No abstract

We report on the design, construction, and operation of a capture-gated neutron detector based on a heterogeneous scintillating structure comprising two scintillator types. A flat, 500 μm thick sheet composed of a mixture of lithium-6-fluoride capture agent, 6 LiF, and zinc sulfide phosphor, ZnS(Ag), is wrapped around scintillating polyvinyl toluene (PVT) in a form of cylinder. The 6 LiF:ZnS(Ag) sheet uses an aluminum foil backing as a support for the scintillating material and as an optical reflector, and its optical properties have been characterized independently. The composite scintillator was tested using 252 Cf, DD fusion, 137 Cs, and 60 Co sources. The intrinsic detection efficiency for neutrons from an unmoderated 252 Cf source and rejection of gammas from 137 Cs were measured to be 3.6% and 10 −6 , respectively. A figure of merit for pulse shape discrimination of 4.6 was achieved, and capture-gated spectroscopic analysis is demonstrated.

No abstract