Power supply system for superconducting magnets at KEKB-IR

At KEKB, a pair of superconducting magnets is installed symmetrically with respect to the Tsukuba Interaction Region in order to focus and steer the beams. Two quadrupole magnets are being prepared to focus the beams, two solenoid coils are to shield the magnetic field of the solenoid coil of the detector, and 6 correction coils are to steer the beams. These magnets are to be energized by high-stability power supplies to maintain a long-term magnetic field. This paper discusses the details concerning the power supplies and their control.