Low Frequency Fluctuations in ICRF-Heated Plasmas on GAMMA 10

The high ion-temperature (> 10 keV) plasma has been performed in ion-cyclotron range of frequency (ICRF) heating experiments on the GAMMA 10 tandem mirror. In such a high performance plasma, low frequency density fluctuations are observed in relation to the applied ICRF powers. A drift-type fluctuation, that is excited when high power ICRFs for the plasma production are applied, is observed in the whole of GAMMA 10 with the finite wave length. The amplitude of the drift-type fluctuation depends strongly on the gas puffing rate, the ICRF antenna configuration and so on. The radial transport of high energy ions due to these fluctuations is studied.