Experimental Scaling for Mass Ablation Rate in Planar Targets Irradiated by Smoothed 0.351 µm Laser Beam

Layered planar targets, consists of Al and Au layers, were irradiated by smoothed 0.351-µm-high power laser with relatively large focus spot on Xingguang II laser facility. The burn-through time of laser ablation to Al sample has been obtained by measuring the delay time of Au N-Band x-ray emission with respect to the Al K-Band x-ray emission. The scaling law of mass ablation rate with the laser flux has been obtained by only varying the laser energy on the target surface on different shots. The experimental scaling law is greatly different from the results of Key et al. [Phys. Fluids 23(1983) 2011] and is in good agreement with the analytical model.