title: High contrast Kr gas jet K alpha x-ray source for high energy density physics experiments.
abstract: A high contrast 12.6 keV Kr K alpha source has been demonstrated on the petawatt-class Titan laser facility using strongly clustering Kr gas jet targets. The contrast ratio (K alpha to continuum) is 65, with a competitive ultrashort pulse laser to x-ray conversion efficiency of 10(-5). Filtered shadowgraphy indicates that the Kr K alpha and K beta x rays are emitted from a roughly 1x2 mm(2) emission volume, making this source suitable for area backlighting and scattering. Spectral calculations indicate a typical bulk electron temperature of 50-70 eV (i.e., mean ionization state 13-16), based on the observed ratio of K alpha to K beta. Kr gas jets provide a debris-free high energy K alpha source for time-resolved diagnosis of dense matter.
authors.affiliation: Physics Department, University of California Los Angeles, Box 951547, Los Angeles, California 90095, USA.
authors.forename: N L
authors.initials: NL
authors.lastname: Kugland
authors.forename: P
authors.initials: P
authors.lastname: Neumayer
authors.forename: T
authors.initials: T
authors.lastname: Döppner
authors.forename: H-K
authors.initials: HK
authors.lastname: Chung
authors.forename: C G
authors.initials: CG
authors.lastname: Constantin
authors.forename: F
authors.initials: F
authors.lastname: Girard
authors.forename: S H
authors.initials: SH
authors.lastname: Glenzer
authors.forename: A
authors.initials: A
authors.lastname: Kemp
authors.forename: C
authors.initials: C
authors.lastname: Niemann