CAS Accelerator Seminars
Radiation safety design of SPring-8 Angstrom Compact Free ELECTRON Laser, SACLA and its key points
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Europe/Zurich
019 (WBGB)
019
WBGB
Description
SPring-8 angstrom compact free electron laser, SACLA, is one of the most powerful X-ray free electron laser facilities and can produce less than 1.0 angstrom wave length of X-ray laser, continuously. SACLA can produce the electrons with the energy of up to 8.5 GeV and the repetition rate of 60 Hz. The accelerated electrons passing through the undulators with about 100 m length go down into beam dump with the inclined angle of 20 degrees, and then the laser lights go straight into the optics hutches and experimental hutches through the shield wall in the direction of the SPring-8 storage ring. The length of the machine including experimental hall is about 700m. In addition to the experimental hall, the X-ray laser lights go through the XFEL-SR inter-available building to perform the experiments to concurrent use. SACLA has now 2 beamlines, one is XFEL beamline BL3, and the other is SR beamline, BL1. In addition to these beamlines, now the new beamline, BL2 is under construction.
In the radiation safety point of view, X-ray free electron laser facilities have some characteristics in comparison with 3rd generation synchrotron radiation facilities. One is that the high energy electrons are always injected into the beam dump and the beamlines must be constructed in the direction of the movements of electrons, and another is that the total number of accelerated electrons of X-ray free electron laser facilities is much larger than that of synchrotron radiation facilities. In addition to the importance of safety interlock systems, therefore, it is important that high energy electrons never come to be mixed in X-ray free electron laser beamlines and the amount of accelerated electron beam losses must be reduced as much as possible. At SACLA, a safety permanent magnet was installed into the X-ray light beam axis, and a beam halo monitor and beam loss monitors were installed within and around the electron transport pipes, respectively. In comparison with the SPring-8 synchrotron radiation facility, radiation sources and shielding design of SACLA including the beamlines, outline of the radiation safety systems including the monitors will be discussed. In addition, SACLA has a plan to operate several beamlines simultaneously with different energies. In the case, the electron beam with different energy is kicked in pulse by pulse to different beamlines. It is a big problem to keep safety and we will also discuss about it.
Contact Luc Patthey, 4562
In the radiation safety point of view, X-ray free electron laser facilities have some characteristics in comparison with 3rd generation synchrotron radiation facilities. One is that the high energy electrons are always injected into the beam dump and the beamlines must be constructed in the direction of the movements of electrons, and another is that the total number of accelerated electrons of X-ray free electron laser facilities is much larger than that of synchrotron radiation facilities. In addition to the importance of safety interlock systems, therefore, it is important that high energy electrons never come to be mixed in X-ray free electron laser beamlines and the amount of accelerated electron beam losses must be reduced as much as possible. At SACLA, a safety permanent magnet was installed into the X-ray light beam axis, and a beam halo monitor and beam loss monitors were installed within and around the electron transport pipes, respectively. In comparison with the SPring-8 synchrotron radiation facility, radiation sources and shielding design of SACLA including the beamlines, outline of the radiation safety systems including the monitors will be discussed. In addition, SACLA has a plan to operate several beamlines simultaneously with different energies. In the case, the electron beam with different energy is kicked in pulse by pulse to different beamlines. It is a big problem to keep safety and we will also discuss about it.
Contact Luc Patthey, 4562