Recent experiments in gas-filled hohlraums suggest that laser beams refract more than calculated by the hydrocode LASNEX. Three-dimensional simulations show that filamentation or forward Brillouin scattering in flowing plasma causes a deflection in the inferred direction of the appropriate magnitude. Simulations also show that temporal beam smoothing can suppress this effect.

• Received 2 January 1996

DOI:https://doi.org/10.1103/PhysRevLett.77.1298