Influence of plasma motion on propagation of supersonic radiation waves

It is shown that in the case of a small-diameter plasma column formed in a gas by a laser pulse, the plasma expansion in the lateral direction reduces the density and the absorption in the central part of the column. Absorption waves are generated as a result of this effect and as a result of emission of radiation by the plasma itself; these waves travel not only antiparallel (opposite) to the laser beam but also parallel to the beam. Numerical solutions of a two-dimensional transient radiation–gasdynamic problem yielded the parameters and made it possible to study the evolution of a plasma under these conditions.