A fast and portable imager for neutron and gamma emitting radionuclides

Al Hamrashdi, Hajir and Cheneler, David and Monk, Stephen David (2020) A fast and portable imager for neutron and gamma emitting radionuclides. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 953. ISSN 0168-9002

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Abstract

Here a novel, real-time, highly-compact imaging system capable of detecting and localising gamma rays, thermal and fast neutrons is reported. The imaging system presented in this research comprises of a front-end containing three detection layers with a unique combination of scintillators optimised for multi-particle detection, and backed with silicon photomultiplier diode arrays to enable source localisation and to maximise efficiency. The system exploits Compton and neutron scattering techniques simultaneously to constitute a dual-mode radiation camera. Application-specific software algorithms are implemented here to process the numerous signals from the system and to reconstruct the location of radioactive sources using a back-projection technique. The three front-end detection layers fit within a volume of 120 mm 120 mm 200 mm, offering a uniquely compact imaging solution. A prototype of the instrument and the associated electronics have been designed using Monte Carlo simulations, and tested with Cs-137 (given its singular gamma-ray component) and Cf-252 (for its mixed neutron and gamma-ray emission). Experimental results indicate that the system can detect and localise both gamma-ray and neutron sources successfully, with intrinsic efficiencies in the order of 10−4. All results have been achieved within a scan time of 60 s and with a further data processing time of less than 60 s, for gamma sources of 300 kBq and neutron sources of 10neutrons per second (total) in close proximity (< 300 mm). Whilst high-speed, mixed-field, particle-imaging systems have numerous applications within both nuclear and non-nuclear fields; this particular system has been optimised for use within the areas of nuclear materials assay and proliferation prevention.

Item Type:
Journal Article
Journal or Publication Title:
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
Additional Information:
This is the author’s version of a work that was accepted for publication in Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 953, 2019 DOI: 10.1016/j.nima.2019.163253
Uncontrolled Keywords:
/dk/atira/pure/subjectarea/asjc/3100/3106
Subjects:
ID Code:
139511
Deposited By:
Deposited On:
13 Dec 2019 14:05
Refereed?:
Yes
Published?:
Published
Last Modified:
22 Sep 2020 04:51