Improved Confinement Phase in Ramping Up Plasma Current by Toroidal Field

Abstract

Using a small pulse of toroidal vortex eletric field (4.4V/m, 0.45ms), plasma current is successfully ramped up from the plateau (55kA) to the second plateau (60kA) with a ramp rate dIp/dt>12MA/s on a time scale much fast than the classical skin time in the HT-6M Tokamak. The phenomena of improved confinement is observed in the present experiment. Particle confinement time is enhanced 2.1 times and energy confinement time, meanwhile, is enhanced 1.6 tines after ramping current up.