Ablation of volatile films by laser heating of substrates

Thermal ablation of frozen layers of solid nitrogen were studied experimentally by irradiating condensed layers on a quartz crystal microbalance with a nitrogen laser at the standard wavelength 337.1 nm. The nitrogen layer is transparent to the incoming laser light and the ablation (vaporization) is caused by heat transfer from the underlying silver substrate layer, Experimental data are compared to calculated data from a three-laver finite-difference heat conduction model. The model takes into account the strong dependence of material parameters on the temperature. Calculated data are presented for water ice as well. The consequences of thermal ablation of volatile films by laser heating of substrates in existing experiments and methods are discussed. (C) 1998 American Institute of Physics. [S0021-8979(98)04702-1].