Mitigation of Photon Active Interrogation Background for Fast Neutron Detection

Photon active interrogation offers solutions to many of the challenges with preventing the proliferation of concealed special nuclear material. A pulse shape discrimination capable organic scintillator based detection approach coupled with the use of a conventional linac offers a cost-effective active interrogation technique. However, there are challenges with mitigating non-target emitted signals. In this investigation, active background has been reduced through shielding and detector placement, and photoneutrons have been detected over the active background. Due to pulse pileup, many neutrons are missed through traditional pulse shape discrimination methods, demonstrating the need for implementation of new advanced techniques.