Effects of magnetic curvature on the lower-hybrid-drift instability.

A local dispersion relation is derived for the lower-hybrid-drift instability including the effects of magnetic curvature associated with transverse electromagnetic perturbations. To account for the curvature drift, an alternative method proposed by Nakamura [Phys. Plasmas 4, 3765 (1997)] is applied to obtain the perturbed distribution function. It is found that the previous treatment, i.e., simulating the curvature drift by a virtual gravitational drift, is considerably inaccurate. When an ambient magnetic field has a curvature so that the curvature drift is directed opposite the ∇B drift, the maximum growth rate increases as long as the radius of curvature is larger than a certain value, while the rate decreases for a sharper magnetic field curvature. At the same time, the wave number giving the maximum growth decreases monotonically. The growth rate is increased by a curvature drift coincident with the ∇B drift. The effects of the magnetic curvature become larger in high-beta plasmas. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]