STATUS OF THE CONTROL SYSTEM FOR THE STB AT TOHOKU UNIVERSITY

A stretcher-booster ring (STB) was constructed and has been commissioned. The STB control system based on personal computers (PCs) and programmable logical controllers (PLCs) has been developed. The PCs respectively function as a database server, a PLC manager, as operator consoles, signal digitizers for wave form observation, video/signal processors for beam monitors, a ramp-up pattern generator for booster-ring mode operation, and as a WWW server for providing accelerator information to the internet. The PLCs are used as an interface between the computer system and accelerator devices, and act as a device driver. Since the STB has three operation modes, its operation is very complex. So the multi-mode STB will operate smoothly, a database system is employed in the core of the control system; database plays a very important role as a control manager rather than simply as a data storeroom. The use of the database enhances the flexibility of the control system. When the booster-ring is used to ramp up beam energy from 300MeV to 1.2GeV, bending and quadrupole magnet currents must be boosted in one second, in accordance with the increasing beam energy. We have developed a ramping wave form generator to drive the magnet power supplies. In this paper, we introduce the STB control system and report on its recent status.