Recent results on heliotron E

Abstract

Recent results of the heating experiment on the Heliotron E plasma are reported. Two heating methods are applied; electron cyclotron resonance heating (ECRH) and neutral injection (NBI) heating. In the ECRH experiment, a currentless high-temperature plasma is produced with the use of a gyrotron capable of delivering an output power of 200 kW for 40-ms duration at 28 GHz. The electron and the ion temperatures at the center − T e(0) and T i(0) − 1.1 keV and 120 eV, respectively, and the average density n e of 5 × 10 12 cm −3 is obtained. The NBI heating has produced the plasma which has the temperatures of T e(0) ∼ T e(0) ∼ 660 eV and the density n e of 3 × 10 13 by the NBI power of about 1.6 MW. The heating efficiency has been found to be about 2 ( eV·P abs ( kW) n e (10 13 cm −3 ), where P abs is the absorbed neutral beam power, for bot perpendicular and 28° co- and counter-injection angles from the normal direction of the torus. The central beta value reaches about 1%.