NONLINEAR EFFECTS IN ELECTRON-CYCLOTRON PLASMA-HEATING

Nonlinear absorption of an ordinary wave propagating through a plasma perpendicular to a unidirectional magnetic field with a frequency close to the electron gyrofrequency is studied. Electron motion is described using a Hamiltonian averaged over rapid gyromotion. The wave evolution in space and time is governed by two equations for the wave amplitude and phase averaged over the wavelength. A case of strong nonlinearity is considered in which the energy absorbed by an electron from the wave is greater than its thermal energy. For this case, the amount of absorbed power is computed analytically assuming it to be small compared with the power of the microwave beam. An effect of nonlinear refraction of the wave is discussed. © 1990 American Institute of Physics.