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Plasma buildup by short-pulse high-power microwaves

Authors :
Yasushige Yano
Sudeep Bhattacharjee
Hiroshi Amemiya
Source :
Journal of Applied Physics. 89:3573-3579
Publication Year :
2001
Publisher :
AIP Publishing, 2001.

Abstract

The buildup of a plasma produced by short-pulse (0.05–1.2 μs), high-power (60–100 kW) microwaves is studied in a pressure range of 10 mTorr–10 Torr, by measurements of the temporal variation of the current and the optical intensity. The plasma is produced in a cylindrical tube and confined by a minimum-B field. The buildup of the electron current and the optical intensity are found to continue beyond the end of the pulse, for a few to tens of μs depending upon the pressure, and a minimum in their peak values and buildup times occur around 1 Torr. Increase in microwave pulse duration increases the buildup rate and peak current, whereas the pulse repetition frequency (10–500 Hz) has only a weak influence. The results are discussed from the growth of electron temperature during the pulse, and the following plasma evolution after the end of pulse. Collisional wave absorption, electron cyclotron heating, and diffusion are found to play important roles in plasma production and maintenance over the pressure range.

Details

ISSN :
10897550 and 00218979
Volume :
89
Database :
OpenAIRE
Journal :
Journal of Applied Physics
Accession number :
edsair.doi...........5067cb2796e9b997e38432781a120988
Full Text :
https://doi.org/10.1063/1.1352565