To facilitate high-sensitivity soft X-ray magnetic circular dichroism experiments, a dynamic local bump system has been developed at the SRRC storage ring. This system was devised to vary dynamically the vertical slope of the electron beam in a bending magnet, producing, in the electron orbit plane, soft X-rays with an alternating elliptical polarization. The local bump was created by using two pairs of vertical correctors located on each side of the bending magnet. The bump strength coef®cient was obtained both from calculated estimation and from measured beam-response matrices. Control electronics for proper bump strength settings were designed to incorporate the existing orbitcorrector function. A corresponding graphic user interface was implemented so that the bump amplitude could be easily adjusted. The performance of this system is presented. Disturbance on the stored electron beam orbit was observed whilē ipping the corrector polarity during EPBM (elliptical polarization from bending magnets) operation. A local feedback loop, developed to eliminate such disturbance on other beamlines, is also described.

Tracking performance of the White circuit is very important for the operation of booster synchrotron. An intensive White circuit tracking performance study in upgraded SRRC booster synchrotron was performed. Tune is the most sensitive parameter that relative to the White circuit tracking. Tune variation during energy ramping reflects the tracking condition. We investigate tracking performance by observed tune variation and to perform tune correction. Study result about the tracking performance and its improvement will summarize in this report.

No abstract

The original injector control system is a turnkey design and it was separated from the storage ring control system. It is not easy to maintain and install new devices. The control system of injector has been rejuvenated recently. There are two basic requirements for this plan, to provide more efficient and stable light source operation, and to reduce the maintenance resource need. Its implementation will also be helpful for improvement on reliability and control response time. Upgrade injector from 1.3 GeV to 1.5 GeV will be done before the end of 1999. The renewed injector control system will be able to provide improved environment for application program development and new devices installation. Automatic control operation for full energy injection will be implemented in SRRC.

Turn-by-turn beam position monitors and phase detector have been implemented recently for Taiwan Light Source (TLS). Transverse as well as longitudinal phase space has been explored using turn-by-turn beam position and phase measurement in single bunch mode. Single bunch longitudinal beam transfer function measurement is also performed with various excitation amplitudes. Preliminary results of these experiments are summary in this report.