High Harmonic Fast Wave Heating in Pegasus
Abstract
An RF power system has been developed to provide up to 1 MW of heating to the Pegasus plasma using high harmonic fast wave (HHFW) heating at frequencies of about 20 times the ion cyclotron frequency (15 MHz). The antenna consists of a pair of straps driven at 180 degrees of phase, with a parallel wavenumber of 10 per meter. The antenna is rotatable to allow alignment with the local magnetic field. The antenna design and phasing were chosen for heating with minimal impurity generation. It has a 50 percent transparency, stainless-steel Faraday shield, closed stainless sidewalls, and closed septum between the straps. The power system consists of the 1 MW (upgradeable to 2 MW) system originally developed on the Phaedrus-T tokamak, but it has been upgraded with new output cables and improved instrumentation. Low-power loading tests into Pegasus plasmas have shown 2 ohms loading resistance (2 straps in parallel, 180 degree phasing). High power tests have begun. The primary goal is to increase the plasma beta, but modifying the plasma resistivity and/or aiding in plasma startup will also be explored.
- Publication:
-
APS Division of Plasma Physics Meeting Abstracts
- Pub Date:
- October 2001
- Bibcode:
- 2001APS..DPPRP1037P