It is shown that the parametric coupling of lower-hybrid waves with purelydamped convective cells leads to a purely growing instability. Under theseparametric instability conditions we found that the magnitude of the diffusioncoefficient obtained is essentially greater than the corresponding one for thecase of a stable plasma when the external pump wave is absent. We alsoinvestigated the inhomogeneous magnetized plasma with a density gradient. Weassume that such a plasma is subjected to the upper-hybrid pump wave which decaysinto the daughter upper-hybrid and electron drift waves. It is shown, in theregion above the instability threshold, that the turbulent diffusioncoefficient grows with an increasing density gradient and the intensity ofthe pump wave and is independent of the magnetic field.
Parametric decay instability near the upper hybrid resonance in magnetically confined fusion plasmas