Saturation of the lower-hybrid-drift instability by mode coupling. Memorandum report

A nonlinear mode-coupling theory of the lower-hybrid-drift instability is presented. A 2-D mode equation is derived which includes the nonlinear polarization and E X B electron drifts, adiabatic ions, and realistic sources and sinks of energy. It is found that the instability saturates by transfering energy from the growing, long wavelength modes to the damped, short wavelength modes. The saturation energy, mean square of the potential fluctuations, and diffusion coefficient are calculated self-consistently.