Status of the KEKB accelerator control system development

KEKB is a 5-year project started in 1994 to convert the existing TRISTAN electron-positron accelerator/collider into an asymmetric one.[1] TRISTAN is a three-stage cascade accelerator/storage ring with a 2.5Gev electron/positron injector Linac, 8GeV Accumulation Ring (AR) and 33GeV accelerator/collider Main Ring (MR). For the KEKB project the Linac will be upgraded to provide intense 8GeV electron and 3.5GeV positron beams to inject directly into the KEKB rings. The KEKB rings, the High Energy Ring (HER) and the Low Energy Ring (LER), will be installed side by side in the tunnel where the TRISTAN MR is at present. The TRISTAN MR will be shut down at the end of 1995 and the equipment will be removed from the MR tunnel. As the 8GeV AR will not be used by KEKB, it will be used as a synchrotron light source and for accelerator experiments. At present, TRISTAN is controlled by a system using mini-computers and CAMAC [2], but modern technologies will be introduced for KEKB controls. To save money and manpower, the CAMAC system will be reused after rearrangement. The present control system for TRISTAN was designed about 15 years ago and has become very hard to maintain. It is clearly important to have a good control system for a modern intense beam asymmetric collider. The quality of the control system required by KEKB is much higher and the quantity greater than that of the present system. However, the progress in the fields of computer hardware and software seems to give us the chance to have a more sophisticated control system and to make it possible for us to construct a control system which satisfies requirements in both quality and quantity. The preliminary design has been reported previously [4].