Plasma current ramp-up by waves in the lower hybrid frequency range on TST-2
Abstract
Noninductive plasma current (Ip) ramp-up by RF power is being studied on TST-2. A tokamak configuration with Ip ~= 1 kA is formed spontaneously by injecting RF power (2.45 GHz, 200 MHz or 21 MHz). Subsequent Ip ramp-up is achieved by gradual increases of RF power and vertical field. As Ip is ramped up, the fraction of RF driven current becomes larger, and a clear dependence on wave directionality becomes observable. Up to 12 kA of Ip has been achieved by launching a traveling wave in the co current drive direction. X-ray measurements indicate gradual increases of electron temperature and superthermal electron population. An attempt is being made to obtain information on superthermal electrons from directional Langmuir probe measurements.
- Publication:
-
APS Division of Plasma Physics Meeting Abstracts
- Pub Date:
- October 2011
- Bibcode:
- 2011APS..DPPNP9082T