The Appearance of Beat Frequencies Caused by AIC Waves in an Analysis of End-Loss Ion Current in the Tandem Mirror

Abstract

Alfévn ion-cyclotron (AIC) waves of various frequencies have been measured in the central cell of a tandem mirror, excited due to non-isotropic ion heating. Differential frequencies of the AIC waves were observed by analyzing the fluctuations of the end-loss ion current. From the analysis of both the frequency and intensity of the fluctuations, it was found that the differential frequencies are generated by the beat phenomenon caused by the AIC waves. The AIC waves affect the ion transport in the velocity space, and this phenomenon can be used to investigate the ion transport from the trapped region to the loss region in the tandem mirror.