Ignition X-ray imager for laser-fusion research at the national ignition facility

摘要

X-ray imaging will be an important diagnostic tool for inertial confinement fusion (ICF) research at the National Ignition Facility (NIF). However, high neutron yields will make x-ray imaging much more difficult than it is at current smaller facilities. We analyze the feasibility and performance of an Ignition X-Ray Imager to be used on cryogenic DT implosions at NIF. The system is intended to provide time-integrated, broadband, moderate-energy x-ray core images of imploding ICF capsules. Highly magnified, spectrally-filtered images created using an array of pinholes placed close to the target will be projected onto a scintillator placed at the target chamber wall. A telescope will be used to relay the scintillator emission to a distant optical detector that is time-gated in order to minimize backgrounds, in particular from neutrons. The system is optimized with respect to spatial-resolution, signal-to-background and signal-to-noise ratios.