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 Ω_i ≪ ω ≪ Ω_e and long parallel wavelengths ɛ≡L_⊥/L_∥ ≪ 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.