2012 journal article

A VHF driven coaxial atmospheric air plasma: electrical and optical characterization

JOURNAL OF PHYSICS D-APPLIED PHYSICS, 45(19).

By: B. Byrns n, D. Wooten n, A. Lindsay n & S. Shannon n 

co-author countries: United States of America πŸ‡ΊπŸ‡Έ
Source: Web Of Science
Added: August 6, 2018

Abstract A coaxially driven VHF plasma source for atmospheric air plasmas has been built and characterized. Electrical and optical characterization of this source present a unique operating regime when compared to state of the art atmospheric systems such as dielectric barrier discharge, pulsed dc, microwave, or ac blown arc discharges. The discharge does not appear to produce streamers or arcs, but instead remains as a steady-state glow located at the end of the inner coaxial power feed. Plasma impedance was determined by comparing the loaded and unloaded impedance of the coaxial source RF input; this termination impedance was combined with a simple high-frequency global model to estimate an electron density of approximately 10 11 cm βˆ’3 at 400 W delivered power in air. Optical emission characterization of the source shows a monotonic increase in emission with respect with power; the relative intensity of the peaks from excited species, however, remains constant over a power range from 300 to 600 W. This unique source geometry presents a possible pathway for high gas throughput, large area, high power density processes such as surface modification, air purification, media removal and chemical surface treatment.