28 GHZ ELECTRON - CYCLOTRON WAVES IN THE THOR TOKAMAK PLASMA
Microwave radiation at 28 GHz has been launched ar power levels up to 130 kW from the low magnetic field side by means of a polarizing antenna which provides a single beam polarized as an O-mode; its efficiency is greater than 96% for TE-01 illumination. The beam width at 3 db is + 4 degrees. A twist reflector inside the vacuum vessel returns the wave polarized as an x-mode with 60% efficiency. The overall transmissivity of the transmission line is greater than 95%. A general agreement with other ECH experiments is observed as far as the dependence of the increase in the energy content on peak density, resonance position and RF power is concerned. An absorption efficiency in the order of 60-70% is deduced from global energy measurements, while the bulk temperature increase is limited to less than 40 eV. Enhanced signals from those diagnostics which are sensitive to suprathermal electrons are also seen during and after the RF pulse. These experimental evidence suggest that both thermal and non thermal effects are induced by the EC waves, either directly at the resonance or through conversion at the upper hybrid layer.
Bibliographic Reference: COURSE AND WORKSHOP ON APPLICATIONS OF RF WAVES TO TOKAMAK PLASMAS, VILLA MONASTERO, VARENNA (ITALY), SEPT. 5-14, 1985 PP. 811-816, VOL. II 908 P., 1985, VOL. I AND VOL. II WRITE TO MONOTYPIA FRANCHI, VIALE UMBRIA 28/C, 06012 CITTA DI CASTELLO, PERUGIA (I
Record Number: 1989124097300 / Last updated on: 1987-01-01
Available languages: en