Calibration and testing of a large-area fast-neutron directional detector

Vanier, P. E.; Forman, L.; Diószegi, I.; Salwen, Cynthia; Ghosh, V.J.

doi:10.1109/nssmic.2007.4436312

Cited by 9 publications

(9 citation statements)

References 3 publications

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“…The equipment employed in this work has been previously described [2][3][4], and it bears some similarity to other systems developed for warhead counting [5] or for basic nuclear physics [6]. Other groups have also used liquid scintillators with pulse shape discrimination of neutrons from gammas [7,8].…”

Section: Prior Workmentioning

confidence: 99%

“…The 8-paddle plastic scintillator detector that was previously described [2][3][4] was mounted in a small truck as shown in the inset of Fig. 1.…”

Section: Hardwarementioning

confidence: 99%

“…The most common detector for fast neutrons is the moderated 3 He system, which is non-directional and has a wide energy response. The DSNS has an advantage in the R sf/cr ratio because it is directional and rejects more than half of the isotropic neutrons from cosmic-rays, which would appear to have negative TOF.…”

Section: Efficiency/cosmic-ray Background Responsementioning

confidence: 99%

“…Individual detectors, in the shape of thick rectangular plates optically coupled to photomultipliers, are not normally sensitive to the direction of incident neutron trajectories. However, when arranged in two planes and coupled to high-bandwidth coincidence-timing electronics they can be used to create a detection system that measures both the direction and the energy spectrum of the fast neutrons, and distinguish them from gamma rays by time of flight [1][2][3][4].…”

Section: Introductionmentioning

confidence: 99%

“…We have compared the detector signal-tonoise ratio with that for a moderated 3 He detector, the 8.2" diameter Bonner sphere. This geometry is the optimal diameter for detection of fission energy neutrons.…”

Section: Introductionmentioning

confidence: 99%

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Directional stand-off detection of fast neutrons and gammas using angular scattering distributions

Vanier

Diószegi

Salwen

et al. 2009

2009 IEEE Nuclear Science Symposium Conference Record (NSS/MIC)

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Abstract-We have investigated the response of a Double Scatter Neutron Spectrometer (DSNS) for sources at long distances (>200 meters). We find that an alternative method for analyzing double scatter data avoids some uncertainties introduced by amplitude measurements in plastic scintillators. Time of flight is used to discriminate between gamma and neutron events, and the kinematic distributions of scattering angles are assumed to apply. Non-relativistic neutrons are most likely to scatter at 45°, while gammas with energies greater than 2 MeV are most likely to be forward scattered. The distribution of scattering angles of fission neutrons arriving from a distant point source generates a 45° cone, which can be back-projected to give the source direction. At the same time, the distribution of Compton-scattered gammas has a maximum in the forward direction, and can be made narrower by selecting events that deposit minimal energy in the first scattering event. We have further determined that the shape of spontaneous fission neutron spectra at ranges >110 m is still significantly different from the cosmic ray background.

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Section: Prior Workmentioning

confidence: 99%

“…The 8-paddle plastic scintillator detector that was previously described [2][3][4] was mounted in a small truck as shown in the inset of Fig. 1.…”

Section: Hardwarementioning

confidence: 99%

Section: Efficiency/cosmic-ray Background Responsementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Directional stand-off detection of fast neutrons and gammas using angular scattering distributions

Vanier

Diószegi

Salwen

et al. 2009

2009 IEEE Nuclear Science Symposium Conference Record (NSS/MIC)

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Radioactive Materials Sensors

Mayo¹,

Stephens²

2008

Wiley Handbook of Science and Technology for Homeland Security

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Providing technical means to detect, prevent, and reverse the threat of potential illicit use of radiological or nuclear materials is among the greatest challenges facing contemporary science and technology. In this short article, we provide a brief description and overview of the State‐of‐the‐art in sensor development for the detection of radioactive materials, as well as an identification of the technical needs and challenges faced by the detection community. We begin with a discussion on γ ray and neutron detectors and spectrometers, followed by a description of imaging sensors, active interrogation, and radiation detection materials' development, before closing with a brief discussion on the unique challenges posed in fielding sensor systems.

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Design and Optimisation of a Three Layers Thermal Neutron, Fast Neutron and Gamma-Ray Imaging System

2020

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The design and configuration of a multi-layered imaging system with the ability to detect thermal neutrons, fast neutrons and gamma rays has been developed and its efficacy demonstrated. The work presented here numerically determines the systems efficiency and spatial resolution, using 252Cf and 137Cs as a case study. The novelty of this detection system lies in the use of small form factor detectors in a three-layer design, which utilises neutron elastic scattering and Compton scattering simultaneously. The current configuration consists of 10 mm thick natural lithium glass (GS10) scintillator integrated with a 20 mm thick plastic scintillator (EJ-204) in the first layer, a 15 mm thick lithium glass (GS10) scintillator in the second and a 30 mm thick CsI(Tl) scintillator forming the final layer. Each of these layers is backed with an 8 x 8 silicon photomultiplier diode (SiPM) array. The overall size of the imaging system is 27 mm x 27 mm x 135 mm. MCNPv6.1 and Geant4-10.04 were alternatively used to optimise the overall configuration and to investigate detection modalities. Results show promising performance with high precision source localisation and characterization abilities. Measurements were virtually obtained of two gamma-ray sources within steel enclosures at angles of 15°, 30° and 50° separation in order to test spatial resolution ability of the system. With the current active size of the system and the 8x8 SiPM configuration, the results estimate the spatial resolution to be close to 30°. The ability of the system to characterise and identify sources based on the type and energy of the radiation emitted, has been investigated and results show that for all radiation types the system can identify the source energy within the energy range of typical reported sources in literature.

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Calibration and testing of a large-area fast-neutron directional detector

Cited by 9 publications

References 3 publications

Directional stand-off detection of fast neutrons and gammas using angular scattering distributions

Directional stand-off detection of fast neutrons and gammas using angular scattering distributions

Radioactive Materials Sensors

Design and Optimisation of a Three Layers Thermal Neutron, Fast Neutron and Gamma-Ray Imaging System

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