title: Soft x-ray images of the laser entrance hole of ignition hohlraums.
abstract: Hohlraums are employed at the national ignition facility to convert laser energy into a thermal x-radiation drive, which implodes a fusion capsule, thus compressing the fuel. The x-radiation drive is measured with a low spectral resolution, time-resolved x-ray spectrometer, which views the region around the hohlraum's laser entrance hole. This measurement has no spatial resolution. To convert this to the drive inside the hohlraum, the size of the hohlraum's opening ("clear aperture") and fraction of the measured x-radiation, which comes from this opening, must be known. The size of the clear aperture is measured with the time integrated static x-ray imager (SXI). A soft x-ray imaging channel has been added to the SXI to measure the fraction of x-radiation emitted from inside the clear aperture. A multilayer mirror plus filter selects an x-ray band centered at 870 eV, near the peak of the x-ray spectrum of a 300 eV blackbody. Results from this channel and corrections to the x-radiation drive are discussed.
authors.affiliation: Lawrence Livermore National Laboratory, Livermore, California 94551-0808, USA. schneider5@llnl.gov
authors.forename: M B
authors.initials: MB
authors.lastname: Schneider
authors.forename: N B
authors.initials: NB
authors.lastname: Meezan
authors.forename: S S
authors.initials: SS
authors.lastname: Alvarez
authors.forename: J
authors.initials: J
authors.lastname: Alameda
authors.forename: S
authors.initials: S
authors.lastname: Baker
authors.forename: P M
authors.initials: PM
authors.lastname: Bell
authors.forename: D K
authors.initials: DK
authors.lastname: Bradley
authors.forename: D A
authors.initials: DA
authors.lastname: Callahan
authors.forename: J R
authors.initials: JR
authors.lastname: Celeste
authors.forename: E L
authors.initials: EL
authors.lastname: Dewald
authors.forename: S N
authors.initials: SN
authors.lastname: Dixit
authors.forename: T
authors.initials: T
authors.lastname: Döppner
authors.forename: D C
authors.initials: DC
authors.lastname: Eder
authors.forename: M J
authors.initials: MJ
authors.lastname: Edwards
authors.forename: M
authors.initials: M
authors.lastname: Fernandez-Perea
authors.forename: E
authors.initials: E
authors.lastname: Gullikson
authors.forename: M J
authors.initials: MJ
authors.lastname: Haugh
authors.forename: S
authors.initials: S
authors.lastname: Hau-Riege
authors.forename: W
authors.initials: W
authors.lastname: Hsing
authors.forename: N
authors.initials: N
authors.lastname: Izumi
authors.forename: O S
authors.initials: OS
authors.lastname: Jones
authors.forename: D H
authors.initials: DH
authors.lastname: Kalantar
authors.forename: J D
authors.initials: JD
authors.lastname: Kilkenny
authors.forename: J L
authors.initials: JL
authors.lastname: Kline
authors.forename: G A
authors.initials: GA
authors.lastname: Kyrala
authors.forename: O L
authors.initials: OL
authors.lastname: Landen
authors.forename: R A
authors.initials: RA
authors.lastname: London
authors.forename: B J
authors.initials: BJ
authors.lastname: MacGowan
authors.forename: A J
authors.initials: AJ
authors.lastname: MacKinnon
authors.forename: T J
authors.initials: TJ
authors.lastname: McCarville
authors.forename: J L
authors.initials: JL
authors.lastname: Milovich
authors.forename: P
authors.initials: P
authors.lastname: Mirkarimi
authors.forename: J D
authors.initials: JD
authors.lastname: Moody
authors.forename: A S
authors.initials: AS
authors.lastname: Moore
authors.forename: M D
authors.initials: MD
authors.lastname: Myers
authors.forename: E A
authors.initials: EA
authors.lastname: Palma
authors.forename: N
authors.initials: N
authors.lastname: Palmer
authors.forename: M J
authors.initials: MJ
authors.lastname: Pivovaroff
authors.forename: J E
authors.initials: JE
authors.lastname: Ralph
authors.forename: J
authors.initials: J
authors.lastname: Robinson
authors.forename: R
authors.initials: R
authors.lastname: Soufli
authors.forename: L J
authors.initials: LJ
authors.lastname: Suter
authors.forename: A T
authors.initials: AT
authors.lastname: Teruya
authors.forename: C A
authors.initials: CA
authors.lastname: Thomas
authors.forename: R P
authors.initials: RP
authors.lastname: Town
authors.forename: S P
authors.initials: SP
authors.lastname: Vernon
authors.forename: K
authors.initials: K
authors.lastname: Widmann
authors.forename: B K
authors.initials: BK
authors.lastname: Young