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Abstract

The particles heated by an obliquely incident electron cyclotron wave are those whose velocities satisfy the resonance condition which is, in the non-relativistic case, omega + k-zv-z + OMEGA = O and in a weakly relativistic plasma, omega + k-zv-z + OMEGA(1 + 1/2 v**2/c-2) = O We concentrate on effects arising from this change in the velocity space region. To calculate the effect of the waves on the particle distribution function we take the usual quasilinear diffusion term. To calculate the current driven we use the theory of Fisch and Boozer. Using the weakly relativistic dielectric tensor elements given by Shkarofsky, we calculate the attenuation of the wave as it passes through the resonance and find values of total current per unit absorbed power to be expected in a Tokamak. A few results are given to illustrate the main effects of the relativistic energy dependence of the cyclotron frequency. e.g. Fig. 4 shows the ratio of the total current to power for a Tokamak of radius 3m and temperature 1 keV (function of angle for the three possible ways of getting energy to the cyclotron resonance). It is found that the current driven in a Maxwellian plasma is far too small to be useful. Further studies of electron cyclotron current drive in non-Maxwellian plasmas are needed, particularly under high power conditions. To achieve significant improvements in current drive efficiency the population of electrons with high parallel velocities must be enhanced.

Additional information

Authors: CAIRNS R A, UNIVERSITY OF ST. ANDREWS (UK);CULHAM LABORATORY, ABINGDON, OXON (UK);OWEN J, UNIVERSITY OF ST. ANDREWS (UK);CULHAM LABORATORY, ABINGDON, OXON (UK);LASHMORE DAVIES C N UNIVERSITY OF ST. ANDREWS (UK), UNIVERSITY OF ST. ANDREWS (UK);CULHAM LABORATORY, ABINGDON, OXON (UK);CULHAM LABORATORY, ABINGDON, OXON (UK), UNIVERSITY OF ST. ANDREWS (UK);CULHAM LABORATORY, ABINGDON, OXON (UK)
Bibliographic Reference: NON-INDUCTIVE CURRENT DRIVE IN TOKAMAKS - IAEA TECHNICAL COMMITTEE MEETING, CULHAM LABORATORY (UK), APRIL 18-21, 1983. PROCEEDINGS: VOL. II, PP. 496-501 WRITE TO CEC LUXEMBOURG, DG XIII/A2, POB 1907 MENTIONING PAPER E 31918 ORA
Availability: Can be ordered online
Record Number: 1989124038200 / Last updated on: 1987-01-01
Category: PUBLICATION
Available languages: en