Power Supply System for Beam Steering

The power supply system for steering the Bates Linac beam provides continuous adjustment of the current from + 2.5A to -2.5A per pair of coils at ±25 volts. A simple, inexpensive system has been assembled from off-shelf components. Separate controls for 26 pairs of coils are provided by means of power operational amplifiers and drivers connected in series with the coils across a common pair of ±30V busses. No current regulation is used. After coils and amplifiers have reached thermal equilibrium (about one-half hour at 2.5A) the current is stable within 0.5%.