Author: Bizen, T.
Paper Title Page
THPC165 Estimations for Demagnetization of ID Permanent Magnets due to Installation of OTR 3281
 
  • Y. Asano
    RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan
  • T. Bizen
    JASRI/SPring-8, Hyogo, Japan
 
  Demagnetization due to high energy electron irradiation is one of the crucial issues for stable operation of X-ray free electron laser (XFEL) and Synchrotron radiation (SR) facilities. Especially, during the commissioning, electron beam is scattered and then hits permanent magnets of insertion devices due to installation of some instrumentations such as OTR (Optical Transition Radiation) for beam diagnosis so that the estimation of demagnetization is very important to perform the commissioning smoothly. Fortunately, we found the index of demagnetization of Nd2Fe14B permanent magnets due to high energy electron irradiation. Star density produced by high energy photo-neutron reproduces experimental results of demagnetization. At SPring-8, in-vacuum type undulators have been employed for XFEL so that we estimate the demagnetization of the undulators for various cases such as electron energy in ranging from 2 GeV to 8 GeV and the permanent magnet gap from 2 mm to 40 mm. And we also estimate the allowable time to be able to insert the OTR.  
 
TUPS012 The Present Status of Vacuum System of XFEL in SPring-8 1542
 
  • T. Bizen
    RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan
  • T. Hasegawa
    RIKEN/SPring-8, Hyogo, Japan
 
  The vacuum component assembly and installation were completed by February in 2011. The total length of the vacuum system is about 630 m. A 455 sputter ion pumps and a 108 NEG cartridge pumps generate vacuum. The average pressures are on the order of ·10-7 Pa or less. The flange developed for C-band waveguide shows high reliability of vacuum seal.