Location of neutron sources using moderator-free directional thermal neutron detectors

The use of neutron detectors designed to record only those thermalized neutrons coming from a highly specific direction can provide enhanced capability for applications such as locating nuclear weapons material or monitoring storage vaults containing special nuclear materials. Such a detection system should be as free of moderator as possible to assure effective directionality. We provide evidence from computer modeling and experimental tests that this technique allows the identification and localization of neutron sources at greater distances and narrower angular resolution than would be possible with conventional moderating neutron detectors.