High Power Heating in the Ion Cyclotron Range of Frequencies in the Wisconsin
A. P. Biddle and J. C. Sprott
Department of Physics, University
of Wisconsin, Madison, WI 53706, U.S.A.
(Received 2 October 1980)
Fast wave heating at the second, third and fourth harmonics of the ion
cyclotron resonance, and slow wave heating at the fundamental in a single
ion species hydrogen plasma, are found to be in good agreement with warm
plasma theory at rf power levels <= 130 kW. Ion heating is negligible
off an eigenmode. Ion body temperatures are more than doubled to 75 eV
from the 35 eV ohmically heated case with tails comprising 8% of the plasma
at 320 eV. No deleterious effects except a non-disruptive 10% shortening
of the discharge length caused by impurity influx are noted. A passive
mode tracking technique allows ~ 40% increase in power deposition in a
passing eigenmode over that of a fixed frequency rf source. Ion temperatures
are limited by charge exchange due to the < 50 eV central temperature
and the small 13 cm radius current channel.
Ref: A. P. Biddle and J. C. Sprott, Plasma
Physics 23, 679-691 (1981)
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