Neutron detection based on capture-gamma sensing and calorimetry

Guntram Pausch; Claus-Michael Herbach; Dean Mitchell; Ralf Lentering; Juergen Stein

doi:10.1117/12.924082

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7 May 2012 Neutron detection based on capture-gamma sensing and calorimetry

Guntram Pausch, Claus-Michael Herbach, Dean Mitchell, Ralf Lentering, Juergen Stein

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Proceedings Volume 8382, Active and Passive Signatures III; 838209 (2012) https://doi.org/10.1117/12.924082
Event: SPIE Defense, Security, and Sensing, 2012, Baltimore, Maryland, United States

Abstract

Passive radiation detection systems have been developed to screen passengers, vehicles, and cargo for illicit radioactive sources by measuring gamma and neutron signatures with separate, specialized sensors. The paper introduces a novel concept combining neutron and gamma sensing in a single detector, thus reducing the overall expense. Low-cost converter media capture thermal neutrons and commute neutron flux in energetic gammas, which are then detected by a common gamma detector. Energy signals above 3 MeV indicate the neutron captures. Two prototype systems are presented: (1) The NCD-BGO, a segmented 655 ml BGO scintillator with embedded Cd absorber, demonstrated an intrinsic thermal-neutron detection efficiency of about 50%. (2) The PVTNG, comprising 75 l of PVT scintillator complemented with PVC panels, exhibited a neutron sensitivity of 1.9 cps/ng of 252Cf, thus almost meeting the corresponding requirement for Radiation Portal Monitors. Moreover, an unconventional construction of scintillator and light readout, combined with innovative electronics and proper detector stabilization, improved the gamma detector performance noticeably and enabled nuclide identification.

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Guntram Pausch, Claus-Michael Herbach, Dean Mitchell, Ralf Lentering, and Juergen Stein "Neutron detection based on capture-gamma sensing and calorimetry", Proc. SPIE 8382, Active and Passive Signatures III, 838209 (7 May 2012); https://doi.org/10.1117/12.924082

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