Time-dependent filamentation and stimulated Brillouin forward scattering in inertial confinement fusion plasmas
- Plasma Physics Division, Naval Research Laboratory, Washington, DC 20375 (United States)
- Institute for Laser Science and Applications and Department of Applied Science, University of California, Davis--Livermore, Livermore, California 94551 (United States)
Numerical simulations of the temporal evolution of laser light filamentation and stimulated Brillouin forward scattering (SBFS) in plasmas, under conditions that are relevant to laser fusion, are presented and analyzed. Long term unsteady behavior of filaments is observed to be the norm. Temporal and spatial incoherence due to filamentation and SBFS are impressed upon time-independent incident laser beams. The bandwidth and angular divergence imposed upon the beam increase with the strength of the interaction. In addition, the spectrum of the transmitted light is redshifted by an amount that increases with the interaction strength. Spectral analysis of the transmitted light reveals that SBFS plays a role in the generation of the observed temporal incoherence. Incident beams with some spatial incoherence but no temporal smoothing are compared to those with {ital ab initio} temporal beam smoothing (TBS). Under typical conditions, TBS beams will undergo far less angular and spectral spreading and far less SBFS than unsmoothed beams.
- OSTI ID:
- 573970
- Journal Information:
- Physics of Plasmas, Vol. 5, Issue 2; Other Information: PBD: Feb 1998
- Country of Publication:
- United States
- Language:
- English
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