title: An x-ray backlit Talbot-Lau deflectometer for high-energy-density electron density diagnostics.
abstract: X-ray phase-contrast techniques can measure electron density gradients in high-energy-density plasmas through refraction induced phase shifts. An 8 keV Talbot-Lau interferometer consisting of free standing ultrathin gratings was deployed at an ultra-short, high-intensity laser system using K-shell emission from a 1-30 J, 8 ps laser pulse focused on thin Cu foil targets. Grating survival was demonstrated for 30 J, 8 ps laser pulses. The first x-ray deflectometry images obtained under laser backlighting showed up to 25% image contrast and thus enabled detection of electron areal density gradients with a maximum value of 8.1 ± 0.5 × 10(23) cm(-3) in a low-Z millimeter sized sample. An electron density profile was obtained from refraction measurements with an error of <8%. The 50 ± 15 μm spatial resolution achieved across the full field of view was found to be limited by the x-ray source-size, similar to conventional radiography.
authors.affiliation: Department of Physics and Astronomy, Johns Hopkins University, Baltimore, Maryland 21218, USA.
authors.forename: M P
authors.initials: MP
authors.lastname: Valdivia
authors.affiliation: Department of Physics and Astronomy, Johns Hopkins University, Baltimore, Maryland 21218, USA.
authors.forename: D
authors.initials: D
authors.lastname: Stutman
authors.affiliation: Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA.
authors.forename: C
authors.initials: C
authors.lastname: Stoeckl
authors.affiliation: Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA.
authors.forename: W
authors.initials: W
authors.lastname: Theobald
authors.affiliation: Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA.
authors.forename: C
authors.initials: C
authors.lastname: Mileham
authors.affiliation: Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA.
authors.forename: I A
authors.initials: IA
authors.lastname: Begishev
authors.affiliation: Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA.
authors.forename: J
authors.initials: J
authors.lastname: Bromage
authors.affiliation: Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA.
authors.forename: S P
authors.initials: SP
authors.lastname: Regan
mesh_terms: D004583:Electrons; D014057:Tomography, X-Ray Computed / Q000295:instrumentation* / Q000379:methods*