title: Development of backlighting sources for a Compton radiography diagnostic of inertial confinement fusion targets (invited).
abstract: We present scaled demonstrations of backlighter sources, emitting bremsstrahlung x rays with photon energies above 75 keV, that we will use to record x-ray Compton radiographic snapshots of cold dense DT fuel in inertial confinement fusion implosions at the National Ignition Facility (NIF). In experiments performed at the Titan laser facility at Lawrence Livermore National Laboratory, we measured the source size and the bremsstrahlung spectrum as a function of laser intensity and pulse length from solid targets irradiated at 2x10(17)-5x10(18) W/cm(2) using 2-40 ps pulses. Using Au planar foils we achieved source sizes down to 5.5 microm and conversion efficiencies of about 1x10(-13) J/J into x-ray photons with energies in the 75-100 keV spectral range. We can now use these results to design NIF backlighter targets and shielding and to predict Compton radiography performance as a function of the NIF implosion yield and associated background.
authors.affiliation: Lawrence Livermore National Laboratory, Livermore, California 94551, USA. tommasini@llnl.gov
authors.forename: R
authors.initials: R
authors.lastname: Tommasini
authors.forename: A
authors.initials: A
authors.lastname: MacPhee
authors.forename: D
authors.initials: D
authors.lastname: Hey
authors.forename: T
authors.initials: T
authors.lastname: Ma
authors.forename: C
authors.initials: C
authors.lastname: Chen
authors.forename: N
authors.initials: N
authors.lastname: Izumi
authors.forename: W
authors.initials: W
authors.lastname: Unites
authors.forename: A
authors.initials: A
authors.lastname: MacKinnon
authors.forename: S P
authors.initials: SP
authors.lastname: Hatchett
authors.forename: B A
authors.initials: BA
authors.lastname: Remington
authors.forename: H S
authors.initials: HS
authors.lastname: Park
authors.forename: P
authors.initials: P
authors.lastname: Springer
authors.forename: J A
authors.initials: JA
authors.lastname: Koch
authors.forename: O L
authors.initials: OL
authors.lastname: Landen
authors.forename: John
authors.initials: J
authors.lastname: Seely
authors.forename: Glenn
authors.initials: G
authors.lastname: Holland
authors.forename: Larry
authors.initials: L
authors.lastname: Hudson