Circuit description of the power systems for pulsed septum magnets at APS

The author describes the design and simulation of power circuits for the four Advanced Photon Source (APS) pulsed septum magnets which will be transformer type or transformer coupled to their switching circuits. Three are for synchrotron injection, extraction, and storage ring injection, operating at a 2 Hz pulse rate; one is for the Positron Accumulator Ring (PAR) operating at a 60 Hz pulse rate for both injection and extraction. The septum current pulse is approximately a half-sine-wave with a base width of approximately 1/3 ms and has a peak current, repeatable within +or-0.05%, in the transformer primary between 3.5 kA and 4.7 kA. The septum magnets have a primary inductance between 16 mu H and 23 mu H. Circuit design considerations of the switching, logic, and simulations are presented.<>