Beaumont, Jonathan S. and Shippen, B. Alan and Mellor, Matthew P. and Joyce, Malcolm J. (2017) Imaging of Fast Neutrons and Gamma Rays from 252Cf in a Heavily Shielded Environment. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 847. pp. 77-85. ISSN 0168-9002
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Abstract
A 75 MBq 252Cf neutron source stored inside a steel water tank was characterised using a compact fast-neutron and gamma-ray imaging system based on a passive slot modulation imaging technique. Radiation fields were imaged from a variety of positions with the source in the stored position (located in the center of the water tank: high shielding) and in the exposed position (located at the edge of the water tank: low shielding). It was possible to locate the 252Cf source in each image and gain additional information of the neutron and gamma-ray fields in the local environment including scatter contributions from the steel shield, floor and walls in proximity to the source. A long exposure image of the stored source, taken over thirty days, identified the location of the radiation source from the low dose ( < 1 μ Sv / h ) field penetrating through 46 cm of water in the storage tank.