title: Deep inner-shell multiphoton ionization by intense x-ray free-electron laser pulses.
abstract: We have investigated multiphoton multiple ionization dynamics of xenon atoms using a new x-ray free-electron laser facility, SPring-8 Angstrom Compact free electron LAser (SACLA) in Japan, and identified that Xe(n+) with n up to 26 is produced at a photon energy of 5.5 keV. The observed high charge states (n≥24) are produced via five-photon absorption, evidencing the occurrence of multiphoton absorption involving deep inner shells. A newly developed theoretical model, which shows good agreement with the experiment, elucidates the complex pathways of sequential electronic decay cascades accessible in heavy atoms. The present study of heavy-atom ionization dynamics in high-intensity hard-x-ray pulses makes a step forward towards molecular structure determination with x-ray free-electron lasers.
authors.affiliation: Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Fukuzawa
authors.forename: S-K
authors.initials: SK
authors.lastname: Son
authors.forename: K
authors.initials: K
authors.lastname: Motomura
authors.forename: S
authors.initials: S
authors.lastname: Mondal
authors.forename: K
authors.initials: K
authors.lastname: Nagaya
authors.forename: S
authors.initials: S
authors.lastname: Wada
authors.forename: X-J
authors.initials: XJ
authors.lastname: Liu
authors.forename: R
authors.initials: R
authors.lastname: Feifel
authors.forename: T
authors.initials: T
authors.lastname: Tachibana
authors.forename: Y
authors.initials: Y
authors.lastname: Ito
authors.forename: M
authors.initials: M
authors.lastname: Kimura
authors.forename: T
authors.initials: T
authors.lastname: Sakai
authors.forename: K
authors.initials: K
authors.lastname: Matsunami
authors.forename: H
authors.initials: H
authors.lastname: Hayashita
authors.forename: J
authors.initials: J
authors.lastname: Kajikawa
authors.forename: P
authors.initials: P
authors.lastname: Johnsson
authors.forename: M
authors.initials: M
authors.lastname: Siano
authors.forename: E
authors.initials: E
authors.lastname: Kukk
authors.forename: B
authors.initials: B
authors.lastname: Rudek
authors.forename: B
authors.initials: B
authors.lastname: Erk
authors.forename: L
authors.initials: L
authors.lastname: Foucar
authors.forename: E
authors.initials: E
authors.lastname: Robert
authors.forename: C
authors.initials: C
authors.lastname: Miron
authors.forename: K
authors.initials: K
authors.lastname: Tono
authors.forename: Y
authors.initials: Y
authors.lastname: Inubushi
authors.forename: T
authors.initials: T
authors.lastname: Hatsui
authors.forename: M
authors.initials: M
authors.lastname: Yabashi
authors.forename: M
authors.initials: M
authors.lastname: Yao
authors.forename: R
authors.initials: R
authors.lastname: Santra
authors.forename: K
authors.initials: K
authors.lastname: Ueda