Electron parallel velocity and temperature gradient driven electrostatic fluctuations in nonuniform magnetoplasmas

Abstract

The combined effects of the electron-temperature (ET) and parallel electron velocity (PEV) gradients on electrostatic instabilities in a nonuniform magnetoplasma are investigated. For this purpose, a hybrid approach is used, in which the electrons are treated as a magnetized fluid, while the ions are described by means of a kinetic description. A new dispersion relation is derived, which shows how different plasma modes are linear coupled in the presence of the ET and PEV gradients. The dispersion relation is analyzed analytically (numerically) to demonstrate the instability of long- and short-wavelength electrostatic modes (to examine the combined effects of ET and PEV gradients) in nonuniform magnetoplasmas. The present results may be useful in understanding the salient features of nonthermal fluctuations and associated anomalous cross-field electron fluxes in forthcoming laboratory experiments. © 2007 American Institute of Physics.