Electron-temperature-gradient-driven drift waves and anomalous electron energy transport

Abstract

By means of a kinetic description for ions and Braginskii's fluid model for electrons, we derive three coupled nonlinear equations governing the dynamics of low-frequency short-wavelength electrostatic waves in the presence of equilibrium density, temperature and magnetic-field gradients in a two-component magnetized plasma. In the linear limit we present a dispersion relation that admits new instabilities of drift waves. An estimate of the anomalous electron energy transport due to non-thermal drift waves is obtained by making use of the saturated wave potential, which is deduced from the mixing-length hypothesis. We also present stationary solutions of the nonlinear equations governing the interaction of linearly unstable drift waves. The relevance of our investigation to wave phenomena in space and laboratory plasmas is pointed out.