Thermalization of Energetic Ion Beam in a Turbulent Plasma

Thermalization of energetic (0.7∼3 keV) ion beam in a turbulent plasma was studied experimentally. A helium ion beam was injected into the fluctuating plasma along the longitudinal magnetic field, and analysed by an electrostatic energy analyser combined with a Daly-type detector. By measuring also the potential fluctuation and the correlation time of the turbulent wave, it was found that the experimental results agreed with the theory of stochastic process in a turbulent plasma.