Instability versus equilibrium propagation of a laser beam in plasma.
We obtain, for the first time, an analytic theory of the forward stimulated Brillouin scattering instability of a spatially and temporally incoherent laser beam that controls the transition between statistical equilibrium and nonequilibrium (unstable) self-focusing regimes of beam propagation. The stability boundary may be used as a comprehensive guide for inertial confinement fusion designs. Well into the stable regime, an analytic expression for the angular diffusion coefficient is obtained, which provides an essential correction to a geometric optic approximation for beam propagation.
Lushnikov
Pavel M
PM
Theoretical Division, Los Alamos National Laboratory, MS-B213, Los Alamos, NM 87545, USA.
Rose
Harvey A
HA