title: Demonstration of a 13-keV Kr K-shell x-ray source at the National Ignition Facility.
abstract: We report 3% conversion efficiency of laser energy into Kr K-shell (≈13 keV) radiation, consistent with theoretical predictions. This is ≈10× greater than previous work. The emission was produced from a 4.1-mm-diameter, 4-mm-tall gas pipe target filled with 1.2 or 1.5 atm of Kr gas. 160 of the National Ignition Facility laser beams deposited ≈700 kJ of 3ω light into the target in an ≈140 TW, 5.0-ns-duration square pulse. The Dante diagnostics measured ≈5 TW into 4π solid angle of ≥12 keV x rays for ≈4 ns, which includes both continuum emission and flux in the Kr He_{α} line at 13 keV.
authors.affiliation: Lawrence Livermore National Laboratory, P.O. Box 808, L-481, Livermore, California 94550, USA.
authors.forename: K B
authors.initials: KB
authors.lastname: Fournier
authors.forename: M J
authors.initials: MJ
authors.lastname: May
authors.forename: J D
authors.initials: JD
authors.lastname: Colvin
authors.forename: M A
authors.initials: MA
authors.lastname: Barrios
authors.forename: J R
authors.initials: JR
authors.lastname: Patterson
authors.forename: S P
authors.initials: SP
authors.lastname: Regan