Calibration of the Fast Neutron Imaging Telescope (FNIT) Prototype Detector

• Published in: IEEE transactions on nuclear science Vol. 56; no. 5; pp. 2947 - 2954
• Main Authors: Bravar, U., Woolf, R.S., Bruillard, P.J., Fluckiger, E.O., Legere, J.S., MacKinnon, A.L., Macri, J.R., Mallik, P.C., McConnell, M.L., Pirard, B., Ryan, J.M.
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.10.2009; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Aircraft manufacture; Calibration; Computer simulation; Detectors; Elastic scattering; Fast neutrons; Imaging; Instruments; Liquids; Monte Carlo methods; Neutron imaging; neutron spectroscopy; Neutrons; Optical design; Prototypes; Scattering; scintillation detectors; Space telescopes; Spectroscopy; Telescopes
• ISSN: 0018-9499; 1558-1578
• DOI: 10.1109/TNS.2009.2028025

The paper describes a novel detector for neutrons in the 1 to 20-MeV energy range with combined imaging and spectroscopic capabilities. The Fast Neutron Imaging Telescope (FNIT) was designed to detect solar neutrons from spacecraft deployed to the inner heliosphere. However, the potential application of this instrument to Special Nuclear Material (SNM) identification was also examined. In either case, neutron detection relies on double elastic neutron-proton (n-p) scattering in liquid scintillator. We optimized the design of FNIT through a combination of Monte Carlo simulations and lab measurements. We then assembled a scaled-down version of the full detector and assessed its performance by exposing it to a neutron beam and an SNM source. The results from these tests, which were used to characterize the response of the complete FNIT detector to fast neutrons, are presented herein.