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Sample records for accelerating monoenergetic protons

  1. Target shape effects on monoenergetic GeV proton acceleration

    Chen, Min; Pukhov, Alexander; Sheng, Zheng-Ming

    2009-01-01

    When a circularly polarized laser pulse interacts with a foil target, there are three stages: pre-hole-boring, hole-boring and the light sail acceleration. We study the electron and ion dynamics in the first stage and find the minimum foil thickness requirement for a given laser intensity. Based on this analysis, we propose to use a shaped foil for ion acceleration, whose thickness varies transversely to match the laser intensity. Then, the target evolves into three regions: the acceleration, transparency and deformation regions. In the acceleration region, the target can be uniformly accelerated producing a mono-energetic and spatially collimated ion beam. Detailed numerical simulations are performed to check the feasibility and robustness of this scheme, such as the influence of shape factors and surface roughness. A GeV mono-energetic proton beam is observed in the three dimensional particle-in-cell simulations when a laser pulse with the focus intensity of 1022W=cm2 is used. The energy conversion efficien...

  2. Laser Acceleration of Quasi-Monoenergetic Protons via Radiation Pressure Driven Thin Foil

    We present a theoretical and simulation study of laser acceleration of quasi-monoenergetic protons in a thin foil irradiated by high intensity laser light. The underlying physics of radiation pressure acceleration (RPA) is discussed, including the importance of optimal thickness and circularly polarized light for efficient acceleration of ions to quasi-monoenergetic beams. Preliminary two-dimensional simulation studies show that certain parameter regimes allow for stabilization of the Rayleigh-Taylor instability and possibility of acceleration of monoenergetic ions to an excess of 200 MeV, making them suitable for important applications such as medical cancer therapy and fast ignition.

  3. Generating high-current monoenergetic proton beams by a circularly polarized laser pulse in the phase-stable acceleration regime.

    Yan, X Q; Lin, C; Sheng, Z M; Guo, Z Y; Liu, B C; Lu, Y R; Fang, J X; Chen, J E

    2008-04-01

    A new ion acceleration method, namely, phase-stable acceleration, using circularly-polarized laser pulses is proposed. When the initial target density n(0) and thickness D satisfy a(L) approximately (n(0)/n(c))D/lambda(L) and D>l(s) with a(L), lambda(L), l(s), and n(c) the normalized laser amplitude, the laser wavelength in vacuum, the plasma skin depth, and the critical density of the incident laser pulse, respectively, a quasiequilibrium for the electrons is established by the light pressure and the space charge electrostatic field at the interacting front of the laser pulse. The ions within the skin depth of the laser pulse are synchronously accelerated and bunched by the electrostatic field, and thereby a high-intensity monoenergetic proton beam can be generated. The proton dynamics is investigated analytically and the results are verified by one- and two-dimensional particle-in-cell simulations. PMID:18517963

  4. Accelerating monoenergetic protons from ultrathin foils by flat-top laser pulses in the directed-Coulomb-explosion regime

    Bulanov, S. S.; Brantov, A.; Bychenkov, V. Yu.; Chvykov, V.; Kalinchenko, G.; Matsuoka, T.; Rousseau, P.; Reed, S; Yanovsky, V.; Litzenberg, D. W.; Krushelnick, K.; Maksimchuk, A.

    2008-01-01

    We consider the effect of laser beam shaping on proton acceleration in the interaction of a tightly focused pulse with ultrathin double-layer solid targets in the regime of directed Coulomb explosion. In this regime, the heavy ions of the front layer are forced by the laser to expand predominantly in the direction of the pulse propagation, forming a moving longitudinal charge separation electric field, thus increasing the effectiveness of acceleration of second-layer protons. The utilization ...

  5. Generation of monoenergetic ion beams with a laser accelerator

    Pfotenhauer, Sebastian M.

    2009-01-29

    A method for the generation of monoenergetic proton and ion beams from a laser-based particle accelerator is presented. This method utilizes the unique space-charge effects occurring during relativistic laser-plasma interactions on solid targets in combination with a dot-like particle source. Due to this unique interaction geometry, MeV proton beams with an intrinsically narrow energy spectrum were obtained, for the first time, from a micrometer-scale laser accelerator. Over the past three years, the acceleration scheme has been consistently improved to enhance both the maximum particle energy and the reliability of the setup. The achieved degree of reliability allowed to derive the first scaling laws specifically for monoenergetic proton beams. Furthermore, the acceleration scheme was expanded on other target materials, enabling the generation of monoenergetic carbon beams. The experimental work was strongly supported by the parallel development of a complex theoretical model, which fully accounts for the observations and is in excellent agreement with numerical simulations. The presented results have an extraordinarily broad scope way beyond the current thesis: The availability of monoenergetic ion beams from a compact laser-plasma beam source - in conjunction with the unique properties of laser-produced particle beams - addresses a number of outstanding applications in fundamental research, material science and medical physics, and will help to shape a new generation of accelerators. (orig.)

  6. Generation of monoenergetic ion beams with a laser accelerator

    A method for the generation of monoenergetic proton and ion beams from a laser-based particle accelerator is presented. This method utilizes the unique space-charge effects occurring during relativistic laser-plasma interactions on solid targets in combination with a dot-like particle source. Due to this unique interaction geometry, MeV proton beams with an intrinsically narrow energy spectrum were obtained, for the first time, from a micrometer-scale laser accelerator. Over the past three years, the acceleration scheme has been consistently improved to enhance both the maximum particle energy and the reliability of the setup. The achieved degree of reliability allowed to derive the first scaling laws specifically for monoenergetic proton beams. Furthermore, the acceleration scheme was expanded on other target materials, enabling the generation of monoenergetic carbon beams. The experimental work was strongly supported by the parallel development of a complex theoretical model, which fully accounts for the observations and is in excellent agreement with numerical simulations. The presented results have an extraordinarily broad scope way beyond the current thesis: The availability of monoenergetic ion beams from a compact laser-plasma beam source - in conjunction with the unique properties of laser-produced particle beams - addresses a number of outstanding applications in fundamental research, material science and medical physics, and will help to shape a new generation of accelerators. (orig.)

  7. Note: A monoenergetic proton backlighter for the National Ignition Facility

    Rygg, J. R.; LePape, S.; Bachmann, B.; Khan, S. F.; Sayre, D. B. [Lawrence Livermore National Laboratory, Livermore, California 94551 (United States); Zylstra, A. B.; Séguin, F. H.; Gatu-Johnson, M.; Lahmann, B. J.; Petrasso, R. D.; Sio, H. W. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Craxton, R. S.; Garcia, E. M.; Kong, Y. Z.; McKenty, P. W. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States); Rinderknecht, H. G. [Lawrence Livermore National Laboratory, Livermore, California 94551 (United States); Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Rosenberg, M. J. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States)

    2015-11-15

    A monoenergetic, isotropic proton source suitable for proton radiography applications has been demonstrated at the National Ignition Facility (NIF). A deuterium and helium-3 gas-filled glass capsule was imploded with 39 kJ of laser energy from 24 of NIF’s 192 beams. Spectral, spatial, and temporal measurements of the 15-MeV proton product of the {sup 3}He(d,p){sup 4}He nuclear reaction reveal a bright (10{sup 10} protons/sphere), monoenergetic (ΔE/E = 4%) spectrum with a compact size (80 μm) and isotropic emission (∼13% proton fluence variation and <0.4% mean energy variation). Simultaneous measurements of products produced by the D(d,p)T and D(d,n){sup 3}He reactions also show 2 × 10{sup 10} isotropically distributed 3-MeV protons.

  8. Simulation of the Quasi-Monoenergetic Protons Generation by Parallel Laser Pulses Interaction with Foils

    Wang, Wei-Quan; Yin, Yan; Zou, De-Bin; Yu, Tong-Pu; Yang, Xiao-Hu; Xu, Han; Yu, Ming-Yang; Ma, Yan-Yun; Zhuo, Hong-Bin; Shao, Fu-Qiu

    2014-11-01

    A new scheme of radiation pressure acceleration for generating high-quality protons by using two overlapping-parallel laser pulses is proposed. Particle-in-cell simulation shows that the overlapping of two pulses with identical Gaussian profiles in space and trapezoidal profiles in the time domain can result in a composite light pulse with a spatial profile suitable for stable acceleration of protons to high energies. At ~2.46 × 1021 W/cm2 intensity of the combination light pulse, a quasi-monoenergetic proton beam with peak energy ~200 MeV/nucleon, energy spread therapy. The proton beam quality can be controlled by adjusting the incidence points of two laser pulses.

  9. Dense monoenergetic proton beams from chirped laser-plasma interaction

    Galow, Benjamin J; Liseykina, Tatyana V; Harman, Zoltan; Keitel, Christoph H

    2011-01-01

    Interaction of a frequency-chirped laser pulse with single protons and a hydrogen plasma cell is studied analytically and by means of particle-in-cell simulations, respectively. Feasibility of generating ultra-intense (10^7 particles per bunch) and phase-space collimated beams of protons (energy spread of about 1 %) is demonstrated. Phase synchronization of the protons and the laser field, guaranteed by the appropriate chirping of the laser pulse, allows the particles to gain sufficient kinetic energy (around 250 MeV) required for such applications as hadron cancer therapy, from state-of-the-art laser systems of intensities of the order of 10^21 W/cm^2.

  10. Medical Proton Accelerator Project

    A project for a medical proton accelerator for cancer treatment is outlined. The project is motivated by the need for a precise modality for cancer curing especially in children. Proton therapy is known by its superior radiation and biological effectiveness as compared to photon or electron therapy. With 26 proton and 3 heavy-ion therapy complexes operating worldwide only one (p) exists in South Africa, and none in south Asia and the Middle East. The accelerator of choice should provide protons with energy 75 MeV for eye treatment and 250 MeV for body treatment. Four treatment rooms are suggested: two with isocentric gantries, one with fixed beams and one for development. Passive scanning is recommended. The project can serve Middle East and North Africa with ∼ 400 million populations. The annual capacity of the project is estimated as 1,100 to be compared with expected radiation cases eligible for proton cancer treatment of not less than 200,000

  11. Mono-Energetic Neutron Fields Using 4 MV Pelletron Accelerator at FRS / JAEA

    Mono-energetic neutron calibration fields have been developed in the energy range of 8 keV to 19 MeV using a 4MV Pelletron accelerator at the Facility of Radiation Standards in the Japan Atomic Energy Agency. The neutron fields with the energies of 8, 27, 144, 250, 565 keV and 1.2, 2.5, 5.0, 14.8, 19 MeV are established. Protons or deuterons are accelerated and transported to bombard various targets for neutron production. The targets are prepared by depositing scandium, lithium fluoride or tritiated titanium on the backing disks for 45Sc(p, n)45Ti, 7Li(p, n)7Be and, 3H(p, n)3He and 3H(d, n)4He reactions, respectively. For 2H(d, n)3He reaction, a gas target is prepared by filling a target cell with D2 gas. A pulsed beam can be derived with the pulsing system installed in the high voltage terminal of the accelerator. The minimum pulse width was evaluated to be 2 ns in FWHM. Neutron fluence rates at the irradiation point were measured with a Bonner sphere, a lithium glass scintillation detector, a silicon semi-conductor detector with a polyethylene radiator and a BC501A organic liquid scintillation detector. Though the maximum fluence rates should not be high enough to obtain the nuclear data using an activation method, they can be available to obtain the nuclear data by using the prompt gamma ray analysis. (author)

  12. First results of laser-proton acceleration with cryogenic hydrogen targets at the POLARIS laser

    Becker, Georg Alexander; Polz, Jens; Kloepfel, Diethard; Ziegler, Wolfgang; Keppler, Sebastian; Liebetrau, Hartmut; Hellwing, Marco [Institut fuer Optik und Quantenelektronik, Friedrich-Schiller-Universitaet, 07743 Jena (Germany); Kalinin, Anton; Costa Fraga, Rui; Grisenti, Robert [Institut fuer Kernphysik, Goethe-Universitaet, 60438 Frankfurt am Main (Germany); Robinson, Alexander [Central Laser Facility, Rutherford-Appleton Laboratory, Chilton, Oxon., OX11 0QX (United Kingdom); Kessler, Alexander; Schorcht, Frank; Hornung, Marco [Helmholtz Institut Jena, 07743 Jena (Germany); Kaluza, Malte Christoph [Institut fuer Optik und Quantenelektronik, Friedrich-Schiller-Universitaet, 07743 Jena (Germany); Helmholtz Institut Jena, 07743 Jena (Germany)

    2015-05-01

    For the first time on the POLARIS laser system, a laser-driven proton acceleration experiment with cryogenic hydrogen droplets and filaments has been performed. Most laser-driven proton acceleration experiments use target materials including metals, plastics or diamond-like carbon. Due to the multitude of ion species accelerated from such targets, understanding the acceleration processes becomes quite complicated. The use of liquid or frozen hydrogen targets reduces the accelerated species to protons only and additionally produces, due to the mass limited droplets or filaments, a higher acceleration field. The experimental setup and results, including isolated monoenergetic peaks in the high energy range of the proton spectra, are discussed.

  13. Quasi-monoenergetic electron acceleration in relativistic laser-plasmas

    Using Particle-in-Cell simulations as well as analytical theory we study electron acceleration in underdense plasmas both in the Bubble regime and in the weakly relativistic periodic wake fields. In the Bubble regime, electron trapping is taken as a function of the propagated distance. The number of trapped electrons depends on the effective phase velocity of the X-point at the rear of the Bubble. For the weakly relativistic periodic wakes, we show that the phase synchronism between the wake and the relativistic electrons can be maintained over very long distances when the plasma density is tapered properly. Moreover, one can use layered plasmas to control and improve the accelerated beam quality. (authors)

  14. Self-Injection and Acceleration of Monoenergetic Electron Beams from Laser Wakefield Accelerators in a Highly Relativistic Regime

    Self-injection and acceleration of monoenergetic electron beams from laser wakefield accelerators are first investigated in the highly relativistic regime, using 100 TW class, 27fs laser pulses. Quasi-monoenergetic multi-bunched beams with energies as high as multi-hundred MeV are observed with simultaneous measurements of side-scattering emissions that indicate the formation of self-channelling and self-injection of electrons into a plasma wake, referred to as a 'bubble'. The three-dimensional particle-in-cell simulations confirmed multiple self-injection of electron bunches into the bubble and their beam acceleration with gradient of 1.5GeV/cm. (physics of gases, plasmas, and electric discharges)

  15. Self-Injection and Acceleration of Monoenergetic Electron Beams from Laser Wakefield Accelerators in a Highly Relativistic Regime

    H. Yoshitama; WEN Xian-Lun; WEN Tian-Shu; WU Yu-Chi; ZHANG Bao-San; ZHU Qi-Hua; HUANG Xiao-Jun; AN Wei-Min; HUNG Wen-Hui; TANG Chuan-Xiang; LIN Yu-Zheng; T. Kameshima; WANG Xiao-Dong; CHEN Li-Ming; H. Kotaki; M. Kando; K. Nakajima; GU Yu-Qiu; GUO Yi; JIAO Chun-Ye; LIU Hong-Jie; PENG Han-Sheng; TANG Chuan-Ming; WANG Xiao-Dong

    2008-01-01

    @@ Self-injection and acceleration of monoenergetic electron beams from laser wakefield accelerators are first in-vestigated in the highly relativistic regime, using 100 TW class, 27 fs laser pulses. Quasi-monoenergetic multi-bunched beams with energies as high as multi-hundredMeV are observed with simultaneous measurements of side-scattering emissions that indicate the formation of self-channelling and self-injection of electrons into a plasma wake, referred to as a 'bubble'. The three-dimensional particle-in-cell simulations confirmed multiple self-injection of electron bunches into the bubble and their beam acceleration with gradient of 1.5 GeV/cm.

  16. Multiple quasi-monoenergetic electron beams from laser-wakefield acceleration with spatially structured laser pulse

    By adjusting the focus geometry of a spatially structured laser pulse, single, double, and treble quasi-monoenergetic electron beams were generated, respectively, in laser-wakefield acceleration. Single electron beam was produced as focusing the laser pulse to a single spot. While focusing the laser pulse to two spots that are approximately equal in energy and size and intense enough to form their own filaments, two electron beams were produced. Moreover, with a proper distance between those two focal spots, three electron beams emerged with a certain probability owing to the superposition of the diffractions of those two spots. The energy spectra of the multiple electron beams are quasi-monoenergetic, which are different from that of the large energy spread beams produced due to the longitudinal multiple-injection in the single bubble

  17. Multiple quasi-monoenergetic electron beams from laser-wakefield acceleration with spatially structured laser pulse

    Ma, Y.; Li, M. H.; Li, Y. F.; Wang, J. G.; Tao, M. Z.; Han, Y. J.; Zhao, J. R.; Huang, K.; Yan, W. C.; Ma, J. L.; Li, Y. T. [Beijing National Laboratory of Condensed Matter Physics, Institute of Physics, CAS, Beijing 100080 (China); Chen, L. M., E-mail: lmchen@iphy.ac.cn [Beijing National Laboratory of Condensed Matter Physics, Institute of Physics, CAS, Beijing 100080 (China); Department of Physics and Astronomy and IFSA Collaborative Innovation Center, Shanghai Jiao Tong University, Shanghai 200240 (China); Li, D. Z. [Institute of High Energy Physics, CAS, Beijing 100049 (China); Chen, Z. Y. [Institute of Fluid Physics, China Academy of Engineering Physics, Mianyang, Sichuan 621999 (China); Sheng, Z. M. [Department of Physics and Astronomy and IFSA Collaborative Innovation Center, Shanghai Jiao Tong University, Shanghai 200240 (China); Department of Physics, Scottish Universities Physics Alliance, University of Strathclyde, Glasgow G4 0NG (United Kingdom); Zhang, J. [Department of Physics and Astronomy and IFSA Collaborative Innovation Center, Shanghai Jiao Tong University, Shanghai 200240 (China)

    2015-08-15

    By adjusting the focus geometry of a spatially structured laser pulse, single, double, and treble quasi-monoenergetic electron beams were generated, respectively, in laser-wakefield acceleration. Single electron beam was produced as focusing the laser pulse to a single spot. While focusing the laser pulse to two spots that are approximately equal in energy and size and intense enough to form their own filaments, two electron beams were produced. Moreover, with a proper distance between those two focal spots, three electron beams emerged with a certain probability owing to the superposition of the diffractions of those two spots. The energy spectra of the multiple electron beams are quasi-monoenergetic, which are different from that of the large energy spread beams produced due to the longitudinal multiple-injection in the single bubble.

  18. Spectral Features in Laser Driven Proton Acceleration from Cylindrical Solid-density Hydrogen Jets

    Curry, Chandra; Gauthier, Maxence; Mishra, Rohini; Kim, Jongjin; Goede, Sebastian; Propp, Adrienne; Fiuza, Frederico; Glenzer, Siegfried H.; Williams, Jackson; Ruby, John; Goyon, Clement; Pak, Art E.; Kerr, Shaun; Tsui, Ying Y.; Ramakrishna, Bhuvanesh; Aurand, Bastian; Willi, Oswald; Roedel, Christian

    2015-11-01

    The generation of monoenergetic proton beams by ultrashort high-intensity laser-plasma interactions is of great interest for applications such as stopping power measurements, fast ignition laser confinement fusion, and ion beam therapy. In general, the commonly used mechanism of target normal sheath acceleration (TNSA) does not provide the required energy spread or maximum proton energy. Here we study alternative acceleration mechanisms, which have been identified in particle in cell (PIC) simulations, to overcome the limitations of TNSA. Using the Titan laser system at the Lawrence Livermore National Laboratory, we investigate proton acceleration from wire targets and a cryogenic solid-density hydrogen jet. Due to the cylindrical geometry, TNSA is suppressed allowing other accelerations mechanisms to become observable. Quasi-monoenergetic features in laser-forward direction are observed in the proton spectrum indicating radiation-pressure-driven acceleration mechanisms. Our experimental results are accompanied by supporting PIC simulations.

  19. Proton Therapy - Accelerating Protons to Save Lives

    Keppel, Cynthia [Hampton University Proton Therapy

    2011-10-25

    In 1946, physicist Robert Wilson first suggested that protons could be used as a form of radiation therapy in the treatment of cancer because of the sharp drop-off that occurs on the distal edge of the radiation dose. Research soon confirmed that high-energy protons were particularly suitable for treating tumors near critical structures, such as the heart and spinal column. The precision with which protons can be delivered means that more radiation can be deposited into the tumor while the surrounding healthy tissue receives substantially less or, in some cases, no radiation. Since these times, particle accelerators have continuously been used in cancer therapy and today new facilities specifically designed for proton therapy are being built in many countries. Proton therapy has been hailed as a revolutionary cancer treatment, with higher cure rates and fewer side effects than traditional X-ray photon radiation therapy. Proton therapy is the modality of choice for treating certain small tumors of the eye, head or neck. Because it exposes less of the tissue surrounding a tumor to the dosage, proton therapy lowers the risk of secondary cancers later in life - especially important for young children. To date, over 80,000 patients worldwide have been treated with protons. Currently, there are nine proton radiation therapy facilities operating in the United States, one at the Hampton University Proton Therapy Institute. An overview of the treatment technology and this new center will be presented.

  20. High intensity circular proton accelerators

    Circular machines suitable for the acceleration of high intensity proton beams include cyclotrons, FFAG accelerators, and strong-focusing synchrotrons. This paper discusses considerations affecting the design of such machines for high intensity, especially space charge effects and the role of beam brightness in multistage accelerators. Current plans for building a new generation of high intensity 'kaon factories' are reviewed. 47 refs

  1. Generation of high-energy mono-energetic heavy ion beams by radiation pressure acceleration of ultra-intense laser pulses

    Generation of high-energy mono-energetic heavy ion beams by radiation pressure acceleration (RPA) of intense laser pulses is investigated. Different from previously studied RPA of protons or light ions, the dynamic ionization of high-Z atoms can stabilize the heavy ion acceleration. A self-organized, stable RPA scheme specifically for heavy ion beams is proposed, where the laser peak intensity is required to match with the large ionization energy gap when the successive ionization state passes the noble gas configurations [such as removing an electron from the helium-like charge state (Z−2)+ to (Z−1)+]. Two-dimensional particle-in-cell simulations show that a mono-energetic Al13+ beam with peak energy 1.0 GeV and energy spread of only 5% can be obtained at intensity of 7×1020 W/cm2 through the proposed scheme. A heavier, mono-energetic, ion beam (Fe26+) can attain a peak energy of 17 GeV by increasing the intensity to 1022 W/cm2

  2. The Bubble regime of laser-plasma acceleration: monoenergetic electrons and the scalability

    Pukhov, A E; Kiselev, S; Kostyukhov, Yu

    2004-01-01

    The Bubble regime of electron acceleration in ultra-relativistic laser plasma is considered. It has been shown that the bubble can produce ultra-short dense bunches of electrons with quasi-monoenergetic energy spectra. The first experiment in this regime done at LOA has confirmed the peaked electron spectrum (J. Faure, et al., {\\it submitted}, 2004). The generated electron bunch may have density an order of magnitude higher than that of the background plasma. The bubble is able to guide the laser pulse over many Rayleigh lengths, thus no preformed plasma channel is needed for high-energy particle acceleration in the bubble regime. In the present work we discuss a simple analytical model for the bubble fields as well as the scaling laws.

  3. High intensity proton accelerator program

    Industrial applications of proton accelerators to the incineration of the long-lived nuclides contained in the spent fuels have long been investigated. Department of Reactor Engineering of Japan Atomic Energy Research Institute (JAERI) has formulated the Accelerator Program through the investigations on the required performances of the accelerator and its development strategies and also the research plan using the accelerator. Outline of the Program is described in the present report. The target of the Program is the construction of the Engineering Test Accelerators (ETA) of the type of a linear accelerator with the energy 1.5 GeV and the proton current ∼10 mA. It is decided that the construction of the Basic Technology Accelerator (BTA) is necessary as an intermediate step, aiming at obtaining the required technical basis and human resources. The Basic Technology Accelerator with the energy of 10 MeV and with the current of ∼10 mA is composed of the ion source, RFQ and DTL, of which system forms the mock-up of the injector of ETA. Development of the high-β structure which constitutes the main acceleration part of ETA is also scheduled. This report covers the basic parameters of the Basic Technology Accelerator (BTA), development steps of the element and system technologies of the high current accelerators and rough sketch of ETA which can be prospected at present. (J.P.N.)

  4. High-Intensity Proton Accelerator

    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.

  5. Proton synchrotron accelerator theory

    This is the text of a series of lectures given as part of the CERN Academic Training Programme and primarily intended for young engineers and technicians in preparation for the running-in of the 400 GeV Super Proton Synchrotron (SPS). Following the definition of basic quantities, the problems of betatron motion and the effect of momentum spread and orbital errors on the transverse motion of the beam are reviewed. Consideration is then given to multipole fields, chromaticity and non-linear resonances. After dealing with basic relations governing longitudinal beam dynamics, the space-charge, resistive-wall and other collective effects are treated, with reference to precautions in the SPS to prevent their occurrence. (Auth.)

  6. Compact quasi-monoenergetic photon sources from laser-plasma accelerators for nuclear detection and characterization

    Geddes, Cameron G.R., E-mail: cgrgeddes@lbl.gov; Rykovanov, Sergey; Matlis, Nicholas H.; Steinke, Sven; Vay, Jean-Luc; Esarey, Eric H.; Ludewigt, Bernhard; Nakamura, Kei; Quiter, Brian J.; Schroeder, Carl B.; Toth, Csaba; Leemans, Wim P.

    2015-05-01

    Near-monoenergetic photon sources at MeV energies offer improved sensitivity at greatly reduced dose for active interrogation, and new capabilities in treaty verification, nondestructive assay of spent nuclear fuel and emergency response. Thomson (also referred to as Compton) scattering sources are an established method to produce appropriate photon beams. Applications are however restricted by the size of the required high-energy electron linac, scattering (photon production) system, and shielding for disposal of the high energy electron beam. Laser-plasma accelerators (LPAs) produce GeV electron beams in centimeters, using the plasma wave driven by the radiation pressure of an intense laser. Recent LPA experiments are presented which have greatly improved beam quality and efficiency, rendering them appropriate for compact high-quality photon sources based on Thomson scattering. Designs for MeV photon sources utilizing the unique properties of LPAs are presented. It is shown that control of the scattering laser, including plasma guiding, can increase photon production efficiency. This reduces scattering laser size and/or electron beam current requirements to scale compatible with the LPA. Lastly, the plasma structure can decelerate the electron beam after photon production, reducing the size of shielding required for beam disposal. Together, these techniques provide a path to a compact photon source system.

  7. Compact quasi-monoenergetic photon sources from laser-plasma accelerators for nuclear detection and characterization

    Near-monoenergetic photon sources at MeV energies offer improved sensitivity at greatly reduced dose for active interrogation, and new capabilities in treaty verification, nondestructive assay of spent nuclear fuel and emergency response. Thomson (also referred to as Compton) scattering sources are an established method to produce appropriate photon beams. Applications are however restricted by the size of the required high-energy electron linac, scattering (photon production) system, and shielding for disposal of the high energy electron beam. Laser-plasma accelerators (LPAs) produce GeV electron beams in centimeters, using the plasma wave driven by the radiation pressure of an intense laser. Recent LPA experiments are presented which have greatly improved beam quality and efficiency, rendering them appropriate for compact high-quality photon sources based on Thomson scattering. Designs for MeV photon sources utilizing the unique properties of LPAs are presented. It is shown that control of the scattering laser, including plasma guiding, can increase photon production efficiency. This reduces scattering laser size and/or electron beam current requirements to scale compatible with the LPA. Lastly, the plasma structure can decelerate the electron beam after photon production, reducing the size of shielding required for beam disposal. Together, these techniques provide a path to a compact photon source system

  8. High-quality dense laser-accelerated proton beams for hadron cancer therapy

    Simulations based on the coupled relativistic equations of motion show that protons stemming from laser-plasma processes (e.g. target normal sheath acceleration) can be efficiently post-accelerated employing pulsed laser beams in different configurations focused to spot radii on the order of the laser wavelength. We demonstrated earlier (2010) that the laser fields 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 a laser set-up.

  9. Novel design concepts for creating and utilizing intense accelerator based beams of mono-energetic fast neutrons

    The delivered intensity from neutron sources plays a major role in the applicability of neutron techniques. This is particularly true when the application requires mono-energetic neutron beams. Development of such neutron sources depends on two main factors; i) the output ion beam current from the accelerator and, ii) the design of the target system for generating neutrons. The design of an intense monoenergetic neutron source reported in this paper is based on a radio-frequency quadrupole deuteron linac system, coupled to a novel high pressure differentially pumped deuterium gas target. The operation of a working system, capable of generating in excess of 1010 neutrons per second is reported, along with examples of diverse applications. Also discussed are proposed improvements to the design, such that in excess of 1012 neutron per second will be generated. (author)

  10. Stable Laser-Driven Proton Beam Acceleration from a Two-Ion-Species Ultrathin Foil

    By using multidimensional particle-in-cell simulations, we present a new regime of stable proton beam acceleration which takes place when a two-ion-species shaped foil is illuminated by a circularly polarized laser pulse. In the simulations, the lighter protons are nearly instantaneously separated from the heavier carbon ions due to the charge-to-mass ratio difference. The heavy ion layer expands in space and acts to buffer the proton layer from the Rayleigh-Taylor-like (RT) instability that would have otherwise degraded the proton beam acceleration. A simple three-interface model is formulated to explain qualitatively the stable acceleration of the light ions. In the absence of the RT instability, the high quality monoenergetic proton bunch persists even after the laser-foil interaction ends.

  11. ACCELERATING POLARIZED PROTONS TO HIGH ENERGY.

    BAI, M.; AHRENS, L.; ALEKSEEV, I.G.; ALESSI, J.; BEEBE-WANG, J.; BLASKIEWICZ, M.; BRAVAR, A.; BRENNAN, J.M.; BRUNO, D.; BUNCE, G.; ET AL.

    2006-10-02

    The Relativistic Heavy Ion Collider (RHIC) is designed to provide collisions of high energy polarized protons for the quest of understanding the proton spin structure. Polarized proton collisions at a beam energy of 100 GeV have been achieved in RHIC since 2001. Recently, polarized proton beam was accelerated to 250 GeV in RHIC for the first time. Unlike accelerating unpolarized protons, the challenge for achieving high energy polarized protons is to fight the various mechanisms in an accelerator that can lead to partial or total polarization loss due to the interaction of the spin vector with the magnetic fields. We report on the progress of the RHIC polarized proton program. We also present the strategies of how to preserve the polarization through the entire acceleration chain, i.e. a 200 MeV linear accelerator, the Booster, the AGS and RHIC.

  12. Novel design concepts for generating intense accelerator based beams of mono-energetic fast neutrons

    Full text: Successful application of neutron techniques in research, medicine and industry depends on the availability of suitable neutron sources. This is particularly important for techniques that require mono-energetic fast neutrons with well defined energy spread. There are a limited number of nuclear reactions available for neutron production and often the reaction yield is low, particularly for thin targets required for the production of mono-energetic neutron beams. Moreover, desired target materials are often in a gaseous form, such as the reactions D(d,n)3He and T(d,n)3He, requiring innovative design of targets, with sufficient target pressure and particle beam handling capability. Additional requirements, particularly important in industrial applications, and for research institutions with limited funds, are the cost effectiveness as well as small size, coupled with reliable and continuous operation of the system. Neutron sources based on high-power, compact radio-frequency quadrupole (RFQ) linacs can satisfy these criteria, if used with a suitable target system. This paper discusses the characteristics of a deuteron RFQ linear accelerator system coupled to a high pressure differentially pumped deuterium target. Such a source, provides in excess of 1010 mono- energetic neutrons per second with minimal slow neutron and gamma-ray contamination, and is utilised for a variety of applications in the field of mineral identification and materials diagnostics. There is also the possibility of utilising a proposed enhanced system for isotope production. The RFQ linear accelerator consists of: 1) Deuterium 25 keV ion source injector; 2) Two close-coupled RFQ resonators, each powered by an rf amplifier supplying up to 300 kW of peak power at 425 MHz; 3) High energy beam transport system consisting of a beam line, a toroid for beam current monitoring, two steering magnets and a quadrupole triplet for beam focusing. Basic technical specifications of the RFQ linac are

  13. Laser Acceleration of Protons Using Multi-Ion Plasma Gaseous Targets and Its Medical Implications

    Shao, Xi; Liu, Tung-Chang; Liu, Chuan-Sheng; Eliasson, Bengt; Hill, Wendell; Wang, Jyhpyng; Chen, Shih-Hung

    2014-10-01

    We present an acceleration scheme by applying a combination of laser radiation pressure and shielded Coulomb repulsion in laser acceleration of protons in multi-species gaseous targets. By using a circularly polarized CO2 laser pulse with a wavelength of 10 μm, the critical density is significantly reduced, and a high-pressure gaseous target can be used to achieve an overdense plasma. This gives us a larger degree of freedom in selecting the foil compounds or mixtures, as well as their density and thickness profiles. An 80 MeV quasi-monoenergetic proton beam can be generated using a half-sine shaped laser beam with peak power 70 TW and pulse duration of 150 wave periods. We compared the effects of modifying the thickness and density of the gaseous targets and showed that the compression of the gaseous target affects significantly in the quasi-monoenergetic property of the proton beams. To assess the feasibility of laser-proton cancer therapy with such a proton accelerator, simulations are carried out to model the interaction of protons with water and determine the depth and lateral dose distribution for particle beams produced from PIC simulation. Comparison between the dosage maps of the proton beams produced with different foil densities and thicknesses is also presented. This work was supported by US DoE Grant DE-SC0008391.

  14. Effect of target composition on proton acceleration in ultraintense laser-thin foil interaction

    Liu Qingcao; Liu Meng; Ding Pengji; Liu Zuoye; Sun Shaohua; Liu Xiaoliang; Lu Xing; Guo Zeqin; Hu Bitao [School of Nuclear Science and Technology, Lanzhou University, Lanzhou 730000 (China); Yu Tongpu [Department of Physics, National University of Defense Technology, Changsha 410073 (China); Institut fuer Theoretische Physik I, Heinrich-Heine-Universitaet Duesseldorf, 40225 Duesseldorf (Germany)

    2012-09-15

    The interactions of ultraintense circularly polarized laser pulses with a mixed solid target and a double-layer target are studied by two-dimensional particle-in-cell simulations. Different carbon and proton compositions in the targets are used in the simulations. It is shown that the proton acceleration mechanisms in both targets are very sensitive to the ion density ratios between protons and carbon ions. For a mixed solid target, a relatively low proton density gives rise to monoenergetic peaks in the proton energy spectrum while a high proton density leads to a large cut-off energy and wide energy spread. With the increase of the ratio, the so-called directed-Coulomb-explosion becomes dominated over the radiation pressure. Surprisingly, for a double-layer target with a front proton layer and an ultrathin rear carbon layer, a highly monoenergetic proton beam with a peak energy of 1.7 GeV/u, an energy spread of {approx}4%, and a divergency angle of 2 Degree-Sign can be obtained, which might have diverse applications in medical therepy and proton imaging in future.

  15. The proton engineering frontier project: accelerator development

    Since launched in 2002 to establish an advanced research facility to promote and support core R and D programs by utilizing highly-characterized proton beams, the Proton Engineering Frontier Project has been devoted to developing a high-current 100-MeV, 20 mA proton linac. The upstream part of the proton linac, up to 20 MeV, has been successfully developed, integrated, and commissioned and has delivered proton beams to users under a limited operation license. The high-energy part of the accelerator and beamlines are under development. The architectural and radiation shielding design of the accelerator building and beam experimental hall has been completed. The site preparation and construction works are in progress in cooperation with the municipal government of Gyeongju city. When the project is completed in 2012, as scheduled, the proton accelerator facility will be capable of delivering highly-characterized proton beams to multiple users by satisfying their dedicated requirements.

  16. Update on Proton Driven Plasma Wakefield Acceleration

    Xia, G; Lotov, K; Pukhov, A; Kumar, N; An, W; Lu, W; Mori, W B; Joshi, C; Huang, C; Muggli, P; Assmann, R; Zimmermann, F

    2010-01-01

    In this paper, the update of proton driven plasma wakefield acceleration (PDPWA) is given. After a brief introduction to the scheme of PDPWA, a future demonstration experiment is discussed. The particle-in-cell simulation results based on the realistic proton beams from the CERN Super Proton Synchrotron (SPS) are presented, followed by a simulation study of proton bunch compression. Presented at AAC’10, 13-19 June 2010, Annapolis, MD, USA

  17. Shielding of medically used proton accelerators

    In several standards of the standards committee radiology (NRA) the shielding of proton accelerators (cyclotrons) for medical utilization is described. Proton beams can be used in nuclear medicine for PET (proton emission tomography) isotope production or for radiotherapeutic use. The dominating radiation from proton induced nuclear reactions is fast neutron radiation. The calculation procedure for appropriate shielding measures according to the NAR standards is described step-by-step. AN adequate shielding of fast neutrons is also sufficient for the generated gamma radiation.

  18. Beam acceleration through proton radio frequency quadrupole accelerator in BARC

    Bhagwat, P. V.; Krishnagopal, S.; Mathew, J. V.; Singh, S. K.; Jain, P.; Rao, S. V. L. S.; Pande, M.; Kumar, R.; Roychowdhury, P.; Kelwani, H.; Rama Rao, B. V.; Gupta, S. K.; Agarwal, A.; Kukreti, B. M.; Singh, P.

    2016-05-01

    A 3 MeV proton Radio Frequency Quadrupole (RFQ) accelerator has been designed at the Bhabha Atomic Research Centre, Mumbai, India, for the Low Energy High Intensity Proton Accelerator (LEHIPA) programme. The 352 MHz RFQ is built in 4 segments and in the first phase two segments of the LEHIPA RFQ were commissioned, accelerating a 50 keV, 1 mA pulsed proton beam from the ion source, to an energy of 1.24 MeV. The successful operation of the RFQ gave confidence in the physics understanding and technology development that have been achieved, and indicate that the road forward can now be traversed rather more quickly.

  19. Recircular accelerator to proton ocular therapy

    Rabelo, Luisa A.; Campos, Tarcisio P.R., E-mail: luisarabelo88@gmail.com, E-mail: tprcampos@pq.cnpq.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Engenharia Nuclear

    2013-07-01

    Proton therapy has been used for the treatment of Ocular Tumors, showing control in most cases as well as conservation of the eyeball, avoiding the enucleation. The protons provide higher energetic deposition in depth with reduced lateral spread, compared to the beam of photons and electrons, with characteristic dose deposition peak (Bragg peak). This technique requires large particle accelerators hampering the deployment a Proton Therapy Center in some countries due to the need for an investment of millions of dollars. This study is related to a new project of an electromagnetic unit of proton circular accelerator to be coupled to the national radiopharmaceutical production cyclotrons, to attend ocular therapy. This project evaluated physical parameters of proton beam circulating through classical and relativistic mechanical formulations and simulations based on an ion transport code in electromagnetic fields namely CST (Computer Simulation Technology). The structure is differentiated from other circular accelerations (patent CTIT/UFMG NRI research group/UFMG). The results show the feasibility of developing compact proton therapy equipment that works like pre-accelerator or post-accelerator to cyclotrons, satisfying the interval energy of 15 MeV to 64 MeV. Methods of reducing costs of manufacture, installation and operation of this equipment will facilitate the dissemination of the proton treatment in Brazil and consequently advances in fighting cancer. (author)

  20. Acceleration of Flare Protons by Langmuir Plasmons

    李晓卿; 张航

    2002-01-01

    We analytically study the turbulent acceleration of solar protons by strong Langmuir plasmons in Cerenkov processes. It is shown that among the wave spectra with self-retained source only the Pelletier spectrum (Wk ∝ k-7/2) can result in the energy spectrum of non-relativistic protons, which gives a good fit to that observed from solarflare events. It is quite possible that strong Langmuir turbulence presents in coronal active region, with three-dimensional, isotropic and stationary spectrum proportional to k-7/2, and is responsible for the acceleration offlare protons.

  1. Proton-driven plasma acceleration at CERN

    Plasma-based acceleration methods have seen important progress over the last years. Recently, it has been proposed to experimentally study plasma acceleration driven by proton beams, in addition to the established research directions of electron and laser-driven plasmas. This talk presents the planned experiment and the research efforts carried out at CERN.

  2. PROTON ACCELERATION AT OBLIQUE SHOCKS

    Acceleration at the shock waves propagating oblique to the magnetic field is studied using a recently developed theoretical/numerical model. The model assumes that resonant hydromagnetic wave-particle interaction is the most important physical mechanism relevant to motion and acceleration of particles as well as to excitation and damping of waves. The treatment of plasma and waves is self-consistent and time dependent. The model uses conservation laws and resonance conditions to find where waves will be generated or damped, and hence particles will be pitch-angle-scattered. The total distribution is included in the model and neither introduction of separate population of seed particles nor some ad hoc escape rate of accelerated particles is needed. Results of the study show agreement with diffusive shock acceleration models in the prediction of power spectra for accelerated particles in the upstream region. However, they also reveal the presence of spectral break in the high-energy part of the spectra. The role of the second-order Fermi-like acceleration at the initial stage of the acceleration is discussed. The test case used in the paper is based on ISEE-3 data collected for the shock of 1978 November 12.

  3. Proton Acceleration at Oblique Shocks

    Galinsky, V. L.; Shevchenko, V. I.

    2011-06-01

    Acceleration at the shock waves propagating oblique to the magnetic field is studied using a recently developed theoretical/numerical model. The model assumes that resonant hydromagnetic wave-particle interaction is the most important physical mechanism relevant to motion and acceleration of particles as well as to excitation and damping of waves. The treatment of plasma and waves is self-consistent and time dependent. The model uses conservation laws and resonance conditions to find where waves will be generated or damped, and hence particles will be pitch-angle-scattered. The total distribution is included in the model and neither introduction of separate population of seed particles nor some ad hoc escape rate of accelerated particles is needed. Results of the study show agreement with diffusive shock acceleration models in the prediction of power spectra for accelerated particles in the upstream region. However, they also reveal the presence of spectral break in the high-energy part of the spectra. The role of the second-order Fermi-like acceleration at the initial stage of the acceleration is discussed. The test case used in the paper is based on ISEE-3 data collected for the shock of 1978 November 12.

  4. Applications of High Intensity Proton Accelerators

    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

  5. Generation of high-energy monoenergetic heavy ion beams by radiation pressure acceleration of ultra-intense laser pulses

    Wu, Dong; He, X T; McGuffey, C; Beg, F N

    2014-01-01

    A novel radiation pressure acceleration (RPA) regime of heavy ion beams from laser-irradiated ultrathin foils is proposed by self-consistently taking into account the ionization dynamics. In this regime, the laser intensity is required to match with the large ionization energy gap when the successive ionization of high-Z atoms passing the noble gas configurations [such as removing an electron from the helium-like charge state $(\\text{Z}-2)^+$ to $(\\text{Z}-1)^+$]. While the target ions in the laser wing region are ionized to low charge states and undergo rapid dispersions due to instabilities, a self-organized, stable RPA of highly-charged heavy ion beam near the laser axis is achieved. It is also found that a large supplement of electrons produced from ionization helps preserving stable acceleration. Two-dimensional particle-in-cell simulations show that a monoenergetic $\\text{Al}^{13+}$ beam with peak energy $1\\ \\text{GeV}$ and energy spread of $5\\%$ is obtained by lasers at intensity $7\\times10^{20}\\ \\text...

  6. Booster linear accelerators for proton therapy

    Radiotherapy using proton beams of energies of order 200 MeV is now accepted as a feasible cancer treatment technique whose widespread use has so far been limited by the high costs of proposed facilities. AEA Technology have identified a low-cost solution using a linear accelerator to boost existing hospital cyclotrons. The present project status and the design of the booster linear accelerator are discussed. (Author) 4 tabs., 2 figs., 2 refs

  7. Experimental control of the beam properties of laser-accelerated protons and carbon ions

    The laser generation of energetic high quality beams of protons and heavier ions has opened up the door to a plethora of applications. These beams are usually generated by the interaction of a short pulse high power laser with a thin metal foil target. They could already be applied to probe transient phenomena in plasmas and to produce warm dense matter by isochoric heating. Other applications such as the production of radioisotopes and tumour radiotherapy need further research to be put into practice. To meet the requirements of each application, the properties of the laser-accelerated particle beams have to be controlled precisely. In this thesis, experimental means to control the beam properties of laser-accelerated protons and carbon ions are investigated. The production and control of proton and carbon ion beams is studied using advanced ion source designs: Experiments concerning mass-limited (i.e. small and isolated) targets are conducted. These targets have the potential to increase both the number and the energy of laser-accelerated protons. Therefore, the influence of the size of a plane foil target on proton beam properties is measured. Furthermore, carbon ion sources are investigated. Carbon ions are of particular interest in the production of warm dense matter and in cancer radiotherapy. The possibility to focus carbon ion beams is investigated and a simple method for the production of quasi-monoenergetic carbon ion beams is presented. This thesis also provides an insight into the physical processes connected to the production and the control of laser-accelerated ions. For this purpose, laser-accelerated protons are employed to probe plasma phenomena on laser-irradiated targets. Electric fields evolving on the surface of laser-irradiated metal foils and hollow metal foil cylinders are investigated. Since these fields can be used to displace, collimate or focus proton beams, understanding their temporal and spatial evolution is crucial for the design of

  8. Experimental control of the beam properties of laser-accelerated protons and carbon ions

    Amin, Munib

    2008-12-15

    The laser generation of energetic high quality beams of protons and heavier ions has opened up the door to a plethora of applications. These beams are usually generated by the interaction of a short pulse high power laser with a thin metal foil target. They could already be applied to probe transient phenomena in plasmas and to produce warm dense matter by isochoric heating. Other applications such as the production of radioisotopes and tumour radiotherapy need further research to be put into practice. To meet the requirements of each application, the properties of the laser-accelerated particle beams have to be controlled precisely. In this thesis, experimental means to control the beam properties of laser-accelerated protons and carbon ions are investigated. The production and control of proton and carbon ion beams is studied using advanced ion source designs: Experiments concerning mass-limited (i.e. small and isolated) targets are conducted. These targets have the potential to increase both the number and the energy of laser-accelerated protons. Therefore, the influence of the size of a plane foil target on proton beam properties is measured. Furthermore, carbon ion sources are investigated. Carbon ions are of particular interest in the production of warm dense matter and in cancer radiotherapy. The possibility to focus carbon ion beams is investigated and a simple method for the production of quasi-monoenergetic carbon ion beams is presented. This thesis also provides an insight into the physical processes connected to the production and the control of laser-accelerated ions. For this purpose, laser-accelerated protons are employed to probe plasma phenomena on laser-irradiated targets. Electric fields evolving on the surface of laser-irradiated metal foils and hollow metal foil cylinders are investigated. Since these fields can be used to displace, collimate or focus proton beams, understanding their temporal and spatial evolution is crucial for the design of

  9. Detection of laser-accelerated protons

    Real-time (Online) detection of laser-accelerated protons is a challenge for any electronic detector system due to the peculiar time structure (≤ ns) and high intensity (≥107 p/cm2) of the generated ion pulses. Besides considerable saturation effects, problems are expected by an electromagnetic interference pulse (EMP), generated during laser-plasma interaction. In the scope of this work, different detection systems were built-up with regard to specific demands of laser-ion-acceleration at the MPQ ATLAS laser, which allow the quantitative analysis of the generated proton beam. A cell irradiation experiment at the ATLAS laser was accomplished to demonstrate the usability of laser-accelerated protons for radiation therapy. Cells were irradiated with a single shot dose of few Gy for a proton energy of 5 MeV. The following cell analysis required the spatially resolved measurement of the dose distribution. Only radiation-sensitive films were applicable because of the small proton range, although they show significant quenching effects for the used proton energy. This was extensively studied in the 3-200 MeV energy range. A film-based dosimetry protocol for low-energy proton irradiations was developed, making the absolute dose determination in the cell experiment possible. The non-electronic detectors (nuclear track detectors, radiation-sensitive films) are still state of the art in laser-accelerated ion diagnostics, although these detectors only allow a delayed in time (offline) detection. A non-electronic system, based on image plates, was thoroughly characterized and calibrated for ongoing experiments at the ATLAS laser, for the first time. Main objective of this work, though, was the set-up of a real-time detection system, which is urgently required, owing to increasing repetition rate of the laser accelerator (>Hz), to advance the parameter optimisation of the laser-acceleration in an efficient way. Systems based on silicon pixel detectors are applicable for

  10. Detection of laser-accelerated protons

    Reinhardt, Sabine

    2012-08-08

    Real-time (Online) detection of laser-accelerated protons is a challenge for any electronic detector system due to the peculiar time structure ({<=} ns) and high intensity ({>=}10{sup 7} p/cm{sup 2}) of the generated ion pulses. Besides considerable saturation effects, problems are expected by an electromagnetic interference pulse (EMP), generated during laser-plasma interaction. In the scope of this work, different detection systems were built-up with regard to specific demands of laser-ion-acceleration at the MPQ ATLAS laser, which allow the quantitative analysis of the generated proton beam. A cell irradiation experiment at the ATLAS laser was accomplished to demonstrate the usability of laser-accelerated protons for radiation therapy. Cells were irradiated with a single shot dose of few Gy for a proton energy of 5 MeV. The following cell analysis required the spatially resolved measurement of the dose distribution. Only radiation-sensitive films were applicable because of the small proton range, although they show significant quenching effects for the used proton energy. This was extensively studied in the 3-200 MeV energy range. A film-based dosimetry protocol for low-energy proton irradiations was developed, making the absolute dose determination in the cell experiment possible. The non-electronic detectors (nuclear track detectors, radiation-sensitive films) are still state of the art in laser-accelerated ion diagnostics, although these detectors only allow a delayed in time (offline) detection. A non-electronic system, based on image plates, was thoroughly characterized and calibrated for ongoing experiments at the ATLAS laser, for the first time. Main objective of this work, though, was the set-up of a real-time detection system, which is urgently required, owing to increasing repetition rate of the laser accelerator (>Hz), to advance the parameter optimisation of the laser-acceleration in an efficient way. Systems based on silicon pixel detectors are

  11. Proton-driven plasma-wakefield acceleration

    Caldwell, Allen; Pukhov, Alexander; Simon, Frank

    2013-01-01

    Plasmas excited by laser beams or bunches of relativistic electrons have been used to produce electric fields of 10–100 GV m$^{-1}$. This has opened up the possibility of building compact particle accelerators at the gigaelectronvolt scale. However, it is not obvious how to scale these approaches to the energy frontier of particle physics—the teraelectronvolt regime. Here, we introduce the possibility of proton-bunch-driven plasma-wakefield acceleration, and demonstrate through numerical simulations that this energy regime could be reached in a single accelerating stage.

  12. Rf cavity primer for cyclic proton accelerators

    The purpose of this note is to describe the electrical and mechanical properites of particle accelerator rf cavities in a manner which will be useful to physics and engineering graduates entering the accelerator field. The discussion will be limited to proton (or antiproton) synchrotron accelerators or storage rings operating roughly in the range of 20 to 200 MHz. The very high gradient, fixed frequency UHF or microwave devices appropriate for electron machines and the somewhat lower frequency and broader bandwidth devices required for heavy ion accelerators are discussed extensively in other papers in this series. While it is common pratice to employ field calculation programs such as SUPERFISH, URMEL, or MAFIA as design aids in the development of rf cavities, we attempt here to elucidate various of the design parameters commonly dealt with in proton machines through the use of simple standing wave coaxial resonator expressions. In so doing, we treat only standing wave structures. Although low-impedance, moderately broad pass-band travelling wave accelerating systems are used in the CERN SPS, such systems are more commonly found in linacs, and they have not been used widely in large cyclic accelerators. Two appendices providing useful supporting material regarding relativistic particle dynamics and synchrotron motion in cyclic accelerators are added to supplement the text

  13. Rf cavity primer for cyclic proton accelerators

    Griffin, J. E.

    1988-04-01

    The electrical and mechanical properities of particle accelerator rf cavities are described in a manner which will be useful to physics and engineering graduates entering the accelerator field. The discussion is limited to proton (or antiproton) synchrotron accelerators or storage rings operating roughly in the range of 20 to 200 MHz. The very high gradient, fixed frequency UHF or microwave devices appropriate for electron machines and the somewhat lower frequency and broader bandwidth devices required for heavy ion accelerators are discussed extensively in other papers in this series. While it is common practice to employ field calculation programs such as SUPERFISH, URMEL, or MAFIA as design aids in the development of rf cavities, we attempt here to elucidate various of the design parameters commonly dealt with in proton machines through the use of simple standing wave coaxial resonator expressions. In so doing, we treat only standing wave structures. Although low-impedance, moderately broad pass-band travelling wave accelerating systems are used in the CERN SPS, such systems are more commonly found in linacs, and they have not been used widely in large cyclic accelerators. Two appendices providing useful supporting material regarding relativistic particle dynamics and synchrotron motion in cyclic accelerators are added to supplement the text.

  14. Radiotherapy using a laser proton accelerator

    Murakami, Masao; Miyajima, Satoshi; Okazaki, Yoshiko; Sutherland, Kenneth L; Abe, Mitsuyuki; Bulanov, Sergei V; Daido, Hiroyuki; Esirkepov, Timur Zh; Koga, James; Yamagiwa, Mitsuru; Tajima, Toshiki

    2008-01-01

    Laser acceleration promises innovation in particle beam therapy of cancer where an ultra-compact accelerator system for cancer beam therapy can become affordable to a broad range of patients. This is not feasible without the introduction of a technology that is radically different from the conventional accelerator-based approach. The laser acceleration method provides many enhanced capabilities for the radiation oncologist. It reduces the overall system size and weight by more than one order of magnitude. The characteristics of the particle beams (protons) make them suitable for a class of therapy that might not be possible with the conventional accelerator, such as the ease for changing pulse intensity, the focus spread, the pinpointedness, and the dose delivery in general. A compact, uncluttered system allows a PET device to be located in the vicinity of the patient in concert with the compact gantry. The radiation oncologist may be able to irradiate a localized tumor by scanning with a pencil-like particle...

  15. Laser driven proton acceleration and beam shaping

    Sinigardi, Stefano

    2014-01-01

    In the race to obtain protons with higher energies, using more compact systems at the same time, laser-driven plasma accelerators are becoming an interesting possibility. But for now, only beams with extremely broad energy spectra and high divergence have been produced. The driving line of this PhD thesis was the study and design of a compact system to extract a high quality beam out of the initial bunch of protons produced by the interaction of a laser pulse with a thin solid target, usi...

  16. Self-truncated ionization injection and consequent monoenergetic electron bunches in laser wakefield acceleration

    The ionization-induced injection in laser wakefield acceleration has been recently demonstrated to be a promising injection scheme. However, the energy spread controlling in this mechanism remains a challenge because continuous injection in a mixed gas target is usually inevitable. Here, we propose that by use of certain initially unmatched laser pulses, the electron injection can be constrained to the very front region of the mixed gas target, typically in a length of a few hundreds micrometers determined by the laser self-focusing and the wake deformation. As a result, the produced electron beam has narrow energy spread and meanwhile contains tens of pC in charge. Both multidimensional simulations and theoretical analysis illustrate the effectiveness of this scheme

  17. DESIGN CRITERIA OF A PROTON FFAG ACCELERATOR.

    RUGGIERO, A.G.

    2004-10-13

    There are two major issues that are to be confronted in the design of a Fixed-Field Alternating-Gradient (FFAG) accelerator, namely: (1) the stability of motion over the large momentum range needed for the beam acceleration, and (2) the compactness of the trajectories over the same momentum range to limit the dimensions of the magnets. There are a numbers of rules that need to be followed to resolve these issues. In particular, the magnet arrangement in the accelerator lattice and the distribution of the bending and focusing fields are to be set properly in accordance with these rules. In this report they describe four of these rules that ought to be applied for the optimum design of a FFAG accelerator, especially in the case of proton beams.

  18. Polarization measurement of laser-accelerated protons

    Raab, Natascha; Engels, Ralf; Engin, Ilhan; Greven, Patrick; Holler, Astrid; Lehrach, Andreas; Maier, Rudolf [Institut für Kernphysik and Jülich Center for Hadron Physics, Forschungszentrum Jülich, 52425 Jülich (Germany); Büscher, Markus, E-mail: m.buescher@fz-juelich.de [Institut für Kernphysik and Jülich Center for Hadron Physics, Forschungszentrum Jülich, 52425 Jülich (Germany); Peter Grünberg Institut (PGI-6), Forschungszentrum Jülich, 52425 Jülich (Germany); Institute for Laser- and Plasma Physics, Heinrich-Heine Universität Düsseldorf, Universitätsstr. 1, 40225 Düsseldorf (Germany); Cerchez, Mirela; Swantusch, Marco; Toncian, Monika; Toncian, Toma; Willi, Oswald [Institute for Laser- and Plasma Physics, Heinrich-Heine Universität Düsseldorf, Universitätsstr. 1, 40225 Düsseldorf (Germany); Gibbon, Paul; Karmakar, Anupam [Institute for Advanced Simulation, Jülich Supercomputing Centre, Forschungszentrum Jülich, 52425 Jülich (Germany)

    2014-02-15

    We report on the successful use of a laser-driven few-MeV proton source to measure the differential cross section of a hadronic scattering reaction as well as on the measurement and simulation study of polarization observables of the laser-accelerated charged particle beams. These investigations were carried out with thin foil targets, illuminated by 100 TW laser pulses at the Arcturus laser facility; the polarization measurement is based on the spin dependence of hadronic proton scattering off nuclei in a Silicon target. We find proton beam polarizations consistent with zero magnitude which indicates that for these particular laser-target parameters the particle spins are not aligned by the strong magnetic fields inside the laser-generated plasmas.

  19. Acceleration of polarized protons in the AGS

    Tsoupas, N.; Ahrens, L.; Bai, M.; Brown, K.; Courant, E.; Glenn, J.W.; Huang, H.; Luccio, A.; MacKay, W.W.; Roser, T.; Schoefer, V.; Zeno, K.

    2010-02-25

    The high energy (s{sup 1/2} = 500 GeV) polarized proton beam experiments performed in RHIC, require high polarization of the proton beam. With the AGS used as the pre-injector to RHIC, one of the main tasks is to preserve the polarization of the proton beam, during the beam acceleration in the AGS. The polarization preservation is accomplished by the two partial helical magnets [1,2,3,4,5,6,7] which have been installed in AGS, and help overcome the imperfection and the intrinsic spin resonances which occur during the acceleration of protons. This elimination of the intrinsic resonances is accomplished by placing the vertical tune Q{sub y} at a value close to 8.98, within the spin-tune stop-band created by the snake. At this near integer tune the perturbations caused by the partial helical magnets is large resulting in large beta and dispersion waves. To mitigate the adverse effect of the partial helices on the optics of the AGS, we have introduced compensation quads[2] in the AGS. In this paper we present the beam optics of the AGS which ameliorates this effect of the partial helices.

  20. ACCELERATING POLARIZED PROTONS TO 250 GEV

    BAI,M.; AHRENS, L.; ALEKSEEV, I.G.; ALESSI, J.; BEEBE-WANG, J.; ET AL.

    2007-06-25

    The Relativistic Heavy Ion Collider (RHIC) as the first high energy polarized proton collider was designed t o provide polarized proton collisions a t a maximum beam energy of 250 GeV. I t has been providing collisions a t a beam energy of 100 Gel' since 2001. Equipped with two full Siberian snakes in each ring, polarization is preserved during the acceleration from injection to 100 GeV with careful control of the betatron tunes and the vertical orbit distortions. However, the intrinsic spin resonances beyond 100 GeV are about a factor of two stronger than those below 100 GeV? making it important t o examine the impact of these strong intrinsic spin resonances on polarization survival and the tolerance for vertical orbit distortions. Polarized protons were accelerated t o the record energy of 250 GeV in RHIC with a polarization of 46% measured a t top energy in 2006. The polarization measurement as a function of beam energy also shows some polarization loss around 136 GeV, the first strong intrinsic resonance above 100 GeV. This paper presents the results and discusses the sensitivity of the polarization survival t o orbit distortions.

  1. Proton external beam in the TANDAR Accelerator

    An external proton beam has been obtained in the TANDAR accelerator with radiological and biomedical purposes. The protons have excellent physical properties for their use in radiotherapy allowing a very good accuracy in the dose spatial distribution inside the tissue so in the side direction as in depth owing to the presence of Bragg curve. The advantage of the accuracy in the dose localization with proton therapy is good documented (M. Wagner, Med. Phys. 9, 749 (1982); M. Goitein and F. Chen, Med. Phys. 10, 831 (1983); M.R. Raju, Rad. Res. 145, 391 (1996)). It was obtained external proton beams with energies between 15-25 MeV, currents between 2-10 p A and a uniform transversal sections of 40 mm2 approximately. It was realized dosimetric evaluations with CR39 and Makrofol foliation. The irradiations over biological material contained experiences In vivo with laboratory animals, cellular and bacterial crops. It was fixed the optimal conditions of position and immobilization of the Wistar rats breeding for the In vivo studies. It was chosen dilutions and sowing techniques adequate for the exposition at the cellular and bacterial crops beam. (Author)

  2. Injection accelerator for proton therapy system

    We have developed the magnet-free alternating phase focusing (APF) linac for proton cancer therapy facilities. This new linac enhances the reliability and serviceability of such facilities. The newly developed linac uses radio-frequency electric field to accelerate as well as focus a beam of protons (hydrogen nuclei). The electric field is designed with 'sawtooth-shaped phase modulation technology', which can generate high-quality beam. The elimination of magnets has resulted in a simplified linac structure that requires very few adjustments, resulting in improved reliability and serviceability. The system uses a resonant coupler to distribute radio-frequency power, the first such commercial application in the world. The ratio-frequency power supply has been integrated into a single unit, simplifying the structure of the facility. There is no need to adjust the ratio-frequency power phase, for easy servicing. (author)

  3. Relative Biological Effectiveness Variation Along Monoenergetic and Modulated Bragg Peaks of a 62-MeV Therapeutic Proton Beam: A Preclinical Assessment

    Chaudhary, Pankaj; Marshall, Thomas I. [Centre for Cancer Research and Cell Biology, School of Medicine, Dentistry and Biomedical Sciences, Queen' s University Belfast, Belfast (United Kingdom); Perozziello, Francesca M.; Manti, Lorenzo [Department of Physics, University of Naples Federico II and INFN Naples Section University of Naples, Naples (Italy); Currell, Frederick J.; Hanton, Fiona [Centre for Plasma Physics, School of Mathematics and Physics, Queen' s University Belfast, Belfast (United Kingdom); McMahon, Stephen J.; Kavanagh, Joy N. [Centre for Cancer Research and Cell Biology, School of Medicine, Dentistry and Biomedical Sciences, Queen' s University Belfast, Belfast (United Kingdom); Cirrone, Giuseppe Antonio Pablo; Romano, Francesco [Istituto Nazionale di Fisica Nucleare, LNS, Catania (Italy); Prise, Kevin M., E-mail: k.prise@qub.ac.uk [Centre for Cancer Research and Cell Biology, School of Medicine, Dentistry and Biomedical Sciences, Queen' s University Belfast, Belfast (United Kingdom); Schettino, Giuseppe [Centre for Cancer Research and Cell Biology, School of Medicine, Dentistry and Biomedical Sciences, Queen' s University Belfast, Belfast (United Kingdom); National Physical Laboratory, Teddington (United Kingdom)

    2014-09-01

    Purpose: The biological optimization of proton therapy can be achieved only through a detailed evaluation of relative biological effectiveness (RBE) variations along the full range of the Bragg curve. The clinically used RBE value of 1.1 represents a broad average, which disregards the steep rise of linear energy transfer (LET) at the distal end of the spread-out Bragg peak (SOBP). With particular attention to the key endpoint of cell survival, our work presents a comparative investigation of cell killing RBE variations along monoenergetic (pristine) and modulated (SOBP) beams using human normal and radioresistant cells with the aim to investigate the RBE dependence on LET and intrinsic radiosensitvity. Methods and Materials: Human fibroblasts (AG01522) and glioma (U87) cells were irradiated at 6 depth positions along pristine and modulated 62-MeV proton beams at the INFN-LNS (Catania, Italy). Cell killing RBE variations were measured using standard clonogenic assays and were further validated using Monte Carlo simulations and the local effect model (LEM). Results: We observed significant cell killing RBE variations along the proton beam path, particularly in the distal region showing strong dose dependence. Experimental RBE values were in excellent agreement with the LEM predicted values, indicating dose-averaged LET as a suitable predictor of proton biological effectiveness. Data were also used to validate a parameterized RBE model. Conclusions: The predicted biological dose delivered to a tumor region, based on the variable RBE inferred from the data, varies significantly with respect to the clinically used constant RBE of 1.1. The significant RBE increase at the distal end suggests also a potential to enhance optimization of treatment modalities such as LET painting of hypoxic tumors. The study highlights the limitation of adoption of a constant RBE for proton therapy and suggests approaches for fast implementation of RBE models in treatment planning.

  4. Relative Biological Effectiveness Variation Along Monoenergetic and Modulated Bragg Peaks of a 62-MeV Therapeutic Proton Beam: A Preclinical Assessment

    Purpose: The biological optimization of proton therapy can be achieved only through a detailed evaluation of relative biological effectiveness (RBE) variations along the full range of the Bragg curve. The clinically used RBE value of 1.1 represents a broad average, which disregards the steep rise of linear energy transfer (LET) at the distal end of the spread-out Bragg peak (SOBP). With particular attention to the key endpoint of cell survival, our work presents a comparative investigation of cell killing RBE variations along monoenergetic (pristine) and modulated (SOBP) beams using human normal and radioresistant cells with the aim to investigate the RBE dependence on LET and intrinsic radiosensitvity. Methods and Materials: Human fibroblasts (AG01522) and glioma (U87) cells were irradiated at 6 depth positions along pristine and modulated 62-MeV proton beams at the INFN-LNS (Catania, Italy). Cell killing RBE variations were measured using standard clonogenic assays and were further validated using Monte Carlo simulations and the local effect model (LEM). Results: We observed significant cell killing RBE variations along the proton beam path, particularly in the distal region showing strong dose dependence. Experimental RBE values were in excellent agreement with the LEM predicted values, indicating dose-averaged LET as a suitable predictor of proton biological effectiveness. Data were also used to validate a parameterized RBE model. Conclusions: The predicted biological dose delivered to a tumor region, based on the variable RBE inferred from the data, varies significantly with respect to the clinically used constant RBE of 1.1. The significant RBE increase at the distal end suggests also a potential to enhance optimization of treatment modalities such as LET painting of hypoxic tumors. The study highlights the limitation of adoption of a constant RBE for proton therapy and suggests approaches for fast implementation of RBE models in treatment planning

  5. Ultra-High Intensity Proton Accelerators and their Applications

    The science and technology of proton accelerators have progressed considerably in the past three decades. Three to four orders of magnitude increase in both peak intensity and average flux have made it possible to construct high intensity proton accelerators for modern applications, such as: spallation neutron sources, kaon factory, accelerator production of tritium, energy amplifier and muon collider drivers. The accelerator design focus switched over from intensity for synchrotrons, to brightness for colliders to halos for spallation sources. An overview of this tremendous progress in both accelerator science and technology is presented, with special emphasis on the new challenges of accelerator physics issues such as: H(-) injection, halo formation and reduction of losses

  6. Protons Surfatron acceleration by electromagnetic wave in space plasma

    In this work fundamental interactions of type wave-particles are discussed. Main object of the investigation is Surfatron accelerations of the protons by single electromagnetic wave. The Surfatron effect of protons acceleration is investigated through numerical simulations, on the basis of nonlinear, nonstationary, second order differential equation for the wave phase at the charged particle’s trajectory. The temporal dynamics of protons Surfatron acceleration for different variants of the initial parameters are studied. The optimal conditions for maximum ultrarelativistic particles Surfatron acceleration by the electromagnetic wave in space plasma are considered. An analytical approximation for protons energy strong growth was done. Key words: Surfatron acceleration, space plasmas, electromagnetic wave, proton, charge trapping

  7. High energy accelerating structures for high gradient proton linac applications

    The high-energy part of a proton linac, following a drift tube section, accelerates protons and H- ions of energies above 150 MeV. High efficiency and high gradients in the accelerating structure considered for this part of a proton linac are studied. Several known and improved structures working at 1350 MHz were optimized for maximum shunt impedance. The study was performed with the extensive use of a computer code--SUPERFISH. The theoretical results of this study are presented

  8. Organ and effective dose conversion coefficients for a sitting female hybrid computational phantom exposed to monoenergetic protons in idealized irradiation geometries

    The conversion coefficients (CCs) relate protection quantities, mean absorbed dose (DT) and effective dose (E), with physical radiation field quantities, such as fluence (Φ). The calculation of CCs through Monte Carlo simulations is useful for estimating the dose in individuals exposed to radiation. The aim of this work was the calculation of conversion coefficients for absorbed and effective doses per fluence (DT/ Φ and E/Φ) using a sitting and standing female hybrid phantom (UFH/NCI) exposure to monoenergetic protons with energy ranging from 2 MeV to 10 GeV. The radiation transport code MCNPX was used to develop exposure scenarios implementing the female UFH/NCI phantom in sitting and standing postures. Whole-body irradiations were performed using the recommended irradiation geometries by ICRP publication 116 (AP, PA, RLAT, LLAT, ROT and ISO). In most organs, the conversion coefficients DT/Φ were similar for both postures. However, relative differences were significant for organs located in the abdominal region, such as ovaries, uterus and urinary bladder, especially in the AP, RLAT and LLAT geometries. Anatomical differences caused by changing the posture of the female UFH/NCI phantom led an attenuation of incident protons with energies below 150 MeV by the thigh of the phantom in the sitting posture, for the front-to-back irradiation, and by the arms and hands of the phantom in the standing posture, for the lateral irradiation. (paper)

  9. Development of cylindrical type proton-recoil proportional counter and its use for absolute measurements of neutron fluences at 144, 250 and 565 keV monoenergetic calibration fields

    A proton-recoil proportional counter has been developed as a standard instrument for measuring neutron fluence at an accelerator-based neutron calibration field. The counter consists of a cylindrical cathode and an external housing in which hydrogen is filled as counting gas. For neutrons in the energy range between 50 keV and 1 MeV, the fluence of the neutron field can be determined by an absolute measurement with the counter. In designing and manufacturing the counter, careful attention has been paid in order to reduce the uncertainty in measured results. For example, the volume of the effective region of the counter was investigated as accurately as possible. The optimum applied voltage for the counter was examined precisely through the electric field analysis. The developed counter was used for determining the reference neutron fluence of the monoenergetic neutron fields at the Facility of Radiation Standards of JAEA. For the 144, 250 and 565 keV neutron fields, it has been able to measure the fluences with the standard uncertainties less than 2%. The measured fluences for 144 and 565 keV have showed good agreement with the values estimated by another measurements with a transfer instrument traceable to primary standards. (author)

  10. Measurements in quasi-monoenergetic neutron beams at the EC-IRMM Van der Graaf accelerator for calibration of the UAB PADC based neutron dosimeter

    Domingo, C., E-mail: carles.domingo@uab.ca [Grup de Fisica de les Radiacions, Departament de Fisica, Edifici C, Universitat Autonoma de Barcelona, E-08193 Bellaterra (Spain); Garcia-Fuste, M.J.; Amgarou, K.; Morales, E.; Castelo, J. [Grup de Fisica de les Radiacions, Departament de Fisica, Edifici C, Universitat Autonoma de Barcelona, E-08193 Bellaterra (Spain)

    2009-10-15

    The UAB PADC based neutron dosimeter was designed to have similar dose responses for thermal and for fast neutrons. A set of calibrations with ISO neutron sources and the realistic SIGMA neutron field at IRSN Cadarache showed this behaviour. Nevertheless, a noticeable decrease of the response to epithermal neutrons is expected because of the small values of cross sections for neutrons at this energy range. The EC NUDAME program gave the opportunity to expose several units of our dosimeter to quasi-monoenergetic beams at the IRMM Van der Graaf accelerator for calibration purposes. The revision of the IRSN Cadarache values with an improved uncertainty treatment and the results of the calibration at IRMM Van der Graaf, in relation to the reference values of the neutron source term obtained using our Bonner sphere spectrometer, are presented in this work.

  11. Intercomparisons of benchmark calculations for the transmission of quasi-monoenergetic neutrons generated by 43- and 68-MeV protons through iron and concrete shields

    To evaluate calculation codes and the nuclear data in the energy region from 20 MeV to 100 MeV, intercomparisons of benchmark calculations with the MORSE-CG, modified HETC-KFA2 and MCNP4A codes were carried out for the transmission of quasi-monoenergetic neutrons generated by 43- and 68-MeV protons through iron and concrete shields. The comparisons between the calculations and the experiments show that the spectra on the axis of the neutron beam calculated by the MORSE-CG and the MCNP4A codes with the DLC-119/HILO86 and HILO86R are in good agreement with those measured. The spectra calculated for the thin shields by the modified HETC-KFA2 code agree well with those measured, while those for the thick shields are higher than measured ones. The spectra at the off-axis positions calculated by the MORSE-CG code agree well with those measured, though the modified HETC-KFA2 code greatly underestimates the measured spectra. (author)

  12. Large Hadron Collider sets proton-acceleration record

    2009-01-01

    "The Large Hadron Collider, the largest atom smasher in the world, broke the record for proton acceleration Monday, sending beams of the particles at 1.18 trillion electron volts, scientists said" (1 paragraph)

  13. Development of highly efficient proton recoil counter telescope for absolute measurement of neutron fluences in quasi-monoenergetic neutron calibration fields of high energy

    Precise calibration of monitors and dosimeters for use with high energy neutrons necessitates reliable and accurate neutron fluences being evaluated with use of a reference point. A highly efficient Proton Recoil counter Telescope (PRT) to make absolute measurements with use of a reference point was developed to evaluate neutron fluences in quasi-monoenergetic neutron fields. The relatively large design of the PRT componentry and relatively thick, approximately 2 mm, polyethylene converter contributed to high detection efficiency at the reference point over a large irradiation area at a long distance from the target. The polyethylene converter thickness was adjusted to maintain the same carbon density per unit area as the graphite converter for easy background subtraction. The high detection efficiency and thickness adjustment resulted in efficient absolute measurements being made of the neutron fluences of sufficient statistical precision over a short period of time. The neutron detection efficiencies of the PRT were evaluated using MCNPX code at 2.61x10-6, 2.16x10-6 and 1.14x10-6 for the respective neutron peak energies of 45, 60 and 75 MeV. The neutron fluences were determined to have been evaluated at an uncertainty of within 6.5% using analysis of measured data and the detection efficiencies. The PRT was also designed so as to be capable of simultaneously obtaining TOF data. The TOF data also increased the reliability of neutron fluence measurements and provided useful information for use in interpreting the source of proton events.

  14. Status Of The Dielectric Wall Accelerator For Proton Therapy

    The Dielectric Wall Accelerator (DWA) offers the potential to produce a high gradient linear accelerator for proton therapy and other applications. The current status of the DWA for proton therapy will be reviewed. Recent progress in SiC photoconductive switch development will be presented. There are serious beam transport challenges in the DWA arising from short pulse excitation of the wall. Solutions to these transport difficulties will be discussed.

  15. High intensity proton accelerator and its application (Proton Engineering Center)

    A plan called PROTON ENGINEERING CENTER has been proposed in JAERI. The center is a complex composed of research facilities and a beam shape and storage ring based on a proton linac with an energy of 1.5 GeV and an average current of 10 mA. The research facilities planned are OMEGA·Nuclear Energy Development Facility, Neutron Facility for Material Irradiation, Nuclear Data Experiment Facility, Neutron Factory, Meson Factory, Spallation Radioisotope Beam Facility, and Medium Energy Experiment Facility, where high intensity proton beam and secondary particle beams such as neutrons, π-mesons, muons, and unstable isotopes originated from the protons are available for promoting the innovative research of nuclear energy and basic science and technology. (author)

  16. Superpower linear proton accelerator for neutron generator and accelerator-driven system

    The perspectives of development of superpower linear proton accelerators for high-intensive neutron generators and accelerator-driven systems are discussed. The main technical characteristics of the projects on neutron generators based on linear accelerators are presented. These projects are developed in USA, Japan, Italy and Russia. The RFQ structures are used in all projects for the initial acceleration of protons up to 5-7 MeV. The different modifications of drift tubes are applied for acceleration up to 100 MeV. The main acceleration (up to 1 GeV) is supposed to perform in superconducting resonators

  17. Project of compact accelerator for cancer proton therapy

    The status of the sub-projetc 'Compact Accelerator' in the framework of the Hadrontherapy Project leaded by Prof. Amaldi is described. Emphasis is given to the reasons of the use of protons for radiotherapy applications, to the results of the preliminary design studies of four types of accelerators as possible radiotherapy dedicated 'Compact Accelerator' and to the scenario of the fonts of financial resources

  18. Enhanced collimated GeV monoenergetic ion acceleration from a shaped foil target irradiated by a circularly polarized laser pulse

    Chen, M; Yu, T P; Sheng, Z M

    2009-01-01

    Using multi-dimensional particle-in-cell (PIC) simulations we study ion acceleration from a foil irradiated by a circularly polarized laser pulse at 1022W/cm^2 intensity. When the foil is shaped initially in the transverse direction to match the laser intensity profile, the center part of the target can be uniformly accelerated for a longer time compared to a usual flat target. Target deformation and undesirable plasma heating are effectively suppressed. The final energy spectrum of the accelerated ion beam is improved dramatically. Collimated GeV quasi-mono-energetic ion beams carrying as much as 18% of the laser energy are observed in multi-dimensional simulations. Radiation damping effects are also checked in the simulations.

  19. Hybrid proton acceleration scheme using relativistic intense laser light

    Andreev, A. A. [Max-Born-Institute, Berlin D-12489 (Germany); Vavilov State Optical Institute, St. Petersburg 199064 (Russian Federation); Platonov, K. Yu. [Vavilov State Optical Institute, St. Petersburg 199064 (Russian Federation); Schnuerer, M. [Max-Born-Institute, Berlin D-12489 (Germany); Prasad, R. [Institute fuer Laser und Plasma Physik, Heinrich Heine University Duesseldorf D-40225 (Germany); Centre for Plasma Physics, The Queen' s University of Belfast, Belfast BT7 1NN (United Kingdom); Ter-Avetisyan, S. [ELI - Extreme Light Infrastructure, Institute of Physics, 18221 Prague (Czech Republic)

    2013-03-15

    Ion acceleration phenomena at relativistic intense laser interaction with thin foil targets are studied to find an efficient laser-target interaction concept at the conditions, where neither the ponderomotive pressure of the laser light nor the hot electron pressure is negligible. Particle in cell simulations and the analytical model are allowing to predict optimum laser-target parameters and suggesting a significant increase of proton energy if a hybrid proton acceleration scheme is used. In the proposed scenario, the laser polarisation is changed during the acceleration process: First with circularly polarised laser light the target is accelerated as a whole by the ponderamotive pressure, and then with linearly polarised laser light the electrons are heated which additionally increases the accelerating field. The calculations are in good agreement with experimental findings.

  20. Hybrid proton acceleration scheme using relativistic intense laser light

    Ion acceleration phenomena at relativistic intense laser interaction with thin foil targets are studied to find an efficient laser-target interaction concept at the conditions, where neither the ponderomotive pressure of the laser light nor the hot electron pressure is negligible. Particle in cell simulations and the analytical model are allowing to predict optimum laser-target parameters and suggesting a significant increase of proton energy if a hybrid proton acceleration scheme is used. In the proposed scenario, the laser polarisation is changed during the acceleration process: First with circularly polarised laser light the target is accelerated as a whole by the ponderamotive pressure, and then with linearly polarised laser light the electrons are heated which additionally increases the accelerating field. The calculations are in good agreement with experimental findings.

  1. Accelerator physics and technology research toward future multi-MW proton accelerators

    Shiltsev, V; Romanenko, A; Valishev, A; Zwaska, R

    2015-01-01

    Recent P5 report indicated the accelerator-based neutrino and rare decay physics research as a centrepiece 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 accelerator physics and technology research toward future multi-MW proton accelerators.

  2. Particle selection for laser-accelerated proton therapy feasibility study

    In this paper we present calculations for the design of a particle selection system for laser-accelerated proton therapy. Laser-accelerated protons coming from a thin high-density foil have broad energy and angular spectra leading to dose distributions that cannot be directly used for therapeutic applications. Our solution to this problem is a compact particle selection and collimation device that delivers small pencil beams of protons with desired energy spectra. We propose a spectrometer-like particle selection and beam modulation system in which the magnetic field will be used to spread the protons spatially according to their energies and emitting angles. Subsequently, an aperture will be used to select the protons within a therapeutic window of energy (energy modulation). It will be shown that for the effective proton spatial differentiation, the primary collimation device should be used, which will collimate protons to the desired angular distribution and limit the spatial mixing of different energy protons once they have traveled through the magnetic system. Due to the angular proton distribution, the spatial mixing of protons of different energies will always be present and it will result in a proton energy spread with the width depending on the energy. For 250 MeV protons, the width (from the maximum to the minimum energy) is found to be 50 MeV for the magnetic field configuration used in our calculations. As the proton energy decreases, its energy width decreases as well, and for 80 MeV protons it equals 9 MeV. The presence of the energy width in the proton energy distribution will modify the depth dose curves needed for the energy modulation calculation. The matching magnetic field setup will ensure the refocusing of the selected protons and the final beam will be collimated by the secondary collimator. The calculations presented in this article show that the dose rate that the selection system can yield is on the order of D=260 Gy/min for a field size

  3. Proton linear accelerators: A theoretical and historical introduction

    From the beginning, the development of linear accelerators has followed a number of different directions. This report surveys the basic ideas and general principles of such machines, pointing out the problems that have led to the various improvements, with the hope that it may also aid further progress. After a brief historical survey, the principal aspects of accelerator theory are covered in some detail: phase stability, focusing, radio-frequency accelerating structures, the detailed calculation of particle dynamics, and space-charge effects at high intensities. These developments apply essentially to proton and ion accelerators, and only the last chapter deals with a few aspects relative to electrons. 134 refs

  4. Proton linear accelerators: A theoretical and historical introduction

    Lapostolle, P.M.

    1989-07-01

    From the beginning, the development of linear accelerators has followed a number of different directions. This report surveys the basic ideas and general principles of such machines, pointing out the problems that have led to the various improvements, with the hope that it may also aid further progress. After a brief historical survey, the principal aspects of accelerator theory are covered in some detail: phase stability, focusing, radio-frequency accelerating structures, the detailed calculation of particle dynamics, and space-charge effects at high intensities. These developments apply essentially to proton and ion accelerators, and only the last chapter deals with a few aspects relative to electrons. 134 refs.

  5. Simultaneous diagnostics of laser-accelerated protons and electrons

    Pulses of energetic protons with energies of several MeV can be produced by focusing an ultra-short intense laser pulse onto a solid target. The protons stem from the target rear side where they gain energy in an electric field that builds up due to charge separation effects triggered by electrons that are accelerated during the interaction of the laser with the target. In order to investigate the acceleration of protons at solid targets which is expected to be strongly correlated to the properties of the electrons that set up the electric field at the target rear side we have set up a diagnostic which allows for the simultaneous online analysis of the accelerated protons as well as electrons. Here we are going to present first experimental results that have been measured at a table-top Ti:Sapphire laser with a pulse length of 30 fs and a peak intensity exceeding 1021 W/cm2. From these data fundamental parameters can be derived that allow for a testing of theoretical scaling laws for the proton acceleration mechanism.

  6. A proposed experiment on the proton driven plasma wakefield acceleration

    Xia, G; Lotov, K; Pukhov, A; Assmann, R; Zimmermann, F

    2010-01-01

    Simulations have shown that a high energy and intense proton beam can drive a large amplitude plasma wave and accelerate an electron beam to the energy frontier in a single plasma channel. To verify this novel idea, a proof-of-principle demonstration experiment is now being planned. The idea is to use the available high energy proton beams either from the Proton Synchrotron (PS) or the Super Proton Synchrotron (SPS) at CERN, to shoot the beam into a plasma cell and to excite the plasma wakefield. A strong density modulation due to the excited plasma wakefield is produced for a long drive beam and this modulated beam in turn produces a high electric field. The proposed experimental setup is introduced in this paper. The interactions between the plasma and the proton beam are simulated and the results are presented. The compression of an SPS bunch is also discussed.

  7. ELECTRON CLOUD EFFECTS IN HIGH INTENSITY PROTON ACCELERATORS.

    WEI,J.; MACEK,R.J.

    2002-04-14

    One of the primary concerns in the design and operation of high-intensity proton synchrotrons and accumulators is the electron cloud and associated beam loss and instabilities. Electron-cloud effects are observed at high-intensity proton machines like the Los Alamos National Laboratory's PSR and CERN's SPS, and investigated experimentally and theoretically. In the design of next-generation high-intensity proton accelerators like the Spallation Neutron Source ring, emphasis is made in minimizing electron production and in enhancing Landau damping. This paper reviews the present understanding of the electron-cloud effects and presents mitigation measures.

  8. A brief history of high power RF proton linear accelerators

    The first mention of linear acceleration was in a paper by G. Ising in 1924 in which he postulated the acceleration of positive ions induced by spark discharges which produced electric fields in gaps between a series of open-quotes drift tubesclose quotes. Ising apparently was not able to demonstrate his concept, most likely due to the limited state of electronic devices. Ising's work was followed by a seminal paper by R. Wideroe in 1928 in which he demonstrated the first linear accelerator. Wideroe was able to accelerate sodium or potassium ions to 50 keV of energy using drift tubes connected alternately to high frequency waves and to ground. Nuclear physics during this period was interested in accelerating protons, deuterons, electrons and alpha particles and not heavy ions like sodium or potassium. To accelerate the light ions required much higher frequencies than available at that time. So linear accelerators were not pursued heavily at that time. Research continued during the 1930s but the development of high frequency RF tubes for radar applications in World War 2 opened the potential for RF linear accelerators after the war. The Berkeley laboratory of E. 0. Lawrence under the leadership of Luis Alvarez developed a new linear proton accelerator concept that utilized drift tubes that required a full RF period to pass through as compared to the earlier concepts. This development resulted in the historic Berkeley 32 MeV proton linear accelerator which incorporated the open-quotes Alvarez drift tubeclose quotes as the basic acceleration scheme using surplus 200 MHz radar components

  9. Enhancing proton acceleration by using composite targets

    Bulanov, S. S.; Esarey, E.; Schroeder, C. B.; Bulanov, S. V.; Esirkepov, T. Zh.; Kando, M.; Pegoraro, F.; Leemans, W. P.

    2015-07-10

    Efficient laser ion acceleration requires high laser intensities, which can only be obtained by tightly focusing laser radiation. In the radiation pressure acceleration regime, where the tightly focused laser driver leads to the appearance of the fundamental limit for the maximum attainable ion energy, this limit corresponds to the laser pulse group velocity as well as to another limit connected with the transverse expansion of the accelerated foil and consequent onset of the foil transparency. These limits can be relaxed by using composite targets, consisting of a thin foil followed by a near critical density slab. Such targets provide guiding of a laser pulse inside a self-generated channel and background electrons, being snowplowed by the pulse, compensate for the transverse expansion. The use of composite targets results in a significant increase in maximum ion energy, compared to a single foil target case.

  10. High proton energies from cone targets: electron acceleration mechanisms

    Recent experiments in the Trident laser facility (Los Alamos National Laboratory) have shown that hollow conical targets with a flat top at the tip can enhance the maximum energy of proton beams created during the interaction of an ultra-intense short laser pulse with the target (Gaillard S A et al 2011 Phys. Plasmas 18 056710). The proton energies that have been seen in these experiments are the highest energies observed so far in laser-driven proton acceleration. This is attributed to a new acceleration mechanism, direct light pressure acceleration of electrons (DLLPA), which increases the number and energy of hot electrons that drive the proton acceleration. This acceleration process of protons due to a two-temperature sheath formed at the flat-top rear side is very robust and produces a large number of protons per shot, similar to what is regularly observed in target normal sheath acceleration (Hatchett S P et al 2000 Phys. Plasmas 7 2076, Maksimchuk A et al 2000 Phys. Rev. Lett. 84 4108, Snavely R A et al 2000 Phys. Rev. Lett. 85 2945) with flat foils. In this paper, we investigate the electron kinetics during DLLPA, showing that they are governed by two mechanisms, both of which lead to continuous electron acceleration along the inner cone wall. Based on our model, we predict the scaling of the hot electron temperature and ion maximum energy with both laser and target geometrical parameters. The scaling of T=mec02a02/4 with the laser strength parameter a0 leads to an ion energy scaling that surpasses that of some recently proposed acceleration mechanisms such as radiation pressure acceleration (RPA), while in addition the maximum electron energy is found to scale linearly with the length of the cone neck. We find that when optimizing parameters, high proton energies suitable for applications can be reached using compact short-pulse laser systems with pulse durations of only a few tens to hundreds of laser periods. (paper)

  11. Quasi-monoenergetic Electron Beams from Laser-plasma Acceleration by Ionization-induced Injection in Low- density Pure Nitrogen

    Tao, Mengze; Hafz, Nasr A. M.; Li, Song; Mirzaie, Mohammad; Chen, Liming; He, Fei; Cheng, Ya; Jie ZHANG

    2014-01-01

    We report a laser wakefield acceleration of electron beams up to 130 MeV from laser-driven 4-mm long nitrogen gas jet. By using a moderate laser intensity (3.5*10^18 W.cm^(-2)) and relatively low plasma densities (0.8*10^18 cm^(-3) to 2.7*10^18 cm^(-3)) we have achieved a stable regime for laser propagation and consequently a stable generation of electron beams. We experimentally studied the dependence of the drive laser energy on the laser-plasma channel and electron beam parameters. The qua...

  12. Generation of high-energy monoenergetic heavy ion beams by radiation pressure acceleration of ultra-intense laser pulses

    Wu, Dong; Qiao, B.; X. T. He; McGuffey, C.; Beg, F. N.

    2014-01-01

    A novel radiation pressure acceleration (RPA) regime of heavy ion beams from laser-irradiated ultrathin foils is proposed by self-consistently taking into account the ionization dynamics. In this regime, the laser intensity is required to match with the large ionization energy gap when the successive ionization of high-Z atoms passing the noble gas configurations [such as removing an electron from the helium-like charge state $(\\text{Z}-2)^+$ to $(\\text{Z}-1)^+$]. While the target ions in the...

  13. Septum magnet for proton extraction system at the IHEP accelerator

    The paper gives a description of the suptum magnet SM for proton slow extraction from the IHEP synchrotron. The SM excitation coil and magnetic core are assembled outside the accelerator vacuum system. The SM is reliable in operation, can be adjusted with a high accuracy with respect to the accelerated beam, moreover it has a low outgassing in the vacuum under residual gas pressure Up to 1.35 10-8. The SM has operated 8 105 cycles

  14. ISABELLE: A Proposal for Construction of a Proton--Proton Storage Accelerator Facility

    None

    1976-05-01

    The construction of an Intersecting Storage Accelerator Facility (ISA or ISABELLE) at Brookhaven National Laboratory is proposed. ISABELLE will permit the exploration of proton-proton collisions at center-of-mass energies continuously variable from 60 to 400 GeV and with luminosities of 1032 to 1033 cm-2 sec-1 over the entire range. An overview of the physics potential of this machine is given, covering the production of charged and neutral intermediate vector bosons, the hadron production at high transverse momentum, searches for new, massive particles, and the energy dependence of the strong interactions. The facility consists of two interlaced rings of superconducting magnets in a common tunnel about 3 km in circumference. The proton beams will collide at eight intersection regions where particle detectors will be arranged for studying the collision processes. Protons of approximately 30 GeV from the AGS will be accumulated to obtain the design current of 10A prior to acceleration to final energy. The design and performance of existing full-size superconducting dipoles and quadrupoles is described. The conceptual design of the accelerator systems and the conventional structures and buildings is presented. A preliminary cost estimate and construction schedule are given. Possible future options such as proton-antiproton, proton-deuteron and electron-proton collisions are discussed.

  15. Laser-accelerated proton beams as a new particle source

    Nuernberg, Frank

    2010-11-15

    The framework of this thesis is the investigation of the generation of proton beams using high-intensity laser pulses. In this work, an experimental method to fully reconstruct laser-accelerated proton beam parameters, called radiochromic film imaging spectroscopy (RIS), was developed. Since the proton beam expansion is a plasma expansion with accompanying electrons, a low-energy electron spectrometer was developed, built and tested to study the electron distribution matching to the proton beam energy distribution. Two experiments were carried out at the VULCAN Petawatt laser with the aim of showing dynamic control and enhancement of proton acceleration using multiple or defocused laser pulses. Irradiating the target with a long pulse, low-intensity laser (10{sup 12} W/cm{sup 2}) prior to the main pulse ({proportional_to}ns), an optimum pre-plasma density scale length of 60 {mu}m is generated leading to an enhancement of the maximum proton energy ({proportional_to}25%), the proton flux (factor of 3) and the beam uniformity. Proton beams were generated more efficiently than previously by driving thinner target foils at a lower intensity over a large area. The optimum condition was a 2 {mu}m foil irradiated with an intensity of 10{sup 19} W/cm{sup 2} onto a 60 {mu}m spot. Laser to proton beam efficiencies of 7.8% have been achieved (2.2% before) - one of the highest conversion efficiencies ever achieved. In the frame of this work, two separate experiments at the TRIDENT laser system have shown that these laser-accelerated proton beams, with their high number of particles in a short pulse duration, are well-suited for creating isochorically heated matter in extreme conditions. Besides the manipulation of the proton beam parameters directly during the generation, the primary aim of this thesis was the capture, control and transport of laser-accelerated proton beams by a solenoidal magnetic field lense for further purpose. In a joint project proposal, the laser and

  16. Laser-accelerated proton beams as a new particle source

    The framework of this thesis is the investigation of the generation of proton beams using high-intensity laser pulses. In this work, an experimental method to fully reconstruct laser-accelerated proton beam parameters, called radiochromic film imaging spectroscopy (RIS), was developed. Since the proton beam expansion is a plasma expansion with accompanying electrons, a low-energy electron spectrometer was developed, built and tested to study the electron distribution matching to the proton beam energy distribution. Two experiments were carried out at the VULCAN Petawatt laser with the aim of showing dynamic control and enhancement of proton acceleration using multiple or defocused laser pulses. Irradiating the target with a long pulse, low-intensity laser (1012 W/cm2) prior to the main pulse (∝ns), an optimum pre-plasma density scale length of 60 μm is generated leading to an enhancement of the maximum proton energy (∝25%), the proton flux (factor of 3) and the beam uniformity. Proton beams were generated more efficiently than previously by driving thinner target foils at a lower intensity over a large area. The optimum condition was a 2 μm foil irradiated with an intensity of 1019 W/cm2 onto a 60 μm spot. Laser to proton beam efficiencies of 7.8% have been achieved (2.2% before) - one of the highest conversion efficiencies ever achieved. In the frame of this work, two separate experiments at the TRIDENT laser system have shown that these laser-accelerated proton beams, with their high number of particles in a short pulse duration, are well-suited for creating isochorically heated matter in extreme conditions. Besides the manipulation of the proton beam parameters directly during the generation, the primary aim of this thesis was the capture, control and transport of laser-accelerated proton beams by a solenoidal magnetic field lense for further purpose. In a joint project proposal, the laser and plasma physics group of the Technische Universitat Darmstadt

  17. Enhanced proton acceleration in an applied longitudinal magnetic field

    Arefiev, Alexey; Fiksel, Gennady

    2016-01-01

    Using two-dimensional particle-in-cell simulations, we examine how an externally applied strong magnetic impacts proton acceleration in laser-irradiated solid-density targets. We find that a kT-level external magnetic field can sufficiently inhibit transverse transport of hot electrons in a flat laser-irradiated target. While the electron heating by the laser remains mostly unaffected, the reduced electron transport during proton acceleration leads to an enhancement of maximum proton energies and the overall number of energetic protons. The resulting proton beam is much better collimated compared to a beam generated without applying a kT-level magnetic field. A factor of three enhancement of the laser energy conversion efficiency into multi-MeV protons is another effect of the magnetic field. The required kT magnetic fields are becoming feasible due to a significant progress that has been made in generating magnetic fields with laser-driven coils using ns-long laser pulses. The predicted improved characterist...

  18. Construction of the ISTRA-56 proton linear accelerator at ITEP

    The status of the ISTRA-56 proton linear accelerator construction, which is designed for proton energy of 56 MeV, beam current of 150-200 mA in a pulse of 30 ms duration with the pulse frequency of 1 Hz, is described. Results of preliminary adjustment with drift tube mockup are presented. On the basis of the GI-27A valve the generators for the power of up to 3.5 Mw in a pulse of 180 Ms duration are produced. Computerized system of data acquisition and control is being developed. The ISTRA-56 accelerator is designed as a new injector of protons to the ITEP synchrotron. 8 refs.; 5 figs.; 1 tab

  19. The joint project for high-intensity proton accelerators

    NONE

    2000-02-01

    Japan Atomic Energy Research Institute (JAERI) and the High Energy Accelerator Research Organization (KEK) are promoting the joint project integrating both the Neutron Science Project (NSP) of JAERI and the Japan Hadron Facility Project (JHF) of KEK for comprehensive studies on basic science and technology using high-intensity proton accelerator. This document describes the joint project prepared by the Joint Project Team of JAERI and KEK to construct accelerators and research facilities necessary both for the NSP and the JHF at the site of JAERI Tokai Establishment. It was originally written in English and translated into Japanese with some corrections. (author)

  20. The joint project for high-intensity proton accelerators

    NONE

    1999-08-01

    Japan Atomic Energy Research Institute (JAERI) and the High Energy Accelerator Research Organization (KEK) agreed to promote the joint project integrating both the Neutron Science Project (NSP) of JAERI and the Japan Hadron Facility Project (JHF) of KEK for comprehensive studies on basic science and technology using high-intensity proton accelerator. This document describes the joint proposal prepared by the Joint Project Team of JAERI and KEK to construct accelerators and research facilities necessary both for the NSP and the JHF at the site of JAERI Tokai Establishment. (author)

  1. The joint project for high-intensity proton accelerators

    Japan Atomic Energy Research Institute (JAERI) and the High Energy Accelerator Research Organization (KEK) agreed to promote the joint project integrating both the Neutron Science Project (NSP) of JAERI and the Japan Hadron Facility Project (JHF) of KEK for comprehensive studies on basic science and technology using high-intensity proton accelerator. This document describes the joint proposal prepared by the Joint Project Team of JAERI and KEK to construct accelerators and research facilities necessary both for the NSP and the JHF at the site of JAERI Tokai Establishment. (author)

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

    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.

  3. High power proton accelerator for nuclear power plant

    The novel nuclear power system--Energy Amplifier, proposed by C. Rubbia, attracts the interest as a prior option for the development of the next generation nuclear power plant in the first half of the 21st century. The accelerator used to drive the system should provide proton beam power tens higher than that of LAMPF. The accelerator physics and technology have been advancing greatly since LAPMF was built more than 20 years ago. These new progresses become the essential basis for the intense beam accelerator to advance up to a much higher beam power. However, some challenges are still being faced, including beam loss, high efficiency, reliability, as well as some technical issues associated with high power CW operation. The accelerator design options to tackle with the difficulties are discussed. The suggestions on R and D of high power accelerator in China are presented

  4. Laser-Accelerated Proton Beams as a New Particle Source

    Nürnberg, Frank

    2010-01-01

    The framework of this thesis is the investigation of the generation of proton beams using high-intensity laser pulses. Today's high power, ultrashort pulse laser systems are capable of achieving laser intensities up to 10^21 W/cm^2. When focused onto thin foil targets, extremely high field gradients of the order of TV/m are produced on the rear side of the target resulting in the acceleration of protons to multi-MeV energies with an exponential spectrum including up to 10^13 particles. This a...

  5. Laser Proton acceleration from mass limited silicon foils

    Zeil, K.; Kraft, S.; Richter, T.; Metzkes, J.; Bussmann, M.; Schramm, U.; Sauerbrey, R.; Cowan, T. E.; Fuchs, J.; Buffechoux, S.

    2009-11-01

    We present recent studies on laser proton acceleration experiments using mass limited silicon targets. Small micro machined silicon foils with 2 μm thickness and 20x20 μm2 to 100x100μm2 size mounted on very tiny stalks were shot with the 100 TW LULI Laser (long pulse 150 fs) and with the new 150 TW DRACO Laser facility (short pulse 30 fs) of the Research Centre Dresden-Rossendorf. The experiments were carried out using high contrast levels. Proton spectra have been measured with magnetic spectrometers and radio chromic film stacks.

  6. A Proton-Driven Plasma Wakefield Acceleration experiment at CERN

    The AWAKE Collaboration has been formed in order to demonstrate protondriven plasma wakefield acceleration for the first time. This technology could lead to future colliders of high energy but of a much reduced length compared to proposed linear accelerators. The SPS proton beam in the CNGS facility will be injected into a 10m plasma cell where the long proton bunches will be modulated into significantly shorter micro-bunches. These micro-bunches will then initiate a strong wakefield in the plasma with peak fields above 1 GV/m that will be harnessed to accelerate a bunch of electrons from about 20MeV to the GeV scale within a few meters. The experimental program is based on detailed numerical simulations of beam and plasma interactions. The main accelerator components, the experimental area and infrastructure required as well as the plasma cell and the diagnostic equipment are discussed in detail. First protons to the experiment are expected at the end of 2016 and this will be followed by an initial 3–4 yea...

  7. Optimizing laser-driven proton acceleration from overdense targets

    Stockem Novo, A.; Kaluza, M. C.; Fonseca, R. A.; Silva, L. O.

    2016-07-01

    We demonstrate how to tune the main ion acceleration mechanism in laser-plasma interactions to collisionless shock acceleration, thus achieving control over the final ion beam properties (e. g. maximum energy, divergence, number of accelerated ions). We investigate this technique with three-dimensional particle-in-cell simulations and illustrate a possible experimental realisation. The setup consists of an isolated solid density target, which is preheated by a first laser pulse to initiate target expansion, and a second one to trigger acceleration. The timing between the two laser pulses allows to access all ion acceleration regimes, ranging from target normal sheath acceleration, to hole boring and collisionless shock acceleration. We further demonstrate that the most energetic ions are produced by collisionless shock acceleration, if the target density is near-critical, ne ≈ 0.5 ncr. A scaling of the laser power shows that 100 MeV protons may be achieved in the PW range.

  8. Optimizing laser-driven proton acceleration from overdense targets

    Stockem Novo, A.; Kaluza, M. C.; Fonseca, R. A.; Silva, L. O.

    2016-01-01

    We demonstrate how to tune the main ion acceleration mechanism in laser-plasma interactions to collisionless shock acceleration, thus achieving control over the final ion beam properties (e. g. maximum energy, divergence, number of accelerated ions). We investigate this technique with three-dimensional particle-in-cell simulations and illustrate a possible experimental realisation. The setup consists of an isolated solid density target, which is preheated by a first laser pulse to initiate target expansion, and a second one to trigger acceleration. The timing between the two laser pulses allows to access all ion acceleration regimes, ranging from target normal sheath acceleration, to hole boring and collisionless shock acceleration. We further demonstrate that the most energetic ions are produced by collisionless shock acceleration, if the target density is near-critical, ne ≈ 0.5 ncr. A scaling of the laser power shows that 100 MeV protons may be achieved in the PW range. PMID:27435449

  9. Measurement and interpretation of laser accelerated protons at GSI

    This thesis is structured into 7 chapters: - Chapter 2 gives an overview of the ultrashort high intensity laser interaction with matter. The laser interaction with an induced plasma is described, starting from the kinematics of single electron motion, followed by collective electron effects and the ponderamotive motion in the laser focus and the plasma transparency for the laser beam. The three different mechanisms prepared to accelerate and propagate electrons through matter are discussed. The following indirect acceleration of protons is explained by the Target Normal Sheath Acceleration (TNSA) mechanism. Finally some possible applications of laser accelerated protons are explained briefly. - Chapter 3 deals with the modeling of geometry and field mapping of magnetic lens. Initial proton and electron distributions, fitted to PHELIX measured data are generated, a brief description of employed codes and used techniques in simulation is given, and the aberrations at the solenoid focal spot is studied. - Chapter 4 presents a simulation study for suggested corrections to optimize the proton beam as a later beam source. Two tools have been employed in these suggested corrections, an aperture placed at the solenoid focal spot as energy selection tool, and a scattering foil placed in the proton beam to smooth the radial energy beam profile correlation at the focal spot due to chromatic aberrations. Another suggested correction has been investigated, to optimize the beam radius at the focal spot by lens geometry controlling. - Chapter 5 presents a simulation study for the de-neutralization problem in TNSA caused by the fringing fields of pulsed magnetic solenoid and quadrupole. In this simulation, we followed an electrostatic model, where the evolution of both, self and mutual fields through the pulsed magnetic solenoid could be found, which is not the case in the quadrupole and only the growth of self fields could be found. The field mapping of magnetic elements is

  10. Inferring Particle Distribution in a Proton Accelerator Experiment

    Lee, HKH; Sanso, B.; Zhou, W.; Higdon, DM

    2006-01-01

    A beam of protons is produced by a linear charged particle accelerator, then focused through the use of successive quadrupoles. The initial state of the beam is unknown, in terms of particle position and momentum. Wire scans provide the only available data on the current state of the beam as it passes through and beyond the focusing region; the goal is to infer the initial state from these position histograms. This setup is that of an inverse problem, in which a computer simula...

  11. Simulation on Buildup of Electron Cloud in Proton Circular Accelerator

    Liu, Yu-Dong; Li, Kai-Wei

    2014-01-01

    Electron cloud interaction with high energy positive beam are believed responsible for various undesirable effects such as vacuum degradation, collective beam instability and even beam loss in high power proton circular accelerator. An important uncertainty in predicting electron cloud instability lies in the detail processes on the generation and accumulation of the electron cloud. The simulation on the build-up of electron cloud is necessary to further studies on beam instability caused by ...

  12. Superpower proton linear accelerators for neutron generators and electronuclear facilities

    The report is a review of projects on the superpower proton linear accelerators (SPLA) for neutron generators (NG) and electronuclear facilities, proposed in the recent years. The beam average output capacity in these projects reaches 100 MW. The basic parameters of certain operating NGs, as well as some projected NGs will the SPLA drivers are presented. The problems on application of superconducting resonators in the SPLA as well as the issues of the SPLA reliability and costs are discussed

  13. Acceleration of Thermal Protons By Generic Phenomenological Mechanisms

    Petrosian, Vahé

    2016-01-01

    We investigate heating and acceleration of protons from a thermal gas with a generic diffusion and acceleration model, and subject to Coulomb scattering and energy loss, as was carried out in Petrosian & East (2008) for electrons. As protons gain energy their loss to electrons becomes important. Thus, we need to solve the coupled proton-electron kinetic equation. We numerically solve the coupled Fokker-Plank equations and computes the time evolution of the spectra of both particles. We show that this can lead to a quasi-thermal component plus a high energy nonthermal tail. We determine the evolution of nonthermal tail and the quasi-thermal component. The results may be used to explore the possibility of inverse bremsstrahlung radiation as a source of hard X-ray emissions from hot sources such as solar flares, accretion disk coronas and the intracluster medium of galaxy clusters. We find that emergence of nonthermal protons is accompanied by excessive heating of the entire plasma, unless the turbulence nee...

  14. Energy enhancement of proton acceleration in combinational radiation pressure and bubble by optimizing plasma density

    Bake, Muhammad Ali; Xie Baisong [Key Laboratory of Beam Technology and Materials Modification of the Ministry of Education, Beijing Normal University, Beijing 100875 (China); College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China); Shan Zhang [Department of Mathematics and Physics, Shijiazhuang Tiedao University, Shijiazhuang 050043 (China); Hong Xueren [College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China); College of Physics and Electronic Engineering, Northwest Normal University, Lanzhou 730070 (China); Wang Hongyu [Department of Physics, Anshan Normal University, Anshan 114005 (China); Shanghai Bright-Tech Information Technology Co. Ltd, Shanghai 200136 (China)

    2012-08-15

    The combinational laser radiation pressure and plasma bubble fields to accelerate protons are researched through theoretical analysis and numerical simulations. The dephasing length of the accelerated protons bunch in the front of the bubble and the density gradient effect of background plasma on the accelerating phase are analyzed in detail theoretically. The radiation damping effect on the accelerated protons energy is also considered. And it is demonstrated by two-dimensional particle-in-cell simulations that the protons bunch energy can be increased by using the background plasma with negative density gradient. However, radiation damping makes the maximal energy of the accelerated protons a little reduction.

  15. Energy enhancement of proton acceleration in combinational radiation pressure and bubble by optimizing plasma density

    The combinational laser radiation pressure and plasma bubble fields to accelerate protons are researched through theoretical analysis and numerical simulations. The dephasing length of the accelerated protons bunch in the front of the bubble and the density gradient effect of background plasma on the accelerating phase are analyzed in detail theoretically. The radiation damping effect on the accelerated protons energy is also considered. And it is demonstrated by two-dimensional particle-in-cell simulations that the protons bunch energy can be increased by using the background plasma with negative density gradient. However, radiation damping makes the maximal energy of the accelerated protons a little reduction.

  16. Quasi-monoenergetic electron acceleration in relativistic laser-plasmas; Acceleration par laser d'electrons quasi-monoenergetiques dans les plasmas relativistes

    Pukhov, A.; Gordienko, S.; Seredov, V. [Heinrich-Heine-Univ., Institut fur Theoretische Physik I, Dusseldorf (Germany); Kostyukov, I. [Institut for Applied Physics RAS (Russian Federation)

    2009-03-15

    Using Particle-in-Cell simulations as well as analytical theory we study electron acceleration in underdense plasmas both in the Bubble regime and in the weakly relativistic periodic wake fields. In the Bubble regime, electron trapping is taken as a function of the propagated distance. The number of trapped electrons depends on the effective phase velocity of the X-point at the rear of the Bubble. For the weakly relativistic periodic wakes, we show that the phase synchronism between the wake and the relativistic electrons can be maintained over very long distances when the plasma density is tapered properly. Moreover, one can use layered plasmas to control and improve the accelerated beam quality. (authors)

  17. Shock-wave proton acceleration from a hydrogen gas jet

    Cook, Nathan; Pogorelsky, Igor; Polyanskiy, Mikhail; Babzien, Marcus; Tresca, Olivier; Maharjan, Chakra; Shkolnikov, Peter; Yakimenko, Vitaly

    2013-04-01

    Typical laser acceleration experiments probe the interaction of intense linearly-polarized solid state laser pulses with dense metal targets. This interaction generates strong electric fields via Transverse Normal Sheath Acceleration and can accelerate protons to high peak energies but with a large thermal spectrum. Recently, the advancement of high pressure amplified CO2 laser technology has allowed for the creation of intense (10^16 Wcm^2) pulses at λ˜10 μm. These pulses may interact with reproducible, high rep. rate gas jet targets and still produce plasmas of critical density (nc˜10^19 cm-3), leading to the transference of laser energy via radiation pressure. This acceleration mode has the advantage of producing narrow energy spectra while scaling well with pulse intensity. We observe the interaction of an intense CO2 laser pulse with an overdense hydrogen gas jet. Using two pulse optical probing in conjunction with interferometry, we are able to obtain density profiles of the plasma. Proton energy spectra are obtained using a magnetic spectrometer and scintillating screen.

  18. Development of inter-digital-H mode linac for laser-plasma based proton accelerator

    We have proposed a compact proton accelerator which employs a transverse electric field of a laser wakefield and VP x B acceleration mechanism. For proof-of principle experiments of a new compact proton accelerator, the injector including the proton source is needed. We have developed a proton source with energy 30 keV. In order to accelerate protons extracted from the proton source up to 1 MeV, we have been designing IH (Inter-digital-H) linear accelerator as the injector to the final stage of the accelerator using lasers and plasmas. We redesigned and made the accelerator cavity after measuring the characteristics of the prototype made of a brass. In this article, we report the characteristics of accelerator cavity and our future plan. (author)

  19. Laser-Produced and Accelerated High Energy Protons

    Cowan, Thomas

    2005-04-01

    Ultra-low emittance, multi-MeV proton beams have recently been produced by the interaction of high-intensity short-pulse lasers with thin metallic foils [1]. The acceleration process proceeds in two steps. First the laser ponderomotively accelerates huge, MA currents of ˜MeV electrons which propagate through the foil and form a dense relativistic electron sheath on the non-irradiated rear surface. This sheath produces an electrostatic field >10^12 V/m that ionizes the surface atoms almost instantaneously, forming a ˜1 nm thick ion layer which, together with the electron sheath, resembles a virtual cathode. The ions are accelerated initially normal to the foil surface, followed by a diverging plasma expansion phase driven by the electron plasma pressure. By structuring the rear surface of the foil, we have succeeded to produce modulations in the transverse phase space of the ions, which resemble fiducial ``beamlets'' within the envelope of the expanding plasma. This allows one to image the initial accelerating sheath, and map the plasma expansion of the beam envelope, to fully reconstruct the transverse phase space. We find that for protons of 10 MeV, the normalized transverse rms emittance is less than 0.004 π mm.mrad [1], i.e. 100-fold better than typical RF accelerators and at substantially higher ion currents exceeding 10 kA. Recent results will be reported on stripping the electrons while maintaining the low emittance from experiments at the LULI 100 TW laser, and theoretical estimates of the lowest emittance which can be expected based on ion heating mechanisms during the initial sheath formation and ion acceleration processes, will be presented. [1] T.E. Cowan, J. Fuchs, H. Ruhl et al., Phys. Rev. Lett. 92, 204801 (2004).

  20. Accelerator technical design report for high-intensity proton accelerator facility project, J-PARC

    This report presents the detail of the technical design of the accelerators for the High-Intensity Proton Accelerator Facility Project, J-PARC. The accelerator complex comprises a 400-MeV room-temperature linac (600-MeV superconducting linac), 3-GeV rapid-cycling synchrotron (RCS), and a 50-GeV synchrotron (MR). The 400-MeV beam is injected to the RCS, being accelerated to 3 GEV. The 1-MW beam thus produced is guided to the Materials Life Science Experimental Facility, with both the pulsed spallation neutron source and muon source. A part of the beam is transported to the MR, which provides the 0.75-MW beam to either the Nuclear and Fundamental Particle Experimental Facility or the Neutrino Production Target. On the other hand, the beam accelerated to 600 MeV by the superconducting linac is used for the Nuclear Waster Transmutation Experiment. In this way, this facility is unique, being multipurpose one, including many new inventions and Research and Development Results. This report is based upon the accomplishments made by the Accelerator Group and others of the Project Team, which is organized on the basis of the Agreement between JAERI and KEK on the Construction and Research and Development of the High-Intensity Proton Accelerator Facility. (author)

  1. Accelerator technical design report for high-intensity proton accelerator facility project, J-PARC

    NONE

    2003-03-01

    This report presents the detail of the technical design of the accelerators for the High-Intensity Proton Accelerator Facility Project, J-PARC. The accelerator complex comprises a 400-MeV room-temperature linac (600-MeV superconducting linac), 3-GeV rapid-cycling synchrotron (RCS), and a 50-GeV synchrotron (MR). The 400-MeV beam is injected to the RCS, being accelerated to 3 GEV. The 1-MW beam thus produced is guided to the Materials Life Science Experimental Facility, with both the pulsed spallation neutron source and muon source. A part of the beam is transported to the MR, which provides the 0.75-MW beam to either the Nuclear and Fundamental Particle Experimental Facility or the Neutrino Production Target. On the other hand, the beam accelerated to 600 MeV by the superconducting linac is used for the Nuclear Waster Transmutation Experiment. In this way, this facility is unique, being multipurpose one, including many new inventions and Research and Development Results. This report is based upon the accomplishments made by the Accelerator Group and others of the Project Team, which is organized on the basis of the Agreement between JAERI and KEK on the Construction and Research and Development of the High-Intensity Proton Accelerator Facility. (author)

  2. Feasibility of using laser ion accelerators in proton therapy

    Bulanov, S V

    2002-01-01

    The feasibility of using the laser plasma as a source of the high-energy ions for the proton radiation therapy is discussed. The proposal is based on the recent inventions of the effective ions acceleration in the experiments and through numerical modeling of the powerful laser radiation interaction with the gaseous and solid state targets. The principal peculiarity of the dependence of the protons energy losses in the tissues (the Bragg peak of losses) facilities the solution of one of the most important problems of the radiation therapy, which consists in realizing the tumor irradiation by sufficiently high and homogeneous dose with simultaneous minimization of the irradiation level, relative to the healthy and neighbouring tissues and organs

  3. Discovery Mondays "Controlling the accelerators: tracking the protons"

    2007-01-01

    Le Centre de contrôle des accélérateurs du CERN.Like a train of particles that picks up speed every time it passes a set of points, by the time they collide the protons and ions in the LHC will have followed their path through the six stages of the CERN accelerator complex, picking up speed at each stage. Operating the controls of this huge complex designed to accelerate the infinitesimally small are its peerless controllers. From the CERN Control Centre, they will be on duty day and night to accelerate the "wagon-loads" of particles, ensuring that they stay on track and lining them up for head-on collisions. At the next Discovery Monday you will discover the path taken by the particles through the accelerator chain. You will gain an insight into the complex work performed by those controlling the particles and learn more about the CERN accelerator complex and its Control Centre. Hop on board for a speed-of-light tour of the C...

  4. Simplified shielding calculation system for high-intensity proton accelerators

    A simplified shielding calculation system is developed for applying conceptual shielding design of facilities in the joint project for high-intensity proton accelerators. The system is composed of neutron transmission calculation part for bulk shielding using simplified formulas: Moyer model and Tesch's formula, and neutron skyshine calculation part using an empirical formula: Stapleton's formula. The system is made with the Microsoft Excel software for user's convenience. This report provides a manual for the system as well as calculation conditions used in the calculation such as Moyer model's parameters. In this report preliminary results based on data at December 8, 1999, are also shown as an example. (author)

  5. An intense neutron generator based on a proton accelerator

    A study has been made of the demand for a neutron facility with a thermal flux of ≥ 1016 n cm-2 sec-1 and of possible methods of producing such fluxes with existing or presently developing technology. Experimental projects proposed by neutron users requiring high fluxes call for neutrons of all energies from thermal to 100 MeV with both continuous-wave and pulsed output. Consideration of the heat generated in the source per useful neutron liberated shows that the (p,xn) reaction with 400 1000 MeV bombarding energies and heavy element targets (e.g. bismuth, lead) is capable of greater specific source strength than other possible methods realizable within the time scale. A preliminary parameter optimization carried through for the accelerator currently promising greatest economy (the separated orbit cyclotron or S.O.C.), reveals that a facility delivering a proton beam of about 65 mA at about 1 BeV would satisfy the flux requirement with a neutron cost significantly more favourable than that projected for a high flux reactor. It is suggested that a proton storage ring providing post-acceleration pulsing of the proton beam should be developed for the facility. With this elaboration, and by taking advantage of the intrinsic microscopic pulse structure provided by the radio frequency duty cycle, a very versatile source may be devised capable of producing multiple beams of continuous and pulsed neutrons with a wide range of energies and pulse widths. The source promises to be of great value for high flux irradiations and as a pilot facility for advanced reactor technology. The proposed proton accelerator also constitutes a meson source capable of producing beams of π and μ mesons and of neutrinos orders of magnitude more intense than those of any accelerator presently in use. These beams, which can be produced simultaneously with the neutron beams, open vast areas of new research in fundamental nuclear structure, elementary particle physics, and perhaps also in

  6. Technical assessment of the Loma Linda University proton therapy accelerator

    1989-10-01

    In April 1986, officials of Loma Linda University requested that Fermilab design and construct a 250 MeV proton synchrotron for radiotherapy, to be located at the Loma Linda University Medical Center. In June 1986 the project, having received all necessary approvals, commenced. In order to meet a desirable schedule providing for operation in early 1990, it was decided to erect such parts of the accelerator as were complete at Fermilab and conduct a precommissioning activity prior to the completion of the building at Loma Linda which will house the final radiotherapy facility. It was hoped that approximately one year would be saved by the precommissioning, and that important information would be obtained about the system so that improvements could be made during installation at Loma Linda. This report contains an analysis by Fermilab staff members of the information gained in the precommissioning activity and makes recommendations about steps to be taken to enhance the performance of the proton synchrotron at Loma Linda. In the design of the accelerator, effort was made to employ commercially available components, or to industrialize the products developed so that later versions of the accelerator could be produced industrially. The magnets could only be fabricated at Fermilab if the schedule was to be met, but efforts were made to transfer that technology to industry. Originally, it was planned to use a 1.7 MeV RFQ fabricated at the Lawrence Berkeley Laboratory as injector, but LBL would have found it difficult to meet the project schedule. After consideration of other options, for example a 3.4 MeV tandem accelerator, a supplier (AccSys Inc.) qualified itself to provide a 2 MeV RFQ on a schedule well matched to the project schedule. This choice was made, but a separate supplier was selected to develop and provide the 425 MHz power amplifier for the RFQ.

  7. Technical assessment of the Loma Linda University proton therapy accelerator

    In April 1986, officials of Loma Linda University requested that Fermilab design and construct a 250 MeV proton synchrotron for radiotherapy, to be located at the Loma Linda University Medical Center. In June 1986 the project, having received all necessary approvals, commenced. In order to meet a desirable schedule providing for operation in early 1990, it was decided to erect such parts of the accelerator as were complete at Fermilab and conduct a precommissioning activity prior to the completion of the building at Loma Linda which will house the final radiotherapy facility. It was hoped that approximately one year would be saved by the precommissioning, and that important information would be obtained about the system so that improvements could be made during installation at Loma Linda. This report contains an analysis by Fermilab staff members of the information gained in the precommissioning activity and makes recommendations about steps to be taken to enhance the performance of the proton synchrotron at Loma Linda. In the design of the accelerator, effort was made to employ commercially available components, or to industrialize the products developed so that later versions of the accelerator could be produced industrially. The magnets could only be fabricated at Fermilab if the schedule was to be met, but efforts were made to transfer that technology to industry. Originally, it was planned to use a 1.7 MeV RFQ fabricated at the Lawrence Berkeley Laboratory as injector, but LBL would have found it difficult to meet the project schedule. After consideration of other options, for example a 3.4 MeV tandem accelerator, a supplier (AccSys Inc.) qualified itself to provide a 2 MeV RFQ on a schedule well matched to the project schedule. This choice was made, but a separate supplier was selected to develop and provide the 425 MHz power amplifier for the RFQ

  8. Experiments on iron shield transmission of quasi-monoenergetic neutrons generated by 43- and 68-MeV protons via the 7Li(p,n) reaction

    In order to provide benchmark data of neutrons transmitted through iron shields in the intermediate-energy region, spatial distributions of neutron energy spectra and reaction rates behind and inside the iron shields of thickness up to 130 cm were measured for 43- and 68-MeVp-7Li neutrons using a quasi-monoenergetic neutron beam source at the 90-MV AVF cyclotron facility of the TLARA facility in JAERI. The measured data by five kinds of detectors: the BC501A detector, the Bonner ball counter, 238U and 232Th fission counters, 7LiF and natLiF TLDs and solid state nuclear track detector, are numerically provided in this report in the energy region between 10-4 eV and the energy of peak neutrons generated by the 7Li(p,n) reaction. (author)

  9. Experiments on iron shield transmission of quasi-monoenergetic neutrons generated by 43- and 68-MeV protons via the {sup 7}Li(p,n) reaction

    Nakashima, Hiroshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Tanaka, Shun-ichi; Nakao, Noriaki [and others

    1996-03-01

    In order to provide benchmark data of neutrons transmitted through iron shields in the intermediate-energy region, spatial distributions of neutron energy spectra and reaction rates behind and inside the iron shields of thickness up to 130 cm were measured for 43- and 68-MeVp-{sup 7}Li neutrons using a quasi-monoenergetic neutron beam source at the 90-MV AVF cyclotron facility of the TLARA facility in JAERI. The measured data by five kinds of detectors: the BC501A detector, the Bonner ball counter, {sup 238}U and {sup 232}Th fission counters, {sup 7}LiF and {sup nat}LiF TLDs and solid state nuclear track detector, are numerically provided in this report in the energy region between 10{sup -4} eV and the energy of peak neutrons generated by the {sup 7}Li(p,n) reaction. (author).

  10. Design of time control system of high current proton linear accelerator

    The high current proton linear accelerator with high duty ratio will be used in accelerator driven sub-critical system. Time control system of high current proton linear accelerator is introduced. During accelerator operation, the system provides necessary trigger and clock signal. Accuracy and stability of the system has important implications for operation of the linear accelerator. Design of serial communication hardware based on ALTERA company cyclone Ⅲ FPGA, programming of serial communication drivers and functional modules, and implement of human-computer interface based on LabVIEW are realized. The testing results show that the whole system meets requirements of time control system of the high current proton accelerator. (authors)

  11. Construction Management for Conventional Facilities of Proton Accelerator

    Proton Engineering Frontier Project, puts its aim to building 100MeV 20mA linear proton accelerator which is national facility for NT, BT, IT, and future technologies, expected to boost up the national industry competitiveness. This R and D, Construction Management is in charge of the supportive works such as site selection, architecture and engineering of conventional facilities, and overall construction management. The major goals of this work are as follows: At first, architecture and engineering of conventional facilities. Second, construction management, supervision and inspection on construction of conventional facilities. Lastly, cooperation with the project host organization, Gyeongju city, for adjusting technically interrelated work during construction. In this research, We completed the basic, detail, and field changed design of conventional facilities. Acquisition of necessary construction and atomic license, radiation safety analysis, site improvement, access road construction were successfully done as well. Also, we participated in the project host related work as follows: Project host organization and site selection, construction technical work for project host organization and procedure management, etc. Consequently, we so fulfilled all of the own goals which were set up in the beginning of this construction project that we could made contribution for installing and running PEFP's developed 100MeV 20mA linear accelerator

  12. Report of the Fixed-Target Proton-Accelerator Group

    The fixed target proton accelerator group divided itself into two roughly equal parts. One sub-group concentrated on a high intensity (1014 protons/sec) moderate energy (30 GeV) machine while the other worked on a moderate intensity (5 x 1011 protons/sec) very high energy (20 TeV) machine. For experiments where the total available energy is adequate, the fixed target option added to a anti p p 20 TeV collider ring has several attractive features: (1) high luminosity afforded by intense beams striking thick solid targets; (2) secondary beams of hadrons, photons, and leptons; and (3) the versatility of a fixed target facility, where many experiments can be performed independently. The proposed experiments considered by the subgroup, including neutrino, photon, hadron, and very short lived particle beams were based both on scaled up versions of similar experiments proposed for Tevatron II at Fermilab and on the 400 GeV fixed target programs at Fermilab and CERN

  13. The JHP 200-MeV proton linear accelerator

    Kato, Takao [National Lab. for High Energy Physics, Tsukuba, Ibaraki (Japan)

    1997-11-01

    A 200-MeV proton linear accelerator for the Japanese Hadron Project (JHP) has been designed. It consists of a 3-MeV radio-frequency quadrupole linac (RFQ), a 50-MeV drift tube linac (DTL) and a 200-MeV separated-type drift tube linac (SDTL). A frequency of 324 MHz has been chosen for all of the rf structures. A peak current of 30 mA (H{sup -} ions) of 400 {mu}sec pulse duration will be accelerated at a repetition rate of 25 Hz. A future upgrade plan up to 400 MeV is also presented, in which annular-coupled structures (ACS) of 972 MHz are used in an energy range of above 150 or 200 MeV. One of the design features is its high performance for a beam-loss problem during acceleration. It can be achieved by separating the transition point in the transverse motion from that of the longitudinal motion. The transverse transition at a rather low-energy range decreases the effects of space-charge, while the longitudinal transition at a rather high-energy range decreases the effects of nonlinear problems related to acceleration in the ACS. Coupled envelope equations and equipartitioning theory are used for the focusing design. The adoption of the SDTL structure improves both the effective shunt impedance and difficulties in fabricating drift tubes with focusing magnets. An accurate beam-simulation code on a parallel supercomputer was used for confirming any beam-loss problem during acceleration. (author)

  14. Acceleration of petaelectronvolt protons in the Galactic Centre

    HESS Collaboration; Abramowski, A.; Aharonian, F.; Benkhali, F. Ait; Akhperjanian, A. G.; Angüner, E. O.; Backes, M.; Balzer, A.; Becherini, Y.; Tjus, J. Becker; Berge, D.; Bernhard, S.; Bernlöhr, K.; Birsin, E.; Blackwell, R.; Böttcher, M.; Boisson, C.; Bolmont, J.; Bordas, P.; Bregeon, J.; Brun, F.; Brun, P.; Bryan, M.; Bulik, T.; Carr, J.; Casanova, S.; Chakraborty, N.; Chalme-Calvet, R.; Chaves, R. C. G.; Chen, A.; Chrétien, M.; Colafrancesco, S.; Cologna, G.; Conrad, J.; Couturier, C.; Cui, Y.; Davids, I. D.; Degrange, B.; Deil, C.; Dewilt, P.; Djannati-Ataï, A.; Domainko, W.; Donath, A.; Drury, L. O'C.; Dubus, G.; Dutson, K.; Dyks, J.; Dyrda, M.; Edwards, T.; Egberts, K.; Eger, P.; Ernenwein, J.-P.; Espigat, P.; Farnier, C.; Fegan, S.; Feinstein, F.; Fernandes, M. V.; Fernandez, D.; Fiasson, A.; Fontaine, G.; Förster, A.; Füßling, M.; Gabici, S.; Gajdus, M.; Gallant, Y. A.; Garrigoux, T.; Giavitto, G.; Giebels, B.; Glicenstein, J. F.; Gottschall, D.; Goyal, A.; Grondin, M.-H.; Grudzińska, M.; Hadasch, D.; Häffner, S.; Hahn, J.; Hawkes, J.; Heinzelmann, G.; Henri, G.; Hermann, G.; Hervet, O.; Hillert, A.; Hinton, J. A.; Hofmann, W.; Hofverberg, P.; Hoischen, C.; Holler, M.; Horns, D.; Ivascenko, A.; Jacholkowska, A.; Jamrozy, M.; Janiak, M.; Jankowsky, F.; Jung-Richardt, I.; Kastendieck, M. A.; Katarzyński, K.; Katz, U.; Kerszberg, D.; Khélifi, B.; Kieffer, M.; Klepser, S.; Klochkov, D.; Kluźniak, W.; Kolitzus, D.; Komin, Nu.; Kosack, K.; Krakau, S.; Krayzel, F.; Krüger, P. P.; Laffon, H.; Lamanna, G.; Lau, J.; Lefaucheur, J.; Lefranc, V.; Lemiére, A.; Lemoine-Goumard, M.; Lenain, J.-P.; Lohse, T.; Lopatin, A.; Lu, C.-C.; Lui, R.; Marandon, V.; Marcowith, A.; Mariaud, C.; Marx, R.; Maurin, G.; Maxted, N.; Mayer, M.; Meintjes, P. J.; Menzler, U.; Meyer, M.; Mitchell, A. M. W.; Moderski, R.; Mohamed, M.; Morå, K.; Moulin, E.; Murach, T.; de Naurois, M.; Niemiec, J.; Oakes, L.; Odaka, H.; Öttl, S.; Ohm, S.; Opitz, B.; Ostrowski, M.; Oya, I.; Panter, M.; Parsons, R. D.; Arribas, M. Paz; Pekeur, N. W.; Pelletier, G.; Petrucci, P.-O.; Peyaud, B.; Pita, S.; Poon, H.; Prokoph, H.; Pühlhofer, G.; Punch, M.; Quirrenbach, A.; Raab, S.; Reichardt, I.; Reimer, A.; Reimer, O.; Renaud, M.; de Los Reyes, R.; Rieger, F.; Romoli, C.; Rosier-Lees, S.; Rowell, G.; Rudak, B.; Rulten, C. B.; Sahakian, V.; Salek, D.; Sanchez, D. A.; Santangelo, A.; Sasaki, M.; Schlickeiser, R.; Schüssler, F.; Schulz, A.; Schwanke, U.; Schwemmer, S.; Seyffert, A. S.; Simoni, R.; Sol, H.; Spanier, F.; Spengler, G.; Spies, F.; Stawarz, Ł.; Steenkamp, R.; Stegmann, C.; Stinzing, F.; Stycz, K.; Sushch, I.; Tavernet, J.-P.; Tavernier, T.; Taylor, A. M.; Terrier, R.; Tluczykont, M.; Trichard, C.; Tuffs, R.; Valerius, K.; van der Walt, J.; van Eldik, C.; van Soelen, B.; Vasileiadis, G.; Veh, J.; Venter, C.; Viana, A.; Vincent, P.; Vink, J.; Voisin, F.; Völk, H. J.; Vuillaume, T.; Wagner, S. J.; Wagner, P.; Wagner, R. M.; Weidinger, M.; Weitzel, Q.; White, R.; Wierzcholska, A.; Willmann, P.; Wörnlein, A.; Wouters, D.; Yang, R.; Zabalza, V.; Zaborov, D.; Zacharias, M.; Zdziarski, A. A.; Zech, A.; Zefi, F.; Żywucka, N.

    2016-03-01

    Galactic cosmic rays reach energies of at least a few petaelectronvolts (of the order of 1015 electronvolts). This implies that our Galaxy contains petaelectronvolt accelerators (‘PeVatrons’), but all proposed models of Galactic cosmic-ray accelerators encounter difficulties at exactly these energies. Dozens of Galactic accelerators capable of accelerating particles to energies of tens of teraelectronvolts (of the order of 1013 electronvolts) were inferred from recent γ-ray observations. However, none of the currently known accelerators—not even the handful of shell-type supernova remnants commonly believed to supply most Galactic cosmic rays—has shown the characteristic tracers of petaelectronvolt particles, namely, power-law spectra of γ-rays extending without a cut-off or a spectral break to tens of teraelectronvolts. Here we report deep γ-ray observations with arcminute angular resolution of the region surrounding the Galactic Centre, which show the expected tracer of the presence of petaelectronvolt protons within the central 10 parsecs of the Galaxy. We propose that the supermassive black hole Sagittarius A* is linked to this PeVatron. Sagittarius A* went through active phases in the past, as demonstrated by X-ray outburstsand an outflow from the Galactic Centre. Although its current rate of particle acceleration is not sufficient to provide a substantial contribution to Galactic cosmic rays, Sagittarius A* could have plausibly been more active over the last 106-107 years, and therefore should be considered as a viable alternative to supernova remnants as a source of petaelectronvolt Galactic cosmic rays.

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

    Galow, Benjamin J; Keitel, Christoph H

    2010-01-01

    Simulations based on the coupled relativistic equations of motion show that protons stemming from laserplasma processes can be efficiently post-accelerated employing 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.

  16. Proton external beam in the TANDAR Accelerator; Haz externo de protones en el acelerador TANDAR

    Rey, R.; Schuff, J.A.; Perez de la Hoz, A.; Debray, M.E.; Hojman, D.; Kreiner, A.J.; Kesque, J.M.; Saint-Martin, G.; Oppezzo, O.; Bernaola, O.A.; Molinari, B.L.; Duran, H.A.; Policastro, L.; Palmieri, M.; Ibanez, J.; Stoliar, P.; Mazal, A.; Caraballo, M.E.; Burlon, A.; Cardona, M.A.; Vazquez, M.E.; Salfity, M.F.; Ozafran, M.J.; Naab, F.; Levinton, G.; Davidson, M.; Buhler, M. [Departamento de Fisica, Comision Nacional de Energia Atomica, Av. Gral. Paz 1499, C.P. 1650 San Martin, Buenos Aires (Argentina)

    1998-12-31

    An external proton beam has been obtained in the TANDAR accelerator with radiological and biomedical purposes. The protons have excellent physical properties for their use in radiotherapy allowing a very good accuracy in the dose spatial distribution inside the tissue so in the side direction as in depth owing to the presence of Bragg curve. The advantage of the accuracy in the dose localization with proton therapy is good documented (M. Wagner, Med. Phys. 9, 749 (1982); M. Goitein and F. Chen, Med. Phys. 10, 831 (1983); M.R. Raju, Rad. Res. 145, 391 (1996)). It was obtained external proton beams with energies between 15-25 MeV, currents between 2-10 p A and a uniform transversal sections of 40 mm{sup 2} approximately. It was realized dosimetric evaluations with CR39 and Makrofol foliation. The irradiations over biological material contained experiences In vivo with laboratory animals, cellular and bacterial crops. It was fixed the optimal conditions of position and immobilization of the Wistar rats breeding for the In vivo studies. It was chosen dilutions and sowing techniques adequate for the exposition at the cellular and bacterial crops beam. (Author)

  17. Probing proton acceleration in W51C with MAGIC

    Reichardt, I.; Carmona, E.; Krause, J.; MAGIC Collaboration

    Located in a dense complex environment, W51C provides an excellent scenario to probe accelerated protons in SNRs and their interaction with surrounding target material. Here we report the observation of extended Very High Energy (VHE) gamma-ray emission from the W51C supernova remnant (SNR) with MAGIC. The VHE observations presented here, obtained with the improved MAGIC stereo system, allow us to pinpoint the VHE gamma-ray emission in the dense shocked molecular cloud surrounding the remnant shell. MAGIC data also allow us to measure, for the first time, the VHE emission spectrum of W51C from the highest Fermi energies up to several TeV. The spatial distribution and spectral properties of the VHE emission suggest a main contribution of hadronic origin of the observed gamma-rays.

  18. Laser-driven proton acceleration enhancement by nanostructured foils

    Margarone, Daniele; Klimo, Ondřej; Kim, I.J.; Prokůpek, Jan; Limpouch, Jiří; Jeong, T.M.; Mocek, Tomáš; Pšikal, Jan; Kim, H. T.; Proška, J.; Nam, K.H.; Štolcová, Lucie; Choi, I.W.; Lee, S.K.; Sung, J.H.; Yu, T.J.; Korn, Georg

    2012-01-01

    Roč. 109, č. 23 (2012), "234801-1"-"234801-5". ISSN 0031-9007 R&D Projects: GA MŠk ED1.1.00/02.0061; GA ČR(CZ) GAP205/11/1165; GA MŠk ED2.1.00/01.0027; GA MŠk EE.2.3.20.0087 Grant ostatní: ELI Beamlines(XE) CZ.1.05/1.1.00/02.0061; HILASE(XE) CZ.1.05/2.1.00/01.0027; OP VK 2 LaserGen(XE) CZ.1.07/2.3.00/20.0087; Laserlab-Europe III(XE) 284464; AVČR(CZ) M100101210 Institutional support: RVO:68378271 Keywords : proton acceleration * laser-nanosphere interaction Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 7.943, year: 2012 http://prl.aps.org/abstract/PRL/v109/i23/e234801

  19. Protons energy loss for laser fusion driven ion acceleration

    Complete text of publication follows. The anomalous generation of plasma blocks by interaction of petawatt-picosecond laser pulses permits side-on ignition of uncompressed solid fusion fuel following an improved application of the hydrodynamic Chu-model for deuterium-tritium. The new possibility of side-on laser ignition depends on accelerated ions and produced ions beams of high energy particles by the nonlinear ponderomotive force of the laser pulse in the plasma block, a re-evolution of the early hydrodynamic analysis for ignition of inertial fusion by including inhibition factor, collective effect of stopping power of alpha particles and the energy loss rate reabsorb to plasma by the protons of plasma block being reduced by about a factor 40.

  20. Static Var Compensator for CERN's Proton Synchrotron Particle Accelerator

    Kahle, K

    2004-01-01

    The following paper summarises the design studies for a new 85Mvar 18kV Static Var Compensator (SVC) for CERN’s Proton Synchrotron (PS) accelerator. Currently, the PS is supplied using a rotating motor-generator set in order to decouple the pulsating load from the electrical network. A study is undertaken to investigate the replacement of this rotating machine by an SVC. The proposed solution comprises a 85Mvar Thyristor Controlled Reactor and seven harmonic filters with a total power of 75Mvar. The paper gives a detailed description of the project background, system design and control strategy. Finally, the results of the computer studies are presented, showing the expected dynamic performance of the SVC.

  1. New frontier of laser particle acceleration: driving protons to 80 MeV by radiation pressure

    Kim, I Jong; Kim, Chul Min; Kim, Hyung Taek; Lee, Chang-Lyoul; Choi, Il Woo; Singhal, Himanshu; Sung, Jae Hee; Lee, Seong Ku; Lee, Hwang Woon; Nickles, Peter V; Jeong, Tae Moon; Nam, Chang Hee

    2014-01-01

    The radiation pressure acceleration (RPA) of charged particles has been considered a challenging task in laser particle acceleration. Laser-driven proton/ion acceleration has attracted considerable interests due to its underlying physics and potential for applications such as high-energy density physics, ultrafast radiography, and cancer therapy. Among critical issues to overcome the biggest challenge is to produce energetic protons using an efficient acceleration mechanism. The proton acceleration by radiation pressure is considerably more efficient than the conventional target normal sheath acceleration driven by expanding hot electrons. Here we report the generation of 80-MeV proton beams achieved by applying 30-fs circularly polarized laser pulses with an intensity of 6.1 x 1020 W/cm2 to ultrathin targets. The radiation pressure acceleration was confirmed from the obtained optimal target thickness, quadratic energy scaling, polarization dependence, and 3D-PIC simulations. We expect this fast energy scalin...

  2. Proton acceleration by RF TE{sub 11} mode in a cylindrical cavity

    Sobajima, Masaaki; Yoshikawa, Kiyoshi; Ohnishi, Masami; Yamamoto, Yasushi; Masuda, Kai [Kyoto Univ., Uji (Japan). Inst. of Advanced Energy

    1997-03-01

    We found that protons are accelerated significantly by RF TE{sub 11} mode in a cylindrical cavity. In this method, protons get the perpendicular kinetic energy, so we thought it might be a compact accelerator, and studied the feasibility by numerical simulation. (author)

  3. Laser-driven proton acceleration and applications: recent results

    Borghesi, M.; Cecchetti, C.A.; Romagnani, L.; Kar, S.; Quinn, K.; Ramakrishna, B.; Wilson, P.A. [Belfast Queens Univ., School of Mathematics and Physics, Northern, Ireland (United Kingdom); Toncian, T.; Pipahl, A.; Jung, R.; Amin, M.; Willi, O. [Dusseldorf Heinrich Heine Univ., Institute for Laser and Plasma Physics (Germany); Fuchs, J.; Antici, P.; Audebert, P.; Brambrink, E. [LULI, UMR 7605 CNRS-CEA-Ecole Polytechnique-Univ., 91 - Palaiseau (France); Clarke, R.J.; Notley, M.; Mora, P.; Grismayer, T. [Central Laser Facility, STFC Rutherford Appleton Laboratory (RAL), Didcot (United Kingdom); D' Humieres, E. [Centre de Physique Theorique, Ecole Polytechnique, CNRS, 91 - Palaiseau (France); Sentoku, Y. [University of Nevada, Physics Dept., Reno, Nevada (United States)

    2009-08-15

    The acceleration of high-energy ion beams following the interaction of short (t < 1 ps) and intense (I{lambda}{sup 2} > 10{sup 18} W cm{sup -2}*{mu}m{sup 2}) laser pulses with solid targets is a field of research currently attracting high interest in the scientific community, due to some of the unique properties of these ion sources, promising routes toward the optimization of their energy content, and a number of possible, innovative applications in the scientific, technological and medical areas. Work on the characterization and development of these sources has progressed enormously over the past few years, thanks to the contribution of many groups worldwide. This paper will report some recent results, obtained in experiments carried out at the RAL and LULI laboratories, in which we investigated the ion acceleration mechanism, developed a technique to control the ion beam divergence and energy spectrum, and applied a proton radiography technique to investigate electric and magnetic field production following laser-matter interaction. (authors)

  4. Beam Loss Calibration Studies for High Energy Proton Accelerators

    Stockner, M

    2007-01-01

    CERN's Large Hadron Collider (LHC) is a proton collider with injection energy of 450 GeV and collision energy of 7 TeV. Superconducting magnets keep the particles circulating in two counter rotating beams, which cross each other at the Interaction Points (IP). Those complex magnets have been designed to contain both beams in one yoke within a cryostat. An unprecedented amount of energy will be stored in the circulating beams and in the magnet system. The LHC outperforms other existing accelerators in its maximum beam energy by a factor of 7 and in its beam intensity by a factor of 23. Even a loss of a small fraction of the beam particles may cause the transition from the superconducting to the normal conducting state of the coil or cause physical damage to machine components. The unique combination of these extreme beam parameters and the highly advanced superconducting technology has the consequence that the LHC needs a more efficient beam cleaning and beam loss measurement system than previous accelerators....

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

    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

  6. On the possibility for precision measurements of differential cross sections for elastic proton-proton scattering at the Protvino accelerator

    Denisov, S. P.; Kozelov, A. V.; Petrov, V. A.

    2016-03-01

    Elastic-scattering data were analyzed, and it was concluded on the basis of this analysis that precisionmeasurements of differential cross sections for elastic proton-proton scattering at the accelerator of the Institute for High Energy Physics (IHEP, Protvino, Russia) over a broad momentum-transfer range are of importance and topical interest. The layout of the respective experimental facility detecting the scattered particle and recoil proton and possessing a high momentum-transfer resolution was examined along with the equipment constituting this facility. The facility in question is able to record up to a billion events of elastic proton-proton scattering per IHEP accelerator run (20 days). Other lines of physics research with this facility are briefly discussed.

  7. Increased laser-accelerated proton energies via direct laser-light-pressure acceleration of electrons in microcone targets

    We present experimental results showing a laser-accelerated proton beam maximum energy cutoff of 67.5 MeV, with more than 5 x 106 protons per MeV at that energy, using flat-top hollow microcone targets. This result was obtained with a modest laser energy of ∼80 J, on the high-contrast Trident laser at Los Alamos National Laboratory. From 2D particle-in-cell simulations, we attribute the source of these enhanced proton energies to direct laser-light-pressure acceleration of electrons along the inner cone wall surface, where the laser light wave accelerates electrons just outside the surface critical density, in a potential well created by a shift of the electrostatic field maximum with respect to that of the magnetic field maximum. Simulations show that for an increasing acceleration length, the continuous loading of electrons into the accelerating phase of the laser field yields an increase in high-energy electrons.

  8. Detailed analysis of the cell-inactivation mechanism by accelerated protons and light ions

    Kundrát, P

    2006-01-01

    Published survival data for V79 cells irradiated by monoenergetic protons, helium-3, carbon, and oxygen ions and for CHO cells irradiated by carbon ions have been analyzed using the probabilistic two-stage model of cell inactivation. Three different classes of DNA damages formed by traversing particles have been distinguished, namely severe single-track damages which might lead to cell inactivation directly, less severe damages where cell inactivation is caused by their combinations, and damages of negligible severity that can be repaired easily. Probabilities of single ions to form these damages have been assessed in dependence on their linear energy transfer (LET) values. Damage induction probabilities increase with atomic number and LET. While combined damages play crucial role at lower LET values, single-track damages dominate in high-LET regions. The yields of single-track lethal damages for protons have been compared with the Monte Carlo estimates of complex DNA lesions, indicating that lethal events co...

  9. Screening Approach to the Activation of Soil and Contamination of Groundwater at Linear Proton Accelerator Sites

    Otto, Thomas

    The activation of soil and the contamination of groundwater at proton accelerator sites with the radionuclides 3H and 22Na are estimated with a Monte-Carlo calculation and a conservative soil- and ground water model. The obtained radionuclide concentrations show that the underground environment of future accelerators must be adequately protected against a migration of activation products. This study is of particular importance for the proton driver accelerator in the planned EURISOL facility.

  10. Nuclear design aspect of the Korean high intensity proton accelerator project

    Chang, Jonghwa; Song, Tae-Yung [Korea Atomic Energy Research Inst., Yusong, Taejon (Korea, Republic of)

    1998-11-01

    A plan to construct a high current proton accelerator has been proposed by KAERI. We are presenting the required nuclear design to support the project as well as a brief overview of the proposed proton accelerator. The target and core design is highlighted to show feasibility of incineration of minor actinides from the spent fuel of light water reactors. Radiation shielding and activation analyses are also important for the design and the license of the accelerator. (author)

  11. Instrumentation for diagnostics and control of laser-accelerated proton (ion) beams

    Bolton, P. R.; Borghesi, M. (Massimo); Brenner, C.; Carroll, D C; Martinis, C.; Fiorini, F.; Flacco, A.; Floquet, V; J. Fuchs; Gallegos, P.; Giove, D.; Green, J S; Green, S; Jones, B.; Kirby, D.

    2014-01-01

    Suitable instrumentation for laser-accelerated proton (ion) beams is critical for development of integrated, laser-driven ion accelerator systems. Instrumentation aimed at beam diagnostics and control must be applied to the driving laser pulse, the laser-plasma that forms at the target and the emergent proton (ion) bunch in a correlated way to develop these novel accelerators. This report is a brief overview of established diagnostic techniques and new developments based on material presented...

  12. The accelerator driven transmutation technology - A study on the linac for proton accelerator

    Han, Bum Soo; Joh, Ki Hun; Kim, Sung Myun; Park, Heung Gyu; Park, Jong Pil; Kang, Bo Sun [Samsung Heavy Industries, Taejon (Korea)

    1999-04-01

    The purpose of this study is to investigate the manufacturing technology of proton accelerators, and to find the adequate manufacturing technique for construction of such proton accelerators. Review of manufacturing technology for RFQ has been carried out - RFQ machine of other country has been reviewed on the aspects of manufacturing, - Machining of engineering mock-up has been performed based on the designed data, - Brazing technology for RFQ, and brazing test and analysis of Copper specimen. Adequate brazing conditions for RFQ - 1st brazing (vane to section, 950 deg C), Filler metal composition: Cu-20Sn, Brazing conditions: peak temp. 950 deg C (holding time 20min, rising rate 7 deg C/min), Atmosphere: H{sub 2}. - 2nd brazing (section to section, 850 deg C or less), Filler metal: Cu-Sn4%-P7.5%-Ag6%, Brazing conditions: peak temp. 750 deg C (holding time 20min, rising rate 7 deg C/min), Atmosphere: H{sub 2}. 8 refs., (author). 31 figs., 6 tabs.

  13. Relative Biological Effectiveness Variation Along Monoenergetic and Modulated Bragg Peaks of a 62-MeV Therapeutic Proton Beam: A Preclinical Assessment

    Chaudhary, Pankaj; I Marshall, Thomas; Perozziello, Francesca M; Manti, Lorenzo; Currell, Frederick J.; Hanton, Fiona; McMahon, Stephen J; Kavanagh, Joy N.; Cirrone, Giuseppe Antonio Pablo; Romano, Francesco; Prise, Kevin M.; SCHETTINO, Giuseppe

    2014-01-01

    iological optimization of proton therapy critically depends on detailed evaluation of relative biological effectiveness (RBE) variations along the Bragg curve. The clinically accepted RBE value of 1.1 is an oversimplification, which disregards the steep rise of linear energy transfer (LET) at the distal end of the spread-out Bragg peak. We observed significant cell killing RBE variations dependent on beam modulation, intrinsic radiosensitivity, and LET in agreement with the LEM predicted valu...

  14. Vlasov modelling of laser-driven collisionless shock acceleration of protons

    Svedung Wettervik, B.; DuBois, T. C.; Fülöp, T.

    2016-05-01

    Ion acceleration due to the interaction between a short high-intensity laser pulse and a moderately overdense plasma target is studied using Eulerian Vlasov-Maxwell simulations. The effects of variations in the plasma density profile and laser pulse parameters are investigated, and the interplay of collisionless shock and target normal sheath acceleration is analyzed. It is shown that the use of a layered-target with a combination of light and heavy ions, on the front and rear side, respectively, yields a strong quasi-static sheath-field on the rear side of the heavy-ion part of the target. This sheath-field increases the energy of the shock-accelerated ions while preserving their mono-energeticity.

  15. Vlasov modelling of laser-driven collisionless shock acceleration of protons

    Wettervik, B Svedung; Fülöp, T

    2015-01-01

    Ion acceleration due to the interaction between a short high-intensity laser pulse and a moderately overdense plasma target is studied using Eulerian Vlasov-Maxwell simulations. The effects of variations in the plasma density profile and laser pulse parameters are investigated, and the interplay of collisionless shock and target normal sheath acceleration is analyzed. It is shown that the use of a layered-target with a combination of light and heavy ions, on the front and rear side respectively, yields a strong quasi-static sheath-field on the rear side of the heavy-ion part of the target. This sheath-field increases the energy of the shock-accelerated ions while preserving their mono-energeticity.

  16. Broad energy spectrum of laser-accelerated protons for spallation-related physics

    A beam of MeV protons, accelerated by ultraintense laser-pulse interactions with a thin target foil, is used to investigate nuclear reactions of interest for spallation physics. The laser-generated proton beam is shown (protons were measured) to have a broad energy distribution, which closely resembles the expected energy spectrum of evaporative protons (below 50 MeV) produced in GeV-proton-induced spallation reactions. The protons are used to quantify the distribution of residual radioisotopes produced in a representative spallation target (Pb), and the results are compared with calculated predictions based on spectra modeled with nuclear Monte Carlo codes. Laser-plasma particle accelerators are shown to provide data relevant to the design and development of accelerator driven systems

  17. AWAKE, The Advanced Proton Driven Plasma Wakefield Acceleration Experiment at CERN

    Gschwendtner, E; Amorim, L.; Apsimon, R.; Assmann, R.; Bachmann, A.M.; Batsch, F.; Bauche, J.; Olsen, V.K. Berglyd; Bernardini, M.; Bingham, R.; Biskup, B.; Bohl, T.; Bracco, C.; Burrows, P.N.; Burt, G.; Buttenschon, B.; Butterworth, A.; Caldwell, A.; Cascella, M.; Chevallay, E.; Cipiccia, S.; Damerau, H.; Deacon, L.; Dirksen, P.; Doebert, S.; Dorda, U.; Farmer, J.; Fedosseev, V.; Feldbaumer, E.; Fiorito, R.; Fonseca, R.; Friebel, F.; Gorn, A.A.; Grulke, O.; Hansen, J.; Hessler, C.; Hofle, W.; Holloway, J.; Huther, M.; Jaroszynski, D.; Jensen, L.; Jolly, S.; Joulaei, A.; Kasim, M.; Keeble, F.; Li, Y.; Liu, S.; Lopes, N.; Lotov, K.V.; Mandry, S.; Martorelli, R.; Martyanov, M.; Mazzoni, S.; Mete, O.; Minakov, V.A.; Mitchell, J.; Moody, J.; Muggli, P.; Najmudin, Z.; Norreys, P.; Oz, E.; Pardons, A.; Pepitone, K.; Petrenko, A.; Plyushchev, G.; Pukhov, A.; Rieger, K.; Ruhl, H.; Salveter, F.; Savard, N.; Schmidt, J.; Seryi, A.; Shaposhnikova, E.; Sheng, Z.M.; Sherwood, P.; Silva, L.; Soby, L.; Sosedkin, A.P.; Spitsyn, R.I.; Trines, R.; Tuev, P.V.; Turner, M.; Verzilov, V.; Vieira, J.; Vincke, H.; Wei, Y.; Welsch, C.P.; Wing, M.; Xia, G.; Zhang, H.

    2015-01-01

    The Advanced Proton Driven Plasma Wakefield Acceleration Experiment (AWAKE) aims at studying plasma wakefield generation and electron acceleration driven by proton bunches. It is a proof-of-principle R&D experiment at CERN and the world's first proton driven plasma wakefield acceleration experiment. The AWAKE experiment will be installed in the former CNGS facility and uses the 400 GeV/c proton beam bunches from the SPS. The first experiments will focus on the self-modulation instability of the long (rms ~12 cm) proton bunch in the plasma. These experiments are planned for the end of 2016. Later, in 2017/2018, low energy (~15 MeV) electrons will be externally injected to sample the wakefields and be accelerated beyond 1 GeV. The main goals of the experiment will be summarized. A summary of the AWAKE design and construction status will be presented.

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

    A pulsed high field solenoid was used in a laser-proton acceleration experiment to collimate and transport the proton beam that was generated at the irradiation of a flat foil by a high intensity laser pulse. 1012 particles at an energy of 2.3 MeV could be caught and transported over a distance of more than 240 mm. Strong space charge effects occur, induced by the high field of the solenoid that forces all co-moving electrons down the the solenoid's axis, building up a strong negative space charge that interacts with the proton beam. This leads to an aggregation of the proton beam around the solenoid's axis and therefore to a stronger focusing effect. The collimation and transport of laser-accelerated protons is the first step to provide these unique beams for further applications like post-acceleration by conventional accelerator structures.

  19. Architecture and Civil Design Status of the Proton Accelerator Research Center in PEFP

    PEFP (Proton Engineering Frontier Project) is scheduled to administrate the conventional facilities design with Gyeongju and complement its unfit points. When construction work starts according to the construction schedule, a field work office will be installed to supervise the Proton Accelerator Conventional Facilities Construction. In this paper, we describe the geological investigation procedure for the construction of the proton accelerator conventional facilities of PEFP. By the geological investigation, data for the reasonable and economic construction work, such as stratum structure and geotechnical characteristics. In Site Plot Plan for PEFP, we classified center as 2 groups such as main facilities and support facilities. We also designed access road of the Proton Accelerator Research Center of PEFP. In architectural design for PEFP, we described the design procedure of the buildings and landscape architectures of the Proton Accelerator Research Center

  20. AWAKE, The Advanced Proton Driven Plasma Wakefield Acceleration Experiment at CERN

    Gschwendtner, E.; Adli, E.; Amorim, L.; Apsimon, R.; Assmann, R.; Bachmann, A.-M.; Batsch, F.; Bauche, J.; Berglyd Olsen, V. K.; Bernardini, M.; Bingham, R.; Biskup, B.; Bohl, T.; Bracco, C.; Burrows, P. N.; Burt, G.; Buttenschön, B.; Butterworth, A.; Caldwell, A.; Cascella, M.; Chevallay, E.; Cipiccia, S.; Damerau, H.; Deacon, L.; Dirksen, P.; Doebert, S.; Dorda, U.; Farmer, J.; Fedosseev, V.; Feldbaumer, E.; Fiorito, R.; Fonseca, R.; Friebel, F.; Gorn, A. A.; Grulke, O.; Hansen, J.; Hessler, C.; Hofle, W.; Holloway, J.; Hüther, M.; Jaroszynski, D.; Jensen, L.; Jolly, S.; Joulaei, A.; Kasim, M.; Keeble, F.; Li, Y.; Liu, S.; Lopes, N.; Lotov, K. V.; Mandry, S.; Martorelli, R.; Martyanov, M.; Mazzoni, S.; Mete, O.; Minakov, V. A.; Mitchell, J.; Moody, J.; Muggli, P.; Najmudin, Z.; Norreys, P.; Öz, E.; Pardons, A.; Pepitone, K.; Petrenko, A.; Plyushchev, G.; Pukhov, A.; Rieger, K.; Ruhl, H.; Salveter, F.; Savard, N.; Schmidt, J.; Seryi, A.; Shaposhnikova, E.; Sheng, Z. M.; Sherwood, P.; Silva, L.; Soby, L.; Sosedkin, A. P.; Spitsyn, R. I.; Trines, R.; Tuev, P. V.; Turner, M.; Verzilov, V.; Vieira, J.; Vincke, H.; Wei, Y.; Welsch, C. P.; Wing, M.; Xia, G.; Zhang, H.

    2016-09-01

    The Advanced Proton Driven Plasma Wakefield Acceleration Experiment (AWAKE) aims at studying plasma wakefield generation and electron acceleration driven by proton bunches. It is a proof-of-principle R&D experiment at CERN and the world's first proton driven plasma wakefield acceleration experiment. The AWAKE experiment will be installed in the former CNGS facility and uses the 400 GeV/c proton beam bunches from the SPS. The first experiments will focus on the self-modulation instability of the long (rms ~12 cm) proton bunch in the plasma. These experiments are planned for the end of 2016. Later, in 2017/2018, low energy (~15 MeV) electrons will be externally injected into the sample wakefields and be accelerated beyond 1 GeV. The main goals of the experiment will be summarized. A summary of the AWAKE design and construction status will be presented.

  1. Acceleration of polarized protons in the KEK 12 GeV Proton Synchrotron

    By computing the spin as well as orbit motion of each particle, it is shown that acceleration of polarized protons is feasible if a rapid change is made in νsub(z) at four medium strong resonances out of eleven in total. The remaining seven resonances are so strong that at each of them, the polarization only changes the sign without a serious loss. The final polarization at 12 GeV will be higher than 83% of the initial one at the injection energy of 0.5 GeV, if the vertical beam radius is 25 mm at the injection. This estimation includes a polarization loss of 7% due to the influence of synchrotron oscillation. (author)

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

    Roychowdhury, P.; Chakravarthy, D. P. [Accelerator and Pulse Power Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)

    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.

  3. Dosimetry in radiation fields around high-energy proton accelerators

    Agosteo, S; Silari, M; Theis, C

    2008-01-01

    Radiation dosimetry at high-energy proton accelerators is a difficult task because of the complexity of the stray radiation field. A good knowledge of this mixed radiation field is very important to be able to select the type of detectors (active and/or passive) to be employed for routine area monitoring and to choose the personal dosimeter legally required for estimating the effective dose received by individuals. At the same time, the response function of the detectors to the mixed field must be thoroughly understood. A proper calibration of a device, which may involve a complex series of measurements in various reference fields, is needed. Monte Carlo simulations provide a complementary – and sometimes the principal – mean of determining the response function. The ambient dose equivalent rates during operation range from a few hundreds of μSv per year to a few mSv per year. To measure such rates one needs detectors of high sensitivity and/or capable of integrating over long periods. The main challenge...

  4. Proton Acceleration in Underdense Plasma by Ultraintense Laguerre-Gaussian Laser Pulse

    Zhang, Xiaomei; Zhang, Lingang; Xu, Jiancai; Wang, Xiaofeng; Wang, Wenpeng; Yi, Longqiong; Shi, Yin

    2014-01-01

    Three-dimensional particle-in-cell simulation is used to investigate the witness proton acceleration in underdense plasma with a short intense Laguerre-Gaussian (LG) laser pulse. Driven by the LG10 laser pulse, a special bubble with an electron pillar on the axis is formed, in which protons can be well-confined by the generated transversal focusing field and accelerated by the longitudinal wakefield. The risk of scattering prior to acceleration with a Gaussian laser pulse in underdense plasma is avoided, and protons are accelerated stably to much higher energy. In simulation, a proton beam has been accelerated to 7 GeV from 1 GeV in underdense tritium plasma driven by a 2.14x1022 W/cm2 LG10 laser pulse.

  5. Optimization of the combined proton acceleration regime with a target composition scheme

    A target composition scheme to optimize the combined proton acceleration regime is presented and verified by two-dimensional particle-in-cell simulations by using an ultra-intense circularly polarized (CP) laser pulse irradiating an overdense hydrocarbon (CH) target, instead of a pure hydrogen (H) one. The combined acceleration regime is a two-stage proton acceleration scheme combining the radiation pressure dominated acceleration (RPDA) stage and the laser wakefield acceleration (LWFA) stage sequentially together. Protons get pre-accelerated in the first stage when an ultra-intense CP laser pulse irradiating an overdense CH target. The wakefield is driven by the laser pulse after penetrating through the overdense CH target and propagating in the underdense tritium plasma gas. With the pre-accelerate stage, protons can now get trapped in the wakefield and accelerated to much higher energy by LWFA. Finally, protons with higher energies (from about 20 GeV up to about 30 GeV) and lower energy spreads (from about 18% down to about 5% in full-width at half-maximum, or FWHM) are generated, as compared to the use of a pure H target. It is because protons can be more stably pre-accelerated in the first RPDA stage when using CH targets. With the increase of the carbon-to-hydrogen density ratio, the energy spread is lower and the maximum proton energy is higher. It also shows that for the same laser intensity around 1022 W cm−2, using the CH target will lead to a higher proton energy, as compared to the use of a pure H target. Additionally, proton energy can be further increased by employing a longitudinally negative gradient of a background plasma density

  6. Optimization of the combined proton acceleration regime with a target composition scheme

    Yao, W. P. [Center for Applied Physics and Technology, HEDPS, State Key Laboratory of Nuclear Physics and Technology, and School of Physics, Peking University, Beijing 100871 (China); Graduate School, China Academy of Engineering Physics, Beijing 100088 (China); Li, B. W., E-mail: li-baiwen@iapcm.ac.cn [Institute of Applied Physics and Computational Mathematics, Beijing 100088 (China); Zheng, C. Y.; Liu, Z. J. [Center for Applied Physics and Technology, HEDPS, State Key Laboratory of Nuclear Physics and Technology, and School of Physics, Peking University, Beijing 100871 (China); Institute of Applied Physics and Computational Mathematics, Beijing 100088 (China); Yan, X. Q. [Center for Applied Physics and Technology, HEDPS, State Key Laboratory of Nuclear Physics and Technology, and School of Physics, Peking University, Beijing 100871 (China); Qiao, B. [Center for Applied Physics and Technology, HEDPS, State Key Laboratory of Nuclear Physics and Technology, and School of Physics, Peking University, Beijing 100871 (China); Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi 030006 (China)

    2016-01-15

    A target composition scheme to optimize the combined proton acceleration regime is presented and verified by two-dimensional particle-in-cell simulations by using an ultra-intense circularly polarized (CP) laser pulse irradiating an overdense hydrocarbon (CH) target, instead of a pure hydrogen (H) one. The combined acceleration regime is a two-stage proton acceleration scheme combining the radiation pressure dominated acceleration (RPDA) stage and the laser wakefield acceleration (LWFA) stage sequentially together. Protons get pre-accelerated in the first stage when an ultra-intense CP laser pulse irradiating an overdense CH target. The wakefield is driven by the laser pulse after penetrating through the overdense CH target and propagating in the underdense tritium plasma gas. With the pre-accelerate stage, protons can now get trapped in the wakefield and accelerated to much higher energy by LWFA. Finally, protons with higher energies (from about 20 GeV up to about 30 GeV) and lower energy spreads (from about 18% down to about 5% in full-width at half-maximum, or FWHM) are generated, as compared to the use of a pure H target. It is because protons can be more stably pre-accelerated in the first RPDA stage when using CH targets. With the increase of the carbon-to-hydrogen density ratio, the energy spread is lower and the maximum proton energy is higher. It also shows that for the same laser intensity around 10{sup 22} W cm{sup −2}, using the CH target will lead to a higher proton energy, as compared to the use of a pure H target. Additionally, proton energy can be further increased by employing a longitudinally negative gradient of a background plasma density.

  7. Optimization of flat-cone targets for enhanced laser-acceleration of protons

    We have analyzed the acceleration of laser-generated protons, produced at the rear surface of flat-cone targets irradiated by an ultra-intense (I∼5x1019 W/cm2) short (400 fs) laser pulse. We used different target sizes and shapes in order to find the optimum target layout. We find that for targets with a too narrow cone structure, the production of the hot electrons, driving the proton acceleration, is located prior to the accelerating rear surface of the target, resulting in a reduced maximum proton energy.

  8. Driving Parts Optimization Design for Radiation Shielding Doors of Proton Accelerator Research Center

    PEFP(Proton Engineering Frontier Project) was Launched in 2002 as one of the 21st Century Frontier R and D Programs of MOST(Ministry of Science and Technology). Gyeongju city was selected as the project host site in March, 2006, where 'Proton Accelerator Research Center' was going to be constructed. After starting the design in 2005, the Architectural and Civil design work has been performed by 2010. Since the Earthwork was started in 2009, the Construction works of Accelerator Facilities has been going smoothly to complete by 2012. In this paper, we describe driving Parts optimization design for radiation shielding doors of Proton Accelerator Research Center

  9. The LILIA experiment: Energy selection and post-acceleration of laser generated protons

    Turchetti, Giorgio; Sinigardi, Stefano; Londrillo, Pasquale; Rossi, Francesco; Sumini, Marco; Giove, Dario; De Martinis, Carlo

    2012-12-01

    The LILIA experiment is planned at the SPARCLAB facility of the Frascati INFN laboratories. We have simulated the laser acceleration of protons, the transport and energy selection with collimators and a pulsed solenoid and the post-acceleration with a compact high field linac. For the highest achievable intensity corresponding to a = 30 over 108 protons at 30 MeV with a 3% spread are selected, and at least107 protons are post-accelerated up to 60 MeV. If a 10 Hz repetition rated can be achieved the delivered dose would be suitable for the treatment of small superficial tumors.

  10. 160 MeV laser-accelerated protons from CH2 nano-targets for proton cancer therapy

    Hegelich, B M; Albright, B J; Cheung, M; Dromey, B; Gautier, D C; Hamilton, C; Letzring, S; Munchhausen, R; Palaniyappan, S; Shah, R; Wu, H -C; Yin, L; Fernández, J C

    2013-01-01

    Proton (and ion) cancer therapy has proven to be an extremely effective even supe-rior method of treatment for some tumors 1-4. A major problem, however, lies in the cost of the particle accelerator facilities; high procurement costs severely limit the availability of ion radiation therapy, with only ~26 centers worldwide. Moreover, high operating costs often prevent economic operation without state subsidies and have led to a shutdown of existing facilities 5,6. Laser-accelerated proton and ion beams have long been thought of as a way out of this dilemma, with the potential to provide the required ion beams at lower cost and smaller facility footprint 7-14. The biggest challenge has been the achievement of sufficient particle energy for therapy, in the 150-250 MeV range for protons 15,16. For the last decade, the maximum exper-imentally observed energy of laser-accelerated protons has remained at ~60 MeV 17. Here we the experimental demonstration of laser-accelerated protons to energies exceeding 150 MeV, re...

  11. Proton an alpha detections by track recording technique in CR-39

    The plastic CR-39 is utilized as proton track detector in the study of the reaction 27A (e, p) and 59Co (e, p), near threshold. Preliminary results are presented for the energy calibration (mean track diameter as a function of proton energy) of CR-39 with mono-energetic protons of a Van de Graaff accelerator, in the energy range 1-3 MeV. (author)

  12. Estimation of the Production of Ozone and Nitric Acid in a Proton Accelerator Facility of the Proton Engineering Frontier Project

    The operation of the high-energy particle accelerator leads to the production of not only radioactive gases, but also radiolytic noxious gases, such as ozone and nitrogen compounds in the air of the facility. Of the radiolytic products, ozone production is usually taken into account for the evaluation of the heath hazard in the operation of the particle accelerator facilities, owing to its high radiolytic yield and much lower maximum acceptable concentration. Nitrogen compounds do not commonly constitute a heath hazard but are of important concern because of its chemical properties of being a strong acid and a strong oxidizing agent. Among the nitrogen compounds, nitric acid is a principal radiolytic compound produced in large quantities and has a potential for the corrosion of the components in the facility. It has founded that at a high-energy proton accelerator facility, nitric acid was produced in the radiolysis of air in beam-loss region. The nitric acid was desorbed on the surface of the magnet, walls, floors and local lead shields. It also tends to be more uniform through the tunnel due to air circulation. In these backgrounds, the production of ozone and nitric acid in proton accelerator facility from Proton Engineering Frontier Project (PEFP) was estimated in this study, because very strong radiation environment leads to an abundant production of nitric acid in such a high-current proton accelerator

  13. Proton acceleration by high-intensity UV laser irradiation with thin foil targets

    Proton acceleration experiments by irradiation of intense ultra-violet lasers with thin foil targets were conducted. Energies and efficiencies of the accelerated protons were investigated over the target thickness from several μm to 50 nm using various materials. In order to irradiate the very thin foil targets, the discharge pre-amplifier in the previous system was removed to reduce amplified spontaneous emission which disturbed the main pulse interactions. A Thomson parabola ion spectrometer with CR39 plastic nuclear track detectors were used to observe spectra of the accelerated protons. The maximum energies and efficiencies of accelerated protons increased with decreasing the target thickness rather than the product of the density and thickness of the targets. These results were explained by a geometrical effect on hot electron recycling. (author)

  14. Influence of Laser Prepulse in Ultra-short Laser-Driven Proton Acceleration

    2011-01-01

    Influence of laser prepulse in ultra-short laser-driven proton acceleration was investigated by the differences in spatial distribution and energy spectrum between different foil-targets. The laser system produced pulses having energies of up to

  15. Near monochromatic 20 Me V proton acceleration using fs laser irradiating Au foils in target normal sheath acceleration regime

    Torrisi, L.; Cutroneo, M.; Ceccio, G.; Cannavò, A.; Batani, D.; Boutoux, G.; Jakubowska, K.; Ducret, J. E.

    2016-04-01

    A 200 mJ laser pulse energy, 39 fs-pulse duration, 10 μm focal spot, p-polarized radiation has been employed to irradiate thin Au foils to produce proton acceleration in the forward direction. Gold foils were employed to produce high density relativistic electrons emission in the forward direction to generate a high electric field driving the ion acceleration. Measurements were performed by changing the focal position in respect of the target surface. Proton acceleration was monitored using fast SiC detectors in time-of-flight configuration. A high proton energy, up to about 20 Me V, with a narrow energy distribution, was obtained in particular conditions depending on the laser parameters, the irradiation conditions, and a target optimization.

  16. Study of response of 3He detectors to monoenergetic neutrons

    In the search of a hybrid system (the coupling of the particle accelerator to an under-critical reactor) for radioactive waste transmutation the TARC (Transmutation by Adiabatic Resonance Crossing) program has been developed. Due to experimental limitations, the time-energy relation at higher neutron energies, particularly, around 2 MeV, which is an important domain for TARC, cannot be applied. Consequently the responses of the 3He ionization neutron detector developed for TARC experiment have been studied using a fast monoenergetic neutron source. The neutrons were produced by the interaction of the proton delivered by Van de Graaff accelerator of CENBG. The originality of the detector consists in its structure of three series of electric conductors which are mounted around the anode: a grid ensuring the detector proportionality, a cylindrical suit of alternating positive voltage and grounded wires aiming at eliminating the radial end effects, serving as veto and two cylinders serving as end plugs to eliminate the perpendicular end effects. Examples of anode spectra conditioned (in anticoincidence) by the mentioned vetoes are given. One can see the contribution of the elastic scattering from H and 3He. By collimating the neutron beam through a borated polyethylene system it was possible to obtain a mapping of the detector allowing the study of its response as a function of the irradiated zones (anode and grid)

  17. A Proposed Experimental Test of Proton-Driven Plasma Wakefield Acceleration Based on CERN SPS

    Xia, G X; Lotov, K; Pukhov, A; Assmann, R; Zimmermann, F; Huang, C; Vieira, J; Lopes, N; Fonseca, RA; Silva, LO; An, W; Joshi, C; Mori, W; Lu, W; Muggli, P

    2011-01-01

    Proton-bunch driven plasma wakefield acceleration (PDPWA) has been proposed as an approach to accelerate electron beam to TeV energy regime in a single plasma section. An experimental test has recently proposed to demonstrate the capability of PDPWA by using proton beams from the CERN SPS. The layout of the experiment is introduced. Particle-in-cell simulation results based on the realistic beam parameters are presented. Presented at PAC2011 New York, 28 March - 1 April 2011.

  18. The R/D of high power proton accelerator technology in China

    Guan Xialing

    2002-12-01

    In China, a multipurpose verification system as a first phase of our ADS program consists of a low energy accelerator (150 MeV/3 mA proton LINAC) and a swimming pool light water subcritical reactor. In this paper the activities of HPPA technology related to ADS in China, which includes the intense proton ECR source, the RFQ accelerator and some other technology of HPPA, are described.

  19. Flare vs. Shock Acceleration of >100 MeV Protons in Large Solar Particle Events

    Cliver, Edward W.

    2016-05-01

    Recently several studies have presented correlative evidence for a significant-to-dominant role for a flare-resident process in the acceleration of high-energy protons in large solar particle events. In one of these investigations, a high correlation between >100 MeV proton fluence and 35 GHz radio fluence is obtained by omitting large proton events associated with relatively weak flares; these outlying events are attributed to proton acceleration by shock waves driven by coronal mass ejections (CMEs). We argue that the strong CMEs and associated shocks observed for proton events on the main sequence of the scatter plot are equally likely to accelerate high-energy protons. In addition, we examine ratios of 0.5 MeV electron to >100 MeV proton intensities in large SEP events, associated with both well-connected and poorly-connected solar eruptions, to show that scaled-up versions of the small flares associated with classical impulsive SEP events are not significant accelerators of >100 MeV protons.

  20. Capture and Transport of Laser Accelerated Protons by Pulsed Magnetic Fields: Advancements Toward Laser-Based Proton Therapy

    Burris-Mog, Trevor J.

    The interaction of intense laser light (I > 10 18 W/cm2) with a thin target foil leads to the Target Normal Sheath Acceleration mechanism (TNSA). TNSA is responsible for the generation of high current, ultra-low emittance proton beams, which may allow for the development of a compact and cost effective proton therapy system for the treatment of cancer. Before this application can be realized, control is needed over the large divergence and the 100% kinetic energy spread that are characteristic of TNSA proton beams. The work presented here demonstrates control over the divergence and energy spread using strong magnetic fields generated by a pulse power solenoid. The solenoidal field results in a parallel proton beam with a kinetic energy spread DeltaE/E = 10%. Assuming that next generation lasers will be able to operate at 10 Hz, the 10% spread in the kinetic energy along with the 23% capture efficiency of the solenoid yield enough protons per laser pulse to, for the first time, consider applications in Radiation Oncology. Current lasers can generate proton beams with kinetic energies up to 67.5 MeV, but for therapy applications, the proton kinetic energy must reach 250 MeV. Since the maximum kinetic energy Emax of the proton scales with laser light intensity as Emax ∝ I0.5, next generation lasers may very well accelerate 250 MeV protons. As the kinetic energy of the protons is increased, the magnetic field strength of the solenoid will need to increase. The scaling of the magnetic field B with the kinetic energy of the protons follows B ∝ E1/2. Therefor, the field strength of the solenoid presented in this work will need to be increased by a factor of 2.4 in order to accommodate 250 MeV protons. This scaling factor seems reasonable, even with present technology. This work not only demonstrates control over beam divergence and energy spread, it also allows for us to now perform feasibility studies to further research what a laser-based proton therapy system

  1. Nuclear Research with Mono-Energetic Neutrons at the JRC Monnet Facility

    The MONNET (MONo energetic NEutron Tower) facility is used for research on neutron-induced reactions with mono-energetic neutrons. MONNET is based on a 7 MV Van-de-Graaff-accelerator, where the accelerated ions, mainly protons and deuterons, are used to produce the neutrons by means of reactions on 7Li, tritium and deuterium-containing targets. Neutrons with energies between practically 0 keV up 10 MeV and between 12.5 and 24 MeV can be produced. However, between En = 7 and 10 MeV and above 19 MeV secondary neutron-producing reactions have to be taken care of. The measurement program focuses on fission research and neutron-induced reaction cross-sections. The MONNET facility also contributes to the nuclear science education and hosts PhD students and post-doc fellows on a regular basis. (author)

  2. Investigation of longitudinal proton acceleration in exploded targets irradiated by intense short-pulse laser

    Gauthier, M. [LULI, École Polytechnique, CNRS, CEA, UPMC, route de Saclay, 91128 Palaiseau (France); CEA, DAM, DIF, 91297 Arpajon (France); Lévy, A. [LULI, École Polytechnique, CNRS, CEA, UPMC, route de Saclay, 91128 Palaiseau (France); Sorbonne Universités, UPMC, Paris 06, CNRS, INSP, UMR 7588, F-75005, Paris (France); D' Humières, E.; Beaucourt, C.; Breil, J.; Feugeas, J. L.; Nicolaï, P.; Tikhonchuk, V. [Univ. Bordeaux, CNRS, CEA, UMR 5107, F-33400 Talence (France); Glesser, M. [LULI, École Polytechnique, CNRS, CEA, UPMC, route de Saclay, 91128 Palaiseau (France); INRS-EMT, Varennes, PQ J3X 1S2 (Canada); Albertazzi, B. [LULI, École Polytechnique, CNRS, CEA, UPMC, route de Saclay, 91128 Palaiseau (France); Univ. Bordeaux, CNRS, CEA, UMR 5107, F-33400 Talence (France); Chen, S. N.; Dervieux, V.; Fuchs, J. [LULI, École Polytechnique, CNRS, CEA, UPMC, route de Saclay, 91128 Palaiseau (France); Pépin, H. [INRS-EMT, Varennes, PQ J3X 1S2 (Canada); Antici, P. [LULI, École Polytechnique, CNRS, CEA, UPMC, route de Saclay, 91128 Palaiseau (France); INRS-EMT, Varennes, PQ J3X 1S2 (Canada); Dipartimento SBAI, Universita di Roma “Sapienza,” Via A. Scarpa 16, 00161 Rome (Italy)

    2014-01-15

    It was recently shown that a promising way to accelerate protons in the forward direction to high energies is to use under-dense or near-critical density targets instead of solids. Simulations have revealed that the acceleration process depends on the density gradients of the plasma target. Indeed, under certain conditions, the most energetic protons are predicted to be accelerated by a collisionless shock mechanism that significantly increases their energy. We report here the results of a recent experiment dedicated to the study of longitudinal ion acceleration in partially exploded foils using a high intensity (∼5 × 10{sup 18} W/cm{sup 2}) picosecond laser pulse. We show that protons accelerated using targets having moderate front and rear plasma gradients (up to ∼8 μm gradient length) exhibit similar maximum proton energy and number compared to proton beams that are produced, in similar laser conditions, from solid targets, in the well-known target normal sheath acceleration regime. Particle-In-Cell simulations, performed in the same conditions as the experiment and consistent with the measurements, allow laying a path for further improvement of this acceleration scheme.

  3. Transporting laser-accelerated protons by a pulsed solenoid to a CH- DTL

    This study demonstrates the transporting and focusing of laser-accelerated protons at energies of ten to several tens of MeV, by a pulsed magnetic solenoid with a field gradient up to 18 T. The unique features of the protons distribution like extremely small emittances and high yield of the order of 1013 protons per shot, make them attractive for study. With respect to transit energies further acceleration by matching into rf linac seems adequate. The bunch injection into a proposed CH- structure is under investigation at IAP Frankfurt. Options and simulation tools are presented.

  4. Programmable Power Supply for AC Switching Magnet of Proton Accelerator

    Jeong, Seong-Hun; Kang Heung Sik; Lee, Chi-Hwan; Lee, Hong-Gi; Park, Ki-Hyeon; Ryu, Chun-Kil; Sik Han, Hong; Suck Suh, Hyung

    2005-01-01

    The 100-MeV PEFP proton linac has two proton beam extraction lines for user' experiment. Each extraction line has 5 beamlines and has 5 Hz operating frequency. An AC switching magnet is used to distribute the proton beam to the 5 beamlines, An AC switching magnet is powered by PWM-controlled bipolar switching-mode converters. This converter is designed to operate at ±350A, 5 Hz programmable step output. The power supply is employed IGBT module and has controlled by a DSP (Digital Signal Process). This paper describes the design and test results of the power supply.

  5. Technical development of high intensity proton accelerators in Japan Atomic Energy Research Institute (JAERI)

    Science and Technology Agency decided 'Options making extra gains of actinides and fission products (OMEGA)' and to promote the related researches. Also in JAERI, the research on the group separation method for separating transuranic elements, strontium and cesium from high level radioactive wastes has been carried out since the beginning of 1970s. Also the concept of the fast reactors using minor actinide mixture fuel is being established, and the accelerator annihilation treatment utilizing the nuclear spallation reaction by high energy protons has been examined. In this report, from the viewpoint of the application of accelerators to atomic energy field, the annihilation treatment method by the nuclear spallation reaction utilizing high intensity proton accelerators, the plan of the various engineering utilization of proton beam, and the development of accelerators in JAERI are described. The way of thinking on the annihilation treatment of radioactive waste, the system using fast neutrons, the way of thinking on the development of high intensity proton accelerator technology, the steps of the development, the research and development for constructing the basic technology accelerator, 2 MeV beam acceleration test, the basic technology accelerator utilization facility and so on are reported. (K.I.)

  6. A dosimetric system for quantitative cell irradiation experiments with laser-accelerated protons

    An integrated dosimetry and cell irradiation system (IDOCIS) with laser-accelerated proton beams was developed, characterized, calibrated and successfully used for systematic in vitro experiments. Due to the broad exponentially shaped energy spectrum, the low-energy range of the protons (<20 MeV) and the high pulse dose, the absolute dosimetry for this beam quality is challenging. Therefore, a dedicated Faraday cup is used as an energy and dose rate independent absolute dosimeter that has been calibrated consistently with three independent methods. A transmission ionization chamber providing online relative dose information is cross-calibrated against the Faraday cup. Providing both online and absolute dose information, the IDOCIS allows for quantitative dosimetric and radiobiological studies at current low-energy laser-accelerated proton beams. Finally, first dosimetric characterizations of a laser-accelerated proton beam with the IDOCIS are presented.

  7. Hollow microspheres as targets for staged laser-driven proton acceleration

    Burza, M; Genoud, G; Persson, A; Svensson, K; Quinn, M; McKenna, P; Marklund, M; Wahlström, C -G; 10.1088/1367-2630/13/1/013030

    2011-01-01

    A coated hollow core microsphere is introduced as a novel target in ultra-intense laser-matter interaction experiments. In particular, it facilitates staged laser-driven proton acceleration by combining conventional target normal sheath acceleration (TNSA), power recycling of hot laterally spreading electrons and staging in a very simple and cheap target geometry. During TNSA of protons from one area of the sphere surface, laterally spreading hot electrons form a charge wave. Due to the spherical geometry, this wave refocuses on the opposite side of the sphere, where an opening has been laser micromachined. This leads to a strong transient charge separation field being set up there, which can post-accelerate those TNSA protons passing through the hole at the right time. Experimentally, the feasibility of using such targets is demonstrated. A redistribution is encountered in the experimental proton energy spectra, as predicted by particle-in-cell simulations and attributed to transient fields set up by oscilla...

  8. Investigation of laser-driven proton acceleration using ultra-short, ultra-intense laser pulses

    We report optimization of laser-driven proton acceleration, for a range of experimental parameters available from a single ultrafast Ti:sapphire laser system. We have characterized laser-generated protons produced at the rear and front target surfaces of thin solid targets (15 nm to 90 μm thicknesses) irradiated with an ultra-intense laser pulse (up to 1020 W⋅cm−2, pulse duration 30 to 500 fs, and pulse energy 0.1 to 1.8 J). We find an almost symmetric behaviour for protons accelerated from rear and front sides, and a linear scaling of proton energy cut-off with increasing pulse energy. At constant laser intensity, we observe that the proton cut-off energy increases with increasing laser pulse duration, then roughly constant for pulses longer than 300 fs. Finally, we demonstrate that there is an optimum target thickness and pulse duration.

  9. Investigation of laser-driven proton acceleration using ultra-short, ultra-intense laser pulses

    Fourmaux, S.; Gnedyuk, S.; Lassonde, P.; Payeur, S.; Pepin, H.; Kieffer, J. C. [INRS-EMT, Universite du Quebec, 1650 Lionel Boulet, Varennes, Quebec J3X 1S2 (Canada); Buffechoux, S.; Albertazzi, B. [INRS-EMT, Universite du Quebec, 1650 Lionel Boulet, Varennes, Quebec J3X 1S2 (Canada); LULI, UMR 7605, CNRS - CEA - Universite Paris 6 - Ecole Polytechnique, 91128 Palaiseau (France); Capelli, D.; Antici, P. [LULI, UMR 7605, CNRS - CEA - Universite Paris 6 - Ecole Polytechnique, 91128 Palaiseau (France); Dipartimento SBAI, Sapienza, Universita di Roma, Via Scarpa 16, 00161 Roma (Italy); Levy, A.; Fuchs, J. [LULI, UMR 7605, CNRS - CEA - Universite Paris 6 - Ecole Polytechnique, 91128 Palaiseau (France); Lecherbourg, L.; Marjoribanks, R. S. [Department of Physics and Institute for Optical Sciences, University of Toronto, Toronto, Ontario M5S 1A7 (Canada)

    2013-01-15

    We report optimization of laser-driven proton acceleration, for a range of experimental parameters available from a single ultrafast Ti:sapphire laser system. We have characterized laser-generated protons produced at the rear and front target surfaces of thin solid targets (15 nm to 90 {mu}m thicknesses) irradiated with an ultra-intense laser pulse (up to 10{sup 20} W Dot-Operator cm{sup -2}, pulse duration 30 to 500 fs, and pulse energy 0.1 to 1.8 J). We find an almost symmetric behaviour for protons accelerated from rear and front sides, and a linear scaling of proton energy cut-off with increasing pulse energy. At constant laser intensity, we observe that the proton cut-off energy increases with increasing laser pulse duration, then roughly constant for pulses longer than 300 fs. Finally, we demonstrate that there is an optimum target thickness and pulse duration.

  10. Control of target-normal-sheath-accelerated protons from a guiding cone

    Zou, D. B. [College of Science, National University of Defense Technology, Changsha 410073 (China); Institut für Theoretische Physik I, Heinrich-Heine-Universität Düsseldorf, Düsseldorf 40225 (Germany); Zhuo, H. B., E-mail: hongbin.zhuo@gmail.com [College of Science, National University of Defense Technology, Changsha 410073 (China); IFSA Collaborative Innovation Center, Shanghai Jiao Tong University, Shanghai 200240 (China); Yang, X. H.; Yu, T. P.; Shao, F. Q. [College of Science, National University of Defense Technology, Changsha 410073 (China); Pukhov, A. [Institut für Theoretische Physik I, Heinrich-Heine-Universität Düsseldorf, Düsseldorf 40225 (Germany)

    2015-06-15

    It is demonstrated through particle-in-cell simulations that target-normal-sheath-accelerated protons can be well controlled by using a guiding cone. Compared to a conventional planar target, both the collimation and number density of proton beams are substantially improved, giving a high-quality proton beam which maintained for a longer distance without degradation. The effect is attributed to the radial electric field resulting from the charge due to the hot target electrons propagating along the cone surface. This electric field can effectively suppress the spatial spread of the protons after the expansion of the hot electrons.

  11. Control of target-normal-sheath-accelerated protons from a guiding cone

    It is demonstrated through particle-in-cell simulations that target-normal-sheath-accelerated protons can be well controlled by using a guiding cone. Compared to a conventional planar target, both the collimation and number density of proton beams are substantially improved, giving a high-quality proton beam which maintained for a longer distance without degradation. The effect is attributed to the radial electric field resulting from the charge due to the hot target electrons propagating along the cone surface. This electric field can effectively suppress the spatial spread of the protons after the expansion of the hot electrons

  12. Optimizing proton therapy at the LBL medical accelerator

    Alonso, J.

    1992-03-01

    This Grant has marked the beginning of a multi-year study process expected to lead to design and construction of at least one, possibly several hospital-based proton therapy facilities in the United States.

  13. Optimizing proton therapy at the LBL medical accelerator. Final report

    Alonso, J.

    1992-03-01

    This Grant has marked the beginning of a multi-year study process expected to lead to design and construction of at least one, possibly several hospital-based proton therapy facilities in the United States.

  14. Optimization of laser accelerated proton beams for possible applications

    Optimization of transported proton beams through a pulsed solenoid in the laser proton experiment LIGHT at GSI has been studied numerically. TraceWin, SRIM and ATIMA codes were employed for this study with an initial distribution generated by MATLAB program fitted to Phelix measured data. Two individual tools have been used to produce protons beam as a later beam source: an aperture located at the solenoid focal spot as energy selection tool; and a scattering foil at a suitable position in the beam path that smoothens the simulated radial energy imprint on the beam profile. The simulation results show that the proton energy spectrum is filtered by the aperture and the radial energy correlation is smoothened.

  15. Pulsars as cosmic ray particle accelerators: Proton orbits

    Thielheim, K. O.

    1985-01-01

    Proton orbits are calculated in the electromagnetic vacuum field of a magnetic point dipole rotating with its angular velocity omega perpendicular to its dipole moment mu by numerical integration of the Lorentz-Dirac equation. Trajectories are shown and discussed for various initial conditions. A critical surface is shown separating initial positions of protons which finally hit the pulsar in the polar region from those which finally recede to infinity.

  16. Accelerating protons to therapeutic energies with ultraintense, ultraclean, and ultrashort laser pulses

    Proton acceleration by high-intensity laser pulses from ultrathin foils for hadron therapy is discussed. With the improvement of the laser intensity contrast ratio to 10-11 achieved on the Hercules laser at the University of Michigan, it became possible to attain laser-solid interactions at intensities up to 1022 W/cm2 that allows an efficient regime of laser-driven ion acceleration from submicron foils. Particle-in-cell (PIC) computer simulations of proton acceleration in the directed Coulomb explosion regime from ultrathin double-layer (heavy ions/light ions) foils of different thicknesses were performed under the anticipated experimental conditions for the Hercules laser with pulse energies from 3 to 15 J, pulse duration of 30 fs at full width half maximum (FWHM), focused to a spot size of 0.8 μm (FWHM). In this regime heavy ions expand predominantly in the direction of laser pulse propagation enhancing the longitudinal charge separation electric field that accelerates light ions. The dependence of the maximum proton energy on the foil thickness has been found and the laser pulse characteristics have been matched with the thickness of the target to ensure the most efficient acceleration. Moreover, the proton spectrum demonstrates a peaked structure at high energies, which is required for radiation therapy. Two-dimensional PIC simulations show that a 150-500 TW laser pulse is able to accelerate protons up to 100-220 MeV energies

  17. Capture and Control of Laser-Accelerated Proton Beams: Experiment and Simulation

    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

  18. Accelerating protons to therapeutic energies with ultraintense, ultraclean, and ultrashort laser pulses

    Bulanov, Stepan S.; Brantov, Andrei; Bychenkov, Valery Yu.; Chvykov, Vladimir; Kalinchenko, Galina; Matsuoka, Takeshi; Rousseau, Pascal; Reed, Stephen; Yanovsky, Victor; Krushelnick, Karl; Litzenberg, Dale William; Maksimchuk, Anatoly

    2008-01-01

    Proton acceleration by high-intensity laser pulses from ultrathin foils for hadron therapy is discussed. With the improvement of the laser intensity contrast ratio to 10−11 achieved on the Hercules laser at the University of Michigan, it became possible to attain laser-solid interactions at intensities up to 1022 W∕cm2 that allows an efficient regime of laser-driven ion acceleration from submicron foils. Particle-in-cell (PIC) computer simulations of proton acceleration in the directed Coulom...

  19. Instrumentation for diagnostics and control of laser-accelerated proton (ion) beams.

    Bolton, P R; Borghesi, M; Brenner, C; Carroll, D C; De Martinis, C; Fiorini, Francesca; Flacco, A; Floquet, V; Fuchs, J; Gallegos, P; Giove, D; Green, J S; Green, S; Jones, B; Kirby, D; McKenna, P; Neely, D; Nuesslin, F; Prasad, R; Reinhardt, S; Roth, M; Schramm, U; Scott, G G; Ter-Avetisyan, S; Tolley, M; Turchetti, G; Wilkens, J J

    2014-05-01

    Suitable instrumentation for laser-accelerated proton (ion) beams is critical for development of integrated, laser-driven ion accelerator systems. Instrumentation aimed at beam diagnostics and control must be applied to the driving laser pulse, the laser-plasma that forms at the target and the emergent proton (ion) bunch in a correlated way to develop these novel accelerators. This report is a brief overview of established diagnostic techniques and new developments based on material presented at the first workshop on 'Instrumentation for Diagnostics and Control of Laser-accelerated Proton (Ion) Beams' in Abingdon, UK. It includes radiochromic film (RCF), image plates (IP), micro-channel plates (MCP), Thomson spectrometers, prompt inline scintillators, time and space-resolved interferometry (TASRI) and nuclear activation schemes. Repetition-rated instrumentation requirements for target metrology are also addressed. PMID:24100298

  20. RF acceleration system for 3 GeV proton synchrotron in JAERI-KEK joint project

    RF acceleration system for 3 GeV proton synchrotron in Joint JAERI-KEK high intensity proton accelerator project is described. In this synchrotron, since 8.3 x 1013 protons must be accelerated from 400 MeV to 3 GeV within 20 ms, wide-band frequency range and high accelerating voltage are required, and the system must be stable under heavy beam loading. From the results of R and D works over the past several years, high gradient rf cavity loaded with Magnetic Alloy and 1.2 MW class push-pull tetrode tube amplifier will be chosen for this system. Their design and R and D works for this synchrotron are reported. Furthermore, since longitudinal beam emittance will be controlled at injection and extraction by the rf manipulation because of alleviation of space charge effect, some simulation results for longitudinal motion by a particle tracking code are reported. (author)

  1. Post-acceleration of laser driven protons with a compact high field linac

    Sinigardi, Stefano; Londrillo, Pasquale; Rossi, Francesco; Turchetti, Giorgio; Bolton, Paul R.

    2013-05-01

    We present a start-to-end 3D numerical simulation of a hybrid scheme for the acceleration of protons. The scheme is based on a first stage laser acceleration, followed by a transport line with a solenoid or a multiplet of quadrupoles, and then a post-acceleration section in a compact linac. Our simulations show that from a laser accelerated proton bunch with energy selection at ~ 30MeV, it is possible to obtain a high quality monochromatic beam of 60MeV with intensity at the threshold of interest for medical use. In the present day experiments using solid targets, the TNSA mechanism describes accelerated bunches with an exponential energy spectrum up to a cut-off value typically below ~ 60MeV and wide angular distribution. At the cut-off energy, the number of protons to be collimated and post-accelerated in a hybrid scheme are still too low. We investigate laser-plasma acceleration to improve the quality and number of the injected protons at ~ 30MeV in order to assure efficient post-acceleration in the hybrid scheme. The results are obtained with 3D PIC simulations using a code where optical acceleration with over-dense targets, transport and post-acceleration in a linac can all be investigated in an integrated framework. The high intensity experiments at Nara are taken as a reference benchmarks for our virtual laboratory. If experimentally confirmed, a hybrid scheme could be the core of a medium sized infrastructure for medical research, capable of producing protons for therapy and x-rays for diagnosis, which complements the development of all optical systems.

  2. Cosmic Ray Protons Accelerated at Cosmological Shocks and Their Impact on Groups and Clusters of Galaxies

    Miniati, Francesco; Ryu, Dongsu; Kang, Hyesung; Jones, T. W.

    2001-01-01

    We investigate the production of cosmic ray (CR) protons at cosmological shocks by performing, for the first time, numerical simulations of large scale structure formation that include directly the acceleration, transport and energy losses of the high energy particles. CRs are injected at shocks according to the thermal leakage model and, thereafter, accelerated to a power-law distribution as indicated by the test particle limit of the diffusive shock acceleration theory. The evolution of the...

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

    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 μm Au) is only modified due to multiple small angle scattering. Thin targets (10 μm) show large source sizes of over 100 μm diameter for 5 MeV protons, which cannot be explained by multiple scattering only and are most likely the result of refluxing electrons

  4. Promoting International Cooperation and Public Acceptance in Utilizing Proton Accelerator Technology

    Proton engineering's main tool will be a high power proton accelerator which is to be established within next 10 years in the frame of Proton engineering Frontier Project. It is necessary for public to understand the meaning and importance of the project so that Project activities such as site preparation can be efficiently completed. And, it is required to establish a sound plan of international cooperation, and to develop user program to establish domestic foundation in utilizing the accelerator. Along with public relations activities through newspapers and broadcasting, there were more than 20 times of project presentations requested by various local governments, universities, and scientific societies. which resulted in strong support of the project from various societies. Based on collected information through actual visits to and internet surveys on foreign accelerators, a recommendation of international cooperation scheme has been made to complement domestic technological weak points, and there were discussions with some foreign organizations for that purpose. Especially, KEK of Japan, IHEP of China and KAERI have been deliberating on planning detail cooperation programs in developing and utilizing accelerator among 3 countries Some research items related with NT/BT/IT and utilizing proton beam were planned to be implemented in the Project. And a user program implemented in the Project In order to be prepared for future use of the accelerator. In order to upbring junior researchers for future days, an accelerator summer school has been planned to be held annually inviting prominent foreign and domestic lecturers

  5. Optimization of the Combined Proton Acceleration Regime with a Target Composition Scheme

    Yao, W P; Zheng, C Y; Liu, Z J; Yan, X Q

    2015-01-01

    A target composition scheme to optimize the combined proton acceleration regime is presented and verified by two-dimensional particle-in-cell (2D PIC) simulations by using an ultra-intense circularly-polarized (CP) laser pulse irradiating an overdense hydrocarbon (CH) target, instead of a pure hydrogen (H) one. The combined acceleration regime is a two-stage proton acceleration scheme combining the radiation pressure dominated acceleration (RPDA) stage and the laser wakefield acceleration (LWFA) stage sequentially together. With an ultra-intense CP laser pulse irradiating an overdense CH target, followed by an underdense tritium plasma gas, protons with higher energies (from about $20$ GeV up to about $30$ GeV) and lower energy spreads (from about $18\\%$ down to about $5\\%$ in full-width at half-maximum, or FWHM) are generated, as compared to the use of a pure H target. It is because protons can be more stably pre-accelerated in the first RPDA stage when using CH targets. With the increase of the carbon-to-hy...

  6. Physics prospects with High Intensity Proton Accelerator (J-PARC) at Tokai

    Nagamiya, S

    2003-01-01

    From Japanese fiscal year JFY01, which started on April 1, 2001, a new accelerator project to provide high-intensity proton beams proceeded into its construction phase. This project, which is now called the J-PARC (Japan Proton Accelerator Research Complex) project, is conducted under a cooperation of two institutions, KEK and JAERI. We set a goal to achieve 1 MW proton beams at 3 GeV and 0.75 MW beams at. The project will be completed within six years, with the anticipated first beams in the spring of 2007. In this article I describe a) the project itself, b) sciences to be pursued at this new accelerator complex and c) the present status and future plans of the project. (5 refs).

  7. Nonlinear laser-seeded modulation instability in a proton driver plasma wakefield accelerator

    Siemon, Carl; Khudik, Vladimir; Yi, S. Austin; Pukhov, Alexander; Shvets, Gennady

    2013-10-01

    A new method for seeding the modulation instability (MI) in a proton driver plasma wakefield accelerator (PDPWA) using a CO2 laser pulse is presented. The proton beam's envelope equation is used to analytically compare the laser seed with previously suggested seeding methods. Simulations demonstrate that a laser pulse placed ahead of a proton beam with a realistic longitudinal density profile leads to peak accelerating gradients that are comparable to those produced by other seeding methods. The nonlinear BNS damping of the MI is analytically shown to lead to instability saturation. The envelope equation is Fourier expanded into a set of coupled, nonlinear equations that describe the evolution of the beam's Fourier components. Peak beam density and peak accelerating gradient during the beam's evolution are estimated.

  8. Proton acceleration with high intensity lasers interacting on micro-cone targets

    D'Humieres, Emmanuel; Cowan, Tom; Gaillard, Sandrine; Le Galloudec, Nathalie; Rassuchine, Jennifer; Sentoku, Yasuhiko

    2006-10-01

    In the last few years, intense research has been conducted on laser-accelerated ion sources and their applications [1,2]. Proton beams accelerated from solid planar targets have exceptional properties that open new opportunities for ion beam generation and control. Experiments conducted at LANL and LULI have shown that high intensity lasers interacting on micro-cone targets can produce proton beams more collimated and more energetic than with planar targets. These micro-cone targets are composed of a curved cone attached to a micro-table. 2D PIC simulations were performed to understand the experiments and separate the effect of the cone from the effect of the micro-table. These new targets could help increase the laser-accelerated protons maximum energy to the 100 MeV range. [1] J. Fuchs et al., Nature Physics 2, 48 (2006). [2] T.Toncian et al., Science Vol. 312, 21 April 2006, p.410-413.

  9. Updated Report Acceleration of Polarized Protons to 120-150 GeV/c at Fermilab

    Courant, E D; Leonova, M A; Lin, A M T; Liu, J; Lorenzon, W; Nees, D A; Raymond, R S; Sivers, D W; Wong, V K; Kourbanis, I; Derbenev, Ya S; Morozov, V S; Crabb, D G; Reimer, P E; O'Fallon, J R; Fidecaro, G; Fidecaro, M; Hinterberger, F; Troshin, S M; Ukhanov, M N; Kondratenko, A M; van Oers, W T H

    2011-01-01

    The SPIN@FERMI collaboration has updated its 1991-95 Reports on the acceleration of polarized protons in Fermilab's Main Injector, which was commissioned by Fermilab. This Updated Report summarizes some updated Physics Goals for a 120-150 GeV/c polarized proton beam. It also contains an updated discussion of the Modifications and Hardware needed for a polarized beam in the Main Injector, along with an updated Schedule and Budget.

  10. The R&D Works on the High Intensity Proton Linear Accelerator for Nuclear Waste Transmutation

    Ito, N; Ino, H; Kawai, M; Kusano, J; Mizumoto, M; Murata, H; Oguri, H; Okumura, Y; Touchi, Y

    1996-01-01

    The R&D works of the 10MeV/10mA proton linear accelerator have been carried out for last four years. A high brightness hydrogen ion source, an RFQ and an RF power source have been developed and examined to achieve 2MeV proton beam. A DTL hot test model was also fabricated and a high power test has been carried out. The present status of the R&D works are described in this paper.

  11. Intensity modulated radiation therapy using laser-accelerated protons: a Monte Carlo dosimetric study

    In this paper we present Monte Carlo studies of intensity modulated radiation therapy using laser-accelerated proton beams. Laser-accelerated protons coming out of a solid high-density target have broad energy and angular spectra leading to dose distributions that cannot be directly used for therapeutic applications. Through the introduction of a spectrometer-like particle selection system that delivers small pencil beams of protons with desired energy spectra it is feasible to use laser-accelerated protons for intensity modulated radiotherapy. The method presented in this paper is a three-dimensional modulation in which the proton energy spectrum and intensity of each individual beamlet are modulated to yield a homogeneous dose in both the longitudinal and lateral directions. As an evaluation of the efficacy of this method, it has been applied to two prostate cases using a variety of beam arrangements. We have performed a comparison study between intensity modulated photon plans and those for laser-accelerated protons. For identical beam arrangements and the same optimization parameters, proton plans exhibit superior coverage of the target and sparing of neighbouring critical structures. Dose-volume histogram analysis of the resulting dose distributions shows up to 50% reduction of dose to the critical structures. As the number of fields is decreased, the proton modality exhibits a better preservation of the optimization requirements on the target and critical structures. It is shown that for a two-beam arrangement (parallel-opposed) it is possible to achieve both superior target coverage with 5% dose inhomogeneity within the target and excellent sparing of surrounding tissue

  12. Study on design of superconducting proton linac for accelerator driven subcritical nuclear power system

    Yu Qi; Xu Tao Guang

    2002-01-01

    As a prior option of the next generation of energy source, the accelerator driven subcritical nuclear power system (ADS) can use efficiently the uranium and thorium resource, transmute the high-level long-lived radioactive wastes and raise nuclear safety. The ADS accelerator should provide the proton beam with tens megawatts. The superconducting linac (SCL) is a good selection of ADS accelerator because of its high efficiency and low beam loss rate. It is constitute by a series of the superconducting accelerating cavities. The cavity geometry is determined by means of the electromagnetic field computation. The SCL main parameters are determined by the particle dynamics computation

  13. Study on design of superconducting proton linac for accelerator driven subcritical nuclear power system

    As a prior option of the next generation of energy source, the accelerator driven subcritical nuclear power system (ADS) can use efficiently the uranium and thorium resource, transmute the high-level long-lived radioactive wastes and raise nuclear safety. The ADS accelerator should provide the proton beam with tens megawatts. The superconducting linac (SCL) is a good selection of ADS accelerator because of its high efficiency and low beam loss rate. It is constitute by a series of the superconducting accelerating cavities. The cavity geometry is determined by means of the electromagnetic field computation. The SCL main parameters are determined by the particle dynamics computation

  14. Collective acceleration of protons by the plasma waves in a counterstreaming electron beam

    A novel advanced accelerator is proposed. The counterstreaming electron beam accelerator relies on the same physical mechanism as that of the plasma accelerator but replaces the stationary plasma in the plasma accelerator by a magnetized relativistic electron beam, drifting antiparallel to the driving source and the driven particles, as the wave supporting medium. The plasma wave in a counterstreaming electron beam can be excited either by a density-ramped driving electron beam or by properly beating two laser beams. The fundamental advantages of the counterstreaming electron beam accelerator over the plasma accelerator are a longer and tunable plasma wavelength, a longer pump depletion length or a larger transformer ratio, and easier pulse shaping for the driving source and the driven beam. Thus the energy gain of the driven particles can be greatly enhanced whereas the trapping threshold can be dramatically reduced so as to admit the possibility for proton acceleration

  15. The JAERI-KEK joint project on high intensity proton accelerator and overview of nuclear transmutation experimental facilities

    A status of the JAERI/KEK joint project on High Intensity Proton Accelerator is overviewed. It is highlighted that Experimental facilities for development of the accelerator driven system (ADS) for nuclear transmutation technology is proposed under the project. (author)

  16. Proposal of experimental facilities for studies of nuclear data and radiation engineering in the intense proton accelerator project

    A proposal is given on the facilities an experiments in the Intense Proton Accelerator Project (J-PARC) relevant to the nuclear data and radiation engineering, nuclear astrophysics, nuclear transmutation, accelerator technology and space technology and so on. (author)

  17. A crystal routine for collimation studies in circular proton accelerators

    Mirarchi, D.; Hall, G.; Redaelli, S.; Scandale, W.

    2015-07-01

    A routine has been developed to simulate interactions of protons with bent crystals in a version of SixTrack for collimation studies. This routine is optimized to produce high-statistics tracking simulations for a highly efficient collimation system, like the one of the CERN Large Hadron Collider (LHC). The routine has recently been reviewed and improved through a comparison with experimental data, benchmarked against other codes and updated by adding better models of low-probability interactions. In this paper, data taken with 400 GeV/c proton beams at the CERN-SPS North Area are used to verify the prediction of the routine, including the results of a more recent analysis.

  18. Proton acceleration from high-intensity laser interactions with thin foil targets

    Measurements of energetic proton production resulting from the interaction of high-intensity laser pulses with foil targets are described. Through the use of layered foil targets and heating of the target material we are able to distinguish three distinct populations of protons. One high energy population is associated with a proton source near the front surface of the target and is observed to be emitted with a characteristic ring structure. A source of typically lower energy, lower divergence protons originates from the rear surface of the target. Finally, a qualitatively separate source of even lower energy protons and ions is observed with a large divergence. Acceleration mechanisms for these separate sources are discussed

  19. Air-born contamination caused in a high-energy proton accelerator room

    Surface contamination caused during the operation of 12-GeV proton synchrotron, KEK have been studied by gamma-ray spectrometry and imaging plate technique. The surface of accelerator component was wiped with the filter paper. PSL value of imaging plate contacted on the filter paper decreased according to the half-life of 2 weeks. Therefore, it was assumed that 32P might be produced from Ar by the high-energy protons and neutrons and deposited on the accelerator components. (author)

  20. Laser accelerated protons captured and transported by a pulse power solenoid

    Burris-Mog, T.; Harres, K.; Nürnberg, F.; Busold, S.; Bussmann, M.; Deppert, O.; Hoffmeister, G.; Joost, M.; Sobiella, M.; Tauschwitz, A.; Zielbauer, B.; Bagnoud, V.; Herrmannsdoerfer, T.; Roth, M.; Cowan, T. E.

    2011-12-01

    Using a pulse power solenoid, we demonstrate efficient capture of laser accelerated proton beams and the ability to control their large divergence angles and broad energy range. Simulations using measured data for the input parameters give inference into the phase-space and transport efficiencies of the captured proton beams. We conclude with results from a feasibility study of a pulse power compact achromatic gantry concept. Using a scaled target normal sheath acceleration spectrum, we present simulation results of the available spectrum after transport through the gantry.

  1. Acceleration of petaelectronvolt protons in the Galactic Centre

    :,; Aharonian, F; Benkhali, F Ait; Akhperjanian, A G; Angüner, E O; Backes, M; Balzer, A; Becherini, Y; Tjus, J Becker; Berge, D; Bernhard, S; Bernlöhr, K; Birsin, E; Blackwell, R; Böttcher, M; Boisson, C; Bolmont, J; Bordas, P; Bregeon, J; Brun, F; Brun, P; Bryan, M; Bulik, T; Carr, J; Casanova, S; Chakraborty, N; Chalme-Calvet, R; Chaves, R C G; Chen, A; Chrétien, M; Colafrancesco, S; Cologna, G; Conrad, J; Couturier, C; Cui, Y; Davids, I D; Degrange, B; Deil, C; deWilt, P; Djannati-Ataï, A; Domainko, W; Donath, A; Drury, L O'C; Dubus, G; Dutson, K; Dyks, J; Dyrda, M; Edwards, T; Egberts, K; Eger, P; Ernenwein, J -P; Espigat, P; Farnier, C; Fegan, S; Feinstein, F; Fernandes, M V; Fernandez, D; Fiasson, A; Fontaine, G; Förster, A; Füßling, M; Gabici, S; Gajdus, M; Gallant, Y A; Garrigoux, T; Giavitto, G; Giebels, B; Glicenstein, J F; Gottschall, D; Goyal, A; Grondin, M -H; Grudzińska, M; Hadasch, D; Häffner, S; Hahn, J; Hawkes, J; Heinzelmann, G; Henri, G; Hermann, G; Hervet, O; Hillert, A; Hinton, J A; Hofmann, W; Hofverberg, P; Hoischen, C; Holler, M; Horns, D; Ivascenko, A; Jacholkowska, A; Jamrozy, M; Janiak, M; Jankowsky, F; Jung-Richardt, I; Kastendieck, M A; Katarzyński, K; Katz, U; Kerszberg, D; Khélifi, B; Kieffer, M; Klepser, S; Klochkov, D; Kluźniak, W; Kolitzus, D; Komin, Nu; Kosack, K; Krakau, S; Krayzel, F; Krüger, P P; Laffon, H; Lamanna, G; Lau, J; Lefaucheur, J; Lefranc, V; Lemiére, A; Lemoine-Goumard, M; Lenain, J -P; Lohse, T; Lopatin, A; Lu, C -C; Lui, R; Marandon, V; Marcowith, A; Mariaud, C; Marx, R; Maurin, G; Maxted, N; Mayer, M; Meintjes, P J; Menzler, U; Meyer, M; Mitchell, A M W; Moderski, R; Mohamed, M; Morå, K; Moulin, E; Murach, T; de Naurois, M; Niemiec, J; Oakes, L; Odaka, H; Öttl, S; Ohm, S; Opitz, B; Ostrowski, M; Oya, I; Panter, M; Parsons, R D; Arribas, M Paz; Pekeur, N W; Pelletier, G; Petrucci, P -O; Peyaud, B; Pita, S; Poon, H; Prokoph, H; Pühlhofer, G; Punch, M; Quirrenbach, A; Raab, S; Reichardt, I; Reimer, A; Reimer, O; Renaud, M; Reyes, R de los; Rieger, F; Romoli, C; Rosier-Lees, S; Rowell, G; Rudak, B; Rulten, C B; Sahakian, V; Salek, D; Sanchez, D A; Santangelo, A; Sasaki, M; Schlickeiser, R; Schüssler, F; Schulz, A; Schwanke, U; Schwemmer, S; Seyffert, A S; Simoni, R; Sol, H; Spanier, F; Spengler, G; Spies, F; Stawarz, Ł; Steenkamp, R; Stegmann, C; Stinzing, F; Stycz, K; Sushch, I; Tavernet, J -P; Tavernier, T; Taylor, A M; Terrier, R; Tluczykont, M; Trichard, C; Tuffs, R; Valerius, K; van der Walt, J; van Eldik, C; van Soelen, B; Vasileiadis, G; Veh, J; Venter, C; Viana, A; Vincent, P; Vink, J; Voisin, F; Völk, H J; Vuillaume, T; Wagner, S J; Wagner, P; Wagner, R M; Weidinger, M; Weitzel, Q; White, R; Wierzcholska, A; Willmann, P; Wörnlein, A; Wouters, D; Yang, R; Zabalza, V; Zaborov, D; Zacharias, M; Zdziarski, A A; Zech, A; Zefi, F; Żywucka, N

    2016-01-01

    Galactic cosmic rays reach energies of at least a few Peta-electronvolts (1 PeV =$10^\\mathbf{15}$ electron volts). This implies our Galaxy contains PeV accelerators (PeVatrons), but all proposed models of Galactic cosmic-ray accelerators encounter non-trivial difficulties at exactly these energies. Tens of Galactic accelerators capable of accelerating particle to tens of TeV (1 TeV =$10^\\mathbf{12}$ electron volts) energies were inferred from recent gamma-ray observations. None of the currently known accelerators, however, not even the handful of shell-type supernova remnants commonly believed to supply most Galactic cosmic rays, have shown the characteristic tracers of PeV particles: power-law spectra of gamma rays extending without a cutoff or a spectral break to tens of TeV. Here we report deep gamma-ray observations with arcminute angular resolution of the Galactic Centre regions, which show the expected tracer of the presence of PeV particles within the central 10~parsec of the Galaxy. We argue that the ...

  2. Monoenergetic neutrino beam for long baseline experiments

    In an electron capture process by a nucleus, emitted neutrinos are monoenergetic. We study a long baseline experiment with such a completely monoenergetic neutrino beam. This talk is based on Refs. 1 and 2. (author)

  3. Simulations of stable compact proton beam acceleration from a two-ion-species ultrathin foil

    We report stable laser-driven proton beam acceleration from ultrathin foils consisting of two ion species: heavier carbon ions and lighter protons. Multidimensional particle-in-cell simulations show that the radiation pressure leads to very fast and complete spatial separation of the species. The laser pulse does not penetrate the carbon ion layer, avoiding the proton Rayleigh-Taylor (RT)-like instability. Ultimately, the carbon ions are heated and spread extensively in space. In contrast, protons always ride on the front of the carbon ion cloud, forming a compact high quality bunch. We introduce a simple three-interface model to interpret the instability suppression in the proton layer. The model is backed by simulations of various compound foils such as carbon-deuterium and carbon-tritium foils. The effects of the carbon ions' charge state on proton acceleration are also investigated. It is shown that with the decrease of the carbon ion charge state, both the RT-like instability and the Coulomb explosion degrade the energy spectrum of the protons. Finally, full 3D simulations are performed to demonstrate the robustness of the stable two-ion-species regime.

  4. A beam intensity monitor for the Loma Linda cancer therapy proton accelerator

    A beam intensity monitor was tested in a 230-MeV proton beam at the Loma Linda Proton Therapy Accelerator during its commissioning at Fermi National Accelerator Laboratory. The intensity monitor was designed to regulate the beam intensity extracted from the proton synchrotron. The proton beam is tunable between 70 and 250 MeV with an adjustable intensity between 1010 and 1011 protons per spill. A beam spill is typically 1 s long with a 2-s repetition period. The intensity monitor must be radiation hard, expose minimum mass to the beam, and measure intensity to 1% in 1-ms time intervals. To this end, a 5-cm-thick xenon gas scintillator optically coupled to a photomultiplier tube (PMT) was tested to measure its response to the proton beam. The gas cell was operated at 1.2 atm of pressure and has 12.7-μm-thick titanium entrance and exit foils. The total mass exposed to the beam is 0.14 g/cm2 and is dominated by the titanium windows. This mass corresponds to a range attenuation equal to 1.4 mm of water. The energy lost to the xenon gas is about 70 keV per proton. Each passing proton will produce approximately 2000 photons. With a detection efficiency on the order of 0.05% for this UV light, one would anticipate over 1010 photoelectrons per second. In a 1-ms time bin there will be approximately 107 photoelectrons. This yields a resolution limited by systematics. For unregulated 0.4-s proton spills, we observe a response bandwidth in excess of 104 Hz. While signal-to-noise and linearity were not easily measured, we estimate as few as 103 protons can be observed suggesting a dynamic range in excess of 105 is available

  5. A beam intensity monitor for the Loma Linda cancer therapy proton accelerator.

    Coutrakon, G; Miller, D; Kross, B J; Anderson, D F; DeLuca, P; Siebers, J

    1991-01-01

    A beam intensity monitor was tested in a 230-MeV proton beam at the Loma Linda Proton Therapy Accelerator during its commissioning at Fermi National Accelerator Laboratory. The intensity monitor was designed to regulate the beam intensity extracted from the proton synchrotron. The proton beam is tunable between 70 and 250 MeV with an adjustable intensity between 10(10) and 10(11) protons per spill. A beam spill is typically 1 s long with a 2-s repetition period. The intensity monitor must be radiation hard, expose minimum mass to the beam, and measure intensity to 1% in 1-ms time intervals. To this end, a 5-cm-thick xenon gas scintillator optically coupled to a photomultiplier tube (PMT) was tested to measure its response to the proton beam. The gas cell was operated at 1.2 atm of pressure and has 12.7-microns-thick titanium entrance and exit foils. The total mass exposed to the beam is 0.14 g/cm2 and is dominated by the titanium windows. This mass corresponds to a range attenuation equal to 1.4 mm of water. The energy lost to the xenon gas is about 70 keV per proton. Each passing proton will produce approximately 2000 photons. With a detection efficiency on the order of 0.05% for this UV light, one would anticipate over 10(10) photoelectrons per second. In a 1-ms time bin there will be approximately 10(7) photoelectrons. This yields a resolution limited by systematics. For unregulated 0.4-s proton spills, we observe a response bandwidth in excess of 10(4) Hz. While signal-to-noise and linearity were not easily measured, we estimate as few as 10(3) protons can be observed suggesting a dynamic range in excess of 10(5) is available. PMID:1656180

  6. Radiological safety aspects of the operation of proton accelerators

    Particle accelerators are finding increased application in both the fundamental and applied sciences and in industry around the world. Positive ion accelerators are being applied in a host of fields, including radiation damage studies, induced activation and dating measurements, radiography, radiotherapy and fusion research. Because these devices can be potent sources of neutrons, it is important that information concerning their safe operation be widely available. This report is conceived as a source book providing authoritative guidance in radioprotection from an important category of radiation sources. It thus supplements other manuals of the IAEA related to the planning and implementation of radiation protection programmes. Refs, figs and tabs

  7. A proton medical accelerator by the SBIR route: An example of technology transfer

    Medical facilities for radiation treatment of cancer with protons have been established in many laboratories throughout the world. Essentially all of these have been designed as physics facilities, however, because of the requirement for protons up to 250 MeV. Most of the experience in this branch of accelerator technology lies in the national laboratories and a few large universities. A major issue is the transfer of this technology to the commercial sector to provide hospitals with simple, reliable, and relatively inexpensive accelerators for this application. The author has chosen the SBIR route to accomplish this goal. ACCTEK Associates have received grants from the National Cancer Institute for development of the medical accelerator and beam delivery systems. Considerable encouragement and help has been received from Argonne National Laboratory and the Department of Energy. The experiences to date and the pros and cons on this approach to commercializing medical accelerators are described. 4 refs., 1 fig

  8. RF properties of 1050 MHz, β = 0.49 Elliptical cavity for High Current Proton Acceleration

    Roy, Amitava; Mondal, J.; Mittal, K. C.

    2008-04-01

    BARC is developing technology for the accelerator driven subcritical system (ADSS) that will be mainly utilized for the transmutation of nuclear waste and enrichment of U233. Design and development of superconducting medium velocity cavity has been taken up as a part of the accelerator driven subcritical system project. We have studied RF properties of 1050 MHz, β = 0.49 single cell Elliptical cavity for possible use in High Current Proton Accelerator. Cavity shape optimization studies have been done by means of 2D cavity tuning code SUPERFISH and 3D High Frequency Simulation code CST Microwave Studio. The cavity peak electric and magnetic fields, power dissipation Pc, quality factor Q and effective shunt impedante ZT2 were calculated for various cavity dimensions using these codes. Based on these analyses a list of design parameter for the inner cell of the cavity has been suggested for possible use in high current proton accelerator.

  9. RF properties of 1050 MHz, β = 0.49 Elliptical cavity for High Current Proton Acceleration

    BARC is developing technology for the accelerator driven subcritical system (ADSS) that will be mainly utilized for the transmutation of nuclear waste and enrichment of U233. Design and development of superconducting medium velocity cavity has been taken up as a part of the accelerator driven subcritical system project. We have studied RF properties of 1050 MHz, β = 0.49 single cell Elliptical cavity for possible use in High Current Proton Accelerator. Cavity shape optimization studies have been done by means of 2D cavity tuning code SUPERFISH and 3D High Frequency Simulation code CST Microwave Studio. The cavity peak electric and magnetic fields, power dissipation Pc, quality factor Q and effective shunt impedante ZT2 were calculated for various cavity dimensions using these codes. Based on these analyses a list of design parameter for the inner cell of the cavity has been suggested for possible use in high current proton accelerator

  10. RF properties of 1050 MHz, {beta} = 0.49 Elliptical cavity for High Current Proton Acceleration

    Roy, Amitava; Mondal, J; Mittal, K C [Accelerator and Pulse Power Division, Bhabha Atomic Research Centre, Trombay, Mumbai - 400 085 (India)], E-mail: aroy@barc.gov.in

    2008-04-15

    BARC is developing technology for the accelerator driven subcritical system (ADSS) that will be mainly utilized for the transmutation of nuclear waste and enrichment of U{sup 233}. Design and development of superconducting medium velocity cavity has been taken up as a part of the accelerator driven subcritical system project. We have studied RF properties of 1050 MHz, {beta} = 0.49 single cell Elliptical cavity for possible use in High Current Proton Accelerator. Cavity shape optimization studies have been done by means of 2D cavity tuning code SUPERFISH and 3D High Frequency Simulation code CST Microwave Studio. The cavity peak electric and magnetic fields, power dissipation P{sub c}, quality factor Q and effective shunt impedante ZT{sup 2} were calculated for various cavity dimensions using these codes. Based on these analyses a list of design parameter for the inner cell of the cavity has been suggested for possible use in high current proton accelerator.

  11. Ultra-short laser-accelerated proton pulses have similar DNA-damaging effectiveness but produce less immediate nitroxidative stress than conventional proton beams.

    Raschke, S; Spickermann, S; Toncian, T; Swantusch, M; Boeker, J; Giesen, U; Iliakis, G; Willi, O; Boege, F

    2016-01-01

    Ultra-short proton pulses originating from laser-plasma accelerators can provide instantaneous dose rates at least 10(7)-fold in excess of conventional, continuous proton beams. The impact of such extremely high proton dose rates on A549 human lung cancer cells was compared with conventionally accelerated protons and 90 keV X-rays. Between 0.2 and 2 Gy, the yield of DNA double strand breaks (foci of phosphorylated histone H2AX) was not significantly different between the two proton sources or proton irradiation and X-rays. Protein nitroxidation after 1 h judged by 3-nitrotyrosine generation was 2.5 and 5-fold higher in response to conventionally accelerated protons compared to laser-driven protons and X-rays, respectively. This difference was significant (p < 0.01) between 0.25 and 1 Gy. In conclusion, ultra-short proton pulses originating from laser-plasma accelerators have a similar DNA damaging potential as conventional proton beams, while inducing less immediate nitroxidative stress, which probably entails a distinct therapeutic potential. PMID:27578260

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

    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

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

    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.

  14. Development of an explosive detection system using a proton accelerator

    The technology of explosive detection using radiation had been studied. On the basis that explosives has nitrogen atoms, the proof of principle experiments had been performed with the gamma ray which interacts with nitrogen atoms. The production of the gamma ray had been confirmed and, the scattered gamma ray from nitrogen had been observed in the experiment at Seoul National University. According to the experimental results, the specifications of the accelerator had been determined, 1.8MeV and 10mA. For a long-life time, a TCP type ion source using rf power have been developed. A tandem type accelerator had been chosen, and the important technologies, accelerating column and high voltage power supply, had been developed. On the basis of these technologies, the 1MV tandem accelerator had been constructed. The production process of C-13 film had been developed, and a 20kW water-cooled target had been fabricated. For gamma ray detection, a array detector with 9 BGO had been constructed, and the SW had been developed for the imaging of explosives. The lead shield had been fabricated for radiation shielding. The constructed system will be tested for the proof of explosive detection.

  15. High voltage technologies for radio frequency (RF) systems of proton accelerators in BARC

    Accelerators were invented to provide energetic particles to investigate the structure of the atomic nucleus. They speed up and increase the energy of a beam of particles by generating electric fields that accelerate the particles and magnetic fields that steer and focus them. An RF accelerator uses electromagnetic fields to propel charged particles to high speeds and to contain them in well-defined beams. The RF power amplifier, which provides electromagnetic fields, converts direct current (D.C.) input power into r.f. output power. The accelerating structures use this r.f. power to accelerate low-charge bunches to high energies. An important program of Department of Atomic Energy is to build accelerator driven sub critical reactor system (ADS). In ADS, high energy proton beam (from the CW particle accelerator, 1 GeV, > 20 mA) strikes a heavy element target which yields copious neutrons by (p, xn) spallation reaction inside a sub-critical core. One of the critical components of ADS is a 1 GeV, high current proton accelerator. It is being built in three phases. In the first phase, a 20 MeV, 30 mA, low energy high intensity proton accelerator (LEHIPA) is under construction at BARC. It requires radio frequency (RF) power for beam acceleration and is provided by high power RF systems. The RF systems require and use high voltage DC technologies (at 100 kV and 65 kV) as their subsystems that are developed with the help of local Indian industries. These technologies are making use of innovative techniques, new insulating materials and new technologies to avoid the critical problems (associated with high voltages) like arcing, sparking, energy deposition under arcing etc. This poster will describe in detail these high voltage technologies developed with the help of local Indian industries. (author)

  16. Shielding design for a proton medical accelerator facility

    Source terms and attenuation lengths for neutrons produced by 250 MeV protons on iron, copper and soft tissue, calculated with the FLUKA Monte Carlo code, were used for the shielding calculations (walls, ceilings, and floors) for the National Centre for Oncological Hadrontherapy to be built in Italy. Appropriate hypotheses on the proton current, beam loss factors, duty factors, occupancy factors and use factors of the shields were adopted. A dose equivalent limit of 1 mSv per year in the areas where the public has access and of 2 mSv per year for facility personnel were assumed. Shielding requirements vary from 1.5 m to about 4 m of ordinary concrete. The results agree with Monte Carlo simulations of the complete geometry of the facility obtained in a previous work. The access mazes to the treatment rooms were designed by the LCS Monte Carlo code by optimizing the length and section of their legs and their wall thicknesses with the dose equivalent limit of 2 mSv per year, fixed in the areas accessed by personnel. The resulting annual neutron dose equivalent at the maze mouth is 0.6 mSv

  17. Improve beam quality of laser proton acceleration with funnel-shaped-hole target

    Yang, Peng; Fan, Da Peng; Li, Yu Xiao

    2016-03-01

    Improve beam quality of laser proton acceleration using a funnel-shaped-hole target is demonstrated through particle simulations. When an intense short pulse laser illuminates a thin foil target with a hole at the rear surface, the proton beam divergence is suppressed compared with that obtained in a traditional flat target. In this paper, a funnel-shaped-hole target is proposed to improve the proton beam quality. Using two-dimensional particle-in-cell (PIC) simulations, three different shapes of target (funnel-shaped-hole target, cylinder-shaped-hole target and flat target) are simulated and compared. The funnel-shaped hole in the rear surface of the target helps to focus the electron cloud significantly and improve the maximum proton energy and suppress the proton beam divergence. Different thicknesses of the new target are also simulated, and the effects of thickness on the divergence angle and proton spectra are investigated. The optimal size of the new target is obtained and the quality of the proton beam is improved significantly. The funnel-shaped-hole target serves as a new method to improve the proton beam quality in laser-plasma interactions.

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

    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.

  19. Laser-driven proton beams: Acceleration mechanism, beam optimization, and radiographic applications

    Borghesi, M.; Romagnani, L.; Kar, S.; Wilson, P.A. [School of Mathematics and Physics, The Queen' s University of Belfast (United Kingdom); Cecchetti, C.A. [School of Mathematics and Physics, The Queen' s University of Belfast (United Kingdom); Also with the Intense Laser Irradiation Laboratory, IPCF-CNR, Pisa (Italy); Toncian, T.; Pipahl, A.; Amin, M.; Jung, R.; Osterholz, J.; Willi, O. [Institute for Laser and Plasma Physics, Heinrich Heine University, Dusseldorf (Germany); Fuchs, J.; Audebert, P.; Brambrink, E. [Laboratoire pour l' Utilisation des Lasers Intenses LULI, UMR 7605 CNRS-CEA-Ecole Polytechnique, 91 - Palaiseau (France); Antici, P. [Laboratoire pour l' Utilisation des Lasers Intenses LULI, UMR 7605 CNRS CEA Ecole Polytechnique, 91 - Palaiseau (France); Frascati National Laboratories INFN, Frascati (Italy); Nazarov, W. [School of Chemistry, University of St. Andrews, St. Andrews (United Kingdom); Clarke, R.J.; Notley, M.; Neely, D. [Central Laser Facility, STFC Rutherford Appleton Laboratory, OX Didcot (United Kingdom); Mora, P.; Grismayer, T. [Centre de Physique Theorique, Ecole Polytechnique, CNRS, 91 - Palaiseau (France); Schurtz, G. [Centre d' Etudes des Lasers Intenses et Applications, UMR 5107 University Bordeaux I-CNRS-CEA, 33 - Talence (France); Schiavi, A. [Dipartimento di Energetica, Universita -La Sapienza-, Rome (Italy); Sentoku, Y.; D' Humieres, E. [Physics Department, MS 220, University of Nevada, Reno, NV (United States)

    2008-08-15

    This paper reviews recent experimental activity in the area of optimization, control, and application of laser-accelerated proton beams, carried out at the Rutherford Appleton Laboratory and the Laboratoire pour l'Utilisation des Lasers Intenses 100 TW facility in France. In particular, experiments have investigated the role of the scale length at the rear of the plasma in reducing target-normal-sheath-acceleration acceleration efficiency. Results match with recent theoretical predictions and provide information in view of the feasibility of proton fast-ignition applications. Experiments aiming to control the divergence of the proton beams have investigated the use of a laser-triggered micro-lens, which employs laser-driven transient electric fields in cylindrical geometry, enabling to focus the emitted protons and select monochromatic beamlets; out of the broad spectrum beam. This approach could be advantageous in view of a variety of applications. The use of laser-driven protons as a particle probe for transient field detection has been developed and applied to a number of experimental conditions. Recent work in this area has focused on the detection of large-scale self-generated magnetic fields in laser-produced plasmas and the investigation of fields associated to the propagation of relativistic electron both on the surface and in the bulk of targets irradiated by high-power laser pulses. (authors)

  20. Fixed Field Alternating Gradient (FFAG)accelerators and their medical application in proton therapy

    Radiotherapy uses particle beams to irradiate and kill cancer tumors while sparing healthy tissues. Bragg peak shape of the proton energy loss in matter allows a ballistic improvement of the dose deposition compared with X rays. Thus, the irradiated volume can be precisely adjusted to the tumour. This thesis, in the frame of the RACCAM project, aims to the study and the design of a proton therapy installation based on a fixed field alternating gradient (FFAG) accelerator in order to build a spiral sector FFAG magnet for validation. First, we present proton therapy to define medical specifications leading to the technical specifications of a proton therapy installation. Secondly, we introduce FFAG accelerators through their past and on-going projects which are on their way around the world before developing the beam dynamic theories in the case of invariant focusing optics (scaling FFAG). We describe modelling and simulation tools developed to study the dynamics in a spiral scaling FFAG accelerator. Then we explain the spiral optic parameter search which has leaded to the construction of a magnet prototype. Finally, we describe the RACCAM project proton therapy installation starting from the injector cyclotron and ending with the extraction system. (author)

  1. Deep-penetration calculations in concrete and iron for shielding of proton therapy accelerators

    Proton accelerators in the energy range of approximately 200 MeV have become increasingly popular for cancer treatment in recent years. These proton therapy facilities usually involve bulky concrete or iron in their shielding design or accelerator structure. Simple shielding data, such as source terms or attenuation lengths for various proton energies and materials are useful in designing accelerator shielding. Understanding the appropriateness or uncertainties associated with these data, which are largely generated from Monte Carlo simulations, is critical to the quality of a shielding design. This study demonstrated and investigated the problems of deep-penetration calculations on the estimation of shielding parameters through an extensive comparison between the FLUKA and MCNPX calculations for shielding against a 200-MeV proton beam hitting an iron target. Simulations of double-differential neutron production from proton bombardment were validated by comparison with experimental data. For the concrete shielding, the FLUKA calculated depth–dose distributions were consistent with the MCNPX results, except for some discrepancies in backward directions. However, for the iron shielding, if FLUKA is used inappropriately then overestimation of neutron attenuation can be expected as shown by this work because of the multigroup treatment for low-energy neutrons in FLUKA. Two neutron energy group structures, three degrees of self-shielding correction, and two iron compositions were considered in this study. Significant variation of the resulting attenuation lengths indicated the importance of problem-dependent multigroup cross sections and proper modeling of iron composition in deep-penetration calculations.

  2. Feasibility Study on the Development of Proton Accelerator II

    Whang, Ki Woong [Korea Accelerator and Plasma Research Association, Seoul (Korea, Republic of)

    1997-09-01

    Present status and research trend of KOMAC (Korea Multipurpose Accelerator Complex)-grade accelerator construction in Europe, Japan, America, and Russia are surveyed in view of basic nuclear technology study in 2nd feasibility study on the KOMAC. KOMAC can be applied to study the increasing of nuclear reactor safety, the Proto-plant of transmutation technology for low cost nuclear fuel, the nuclear data production, the life science, mechanical dynamics, the structure probe, the radioisotope production, the cancer therapy, and the defense industry etc. And also KOMAC structure selection is investigated in point of utilization aims referred from various proposal of LANL and ORNL in USA, Neutron Science Research program in Japan, Energy Amplifier in Europe, and Institute of Theoretical and Experimental physics in Russia. As a result of meeting, study team is approached to the conclusion the KOMAC should be constructed to get the nuclear transmutation technology and the world leadership in future nuclear industry. Member`s opinion of study team agreed new nuclear technology, such as Accelerator Driven Energy Amplifier will be possible to sustain a survival of human being in post 21c. 7 tabs., 10 figs. (author)

  3. Activation of the IFMIF prototype accelerator and beam dump by deuterons and protons

    Simakov, S. P.; Bém, Pavel; Burjan, Václav; Fischer, U.; Forrest, R.A.; Götz, Miloslav; Honusek, Milan; Klein, H.; Kroha, Václav; Novák, Jan; Sauer, A.; Šimečková, Eva; Tiede, R.

    2008-01-01

    Roč. 83, 10-12 (2008), s. 1543-1547. ISSN 0920-3796 R&D Projects: GA MPO 2A-1TP1/101 Institutional research plan: CEZ:AV0Z10480505 Keywords : IFMIF * Protons and deuterons accelerator * Beam dump Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 0.828, year: 2008

  4. Isochoric heating of matter by laser-accelerated high-energy protons

    Antici, P.; Fuchs, J.; Benuzzi, A.; Brambrink, E.; Esposito, M.; Koenig, M.; Ravasio, A.; Audebert, P. [Paris-6 Univ., Ecole Polytechnique, Lab. pour l' Utilisation des Lasers Intenses, UMR 7605 CNRS-CEA, 91 - Palaiseau (France); Antici, P.; Atzeni, S.; Schiavi, A. [Roma Univ. La Sapienza, Dipt. di Energetica ed INFM (Italy); Schreiber, J. [Munchen Ludwig-Maximilan-Univ., Max-Planck-Institut fur Quantenoptik and Physik Dept., Garching (Germany)

    2006-06-15

    We describe an experiment on isochoric heating of matter by intense laser-accelerated protons. The experiment was performed using the LULI 100 TW facility with 15-20 J on target energy and > 10{sup 19} W.cm{sup -2} maximum focused intensity. Focusing the laser on a 10 micron thick Au foil, we accelerated forward a laminar proton beam with a maximum energy of 16 MeV. This proton beam irradiated and heated a secondary target positioned after a variable vacuum gap. The heating was diagnosed by 1- and 2-dimensional time-resolved measurements of the optical self-emission of the heated target rear-surface. Detailed results as a function of the Z and the thickness of the secondary target as well as analysis, including a full modelling of the target heating with a 2-dimensional hydro-code (DUED) coupled to a proton energy deposition code, were obtained. We have also studied the efficiency of heating as a function of the primary target topology, i.e. either flat, which results in a diverging proton beam, or curved, which has the ability of focusing partly the proton beam. (authors)

  5. VHEeP: A very high energy electron-proton collider based on proton-driven plasma wakefield acceleration

    Caldwell, Allen

    2015-01-01

    Based on current CERN infrastructure, an electron-proton collider is proposed at a centre-of-mass energy of about 9 TeV. A 7 TeV LHC bunch is used as the proton driver to create a plasma wakefield which then accelerates electrons to 3 TeV, these then colliding with the other 7 TeV LHC proton beam. The basic parameters of the collider are presented, which although of very high energy, has integrated luminosities of the order of 1 pb$^{-1}$/year. For such a collider, with a centre-of-mass energy 30 times greater than HERA, parton momentum fractions, $x$, down to about $10^{-8}$ are accessible for $Q^2$ of 1 GeV$^2$ and could lead to effects of saturation or some other breakdown of DGLAP being observed. The total photon-proton cross section can be measured up to very high energies and also at different energies as the possibility of varying the electron beam energy is assumed; this could have synergy with cosmic-ray physics. Other physics which can be pursued at such a collider are contact interaction searches, ...

  6. Future colliders based on a modulated proton bunch driven plasma wakefield acceleration

    Xia, Guoxing; Muggli, Patric

    2012-01-01

    Recent simulation shows that a self-modulated high energy proton bunch can excite a large amplitude plasma wakefield and accelerate an externally injected electron bunch to the energy frontier in a single stage acceleration through a long plasma channel. Based on this scheme, future colliders, either an electron-positron linear collider (e+-e- collider) or an electron-hadron collider (e-p collider) can be conceived. In this paper, we discuss some key design issues for an e+-e- collider and a high energy e-p collider, based on the existing infrastructure of the CERN accelerator complex.

  7. Micro-sphere layered targets efficiency in laser driven proton acceleration

    Floquet, V.; Martin, Ph.; Ceccotti, T. [CEA, IRAMIS, SPAM, F-91191 Gif-sur-Yvette (France); Klimo, O.; Psikal, J.; Limpouch, J.; Proska, J.; Novotny, F.; Stolcova, L. [FNSPE, Czech Technical University in Prague, CR-11519 Prague (Czech Republic); Velyhan, A. [Institute of Physics v.v.i. ASCR, Na Slovance 1999, Prague (Czech Republic); Macchi, A. [Istituto Nazionale di Ottica, Consiglio Nazionale delle Ricerche, research unit “Adriano Gozzini,” Via G. Moruzzi 1, 56124 Pisa (Italy); Dipartimento di Fisica “Enrico Fermi,” Università di Pisa, largo Bruno Pontecorvo 3, 56127 Pisa (Italy); Sgattoni, A. [Dipartimento di Energia, Politecnico di Milano, Milano (Italy); Istituto Nazionale di Ottica, Consiglio Nazionale delle Ricerche, research unit “Adriano Gozzini,” Via G. Moruzzi 1, 56124 Pisa (Italy); Vassura, L. [LULI, UMR7605, CNRS-CEA-Ecole Polytechnique-Paris 6, 91128 Palaiseau (France); Dipartimento SBAI, Università di Roma “La Sapienza,” Via A. Scarpa 14, 00161 Roma (Italy); Labate, L.; Baffigi, F.; Gizzi, L. A. [Istituto Nazionale di Ottica, Consiglio Nazionale delle Ricerche, research unit “Adriano Gozzini,” Via G. Moruzzi 1, 56124 Pisa (Italy)

    2013-08-28

    Proton acceleration from the interaction of high contrast, 25 fs laser pulses at >10{sup 19} W/cm{sup 2} intensity with plastic foils covered with a single layer of regularly packed micro-spheres has been investigated experimentally. The proton cut-off energy has been measured as a function of the micro-sphere size and laser incidence angle for different substrate thickness, and for both P and S polarization. The presence of micro-spheres with a size comparable to the laser wavelength allows to increase the proton cut-off energy for both polarizations at small angles of incidence (10∘). For large angles of incidence, however, proton energy enhancement with respect to flat targets is absent. Analysis of electron trajectories in particle-in-cell simulations highlights the role of the surface geometry in the heating of electrons.

  8. Experimental stand for studying the impact of laser-accelerated protons on biological objects

    Burdonov, K. F.; Eremeev, A. A.; Ignatova, N. I.; Osmanov, R. R.; Sladkov, A. D.; Soloviev, A. A.; Starodubtsev, M. V.; Ginzburg, V. N.; Kuz'min, A. A.; Maslennikova, A. V.; Revet, G.; Sergeev, A. M.; Fuchs, J.; Khazanov, E. A.; Chen, S.; Shaykin, A. A.; Shaikin, I. A.; Yakovlev, I. V.

    2016-04-01

    An original experimental stand is presented, aimed at studying the impact of high-energy protons, produced by the laser-plasma interaction at a petawatt power level, on biological objects. In the course of pilot experiments with the energy of laser-accelerated protons up to 25 MeV, the possibility is demonstrated of transferring doses up to 10 Gy to the object of study in a single shot with the magnetic separation of protons from parasitic X-ray radiation and fast electrons. The technique of irradiating the cell culture HeLa Kyoto and measuring the fraction of survived cells is developed. The ways of optimising the parameters of proton beams and the suitable methods of their separation with respect to energy and transporting to the studied living objects are discussed. The construction of the stand is intended for the improvement of laser technologies for hadron therapy of malignant neoplasms.

  9. RF properties of 700 MHz, = 0.42 elliptical cavity for high current proton acceleration

    Amitava Roy; J Mondal; K C Mittal

    2008-12-01

    BARC is developing a technology for the accelerator-driven subcritical system (ADSS) that will be mainly utilized for the transmutation of nuclear waste and enrichment of U233. Design and development of superconducting medium velocity cavity has been taken up as a part of the accelerator-driven subcritical system project. We have studied RF properties of 700 MHz, = 0.42 single cell elliptical cavity for possible use in high current proton acceleration. The cavity shape optimization studies have been done using SUPERFISH code. A calculation has been done to find out the velocity range over which this cavity can accelerate protons efficiently and to select the number of cells/cavity. The cavity's peak electric and magnetic fields, power dissipation c, quality factor and effective shunt impedance 2 were calculated for various cavity dimensions using these codes. Based on these analyses a list of design parameters for the inner cell of the cavity has been suggested for possible use in high current proton accelerator.

  10. Reliability and availability of high power proton accelerators

    It has become increasingly important to address the issues of operational reliability and availability of an accelerator complex early in its design and construction phases. In this context, reliability addresses the mean time between failures and the failure rate, and availability takes into account the failure rate as well as the length of time required to repair the failure. Methods to reduce failure rates include reduction of the number of components and over-design of certain key components. Reduction of the on-line repair time can be achieved by judiciously designed hardware, quick-service spare systems, and redundancy. In addition, provisions for easy inspection and maintainability are important for both reduction of the failure rate as well as reduction of the time to repair. The radiation safety exposure principle of ALARA (As Low As Reasonably Achievable) is easier to comply with when easy inspection capability and easy maintainability are incorporated into the design. Discussions of past experience in improving accelerator availability, some recent developments, and potential R and D items are presented

  11. Tree-code simulations of proton acceleration from laser-irradiated wire targets

    Recent experiments using Terawatt lasers to accelerate protons deposited on thin wire targets are modeled with a new type of gridless plasma simulation code. In contrast to conventional mesh-based methods, this technique offers a unique capability in emulating the complex geometry and open-ended boundary conditions characteristic of contemporary experimental conditions. Comparisons of ion acceleration are made between the tree code and standard particle-in-cell simulations for a typical collisionless 'hole boring' scenario in slab geometry. The utility of the gridless approach is emphasized by a series of simulations in 'wire' geometry, in which electrons are permitted to circulate around the target at arbitrary distances from the focal region. The simulations reveal a number of features in common with recent experimental observations, including a disclike emission pattern of the MeV protons accelerated away from the wire

  12. Difference in acceleration of electrons, protons and deuterons in a laser beam

    A. Dubik

    2010-07-01

    Full Text Available Purpose: The aim of this paper is to find in a numerical way the main differences in the trajectories and kinetic energies of electrons, protons and deuterons accelerated in the laser or maser beams propagating in a vacuum, with an additionally applied external static co-axial magnetic field. The accelerated particles to the well defined energies are of interest in many applications, among others in medicine or in processing of different materials.Design/methodology/approach: Due to differences in masses the comparison between the acceleration processes of electrons, protons and deuterons is possible to perform after appropriate parameters of radiation of a laser, maser and a static magnetic field have been designed.Findings: The quantitative illustrations of the calculation results in a graphical form enable to discuss the main differences in the acceleration process of electrons, protons and deuterons. It was found that the rate at which a particle gains the energy depends not only on the particle’s mass but also on the stage of the process. Due to the mass differences, in order to keep a particle inside the radiation beam, significantly different static magnetic fields should be used to each kind of a particle. The authors have found an answer to the question why the rate at which particles energy increases in time, is different for different particles and why the difference depends on a stage of the acceleration process.Research limitations/implications: Limits in the energy of accelerated particles are caused by the limits of laser or maser beam energy or power available at present and the static magnetic fields.Originality/value: The authors show, in an exact numerical way, the values of the acceleration equipment parameters which should be selected to obtain the desired energy of the accelerated particles. It is explained why the rate at which a particle gains the energy depends on the stage of the process and on the particle’s mass.

  13. Conceptual study of high power proton linac for accelerator driven subcritical nuclear power system

    Yu Qi; Ouyang Hua Fu; Xu Tao Guang

    2001-01-01

    As a prior option of the next generation of energy source, the accelerator driven subcritical nuclear power system (ADS) can use efficiently the uranium and thorium resource, transmute the high-level long-lived radioactive wastes and raise nuclear safety. The ADS accelerator should provide the proton beam with tens megawatts. The superconducting linac is a good selection of ADS accelerator because of its high efficiency and low beam loss rate. The ADS accelerator presented by the consists of a 5 MeV radio-frequency quadrupole, a 100 MeV independently phased superconducting cavity linac and a 1 GeV elliptical superconducting cavity linac. The accelerating structures and main parameters are determined and the research and development plan is considered

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

    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.

  15. Non scaling fixed field gradient accelerator design for proton and carbon therapy

    The Fixed Field Alternating Gradient (FFAG) accelerators became again a subject of great interest in many accelerator physics applications, after more than fifty years of their first appearance. The original FFAG's are the 'scaling' design where particle orbits during acceleration scale with momentum. In Japan a number of scaling FFAG's have been built, or are under construction. The original designs are proposed and used in many applications: proton acceleration in medical field for cancer therapy, electron acceleration for the low (food radiation, electron demonstration ring) and high energies (future e-RHIC 10 GeV), acceleration of muons (the 'PRISM'-project in Japan), proton acceleration for the AGS upgrade at Brookhaven National Laboratory, etc. There are many advantages of the scaling FFAG with respect to the today common use of synchrotrons, cyclotrons, or linear accelerators-linacs: the magnetic field is fixed, possibility of high repetition rate. Disadvantages of the scaling FFAG are the large required aperture and large circumference. This is due to the scaling law between the orbit and momentum and the relatively large opposite bending field requirement. This proposed non-scaling design had been extensively investigated in many respects. A European proposal to build a non-scaling FFAG electron demonstration ring is in progress. Recent international CYCLOTRON conference had dedicated time for the update on the FFAG acceleration. The non-scaling FFAG's should dramatically reduce required aperture and circumferences. If the fixed magnetic field produces the linear gradient, there is a tune variation during fast acceleration and resonances are a crossed. The small dispersion function and strong focusing in this design reduces the aperture size for almost an order of magnitude with respect to standard scaling FFAG design. We present one of the possible applications of the non-scaling proton and carbon cancer therapy FFAG accelerator. The cancer proton therapy

  16. Cosmic Ray Protons Accelerated at Cosmological Shocks and Their Impact on Groups and Clusters of Galaxies

    Miniati, F; Kang, H; Jones, T W; Miniati, Francesco; Ryu, Dongsu; Kang, Hyesung

    2001-01-01

    We investigate the production of cosmic ray (CR) protons at cosmological shocks by performing, for the first time, numerical simulations of large scale structure formation that include directly the acceleration, transport and energy losses of the high energy particles. CRs are injected at shocks according to the thermal leakage model and, thereafter, accelerated to a power-law distribution as indicated by the test particle limit of the diffusive shock acceleration theory. The evolution of the CR protons accounts for losses due to adiabatic expansion/compression, Coulomb collisions and inelastic p-p scattering. Our results suggest that CR protons produced at shocks formed in association with the process of large scale structure formation could amount to a substantial fraction of the total pressure in the intra-cluster medium. Their presence should be easily revealed by GLAST through detection of gamma-ray flux from the decay of neutral pions produced in inelastic p-p collisions of such CR protons with nuclei o...

  17. Scaling of TNSA-accelerated proton beams with laser energy and focal spot size

    Obst, Lieselotte; Metzkes, Josefine; Schramm, Ulrich [Helmholtz-Zentrum Dresden - Rossendorf, Dresden (Germany); Technische Universitaet Dresden, Dresden (Germany); Zeil, Karl; Kraft, Stephan [Helmholtz-Zentrum Dresden - Rossendorf, Dresden (Germany)

    2014-07-01

    We investigate the acceleration of high energy proton pulses generated by relativistic laser-plasma interaction. The scope of this work was the systematic investigation of the scaling of the laser proton acceleration process in the ultra-short pulse regime in order to identify feasible routes towards the potential medical application of this accelerator technology for the development of compact proton sources for radiation therapy. We present an experimental study of the proton beam properties under variation of the laser intensity irradiating thin foil targets. This was achieved by employing different parabolic mirrors with various focal lengths. Hence, in contrast to moving the target in and out of focus, the target was always irradiated with an optimized focal spot. By observing the back reflected light of the laser beam from the target front side, pre-plasma effects on the laser absorption could be investigated. The study was performed at the 150 TW Draco Laser facility of the Helmholtz-Zentrum Dresden-Rossendorf with ultrashort (30 fs) laser pulses of intensities of about 8 . 10{sup 20} W/cm{sup 2}.

  18. Warp simulations for capture and control of laser-accelerated proton beams

    The capture of laser-accelerated proton beams accompanied by co-moving electrons via a solenoid field has been studied with particle-in-cell simulations. The main advantages of the Warp simulation suite that was used, relative to envelope or tracking codes, are the possibility of including all source parameters energy resolved, adding electrons as second species and considering the non-negligible space-charge forces and electrostatic self-fields. It was observed that the influence of the electrons is of vital importance. The magnetic effect on the electrons out balances the space-charge force. Hence, the electrons are forced onto the beam axis and attract protons. Besides the energy dependent proton density increase on axis, the change in the particle spectrum is also important for future applications. Protons are accelerated/decelerated slightly, electrons highly. 2/3 of all electrons get lost directly at the source and 27% of all protons hit the inner wall of the solenoid.

  19. Transport of laser accelerated proton beams and isochoric heating of matter

    The acceleration of intense proton and ion beams by ultra-intense lasers has matured to a point where applications in basic research and technology are being developed. Crucial for harvesting the unmatched beam parameters driven by the relativistic electron sheath is the precise control of the beam. We report on recent experiments using the PHELIX laser at GSI, the VULCAN laser at RAL and the TRIDENT laser at LANL to control and use laser accelerated proton beams for applications in high energy density research. We demonstrate efficient collimation of the proton beam using high field pulsed solenoid magnets, a prerequisite to capture and transport the beam for applications. Furthermore we report on two campaigns to use intense, short proton bunches to isochorically heat solid targets up to the warm dense matter state. The temporal profile of the proton beam allows for rapid heating of the target, much faster than the hydrodynamic response time thereby creating a strongly coupled plasma at solid density. The target parameters are then probed by X-ray Thomson scattering (XRTS) to reveal the density and temperature of the heated volume. This combination of two powerful techniques developed during the past few years allows for the generation and investigation of macroscopic samples of matter in states present in giant planets or the interior of the earth.

  20. Warp simulations for capture and control of laser-accelerated proton beams

    The capture of laser-accelerated proton beams accompanied by co-moving electrons via a solenoid field has been studied with particle-in-cell simulations. The main advantages of the Warp simulation suite that we have used, relative to envelope or tracking codes, are the possibility of including all source parameters energy resolved, adding electrons as second species and considering the non-negligible space-charge forces and electrostatic self-fields. It was observed that the influence of the electrons is of vital importance. The magnetic effect on the electrons outbalances the space-charge force. Hence, the electrons are forced onto the beam axis and attract protons. Beside the energy dependent proton density increase on axis, the change in the particle spectrum is also important for future applications. Protons are accelerated/decelerated slightly, electrons highly. 2/3 of all electrons get lost directly at the source and 27% of all protons hit the inner wall of the solenoid.

  1. High quality proton beams from hybrid integrated laser-driven ion acceleration systems

    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 15M€. 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

  2. High quality proton beams from hybrid integrated laser-driven ion acceleration systems

    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.

  3. Comparison of scaling laws with PIC simulations for proton acceleration with long wavelength pulses

    We have performed a survey of proton acceleration induced by long wavelength pulses to explore their peak energy dependence on the pulse intensity, target thickness and density. The simulations carried out with the PIC code ALADYN for a circularly polarized pulse have been compared with the scaling laws for radiation pressure acceleration (RPA) in the thick target and thin target regimes known as hole boring (HB) and relativistic mirror (RM) respectively. Since the critical density scales as λ-2, longer wavelength pulses allow to work with low density targets several microns thick and with moderate laser power. Under these conditions is possible to enter the RM region, where the key parameter is the ratio α between twice laser energy and the mirror rest energy; the corresponding acceleration efficiency is given by α/(1+α). For a fixed intensity the minimum thickness of the target, and consequently the highest acceleration, is determined by the threshold of self induced transparency. In this case the number of accelerated particles scales with λ whereas the total energy does not depend on it. The agreement of PIC simulations with RPA and RM scalings, including the transition regions, suggests that these scalings can safely be used as the first step in the parametric scans also for large wavelength pulses such as CO2 lasers, to explore possible alternatives to short wavelength very high power Ti:Sa lasers for proton acceleration.

  4. Proton acceleration with ultra-high intensity laser: study and application to isochoric heating

    The interaction of ultra-high intensity, ultra-short laser pulses with matter is an interesting source of energetic ions. During this work, we studied the production of energetic protons and their application to isochoric heating using kinetics and hydrodynamics code. We first considered the behavior of the maximum proton kinetic energy with the Target Normal Sheath Acceleration (TNSA) mechanism, in the sub-ps interaction regime, as a function of different parameters, especially the laser pulse duration. We showed that stretching the pulse duration, with a constant laser energy, led to the preheating and the expansion of the plasma slab. This expansion can be beneficial or detrimental regarding the maximum proton kinetic energy. The results we obtained helped to explain an experimental study carried out at the Laboratoire d'Optique Appliquee. We then developed a semi-analytical model trying to describe the maximum proton kinetic energy that can be produced in the TNSA regime. The results we obtained can retrieve the minimum intensity, of the order of 6.1021 W/cm2, that is required to reach proton energies of 150 MeV with femtosecond, few joules laser pulses. As a final step, we were interested in the use of these proton beams for isochoric heating. We first characterized the proton distribution function produced by targets consisting in an heavy substrate with an hydrogen is deposited at the rear side. By the mean of hydrodynamics simulations, we studied the characteristic expansion time of the heated target by varying several parameters such as the heated sample distance from the proton source, the intensity and focal spot size of the laser, and the areal density of the dot. Finally, we extended the previous study to cylindrical targets and we demonstrated that it is possible to counterbalance the natural divergence of the proton beam and hence, to reach higher temperatures. (author)

  5. High current, high energy proton beams accelerated by a sub-nanosecond laser

    Margarone, Daniele; Krása, Josef; Picciotto, A.; Torrisi, L.; Láska, Leoš; Velyhan, Andriy; Prokůpek, Jan; Ryc, L.; Parys, P.; Ullschmied, Jiří; Rus, Bedřich

    2011-01-01

    Roč. 653, č. 1 (2011), s. 159-163. ISSN 0168-9002 R&D Projects: GA ČR(CZ) GAP205/11/1165; GA AV ČR IAA100100715; GA MŠk(CZ) 7E09092 Grant ostatní: FP 7 Extreme light infrastructure preparatory phase (ELI-PP)(XE) INFRA-2007-2.2-01 212105 Institutional research plan: CEZ:AV0Z10100523; CEZ:AV0Z20430508 Keywords : laser -acceleration * proton beam * high ion current * time-of-flight * proton energy distribution Subject RIV: BH - Optics, Masers, Laser s Impact factor: 1.207, year: 2011

  6. Employing laser-accelerated proton beams to diagnose high intensity laser-plasma interactions

    Sarri, G.; Cecchetti, C. A.; Quinn, K.; Norreys, P. A.; Trines, R.; Willi, O.; Fuchs, J.; McKenna, P.; Quinn, M.; Pegoraro, F.; Bulanov, S. V.; Borghesi, M. [School of Mathematics and Physics, Queen' s University Belfast, BT7 1NN (United Kingdom); Istituto Nazionale di Ottica (INO-CNR) (Italy); School of Mathematics and Physics, Queen' s University Belfast, BT7 1NN (United Kingdom); STFC Rutherford Appleton Laboratory, Didcot, OX11 0QX (United Kingdom); Institut fur Laser und Plasmaphysik, Heinrich-Heine-Universitaat, Dusseldorf (Germany); LULI, Ecole Polytechnique, CNRS, CEA, UPMC, route de Saclay, 91128 Palaiseau (France); SUPA, Department of Physics, University of Strathclyde, Glasgow G4 0NG (United Kingdom); Dipartimento di Fisica, Universita di Pisa and INFM, Pisa (Italy); APRC, JAEA, Kizugawa, Kyoto, 619-0215 (Japan); School of Mathematics and Physics, Queen' s University Belfast, BT7 1NN (United Kingdom)

    2012-07-09

    A review of the proton radiography technique will be presented. This technique employs laser-accelerated laminar bunches of protons to diagnose the temporal and spatial characteristic of the electric and magnetic fields generated during high-intensity laser-plasma interactions. The remarkable temporal and spatial resolution that this technique can achieve (of the order of a picosecond and a few microns respectively) candidates this technique as the preferrable one, if compared to other techniques, to probe high intensity laser-matter interactions.

  7. Enhanced laser-driven proton-acceleration from limited mass targets by high temporal contrast ultra-intense lasers

    Buffechoux, S.; Nakatsutsumi, M.; Mancic, A.; Audebert, P.; Fuchs, J.; Antici, P. [UPMC, CNRS, Ecole Polytech, LULI, CEA, F-91128 Palaiseau (France); Fourmaux, S.; Pepin, H.; Buffechoux, S. [INRS-EMT, Varennes, Quebec, (Canada); Andreev, A. [Vavilov State Optical Institute, St. Petersburg (Russian Federation); Zeil, K.; Burris, T.; Cowan, T. [FZD, Rossendorf (Germany); Sarri, G.; Borghesi, M. [School of Mathematics and Physics, The Queen' s University, Belfast (United Kingdom); Amin, M.; Willi, O. [Institut fur Laser und Plasma Physik, Heinrich-Heine-Universitat Dusseldorf, Universitatstrasse 1, 40225 Dusseldorf (Germany); Gaillard, S. [Physics Department, MS-220, University of Nevada, Reno, Nevada 89557 (United States); Tampo, A. [JAEA-KPSI-PRMC, Kizu (Japan); Antici, P. [Dipartimento di Energetica, Universita di Roma -La Sapienza, - Via Scarpa 14-16, 00161 Roma (Italy)

    2010-07-01

    Beam optimization of laser-accelerated protons is required to progress towards the development of applications, e.g. for fast ignition of fusion targets or dense plasma radiography. For this, three areas of improvement need to be pursued: increasing the maximum proton energy, enhancing the laser-to-protons conversion efficiency and reducing the beam divergence. Here we report on the reasoning which led us to envision limited size target to improve protons acceleration. We point out that pre plasma leakage from the target front side is a critical issue to allow efficient acceleration from such limited size targets and show that with very high temporal contrast laser pulses proton acceleration is improved in such targets. (authors)

  8. Constraining the electron and proton acceleration efficiencies in merger shocks in galaxy clusters

    Vazza, F; Brueggen, M; Huber, B

    2015-01-01

    Radio relics in galaxy clusters are associated with powerful shocks that (re)accelerate relativistic electrons. It is widely believed that the acceleration proceeds via diffusive shock acceleration. In the framework of thermal leakage, the ratio of the energy in relativistic electrons to the energy in relativistic protons should should be smaller than $K_{\\rm e/p} \\sim 10^{-2}$. The relativistic protons interact with the thermal gas to produce $\\gamma$-rays in hadronic interactions. Combining observations of radio relics with upper limits from $\\gamma$-ray observatories can constrain the ratio $K_{\\rm e/p}$. In this work we selected 10 galaxy clusters that contain double radio relics, and derive new upper limits from the stacking of $\\gamma$-ray observations by FERMI. We modelled the propagation of shocks using a semi-analytical model, where we assumed a simple geometry for shocks and that cosmic ray protons are trapped in the intracluster medium. Our analysis shows that diffusive shock acceleration has diffi...

  9. Reduce proton energy spread by target ablation

    Zhao, Shuan; Chen, Jiaer; Yan, Xueqing

    2015-01-01

    It's shown that, with strong target ablation monoenergetic protons along the laser direction is available during the laser aluminum foil interaction, which is different from the classic TNSA theory. When the laser pre-pulse is too strong that the whole target is vaporized, the energetic electrons generated in the gas preplasma will play an important role for the ion acceleration because the sheath field will not be available. These electrons beam, which is highly directional, will setup triangle envelope acceleration field along the laser direction at the target rear, reducing the ion energy spread.

  10. Evaluation of neutron dose equivalent from the Mevion S250 proton accelerator: measurements and calculations

    Neutron production is of concern for proton therapy, especially for passive scattering proton beam delivery methods. The levels of neutron dose equivalent vary significantly with system design and treatment parameters. The purpose of this study was to examine neutron dose equivalent per therapeutic dose (H/D) around the Mevion S250 proton therapy system, a novel design of proton therapy systems. The benchmark comparisons between measurement and simulation were found to be within a factor of 2 for most cases. The H/D values were evaluated as a function of various parameters. The results showed that, at a standard reference condition (10 × 10 cm2 field size, distance 1 m detector-to-isocenter lateral to the primary proton beam direction), the H/D values range from 0.72 to 3.37 mSv Gy−1 for all configurations studied. The H/D values generally (1) decreased as the neutron detectors moved away from the isocenter, (2) decreased with increasing aperture field sizes, (3) increased with increasing angle from the initial beam axis and (4) were independent of treatment nozzle position. The H/D trends were consistent with other existing passive scattering proton accelerators reported in the literature. (paper)

  11. Application of laser-accelerated high-energy protons for isochoric heating of matter

    Antici, P.; Fuchs, J.; Audebert, P.; Benuzzi, A.; Brambrink, E.; Exposito, M.; Koenig, M.; Ravasio, A.; Schreiber, J.

    2005-07-01

    We have evaluated the interest of using laser-accelerated protons to heat matter isochorically and compared it to heating by fast electrons. The experiment was performed using the two intense short pulses of the LULI 100 TW facility with 15-20 J energy and> 10- 19 W. cm-2 intensity each. One beam, focused on a 10 micron thick Au foil, generated forward a laminar proton beam with a maximum energy of 16 MeV. this proton beam irradiated and heated a secondary target positioned after a vacuum gap. The heating was diagnosed in three different ways: (i) by 1D and 2D time-resolved measurement of the optical self-emission of the heated target rear-surface, (ii) by time-resolved interferometry of a chirped probe beam reflecting on the heated target rear-surface, (iii) by x-ray absorption spectroscopy of the secondary target using a laser produced backlighter. Detailed results as a function of the Z and the thickness of the secondary target as well as analysis, including a full modeling of the target heating with a hydro-code (MULTI) coupled to a proton energy deposition code, will be presented. We have also studied the efficiency of heating as a function of the primary target topology, i. e. either flat, which results in a diverging proton beam, or curved, which has the ability of focusing partly the proton beam. (Author)

  12. Advanced low-beta cavity development for proton and ion accelerators

    Recent developments in designing and processing low-beta superconducting cavities at Argonne National Laboratory are very encouraging for future applications requiring compact proton and ion accelerators. One of the major benefits of these accelerating structures is achieving real-estate accelerating gradients greater than 3 MV/m very efficiently either continuously or for long-duty cycle operation (>1%). The technology has been implemented in low-beta accelerator cryomodules for the Argonne ATLAS heavy-ion linac where the cryomodules are required to have real-estate gradients of more than 3 MV/m. In offline testing low-beta cavities with even higher gradients have already been achieved. This paper will review this work where we have achieved surface fields greater than 166 mT magnetic and 117 MV/m electric in a 72 MHz quarter-wave resonator optimized for β = 0.077 ions

  13. Development of linear proton accelerators with the high average beam power

    Bomko, V A; Egorov, A M

    2001-01-01

    Review of the current situation in the development of powerful linear proton accelerators carried out in many countries is given. The purpose of their creation is solving problems of safe and efficient nuclear energetics on a basis of the accelerator-reactor complex. In this case a proton beam with the energy up to 1 GeV, the average current of 30 mA is required. At the same time there is a needed in more powerful beams,for example, for production of tritium and transmutation of nuclear waste products. The creation of accelerators of such a power will be followed by the construction of linear accelerators of 1 GeV but with a more moderate beam current. They are intended for investigation of many aspects of neutron physics and neutron engineering. Problems in the creation of efficient constructions for the basic and auxiliary equipment, the reliability of the systems, and minimization of the beam losses in the process of acceleration will be solved.

  14. Report of the advisory group meeting on the utilization of particle accelerators for proton therapy

    Accelerated protons and light ions, being electrically charged and much heavier than electrons, have definite ranges in tissue with distinct Bragg peak with sharp distal falloffs and sharp lateral dose penumbra. Radiations oncologists could take advantage of these characteristics to deposit a high dose in an irregularly shaped tumor volume while sparing the surrounding healthy tissues and critical organs. This could lead to enhanced tumor control with reduced complications. The Advisory Group has recommended a number of measures to promote and support the spread of medically dedicated particle accelerator facilities and technology

  15. Proton Acceleration and High-Energy Density Physics from Laser Foil Interactions

    Norreys, Peter A; Dangor, A E; Krushelnick, Karl; Tatarakis, M; Wei, M; Zepf, Matthew

    2005-01-01

    Intense laser plasma interactions have long been shown to be a source of very energetic ions - from the first experiments in the 1970's. However, there has been a recent revival of interest in the production of protons and ions from the such plasmas - primarily from the observation of collimated beams of protons and heavier ions which were observed at the rear thin foil targets irradiated by ultra-high intensity laser pulses (such that I > 1018 W/cm2). These ion beams have unique properties which may make them suitable for a variety of applications such as for probing high density plasmas, for fast ignition in inertial confinement fusion, as an ion source for subsequent acceleration stages in a particle accelerator or potentially for medical applications. Recent experimental results will be reviewed and the potential for such future applications will be highlighted.

  16. Shock wave acceleration of protons in inhomogeneous plasma interacting with ultrashort intense laser pulses

    Lecz, Zs. [ELI-ALPS, ELI-HU Nkft., Szeged (Hungary); Andreev, A. [ELI-ALPS, ELI-HU Nkft., Szeged (Hungary); Max-Born Institute, Berlin (Germany)

    2015-04-15

    The acceleration of protons, triggered by solitary waves in expanded solid targets is investigated using particle-in-cell simulations. The near-critical density plasma is irradiated by ultrashort high power laser pulses, which generate the solitary wave. The transformation of this soliton into a shock wave during propagation in plasma with exponentially decreasing density profile is described analytically, which allows to obtain a scaling law for the proton energy. The high quality proton bunch with small energy spread is produced by reflection from the shock-front. According to the 2D simulations, the mechanism is stable only if the laser pulse duration is shorter than the characteristic development time of the parasitic Weibel instability.

  17. Design of rod-type high current proton radio frequency quadrupole accelerator for ANURIB project @ VECC

    A high current rod type RFQ accelerating protons to 1 MeV has been envisaged as the injector to 50 MeV proton driver for the ANURIB facility. This would be used to produce p-rich radioactive nuclei complementing the n-rich nuclei production via the photo fission route. Rod type structure has been chosen owing to ease of machining and well separated dangerous dipole modes appearing in vane type structures, This paper will describe the beam dynamics design of 5 mA proton beam through the RFQ, starting from efficient physical parameter optimization followed by corroborative studies using tracking codes. Preliminary RF structure of 80 MHz RFQ would also be presented. (author)

  18. Hadron Fluence Measurements with LiF-TLD Sensors at the Proton Synchrotron Accelerator at CERN

    Ilgner, Christoph; Obryk, Barbara

    2010-01-01

    In view of the implementation of beam-monitoring sensors for CERN's Large Hadron Collider (LHC), and also in order to validate Thermoluminescence Detectors as a versatile tool to measure ionizing radiation doses in mixed fields at hadron colliders such as the LHC, chemical vapor deposition diamond sensors have been evaluated and calibrated at CERN's Proton Synchrotron accelerator. Special attention was paid to understanding whether lithiumfluoride thermoluminescence detectors are suitable as measuring devices in these radiation fields.

  19. Real time data acquisition system for the High Current Test Facility proton accelerator

    A real time data acquisition system was developed to monitor and control the High Current Test Facility Proton Accelerator. It is a PDP-8/E computer system with virtual memory capability that is fully interrupt driven and operates under a real-time, multi-tasking executive. The application package includes mode selection to automatically modify programs and optimize operation under varying conditions. (U.S.)

  20. Hadron Fluence Measurements with LiF-TLD Sensors at the Proton Synchrotron Accelerator at CERN

    Ilgner, Christoph; Budzanowski, Maciej; Obryk, Barbara

    2010-01-01

    In view of the implementation of beam-monitoring sensors for CERN's Large Hadron Collider (LHC), and also in order to validate Thermoluminescence Detectors as a versatile tool to measure ionizing radiation doses in mixed fields at hadron colliders such as the LHC, chemical vapor deposition diamond sensors have been evaluated and calibrated at CERN's Proton Synchrotron accelerator. Special attention was paid to understanding whether lithiumfluoride thermoluminescence detectors are suitable as ...

  1. Extraction of the Proton Beam from the 70 GeV IHEP Accelerator

    A.G. Afonin; Baranov, V. T.; Biryukov, V. M.; Ivanov, I. M.; Kardash, A. A.; Kotov, V. I.; Maisheev, V. A.; Terekhov, V. I.; Troyanov, E. F.; Fedotov, Yu. S.; Chepegin, V. N.; Chesnokov, Yu. A.

    2005-01-01

    This paper presents the physical background for particle extraction from IHEP accelerator using short bent silicon crystals, analyses the results of the studies, considers in detail the regime of simultaneous work of crystal extraction and several internal targets. It is experimentally shown that the use of short crystals allows the extraction of beams with intensity of 10e12 proton/cycle with efficiency of 85%.

  2. Performance of solenoids vs. quadrupoles in focusing and energy selection of laser accelerated protons

    Hofmann, Ingo

    2013-01-01

    Using laser accelerated protons or ions for various applications - for example in particle therapie or short-pulse radiographic diagnostics - requires an effective method of focusing and energy selection. We derive an analytical scaling for the performance of a solenoid compared with a doublet/triplet as function of the energy, which is confirmed by TRACEWIN simulations. The scaling shows that above a few MeV a solenoid needs to be pulsed or super-conducting, whereas the quadrupoles can remai...

  3. Benchmark calculations on neutrons streaming through mazes at proton accelerator facilities

    In accelerator shielding designs one of the important issues is to estimate radiation streaming through mazes and ducts. In order to validate the accuracy of the calculation methods concerning such neutron streaming, benchmark analyses were carried out using two kinds of benchmark problems based on past experiments. The analyses showed that the design methods were applicable to neutron streaming calculations of proton accelerator facilities with an uncertainty within a factor of two. In the analyses, relative comparisons were conducted using a radiation source generated by GeV energy protons, and absolute comparisons were conducted using a low-energy neutron source of a few tens of MeV. A radiation streaming experiment was planned and carried out at KEK using a radiation source produced by a thin copper target irradiated by 12 GeV protons. The preliminary experimental analysis is presented below. In addition, the authors propose to compile benchmark problems on radiation streaming for accelerator facilities and to search for possible new streaming experiments at other facilities. (authors)

  4. Enhanced proton acceleration by ultrashort laser pulse interaction with nanostructured thin films

    Enhancement of local electromagnetic field in nanostructured targets as opposed to plain polished targets has been experimentally observed and studied. This increase in field strength leads to enhanced hot electron generation, which gives rise to highly energetic ions through Target Normal Sheath Acceleration. As the laser energy coupled to the electrons increases, the sheath magnitude is expected to increase, leading to an enhancement in ion acceleration. We investigate energy enhancements in ions generated as a result of intense femtosecond laser interaction with nanostructured thin film targets, comprising 2 μm Ta foil coated with 100-200 nm diameter Ta clusters. The optimum nanoparticle size of 100 nm corresponding to maximum laser energy absorption has been predetermined through PIC simulations. The accelerated ions have been studied using Thompson parabola spectrometer at a laser intensity of 15 x 1019 W/cm2 at the TIFR high contrast 100 TW Ti:Sapphire laser facility. The proton cut-off energy is observed to increase rapidly with increasing cluster density till a saturation is reached. The enhancement in the proton cut-off energy is observed to be three-fold as compared to the proton cut-off energy for unstructured foils. (author)

  5. Core characteristics on a hybrid type fast reactor system combined with proton accelerator

    Kowata, Yasuki; Otsubo, Akira [Power Reactor and Nuclear Fuel Development Corp., Oarai, Ibaraki (Japan). Oarai Engineering Center

    1997-06-01

    In our study on a hybrid fast reactor system, we have investigated it from the view point of transmutation ability of trans-uranium (TRU) nuclide making the most effective use of special features (controllability, hard neutron spectrum) of the system. It is proved that a proton beam is superior in generation of neutrons compared with an electron beam. Therefore a proton accelerator using spallation reaction with a target nucleus has an advantage to transmutation of TRU than an electron one. A fast reactor is expected to primarily have a merit that the reactor can be operated for a long term without employment of highly enriched plutonium fuel by using external neutron source such as the proton accelerator. Namely, the system has a desirable characteristic of being possible to self-sustained fissile plutonium. Consequently in the present report, core characteristics of the system were roughly studied by analyses using 2D-BURN code. The possibility of self-sustained fuel was investigated from the burnup and neutronic calculation in a cylindrical core with 300w/cc of power density without considering a target material region for the accelerator. For a reference core of which the height and the radius are both 100 cm, there is a fair prospect that a long term reactor operation is possible with subsequent refueling of natural uranium, if the medium enriched (around 10wt%) uranium or plutonium fuels are fully loaded in the initial core. More precise analyses will be planed in a later fiscal year. (author)

  6. How to Produce a Reactor Neutron Spectrum Using a Proton Accelerator

    Burns, K.; Wootan, D.; Gates, R.; Schmitt, B.; Asner, D. M.

    A method for reproducing the neutron energy spectrum present in the core of an operating nuclear reactor using an engineered target in an accelerator proton beam is proposed. The protons interact with a target to create neutrons through various (p,n) type reactions. Spectral tailoring of the emitted neutrons can be used to modify the energy of the generated neutron spectrum to represent various reactor spectra. Through the use of moderators and reflectors, the neutron spectrum can be modified to reproduce many different spectra of interest including spectra in small thermal test reactors, large pressurized water reactors, and fast reactors. The particular application of this methodology is the design of an experimental approach for using an accelerator to measure the betas produced during fission to be used to reduce uncertainties in the interpretation of reactor antineutrino measurements. This approach involves using a proton accelerator to produce a neutron field representative of a power reactor, and using this neutron field to irradiate fission foils of the primary isotopes contributing to fission in the reactor, creating unstable, neutron rich fission products that subsequently beta decay and emit electron antineutrinos. A major advantage of an accelerator neutron source over a neutron beam from a thermal reactor is that the fast neutrons can be slowed down or tailored to approximate various power reactor spectra. An accelerator based neutron source that can be tailored to match various reactor neutron spectra provides an advantage for control in studying how changes in the neutron spectra affect parameters such as the resulting fission product beta spectrum.

  7. How to produce a reactor neutron spectrum using a proton accelerator

    Burns, Kimberly A.; Wootan, David W.; Gates, Robert O.; Schmitt, Bruce E.; Asner, David M.

    2015-01-01

    A method for reproducing the neutron energy spectrum present in the core of an operating nuclear reactor using an engineered target in an accelerator proton beam is proposed. The protons interact with a target to create neutrons through various (p,n) type reactions. Spectral tailoring of the emitted neutrons can be used to modify the energy of the generated neutron spectrum to represent various reactor spectra. Through the use of moderators and reflectors, the neutron spectrum can be modified to reproduce many different spectra of interest including spectra in small thermal test reactors, large pressurized water reactors, and fast reactors. The particular application of this methodology is the design of an experimental approach for using an accelerator to measure the betas produced during fission to be used to reduce uncertainties in the interpretation of reactor antineutrino measurements. This approach involves using a proton accelerator to produce a neutron field representative of a power reactor, and using this neutron field to irradiate fission foils of the primary isotopes contributing to fission in the reactor, creating unstable, neutron rich fission products that subsequently beta decay and emit electron antineutrinos. A major advantage of an accelerator neutron source over a neutron beam from a thermal reactor is that the fast neutrons can be slowed down or tailored to approximate various power reactor spectra. An accelerator based neutron source that can be tailored to match various reactor neutron spectra provides an advantage for control in studying how changes in the neutron spectra affect parameters such as the resulting fission product beta spectrum.

  8. Radiograaff, a proton irradiation facility for radiobiological studies at a 4 MV Van de Graaff accelerator

    Constanzo, J. [Université de Lyon, F-69622, Lyon (France); Université Lyon 1, Villeurbanne (France); CNRS/IN2P3, Institut de Physique Nucléaire de Lyon, F-69622 Villeurbanne (France); Fallavier, M., E-mail: m.fallavier@ipnl.in2p3.fr [Université de Lyon, F-69622, Lyon (France); Université Lyon 1, Villeurbanne (France); CNRS/IN2P3, Institut de Physique Nucléaire de Lyon, F-69622 Villeurbanne (France); Alphonse, G. [Université de Lyon, F-69622, Lyon (France); Université Lyon 1, Villeurbanne (France); Faculté de Médecine Lyon-Sud, LRCM, F-69921 Oullins (France); Hospices-Civils-de-Lyon, CHLS, F-69495 Pierre-Bénite (France); Bernard, C. [Université de Lyon, F-69622, Lyon (France); Université Lyon 1, Villeurbanne (France); CNRS/IN2P3, Institut de Physique Nucléaire de Lyon, F-69622 Villeurbanne (France); Battiston-Montagne, P. [Université de Lyon, F-69622, Lyon (France); Université Lyon 1, Villeurbanne (France); Faculté de Médecine Lyon-Sud, LRCM, F-69921 Oullins (France); Rodriguez-Lafrasse, C. [Université de Lyon, F-69622, Lyon (France); Université Lyon 1, Villeurbanne (France); Faculté de Médecine Lyon-Sud, LRCM, F-69921 Oullins (France); Hospices-Civils-de-Lyon, CHLS, F-69495 Pierre-Bénite (France); and others

    2014-09-01

    A horizontal beam facility for radiobiological experiments with low-energy protons has been set up at the 4 MV Van de Graaff accelerator of the Institut de Physique Nucléaire de Lyon. A homogeneous irradiation field with a suitable proton flux is obtained by means of two collimators and two Au-scattering foils. A monitoring chamber contains a movable Faraday cup, a movable quartz beam viewer for controlling the intensity and the position of the initial incident beam and four scintillating fibers for beam monitoring during the irradiation of the cell samples. The beam line is ended by a thin aluminized Mylar window (12 μm thick) for the beam extraction in air. The set-up was simulated by the GATE v6.1 Monte-Carlo platform. The measurement of the proton energy distribution, the evaluation of the fluence-homogeneity over the sample and the calibration of the monitoring system were performed using a silicon PIPS detector, placed in air in the same position as the biological samples to be irradiated. The irradiation proton fluence was found to be homogeneous to within ±2% over a circular field of 20 mm diameter. As preliminary biological experiment, two Human Head and Neck Squamous Carcinoma Cell lines (with different radiosensitivities) were irradiated with 2.9 MeV protons. The measured survival curves are compared to those obtained after X-ray irradiation, giving a Relative Biological Efficiency between 1.3 and 1.4.

  9. Radiograaff, a proton irradiation facility for radiobiological studies at a 4 MV Van de Graaff accelerator

    A horizontal beam facility for radiobiological experiments with low-energy protons has been set up at the 4 MV Van de Graaff accelerator of the Institut de Physique Nucléaire de Lyon. A homogeneous irradiation field with a suitable proton flux is obtained by means of two collimators and two Au-scattering foils. A monitoring chamber contains a movable Faraday cup, a movable quartz beam viewer for controlling the intensity and the position of the initial incident beam and four scintillating fibers for beam monitoring during the irradiation of the cell samples. The beam line is ended by a thin aluminized Mylar window (12 μm thick) for the beam extraction in air. The set-up was simulated by the GATE v6.1 Monte-Carlo platform. The measurement of the proton energy distribution, the evaluation of the fluence-homogeneity over the sample and the calibration of the monitoring system were performed using a silicon PIPS detector, placed in air in the same position as the biological samples to be irradiated. The irradiation proton fluence was found to be homogeneous to within ±2% over a circular field of 20 mm diameter. As preliminary biological experiment, two Human Head and Neck Squamous Carcinoma Cell lines (with different radiosensitivities) were irradiated with 2.9 MeV protons. The measured survival curves are compared to those obtained after X-ray irradiation, giving a Relative Biological Efficiency between 1.3 and 1.4

  10. Beam loss monitor system of the rapid cycling synchrotron of Japan Proton Accelerator Research Complex

    The 3 GeV Rapid Cycling Synchrotron (RCS) of the Japan Proton Accelerator Research Complex (J-PARC) provides more than 300 kW beam to the Material and Life Science Facility (MLF) and the Main Ring (MR). In such high intensity hadron accelerator, the lost protons that are a fraction of the beam less than 0.1% cause many problems. Those particles bring about a serious radioactivation and a malfunction of the accelerator components. Therefore, the beam loss monitor (BLM) is one of the most important equipment to observe the state of the beam during operation, and to keep a steady operation. Moreover, if we set operation parameters of BLM adequately, it can detect the beam loss that is 10-6 fraction of the beam. Thus it enables fine-tuning of the accelerator. In the J-PARC RCS, a proportional counter and a plastic scintillation counter are used for the beam commission and the stable operation as BLM. We report present status of the BLM system in J-PARC RCS. (author)

  11. Fabrication of nanostructured targets for improved laser-driven proton acceleration

    Barberio, M.; Scisciò, M.; Veltri, S.; Antici, P.

    2016-07-01

    In this work, we present a novel realization of nanostructured targets suitable for improving laser-driven proton acceleration experiments, in particular with regard to the Target-Normal-Sheath Acceleration (TNSA) acceleration mechanism. The nanostructured targets, produced as films, are realized by a simpler and cheaper method than using conventional lithographic techniques. The growth process includes a two step approach for the production of the gold nanoparticle layers: 1) Laser Ablation in Solution and 2) spray-dry technique using a colloidal solution on target surfaces (Aluminum, Mylar and Multi Walled Carbon Nanotube). The obtained nanostructured films appear, at morphological and chemical analysis, uniformly nanostructured and the nanostructure distributed on the target surfaces without presence of oxides or external contaminants. The obtained targets show a broad optical absorption in all the visible region and a surface roughness that is two times greater than non-nanostructured targets, enabling a greater laser energy absorption during the laser-matter interaction experiments producing the laser-driven proton acceleration.

  12. Laser acceleration of protons from near critical density targets for application to radiation therapy

    Bulanov, S S; Pirozhkov, A S; Thomas, A G R; Willingale, L; Krushelnick, K; Maksimchuk, A

    2010-01-01

    Laser accelerated protons can be a complimentary source for treatment of oncological diseases to the existing hadron therapy facilities. We demonstrate how the protons, accelerated from near-critical density plasmas by laser pulses having relatively small power, reach energies which may be of interest for medical applications. When an intense laser pulse interacts with near-critical density plasma it makes a channel both in the electron and then in the ion density. The propagation of a laser pulse through such a self-generated channel is connected with the acceleration of electrons in the wake of a laser pulse and generation of strong moving electric and magnetic fields in the propagation channel. Upon exiting the plasma the magnetic field generates a quasi-static electric field that accelerates and collimates ions from a thin filament formed in the propagation channel. Two-dimensional Particle-in-Cell simulations show that a 100 TW laser pulse tightly focused on a near-critical density target is able to acce...

  13. Physics design of a CW high-power proton Linac for accelerator-driven system

    Rajni Pande; Shweta Roy; S V L S Rao; P Singh; S Kailas

    2012-02-01

    Accelerator-driven systems (ADS) have evoked lot of interest the world over because of their capability to incinerate the MA (minor actinides) and LLFP (long-lived fission products) radiotoxic waste and their ability to utilize thorium as an alternative nuclear fuel. One of the main subsystems of ADS is a high energy (∼1 GeV) and high current (∼30 mA) CW proton Linac. The accelerator for ADS should have high efficiency and reliability and very low beam losses to allow hands-on maintenance. With these criteria, the beam dynamics simulations for a 1 GeV, 30 mA proton Linac has been done. The Linac consists of normal-conducting radio-frequency quadrupole (RFQ), drift tube linac (DTL) and coupled cavity drift tube Linac (CCDTL) structures that accelerate the beam to about 100 MeV followed by superconducting (SC) elliptical cavities, which accelerate the beam from 100 MeV to 1 GeV. The details of the design are presented in this paper.

  14. Structural activation calculations due to proton beam loss in the APT accelerator design

    For the new, high-power accelerators currently being designed, the amount of activation of the accelerator structure has become an important issue. To quantify this activation, a methodology was utilized that coupled transport and depletion codes to obtain dose rate estimates at several locations near the accelerator. This research focused on the 20 and 100 MeV sections of the Bridge-Coupled Drift Tube Linear Accelerator. The peak dose rate was found to be approximately 6 mR/hr in the 100 MeV section near the quadrupoles at a 25-cm radius for an assumed beam loss of 1 nA/m. It was determined that the activation was dominated by the proton interactions and subsequent spallation product generation, as opposed to the presence of the generated neutrons. The worst contributors were the spallation products created by proton bombardment of iron, and the worst component was the beam pipe, which consists mostly of iron. No definitive conclusions about the feasibility of hands-on maintenance can be determined, as the design is still not finalized

  15. Final environmental impact statement. Proton--Proton Storage Accelerator Facility (ISABELLE), Brookhaven National Laboratory, Upton, New York

    Liverman, James L.

    1978-08-01

    An Environmental Impact Statement for a proposed research facility (ISABELLE) to be built at Brookhaven National Laboratory (BNL) is presented. It was prepared by the Department of Energy (DOE) following guidelines issued for such analyses. In keeping with DOE policy, this statement presents a concise and issues-oriented analysis of the significant environmental effects associated with the proposed action. ISABELLE is a proposed physics research facility where beams of protons collide providing opportunities to study high energy interactions. The facility would provide two interlaced storage ring proton accelerators, each with an energy up to 400 GeV intersecting in six experimental areas. The rings are contained in a tunnel with a circumference of 3.8 km (2.3 mi). The facility will occupy 250 ha (625 acres) in the NW corner of the existing BNL site. A draft Environmental Impact Statement for this proposed facility was issued for public review and comment by DOE on February 21, 1978. The principal areas of concern expressed were in the areas of radiological impacts and preservation of cultural values. After consideration of these comments, appropriate actions were taken and the text of the statement has been amended to reflect the comments. The text was annotated to indicate the origin of the comment. The Appendices contain a glossary of terms and listings of metric prefixes and conversions and symbols and abbreviations.

  16. Final environmental impact statement. Proton--Proton Storage Accelerator Facility (ISABELLE), Brookhaven National Laboratory, Upton, New York

    An Environmental Impact Statement for a proposed research facility (ISABELLE) to be built at Brookhaven National Laboratory (BNL) is presented. It was prepared by the Department of Energy (DOE) following guidelines issued for such analyses. In keeping with DOE policy, this statement presents a concise and issues-oriented analysis of the significant environmental effects associated with the proposed action. ISABELLE is a proposed physics research facility where beams of protons collide providing opportunities to study high energy interactions. The facility would provide two interlaced storage ring proton accelerators, each with an energy up to 400 GeV intersecting in six experimental areas. The rings are contained in a tunnel with a circumference of 3.8 km (2.3 mi). The facility will occupy 250 ha (625 acres) in the NW corner of the existing BNL site. A draft Environmental Impact Statement for this proposed facility was issued for public review and comment by DOE on February 21, 1978. The principal areas of concern expressed were in the areas of radiological impacts and preservation of cultural values. After consideration of these comments, appropriate actions were taken and the text of the statement has been amended to reflect the comments. The text was annotated to indicate the origin of the comment. The Appendices contain a glossary of terms and listings of metric prefixes and conversions and symbols and abbreviations

  17. An outline of the proton accelerator for the neutron science project

    Mizumoto, Motoharu; Kusano, Joichi; Hasegawa, Kazuo [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment] [and others

    1997-11-01

    A research project has been proposed in JAERI aiming at exploring new basic researches and nuclear energy engineering based on a high intensity proton linac with a 1.5 GeV and 8 MW beam. The research complex will be composed of facilities such as the Neutron Scattering Facility for condensed matter physics and the Nuclear Energy Related Facility for engineering test of nuclear waste transmutation. The R and D has been carried out for the components of the low energy part of the accelerator; ion source, RFQ, DTL and RF source. For the high energy portion above 100 MeV, the development on a superconducting accelerating cavity as a major option has been performed. The paper will present the summary on a development plan to build the accelerator and the results of conceptual design study and the R and D work. (author)

  18. Digital low-level RF control system for high intensity proton RFQ accelerator

    The resonant frequency of the high intensity proton RFQ accelerator at the Institute of High Energy Physics is 352.2 MHz, and the control precision of the accelerating field is ± 1 degree in phase, respectively. In order to accomplish these requirements, a digital low-level RF (LLRF) control system is adopted. This system includes three parts: the accelerating field amplitude and phase control, the cavity resonant frequency control and the high power interlock protection. The down-conversion of the cavity sampling signal and the up-conversion of the feedback excitation signal are realized by the analog devices. The real time feedback control of amplitude and phase adopts digital I/Q demodulation, and is assembled in a FPGA block, where three DSP blocks are used for communication and cooperate the FPGA to process data. The online debugging result satisfies the requirements of the control precision. (authors)

  19. Shielding benchmark experiments through concrete and iron with high-energy proton and heavy ion accelerators

    The deep penetration of neutrons through thick shield has become a very serious problem in the shielding design of high-energy, high-intensity accelerator facility. In the design calculation, the Monte Carlo transport calculation through thick shields has large statistical errors and the basic nuclear data and model used in the existing Monte Carlo codes are not well evaluated because of very few experimental data. It is therefore strongly needed to do the deep penetration experiment as shielding benchmark for investigating the calculation accuracy. Under this circumference, we performed the following two shielding experiments through concrete and iron, one with a 800 MeV proton accelerator of the rutherford appleton laboratory (RAL), England and the other with a high energy heavy iron accelerator of the national institute of radiological sciences (NIRS), Japan. Here these two shielding benchmark experiments are outlined. (orig.)

  20. Research program for the 660 MeV proton accelerator driven MOX-plutonium subcritical assembly

    Barashenkov, V. S.; Buttsev, V. S.; Buttseva, G. L.; Dudarev, S. Ju.; Polanski, A.; Puzynin, I. V.; Sissakian, A. N.

    2000-07-01

    This paper presents the research program of the Experimental Accelerator Driven System (ADS), which employs a subcritical assembly and a 660 MeV proton accelerator operating in the Laboratory of Nuclear Problems at the Joint Institute for Nuclear Research in Dubna. Mixed-oxide (MOX) fuel (25% PuO2+75% UO2) designed for the BN-600 reactor use will be adopted for the core of the assembly. The present conceptual design of the experimental subcritical assembly is based on a core nominal unit capacity of 15 kW (thermal). This corresponds to the multiplication coefficient keff=0.945, energetic gain G=30, and accelerator beam power of 0.5 kW.

  1. Shielding benchmark experiments through concrete and iron with high-energy proton and heavy ion accelerators

    Nakamura, T.; Sasaki, M.; Nunomiya, T.; Iwase, H. [Tohoku Univ., Sendai (Japan). Dept. of Quantum Science and Energy Engineering; Nakao, N.; Shibata, T. [High Energy Accelerator Research Organization (KEK), Ibaraki (Japan); Kim, E. [Japan Atomic Energy Research Inst. (JAERI), Ibaraki (Japan). Tokai Establishment; Kurosawa, T. [Japan Synchrotron Radiation Research Inst. (JASRI), Hyogo (Japan); Taniguchi, S. [Electrotechnical Lab. (ETL), Tsukuba, Ibaraki (Japan); Uwamino, Y.; Ito, S. [The Inst. of Physical and Chemical Research (RIKEN), Saitama (Japan); Fukumura, A. [National Inst. of Radiological Sciences (NIRS), Chiba (Japan); Perry, D.R.; Wright, P. [Rutherford Appleton Lab. (RAL), Didcot, Oxfordshire (United Kingdom). Health and Safety Group

    2001-07-01

    The deep penetration of neutrons through thick shield has become a very serious problem in the shielding design of high-energy, high-intensity accelerator facility. In the design calculation, the Monte Carlo transport calculation through thick shields has large statistical errors and the basic nuclear data and model used in the existing Monte Carlo codes are not well evaluated because of very few experimental data. It is therefore strongly needed to do the deep penetration experiment as shielding benchmark for investigating the calculation accuracy. Under this circumference, we performed the following two shielding experiments through concrete and iron, one with a 800 MeV proton accelerator of the rutherford appleton laboratory (RAL), England and the other with a high energy heavy iron accelerator of the national institute of radiological sciences (NIRS), Japan. Here these two shielding benchmark experiments are outlined. (orig.)

  2. Injector and beam transport simulation study of proton dielectric wall accelerator

    Zhao, Quantang, E-mail: zhaoquantang@impcas.ac.cn [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Graduate University of Chinese Academy of Sciences, Beijing 100049 (China); Yuan, P.; Zhang, Z.M.; Cao, S.C [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Shen, X.K. [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Graduate University of Chinese Academy of Sciences, Beijing 100049 (China); Jing, Y.; Ma, Y.Y. [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Yu, C.S. [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Graduate University of Chinese Academy of Sciences, Beijing 100049 (China); Li, Z.P.; Liu, M.; Xiao, R.Q.; Zhao, H.W. [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China)

    2012-12-01

    A simulation study of a short-pulsed proton injector for, and beam transport in, a dielectric wall accelerator (DWA) has been carried out using the particle-in-cell (PIC) code Warp. It was shown that applying 'tilt pulse' voltage waveforms on three electrodes enables the production of a shorter bunch by the injector. The fields in the DWA beam tube were simulated using Computer Simulation Technology's Microwave Studio (CST MWS) package, with various choices for the boundary conditions. For acceleration in the DWA, the beam transport was simulated with Warp, using applied fields obtained by running CST MWS. Our simulations showed that the electric field at the entrance to the DWA represents a challenging issue for the beam transport. We thus simulated a configuration with a mesh at the entrance of the DWA, intended to improve the entrance field. In these latter simulations, a proton bunch was successfully accelerated from 130 keV to about 36 MeV in a DWA with a length of 36.75 cm. As the beam bunch progresses, its transverse dimensions diminish from (roughly) 0.5 Multiplication-Sign 0.5 cm to 0.2 Multiplication-Sign 0.4 cm. The beam pulse lengthens from 1 cm to 2 cm due to lack of longitudinal compression fields. -- Highlights: Black-Right-Pointing-Pointer A pulse proton injector with tilt voltages on the three electrodes was simulated. Black-Right-Pointing-Pointer The fields in different part of the DWA were simulated with CST and analyzed. Black-Right-Pointing-Pointer The proton beam transport in DWA was simulated with Warp successfully. Black-Right-Pointing-Pointer The simulation can help for designing a real DWA.

  3. Injector and beam transport simulation study of proton dielectric wall accelerator

    A simulation study of a short-pulsed proton injector for, and beam transport in, a dielectric wall accelerator (DWA) has been carried out using the particle-in-cell (PIC) code Warp. It was shown that applying “tilt pulse” voltage waveforms on three electrodes enables the production of a shorter bunch by the injector. The fields in the DWA beam tube were simulated using Computer Simulation Technology’s Microwave Studio (CST MWS) package, with various choices for the boundary conditions. For acceleration in the DWA, the beam transport was simulated with Warp, using applied fields obtained by running CST MWS. Our simulations showed that the electric field at the entrance to the DWA represents a challenging issue for the beam transport. We thus simulated a configuration with a mesh at the entrance of the DWA, intended to improve the entrance field. In these latter simulations, a proton bunch was successfully accelerated from 130 keV to about 36 MeV in a DWA with a length of 36.75 cm. As the beam bunch progresses, its transverse dimensions diminish from (roughly) 0.5×0.5 cm to 0.2×0.4 cm. The beam pulse lengthens from 1 cm to 2 cm due to lack of longitudinal compression fields. -- Highlights: ► A pulse proton injector with tilt voltages on the three electrodes was simulated. ► The fields in different part of the DWA were simulated with CST and analyzed. ► The proton beam transport in DWA was simulated with Warp successfully. ► The simulation can help for designing a real DWA.

  4. Development of the heat sink structure of a beam dump for the proton accelerator

    The beam dump is the essential component for the good beam quality and the reliable performance of the proton accelerator. The beam dump for a 20 MeV and 20 mA proton accelerator was designed and manufactured in this study. The high heats deposited, and the large amount of radioactivity produced in beam dump should be reduced by the proper heat sink structure. The heat source by the proton beam of 20 MeV and 20 mA was calculated. The radioactivity assessments of the beam dump were carried out for the economic shielding design with safety. The radioactivity by the protons and secondary neutrons in designed beam dump were calculated in this sturdy. The effective engineering design for the beam dump cooling was performed, considering the mitigation methods of the deposited heats with small angle, the power densities with the stopping ranges in the materials and the heat distributions in the beam dump. The heat sink structure of the beam dump was designed to meet the accelerator characteristics by placing two plates of 30 cm by 60 cm at an angle of 12 degree. The highest temperatures of the graphite, copper, and copper faced by cooling water were designed to be 223 degree, 146 degree, and 85 degree, respectively when the velocity of cooling water was 3 m/s. The heat sink structure was manufactured by the brazing graphite tiles to a copper plate with the filler alloy of Ti-Cu-Ag. The brazing procedure was developed. The tensile stress of the graphite was less than 75% of a maximum tensile stress during the accelerator operation based on the analysis. The safety analyses for the commissioning of the accelerator operation were also performed. The specimens from the brazed parts of beam dump structure were made to identify manufacturing problems. The soundness of the heat sink structure of the beam dump was confirmed by the fatigue tests of the brazed specimens of the graphite-copper tile components with the repetitive heating and cooling. The heat sink structure developed

  5. A high brightness proton injector for the Tandetron accelerator at Jožef Stefan Institute

    Pelicon, Primož, E-mail: primoz.pelicon@ijs.si [Jožef Stefan Institute, Association EURATOM-MHEST, Jamova 39, SI-1000 Ljubljana (Slovenia); Podaru, Nicolae C., E-mail: info@highvolteng.com [High Voltage Engineering Europa B.V., P.O. Box 99, Amersfoort 3800AB (Netherlands); Vavpetič, Primož; Jeromel, Luka [Jožef Stefan Institute, Association EURATOM-MHEST, Jamova 39, SI-1000 Ljubljana (Slovenia); Ogrinc Potocnik, Nina [Jožef Stefan Institute, Association EURATOM-MHEST, Jamova 39, SI-1000 Ljubljana (Slovenia); LOTRIČ Metrology ltd, Selca 163, SI-4227 Selca (Slovenia); Ondračka, Simon [Jožef Stefan Institute, Association EURATOM-MHEST, Jamova 39, SI-1000 Ljubljana (Slovenia); Gottdang, Andreas; Mous, Dirk J.M. [High Voltage Engineering Europa B.V., P.O. Box 99, Amersfoort 3800AB (Netherlands)

    2014-08-01

    Jožef Stefan Institute recently commissioned a high brightness H{sup −} ion beam injection system for its existing tandem accelerator facility. Custom developed by High Voltage Engineering Europa, the multicusp ion source has been tuned to deliver at the entrance of the Tandetron™ accelerator H{sup −} ion beams with a measured brightness of 17.1 A m{sup −2} rad{sup −2} eV{sup −1} at 170 μA, equivalent to an energy normalized beam emittance of 0.767 π mm mrad MeV{sup 1/2}. Upgrading the accelerator facility with the new injection system provides two main advantages. First, the high brightness of the new ion source enables the reduction of object slit aperture and the reduction of acceptance angle at the nuclear microprobe, resulting in a reduced beam size at selected beam intensity, which significantly improves the probe resolution for micro-PIXE applications. Secondly, the upgrade strongly enhances the accelerator up-time since H and He beams are produced by independent ion sources, introducing a constant availability of {sup 3}He beam for fusion-related research with NRA. The ion beam particle losses and ion beam emittance growth imply that the aforementioned beam brightness is reduced by transport through the ion optical system. To obtain quantitative information on the available brightness at the high-energy side of the accelerator, the proton beam brightness is determined in the nuclear microprobe beamline. Based on the experience obtained during the first months of operation for micro-PIXE applications, further necessary steps are indicated to obtain optimal coupling of the new ion source with the accelerator to increase the normalized high-energy proton beam brightness at the JSI microprobe, currently at 14 A m{sup −2} rad{sup −2} eV{sup −1}, with the output current at 18% of its available maximum.

  6. Proton-driven plasma wakefield acceleration: a path to the future of high-energy particle physics

    Assmann, R; Bohl, T; Bracco, C; Buttenschön, B; Butterworth, A; Caldwell, A; Chattopadhyay, S; Cipiccia, S; Feldbaumer, E; Fonseca, R A; Goddard, B; Gross, M; Grulke, O; Gschwendtner, E; Holloway, J; Huang, C; Jaroszynski, D; Jolly, S; Kempkes, P; Lopes, N; Lotov, K; Machacek, J; Mandry, S R; McKenzie, J W; Meddahi, M; Militsyn, B L; Moschuering, N; Muggli, P; Najmudin, Z; Noakes, T C Q; Norreys, P A; Öz, E; Pardons, A; Petrenko, A; Pukhov, A; Rieger, K; Reimann, O; Ruhl, H; Shaposhnikova, E; Silva, L O; Sosedkin, A; Tarkeshian, R; Trines, R M G N; Tückmantel, T; Vieira, J; Vincke, H; Wing, M; Xia G , G

    2014-01-01

    New acceleration technology is mandatory for the future elucidation of fundamental particles and their interactions. A promising approach is to exploit the properties of plasmas. Past research has focused on creating large-amplitude plasma waves by injecting an intense laser pulse or an electron bunch into the plasma. However, the maximum energy gain of electrons accelerated in a single plasma stage is limited by the energy of the driver. Proton bunches are the most promising drivers of wakefields to accelerate electrons to the TeV energy scale in a single stage. An experimental program at CERN { the AWAKE experiment { has been launched to study in detail the important physical processes and to demonstrate the power of proton-driven plasma wakefield acceleration. Here we review the physical principles and some experimental considerations for a future proton-driven plasma wakefield accelerator.

  7. Proton-driven plasma wakefield acceleration: a path to the future of high-energy particle physics

    Assmann, R; Bohl, T; Bracco, C; Buttenschon, B; Butterworth, A; Caldwell, A; Chattopadhyay, S; Cipiccia, S; Feldbaumer, E; Fonseca, R A; Goddard, B; Gross, M; Grulke, O; Gschwendtner, E; Holloway, J; Huang, C; Jaroszynski, D; Jolly, S; Kempkes, P; Lopes, N; Lotov, K; Machacek, J; Mandry, S R; McKenzie, J W; Meddahi, M; Militsyn, B L; Moschuering, N; Muggli, P; Najmudin, Z; Noakes, T C Q; Norreys, P A; Oz, E; Pardons, A; Petrenko, A; Pukhov, A; Rieger, K; Reimann, O; Ruhl, H; Shaposhnikova, E; Silva, L O; Sosedkin, A; Tarkeshian, R; Trines, R M G N; Tuckmantel, T; Vieira, J; Vincke, H; Wing, M; Xia, G

    2014-01-01

    New acceleration technology is mandatory for the future elucidation of fundamental particles and their interactions. A promising approach is to exploit the properties of plasmas. Past research has focused on creating large-amplitude plasma waves by injecting an intense laser pulse or an electron bunch into the plasma. However, the maximum energy gain of electrons accelerated in a single plasma stage is limited by the energy of the driver. Proton bunches are the most promising drivers of wakefields to accelerate electrons to the TeV energy scale in a single stage. An experimental program at CERN -- the AWAKE experiment -- has been launched to study in detail the important physical processes and to demonstrate the power of proton-driven plasma wakefield acceleration. Here we review the physical principles and some experimental considerations for a future proton-driven plasma wakefield accelerator.

  8. ELECTRON AND PROTON ACCELERATION DURING THE FIRST GROUND LEVEL ENHANCEMENT EVENT OF SOLAR CYCLE 24

    Li, C.; Sun, L. P. [School of Astronomy and Space Science, Nanjing University, Nanjing 210093 (China); Firoz, Kazi A. [Key Laboratory of Dark Matter and Space Astronomy, Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210008 (China); Miroshnichenko, L. I., E-mail: lic@nju.edu.cn [N. V. Pushkov Institute of Terrestrial Magnetism, Ionosphere and Radio Wave Propagation (IZMIRAN), Russian Academy of Sciences, Troitsk, 142190 Moscow Region (Russian Federation)

    2013-06-10

    High-energy particles were recorded by near-Earth spacecraft and ground-based neutron monitors (NMs) on 2012 May 17. This event was the first ground level enhancement (GLE) of solar cycle 24. In this study, we try to identify the acceleration source(s) of solar energetic particles by combining in situ particle measurements from the WIND/3DP, GOES 13, and solar cosmic rays registered by several NMs, as well as remote-sensing solar observations from SDO/AIA, SOHO/LASCO, and RHESSI. We derive the interplanetary magnetic field (IMF) path length (1.25 {+-} 0.05 AU) and solar particle release time (01:29 {+-} 00:01 UT) of the first arriving electrons by using their velocity dispersion and taking into account contamination effects. We found that the electron impulsive injection phase, indicated by the dramatic change in the spectral index, is consistent with flare non-thermal emission and type III radio bursts. Based on the potential field source surface concept, modeling of the open-field lines rooted in the active region has been performed to provide escape channels for flare-accelerated electrons. Meanwhile, relativistic protons are found to be released {approx}10 minutes later than the electrons, assuming their scatter-free travel along the same IMF path length. Combining multi-wavelength imaging data of the prominence eruption and coronal mass ejection (CME), we obtain evidence that GLE protons, with an estimated kinetic energy of {approx}1.12 GeV, are probably accelerated by the CME-driven shock when it travels to {approx}3.07 solar radii. The time-of-maximum spectrum of protons is typical for shock wave acceleration.

  9. Acceleration of Ultra-Low Emittance Proton and Ion Beams with High Intensity Lasers

    Cowan, Thomas E.

    2002-11-01

    Intense beams of several MeV protons and ions, generated by the interaction of high-intensity short pulse lasers with thin foils, have been observed by many researchers in recent years.(S.P. Hatchett et al., Phys. Plasmas 7, 2076 (2000); T.E. Cowan et al., Nucl. Inst. Meth. A 455, 130 (2000); R.A. Snavely et al., Phys. Rev. Lett. 85, 2945 (2000); S.C. Wilks et al., Phys. Plasmas 8, 532 (2000); E. Clark et al., Phys. Rev. Lett. 84, 670 (2000).) In experiments performed at the 100 TW LULI laser, we have succeeded to control the ion acceleration process to produce ultra high quality proton beams, whose transverse emittance is laser-plasma interaction, of the transport of MA currents of relativistic electrons through the target substrate, and of the surface topology and source material layering on the target foil rear-surface.(M. Roth et al., Phys. Rev. ST Accel. Beams 5, 061002 (2002).) By varying the source material, we also accelerated light ion beams, such as He-like fluorine, to over 5 MeV/nucleon.(M. Hegelich et al., Phys. Rev. Lett. 89, 085002 (2002).) From PIC simulations we understand the highest-energy and lowest-divergence proton acceleration as a transient laser-driven virtual cathode effect occurring at the target rear-surface. We have also confirmed the acceleration of ions from the front surface (A. Maksimchuk et al., Phys. Rev. Lett. 84, 4108 (2000).), which we find exhibits an intense low-energy component, but only a tenuous high-energy component, in agreement with PIC simulations. This work was performed with corporate support of General Atomics.

  10. Proton-Proton Colliding-Beam Storage Rings for the National Accelerator Laboratory: Design Study 1968

    None

    1968-01-01

    This report describes the design studies on colliding-beam storage rings carried out at the National Accelerator Laboratory in the summer and fall of 1968. These studies were under the direction of Lee C. Teng. M. Stanley Livingston also played an important part in catalyzing the studies. Dr. Teng's preface, immediately following, gives a chronology of the study and lists the participants in various aspects. The purpose of the study has been to develop realistic cost estimates upon which future plans can be based. It is to be emphasized that this is not a proposal for construction. The major results of the study are that 100-100 BeV colliding beam rings can be built for approximately 75 million dollars (in 1968 dollars), utilizing conventional steel and copper magnets. This estimate includes no equipment for physics experiments. A system utilizing steel magnets that are excited by superconducting coils is estimated to cost somewhat less. A similar system using cryogenic aluminum coils appears to be slightly more costly at this time than the conventional magnet. A number of storage rings built of superconducting magnets have also been analyzed on the premise (undemonstrated as yet) that they would in fact operate satisfactorily. Such magnets designed using present technology for relatively low fields, about 40 kG, appear to be competitive with conventional magnets. Evidently a total colliding-beam facility, including experimental equipment, could be built at NAL for a sum of the order of 100 million 1968 dollars. It should be added that the terms of reference of these design studies gave emphasis to a straightforward, conservative design. Further design work and advances in technology might very well result in a significant reduction in cost or, at the same cost, provide for a greater scope.

  11. Defocusing beam line design for an irradiation facility at the TAEA SANAEM Proton Accelerator Facility

    Gencer, A.; Demirköz, B.; Efthymiopoulos, I.; Yiğitoğlu, M.

    2016-07-01

    Electronic components must be tested to ensure reliable performance in high radiation environments such as Hi-Limu LHC and space. We propose a defocusing beam line to perform proton irradiation tests in Turkey. The Turkish Atomic Energy Authority SANAEM Proton Accelerator Facility was inaugurated in May 2012 for radioisotope production. The facility has also an R&D room for research purposes. The accelerator produces protons with 30 MeV kinetic energy and the beam current is variable between 10 μA and 1.2 mA. The beam kinetic energy is suitable for irradiation tests, however the beam current is high and therefore the flux must be lowered. We plan to build a defocusing beam line (DBL) in order to enlarge the beam size, reduce the flux to match the required specifications for the irradiation tests. Current design includes the beam transport and the final focusing magnets to blow up the beam. Scattering foils and a collimator is placed for the reduction of the beam flux. The DBL is designed to provide fluxes between 107 p /cm2 / s and 109 p /cm2 / s for performing irradiation tests in an area of 15.4 cm × 21.5 cm. The facility will be the first irradiation facility of its kind in Turkey.

  12. Comparison of different shielding materials used at proton accelerators and cost-benefit analysis

    During last decades physicians' and physicist's experience and confidence in proton beam radiotherapy has grown significantly. Construction of a number of new proton therapy facilities is already underway, and several are in planning stages for the near future. Cost-effective shielding design of these facilities is important. We present comparative analysis of different shielding materials that are typically used at proton accelerators and in proton radiotherapy facilities. We have used Geant4 tool-kit for simulation of the passage of particles through matter. We have analyzed shielding properties of iron, borated concrete, a water tank with borated polyethylene walls, borated polyethylene, and borated fire retardant plywood. We have simulated 240 MeV protons incident on a thin copper target that generated radiation fields of primary protons as well as secondaries produced in the target incident on the shielding block. We found that iron is most effective per unit length. It may be the most cost-effective option if one considers using the so called SEG blocks in combination with 1 to 2 ft of concrete layer. The material of the SEG block consists primarily of iron from recycled government facility metals, and is slightly radioactive. The slight inherent radioactivity as well as low energy (< 847 keV) secondary neutrons from iron will be shielded by a thin concrete layer. We also find that borated fire retardant plywood can be a cost-effective alternative for borated polyethylene in many shielding applications where borated polyethylene sheets are used that are arguably not less fire hazardous. (authors)

  13. Computer simulation of the three-dimensional regime of proton acceleration in the interaction of laser radiation with a thin spherical target

    Results from particle-in-cell simulations of the three-dimensional regime of proton acceleration in the interaction of laser radiation with a thin spherical target are presented. It is shown that the density of accelerated protons can be several times higher than that in conventional accelerators. The focusing of fast protons created in the interaction of laser radiation with a spherical target is demonstrated. The focal spot of fast protons is localized near the center of the sphere. The conversion efficiency of laser energy into fast ion energy attains 5%. The acceleration mechanism is analyzed and the electron and proton energy spectra are obtained

  14. Calculations of dose attenuation in slowly curving tunnel geometries at a high-energy proton accelerator

    Vincke, Helmut H

    2003-01-01

    The CERN Neutrino beam to Gran Sasso (CNGS) project and the Large Hadron Collider (LHC) will receive 450 GeV/c protons extracted from the Super Proton Synchrotron (SPS). In the tunnels leading to the CNGS target and the LHC accelerator there is a 150 m straight section where a beam dump (TED) can be moved into the beam chamber, intercepting the proton beam. After the TED, the beam is routed into either the 700m slowly curving TT41 tunnel (CNGS) or the TI8 tunnel consisting of a 400 m straight section followed by a curved 1.5 km long tunnel (LHC). The curved tunnels have a radius of approximately 1 km. During tests a proton beam of 1.2 multiplied by 10**1**3 s**- **1 could be sent to the dump. The question posed was how close to the TED could access be allowed during dumping operations. Initial simulations using the FLUKA Monte-Carlo transport program were optimised assuming that the high-energy muon contribution dominates. Discrepancies with an analytically based calculation led to a revision of this optimisa...

  15. Dose conversion coefficients in the shielding design calculation for high energy proton accelerator facilities

    Dose quantity in the shielding design calculation was changed from the 1 cm depth dose equivalent to effective dose on the occasion of the introduction of the International Commission on Radiological Protection (ICRP) 1990 Recommendations (ICRP Publication 60) into domestic laws. As dose conversion coefficients in the shielding design calculation for accelerator facilities, the values for front irradiation (AP irradiation geometry) of neutrons below 20 MeV based on the ICRP Publication 74 are listed in the accompanying table of the domestic laws, but the values for neutrons above 20 MeV are not shown in the accompanying table. The status of dose conversion coefficients for neutrons above 20 MeV was surveyed and the effective dose rates behind the concrete shield of proton accelerator facilities were obtained by using typical neutron spectra and various dose conversion coefficients. As a result of consideration, the effective dose conversion coefficients for front irradiation of neutrons above 20 MeV evaluated by using HERMES code system was recommended for high energy neutrons in the shielding design calculation of proton accelerator facilities and 77 energy group averaged dose conversion coefficients was produced from thermal energy to 2 GeV. (author)

  16. Measurement of radioactivity induced by GeV-protons and spallation neutrons using AGS accelerator

    Measurement of radioactivity induced by high-energy protons with energy of 2.83 and 24 GeV and spallation neutrons produced by bombarding a mercury target with the high-energy protons were performed by using the AGS (Alternative Gradient Synchrotron) accelerator at Brookhaven National Laboratory. The samples of boron, carbon, aluminum, iron, copper, niobium, mercury-oxide, lead, bismuth, acrylic resin, SS-316, Inconel-625 and Inconel-718 were irradiated around the mercury target. After the irradiation, the radioactivity of each sample was measured by using HPGe detectors at the cooling time between 2 h and 200 d. In the processing of the measured γ-ray spectra, more than 90 radioactive nucleus were identified, and the radioactivity production data were obtained. This report gives the experimental procedure, the data processing and the experimental results. (author)

  17. Delbrueck scattering of monoenergetic photons

    The Delbrueck effect was experimentally investigated in high Z nuclei with monoenergetic photons in the range 6.8-11.4 MeV. Two different methods were used for measurements of the differential scattering cross-section, in the 25-140 deg range and in the forward direction (theta = 1.5 deg), respectively. The known Compton scattering cross-section was used in a new and unique way for the determination of the elastic scattering cross-section. Isolation of the contribution of the real Delbrueck amplitudes to the cross-section was crried out successfully. Experimental confirmation of the theoretical calculations of Papatzacos and Mork and measurement, for the first time, of the Rayleigh scattering in the 10 MeV region are also reported. One of the most interesting findings is the presence of Coulomb corrections in Delbrueck scattering at these energies. More theoretical effort is needed in this last direction. (author)

  18. SEE Measurements and Simulations Using Mono-Energetic GeV-Energy Hadron Beams

    Alia, Ruben Garcia; Brugger, Markus; Roed, Ketil; Uznanski, Slawosz; Wrobel, Frederic; Ferlet-Cavrois, Veronique; Danzeca, Salvatore; Saigne, Frederic; Spiezia, Giovanni

    2013-01-01

    Single Event Upset (SEU) measurements were performed on the ESA SEU Monitor using mono-energetic GeV-energy hadron beams available in the North Experimental Area at CERN. A 400 GeV proton beam in the H4IRRAD test area and a 120 GeV mixed pion and proton beam at the CERN-EU high Energy Reference Field facility (CERF) were used for this purpose. The resulting cross section values are presented and discussed as well as compared to the several hundred MeV case (typical for standard test facilities) from a physical interaction perspective with the intention of providing a more general understanding of the behavior. Moreover, the implications of the cross section dependence with energy above the several hundred MeV range are analyzed for different environments. In addition, analogous measurements are proposed for Single Event Latchup (SEL), motivated by discussed simulation results. Finally, a brief introduction of the future CHARM (CERN High-energy AcceleratoR Mixed facility) test installation is included.

  19. Accelerating Protons to Therapeutic Energies with Ultra-Intense Ultra-Clean and Ultra-Short Laser Pulses

    Bulanov, Stepan S.; Brantov, Andrei; Bychenkov, Valery Yu.; Chvykov, Vladimir; Kalinchenko, Galina; Matsuoka, Takeshi; Rousseau, Pascal; Reed, Stephen; Yanovsky, Victor; Krushelnick, Karl; Litzenberg, Dale William; Maksimchuk, Anatoly

    2008-01-01

    Proton acceleration by high-intensity laser pulses from ultra-thin foils for hadron therapy is discussed. With the improvement of the laser intensity contrast ratio to 10-11 achieved on Hercules laser at the University of Michigan, it became possible to attain laser-solid interactions at intensities up to 1022 W/cm2 that allows an efficient regime of laser-driven ion acceleration from submicron foils. Particle-In-Cell (PIC) computer simulations of proton acceleration in the Directed Coulomb e...

  20. Design, fabrication and testing of a large cylindrical vacuum vessel for proton linear accelerator

    The paper deals with engineering design, fabrication, copper plating and vacuum design and leak testing of the first prototype segment of Alveraz type drift tube Proton Linear Accelerator (DTL) being developed at CAT. The prototype drift tube linac segment is a long horizontal cylindrical vacuum vessel. The cylindrical cavity is internally machined and copper plated from inside and operates at 202 MHz (RF) with a vacuum better than 1 x 10-6 mbar. There are 34 openings provided for vacuum pumps, RF input and monitoring loops, piston tuners etc. and a large openings for insertions of drift tubes from top of the tank. (author)

  1. Development of a large proton accelerator for innovative researches; development of high power RF source

    Chung, K. H.; Lee, K. O.; Shin, H. M.; Chung, I. Y. [KAPRA, Seoul (Korea); Kim, D. I. [Inha University, Incheon (Korea); Noh, S. J. [Dankook University, Seoul (Korea); Ko, S. K. [Ulsan University, Ulsan (Korea); Lee, H. J. [Cheju National University, Cheju (Korea); Choi, W. H. [Korea Advanced Institute of Science and Technology, Taejeon (Korea)

    2002-05-01

    This study was performed with objective to design and develop the KOMAC proton accelerator RF system. For the development of the high power RF source for CCDTL(coupled cavity drift tube linac), the medium power RF system using the UHF klystron for broadcasting was integrated and with this RF system we obtained the basic design data, operation experience and code-validity test data. Based on the medium power RF system experimental data, the high power RF system for CCDTL was designed and its performed was analyzed. 16 refs., 64 figs., 27 tabs. (Author)

  2. Project of compact accelerator for cancer proton therapy; Progetto di acceleratore compatto per terapia oncologica con protoni (TOP)

    Picardi, L.; Ronsivalle, C.; Vignati, A. [ENEA, Cntro Ricerche Frascati, Rome (Italy). Dip. Innovazione

    1995-04-01

    The status of the sub-project `Compact Accelerator` in the framework of the Hadrontherapy Project leaded by Prof. Amaldi is described. Emphasis is given to the reasons of the use of protons for radiotherapy applications, to the results of the preliminary design studies of four types of accelerators as possible radiotherapy dedicated `Compact Accelerator` and to the scenario of the fonts of financial resources.

  3. Determination of cross sections for the production of low-energy monoenergetic neutron fields

    The response of a neutron detector, defined as the reading of the device per unit of incident fluence or dose, varies with neutron energy. The experimental determination of this variation, i.e. of the response function of this instrument, has to be performed by facilities producing monoenergetic neutron fields. These neutrons are commonly produced by interaction between accelerated ions (proton or deuteron) onto a thin target composed of a reactive layer deposited on a metallic backing. Using the 7Li(p, n), 3H(p, n), 2H(d, n) and 3H(d, n) reactions, monoenergetic neutrons are obtained between 120 keV and 20 MeV in the ion beam direction (0 deg.). To reach lower neutron energies, the angle of the measuring point with respect to the ion beam direction can be increased. However, this method presents several problems of neutron energy and fluence homogeneities over the detector surface, as well as an important increase of the scattered neutron contribution. Another solution is to investigate other nuclear reactions, as 45Sc(p, n) allowing to extend the neutron energy range down to 8 keV at 0 deg.. A complete study of this reaction and its cross section has been undertaken within the framework of a scientific cooperation between the laboratory of neutron metrology and dosimetry (IRSN, France), two European national metrological institutes, the National Physical Laboratory (UK) and the Physikalisch-Technische Bundesanstalt (Germany), and IRMM, the Institute for Reference Materials and Measurements (EC). In parallel, other possible reactions have been investigated: 65Cu(p, n), 51V(p, n), 57Fe(p, n), 49Ti(p, n), 53Cr(p, n) and 37Cl(p, n). They were compared in terms of neutron fluence and minimum energy of the produced neutrons. (author)

  4. Transmutation of neptunium, americium, technetium, and iodine in fast spectrum cores driven by accelerated protons

    A neutronic analysis is presented of three incinerator subcritical lattices, driven by accelerated protons and designed to transmute the minor actinides, the 99Tc and the 129I, of light water reactor (LWR) waste. A calculational methodology must first be established to enable a neutronic burnup analysis of fission cores driven by high-energy protons. The methodology is based on the following codes: HERMES, the Forschungszentrum Juelich adaptation of HETC, for high-energy interactions; MCNP3, for neutron interactions below 20 MeV of neutron energy; and KORIGEN, the Forschungszentrum Karlsruhe adaptation of ORIGEN, for burnup analysis. A result of applying the methodology is that the minor actinides, the 99Tc, and the 129I, of LWR waste may be transmuted in subcritical cores, driven by the spallation neutrons emanating from the bombardment of the cores with 1600-MeV protons. Three cores types are required. Core type 1 is fueled by the minor actinides and is a modification of the Brookhaven National Laboratory PHOENIX. With a proton current of 20 mA, the core incinerates the minor actinide waste of 14 LWRs. Core type 2 contains the 99Tc, 129I, and plutonium waste of 19 LWRs. With a proton beam of 130 mA, the core incinerates the technetium and 60% of the iodine. With a faction of the plutonium coming out of this core, the remaining 40% of 129I is incinerated in core type 3. All three cores run to 100,000 MWd/tonne or slightly higher; on the average, no core is a net consumer of grid electricity; all are cooled by sodium but remain subcritical with the loss of coolant

  5. Algebraic-numeric calculations of proton trajectories in bending magnets of synchrotron accelerator

    We study a solution of nonlinear differential equation of the second degree which describes the trajectories of the charged particles in the fully inhomogeneous field of cyclic accelerator. We give the clear mathematical statement of the problem and algorithm of solving it. We realize this algorithm on the Computer Algebra System REDUCE 3.2. Our algorithm is based both on the existence of exact solution in terms of hyperelliptic integral and on the existence of power series solution of specific inversion problem. We use the known REDUCE procedures of operation on generalized power series. Using the FORTRAN code we give the numerical analysis of these series in the close relation to the concrete physical situation. We apply our results to the beam dynamics modelling of the protons in the bending magnets in synchrotron accelerator. 18 refs.; 2 figs

  6. The safe, economical operation of a slightly subcritical reactor and transmutor with a small proton accelerator

    I suggest that an accelerator can be used to increase the safety and neutron economy of a power reactor and a transmutor of long-lived radioactive wastes, such as minor actinides and fission products, by providing neutrons for its subcritical operation. Instead of the large subcriticality k=0.9-0.95 which we originally proposed for such transmutor, we propose to use a slightly subcritical reactor, such as k=0.99, which will avoid many of the technical difficulties that are associated with large subcriticality, such as localized power peaking, radiation damage due to injection of medium-energy protons, the high current accelerator, and the requirement for a long beam-expansion section. We analyze the power drop that occurred in Phenix reactor, and show that the operating this reactor in subcritical conditions improves safety. (author). 13 refs., 5 figs

  7. Multiphysics Analysis of Frequency Detuning in Superconducting RF Cavities for Proton Particle Accelerators

    Awida, M. H. [Fermilab; Gonin, I. [Fermilab; Passarelli, D. [Fermilab; Sukanov, A. [Fermilab; Khabiboulline, T. [Fermilab; Yakovlev, V. [Fermilab

    2016-01-22

    Multiphysics analyses for superconducting cavities are essential in the course of cavity design to meet stringent requirements on cavity frequency detuning. Superconducting RF cavities are the core accelerating elements in modern particle accelerators whether it is proton or electron machine, as they offer extremely high quality factors thus reducing the RF losses per cavity. However, the superior quality factor comes with the challenge of controlling the resonance frequency of the cavity within few tens of hertz bandwidth. In this paper, we investigate how the multiphysics analysis plays a major role in proactively minimizing sources of frequency detuning, specifically; microphonics and Lorentz Force Detuning (LFD) in the stage of RF design of the cavity and mechanical design of the niobium shell and the helium vessel.

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

    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.

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

    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

  10. Study of a spoke-type superconducting cavity for high power proton accelerators

    Since a few years, a lot of projects (especially dedicated to transmutation, radioactive beams production, spallation neutron sources or neutrinos factories) are based on high power proton linear accelerators. It has been demonstrated, thanks to their excellent RF performances, that superconducting elliptical cavities represent the best technological solution for the high energy part of these linacs (proton energy from typically 100 MeV). On the contrary, between 5 and 100 MeV, nothing is clearly settled and intensive studies on low-beta cavities are under progress. The main objective of this thesis is the study of a new low-beta cavity, called 'spoke', which could be used in the low energy part of European XADS (experimental accelerator driven system) and EURISOL (European isotope separation on-line) accelerators projects. A complete study of a beta 0.35 spoke cavity has been done: from its electromagnetic and mechanical optimization to warm and, above all, cold experimental tests: an accelerating field of 12.2 MV/m has been reached at T=4.2 K, that is to say one of the best value among the spoke cavities performances in the world. It has been shown that the specific ratio of a third, between the spoke bar diameter and the cavity length, led to optimize the surface electromagnetic fields. Moreover, spoke cavities can be used without any trouble, in the low energy part, due to their good rigidity. The experimental measurements performed on the cavity have confirmed the theoretical calculations, especially, concerning the expected frequency and mechanical behavior. Another study, performed on elliptical cavities, gave an explanation of the discrepancies between the measured and calculated frequencies thanks to a precise 3-dimensional geometrical control. (author)

  11. Study and optimization of a LINAC drift tube for high intensity proton acceleration

    High intensity proton accelerators lead to specific problems related to the need to limit beam losses. The problem is more acute in the low energy part (up to 20 MeV) where the beam transport is the most difficult. The drift tube linac (DTL) remains the reference structure for energies of a few MeV to a few dozens MeV despite the arising of some new cavity types. This thesis purpose is to design such a DTL for a high intensity proton accelerator. Until now, no such continuous wave cavity has ever been operated. To ensure the viability of such an accelerator, a short four cells prototype is designed, built and tested under nominal RF conditions. This prototype is fully representative of a complete machine except for its length. The design complexity comes from the combination of RF electromagnetism, thermal exchanges, mechanics, ultra-vacuum engineering and manufacturing constraints. More specifically, the electromagnets alignment is a primary factor, and reliability, despite being usually of secondary importance in particles accelerator science, is here a major concern considering potential industrial applications of this machine. The prototype design includes the cavity itself, but also quadrupole electromagnets whose feasibility is a limiting factor, considering the very small space available to them. Two different magnet types and associated drift tubes are studied and manufactured, to be tested in the prototype cavity. The experimental part is focused on mechanical and thermal aspects. The electromagnetic properties of the cavity are also checked. As a conclusion of this thesis, technical and conceptual improvements as suggested by the manufacturing and experimental phases are presented, to be implemented in a complete cavity. (author)

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

    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. PMID:23410447

  13. A new beam loss detector for low-energy proton and heavy-ion accelerators

    Liu, Zhengzheng, E-mail: liuz@frib.msu.edu; Crisp, Jenna; Russo, Tom; Webber, Robert; Zhang, Yan

    2014-12-11

    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 (LMR), to be implemented upstream of each FRIB cryomodule, as part of the direct loss monitoring system to fulfill the needs of machine protection. - Highlights: • Traditional BLM is not effective for beam loss monitoring at FRIB low energy linac segments. • We developed LMR to intercept a small portion of beam loss and output voltage signals. • We made a prototype LMR and demonstrated its functionality to monitor small beam losses. • The LMR is very sensitive for small beam losses and is independent of beam current. • The LMR is especially useful for loss monitoring at low energy ion/proton accelerators.

  14. A new beam loss detector for low-energy proton and heavy-ion accelerators

    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 (LMR), to be implemented upstream of each FRIB cryomodule, as part of the direct loss monitoring system to fulfill the needs of machine protection. - Highlights: • Traditional BLM is not effective for beam loss monitoring at FRIB low energy linac segments. • We developed LMR to intercept a small portion of beam loss and output voltage signals. • We made a prototype LMR and demonstrated its functionality to monitor small beam losses. • The LMR is very sensitive for small beam losses and is independent of beam current. • The LMR is especially useful for loss monitoring at low energy ion/proton accelerators

  15. A conceptual design of the DTL-SDTL for the JAERI high intensity proton accelerator

    Ino, Hiroshi; Kabeya, Zenzaburo [Mitsubishi Heavy Industries Ltd., Tokyo (Japan); Chishiro, Etsuji; Ouchi, Nobuo; Hasegawa, Kazuo; Mizumoto, Motoharu

    1998-08-01

    A high intensity proton linear accelerator with an energy of 1.5 GeV and an average beam power of 8 MW has been proposed for the Neutron Science Project (NSP) at JAERI. This linac starts with radio-frequency quadrupole (RFQ) linac, which is followed by a drift-tube linac (DTL), separated-type DTL (SDTL), and a superconducting structure. In this report, we focus on the DTL and SDTL part of the accelerator. The DTL accelerates the beam from 2 to 51 MeV, and SDTL accelerates the beam from 51 to 10 MeV. Since the main features of the requirement for the DTL-SDTL are high peak current ({approx}30 mA) and a high-duty factor ({approx}CW), the conceptual design should be determined not only based on the result of a beam-dynamics calculation, but by careful study of the cooling problems. The design processes of the DTL-SDTL and the matching sections (RFQ to DTL, CW-Pulse merge section, and SDTL to SCC) and the result of a heat transfer analysis of DTL are described. (author)

  16. Estimation of thermal neutron fluences in the concrete of proton accelerator facilities from 36Cl production

    Bessho, K.; Matsumura, H.; Miura, T.; Wang, Q.; Masumoto, K.; Hagura, H.; Nagashima, Y.; Seki, R.; Takahashi, T.; Sasa, K.; Sueki, K.; Matsuhiro, T.; Tosaki, Y.

    2007-06-01

    The thermal neutron fluence that poured into the shielding concrete of proton accelerator facilities was estimated from the in situ production of 36Cl. The thermal neutron fluences at concrete surfaces during 10-30 years of operation were in the range of 1012-1014 n/cm2. The maxima in thermal neutron fluences were observed at ≈5-15 cm in the depths analyzed for 36Cl/35Cl by AMS. These characteristics imply that thermalization of neutrons occurred inside the concrete. Compared to the several tens of MeV cyclotrons, secondary neutrons penetrate deeper into the concrete at the high-energy accelerators possessing acceleration energies of 400 MeV and 12 GeV. The attenuation length of neutrons reflects the energy spectra of secondary neutrons emitted by the nuclear reaction at the beam-loss points. Increasing the energy of secondary neutrons shifts the maximum in the thermal neutron fluences to deeper positions. The data obtained in this study will be useful for the radioactive waste management at accelerator facilities.

  17. Estimation of thermal neutron fluences in the concrete of proton accelerator facilities from 36Cl production

    The thermal neutron fluence that poured into the shielding concrete of proton accelerator facilities was estimated from the in situ production of 36Cl. The thermal neutron fluences at concrete surfaces during 10-30 years of operation were in the range of 1012-1014 n/cm2. The maxima in thermal neutron fluences were observed at ∼5-15 cm in the depths analyzed for 36Cl/35Cl by AMS. These characteristics imply that thermalization of neutrons occurred inside the concrete. Compared to the several tens of MeV cyclotrons, secondary neutrons penetrate deeper into the concrete at the high-energy accelerators possessing acceleration energies of 400 MeV and 12 GeV. The attenuation length of neutrons reflects the energy spectra of secondary neutrons emitted by the nuclear reaction at the beam-loss points. Increasing the energy of secondary neutrons shifts the maximum in the thermal neutron fluences to deeper positions. The data obtained in this study will be useful for the radioactive waste management at accelerator facilities

  18. Numerical studies of electron acceleration behind self-modulating proton beam in plasma with a density gradient

    Petrenko, A.; Lotov, K.; Sosedkin, A.

    2016-09-01

    Presently available high-energy proton beams in circular accelerators carry enough momentum to accelerate high-intensity electron and positron beams to the TeV energy scale over several hundred meters of the plasma with a density of about 1015cm-3. However, the plasma wavelength at this density is 100-1000 times shorter than the typical longitudinal size of the high-energy proton beam. Therefore the self-modulation instability (SMI) of a long (~10 cm) proton beam in the plasma should be used to create the train of micro-bunches which would then drive the plasma wake resonantly. Changing the plasma density profile offers a simple way to control the development of the SMI and the acceleration of particles during this process. We present simulations of the possible use of a plasma density gradient as a way to control the acceleration of the electron beam during the development of the SMI of a 400 GeV proton beam in a 10 m long plasma. This work is done in the context of the AWAKE project-the proof-of-principle experiment on proton driven plasma wakefield acceleration at CERN.

  19. Investigation of polyethylene detector and adiabatic calorimeter in the radiation filds of proton accelerators

    The results on investigation of the absorbed energy detectors used at IHEP, i. e., polyethylene detector (PD)-based on hydrogen release from polymer under effect of ionizing radiation and adiabatic calorimeter (AC) are presented. The sensitivity function for these detectors for 6 MeV-3000 GeV hadrons have been calculated. The PD and AC readings have been measured and calculated for the radiation fields near the IHEP proton synchrotron vacuum chamber. The dependence of the calorimeter readings on the working medium has been studied. The PD has been calibrated with the AC. It is ahown that in the hadron spectra the calorimeter readings do not depend on the working medium in the limit of 8%. The PD calibration enchanced the accuracy of radiation dose measuring in the accelerator radiation mixed field. The sensitivity function calculations showed that detectors studied applied for measuring absorved dose have the energy threshold, so for PD it is equal 18 MEV for protons, 6 MeV for charged poins. Results of investigations showed the possibility of PD utilization for measuring absorbed dose in different structural materials operating in mixed radiation fields of accelerators

  20. Development of an H- ion source for Japan Proton Accelerator Research Complex upgrade

    A cesium (Cs) free H- ion source driven with a lanthanum hexaboride (LaB6) filament was adopted as an ion source for the first stage of the Japan Proton Accelerator Research Complex (J-PARC). At present, the maximum H- ion current produced by the ion source is 38 mA, using which J-PARC can produce a proton beam power of 0.6 MW by accelerating it with the 181 MeV linac and the 3 GeV rapid cycling synchrotron. In order to satisfy the beam power of 1 MW required for the second stage of the J-PARC in the near future, we have to increase the ion current to more than 60 mA. Therefore, we have started to develop a Cs-seeded ion source by adding an external Cs-seeding system to a J-PARC test ion source that has a structure similar to that of the J-PARC ion source except for the fact that the plasma chamber is slightly larger. As a result, a H- ion current of more than 70 mA was obtained from the ion source using a tungsten filament instead of a LaB6 filament with a low arc discharge power of 15 kW (100 V, 150 A).

  1. Multiturn septum magnets for proton beam extraction from the IHEP accelerator

    Structure of multiturn septum magnet for he systems of proton beam extraction from the IHEP accelerator is described. Excitation coil, magnet core and all communications are located outside the accelerator vacuum volume. The magnet is characterized by a low gas release to the vacuum volume under the residual gas pressures of up to 1x10 -8Pa. The transition from monoturn excitation coil to multiturn one allowed one to decrease the value of necessary current and thus to reduce the energy loss in the bus duct from the power supply source to septum magnet. This allows one to increase the duration of slow proton extraction under the same power consumption. For example, after transition to two- and four-turn septum magnets the slow extraction duration can be increased up to two seconds, i.e.-doubled, which opens up a possibility to organize the particle beam extraction along two separate transport channels. By the present time the septum magnet has made 300000 cycles within the framework of physical experiments

  2. Chromatic energy filter and characterization of laser-accelerated proton beams for particle therapy

    Hofmann, Ingo; Meyer-ter-Vehn, Jürgen; Yan, Xueqing; Al-Omari, Husam

    2012-07-01

    The application of laser accelerated protons or ions for particle therapy has to cope with relatively large energy and angular spreads as well as possibly significant random fluctuations. We suggest a method for combined focusing and energy selection, which is an effective alternative to the commonly considered dispersive energy selection by magnetic dipoles. Our method is based on the chromatic effect of a magnetic solenoid (or any other energy dependent focusing device) in combination with an aperture to select a certain energy width defined by the aperture radius. It is applied to an initial 6D phase space distribution of protons following the simulation output from a Radiation Pressure Acceleration model. Analytical formula for the selection aperture and chromatic emittance are confirmed by simulation results using the TRACEWIN code. The energy selection is supported by properly placed scattering targets to remove the imprint of the chromatic effect on the beam and to enable well-controlled and shot-to-shot reproducible energy and transverse density profiles.

  3. Beyond the CMSSM without an accelerator: proton decay and direct dark matter detection

    We consider two potential non-accelerator signatures of generalizations of the well-studied constrained minimal supersymmetric standard model (CMSSM). In one generalization, the universality constraints on soft supersymmetry-breaking parameters are applied at some input scale Minbelow the grand unification (GUT) scale MGUT, a scenario referred to as ‘sub-GUT’. The other generalization we consider is to retain GUT-scale universality for the squark and slepton masses, but to relax universality for the soft supersymmetry-breaking contributions to the masses of the Higgs doublets. As with other CMSSM-like models, the measured Higgs mass requires supersymmetric particle masses near or beyond the TeV scale. Because of these rather heavy sparticle masses, the embedding of these CMSSM-like models in a minimal SU(5) model of grand unification can yield a proton lifetime consistent with current experimental limits, and may be accessible in existing and future proton decay experiments. Another possible signature of these CMSSM-like models is direct detection of supersymmetric dark matter. The direct dark matter scattering rate is typically below the reach of the LUX-ZEPLIN (LZ) experiment if Min is close to MGUT, but it may lie within its reach if Min≲1011 GeV. Likewise, generalizing the CMSSM to allow non-universal supersymmetry-breaking contributions to the Higgs offers extensive possibilities for models within reach of the LZ experiment that have long proton lifetimes

  4. Beyond the CMSSM without an accelerator: proton decay and direct dark matter detection

    We consider two potential non-accelerator signatures of generalizations of the well-studied constrained minimal supersymmetric standard model (CMSSM). In one generalization, the universality constraints on soft supersymmetry-breaking parameters are applied at some input scale Min below the grand unification (GUT) scale MGUT, a scenario referred to as 'sub-GUT'. The other generalization we consider is to retain GUT-scale universality for the squark and slepton masses, but to relax universality for the soft supersymmetry-breaking contributions to the masses of the Higgs doublets. As with other CMSSM-like models, the measured Higgs mass requires supersymmetric particle masses near or beyond the TeV scale. Because of these rather heavy sparticle masses, the embedding of these CMSSM-like models in a minimal SU(5) model of grand unification can yield a proton lifetime consistent with current experimental limits, and may be accessible in existing and future proton decay experiments. Another possible signature of these CMSSM-like models is direct detection of supersymmetric dark matter. The direct dark matter scattering rate is typically below the reach of the LUX-ZEPLIN (LZ) experiment if Min is close to MGUT, but it may lie within its reach if Min proton lifetimes. (orig.)

  5. Medical accelerator project for proton and carbon therapy in Hyogo Prefectural Government

    Hyogo Prefectural Government starts building a facility for proton radiation therapy that will also provide carbon therapy. The facility will be completed in 2000. Its output energy can be charged to 230 MeV/u proton beam and to 320 MeV/u carbon beam. In 1995, fundamental design of an accelerator was ordered. In the present plan, five rooms are to be provided for medical treatment. Different beam lines will be equipped in each room, one horizontal, one vertical with horizontal, two gantries, and one 45-degree oblique beam. 50-bed hospital will be built on an adjacent site to accommodate up to more than one thousand patients a year. These medical facilities will be part of the Harima Science Garden City, where Super Photon ring-8 GeV synchrotron radiation facility (SPring-8) is now building, which will be one of the most powerful synchrotron facilities in the world when completed in 1997. In the future, the medical imaging of using the beam of SPring-8 will be possible to diagnose the early cancer, which will be treated by proton or carbon beams without surgery. (author)

  6. Experimental study of proton acceleration with ultra-high intensity, high contrast laser beam

    This thesis reports experimental work in the domain of laser-matter interaction to study the production of energetic proton beams. The ion beams accelerated by laser have been increasing in quality, in energy and in repeatability as laser technology keeps improving. The presence of the pedestal before the high peak laser pulse introduces many unknowns in the accelerating conditions that are created on the front and on the rear surface of the target. The first part of the experimental activities is focused to a better comprehension and the experimental validation of the interaction of a 'pedestal-like', moderate intensity, laser pulse on Aluminum targets. The developed interferometric technique proved to be reliable and produced a complete set of maps of the early stages of the plasma expansion. The reflectometry experiment stresses the importance of the quality of the metallic targets and underlines some obscure points on the behaviour of the rear surface of the illuminated foil. For instance the reflectometry measurements on the thicker targets are significantly different from what is foreseen by the simulations about the timescale of the shock break out. In the second part, the XPW laser pulse is used in ion acceleration from thin metal foils. The laser and target parameters are varied to put in evidence the dependence of the ion beam to the experimental condition. In conclusion I can say that first, during the variation of the target thickness, an optimum is put in evidence. Secondly, the correlation between the laser pulse duration and the proton cutoff energy is qualitatively different between thicker (15 μm) and thinner (1.5 μm, 3 μm) targets. For the first, an optimal pulse duration exists while for the seconds, no variation is found - in the searched space - from the monotonic decreasing of the cutoff energy with the peak intensity. The experimental results put however in evidence some points that are not completely understood. (A.C.)

  7. Enhanced target normal sheath acceleration of protons from intense laser interaction with a cone-tube target

    Laser driven proton acceleration is proposed to be greatly enhanced by using a cone-tube target, which can be easily manufactured by current 3D-print technology. It is observed that energetic electron bunches are generated along the tube and accelerated to a much higher temperature by the combination of ponderomotive force and longitudinal electric field which is induced by the optical confinement of the laser field. As a result, a localized and enhanced sheath field is produced at the rear of the target and the maximum proton energy is about three-fold increased based on the two-dimentional particle-in-cell simulation results. It is demonstrated that by employing this advanced target scheme, the scaling of the proton energy versus the laser intensity is much beyond the normal target normal sheath acceleration (TNSA) case

  8. Enhanced target normal sheath acceleration of protons from intense laser interaction with a cone-tube target

    K. D. Xiao

    2016-01-01

    Full Text Available Laser driven proton acceleration is proposed to be greatly enhanced by using a cone-tube target, which can be easily manufactured by current 3D-print technology. It is observed that energetic electron bunches are generated along the tube and accelerated to a much higher temperature by the combination of ponderomotive force and longitudinal electric field which is induced by the optical confinement of the laser field. As a result, a localized and enhanced sheath field is produced at the rear of the target and the maximum proton energy is about three-fold increased based on the two-dimentional particle-in-cell simulation results. It is demonstrated that by employing this advanced target scheme, the scaling of the proton energy versus the laser intensity is much beyond the normal target normal sheath acceleration (TNSA case.

  9. Enhanced target normal sheath acceleration of protons from intense laser interaction with a cone-tube target

    Xiao, K. D.; Huang, T. W. [Center for Applied Physics and Technology, HEDPS, and School of Physics, Peking University, Beijing 100871 (China); Zhou, C. T., E-mail: zcangtao@iapcm.ac.cn [Center for Applied Physics and Technology, HEDPS, and School of Physics, Peking University, Beijing 100871 (China); Institute of Applied Physics and Computational Mathematics, Beijing 100094 (China); College of Electronic Science and Technology, Shenzhen University, Shenzhen 518060 (China); Qiao, B., E-mail: bqiao@pku.edu.cn [Center for Applied Physics and Technology, HEDPS, and School of Physics, Peking University, Beijing 100871 (China); State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871 (China); Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi, 030006 (China); Wu, S. Z. [Institute of Applied Physics and Computational Mathematics, Beijing 100094 (China); Ruan, S. C. [College of Electronic Science and Technology, Shenzhen University, Shenzhen 518060 (China); He, X. T. [Center for Applied Physics and Technology, HEDPS, and School of Physics, Peking University, Beijing 100871 (China); Institute of Applied Physics and Computational Mathematics, Beijing 100094 (China)

    2016-01-15

    Laser driven proton acceleration is proposed to be greatly enhanced by using a cone-tube target, which can be easily manufactured by current 3D-print technology. It is observed that energetic electron bunches are generated along the tube and accelerated to a much higher temperature by the combination of ponderomotive force and longitudinal electric field which is induced by the optical confinement of the laser field. As a result, a localized and enhanced sheath field is produced at the rear of the target and the maximum proton energy is about three-fold increased based on the two-dimentional particle-in-cell simulation results. It is demonstrated that by employing this advanced target scheme, the scaling of the proton energy versus the laser intensity is much beyond the normal target normal sheath acceleration (TNSA) case.

  10. Enhanced target normal sheath acceleration of protons from intense laser interaction with a cone-tube target

    Xiao, K. D.; Huang, T. W.; Zhou, C. T.; Qiao, B.; Wu, S. Z.; Ruan, S. C.; He, X. T.

    2016-01-01

    Laser driven proton acceleration is proposed to be greatly enhanced by using a cone-tube target, which can be easily manufactured by current 3D-print technology. It is observed that energetic electron bunches are generated along the tube and accelerated to a much higher temperature by the combination of ponderomotive force and longitudinal electric field which is induced by the optical confinement of the laser field. As a result, a localized and enhanced sheath field is produced at the rear of the target and the maximum proton energy is about three-fold increased based on the two-dimentional particle-in-cell simulation results. It is demonstrated that by employing this advanced target scheme, the scaling of the proton energy versus the laser intensity is much beyond the normal target normal sheath acceleration (TNSA) case.

  11. GPU-accelerated automatic identification of robust beam setups for proton and carbon-ion radiotherapy

    We demonstrate acceleration on graphic processing units (GPU) of automatic identification of robust particle therapy beam setups, minimizing negative dosimetric effects of Bragg peak displacement caused by treatment-time patient positioning errors. Our particle therapy research toolkit, RobuR, was extended with OpenCL support and used to implement calculation on GPU of the Port Homogeneity Index, a metric scoring irradiation port robustness through analysis of tissue density patterns prior to dose optimization and computation. Results were benchmarked against an independent native CPU implementation. Numerical results were in agreement between the GPU implementation and native CPU implementation. For 10 skull base cases, the GPU-accelerated implementation was employed to select beam setups for proton and carbon ion treatment plans, which proved to be dosimetrically robust, when recomputed in presence of various simulated positioning errors. From the point of view of performance, average running time on the GPU decreased by at least one order of magnitude compared to the CPU, rendering the GPU-accelerated analysis a feasible step in a clinical treatment planning interactive session. In conclusion, selection of robust particle therapy beam setups can be effectively accelerated on a GPU and become an unintrusive part of the particle therapy treatment planning workflow. Additionally, the speed gain opens new usage scenarios, like interactive analysis manipulation (e.g. constraining of some setup) and re-execution. Finally, through OpenCL portable parallelism, the new implementation is suitable also for CPU-only use, taking advantage of multiple cores, and can potentially exploit types of accelerators other than GPUs.

  12. Construction of monoenergetic neutron calibration fields using 45Sc(p, n) 45Ti reaction at JAEA

    The 8 and 27 keV monoenergetic neutron calibration fields have been developed by using 45Sc(p, n)45Ti reaction. Protons from a 4-MV Pelletron accelerator are used to bombard a thin scandium target evaporated onto a platinum disc. The proton energies are finely adjusted to the resonance to generate the 8 and 27 keV neutrons by applying a high voltage to the target assemblies. The neutron energies were measured using the time-of-flight method with a lithium glass scintillation detector. The neutron fluences at a calibration point located at 50 cm from the target were evaluated using Bonner spheres. A long counter was placed at 2.2 m from the target and at 60 deg. to the direction of the proton beam in order to monitor the fluence at the calibration point. Fluence and dose equivalent rates at the calibration point are sufficient to calibrate many types of the neutron survey metres. (authors)

  13. Study of technical issues on proton beam line tunnel in material/life science experimental facility of high intensity proton accelerator project

    Sakamoto, Shinichi [High Energy Accelerator Research Organization, Tsukuba, Ibaraki (Japan); Meigo, Shin-ichiro; Konno, Chikara [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment] [and others

    2001-12-01

    The so called NM Tunnel, which is a specific proton beam line space for the muon experiment and the spallation neutron source, is placed in the Material/Life Science Experimental Facility under the JAERI-KEK Joint project on the High Intensity Proton Accelerator. The group relevant to the NM tunnel has studied extensively technical issues associated from various aspects since last year. As a result, a basic structure of the NM Tunnel has been established as the initial phase. In viewing the importance for the facility design, this report summaries studies done by members of the group. (author)

  14. Enhancement on Laser Intensity and Proton Acceleration Using Micro-tube Plasma Lens Targets

    Snyder, Joseph; Akli, Kramer

    2016-01-01

    A hollow cylindrical micron-scale structure is proposed to enhance and manipulate the laser plasma interaction. It is shown through 3-D particle-in-cell simulations that the incident laser pulse intensity is enhanced within the tube. A detailed study of the intensification optimizes the tube dimensions and provides a characterization of the in-tube intensity. By coupling the micro-tube plasma lens to a traditional flat interface, we show an increase in on-target intensity. We detail proton energy enhancement as a potential application of the micro-tube plasma lens target, where the tube structure acts to focus the light and provide additional electrons that enhance the accelerating sheath field.

  15. Microfabrication of silicon hydrogenated thin targets for multi-MeV laser-driven proton acceleration

    Picciotto, A.; Margarone, Daniele; Crivellari, M.; Bellutti, P.; Colpo, S.; Torrisi, L.; Krása, Josef; Velyhan, Andriy; Ullschmied, Jiří

    2011-01-01

    Roč. 4, č. 12 (2011), "126401-1"-"126401-3". ISSN 1882-0778 R&D Projects: GA ČR(CZ) GAP205/11/1165; GA MŠk(CZ) 7E09092; GA MŠk ED1.1.00/02.0061; GA MŠk EE.2.3.20.0087 Grant ostatní: ELI Beamlines(XE) CZ.1.05/1.1.00/02.0061; OP VK 2 LaserGen(XE) CZ.1.07/2.3.00/20.0087 Institutional research plan: CEZ:AV0Z10100523; CEZ:AV0Z20430508 Keywords : silicon microfabrication * hydrogen ated targets * lasers * proton acceleration Subject RIV: BH - Optics, Masers, Lasers Impact factor: 3.013, year: 2011

  16. Proton driven acceleration by intense laser pulses irradiating thin hydrogenated targets

    Torrisi, L.; Cutroneo, M.; Cavallaro, S.; Giuffrida, L.; Andò, L.; Cirrone, P.; Bertuccio, G.; Puglisi, D.; Calcagno, L.; Verona, C.; Picciotto, A.; Krása, Josef; Margarone, Daniele; Velyhan, Andriy; Láska, Leoš; Krouský, Eduard; Pfeifer, Miroslav; Skála, Jiří; Ullschmied, Jiří; Wolowski, J.; Badziak, J.; Rosinski, M.; Ryc, L.; Szydlowski, A.

    2013-01-01

    Roč. 272, May (2013), s. 2-5. ISSN 0169-4332 R&D Projects: GA MŠk ED1.1.00/02.0061; GA MŠk EE2.3.20.0279; GA MŠk EE.2.3.20.0087; GA MŠk(CZ) 7E09092; GA MŠk(CZ) LC528 Grant ostatní: ELI Beamlines(XE) CZ.1.05/1.1.00/02.0061; OPVK 3 Laser Zdroj(XE) CZ.1.07/2.3.00/20.0279; OP VK 2 LaserGen(XE) CZ.1.07/2.3.00/20.0087; 7FP LASERLAB-EUROPE(XE) 228334 Institutional support: RVO:68378271 Keywords : laser-matter-interaction * plasma * proton-acceleration * hydrogenated-target Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 2.538, year: 2013

  17. DESIGN CONSIDERATIONS OF FAST KICKER SYSTEMS FOR HIGH INTENSITY PROTON ACCELERATORS

    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

  18. Performance of solenoids vs. quadrupoles in focusing and energy selection of laser accelerated protons

    Hofmann, Ingo

    2013-01-01

    Using laser accelerated protons or ions for various applications - for example in particle therapie or short-pulse radiographic diagnostics - requires an effective method of focusing and energy selection. We derive an analytical scaling for the performance of a solenoid compared with a doublet/triplet as function of the energy, which is confirmed by TRACEWIN simulations. The scaling shows that above a few MeV a solenoid needs to be pulsed or super-conducting, whereas the quadrupoles can remain conventional. The transmission of the triplet is found only 25% lower than that of the equivalent solenoid. Both systems are equally suitable for energy selection based on their chromatic effect as is shown using an initial distribution following the RPA simulation model by Yan et al.\\cite{yan2009}.

  19. Research Programme for the 660 Mev Proton Accelerator Driven MOX-Plutonium Subcritical Assembly

    Barashenkov, V S; Buttseva, G L; Dudarev, S Yu; Polanski, A; Puzynin, I V; Sissakian, A N

    2000-01-01

    The paper presents a research programme of the Experimental Acclerator Driven System (ADS), which employs a subcritical assembly and a 660 MeV proton acceletator operating at the Laboratory of Nuclear Problems of the JINR, Dubna. MOX fuel (25% PuO_2 + 75% UO_2) designed for the BN-600 reactor use will be adopted for the core of the assembly. The present conceptual design of the experimental subcritical assembly is based on a core of a nominal unit capacity of 15 kW (thermal). This corresponds to the multiplication coefficient k_eff = 0.945, energetic gain G = 30 and the accelerator beam power 0.5 kW.

  20. Proton acceleration beyond 100 EeV by an oblique shock wave in the jet of 3C 273

    Honda, Yasuko S.; Honda, Mitsuru

    2004-01-01

    We estimate the highest energy of proton diffusively accelerated by shock in knot A1 of the jet in luminous nearby quasar 3C 273. Referring to the recent polarization measurements using very long baseline interferometry (VLBI), we consider the shock propagation across magnetic field lines, namely, configuration of the oblique shock. For larger inclination of the field lines, the effects of particle reflection at the shock front are more pronounced, to significantly increase acceleration effic...

  1. Development of a monoenergetic neutron beam (Theoretical aspects, experimental developments and applications)

    By the use of a neutron time of flight system at the Tandem Accelerator of the National Nuclear Research Institute; with neutrons provided by means of the 2 H(d, n) 3 He we intend to use the associated particle technique in order to have monoenergetic neutrons. This neutron beam will be used both in basic and applied research. (Author)

  2. Development of a monoenergetic neutron beam (Theoretical aspects, experimental developments and applications)

    Varela-G, A

    2003-01-01

    By the use of a neutron time of flight system at the Tandem Accelerator of the National Nuclear Research Institute; with neutrons provided by means of the sup 2 H(d, n) sup 3 He we intend to use the associated particle technique in order to have monoenergetic neutrons. This neutron beam will be used both in basic and applied research. (Author)

  3. Accelerating parameter identification of proton exchange membrane fuel cell model with ranking-based differential evolution

    Parameter identification of PEM (proton exchange membrane) fuel cell model is a very active area of research. Generally, it can be treated as a numerical optimization problem with complex nonlinear and multi-variable features. DE (differential evolution), which has been successfully used in various fields, is a simple yet efficient evolutionary algorithm for global numerical optimization. In this paper, with the objective of accelerating the process of parameter identification of PEM fuel cell models and reducing the necessary computational efforts, we firstly present a generic and simple ranking-based mutation operator for the DE algorithm. Then, the ranking-based mutation operator is incorporated into five highly-competitive DE variants to solve the PEM fuel cell model parameter identification problems. The main contributions of this work are the proposed ranking-based DE variants and their application to the parameter identification problems of PEM fuel cell models. Experiments have been conducted by using both the simulated voltage–current data and the data obtained from the literature to validate the performance of our approach. The results indicate that the ranking-based DE methods provide better results with respect to the solution quality, the convergence rate, and the success rate compared with their corresponding original DE methods. In addition, the voltage–current characteristics obtained by our approach are in good agreement with the original voltage–current curves in all cases. - Highlights: • A simple and generic ranking-based mutation operator is presented in this paper. • Several DE (differential evolution) variants are used to solve the parameter identification of PEMFC (proton exchange membrane fuel cells) model. • Results show that our method accelerates the process of parameter identification. • The V–I characteristics are in very good agreement with experimental data

  4. Beyond the CMSSM without an accelerator: proton decay and direct dark matter detection

    Ellis, John [King' s College London, Theoretical Physics and Cosmology Group, Department of Physics, London (United Kingdom); CERN, TH Division, Physics Department, Geneva 23 (Switzerland); Evans, Jason L.; Olive, Keith A. [University of Minnesota, William I. Fine Theoretical Physics Institute, School of Physics and Astronomy, Minneapolis, MN (United States); Luo, Feng [CERN, TH Division, Physics Department, Geneva 23 (Switzerland); Nagata, Natsumi [University of Minnesota, William I. Fine Theoretical Physics Institute, School of Physics and Astronomy, Minneapolis, MN (United States); University of Tokyo, Kavli IPMU (WPI), UTIAS, Kashiwa, Chiba (Japan); Sandick, Pearl [University of Utah, Department of Physics and Astronomy, Salt Lake City, UT (United States)

    2016-01-15

    We consider two potential non-accelerator signatures of generalizations of the well-studied constrained minimal supersymmetric standard model (CMSSM). In one generalization, the universality constraints on soft supersymmetry-breaking parameters are applied at some input scale M{sub in} below the grand unification (GUT) scale M{sub GUT}, a scenario referred to as 'sub-GUT'. The other generalization we consider is to retain GUT-scale universality for the squark and slepton masses, but to relax universality for the soft supersymmetry-breaking contributions to the masses of the Higgs doublets. As with other CMSSM-like models, the measured Higgs mass requires supersymmetric particle masses near or beyond the TeV scale. Because of these rather heavy sparticle masses, the embedding of these CMSSM-like models in a minimal SU(5) model of grand unification can yield a proton lifetime consistent with current experimental limits, and may be accessible in existing and future proton decay experiments. Another possible signature of these CMSSM-like models is direct detection of supersymmetric dark matter. The direct dark matter scattering rate is typically below the reach of the LUX-ZEPLIN (LZ) experiment if M{sub in} is close to M{sub GUT}, but it may lie within its reach if M{sub in} proton lifetimes. (orig.)

  5. Beyond the CMSSM without an accelerator: proton decay and direct dark matter detection

    Ellis, John; Evans, Jason L.; Luo, Feng; Nagata, Natsumi; Olive, Keith A.; Sandick, Pearl

    2016-01-01

    We consider two potential non-accelerator signatures of generalizations of the well-studied constrained minimal supersymmetric standard model (CMSSM). In one generalization, the universality constraints on soft supersymmetry-breaking parameters are applied at some input scale M_{in} below the grand unification (GUT) scale M_{GUT}, a scenario referred to as `sub-GUT'. The other generalization we consider is to retain GUT-scale universality for the squark and slepton masses, but to relax universality for the soft supersymmetry-breaking contributions to the masses of the Higgs doublets. As with other CMSSM-like models, the measured Higgs mass requires supersymmetric particle masses near or beyond the TeV scale. Because of these rather heavy sparticle masses, the embedding of these CMSSM-like models in a minimal SU(5) model of grand unification can yield a proton lifetime consistent with current experimental limits, and may be accessible in existing and future proton decay experiments. Another possible signature of these CMSSM-like models is direct detection of supersymmetric dark matter. The direct dark matter scattering rate is typically below the reach of the LUX-ZEPLIN (LZ) experiment if M_{in} is close to M_{GUT}, but it may lie within its reach if M_{in} ≲ 10^{11} GeV. Likewise, generalizing the CMSSM to allow non-universal supersymmetry-breaking contributions to the Higgs offers extensive possibilities for models within reach of the LZ experiment that have long proton lifetimes.

  6. Beyond the CMSSM without an accelerator: proton decay and direct dark matter detection

    Ellis, John [Theoretical Physics and Cosmology Group, Department of Physics, King’s College London, Strand, WC2R 2LS, London (United Kingdom); TH Division, Physics Department, CERN, 1211, Geneva 23 (Switzerland); Evans, Jason L. [William I. Fine Theoretical Physics Institute, School of Physics and Astronomy, University of Minnesota, 55455, Minneapolis, MN (United States); Luo, Feng [TH Division, Physics Department, CERN, 1211, Geneva 23 (Switzerland); Nagata, Natsumi [William I. Fine Theoretical Physics Institute, School of Physics and Astronomy, University of Minnesota, 55455, Minneapolis, MN (United States); Kavli IPMU (WPI), UTIAS, University of Tokyo, 277-8583, Kashiwa, Chiba (Japan); Olive, Keith A. [William I. Fine Theoretical Physics Institute, School of Physics and Astronomy, University of Minnesota, 55455, Minneapolis, MN (United States); Sandick, Pearl, E-mail: sandick@physics.utah.edu [Department of Physics and Astronomy, University of Utah, 84112, Salt Lake City, UT (United States)

    2016-01-05

    We consider two potential non-accelerator signatures of generalizations of the well-studied constrained minimal supersymmetric standard model (CMSSM). In one generalization, the universality constraints on soft supersymmetry-breaking parameters are applied at some input scale M{sub in}below the grand unification (GUT) scale M{sub GUT}, a scenario referred to as ‘sub-GUT’. The other generalization we consider is to retain GUT-scale universality for the squark and slepton masses, but to relax universality for the soft supersymmetry-breaking contributions to the masses of the Higgs doublets. As with other CMSSM-like models, the measured Higgs mass requires supersymmetric particle masses near or beyond the TeV scale. Because of these rather heavy sparticle masses, the embedding of these CMSSM-like models in a minimal SU(5) model of grand unification can yield a proton lifetime consistent with current experimental limits, and may be accessible in existing and future proton decay experiments. Another possible signature of these CMSSM-like models is direct detection of supersymmetric dark matter. The direct dark matter scattering rate is typically below the reach of the LUX-ZEPLIN (LZ) experiment if M{sub in} is close to M{sub GUT}, but it may lie within its reach if M{sub in}≲10{sup 11} GeV. Likewise, generalizing the CMSSM to allow non-universal supersymmetry-breaking contributions to the Higgs offers extensive possibilities for models within reach of the LZ experiment that have long proton lifetimes.

  7. Phase II trial of proton beam accelerated partial breast irradiation in breast cancer

    Background and purpose: Here, we report the results of our phase II, prospective study of proton beam accelerated partial breast irradiation (PB-APBI) in patients with breast cancer after breast conserving surgery (BCS). Materials and methods: Thirty patients diagnosed with breast cancer were treated with PB-APBI using a single-field proton beam or two fields after BCS. The treatment dose was 30 cobalt gray equivalent (CGE) in six CGE fractions delivered once daily over five consecutive working days. Results: All patients completed PB-APBI. The median follow-up time was 59 months (range: 43–70 months). Of the 30 patients, none had ipsilateral breast recurrence or regional or distant metastasis, and all were alive at the last follow-up. Physician-evaluated toxicities were mild to moderate, except in one patient who had severe wet desquamation at 2 months that was not observed beyond 6 months. Qualitative physician cosmetic assessments of good or excellent were noted in 83% and 80% of the patients at the end of PB-APBI and at 2 months, respectively, and decreased to 69% at 3 years. A good or excellent cosmetic outcome was noted in all patients treated with a two-field proton beam at any follow-up time point except for one. For all patients, the mean percentage breast retraction assessment (pBRA) value increased significantly during the follow-up period (p = 0.02); however, it did not increase in patients treated with two-field PB-APBI (p = 0.3). Conclusions: PB-APBI consisting of 30 CGE in six CGE fractions once daily for five consecutive days can be delivered with excellent disease control and tolerable skin toxicity to properly selected patients with early-stage breast cancer. Multiple-field PB-APBI may achieve a high rate of good-to-excellent cosmetic outcomes. Additional clinical trials with larger patient groups are needed

  8. Reaction mechanisms in the plasma focus - investigations on accelerated deuterons and reaction protons

    The Plasma focus POSEIDON (W0=280 kJ; U0=60 kV) exhibits two distinct phases of high suprathermal fusion production. The first, pinch or quiescent phase shows a stable, radially well confined plasma. The second, unstable phase corresponds to m=0 instabilities and subsequent break-up of the plasma. For an analysis of the mechanisms leading to the high fusion production in both phases, a new model, the ''Gyrating Particle Model'' (GPM), was developed. In the GPM the trajectories of fast deuterons in the time varying focus structures are determined by a ray-tracing code. The profiles nsub(e)(r,z,t) and Tsub(e)(r,z,t) for both phases are taken from measurements in a schematized form. The deuteron acceleration process is not treated, i.e. arbitrary initial distribution functions of the deuterons are taken at the beginning of each phase. Coulomb collisions with the thermal plasma electrons describing the energy loss of the fast deuterons and fusion collisions with the thermal deuterons are treated with the help of Monte Carlo methods. Other reaction mechanisms, such as beam-beam or thermal production, are neglected. The trajectories of the reaction protons in the focus-field are traced up to measuring positions outside of the focus pinch. Thus, measurable quantities such as spatial, angular and spectral distributions and time evolution of the reaction protons and neutrons are obtained and compared with experimental results. (orig./GG)

  9. Development of hybrid gas detectors for monitoring neutrons induced from the Large Intensity Proton Linear Accelerator

    The purpose of the research is developments of new hybrid-neutron detectors to measure neutron fluxes where proton accelerators are operated for the purpose of neutron therapy or various industrial applications. The framework of the R and D based upon GEANT simulations was developed for 10B and Gd2O3 hybrid scintillation detectors. The simulation results were applied to design the detector structures and to determine the proper test method where neutron sources were used. The detector response functions for the 10B and Gd2O3 hybrid scintillators were measured by proper calibrations by using neutrons emitted from a 0.5 Ci 252Cf isotope. Furthermore, the detector characteristics were obtained by the comparisons of the neutron signals with those of the gamma-rays emitted from the 137Cs and 60Co sources. We have performed a feasibility study for the future applications of the 10B and Gd2O3 hybrid scintillators to medical imaging of the thermal neutron fields for neutron-beam therapies. A radiation hardness tested for the Resistive Plate Chamber of the CMS/LHC experiment was performed by using the fast neutrons produced by the M50 proton cyclotron in KIRAMS and a 10 mm thick beryllium target. Four tests with cosmic muons have been carried out before and after the neutron irradiation to investigate the effects on the characteristics of the detectors. No significant degradation of the detector characteristics due to the effect, equivalent to 45 Gy, has been observed

  10. Beyond the CMSSM without an Accelerator: Proton Decay and Direct Dark Matter Detection

    Ellis, John; Luo, Feng; Nagata, Natsumi; Olive, Keith A; Sandick, Pearl

    2016-01-01

    We consider two potential non-accelerator signatures of generalizations of the well-studied constrained minimal supersymmetric standard model (CMSSM). In one generalization, the universality constraints on soft supersymmetry-breaking parameters are applied at some input scale $M_{in}$ below the grand unification (GUT) scale $M_{GUT}$, a scenario referred to as `sub-GUT'. The other generalization we consider is to retain GUT-scale universality for the squark and slepton masses, but to relax universality for the soft supersymmetry-breaking contributions to the masses of the Higgs doublets. As with other CMSSM-like models, the measured Higgs mass requires supersymmetric particle masses near or beyond the TeV scale. Because of these rather heavy sparticle masses, the embedding of these CMSSM-like models in a minimal SU(5) model of grand unification can yield a proton lifetime consistent with current experimental limits, and may be accessible in existing and future proton decay experiments. Another possible signat...

  11. Global numerical modeling of energetic proton acceleration in a coronal mass ejection traveling through the solar corona

    The acceleration of protons and electrons to high (sometimes GeV/nucleon) energies by solar phenomena is a key component of space weather. These solar energetic particle (SEP) events can damage spacecraft and communications, as well as present radiation hazards to humans. In-depth particle acceleration simulations have been performed for idealized magnetic fields for diffusive acceleration and particle propagation, and at the same time the quality of MHD simulations of coronal mass ejections (CMEs) has improved significantly. However, to date these two pieces of the same puzzle have remained largely decoupled. Such structures may contain not just a shock but also sizable sheath and pileup compression regions behind it, and may vary considerably with longitude and latitude based on the underlying coronal conditions. In this work, we have coupled results from a detailed global three-dimensional MHD time-dependent CME simulation to a global proton acceleration and transport model, in order to study time-dependent effects of SEP acceleration between 1.8 and 8 solar radii in the 2005 May 13 CME. We find that the source population is accelerated to at least 100 MeV, with distributions enhanced up to six orders of magnitude. Acceleration efficiency varies strongly along field lines probing different regions of the dynamically evolving CME, whose dynamics is influenced by the large-scale coronal magnetic field structure. We observe strong acceleration in sheath regions immediately behind the shock.

  12. Proton beam of 2 MeV 1.6 mA on a tandem accelerator with vacuum insulation

    A source of epithermal neutrons based on a tandem accelerator with vacuum insulation for boron neutron capture therapy of malignant tumors was proposed and constructed. Stationary proton beam with 2 MeV energy, 1.6 mA current, 0.1% energy monochromaticity and 0.5% current stability has just been obtained

  13. Development of a Compton Camera for Online Range Monitoring of Laser-Accelerated Proton Beams via Prompt-Gamma Detection

    Thirolf, P.G.; Lang, C.; Aldawood, S.; Van der Kolff, H.G.; Maier, L.; Schaart, D.R.; Parodi, K.

    2014-01-01

    Presently large efforts are conducted in Munich towards the development of proton beams for bio-medical applications, generated via the technique of particle acceleration from high-power, short-pulse lasers. While so far mostly offline diagnostics tools are used in this context, we aim at developing

  14. Numerical Studies of Electron Acceleration Behind Self-Modulating Proton Beam in Plasma with a Density Gradient

    Petrenko, Alexey; Sosedkin, Alexander

    2015-01-01

    Presently available high-energy proton beams in circular accelerators carry enough momentum to accelerate high-intensity electron and positron beams to the TeV energy scale over several hundred meters of the plasma with a density of about 1e15 1/cm^3. However, the plasma wavelength at this density is 100-1000 times shorter than the typical longitudinal size of the high-energy proton beam. Therefore the self-modulation instability (SMI) of a long (~10 cm) proton beam in the plasma should be used to create the train of micro-bunches which would then drive the plasma wake resonantly. Changing the plasma density profile offers a simple way to control the development of the SMI and the acceleration of particles during this process. We present simulations of the possible use of a plasma density gradient as a way to control the acceleration of the electron beam during the development of the SMI of a 400 GeV proton beam in a 10 m long plasma. This work is done in the context of the AWAKE project --- the proof-of-prin...

  15. Laser-driven proton and deuteron acceleration from a pure solid-density H2/D2 cryogenic jet

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

    2015-11-01

    Laser-driven proton acceleration has become of tremendous interest for the fundamental science and the potential applications in tumor therapy and proton radiography. We have developed a cryogenic liquid hydrogen jet, which can deliver a self-replenishing target of pure solid-density hydrogen or deuterium. This allows for a target compatible with high-repetition-rate experiments and results in a pure hydrogen plasma, facilitating comparison with simulations. A new modification has allowed for the formation of jets with rectangular profiles, facilitating comparison with foil targets. This jet was installed at the Titan laser and driven by laser pulses of 40-60 J of 527 nm laser light in 1 ps. The resulting proton and deuteron spectra were measured in multiple directions with Thomson parabola spectrometers and RCF stacks. The spectral and angular information suggest contribution from both the TNSA and RPA acceleration mechanisms.

  16. Development and utilization of various target assemblies for proton beam irradiation setup at 14 UD BARC-TIFR pelletron accelerator facility

    Drift space above analyzing magnet is modified to accommodate a proton beam setup at 6 meter level of 14UD BARC-TIFR Pelletron Accelerator Facility. This setup is capable of delivering proton beam in the energy range of 2 MeV to 26 MeV and current in μA range. The shielding at this level is such that radiation is within permissible limit when high proton beam current is accelerated. (author)

  17. Effects of nanosecond-scale prepulse on generation of high-energy protons in target normal sheath acceleration

    A pulse cleaner based on noncollinear optical-parametric amplification and second-harmonic generation processes is used to improve the contrast of a laser of peak intensity ∼2 × 1019 W/cm2 to ∼1011 at 100 ps before the peak of the main pulse. A 7 MeV proton beam is observed when a 2.5 μm-thick Al foil is irradiated by this high-contrast laser. The maximum proton energy decreases to 2.9 MeV when a low-contrast (∼108) laser is used. Two-dimensional particle-in-cell simulations combined with MULTI simulations show that the maximum proton energy sensitively relies on the detecting direction. The ns-time-scale prepulse can bend a thin target before the main pulse arrives, which reduces maximum proton energy in the target normal sheath acceleration.

  18. Application of laser-accelerated protons to the demonstration of DNA double-strand breaks in human cancer cells

    Yogo, A.; Sato, K.; Nishikino, M.; Mori, M.; Teshima, T.; Numasaki, H.; Murakami, M.; Demizu, Y.; Akagi, S.; Nagayama, S.; Ogura, K.; Sagisaka, A.; Orimo, S.; Nishiuchi, M.; Pirozhkov, A. S.; Ikegami, M.; Tampo, M.; Sakaki, H.; Suzuki, M.; Daito, I.; Oishi, Y.; Sugiyama, H.; Kiriyama, H.; Okada, H.; Kanazawa, S.; Kondo, S.; Shimomura, T.; Nakai, Y.; Tanoue, M.; Sasao, H.; Wakai, D.; Bolton, P. R.; Daido, H.

    2009-05-01

    We report the demonstrated irradiation effect of laser-accelerated protons on human cancer cells. In vitro (living) A549 cells are irradiated with quasimonoenergetic proton bunches of 0.8-2.4 MeV with a single bunch duration of 15 ns. Irradiation with the proton dose of 20 Gy results in a distinct formation of γ-H2AX foci as an indicator of DNA double-strand breaks generated in the cancer cells. This is a pioneering result that points to future investigations of the radiobiological effects of laser-driven ion beams. Unique high-current and short-bunch features make laser-driven proton bunches an excitation source for time-resolved determination of radical yields.

  19. Heating and Non-thermal Particle Acceleration in Relativistic, Transverse Magnetosonic Shock Waves in Proton-Electron-Positron Plasmas

    Amato, E; Amato, Elena; Arons, Jonathan

    2006-01-01

    We report the results of 1D particle-in-cell simulations of ultrarelativistic shock waves in proton-electron-positron plasmas. We consider magnetized shock waves, in which the upstream medium carries a large scale magnetic field, directed transverse to the flow. Relativistic cyclotron instability of each species as the incoming particles encounter the increasing magnetic field within the shock front provides the basic plasma heating mechanism. The most significant new results come from simulations with mass ratio $m_p/m_\\pm = 100$. We show that if the protons provide a sufficiently large fraction of the upstream flow energy density (including particle kinetic energy and Poynting flux), a substantial fraction of the shock heating goes into the formation of suprathermal power-law spectra of pairs. Cyclotron absorption by the pairs of the high harmonic ion cyclotron waves, emitted by the protons, provides the non-thermal acceleration mechanism. As the proton fraction increases, the non-thermal efficiency increas...

  20. Characterization of proton and heavier ion acceleration in ultrahigh-intensity laser interactions with heated target foils

    Proton and heavy ion acceleration in ultrahigh intensity (∼2x1020 W cm-2) laser plasma interactions has been investigated using the new petawatt arm of the VULCAN laser. Nuclear activation techniques have been applied to make the first spatially integrated measurements of both proton and heavy ion acceleration from the same laser shots with heated and unheated Fe foil targets. Fe ions with energies greater than 10 MeV per nucleon have been observed. Effects of target heating on the accelerated ion energy spectra and the laser-to-ion energy conversion efficiencies are discussed. The laser-driven production of the long-lived isotope 57Co (271 days) via a heavy ion induced reaction is demonstrated

  1. SU-E-T-528: Robustness Evaluation for Fiducial-Based Accelerated Partial Breast Proton Therapy

    Zhao, L; Rana, S; Zheng, Y [Procure Proton Therapy Center, Oklahoma City, OK (United States)

    2014-06-01

    Purpose: To investigate the robustness of the proton treatment plans in the presence of rotational setup error when patient is aligned with implanted fiducials. Methods: Five Stage I invasive breast cancer patients treated with the APBP protocol (PCG BRE007-12) were studied. The rotational setup errors were simulated by rotating the original CT images around the body center clockwise and counterclockwise 5 degrees (5CW and 5CCW). Manual translational registration was then performed to match the implanted fiducials on the rotated images to the original dataset. Patient contours were copied to the newly created CT set. The original treatment plan was applied to the new CT dataset with the beam isocenter placed at the geometrical center of PTV. The dose distribution was recalculated for dosimetric parameters comparison. Results: CTV and PTV (D95 and V95) coverages were not significantly different between the two simulated plans (5CW and 5CCW) and the original plan. PTV D95 and CTV D95 absolute difference among the three plans were relatively small, with maximum changes of 0.28 CGE and 0.15 CGE, respectively. PTV V95 and CTV V95 absolute differences were 0.79% and 0.48%. The dosage to the thyroid, heart, contralateral breast and lung remained zero for all three plans. The Dmax and Dmean to the volume of ipsilateral breast excluding CTV were compared, with maximum difference values of 1.02 CGE for Dmax and 3.56 CGE for Dmean. Ipsilateral lung Dmean maintained no significant changes through the three plan comparison, with the largest value 0.32 CGE. Ipsilateral lung Dmax was the most sensitive parameter to this simulation study, with a maximum difference at 20.2 CGE. Conclusion: Our study suggests that fiducial-based Accelerated Partial Breast Proton Therapy is robust with respect to +/− 5 degree patient setup rotational errors, as long as the internal fiducial markers are used for patient alignment.

  2. Guiding and collimation of laser-accelerated proton beams using thin foils followed with a hollow plasma channel

    It is proposed that guided and collimated proton acceleration by intense lasers can be achieved using an advanced target—a thin foil followed by a hollow plasma channel. For the advanced target, the laser-accelerated hot electrons can be confined in the hollow channel at the foil rear side, which leads to the formation of transversely localized, Gaussian-distributed sheath electric field and resultantly guiding of proton acceleration. Further, due to the hot electron flow along the channel wall, a strong focusing transverse electric field is induced, taking the place of the original defocusing one driven by hot electron pressure in the case of a purely thin foil target, which results in collimation of proton beams. Two-dimensional particle-in-cell simulations show that collimated proton beams with energy about 20 MeV and nearly half-reduced divergence of 26° are produced at laser intensities 1020 W/cm2 by using the advanced target

  3. Maximum proton kinetic energy and patient-generated neutron fluence considerations in proton beam arc delivery radiation therapy

    proton kinetic energy from 250 to 200 MeV decreases the total neutron energy fluence produced by stopping a monoenergetic pencil beam in a water phantom by a factor of 2.3. It is possible to significantly lower the requirements on the maximum kinetic energy of a compact proton accelerator if the ability to treat a small percentage of patients with rotational therapy is sacrificed. This decrease in maximum kinetic energy, along with the corresponding decrease in neutron production, could lower the cost and ease the engineering constraints on a compact proton accelerator treatment facility.

  4. Neutron yield and induced radioactivity: a study of 235-MeV proton and 3-GeV electron accelerators

    This study evaluated the magnitude of potential neutron yield and induced radioactivity of two new accelerators in Taiwan: a 235-MeV proton cyclotron for radiation therapy and a 3-GeV electron synchrotron serving as the injector for the Taiwan Photon Source. From a nuclear interaction point of view, neutron production from targets bombarded with high-energy particles is intrinsically related to the resulting target activation. Two multi-particle interaction and transport codes, FLUKA and MCNPX, were used in this study. To ensure prediction quality, much effort was devoted to the associated benchmark calculations. Comparisons of the accelerators' results for three target materials (copper, stainless steel and tissue) are presented. Although the proton-induced neutron yields were higher than those induced by electrons, the maximal neutron production rates of both accelerators were comparable according to their respective beam outputs during typical operation. Activation products in the targets of the two accelerators were unexpectedly similar because the primary reaction channels for proton- and electron-induced activation are (p,pn) and (γ,n), respectively. The resulting residual activities and remnant dose rates as a function of time were examined and discussed. (authors)

  5. Computational study of transport and energy deposition of intense laser-accelerated proton beams in solid density matter

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

    2015-11-01

    With intense proton beams accelerated by high power short pulse lasers, solid targets are isochorically heated to become partially-ionized warm or hot dense matter. In this regime, the thermodynamic state of the matter significantly changes, varying the proton stopping power where both bound and free electrons contribute. Additionally, collective beam-matter interaction becomes important to the beam transport. We present self-consistent hybrid particle-in-cell (PIC) simulation results of proton beam transport and energy deposition in solid-density matter, where the individual proton stopping and the collective effects are taken into account simultaneously with updates of stopping power in the varying target conditions and kinetic motions of the beam in the driven fields. Broadening of propagation range and self-focusing of the beam led to unexpected target heating by the intense proton beams, with dependence on the beam profiles and target conditions. The behavior is specifically studied for the case of an experimentally measured proton beam from the 1.25 kJ, 10 ps OMEGA EP laser transporting through metal foils. This work was supported by the U.S. DOE under Contracts No. DE-NA0002034 and No. DE-AC52-07NA27344 and by the U.S. AFOSR under Contract FA9550-14-1-0346.

  6. Design and construction of the clean room for proton beam accelerator assembly

    The objective of this report is to design, construction and evaluation of clean room for proton beam accelerator assembly. The design conditions o Class : 1,000(1,000 ea ft3), o Flow Rate : 200 m3/h m2, o Temperature : 22 deg C±2, o Humidity : 55%±5. The main design results are summarized as follows: o Air-handling unit : Cooling Capacity : 13,500 kcal/h, Heating Capacity : 10,300 kcal/h, Humidity Capacity : 4 kg/h, Flow Rate : 150 CMM o Air Shower : Flow Rate : 35 CMM, Size : 1500 x 1000 x 2200, Material : In-steel, Out-SUS304, Filter : PRE + HEPA, AIR Velocity : 25 m/s o Relief Damper : Size : Φ250, Casing : SS41, Blade : AL, Shaft : SUS304, Weight Ring : SS41, Grill : AL o HEPA Filter Box : Filter Box Size : 670 x 670 x 630, Filter Size : 610 x 610 x 150, Frame: Poly Wood, Media : Glass Fiber, Filter Efficiency : 0.3μm, 99.97%, Separator : AL, Flow Rate : 17 CMM, Damper Size : Φ300 Following this report will be used important data for the design, construction, operation and maintenance of the clean room, for high precision apparatus assembly laboratory

  7. Numerical simulations of recent proton acceleration experiments with sub-100 TW laser systems

    Sinigardi, Stefano

    2016-09-01

    Recent experiments carried out at the Italian National Research Center, National Optics Institute Department in Pisa, are showing interesting results regarding maximum proton energies achievable with sub-100 TW laser systems. While laser systems are being continuously upgraded in laboratories around the world, at the same time a new trend on stabilizing and making ion acceleration results reproducible is growing in importance. Almost all applications require a beam with fixed performance, so that the energy spectrum and the total charge exhibit moderate shot to shot variations. This result is surely far from being achieved, but many paths are being explored in order to reach it. Some of the reasons for this variability come from fluctuations in laser intensity and focusing, due to optics instability. Other variation sources come from small differences in the target structure. The target structure can vary substantially, when it is impacted by the main pulse, due to the prepulse duration and intensity, the shape of the main pulse and the total energy deposited. In order to qualitatively describe the prepulse effect, we will present a two dimensional parametric scan of its relevant parameters. A single case is also analyzed with a full three dimensional simulation, obtaining reasonable agreement between the numerical and the experimental energy spectrum.

  8. Recovery mechanisms in proton exchange membrane fuel cells after accelerated stress tests

    Zhang, Xu; Guo, Liejin; Liu, Hongtan

    2015-11-01

    The mechanisms of performance recovery after accelerated stress test (AST) in proton exchange membrane fuel cells (PEMFCs) are systematically studied. Experiments are carried out by incorporating a well-designed performance recovery procedure right after the AST protocol. The experiment results show that the cell performance recovers significantly from the degraded state after the AST procedure. The results from cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) measurements further show that the performance recovery can be divided into kinetic and mass transport recoveries. It is further determined that the kinetic recovery, i.e. the recovery of electrochemical active area (ECA), is due to two distinct mechanisms: the reduction of platinum oxide and the re-attachment of detached platinum nanoparticles onto the carbon surface. The mass transport resistance is probably due to reduction of hydrophilic oxide groups on the carbon surface and the microstructure change that alleviates flooding. Performance comparisons show that the recovery procedure is highly effective, indicating the results of AST significantly over-estimate the true degradation in a PEM fuel cell. Therefore, a recovery procedure is highly recommended when an AST protocol is used to evaluate cell degradations to avoid over-estimating true performance degradations in PEMFCs.

  9. Hydraulic characteristics of sedimentary deposits at the J-PARC proton-accelerator, Japan

    Marui Atsunao

    2007-12-01

    Full Text Available Hydraulic characteristics of sediments were investigated at J-PARC for the purpose of site characterization in relation with the construction of Japan's largest proton-accelerator. A total of 340 samples extracted from 9 exploratory wells were examined by standard laboratory tests and complemented with statistical analyses to quantitatively determine the main terrain attributes. Two main hydro-geological units were recognized, although a number of embedded layers defined a
    multilevel aquifer. Grain-size distribution derived from sieve analysis and the coefficient of uniformity showed that soils are poorly sorted. On the other hand, hydraulic conductivity was measured by a
    number of parameters such as a log-normal distribution. Conductivity was also predicted by empirical formulas, yielding values up to three orders of magnitude higher. Discrepancies were explained in
    terms of soil anisotropy and intrinsic differences in the calculation methods. Based on the Shepherd's approach, a power relationship between permeability and grain size was found at 2 wells. Hydraulic
    conductivity was also correlated to porosity. However, this  nterdependence was not systematic and therefore, properties at many parts of the profile were considered to be randomly distributed. Finally,
    logs of electrical conductivity suggested that variations of soil hydraulic properties can be associated to changes in water quality. In spite of the remaining uncertainties, results yielded from the study are useful to better understand the numerical modelling of the subsurface system in the site.

  10. Visual outcome of accelerated fractionated radiation for advanced sinonasal malignancies employing photons/protons

    Purpose: To investigate the visual outcomes of patients with advanced sinonasal malignancies treated with proton/photon accelerated fractionated radiation (AFR). Patients and methods: Between 1991 and 2001, AFR was used to treat 36 patients with advanced stage primary (n = 33) or recurrent (n = 3) nasal or paranasal malignant tumors. Full ophthalmologic follow-up was documented. The median dose to the gross tumor volume (GTV) was 69.6 CGE (range 60.8-77). Visual complications were graded according to the National Cancer Institute Common Toxicity Criteria (CTC) and the late effects of normal tissue (LENT) scoring systems. The median follow-up was 52.4 months (range 17-122.8). Results: Thirteen patients developed late visual/ocular toxicity. Cataracts were LENT grade 1 and 3 in 2 patients and 1 patient, respectively. One LENT grade 1 vascular retinopathy and 1 optic neuropathy were also observed. Three and five patients presented with nasolacrimal duct stenosis (CTC grade 2, 2 patients; CTC grade 3, 1 patient) and dry-eye syndrome (CTC grade 1, 1 patient; CTC grade 2, 4 patients), respectively. The 3- and 5-year probability of LENT/CTC grade ≥2 visual toxicity were 15.8 ± 6.7% and 20.7 ± 7.8%, respectively. Conclusions: AFR for locally advanced nasal cavity and paranasal sinus tumors enables delivery of 70 CGE to the tumor with acceptable ophthalmologic complications

  11. Performance of solenoids versus quadrupoles in focusing and energy selection of laser accelerated protons

    Hofmann, Ingo

    2013-04-01

    Using laser accelerated protons or ions for various applications—for example in particle therapy or short-pulse radiographic diagnostics—requires an effective method of focusing and energy selection. We derive an analytical scaling for the performance of a solenoid compared with a doublet/triplet as function of the energy, which is confirmed by TRACEWIN simulations. Generally speaking, the two approaches are equivalent in focusing capability, if parameters are such that the solenoid length approximately equals its diameter. The scaling also shows that this is usually not the case above a few MeV; consequently, a solenoid needs to be pulsed or superconducting, whereas the quadrupoles can remain conventional. It is also important that the transmission of the triplet is found only 25% lower than that of the equivalent solenoid. Both systems are equally suitable for energy selection based on their chromatic effect as is shown using an initial distribution following the RPA simulation model by Yan et al. [Phys. Rev. Lett. 103, 135001 (2009PRLTAO0031-900710.1103/PhysRevLett.103.135001].

  12. Neutralization and transport of high-current proton beams in a two-stage linear induction accelerator

    Golkowski, Cz.; Kerslick, G. S.; Nation, J. A.; Ivers, J.

    1992-03-01

    Experimental results on the propagation and transport efficiency of a 1 MV, 5 kA, 50 ns annular proton beam through a two-stage linear induction accelerator are presented. The beam is generated in a magnetically insulated diode and propagates with high-efficiency along a 0.6 T axial magnetic field to a second accelerating gap located 30 cm downstream. The second accelerating gap increases the beam energy to 1.3 MeV. A full-cusp geometry provides the magnetic insulation in both the diode and the second gap. We report in this paper an 86% (±5%) transport efficiency and an increase of 1.6° in the beam divergence for propagation through the post acceleration gap.

  13. Recommendation for a injector-cyclotron and ion sources for the acceleration of heavy ions and polarized protons and deuterons

    It was decided to accelerate both heavy and light ions with the open-sector cyclotron. The injector SPS1, was used for light ions and SPS2 for heavy ions. Provision was also made for the acceleration of polarized neutrons. To enable this, the injector must have an axial injection system. The working of a source of polarized ions and inflectors for an axial injection system is discussed. The limitations of the open-sector cyclotron on the acceleration of heavy ions are also dealt with. The following acceleration/ion source combinations are discussed: i) The open-sector cyclotron and a k=40 injector cyclotron with a Penning ion source, and a stripper between the injector and the open-sector cyclotron and also a source of polarized protons and deuterons; ii) The acceleration/ion source combination with the addition of electron beam ion sources; iii) The open-sector cyclotron and a k=11 injector cyclotron with a electron beam ion source and a source of polarized protons and deuterons

  14. Free standing diamond-like carbon thin films by PLD for laser based electrons/protons acceleration

    Thema, F.T.; Beukes, P.; Ngom, B.D. [UNESCO Africa Chair in Nanosciences-Nanotechnology, College of Graduate Studies, University of South Africa, Muckleneuk Ridge, PO Box 392, Pretoria (South Africa); Nanosciences African Network (NANOAFNET), iThemba LABS-National Research Foundation, 1 Old Faure Road, Somerset West, 7129, PO Box722, Western Cape Province (South Africa); Manikandan, E., E-mail: mani@tlabs.ac.za [UNESCO Africa Chair in Nanosciences-Nanotechnology, College of Graduate Studies, University of South Africa, Muckleneuk Ridge, PO Box 392, Pretoria (South Africa); Nanosciences African Network (NANOAFNET), iThemba LABS-National Research Foundation, 1 Old Faure Road, Somerset West, 7129, PO Box722, Western Cape Province (South Africa); Central Research Laboratory, Sree Balaji Medical College & Hospital (SBMCH), Chrompet, Bharath University, Chennai, 600044 (India); Maaza, M., E-mail: maaza@tlabs.ac.za [UNESCO Africa Chair in Nanosciences-Nanotechnology, College of Graduate Studies, University of South Africa, Muckleneuk Ridge, PO Box 392, Pretoria (South Africa); Nanosciences African Network (NANOAFNET), iThemba LABS-National Research Foundation, 1 Old Faure Road, Somerset West, 7129, PO Box722, Western Cape Province (South Africa)

    2015-11-05

    This study we reports for the first time on the synthesis and optical characteristics of free standing diamond-like carbon (DLC) deposited by pulsed laser deposition (PLD) onto graphene buffer layers for ultrahigh intensity laser based electron/proton acceleration applications. The fingerprint techniques of micro-Raman, UV–VIS–NIR and the IR spectroscopic investigations indicate that the suitability of such free standing DLC thin-films within the laser window and long wave infrared (LWIR) spectral range and hence their appropriateness for the targeted applications. - Highlights: • We report for the first time synthesis of free standing diamond-like carbon. • Pulsed laser deposition onto graphene buffer layers. • Fingerprint techniques of micro-Raman, UV–VIS–NIR and the IR spectroscopic investigations. • Ultrahigh intensity laser based electron/proton acceleration applications. • This material's suitable for the laser window and long wave infrared (LWIR) spectral range.

  15. Free standing diamond-like carbon thin films by PLD for laser based electrons/protons acceleration

    This study we reports for the first time on the synthesis and optical characteristics of free standing diamond-like carbon (DLC) deposited by pulsed laser deposition (PLD) onto graphene buffer layers for ultrahigh intensity laser based electron/proton acceleration applications. The fingerprint techniques of micro-Raman, UV–VIS–NIR and the IR spectroscopic investigations indicate that the suitability of such free standing DLC thin-films within the laser window and long wave infrared (LWIR) spectral range and hence their appropriateness for the targeted applications. - Highlights: • We report for the first time synthesis of free standing diamond-like carbon. • Pulsed laser deposition onto graphene buffer layers. • Fingerprint techniques of micro-Raman, UV–VIS–NIR and the IR spectroscopic investigations. • Ultrahigh intensity laser based electron/proton acceleration applications. • This material's suitable for the laser window and long wave infrared (LWIR) spectral range

  16. Development of the integrated control system for the microwave ion source of the PEFP 100-MeV proton accelerator

    Song, Young-Gi; Seol, Kyung-Tae; Jang, Ji-Ho; Kwon, Hyeok-Jung; Cho, Yong-Sub

    2012-07-01

    The Proton Engineering Frontier Project (PEFP) 20-MeV proton linear accelerator is currently operating at the Korea Atomic Energy Research Institute (KAERI). The ion source of the 100-MeV proton linac needs at least a 100-hour operation time. To meet the goal, we have developed a microwave ion source that uses no filament. For the ion source, a remote control system has been developed by using experimental physics and the industrial control system (EPICS) software framework. The control system consists of a versa module europa (VME) and EPICS-based embedded applications running on a VxWorks real-time operating system. The main purpose of the control system is to control and monitor the operational variables of the components remotely and to protect operators from radiation exposure and the components from critical problems during beam extraction. We successfully performed the operation test of the control system to confirm the degree of safety during the hardware performance.

  17. Status of intense permanent magnet proton source for China-accelerator driven sub-critical system Linac

    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. Status of intense permanent magnet proton source for China-accelerator driven sub-critical system Linac

    Wu, Q., E-mail: wuq@impcas.ac.cn; Ma, H. Y.; Yang, Y.; Sun, L. T.; Zhang, X. Z.; Zhang, Z. M.; Zhao, H. Y.; He, Y.; Zhao, H. W. [Institute of Modern Physics (IMP), Chinese Academy of Sciences, Lanzhou 730000 (China)

    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.

  19. Future laser-accelerated proton beams at ELI-Beamlines as potential source of positron emitters for PET

    The development of novel compact PET radionuclide production systems is of great interest to promote the diffusion of PET diagnostics, especially in view of the continuous development of novel, fast and efficient, radiopharmaceutical methods of labeling. We studied the feasibility to produce clinically-relevant amounts of PET isotopes by means of laser-accelerated proton sources expected at the ELI-Beamlines facility where a PW, 30 fs, 10 Hz laser system will be available. The production yields of several positron emitters were calculated through the TALYS software, by taking into account three possible scenarios of broad proton spectra expected, with maximum energies ranging from about 8 MeV to 100 MeV. With the hypothesized proton fluencies, clinically-relevant amounts of radionuclides can be obtained, suitable to prepare single doses of radiopharmaceuticals exploiting modern fast and efficient labeling systems

  20. Future laser-accelerated proton beams at ELI-Beamlines as potential source of positron emitters for PET

    Amato, E.; Italiano, A.; Margarone, D.; Pagano, B.; Baldari, S.; Korn, G.

    2016-04-01

    The development of novel compact PET radionuclide production systems is of great interest to promote the diffusion of PET diagnostics, especially in view of the continuous development of novel, fast and efficient, radiopharmaceutical methods of labeling. We studied the feasibility to produce clinically-relevant amounts of PET isotopes by means of laser-accelerated proton sources expected at the ELI-Beamlines facility where a PW, 30 fs, 10 Hz laser system will be available. The production yields of several positron emitters were calculated through the TALYS software, by taking into account three possible scenarios of broad proton spectra expected, with maximum energies ranging from about 8 MeV to 100 MeV. With the hypothesized proton fluencies, clinically-relevant amounts of radionuclides can be obtained, suitable to prepare single doses of radiopharmaceuticals exploiting modern fast and efficient labeling systems.

  1. Thermal hydraulic studies of spallation target for one-way coupled Indian accelerator driven systems with low energy proton beam

    V Mantha; A K Mohanty; P Satyamurthy

    2007-02-01

    BARC has recently proposed a one-way coupled ADS reactor. This reactor requires typically ∼ 1 GeV proton beam with 2 mA of current. Approximately 8 kW of heat is deposited in the window of the target. Circulating liquid metal target (lead/lead-bismuth-eutectic) has to extract this heat and this is a critical R&D problem to be solved. At present there are very few accelerators, which can give few mA and high-energy proton beam. However, accelerators with low energy and hundreds of micro-ampere current are commercially available. In view of this, it is proposed in this paper to simulate beam window heating of ∼ 8 kW in the target with low-energy proton beam. Detailed thermal analysis in the spallation and window region has been carried out to study the capability of heat extraction by circulating LBE for a typical target loop with a proton beam of 30 MeV energy and current of 0.267 mA. The heat deposition study is carried out using FLUKA code and flow analysis by CFD code. The detailed analysis of this work is presented in this paper.

  2. Design and development of high power pulsed technologies and systems for H- and proton accelerators

    For energizing the 3 MeV RFQ, under development at RRCAT, a 1 MW pulsed RF system operating at 352.2 MHz is required. The characteristics of the pulsed RF delivered to RFQ are important for its correct operation. Keeping in view these requirements, in house design and development of crucial technologies like high voltage solid state pulse modulators, WR 2300 waveguide components, solid state high voltage switches, high voltage high power pulse transformers, advanced solid state Marx modulator, high power RF/Microwave test facilities etc has been initiated. A 1 MW pulsed test stand at 352.21 MHz has been developed and tested using TH 2089 klystrons provided by CERN. A solid state bouncer modulator with 500 microsecs pulse duration, 25 Hz pulse repetition rate, giving output voltage upto 100 kV for energizing klystron for pulsed RFQ has been designed, integrated and testing has been started. Design and prototype development of advanced solid state Marx modulator has also been carried out. The WR 2300 waveguide components have also been developed and tested at low power as well as 1 MW pulsed power at the test stand. The WR 2300 waveguide transmission line with full height dual directional coupler, harmonic filter, three port junction circulator, full height to half height transition, half height waveguide sections, E and H bends, power dividers, flexible waveguides, phase shifter, 45 deg E plane bends, RF loads etc. was assembled and tested at 1 MW pulsed power. Utilizing the experience gathered, design of WR 2300 waveguide transmission system for LEHIPA project of BARC was also done. Development of 1.3 GHz RF systems and cavity test set ups for characterizing the superconducting cavities is in advanced stage. A solid state bouncer compensated long pulse modulator operating at 100 kV, 20 A with 800 microsecs pulse duration at 2 Hz PRR, was successfully designed, developed and supplied to CERN for LINAC 4 proton accelerator project under DAE CERN collaboration in

  3. Accelerating Protons to Therapeutic Energies with Ultra-Intense Ultra-Clean and Ultra-Short Laser Pulses

    Bulanov, Stepan S; Bychenkov, Valery Yu; Chvykov, Vladimir; Kalinchenko, Galina; Matsuoka, Takeshi; Rousseau, Pascal; Reed, Stephen; Yanovsky, Victor; Krushelnick, Karl; Litzenberg, Dale William; Maksimchuk, Anatoly

    2008-01-01

    Proton acceleration by high-intensity laser pulses from ultra-thin foils for hadron therapy is discussed. With the improvement of the laser intensity contrast ratio to 10-11 achieved on Hercules laser at the University of Michigan, it became possible to attain laser-solid interactions at intensities up to 1022 W/cm2 that allows an efficient regime of laser-driven ion acceleration from submicron foils. Particle-In-Cell (PIC) computer simulations of proton acceleration in the Directed Coulomb explosion regime from ultra-thin double-layer (heavy ions / light ions) foils of different thicknesses were performed under the anticipated experimental conditions for Hercules laser with pulse energies from 3 to 15 J, pulse duration of 30 fs at full width half maximum (FWHM), focused to a spot size of 0.8 microns (FWHM). In this regime heavy ions expand predominantly in the direction of laser pulse propagation enhancing the longitudinal charge separation electric field that accelerates light ions. The dependence of the ma...

  4. Energetic electron beam and proton beam generations with the APRI ultrahigh-intensity Ti:sapphire laser system

    A 100-TW class ultrashort, ultrahigh-intensity Ti:sapphire laser system is operating and the upgrade to 300-TW is underway in APRI. With this layer system, series of experiments on high field physics, such as high harmonics generation, electron acceleration, proton generation, and x-ray generation, have been performed through domestic or international collaboration. In the electron acceleration experiment, we have observed highly directional electron beams and, in some shots, quasi-monoenergetic electron beams were generated. In the proton generation experiment, we observed protons with the maximum energy of ∼2.4 MeV emitted from a 5-μm thick copper tape target which was irradiated by laser pulses with peak intensity of ∼1.4x1018 W/cm2. The energy conversion efficiency from laser to proton was >1.4%. (author)

  5. Works on construction of proton and H- ion linear accelerator of the IYaI AN SSSR meson factory

    Results of beam study in the injection channel (the energy of 0.75 MeV) of a linear accelerators of meson factory are presented. Data on the adjustment of basic systems of the initial (the energy of 100 MeV) and main (the energy of 600 MeV) parts of the accelerator are given. Results of HF excitation of the first resonator and acceleration of a proton beam in it up to the energy of 20.5 MeV are provided. Radiotechnical adjustment of the resonators is realized. The system of HF power supply is mounted and its complex adjustment is realized. 3 refs.; 4 figs.; 1 tab

  6. External proton and Li beams

    In the frame of a feasibility study to introduce proton therapy in Argentina in a collaborative agreement between the Physics and Radiobiology Departments of the National Atomic Energy Commission or Argentina and the Centre de Protontherapie de Orsay, France, external proton and Li beams were produced at the TANDAR accelerator in Buenos Aires. The specific aim of this work was to start radiobiology studies on cell cultures and small laboratory animals. In particular we seek to determine here the relative biological effectiveness, RBE, for proton and Li beams as a function of energy for different tumor and normal cell lines. The 24 MeV proton beam was diffused using a 25 μm gold foil and extracted through a Kapton window to obtain a homogeneous field (constant to 95%) of about 7 cm in diameter. Measurements were carried out with quasi-monoenergetic beams (of 20.2 ± 0.07 MeV, 2.9 ± 0.10 MeV y 1.5 ± 0.1 MeV for protons and 21.4 ± 0.4 MeV for Lithium). Proton fluence and Bragg peaks were measured. The dose delivered in each case was monitored on-line with a calibrated transmission ionization chamber. Three cell lines PDV, PDVC 57 and V 79 (as a reference) were irradiated with γ-rays, proton and lithium beams with linear energy transfer (LET) from 2 to 100 keV/μm. RBE values in the range of 1.2-5.9 were obtained. In addition preliminary studies on chromosomal aberrations and viability of alveolar macrophages were carried out. (author)

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

    Saini, Arun [Univ. of Delhi, New Delhi (India)

    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.

  8. Reliability studies of a high-power proton accelerator for accelerator-driven system applications for nuclear waste transmutation

    The main effort of the present study is to analyze the availability and reliability of a high-performance linac (linear accelerator) conceived for Accelerator-Driven Systems (ADS) purpose and to suggest recommendations, in order both to meet the high operability goals and to satisfy the safety requirements dictated by the reactor system. Reliability Block Diagrams (RBD) approach has been considered for system modelling, according to the present level of definition of the design: component failure modes are assessed in terms of Mean Time Between Failure (MTBF) and Mean Time To Repair (MTTR), reliability and availability figures are derived, applying the current reliability algorithms. The lack of a well-established component database has been pointed out as the main issue related to the accelerator reliability assessment. The results, affected by the conservative character of the study, show a high margin for the improvement in terms of accelerator reliability and availability figures prediction. The paper outlines the viable path towards the accelerator reliability and availability enhancement process and delineates the most proper strategies. The improvement in the reliability characteristics along this path is shown as well

  9. Generation and focusing of short pulse high intensity laser accelerated protons

    Foord, Mark E.

    2011-10-01

    Much progress has recently been reported in generating MeV energy protons from intense laser-matter interactions, having potential applications in areas such as radiography, oncology, and ion-proton beam fast ignition. Experiments were conducted on the sub-ps LANL Trident laser, where we systematically investigated proton focusing and conversion efficiency from curved surface targets in both open and closed cone-shaped target geometries. We clearly show that the focusing is strongly affected by the electric fields in the beam, bending the trajectories near the axis. We also find that in the cone geometry, a sheath electric field effectively ``channels'' the proton beam through the cone tip, substantially improving the beam focusing properties. The far-field energy and angular distribution of the proton beam were measured using a mesh that images the beam onto a RCF detector. For the cone-shaped targets using a 300 μm-radius curved surface foil, a 60 μm diameter proton spot was determined. Proton generation and focusing were modeled using 2-D hybrid PIC simulations, which compared well with RCF data. The proton conversion efficiency varied strongly with the target geometry. Simulations indicate this is due to that charge flow on the structure and the coupling to the hot electrons and electric fields in the plasma. Work performed under US DOE contract DE-AC52-07NA27344

  10. Focusing of short-pulse high-intensity laser-accelerated proton beams

    Bartal, Teresa; Foord, Mark E.; Bellei, Claudio; Key, Michael H.; Flippo, Kirk A.; Gaillard, Sandrine A.; Offermann, Dustin T.; Patel, Pravesh K.; Jarrott, Leonard C.; Higginson, Drew P.; Roth, Markus; Otten, Anke; Kraus, Dominik; Stephens, Richard B.; McLean, Harry S.; Giraldez, Emilio M.; Wei, Mingsheng S.; Gautier, Donald C.; Beg, Farhat N.

    2012-02-01

    Recent progress in generating high-energy (>50MeV) protons from intense laser-matter interactions (1018-1021Wcm-2 refs , , , , , , ) has opened up new areas of research, with applications in radiography, oncology, astrophysics, medical imaging, high-energy-density physics, and ion-proton beam fast ignition. With the discovery of proton focusing with curved surfaces, rapid advances in these areas will be driven by improved focusing technologies. Here we report on the first investigation of the generation and focusing of a proton beam using a cone-shaped target. We clearly show that the focusing is strongly affected by the electric fields in the beam in both open and enclosed (cone) geometries, bending the trajectories near the axis. Also in the cone geometry, a sheath electric field effectively `channels' the proton beam through the cone tip, substantially improving the beam focusing properties. These results agree well with particle simulations and provide the physics basis for many future applications.

  11. Enhanced proton acceleration by intense laser interaction with an inverse cone target

    Bake, Muhammad Ali; Aimidula, Aimierding; Xiaerding, Fuerkaiti; Rashidin, Reyima

    2016-08-01

    The generation and control of high-quality proton bunches using focused intense laser pulse on an inverse cone target is investigated with a set of particle-in-cell simulations. The inverse cone is a high atomic number conical frustum with a thin solid top and open base, where the laser impinges onto the top surface directly, not down the open end of the cone. Results are compared with a simple planar target, where the proton angular distribution is very broad because of transverse divergence of the electromagnetic fields behind the target. For a conical target, hot electrons along the cone wall surface induce a transverse focusing sheath field. This field can effectively suppress the spatial spreading of the protons, resulting in a high-quality small-emittance, low-divergence proton beam. A slightly lower proton beam peak energy than that of a conventional planar target was also found.

  12. Filamentation control and collimation of laser accelerated MeV protons

    Ramakrishna, B.; Tayyab, M.; Bagchi, S.; Mandal, T.; Upadhyay, A.; Weng, S. M.; Murakami, M.; Cowan, T. E.; Chakera, J. A.; Naik, P. A.; Gupta, P. D.

    2015-12-01

    We demonstrate experimentally that the proton beam filamentation in dense plasma can be controlled in multi-layered (Al-CH-Al) sandwich targets. We observe up to three-fold reduction in the MeV proton beam divergence (~12°) from these targets as a result of decrease in filamentary structures in the proton beam profile. Strong self-generated resistive magnetic fields in targets with a high-Z transport layer are mainly responsible for this observed effect. Enhancement in the proton flux and energy is also observed from these targets. Supported by a matching 2D particle-in-cell (PIC) simulation and theoretical considerations, we suggest that these targets can be very effectively implemented to collimate proton beams useful for ion oncology applications or advanced fast igniter approach of inertial confinement fusion (ICF).

  13. The affect of erbium hydride on the conversion efficience to accelerated protons from ultra-shsort pulse laser irradiated foils

    Offermann, Dustin Theodore [The Ohio State Univ., Columbus, OH (United States)

    2008-01-01

    This thesis work explores, experimentally, the potential gains in the conversion efficiency from ultra-intense laser light to proton beams using erbium hydride coatings. For years, it has been known that contaminants at the rear surface of an ultra-intense laser irradiated thin foil will be accelerated to multi-MeV. Inertial Confinement Fusion fast ignition using proton beams as the igniter source requires of about 1016 protons with an average energy of about 3MeV. This is far more than the 1012 protons available in the contaminant layer. Target designs must include some form of a hydrogen rich coating that can be made thick enough to support the beam requirements of fast ignition. Work with computer simulations of thin foils suggest the atomic mass of the non-hydrogen atoms in the surface layer has a strong affect on the conversion efficiency to protons. For example, the 167amu erbium atoms will take less energy away from the proton beam than a coating using carbon with a mass of 12amu. A pure hydrogen coating would be ideal, but technologically is not feasible at this time. In the experiments performed for my thesis, ErH3 coatings on 5 μm gold foils are compared with typical contaminants which are approximately equivalent to CH1.7. It will be shown that there was a factor of 1.25 ± 0.19 improvement in the conversion efficiency for protons above 3MeV using erbium hydride using the Callisto laser. Callisto is a 10J per pulse, 800nm wavelength laser with a pulse duration of 200fs and can be focused to a peak intensity of about 5 x 1019W/cm2. The total number of protons from either target type was on the order of 1010. Furthermore, the same experiment was performed on the Titan laser, which has a 500fs pulse duration, 150J of energy and can be focused to about 3 x 1020 W/cm2. In this experiment 1012 protons were seen from both erbium hydride and

  14. Shielding analysis of proton therapy accelerators: a demonstration using Monte Carlo-generated source terms and attenuation lengths.

    Lai, Bo-Lun; Sheu, Rong-Jiun; Lin, Uei-Tyng

    2015-05-01

    Monte Carlo simulations are generally considered the most accurate method for complex accelerator shielding analysis. Simplified models based on point-source line-of-sight approximation are often preferable in practice because they are intuitive and easy to use. A set of shielding data, including source terms and attenuation lengths for several common targets (iron, graphite, tissue, and copper) and shielding materials (concrete, iron, and lead) were generated by performing Monte Carlo simulations for 100-300 MeV protons. Possible applications and a proper use of the data set were demonstrated through a practical case study, in which shielding analysis on a typical proton treatment room was conducted. A thorough and consistent comparison between the predictions of our point-source line-of-sight model and those obtained by Monte Carlo simulations for a 360° dose distribution around the room perimeter showed that the data set can yield fairly accurate or conservative estimates for the transmitted doses, except for those near the maze exit. In addition, this study demonstrated that appropriate coupling between the generated source term and empirical formulae for radiation streaming can be used to predict a reasonable dose distribution along the maze. This case study proved the effectiveness and advantage of applying the data set to a quick shielding design and dose evaluation for proton therapy accelerators. PMID:25811254

  15. Control of proton energy in ultra-high intensity laser-matter interaction

    Recent breakthroughs in short pulse laser technology resulted in (i) generation of ultra-high intensity (2x1022 W/cm2) and (ii) ultra-high contrast (10-11) short pulses at the Hercules facility of the University of Michigan, which has created the possibility of exploring a new regime of ion acceleration - the regime of Directed Coulomb Explosion (DCE). In this regime of sufficiently high laser intensities and target thicknesses approaching the relativistic plasma skin depth it is possible to expel electrons from the target focal volume by the laser's ponderomotive force allowing for direct laser ion acceleration combined with a Coulomb explosion. That results in greater than 100 MeV protons with a quasi-monoenergetic energy spectrum. The utilization of beam shaping, namely, the use of flat-top beams, leads to more efficient proton acceleration due to the increase of the longitudinal field. According to the results of 2D PIC simulations a 500 TW laser pulse with a super-Gaussian beam profile interacting with 0.1 micron aluminium-hydrogen foil is able to produce monoenergetic protons with the energy up to 240 MeV.

  16. Control of proton energy in ultra-high intensity laser-matter interaction

    Maksimchuk, A; Bulanov, S S; Chvykov, V; Dollar, F; Kalintchenko, G; Matsuoka, T; Reed, S; Yanovsky, V; Krushelnick, K [FOCUS Center and Center for Ultrafast Optical Science, University of Michigan, Ann Arbor, 48109 (United States); Brantov, A; Bychenkov, V Yu [P. N. Lebedev Physics Institute, Russian Academy of Sciences, Moscow 119991 (Russian Federation); Litzenberg, D, E-mail: tolya@umich.ed [Department of Radiation Oncology, University of Michigan, Ann Arbor, 48109 (United States)

    2010-08-01

    Recent breakthroughs in short pulse laser technology resulted in (i) generation of ultra-high intensity (2x10{sup 22} W/cm{sup 2}) and (ii) ultra-high contrast (10{sup -11}) short pulses at the Hercules facility of the University of Michigan, which has created the possibility of exploring a new regime of ion acceleration - the regime of Directed Coulomb Explosion (DCE). In this regime of sufficiently high laser intensities and target thicknesses approaching the relativistic plasma skin depth it is possible to expel electrons from the target focal volume by the laser's ponderomotive force allowing for direct laser ion acceleration combined with a Coulomb explosion. That results in greater than 100 MeV protons with a quasi-monoenergetic energy spectrum. The utilization of beam shaping, namely, the use of flat-top beams, leads to more efficient proton acceleration due to the increase of the longitudinal field. According to the results of 2D PIC simulations a 500 TW laser pulse with a super-Gaussian beam profile interacting with 0.1 micron aluminium-hydrogen foil is able to produce monoenergetic protons with the energy up to 240 MeV.

  17. Development of a Compton Camera for Online Range Monitoring of Laser-Accelerated Proton Beams via Prompt-Gamma Detection

    Thirolf P.G.

    2014-03-01

    Full Text Available Presently large efforts are conducted in Munich towards the development of proton beams for bio-medical applications, generated via the technique of particle acceleration from high-power, short-pulse lasers. While so far mostly offline diagnostics tools are used in this context, we aim at developing a reliable and accurate online range monitoring technique, based on the position-sensitive detection of prompt γ rays emitted from nuclear reactions between the proton beam and the biological sample. For this purpose, we develop a Compton camera, designed to be able to track not only the Compton scattering of the primary photon, but also to detect the secondary Compton electron, thus reducing the Compton cone to an arc segment and by this increasing the source reconstruction efficiency. Design specifications and the status of the protype system are discussed.

  18. Study and optimization of a LINAC drift tube for high intensity proton acceleration; Etude et optimisation d'un LINAC a tubes de glissement pour acceleration de forts courants de protons en continu

    Bernaudin, P.E

    2002-09-01

    High intensity proton accelerators lead to specific problems related to the need to limit beam losses. The problem is more acute in the low energy part (up to 20 MeV) where the beam transport is the most difficult. The drift tube linac (DTL) remains the reference structure for energies of a few MeV to a few dozens MeV despite the arising of some new cavity types. This thesis purpose is to design such a DTL for a high intensity proton accelerator. Until now, no such continuous wave cavity has ever been operated. To ensure the viability of such an accelerator, a short four cells prototype is designed, built and tested under nominal RF conditions. This prototype is fully representative of a complete machine except for its length. The design complexity comes from the combination of RF electromagnetism, thermal exchanges, mechanics, ultra-vacuum engineering and manufacturing constraints. More specifically, the electromagnets alignment is a primary factor, and reliability, despite being usually of secondary importance in particles accelerator science, is here a major concern considering potential industrial applications of this machine. The prototype design includes the cavity itself, but also quadrupole electromagnets whose feasibility is a limiting factor, considering the very small space available to them. Two different magnet types and associated drift tubes are studied and manufactured, to be tested in the prototype cavity. The experimental part is focused on mechanical and thermal aspects. The electromagnetic properties of the cavity are also checked. As a conclusion of this thesis, technical and conceptual improvements as suggested by the manufacturing and experimental phases are presented, to be implemented in a complete cavity. (author)

  19. Study of a plasma created by an accelerated proton beam for the characterization of a nuclear pumped laser medium

    Processes leading to laser effect in nuclear induced plasmas can be studied with simulation experiments using charged particles beams. Such an experiment has been performed with a proton beam (2 MeV, 2 μA/cm2) produced by a Van de Graaff accelerator. This beam is an excitation and ionisation source quite comparable to the laser medium source of a reactor experiment. The plasma created in a Ne target (about 100 torrs) containing N2 impurities has been studied: - experimentally using R.F. diagnostics and spectroscopy; - theoretically by calculating the electronic distribution function in the low and medium energy region

  20. Evaluation of a personal and environmental dosemeter based on CR-39 track detectors in quasi-monoenergetic neutron fields

    In this paper, the evaluation of the dosimetric capability of a detector based on a CR-39 solid-state nuclear track detector coupled to a 1 cm thickness of PMMA radiator was made with the aim of understanding the applicability of this technique to personal and environmental neutron dosimetry. The dosemeter has been exposed to monoenergetic and quasi-monoenergetic neutron beams at PTB in Braunschweig, Germany and at Ithemba Laboratories, in Faure, South Africa, with peak energies ranging from 0.565 to 100 MeV. The results showed a response that is almost independent of the neutron energy in the whole energy range. Solid-state nuclear track detectors (SSNTDs) can be successfully used to measure particle linear energy transfer (LET) by measuring the track image parameters(1, 2). For practical applications, the LET can be used to derive a good approximation of the ambient dose equivalent and the personal dose equivalent(2). The detector, meant for neutron dosimetry, is realised by coupling the CR-39 SSNTD, primarily made of polyallyl diglycol carbonate (PADC) to a PMMA [composition (C5O2H8)n] radiator. The neutron interaction in PMMA provides recoil proton via (n,p) elastic scattering. This channel of charged particle production dominates up to a neutron energy of around 7-8 MeV. For higher neutron energies, elastic and inelastic scattering cross section of oxygen and carbon becomes important. The effect on the passive detectors is that tracks are not only produced by recoil protons but by heavier charged secondary particles. The exact evaluation of the secondary particle energy distribution is out of the scope of the present paper. Using the method described in this paper, the response of the PADC detectors, coupled with plastic converters proved to be almost independent of the neutron energy, in a wide energy range (0.565-100 MeV). This is particularly interesting for personal and environmental dosimetry applications, since this neutron energy range is wide enough

  1. Measurement of DNA Double-Strand Break Yield in Human Cancer Cells by High-Current, Short-Duration Bunches of Laser-Accelerated Protons

    Yogo, Akifumi; Sato, Katsutoshi; Nishikino, Masaharu; Maeda, Takuya; Sakaki, Hironao; Hori, Toshihiko; Ogura, Koichi; Nishiuchi, Mamiko; Teshima, Teruki; Nishimura, Hiroaki; Kondo, Kiminori; Bolton, Paul R.; Kawanishi, Shunichi

    2011-10-01

    To investigate the radiobiological effects of high dose rates that are attributed to high current, short bunch beam generation with laser-dreven ion acceleration, we have developed an experimental setup that uses laser-accelerated protons. In-vitro human lung cancer cells: A549 pulmonary adenocarcinoma are irradiated with a laser-accelerated proton bunches with a duration of 2×10-8 s and flux of ˜1015 cm-2 s-1, amounting to single bunch absorbed dose at the 1 Gy level. The double-strand break (DSB) yield in cell DNA is analyzed for the laser-accelerated proton beam at an average LET of 41 keV/µm.

  2. High-power proton linear accelerators for neutron generators and ADS (projects review)

    Lazarev, N V

    2000-01-01

    The review of the suggestions of superpower linear accelerators for electric nuclear plants and high intensive neutron generators is given. The most important engineering resolutions, characteristics and state of the art of the linear accelerators with middle power of accelerated beam in the range from 1 to 100 MW: APT, SNS, JAERI/KEK, TRISPAL, TRASCO, ESS, KOMAC, Energy Amplifier, IFMIF, collaborative suggestions of ITEhF, MRTI and IFVEh, and other scientific centers are discussed

  3. A long-term study of personal neutron monitors in stray fields around high energy proton accelerators

    The results are presented of a long-term study of personal neutron monitors intended to be used in stray fields around high energy proton accelerators. The aim of this study was to investigate the possibility of using the NTA emulsion, CR-39, and Makrofol (polycarbonate) as personal monitors over extended periods given the low neutron dose rates outside the biological shielding of the accelerators operated at CERN. Considering the low doses recorded, a conservative interpretation of the detector result in terms of dose equivalent is nearly always possible, thus overcoming the problems of energy response of the detectors under test. The results show that any of the track detectors can be used for the purpose of long-term monitoring, so that the final decision on the choice is based on the costs involved. (author)

  4. Proton injector acceptance tests for a Dielectric Wall Accelerator (DWA):characterisation of Advanced Injection System of Light Ions (AISLI)

    Peng, S.X., E-mail: sxpeng@pku.edu.cn; Ren, H.T.; Xu, Y.; Zhang, T.; Zhao, J.; Zhang, A.L.; Guo, Z.Y.; Chen, J.E.

    2014-11-01

    To demonstrate the acceleration capability of a Dielectric Wall Accelerator (DWA), a proton injector has been developed at Peking University (PKU). It is composed of a compact permanent magnet 2.45 GHz Electron Cyclotron Resonance Ion Source (PKU PMECRIS) associated with a LEBT of two electrostatic Einzel lenses [1]. This injector is named as Advanced Injector System of Light Ions (AISLI). The acceptance tests have been performed with a 40 keV–55 mA hydrogen beam successfully passing through a ϕ 10 mm aperture diaphragm. This diaphragm is located 200 mm downstream the plasma emission hole at the location of the future DWA entrance flange. The beam rms emittance reached about 0.10 π mm mrad in pulsed mode. This article describes the AISLI experimental setup, the measurement principle and the obtained beam characteristics.

  5. Measurements and modeling of gamma absorbed doses due to releases from a linear proton accelerator: experimental design and preliminary results

    External radiation levels due to positron annihilation radiation from 11C, 13N, and 15O released by the 800 MeV linear proton accelerator at the Los Alamos Meson Physics Facility (LAMPF) have been monitored at a fence-line location both by thermoluminescent dosimeters (TLDs) and high pressure ionization chambers (HPICs). The accelerator is located in irregular terrain consisting of mesas and canyons. Fifteen-minute, accumulated external radiation levels were recorded with the HPICs. Instruments on a nerby meteorological tower concurrently measured wind speed and direction at three levels, temperature at two levels, solar radiation, and rainfall. Real-time radionuclide release rates and stack velocities were measured at the release point with in-stack monitors. This paper presents analyses of short-term radiation levels using HPICs and long-term levels using TLDs. Work being done to develop a computer model to predict external radiation levels based on meteorological data is also discussed

  6. Proton injector acceptance tests for a Dielectric Wall Accelerator (DWA):characterisation of Advanced Injection System of Light Ions (AISLI)

    To demonstrate the acceleration capability of a Dielectric Wall Accelerator (DWA), a proton injector has been developed at Peking University (PKU). It is composed of a compact permanent magnet 2.45 GHz Electron Cyclotron Resonance Ion Source (PKU PMECRIS) associated with a LEBT of two electrostatic Einzel lenses [1]. This injector is named as Advanced Injector System of Light Ions (AISLI). The acceptance tests have been performed with a 40 keV–55 mA hydrogen beam successfully passing through a ϕ 10 mm aperture diaphragm. This diaphragm is located 200 mm downstream the plasma emission hole at the location of the future DWA entrance flange. The beam rms emittance reached about 0.10 π mm mrad in pulsed mode. This article describes the AISLI experimental setup, the measurement principle and the obtained beam characteristics

  7. Development of 650 MHz solid state RF amplifier for proton accelerator

    Design and development of 30 kW high powers RF source at 650 MHz, using solid RF state technology, has been initiated at RRCAT. The indigenous technology development efforts will be useful for the proposed high power proton accelerators for SNS/ADS applications. In this 650 MHz amplifier scheme, 30 kW CW RF power will be generated using modular combination of 8 kW amplifier units. Necessary studies were carried out for device selection, choice of amplifier architecture and design of high power combiners and dividers. Presently RF amplifier delivering 250 W at 650 MHz has been fabricated and tested. Towards development of high power RF components, design and engineering prototyping of 16-port power combiner, directional coupler and RF dummy loads has been completed. The basic 8 kW amplifier unit is designed to provide power gain of 50 dB, bandwidth of 20 MHz and spurious response below 30 dB from fundamental signal. Based on the results of circuit simulation studies and engineering prototyping of amplifier module, two RF transistor viz. MRF3450 and MRF 61K were selected as solid state active devices. Impedance matching network in amplifier module is designed using balanced push pull configuration with transmission line BALUN. Due to high circulating current near drain side, metal clad RF capacitors were selected which helps in avoiding hot spot from output transmission path, ensuring continuous operation at rated RF power without damage to RF board. 350 W circulator is used to protect the RF devices from reflected power. Based on the prototype design and measured performance, one of these RF transistors will be selected to be used as workhorse for all amplifier modules. Two amplifier modules are mounted on water cooled copper heat-sink ensuring proper operating temperature for reliable and safe operation of amplifier. Also real time control system and data logger has been developed to provide DAQ and controls in each rack. For power combining and power measurement

  8. Observation of gaseous nitric acid production at a high-energy proton accelerator facility

    Kanda, Y; Nakajima, H

    2005-01-01

    High-energy protons and neutrons produce a variety of radionuclides as well as noxious and oxidative gases, such as ozone and nitric acid, in the air mainly through the nuclear spallation of atmospheric elements. Samples were collected from the surfaces of magnets, walls, and floors in the neutrino beamline tunnel and the target station of the KEK 12-GeV proton synchrotron facility by wiping surfaces with filter paper. Considerably good correlations were found between the amounts of nitrate and tritium and between those of nitrate and /sup 7/Be. This finding gives evidence that at high-energy proton facilities, nitric acid is produced in the radiolysis of air in beam- loss regions. Also, the nitric acid on the surfaces was found to be desorbed and tended to be more uniform throughout the tunnel due to air circulation. The magnitude of diminishing from the surfaces was in the order of tritium>nitrate>/sup 7/Be1).

  9. Observation of gaseous nitric acid production at a high-energy proton accelerator facility

    High-energy protons and neutrons produce a variety of radionuclides as well as noxious and oxidative gases, such as ozone and nitric acid, in the air mainly through the nuclear spallation of atmospheric elements. Samples were collected from the surfaces of magnets, walls, and floors in the neutrino beamline tunnel and the target station of the KEK 12-GeV proton synchrotron facility by wiping surfaces with filter paper. Considerably good correlations were found between the amounts of nitrate and tritium and between those of nitrate and 7Be. This finding gives evidence that at high-energy proton facilities, nitric acid is produced in the radiolysis of air in beam-loss regions. Also, the nitric acid on the surfaces was found to be desorbed and tended to be more uniform throughout the tunnel due to air circulation. The magnitude of diminishing from the surfaces was in the order of tritium>nitrate>7Be

  10. A research plan based on high intensity proton accelerator Neutron Science Research Center

    Mizumoto, Motoharu [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1997-03-01

    A plan called Neutron Science Research Center (NSRC) has been proposed in JAERI. The center is a complex composed of research facilities based on a proton linac with an energy of 1.5GeV and an average current of 10mA. The research facilities will consist of Thermal/Cold Neutron Facility, Neutron Irradiation Facility, Neutron Physics Facility, OMEGA/Nuclear Energy Facility, Spallation RI Beam Facility, Meson/Muon Facility and Medium Energy Experiment Facility, where high intensity proton beam and secondary particle beams such as neutron, pion, muon and unstable radio isotope (RI) beams generated from the proton beam will be utilized for innovative researches in the fields on nuclear engineering and basic sciences. (author)

  11. A conceptual design of the RF system for the NSP high intensity proton accelerator at JAERI

    JAERI has been proposing the Neutron Science Project which aims at exploring the fields of basic science and nuclear technology using a high power spallation neutron source. The neutron source will be driven by a high intensity linear accelerator with an energy of 1.5 GeV and an average beam current of 5.33 mA and beam power of 8 MW. The RF system for the accelerator consists of a high-energy accelerator part and a low energy accelerator part. The maximum RF power requirements at the high and low energy accelerator parts are 25 MW and 8.3 MW, respectively. In this report, we describe the conceptual design of the RF system. In the low energy accelerator part, we estimated the requirement for the high-power amplifier tube and made the basis design for RF components. In the high energy accelerator part, we studied the effect of tuning errors, Lorentz forces and microphonics in the superconducting cavity. We calculated the klystron efficiency and supply power in the arrangement of where one klystron distributes the RF power to four cavities. We also considered an IOT RF system. Finally, we describe the electrical capacity and quantity of cooling water in the RF system. (author)

  12. Characterization of Monoenergetic Neutron Reference Fields with a High Resolution Diamond Detector

    Zimbal, A; Nolte, R; Schuhmacher, H

    2009-01-01

    A novel radiation detector based on an artificial single crystal diamond was used to characterize in detail the energy distribution of neutron reference fields at the Physikalisch-Technische Bundesanstalt (PTB) and their contamination with charged particles. The monoenergetic reference fields at PTB in the neutron energy range from 1.5 MeV up to 19 MeV are generated by proton and deuteron beams impinging on solid and gas targets of tritium and deuterium. The energy of the incoming particles and the variation of the angle under which the measurement is performed produce monoenergetic reference fields with different mean energies and line shapes. In this paper we present high resolution neutron spectrometry measurements of different monoenergetic reference fields. The results are compared with calculated spectra taking into account the actual target parameters. Line structures in the order of 80 keV for a neutron energy of 9 MeV were resolved. The shift of the mean energy and the increasing of the width of the ...

  13. Quasi-Monoenergetic Neutron Beam and its Application at the RCNP Cyclotron Facility

    A quasi-monoenergetic neutron field using 7Li(p,n) reaction for the higher energy range of 100 to 400 MeV has been developed at the RCNP cyclotron facility of Osaka University. The neutron energy spectra at angles from 0° to 30° have been investigated for the proton beams with the energies of 140, 250, 350 and 392 MeV. The highest neutron fluence reaches 1.0 × 1010 n/sr /μC, and the contribution of peak intensity to the total intensity varied between 0.4 and 0.5. Using the quasi-monoenergetic neutron beam, measurement of neutron induced activation cross sections, elastic scattering cross sections for neutron and a shielding benchmark experiment have been performed, successfully. Thus quasi-monoenergetic neutron field at RCNP are suitable for measurement of nuclear data, shielding experiments and the calibration of monitors in the energy region from 100 to 400 MeV. (author)

  14. Electron heating in radiation-pressure-driven proton acceleration with a circularly polarized laser

    Paradkar, B. S.; Krishnagopal, S.

    2016-02-01

    Dynamics of electron heating in the radiation-pressure-driven acceleration through self-induced transparency (SIT) is investigated with the help of particle-in-cell simulations. The SIT is achieved through laser filamentation which is seeded by the transverse density modulations due to the Rayleigh-Taylor-like instability. We observe stronger SIT induced electron heating for the longer duration laser pulses leading to deterioration of accelerated ion beam quality (mainly energy spread). Such heating can be controlled to obtain a quasimonoenergetic beam by cascaded foils targets where a second foil behind the main accelerating foil acts as a laser reflector to suppress the SIT.

  15. Anti-proton tune measurements for the Fall 1995 accelerator studies

    Marriner, john; /Fermilab

    1996-04-01

    A system to measure the tunes of a single antiproton (or proton) bunch was built and has been commissioned. The system achieved high sensitivity with a novel closed-orbit suppression system. The use of high bandwidth directional pickpus and kickers in conjunction with precise timing gates enabled the measurement of the tune of a single bunch.

  16. Fast neutron dosimetry for radioprotection near large accelerators. Application to the proton synchrotron Saturne

    Methods are described that are used for the measurement of a neutron flux, and of the corresponding energy flux and dose absorbed. The methods are checked experimentally by the use of neutron sources of known energy distribution. The conditions of use of a proportional counter for recoil protons are described. The experimental results obtained with the synchrotron SATURNE at Saclay are described. (author)

  17. Proton acceleration and its energy spectra during coalescence of two parallel current loops

    Shimada, Kazuaki; Sakai, Jun-Ichi

    2004-01-01

    We investigate the plasma dynamics during coalescence of two parallel current loops by using a resistive MHD code. We investigate the orbit of many protons in the electromagnetic fields obitained from the MHD simunations. We investigate two cases of the coalescence precess: as the original loop current for both cases of co-helicity and counter-helicity.

  18. Enhanced radiation pressure-assisted acceleration by temporally tuned counter-propagating pulses

    Within the last decade, laser-ion acceleration has become a field of broad interest. The possibility to generate short proton- or heavy ion bunches with an energy of a few tens of MeV by table-top laser systems could open new opportunities for medical or technical applications. Nevertheless, today's laser-acceleration schemes lead mainly to a temperature-like energy distribution of the accelerated ions, a big disadvantage compared to mono-energetic beams from conventional accelerators. Recent results [1] of laser-ion acceleration using radiation-pressure appear promising to overcome this drawback. In this paper, we demonstrate the influence of a second counter-propagating laser pulse interacting with a nm-thick target, creating a well defined pre-plasma

  19. Producing Mono-energetic Neutrons for Research

    Jepeal, Steven

    2014-09-01

    Free neutrons are seldom produced in nature and are unstable, decaying back to protons with a mean life of 881s. The only natural sources are spontaneous fission of actinides and cosmic ray interactions, both of which are rare processes. The detection of neutrons indicates unusual nuclear activity, allowing neutron detection the roll of the ``smoking gun'' for seeking potential nuclear terrorism. Recently, there has been a push for the development of new neutron detectors, ideally sufficiently inexpensive that a detector can be carried by all first responders such as police and fire fighters. One promising new material is the inorganic scintillator CLYC, a crystal of chlorine, lithium, yttrium and cesium. CLYC has a high energy resolution not only for gamma rays, but also for fast neutrons. At the University of Massachusetts, Lowell, CLYC is being developed in collaboration with local industrial companies. To evaluate its response to neutrons, in to 500 keV to 4 MeV energy range, the CN Van de Graaff generator is used to produce neutrons, via the 7Li(p,n)7Be reaction. However, the important energy regime of 4--10 MeV is currently inaccessible. This current project is to build a gas-cell target to enable the D(d,n)3He reaction and produce neutrons of energy up to 9 MeV, an approach that has been used successfully at the University of Kentucky. The project involves some mechanical engineering management, then chamber construction, vacuum testing, developing thin window technology, and finally commissioning of the gas cell using accelerated beams. The commissioning will be physics rich in quantifying the flux and energy resolution of the neutron beam produced. Free neutrons are seldom produced in nature and are unstable, decaying back to protons with a mean life of 881s. The only natural sources are spontaneous fission of actinides and cosmic ray interactions, both of which are rare processes. The detection of neutrons indicates unusual nuclear activity, allowing

  20. Experimental study on neutronics in bombardment of thick targets by high energy proton beams for accelerator-driven sub-critical system

    The experimental study on neutronics in the target region of accelerator-driven sub-critical system is carried out by using the high energy accelerator in Joint Institute for Nuclear Research, Dubna, Russia. The experiments with targets U(Pb), Pb and Hg bombarded by 0.533, 1.0, 3.7 and 7.4 GeV proton beams show that the neutron yield ratio of U(Pb) to Hg and Pb to Hg targets is (2.10 +- 0.10) and (1.76 +- 0.33), respectively. Hg target is disadvantageous to U(Pb) and Pb targets to get more neutrons. Neutron yield drops along 20 cm thick targets as the thickness penetrated by protons increases. The lower the energy of protons, the steeper the neutron yield drops. In order to get more uniform field of neutrons in the targets, the energy of protons from accelerators should not be lower than 1 GeV. The spectra of secondary neutrons produced by different energies of protons are similar, but the proportion of neutrons with higher energy gradually increases as the proton energy increases

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

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

    2009-01-01

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

  2. Shielding properties of iron at high energy proton accelerators studied by a Monte Carlo code

    Shielding properties of a lateral iron shield and of iron and concrete shields at angles between 5deg and 30deg are studied by means of the Monte Carlo program FLUNEV (DESY-D3 version of the FLUKA code extended for emission and transport of low energy neutrons). The following quantities were calculated for a high energy proton beam hitting an extended iron target: total and partial dose equivalents, attenuation coefficients, neutron spectra, star densities (compared also with the CASIM code) and quality factors. The dependence of the dose equivalent on the energy of primary protons, the effect of a concrete layer behind a lateral iron shielding and the total number of neutrons produced in the target were also estimated. (orig.)

  3. Isochoric heating of matter by laser-accelerated high-energy protons

    Fuchs, Julien; Mancic, Ana; Robiche, Jerome; Antici, Patrizio; Lancia, Livia; Audebert, Patrick; Combis, Patrick; Renaudin, Patrick; Kimura, Tomoaki; Kodama, Ryosuke; Nakatsutsumi, Motoaki

    2008-04-01

    Producing matter at a high temperature (1-25 eV) and solid density is of prime interest for fundamental plasma physics or ICF. The use of laser-based high energy proton beams to achieve such state of matter is interesting since they are short (LULI 100 TW facility, experiments to characterize the achieved state of matter, coupled to a detailed hydro-modeling. A laser-generated proton beam irradiated and heated a secondary target positioned after a vacuum gap. Three diagnostics were used: (i) 1D time-resolved optical self-emission of the heated target rear-surface at two wavelengths, (ii) time-resolved interferometry of a chirped probe beam reflecting off the heated target rear-surface, (iii) x-ray absorption spectroscopy through the heated target using a laser-produced backlighter detecting its Kα-edge softening.

  4. Characterization of warm dense matter produced by laser-accelerated high-energy protons

    Nakatsutsumi, M.; Fuchs, J.; Mancic, A.; Robiche, J.; Renaudin, P.; Combis, P.; Dorchies, F.; Harmand, M.; Maynard, G.; Vassaux, J.; Mora, P.; Antici, P.; Fourmaux, S.; Audebert, P.

    2008-11-01

    Producing warm dense plasmas (WDM: solid density, few eV ˜ few 10s eV) is of interest for fundamental plasma physics or ICF. Laser-produced proton heating is of interest since they are short (LULI 100 TW facility to create and characterize WDM. We used, (i) 2D time-resolved optical self-emission of the heated target, (ii) surface expansion velocity measurement through phase measurements of a reflecting probe beam, and (iii) x-ray absorption spectroscopy. We showed that we could produce quasi-uniform heating of solids, as suited for e.g. EoS measurements. Time-resolved solid-liquid-plasma transition has been measured, as well as energy-loss of MeV protons in warm dense plasmas.

  5. Decursin was Accelerated Human Lung Cancer Cell Death Caused by Proton Beam Irradiation via Blocking the p42/44 MAPK pathway

    Decursin, which is one of the extract of Angelica gigas Nakai root, has been traditionally used in Korean folk medicine as a tonic and for treatment of anemia and other common diseases. There are some reports about the pharmacological properties of decursin showing anti-bacterial and anti-amnestic effect, depression of cardiac contraction, antitumor and anti-angiogenic activity. Cell death induced by proton beam is identified as apoptosis. The study investigated that genes involved in apoptosis are checked by RT-PCR and used LET instead of SPBP of proton beam. Apoptosis is the tight regulated by multi-protein action in physiological cell death program. Proton therapy is an attractive approach for the treatment of deep-seated tumor. Recently, many researchers tried to new therapeutic strategy, combination of proton therapy and chemotherapy, in order to increase therapeutic effect. In this study, we investigate whether decursin can accelerate effect of human lung cell apoptosis in proton irradiated cancer cells

  6. Decursin was Accelerated Human Lung Cancer Cell Death Caused by Proton Beam Irradiation via Blocking the p42/44 MAPK pathway

    Jung, Myung Hwan; Ra, Se Jin; Kim, Kye Ryung [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2011-10-15

    Decursin, which is one of the extract of Angelica gigas Nakai root, has been traditionally used in Korean folk medicine as a tonic and for treatment of anemia and other common diseases. There are some reports about the pharmacological properties of decursin showing anti-bacterial and anti-amnestic effect, depression of cardiac contraction, antitumor and anti-angiogenic activity. Cell death induced by proton beam is identified as apoptosis. The study investigated that genes involved in apoptosis are checked by RT-PCR and used LET instead of SPBP of proton beam. Apoptosis is the tight regulated by multi-protein action in physiological cell death program. Proton therapy is an attractive approach for the treatment of deep-seated tumor. Recently, many researchers tried to new therapeutic strategy, combination of proton therapy and chemotherapy, in order to increase therapeutic effect. In this study, we investigate whether decursin can accelerate effect of human lung cell apoptosis in proton irradiated cancer cells

  7. A Data-Driven Analytic Model for Proton Acceleration by Large-Scale Solar Coronal Shocks

    Kozarev, Kamen A

    2016-01-01

    We have recently studied the development of an eruptive filament-driven, large-scale off-limb coronal bright front (OCBF) in the low solar corona (Kozarev et al. 2015), using remote observations from Solar Dynamics Observatory's Advanced Imaging Assembly EUV telescopes. In that study, we obtained high-temporal resolution estimates of the OCBF parameters regulating the efficiency of charged particle acceleration within the theoretical framework of diffusive shock acceleration (DSA). These parameters include the time-dependent front size, speed, and strength, as well as the upstream coronal magnetic field orientations with respect to the front's surface normal direction. Here we present an analytical particle acceleration model, specifically developed to incorporate the coronal shock/compressive front properties described above, derived from remote observations. We verify the model's performance through a grid of idealized case runs using input parameters typical for large-scale coronal shocks, and demonstrate ...

  8. DTL cavity design and beam dynamics for a TAC linear proton accelerator

    Caliskan, A.; Yılmaz, M.

    2012-02-01

    A 30 mA drift tube linac (DTL) accelerator has been designed using SUPERFISH code in the energy range of 3-55 MeV in the framework of the Turkish Accelerator Center (TAC) project. Optimization criteria in cavity design are effective shunt impedance (ZTT), transit-time factor and electrical breakdown limit. In geometrical optimization we have aimed to increase the energy gain in each RF gap of the DTL cells by maximizing the effective shunt impedance (ZTT) and the transit-time factor. Beam dynamics studies of the DTL accelerator have been performed using beam dynamics simulation codes of PATH and PARMILA. The results of both codes have been compared. In the beam dynamical studies, the rms values of beam emittance have been taken into account and a low emittance growth in both x and y directions has been attempted.

  9. DTL cavity design and beam dynamics for a TAC linear proton accelerator

    A 30 mA drift tube linac (DTL) accelerator has been designed using SUPERFISH code in the energy range of 3-55 MeV in the framework of the Turkish Accelerator Center (TAC) project. Optimization criteria in cavity design are effective shunt impedance (ZTT), transit-time factor and electrical breakdown limit. In geometrical optimization we have aimed to increase the energy gain in each RF gap of the DTL cells by maximizing the effective shunt impedance (ZTT) and the transit-time factor. Beam dynamics studies of the DTL accelerator have been performed using beam dynamics simulation codes of PATH and PARMILA. The results of both codes have been compared. In the beam dynamical studies, the rms values of beam emittance have been taken into account and a low emittance growth in both x and y directions has been attempted. (authors)

  10. The design of a proton recoil telescope for 14 MeV neutron spectrometry

    Hawkes, N P; Croft, S; Jarvis, O N; Sherwood, A C

    2002-01-01

    As part of the design effort for a 14 MeV neutron spectrometer for the Joint European Torus (JET), computer codes were developed to calculate the response of a proton recoil telescope comprising a proton radiator film mounted in front of a proton detector. The codes were used to optimise the geometrical configuration in terms of efficiency and resolution, bearing in mind the constraints imposed by the proposed application as a JET neutron diagnostic for the Deuterium-Tritium phase. A prototype instrument was built according to the optimised design, and tested with monoenergetic 14 MeV neutrons from the Harwell 500 keV Van de Graaff accelerator. The measured energy resolution and absolute efficiency were found to be in acceptable agreement with the calculations. Based on this work, a multi-radiator production version of the spectrometer has now been constructed and successfully deployed at JET.

  11. Use of a Van de Graaff proton accelerator for neutron radiography

    A neutron radiographic capability has been established at the Pantex ERDA Plant. A 3 MeV Van de Graaff accelerator is being used to make neutron radiographs in order to observe defects of explosives encased in metal containers and ''O'' ring integrity

  12. Use of a Van de Graaff proton accelerator for neutron radiography

    Cassidy, J.P.

    1976-12-01

    A neutron radiographic capability has been established at the Pantex ERDA Plant. A 3 MeV Van de Graaff accelerator is being used to make neutron radiographs in order to observe defects of explosives encased in metal containers and ''O'' ring integrity.

  13. Design of 7 MeV drift tube linac as injector of proton accelerator for cancer therapy

    A 324 MHz drift-tube linac(DTL) is designed for proton cancer therapy. The design demands low power dissipation and short tank. The DTL accelerates beam from 2.5 MeV to 7 MeV, with RF power of 265 kW and total length of 1.9 m. The DTL uses permanent-quadrupole magnet(PQM) inside the drift tubes arranged in an FODO lattice. A new matching method is designed. In stead of the traditional beam transport line, the first four cells in DTL are designed as matching section. It causes the beam ellipse from radio-frequency quadrupole linac(RFQ) to satisfy conditions specified by the DTL periodic structure. The dynamics simulation was performed with PARMILA, and almost no emittance growth has been found. (authors)

  14. Pilot experiment on proton acceleration using the 25 TW femtosecond Ti:Sapphire laser system at PALS

    Prokůpek, Jan; Margarone, Daniele; Hřebíček, Jan; Krůs, Miroslav; Velyhan, Andriy; Pšikal, J.; Pfeifer, Miroslav; Mocek, Tomáš; Krása, Josef; Ullschmied, Jiří; Jungwirth, Karel; Korn, Georg; Rus, Bedřich

    2012-01-01

    Roč. 690, Oct (2012), s. 48-52. ISSN 0168-9002 R&D Projects: GA MŠk ED1.1.00/02.0061; GA MŠk ED2.1.00/01.0027; GA ČR(CZ) GAP205/11/1165; GA MŠk EE.2.3.20.0087; GA MŠk LM2010014 Grant ostatní: ELI Beamlines(XE) CZ.1.05/1.1.00/02.0061; HILASE(XE) CZ.1.05/2.1.00/01.0027; OP VK 2 Laser Gen(XE) CZ.1.07/2.3.00/20.0087; AVČR(CZ) M100101210 Institutional research plan: CEZ:AV0Z10100523; CEZ:AV0Z20430508 Keywords : laser driven acceleration * proton beams * ion diagnostics Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 1.142, year: 2012

  15. Evidence of resonant surface wave excitation in the relativistic regime through measurements of proton acceleration from grating targets

    Ceccotti, T; Sgattoni, A; Bigongiari, A; Raynaud, M; Riconda, C; Heron, A; Baffigi, F; Labate, L; Gizzi, L A; Vassura, L; Fuchs, J; Passoni, M; Kveton, M; Novotny, F; Possolt, M; Prokupek, J; Proska, J; Psikal, J; Stolcova, L; Velyhan, A; Bougeard, M; D'Oliveira, P; Tcherbakoff, O; Reau, F; Martin, P; Macchi, A

    2013-01-01

    The interaction of laser pulses with thin grating targets, having a periodic groove at the irradiated surface, has been experimentally investigated. Ultrahigh contrast ($\\sim 10^{12}$) pulses allowed to demonstrate an enhanced laser-target coupling for the first time in the relativistic regime of ultra-high intensity $>10^{19} \\mbox{W/cm}^{2}$. A maximum increase by a factor of 2.5 of the cut-off energy of protons produced by Target Normal Sheath Acceleration has been observed with respect to plane targets, around the incidence angle expected for resonant excitation of surface waves. A significant enhancement is also observed for small angles of incidence, out of resonance.

  16. High Current Proton and Deuteron Beams for Accelerators and Neutron Generators

    Skalyga, V.; Izotov, I.; Razin, S.; Sidorov, A.; Golubev, S.; Maslennikova, A.; Volovecky, A.; Koivisto, Hannu; Tarvainen, Olli; Kalvas, Taneli

    2014-01-01

    This paper presents the latest results of high current proton and deuteron beam production at SMIS 37 facility at the Institute of Applied Physics (IAP RAS). In this experimental setup the plasma is created and the electrons are heated by 37.5 GHz gyrotron radiation with power up to 100 kW in a simple mirror trap fulfilling the ECR condition. High microwave power and frequency allow sustaining higher density hydrogen plasma (ne up to 2·1013 cm-3) in comparison to conve...

  17. Design study of Be-target for proton accelerator based neutron source with 13MeV cyclotron

    There is a cyclotron named KIRAMS-13 in Pusan National University, Busan, Korea, which has the proton energy of 13MeV and the beam current of 0.05mA. Originally, it was developed for producing medical radioisotopes and nuclear physics research. To improve the utilization of the facility, we are considering the possibilities of installing a neutron generation target in it. The Beryllium target has been considered and neutrons can be generated by 9Be(p,n)9B reaction above the threshold proton energy of 2.057MeV. In this presentation, we suggest candidate materials and structures, thicknesses, metal layers and cooling systems of target, which is optimal for the KIRAMS-13. We chose the Beryllium material of 1.14mm thick, which is calculated by stopping power of Beryllium, based on PSTAR, NIST. As for the cooling system, we chose to use water as a coolant, which will also act as a moderator. As protons pass through the target, hydrogen ions continue to pile up in the material and this makes the material brittle. To solve this problem, we chose Vanadium material because it has high hydrogen diffusion coefficient and short half-life isotope after being activated by neutrons. We simulated the neutron characteristics by the Monte Carlo simulation code, Geant4, CERN and performed thermal analysis on the target. The design of target system is very important to produce neutrons for the desired purposes. There are several other existing facilities in Korea, in addition to the cyclotron facility considered in this study, where new neutron target system can be installed and neutrons can be generated. Two prominent facilities are KOMAC, Gyeongju and RFT-30, Jeongeup and we are planning to do study on the possibilities of utilizing the accelerators for neutron generation.

  18. Thick target benchmark test for the code used in the design of high intensity proton accelerator project

    In the neutronics design for the JAERI and KEK Joint high intensity accelerator facilities, transport codes of NMTC/JAM, MCNPX and MARS are used. In order to confirm the predict ability for these code, it is important to compare with the experiment result. For the validation of the source term of neutron, the calculations are compared with the experimental spectrum of neutrons produced from thick target, which are carried out at LANL and KEK. As for validation of low energy incident case, the calculations are compared with experiment carried out at LANL, in which target of C, Al, Fe, and 238U are irradiated with 256-MeV protons. By the comparison, it is found that both NMTC/JAM and MCNPX show good agreement with the experiment within by a factor of 2. MARS shows good agreement for C and Al target. MARS, however, gives rather underestimation for all targets in the neutron energy region higher than 30 MeV. For the validation high incident energy case, the codes are compared with the experiment carried out at KEK. In this experiment, W and Pb targets are bombarded with 0.5- and 1.5-GeV protons. Although slightly disagreement exists, NMTC/JAM, MCNPX and MARS are in good agreement with the experiment within by a factor of 2. (author)

  19. Study on bulk shielding for a spallation neutron source facility in the high-intensity proton accelerator project

    Maekawa, F; Takada, H; Teshigawara, M; Watanabe, N

    2002-01-01

    Under the JAERI-KEK High-Intensity Proton Accelerator Project, a spallation neutron source driven by a 3 GeV-1 MW proton beam is planed to be constructed in a main part of the Materials and Life Science Facility. This report describes results of a study on bulk shielding performance of a biological shield for the spallation neutron source by means of a Monte Carlo calculation method, that is important in terms of radiation safety and cost reduction. A shielding configuration was determined as a reference case by considering preliminary studies and interaction with other components, then shielding thickness that was required to achieve a target dose rate of 1 mu Sv/h was derived. Effects of calculation conditions such as shielding materials and dimensions on the shielding performance was investigated by changing those parameters. By taking all the results and design margins into account, a shielding configuration that was identified as the most appropriate was finally determined as follows. An iron shield regi...

  20. Ion acceleration from relativistic laser nano-target interaction

    Laser-ion acceleration has been of particular interest over the last decade for fundamental as well as applied sciences. Remarkable progress has been made in realizing laser-driven accelerators that are cheap and very compact compared with conventional rf-accelerators. Proton and ion beams have been produced with particle energies of up to 50 MeV and several MeV/u, respectively, with outstanding properties in terms of transverse emittance and current. These beams typically exhibit an exponentially decaying energy distribution, but almost all advanced applications, such as oncology, proton imaging or fast ignition, require quasimonoenergetic beams with a low energy spread. The majority of the experiments investigated ion acceleration in the target normal sheath acceleration (TNSA) regime with comparably thick targets in the μm range. In this thesis ion acceleration is investigated from nm-scaled targets, which are partially produced at the University of Munich with thickness as low as 3 nm. Experiments have been carried out at LANL's Trident high-power and high-contrast laser (80 J, 500 fs, λ=1054 nm), where ion acceleration with these nano-targets occurs during the relativistic transparency of the target, in the so-called Breakout afterburner (BOA) regime. With a novel high resolution and high dispersion Thomson parabola and ion wide angle spectrometer, thickness dependencies of the ions angular distribution, particle number, average and maximum energy have been measured. Carbon C6+ energies reached 650 MeV and 1 GeV for unheated and heated targets, respectively, and proton energies peaked at 75 MeV and 120 MeV for diamond and CH2 targets. Experimental data is presented, where the conversion efficiency into carbon C6+ (protons) is investigated and found to have an up to 10fold (5fold) increase over the TNSA regime. With circularly polarized laser light, quasi-monoenergetic carbon ions have been generated from the same nm-scaled foil targets at Trident with an

  1. Ion acceleration from relativistic laser nano-target

    Jung, Daniel

    2012-01-06

    Laser-ion acceleration has been of particular interest over the last decade for fundamental as well as applied sciences. Remarkable progress has been made in realizing laser-driven accelerators that are cheap and very compact compared with conventional rf-accelerators. Proton and ion beams have been produced with particle energies of up to 50 MeV and several MeV/u, respectively, with outstanding properties in terms of transverse emittance and current. These beams typically exhibit an exponentially decaying energy distribution, but almost all advanced applications, such as oncology, proton imaging or fast ignition, require quasimonoenergetic beams with a low energy spread. The majority of the experiments investigated ion acceleration in the target normal sheath acceleration (TNSA) regime with comparably thick targets in the {mu}m range. In this thesis ion acceleration is investigated from nm-scaled targets, which are partially produced at the University of Munich with thickness as low as 3 nm. Experiments have been carried out at LANL's Trident high-power and high-contrast laser (80 J, 500 fs, {lambda}=1054 nm), where ion acceleration with these nano-targets occurs during the relativistic transparency of the target, in the so-called Breakout afterburner (BOA) regime. With a novel high resolution and high dispersion Thomson parabola and ion wide angle spectrometer, thickness dependencies of the ions angular distribution, particle number, average and maximum energy have been measured. Carbon C{sup 6+} energies reached 650 MeV and 1 GeV for unheated and heated targets, respectively, and proton energies peaked at 75 MeV and 120 MeV for diamond and CH{sub 2} targets. Experimental data is presented, where the conversion efficiency into carbon C{sup 6+} (protons) is investigated and found to have an up to 10fold (5fold) increase over the TNSA regime. With circularly polarized laser light, quasi-monoenergetic carbon ions have been generated from the same nm-scaled foil

  2. Accelerator

    The invention claims equipment for stabilizing the position of the front covers of the accelerator chamber in cyclic accelerators which significantly increases accelerator reliability. For stabilizing, it uses hydraulic cushions placed between the electromagnet pole pieces and the front chamber covers. The top and the bottom cushions are hydraulically connected. The cushions are disconnected and removed from the hydraulic line using valves. (J.P.)

  3. A GPU-accelerated and Monte Carlo-based intensity modulated proton therapy optimization system

    Purpose: Conventional spot scanning intensity modulated proton therapy (IMPT) treatment planning systems (TPSs) optimize proton spot weights based on analytical dose calculations. These analytical dose calculations have been shown to have severe limitations in heterogeneous materials. Monte Carlo (MC) methods do not have these limitations; however, MC-based systems have been of limited clinical use due to the large number of beam spots in IMPT and the extremely long calculation time of traditional MC techniques. In this work, the authors present a clinically applicable IMPT TPS that utilizes a very fast MC calculation. Methods: An in-house graphics processing unit (GPU)-based MC dose calculation engine was employed to generate the dose influence map for each proton spot. With the MC generated influence map, a modified least-squares optimization method was used to achieve the desired dose volume histograms (DVHs). The intrinsic CT image resolution was adopted for voxelization in simulation and optimization to preserve spatial resolution. The optimizations were computed on a multi-GPU framework to mitigate the memory limitation issues for the large dose influence maps that resulted from maintaining the intrinsic CT resolution. The effects of tail cutoff and starting condition were studied and minimized in this work. Results: For relatively large and complex three-field head and neck cases, i.e., >100 000 spots with a target volume of ∼1000 cm3 and multiple surrounding critical structures, the optimization together with the initial MC dose influence map calculation was done in a clinically viable time frame (less than 30 min) on a GPU cluster consisting of 24 Nvidia GeForce GTX Titan cards. The in-house MC TPS plans were comparable to a commercial TPS plans based on DVH comparisons. Conclusions: A MC-based treatment planning system was developed. The treatment planning can be performed in a clinically viable time frame on a hardware system costing around 45 000

  4. A GPU-accelerated and Monte Carlo-based intensity modulated proton therapy optimization system

    Ma, Jiasen, E-mail: ma.jiasen@mayo.edu; Beltran, Chris; Seum Wan Chan Tseung, Hok; Herman, Michael G. [Department of Radiation Oncology, Division of Medical Physics, Mayo Clinic, 200 First Street Southwest, Rochester, Minnesota 55905 (United States)

    2014-12-15

    Purpose: Conventional spot scanning intensity modulated proton therapy (IMPT) treatment planning systems (TPSs) optimize proton spot weights based on analytical dose calculations. These analytical dose calculations have been shown to have severe limitations in heterogeneous materials. Monte Carlo (MC) methods do not have these limitations; however, MC-based systems have been of limited clinical use due to the large number of beam spots in IMPT and the extremely long calculation time of traditional MC techniques. In this work, the authors present a clinically applicable IMPT TPS that utilizes a very fast MC calculation. Methods: An in-house graphics processing unit (GPU)-based MC dose calculation engine was employed to generate the dose influence map for each proton spot. With the MC generated influence map, a modified least-squares optimization method was used to achieve the desired dose volume histograms (DVHs). The intrinsic CT image resolution was adopted for voxelization in simulation and optimization to preserve spatial resolution. The optimizations were computed on a multi-GPU framework to mitigate the memory limitation issues for the large dose influence maps that resulted from maintaining the intrinsic CT resolution. The effects of tail cutoff and starting condition were studied and minimized in this work. Results: For relatively large and complex three-field head and neck cases, i.e., >100 000 spots with a target volume of ∼1000 cm{sup 3} and multiple surrounding critical structures, the optimization together with the initial MC dose influence map calculation was done in a clinically viable time frame (less than 30 min) on a GPU cluster consisting of 24 Nvidia GeForce GTX Titan cards. The in-house MC TPS plans were comparable to a commercial TPS plans based on DVH comparisons. Conclusions: A MC-based treatment planning system was developed. The treatment planning can be performed in a clinically viable time frame on a hardware system costing around 45

  5. Accelerator experiments with soft protons and hyper-velocity dust particles: application to ongoing projects of future X-ray missions

    Perinati, E.; Diebold, S.; Kendziorra, E.;

    2012-01-01

    We report on our activities, currently in progress, aimed at performing accelerator experiments with soft protons and hyper-velocity dust particles. They include tests of different types of X-ray detectors and related components (such as filters) and measurements of scattering of soft protons and...... hyper-velocity dust particles off X-ray mirror shells. These activities have been identified as a goal in the context of a number of ongoing space projects in order to assess the risk posed by environmental radiation and dust and qualify the adopted instrumentation with respect to possible damage or...... performance degradation. In this paper we focus on tests for the Silicon Drift Detectors (SDDs) used aboard the LOFT space mission. We use the Van de Graaff accelerators at the University of T\\"ubingen and at the Max Planck Institute for Nuclear Physics (MPIK) in Heidelberg, for soft proton and hyper...

  6. Search for monoenergetic γ rays from psi (3684) decay

    Results are reported of a search for monoenergetic γ rays with energies above 50 MeV from psi (3684) decay using large NaI(Tl) spectrometers. No clear evidence for emission of such radiation was found

  7. STEREO/SEPT observations of upstream particle events: almost monoenergetic ion beams

    A. Klassen

    2009-05-01

    Full Text Available We present observations of Almost Monoenergetic Ion (AMI events in the energy range of 100–1200 keV detected with the Solar Electron and Proton Telescope (SEPT onboard both STEREO spacecraft. The energy spectrum of AMI events contain 1, 2, or 3 narrow peaks with the relative width at half maximum of 0.1–0.7 and their energy maxima varies for different events from 120 to 1200 keV. These events were detected close to the bow-shock (STEREO-A&B and to the magnetopause at STEREO-B as well as unexpectedly far upstream of the bow-shock and far away from the magnetotail at distances up to 1100 RE (STEREO-B and 1900 RE (STEREO-A. We discuss the origin of AMI events, the connection to the Earth's bow-shock and to the magnetosphere, and the conditions of the interplanetary medium and magnetosphere under which these AMI bursts occur. Evidence that the detected spectral peaks were caused by quasi-monoenergetic beams of protons, helium, and heavier ions are given. Furthermore, we present the spatial distribution of all AMI events from December 2006 until August 2007.

  8. Energy production in a thorium subcritical lattice driven by accelerated protons

    It has been proposed to sustain a thorium fuel cycle in a tight lattice driven by spallation reactions neutrons, these reactions being initiated by bombarding the lattice with high- energy, high-current, protons. The proposal lacks a consistent evolution calculation of actinides and fission product densities. In order to assess the true potential of the concept, the capacity of a criticality burnup calculation with the WIMS code was tested as a replacement to a source-driven' burnup calculation. Tests of 'source-driven' burnup were conducted with calculations based on a package program combining the high-energy code HETC, the Monte-Carlo code MCNP, and the depletion code KORIGEN. (author). 2 refs., 1 tab

  9. Characterization techniques for fixed-field alternating gradient accelerators and beam studies using the KURRI 150 MeV proton FFAG

    Sheehy, S L; Machida, S; Rogers, C; Prior, C R; Volat, L; Tahar, M Haj; Ishi, Y; Kuriyama, Y; Sakamoto, M; Uesugi, T; Mori, Y

    2015-01-01

    In this paper we describe the methods and tools used to characterize a 150 MeV proton scaling Fixed Field Alternating Gradient (FFAG) accelerator at Kyoto University Research Reactor Institute. Many of the techniques used are unique to this class of machine and are thus of relevance to any future FFAG accelerator. For the first time we detail systematic studies undertaken to improve the beam quality of the FFAG. The control of beam quality in this manner is crucial to demonstrating high power operation of FFAG accelerators in future.

  10. Characterization techniques for fixed-field alternating gradient accelerators and beam studies using the KURRI 150 MeV proton FFAG

    Sheehy, S. L.; Kelliher, D. J.; Machida, S.; Rogers, C.; Prior, C. R.; Volat, L.; Haj Tahar, M.; Ishi, Y.; Kuriyama, Y.; Sakamoto, M.; Uesugi, T.; Mori, Y.

    2016-07-01

    In this paper we describe the methods and tools used to characterize a 150 MeV proton scaling fixed field alternating gradient (FFAG) accelerator at Kyoto University Research Reactor Institute. Many of the techniques used are unique to this class of machine and are thus of relevance to any future FFAG accelerator. For the first time we detail systematic studies undertaken to improve the beam quality of the FFAG. The control of beam quality in this manner is crucial to demonstrating high power operation of FFAG accelerators in future.

  11. Calibration of activation detectors in a monoenergetic neutron beam. Contribution to criticality dosimetry

    Activation detectors have been calibrated for critical dosimetry applications. Measurements are made using a monoenergetic neutron flux. 14 MeV neutrons obtained par (D-T) reaction are produced by 150 kV accelerator. Neutron flux determined by different methods leads us to obtain an accuracy better than 6%. The present dosimetric system (Activation Neutron Spectrometer - SNAC) gives few informations in the (10 keV - 2 MeV) energetic range. The system has been improved and modified so that SNAC detectors must be read out by gamma spectrometer

  12. Design and rf tuning of the KEK 40 MeV proton linear accelerator

    An Alvarez linac was designed and constructed on the basis of a model linac study to increase the output energy from 20 to 40 MeV. The linac was tuned by frequency tuners and post couplers. Stabilization of the field was achieved and a variation within ± 0.7 % of the accelerating field was obtained. An equivalent circuit analysis which can numerically solve loop equations, including stem and post currents in addition to tank current, can explain the rf characteristics of a postcoupled structure. (author)

  13. Tests of a Compton imaging prototype in a monoenergetic 4.44 MeV photon field—a benchmark setup for prompt gamma-ray imaging devices

    Golnik, C.; Bemmerer, D.; Enghardt, W.; Fiedler, F.; Hueso-González, F.; Pausch, G.; Römer, K.; Rohling, H.; Schöne, S.; Wagner, L.; Kormoll, T.

    2016-06-01

    The finite range of a proton beam in tissue opens new vistas for the delivery of a highly conformal dose distribution in radiotherapy. However, the actual particle range, and therefore the accurate dose deposition, is sensitive to the tissue composition in the proton path. Range uncertainties, resulting from limited knowledge of this tissue composition or positioning errors, are accounted for in the form of safety margins. Thus, the unverified particle range constrains the principle benefit of proton therapy. Detecting prompt γ-rays, a side product of proton-tissue interaction, aims at an on-line and non-invasive monitoring of the particle range, and therefore towards exploiting the potential of proton therapy. Compton imaging of the spatial prompt γ-ray emission is a promising measurement approach. Prompt γ-rays exhibit emission energies of several MeV. Hence, common radioactive sources cannot provide the energy range a prompt γ-ray imaging device must be designed for. In this work a benchmark measurement-setup for the production of a localized, monoenergetic 4.44 MeV γ-ray source is introduced. At the Tandetron accelerator at the HZDR, the proton-capture resonance reaction 15N(p,α γ4.439)12C is utilized. This reaction provides the same nuclear de-excitation (and γ-ray emission) occurrent as an intense prompt γ-ray line in proton therapy. The emission yield is quantitatively described. A two-stage Compton imaging device, dedicated for prompt γ-ray imaging, is tested at the setup exemplarily. Besides successful imaging tests, the detection efficiency of the prototype at 4.44 MeV is derived from the measured data. Combining this efficiency with the emission yield for prompt γ-rays, the number of valid Compton events, induced by γ-rays in the energy region around 4.44 MeV, is estimated for the prototype being implemented in a therapeutic treatment scenario. As a consequence, the detection efficiency turns out to be a key parameter for prompt

  14. A porous proton-relaying metal-organic framework material that accelerates electrochemical hydrogen evolution

    Hod, Idan; Deria, Pravas; Bury, Wojciech; Mondloch, Joseph E.; Kung, Chung-Wei; So, Monica; Sampson, Matthew D.; Peters, Aaron W.; Kubiak, Cliff P.; Farha, Omar K.; Hupp, Joseph T.

    2015-09-01

    The availability of efficient hydrogen evolution reaction (HER) catalysts is of high importance for solar fuel technologies aimed at reducing future carbon emissions. Even though Pt electrodes are excellent HER electrocatalysts, commercialization of large-scale hydrogen production technology requires finding an equally efficient, low-cost, earth-abundant alternative. Here, high porosity, metal-organic framework (MOF) films have been used as scaffolds for the deposition of a Ni-S electrocatalyst. Compared with an MOF-free Ni-S, the resulting hybrid materials exhibit significantly enhanced performance for HER from aqueous acid, decreasing the kinetic overpotential by more than 200 mV at a benchmark current density of 10 mA cm-2. Although the initial aim was to improve electrocatalytic activity by greatly boosting the active area of the Ni-S catalyst, the performance enhancements instead were found to arise primarily from the ability of the proton-conductive MOF to favourably modify the immediate chemical environment of the sulfide-based catalyst.

  15. Design of high power radio frequency radial combiner for proton accelerator.

    Jain, Akhilesh; Sharma, Deepak Kumar; Gupta, Alok Kumar; Hannurkar, P R

    2009-01-01

    A simplified design method has been proposed for systematic design of novel radio frequency (rf) power combiner and divider, incorporating radial slab-line structure, without using isolation resistor and external tuning mechanism. Due to low insertion loss, high power capability, and rigid mechanical configuration, this structure is advantageous for modern solid state rf power source used for feeding rf energy to superconducting accelerating structures. Analysis, based on equivalent circuit and radial transmission line approximation, provides simple design formula for calculating combiner parameters. Based on this method, novel 8-way and 16-way power combiners, with power handling capability of 4 kW, have been designed, as part of high power solid state rf amplifier development. Detailed experiments showed good performance in accordance with theory. PMID:19191467

  16. ActiWiz – optimizing your nuclide inventory at proton accelerators with a computer code

    Vincke, Helmut

    2014-01-01

    When operating an accelerator one always faces unwanted, but inevitable beam losses. These result in activation of adjacent material, which in turn has an obvious impact on safety and handling constraints. One of the key parameters responsible for activation is the chemical composition of the material which often can be optimized in that respect. In order to facilitate this task also for non-expert users the ActiWiz software has been developed at CERN. Based on a large amount of generic FLUKA Monte Carlo simulations the software applies a specifically developed risk assessment model to provide support to decision makers especially during the design phase as well as common operational work in the domain of radiation protection.

  17. Transport of a high brightness proton beam through the Munich tandem accelerator

    Moser, M., E-mail: marcus.moser@unibw.de [Universität der Bundeswehr München, Institut für Angewandte Physik und Messtechnik LRT2, Department für Luft- und Raumfahrttechnik, 85577 Neubiberg (Germany); Greubel, C. [Universität der Bundeswehr München, Institut für Angewandte Physik und Messtechnik LRT2, Department für Luft- und Raumfahrttechnik, 85577 Neubiberg (Germany); Carli, W. [Beschleunigerlabor MLL, 85478 Garching (Germany); Peeper, K.; Reichart, P.; Urban, B.; Vallentin, T. [Universität der Bundeswehr München, Institut für Angewandte Physik und Messtechnik LRT2, Department für Luft- und Raumfahrttechnik, 85577 Neubiberg (Germany); Dollinger, G., E-mail: guenther.dollinger@unibw.de [Universität der Bundeswehr München, Institut für Angewandte Physik und Messtechnik LRT2, Department für Luft- und Raumfahrttechnik, 85577 Neubiberg (Germany)

    2015-04-01

    Basic requirement for ion microprobes with sub-μm beam focus is a high brightness beam to fill the small phase space usually accepted by the ion microprobe with enough ion current for the desired application. We performed beam transport simulations to optimize beam brightness transported through the Munich tandem accelerator. This was done under the constraint of a maximum ion current of 10 μA that is allowed to be injected due to radiation safety regulations and beam power constrains. The main influence of the stripper foil in conjunction with intrinsic astigmatism in the beam transport on beam brightness is discussed. The calculations show possibilities for brightness enhancement by using astigmatism corrections and asymmetric filling of the phase space volume in the x- and y-direction.

  18. Transport of a high brightness proton beam through the Munich tandem accelerator

    Basic requirement for ion microprobes with sub-μm beam focus is a high brightness beam to fill the small phase space usually accepted by the ion microprobe with enough ion current for the desired application. We performed beam transport simulations to optimize beam brightness transported through the Munich tandem accelerator. This was done under the constraint of a maximum ion current of 10 μA that is allowed to be injected due to radiation safety regulations and beam power constrains. The main influence of the stripper foil in conjunction with intrinsic astigmatism in the beam transport on beam brightness is discussed. The calculations show possibilities for brightness enhancement by using astigmatism corrections and asymmetric filling of the phase space volume in the x- and y-direction

  19. Cathodic protection of proton beam piping at Fermi National Accelerator Laboratory, Batavia, Illinois

    Fermilab has some 25,000 (7,600 meters) feet of bare steel high energy particle beam piping ranging in size from 6-inch to 72-inch (150 mm to 1,800 mm). The piping is used to contain high energy particle beams traveling from the accelerator ring to targets. The cathodic protection required a complex design to overcome many shielding problems and to avoid interference with the many other underground structures on the site. Since cathodic protection current traveling through some of the magnet enclosures could affect beam instrumentation, careful attention had to be paid to dielectric isolation. A combination of surface and deep anodes were used, with special concern for environmental protection

  20. The Energy Selection System for the laser-accelerated proton beams at ELI-Beamlines

    Tramontana, A.; Candiano, G.; Carpinelli, M.; Cirrone, G.A.P.; Cuttone, G.; Bijan Jia, S.; Korn, Georg; Licciardello, T.; Maggiore, Mario; Manti, L.; Margarone, Daniele; Pisciotta, P.; Romano, F.; Stancampiano, C.; Schillaci, Francesco; Scuderi, Valentina

    2014-01-01

    Roč. 9, May (2014), s. 1-11. ISSN 1748-0221 R&D Projects: GA MŠk ED1.1.00/02.0061; GA MŠk EE2.3.20.0279; GA MŠk EE.2.3.20.0087 Grant ostatní: ELI Beamlines(XE) CZ.1.05/1.1.00/02.0061; LaserZdroj (OP VK 3)(XE) CZ.1.07/2.3.00/20.0279; OP VK 2 LaserGen(XE) CZ.1.07/2.3.00/20.0087 Institutional support: RVO:68378271 Keywords : instrumentation for hadron therapy * wake-field acceleration (laser-driven, electron-driven) * plasma diagnostics * charged-particle spectroscopy Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 1.399, year: 2014

  1. Proposals and demands for High-Intensity Proton Accelerator Facilities (background and process). Summary of a join project of four sections of AESJ

    Four sections (reactor physics, radiation engineering, accelerator beam science and nuclear data) of Atomic Energy Society of Japan (AESJ) discussed proposals and demands for a High-Intensity Proton Accelerator Facilities. This report summarized the background, the process of discussion, relation among four sections and proposals of themes. Four proposals were offered as follows; 1) construction of device in the neutron beam line for matter and life science experimental facility, 2) utilization of T0 beam line in the nuclear and elementary particles experimental facility, 3) foundation of experimental beam line in the nuclear transmutation experimental facility and 4) demands for reactor physics experimental device in the nuclear transmutation experimental facility. The objects of the mater and life science experimental facility are synthesis of elements and transmutation study of long-lived nuclide using from epithermal to some hundred keV neutron. By the nuclear transmutation experimental facility, the fundamental data of nuclear transmutation physics and engineering on proton and neutron, elementary process and effects of cosmic radioactive ray and research of medical technology of beam are studied by from a few MeV to about 600 MeV neutron or proton beam. ADS target engineering, shielding of accelerator and interaction between high-energy cosmic rays are researched with some GeV neutron, proton and π meson by the nuclear and elementary particle experimental facility. (S.Y.)

  2. The scattering of neutrons in a high energy proton accelerator enclosure and the production of 41Ar and 14C activity

    The neutron field inside high energy and high intensity proton accelerators can produce activation of air. The neutrons backscattered by the concrete walls contribute largely to production of 41Ar and 14C concentration. With this in mind, the back scattering of neutrons by concrete walls and the concentration of 41Ar and 14C is studied in detail in a proton accelerator facility for proton energies from 100 - 500 MeV using FLUKA Monte Carlo code. The estimated neutron albedo/backscatter factors (integrated over 2π solid angle) by the 100 MeV proton beam falling on the copper target is estimated along the forward, backward and lateral directions are more than 50%. The build-up of 41Ar and 14C concentration for a 24 hr proton beam irradiation and for the next 24 hours after the beam shut down are estimated. Although the 14C induced activity is very small as compared to the 41Ar activity, but significant due to the longer half life. The absence of concrete roof of the facility reduces the 41Ar concentration almost by a factor of 2. (author)

  3. Potential and energy of the monoenergetic electrons in an alternative ellipsoid bubble model

    The electron acceleration in the bubble regime is considered during the intense laser-plasma interaction. The presented ellipsoid cavity model is more consistent than the previous spherical model, and it explains the monoenergetic electron trajectory more accurately. At the relativistic region, the maximum energy of electrons in the ellipsoid model is about 24% more than the spherical model, and this is confirmed by PIC and the measured experimental results reported here. The electron energy spectrum is also calculated, and it is found that the energy distribution ratio of electrons ΔE/E for the ellipsoid model in the here reported condition is about 11% which is less than the one third that of the spherical model. It is in good agreement with the experimentally measured value in the same condition. In this regime, the parameters of the quasi-monoenergetic electrons output beam can be described more appropriately. In this work, 10 TW from 16.6 TW, 500 mJ, and 30-fs laser pulse was focused on the best matched point above a 2-mm-diameter pulsed He gas jet to obtain a stable ellipsoid bubble. Laser intensity of 1.42x1019 W cm-2 corresponding to a normalized vector potential of a0=2.6 focused in a 100-μm2 spot at the focal point and 1 mm above the edge of the gas jet with an electron density of 1x1019 cm-3 accelerates electrons to the relativistic velocities. The obtained monoenergetic electron energy spectrum is properly explained by the ellipsoid model introduced here.

  4. Development of a monoenergetic neutron beam (Theoretical aspects, experimental developments and applications); Desarrollo de un haz de neutrones monoenergeticos (Aspectos teoricos, desarrollos experimentales y aplicaciones)

    Varela G, A

    2003-07-01

    By the use of a neutron time of flight system at the Tandem Accelerator of the National Nuclear Research Institute; with neutrons provided by means of the {sup 2} H(d, n) {sup 3} He we intend to use the associated particle technique in order to have monoenergetic neutrons. This neutron beam will be used both in basic and applied research. (Author)

  5. Electron and proton acceleration during the first ground level enhancement of solar cycle 24

    Li, C; Sun, L P; Miroshnichenko, L I

    2013-01-01

    High-energy particles were recorded by near-Earth spacecraft and ground-based neutron monitors (NMs) on 2012 May 17. This event was the first ground level enhancement (GLE) of solar cycle 24. In this study, we try to identify the acceleration source(s) of solar energetic particles by combining in situ particle measurements from the WIND/3DP, GOES 13, and solar cosmic rays registered by several NMs, as well as remote-sensing solar observations from SDO/AIA, SOHO/LASCO, and RHESSI. We derive the interplanetary magnetic field (IMF) path length (1.25 +/- 0.05 AU) and solar particle release time (01:29 +/- 00:01 UT) of the first arriving electrons by using their velocity dispersion and taking into account contamination effects. We found that the electron impulsive injection phase, indicated by the dramatic change in the spectral index, is consistent with flare non-thermal emission and type III radio bursts. Based on the potential field source surface concept, modeling of the open-field lines rooted in the active r...

  6. OVERVIEW OF MONO-ENERGETIC GAMMA-RAY SOURCES & APPLICATIONS

    Hartemann, F V; Albert, F; Anderson, G G; Anderson, S G; Bayramian, A J; Betts, S M; Chu, T S; Cross, R R; Ebbers, C A; Fisher, S E; Gibson, D J; Ladran, A S; Marsh, R A; Messerly, M J; O' Neill, K L; Semenov, V A; Shverdin, M Y; Siders, C W; McNabb, D P; Barty, C P; Vlieks, A E; Jongewaard, E N; Tantawi, S G; Raubenheimer, T O

    2010-05-18

    Recent progress in accelerator physics and laser technology have enabled the development of a new class of tunable gamma-ray light sources based on Compton scattering between a high-brightness, relativistic electron beam and a high intensity laser pulse produced via chirped-pulse amplification (CPA). A precision, tunable Mono-Energetic Gamma-ray (MEGa-ray) source driven by a compact, high-gradient X-band linac is currently under development and construction at LLNL. High-brightness, relativistic electron bunches produced by an X-band linac designed in collaboration with SLAC NAL will interact with a Joule-class, 10 ps, diode-pumped CPA laser pulse to generate tunable {gamma}-rays in the 0.5-2.5 MeV photon energy range via Compton scattering. This MEGa-ray source will be used to excite nuclear resonance fluorescence in various isotopes. Applications include homeland security, stockpile science and surveillance, nuclear fuel assay, and waste imaging and assay. The source design, key parameters, and current status are presented, along with important applications, including nuclear resonance fluorescence. In conclusion, we have optimized the design of a high brightness Compton scattering gamma-ray source, specifically designed for NRF applications. Two different parameters sets have been considered: one where the number of photons scattered in a single shot reaches approximately 7.5 x 10{sup 8}, with a focal spot size around 8 {micro}m; in the second set, the spectral brightness is optimized by using a 20 {micro}m spot size, with 0.2% relative bandwidth.

  7. Development of the high quality electron source using the staged laser wakefield acceleration

    Stable and monoenergetic electron beams are necessary for ultrafast electron imaging with using laser wakefield acceleration. Quasi-monoenergetic electron beams, which have electron energy of ∼MeV, are generated by using staged laser wakefield acceleration driven by two coaxial laser pulses. Furthermore, electron energy spectra changed by controlling the injection timing of two pulses. (author)

  8. Study of a power coupler for superconducting RF cavities used in high intensity proton accelerator

    The coaxial power coupler needed for superconducting RF cavities used in the high energy section of the EUROTRANS driver should transmit 150 kW (CW operation) RF power to the protons beam. The calculated RF and dielectric losses in the power coupler (inner and outer conductor, RF window) are relatively high. Consequently, it is necessary to design very carefully the cooling circuits in order to remove the generated heat and to ensure stable and reliable operating conditions for the coupler cavity system. After calculating all type of losses in the power coupler, we have designed and validated the inner conductor cooling circuit using numerical simulations results. We have also designed and optimized the outer conductor cooling circuit by establishing its hydraulic and thermal characteristics. Next, an experiment dedicated to study the thermal interaction between the power coupler and the cavity was successfully performed at CRYOHLAB test facility. The critical heat load Qc for which a strong degradation of the cavity RF performance was measured leading to Qc in the range 3 W-5 W. The measured heat load will be considered as an upper limit of the residual heat flux at the outer conductor cold extremity. A dedicated test facility was developed and successfully operated for measuring the performance of the outer conductor heat exchanger using supercritical helium as coolant. The test cell used reproduces the realistic thermal boundary conditions of the power coupler mounted on the cavity in the cryo-module. The first experimental results have confirmed the excellent performance of the tested heat exchanger. The maximum residual heat flux measured was 60 mW for a 127 W thermal load. As the RF losses in the coupler are proportional to the incident RF power, we can deduce that the outer conductor heat exchanger performance is continued up to 800 kW RF power. Heat exchanger thermal conductance has been identified using a 2D axisymmetric thermal model by comparing

  9. 3-dimensional shielding design for a spallation neutron source facility in the high-intensity proton accelerator project

    Tamura, Masaya; Maekawa, Fujio [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2003-03-01

    Evaluation of shielding performance for a 1 MW spallation neutron source facility in the Materials and Life Science Facility being constructed in the High-Intensity Proton Accelerator Project (J-PARC) is important from a viewpoint of radiation safety and optimization of arrangement of components. This report describes evaluated results for the shielding performance with modeling three-dimensionally whole structural components including gaps between them in detail. A Monte Carlo calculation method with MCNPX2.2.6 code and LA-150 library was adopted. Streaming and void effects, optimization of shield for cost reduction and optimization of arrangement of structures such as shutters were investigated. The streaming effects were investigated quantitatively by changing the detailed structure of components and gap widths built into the calculation model. Horizontal required shield thicknesses were ranged from about 6.5 m to 7.5 m as a function of neutron beam line angles. A shutter mechanism for a horizontal neutron reflectometer that was directed downward was devised, and it was shown that the shielding performance of the shutter was acceptable. An optimal biological shield configuration was finally determined according to the calculated results. (author)

  10. Nonlinear Alfvén waves, discontinuities, proton perpendicular acceleration, and magnetic holes/decreases in interplanetary space and the magnetosphere: intermediate shocks?

    B. T. Tsurutani

    2005-01-01

    Full Text Available Alfvén waves, discontinuities, proton perpendicular acceleration and magnetic decreases (MDs in interplanetary space are shown to be interrelated. Discontinuities are the phase-steepened edges of Alfvén waves. Magnetic decreases are caused by a diamagnetic effect from perpendicularly accelerated (to the magnetic field protons. The ion acceleration is associated with the dissipation of phase-steepened Alfvén waves, presumably through the Ponderomotive Force. Proton perpendicular heating, through instabilities, lead to the generation of both proton cyclotron waves and mirror mode structures. Electromagnetic and electrostatic electron waves are detected as well. The Alfvén waves are thus found to be both dispersive and dissipative, conditions indicting that they may be intermediate shocks. The resultant 'turbulence' created by the Alfvén wave dissipation is quite complex. There are both propagating (waves and nonpropagating (mirror mode structures and MDs byproducts. Arguments are presented to indicate that similar processes associated with Alfvén waves are occurring in the magnetosphere. In the magnetosphere, the 'turbulence' is even further complicated by the damping of obliquely propagating proton cyclotron waves and the formation of electron holes, a form of solitary waves. Interplanetary Alfvén waves are shown to rapidly phase-steepen at a distance of 1AU from the Sun. A steepening rate of ~35 times per wavelength is indicated by Cluster-ACE measurements. Interplanetary (reverse shock compression of Alfvén waves is noted to cause the rapid formation of MDs on the sunward side of corotating interaction regions (CIRs. Although much has been learned about the Alfvén wave phase-steepening processfrom space plasma observations, many facets are still not understood. Several of these topics are discussed for the interested researcher. Computer simulations and theoretical developments will be particularly useful in making further progress in

  11. Implementation of a mass spectrometer operating in the external beam of a proton accelerator. Application to the study of short-lived isotopes produced by uranium fission

    Implementation and use of a mass spectrometer operating directly in the external beam of a proton accelerator has proven to be a very fruitful way to study short-lived nuclides in both areas covered: measuring production cross sections and nuclear spectroscopy. The results obtained in this work are only a first step and can be developed in different directions in which the study was discussed and an extension to elements other than alkali may be considered. (author)

  12. The precise energy spectra measurement of laser-accelerated MeV/n-class high-Z ions and protons using CR-39 detectors

    Kanasaki, M.; Jinno, S.; Sakaki, H.; Kondo, K.; Oda, K.; Yamauchi, T.; Fukuda, Y.

    2016-03-01

    The diagnosis method, using a combination of a permanent magnet and CR-39 track detectors, has been developed to separately measure the energy spectrum of the laser-accelerated MeV/n-class high-Z ions and that of MeV protons. The main role of magnet is separating between high-Z ions and protons, not for the usual energy spectrometer, while ion energy was precisely determined from careful analysis of the etch pit shapes and the etch pit growth behaviors in the CR-39. The method was applied to laser-driven ion acceleration experiments using CO2 clusters embedded in a background H2 gas. Ion energy spectra with uncertainty ΔE  =  0.1 MeV n‑1 for protons and carbon/oxygen ions were simultaneously obtained separately. The maximum energies of carbon/oxygen ions and protons were determined as 1.1  ±  0.1 MeV and 1.6  ±  0.1 MeV n‑1, respectively. The sharp decrease around 1 MeV n‑1 observed in the energy spectrum of carbon/oxygen ions could be due to a trace of the ambipolar hydrodynamic expansion of CO2 clusters. Thanks to the combination of the magnet and the CR-39, the method is robust against electromagnetic pulse (EMP).

  13. Suppression of multiple ion bunches and generation of monoenergetic ion beams in laser foil-plasma

    Zhang Shan; Xie Bai-Song; Hong Xue-Ren; Wu Hai-Cheng; Aimierding Aimidula; Zhao Xue-Yan; Liu Ming-Ping

    2011-01-01

    In one-dimensional particle-in-cell simulations, this paper shows that the formation of multiple ion bunches is disadvantageous to the generation of monoenergetic ion beams and can be suppressed by choosing an optimum target thickness in the radiation pressure acceleration mechanism by a circularly polarised laser pulse. As the laser pulse becomes intense, the optimum target thickness obtained by a non-relativistic treatment is no longer adequate. Considering the relativistic Doppler-shifted pressure, it proposes a relativistic formulation to determine the optimum target thickness. The theoretical predictions agree with the simulation results well. The model is also valid for two-dimensional cases. The accelerated ion beams can be compelled to be more stable by choosing the optimum target thickness when they exhibit some unstable behaviours.

  14. Measurement of Neutron Yield Varing With Proton Energy in keV Region

    LI; Wei; CHEN; Jun; LI; Chun-juan; LIU; Yi-na; WANG; Zhi-qiang; LUO; Hai-long; ZHANG; Wei-hua

    2012-01-01

    <正>Because of the reaction of 45Sc(p, n)45Ti exhibits a series of resonance peaks, and the resonance width is very narrow. For producing monoenergetic neutron the thin target is used and the proton energy

  15. Foundation of an analytical proton beamlet model for inclusion in a general proton dose calculation system

    Ulmer, W

    2010-01-01

    We have developed a model for proton depth dose and lateral distributions based on Monte Carlo calculations (GEANT4) and an integration procedure of the Bethe-Bloch equation (BBE). The model accounts for the transport of primary and secondary protons, the creation of recoil protons and heavy recoil nuclei as well as lateral scattering of these contributions. The buildup, which is experimentally observed in higher energy depth dose curves, is modeled by inclusion of two different origins: 1. Secondary reaction protons with a contribution of ca. 65 % of the buildup (for monoenergetic protons). 2. Landau tails as well as Gaussian type of fluctuations for range straggling effects. All parameters of the model for initially monoenergetic proton beams have been obtained from Monte Carlo calculations or checked by them. Furthermore, there are a few parameters, which can be obtained by fitting the model to measured depth dose curves in order to describe individual characteristics of the beamline - the most important b...

  16. Dose coefficients for radionuclides produced in high energy proton accelerator facilities. Coefficients for radionuclides not listed in ICRP publications

    Effective dose coefficients, the committed effective dose per unit intake, by inhalation and ingestion have been calculated for 304 nuclides, including (1) 230 nuclides with half-lives ≥ 10 min and their daughters that are not listed in ICRP Publications and (2) 74 nuclides with half-lives < 10 min that are produced in a spallation target. Effective dose coefficients for inhalation of soluble or reactive gases have been calculated for 21 nuclides, and effective dose rates for inert gases have been calculated for 9 nuclides. Dose calculation was carried out using a general-purpose nuclear decay database DECDC developed at JAERI and a decay data library newly compiled from the ENSDF for the nuclides abundantly produced in a spallation target. The dose coefficients were calculated with the computer code DOCAP based on the respiratory tract model and biokinetic model of ICRP. The effective dose rates were calculated by considering both external irradiation from the surrounding cloud and irradiation of the lungs from the gas within them. The calculated results are presented as tables, which are the same forms as those in ICRP Publs. 68 and 72. The complete listings of the dose coefficients are arranged on a CD-ROM, DoseCD, as indexed tables for inhalation of 10 particle sizes, ingestion and injection into blood for workers and members of the public. The dose coefficients calculated in the present study as well as those published in a series of ICRP Publications will be sufficient to calculate internal doses for a variety of radionuclides produced in high energy proton accelerator facilities. (author)

  17. Proton magnetic resonance spectroscopy reveals neuroprotection by oral minocycline in a nonhuman primate model of accelerated NeuroAIDS.

    Eva-Maria Ratai

    Full Text Available BACKGROUND: Despite the advent of highly active anti-retroviral therapy (HAART, HIV-associated neurocognitive disorders continue to be a significant problem. In efforts to understand and alleviate neurocognitive deficits associated with HIV, we used an accelerated simian immunodeficiency virus (SIV macaque model of NeuroAIDS to test whether minocycline is neuroprotective against lentiviral-induced neuronal injury. METHODOLOGY/PRINCIPAL FINDINGS: Eleven rhesus macaques were infected with SIV, depleted of CD8+ lymphocytes, and studied until eight weeks post inoculation (wpi. Seven animals received daily minocycline orally beginning at 4 wpi. Neuronal integrity was monitored in vivo by proton magnetic resonance spectroscopy and post-mortem by immunohistochemistry for synaptophysin (SYN, microtubule-associated protein 2 (MAP2, and neuronal counts. Astrogliosis and microglial activation were quantified by measuring glial fibrillary acidic protein (GFAP and ionized calcium binding adaptor molecule 1 (IBA-1, respectively. SIV infection followed by CD8+ cell depletion induced a progressive decline in neuronal integrity evidenced by declining N-acetylaspartate/creatine (NAA/Cr, which was arrested with minocycline treatment. The recovery of this ratio was due to increases in NAA, indicating neuronal recovery, and decreases in Cr, likely reflecting downregulation of glial cell activation. SYN, MAP2, and neuronal counts were found to be higher in minocycline-treated animals compared to untreated animals while GFAP and IBA-1 expression were decreased compared to controls. CSF and plasma viral loads were lower in MN-treated animals. CONCLUSIONS/SIGNIFICANCE: In conclusion, oral minocycline alleviates neuronal damage induced by the AIDS virus.

  18. Novel recoil nuclei detectors to qualify the AMANDE facility as a Standard for mono-energetic neutron fields

    Allaoua, A.; Guillaudin, O.; Higueret, S.; Husson, D.; Lebreton, L.; Mayet, F.; Nourreddine, M.; Santos, D.; Trichet, A.

    2008-01-01

    The AMANDE facility at IRSN-Cadarache produces mono-energetic neutron fields from 2 keV to 20 MeV with metrological quality. To be considered as a standard facility, characteristics of neutron field i.e fluence distribution must be well known by a device using absolute measurements. The development of new detector systems allowing a direct measurement of neutron energy and fluence has started in 2006. Using the proton recoil telescope principle with the goal of increase the efficiency, two sy...

  19. Study and development of detectors dedicated to reference measurements of monoenergetic neutron fields

    One of the main activities of the LMDN laboratory (Laboratory for neutron metrology and dosimetry ) is the development of a technical set of facilities producing neutron yields, in form of mono-energetic or broad yields. The provision of these yields allows the calibration and the development of instruments of measurements devoted to neutrons. The AMANDE facility produces fields of monoenergetic neutrons between 2 keV and 20 MeV with a metrological quality. The facility requires determining in an absolute way, characteristics of energy and fluence of the neutron fields. The development of an instrument allowing a direct measurement of neutron energy and fluence was planned for recognition of this facility as reference. The constituent elements of the system were studied in order to increase the efficiency of the detector in comparison with that of some existing proton recoil telescope. To cover the wide energy range of the produced neutrons, two solutions are investigated. A recoil proton telescope using CMOS sensor (RPT-CMOS) is studied for measurements at the high energies; it is developed in collaboration with the IPHC RAMSES laboratory of Strasbourg. The gaseous μ-time projection chamber for the neutron detection (μ-TPC neutron) will be dedicated to the lowest energies. The study of this device for application at the AMANDE facility is performed in collaboration with the LPSC Grenoble. Simulations of systems and comparisons with the literature were performed with the transport Monte Carlo code MCNPX, to choose the components and the geometry, and thereby assess and optimize efficiency and detection limits of these devices. These computation results are presented. Measurement campaigns were realised during last three years with the first prototypes. Thanks to these, a comparison between experimental results and calculations was enabled, to validate the modelling and to estimate performances expected from these systems. These results are also presented. (author)

  20. SU-E-T-533: LET Dependence Correction of Radiochromic Films for Application in Low Energy Proton Irradiation

    Purpose: Many cell irradiation experiments with low-energy laser-driven ions rely on radiochromic films (RCF), because of their dose-rate independent response and superior spatial resolution. RCF dosimetry in low-energy ion beams requires a correction of the LET dependent film response. The relative efficiency (RE), the ratio of photon to proton dose that yields the same film darkening, is a measure for the film’s LET dependence. A direct way of RE determination is RCF irradiation with low-energy mono-energetic protons and hence, well-defined LET. However, RE is usually determined using high energy proton depth dose measurements where RE corrections require knowledge of the average LET in each depth, which can be either track (tLET) or dose (dLET) averaged. The appropriate LET concept has to be applied to allow a proper film response correction. Methods: Radiochromic EBT2 and EBT3 films were irradiated in clinical photon and proton beams. For each depth of the 200 MeV proton depth dose curve, tLET and dLET were calculated by special user routines from the Monte Carlo code FLUKA. Additional irradiations with mono-energetic low energy protons (4–20 MeV) serve as reference for the RE determination. Results: The difference of dLET and tLET increases with depth, with the dLET being almost twice as large as the tLET for the maximum depth. The comparison with mono-energetic measurements shows a good agreement of the RE for the dLET concept, while a considerably steeper drop in RE is observed when applying the tLET. Conclusion: RCF can be used as reference dosimeter for biomedical experiments with low-energy proton beams if appropriate LET corrections are applied. When using depth dose measurements from clinical proton accelerators for these corrections, the concept of dLET has to be applied. Acknowledgement: This work was funded by the DFG Cluster of Excellence ‘Munich-Centre for Advanced Photonics’ (MAP). This work was funded by the DFG Cluster of Excellence