A new modulator controller of the PLS linac

The 2-GeV electron linac at Pohang accelerator laboratory (PAL) has been operated continuously as a full energy injector for the Pohang Light Source (PLS) since Dec. 1994. There have been continuous efforts to improve the klystron-modulator (K&M) system to make it more stable and reliable. To improve self-diagnostic, operation, monitoring, and remote communication, we developed a new modulator controller based on an industrial PC platform. The modulator controller mainly consisted of an interlock signal conditioning module, a fast pulse signal-conditioning module, and the main PC platform. Operating system of the PC is Windows NT 4.0, and application software is developed with C++. The interlock signal-conditioning module generally carries digital and slowly varying clean analog signals. The fast pulse signal-conditioning module is used for preconditioning fast pulse and DC signals that inherently have high noise levels, such signals as a beam voltage, a beam current, an EOLC current, a HVDC voltage, and a HVDC current. All operation data of the K&M system can be acquired and saved in real time. We are upgrading the main PLS, control system with EPICS. The industrial PC platform will function as an input/output controller (IOC) in the future EPICS PLS control system.