Lower Hybrid Heating of an Electron-Cyclotron-Resonance Plasma in a Canted Magnetic Mirror

Plasma heating at the lower hybrid resonance was studied experimentally in a canted magnetic mirror in order to determine the effects of magnetic field curvature on heating efficiency. Heating occurred mainly on what would be the "outside" of an equivalent torus, peaking near the hybrid resonant layer. The best conditions for heating were seen to be a relatively flat density profile of magnitude slightly below that where hybrid resonance would be expected. The density profile was seen to move "outward" as cant angle was increased, while the hybrid layers were seen to move oppositely, toward what would be the inside of the torus. No significant deleterious effects on the efficiency of the lower hybrid resonant heating (LHRH) were observed as the canting was changed.