Nonlinear wave optics of parametric pump radiation in an inhomogeneous plasma

Journal Article · Sat Dec 01 04:00:00 EST 1973 · Phys. Fluids, v. 16, no. 12, pp. 2257-2269

DOI:https://doi.org/10.1063/1.1694294· OSTI ID:4314220

DuBois, D F; Goldman, M V; McKinnis, D

The nonlinear propagation of an intense (pump) beam of electromagnetic radiation that excites a parametric decay instability in an inhomogeneous plasma is calculated self-consistently. A generalization to an inhomogeneous plasma of the nonlinear absorptive conductivity calculated according to several recent theories for the saturated electron-ion-decay instability in a homogeneous plasma is added to the linear absorptive conductivity in the wave equation. A model is introduced for the qualitative change in the pump dependence of the nonlinear conductivity in the strong pumping limit. The resulting nonlinear wave equation for radiation propagating into a stratified plasma is integrated numerically. Application is made to the anomalous absorption of the modified radiation in ionosphere modification experiments and to absorption of laser-radiation in laser- produced plasmas. The reflection coefficient is computed as a function of incident power. Also computed are waveforms, the Poynting flux, and the ponderomotive force. Thesc are displayed as functions of position in the plasma. A distinct standing-wave pattem is showm to perist very near the reflection point even in cases of nearly total absorption. (auth)

• Research Organization: University of Colorado, Boulder, Colorado 80302
• Sponsoring Organization: USDOE
• NSA Number: NSA-29-023261
• OSTI ID: 4314220
• Journal Information: Phys. Fluids, v. 16, no. 12, pp. 2257-2269, Journal Name: Phys. Fluids, v. 16, no. 12, pp. 2257-2269; ISSN PFLDA
• Country of Publication: United States
• Language: English

Related Subjects

*INHOMOGENEOUS PLASMA-- WAVE PROPAGATION
ABSORPTION
BEAMS
IONOSPHERE
LASERS
N70900* --Physics--Controlled Thermonuclear Research--Wave Phenomena
NONLINEAR PROBLEMS
PLASMA INSTABILITY
PLASMA PRODUCTION