Session RP1 - Poster Session VIII.
POSTER session, Thursday afternoon, October 30
Fran Hill Southeast Exhibit Hall, ACC
Second harmonic X-mode ECH produces and heats the plasma in HSX. Ray tracing calculations predict 40% first pass absorption at a plasma density of 1.5 x 10^18 m-3 and T_e of 400 eV. A set of absolutely calibrated microwave detectors is installed to measure the wave absorption,. The absorption efficiency is very high (about 0.9) in the QHS and Mirror configurations and drops to 0.6 in the Anti-Mirror mode where deeply trapped particles have direct loss orbits. Neutral gas breakdown studies show factors of five higher density growth rates in QHS compared to anti-Mirror. For QHS, the stored energy increases linearly with launched power and plasma density. The radiated power (mainly OII at the edge) increases linearly with absorbed power. Teo measured by Thomson scattering also rises linearly with heating power and reaches ~600 eV at 100 kW of launched power. A four channel ECE system has been implemented on HSX to provide information on the electron temperature profile.