On the ion acceleration by high power electromagnetic waves in the radiation pressure dominated regime

When the laser pulse radiation pressure is dominant, the efficiency of the laser energy transformation into the energy of relativistic ions is very high. An analysis of the stability of a thin plasma slab accelerated by the radiation pressure shows that the onset of a Rayleigh-Taylor-like instability can lead to transverse bunching of the slab. At the nonlinear stage of the instability development the plasma slab breaks up into separated clumps, which are accelerated by the wave radiation pressure. An indication of the effect of radiation pressure on the bulk target ions is obtained in the experimental studies of plasma jets ejected from the rear side of thin solid targets irradiated by ultra-intense laser pulses. (authors)