Electron cyclotron current drive in a lower hybrid current drive plasma

摘要

Electron cyclotron(EC)current drive experiments drive experiments were carried out in lower hybrid current drive(LHCP)plasmas on the WT-3 tokamak. Using oblique injection of EC waves, plasma current is ramped up in a frequency rangeω/Ω≌1.1-1.4, whereΩ_e is the EC frequency at the plasma centre. This ramp-up is ascribed to selective EC heating of fast electrons in LHCD plasmas via the fundamental EC resonance at the upshifted frequency due to the Doppler effect. Fast electron momentum distribution are estimated from bremsstrahlung hard X ray spectra.