Electrostatic ion cyclotron waves: Plasma heating, frequency shifts and linewidths

Abstract

Ion cyclotron waves cannot be quasilinearly stabilized in Q-machine experiments because the electron distribution function does not have time to flatten while electrons pass through the plasma volume. We invoke a turbulently dissipative (or ‘resonance broadening’) model to explain the observed steady-state mode saturation. We give a qualitative picture of the important nonlinear features and their implications for plasma heating experiments. We extend the turbulently dissipative model to give nonlinear frequency shifts and a description of the mode linewidths in steady-state experiments. Turbulent resistivity is calculated and found to be unobservably small compared to the classical value. Implications for further experiments are discussed.