Experimental study of energy transport in thin Al and Au foils irradiated with a 263-nm laser

Irradiating an ultraviolet (uv) laser on aluminum (Al) and gold (Au) thin targets, emissions from the rear side of the targets were temporally resolved. A clear difference was observed between the above two targets. Given the fact that absorbed laser energy can be converted with a very high efficiency to soft x rays in a high-Z plasma, a characteristic emission peak only observed for Au targets was attributed to the effect of soft x-ray energy transport. The observed results were compared with those computed by a one-dimensional hydrodynamic simulation himico. The ablation pressures estimated from the emissions indicate that the pressure scaling for Au is close to the one by x-ray drivers rather than by a uv laser.