Laser ablation of gold; Experiment and atomistic simulation

Starikov, S. V.*; Stegailov, V. V.*; Norman, G. E.*; Fortov, V. E.*; Ishino, Masahiko; Tanaka, Momoko; Hasegawa, Noboru; Nishikino, Masaharu; Oba, Toshiyuki*; Kaihori, Takeshi; Ochi, Yoshihiro; Imazono, Takashi; Kawachi, Tetsuya; Tamotsu, Satoshi*; Pikuz, T. A.*; Skobelev, I. Y.*; Faenov, A. Ya.*

The interaction of radiation of a picosecond X-ray laser (wavelength = 13.9 nm) with targets made of a thick gold film has been studied theoretically and experimentally. It has been shown experimentally that the action of individual X-ray laser pulses with a fluence of 21 mJ/cm initiates the nanostructuring of the gold surface. Explicitly taking into account the electron subsystem, we have proposed an atomistic model of ablation that makes it possible to adequately described the experimental results. The atomistic simulation involves the ion-ion potential depending on the electron temperature . The use of such a potential makes it possible to take into account an increase in the pressure in the system with increasing and to reveal two laser ablation mechanisms.