Keyword: storage-ring
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THPSC11 NSLS-II Booster Vacuum System vacuum, booster, electron, radiation 342
 
  • A.M. Semenov, V.V. Anashin, S.M. Gurov, V.A. Kiselev, A.A. Krasnov
    BINP SB RAS, Novosibirsk, Russia
  • H.-C. Hseuh, T.V. Shaftan
    BNL, Upton, Long Island, New York, USA
 
  One of the last SR source third generation (NSLS-II) is constructed in Brookhaven National Laboratory in present time. To raise the operation effectiveness in continued mode with irradiation of maximum brightness injectors of these SR sources is operated continually on the energy up to energy of the main ring (linac or synchrotron booster). The injection on the full energy allows add electrons to early moved electrons in a storage ring rather than to regulate a magnet system. This operating mode is often named "Top-Up". NSLS-II consists of a linear accelerator on the electron energy up to 200 MeV, a synchrotron booster on the energy 3 GeV, a main storage ring. The status and review of vacuum system are written in this report.  
 
THPSC14 Electron Emission and Trapping in Non-Uniform Fields of Magnet Structure and Insertion Devices at SR Source Siberia-2 electron, quadrupole, vacuum, wiggler 350
 
  • V.I. Moiseev, V. Korchuganov, N.V. Smolyakov
    NRC, Moscow, Russia
 
  In vacuum chamber of SR source, scattered photons provide high intensity flows of photo emitted electrons along the magnetic fields lines. The unperturbed electrons reach the opposite walls. The relativistic bunches influence the trajectories of low energy electrons. These electrons can be trapped by non-uniform magnetic field. The low energy electron distributions change the operating settings of the storage ring. For Siberia-2 case, the low energy electron densities are evaluated both in quadrupole lenses and in superconducting wiggler on 7.5 T field. The qualitative description of the trapped electrons behavior was developed. In calculations, the analitical solution was obtained and used for estimations of the single impact of relativistic bunch.  
 
THPSC26 Distributed Beam Loss Monitor Based on the Cherenkov Effect in Optical Fiber electron, radiation, positron, linac 374
 
  • Yu. Maltseva, F.E. Emanov, A.V. Petrenko, V.G. Prisekin
    BINP SB RAS, Novosibirsk, Russia
  • F.E. Emanov
    NSU, Novosibirsk, Russia
  • A.V. Petrenko
    CERN, Geneva, Switzerland
 
  A distributed beam loss monitor based on the Cherenkov effect in optical fiber has been implemented for the VEPP-5 electron and positron linacs and the 510 MeV damping ring at the Budker INP. The monitor operation is based on detection of the Cherenkov radiation generated in optical fiber by means of relativistic particles created in electromagnetic shower after highly relativistic beam particles (electrons or positrons) hit the vacuum pipe. The main advantage of the distributed monitor compared to local ones is that a long optical fiber section can be used instead of a large number of local beam loss monitors. In our experiments the Cherenkov light was detected by photomultiplier tube (PMT). Timing of PMT signal gives the location of the beam loss. In the experiment with 20 m long optical fiber we achieved 3 m spatial resolution. To improve spatial resolution optimization and selection process of optical fiber and PMT are needed and according to our theoretical estimations 0.5 m spatial resolution can be achieved. We also suggest similar techniques for detection of electron (or positron) losses due to Touschek effect in storage rings.