Pulsed Power Supply System for the "Fast" Quadrupoles in the AGS

In the acceleration of polarized protons in the AGS, a number of depolarizing resonances will be encountered. Depolarization due to the so-called intrinsic resonances will be minimized by crossing each resonance in less than one beam revolution period (-2 ¿s). This will be accomplished with a set of twelve "fast" tune-shifting quadrupoles distributed symmetrically around the ring. During a typical acceleration cycle, the fast quads will be energized with a burst of alternating polarity, fast rise/slow fall triangular current pulses. The amplitude of these pulses will vary from 160 A to about 2700 A peak. This paper describes the development of the pulsed power supply for the fast quads, the construction of a prototype modulator and some of the initial test results obtained with the prototype.