Keyword: acceleration
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MOPEA018 Feasibility Study of Heavy Ion Storage and Acceleration in the HESR with Stochastic Cooling and Internal Targets target, cavity, ion, simulation 106
 
  • H. Stockhorst, R. Maier, D. Prasuhn, R. Stassen
    FZJ, Jülich, Germany
  • T. Katayama
    GSI, Darmstadt, Germany
  
  Stochastic cooling of heavy ions is investigated under the constraint of the present hardware design of the cooling system and RF cavities as well as the given magnet design as foreseen for anti-proton cooling in the HESR of the FAIR facility. A bare uranium beam is injected from the collector ring CR into the HESR at 740 MeV/u. The beam preparation for an internal target experiment with cooling is outlined. The acceleration of the ion beam to 2 GeV/u is studied under the basic condition of the available cavity voltages and the maximum magnetic field ramp rate in the HESR. The cooling simulations include the beam-target interaction due to a Hydrogen and Xenon target. Diffusion due to Schottky and thermal noise as well as intra beam scattering is accounted for. Due to the higher charge states of the ions Schottky particle noise power becomes an important issue. The analysis considers the electronic power limitation to 500 W in case of momentum cooling. Fast Filter cooling is only available if the revolution harmonics do not overlap in the cooling bandwidth. Since overlap occurs for lower energies the application of the Time-Of-Flight (TOF) momentum cooling method is discussed.  
 
MOPEA038 Coherent Wiggler Radiation of Picosecond CW Electron Beam Produced by DC-SRF Photoinjector wiggler, radiation, electron, SRF 160
 
  • S. Huang, J.E. Chen, S. Chen, K.X. Liu, S.W. Quan, Zh.W. Wang, X.D. Wen, F. Zhu
    PKU, Beijing, People's Republic of China
  
  The DC-SRF photoinjector at Peking University is capable of providing CW electron beam with the energy of 3-5 MeV. The beam has high repetition rate, picosecond bunch length and high quality, which can be used to produce high repetition rate THz wave by wiggler radiation. Through off-crest acceleration, electron beam from the injector may be bunched, which will lead to coherent enhancement of the radiation power. With current setup of the DC-SRF injector and a 10-period wiggler, THz radiation power of 10s mW to a few watts can be achieved within the wavelength range of 200 μm to 500 μm. In this work, we will present the calculation results about THz radiation produced by the electron beam from DC-SRF photoinjector. The preparation for the experiments will be also described.  
 
MOPFI028 Physical Design Progress of an 800 MeV High Power Proton Driver extraction, cyclotron, space-charge, injection 342
 
  • J.J. Yang, Shizhong. An, M. Li, T.J. Zhang, J.Q. Zhong
    CIAE, Beijing, People's Republic of China
  
  We presented the conceptual design of an 800 MeV high power proton ring cyclotron in the paper[1] . A more detailed physical design was carried out since then. The most challenging issues regarding the high power operation, including the space charge effects and beam loss during the extraction, are quantitatively studied by using state-of-the-art high performance computation technique. On that basis the fundamental structure of the cyclotron is adjusted and optimized so as to meet the requirements of MW-class operation. Reference: [1] T. Zhang, J. Yang, M. Li, et. al., Conceptual design of an 800 MeV high power proton driver, Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms 269(24) (2011) 2964-2967  
 
MOPFI038 Generation and Measurement of Sub-picosecond Electron Bunch in Photocathode RF Gun laser, electron, radiation, emittance 372
 
  • W.W. Li, Z.G. He, R. Huang, Q.K. Jia, G. Zhou
    USTC/NSRL, Hefei, Anhui, People's Republic of China
  
  The generation of subpicosecond electron bunch in the photocathode rf gun was considered and simulated by improving the acceleration gradient of the gun, suitably tuning the charge of the electron bunch and the acceleration phase. To measure the length of the electron bunch, the design of a nondestructive bunch length measurement technology was also presented in this paper.  
 
MOPFI041 Study of Beam Longitudinal Motion for SSC extraction, simulation, injection, cyclotron 378
 
  • X.N. Li, Y.J. Yuan
    IMP, Lanzhou, People's Republic of China
  
  The injection, acceleration and extraction of SSC（Separate Sector Cyclotron） is analyzed and simulated to get the longitudinal acceptance, using the typical ion 238U36+ with energy 9.7MeV/u. In order to study the actual longitudinal acceptance of SSC, the isochronous magnetic field model in coincidence with the real one is established by Kr-Kb and Lagrange methods based on the actual measurement. Under the isochronous magnetic field, the longitudinal acceptance at the injection, acceleration and extraction is calculated. From the simulation results the transmission efficiency is very low in SSC because of the large phase width of the beam from the injector SFC (Sector Focus Cyclotron). In the machine commissioning, the phase width of the beam line from SFC to SSC is measured by the phase probe, the results show that the actual phase width is larger than the acceptance of SSC.  
 
MOPFI078 The Possibility of Generation of High Energy Electron Beam at the SNS Facility electron, laser, linac, solenoid 458
 
  • T.V. Gorlov, A.V. Aleksandrov, V.V. Danilov
    ORNL, Oak Ridge, Tennessee, USA
  
  Funding: ORNL/SNS is managed by UT-Battelle, LLC, for the U.S. Department of Energy under contract DE-AC05-00OR22725
The linac of the SNS accelerator facility can be used to produce an electron beam with 300-400 MeV energy. At present there are a few predesigned experiments with electron beam that can be alternatively carried out at the SNS. However, the SNS linac is designed and optimized for acceleration of H− , which brings some problems when considering direct acceleration of electrons. Alternative machine setup for electron acceleration and transport are discussed. Here, we present a study of the optimal electron beam parameters that can be achieved without any significant changes of the SNS accelerator. 		 
 
MOPME006 The New Orbit Correction System at ELSA polarization, electron, closed-orbit, extraction 479
 
  • J.-P. Thiry, A. Balling, A. Dieckmann, F. Frommberger, W. Hillert
    ELSA, Bonn, Germany
  
  ELSA is a fast ramping stretcher ring currently supplying polarized electrons with energies up to 2.4 GeV. To preserve the degree of polarization, the vertical orbit needs to be continuously corrected during beam acceleration. The acceleration is usually performed within 300 ms, with a maximum ramping speed of 6 GeV/s. We aim to achieve a vertical rms deviation not exceeding 50 μm all along the fast energy ramp. In the near future we plan to accelerate polarized electrons up to 3.2 GeV. Therefore, both the power supplies and the corrector magnets have been currently upgraded: first, new power supplies working with a pulsed transistor H-Bridge were developed and successfully installed. Additionally, the existing vertical corrector magnets will now be replaced by newly developed ones. In our contribution, we will present the new correction hardware supplemented by the beam position monitors and their readout electronics.  
 
MOPME021 Ionization Profile Monitor (IPM) of J-PARC 3-GeV RCS electron, ion, injection, vacuum 515
 
  • H. Harada, K. Yamamoto
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
  • S. Kato
    Tohoku University, Graduate School of Science, Sendai, Japan
  
  Ionization profile monitors (IPM) were installed in the 3-GeV RCS ring of J-PARC and used to observe the beam-profile for the transverse plane in beam commissioning. These electrodes and MCPs of IPMs were upgraded in 2012 summer shutdown in order to improve the external electric field for leading the electrons and ions to MCPs. This presentation will be described the results of observed beam profile in beam commissioning and be discussed the new issues for the ion and electron collection mode.  
 
MOPWA038 Flashbox Compact Beam Spectrometer and its Application to the High-gradient Acceleration Study electron, ion, dipole, accelerating-gradient 753
 
  • A. Dubrovskiy, F. Tecker
    CERN, Geneva, Switzerland
  • M. Jacewicz, R.J.M.Y. Ruber, V.G. Ziemann
    Uppsala University, Uppsala, Sweden
  
  A Flashbox compact spectrometer has been developed for the Two-beam Test Stand (TBTS), which is a part of the CLIC test facility CTF3 at CERN. It is used to study limitations of high-gradient acceleration in X-band structures being prototyped in the TBTS. The Flashbox is built around the beam tube such that an electron beam can pass to be accelerated in the X-band structure while charged particles emitted from the accelerating structure can be intercepted on the spectrometer consisting of detector plates aligned along the beam axis in combination with magnetic and electric fields. The Flashbox has made it possible to identify electrons and ions emitted by the accelerating structure during RF breakdown. We describe the Flashbox and first results.  
 
MOPWA085 Spin Dynamics Simulations and Horizontal Intrinsic Resonance Studies in the AGS using the Zgoubi Code polarization, simulation, resonance, extraction 870
 
  • Y. Dutheil, L. A. Ahrens, H. Huang, F. Méot, V.H. Ranjbar, T. Roser, V. Schoefer, N. Tsoupas
    BNL, Upton, Long Island, New York, USA
  
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
A critical point for the polarized proton program of the RHIC is the polarization transmission through the AGS acceleration cycle. Recent developments in the Zgoubi model of the AGS allow multi-particle tracking with realistic beam and machine conditions on a large scale computing system. This gives the opportunity to simulate the influence of many beam and machine conditions on the polarization transmission and leads to a better understanding of the depolarization processes, for instance the horizontal intrinsic resonances, that cannot be accurately explored by the conventional simulation approaches or by the experiments with beam. This paper introduces the developments realized on the Zgoubi code to run these simulations and shows some of the latest results. 		 
 
MOPWO018 Cellular Automaton Simulating the Motion of the Charged Particles Beam controls, simulation, lattice 918
 
  • S.N. Andrianov, N.V. Kulabukhova
    St. Petersburg State University, St. Petersburg, Russia
  • V. Ryabusha
    Saint Petersburg State University, Saint Petersburg, Russia
  
  In this research we formulate and formalize the rules for the cellular automaton that emulates the motion of the charged particles beam under the effect of Coulomb force for one-, two- and three-dimensional cases. In this research we also describe the main principles of the realization of this approach in a paralleled cluster environment.  
 
MOPWO067 Beam Dynamics Simulations with a GPU-accelerated Version of Elegant simulation, collective-effects, storage-ring, controls 1040
 
  • I.V. Pogorelov, K.M. Amyx, J. Balasalle, J.R. King
    Tech-X, Boulder, Colorado, USA
  • M. Borland, R. Soliday
    ANL, Argonne, USA
  
  Funding: Work supported by the US DOE Office of Science, Office of Basic Energy Sciences under grant number DE-SC0004585, and by Tech-X Corporation
Large scale particle tracking and tracking-based lattice optimization simulations can derive significant benefit from efficient implementation of general-purpose particle tracking on GPUs. We present the latest results of our work on accelerating Argonne National Lab's accelerator simulation code ELEGANT*,** using CUDA-enabled GPUs. A sufficiently large number of Elegant beamline elements has been ported to GPUs to allow the GPU-accelerated simulation of realistic test lattices. We will identify some of performance-limiting factors, and briefly discuss optimization techniques for efficient utilization of the device memory space, with an emphasis on register usage. We also present a novel hardware-assisted technique for efficiently calculating a histogram from a large distribution of particle coordinates, and compare this to data-parallel implementations.
* M. Borland, Elegant: A Flexible SDDS-compliant Code for Accelerator Simulation, APS LS-287, September 2000
** Y. Wang, M. Borland, in Proc. of PAC07, THPAN095 (2007)
 		 
 
TUYB103 Status and Plans for the Polarized Hadron Collider at RHIC polarization, proton, resonance, luminosity 1106
 
  • M. Bai, L. A. Ahrens, E.C. Aschenauer, G. Atoian, J. Beebe-Wang, M. Blaskiewicz, J.M. Brennan, K.A. Brown, D. Bruno, R. Connolly, T. D'Ottavio, K.A. Drees, Y. Dutheil, O. Eyser, W. Fischer, C.J. Gardner, J.W. Glenn, X. Gu, M. Harvey, T. Hayes, H. Huang, R.L. Hulsart, A.I. Kirleis, J.S. Laster, C. Liu, Y. Luo, Y. Makdisi, G.J. Marr, A. Marusic, F. Méot, K. Mernick, R.J. Michnoff, M.G. Minty, C. Montag, J. Morris, S. Nemesure, P.H. Pile, A. Poblaguev, V. Ptitsyn, V.H. Ranjbar, G. Robert-Demolaize, T. Roser, W.B. Schmidke, V. Schoefer, F. Severino, T.C. Shrey, D. Smirnov, K.S. Smith, D. Steski, S. Tepikian, D. Trbojevic, N. Tsoupas, J.E. Tuozzolo, G. Wang, M. Wilinski, K. Yip, A. Zaltsman, A. Zelenski, K. Zeno, S.Y. Zhang
    BNL, Upton, Long Island, New York, USA
  
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
As the world’s only high energy polarized proton collider, the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL) has been providing collisions of polarized proton beams at beam energy from 100~GeV to 255~GeV for the past decade to explore the proton spin structure as well as other spin dependent measurements. With the help of two Siberian Snakes per accelerator plus outstanding beam control, beam polarization is preserved up to 100~GeV. About 10% polarization loss has been observed during the acceleration between 100~GeV and 255~GeV due to several strong depolarizing resonances. Moderate polarization loss was also observed during a typical 8 hour physics store. This presentation will overview the achieved performance of RHIC, both polarization as well as luminosity. The plan for providing high energy polarized He-3 collisions at RHIC will also be covered.
This work is on behalf of RHIC team. 		 
slides icon Slides TUYB103 [12.854 MB]  
 
TUOCB101 Argonne Wakefield Accelerator (AWA): A Facility for the Development of High Gradient Accelerating Structures and Wakefield Measurements wakefield, electron, linac, gun 1111
 
  • M.E. Conde, S.P. Antipov, D.S. Doran, W. Gai, C.-J. Jing, R. Konecny, W. Liu, J.G. Power, E.E. Wisniewski, Z.M. Yusof
    ANL, Argonne, USA
  • S.P. Antipov, C.-J. Jing, R. Konecny
    Euclid TechLabs, LLC, Solon, Ohio, USA
  • E.E. Wisniewski, Z.M. Yusof
    Illinois Institute of Technology, Chicago, Illinois, USA
  
  Funding: Work supported by the U.S. Department of Energy under contract No. DE-AC02-06CH11357.
The recently upgraded AWA facility is being commissioned. Operation of the new L-Band RF gun with a Cesium Telluride photocathode will generate long electron bunch trains, with high charge per bunch (up to 100 nC). The six new linac tanks will boost the beam energy to 75 MeV, making it an extremely well suited drive beam to excite wakefields in structures. One of the main goals of the facility is to generate RF pulses with GW power levels, corresponding to accelerating gradients of hundreds of MV/m and energy gains on the order of 100 MeV per structure. A key aspect of the studies and experiments carried out at the AWA facility is the use of relatively short RF pulses (15 – 25 ns), which is believed to mitigate the risk of breakdown and structure damage. 		 
slides icon Slides TUOCB101 [3.416 MB]  
 
TUODB201 Recent Progress on the Development of a High Gradient RF System using High Impedance Magnetic Alloy, FT3L cavity, impedance, synchrotron, controls 1152
 
  • C. Ohmori, K. Hara, K. Hasegawa, M. Toda, M. Yoshii
    KEK, Ibaraki, Japan
  • M. Nomura, A. Schnase, T. Shimada, F. Tamura, M. Yamamoto
    JAEA/J-PARC, Tokai-mura, Japan
  
  An upgrade project of J-PARC MR (Main Ring) includes developments of high gradient RF cavities and magnet power supplies for high repetition rate. A dedicated production system for high impedance magnetic alloy (FT3L) cores was assembled in J-PARC. This setup demonstrated that we can produce material with two times higher muQf product compared to the cores used for present cavities. And, the new results also show up to 20% higher impedance than the 2011 production with the former setup. In this summer, the system will be used for mass production of 200 FT3L cores for J-PARC MR. The cores produced in 2011 are already used for standard machine operation. The operation experience shows that the power loss in the cores was reduced significantly as expected. The scenario describing the upgrade plan of MR and the cavity replacements is reported. By the replacement plan, the total acceleration voltage will be almost doubled, while the number of RF stations remains the same.  
slides icon Slides TUODB201 [5.105 MB]  
 
TUPEA016 Relativistic Theory for Laser-ion Acceleration ion, electron, plasma, laser 1193
 
  • Y.S. Huang, Y.J. Shi, X.Z. Tang, N.Y. Wang
    CIAE, Beijing, People's Republic of China
  
  Funding: The Key Project of Chinese National Programs for Fundamental Research (973 Program) under contract No. 2011CB808104 and the Chinese National Natural Science Foundation under contract No. 11105233.
An analytical relativistic model is proposed to describe the relativistic ion acceleration in the interaction of ultra-intense laser pulses with thin-foil plasmas. It is found that there is a critical value of the ion momentum to make sure that the ions are trapped by the light sail and accelerated in the radiation pressure acceleration (RPA) region. If the initial ion momentum is smaller than the critical value, that is in the classical case of RPA, the potential has a deep well and traps the ions to be accelerated. There is a new ion acceleration region different from RPA, called ultra-relativistic acceleration, if the ion momentum exceeds the critical value. In this case, ions will experience a potential downhill. The dependence of the ion momentum and the self-similar variable at the ion front on the acceleration time has been obtained. The critical conditions of the laser and plasma parameters which identify the two acceleration modes have been achieved. No matter RPA or ultra-relativistic acceleration, the potential difference is a constant, which dedicates the maximum ion energy. 		 
 
TUPEA018 Recent Progress of Laser Plasma Proton Accelerator at Peking University laser, plasma, proton, target 1199
 
  • X.Q. Yan, J.E. Chen, H.Z. Fu, Y.X. Geng, Z.Y. Guo, C. Lin, Y.R. Lu, Y. Shang, Z.X. Yuan, S. Zhao, K. Zhu
    PKU, Beijing, People's Republic of China
  
  Funding: National Natural Science Foundation of China (Grant Nos.10935002, 10835003, 11025523)
Recent a project called Laser plasma Proton Accelerator (LAPA) is approved by MOST in China. A prototype of laser driven proton accelerator (1~15MeV) based on the PSA mechanism and plasma lens is going to be built at Peking University in the next five years. It can be used for the applications such as cancer therapy, plasma imaging and fast ignition for inertial confine fusion. The recent progress of LAPA is reported here. 		 
 
TUPEA019 Proton Acceleration driven by High Energy Density Electrons proton, laser, plasma, electron 1202
 
  • S. Zhao, C. Chao, J.E. Chen, H.Z. Fu, Y.X. Geng, C. Lin, B. Liu, H. Wang, X.Q. Yan
    PKU, Beijing, People's Republic of China
  
  Resonance Electrons Driving Ion Acceleration S. Zhao, C. Lin, X. Q. Yan Institute of Heavy Ion Physics, Peking University Proton acceleration driven by resonance electrons is proposed. Energetic electron beam generated through direct laser acceleration in the near critical dense plasma is dense and directional. When interacting with a thin foil target, resonance electrons can transmit the target and drive periodical electrostatic field at the back surface, therefore protons are more efficiently accelerated in a much longer distance in propagation direction of resonance electrons, compared to the classical target normal sheath acceleration. For a Gaussian laser pulse with pulse duration of 80fs, peak intensity I=1.38*108W/cm2 , the cutoff energy of the output collimated proton beam is 14MeV, enhanced by a factor of 3 or 4. The scaling law predicts hundreds MeV Proton beam can be generated in laser intensity of 1020W/cm2.  
 
TUPEA049 Wakefields of Ultrarelativistic Bunches in Cold Magnetized Plasma wakefield, plasma, radiation, electron 1241
 
  • S.N. Galyamin, A.V. Tyukhtin
    Saint-Petersburg State University, Russia
  
  Funding: Work is supported by Russian Foundation for Basic Research and the Dmitry Zimin "Dynasty" Foundation.
We deal with electromagnetic field of various bunches moving in a cold magnetized plasma along the external magnetic field. The main attention is paid to the case of ultrarelativistic motion. First, for the case of point charge, we obtain the approximate formulas which are valid in the far-field zone and in the vicinity of the charge trajectory. These expressions predict the beating behavior of the far field and the harmonic behavior of the near field. Moreover, the magnitude of the longitudinal components of both electric and magnetic field as well as the transversal electric field possess singularity on the charge trajectory. Second, using formulas for the point charge field as Green function, we develop an effective algorithm for calculation of the bunch wakefield. Plots of wakefields produced by typical bunches are given. Prospects of using the bunch field properties for further development of the plasma wakefield acceleration technique are discussed. 		 
 
TUPEA055 Quasistatic Field Influence on Bunches Focusing by Wakefields in the Plasma-dielectric Waveguide plasma, wakefield, focusing, electron 1256
 
  • R.R. Kniaziev
    KhNU, Kharkov, Ukraine
  • G.V. Sotnikov
    NSC/KIPT, Kharkov, Ukraine
  
  Funding: The research is supported in part by Global Initiatives for Proliferation Prevention (GIPP) program, project ANL-T2-247-UA (STCU Agreement P522).
Acceleration of charged particles by wakefields, excited by a drive electron bunch in the dielectric waveguide, is a perspective method in accelerator physics. We have previously proposed using plasma, filling the drift channel of the dielectric structure (DS), for focusing of the accelerated bunch*. The analytical expressions, obtained for the components of the electromagnetic field, considered only the propagating wake field, and did not consider quasi-static fields of electron bunches that are important for calculating bunches dynamics. In this paper we report the result of numerical calculations of the influence of quasistatic field of bunches on focusing by wake fields in the plasma-dielectric accelerator. We refine analytical expressions for the electromagnetic field by adding components of bunch quasi-static fields and show the correlation of total force and their quasi-static components.
* R.R. Knyazev, G.V. Sotnikov. Focusing of accelerated particles by wakefields of a drive bunch in a plasma-dielectric waveguide. Proc. of IPAC2012, New Orleans, Louisiana, USA, paper weppp003.pdf 		 
 
TUPEA056 Concept of Dielectric Wakefield Accelerator Driven by a Long Sequence of Electron Bunches wakefield, electron, injection, resonance 1259
 
  • I.N. Onishchenko, V. Kiselev, A. Linnik, G.V. Sotnikov
    NSC/KIPT, Kharkov, Ukraine
  
  Funding: This study is supported by Global Initiatives for Proliferation Prevention (GIPP) program, project ANL-T2-247-UA (STCU Agreement P522)
The scheme of a two-beam accelerator type is considered that is based on wakefield excitation in rectangular dielectric resonator by a sequence of electron bunches with the aim to enhance wakefield intensity due to multi-bunch coherent excitation, multi-mode summation, and wakefield accumulation in resonator. The sequence of bunches can be divided into exciting and accelerated parts in any proportion by means at the proper detuning of bunch repetition frequency relative to the frequency of principle eigen mode of the resonator. A train of 6000 electron bunches, each of energy 4.5МeV, charge 0.16nC, duration 60psec, diameter 1.0cm, and angular spread 0.05 mrad is produced with the linear resonant accelerator. Bunch repetition frequency is 2805 MHz and can be varied within 2MHz by changing master oscillator frequency. Bunches are injected into copper rectangular waveguide of cross-section 8.5x18.0cm2 and length 75cm along wide sides of which Teflon plates are placed. The plate thickness is chosen 1.67cm so that the frequency of excited eigen mode coincides with bunch repetition frequency. 		 
 
TUPEA057 Optimization of Rectangular Dielectric Structures for the Planned Wakefield Acceleration Experiments in KIPT wakefield, electron, accelerating-gradient, vacuum 1262
 
  • G.V. Sotnikov, K.V. Galaydych, V. Kiselev, P.I. Markov, I.N. Onishchenko
    NSC/KIPT, Kharkov, Ukraine
  
  Funding: This study is supported by Global Initiatives for Proliferation Prevention (GIPP) program, project ANL-T2-247-UA (STCU Agreement P522).
We, at the Kharkov Institute of Physics and Technology, planned experimental test of the basic principles of the multi-bunch multi-mode wakefield accelerator. For this purpose we carried out a series of calculations of wakefield excitation and dynamics of the drive and witness bunches in rectangular structures with a dielectric substrate. For optimization two rectangular vacuum waveguides of R32 (72.14mm x 34.04mm) and R26 (86.36mm x 43.18mm) which were filled with the dielectric covering two any opposite metal walls of a waveguide were chosen. As possible dielectric Alumina, Cordierite, or Teflon were tested. It was supposed that the structure will be energized by sequence of electron bunches (bunch repetition frequency is 2.805 GHz), having energy of 4.5 MeV. As the candidate for operating mode LSM-wave or LSE-wave, with frequency to equal the bunch repetition frequency or its doubled frequency were tested. The gradient of an accelerating field, small transverse deflection (or divergence) of drive and witness bunches were the main criteria of optimization. As a result of optimization we propose some dielectric structures for future wakefield experiments in KIPT. 		 
 
TUPEA064 A Proposed Plasma Accelerator Research Station at CLARA Facility plasma, electron, wakefield, simulation 1280
 
  • G.X. Xia, K. Hanahoe
    UMAN, Manchester, United Kingdom
  • D. Angal-Kalinin, J.A. Clarke, J.K. Jones, P.H. Williams
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
  • J.D.A. Smith
    TXUK, Warrington, United Kingdom
  
  We propose a Plasma Accelerator Research Station (PARS) based at proposed FEL test facility Compact Linear Accelerator for Research and Applications (CLARA) at Daresbury lab. The idea is to use the relativistic electron beam from CLARA, to investigate some key issues in electron beam transport and in the electron beam driven plasma wakefield acceleration, e.g. the two bunch acceleration for CLARA beam energy doubling, high transformer ratio, long bunch self-modulation and the related beam instabilities. This paper discusses the feasibility studies of electron beam parameters to meet the requirements for beam driven wakefield acceleration and the possible experiments which can be conducted at PARS beam line.  
 
TUPEA065 Design of a Photonic Crystal Accelerator for Basic Radiation Biology laser, vacuum, electron, simulation 1283
 
  • A. Aimidula, C.P. Welsch
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
  • A. Aimidula, C.P. Welsch
    The University of Liverpool, Liverpool, United Kingdom
  • K. Koyama, Y. Matsumura
    University of Tokyo, Tokyo, Japan
  • T. Natsui, M.Y. Yoshida
    KEK, Ibaraki, Japan
  • M. Uesaka
    The University of Tokyo, Nuclear Professional School, Ibaraki-ken, Japan
  • G.X. Xia
    UMAN, Manchester, United Kingdom
  
  Funding: This work is supported by the EU under Grant Agreement 289485, the STFC Cockcroft Institute Core Grant No. ST/G008248/1 and KAKENHI, Grant-in-Aid for Scientific Research (C) 24510120.
The application of photonic crystals to realize an on-chip electron beam source for fundamental radiation biology is highly interesting for a number of applications. The unique combination of nanometer beam size and attosecond-short pulses has a very promising potential for use in microscopic and ultra-fast analyses of damage and repair of radiation-irradiated DNA and chromosomes. Simulations studies indicate an output electron beam energy, beam intensity and device size of the order of MeVs, fCs and a few cm, respectively. In this contribution, first results from numerical studies into the design of such compact accelerator structure are presented. The dimensions of a novel dual grating-based acceleration structure are shown together with the estimated laser parameters. Finally, a system consisting of an electron injector and multi-stage accelerating structures is proposed, which corresponds to a miniaturized optical linear accelerator. 		 
 
TUPEA071 THz Bench Tests of a Slab-symmetric Dielectric Waveguide laser, simulation, wakefield, emittance 1292
 
  • F. Lemery, H. Panuganti, P. Piot
    Northern Illinois University, DeKalb, Illinois, USA
  • D. Mihalcea, P. Piot
    Fermilab, Batavia, USA
  • P. Stoltz
    Tech-X, Boulder, Colorado, USA
  
  Funding: This work is supported by DTRA contract HDTRA1-10-1-0051 and by the U.S. DOE contracts DE-FG02-08ER41532 and DE-AC02-07CH11359.
Dielectric-lined waveguides (DLW) are becoming more popular for beam driven acceleration applications. An experiment to demonstrate beam-driven acceleration using a slab-symmetric dielectric-lined waveguide driven by a flat beam is in preparation at the Advanced Superconducting Test Accelerator (ASTA) at Fermilab. In this paper we characterize the structure using a THz pulse obtained from optical rectification using an amplified laser pulse. After propagation through the DLW structure, the THz pulse is analyzed using a Michelson interferometer and single-shot electro-optical imaging. Data for various gap size will be presented. 		 
 
TUPEA072 Toward a Dielectric-Wakefield Energy Doubler at the Fermilab's Advanced Superconducting Test Accelerator emittance, electron, simulation, wakefield 1295
 
  • F. Lemery, D. Mihalcea, P. Piot, C.R. Prokop
    Northern Illinois University, DeKalb, Illinois, USA
  • P. Piot, Y.-E. Sun
    Fermilab, Batavia, USA
  • P. Stoltz
    Tech-X, Boulder, Colorado, USA
  
  Funding: This work is supported by DTRA contract HDTRA1-10-1-0051 and by the U.S. DOE contracts DE-FG02-08ER41532 and DE-AC02-07CH11359.
The Advanced Superconducting Test Accelerator (ASTA), presently under construction at Fermilab, will produce high-charge (~<3 nC) electron bunches with energies ranging from 50 to eventually 750 MeV. The facility is based on a superconducting linac capable of producing up to 3000 bunches in 1-ms macropulses repeated at 5 Hz. In this paper we explore the use of a short dielectric-lined-waveguide (DLW) linac to significantly increase the bunch energy. The method consists in (1) using advanced phase space manipulation techniques to shape the beam distribution and enhance the transformer ratio, and (2) optimize the generation and acceleration of a low-charge witness bunches. Start-to-end simulations of the proposed concept are presented. This DLW module could also be used to test some aspects of a recently proposed concept for a multiuser short-wavelength free-electron laser utilizing a series of DLW linacs*.
* C. Jing et al., “A Compact Soft X-ray Free-Electron Laser Facility based on a Dielectric Wakefield Accelerator”, Advanced Photon Source LS Note LS-332, Argonne National Laboratory (2012). 		 
 
TUPEA079 Experimental Search For Acceleration in the Micro-accelerator Platform laser, electron, vacuum, coupling 1307
 
  • J.C. McNeur, K.S. Hazra, B. Matthews, E.B. Sozer, G. Travish
    UCLA, Los Angeles, USA
  • R.J. England, B. Montazeri, K. Soong, Z. Wu
    SLAC, Menlo Park, California, USA
  • E.A. Peralta
    Stanford University, Stanford, California, USA
  • R.B. Yoder
    Goucher College, Baltimore, USA
  
  The results of recent experimental efforts to observe acceleration in the Micro-Accelerator Platform (MAP) are detailed. The MAP is a slab-symmetric dielectric laser accelerator that when side illuminated by an optical laser, accelerates electrons via a standing wave resonance. This structure has been placed in the beamline at the NLCTA experimental hall at SLAC. A 60 MeV electron beam traverses the MAP when it is illuminated by a laser and, using a camera placed around a spectrometer bend magnet, signs of acceleration in the energy spectrum of the beam are searched for. The details of this search, as well as simulations that motivate the search, are elaborated on below.  
 
TUPEA080 Numerical Modeling and Experimental Data Analysis for Dielectric Laser Accelerators laser, electron, vacuum, GUI 1310
 
  • E.B. Sozer, K.S. Hazra, J.C. McNeur, G. Travish
    UCLA, Los Angeles, USA
  • R.J. England, K. Soong
    SLAC, Menlo Park, California, USA
  • E.A. Peralta
    Stanford University, Stanford, California, USA
  • R.B. Yoder
    Goucher College, Baltimore, USA
  
  Funding: Work supported by a grant for the US Defense Threat Reduction Agency (DTRA).
Work on Dielectric Laser Accelerators (DLAs) has been ongoing for the past decade. These devices come in a variety of configurations but share the use of lasers as power sources and dielectrics as the primary building material. While these devices have many of the same characteristics and dynamics as conventional accelerating structures, they operate in a dramatically different regime. One version of these DLAs is the Micro Accelerator Platform (MAP): a slab-symmetric device operated with a standing wave (Pi-mode) and powered by a transversely coupled laser. The coupler is essentially a transmissive diffraction grating and therefore reinforced the desired mode. The remainder of the structure is composed of two Distributed Bragg Reflectors (DBRs) which serve to form a resonant cavity in an evacuated bounded by the reflectors. The MAP has now undergone experimental testing at SLAC’s E-163. As with many advanced accelerators, identifying the best data analysis approach demands extensive numerical modelling of the anticipated beam parameters and development of data visualization tools. We present the latest numerical results and data analysis tools developed for dielectric laser acceleration experiments with MAP. 		 
 
TUPFI003 The Accelerator Design of Muon g-2 Experiment at J-PARC rfq, target, proton, beam-transport 1334
 
  • S. Artikova, F. Naito, M. Yoshida
    KEK, Ibaraki, Japan
  
  New muon g-2 experiment at J-PARC is aimed to improve the precise measurement of the muon g-2. In this experiment, the ultra-cold muons created in the muonium target region is reaccelerated to around 300MeV/c in momentum (210 MeV kinetic energy) to then be injected into the muon g-2 storage ring to measure the decay products depending on the muon spin. The linac has advantage over circular accelerators to shorten the reacceleration time in the limited life time of muon. The muon linac consists of the initial acceleration (to 0.01 of v/c), bunching section (0.01 to 0.08 of v/c), low beta section (0.08 to 0.3 of v/c), middle beta section (0.3 to 0.7 of v/c) and high beta section (0.7 to 0.94 of v/c). As a part of the design consideration of this linac, we mainly present the simulation result of initial acceleration and further acceleration of muons with RFQ. An electric field is used to extract the ultra-cold muons from the laser ionization region and RF field is used to create some bunches and to accelerate to higher energies.  
 
TUPFI040 Experimental Verification of the CLIC Two-Beam Acceleration Technology in CTF3 linac, feedback, collider, bunching 1436
 
  • P. Skowroński, A. Andersson, J. Barranco, B. Constance, R. Corsini, S. Döbert, A. Dubrovskiy, W. Farabolini, E. Ikarios, R.L. Lillestøl, T. Persson, F. Tecker
    CERN, Geneva, Switzerland
  • W. Farabolini
    CEA/DSM/IRFU, France
  • E. Ikarios
    National Technical University of Athens, Athens, Greece
  • M. Jacewicz, A. Palaia, R.J.M.Y. Ruber
    Uppsala University, Uppsala, Sweden
  • R.L. Lillestøl
    University of Oslo, Oslo, Norway
  • T. Persson
    Chalmers University of Technology, Chalmers Tekniska Högskola, Gothenburg, Sweden
  
  The Compact Linear Collider (CLIC) International Collaboration is pursuing an extensive R&D program towards a multi-TeV electron-positron collider. In particular, the development of two beam acceleration technology is the focus of the CLIC test facility CTF3. In this paper we summarize the most recent results obtained at CTF3: the results of the studies on the drive beam generation are presented, the achieved two beam acceleration performance is reported and the measured break-down rates and related observations are summarized. The stability of deceleration process performed over 13 subsequent modules and the comparison of the obtained results with the theoretical expectations are discussed. We also outline and discuss the future experimental program.  
 
TUPME019 Simulation for Control of Longitudinal Beam Emittance in J-PARC MR emittance, injection, bunching, simulation 1610
 
  • M. Yamamoto, M. Nomura, A. Schnase, T. Shimada, F. Tamura
    JAEA/J-PARC, Tokai-mura, Japan
  • E. Ezura, K. Hara, K. Hasegawa, C. Ohmori, A. Takagi, K. Takata, M. Toda, M. Yoshii
    KEK, Ibaraki, Japan
  
  The J-PARC MR receives a high intensity beam from the RCS. The designed longitudinal emittance of the RCS is 5 eVs, whereas the MR rf bucket has enough margin to accept up to 10 eVs. Although the RCS emittance can be increased by using PM method and a large emittance is desirable to increase the bunching factor and to avoid instability, it is difficult to receive such large emittance beam in the MR because of the MR kicker performance. We have performed the particle tracking simulation of longitudinal emittance control for enlarging the beam emittance by PM method and for keeping the bunching factor high using 2nd harmonic rf during the MR injection period.  
 
TUPME020 Design of a TeV Beam Driven Plasma-wakefield Linear Collider plasma, linac, collider, linear-collider 1613
 
  • E. Adli
    University of Oslo, Oslo, Norway
  • W. An, C. Joshi, W.B. Mori
    UCLA, Los Angeles, California, USA
  • J.-P. Delahaye, S.J. Gessner, M.J. Hogan, T.O. Raubenheimer
    SLAC, Menlo Park, California, USA
  • P. Muggli
    MPI, Muenchen, Germany
  
  Funding: This work is supported by the Research Council of Norway and U.S. Department of Energy under contract number DE-AC02-76SF00515.
A novel design of a 500 GeV c.m. beam-driven PWFA linear collider with effective accelerating gradient on the order of 1 GV/m and extendable in the multi-TeV energy range is presented. The main bunches collide in CW mode at several kHz repetition frequency. They are accelerated and focused with several GV/m fields generated in plasma cells by drive bunches with very good transfer efficiency. The drive bunches are themselves accelerated by a CW superconducting rf recirculating linac. We consider the overall optimizations for the proposed design, compare the efficiency with similar collider designs like ILC and CLIC and we outline the major R&D challenges. 		 
 
TUPME039 The Drive Beam Phase Stability in CTF3 and its Relation to the Bunch Compression Factor linac, pick-up, klystron, linear-collider 1655
 
  • E. Ikarios, A. Andersson, J. Barranco, B. Constance, R. Corsini, A. Gerbershagen, T. Persson, P.K. Skowroński, F. Tecker
    CERN, Geneva, Switzerland
  
  The proposed Compact Linear Collider (CLIC) is based on a two-beam acceleration scheme. The energy needed to accelerate a low intensity "main" beam is provided by a high intensity, low energy "drive" beam. The precision and stability of the phase relation between two beams is crucial for the performance of the scheme. The tolerable phase jitter is 0.2 deg rms at 12GHz. For this reason it is fundamental to understand the main possible causes of the drive beam timing jitter. Experimental work aimed at such understanding was done in the CLIC Test Facility (CTF3) where a drive beam with characteristics similar to the CLIC one is produced. Several phase measurements allowed us to conclude that the main source of phase jitter is energy jitter of the beam transformed and amplified into phase jitter when passing through a magnetic chicane. This conclusion is supported by measurements done with different momentum compaction values in the chicane. In this paper the results of these several phase measurements will be presented and compared with expectations.  
 
TUPME047 Sub-Harmonic Bunching System of CLIC Drive Beam Injector space-charge, bunching, collider, klystron 1670
 
  • S. Sanaye Hajari, S. Döbert, S. Döbert, H. Shaker
    CERN, Geneva, Switzerland
  • S. Sanaye Hajari, H. Shaker
    IPM, Tehran, Iran
  
  In the Compact Linear Collider (CLIC) the RF power for the acceleration of the Main Beam is extracted from a high-current Drive Beam that runs parallel with the main linac. The sub-harmonic bunching system of the drive beam injector has been studied in detail and optimized. The model consists of a thermionic gun, three travelling wave sub-harmonic bunchers followed by a tapered travelling wave buncher. The simulation of the beam dynamics has been carried out with PARMELA with the goal of optimizing the overall bunching process and in particular capturing particles as much as possible in the buncher acceptance and decreasing the satellite population.  
 
TUPWA010 A Trial to Reduce the Kicker Impedance of 3-GeV RCS in J-PARC kicker, impedance, resonance, status 1742
 
  • Y. Shobuda, N. Hayashi, T. Takayanagi
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
  • Y. Irie
    KEK, Ibaraki, Japan
  • T. Toyama
    J-PARC, KEK & JAEA, Ibaraki-ken, Japan
  
  At 3GeV RCS in J-PARC, the kicker impedance has been considered to be the dominant source to cause the beam instability. Recently, experimental studies demonstrate that the beam instability is suppressed by reducing the kicker impedance. In this report, a trial to reduce the kicker impedance is reported.  
 
TUPWO054 Recent Results from the EMMA Experiment simulation, betatron, synchrotron, closed-orbit 1988
 
  • B.D. Muratori, J.K. Jones
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
  • R. Appleby, J.M. Garland, H.L. Owen
    UMAN, Manchester, United Kingdom
  • J.S. Berg, F. Méot
    BNL, Upton, Long Island, New York, USA
  • C.S. Edmonds, J.K. Jones, I.W. Kirkman, B.D. Muratori, A. Wolski
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
  • C.S. Edmonds, I.W. Kirkman, A. Wolski
    The University of Liverpool, Liverpool, United Kingdom
  • D.J. Kelliher, S. Machida
    STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
  • J. Pasternak
    STFC/RAL, Chilton, Didcot, Oxon, United Kingdom
  • J. Pasternak
    Imperial College of Science and Technology, Department of Physics, London, United Kingdom
  
  EMMA (Electron Model for Many Applications) is a prototype non-scaling electron FFAG hosted at Daresbury Laboratory. After a recent demonstration of acceleration in the serpentine channel, the injected EMMA beam was further studied. This entails the continuation of the exploration of the large transverse and longitudinal acceptance and the effects of slower integer tune crossing on the betatron amplitude. A single closed orbit correction that is effective at multiple momenta (and hence over a significant range in tune space) was implemented. A comparison with a detailed model based on measured field maps, and the experimental mapping of the machine by relating the initial and final phase space coordinates was also done. These recent results together with more practical improvements such as injection orbit matching with real-time monitoring of the coordinates in the transverse phase space will be reported in this paper.  
 
TUPWO055 Phase Rotation Experiment at EMMA for testing Applicability of a Non-scaling FFAG for PRISM System extraction, synchrotron, background, electron 1991
 
  • B.D. Muratori, J.K. Jones
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
  • R.T.P. D'Arcy
    UCL, London, United Kingdom
  • J.K. Jones, B.D. Muratori
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
  • D.J. Kelliher, S. Machida
    STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
  • H.L. Owen
    UMAN, Manchester, United Kingdom
  • J. Pasternak
    STFC/RAL, Chilton, Didcot, Oxon, United Kingdom
  • J. Pasternak
    Imperial College of Science and Technology, Department of Physics, London, United Kingdom
  
  EMMA is the world’s first non-scaling FFAG, based at Daresbury Laboratory. EMMA has a very large acceptance and has demonstrated acceleration in the serpentine channel. PRISM (Phase Rotated Intense Slow Muon source) is a next generation muon to electron conversion experiment aiming to obtain intense quasi-monochromatic low energy muon beams by performing RF phase rotation in an FFAG ring. Current baseline design for PRISM applies the scaling FFAG ring, but an alternative machine could be based on a ns-FFAG principle. As the transverse-longitudinal coupling is present in ns-FFAGs due to a natural chromaticity, its effect on the final energy spread and beam quality needs to be tested. In order to gauge the expected results, an experiment was designed to be performed on EMMA. We report here the details of this experiment and the results gathered from EMMA operation.  
 
WEPWA004 Multi-turn ERL Based Light Source: Analysis of Injection and Recovery Schemes linac, cryomodule, optics, injection 2129
 
  • Y. Petenev, T. Atkinson, A.V. Bondarenko, A.N. Matveenko
    HZB, Berlin, Germany
  
  The optics simulation group at HZB is designing a multi-turn energy recovery linac -based light source. Using the superconducting Linac technology, the Femto-Science-Factory(FSF) will provide its users with ultra-bright photon beams of angstrom wavelength. The FSF is intended to be a multi-user facility and offer a variety of operation modes. The driver of the facility is a 6GeV multiturn energy recovery linac with a split linac. In this paper we compare different schemes of beam acceleration: a direct injection scheme with acceleration in a 6 GeV linac, a two-stage injection with acceleration in a 6 GeV linac, and a multi-turn (3-turn) scheme with a two-stage injection and two main 1 GeV linacs. The key points were costs and beam break up instability.  
 
WEPWO054 Multistep Mechanical Analyses of Centrifugal Barrel Polishing Barrel and Cavity cavity, simulation, SRF, niobium 2426
 
  • M. Chen, C.A. Cooper, L. Ristori
    Fermilab, Batavia, USA
  
  Funding: US Department of Energy
Fermilab has successfully demonstrated the ability to improve the performance of damaged 1.3 GHz single cell and 9-cell Tesla–type cavities by using a modified centrifugal barrel polishing (CBP) process that leaves a mirror finish on the inside of the cavity. Fermilab now is developing and constructing a new CBP machine which can handle both 650 MHz and 1.3 GHz cavities. The new machine will have a larger moment arm and therefore impart more force on the cavity and machine. Because of these increased forces the effects on cavity supports and machine design were examined. This paper will document the multistep mechanical analyses for the CBP barrel and cavity, calculations of the fatigue life and the requirements for the structural welds. 		 
 
WEPWO076 Development of Ultra High Gradient and High Q0 Superconducting Radio Frequency Cavities cavity, niobium, SRF, cryogenics 2474
 
  • R.L. Geng, W.A. Clemens, J. Follkie, T. Harris, D. Machie, R. Martin, A.D. Palczewski, E. Perry, G. Slack, R.S. Williams
    JLAB, Newport News, Virginia, USA
  • C. Adolphsen, Z. Li
    SLAC, Menlo Park, California, USA
  • J.K. Hao, Y.M. Li, K.X. Liu
    PKU, Beijing, People's Republic of China
  • P. Kushnick
    JLab, Newport News, Virginia, USA
  
  Funding: Work supported by DOE. Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177.
We report on the recent progress at Jefferson Lab in developing ultra high gradient and high Q0 superconducting radio frequency (SRF) cavities for future SRF based machines. A new 1300 MHz 9-cell prototype cavity is being fabricated. This cavity has an optimized shape in terms of the ratio of the peak surface field (both magnetic and electric) to the acceleration gradient, hence the name low surface field (LSF) shape. The goal of the effort is to demonstrate an acceleration gradient of 50 MV/m with Q0 of 1010 at 2 K in a 9-cell SRF cavity. Fine-grain niobium material is used. Conventional forming, machining and electron beam welding method are used for cavity fabrication. New techniques are adopted to ensure repeatable, accurate and inexpensive fabrication of components and the full assembly. The completed cavity is to be first mechanically polished to a mirror-finish, a newly acquired in-house capability at JLab, followed by the proven ILC-style processing recipe established already at JLab. In parallel, new single-cell cavities made from large-grain niobium material are made to further advance the cavity treatment and processing procedures, aiming for the demonstration of an acceleration gradient of 50 MV/m with Q0 of 2·1010 at 2K.
The U.S. Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce this manuscript for U.S. Government purposes. 		 
 
WEPEA001 Simulation Studies of Longitudinal RF-noise and Phase Displacement Acceleration as Driving Mechanism for the MedAustron Synchrotron Slow Extraction extraction, simulation, resonance, synchrotron 2501
 
  • U. Dorda
    EBG MedAustron, Wr. Neustadt, Austria
  • M. Benedikt, H.O. Schönauer, A. Wastl
    CERN, Geneva, Switzerland
  
  MedAustron is a synchrotron based hadron therapy and research facility located in Austria currently entering the installation stage. It is an implementation of the CERN-PIMMS design which proposed induction acceleration by a betatron core as the driving mechanism for the third-order slow resonant extraction. Primarily in order to increase the accelerators flexibility towards future irradiation schemes but also as back-up options, two alternative extraction driving mechanism have been studied: Longitudinal RF-noise and phase displacement acceleration. The advantages as well as the corresponding limitations are explained, analytical estimates and particle tracking results performed with the 2D tracking codes LONG1D and a specifically developed Python based simulation code are presented.  
 
WEPEA016 Upgrade Study of JPARC Main Ring Fast Extraction Septa System septum, extraction, injection, kicker 2531
 
  • K. Fan, K. Ishii, H. Matsumoto, N. Matsumoto, Y. Morita
    KEK, Ibaraki, Japan
  
  The JPARC main ring fast extraction (FX) system has two functions, deliver high power beam to the neutrino experimental facility and dump the beam at any time in case of hardware failures. The present FX system consists of five pair of bipolar kickers and eight pair of bipolar septa. In order to raise the beam power to the design limit, both the beam intensity and the repetition rate will increase gradually. The FX system needs to be upgraded to satisfy the new requirements. The upgrade includes FX orbit optimization and new design of devices. Firstly, the conventional multi-turn low-field septa will be replaced by eddy current type septa. Several configurations of the new design has been studied to realize the requirements of thinner septum, higher field quality, lower leakage and higher mechanical stability. To provide sufficient flat top field for the FX beam, superposition of 3rd harmonic pulse has been employed.  
 
WEPEA024 Combine Effects of Space Charge and Chromaticity Sextupoles at CSNS/RCS sextupole, emittance, simulation, space-charge 2552
 
  • S.Y. Xu, S. Wang
    IHEP, Beijing, People's Republic of China
  
  Most high current proton synchrotrons, such as The Rapid Cycling Synchrotron (RCS) of The China Spallation Neutron Source (CSNS), are operated under the transition energy, and the natural chromaticity is small. These proton synchrotrons can work without chromatic correction. To reduce the tune spread produced by the chromaticity, chromatic correction is considered by using chromaticity sextupoles for this type of proton synchrotrons, such as J-PARC and SNS. Many chromatic correction schemes are compared for the CSNS/RCS, and the harmonic sextupoles are considered to correct nonlinear effect of chromaticity sextupoles. The dynamic aperture is obtained by particle tracking, and the combine effects of sextupole field and space charge effects are investigated by using the code ORBIT and SIMPSONS.  
 
WEPEA030 Simulation of Beam Capture Process in HIRFL-CSRm simulation, extraction, cavity, injection 2564
 
  • P. Li, P. Jiang, J.W. Xia, J.C. Yang, Y.J. Yuan
    IMP, Lanzhou, People's Republic of China
  
  In this paper, the beam capture processes are simulated in CSRm with the real RF cavity curves. By now, CSRm can accelerate all ions from protons up to the heaviest element, uranium, with variable energies and different efficiency. During the beam capture processes, the capture voltage and capture time must be cheese properly to avoid the beam loss. Moreover, the mismatch between the actual and the setting beam energy and space charge effect are investigated for high beam capture efficiency. The evolution of longitudinal phase space during the capture processes is presented in this simulation too.  
 
WEPEA036 Spin Tune Decoherence Effects in Electro- and Magnetostatic Structures betatron, sextupole, emittance, synchrotron 2579
 
  • Y. Senichev, R. Maier, D. Zyuzin
    FZJ, Jülich, Germany
  • N.V. Kulabukhova
    St. Petersburg State University, St. Petersburg, Russia
  
  In Electric Dipole Moment search experiments with polarized beams the coherence of spin oscillations of particles has a crucial role. The decoherent effects arise due to spin tune dependence on particle energy and particle trajectory in focusing-deflecting fields. They are described through the n-th order spin tune aberrations. Since the first order is suppressed by RF field, the second order plays crucial role. It depends on the orbit lengthening and on the odd order field components. We consider the spin decoherence effects and methods of their compensation in different channels, electrostatic, magnetostatic linking the decoherence effects with common characteristics such as the momentum compaction factor, the chromaticity and others.  
 
WEPEA060 Plans for the Upgrade of CERN's Heavy Ion Complex ion, injection, luminosity, linac 2645
 
  • D. Manglunki, M. E. Angoletta, H. Bartosik, A. Blas, D. Bodart, M.A. Bodendorfer, T. Bohl, J. Borburgh, E. Carlier, J.-M. Cravero, H. Damerau, L. Ducimetière, A. Findlay, R. Garoby, S.S. Gilardoni, B. Goddard, S. Hancock, E.B. Holzer, J.M. Jowett, T. Kramer, D. Kuchler, A.M. Lombardi, Y. Papaphilippou, S. Pasinelli, R. Scrivens, G. Tranquille
    CERN, Geneva, Switzerland
  
  To reach a luminosity higher than 6×1027 Hz/cm2 for Pb-Pb collisions, as expected by the ALICE experiment after its upgrade during the 2nd Long LHC Shutdown (LS2), several upgrades will have to be performed in the CERN accelerator complex, from the source to the LHC itself. This paper first details the present limitations and then describes the strategy for the different machines in the ion injector chain. Both filling schemes and possible hardware upgrades are discussed.  
 
WEPEA073 A 180 MeV Injection Upgrade Design for the ISIS Synchrotron injection, space-charge, synchrotron, simulation 2678
 
  • J.W.G. Thomason, D.J. Adams, B.S. Drumm, D.J.S. Findlay, I.S.K. Gardner, M.C. Hughes, S.J.S. Jago, B. Jones, R.J. Mathieson, S.J. Payne, B.G. Pine, A. Seville, H. V. Smith, C.M. Warsop, R.E. Williamson
    STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
  • J. Pasternak
    STFC/RAL, Chilton, Didcot, Oxon, United Kingdom
  • D.C. Plostinar, C.R. Prior, G.H. Rees
    STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
  
  ISIS is the spallation neutron source at the Rutherford Appleton Laboratory in the UK. Obsolescence and reliability issues are motivating plans to replace the present 70 MeV H minus linac, and this paper presents an overview of a design to allow injection of beam into the present ISIS ring at 180 MeV, which would increase intensity as a result of reduced space charge and optimised injection. The key topics addressed are design of the injection straight, injection painting and dynamics, foil specifications, acceleration dynamics, transverse space charge, instabilities, RF beam loading and activation.  
 
WEPFI018 Comparison of High Gradient Performance in Varying Cavity Geometries damping, vacuum, coupling, HOM 2741
 
  • T. Higo, T. Abe, Y. Arakida, Y. Higashi, S. Matsumoto, T. Shidara, T. Takatomi, M. Yamanaka
    KEK, Ibaraki, Japan
  • A. Grudiev, G. Riddone, W. Wuensch
    CERN, Geneva, Switzerland
  
  Four types of CLIC prototype TW accelerator structures were high-gradient tested at Nextef, KEK, up to 100 MV/m level and the fifth is under test now. The ramping speed of each processing and the resultant breakdown rate were compared among them. From this comparison, it was found that the ramping speed of the structures with opening ports for HOM damping with magnetic coupling became slow and the resultant breakdown rate became high. It was also found that that with lower surface magnetic field showed faster ramping in processing and lower breakdown rate. This indicates the role of the magnetic field on vacuum breakdowns in copper structure at the region of several tens to 100 MV/m. In this paper, we review the processing stage and the high gradient performance of these structures trying to discuss the relevant parameters, surface electric field, surface magnetic field and other parameters such as Sc, “complex pointing vector”, to the performance difference.  
 
WEPFI063 Progress on the ISIS Synchrotron Low Power RF System Upgrade controls, cavity, synchrotron, proton 2839
 
  • A. Seville, D.B. Allen, D. Bayley, N.E. Farthing, I.S.K. Gardner, R.J. Mathieson
    STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
  • W.L. Huang
    IHEP, Beijing, People's Republic of China
  
  The ISIS synchrotron at the Rutherford Appleton Laboratory in the UK now routinely uses a dual harmonic RF system to accelerate beam currents in excess of 230 uA to operate two target stations simultaneously. To give more stable control of the RF voltage at each of the fundamental (1RF) and second harmonic (2RF) cavities, changes have been made to the low power RF (LPRF) control systems. A new FPGA based master oscillator has been implemented using a National Instruments FlexRIO module. The replacement master oscillator has been tested with beam for the first time. This paper reports on the tests of the FlexRIO master oscillator and describes plans for the gradual replacement of the remaining parts of the LPRF system.  
 
WEPME023 Study of the Vibration of the AC Dipole and Magnetic Measurement Girder for CSNS/RCS dipole, resonance, damping, synchrotron 2980
 
  • R.H. Liu, L. Kang, H. Qu, G.Y. Wang, H.J. Wang, J. S. Zhang
    IHEP, Beijing, People's Republic of China
  
  The dipole magnet of the China Spallation Neutron Source Rapid-cycling Synchrotron (RCS) will be operated at a 25Hz sinusoidal alternating current which causes severe vibration. The vibration will influence the long-term safety and reliable operation of the magnet. By taking the magnet and magnetic measurement girder as a specific model system, a method for analyzing and studying the dynamic characteristic of the system is put forward by combining theoretical calculation with experimental testing. And the ctive vibration of magnet is different with passive vibration which was causes by ground vibration, so a new isolator was designed to decrease the vibratory force and avoid the resonance phenomenon.  
 
WEPME063 Progress Report on Development of a 5-μm Drive Laser for Dielectric Laser Acceleration laser, focusing, HOM, alignment 3079
 
  • G. Xu, I. Jovanovic, S.F. Wandel
    Penn State University, University Park, Pennsylvania, USA
  • E.R. Arab
    PBPL, Los Angeles, USA
  • P.D. Hoang, P. Musumeci, B.D. O'Shea, J.B. Rosenzweig
    UCLA, Los Angeles, USA
  • A.Y. Murokh, A.G. Ovodenko
    RadiaBeam, Santa Monica, USA
  • I. Pogorelsky
    BNL, Upton, Long Island, New York, USA
  
  Funding: This work has been sponsored by Defense Advanced Research Project Agency.
A simple and robust ultrafast, high-peak-power 5-μm laser source for pumping a dielectric photonic structure for high-gradient electron acceleration has been designed and is being constructed. The use of long wavelength drive lasers can mitigate the problem of dielectric structure breakdown caused by multiphoton ionization. In addition, structure fabrication requirements are relaxed, and greater energy can be stored in the structure. The 5-μm laser source consists of two components: (1) a type-II-beta-barium borate-based 2-μm optical parametric amplifier (OPA) as a pump source, and (2) a type-I-zinc-germaniu-phosphate-based 5-μm OPA to produce mJ-class, <100 fs pulses. Our supercontinuum seeded two-stage 2-μm OPA is pumped by a Ti:sapphire amplifier and produces pulse energy of ~1.4 mJ with a pulse duration of 42 fs (~6 optical cycles). Carrier-envelope phase (CEP) stabilization is passively established for 2 μm pulses in our OPA design. An modified design of seed pulse generation for the 5-μm OPA based on several cascaded parametric processes can also result in CEP-stable operation for 5-μm amplified pulses. 		 
 
THOBB103 THz Electron-pulse-train Dynamics in a MeV Photo-injector electron, cathode, bunching, laser 3109
 
  • F.H. Chao, C.H. Chen, Y.-C. Huang
    NTHU, Hsinchu, Taiwan
  • P.J. Chou
    NSRRC, Hsinchu, Taiwan
  
  A conventional free electron laser (FEL) is bulky and expensive. In order to quickly build up the FEL power in a short undulator, a laser technology has been proposed to generate a pre-bunched electron pulse-train with a THz bunching frequency from a photoinjector*. The bunching factor** of an accelerated pulse-train beam is influenced by the beam radius, initial bunching frequency, space charge force, acceleration gradient, and acceleration phase in an accelerator. For a given RF accelerator and initial beam parameters, there is a limitation on the maximally attainable bunching factor and bunching frequency for the accelerated pulse-train beam. This paper presents a theoretical analysis for the bunching factor and bunching frequency of an accelerated pulse-train beam subject to nominal initial beam conditions in a photoinjector. The theoretical analysis is compared with the simulation results from the simulation code, PARMELA. To obtain an output bunching factor larger than 0.5%, our simulation study indicates that the maximum bunching frequency at the cathode is 25 THz for a 150 A beam current under a peak acceleration field of 80 MV/m.
* Y.C. Huang, C.H. Chen, A.P. Lee, W.K. Lau, S.G. Liu, NIM, A, 637, S1–S6 (2011).
** Y.C Huang, Appl. Phys. Lett., 96, 231503 (2010). 		 
slides icon Slides THOBB103 [3.076 MB]  
 
THPPA01 Realization of New Charge-state Stripper for High-power Uranium Ion Beams stripper, ion, target, electron 3135
 
  • H. Imao
    RIKEN Nishina Center, Wako, Japan
  
  Recent works to realize the new charge-state stripper using recirculating helium gas are presented. Very limited lifetimes of conventional solid-state strippers due to huge dE/dx for very heavy ion beams (e.g., for uranium ions, several thousand times larger than protons at the energy around 10 MeV/u) were a principal bottleneck for their multi-stage acceleration at high intensities. The new stripping system is characterized by its infinite lifetime, efficient stripping and small beam degradation even for the world’s most intense uranium ion beams provided by the RIBF (more than 1 pμA at the injected energy of 11 MeV/u). Successful operations of the system in 2012 greatly contribute to the remarkable expansion of the accelerator performance of the RIBF that will allow an enormous breakthrough for exploring new domains of the nuclear world in the next several years; the peak intensity of the uranium beam has reached 15.1 pnA (almost 1011 pps) at 345 MeV/u and the average intensity provided for the users has become ten times higher than it was in 2011.  
slides icon Slides THPPA01 [6.535 MB]  
 
THPFI007 Increasing the Stability of the Electron Beam of the S-DALINAC linac, electron, feedback, dipole 3303
 
  • F. Hug, T. Bahlo, C. Burandt, J. Conrad, L.E. Jürgensen, M. Kleinmann, M. Konrad, T. Kürzeder, N. Pietralla
    TU Darmstadt, Darmstadt, Germany
  • R. Eichhorn
    CLASSE, Ithaca, New York, USA
  
  Funding: Funded by DFG through SFB 634
The S-DALINAC is a superconducting recirculating electron accelerator with a final energy of 130 MeV. It operates in cw at 3 GHz. It accelerates beams of either unpolarized or polarized electrons and is used as a source for nuclear- and astrophysical experiments at the university of Darmstadt since 1987. We will report on two future upgrade plans for increasing the operation stability of the accelerator: A high energy scraper system for collimating the beam before it is delivered to the experiments and a rf feedback system to fix the rf phase of the beam leaving the injector linac by measurements on a rf monitor. 		 
 
THPFI028 Anti-earthquake Structural Design for CSNS Beam Dump vacuum, neutron 3358
 
  • X.J. Nie, L. Kang, L. Liu, H. Qu
    IHEP, Beijing, People's Republic of China
  
  To ensure the beam dump shield iron can resist the damage of earthquake and maintain the normal protective capability, anti-earthquake design was carried out in this paper. The parts for seismic resistance were designed according to the feature of foundation building. The force model was reached through the analysis of seismic load. The structure dimension was decided on the basis of the theory of strength. A pre-buried plate with hooks was achieved and the force model was simplified as fixed end. The minimal diameter of hook showed 30mm. The fixing device with plate decreases the precision requirement of foundation building and can be used to fix the shield iron to resist the earthquake.  
 
THPFI058 Qualification of a Glassy Carbon Blade for a LHC Fast Vacuum Valve vacuum, accumulation, background, scattering 3424
 
  • C. Garion, P. Coly
    CERN, Geneva, Switzerland
  
  To protect sensitive LHC machine systems against an unexpected gas inrush, a fast vacuum valve system is under development at CERN. The design of the shutter has to be compatible with dynamic loads occurring during the fast closure, namely in the 20 ms range. The material has to fulfil all main requirements such as transparency, high melting temperature, dust free and adequate leak tightness. A development of a blade in vitreous carbon material has been carried out at CERN. The blade has been successfully integrated in a commercial pendulum fast valve. In this paper, the vacuum and mechanical qualification tests are presented.  
 
THPWA011 Concepts of 220 MeV Racetrack Microtron for Non-destructive Nuclear Material Detection System electron, microtron, gun, simulation 3651
 
  • T. Hori, T. Kii, R. Kinjo, H. Ohgaki, M. Omer, H. Zen
    Kyoto University, Institute for Advanced Energy, Kyoto, Japan
  • I. Daito, R. Hajima, T. Hayakawa, M. Kando, H. Kotaki
    JAEA, Kyoto, Japan
  • F. Sakai
    SHI, Tokyo, Japan
  
  Funding: Japan Science and Technology Agency Special Coordination Funds for Promoting Science and Technology (Grant No. 066)
A nuclear material detection system (NMDS) using the quasi-monochromatic gamma-ray beam from a laser Compton scattering (LCS) source is proposed for the container inspection, where nuclear resonance fluorescence method is to be employed for the specific isotope identification such as U-235. In the system an electron beam of good quality at about 220-MeV must be provided for LCS. One of the most promising electron source is a compact electron accelerator named racetrack microtron (RTM). Some concepts of RTM suitable for NMDS and expected beam qualities will be presented. 		 
 
THPWA012 The Development of a New Type of Electron Microscope using Superconducting RF Acceleration cavity, electron, gun, cathode 3654
 
  • N. Higashi
    The University of Tokyo, Graduate School of Science, Tokyo, Japan
  • A. Enomoto, Y. Funahashi, T. Furuya, Y. Kamiya, S. Michizono, M. Nishiwaki, H. Sakai, M. Sawabe, K. Ueno, M. Yamamoto
    KEK, Ibaraki, Japan
  • M. Kuriki
    HU/AdSM, Higashi-Hiroshima, Japan
  • S. Yamashita
    ICEPP, Tokyo, Japan
  
  We are developing a new type of electron microscope (EM), which adopts RF acceleration in order to exceed the energy limit of DC acceleration used in conventional EMs. It enables us to make a high-voltage EM more compact and to examine thicker specimens, and possibly to get better spatial resolution. Using a superconducting RF cavity, we can operate the EM in CW mode to obtain a beam flux comparable to that in DC mode. Low energy dispersion ΔE/E , e.g. 10-6 or better, is required for good spatial resolution in EMs, while it is usually between 10-3 to 10-4 in accelerators. We have thus designed a special type of cavity that can be excited with the fundamental and second-harmonic frequencies simultaneously; TM010 and TM020. With the two-mode cavity, the energy dispersion of the order of 10-5 would be obtained by modifying the peak of accelerating field to be flattened. As the proof-of-principle of our concept, we are developing the prototype using a 300 keV transmission electron microscope (TEM), to which a new photocathode gun and the two-mode cavity are attached. We have already manufactured the cavity and it is under test, and the gun is under construction.  
 
THPWA044 R&D into Laser Applications for Accelerators laser, electron, cathode, vacuum 3729
 
  • C.P. Welsch
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
  • C.P. Welsch
    The University of Liverpool, Liverpool, United Kingdom
  
  Funding: Work supported by the EU under Grant Agreement 289191.
Lasers can be used for the generation of high brightness electron and exotic ion beams, the acceleration of particles with the highest accelerating gradients, as well as for the characterization of many complex particle beams by means of laser-based beam diagnostics methods. In addition, (free electron) lasers can be used for achieving the highest time resolution and strongest fields for experiments in atomic physics, chemistry and biology, i.e. for studies into the dynamics of some of the most fundamental processes in nature. Without constant progress in laser technology and close collaboration between laser experts and accelerator scientists, many of today's most advanced experiments would simply be impossible. The LA3NET consortium combines developments into laser technology and sensors with their application at advanced accelerator facilities, providing complex beams ranging from highest brightness electron beams to high intensity proton beams. This contribution presents the consortium's broad, yet closely interconnected experimental program. 		 
 
THPWA050 Beam Conditioning System for Laser-driven Hadron Therapy proton, ion, laser, target 3743
 
  • K.E. Woods, S. Boucher, F.H. O'Shea
    RadiaBeam, Santa Monica, USA
  • B.M. Hegelich
    The University of Texas at Austin, Austin, Texas, USA
  
  While the superior therapeutic efficacy of hadron therapy has been clearly demonstrated, its availability to cancer patients is limited by the cost and size of current systems. RadiaBeam Technologies, in collaboration with the UCLA Department of Radiation Oncology and the University of Texas at Austin, is proposing the utilization of innovative laser-driven ion acceleration (LDIA) technology for the development of a compact, inexpensive proton therapy system that can ultimately be adapted for the acceleration of carbon ions. At less than a third the price of the average proton therapy unit, the realization of this system would make hadron therapy a much more realistic option for hospitals and clinics worldwide. However, LDIA produces a beam with large divergence, wide energy spread with multiple ion species, and a significant background of electrons and X-rays. Thus, a major challenge for clinical implementation of LDIA is the development of a post-target beam conditioning system for collimation, focusing, energy selection, background shielding, and scanning. This paper will discuss the progress of our design of such a system and plans for future testing.  
 
THPWO028 Commissioning Plan for Energy Upgrade of J-PARC Linac linac, injection, quadrupole, DTL 3821
 
  • M. Ikegami, Z. Fang, K. Futatsukawa, T. Miyao
    KEK, Ibaraki, Japan
  • Y. Liu
    KEK/JAEA, Ibaraki-Ken, Japan
  • T. Maruta
    J-PARC, KEK & JAEA, Ibaraki-ken, Japan
  • A. Miura, J. Tamura
    JAEA/J-PARC, Tokai-mura, Japan
  
  In J-PARC linac, we plan to have an energy and intensity upgrade in summer 2013. The upgrade involves replacement of the ion source and RFQ (Radio Frequency Quadrupole linac), and addition of ACS (Annular Coupled Structure linac) cavities after existing SDTL (Separate Drift Tube Linac) section. With this upgrade, the design peak current will be increased from the present 30 mA to 50 mA, and the energy from 181 MeV to 400 MeV. This significant upgrade will be followed by a full-scale beam commissioning campaign. In this paper, we present the plan for the commissioning with outlining the assumed commissioning schemes.  
 
THPWO038 Electron Stripping of High-intensity 238U Ion Beam with Recirculating He Gas stripper, ion, electron, target 3851
 
  • H. Imao
    RIKEN Nishina Center for Accelerator-Based Science, Wako, Saitama, Japan
  • T. Dantsuka, M. Fujimaki, N. Fukunishi, H. Hasebe, O. Kamigaito, M. Kase, H. Kuboki, K. Kumagai, T. Maie, H. Okuno, T. Watanabe, Y. Watanabe, K. Yamada, Y. Yano
    RIKEN Nishina Center, Wako, Japan
  
  Next-generation in-flight RI beam facilities such as RIBF and FRIB pursue powerful and energetic 238U ion beams to produce thousands of new isotopes. For their efficient acceleration, a durable electron stripper in the intermediate energy region around 10-20 MeV/u is indispensable. However, there is no available stripper for the U beams with the intensity of more than 1 puA so far because of the lifetime problem of thin solid strippers caused by high energy loss. 　In the present study, a novel electron stripping system employing high-flow rate He gas circulation (200 L/min) has been developed. He gas with the thickness of 0.6 mg/cm2 is confined and separated from beamline vacuum using five-stage differentially-pumped sections. To avoid huge gas consumption, a clean gas recycling is achieved with multi-stage mechanical booster pump array. The recycling rate of He gas was achieved as more than 99%. The system was successfully operated in user runs with U35+ beams more than 1 puA injected at 10.8 MeV/u for the first time. U64+ beams were stably delivered to subsequent accelerators with the stripping efficiency of 23% without any deterioration of the system.  
 
THPWO091 Staging Scenarios for Project-X linac, emittance, lattice, rfq 3972
 
  • N. Solyak, J.-P. Carneiro, V.A. Lebedev, S. Nagaitsev, J.-F. Ostiguy, A. Saini, A. Vivoli, V.P. Yakovlev
    Fermilab, Batavia, USA
  
  Funding: US DOE under contract DE-AC02-76CH03000.
Project-X is a high intensity proton source in development at Fermilab. At its heart is a linac based on superconducting technology comprising two distinct sections. The first one operates in CW mode and delivers beam with a flexible time structure to simultaneous experimental programs at 1 and 3 GeV. The second one operates in pulsed mode and accelerates a modest fraction (5%) of the beam from 3 GeV to 8 GeV for accumulation in the existing Main Injector complex. In an era of constrained budgets, construction in stages -with each stage capable of supporting worthy scientific programs - may be advantageous. Requirements for each program, coupled to the physical constraints imposed by the Fermilab site have led to a few possible scenarios, which are discussed in this contribution. In particular, we examine the implications of introducing bends in the linac at 1 and 3 GeV in terms of overall performance, flexibility and cost.