Current Status of Control System for PLS 2-GeV Linac

The PLS 2-GeV electron linac at the Pohang Accelerator Laboratory (PAL) has been served as a full energy injector to the storage ring called the Pohang Light Source (PLS) since September 1994. The linac uses eleven 80-MW klystrons driven by 200-MW modulators. There are 42 constant gradient accelerating sections and 6 quadrupole triplets. A graphic-based real-time control system has been developed and used for the commissioning and the normal operation since 1994. The system has three layers of hierarchy; operator interface for machine control, device interface for data acquisition, and the supervisory layer which provides effective data processing and networking. After providing basic skeleton of machine control system, we added several features such as modulator control windows and RF signal display windows. Also, for beam diagnostics, beam loss monitors are added in the linac and the beam transport line. In this paper, we report the current status of the control system and upgrades during 1995-1996 period.