A Versatile High-Power Laser System for High Spatial Resolution Nanosecond Plasma Diagnostic in Electron-Beam Driven HPM Sources.
Abstract
The purpose of the acquired instrumentation was to perform high spatial resolution and nanosecond time resolution plasma diagnostics in intense electron beam-driven high power microwave (HPM) sources to better understand the "pulse shortening" problem. We have thus performed the first laser interferometry measurement inside a high power backward wave oscillator (or any other intense beam-driven HPM source for that matter) during the course of microwave generation reported in the literature. Line-integrated electron densities between 9 x 10(exp 15) and 2 x 10(exp 16)/sq cm for microwave powers between 20 and 120 MW have been measured. The two main sources of the measured electron density are postulated to be: (1) plasma generated from the cutoff neck due to beam scrape off and, (2) material removed and ionized from the slow wave structure walls during microwave generation. A catastrophic microwave discharge results in termination of subsequent microwave generation. Novel modifications to the inlet of the slow wave structure in intense beam-driven backward wave oscillators are suggested as a result of this research.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 01, 1999
- Accession Number
- ADA359964
Entities
People
- Edl Schamiloglu
Organizations
- University of New Mexico