Nonlinear Resonance Cone Surfaces

The nonlinear modification of the equation describing the surface (the resonance cone) on which the maximum electric field occurs in a magnetized plasma excited by an arbitrary, axially symmetric, localized RF source is derived. The nonlinearity is assumed to be due to the ponderomotive force. The nonlinear modification of the slope of the resonance cone is most pronounced near the plasma and upper hybrid frequencies, and is inversely proportional to the distance from the exciter. For frequencies of the lower branch the slope is decreased, whereas for upper branch frequencies the slope is increased.