Plasma confining potential self-consistently formed by local electron cyclotron resonance in a well-shaped magnetic field

Abstract

It is clearly demonstrated by means of two-and-a-half-dimensional particle simulations that a plasma potential structure is created by local electron cyclotron resonance (ECR) in a plasma flow along a well-shaped magnetic field. The potential structure consists of a negative potential dip and a positive potential hump (plug/barrier potential) around the ECR point at the magnetic-well bottom. In addition, the simulation points out that a spatial deviation of the electron- and ion-density profiles is generated by the ECR, resulting in the formation of the plug/barrier potential to self-consistently compensate it. According to an analysis of the ion energy distribution function parallel to the magnetic field in the upstream region, the height of the plug potential is found to reach the value equivalent to the ion energy corresponding to the high-energy tail component, plugging most of the ions not to pass through the region of the magnetic variation.