title: Demonstration of up-conversion fluorescence from Ar clusters in intense free-electron-laser fields.
abstract: Extreme ultraviolet (EUV) fluorescence emitted from Ar clusters irradiated by intense EUV free electron laser (FEL) pulses has been investigated. The EUV fluorescence spectra display rich structure at wavelengths shorter than the incident FEL wavelength of 51 nm. The results suggest that multiply-charged ions are produced following the ion-electron recombination processes which occur in the nanoplasma created by multi-photon excitation during the intense EUV-FEL pulses.
authors.affiliation: UVSOR, IMS, Nishigo-Naka 38, Myodaiji, Okazaki, Aichi 444-8585, Japan. iwayama@ims.ac.jp
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Iwayama
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Nagasono
authors.forename: James R
authors.initials: JR
authors.lastname: Harries
authors.forename: Eiji
authors.initials: E
authors.lastname: Shigemasa
mesh_terms: D001128:Argon / Q000737:chemistry* / Q000528:radiation effects*; D003198:Computer Simulation; D004579:Electron Transport / Q000528:radiation effects; D004583:Electrons; D005453:Fluorescence; D007834:Lasers; D008027:Light; D008956:Models, Chemical
chemical_list: D001128:Argon