title: Spatially resolved analysis of Kα x-ray emission from plasmas induced by a femtosecond weakly relativistic laser pulse at various polarizations.
abstract: Spatially resolved K-shell spectroscopy is used here to investigate the interaction of an ultrashort laser pulse (λ=800 nm, τ=40 fs) with a Ti foil under intense irradiation (Iλ(2)=2×10(18)Wμm(2)cm(-2)) and the following fast electron generation and transport into the target. The effect of laser pulse polarization (p, s, and circular) on the Kα yield and line shape is probed. The radial structure of intensity and width of the lines, obtained by a discretized Abel deconvolution algorithm, suggests an annular distribution of both the hot electron propagation into the target and the target temperature. An accurate modeling of Kα line shapes was performed, revealing temperature gradients, going from a few eV up to 15-20 eV, depending on the pulse polarization. Results are discussed in terms of mechanisms of hot electron generation and of their transport through the preplasma in front of the target.
authors.affiliation: Intense Laser Irradiation Laboratory (ILIL), INO-CNR, Via G. Moruzzi 1, 56124 Pisa, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Cristoforetti
authors.forename: M P
authors.initials: MP
authors.lastname: Anania
authors.forename: A Ya
authors.initials: AY
authors.lastname: Faenov
authors.forename: A
authors.initials: A
authors.lastname: Giulietti
authors.forename: D
authors.initials: D
authors.lastname: Giulietti
authors.forename: S B
authors.initials: SB
authors.lastname: Hansen
authors.forename: P
authors.initials: P
authors.lastname: Koester
authors.forename: L
authors.initials: L
authors.lastname: Labate
authors.forename: T
authors.initials: T
authors.lastname: Levato
authors.forename: T A
authors.initials: TA
authors.lastname: Pikuz
authors.forename: L A
authors.initials: LA
authors.lastname: Gizzi
mesh_terms: D003198:Computer Simulation; D007834:Lasers; D008956:Models, Chemical; D058626:Plasma Gases / Q000737:chemistry* / Q000528:radiation effects*; D014965:X-Rays
chemical_list: D058626:Plasma Gases