Coupling of ICRF Waves and Axial Transport of High-Energy Ions Owing to Spontaneously Excited Waves in the GAMMA 10 Tandem Mirror

Plasmas with high ion-temperature of several keV and strong temperature anisotropy of more than 10 have been produced by using ion-cyclotron range of frequency (ICRF) heating in the GAMMA 10 tandem mirror. In such high performance plasmas with strong anisotropy, high-frequency fluctuations, so-called Alfvén-Ion-Cyclotron (AIC) waves, are spontaneously excited. The AIC waves have several discrete peaks in the frequency spectrum. Couplings between ICRF waves for heating and excited AIC waves are clearly observed in the central cell of GAMMA 10. Low frequency waves which have differential frequencies between discrete peaks of the AIC waves are also observed. Parametric decay of ICRF waves are discussed and pitch angle scattering of high-energy ions owing to those low-frequency waves are clearly detected. Energy transport along the magnetic field line is one of the important subjects when the ICRF power is injected in the perpendicular direction to magnetic field line.