Design and calibration of an optically segmented single volume scatter camera for neutron imaging

Journal Article · Wed Apr 28 00:00:00 EDT 2021 · Journal of Instrumentation

DOI:https://doi.org/10.1088/1748-0221/16/04/p04013· OSTI ID:1781549

Galindo-Tellez, A. ^[1]; Keefe, K. ^[1]; Adamek, E. ^[1]; Brubaker, E. ^[2]; Crow, B. ^[1]; Dorrill, R. ^[1]; Druetzler, A. ^[1]; Felix, C. J. ^[1]; Kaneshige, N. ^[1]; Learned, J. G. ^[1]; Manfredi, J. J. ^[3]; Nishimura, K. ^[1]; Pinto Souza, B. ^[1]; Schoen, D. ^[1]; Sweany, Melinda ^[2]

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1. Univ. of Hawaii at Manoa, Honolulu, HI (United States)
2. Sandia National Lab. (SNL-CA), Livermore, CA (United States)
3. Univ. of California, Berkeley, CA (United States)

The Optically Segmented Single Volume Scatter Camera (OS-SVSC) aims to image neutron sources for non-proliferation applications using the kinematic reconstruction of elastic double-scatter events. Our prototype system consists of 64 EJ-204 organic plastic scintillator bars, each measuring 5mm × 5mm × 200mm and individually wrapped in Teflon tape. The scintillator array is optically coupled to two silicon photomultiplier ArrayJ-60035 64P-PCB arrays, each comprised of 64 individual 6x6mm J-Series sensors arranged in an 8 × 8 array. We report on the design details, including component selections, mechanical design and assembly, and the electronics system. The described design leveraged existing off-the-shelf solutions to support the rapid development of a phase 1 prototype. Several valuable lessons were learned from component and system testing, including those related to the detector's mechanical structure and electrical crosstalk that we conclude originates in the commercial photodetector arrays and the associated custom breakout cards. We detail our calibration efforts, beginning with calibrations for the electronics, based on the IRS3D application-specific integrated circuits, and their associated timing resolutions, ranging from 3090ps. With electronics calibrations applied, energy and position calibrations were performed for a set of edge bars using ²²Na and ⁹⁰Sr, respectively, reporting an average resolution of 12.07±0.03mm for energy depositions between 900keVee and 1000keVee. We further demonstrate a position calibration method for the internal bars of the matrix using cosmic-ray muons as an alternative to emission sources that cannot easily access these bars, with an average measured resolution of 14.86+-0.29mm for depositions between 900keVee and 1000keVee. The coincident time resolution reported between pairs of bars measured up to 400ps from muon acquisitions. Energy and position calibration values measured with muons are consistent with those obtained using particle emission sources.

• Research Organization: Sandia National Lab. (SNL-CA), Livermore, CA (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA), Office of Defense Nuclear Nonproliferation
• Grant/Contract Number: AC04-94AL85000; NA0003525
• OSTI ID: 1781549
• Report Number(s): SAND-2021-2869J; 694706
• Journal Information: Journal of Instrumentation, Vol. 16, Issue 04; ISSN 1748-0221
• Publisher: Institute of Physics (IOP)
• Country of Publication: United States
• Language: English

Related Subjects

47 OTHER INSTRUMENTATION
neutron detectors (fast neutrons)
search for radioactive and fissile materials
detector alignment and calibration methods (lasers
sources
particle-beams)