Nonlinear Theory of Electron Oscillations of a Collisionless Plasma in a Uniform Magnetic Field

摘要

Possibility of excitation of finite amplitude longitudinal waves in a collisionless and cold plasma in the presence of uniform magnetic field is demonstrated. Such waves are found to be anharmonic in shape, in contrast to the usual harmonic, that is, sinusoidal waves of the linear theory. These nonlinear plasma waves arise as a result of nonlinear motion and the dispersive nature of plasma media. The two competing processes, nonlinearity and dispersion in a moving plasma medium strike a balance to produce a quasi-steady state which can support finite amplitude waves. These waves are associated with large amplitude oscillating electric fields which may be responsible for coherent radio-to-microwave radiation from coronal plasma and particle acceleration during solar flares. The estimate of sporadic electromagnetic and particulate radiation is important for application to the solar flare patrol and the Air Force Communications System. (Author)