Experiments on parametric instability of lower hybrid mode

Near the lower hybrid frequency a h.f. electric field was applied to an argon plasma in a glass tube, perpendicularly to longitudinal magnetic field. At certain value of the electric field the low and high frequency oscillations were excited. The matching conditions for frequency and wave number, were confirmed. The low frequency oscillation was identified to be the electro-static ion cyclotron wave (cyclotron sound), and the connection of plasma heating with the parametric instability was examined. (author)