High Repetition Rate Pulsers for Beam Switching Magnets

This paper describes a type of pulsed power supply which has been developed to energize deflection magnets with a field of either direction, for a right or left beam deflection, on a pulse-to-pulse basis, at repetition rates up to 360 pulses per second, and to recover most of the energy at the end of the pulse. The scheme consists basically of using ignitron tubes to switch energy stored in a capacitor bank to the pulsed magnet and back to the capacitor bank with relatively small losses, and using a dc supply to recharge the capacitor bank between pulses. Two capacitor banks, one charged to a positive polarity and the other to a negative polarity, with their associated ignitron tubes, are connected to one magnet to permit energizing the magnet with a field in either direction as desired on a pulse-to-pulse basis. The two capacitor banks can be charged to different voltages, thus permitting the deflection of two different energy beam pulses. The current pulse through the magnet is a one-cycle sine wave of the resonant frequency of the capacitance of the energy storage bank and the inductance of the magnet, with the timing of the pulse arranged such that the beam passes through the magnet at the peak of the sine wave. Regulation of the peak current in the magnets to the order of 0.1% has been achieved.