Modelling extreme ultraviolet ablation interactions

Compact extreme ultraviolet (EUV) laser sources can be used for laboratory-scale ablation experiments at intensities of 1 × 1011 Wcm−2 and higher. The depths of ablation achieved using focused laser output at 46.9 nm to irradiate solid targets of aluminum, gold, and copper have been modeled. Two simple models are considered; an adaptation of an ultra-short pulse model, and an ablation velocity model. We show that the attenuation length of the material plays an important role in the physics of the ablation. A more detailed one-dimensional model including absorption by inverse bremsstrahlung absorption and photo-ionization, corrected to include electron degeneracy effects, is used to evaluate the opacity of the ablation plasma and subsequent ablation depths.