title: Calibration of scintillation-light filters for neutron time-of-flight spectrometers at the National Ignition Facility.
abstract: Sixty-four neutral density filters constructed of metal plates with 88 apertures of varying diameter have been radiographed with a soft x-ray source and CCD camera at National Security Technologies, Livermore. An analysis of the radiographs fits the radial dependence of the apertures' image intensities to sigmoid functions, which can describe the rapidly decreasing intensity towards the apertures' edges. The fitted image intensities determine the relative attenuation value of each filter. Absolute attenuation values of several imaged filters, measured in situ during calibration experiments, normalize the relative quantities which are now used in analyses of neutron spectrometer data at the National Ignition Facility.
authors.affiliation: Lawrence Livermore National Laboratory, Livermore, California 94550, USA.
authors.forename: D B
authors.initials: DB
authors.lastname: Sayre
authors.affiliation: Lawrence Livermore National Laboratory, Livermore, California 94550, USA.
authors.forename: F
authors.initials: F
authors.lastname: Barbosa
authors.affiliation: Lawrence Livermore National Laboratory, Livermore, California 94550, USA.
authors.forename: J A
authors.initials: JA
authors.lastname: Caggiano
authors.affiliation: National Security Technologies, Livermore, California 94551, USA.
authors.forename: V N
authors.initials: VN
authors.lastname: DiPuccio
authors.affiliation: Lawrence Livermore National Laboratory, Livermore, California 94550, USA.
authors.forename: M J
authors.initials: MJ
authors.lastname: Eckart
authors.affiliation: Lawrence Livermore National Laboratory, Livermore, California 94550, USA.
authors.forename: G P
authors.initials: GP
authors.lastname: Grim
authors.affiliation: Lawrence Livermore National Laboratory, Livermore, California 94550, USA.
authors.forename: E P
authors.initials: EP
authors.lastname: Hartouni
authors.affiliation: Lawrence Livermore National Laboratory, Livermore, California 94550, USA.
authors.forename: R
authors.initials: R
authors.lastname: Hatarik
authors.affiliation: National Security Technologies, Livermore, California 94551, USA.
authors.forename: F A
authors.initials: FA
authors.lastname: Weber