Optical Measurements of Air Plasma
Abstract
Electron-beam impact ionization of air was studied in the context of optical diagnostics. The electron beam originates in a pulsed 100 keV 20-mA source and propagated through a 1/2 - mil aluminum transmission window into a 400-liter test cell. Plasma production in air was investigated over the pressure range of 636 Torr to 1 mTorr with pulse durations from 1 ms to 10 ms. Microwave diagnostics were used to quantify electron density and power; and an optical diagnostic was used to quantify ozone production. An additional effort to quantify byproducts of electron impact ionization, that are produced or consumed in the air plasma, resulted in preliminary results using laser-diode absorption spectroscopy to detect water vapor, carbon dioxide, and nitrous oxide. A transmission window and sensor to monitor the beam current was refined from a system that used a 1-mil aluminum foil to one with a 1/2-mil foil, which has greatly increased the beam current propagating through the foil into the test cell. This bas improved the signal-to-noise-ratio for both the microwave and optical diagnostics.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 05, 2008
- Accession Number
- ADA481323
Entities
People
- Robert J. Vidmar
Organizations
- University of Nevada, Reno