ion Beam Pulses by Electrons

    SciTech Connect

    Kaganovich, I. D.; Davidson, R. C.; Dorf, M. A.; Startsev, E. A.; Sefkow, A. B.; Lee, E. P.; Friedman, A.

    2010-04-28

    Neutralization and focusing of intense charged particle beam pulses by electrons forms the basis for a wide range of applications to high energy accelerators and colliders, heavy ion fusion, and astrophysics. For example, for ballistic propagation of intense ion beam pulses, background plasma can be used to effectively neutralize the beam charge and current, so that the self-electric and self- magnetic fields do not affect the ballistic propagation of the beam. From the practical perspective of designing advanced plasma sources for beam neutralization, a robust theory should be able to predict the self-electric and self-magnetic fields during beam propagation through the background plasma. The major scaling relations for the self-electric and self-magnetic fields of intense ion charge bunches propagating through background plasma have been determined taking into account the effects of transients during beam entry into the plasma, the excitation of collective plasma waves, the effects of gas ionization, finite electron temperature, and applied solenoidal and dipole magnetic fields. Accounting for plasma production by gas ionization yields a larger self-magnetic field of the ion beam compared to the case without ionization, and a wake of current density and self-magnetic field perturbations is generated behind the beam pulse. A solenoidal magnetic field can be applied for controlling the beam propagation. Making use of theoretical models and advanced numerical simulations, it is shown that even a small applied magnetic field of about 100G can strongly affect the beam neutralization. It has also been demonstrated that in the presence of an applied magnetic field the ion beam pulse can excite large-amplitude whistler waves, thereby producing a complex structure of self-electric and self-magnetic fields. The presence of an applied solenoidal magnetic field may also cause a strong enhancement of the radial self-electric field of the beam pulse propagating through the

  13. Physics of neutralization of intense high-energy ion beam pulses by electrons

    SciTech Connect

    Kaganovich, I. D.; Davidson, R. C.; Dorf, M. A.; Startsev, E. A.; Sefkow, A. B.; Lee, E. P.; Friedman, A.

    2010-05-15

    Neutralization and focusing of intense charged particle beam pulses by electrons form the basis for a wide range of applications to high energy accelerators and colliders, heavy ion fusion, and astrophysics. For example, for ballistic propagation of intense ion beam pulses, background plasma can be used to effectively neutralize the beam charge and current, so that the self-electric and self-magnetic fields do not affect the ballistic propagation of the beam. From the practical perspective of designing advanced plasma sources for beam neutralization, a robust theory should be able to predict the self-electric and self-magnetic fields during beam propagation through the background plasma. The major scaling relations for the self-electric and self-magnetic fields of intense ion charge bunches propagating through background plasma have been determined taking into account the effects of transients during beam entry into the plasma, the excitation of collective plasma waves, the effects of gas ionization, finite electron temperature, and applied solenoidal and dipole magnetic fields. Accounting for plasma production by gas ionization yields a larger self-magnetic field of the ion beam compared to the case without ionization, and a wake of current density and self-magnetic field perturbations is generated behind the beam pulse. A solenoidal magnetic field can be applied for controlling the beam propagation. Making use of theoretical models and advanced numerical simulations, it is shown that even a small applied magnetic field of about 100 G can strongly affect the beam neutralization. It has also been demonstrated that in the presence of an applied magnetic field the ion beam pulse can excite large-amplitude whistler waves, thereby producing a complex structure of self-electric and self-magnetic fields. The presence of an applied solenoidal magnetic field may also cause a strong enhancement of the radial self-electric field of the beam pulse propagating through the

  14. Physics of Neutralization of Intense Charged Particle Beam Pulses by a Background Plasma

    SciTech Connect

    Kaganovich, I.D.; Davidson, R.C.; Dorf, M.A.; Startsev, E.A.; Sefkow, A.B; Friedman, A.F.; Lee, E.P.

    2009-09-03

    Neutralization and focusing of intense charged particle beam pulses by a background plasma forms the basis for a wide range of applications to high energy accelerators and colliders, heavy ion fusion, and astrophysics. For example, for ballistic propagation of intense ion beam pulses, background plasma can be used to effectively neutralize the beam charge and current, so that the self-electric and self-magnetic fields do not affect the ballistic propagation of the beam. From the practical perspective of designing advanced plasma sources for beam neutralization, a robust theory should be able to predict the self-electric and self-magnetic fields during beam propagation through the background plasma. The major scaling relations for the self-electric and self-magnetic fields of intense ion charge bunches propagating through background plasma have been determined taking into account the effects of transients during beam entry into the plasma, the excitation of collective plasma waves, the effects of gas ionization, finite electron temperature, and applied solenoidal and dipole magnetic fields. Accounting for plasma production by gas ionization yields a larger self-magnetic field of the ion beam compared to the case without ionization, and a wake of current density and self-magnetic field perturbations is generated behind the beam pulse. A solenoidal magnetic field can be applied for controlling the beam propagation. Making use of theoretical models and advanced numerical simulations, it is shown that even a small applied magnetic field of about 100G can strongly affect the beam neutralization. It has also been demonstrated that in the presence of an applied magnetic field the ion beam pulse can excite large-amplitude whistler waves, thereby producing a complex structure of self-electric and self-magnetic fields. The presence of an applied solenoidal magnetic field may also cause a strong enhancement of the radial self-electric field of the beam pulse propagating

  15. Deposition and surface treatment with intense pulsed ion beams

    SciTech Connect

    Olson, J.C.; Davis, H.A.; Rej, D.J.; Waganaar, W.J.; Stinnett, R.W.; McIntyre, D.C.

    1995-02-08

    Intense pulsed ion beams (500 keV, 30 kA, 0.5 {mu}s) are being investigated for materials processing. Demonstrated and potential applications include film deposition, glazing and joining, alloying and mixing, cleaning and polishing, corrosion improvement, polymer surface treatments, and nanophase powder synthesis. Initial experiments at Los Alamos have emphasized thin-film formation by depositing beam ablated target material on substrates. We have deposited films with complex stoichiometry such as YBa{sub 2}Cu{sub 3}O{sub 7-x}, and formed diamond-like-carbon films. Instantaneous deposition rates of 1 mm/sec have been achieved because of the short ion range (typically 1{mu}m), excellent target coupling, and the inherently high energy of these beams. Currently the beams are produced in single shot uncomplicated diodes with good electrical efficiency. High-voltage modulator technology and diodes capable of repetitive firing, needed for commercial application, are being developed.

  16. Acceleration of Polarized Beams Using Multiple Strong Partial Siberian Snakes

    NASA Astrophysics Data System (ADS)

    Roser, T.; Ahrens, L. A.; Bai, M.; Courant, E. D.; Glenn, J. W.; Gupta, R. C.; Huang, H.; Luccio, A. U.; Mackay, W. W.; Tsoupas, N.; Willen, E.; Okamura, M.; Takano, J.

    2005-08-01

    Acceleration of polarized protons in the energy range of 5 to 25 GeV is particularly difficult since depolarizing spin resonances are strong enough to cause significant depolarization, but full Siberian snakes cause intolerably large orbit excursions. Using a 20 - 30 % partial Siberian snake, both imperfection and intrinsic resonances can be overcome. Such a strong partial Siberian snake was designed for the Brookhaven AGS using a dual pitch helical super-conducting dipole. Multiple strong partial snakes are also discussed for spin matching at beam injection and extraction.

  17. ACCELERATION OF POLARIZED BEAMS USING MULTIPLE STRONG PARTIAL SIBERIAN SNAKES.

    SciTech Connect

    ROSER,T.AHRENS,L.BAI,M.ET AL.

    2004-07-05

    Acceleration of polarized protons in the energy range of 5 to 25 GeV is particularly difficult since depolarizing spin resonances are strong enough to cause significant depolarization but full Siberian snakes cause intolerably large orbit excursions. Using a 20-30% partial Siberian snake both imperfection and intrinsic resonances can be overcome. Such a strong partial Siberian snake was designed for the Brookhaven AGS using a dual pitch helical superconducting dipole. Multiple strong partial snakes are also discussed for spin matching at beam injection and extraction.

  18. ACCELERATION OF POLARIZED BEAMS USING MULTIPLE STRONG PARTIAL SIBERIAN SNAKES.

    SciTech Connect

    ROSER,T.; AHRENS,L.; BAI,M.; COURANT,E.; GLENN,J.W.; GUPTA,R.C.; HUANG,H.; LUCCIO,A.U.; MACKAY,W.W.; TSOUPAS,N.; WILLEN,E.; OKAMURA,M.; TAKANO,J.

    2004-10-10

    Acceleration of polarized protons in the energy range of 5 to 25 GeV is particularly difficult since depolarizing spin resonances are strong enough to cause significant depolarization but full Siberian snakes cause intolerably large orbit excursions. Using a 20-30% partial Siberian snake both imperfection and intrinsic resonances can be overcome. Such a strong partial Siberian snake was designed for the Brookhaven AGS using a dual pitch helical superconducting dipole. Multiple strong partial snakes are also discussed for spin matching at beam injection and extraction.

  19. Electron Beam Transport in Advanced Plasma Wave Accelerators

    SciTech Connect

    Williams, Ronald L

    2013-01-31

    The primary goal of this grant was to develop a diagnostic for relativistic plasma wave accelerators based on injecting a low energy electron beam (5-50keV) perpendicular to the plasma wave and observing the distortion of the electron beam's cross section due to the plasma wave's electrostatic fields. The amount of distortion would be proportional to the plasma wave amplitude, and is the basis for the diagnostic. The beat-wave scheme for producing plasma waves, using two CO2 laser beam, was modeled using a leap-frog integration scheme to solve the equations of motion. Single electron trajectories and corresponding phase space diagrams were generated in order to study and understand the details of the interaction dynamics. The electron beam was simulated by combining thousands of single electrons, whose initial positions and momenta were selected by random number generators. The model was extended by including the interactions of the electrons with the CO2 laser fields of the beat wave, superimposed with the plasma wave fields. The results of the model were used to guide the design and construction of a small laboratory experiment that may be used to test the diagnostic idea.

  20. Progress on the relativistic klystron two-beam accelerator prototype

    SciTech Connect

    Anderson, D E; Eylon, S; Henestroza,E; Houck, T L; S M, Lidia; Vanecek, D L; Westenskow, G A; Yu, S S

    1998-07-05

    The technical challenge for making two-beam accelerators into realizable power sources lies in the creation of the drive beam and in its propagation over long distances through multiple extraction sections. This year we have been constructing a 1.2-kA, l-MeV, electron induction prototype injector as a collaborative effort between LBL and LLNL. The electron source will be a 3.5"-diameter, thermionic, flat-surface cathode with a maximum shroud field stress of approximately 165 kV/cm. Additional design parameters for the injector include a pulse length of over 120-ns flat top (1% energy variation), and a normalized edge emittance of less than 200 {pi}-mm-mr. Planned diagnostics include an isolated cathode with resistive divider for direct measurement of current emission, resistive-wall and magnetic probe current monitors for measuring beam current and centroid position, capacitive probes for measuring A-K gap voltage, an energy spectrometer, and a pepper-pot emittance diagnostic. Details of the injector, beam line, and diagnostics are presented.

  1. Dosimetric advantages of IMPT over IMRT for laser-accelerated proton beams

    NASA Astrophysics Data System (ADS)

    Luo, W.; Li, J.; Fourkal, E.; Fan, J.; Xu, X.; Chen, Z.; Jin, L.; Price, R.; Ma, C.-M.

    2008-12-01

    As a clinical application of an exciting scientific breakthrough, a compact and cost-efficient proton therapy unit using high-power laser acceleration is being developed at Fox Chase Cancer Center. The significance of this application depends on whether or not it can yield dosimetric superiority over intensity-modulated radiation therapy (IMRT). The goal of this study is to show how laser-accelerated proton beams with broad energy spreads can be optimally used for proton therapy including intensity-modulated proton therapy (IMPT) and achieve dosimetric superiority over IMRT for prostate cancer. Desired energies and spreads with a varying δE/E were selected with the particle selection device and used to generate spread-out Bragg peaks (SOBPs). Proton plans were generated on an in-house Monte Carlo-based inverse-planning system. Fifteen prostate IMRT plans previously used for patient treatment have been included for comparison. Identical dose prescriptions, beam arrangement and consistent dose constrains were used for IMRT and IMPT plans to show the dosimetric differences that were caused only by the different physical characteristics of proton and photon beams. Different optimization constrains and beam arrangements were also used to find optimal IMPT. The results show that conventional proton therapy (CPT) plans without intensity modulation were not superior to IMRT, but IMPT can generate better proton plans if appropriate beam setup and optimization are used. Compared to IMRT, IMPT can reduce the target dose heterogeneity ((D5-D95)/D95) by up to 56%. The volume receiving 65 Gy and higher (V65) for the bladder and the rectum can be reduced by up to 45% and 88%, respectively, while the volume receiving 40 Gy and higher (V40) for the bladder and the rectum can be reduced by up to 49% and 68%, respectively. IMPT can also reduce the whole body non-target tissue dose by up to 61% or a factor 2.5. This study has shown that the laser accelerator under development has a

  2. Dosimetric advantages of IMPT over IMRT for laser-accelerated proton beams.

    PubMed

    Luo, W; Li, J; Fourkal, E; Fan, J; Xu, X; Chen, Z; Jin, L; Price, R; Ma, C-M

    2008-12-21

    As a clinical application of an exciting scientific breakthrough, a compact and cost-efficient proton therapy unit using high-power laser acceleration is being developed at Fox Chase Cancer Center. The significance of this application depends on whether or not it can yield dosimetric superiority over intensity-modulated radiation therapy (IMRT). The goal of this study is to show how laser-accelerated proton beams with broad energy spreads can be optimally used for proton therapy including intensity-modulated proton therapy (IMPT) and achieve dosimetric superiority over IMRT for prostate cancer. Desired energies and spreads with a varying deltaE/E were selected with the particle selection device and used to generate spread-out Bragg peaks (SOBPs). Proton plans were generated on an in-house Monte Carlo-based inverse-planning system. Fifteen prostate IMRT plans previously used for patient treatment have been included for comparison. Identical dose prescriptions, beam arrangement and consistent dose constrains were used for IMRT and IMPT plans to show the dosimetric differences that were caused only by the different physical characteristics of proton and photon beams. Different optimization constrains and beam arrangements were also used to find optimal IMPT. The results show that conventional proton therapy (CPT) plans without intensity modulation were not superior to IMRT, but IMPT can generate better proton plans if appropriate beam setup and optimization are used. Compared to IMRT, IMPT can reduce the target dose heterogeneity ((D5-D95)/D95) by up to 56%. The volume receiving 65 Gy and higher (V65) for the bladder and the rectum can be reduced by up to 45% and 88%, respectively, while the volume receiving 40 Gy and higher (V40) for the bladder and the rectum can be reduced by up to 49% and 68%, respectively. IMPT can also reduce the whole body non-target tissue dose by up to 61% or a factor 2.5. This study has shown that the laser accelerator under development has

  3. Gas Filled RF Resonator Hadron Beam Monitor for Intense Neutrino Beam Experiments

    SciTech Connect

    Yonehara, Katsuya; Abrams, Robert; Dinkel, Holly; Freemire, Ben; Johnson, Rolland; Kazakevich, Grigory; Tollestrup, Alvin; Zwaska, Robert

    2016-06-01

    MW-class beam facilities are being considered all over the world to produce an intense neutrino beam for fundamental particle physics experiments. A radiation-robust beam monitor system is required to diagnose the primary and secondary beam qualities in high-radiation environments. We have proposed a novel gas-filled RF-resonator hadron beam monitor in which charged particles passing through the resonator produce ionized plasma that changes the permittivity of the gas. The sensitivity of the monitor has been evaluated in numerical simulation. A signal manipulation algorithm has been designed. A prototype system will be constructed and tested by using a proton beam at the MuCool Test Area at Fermilab.

  4. Acceleration and stability of a high-current ion beam in induction fields

    NASA Astrophysics Data System (ADS)

    Karas', V. I.; Manuilenko, O. V.; Tarakanov, V. P.; Federovskaya, O. V.

    2013-03-01

    A one-dimensional nonlinear analytic theory of the filamentation instability of a high-current ion beam is formulated. The results of 2.5-dimensional numerical particle-in-cell simulations of acceleration and stability of an annular compensated ion beam (CIB) in a linear induction particle accelerator are presented. It is shown that additional transverse injection of electron beams in magnetically insulated gaps (cusps) improves the quality of the ion-beam distribution function and provides uniform beam acceleration along the accelerator. The CIB filamentation instability in both the presence and the absence of an external magnetic field is considered.

  5. Acceleration and stability of a high-current ion beam in induction fields

    SciTech Connect

    Karas', V. I.; Manuilenko, O. V.; Tarakanov, V. P.; Federovskaya, O. V.

    2013-03-15

    A one-dimensional nonlinear analytic theory of the filamentation instability of a high-current ion beam is formulated. The results of 2.5-dimensional numerical particle-in-cell simulations of acceleration and stability of an annular compensated ion beam (CIB) in a linear induction particle accelerator are presented. It is shown that additional transverse injection of electron beams in magnetically insulated gaps (cusps) improves the quality of the ion-beam distribution function and provides uniform beam acceleration along the accelerator. The CIB filamentation instability in both the presence and the absence of an external magnetic field is considered.

  6. Electron beam dynamics in the DARHT-II linear induction accelerator

    SciTech Connect

    Ekdahl, Carl A; Abeyta, Epifanio O; Aragon, Paul; Archuleta, Rita; Cook, Gerald; Dalmas, Dale; Esquibel, Kevin; Gallegos, Robert A; Garnett, Robert; Harrison, James F; Johnson, Jeffrey B; Jacquez, Edward B; Mccuistian, Brian T; Montoya, Nicholas A; Nath, Subrata; Nielsen, Kurt; Oro, David; Prichard, Benjamin; Rowton, Lawrence; Sanchez, Manolito; Scarpetti, Raymond; Schauer, Martin M; Seitz, Gerald; Schulze, Martin; Bender, Howard A; Broste, William B; Carlson, Carl A; Frayer, Daniel K; Johnson, Douglas E; Tom, C Y; Trainham, C; Genoni, Thomas; Hughes, Thomas; Toma, Carsten

    2008-01-01

    The DARHT-II linear induction accelerator (LIA) accelerates a 2-kA electron beam to more than 17 MeV. The beam pulse has a greater than 1.5-microsecond flattop region over which the electron kinetic energy is constant to within 1%. The beam dynamics are diagnosed with 21 beam-position monitors located throughout the injector, accelerator, and after the accelerator exit, where we also have beam imaging diagnostics. We discuss the tuning of the injector and accelerator, and present data for the resulting beam dynamics. We discuss the tuning procedures and other methods used to minimize beam motion, which is undesirable for its application as a bremsstrahlung source for multi-pulse radiography of exlosively driven hydrodynamic experiments. We also present beam stability measurements, which we relate to previous stability experiments at lower current and energy.

  7. Beam dynamics activities at the Thomas Jefferson National Accelerator Facility (Jefferson Lab)

    SciTech Connect

    Douglas, D.R.

    1997-12-01

    The Thomas Jefferson National Accelerator Facility (Jefferson Lab) has been funded by the US Navy to build an infra-red FEL driven by an energy-recovering compact SRF-based linear accelerator. The machine is to produce a 1 kW IR photon beam. The Jefferson Lab Accelerator Division is presently engaged in detailed design and beam dynamics studies for the driver accelerator. Principle beam dynamics and beam transport considerations include: (1) generation and transport of a high-quality, high-current, space-charge dominated beam; (2) the impact of coherent synchrotron radiation (CSR) during beam recirculation transport; (3) low-loss transport of a large momentum spread, high-current beam; (4) beam break up (BBU) instabilities in the recirculating accelerator; (5) impedance policing of transport system components; and (6) RF drive system control during energy recovery and FEL operation.

  8. Transport of intense beams of highly charged ions

    NASA Astrophysics Data System (ADS)

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

    2005-10-01

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

  9. LHC cryogenics – new experience of run with increased beam energy and intensity

    NASA Astrophysics Data System (ADS)

    Brodzinski, K.; Claudet, S.; Delikaris, D.; Delprat, L.; Ferlin, G.; Rogez, E.; Tavian, L.

    2017-03-01

    After the LHC first long shut down (LS1), when necessary consolidation and maintenance activities were performed on different technical systems, the Large Hadron Collider was progressively cooled down from ambient to operation temperatures from May of 2014. Prior to physics run with increased beam energy to 6.5 TeV/beam, increased beam intensity and modified beam injection scheme, several qualifications and tests affecting cryogenic system have been performed to ensure stable run of the accelerator. New beam parameters were gradually applied to the accelerator, reducing operational margins of cryogenic capacity from previous run. The process optimization and related updates in the control system were applied. This paper will briefly recall the main consolidations performed on the cryogenic system during LS1. The cool down process and behaviour of the cryogenic system during qualifications and tests will be presented. Difficulties and applied solutions during the run will be discussed. The availability and helium losses statistics for full year operation of 2015 will be given.

  10. Prospective Trial of Accelerated Partial Breast Intensity-Modulated Radiotherapy

    SciTech Connect

    Leonard, Charles . E-mail: charles.leonard@usoncology.com; Carter, Dennis; Kercher, Jane; Howell, Kathryn; Henkenberns, Phyllis; Tallhamer, Michael; Cornish, Patricia C.; Hunter, Kari C.; Kondrat, Janis

    2007-04-01

    Purpose: To examine the feasibility and acute toxicities of an accelerated, partial breast, intensity-modulated radiotherapy (IMRT) protocol. Methods and Materials: Between February 2004 and August 2005, 55 patients with Stage I breast cancer and initial follow-up were enrolled at four facilities on a HealthONE and Western institutional review board-approved accelerated partial breast IMRT protocol. All patients were treated in 10 equal fractions delivered twice daily within 5 consecutive days. The first 7 patients were treated to 34 Gy, and the remaining 48 patients were treated to 38.5 Gy. Results: The median follow-up after IMRT was 10 months (range, <1-19) and after diagnosis was 11.5 months (range, 2-21). No local or distant recurrences developed. The T stage distribution was as follows: T1a in 11 patients, T1b in 24, and T1c in 20. The median tumor size was 9 mm (range, 1-20 mm). Breast cosmesis was judged by the patient as poor by 2, good by 12, and excellent by 40 (1 patient was legally blind) and by the physician as poor for 1, good for 10, and excellent for 44 patients. Breast pain, as judged by patient, was none in 34, mild in 19, moderate in 2, and severe in 0 patients. There was a single report of telangiectasia but no incidents of significant edema. Compared with historic controls for whom three-dimensional treatment planning techniques were used, IMRT provided similar dose delivery to the target while reducing the volume of normal breast included in the 100%, 75%, and 50% isodose lines. Conclusion: This initial report prospectively explored the feasibility of accelerated partial breast IMRT. After short-term follow-up, the dose delivery and clinical outcomes were very acceptable. We believe this regimen deserves additional investigation under institutional review board guidance.

  11. Survey of Collective Instabilities and Beam-Plasma Interactions in Intense Heavy Ion Beams

    SciTech Connect

    Davidson, Ronald C.; Dorf, Mikhail A.; Kaganovich, Igor D.; Qin, Hong; Startsev, Edward A.; Rose, David V.; Lund, Steven M.; Welch, Dale R.; Sefkow, Adam

    2008-06-19

    This paper presents a survey of the present theoretical understanding based on advanced analytical and numerical studies of collective processes and beam-plasma interactions in intense heavy ion beams for applications to ion-beam-driven high energy density physics and heavy ion fusion. The topics include: discussion of the conditions for quiescent beam propagation over long distances; and the electrostatic Harris instability and the transverse electromagnetic Weibel instability in highly anisotropic, intense one-component ion beams. In the longitudinal drift compression and transverse compression regions, collective processes associated with the interaction of the intense ion beam with a charge-neutralizing background plasma are described, including the electrostatic electron-ion two-stream instability, the multispecies electromagnetic Weibel instability, and collective excitations in the presence of a solenoidal magnetic field. The effects of a velocity tilt on reducing two-stream instability growth rates are also discussed. Operating regimes are identified where the possible deleterious effects of collective processes on beam quality are minimized.

  12. Three-dimensional numerical studies of the temperature anisotropy instability in intense charged particle beams

    NASA Astrophysics Data System (ADS)

    Startsev, Edward A.; Davidson, Ronald C.; Qin, Hong

    2005-05-01

    In neutral plasmas with a uniform magnetic field and strongly anisotropic distribution function (T∥/T⊥≪1) an electrostatic Harris-type collective instability may develop if the plasma is sufficiently dense. Such anisotropies develop naturally in accelerators, and a similar instability may lead to a deterioration of the beam quality in a one-component nonneutral charged particle beam. The instability may also lead to an increase in the longitudinal velocity spread, which would make the focusing of the beam difficult and impose a limit on the minimum spot size achievable in heavy ion fusion experiments. This paper reports the results of recent numerical studies of the temperature anisotropy instability using the newly developed Beam Eigenmodes And Spectra (bEASt) code for space-charge-dominated, low-emittance beams with large tune depression (ν/ν0≪1). Such high-intensity beams are relevant to next-step experiments such as the Integrated Beam Experiment (IBX), which would serve as proof-of-principal experiment for heavy-ion fusion.

  13. Method of active charge and current neutralization of intense ion beams for ICF

    SciTech Connect

    Guiragossian, Z.G.T.; Orthel, J.L.; Lemons, D.S.; Thode, L.E.

    1981-01-01

    Methods of generating the beam neutralization electrons with required properties are given in the context of a Light Ion Fusion Experiment (LIFE) designed accelerator. Recently derived envelope equations for neutralized and ballistically focused intense ion beams are applied to the LIFE geometry in which 10 MeV He/sup +/ multiple beamlets coalesce and undergo 45:1 radial compression while beam pulses experience a 20:1 axial compression in the propagation range of 10 m. Both active and auto-neutralization methods are examined and found to produce initial electron temperatures consistent with the requirement of the envelope equation for both radial and axial adiabatic beam pulse compressions. The stability of neutralized beam propagation is also examined concerning the Pierce type electrostatic instability and for the case of LIFE beams it is found to have insignificant effect. A scaled experimental setup is presented which can serve to perform near term tests on the ballistically focused propagation of neutralized light ion beams.

  14. High intensity positron beam and angular correlation experiments at Livermore

    SciTech Connect

    Howell, R.H.; Rosenberg, I.J.; Meyer, P.; Fluss, M.J.

    1985-03-01

    A positron beam apparatus that produces a variable energy positron beam with sufficient intensity to perform new positron experiments in an ultrahigh vacuum environment has been installed at the Lawrence Livermore 100 MeV electron linac. We have installed two large area position sensitive gamma-ray detectors to measure angular correlations in two dimensions and a separate highly collimated detector to measure positronium energy distributions by time-of-flight velocity determination. Data from measurements on single crystals of Cu will be described.

  15. Intense ion-beam dynamics in the NICA collider

    NASA Astrophysics Data System (ADS)

    Kozlov, O. S.; Meshkov, I. N.; Sidorin, A. O.; Trubnikov, G. V.

    2016-12-01

    The problems of intense ion-beam dynamics in the developed and optimized optical structure of the NICA collider are considered. Conditions for beam collisions and obtaining the required parameters of luminosity in the operation energy range are discussed. The restriction on collider luminosity is related to effects of the domination of the space charge and intrabeam scattering. Applying methods of cooling, electron and stochastic ones, will permit one to suppress these effects and reach design luminosity. The work also deals with systems of magnetic field correction and problems of calculating the dynamic aperture of the collider.

  16. On the speed and acceleration of electron beams triggering interplanetary type III radio bursts

    NASA Astrophysics Data System (ADS)

    Krupar, V.; Kontar, E. P.; Soucek, J.; Santolik, O.; Maksimovic, M.; Kruparova, O.

    2015-08-01

    Aims: Type III radio bursts are intense radio emissions triggered by beams of energetic electrons often associated with solar flares. These exciter beams propagate outwards from the Sun along an open magnetic field line in the corona and in the interplanetary (IP) medium. Methods: We performed a statistical survey of 29 simple and isolated IP type III bursts observed by STEREO/Waves instruments between January 2013 and September 2014. We investigated their time-frequency profiles in order to derive the speed and acceleration of exciter electron beams. Results: We show these beams noticeably decelerate in the IP medium. Obtained speeds range from ~0.02c up to ~0.35c depending on initial assumptions. It corresponds to electron energies between tens of eV and hundreds of keV, and in order to explain the characteristic energies or speeds of type III electrons (~0.1c) observed simultaneously with Langmuir waves at 1 au, the emission of type III bursts near the peak should be predominately at double plasma frequency. Derived properties of electron beams can be used as input parameters for computer simulations of interactions between the beam and the plasma in the IP medium. Appendix A is available in electronic form at http://www.aanda.org

  17. Status of intense permanent magnet proton source for China-accelerator driven sub-critical system Linac

    SciTech Connect

    Wu, Q. Ma, H. Y.; Yang, Y.; Sun, L. T.; Zhang, X. Z.; Zhang, Z. M.; Zhao, H. Y.; He, Y.; Zhao, H. W.

    2016-02-15

    Two compact intense 2.45 GHz permanent magnet proton sources and their corresponding low energy beam transport (LEBT) system were developed successfully for China accelerator driven sub-critical system in 2014. Both the proton sources operate at 35 kV potential. The beams extracted from the ion source are transported by the LEBT, which is composed of two identical solenoids, to the 2.1 MeV Radio-Frequency Quadrupole (RFQ). In order to ensure the safety of the superconducting cavities during commissioning, an electrostatic-chopper has been designed and installed in the LEBT line that can chop the continuous wave beam into a pulsed one. The minimum width of the pulse is less than 10 μs and the fall/rise time of the chopper is about 20 ns. The performance of the proton source and the LEBT, such as beam current, beam profile, emittance and the impact to RFQ injection will be presented.

  18. Nonlinear stability in the transport of intense bunched beams

    NASA Astrophysics Data System (ADS)

    Corrêa da Silva, Thales M.; Rizzato, Felipe B.; Pakter, Renato; Levin, Yan

    2016-11-01

    The paper investigates the nonlinear coupling of envelope modes of oscillation for intense bunched beams. Initially, the analysis concentrates on the case of spherically symmetric beams for which longitudinal and transverse focusing forces are assumed to be the same. It is investigated how externally induced spherically symmetric breathing oscillations may nonlinearly drive the growth of ellipsoidal modes which can break the spherical beam symmetry. Next, a more general case in which the focusing forces are not symmetric such that the matched beam already presents an ellipsoidal shape is studied. It is found that depending on the parameters of the system, even a very small mismatch amplitude can drive an instability, which leads to an effective coupling of longitudinal and transversal envelope oscillations by means of the space-charge forces. Use is made of Poincaré plots and the stability index of periodic orbits to perform a detailed analysis of the location of the instability in the parameter space and how it affects the beam transport. Self-consistent numerical simulations are performed in order to verify the onset of the nonlinear instability and its effect on the evolution of the RMS size and emittance of the beam.

  19. Collimated multi-MeV ion beams from high-intensity laser interactions with underdense plasma.

    PubMed

    Willingale, L; Mangles, S P D; Nilson, P M; Clarke, R J; Dangor, A E; Kaluza, M C; Karsch, S; Lancaster, K L; Mori, W B; Najmudin, Z; Schreiber, J; Thomas, A G R; Wei, M S; Krushelnick, K

    2006-06-23

    A beam of multi-MeV helium ions has been observed from the interaction of a short-pulse high-intensity laser pulse with underdense helium plasma. The ion beam was found to have a maximum energy for He2+ of (40(+3)(-8)) MeV and was directional along the laser propagation path, with the highest energy ions being collimated to a cone of less than 10 degrees. 2D particle-in-cell simulations show that the ions are accelerated by a sheath electric field that is produced at the back of the gas target. This electric field is generated by transfer of laser energy to a hot electron beam, which exits the target generating large space-charge fields normal to its boundary.

  20. Self-reconstruction of diffraction-free and accelerating laser beams in scattering media

    NASA Astrophysics Data System (ADS)

    Ersoy, T.; Yalizay, B.; Akturk, S.

    2012-12-01

    We experimentally investigate propagation of laser beams with different intensity profiles in highly scattering media. We generate transverse laser amplitude profiles with Gaussian, Bessel and Airy function envelopes. We then propagate these beams through optical phantoms formed with variable density intralipid solutions. At the sample exit, we compare change in maximum intensities, as well as beam profile reconstruction. We show that self-reconstruction properties of Bessel and Airy beams bring about slower decrease in maximum intensity with increasing scatterer density. On the other hand, the beam profiles deteriorate faster, as compared to reference Gaussian beams. Slower decrease in the intensity can be attributed to the wavevector spectra providing a continuous flow of energy to the beam center, while beam deterioration is linked to total beam volume in the scattering medium. These results show that beam shaping methods can significantly enhance delivery of intense light deeper into turbid media, but this enhancement is compromised by stronger speckling of beam profiles.

  1. Intensity Effects of the FACET Beam in the SLAC Linac

    SciTech Connect

    Decker, F.-J.; Lipkowitz, N.; Sheppard, J.; White, G.R.; Wienands, U.; Woodley, M.; Yocky, G.; /SLAC

    2012-07-03

    The beam for FACET (Facility for Advanced aCcelerator Experimental Tests) at SLAC requires an energy-time correlation ('chirp') along the linac, so it can be compressed in two chicanes, one at the midpoint in sector 10 and one W-shaped chicane just before the FACET experimental area. The induced correlation has the opposite sign to the typical used for BNS damping, and therefore any orbit variations away from the center kick the tail of the beam more than the head, causing a shear in the beam and emittance growth. Any dispersion created along the linac has similar effects due to the high (>1.2% rms) energy spread necessary for compression. The initial huge emittances could be reduced by a factor of 10, but were still bigger than expected by a factor of 2-3. Normalized emittance of 3 {micro}m-rad in Sector 2 blew up to 150 {micro}m-rad in Sector 11 but could be reduced to about 6-12 {micro}m-rad, for the vertical plane although the results were not very stable. Investigating possible root causes for this, we found locations where up to 10 mm dispersion was created along the linac, which were finally verified with strong steering and up to 7 mm settling of the linac accelerator at these locations.

  2. Studies of Ion Acceleration from Thin Solid-Density Targets on High-Intensity Lasers

    NASA Astrophysics Data System (ADS)

    Willis, Christopher R.

    Over the past two decades, a number of experiments have been performed demonstrating the acceleration of ions from the interaction of an intense laser pulse with a thin, solid density target. These ions are accelerated by quasi-static electric fields generated by energetic electrons produced at the front of the target, resulting in ion energies up to tens of MeV. These ions have been widely studied for a variety of potential applications ranging from treatment of cancer to the production of neutrons for advanced radiography techniques. However, realization of these applications will require further optimization of the maximum energy, spectrum, or species of the accelerated ions, which has been a primary focus of research to date. This thesis presents two experiments designed to optimize several characteristics of the accelerated ion beam. The first of these experiments took place on the GHOST laser system at the University of Texas at Austin, and was designed to demonstrate reliable acceleration of deuterium ions, as needed for the most efficient methods of neutron generation from accelerated ions. This experiment leveraged cryogenically cooled targets coated in D2 O ice to suppress the protons which typically dominate the accelerated ions, producing as many as 2 x 1010 deuterium ions per 1 J laser shot, exceeding the proton yield by an average ratio of 5:1. The second major experiment in this work was performed on the Scarlet laser system at The Ohio State University, and studied the accelerated ion energy, yield, and spatial distribution as a function of the target thickness. In principle, the peak energy increases with decreasing target thickness, with the thinnest targets accessing additional acceleration mechanisms which provide favorable scaling with the laser intensity. However, laser prepulse characteristics provide a lower bound for the target thickness, yielding an optimum target thickness for ion acceleration which is dependent on the laser system. This

  3. Studies of beam dynamics in relativistic klystron two-beam accelerators

    SciTech Connect

    Lidia, Steven M.

    1999-11-01

    Two-beam accelerators (TBAs) based upon free-electron lasers (FELs) or relativistic klystrons (RK-TBAs) have been proposed as efficient power sources for next generation high-energy linear colliders. Studies have demonstrated the possibility of building TBAs from X-band (~8-12 GHz) through Ka band (~ 30-35 GHz) frequency regions. Provided that further prototyping shows stable beam propagation with minimal current loss and production of good quality, high-power rf fields, this technology is compatible with current schemes for electron-positron colliders in the multi-TeV center-of-mass scale. A new method of simulating the beam dynamics in accelerators of this type has been developed in this dissertation. There are three main components to this simulation. The first is a tracking algorithm to generate nonlinear transfer maps for pushing noninteracting particles through the external fields. The second component is a 3D Particle-In-Cell (PIC) algorithm that solves a set of Helmholtz equations for the self-fields, including the conducting boundary condition, and generates impulses that are interleaved with the nonlinear maps by means of a split-operation algorithm. The Helmholtz equations are solved by a multi-grid algorithm. The third component is an equivalent circuit equation solver that advances the modal rf cavity fields in time due to excitation by the modulated beam. The RTA project is described, and the simulation code is used to design the latter portions of the experiment. Detailed calculations of the beam dynamics and of the rf cavity output are presented and discussed. A beamline design is presented that will generate nearly 1.2 GW of power from 40 input, gain, and output rv cavities over a 10 m distance. The simulations show that beam current losses are acceptable, and that longitudinal and transverse focusing techniques are sufficient capable of maintaining a high degree of beam quality along the entire beamline. Additional experimental efforts are also

  4. Accelerated nonrigid intensity-based image registration using importance sampling.

    PubMed

    Bhagalia, Roshni; Fessler, Jeffrey A; Kim, Boklye

    2009-08-01

    Nonrigid image registration methods using intensity-based similarity metrics are becoming increasingly common tools to estimate many types of deformations. Nonrigid warps can be very flexible with a large number of parameters and gradient optimization schemes are widely used to estimate them. However, for large datasets, the computation of the gradient of the similarity metric with respect to these many parameters becomes very time consuming. Using a small random subset of image voxels to approximate the gradient can reduce computation time. This work focuses on the use of importance sampling to reduce the variance of this gradient approximation. The proposed importance sampling framework is based on an edge-dependent adaptive sampling distribution designed for use with intensity-based registration algorithms. We compare the performance of registration based on stochastic approximations with and without importance sampling to that using deterministic gradient descent. Empirical results, on simulated magnetic resonance brain data and real computed tomography inhale-exhale lung data from eight subjects, show that a combination of stochastic approximation methods and importance sampling accelerates the registration process while preserving accuracy.

  5. All-optical steering of laser-wakefield-accelerated electron beams.

    PubMed

    Popp, A; Vieira, J; Osterhoff, J; Major, Zs; Hörlein, R; Fuchs, M; Weingartner, R; Rowlands-Rees, T P; Marti, M; Fonseca, R A; Martins, S F; Silva, L O; Hooker, S M; Krausz, F; Grüner, F; Karsch, S

    2010-11-19

    We investigate the influence of a tilted laser-pulse-intensity front on laser-wakefield acceleration. Such asymmetric light pulses may be exploited to obtain control over the electron-bunch-pointing direction and in our case allowed for reproducible electron-beam steering in an all-optical way within an 8 mrad opening window with respect to the initial laser axis. We also discovered evidence of collective electron-betatron oscillations due to off-axis electron injection into the wakefield induced by a pulse-front tilt. These findings are supported by 3D particle-in-cell simulations.

  6. Early Beam Injection Scheme for the Fermilab Booster: A Path for Intensity Upgrade

    SciTech Connect

    Bhat, C. M.

    2015-10-28

    Over the past decade, Fermilab has focused efforts on the intensity frontier physics and is committed to increase the average beam power delivered to the neutrino and muon programs substantially. Many upgrades to the existing injector accelerators, namely, the current 400 MeV LINAC and the Booster, are in progress under the Proton Improvement Plan (PIP). Proton Improvement Plan-II (PIP-II) proposes to replace the existing 400 MeV LINAC by a new 800 MeV LINAC, as an injector to the Booster which will increase Booster output power by nearly a factor of two from the PIP design value by the end of its completion. In any case, the Fermilab Booster is going to play a very significant role for nearly next two decades. In this context, I have developed and investigated a new beam injection scheme called "early injection scheme" (EIS) for the Booster with the goal to significantly increase the beam intensity output from the Booster thereby increasing the beam power to the HEP experiments even before PIP-II era. The scheme, if implemented, will also help improve the slip-stacking efficiency in the MI/RR. Here I present results from recent simulations, beam studies, current status and future plans for the new scheme.

  7. Monoenergetic beams of relativistic electrons from intense laser-plasma interactions.

    PubMed

    Mangles, S P D; Murphy, C D; Najmudin, Z; Thomas, A G R; Collier, J L; Dangor, A E; Divall, E J; Foster, P S; Gallacher, J G; Hooker, C J; Jaroszynski, D A; Langley, A J; Mori, W B; Norreys, P A; Tsung, F S; Viskup, R; Walton, B R; Krushelnick, K

    2004-09-30

    High-power lasers that fit into a university-scale laboratory can now reach focused intensities of more than 10(19) W cm(-2) at high repetition rates. Such lasers are capable of producing beams of energetic electrons, protons and gamma-rays. Relativistic electrons are generated through the breaking of large-amplitude relativistic plasma waves created in the wake of the laser pulse as it propagates through a plasma, or through a direct interaction between the laser field and the electrons in the plasma. However, the electron beams produced from previous laser-plasma experiments have a large energy spread, limiting their use for potential applications. Here we report high-resolution energy measurements of the electron beams produced from intense laser-plasma interactions, showing that--under particular plasma conditions--it is possible to generate beams of relativistic electrons with low divergence and a small energy spread (less than three per cent). The monoenergetic features were observed in the electron energy spectrum for plasma densities just above a threshold required for breaking of the plasma wave. These features were observed consistently in the electron spectrum, although the energy of the beam was observed to vary from shot to shot. If the issue of energy reproducibility can be addressed, it should be possible to generate ultrashort monoenergetic electron bunches of tunable energy, holding great promise for the future development of 'table-top' particle accelerators.

  8. Automatic Beam Path Analysis of Laser Wakefield Particle Acceleration Data

    SciTech Connect

    Rubel, Oliver; Geddes, Cameron G.R.; Cormier-Michel, Estelle; Wu, Kesheng; Prabhat,; Weber, Gunther H.; Ushizima, Daniela M.; Messmer, Peter; Hagen, Hans; Hamann, Bernd; Bethel, E. Wes

    2009-10-19

    Numerical simulations of laser wakefield particle accelerators play a key role in the understanding of the complex acceleration process and in the design of expensive experimental facilities. As the size and complexity of simulation output grows, an increasingly acute challenge is the practical need for computational techniques that aid in scientific knowledge discovery. To that end, we present a set of data-understanding algorithms that work in concert in a pipeline fashion to automatically locate and analyze high energy particle bunches undergoing acceleration in very large simulation datasets. These techniques work cooperatively by first identifying features of interest in individual timesteps, then integrating features across timesteps, and based on the information derived perform analysis of temporally dynamic features. This combination of techniques supports accurate detection of particle beams enabling a deeper level of scientific understanding of physical phenomena than hasbeen possible before. By combining efficient data analysis algorithms and state-of-the-art data management we enable high-performance analysis of extremely large particle datasets in 3D. We demonstrate the usefulness of our methods for a variety of 2D and 3D datasets and discuss the performance of our analysis pipeline.

  9. Ultracold electron bunch generation via plasma photocathode emission and acceleration in a beam-driven plasma blowout.

    PubMed

    Hidding, B; Pretzler, G; Rosenzweig, J B; Königstein, T; Schiller, D; Bruhwiler, D L

    2012-01-20

    Beam-driven plasma wakefield acceleration using low-ionization-threshold gas such as Li is combined with laser-controlled electron injection via ionization of high-ionization-threshold gas such as He. The He electrons are released with low transverse momentum in the focus of the copropagating, nonrelativistic-intensity laser pulse directly inside the accelerating or focusing phase of the Li blowout. This concept paves the way for the generation of sub-μm-size, ultralow-emittance, highly tunable electron bunches, thus enabling a flexible new class of an advanced free electron laser capable high-field accelerator.

  10. Intensity Modulated Radiotherapy with High Energy Photon and Hadron Beams

    NASA Astrophysics Data System (ADS)

    Oelfke, U.

    2004-07-01

    This short contribution will briefly describe the basic concepts of intensity modulated radiation therapy with high energy photons (IMRT) and charged particle beams (IMPT). Dose delivery and optimization strategies like the `Inverse Planning' approach will be explained for both radiation modalities and their potential advantages are demonstrated for characteristic clinical examples. Finally, future development like image guided radiotherapy (IGRT) and adaptive radiation therapy, based on functional imaging methods, will be introduced.

  11. Time Resolved Imaging of Longitudinal Modulations in Intense Beams

    NASA Astrophysics Data System (ADS)

    Tian, Kai

    2007-11-01

    The longitudinal evolution of high intensity beams is not well understood despite its importance to the success of such applications as free electron lasers and light sources, heavy ion inertial fusion, and high energy colliders. For example any amplification of current modulations in an FEL photoinjector can lead to unwanted coherent synchrotron radiation further downstream in compression chicanes or bends. A significant factor usually neglected is the coupling to the transverse dynamics which can strongly affect the longitudinal evolution. Previous experiments at the University of Maryland have revealed much about the longitudinal physics of space-charge dominated beams by monitoring the evolution of longitudinal perturbations. For the first time, experimental results are presented here which reveal the effect of longitudinal perturbations on the transverse beam distribution, with the aid of several new diagnostics that capture detailed time-resolved density images. A longitudinal modulation of the particle density is deliberately generated at the source, and its evolution is tracked downstream using a number of diagnostics such as current monitors, high-resolution energy analyzers, as well as the transverse imaging devices. The latter consist of a high-resolution 16-bit gated camera coupled with very fast emitters such as prompt optical transition radiation (OTR) from an alumina screen, or fast Phosphor screens with 3-ns time resolution. Simulations using the particle-in-cell code WARP are applied to cross-check the experimental results. These experiments and especially the comparisons to simulation represent significant progress towards understanding the longitudinal physics of intense beams.

  12. Laser-driven beam lines for delivering intensity modulated radiation therapy with particle beams

    PubMed Central

    Hofmann, Kerstin M; Schell, Stefan; Wilkens, Jan J

    2012-01-01

    Abstract Laser-accelerated particles are a promising option for radiation therapy of cancer by potentially combining a compact, cost-efficient treatment unit with the physical advantages of charged particle beams. To design such a treatment unit we consider different dose delivery schemes and analyze the necessary devices in the required particle beam line for each case. Furthermore, we point out that laser-driven treatment units may be ideal tools for motion adaptation during radiotherapy. Reasons for this are the potential of a flexible gantry and the time structure of the beam with high particle numbers in ultrashort bunches. One challenge that needs to be addressed is the secondary radiation produced in several beam line elements. (© 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) PMID:22930653

  13. Laser-driven beam lines for delivering intensity modulated radiation therapy with particle beams.

    PubMed

    Hofmann, Kerstin M; Schell, Stefan; Wilkens, Jan J

    2012-11-01

    Laser-accelerated particles are a promising option for radiation therapy of cancer by potentially combining a compact, cost-efficient treatment unit with the physical advantages of charged particle beams. To design such a treatment unit we consider different dose delivery schemes and analyze the necessary devices in the required particle beam line for each case. Furthermore, we point out that laser-driven treatment units may be ideal tools for motion adaptation during radiotherapy. Reasons for this are the potential of a flexible gantry and the time structure of the beam with high particle numbers in ultrashort bunches. One challenge that needs to be addressed is the secondary radiation produced in several beam line elements.

  14. Positron Acceleration by Plasma Wakefields Driven by a Hollow Electron Beam

    NASA Astrophysics Data System (ADS)

    Jain, Neeraj; Antonsen, T. M.; Palastro, J. P.

    2015-11-01

    A scheme for positron plasma wakefield acceleration using hollow or donut-shaped electron driver beams is studied. An annular-shaped, electron-free region forms around the hollow driver beam, creating a favorable region (longitudinal field is accelerating and transverse field is focusing) for positron acceleration. For Facility for Advanced Accelerator Experimental Tests (FACET)-like parameters, the hollow beam driver produces accelerating gradients on the order of 10 GV /m . The accelerating gradient increases linearly with the total charge in the driver beam. Simulations show acceleration of a 23-GeV positron beam to 35.4 GeV with a maximum energy spread of 0.4% and very small emittance over a plasma length of 140 cm is possible.

  15. Optical transition radiation used in the diagnostic of low energy and low current electron beams in particle accelerators

    NASA Astrophysics Data System (ADS)

    Silva, T. F.; Bonini, A. L.; Lima, R. R.; Maidana, N. L.; Malafronte, A. A.; Pascholati, P. R.; Vanin, V. R.; Martins, M. N.

    2012-09-01

    Optical transition radiation (OTR) plays an important role in beam diagnostics for high energy particle accelerators. Its linear intensity with beam current is a great advantage as compared to fluorescent screens, which are subject to saturation. Moreover, the measurement of the angular distribution of the emitted radiation enables the determination of many beam parameters in a single observation point. However, few works deals with the application of OTR to monitor low energy beams. In this work we describe the design of an OTR based beam monitor used to measure the transverse beam charge distribution of the 1.9-MeV electron beam of the linac injector of the IFUSP microtron using a standard vision machine camera. The average beam current in pulsed operation mode is of the order of tens of nano-Amps. Low energy and low beam current make OTR observation difficult. To improve sensitivity, the beam incidence angle on the target was chosen to maximize the photon flux in the camera field-of-view. Measurements that assess OTR observation (linearity with beam current, polarization, and spectrum shape) are presented, as well as a typical 1.9-MeV electron beam charge distribution obtained from OTR. Some aspects of emittance measurement using this device are also discussed.

  16. Optical transition radiation used in the diagnostic of low energy and low current electron beams in particle accelerators.

    PubMed

    Silva, T F; Bonini, A L; Lima, R R; Maidana, N L; Malafronte, A A; Pascholati, P R; Vanin, V R; Martins, M N

    2012-09-01

    Optical transition radiation (OTR) plays an important role in beam diagnostics for high energy particle accelerators. Its linear intensity with beam current is a great advantage as compared to fluorescent screens, which are subject to saturation. Moreover, the measurement of the angular distribution of the emitted radiation enables the determination of many beam parameters in a single observation point. However, few works deals with the application of OTR to monitor low energy beams. In this work we describe the design of an OTR based beam monitor used to measure the transverse beam charge distribution of the 1.9-MeV electron beam of the linac injector of the IFUSP microtron using a standard vision machine camera. The average beam current in pulsed operation mode is of the order of tens of nano-Amps. Low energy and low beam current make OTR observation difficult. To improve sensitivity, the beam incidence angle on the target was chosen to maximize the photon flux in the camera field-of-view. Measurements that assess OTR observation (linearity with beam current, polarization, and spectrum shape) are presented, as well as a typical 1.9-MeV electron beam charge distribution obtained from OTR. Some aspects of emittance measurement using this device are also discussed.

  17. Collection and focusing of laser accelerated ion beams for therapy applications

    NASA Astrophysics Data System (ADS)

    Hofmann, Ingo; Meyer-Ter-Vehn, Jürgen; Yan, Xueqing; Orzhekhovskaya, Anna; Yaramyshev, Stepan

    2011-03-01

    Experimental results in laser acceleration of protons and ions and theoretical predictions that the currently achieved energies might be raised by factors 5-10 in the next few years have stimulated research exploring this new technology for oncology as a compact alternative to conventional synchrotron based accelerator technology. The emphasis of this paper is on collection and focusing of the laser produced particles by using simulation data from a specific laser acceleration model. We present a scaling law for the “chromatic emittance” of the collector—here assumed as a solenoid lens—and apply it to the particle energy and angular spectra of the simulation output. For a 10 Hz laser system we find that particle collection by a solenoid magnet well satisfies requirements of intensity and beam quality as needed for depth scanning irradiation. This includes a sufficiently large safety margin for intensity, whereas a scheme without collection—by using mere aperture collimation—hardly reaches the needed intensities.

  18. The Electron Cloud as a Limiting Factor for High-Intensity Particle Accelerators

    NASA Astrophysics Data System (ADS)

    Zwaska, Bob

    2011-11-01

    The electron cloud is an accumulation of electrons in the vacuum of an accelerator. These electrons can cause instabilities in the beam and other negative effects in the accelerator. I will describe the electron cloud mechanism and a campaign of experiments at Fermilab to understand the effect and control it for future accelerators.

  19. Acceleration of highly charged GeV Fe ions from a low-Z substrate by intense femtosecond laser

    SciTech Connect

    Nishiuchi, M. Sakaki, H.; Esirkepov, T. Zh.; Pirozhkov, A. S.; Sagisaka, A.; Ogura, K.; Kiriyama, H.; Fukuda, Y.; Kando, M.; Bulanov, S. V.; Kondo, K.; Nishio, K.; Orlandi, R.; Koura, H.; Imai, K.; Pikuz, T. A.; Faenov, A. Ya.; Skobelev, I. Yu.; Sako, H.; Matsukawa, K.; and others

    2015-03-15

    Almost fully stripped Fe ions accelerated up to 0.9 GeV are demonstrated with a 200 TW femtosecond high-intensity laser irradiating a micron-thick Al foil with Fe impurity on the surface. An energetic low-emittance high-density beam of heavy ions with a large charge-to-mass ratio can be obtained, which is useful for many applications, such as a compact radio isotope source in combination with conventional technology.

  20. Acceleration of highly charged GeV Fe ions from a low-Z substrate by intense femtosecond laser

    NASA Astrophysics Data System (ADS)

    Nishiuchi, M.; Sakaki, H.; Esirkepov, T. Zh.; Nishio, K.; Pikuz, T. A.; Faenov, A. Ya.; Skobelev, I. Yu.; Orlandi, R.; Sako, H.; Pirozhkov, A. S.; Matsukawa, K.; Sagisaka, A.; Ogura, K.; Kanasaki, M.; Kiriyama, H.; Fukuda, Y.; Koura, H.; Kando, M.; Yamauchi, T.; Watanabe, Y.; Bulanov, S. V.; Kondo, K.; Imai, K.; Nagamiya, S.

    2015-03-01

    Almost fully stripped Fe ions accelerated up to 0.9 GeV are demonstrated with a 200 TW femtosecond high-intensity laser irradiating a micron-thick Al foil with Fe impurity on the surface. An energetic low-emittance high-density beam of heavy ions with a large charge-to-mass ratio can be obtained, which is useful for many applications, such as a compact radio isotope source in combination with conventional technology.

  1. ``Accelerators and Beams,'' multimedia computer-based training in accelerator physics

    NASA Astrophysics Data System (ADS)

    Silbar, R. R.; Browman, A. A.; Mead, W. C.; Williams, R. A.

    1999-06-01

    We are developing a set of computer-based tutorials on accelerators and charged-particle beams under an SBIR grant from the DOE. These self-paced, interactive tutorials, available for Macintosh and Windows platforms, use multimedia techniques to enhance the user's rate of learning and length of retention of the material. They integrate interactive "On-Screen Laboratories," hypertext, line drawings, photographs, two- and three-dimensional animations, video, and sound. They target a broad audience, from undergraduates or technicians to professionals. Presently, three modules have been published (Vectors, Forces, and Motion), a fourth (Dipole Magnets) has been submitted for review, and three more exist in prototype form (Quadrupoles, Matrix Transport, and Properties of Charged-Particle Beams). Participants in the poster session will have the opportunity to try out these modules on a laptop computer.

  2. AGS SUPER NEUTRINO BEAM FACILITY ACCELERATOR AND TARGET SYSTEM DESIGN (NEUTRINO WORKING GROUP REPORT-II).

    SciTech Connect

    DIWAN,M.; MARCIANO,W.; WENG,W.; RAPARIA,D.

    2003-04-21

    This document describes the design of the accelerator and target systems for the AGS Super Neutrino Beam Facility. Under the direction of the Associate Laboratory Director Tom Kirk, BNL has established a Neutrino Working Group to explore the scientific case and facility requirements for a very long baseline neutrino experiment. Results of a study of the physics merit and detector performance was published in BNL-69395 in October 2002, where it was shown that a wide-band neutrino beam generated by a 1 MW proton beam from the AGS, coupled with a half megaton water Cerenkov detector located deep underground in the former Homestake mine in South Dakota would be able to measure the complete set of neutrino oscillation parameters: (1) precise determination of the oscillation parameters {Delta}m{sub 32}{sup 2} and sin{sup 2} 2{theta}{sub 32}; (2) detection of the oscillation of {nu}{sub {mu}}-{nu}{sub e} and measurement of sin{sup 2} 2{theta}{sub 13}; (3) measurement of {Delta}m{sub 21}{sup 2} sin 2{theta}{sub 12} in a {nu}{sub {mu}} {yields} {nu}{sub e} appearance mode, independent of the value of {theta}{sub 13}; (4) verification of matter enhancement and the sign of {Delta}m{sub 32}{sup 2}; and (5) determination of the CP-violation parameter {delta}{sub CP} in the neutrino sector. This report details the performance requirements and conceptual design of the accelerator and the target systems for the production of a neutrino beam by a 1.0 MW proton beam from the AGS. The major components of this facility include a new 1.2 GeV superconducting linac, ramping the AGS at 2.5 Hz, and the new target station for 1.0 MW beam. It also calls for moderate increase, about 30%, of the AGS intensity per pulse. Special care is taken to account for all sources of proton beam loss plus shielding and collimation of stray beam halo particles to ensure equipment reliability and personal safety. A preliminary cost estimate and schedule for the accelerator upgrade and target system are also

  3. Frequency multiplying oscillator with an electron beam accelerated in a drift space

    SciTech Connect

    Jang, Kyu-Ha; Lee, Kitae; Hee Park, Seong; Uk Jeong, Young; Miginsky, S.

    2012-07-02

    In a uniform acceleration region, the behavior of a velocity-modulated electron beam has been analyzed using a particle-in-cell code. By making use of one of the accelerated harmonic components of the velocity-modulated electron beam, we demonstrate a frequency multiplying oscillator for a compact THz emitter, which employs multiple electron beams and a higher order mode resonator to modulate the electron beam without an additional driving source.

  4. Focusing Intense Charged Particle Beams with Achromatic Effects for Heavy Ion Fusion

    NASA Astrophysics Data System (ADS)

    Mitrani, James; Kaganovich, Igor

    2012-10-01

    Final focusing systems designed to minimize the effects of chromatic aberrations in the Neutralized Drift Compression Experiment (NDCX-II) are described. NDCX-II is a linear induction accelerator, designed to accelerate short bunches at high current. Previous experiments showed that neutralized drift compression significantly compresses the beam longitudinally (˜60x) in the z-direction, resulting in a narrow distribution in z-space, but a wide distribution in pz-space. Using simple lenses (e.g., solenoids, quadrupoles) to focus beam bunches with wide distributions in pz-space results in chromatic aberrations, leading to lower beam intensities (J/cm^2). Therefore, the final focusing system must be designed to compensate for chromatic aberrations. The paraxial ray equations and beam envelope equations are numerically solved for parameters appropriate to NDCX-II. Based on these results, conceptual designs for final focusing systems using a combination of solenoids and/or quadrupoles are optimized to compensate for chromatic aberrations. Lens aberrations and emittance growth will be investigated, and analytical results will be compared with results from numerical particle-in-cell (PIC) simulation codes.

  5. Short-pulse, high-energy radiation generation from laser-wakefield accelerated electron beams

    NASA Astrophysics Data System (ADS)

    Schumaker, Will

    2013-10-01

    Recent experimental results of laser wakefield acceleration (LWFA) of ~GeV electrons driven by the 200TW HERCULES and the 400TW ASTRA-GEMINI laser systems and their subsequent generation of photons, positrons, and neutrons are presented. In LWFA, high-intensity (I >1019 W /cm2), ultra-short (τL < 1 / (2 πωpe)) laser pulses drive highly nonlinear plasma waves which can trap ~ nC of electrons and accelerate them to ~GeV energies over ~cm lengths. These electron beams can then be converted by a high-Z target via bremsstrahlung into low-divergence (< 20 mrad) beams of high-energy (<600 MeV) photons and subsequently into positrons via the Bethe-Heitler process. By increasing the material thickness and Z, the resulting Ne+ /Ne- ratio can approach unity, resulting in a near neutral density plasma jet. These quasi-neutral beams are presumed to retain the short-pulse (τL < 40 fs) characteristic of the electron beam, resulting in a high peak density of ne- /e+ ~ 1016 cm-3 , making the source an excellent candidate for laboratory study of astrophysical leptonic jets. Alternatively, the electron beam can be interacted with a counter-propagating, ultra-high intensity (I >1021 W /cm2) laser pulse to undergo inverse Compton scattering and emit a high-peak brightness beam of high-energy photons. Preliminary results and experimental sensitivities of the electron-laser beam overlap are presented. The high-energy photon beams can be spectrally resolved using a forward Compton scattering spectrometer. Moreover, the photon flux can be characterized by a pixelated scintillator array and by nuclear activation and (γ,n) neutron measurements from the photons interacting with a secondary solid target. Monte-Carlo simulations were performed using FLUKA to support the yield estimates. This research was supported by DOE/NSF-PHY 0810979, NSF CAREER 1054164, DARPA AXiS N66001-11-1-4208, SF/DNDO F021166, and the Leverhulme Trust ECF-2011-383.

  6. Radiation pressure acceleration of corrugated thin foils by Gaussian and super-Gaussian beams

    SciTech Connect

    Adusumilli, K.; Goyal, D.; Tripathi, V. K.

    2012-01-15

    Rayleigh-Taylor instability of radiation pressure accelerated ultrathin foils by laser having Gaussian and super-Gaussian intensity distribution is investigated using a single fluid code. The foil is allowed to have ring shaped surface ripples. The radiation pressure force on such a foil is non-uniform with finite transverse component F{sub r}; F{sub r} varies periodically with r. Subsequently, the ripple grows as the foil moves ahead along z. With a Gaussian beam, the foil acquires an overall curvature due to non-uniformity in radiation pressure and gets thinner. In the process, the ripple perturbation is considerably washed off. With super-Gaussian beam, the ripple is found to be more strongly washed out. In order to avoid transmission of the laser through the thinning foil, a criterion on the foil thickness is obtained.

  7. Vaccine Biotechnology by Accelerated Electron Beam and Microwave Irradiation

    NASA Astrophysics Data System (ADS)

    Craciun, Gabriela D.; Togoe, Iulian I.; Tudor, Laurentiu M.; Martin, Diana I.; Manaila, Elena N.; Ighigeanu, Daniel I.; Iacob, Nicusor I.; Oproiu, Constantin V.

    2007-04-01

    A new biotechnology for obtaining a commercial vaccine that contains either Fusobacterium necrophorum (F.n.) exotoxins inactivated by accelerated electron beam (EB) and microwave (MW) irradiation, or exotoxins isolated from F.n. cultures irradiated with EB+MW, is presented. This vaccine is designed for prophylaxis of ruminant infectious pododermatitis (IP) produced by F.n. Also, the research results concerning the effects of combined chemical adjuvant and EB+MW irradiation on F.n. immune capacity are discussed. The vaccine's efficacy will be tested in ruminant farms in which IP evolves. It is expected that this new vaccine to offer a better protection, more than 60%, which is the best presently obtained result in ruminant farms.

  8. METHOD OF PRODUCING AND ACCELERATING AN ION BEAM

    NASA Technical Reports Server (NTRS)

    Foster, John E. (Inventor)

    2005-01-01

    A method of producing and accelerating an ion beam comprising the steps of providing a magnetic field with a cusp that opens in an outward direction along a centerline that passes through a vertex of the cusp: providing an ionizing gas that sprays outward through at least one capillary-like orifice in a plenum that is positioned such that the orifice is on the centerline in the cusp, outward of the vortex of the cusp; providing a cathode electron source, and positioning it outward of the orifice and off of the centerline; and positively charging the plenum relative to the cathode electron source such that the plenum functions as m anode. A hot filament may be used as the cathode electron source, and permanent magnets may be used to provide the magnetic field.

  9. Electron-Beam Dynamics for an Advanced Flash-Radiography Accelerator

    SciTech Connect

    Ekdahl, Carl

    2015-11-17

    Beam dynamics issues were assessed for a new linear induction electron accelerator being designed for multipulse flash radiography of large explosively driven hydrodynamic experiments. Special attention was paid to equilibrium beam transport, possible emittance growth, and beam stability. Especially problematic would be high-frequency beam instabilities that could blur individual radiographic source spots, low-frequency beam motion that could cause pulse-to-pulse spot displacement, and emittance growth that could enlarge the source spots. Furthermore, beam physics issues were examined through theoretical analysis and computer simulations, including particle-in-cell codes. Beam instabilities investigated included beam breakup, image displacement, diocotron, parametric envelope, ion hose, and the resistive wall instability. The beam corkscrew motion and emittance growth from beam mismatch were also studied. It was concluded that a beam with radiographic quality equivalent to the present accelerators at Los Alamos National Laboratory will result if the same engineering standards and construction details are upheld.

  10. Electron-beam dynamics for an advanced flash-radiography accelerator

    SciTech Connect

    Ekdahl, Carl August Jr.

    2015-06-22

    Beam dynamics issues were assessed for a new linear induction electron accelerator. Special attention was paid to equilibrium beam transport, possible emittance growth, and beam stability. Especially problematic would be high-frequency beam instabilities that could blur individual radiographic source spots, low-frequency beam motion that could cause pulse-to-pulse spot displacement, and emittance growth that could enlarge the source spots. Beam physics issues were examined through theoretical analysis and computer simulations, including particle-in cell (PIC) codes. Beam instabilities investigated included beam breakup (BBU), image displacement, diocotron, parametric envelope, ion hose, and the resistive wall instability. Beam corkscrew motion and emittance growth from beam mismatch were also studied. It was concluded that a beam with radiographic quality equivalent to the present accelerators at Los Alamos will result if the same engineering standards and construction details are upheld.

  11. High quality proton beams from hybrid integrated laser-driven ion acceleration systems

    NASA Astrophysics Data System (ADS)

    Sinigardi, Stefano; Turchetti, Giorgio; Rossi, Francesco; Londrillo, Pasquale; Giove, Dario; De Martinis, Carlo; Bolton, Paul R.

    2014-03-01

    We consider a hybrid acceleration scheme for protons where the laser generated beam is selected in energy and angle and injected into a compact linac, which raises the energy from 30 to 60 MeV. The laser acceleration regime is TNSA and the energy spectrum is determined by the cutoff energy and proton temperature. The dependence of the spectrum on the target properties and the incidence angle is investigated with 2D PIC simulations. We base our work on widely available technologies and on laser with a short pulse, having in mind a facility whose cost is approximately 15 M €. Using a recent experiment as the reference, we choose the laser pulse and target so that the energy spectrum obtained from the 3D PIC simulation is close to the one observed, whose cutoff energy was estimated to be over 50 MeV. Laser accelerated protons in the TNSA regime have wide energy spectrum and broad divergence. In this paper we compare three transport lines, designed to perform energy selection and beam collimation. They are based on a solenoid, a quadruplet of permanent magnetic quadrupoles and a chicane. To increase the maximum available energy, which is actually seen as an upper limit due to laser properties and available targets, we propose to inject protons into a small linac for post-acceleration. The number of selected and injected protons is the highest with the solenoid and lower by one and two orders of magnitude with the quadrupoles and the chicane respectively. Even though only the solenoid enables achieving to reach a final intensity at the threshold required for therapy with the highest beam quality, the other systems will be very likely used in the first experiments. Realistic start-to-end simulations, as the ones reported here, are relevant for the design of such experiments.

  12. Beam dynamics and stability analysis of an intense beam in a continuously twisted quadrupole focusing channel

    NASA Astrophysics Data System (ADS)

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

    2016-11-01

    This paper describes the dynamics of a space-charge-dominated beam through a continuously twisted quadrupole magnet using ten independent first-order differential equations of the beam matrix elements under the assumption of linear space-charge force. Various beam optical properties of the magnet and the evolution of the emittance that results from the coupling between the two transverse planes are studied. The perturbed equations of motion around the matched beam envelopes have been derived and utilized to analyze the stability properties of the intense beam transport by calculating the eigenvalues of the transfer map over one lattice period. Detailed analysis shows the presence of instability due to parametric resonances in a twisted quadrupole channel which generally does not appear in the FODO quadrupole channel. A 2D particle-in-cell simulation code has been developed and utilized to verify the analytical results and to examine the behavior of the intense beam with Gaussian (GA) distribution in the twisted quadrupole channel.

  13. Generation of low-emittance electron beams in electrostatic accelerators for FEL applications

    NASA Astrophysics Data System (ADS)

    Teng, Chen; Elias, Luis R.

    1995-02-01

    This paper reports results of transverse emittance studies and beam propagation in electrostatic accelerators for free electron laser applications. In particular, we discuss emittance growth analysis of a low current electron beam system consisting of a miniature thermoionic electron gun and a National Electrostatics Accelerator (NEC) tube. The emittance growth phenomenon is discussed in terms of thermal effects in the electron gun cathode and aberrations produced by field gradient changes occurring inside the electron gun and throughout the accelerator tube. A method of reducing aberrations using a magnetic solenoidal field is described. Analysis of electron beam emittance was done with the EGUN code. Beam propagation along the accelerator tube was studied using a cylindrically symmetric beam envelope equation that included beam self-fields and the external accelerator fields which were derived from POISSON simulations.

  14. Preferential acceleration and magnetic field enhancement in plasmas with e+/e- beam injection

    NASA Astrophysics Data System (ADS)

    Huynh, Cong Tuan; Ryu, Chang-Mo

    2016-03-01

    A theoretical model of current filaments predicting preferential acceleration/deceleration and magnetic field enhancement in a plasma with e+/e- beam injection is presented. When the e+/e- beams are injected into a plasma, current filaments are formed. The beam particles are accelerated or decelerated depending on the types of current filaments in which they are trapped. It is found that in the electron/ion ambient plasma, the e+ beam particles are preferentially accelerated, while the e- beam particles are preferentially decelerated. The preferential particle acceleration/deceleration is absent when the ambient plasma is the e+/e- plasma. We also find that the particle momentum decrease can explain the magnetic field increase during the development of Weibel/filamentation instability. Supporting simulation results of particle acceleration/deceleration and magnetic field enhancement are presented. Our findings can be applied to a wide range of astrophysical plasmas with the e+/e- beam injection.

  15. Particle selection and beam collimation system for laser-accelerated proton beam therapy.

    PubMed

    Luo, Wei; Fourkal, Eugene; Li, Jinsheng; Ma, Chang-Ming

    2005-03-01

    In a laser-accelerated proton therapy system, the initial protons have broad energy and angular distributions, which are not suitable for direct therapeutic applications. A compact particle selection and collimation device is needed to deliver small pencil beams of protons with desired energy spectra. In this work, we characterize a superconducting magnet system that produces a desired magnetic field configuration to spread the protons with different energies and emitting angles for particle selection. Four magnets are set side by side along the beam axis; each is made of NbTi wires which carry a current density of approximately 10(5) A/cm2 at 4.2 K, and produces a magnetic field of approximately 4.4 T in the corresponding region. Collimation is applied to both the entrance and the exit of the particle selection system to generate a desired proton pencil beam. In the middle of the magnet system, where the magnetic field is close to zero, a particle selection collimator allows only the protons with desired energies to pass through for therapy. Simulations of proton transport in the presence of the magnetic field show that the selected protons have successfully refocused on the beam axis after passing through the magnetic field with the optimal magnet system. The energy spread for any given characteristic proton energy has been obtained. It is shown that the energy spread is a function of the magnetic field strength and collimator size and reaches the full width at half maximum of 25 MeV for 230 MeV protons. Dose distributions have also been calculated with the GEANT3 Monte Carlo code to study the dosimetric properties of the laser-accelerated proton beams for radiation therapy applications.

  16. Designing of the low energy beam lines with achromatic condition in the RAON accelerator

    NASA Astrophysics Data System (ADS)

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

    2017-01-01

    The RAON accelerator has been built to create and accelerate stable heavy-ion beams and rare isotope beams. The stable heavy-ion beams are generated by the superconducting electron cyclotron resonance ion source and accelerated by the low energy superconducting linac SCL1. The beams accelerated by the SCL1 are re-accelerated by the high energy superconducting linac SCL2 for the generation of rare isotope beams by using the in-flight fragmentation system or are put to use in the low energy experimental halls, which include the neutron science facility and the KOrea Broad acceptance Recoil spectrometer and Apparatus after having passed through the low energy beam lines which have long deflecting sections. At the end of each beam line in the low energy experimental halls, the beams should meet the targets of the two facilities with the specific requirements satisfied. Namely, if the beam is to be sent safely and accurately to the targets and simultaneously, satisfy the requirements, an achromatic lattice design needs to be applied in each beam line. In this paper, we will present the lattice design of the low energy beam lines and describe the results of the beam dynamics simulations. In addition, the correction of the beam orbit, which is distorted by machine imperfections, will be discussed.

  17. External-Beam Accelerated Partial Breast Irradiation Using Multiple Proton Beam Configurations

    SciTech Connect

    Wang Xiaochun; Amos, Richard A.; Zhang Xiaodong; Taddei, Phillip J.; Woodward, Wendy A.; Hoffman, Karen E.; Yu, Tse Kuan; Tereffe, Welela; Oh, Julia; Perkins, George H.; Salehpour, Mohammad; Zhang, Sean X.; Sun, Tzou Liang; Gillin, Michael; Buchholz, Thomas A.; Strom, Eric A.

    2011-08-01

    Purpose: To explore multiple proton beam configurations for optimizing dosimetry and minimizing uncertainties for accelerated partial breast irradiation (APBI) and to compare the dosimetry of proton with that of photon radiotherapy for treatment of the same clinical volumes. Methods and Materials: Proton treatment plans were created for 11 sequential patients treated with three-dimensional radiotherapy (3DCRT) photon APBI using passive scattering proton beams (PSPB) and were compared with clinically treated 3DCRT photon plans. Monte Carlo calculations were used to verify the accuracy of the proton dose calculation from the treatment planning system. The impact of range, motion, and setup uncertainty was evaluated with tangential vs. en face beams. Results: Compared with 3DCRT photons, the absolute reduction of the mean of V100 (the volume receiving 100% of prescription dose), V90, V75, V50, and V20 for normal breast using protons are 3.4%, 8.6%, 11.8%, 17.9%, and 23.6%, respectively. For breast skin, with the similar V90 as 3DCRT photons, the proton plan significantly reduced V75, V50, V30, and V10. The proton plan also significantly reduced the dose to the lung and heart. Dose distributions from Monte Carlo simulations demonstrated minimal deviation from the treatment planning system. The tangential beam configuration showed significantly less dose fluctuation in the chest wall region but was more vulnerable to respiratory motion than that for the en face beams. Worst-case analysis demonstrated the robustness of designed proton beams with range and patient setup uncertainties. Conclusions: APBI using multiple proton beams spares significantly more normal tissue, including nontarget breast and breast skin, than 3DCRT using photons. It is robust, considering the range and patient setup uncertainties.

  18. Fluence and dose measurements for an accelerator neutron beam

    NASA Astrophysics Data System (ADS)

    Liu, Z.; Byun, S. H.; McNeill, F. E.; Mothersill, C. E.; Seymour, C. B.; Prestwich, W. V.

    2007-10-01

    The 3 MV Van de Graaff accelerator at McMaster University accelerator laboratory is extended to a neutron irradiation facility for low-dose bystander effects research. A long counter and an Anderson-Braun type neutron monitor have been used as monitors for the determination of the total fluence. Activation foils were used to determine the thermal neutron fluence rate (around 106 neutrons s-1). Meanwhile, the interactions of neutrons with the monitors have been simulated using a Monte Carlo N Particle (MCNP) code. Bystander effects, i.e. damage occurring in cells that were not traversed by radiation but were in the same radiation environment, have been well observed following both alpha and gamma irradiation of many cell lines. Since neutron radiation involves mixed field (including gamma and neutron radiations), we need to differentiate the doses for the bystander effects from the two radiations. A tissue equivalent proportional counter (TEPC) filled with propane based tissue equivalent gas simulating a 2 μm diameter tissue sphere has been investigated to estimate the neutron and gamma absorbed doses. A photon dose contamination of the neutron beam is less than 3%. The axial dose distribution follows the inverse square law and lateral and vertical dose distributions are relatively uniform over the irradiation area required by the biological study.

  19. Education in a rapidly advancing technology: Accelerators and beams

    NASA Astrophysics Data System (ADS)

    Month, Mel

    2000-06-01

    The field of accelerators and beams (A&B) is one of today's fast changing technologies. Because university faculties have not been able to keep pace with the associated advancing knowledge, universities have not been able to play their traditional role of educating the scientists and engineers needed to sustain this technology for use in science, industry, commerce, and defense. This problem for A&B is described and addressed. The solution proposed, a type of "distance" education, is the U.S. Particle Accelerator School (USPAS) created in the early 1980s. USPAS provides the universities with a means of serving the education needs of the institutions using A&B, primarily but not exclusively the national laboratories. The field of A&B is briefly summarized. The need for education outside the university framework, the raison d'être for USPAS, the USPAS method, program structure, and curriculum, and particular USPAS-university connections are explained. The management of USPAS is analyzed, including its unique administrative structure, its institutional ties, and its operations, finance, marketing, and governmental relations. USPAS performance over the years is documented and a business assessment is made. Finally, there is a brief discussion of the future potential for this type of educational program, including possible extrapolation to new areas and/or different environments, in particular, its extra-government potential and its international possibilities.

  20. Laser-Accelerated Proton Beams as Diagnostics for Cultural Heritage.

    PubMed

    Barberio, M; Veltri, S; Scisciò, M; Antici, P

    2017-03-07

    This paper introduces the first use of laser-generated proton beams as diagnostic for materials of interest in the domain of Cultural Heritage. Using laser-accelerated protons, as generated by interaction of a high-power short-pulse laser with a solid target, we can produce proton-induced X-ray emission spectroscopies (PIXE). By correctly tuning the proton flux on the sample, we are able to perform the PIXE in a single shot without provoking more damage to the sample than conventional methodologies. We verify this by experimentally irradiating materials of interest in the Cultural Heritage with laser-accelerated protons and measuring the PIXE emission. The morphological and chemical analysis of the sample before and after irradiation are compared in order to assess the damage provoked to the artifact. Montecarlo simulations confirm that the temperature in the sample stays safely below the melting point. Compared to conventional diagnostic methodologies, laser-driven PIXE has the advantage of being potentially quicker and more efficient.

  1. Education in a rapidly advancing technology: Accelerators and beams

    SciTech Connect

    Month, Mel

    2000-06-01

    The field of accelerators and beams (A and B) is one of today's fast changing technologies. Because university faculties have not been able to keep pace with the associated advancing knowledge, universities have not been able to play their traditional role of educating the scientists and engineers needed to sustain this technology for use in science, industry, commerce, and defense. This problem for A and B is described and addressed. The solution proposed, a type of ''distance'' education, is the U.S. Particle Accelerator School (USPAS) created in the early 1980s. USPAS provides the universities with a means of serving the education needs of the institutions using A and B, primarily but not exclusively the national laboratories. The field of A and B is briefly summarized. The need for education outside the university framework, the raison d'etre for USPAS, the USPAS method, program structure, and curriculum, and particular USPAS-university connections are explained. The management of USPAS is analyzed, including its unique administrative structure, its institutional ties, and its operations, finance, marketing, and governmental relations. USPAS performance over the years is documented and a business assessment is made. Finally, there is a brief discussion of the future potential for this type of educational program, including possible extrapolation to new areas and/or different environments, in particular, its extra-government potential and its international possibilities. (c) 2000 American Association of Physics Teachers.

  2. Laser-Accelerated Proton Beams as Diagnostics for Cultural Heritage

    NASA Astrophysics Data System (ADS)

    Barberio, M.; Veltri, S.; Scisciò, M.; Antici, P.

    2017-03-01

    This paper introduces the first use of laser-generated proton beams as diagnostic for materials of interest in the domain of Cultural Heritage. Using laser-accelerated protons, as generated by interaction of a high-power short-pulse laser with a solid target, we can produce proton-induced X-ray emission spectroscopies (PIXE). By correctly tuning the proton flux on the sample, we are able to perform the PIXE in a single shot without provoking more damage to the sample than conventional methodologies. We verify this by experimentally irradiating materials of interest in the Cultural Heritage with laser-accelerated protons and measuring the PIXE emission. The morphological and chemical analysis of the sample before and after irradiation are compared in order to assess the damage provoked to the artifact. Montecarlo simulations confirm that the temperature in the sample stays safely below the melting point. Compared to conventional diagnostic methodologies, laser-driven PIXE has the advantage of being potentially quicker and more efficient.

  3. Laser-Accelerated Proton Beams as Diagnostics for Cultural Heritage

    PubMed Central

    Barberio, M.; Veltri, S.; Scisciò, M.; Antici, P.

    2017-01-01

    This paper introduces the first use of laser-generated proton beams as diagnostic for materials of interest in the domain of Cultural Heritage. Using laser-accelerated protons, as generated by interaction of a high-power short-pulse laser with a solid target, we can produce proton-induced X-ray emission spectroscopies (PIXE). By correctly tuning the proton flux on the sample, we are able to perform the PIXE in a single shot without provoking more damage to the sample than conventional methodologies. We verify this by experimentally irradiating materials of interest in the Cultural Heritage with laser-accelerated protons and measuring the PIXE emission. The morphological and chemical analysis of the sample before and after irradiation are compared in order to assess the damage provoked to the artifact. Montecarlo simulations confirm that the temperature in the sample stays safely below the melting point. Compared to conventional diagnostic methodologies, laser-driven PIXE has the advantage of being potentially quicker and more efficient. PMID:28266496

  4. Decontamination of Ametryne HDPE packaging using electron beam accelerator

    NASA Astrophysics Data System (ADS)

    Duarte, C. L.; Andrade, D. C.; Melo, R. P.; Nagatomi, H. R.; Mori, M. N.

    2009-07-01

    This paper is part of a project to evaluate pesticide degradation on commercial polymeric (high-density polyethylene, HDPE) packaging material. The herbicide studied was Ametryne whose residues may be detectable in water, soil and on the surfaces for months or years, depending on the pesticide formulation and type of application. In order to evaluate the efficiency of radiation processing on removal of the pesticides contamination; the packaging material were irradiated using Radiation Dynamics Electron Beam Accelerator with 1,5 MeV energy and 37 kW, in batch system. The samples were irradiated with water, in various absorbed doses. Ametryne was analyzed by gas chromatography after extraction with hexane/dichloromethane (1:1 v/v) solution. The radiation processing yield was evaluated by the destruction G-value (Gd), and the electron beam irradiation processing, showed higher efficiency in destroying Ametryne in the HDPE packaging when the samples were irradiated in the presence of small quantities of water.

  5. Recent Progress in High Intensity Operation of the Fermilab Accelerator Complex

    SciTech Connect

    Convery, Mary E

    2016-10-05

    We report on the status of the Fermilab accelerator com-plex. Beam delivery to the neutrino experiments surpassed our goals for the past year. The Proton Improvement Plan is well underway with successful 15 Hz beam operation. Beam power of 700 kW to the NOvA experiment was demonstrated and will be routine in the next year. We are also preparing the Muon Campus to commission beam to the g-2 experiment.

  6. Ion Acceleration from the Interaction of Ultra-Intense Lasers with Solid Foils

    SciTech Connect

    Allen, Matthew M.

    2004-01-01

    The discovery that ultra-intense laser pulses (I > 1018 W/cm2) can produce short pulse, high energy proton beams has renewed interest in the fundamental mechanisms that govern particle acceleration from laser-solid interactions. Experiments have shown that protons present as hydrocarbon contaminants on laser targets can be accelerated up to energies > 50 MeV. Different theoretical models that explain the observed results have been proposed. One model describes a front-surface acceleration mechanism based on the ponderomotive potential of the laser pulse. At high intensities (I > 1018 W/cm2), the quiver energy of an electron oscillating in the electric field of the laser pulse exceeds the electron rest mass, requiring the consideration of relativistic effects. The relativistically correct ponderomotive potential is given by Up = ([1 + Iλ2/1.3 x 1018]1/2 - 1) m{sub o}c2, where Iλ2 is the irradiance in W μm2/cm2 and moc2 is the electron rest mass. At laser irradiance of Iλ2 ~ 1020 W μm2/cm2, the ponderomotive potential can be of order several MeV. A few recent experiments--discussed in Chapter 3 of this thesis--consider this ponderomotive potential sufficiently strong to accelerate protons from the front surface of the target to energies up to tens of MeV. Another model, known as Target Normal Sheath Acceleration (TNSA), describes the mechanism as an electrostatic sheath on the back surface of the laser target. According to the TNSA model, relativistic hot electrons created at the laser-solid interaction penetrate the foil where a few escape to infinity. The remaining hot electrons are retained by the target potential and establish an electrostatic sheath on the back surface of the target. In this thesis we present several experiments that study the accelerated ions by

  7. Modeling nitrogen plasmas produced by intense electron beams

    NASA Astrophysics Data System (ADS)

    Angus, J. R.; Mosher, D.; Swanekamp, S. B.; Ottinger, P. F.; Schumer, J. W.; Hinshelwood, D. D.

    2016-05-01

    A new gas-chemistry model is presented to treat the breakdown of a nitrogen gas with pressures on the order of 1 Torr from intense electron beams with current densities on the order of 10 kA/cm2 and pulse durations on the order of 100 ns. For these parameter regimes, the gas transitions from a weakly ionized molecular state to a strongly ionized atomic state on the time scale of the beam pulse. The model is coupled to a 0D-circuit model using the rigid-beam approximation that can be driven by specifying the time and spatial profiles of the beam pulse. Simulation results are in good agreement with experimental measurements of the line-integrated electron density from experiments done using the Gamble II generator at the Naval Research Laboratory. It is found that the species are mostly in the ground and metastable states during the atomic phase, but that ionization proceeds predominantly through thermal ionization of optically allowed states with excitation energies close to the ionization limit.

  8. Characteristics of the photon beam from a new 25-MV linear accelerator

    SciTech Connect

    Aldrich, J.E.; Andrew, J.W.; Michaels, H.B.; O'Brien, P.F.

    1985-09-01

    The Therac 25 is a relatively compact therapy machine, the heart of which is a double-pass electron linear accelerator. The electron beam is injected into the accelerator at the treatment head end of the machine and is accelerated back down the arm to an energy of 13 MeV. At this end of the machine a magnet system reflects the beam back into the structure where it gains up to an additional 12 MeV of energy. After leaving the linear accelerator the beam is bent by an achromatic head magnet through 270 degrees to the treatment head. The machine produces eight electron beams and a 25-MV photon beam. In this work only the parameters of the photon beam are addressed based on measurements at the first two clinical sites. Percentage depth doses, tissue phantom ratios, and beam symmetry and stability are presented and discussed.

  9. Characteristics of the photon beam from a new 25-MV linear accelerator.

    PubMed

    Aldrich, J E; Andrew, J W; Michaels, H B; O'Brien, P F

    1985-01-01

    The Therac 25 is a relatively compact therapy machine, the heart of which is a double-pass electron linear accelerator. The electron beam is injected into the accelerator at the treatment head end of the machine and is accelerated back down the arm to an energy of 13 MeV. At this end of the machine a magnet system reflects the beam back into the structure where it gains up to an additional 12 MeV of energy. After leaving the linear accelerator the beam is bent by an achromatic head magnet through 270 degrees to the treatment head. The machine produces eight electron beams and a 25-MV photon beam. In this work only the parameters of the photon beam are addressed based on measurements at the first two clinical sites. Percentage depth doses, tissue phantom ratios, and beam symmetry and stability are presented and discussed.

  10. Means and method for the focusing and acceleration of parallel beams of charged particles

    DOEpatents

    Maschke, Alfred W.

    1983-07-05

    A novel apparatus and method for focussing beams of charged particles comprising planar arrays of electrostatic quadrupoles. The quadrupole arrays may comprise electrodes which are shared by two or more quadrupoles. Such quadrupole arrays are particularly adapted to providing strong focussing forces for high current, high brightness, beams of charged particles, said beams further comprising a plurality of parallel beams, or beamlets, each such beamlet being focussed by one quadrupole of the array. Such arrays may be incorporated in various devices wherein beams of charged particles are accelerated or transported, such as linear accelerators, klystron tubes, beam transport lines, etc.

  11. Relationships between peak ground acceleration, peak ground velocity, and modified mercalli intensity in California

    USGS Publications Warehouse

    Wald, D.J.; Quitoriano, V.; Heaton, T.H.; Kanamori, H.

    1999-01-01

    We have developed regression relationships between Modified Mercalli Intensity (Imm) and peak ground acceleration (PGA) and velocity (PGV) by comparing horizontal peak ground motions to observed intensities for eight significant California earthquakes. For the limited range of Modified Mercalli intensities (Imm), we find that for peak acceleration with V ??? Imm ??? VIII, Imm = 3.66 log(PGA) - 1.66, and for peak velocity with V ??? Imm ??? IX, Imm = 3.47 log(PGV) + 2.35. From comparison with observed intensity maps, we find that a combined regression based on peak velocity for intensity > VII and on peak acceleration for intensity < VII is most suitable for reproducing observed Imm patterns, consistent with high intensities being related to damage (proportional to ground velocity) and with lower intensities determined by felt accounts (most sensitive to higher-frequency ground acceleration). These new Imm relationships are significantly different from the Trifunac and Brady (1975) correlations, which have been used extensively in loss estimation.

  12. Design Considerations of Fast Kicker Systems for High Intensity Proton Accelerators

    SciTech Connect

    Zhang, W; Sandberg, J; Parson, W M; Walstrom, P; Murray, M M; Cook, E; Hartouni, E

    2001-06-12

    In this paper, we discuss the specific issues related to the design of the Fast Kicker Systems for high intensity proton accelerators. To address these issues in the preliminary design stage can be critical since the fast kicker systems affect the machine lattice structure and overall design parameters. Main topics include system architecture, design strategy, beam current coupling, grounding, end user cost vs. system cost, reliability, redundancy and flexibility. Operating experience with the Alternating Gradient Synchrotron injection and extraction kicker systems at Brookhaven National Laboratory and their future upgrade is presented. Additionally, new conceptual designs of the extraction kicker for the Spallation Neutron Source at Oak Ridge and the Advanced Hydrotest Facility at Los Alamos are discussed.

  13. Design Aspects of Focal Beams From High-Intensity Arrays

    PubMed Central

    Stephens, Douglas N.; Kruse, Dustin E.; Qin, Shengping; Ferrara, Katherine W.

    2011-01-01

    As the applications of ultrasonic thermal therapies expand, the design of the high-intensity array must address both the energy delivery of the main beam and the character and relevance of off-target beam energy. We simulate the acoustic field performance of a selected set of circular arrays organized by array format, including flat versus curved arrays, periodic versus random arrays, and center void diameter variations. Performance metrics are based on the −3-dB focal main lobe (FML) positioning range, axial grating lobe (AGL) temperatures, and side lobe levels. Using finite-element analysis, we evaluate the relative heating of the FML and the AGLs. All arrays have a maximum diameter of 100λ, with element count ranging from 64 to 1024 and continuous wave frequency of 1.5 MHz. First, we show that a 50% spherical annulus produces focus beam side lobes which decay as a function of lateral distance at nearly 87% of the exponential rate of a full aperture. Second, for the arrays studied, the efficiency of power delivery over the −3-dB focus positioning range for spherical arrays is at least 2-fold greater than for flat arrays; the 256-element case shows a 5-fold advantage for the spherical array. Third, AGL heating can be significant as the focal target is moved to its distal half-intensity depth from the natural focus. Increasing the element count of a randomized array to 256 elements decreases the AGL-to-FML heating ratio to 0.12 at the distal half-intensity depth. Further increases in element count yield modest improvements. A 49% improvement in the AGL-to-peak heating ratio is predicted by using the Sumanaweera spiral element pattern with randomization. PMID:21859578

  14. Comparing the dosimetric characteristics of the electron beam from dedicated intraoperative and conventional radiotherapy accelerators.

    PubMed

    Baghani, Hamid Reza; Aghamiri, Seyed Mahmoud Reza; Mahdavi, Seyed Rabi; Akbari, Mohammad Esmail; Mirzaei, Hamid Reza

    2015-03-08

    The specific design of the mobile dedicated intraoperative radiotherapy (IORT) accelerators and different electron beam collimation system can change the dosimetric characteristics of electron beam with respect to the conventional accelerators. The aim of this study is to measure and compare the dosimetric characteristics of electron beam produced by intraoperative and conventional radiotherapy accelerators. To this end, percentage depth dose along clinical axis (PDD), transverse dose profile (TDP), and output factor of LIAC IORT and Varian 2100C/D conventional radiotherapy accelerators were measured and compared. TDPs were recorded at depth of maximum dose. The results of this work showed that depths of maximum dose, R90, R50, and RP for LIAC beam are lower than those of Varian beam. Furthermore, for all energies, surface doses related to the LIAC beam are substantially higher than those of Varian beam. The symmetry and flatness of LIAC beam profiles are more desirable compared to the Varian ones. Contrary to Varian accelerator, output factor of LIAC beam substantially increases with a decrease in the size of the applicator. Dosimetric characteristics of beveled IORT applicators along clinical axis were different from those of the flat ones. From these results, it can be concluded that dosimetric characteristics of intraoperative electron beam are substantially different from those of conventional clinical electron beam. The dosimetric characteristics of the LIAC electron beam make it a useful tool for intraoperative radiotherapy purposes.

  15. Particle Accelerators in China

    NASA Astrophysics Data System (ADS)

    Zhang, Chuang; Fang, Shouxian

    As the special machines that can accelerate charged particle beams to high energy by using electromagnetic fields, particle accelerators have been widely applied in scientific research and various areas of society. The development of particle accelerators in China started in the early 1950s. After a brief review of the history of accelerators, this article describes in the following sections: particle colliders, heavy-ion accelerators, high-intensity proton accelerators, accelerator-based light sources, pulsed power accelerators, small scale accelerators, accelerators for applications, accelerator technology development and advanced accelerator concepts. The prospects of particle accelerators in China are also presented.

  16. Beam Phase Space of an Intense Ion Beam in a Neutralizing Plasma

    NASA Astrophysics Data System (ADS)

    Seidl, Peter A.; Bazouin, Guillaume; Beneytout, Alice; Lidia, Steven M.; Vay, Jean-Luc; Grote, David P.

    2011-10-01

    The Neutralized Drift Compression Experiment (NDCX-I) generates high intensity ion beams to explore warm dense matter physics. Transverse final focusing is accomplished with an 8-Tesla, 10-cm long pulsed solenoid magnet combined with a background neutralizing plasma to effectively cancel the space charge field of the ion beam. We report on phase space measurements of the beam before the neutralization channel and of the focused ion beam at the target plane. These are compared to WARP particle-in-cell simulations of the ion beam propagation through the focusing system and neutralizing plasma. Due to the orientation of the plasma sources with respect to the focusing magnet, the plasma distribution within the final focusing lens is strongly affected by the magnetic field, an effect which can influence the peak intensity at the target and which is included in the model of the experiment. Work performed under auspices of U.S. DoE by LLNL, LBNL under Contracts DE-AC52-07NA27344, DE-AC02-05CH1123.

  17. GEANT4 simulations for beam emittance in a linear collider based on plasma wakefield acceleration

    SciTech Connect

    Mete, O. Xia, G.; Hanahoe, K.; Labiche, M.

    2015-08-15

    Alternative acceleration technologies are currently under development for cost-effective, robust, compact, and efficient solutions. One such technology is plasma wakefield acceleration, driven by either a charged particle or laser beam. However, the potential issues must be studied in detail. In this paper, the emittance evolution of a witness beam through elastic scattering from gaseous media and under transverse focusing wakefields is studied.

  18. Thermodynamic Bounds on Nonlinear Electrostatic Perturbations in Intense Charged Particle Beams

    SciTech Connect

    Nikolas C. Logan and Ronald C. Davidson

    2012-07-18

    This paper places a lowest upper bound on the field energy in electrostatic perturbations in single-species charged particle beams with initial temperature anisotropy (TllT⊥ < 1). The result applies to all electrostatic perturbations driven by the natural anisotropies that develop in accelerated particle beams, including Harris-type electrostatic instabilities, known to limit the luminosity and minimum spot size attainable in experiments. The thermodynamic bound on the field perturbation energy of the instabilities is obtained from the nonlinear Vlasov-Poisson equations for an arbitrary initial distribution function, including the effects of intense self-fields, finite geometry and nonlinear processes. This paper also includes analytical estimates of the nonlinear bounds for space-charge-dominated and emittance-dominated anisotropic bi-Maxwellian distributions.

  19. Traceable charge measurement of the pulses of a 27 MeV electron beam from a linear accelerator

    NASA Astrophysics Data System (ADS)

    Schüller, A.; Illemann, J.; Renner, F.; Makowski, C.; Kapsch, R.-P.

    2017-03-01

    This work presents a detailed description of measuring devices and calibration procedures which enable the nondestructive (non-intercepting) absolute measurement of the charge of individual beam pulses (macro-pulses) from an electron linear accelerator traceable to primary standards with high accuracy, i.e. with an expanded measurement uncertainty < 0.1%. In particular, we demonstrate the readout and calibration of a Bergoz integrating current transformer which is frequently applied at many different types of accelerators as a beam intensity monitor. The current transformer signal is calibrated against the absolute charge measurement by means of a custom-made compact Faraday cup with a high degree of collection efficiency for electron beams in the energy range of 6 MeV to 50 MeV (99.2% at 27 MeV), which is well known from measurements and consistently described by Monte Carlo calculations.

  20. Issues and R&D Required for the Intensity Frontier Accelerators

    SciTech Connect

    Shiltsev, V.; Henderson, S.; Hurh, P.; Kourbanis, I.; Lebedev, V.

    2013-09-26

    Operation, upgrade and development of accelerators for Intensity Frontier face formidable challenges in order to satisfy both the near-term and long-term Particle Physics program. Here we discuss key issues and R&D required for the Intensity Frontier accelerators.

  1. Error-induced beam degradation in Fermilab's accelerators

    NASA Astrophysics Data System (ADS)

    Yong, Sung-Yong Phil

    In Part I, three independent models of Fermilab's Booster synchrotron are presented. All three models are constructed to investigate and to explore the effects of unavoidable machine errors on a proton beam under the influence of space-charge effects. The first is a stochastic noise model. Electric current fluctuations arising from power supplies are ubiquitous and unavoidable and are a source of instabilities in accelerators of all types. A new noise module for generating the Ornstein-Uhlenbeck (O-U) stochastic noise is first created and incorporated into the existing Object-oriented Ring Beam Injection and Tracking (ORBIT-FNAL) package. After being convinced that the noise does matter to a beam with a preliminary model, we proceed to measure directly current ripples and common-mode voltages from all four Gradient Magnet Power Supplies (GMPS). Then, the current signals are Fourier-analyzed. Based upon the power spectra of current signals, we tune up the Ornstein-Uhlnbeck noise model. As a result, we are able to closely match the frequency spectra between current measurements and the modeled O-U stochastic noise. The stochastic noise modeled upon measurements is applied to the Booster beam in the presence of the full space-charge effects. This noise model, accompanied by a suite of beam diagnostic calculations, manifests that the stochastic noise, impinging upon the beam and coupled to the space-charge effects, can substantially enhance the beam degradation process throughout the injection period. The second model is a magnet misalignment model. It is the first time to utilize the latest beamline survey data for building a magnet-by-magnet misalignment model. Given as-found survey fiducial coordinates, we calculate all types of magnet alignment errors (station error, pitch, yaw, roll, twists, etc.) are implemented in the model. We then follow up with statistical analysis to understand how each type of alignment errors are currently distributed around the Booster

  2. Error-Induced Beam Degradation in Fermilab's Accelerators

    SciTech Connect

    Yoon, Sung-Young Phil

    2008-01-01

    In Part I, three independent models of Fermilab's Booster synchrotron are presented. All three models are constructed to investigate and explore the effects of unavoidable machine errors on a proton beam under the influence of space-charge effects. The first is a stochastic noise model. Electric current fluctuations arising from power supplies are ubiquitous and unavoidable and are a source of instabilities in accelerators of all types. A new noise module for generating the Ornstein-Uhlenbeck (O-U) stochastic noise is first created and incorporated into the existing Object-oriented Ring Beam Injection and Tracking (ORBIT-FNAL) package. After being convinced with a preliminary model that the noise, particularly non-white noise, does matter to beam quality, we proceeded to measure directly current ripples and common-mode voltages from all four Gradient Magnet Power Supplies (GMPS). Then, the current signals are Fourier-analyzed. Based upon the power spectra of current signals, we tune up the Ornstein-Uhlnbeck noise model. As a result, we are able to closely match the frequency spectra between current measurements and the modeled O-U stochastic noise. The stochastic noise modeled upon measurements is applied to the Booster beam in the presence of the full space-charge effects. This noise model, accompanied by a suite of beam diagnostic calculations, manifests that the stochastic noise, impinging upon the beam and coupled to the space-charge effects, can substantially enhance the beam degradation process throughout the injection period. The second model is a magnet misalignment model. It is the first time to utilize the latest beamline survey data for building a magnet-by-magnet misalignment model. Given as-found survey fiducial coordinates, we calculate all types of magnet alignment errors (station error, pitch, yaw, roll, twists, etc.) are implemented in the model. We then follow up with statistical analysis to understand how each type of alignment errors are

  3. High Intensity e-beam Diode Development for Flash X-ray Radiography

    NASA Astrophysics Data System (ADS)

    Oliver, Bryan

    2007-11-01

    A variety of electron beam diodes are being used and developed for the purpose of creating high-brightness, flash x-ray radiography sources. In these diodes, high energy (multi MeV), high current (multi kA), small spot (multi mm) electron beams are generated and stopped in high atomic number anode-targets (typically Ta or W). Beam stopping in the target creates copious amounts of bremsstrahlung radiation. In addition, beam heating of the target liberates material, either in the form of low density (˜10^12-10^14 cm-3) ion emission or higher density (> 10^15 cm-3) plasma. In all cases, beam/target collective effects dominate the diode and beam characteristics, affecting the radiation properties (dose and spot-size). Recent experiments at Sandia National Laboratories have demonstrated diodes capable of producing > 350 rad@m with 1.7mm FWHM x-ray source distributions. A review of our present theoretical understanding of the diode (s) operation and our experimental and simulation methods to investigate them will be presented. Emphasis will be given to e- beam sources used on state-of-the-art Inductive Voltage Adder (IVA) pulsed-power accelerators. In particular, the physics of magnetically pinched diodes (e.g. the rod-pinch [1,2]), gas-cell focusing diodes [3] and the magnetically immersed [4] diode will be discussed. Various proposed methods to optimize the x-ray intensity and the direction of future diode research will be discussed. [1] G. Cooperstein, et al., Phys. Plasmas 8, 4618 (2001).[2] B.V. Oliver et al., Phys. Plasmas 11, 3976 (2004)[3] B.V. Oliver, et al., IEEE Trans. on Plasma Science 33, 704 (2005).[4] M.G. Mazarakis, et al., Appl. Phys. Lett. 70, 832 (1997)

  4. SU-E-J-17: A Study of Accelerator-Induced Cerenkov Radiation as a Beam Diagnostic and Dosimetry Tool

    SciTech Connect

    Bateman, F; Tosh, R

    2014-06-01

    Purpose: To investigate accelerator-induced Cerenkov radiation imaging as a possible beam diagnostic and medical dosimetry tool. Methods: Cerenkov emission produced by clinical accelerator beams in a water phantom was imaged using a camera system comprised of a high-sensitivity thermoelectrically-cooled CCD camera coupled to a large aperture (f/0.75) objective lens with 16:1 magnification. This large format lens allows a significant amount of the available Cerenkov light to be collected and focused onto the CCD camera to form the image. Preliminary images, obtained with 6 MV photon beams, used an unshielded camera mounted horizontally with the beam normal to the water surface, and confirmed the detection of Cerenkov radiation. Several improvements were subsequently made including the addition of radiation shielding around the camera, and altering of the beam and camera angles to give a more favorable geometry for Cerenkov light collection. A detailed study was then undertaken over a range of electron and photon beam energies and dose rates to investigate the possibility of using this technique for beam diagnostics and dosimetry. Results: A series of images were obtained at a fixed dose rate over a range of electron energies from 6 to 20 MeV. The location of maximum intensity was found to vary linearly with the energy of the beam. A linear relationship was also found between the light observed from a fixed point on the central axis and the dose rate for both photon and electron beams. Conclusion: We have found that the analysis of images of beam-induced Cerenkov light in a water phantom has potential for use as a beam diagnostic and medical dosimetry tool. Our future goals include the calibration of the light output in terms of radiation dose and development of a tomographic system for 3D Cerenkov imaging in water phantoms and other media.

  5. Hyperenergetic manned aerospacecraft propelled by intense pulsed microwave power beam

    NASA Astrophysics Data System (ADS)

    Myrabo, Leik N.

    1995-09-01

    The objective of this research was to exploit wireless power transmission (microwave/millimeter)--to lower manned space transportation costs by two or three orders of magnitude. Concepts have been developed for lightweight, mass-producible, beam-propelled aerospacecraft called Lightcraft. The vehicles are designed for a 'mass-poor, energy-rich' (i.e. hyper-energentic flight infrastructure which utilizes remote microwave power stations to build an energy-beam highway to space. Although growth in laser power levels has lagged behind expectations, microwave and millimeter-wave source technology now exists for rapid scaling to the megawatt and gigawatt time-average power levels. The design exercise focused on the engine, structure, and receptive optics requirements for a 15 meter diameter, 5 person Earth- to-moon aerospacecraft. Key elements in the airbreathing accelerator propulsion system are: a) a 'flight-weight' 35GHz rectenna electric powerplant, b) microwave-induced 'Air Spike' and perimeter air-plasma generators, and c) MagnetoHydroDynamic-Fanjet engine with its superconducting magnets and external electrodes.

  6. Cathode Plasma Formation in High Intensity Electron Beam Diodes

    NASA Astrophysics Data System (ADS)

    Johnston, Mark; Kiefer, Mark; Oliver, Bryan; Bennett, Nichelle; Droemer, Darryl; Bernshtam, V.; Doron, R.; Maron, Yitzhak

    2013-10-01

    This talk will detail the experimental results and conclusions obtained for cathode plasma formation on the Self-Magnetic Pinch (SMP) diode fielded on the RITS-6 accelerator (4-7.5 MeV) at Sandia National Laboratories. The SMP diode utilizes a hollowed metal cathode to produce high power (TW), focused electron beams (<3 mm diameter) which are used for flash x-ray radiography applications. Optical diagnostics include high speed (<10 ns) framing cameras, optical streak cameras, and spectroscopy. The cathode plasma in this high electric (MV/cm) and magnetic (>10 Tesla) field environment forms well-defined striations. These striations have been examined for a number of different cathode sizes, vacuum gap spacings, and diode voltages. Optical streak images have been taken to determine the time evolution of the plasma, and optical spectroscopy has been employed to determine its constituents as well as their densities and temperatures inferred from detailed time-dependent, collisional-radiative (CR) and radiation transport modelings. Comments will be made as to the overall effect of the cathode plasma in regards to the diode impedance and electron beam focusing. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  7. Useful technique for analysis and control of the acceleration beam phase in the azimuthally varying field cyclotron

    NASA Astrophysics Data System (ADS)

    Kurashima, Satoshi; Yuyama, Takahiro; Miyawaki, Nobumasa; Kashiwagi, Hirotsugu; Okumura, Susumu; Fukuda, Mitsuhiro

    2010-03-01

    We have developed a new technique for analysis and control of the acceleration beam phase in the cyclotron. In this technique, the beam current pattern at a fixed radius r is measured by slightly scanning the acceleration frequency in the cyclotron. The acceleration beam phase is obtained by analyzing symmetry of the current pattern. Simple procedure to control the acceleration beam phase by changing coil currents of a few trim coils was established. The beam phase width is also obtained by analyzing gradient of the decreasing part of the current pattern. We verified reliability of this technique with 260 MeV N20e7+ beams which were accelerated on different tuning condition of the cyclotron. When the acceleration beam phase was around 0°, top of the energy gain of cosine wave, and the beam phase width was about 6° in full width at half maximum, a clear turn pattern of the beam was observed with a differential beam probe in the extraction region. Beam phase widths of ion beams at acceleration harmonics of h =1 and h =2 were estimated without beam cutting by phase-defining slits. We also calculated the beam phase widths roughly from the beam current ratio between the injected beam and the accelerated beam in the cyclotron without operating the beam buncher. Both beam phase widths were almost the same for h =1, while phase compressions by a factor of about 3 were confirmed for h =2.

  8. Useful technique for analysis and control of the acceleration beam phase in the azimuthally varying field cyclotron

    SciTech Connect

    Kurashima, Satoshi; Yuyama, Takahiro; Miyawaki, Nobumasa; Kashiwagi, Hirotsugu; Okumura, Susumu; Fukuda, Mitsuhiro

    2010-03-15

    We have developed a new technique for analysis and control of the acceleration beam phase in the cyclotron. In this technique, the beam current pattern at a fixed radius r is measured by slightly scanning the acceleration frequency in the cyclotron. The acceleration beam phase is obtained by analyzing symmetry of the current pattern. Simple procedure to control the acceleration beam phase by changing coil currents of a few trim coils was established. The beam phase width is also obtained by analyzing gradient of the decreasing part of the current pattern. We verified reliability of this technique with 260 MeV {sup 20}Ne{sup 7+} beams which were accelerated on different tuning condition of the cyclotron. When the acceleration beam phase was around 0 deg., top of the energy gain of cosine wave, and the beam phase width was about 6 deg. in full width at half maximum, a clear turn pattern of the beam was observed with a differential beam probe in the extraction region. Beam phase widths of ion beams at acceleration harmonics of h=1 and h=2 were estimated without beam cutting by phase-defining slits. We also calculated the beam phase widths roughly from the beam current ratio between the injected beam and the accelerated beam in the cyclotron without operating the beam buncher. Both beam phase widths were almost the same for h=1, while phase compressions by a factor of about 3 were confirmed for h=2.

  9. Case studies in space charge and plasma acceleration of charged beams

    NASA Astrophysics Data System (ADS)

    Bazzani, Armando; Giovannozzi, Massimo; Londrillo, Pasquale; Sinigardi, Stefano; Turchetti, Giorgio

    2014-10-01

    Plasma acceleration with electron or proton driver beams is a challenging opportunity for high-energy physics. An energy doubling experiment with electron drivers was successfully performed at SLAC and a key experiment AWAKE with proton drivers is on schedule at CERN. Simulations play an important role in choosing the best experimental conditions and in interpreting the results. The Vlasov equation is the theoretical tool to describe the interaction of a driver particle beam or a driver laser pulse with a plasma. Collective effects, such as tune shift and mismatch instabilities, appear in high intensity standard accelerators and are described by the Poisson-Vlasov equation. In the paper, we review the Vlasov equation in the electrostatic and fully electromagnetic cases. The general framework of variational principles is used to derive the equation, the local form of the balance equations and related conservation laws. In the electrostatic case, we remind the analytic Kapchinskij-Vladimirskij (K-V) model and we propose an extension of the adiabatic theory for Hamiltonian systems, which ensures stability for perturbation of size ɛ on times of order 1 / ɛ. The variational framework is used to derive the Maxwell-Vlasov equations and related conservation laws and to briefly sketch the particle-in-cell (PIC) approximation schemes. Finally, the proton-driven acceleration is examined in the linear and quasi-linear regime. A PIC simulation with the code ALaDyn developed at Bologna University is presented to illustrate the longitudinal and transverse fields evolution which allow a witness electron bunch to be accelerated with a gradient of a few GeV/m. We also present some remarks on future perspectives.

  10. Acceleration of positrons by a relativistic electron beam in the presence of quantum effects

    SciTech Connect

    Niknam, A. R.; Aki, H.; Khorashadizadeh, S. M.

    2013-09-15

    Using the quantum magnetohydrodynamic model and obtaining the dispersion relation of the Cherenkov and cyclotron waves, the acceleration of positrons by a relativistic electron beam is investigated. The Cherenkov and cyclotron acceleration mechanisms of positrons are compared together. It is shown that growth rate and, therefore, the acceleration of positrons can be increased in the presence of quantum effects.

  11. A new beam loss detector for low-energy proton and heavy-ion accelerators

    NASA Astrophysics Data System (ADS)

    Liu, Zhengzheng; Crisp, Jenna; Russo, Tom; Webber, Robert; Zhang, Yan

    2014-12-01

    The Facility for Rare Isotope Beams (FRIB) to be constructed at Michigan State University shall deliver a continuous, 400 kW heavy ion beam to the isotope production target. This beam is capable of inflicting serious damage on accelerator components, e.g. superconducting RF accelerating cavities. A Beam Loss Monitoring (BLM) System is essential for detecting beam loss with sufficient sensitivity and promptness to inform the machine protection system (MPS) and operations personnel of impending dangerous losses. Radiation transport simulations reveal shortcomings in the use of ionization chambers for the detection of beam losses in low-energy, heavy-ion accelerators. Radiation cross-talk effects due to the folded geometry of the FRIB LINAC pose further complications to locating specific points of beam loss. We propose a newly developed device, named the Loss Monitor Ring (LMR1

  12. Laser Ion Acceleration from the Interaction of Ultra-Intense laser Pulse with thi foils

    SciTech Connect

    Allen, Matthew Mark

    2004-03-12

    The discovery that ultra-intense laser pulses (I > 1018 W/cm2) can produce short pulse, high energy proton beams has renewed interest in the fundamental mechanisms that govern particle acceleration from laser-solid interactions. Experiments have shown that protons present as hydrocarbon contaminants on laser targets can be accelerated up to energies > 50 MeV. Different theoretical models that explain the observed results have been proposed. One model describes a front-surface acceleration mechanism based on the ponderomotive potential of the laser pulse. At high intensities (I > 1018 W/cm2), the quiver energy of an electron oscillating in the electric field of the laser pulse exceeds the electron rest mass, requiring the consideration of relativistic effects. The relativistically correct ponderomotive potential is given by Up = ([1 + Iλ2/1.3 x 1018]1/2 - 1) moc2, where Iλ2 is the irradiance in Wμm2/cm2 and moc2 is the electron rest mass.At laser irradiance of Iλ2 ~ 1018 Wμm2/cm2, the ponderomotive potential can be of order several MeV. A few recent experiments--discussed in Chapter 3 of this thesis--consider this ponderomotive potential sufficiently strong to accelerate protons from the front surface of the target to energies up to tens of MeV. Another model, known as Target Normal Sheath Acceleration (TNSA), describes the mechanism as an electrostatic sheath on the back surface of the laser target. According to the TNSA model, relativistic hot electrons created at the laser-solid interaction penetrate the foil where a few escape to infinity. The remaining hot electrons are retained by the target potential and establish an electrostatic sheath on the back surface of the target.

  13. Plasma dynamics of the interaction of intense ion beams with ''sub'' and ''super'' range plane targets

    SciTech Connect

    Long, K.A.; Tahir, N.A.

    1986-01-01

    Analytic and numerical solutions for the problem of the interaction of intense ion beams with matter in the form of plane targets are considered in this paper. The theory of the interaction of protons with matter at low energies is discussed and calculations are presented for the energy loss of protons in aluminum and gold. Zero- and one-dimensional models are developed and the results are compared to numerical simulations carried out with the one-dimensional Lagrangian hydrodynamic code Medusa (Comp. Phys. Comm. 1, 271 (1974)), which has been extended to include the various physical effects needed to carry out realistic simulations of the interaction of ion beams with matter. The theory and simulation of the acceleration of foils by intense ion beams is also considered and representative results are given. The theoretical results are used to investigate the optimum conditions in which to carry out stopping power experiments for ions in hot, dense plasmas, so that the theory can be tested. These results are needed in order to perform more realistic pellet calculations for inertial fusion.

  14. Broadband source localization using horizontal-beam acoustic intensity striations.

    PubMed

    Turgut, Altan; Orr, Marshall; Rouseff, Daniel

    2010-01-01

    Waveguide invariant theory is applied to horizontal line array (HLA) beamformer output to localize moving broadband noise sources from measured acoustic intensity striation patterns. Acoustic signals emitted by ships of opportunity (merchant ships) were simultaneously recorded on a HLA and three hydrophones separated by 10 km during the RAGS03 (relationship between array gain and shelf-break fluid processes) experiment. Hough transforms are used to estimate both the waveguide invariant parameter "beta" and the ratio of source range at the closest point of approach to source speed from the observed striation patterns. Broadband (50-150-Hz) acoustic data-sets are used to demonstrate source localization capability as well as inversion capability of waveguide invariant parameter beta. Special attention is paid to bathymetric variability since the acoustic intensity striation patterns seem to be influenced by range-dependent bathymetry of the experimental area. The Hough transform method is also applied to the HLA beam-time record data and to the acoustic intensity data from three distant receivers to validate the estimation results from HLA beamformer output. Good agreement of the results from all three approaches suggests the feasibility of locating broadband noise sources and estimating waveguide invariant parameter beta in shallow waters.

  15. Beam dynamics and error study of the medium energy beam transport line in the Korea Heavy-Ion Medical Accelerator

    NASA Astrophysics Data System (ADS)

    Kim, Chanmi; Kim, Eun-San; Hahn, Garam

    2016-11-01

    The Korea Heavy Ion Medical Accelerator consists of an injector and a synchrotron for an ion medical accelerator that is the first carbon-ion therapy system in Korea. The medium energy beam transport(MEBT) line connects the interdigital H-mode drift tube linac and the synchrotron. We investigated the beam conditions after the charge stripper by using the LISE++ and the SRIM codes. The beam was stripped from C4+ into C6+ by using the charge stripper. We investigated the performance of a de-buncher in optimizing the energy spread and the beam distribution in z-dW/W (direction of beam progress-beam and energy) phase. We obtained the results of the tracking simulation and the error analysis by using the TRACK code. Possible misalignments and rotations of the magnets were considered in the simulations. States of the beam were examined when errors occurred in the magnets by the applying analytic fringe field model in TRACK code. The condition for the beam orbit was optimized by using correctors and profile monitors to correct the orbit. In this paper, we focus on the beam dynamics and the error studies dedicated to the MEBT beam line and show the optimized beam parameters for the MEBT.

  16. Absorbed dose distributions for X-ray beams and beams of electrons from the Therac 20 Saturne linear accelerator.

    PubMed

    Tronc, D; Noël, A

    1978-11-01

    After a brief description of the Therac 20 Saturne linear accelerator a complete set of absorbed-dose distribution values is given. These values define the depths on the axis as a function of the depth dose and define the penumbra (as characterized by the positions of the intersections of the isodose curves with planes parallel to the phantom surface) for beams of X-rays and for beams of electrons. Tissue-maximum ratios are given for beams of X-rays. Analytical values for the electron depth dose curve are compared with the values obtained on the Sagittaire linear accelerator.

  17. Varying stopping and self-focusing of intense proton beams as they heat solid density matter

    NASA Astrophysics Data System (ADS)

    Kim, J.; McGuffey, C.; Qiao, B.; Wei, M. S.; Grabowski, P. E.; Beg, F. N.

    2016-04-01

    Transport of intense proton beams in solid-density matter is numerically investigated using an implicit hybrid particle-in-cell code. Both collective effects and stopping for individual beam particles are included through the electromagnetic fields solver and stopping power calculations utilizing the varying local target conditions, allowing self-consistent transport studies. Two target heating mechanisms, the beam energy deposition and Ohmic heating driven by the return current, are compared. The dependences of proton beam transport in solid targets on the beam parameters are systematically analyzed, i.e., simulations with various beam intensities, pulse durations, kinetic energies, and energy distributions are compared. The proton beam deposition profile and ultimate target temperature show strong dependence on intensity and pulse duration. A strong magnetic field is generated from a proton beam with high density and tight beam radius, resulting in focusing of the beam and localized heating of the target up to hundreds of eV.

  18. Formation of High Charge State Heavy Ion Beams with intense Space Charge

    SciTech Connect

    Seidl, P.A.; Vay, J-L.

    2011-03-01

    High charge-state heavy-ion beams are of interest and used for a number of accelerator applications. Some accelerators produce the beams downstream of the ion source by stripping bound electrons from the ions as they pass through a foil or gas. Heavy-ion inertial fusion (HIF) would benefit from low-emittance, high current ion beams with charge state >1. For these accelerators, the desired dimensionless perveance upon extraction from the emitter is {approx}10{sup -3}, and the electrical current of the beam pulse is {approx}1 A. For accelerator applications where high charge state and very high current are desired, space charge effects present unique challenges. For example, in a stripper, the separation of charge states creates significant nonlinear space-charge forces that impact the beam brightness. We will report on the particle-in-cell simulation of the formation of such beams for HIF, using a thin stripper at low energy.

  19. The stress intensity factor for the double cantilever beam

    NASA Technical Reports Server (NTRS)

    Fichter, W. B.

    1983-01-01

    Fourier transforms and the Wiener-Hopf technique are used in conjunction with plane elastostatics to examine the singular crack tip stress field in the double cantilever beam (DCB) specimen. In place of the Dirac delta function, a family of functions which duplicates the important features of the concentrated forces without introducing unmanageable mathematical complexities is used as a loading function. With terms of order h-squared/a-squared retained in the series expansion, the dimensionless stress intensity factor is found to be K (h to the 1/2)/P = 12 to the 1/2 (a/h + 0.6728 + 0.0377 h-squared/a-squared), in which P is the magnitude of the concentrated forces per unit thickness, a is the distance from the crack tip to the points of load application, and h is the height of each cantilever beam. The result is similar to that obtained by Gross and Srawley by fitting a line to discrete results from their boundary collocation analysis.

  20. Infrared imaging diagnostics for intense pulsed electron beam

    SciTech Connect

    Yu, Xiao; Shen, Jie; Liu, Wenbin; Zhong, Haowen; Zhang, Jie; Zhang, Gaolong; Le, Xiaoyun; Qu, Miao; Yan, Sha

    2015-08-15

    Infrared imaging diagnostic method for two-dimensional calorimetric diagnostics has been developed for intense pulsed electron beam (IPEB). By using a 100-μm-thick tungsten film as the infrared heat sink for IPEB, the emitting uniformity of the electron source can be analyzed to evaluate the efficiency and stability of the diode system. Two-dimensional axisymmetric finite element method heat transfer simulation, combined with Monte Carlo calculation, was performed for error estimation and optimization of the method. The test of the method was finished with IPEB generated by explosive emission electron diode with pulse duration (FWHM) of 80 ns, electron energy up to 450 keV, and a total beam current of over 1 kA. The results showed that it is possible to measure the cross-sectional energy density distribution of IPEB with energy sensitivity of 0.1 J/cm{sup 2} and spatial resolution of 1 mm. The technical details, such as irradiation protection of bremsstrahlung γ photons and the functional extensibility of the method were discussed in this work.

  1. Infrared imaging diagnostics for intense pulsed electron beam.

    PubMed

    Yu, Xiao; Shen, Jie; Qu, Miao; Liu, Wenbin; Zhong, Haowen; Zhang, Jie; Yan, Sha; Zhang, Gaolong; Le, Xiaoyun

    2015-08-01

    Infrared imaging diagnostic method for two-dimensional calorimetric diagnostics has been developed for intense pulsed electron beam (IPEB). By using a 100-μm-thick tungsten film as the infrared heat sink for IPEB, the emitting uniformity of the electron source can be analyzed to evaluate the efficiency and stability of the diode system. Two-dimensional axisymmetric finite element method heat transfer simulation, combined with Monte Carlo calculation, was performed for error estimation and optimization of the method. The test of the method was finished with IPEB generated by explosive emission electron diode with pulse duration (FWHM) of 80 ns, electron energy up to 450 keV, and a total beam current of over 1 kA. The results showed that it is possible to measure the cross-sectional energy density distribution of IPEB with energy sensitivity of 0.1 J/cm(2) and spatial resolution of 1 mm. The technical details, such as irradiation protection of bremsstrahlung γ photons and the functional extensibility of the method were discussed in this work.

  2. Beam characterization of FLASH from beam profile measurement by intensity transport equation and reconstruction of the Wigner distribution function

    NASA Astrophysics Data System (ADS)

    Schäfer, Bernd; Mey, Tobias; Mann, Klaus; Keitel, Barbara; Kreis, Svea; Kuhlmann, Marion; Plönjes, Elke; Tiedtke, Kai

    2013-05-01

    Beam parameters of the free-electron laser FLASH @13.5 nm in two different operation modes were determined from beam profile measurements and subsequent reconstruction of the Wigner distribution function behind the ellipsoidal focusing mirror at beamline BL2. 40 two-dimensional single pulse intensity distributions were recorded at each of 65 axial positions around the waist of the FEL beam with a magnifying EUV sensitized CCD camera. From these beam profile data the Wigner distribution function based on different levels of averaging could be reconstructed by an inverse Radon transform. For separable beams this yields the complete Wigner distribution, and for beams with zero twist the information is still sufficient for wavefront determination and beam propagation through stigmatic systems. The obtained results are compared to wavefront reconstructions based on the transport of intensity equation. A future setup for Wigner distribution measurements of general beams is discussed.

  3. Beam shaping assembly optimization for (7)Li(p,n)(7)Be accelerator based BNCT.

    PubMed

    Minsky, D M; Kreiner, A J

    2014-06-01

    Within the framework of accelerator-based BNCT, a project to develop a folded Tandem-ElectroStatic-Quadrupole accelerator is under way at the Atomic Energy Commission of Argentina. The proposed accelerator is conceived to deliver a proton beam of 30mA at about 2.5MeV. In this work we explore a Beam Shaping Assembly (BSA) design based on the (7)Li(p,n)(7)Be neutron production reaction to obtain neutron beams to treat deep seated tumors.

  4. Beam position and energy monitoring in compact linear accelerators for radiotherapy.

    PubMed

    Ruf, Marcel; Müller, Sven; Setzer, Stefan; Schmidt, Lorenz-Peter

    2014-02-01

    The experimental verification of a novel sensor topology capable of measuring both the position and energy of an electron beam inside a compact electron linear accelerator for radiotherapy is presented. The method applies microwave sensing techniques and allows for the noninterceptive monitoring of the respective beam parameters within compact accelerators for medical or industrial purposes. A state space feedback approach is described with the help of which beam displacements, once detected, can be corrected within a few system macropulses. The proof-of-principle experiments have been conducted with a prototype accelerator and customized hardware. Additionally, closed-loop operation with high accuracy is demonstrated.

  5. Capture and Control of Laser-Accelerated Proton Beams: Experiment and Simulation

    SciTech Connect

    Nurnberg, F; Alber, I; Harres, K; Schollmeier, M; Roth, M; Barth, W; Eickhoff, H; Hofmann, I; Friedman, A; Grote, D; Logan, B G

    2009-05-13

    This paper summarizes the ongoing studies on the possibilities for transport and RF capture of laser-accelerated proton beams in conventional accelerator structures. First results on the capture of laser-accelerated proton beams are presented, supported by Trace3D, CST particle studio and Warp simulations. Based on these results, the development of the pulsed high-field solenoid is guided by our desire to optimize the output particle number for this highly divergent beam with an exponential energy spectrum. A future experimental test stand is proposed to do studies concerning the application as a new particle source.

  6. 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.

  7. Studies of high density baryon matter with high intensity heavy-ion beams at J-PARC

    NASA Astrophysics Data System (ADS)

    Sako, H.; Harada, H.; Sakaguchi, T.; Chujo, T.; Esumi, S.; Gunji, T.; Hasegawa, S.; Hwang, S. H.; Ichikawa, Y.; Imai, K.; Itakura, K.; Kaneta, M.; Kim, B. C.; Kinsho, M.; Kitazawa, M.; Liu, Y.; Masui, H.; Nagamiya, S.; Nishio, K.; Okamura, M.; Oyama, K.; Ozawa, K.; Saha, P. K.; Sakaguchi, A.; Sato, S.; Shigaki, K.; Sugimura, H.; Tanida, K.; Tamura, J.; Tamura, H.; Nara, Y.; Saito, T. R.

    2016-12-01

    In J-PARC heavy-ion project, we aim at studies of QCD phase structures and hadron properties in high baryon density close to the neutron star core. We have developed a heavy-ion acceleration scheme with a new linac and a new booster with existing two synchrotrons with the goal beam rate of about 1011 Hz. We have also designed a large acceptance spectrometer based on a toroidal magnet. We have evaluated the spectrometer performance, and demonstrated reconstructing dielectron and dimuon spectra with full detector simulations. Finally, we designed a hypernuclear spectrometer which can utilize the full intensity ion beams.

  8. Beam line shielding calculations for an Electron Accelerator Mo-99 production facility

    SciTech Connect

    Mocko, Michal

    2016-05-03

    The purpose of this study is to evaluate the photon and neutron fields in and around the latest beam line design for the Mo-99 production facility. The radiation dose to the beam line components (quadrupoles, dipoles, beam stops and the linear accelerator) are calculated in the present report. The beam line design assumes placement of two cameras: infra red (IR) and optical transition radiation (OTR) for continuous monitoring of the beam spot on target during irradiation. The cameras will be placed off the beam axis offset in vertical direction. We explored typical shielding arrangements for the cameras and report the resulting neutron and photon dose fields.

  9. Fusion reactions initiated by laser-accelerated particle beams in a laser-produced plasma.

    PubMed

    Labaune, C; Baccou, C; Depierreux, S; Goyon, C; Loisel, G; Yahia, V; Rafelski, J

    2013-01-01

    The advent of high-intensity-pulsed laser technology enables the generation of extreme states of matter under conditions that are far from thermal equilibrium. This in turn could enable different approaches to generating energy from nuclear fusion. Relaxing the equilibrium requirement could widen the range of isotopes used in fusion fuels permitting cleaner and less hazardous reactions that do not produce high-energy neutrons. Here we propose and implement a means to drive fusion reactions between protons and boron-11 nuclei by colliding a laser-accelerated proton beam with a laser-generated boron plasma. We report proton-boron reaction rates that are orders of magnitude higher than those reported previously. Beyond fusion, our approach demonstrates a new means for exploring low-energy nuclear reactions such as those that occur in astrophysical plasmas and related environments.

  10. Modification of the velocity distribution of H(2) molecules in a supersonic beam by intense pulsed optical gradients.

    PubMed

    Ramirez-Serrano, Jaime; Strecker, Kevin E; Chandler, David W

    2006-07-07

    We report the acceleration and deceleration of H(2) molecules in a supersonic molecular beam by means of its interaction with an intense optical gradient from a nanosecond far-off-resonant optical pulse. The strong optical gradients are formed in the interference pattern of two intense optical pulses at 532 nm. The velocity distribution of the molecular beam, before and after the applied optical pulse, is measured by a velocity-mapped ion imaging technique. Changes in velocity up to 202 m s(-1)+/- 61 m s(-1) are observed in a molecular beam initially travelling at a mean speed of 563 m s(-1). We report the dependence of this change in velocity with the strength of the optical gradient applied.

  11. DEVELOPMENT OF ACCELERATOR DATA REPORTING SYSTEM AND ITS APPLICATION TO TREND ANALYSIS OF BEAM CURRENT DATA

    SciTech Connect

    Padilla, M.J.; Blokland, W.

    2009-01-01

    Detailed ongoing information about the ion beam quality is crucial to the successful operation of the Spallation Neutron Source at Oak Ridge National Laboratory. In order to provide the highest possible neutron production time, ion beam quality is monitored to isolate possible problems or performance-related issues throughout the accelerator and accumulator ring. For example, beam current monitor (BCM) data is used to determine the quality of the beam transport through the accelerator. In this study, a reporting system infrastructure was implemented and used to generate a trend analysis report of the BCM data. The BCM data was analyzed to facilitate the identifi cation of monitor calibration issues, beam trends, beam abnormalities, beam deviations and overall beam quality. A comparison between transformed BCM report data and accelerator log entries shows promising results which represent correlations between the data and changes made within the accelerator. The BCM analysis report is one of many reports within a system that assist in providing overall beam quality information to facilitate successful beam operation. In future reports, additional data manipulation functions and analysis can be implemented and applied. Built-in and user-defi ned analytic functions are available throughout the reporting system and can be reused with new data.

  12. 14 CFR 23.1395 - Maximum intensities in overlapping beams of position lights.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... AIRPLANES Equipment Lights § 23.1395 Maximum intensities in overlapping beams of position lights. No position light intensity may exceed the applicable values in the following equal or exceed the applicable... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Maximum intensities in overlapping beams...

  13. 14 CFR 27.1395 - Maximum intensities in overlapping beams of forward and rear position lights.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Equipment Lights § 27.1395 Maximum intensities in overlapping beams of forward and rear position lights. No position light intensity may exceed the applicable values in the following table, except as provided in... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Maximum intensities in overlapping beams...

  14. 14 CFR 29.1395 - Maximum intensities in overlapping beams of forward and rear position lights.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Equipment Lights § 29.1395 Maximum intensities in overlapping beams of forward and rear position lights. No position light intensity may exceed the applicable values in the following table, except as provided in... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Maximum intensities in overlapping beams...

  15. 14 CFR 23.1395 - Maximum intensities in overlapping beams of position lights.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... AIRPLANES Equipment Lights § 23.1395 Maximum intensities in overlapping beams of position lights. No position light intensity may exceed the applicable values in the following equal or exceed the applicable... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Maximum intensities in overlapping beams...

  16. 14 CFR 27.1395 - Maximum intensities in overlapping beams of forward and rear position lights.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Equipment Lights § 27.1395 Maximum intensities in overlapping beams of forward and rear position lights. No position light intensity may exceed the applicable values in the following table, except as provided in... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Maximum intensities in overlapping beams...

  17. 14 CFR 29.1395 - Maximum intensities in overlapping beams of forward and rear position lights.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Equipment Lights § 29.1395 Maximum intensities in overlapping beams of forward and rear position lights. No position light intensity may exceed the applicable values in the following table, except as provided in... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Maximum intensities in overlapping beams...

  18. 14 CFR 23.1395 - Maximum intensities in overlapping beams of position lights.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... AIRPLANES Equipment Lights § 23.1395 Maximum intensities in overlapping beams of position lights. No position light intensity may exceed the applicable values in the following equal or exceed the applicable... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Maximum intensities in overlapping beams...

  19. 14 CFR 23.1395 - Maximum intensities in overlapping beams of position lights.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... AIRPLANES Equipment Lights § 23.1395 Maximum intensities in overlapping beams of position lights. No position light intensity may exceed the applicable values in the following equal or exceed the applicable... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Maximum intensities in overlapping beams...

  20. 14 CFR 23.1395 - Maximum intensities in overlapping beams of position lights.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... AIRPLANES Equipment Lights § 23.1395 Maximum intensities in overlapping beams of position lights. No position light intensity may exceed the applicable values in the following equal or exceed the applicable... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Maximum intensities in overlapping beams...

  1. 14 CFR 27.1395 - Maximum intensities in overlapping beams of forward and rear position lights.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Equipment Lights § 27.1395 Maximum intensities in overlapping beams of forward and rear position lights. No position light intensity may exceed the applicable values in the following table, except as provided in... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Maximum intensities in overlapping beams...

  2. 14 CFR 29.1395 - Maximum intensities in overlapping beams of forward and rear position lights.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Equipment Lights § 29.1395 Maximum intensities in overlapping beams of forward and rear position lights. No position light intensity may exceed the applicable values in the following table, except as provided in... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Maximum intensities in overlapping beams...

  3. 14 CFR 27.1395 - Maximum intensities in overlapping beams of forward and rear position lights.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Equipment Lights § 27.1395 Maximum intensities in overlapping beams of forward and rear position lights. No position light intensity may exceed the applicable values in the following table, except as provided in... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Maximum intensities in overlapping beams...

  4. 14 CFR 29.1395 - Maximum intensities in overlapping beams of forward and rear position lights.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Equipment Lights § 29.1395 Maximum intensities in overlapping beams of forward and rear position lights. No position light intensity may exceed the applicable values in the following table, except as provided in... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Maximum intensities in overlapping beams...

  5. 14 CFR 29.1395 - Maximum intensities in overlapping beams of forward and rear position lights.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Equipment Lights § 29.1395 Maximum intensities in overlapping beams of forward and rear position lights. No position light intensity may exceed the applicable values in the following table, except as provided in... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Maximum intensities in overlapping beams...

  6. 14 CFR 27.1395 - Maximum intensities in overlapping beams of forward and rear position lights.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Equipment Lights § 27.1395 Maximum intensities in overlapping beams of forward and rear position lights. No position light intensity may exceed the applicable values in the following table, except as provided in... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Maximum intensities in overlapping beams...

  7. Differential acceleration in the final beam lines of a Heavy Ion Fusion driver

    SciTech Connect

    Friedman, Alex

    2013-10-19

    A long-standing challenge in the design of a Heavy Ion Fusion power plant is that the ion beams entering the target chamber, which number of order a hundred, all need to be routed from one or two multi-beam accelerators through a set of transport lines. The beams are divided into groups, which each have unique arrival times and may have unique kinetic energies. It is also necessary to arrange for each beam to enter the target chamber from a prescribed location on the periphery of that chamber. Furthermore, it has generally been assumed that additional constraints must be obeyed: that the path lengths of the beams in a group must be equal, and that any delay of \\main-pulse" beams relative to \\foot-pulse" beams must be provided by the insertion of large delay-arcs in the main beam transport lines. Here we introduce the notion of applying \\di erential acceleration" to individual beams or sets of beam at strategic stages of the transport lines. That is, by accelerating some beams \\sooner" and others \\later," it is possible to simplify the beam line con guration in a number of cases. For example, the time delay between the foot and main pulses can be generated without resorting to large arcs in the main-pulse beam lines. It is also possible to use di erential acceleration to e ect the simultaneous arrival on target of a set of beams ( e.g., for the foot-pulse) without requiring that their path lengths be precisely equal. We illustrate the technique for two model con gurations, one corresponding to a typical indirect-drive scenario requiring distinct foot and main energies, and the other to an ion-driven fast-ignition scenario wherein the foot and main beams share a common energy.

  8. Differential acceleration in the final beam lines of a Heavy Ion Fusion driver

    DOE PAGES

    Friedman, Alex

    2013-10-19

    A long-standing challenge in the design of a Heavy Ion Fusion power plant is that the ion beams entering the target chamber, which number of order a hundred, all need to be routed from one or two multi-beam accelerators through a set of transport lines. The beams are divided into groups, which each have unique arrival times and may have unique kinetic energies. It is also necessary to arrange for each beam to enter the target chamber from a prescribed location on the periphery of that chamber. Furthermore, it has generally been assumed that additional constraints must be obeyed: thatmore » the path lengths of the beams in a group must be equal, and that any delay of \\main-pulse" beams relative to \\foot-pulse" beams must be provided by the insertion of large delay-arcs in the main beam transport lines. Here we introduce the notion of applying \\di erential acceleration" to individual beams or sets of beam at strategic stages of the transport lines. That is, by accelerating some beams \\sooner" and others \\later," it is possible to simplify the beam line con guration in a number of cases. For example, the time delay between the foot and main pulses can be generated without resorting to large arcs in the main-pulse beam lines. It is also possible to use di erential acceleration to e ect the simultaneous arrival on target of a set of beams ( e.g., for the foot-pulse) without requiring that their path lengths be precisely equal. We illustrate the technique for two model con gurations, one corresponding to a typical indirect-drive scenario requiring distinct foot and main energies, and the other to an ion-driven fast-ignition scenario wherein the foot and main beams share a common energy.« less

  9. Automated detection and analysis of particle beams in laser-plasma accelerator simulations

    SciTech Connect

    Ushizima, Daniela Mayumi; Geddes, C.G.; Cormier-Michel, E.; Bethel, E. Wes; Jacobsen, J.; Prabhat, ,; R.ubel, O.; Weber, G,; Hamann, B.

    2010-05-21

    Numerical simulations of laser-plasma wakefield (particle) accelerators model the acceleration of electrons trapped in plasma oscillations (wakes) left behind when an intense laser pulse propagates through the plasma. The goal of these simulations is to better understand the process involved in plasma wake generation and how electrons are trapped and accelerated by the wake. Understanding of such accelerators, and their development, offer high accelerating gradients, potentially reducing size and cost of new accelerators. One operating regime of interest is where a trapped subset of electrons loads the wake and forms an isolated group of accelerated particles with low spread in momentum and position, desirable characteristics for many applications. The electrons trapped in the wake may be accelerated to high energies, the plasma gradient in the wake reaching up to a gigaelectronvolt per centimeter. High-energy electron accelerators power intense X-ray radiation to terahertz sources, and are used in many applications including medical radiotherapy and imaging. To extract information from the simulation about the quality of the beam, a typical approach is to examine plots of the entire dataset, visually determining the adequate parameters necessary to select a subset of particles, which is then further analyzed. This procedure requires laborious examination of massive data sets over many time steps using several plots, a routine that is unfeasible for large data collections. Demand for automated analysis is growing along with the volume and size of simulations. Current 2D LWFA simulation datasets are typically between 1GB and 100GB in size, but simulations in 3D are of the order of TBs. The increase in the number of datasets and dataset sizes leads to a need for automatic routines to recognize particle patterns as particle bunches (beam of electrons) for subsequent analysis. Because of the growth in dataset size, the application of machine learning techniques for

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

    NASA Astrophysics Data System (ADS)

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

    2012-12-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2013-01-01

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

  12. Optics measurement and correction during beam acceleration in the Relativistic Heavy Ion Collider

    SciTech Connect

    Liu, C.; Marusic, A.; Minty, M.

    2014-09-09

    To minimize operational complexities, setup of collisions in high energy circular colliders typically involves acceleration with near constant β-functions followed by application of strong focusing quadrupoles at the interaction points (IPs) for the final beta-squeeze. At the Relativistic Heavy Ion Collider (RHIC) beam acceleration and optics squeeze are performed simultaneously. In the past, beam optics correction at RHIC has taken place at injection and at final energy with some interpolation of corrections into the acceleration cycle. Recent measurements of the beam optics during acceleration and squeeze have evidenced significant beta-beats which if corrected could minimize undesirable emittance dilutions and maximize the spin polarization of polarized proton beams by avoidance of higher-order multipole fields sampled by particles within the bunch. In this report the methodology now operational at RHIC for beam optics corrections during acceleration with simultaneous beta-squeeze will be presented together with measurements which conclusively demonstrate the superior beam control. As a valuable by-product, the corrections have minimized the beta-beat at the profile monitors so reducing the dominant error in and providing more precise measurements of the evolution of the beam emittances during acceleration.

  13. Beam dynamic design of a high intensity injector for proton linac

    NASA Astrophysics Data System (ADS)

    Dou, Wei-Ping; Wang, Zhi-Jun; Jia, Fang-Jian; He, Yuan; Wang, Zhi; Lu, Yuan-Rong

    2016-08-01

    A compact room-temperature injector is designed to accelerate 100 mA proton beam from 45 keV to 4.06 MeV for the proposed high intensity proton linac at State Key Lab of Nuclear Physics and Technology in Peking university. The main feature is that the Radio Frequency Quadruple (RFQ) and the Drift Tube linac (DTL) sections are merged in one piece at the total length of 276 cm. The beam is matched in transverse directions with an compact internal doublet instead of an external matching section in between. The design has reached a high average accelerating gradient up to 1.55 MV/m with transmission efficiency of 95.9% at the consideration of high duty factor operation. The operation frequency is chose to be 200 MHz due to the already available RF power source. The injector combines a 150 cm long 4-vanes RFQ internal section from 45 keV to 618 keV with a 126 cm long H-type DTL section to 4.06 MeV. In general the design satisfy the challenges of the project requirements. And the details are presented in this paper.

  14. Beam quality study for a grating-based dielectric laser-driven accelerator

    NASA Astrophysics Data System (ADS)

    Wei, Y.; Jamison, S.; Xia, G.; Hanahoe, K.; Li, Y.; Smith, J. D. A.; Welsch, C. P.

    2017-02-01

    Dielectric laser-driven accelerators (DLAs) based on grating structures are considered to be one of the most promising technologies to reduce the size and cost of future particle accelerators. They offer high accelerating gradients of up to several GV/m in combination with mature lithographic techniques for structure fabrication. This paper numerically investigates the beam quality for acceleration of electrons in a realistic dual-grating DLA. In our simulations, we use beam parameters of the future Compact Linear Accelerator for Research and Applications facility to load an electron bunch into an optimized 100-period dual-grating structure where it interacts with a realistic laser pulse. The emittance, energy spread, and loaded accelerating gradient for modulated electrons are then analyzed in detail. Results from simulations show that an accelerating gradient of up to 1.13 ± 0.15 GV/m with an extremely small emittance growth, 3.6%, can be expected.

  15. Hollow structure formation of intense ion beams with sharp edge in background plasmas

    SciTech Connect

    Hu, Zhang-Hu; Wang, You-Nian

    2016-02-15

    The transport of intense ion beams with sharp radial beam edge in plasmas has been studied with two-dimensional electromagnetic particle simulations. The initial solid beam evolves into a hollow beam due to the nonlinear sharp transverse force peak in the regions of beam edge. The magnitude and nonlinearity of this peak are enhanced as the ion beam travels further into the plasma, due to the self-consistent interactions between the beam ions and the plasma electrons. This structure formation is shown to be independent on the beam radius.

  16. Nuclear Structure at the Legnaro National Laboratories:. from High Intensity Stable to Radioactive Nuclear Beams

    NASA Astrophysics Data System (ADS)

    de Angelis, G.

    2007-04-01

    To understand the properties of a nucleus, apart from establishing the interaction between its components, it is necessary to determine the arrangement of the nucleons, i.e. the structure of a nucleus. So far our knowledge about the structure of nuclei is mostly limited to nuclei close to the valley of stability, or nuclei with a deficiency of neutrons, which can be produced in fusion-evaporation reactions with stable beams and stable targets. Future perspectives in nuclear structure rely on radioactive ion beams (RIB) as well as on high intensity beams of stable ions (HISB). A world wide effort is presently going on in order to built the next generation radioactive ion beam facilities like the FAIR and the EURISOL projects. The LNL are contributing to such development through the design study of the EURISOL project as well as through the design and construction of the intermediate facility SPES. Concerning the instrumentation, particularly powerful is the combination of large acceptance spectrometers with highly segmented γ-detector arrays. An example is the CLARA γ-ray detector array coupled with the PRISMA spectrometer at the Legnaro National Laboratories (LNL). The physics aims achievable with such device complement studies performed with current radioactive beam (RIB) facilities. With this set-up we have recently investigated the stability of the N=50 shell closure. Here the comparison of the experimental data with shell model calculations seems to indicate a persistence of the N=50 shell gap down to Z=31. Also the study of proton rich nuclei can strongly benefit from the use of high intensity stable beams using fusion evaporation reactions at energies close to the Coulomb barrier. Future perspectives at LNL are based on an increase in intensity as well as on the availability of heavy ion species. Moreover a new ISOL facility (SPES) dedicated to the production and acceleration of radioactive neutron rich species is now under development at LNL. Among the new

  17. Demons deformable registration of CT and cone-beam CT using an iterative intensity matching approach

    SciTech Connect

    Nithiananthan, Sajendra; Schafer, Sebastian; Uneri, Ali; and others

    2011-04-15

    Purpose: A method of intensity-based deformable registration of CT and cone-beam CT (CBCT) images is described, in which intensity correction occurs simultaneously within the iterative registration process. The method preserves the speed and simplicity of the popular Demons algorithm while providing robustness and accuracy in the presence of large mismatch between CT and CBCT voxel values (''intensity''). Methods: A variant of the Demons algorithm was developed in which an estimate of the relationship between CT and CBCT intensity values for specific materials in the image is computed at each iteration based on the set of currently overlapping voxels. This tissue-specific intensity correction is then used to estimate the registration output for that iteration and the process is repeated. The robustness of the method was tested in CBCT images of a cadaveric head exhibiting a broad range of simulated intensity variations associated with x-ray scatter, object truncation, and/or errors in the reconstruction algorithm. The accuracy of CT-CBCT registration was also measured in six real cases, exhibiting deformations ranging from simple to complex during surgery or radiotherapy guided by a CBCT-capable C-arm or linear accelerator, respectively. Results: The iterative intensity matching approach was robust against all levels of intensity variation examined, including spatially varying errors in voxel value of a factor of 2 or more, as can be encountered in cases of high x-ray scatter. Registration accuracy without intensity matching degraded severely with increasing magnitude of intensity error and introduced image distortion. A single histogram match performed prior to registration alleviated some of these effects but was also prone to image distortion and was quantifiably less robust and accurate than the iterative approach. Within the six case registration accuracy study, iterative intensity matching Demons reduced mean TRE to (2.5{+-}2.8) mm compared to (3.5{+-}3.0) mm

  18. High quality electron beam acceleration by ionization injection in laser wakefields with mid-infrared dual-color lasers

    NASA Astrophysics Data System (ADS)

    Zeng, Ming; Luo, Ji; Chen, Min; Mori, Warren B.; Sheng, Zheng-Ming; Hidding, Bernhard

    2016-06-01

    For the laser wakefield acceleration, suppression of beam energy spread while keeping sufficient charge is one of the key challenges. In order to achieve this, we propose bichromatic laser ionization injection with combined laser wavelengths of 2.4 μ m and 0.8 μ m for wakefield excitation and triggering electron injection via field ionization, respectively. A laser pulse at 2.4 μ m wavelength enables one to drive an intense acceleration structure with a relatively low laser power. To further reduce the requirement of laser power, we also propose to use carbon dioxide as the working gas medium, where carbon acts as the injection element. Our three dimensional particle-in-cell simulations show that electron beams at the GeV energy level with both low energy spreads (around 1%) and high charges (several tens of picocoulomb) can be obtained by the use of this scheme with laser peak power totaling sub-100 TW.

  19. Considerations of the low-velocity stage of a radioactive beams accelerator

    SciTech Connect

    Talbert, W.L.

    1992-12-01

    Studies of the low-velocity stages of a radioactive beams accelerator are summarized, highlighting the limitations of existing RFQ technology when applied to the specifications of the IsoSpin Laboratory.

  20. Undulator-Based Laser Wakefield Accelerator Electron Beam Energy Spread and Emittance Diagnostic

    SciTech Connect

    Bakeman, M.S.; Van Tilborg, J.; Nakamura, K.; Gonsalves, A.; Osterhoff, J.; Sokollik, T.; Lin, C.; Robinson, K.E.; Schroeder, C.B.; Toth, Cs.; Weingartner, R.; Gruner, F.; Esarey, E.; Leemans, W.P.

    2010-06-01

    The design and current status of experiments to couple the Tapered Hybrid Undulator (THUNDER) to the Lawrence Berkeley National Laboratory (LBNL) laser plasma accelerator (LPA) to measure electron beam energy spread and emittance are presented.