Obliquely propagating generalized lower-hybrid drift instability with nonlocal two-fluid theory in current sheet equilibrium

Abstract

By employing nonlocal two-fluid analysis, a class of obliquely propagating current sheet drift instabilities with frequency in the lower-hybrid frequency range is investigated. A series of unstable modes with multiple eigenstates are found by numerical simulation after electrostatic approximation. It is found that the growth rate of the unstable modes, whose eigenfunctions are localized at the current sheet edge, increases as the propagation more oblique. However, as the wave vector attains more and more field-aligned components, the maximum growth rate suffers an acute drop after a certain critical angle, beyond which it finally diminishes. On the other hand, the growth rate associated with modes located near the center of the current sheet is found to be less sensitive to the increase in propagation angle, although it does undergo a gradual decrease until it is stabilized when the mode becomes near-field aligned.