Development of a Scintillator based Coded-aperture Neutron Imaging System

Cieslak, M.J. and Gamage, K.A.A. (2018) Development of a Scintillator based Coded-aperture Neutron Imaging System. Neutron Detectors and Related Applications, Trento, Italy, July 2018.

Abstract

Coded-aperture imaging has been wieldy used in X-ray and gamma-ray detection and localisation systems. The same approach has also been successfully employed in large scale neutron imagers, where single channel detectors act as individual cells. Moreover, utilisation of organic scintillators allowed dual particle (neutron and gamma) detection, based on pulse shape discrimination (PSD) techniques. However, large scale systems can be difficult to deploy on nuclear decommissioning sites, where nuclear waste streams are often located in areas that are technically difficult to access. In this study, we present the results of initial testing of a small scale, easily deployable mixed-field coded-aperture imaging system. It is believed that a small scale pixelated organic plastic scintillator (EJ-299-34) has been used for the first time in this type of application. The scintillator was coupled with Hamamatsu H9500 multi anode photomultiplier tube, where scintillator pixels and Hamamatsu H9500 anodes match in size. Rank-7 coded-aperture made of W was placed 10 cm in front of the scintillator and the overall system was bounded by a W enclosure. Prior to mixed-field assay, the imaging system developed in this study was exposed to single particle fields (137Cs for gamma-rays, 252Cf for neutrons – with gamma-ray photons blocked using 10 cm Pb shielding) to examine its localisation capabilities. First results obtained suggest that the system performs very well in single particle fields, whereas the mixed-filed operation is impaired by the low-quality pulse shape of the output signal obtained.

• Item Type: Conference or Workshop Item
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Gamage, Professor Kelum
• Authors: Cieslak, M.J., and Gamage, K.A.A.
• College/School: College of Science and Engineering > School of Engineering