Design of a north pole Neutron Time-of-Flight (NTOF) system at NIF

[摘要] A north pole NTOF system for neutron spectroscopy is being implemented at the NIF. The design is centered around a fast scintillator with low mass housing fielded 21.6m from target chamber center at θ=18°,φ=304°. The line-of-sight (LOS) features a primary port collimator, two secondary collimators in the intervening concrete floors, and a beam dump with a backscatter shield. Because the detector is being fielded on the roof of the NIF building, diagnostic options such as optical and electrical attenuation are remotely controlled, saving setup time and increasing shot rate. The expected performance of the diagnostic is excellent with high sensitivity to both high-energy reaction-in-flight neutrons as well as lower energy down-scattered neutrons.

[发布机构] Lawrence Livermore National Laboratory, Livermore; CA; 94550, United States^1

[关键词] Fast scintillator;High sensitivity;Line of Sight;Lower energies;Neutron spectroscopy;Neutron time of flight;Scattered neutron;Target chamber center