Tuning magnet current-conditioning system for RF cavity in a high-intensity proton accelerator

The development of a current-conditioning system for the tuning magnet of an RF cavity in a high-intensity proton accelerator is described. The conceived system has a bridge configuration consisting of a power amplifier, transistor switch, and power diodes. It works as a power amplifier during the acceleration period and recovers into the capacitor bank the inductive energy stored in the tuning magnet during the reset period. The system operation concept was verified by computer simulation, and the system design was based on the test results of a 1/100th scale model, which was built to evaluate the feasibility of hardware realization. The hardware system was built with commercially available components and tested in connection with a prototype RF cavity at the Los Alamos National Laboratory. This system can provide an accurate current waveform (low ripple), recover the inductive energy in the tuning magnet, and easily control the DC bias level