title: Picosecond time-resolved X-ray absorption spectroscopy of ultrafast aluminum plasmas.
abstract: We have used point-projection K-shell absorption spectroscopy to infer the ionization and recombination dynamics of transient aluminum plasmas. Two femtosecond beams of the 100 TW laser at the LULI facility were used to produce an aluminum plasma on a thin aluminum foil (83 or 50 nm), and a picosecond x-ray backlighter source. The short-pulse backlighter probed the aluminum plasma at different times by adjusting the delay between the two femtosecond driving beams. Absorption x-ray spectra at early times are characteristic of a dense and rather homogeneous plasma. Collisional-radiative atomic physics coupled with hydrodynamic simulations reproduce fairly well the measured average ionization as a function of time.
authors.affiliation: Laboratoire pour l'Utilisation des Lasers Intenses (LULI), UMR 7605, CNRS-CEA-Université Paris VI-Ecole Polytechnique, 91128 Palaiseau, France.
authors.forename: P
authors.initials: P
authors.lastname: Audebert
authors.forename: P
authors.initials: P
authors.lastname: Renaudin
authors.forename: S
authors.initials: S
authors.lastname: Bastiani-Ceccotti
authors.forename: J-P
authors.initials: JP
authors.lastname: Geindre
authors.forename: C
authors.initials: C
authors.lastname: Chenais-Popovics
authors.forename: S
authors.initials: S
authors.lastname: Tzortzakis
authors.forename: V
authors.initials: V
authors.lastname: Nagels-Silvert
authors.forename: R
authors.initials: R
authors.lastname: Shepherd
authors.forename: I
authors.initials: I
authors.lastname: Matsushima
authors.forename: S
authors.initials: S
authors.lastname: Gary
authors.forename: F
authors.initials: F
authors.lastname: Girard
authors.forename: O
authors.initials: O
authors.lastname: Peyrusse
authors.forename: J-C
authors.initials: JC
authors.lastname: Gauthier