2-DIMENSIONAL PLASMA-FLOW PAST A LASER-BEAM

Analytical results are presented for laser beam deflection rate due to plasma flow when the ponderomotive force (PMF) is static and given. E xplicit expressions are obtained in various parameter regimes includin g that of weak PMF for the case of a coherent (diffraction limited) be am and a beam whose fluctuations are spatially homogeneous, as in the case of a model random phase plate beam. When the Landau damping coeff icient, gamma(0), is negligible and the beam is either coherent and cy lindrically symmetric, or random with isotropic fluctuations, the defl ection rate is obtained as a closed form function of plasma flow Mach number, M. For finite damping, results are expressed in terms of a uni versal, one dimensional integral parameterized by M and gamma(0). For arbitrary PMF and M small, the problem is identified with one in the t heory of random dielectric media. (C) 1997 American Institute of Physi cs.