Electrostatic-mode coupling of beat-excited electron plasma waves

Thesis/Dissertation · Wed Jan 01 00:00:00 EST 1986

OSTI ID:5852313

Darrow, C B

The nature of the spectrum of electrostatic waves excited when two laser beams beat in a plasma containing a density ripple is investigated theoretically, experimentally, and computationally. A theoretical model for the beat-wave-excitation process in a rippled-density plasma is developed. The model predicts the generation of a rich spectrum of plasma modes with frequencies equal to the beat frequency of the two laser beams and wave numbers equal to integer multiples of the ripple wavenumber. For commonly encountered experimental parameters, a new beat-wave saturation mechanism was found that can limit the amplitude of the beat wave to a value below that expected for the widely quoted relativistic detuning process. The effects of stimulated Raman scattering, ion wave harmonics, and other coupling mechanisms are also discussed. CO/sub 2/ laser experiments designed to study and characterize beat-wave excitation and mode coupling were conducted. Results of collective ruby laser Thomson scattering and other measurements of the electrostatic and scattered electromagnetic spectra are presented. Despite the richness in physics of the experiment, the simple model is able to predict the observed behavior and characteristics of the beat wave and coupled modes.

• Research Organization: California Univ., Los Angeles (USA)
• OSTI ID: 5852313
• Resource Relation: Other Information: Thesis (Ph. D)
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ELECTRON PLASMA WAVES
EXCITATION
ION WAVES
LASER RADIATION
MATHEMATICAL MODELS
MODE LOCKING
THOMSON SCATTERING
ELECTROMAGNETIC RADIATION
ENERGY-LEVEL TRANSITIONS
INELASTIC SCATTERING
PLASMA WAVES
RADIATIONS
SCATTERING
700108* - Fusion Energy- Plasma Research- Wave Phenomena