Linear and Nonlinear Wave-Particle Cyclotron Interaction for Whistler-Mode Waves in an Anisotropic Plasma

摘要

The temporal behavior of a large-amplitude whistler mode is analyzed in an anisotropic plasma. The nonlinear equation is solved for the wave amplitude as a function of time. It is found that, in the t approaches 0+ limit, the solution reproduces the linear theory. In the t approaches infinity limit the author finds that the amplitude approaches a limiting value, i.e. saturation sets in. Arguments are then given for the existence of frequency bands for which the linear growth rate and the nonlinear value of the saturated logarithmic decrement are of opposite sign. This means that for these frequencies, the linear and nonlinear theory are in conflict in their predictions of ultimate growth or damping of the wave. The reasons for and implications of this phenomenon are discussed, and a comparison with nonlinear electrostatic modes is made. (Author)