• M. Kago, T. Matsushita, N. Nariyama, C. Saji, R. Tanaka, A. Yamashita
  JASRI/SPring-8, Hyogo-ken
• Y. Asano, T. Fukui, T. Itoga
  RIKEN/SPring-8, Hyogo

The accelerator safety interlock system (ASIS) for the XFEL/SPring-8 protects personnel from radiation hazard. We designed the ASIS consisting of three independent systems; a central interlock system, an emergency interlock system and a beam route interlock system. The central interlock system monitors the machine tunnel security, status of beam line interlock system and radiation monitoring system. The emergency interlock system monitors status of emergency stop buttons. The beam route interlock system monitors electron beam route by inputting the current of the bending magnets at the electron-beam switching points. If any system trips, or if any system detects unsafe status, the permission signal for the accelerator operation from the system is off and the electron beam is inhibited. In addition, it is demanded that the permission signals must be transmitted within 16.6 ms. Therefore, the stability and fast response are required for the XFEL safety interlock system. We adopted programmable logic controllers (PLC) for the stability, and developed optical modules for the fast signal transmission. This paper describes system design of the ASIS.