A one microsecond, thirty-five kilojoule, one hertz pulse generator'

Abstract

A repetitive high-voltage pulser has been developed at Sandia National Laboratories that will drive a vacuum diode for electron beam production. It is a 1 /spl mu/s, 200-kV, 1-ohm, 35-kJ unit that is designed to operate in the 1-10 Hz range (this report will cover the 1-Hz operation). The design concept utilizes a pulse forming network (PFN) to form the output waveshape. The pulser is developed in a modular concept that will allow series/parallel operation of the PFNs to meet changing energy and/or voltage needs. Achieving sufficiently low inductance is generally the chief design challenge in producing a low-impedance PFN. Because it allows the greatest amount of inductance in the circuit, the Guillemin/sup 1/ type C' PFN is used in each module. Several capacitive stages are charged to +100 kV (maximum) and then discharged (by spark-gap switches) through turned inductances to obtain a relatively square waveform. A PFN consisting of two stages (the main energy storage stage and a pulse shaping stage) was evaluated in this study. Each stage generates a different harmonic of the desired waveshape. When the outputs of both stages are added together at the load, the resultant waveform has the desired shape and amplitude. This paper focuses on the design and operation of the high-voltage module and a pulser which was developed using two of the modules in series. Design philosophy, module fabrication. and operational results will be presented. Each component of the pulser is discussed.