Formation of Low Aspect Ratio Torus Equilibria by ECH in the LATE Device

Abstract

By ECH under a steady Bv field, a closed field equilibrium of a low aspect ratio as low as R/a = 1.4 is spontaneously formed in the LATE device. After the spontaneous formation, the plasma current has increased further up to Ip = 7.2 kA by 2.45 GHz, 30 kW and Ip = 11 kA by 5 GHz, 120 kW, by increasing the microwave power with a slow ramp of Bv for the equilibrium of the plasma loop at larger currents. Both amount to 12% of the total toroidal coil current. ECH/ECCD at 2nd harmonic resonance of EBW supports the plasma. An outline of the theoretical considerations for the formation process is presented.