Ponderomotive coupling and scattering of lower hybrid waves by density fluctuations in a tokamak plasma

The nonlinear coupling of lower hybrid (LH) waves with low frequency density fluctuations, via ponderomotive (PM) forces, is numerically studied by means of a 2D code which solves the coupled equations for the slowly varying amplitude of the LH electric field and for the plasma density. It is shown that the continuous injection of LH power excites small scale density perturbations corresponding to a broadening of the pump wave spectrum.