title: Fast-electron-relaxation measurement for laser-solid interaction at relativistic laser intensities.
abstract: We present measurements of the fast-electron-relaxation time in short-pulse (0.5 ps) laser-solid interactions for laser intensities of 10(17), 10(18), and 10(19) Wcm2, using a picosecond time-resolved x-ray spectrometer and a time-integrated electron spectrometer. We find that the laser coupling to hot electrons increases as the laser intensity becomes relativistic, and that the thermalization of fast electrons occurs over time scales on the order of 10 ps at all laser intensities. The experimental data are analyzed using a combination of models that include Kalpha generation, collisional coupling, and plasma expansion.
authors.affiliation: Physics and Advanced Technologies, Lawrence Livermore National Laboratory, University of California, Livermore, California 94550, USA.
authors.forename: H
authors.initials: H
authors.lastname: Chen
authors.forename: R
authors.initials: R
authors.lastname: Shepherd
authors.forename: H K
authors.initials: HK
authors.lastname: Chung
authors.forename: A
authors.initials: A
authors.lastname: Kemp
authors.forename: S B
authors.initials: SB
authors.lastname: Hansen
authors.forename: S C
authors.initials: SC
authors.lastname: Wilks
authors.forename: Y
authors.initials: Y
authors.lastname: Ping
authors.forename: K
authors.initials: K
authors.lastname: Widmann
authors.forename: K B
authors.initials: KB
authors.lastname: Fournier
authors.forename: G
authors.initials: G
authors.lastname: Dyer
authors.forename: A
authors.initials: A
authors.lastname: Faenov
authors.forename: T
authors.initials: T
authors.lastname: Pikuz
authors.forename: P
authors.initials: P
authors.lastname: Beiersdorfer