Measurement of Alfvén ion-cyclotron wave using both X- and O-mode reflectometers

Abstract

Alfvén ion-cyclotron wave excited in the central-cell plasma of the GAMMA 10 tandem mirror is investigated by a reflectometer system. The Fourier amplitude of the instability strongly depends on the anisotropy of the ion velocity distribution function and the plasma β value. The ratio 0.2–0.3 between O-mode and X-mode reflectometer signals suggests that a magnetic fluctuation level similar to the density fluctuation level is excited in the plasma due to the instability.