Tuning magnet power supply

The particles in a rapid cycling accelerator are accelerated by RF cavities, which are tuned by DC-biased ferrite cores. The tuning is achieved by the regulation of bias current, which is produced by a power supply. The tuning magnet power supply utilizes a bridge circuit, supplied by a three-phase rectifier. During the rise of the current, when the particles are accelerated, the current is controlled with precision by the bridge which operates as a power amplifier. During the fall of the current, the bridge operates in a switching mode and recovers the energy stored in the ferrites. The recovered energy is stored in a capacitor bank. The bridge circuit is built with 150 power transistors. The drive, protection, and control circuit were designed and built from commercial components. The system will be used for an RF cavity experiment in Los Alamos and will serve as a prototype tuning power supply for future accelerators