Ultrafast lasers and solids in highly excited states: results of hydrodynamics and molecular dynamics simulations

25th IUPAP Conference on Computational Physics

物理学;计算机科学

Inogamov, Nail A.^1 ; Zhakhovsky, Vasily V.^2 ; Khokhlov, Viktor A.^1 ; Ashitkov, Sergey I.^2 ; Emirov, Yusuf N.^3 ; Khichshenko, Konstantin V.^2 ; Faenov, Anatoly Ya^2,4 ; Pikuz, Tatiana A.^4 ; Ishino, Masahiko^4 ; Kando, Masaki^4 ; Hasegawa, Nobory^4 ; Nishikino, Masaharu^4 ; Komarov, Pavel S.^2 ; Demaske, Brian J.^5 ; Agranat, Mikhail B.^2 ; Anisimov, Sergey I.^1 ; Kawachi, Tetsuya^4 ; Oleynik, Ivan I.^1

Landau Institute for Theoretical Physics, Russian Academy of Sciences, Russia^1

Joint Institute for High Temperatures, Russian Academy of Sciences, Russia^2

Advance Materials Research Institute, Florida International University, United States^3

Quantum Beam Science Directorate, Japan Atomic Energy Agency, Japan^4

Department of Physics, University of South Florida, United States^5

关键词: Highly excited state;    Laser action;    Laser illumination;    Molecular dynamics simulations;    Optical wavelength;    Plasmon effects;    Single shots;    Surface layers;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/510/1/012041/pdf
DOI  :  10.1088/1742-6596/510/1/012041

学科分类：计算机科学（综合）

来源: IOP

【 摘 要 】

Action of ultrafast optical and X-ray lasers on metals is considered. It is known that under certain conditions surface structures appear as result of irradiation. Generation of nano-structures is usually associated with excitation of surface plasmons. But often structures do not have forms of ripples, and their spacial scales are order of magnitude less than optical wavelength. In the paper full description of surface nano-structures is given for the case of single shot laser action onto well polished boundaries. Plasmon effects are insignificant for this case and also for X-ray pulses. It is shown that structures are formed after laser illumination in a process of mechanical spallation of ultrathin surface layer of molten metal. Spallation is accompanied by a strong foaming of melt, breaking of foam, and freezing of foam remnants. Those remnants form chaotic nano-structures observed in experiments.