Feedback Controls for the TRISTAN Light Facility

Toshihiro Mimashi, Takashi Kawamoto, Atsuyoshi Akiyama,
Hitoshi Fukuma, Makoto Tobiyama, Hiroshi Sugiyama

National Laboratory for High Energy Physics (KEK) Japan

Susumu Yoshida
Kanto Information Service Corp.

The photon factory experiment is running on the TRISTAN super light facility from September to December 1995. The feedback system was developed for this project to maintain the stability of light at the experimental hall. Two kinds of feedback systems are prepared, the fast feedback system and the slow feedback system. The fast feedback system maintains the stability of the electron beam position and stop at the center of an undulator. The feedback system is composed of two beam position monitors and four horizontal steering magnets and four vertical steering magnets. The feedback control system reads the signal from the beam position monitors and calculates the steering magnet kick angles and sets them. It is required that the feedback cycle be 20 Hz and the time delay from the beam position read to the steering magnet kickangle set is designed less than 5m sec. This control system was built using EPICS. The slow feedback system takes care of the movement of the extraction line. The slow feedback system adjusts the current of steering magnets by looking at the wire scanner data in the experimental hall.