Gated x-ray detector for the National Ignition Facility

Abstract

Two new gated x-ray imaging cameras have recently been designed, constructed, and delivered to the National Ignition Facility in Livermore, CA. These gated x-Ray detectors are each designed to fit within an aluminum airbox with a large capacity cooling plane and are fitted with an array of environmental housekeeping sensors. These instruments are significantly different from earlier generations of gated x-ray images due, in part, to an innovative impedance matching scheme, advanced phosphor screens, pulsed phosphor circuits, precision assembly fixturing, unique system monitoring, and complete remote computer control. Preliminary characterization has shown repeatable uniformity between imaging strips, improved spatial resolution, and no detectable impedance reflections.

Nuclear imaging of the fuel assembly in ignition experiments

“…Since the NIF neutron imaging system views the imploded capsule along a direction orthogonal to the hohlraum axis, the image contours are revolved around the axis parallel to the hohlraum axis and through their, P 1 ¼ 0, centers, forming bounding surfaces for the corresponding volumes. Using the primary neutron yield, ion temperature, and burn width from either the Gamma Reaction History diagnostic 20 or gated X-ray imaging diagnostic, 21,22 state variables, including, density, pressure, and adiabat may be calculated. This approach is complementary to the more sophisticated approach of Cerjan et al 11 which does not include the primary and scattered neutron image data.…”

Symmetry tuning with megajoule laser pulses at the National Ignition Facility

“…Images of the capsule self-emission are collected with a CCD based gated x-ray detector [16] on the equator at 90-78 (Theta-Phi) in the NIF chamber coordinates [17]. A pinhole imaging snout is mounted to the GXD having a pinhole array with 8 m diameter pinholes.…”

Monte Carlo simulations of microchannel plate detectors. I. Steady-state voltage bias results

“…19,20,21 These detectors quantitative measurements are critical for a comprehensive understanding of the experimental results. To assist their characterizations and to aid design improvements, a more comprehensive Monte Carlo simulation model for the MCP detector is needed.…”