Theory of filamentation instability and stimulated Brillouin scattering with nonlocal hydrodynamics

A linear theory of stimulated Brillouin scattering and filamentation instab ilities has been formulated using nonlocal transport equations for a laser heated plasma, resulting in a model which is fully equivalent to a lineariz ed kinetic description. The inverse-Bremsstrahlung heating, nonlocal energy redistribution, and ponderomotive laser-plasma interactions are correctly taken into account contributing to a new generalized driving force for thes e instabilities. Temporal and spatial growth rates, thresholds and dominant perturbation wavelengths are obtained. This theory predicts substantial mo difications of the ponderomotive results for conditions relevant to many la ser plasma interaction experiments. A new nonlocal and nonlinear model of l aser propagation in weakly collisional plasmas has been derived. (C) 2000 A merican Institute of Physics. [S1070-664X(00)00205-6].