Effect of Finite Electron Drift Velocity on the Resonant Excitation of a Nonuniform Plasma,
CALIFORNIA UNIV LOS ANGELES PLASMA PHYSICS GROUP
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An exact analytic solution of the external resonant excitation of a nonuniform plasma in the presence of a zero order finite electron drift is presented. The process of linear mode conversion of the long wavelength external radiation, of frequency omega, into a Langmuir wave limits the peak amplitude of the cold plasma resonance at omega omega sub p, where omega sub p is the local electron plasma frequency. The finite electron drift alters the effective group velocity of the Langmuir wave, and thus it modifies the peak amplitude of the resonance in a significant manner. For drifts toward the overdense side an amplitude enhancement is obtained, while for drifts toward the underdense side a severe quenching takes place. The effect is governed by a single scaled drift parameter, and significant modifications arise when its absolute value is greater than 1.
- Plasma Physics and Magnetohydrodynamics