Low-threshold surface modification of metals irradiated by picosecond soft X-ray laser pulses; Observation and modeling

ピコ秒軟X線レーザー照射による金属表面変形の低いしきい値について; 観測とモデル化

Pikuz, T.; Faenov, A.*; 石野 雅彦; Starikov, S. V.*; Stegailov, V. V.*; Norman, G. E.*; Fortov, V.*; Skobelev, I.*; Inogamov, N. A.*; Zhakhovsky, V. V.*; 保 智己*; 田中 桃子; 長谷川 登; 錦野 将元; 海堀 岳史*; 神門 正城; 河内 哲哉

Pikuz, T.; Faenov, A.*; Ishino, Masahiko; Starikov, S. V.*; Stegailov, V. V.*; Norman, G. E.*; Fortov, V.*; Skobelev, I.*; Inogamov, N. A.*; Zhakhovsky, V. V.*; Tamotsu, Satoshi*; Tanaka, Momoko; Hasegawa, Noboru; Nishikino, Masaharu; Kaihori, Takeshi*; Kando, Masaki; Kawachi, Tetsuya

Systematic experimental and theoretical studies of the surface modifications resulting from the interactions of both single and multiple SXRL pulses irradiation of metals have been provided. Developed models show that relatively slow electron-ionic relaxation in such metals results in maintaining of the high electron pressure in the near surface region for several picoseconds, that is sufficiently long for the development of the hydrodynamic response that causes the negative pressure region formation and the nanostructuring of a thin surface layer. Obtained results demonstrate that tensile stress created in metals by short X-ray pulse can produce spallative ablation of target even for drastically small X-ray fluencies, which open new opportunities for material nano processing.