title: Near-ultraviolet luminescence of N2 irradiated by short X-ray pulses.
abstract: The Linac Coherent Light Source is an x-ray free-electron laser that recently demonstrated lasing in the 1.5-15 Å wavelength range. We report on luminescence measurements of a molecular nitrogen gas irradiated by ∼2  mJ, 80 fs x-ray pulses at energies of 0.83, 2.7, and 8.3 keV. These results provide a direct test of our current understanding of photoabsorption, electron dynamics, and fluorescence processes for such intense, ultrashort x-ray pulses. At 0.83 keV, the duration of the fluorescence signal depends strongly on space-charge effects. At 8.3 keV, space-charge effects are weak, and the signal duration is determined by the Auger electron dynamics.
authors.affiliation: Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA.
authors.forename: Stefan P
authors.initials: SP
authors.lastname: Hau-Riege
authors.forename: Richard M
authors.initials: RM
authors.lastname: Bionta
authors.forename: Dmitri D
authors.initials: DD
authors.lastname: Ryutov
authors.forename: Richard A
authors.initials: RA
authors.lastname: London
authors.forename: Elden
authors.initials: E
authors.lastname: Ables
authors.forename: Keith I
authors.initials: KI
authors.lastname: Kishiyama
authors.forename: Stewart
authors.initials: S
authors.lastname: Shen
authors.forename: Mark A
authors.initials: MA
authors.lastname: McKernan
authors.forename: Donn H
authors.initials: DH
authors.lastname: McMahon
authors.forename: Marc
authors.initials: M
authors.lastname: Messerschmidt
authors.forename: Jacek
authors.initials: J
authors.lastname: Krzywinski
authors.forename: Peter
authors.initials: P
authors.lastname: Stefan
authors.forename: James
authors.initials: J
authors.lastname: Turner
authors.forename: Beata
authors.initials: B
authors.lastname: Ziaja