Real-time neutron source localization and identification with a hand-held, volumetrically-sensitive, moderating-type neutron spectrometer

Measuring source-dependent properties of free neutrons over a large neutron energy range, with hand-portable instrumentation, continues to push the frontier of neutron detection instrumentation design and analysis techniques. Building on prior work - C.B. Hoshor, et al., A portable and wide energy range semiconductor-based neutron spectrometer, Nucl. Instrum. Methods Phys. Res. A 803 (2015) 68-81 - which focused on demonstrating one-dimensional-based energy-dependent neutron measurement and analysis with a new class of solid-state moderating-type spectrometer, this work introduces two “core” algorithmic methodologies that expand the analysis of neutron thermalization measurements to three spatial dimensions to determine the location and identity of neutron radiation sources in real time. Two extensions of these core methodologies are then proposed to further improve both the accuracy and reliability of source location and identity determinations with this new class of hand-held instrumentation. In 432 preliminary simulation tests, these method extensions are shown to decrease the average source location error by 64% and provide correct identity determinations in all test cases.