Plasma confinement and RF heating on the heliotron DM and D devices

The parameters of the Heliotron DM device, the purpose of the experiment and preliminary results for the confinement of Ohmic plasma are described. It is observed that the magnetic limiter configuration is well established. A high-current-density plasma (j approximately 150Acm-2, B approximately 9kG) has been obtained. Two kinds of RF heating experiments, one involving an ion cyclotron wave (ω approximately ωsub(ci)) and the other one a shear Alfven wave (ω approximately ksub(parallel) vsub(A), are reported. The successful plasma heating in both cases is explained by mode-converted processes at the perpendicular resonance in the hot-electron plasma. (author)