EMISSION OF NON-THERMAL CYCLOTRON RADIATION FROM ICRF HEATED TFR TOKAMAK PLASMAS
Simultaneous observation of cyclotron emission radiated in the equatorial plane on the high and low magnetic field sides of a torus can be a very sensitive diagnostic to investigate the evolution of the electron distribution function. Of special interest is the study of the emitted radiation when a small mildly superthermal component of electrons is created by RF heating via electron Landau damping. In this case the theory predicts that, for a given frequency, the radiation intensities toward the high and low magnetic field sides of the torus can be different, resulting from the combination of relativistic mass variation and magnetic field inhomogeneity. The results of the observation of a strongly asymmetric emission in the TFR tokamak during 1 MW ICRF heating experiments are reported. A first attempt to explain these results within the framework of the theory of the cyclotron emission of a Maxwellian plasma with a superimposed small superthermal population which is attributed to the absorption of te slow converted wave by the electron population through Landau damping is also presented. Using a two-Maxwellian trial distribution from the best fit with the experimental results the main parameters of the superthermal population and its spatial distribution are estimated.
Bibliographic Reference: WORKSHOP ON DIAGNOSTICS FOR FUSION REACTOR CONDITIONS, VARENNA, COMO (ITALY), SEPT. 6-17, 1982, PP. 169-175 351 P., 1983, ISBN 0-08-031161-X WRITE TO PERGAMON PRESS LTD., HEADINGTON HILL HALL, OXFORD, OX3 0BW (ENGLAND), PRICE: UKL 47, (EUR 8351 EN).
Record Number: 1989123107700 / Last updated on: 1987-01-01
Available languages: en