Parametric excitation of backward ion cyclotron wave with a pump in the lower hybrid range

Experimental results of a resonant decay of a whistler wave into a lower hybrid wave and a backward ion cyclotron wave in argon and neon plasmas are presented. For omega 0 >4 omega LH the parametrically excited modes obey the dispersion relations of the linear theory and the selection rules of the resonant decay. Thresholds, behaviour and absolute values, are compared with results of homogeneous theories of parametric instabilities.