Abstract
Parametric excitation of ion-ion hybrid mode by a large amplitude lower hybrid wave in a two ion species D-T plasma is investigated. The sideband lower hybrid wave, generated in the nonlinear coupling process, beats with the pump to exert a parallel ponderomotive force on electrons driving the low frequency mode. The density perturbation associated with the latter couples with the
drift due to the pump to produce a nonlinear current driving the sideband. The ion-ion hybrid mode frequency in a 50:50 D-T plasma is close to geometric mean of deuterium and tritium cyclotron frequencies. The growth rate increases with the wave number of the mode. It also increases with the increase in the ratio of deuterium to tritium density.