Pulse-shape analysis of neutron-induced scintillation light in Ni-doped ⁶LiF/ZnS

Alternatives to ³ He are being investigated for gamma-ray insensitive neutron detection applications, including plutonium assay. One promising material is lithium-6 fluoride with silver activated zinc sulfide ⁶ LiF/ZnS(Ag) in conjunction with a wavelength shifting plastic. Doping the ⁶ LiF/ZnS(Ag) with nickel (Ni) has been proposed as a means of reducing the decay time of neutron signal pulses. This research performed a pulse shape comparison between Ni-doped and non-doped ⁶ LiF/ZnS(Ag) neutron pulses. The Ni-doped ⁶ LiF/ZnS(Ag) had a 32.7% ± 0.3 increase in neutron pulse height and a 32.4% ± 0.3 decrease in neutron pulse time compared to the non-doped ⁶ LiF/ZnS(Ag). Doping ⁶ LiF/ZnS(Ag) with nickel may allow neutron detector operation with improved signal to noise ratios, and reduced pulse pileup affects, increasing the accuracy and range of source activities with which such a detector could operate.