Measurement of Atmospheric Pressure Air Plasma via Pulsed Electron Beam and Sustaining Electric Field

摘要

An apparatus to study the generation of plasma in air was designed, fabricated, and assembled. A 400-liter test cell was developed to study plasma in air which has a pressure that can be varied from standard atmospheric pressure at sea level to 1 mTorr at 300,000 ft. Plasma is generated by impact ionization of air due to bombardment by a 100-kev electron beam. Microwave diagnostics quantify electron number density and optical diagnostics quantify ozone production. A particle in cell plasma code (MAGIC) and an air-chemistry code are used to quantify beam propagation through an electron-beam transmission window into air and the volumetric ionization rate within the test cell. Sensors were developed to monitor beam current incident on a transmission window and the resulting plasma formed in air on the transmission side of the window. Diagnostics from multiple sensors are acquired simultaneously for studies of power required to generate and maintain plasma in air on the timescale of 1 ms.