Abstract
Plasma was generated in the focal region of a multikilowatt, 4.7-GHz continuous-wave (CW) microwave beam far removed from the walls of the vacuum chamber, minimizing the nonideal effects associated with plasma-wall and beam-wall interactions. Experiments were conducted with gas mixtures of argon, nitrogen, and oxygen at gas pressures ranging from 100 to 200 mtorr. Three types of discharges were observed during these experiments: unstable, quasi-stable, and stable discharges. It was determined that the stability of the discharges could be controlled through adjustments of the gas composition, gas pressure, and power of the microwave beam. This article reports on the operational conditions in which stable discharges were achieved and the general behavior of these discharges as the control parameters were varied.
Original language | English |
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Article number | 9211798 |
Pages (from-to) | 3832-3839 |
Number of pages | 8 |
Journal | IEEE Transactions on Plasma Science |
Volume | 48 |
Issue number | 11 |
DOIs | |
State | Published - Nov 2020 |
Funding
Manuscript received April 7, 2020; accepted September 6, 2020. Date of publication October 2, 2020; date of current version November 10, 2020. This work was supported by the Directed Energy Directorate of the United States Air Force Research Laboratory. The review of this article was arranged by Senior Editor D. A. Shiffler. (Corresponding author: Adrian Lopez.) Adrian Lopez was with the United States Air Force Research Laboratory, Kirtland Air Force Base, Albuquerque, NM 87117 USA. He is now with the Oak Ridge National Laboratory, Oak Ridge, TN 37830, USA (e-mail: [email protected]).
Keywords
- Electrodeless discharges
- microwave breakdown
- microwave plasma
- plasma stability