Laser beam deflection in nonlinearly steepened flow profiles

A simple model is presented for laser beam deflection by nonlinear induced profile changes near the sonic point in an expanding plasma. The deflection angle scales as a weak power of the laser intensity, since the flow is resonantly perturbed. A significant deflection can occur even in the absence of filamentation which, however, can further enhance the deflection angle. Improved calculations of filamentation in flowing plasmas require consideration of these self-consistent modifications of the zeroth-order state, which can act to stabilize the instability. LASNEX calculations are used to illustrate the self-consistent profile changes and beam deflection. (Author)