Light scattering by a relativistic plasma driven by an ultraintense laser source

By means of the numerical study of the dynamics of a plasma irradiated by a n ultraintense laser beam, we analyze two major effects induced by the rela tivistic dynamics of the target's particles. First, we show how the magneti c term in the Lorentz force leads to inhomogeneities in the plasma surface- charge density. We demonstrate that the induced inhomogeneities are regular when the impinging field intensity has a uniform transversal profile. This regularity gives rise to a grating-like structure, which may be detected b y observation of the held reflected by the plasma target. The second effect studied is linked with the anisotropic character of the Lienard-Wiechert f ields associated with the plasma particles. This velocity-dependent anisotr opy enhances plasma oscillations as the plasma particles quiver in response to the incident electromagnetic wave. The result of this plasmon enhanceme nt may be observed by inspection of the harmonic intensities of the light t ransmitted by a thin plasma slab irradiated by a high-intensity laser beam.