Design of a radiographic integrated test stand (RITS) based on a voltage adder, to drive a diode immersed in an high magnetic field

Abstract

Advanced radiography capabilities can be provided by diodes in which a <1 mm diameter cathode is immersed in a /spl sim/60 T magnetic field and pulsed to /spl sim/16 MV. An electron current of /spl sim/50 kA is constrained by the magnetic field to /spl sim/1 mm at the anode, and produces V 1 krad at 1 m. A 16 MV, 50 ns flat-top voltage adder has been designed that is optimum to develop such diodes. The adder approach is chosen to give a relatively short risetime and low prepulse. It also has the advantage of being re-configurable to provide two 8 MV pulses. The pulser uses standard Marxes, intermediate stores, and water PFLs. Novel features include an oil prepulse switch, an induction cell that is fed from one point, and a blocking network to couple two pulses to one cell. Based on detailed simulations, a design has been completed through detailed drawings and prototype hardware will be tested next year.