Experimental data are presented which show that during lower-hybrid, radio-frequency heating of the Princeton University adiabatic toroidal compressor tokamak, parametric instabilities are excited, and the ion heating correlates with the presence of the parametric spectra. A theoretical interpretation of the parametric instabilities is presented.

• Received 29 November 1976

DOI:https://doi.org/10.1103/PhysRevLett.38.230