REDUCED MAGNETOFLUID DYNAMICS IN THE LOWER-HYBRID FREQUENCY-RANGE

The electromagnetic two-fluid dynamics for plasmas in a strong applied magnetic field is investigated using a model for phenomena having frequencies in the range OMEGA-i much less than omega much less than OMEGA-e, and long parallel wavelengths epsilon = L perpendicular-to/L parallel-to much less than 1. The model retains the essential nonlinear physics of the magnetosonic, lower-hybrid, and oblique whistler waves. At least two unstable modes can exist for equilibria with magnetic shear; a local magnetic interchange whistler mode and a collisionless tearing mode. These modes are studied using a quadratic energy relation for linear stability and by three-dimensional time-dependent numerical computations.