FACILITY UTILITY CONTROL SYSTEM OF XFEL/SPRING-8

The XFEL facility under construction at SPring-8 requires highly stable RF phase and intensity control for steady X-ray lasing. The RF conditions are very sensitive to facility utilities and environmental conditions such as air temperature, power line voltage, and in particular, the cooling water temperature of accelerating structures. Therefore, these utilities need to be monitored with a required sampling rate and resolution from the viewpoint of the accelerator control. In particular, the cooling water for the accelerating structure should be controlled seamlessly from the XFEL control system to achieve steady lasing. We have designed and constructed a control system for the facility utilities as a part of the XFEL accelerator control using the MADOCA framework. In this system, all the data from the facility utilities are stored in the same database. This should help in investigating the relations between the beam stability and the environmental conditions. All the utility equipment is controlled using PLCs connected to VME systems through FL-net. We set up PLC touch panels to support the daily management independently of the accelerator control system.