Lower hybrid electron cyclotron heating and associated parallel cooling

Abstract

We have observed cxpcrimcntally that during electron cyclotron heating the electron longitudinal temperature drops as the perpendicular temperature increases. An r.f. source of 2.45 GHz and 1.0 kW was used. When an addilional r.i. source (lower hybrid wave) of 30 MHz and 0.35 kW was introduced, it heated the plasma via the lower hybrid res~nance at I = 5.0 cm without, however, destroying the anisotropy in the temperature. The experiment was carried out in a linear mirror machine with a lowdensity (-10" cm-') weakly-ionized ( < 1 .0%) plasma.