Design and optimization of a lowimpedance pulsed power marx generator to drive a relativistic x-band magnetron

Abstract

Summary form only given. The relativistic magnetron provides a low-impedance (10-20 U) load that inherently needs matching to a low-impedance pulsed-power supply (gigawatt or greater power) to operate with maximum efficiency. One of the most common and reliable pulsed-power drivers used to accomplish this is a Marx generator. The University of New Mexico previously used a modified Pulseradreg 110 A electron beam accelerator to produce high-power microwaves from a backward wave oscillator (BWO), which was a high-impedance load (130 U). This driver will be used for planned experiments driving an X-band relativistic magnetron. The main part of the Pulserad's assembly is a Marx generator composed of capacitors, spark gaps and resistors electrically arranged in an 11-stage Marx circuit. The output impedance of the Marx generator is about ~35 U (which is why a shunt resistor was required to facilitate operation with the BWO), maximum charging voltage of each single stage is <100 kV, and total stored energy is about 600 Joules. In this presentation results of the design and optimization efforts aimed at reducing the intrinsic impedance of the Marx generator are discussed. In order to provide power from the Marx generator to an X-band relativistic magnetron, a coaxial transmission line and a vacuum-insulator interface will be used and their design will be discussed