Observation of Competition between Drift Instability and Flute Instability in a Bounded Linear ECR Plasma

Abstract

Competition behavior between the drift instability and the flute instability has been investigated experimentally in a bounded linear electron cyclotron resonance (ECR) plasma. Time evolutions of the fluctuation in ion saturation currents clearly show the successive appearance of the two instabilities. The drift instability is excited first, then the flute instability appears along with the suppression of the drift instability, and finally, both fluctuations are stabilized. The cyclic competition process in these instabilities continues periodically, and is closely related to the radial density profile.