Author: Li, Z.
Paper Title Page
WEPS050 The MEBT Design for the China Accelerator Driven System 2604
 
  • H. Geng, H.F. Ouyang, J. Tang
    IHEP Beijing, Beijing, People's Republic of China
  • Z. Li, S. Pei, F. Yan
    IHEP Beijng, Beijing, People's Republic of China
 
  The Medium Eneryg Beam Transport (MEBT) line plays an important role in transporting and matching the beam from the RFQ exit to the entrance to the next type of acceleration structures while provides enough beam diagnostics for beam commissing and tuning. The beam dynamics design for the 1GeV China Accelerator Driven System (CADS) is making great progress. In this paper, we will describe the design–both element choosing and beam dynamics study of the 3MeV MEBT for the CADS project.  
 
MOPC071 Status of High Power Tests of Normal Conducting Short Standing Wave Structures* 241
 
  • V.A. Dolgashev, Z. Li, S.G. Tantawi, A.D. Yeremian
    SLAC, Menlo Park, California, USA
  • Y. Higashi
    KEK, Ibaraki, Japan
  • B. Spataro
    INFN/LNF, Frascati (Roma), Italy
 
  Funding: Work Supported by Doe Contract No. DE-AC02-76SF00515
We report results of continuing high power tests of short standing wave structures. These tests are part of an experimental and theoretical study of basic physics of rf breakdown in 11.4 GHz, normal conducting structures. The goal of this study is to determine the accelerating gradient capability of normal conducting rf powered particle accelerators. We have tested structures of different geometries, cell joining techniques, and materials. We found that the breakdown rate dependence on peak magnetic fields is stronger than on peak surface electric fields for cylindrically symmetric structures powered via a TM01 mode launcher. We report test results for structures powered by side-coupled rectangular waveguides. We found that increased rf magnetic field due to the side-coupling increases the breakdown rate as compared to the same accelerating gradient in cylindrically symmetric structures.
 
 
MOPC067 X-Band Test Station at Lawrence Livermore National Laboratory 235
 
  • R.A. Marsh, F. Albert, S.G. Anderson, C.P.J. Barty, G.K. Beer, R.R. Cross, G.A. Deis, C.A. Ebbers, D.J. Gibson, F.V. Hartemann, T.L. Houck
    LLNL, Livermore, California, USA
  • C. Adolphsen, A.E. Candel, T.S. Chu, E.N. Jongewaard, Z. Li, C. Limborg-Deprey, T.O. Raubenheimer, S.G. Tantawi, A.E. Vlieks, F. Wang, J.W. Wang, F. Zhou
    SLAC, Menlo Park, California, USA
 
  Funding: This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.
An X-band multi-bunch test station is being built at LLNL to investigate the science and technology paths required to boost the current mono-energetic gamma-ray (MEGa-Ray) brightness by orders of magnitude. The test station will consist of a 5.5 cell X-band RF photoinjector, single accelerator section, and beam diagnostics. Beam quality must be exceedingly high in order to produce narrow-bandwidth gamma-rays, requiring a robust state of the art photoinjector. The photoinjector will be a high gradient (200 MV/m peak surface field on the cathode) standing wave structure, featuring a dual feed racetrack coupler, elliptical irises, and an optimized first cell length. A solid-state Scandinova modulator will power a single SLAC XL4 11.424 GHz 50 MW klystron. RF distribution will allow for full powering of the photoinjector with the balance of the RF powering a single accelerator section so that the electron parameters can be measured. The status of the facility will be presented including commissioning schedule and first experiment plans. Future experimental programs pertinent to Compton scattering R&D, high gradient structure testing, and light source development will be discussed.
 
 
WEPC125 Higher Order Modes in Coupled Cavities of the FLASH Module ACC39 2301
 
  • R.M. Jones, I.R.R. Shinton
    UMAN, Manchester, United Kingdom
  • Z. Li
    SLAC, Menlo Park, California, USA
 
  We analyse the higher order modes (HOMs) in the 3.9GHz bunch shaping cavities installed in the FLASH facility at DESY. A suite of finite element computer codes (including HFSS and ACE3P) and globalised scattering matrix calculations are used to investigate the modes in these cavities. This study is primarily focused on the dipole component of the multiband expansion of the wakefield, with the emphasis being on the development of a HOM-based BPM system for ACC39. Coupled inter-cavity modes are simulated together with a limited band of trapped modes.  
 
TUPO024 Precision X-band Linac Technologies for Nuclear Photonics Gamma-ray Sources 1491
 
  • F.V. Hartemann, F. Albert, S.G. Anderson, C.P.J. Barty, A.J. Bayramian, R.R. Cross, G.A. Deis, C.A. Ebbers, D.J. Gibson, T.L. Houck, R.A. Marsh, M. J. Messerly, S.S.Q. Wu
    LLNL, Livermore, California, USA
  • C. Adolphsen, A.E. Candel, T.S. Chu, M.V. Fazio, E.N. Jongewaard, Z. Li, C. Limborg-Deprey, T.O. Raubenheimer, S.G. Tantawi, A.E. Vlieks, F. Wang, J.W. Wang, F. Zhou
    SLAC, Menlo Park, California, USA
  • D. Cutoiu
    Horia Hulubei National Institute for Physics and Nuclear Engineering, Bucharest, Romania
  • D. Ighigeanu, M. Toma
    INFLPR, Bucharest - Magurele, Romania
  • V.A. Semenov
    UCB, Berkeley, California, USA
 
  Funding: This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.
Nuclear photonics is an emerging field of research requiring new tools, including high spectral brightness, tunable gamma-ray sources; high photon energy, ultrahigh-resolution crystal spectrometers; and novel detectors. This presentation focuses on the precision linac technology required for Compton scattering gamma-ray light sources, and on the optimization of the laser and electron beam pulse format to achieve unprecedented spectral brightness. Within this context, high-gradient X-band technology will be shown to offer optimal performance in a compact package, when used in conjunction with the appropriate pulse format, and photocathode illumination and interaction laser technologies.