Saturation of the decay instability for comparable electron and ion temperatures
We present a model for the nonlinear evolution of the electron plasma-ion acoustic decay instability when the electron to ion temperature ratio is of order unity. Ion nonlinear Landau damping is found to be the dominant saturation mechanism. The saturateed spectral intensity is computed analytically and is found to be highly peaked in the direction along the pump electric field. For pump-field intensities, E/sub 0//sup 2//4..pi.., large compared to the threshold value, E/sub T//sup 2//4..pi.., the total fluctuation energy density, E/sub W//sup 2//4..pi.., varies as the square of the pump intensity. The absorption coefficient is larger than the ordinary collisional absorption, nu/sub c/, by a factor (..pi../8 (nu/sub e/..omega../sub a//nu/sub c/nu/sub a/)(E/sub 0//E/sub T/)/sup 2/ + 1), with ..omega../sub a/ the acoustic frequency, and nu/sub e/(nu/sub a/) plasma (acoustic) wave damping decrement. An estimate is given of the energy that the enhanced fluctuations absorb from an electromagnetic wave incident on an inhomogeneous plasma. 13 refs.
- Research Organization:
- Princeton Univ., NJ (USA). Plasma Physics Lab.
- DOE Contract Number:
- AC02-76CH03073
- OSTI ID:
- 6014528
- Report Number(s):
- MATT-876; ON: DE88002005
- Country of Publication:
- United States
- Language:
- English
Similar Records
Theory of plasma heating by nonlinear excitation of lower hybrid resonance
Damping of large-amplitude plasma waves in a collisionless plasma
Related Subjects
700107 -- Fusion Energy-- Plasma Research-- Instabilities
700108* -- Fusion Energy-- Plasma Research-- Wave Phenomena
DAMPING
DECAY INSTABILITY
ELECTRIC FIELDS
ELECTROMAGNETIC RADIATION
ELECTRON TEMPERATURE
ENERGY DENSITY
FLUCTUATIONS
HOMOGENEOUS PLASMA
INHOMOGENEOUS PLASMA
INSTABILITY
ION ACOUSTIC WAVES
ION TEMPERATURE
ION WAVES
LANDAU DAMPING
NONLINEAR PROBLEMS
PARAMETRIC INSTABILITIES
PLASMA
PLASMA INSTABILITY
PLASMA MACROINSTABILITIES
PLASMA WAVES
RADIATIONS
VARIATIONS