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Abstract

Present-day RF heating and current drive experiments in tokamaks are very often characterised by strong distortions of the electron or ion velocity distribution functions. This is due to the RF-induced diffusion in velocity space which, for high wave power, can easily be dominant over Coulomb collisions and lead to the generation of high energy tails. These distorted distribution functions can be described by simple analytical models in special cases only. A unified approach to describe the plasma behaviour in these regimes consists of solving the appropriate quasilinear Fokker-Planck equation for the phase-space distribution function. The main physical effects to be included in this equation and the numerical methods used to solve it are discussed. In order to illustrate the method, some applications to electron-cyclotron and lower-hybrid waves interacting with superthermal electrons are presented.

Additional information

Authors: GIRUZZI G, CEA, Département de Recherches sur la Fusion Contrôlée, Saint-Paul-lez-Durance (FR)
Bibliographic Reference: Paper presented: International Workshop "Strong Microwaves in Plasmas", Suzdal (SU), Sept. 18-23, 1990
Availability: Available from (1) as Paper EN 35755 ORA
Record Number: 199011586 / Last updated on: 1994-12-02
Category: PUBLICATION
Original language: en
Available languages: en