Numerical modeling of pulsed laser evaporation of aluminum targets

A one dimensional thermal model was used to investigate the pulsed laser evaporation of aluminum targets. The gasdynamic flow of the vapor was predicted by solving one dimensional compressible flow equations for an inviscid fluid. The variation of the threshold laser fluence for target evaporation with respect to target surface reflectivity was investigated. The threshold laser fluence predicted by a thermal evaporation model was larger than the values obtained experimentally. The effects of the ambient pressure and the laser fluence on the local Mach number of the vapor at the edge of the Knudsen layer were studied. The structure of the gasdynamic flow including the shock wave and the contact surface was shown in the density profiles. (C) 1998 Elsevier Science B.V