Electron cyclotron emission from tokamak plasmas with mildly superthermal electrons

Abstract

The emission of cyclotron radiation from a tokamak plasma in the presence of a high toroidal current is investigated. For the fundamental frequency, a theory of the radiation which consistently includes the hot plasma polarization effects is developed. The high current density electron system is described by a distribution function which is the sum of two Maxwellian functions representing the body of the electron population and a small fraction of superthermal drifting electrons, respectively. The emission of the ordinary and extraordinary modes in the equatorial plane of the torus for quasi-perpendicular propagation is investigated numerically. It is found that the radiation temperature deduced from the emission of radiation on the high Bt side of the torus differs from that on the low Bt side, where Bt is the confining magnetic field.