Charge and Nuclear Dynamics Induced by Deep Inner-Shell Multiphoton Ionization of CH3I Molecules by Intense X‑ray Free-Electron Laser Pulses

• Published in: The journal of physical chemistry letters Vol. 6; no. 15; pp. 2944 - 2949
• Main Authors: Motomura, Koji, Kukk, Edwin, Fukuzawa, Hironobu, Wada, Shin-ichi, Nagaya, Kiyonobu, Ohmura, Satoshi, Mondal, Subhendu, Tachibana, Tetsuya, Ito, Yuta, Koga, Ryosuke, Sakai, Tsukasa, Matsunami, Kenji, Rudenko, Artem, Nicolas, Christophe, Liu, Xiao-Jing, Miron, Catalin, Zhang, Yizhu, Jiang, Yuhai, Chen, Jianhui, Anand, Mailam, Kim, Dong Eon, Tono, Kensuke, Yabashi, Makina, Yao, Makoto, Ueda, Kiyoshi
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 06.08.2015
• Subjects: Coulomb explosion; multiphoton multiple ionization; X-ray free-electron laser; ultrafast dynamics; charge transfer
• ISSN: 1948-7185; 1948-7185
• DOI: 10.1021/acs.jpclett.5b01205

In recent years, free-electron lasers operating in the true X-ray regime have opened up access to the femtosecond-scale dynamics induced by deep inner-shell ionization. We have investigated charge creation and transfer dynamics in the context of molecular Coulomb explosion of a single molecule, exposed to sequential deep inner-shell ionization within an ultrashort (10 fs) X-ray pulse. The target molecule was CH3I, methane sensitized to X-rays by halogenization with a heavy element, iodine. Time-of-flight ion spectroscopy and coincident ion analysis was employed to investigate, via the properties of the atomic fragments, single-molecule charge states of up to +22. Experimental findings have been compared with a parametric model of simultaneous Coulomb explosion and charge transfer in the molecule. The study demonstrates that including realistic charge dynamics is imperative when molecular Coulomb explosion experiments using short-pulse facilities are performed.