STABILIZING EFFECTS OF HOT ELECTRONS ON LOW FREQUENCY PLASMA DRIFT WAVES

The MHD equation is used to study the stabilization of low frequency drift waves driven by density gradient of plasma in a hot electron plasma. The dispersion relation is derived, and the stabilizing effects of hot electrons are discussed. The physical mechanism for hot electron stabilization of the low frequency plasma perturbations is charge uncovering due to the hot electron component, which depends only on a, the ratio of Nb/Nt, but not on the value of βh. The hot electrons can reduce the growth rate of the interchange mode and drift wave driven by the plasma, and suppress the anomalous plasma transport caused by the drift wave. Without including the effect of βh, the stabilization of the interchange mode requires α≈2%, and the stabilization of the drift wave requires α≈40%. The theoretical analyses predict that the drift wave is the most dangerois low frequency instability in the hot electron plasma.