High power microwave generation and beam transport in the PASOTRON/sup TM/ BWO source

Abstract

Summary form only given, as follows. The PASOTRON/sup TM/ high-power microwave source utilizes a unique plasma-cathode electron gun and self-generated plasma channel to inject a long-pulse electron beam into a slow-wave structure for microwave generation. The plasma-channel beam transport eliminates the need for an externally-applied axial magnetic field to confine the beam, which results in a very compact low weight HPM source compared to conventional technologies. The PASOTRON/sup TM/ is normally configured as a backward-wave oscillator (BWO), and has produced over 10-MW of peak power and /spl ges/500 Joules per pulse. We will present the operation of the PASOTRON/sup TM/ device for a variety of rippled-wall and helix slow-wave structures. The physics of the plasma channel formation and beam focusing has been studied and a computer model of this process has evolved. A diagnostic tube with two rows of probes extending down the length of the tube at 90/spl deg/ to each other has been used to examine the radial profile of the beam as it propagates as a function of time and axial distance. The dynamics of the plasma channel formation and the plasma density over time will be presented and compared to the model.