Parametric conversion of a lower hybrid wave into a whistler in a plasma

A large amplitude lower hybrid wave parametrically decays into a whistler wave and a low frequency lower hybrid wave in a plasma. The density perturbation due to the low frequency wave couples with the oscillatory velocity due to the pump wave to produce a nonlinear current, driving the whistler. The pump and whistler exert a low frequency ponderomotive force on electrons, driving the lower hybrid decay wave. The growth rate of the parametric instability scales linearly with the amplitude of the pump wave. It decreases with the electron cyclotron frequency. The process is relevant to beam plasma systems where lower hybrid waves are excited with greater ease and the whistler sideband wave can be seen outside the plasma as electromagnetic emission. (c) 2008 American Institute of Physics.