A Compact, Low Jitter, 1 kHz Pulse Repetition Rate Gas-Switched Pulse Generator System

Abstract

We present the results of an experimental research effort focused on developing a compact, low jitter, command triggered, high peak power, high pulse repetition rate (PRR), gas-switched pulse generator system. The pulse generator is command triggered by a single TTL level pulse generated by a control system implemented using software and a computer interface card. The TTL trigger pulse fires a solid-state trigger pulser that closes the first stage switch in a modular Marx-like pulse generator. The control system also sets the charge voltage of a 2500 J/s high voltage capacitor charging power supply and inhibits capacitor charging during firing of the pulse generator. The individual Marx stages are compact and stackable and utilize surface mount multilayer ceramic chip capacitors and field enhanced spark gap switches. The stage capacitors are charged in parallel through mutually coupled inductors in series with resistors. This charging scheme allows for high PRR operation limited only by the stage switch recovery time and the power of the capacitor charging power supply. The stage switches are optically coupled to aid in Marx erection and to minimize system jitter. The Marx generator is housed in a pressure vessel and operated in a low pressure dry air environment. The design exhibits a low inductance which is estimated to be <20 nH based on the measured output voltage rise time and load resistance. The pulse generator system has been operated in a burst mode at a PRR in excess of 1 kHz with good output voltage regulation. The jitter of the Marx generator, characterized independent of the trigger pulse, was measured and found to be ~500 ps.