Control system for the two-arm spectrometer system at RCNP

We have designed and constructed a new control system for the two-arm spectrometers and West–South (WS) beam line at RCNP. The system controls not only the magnets of the spectrometers but also movable devices such as slits. All the instruments are controlled by the system through a local area network. For the dipole magnets of the spectrometers, a high-performance feedback system based on a proportional–integral–differential algorithm was implemented. We have succeeded to change and stabilize the magnetic fields within ±0.05 mT in about 5 min and within about ±0.02 mT after 10 min. The performance of the feedback system satisfies the requirement for the high-resolution experiments with the Grand Raiden spectrometer by using the dispersive beam from the WS beam line.