Neutron Detection With Gamma-Ray Spectrometers for Border Security Applications

Mitchell, Dean J.; Harding, Lee; Smith, K.

doi:10.1109/tns.2010.2052829

Cited by 11 publications

(9 citation statements)

References 3 publications

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“…Similar results have been gained through Monte Carlo simulations in Ref. [4], in which Mitchell et al conclude that their NaI-based portal monitor is superior to a 3 He-based portal monitor when certain source shields are applied.…”

Section: Discussionsupporting

confidence: 74%

“…PVC, which was also used in Refs [4,5], is a good converter due to the high-energy photons emitted by chlorine (see Ref. [7] for a detailed study).…”

Section: Experiments With Ambe and 252 Cf Sourcesmentioning

confidence: 99%

“…This approach has received little attention until recently (see Refs. [4][5][6][7]). The origin of high-energy photons can be divided into two groups:…”

Section: Introductionmentioning

confidence: 99%

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Neutron detection with a NaI spectrometer using high-energy photons

Holm

Perajärvi

Sihvonen

et al. 2013

Nuclear Instruments and Methods in Physics Research Section A:

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Section: Discussionsupporting

confidence: 74%

“…PVC, which was also used in Refs [4,5], is a good converter due to the high-energy photons emitted by chlorine (see Ref. [7] for a detailed study).…”

Section: Experiments With Ambe and 252 Cf Sourcesmentioning

confidence: 99%

See 1 more Smart Citation

Neutron detection with a NaI spectrometer using high-energy photons

Holm

Perajärvi

Sihvonen

et al. 2013

Nuclear Instruments and Methods in Physics Research Section A:

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“…Designs investigated in this research and in the literature have focused on alternating layers of polyethylene and steel. Multi-layered (up to 10) configurations developed by Mitchell et al [2010] at Sandia National Laboratory were initially investigated. Interestingly, a bi-layered approach works nearly as well as the multi-layer designs with thinner layers.…”

Section: Collimator Design and Description Of Current Sensor Arraymentioning

confidence: 99%

“…Modeled gamma-ray count rate over 3-8.5 MeV in a 7.6 cm × 7.6 cm NaI detector from 234 U neutrons for several collimator designs and a fixed 5 wt% UF 6 30B cylinder. Crosssectional views through collimator designs are shown below the chart (Pink=poly, red=steel, green=NaI) [Mitchell 2010] In addition to optimizing the collimator design, we also applied modeling to an investigation of the optimum number and position of the poly fences. The dimensions of each fence segment are 120 × 30 × 2.5 cm 3 .…”

Section: Collimator Design and Description Of Current Sensor Arraymentioning

confidence: 99%

Automated UF6 Cylinder Enrichment Assay: Status of the Hybrid Enrichment Verification Array (HEVA) Project: POTAS Phase II

Jordan¹,

Orton²,

Mace³

et al. 2012

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This document was printed on recycled paper. iii ABSTRACT Pacific Northwest National Laboratory (PNNL) is developing a technique that will allow the International Atomic Energy Agency (IAEA) to automate UF 6 cylinder nondestructive assay (NDA) verification currently performed at enrichment plants. The IAEA has recently proposed the concept of an unattended cylinder verification station (UCVS), a concept with similarities to previous PNNL work, to positively identify each cylinder and measure its mass and enrichment. This report summarizes the status of the research and development of an enrichment assay methodology supporting the unattended cylinder verification station concept that has been ongoing for several years. The described enrichment assay approach exploits a hybrid of two passively-detected ionizing-radiation signatures: the traditional enrichment meter signature (186-keV photon peak area) and a non-traditional signature, manifested in the high-energy (3 to 8 MeV) gamma-ray continuum, generated by neutron emission from UF 6 . PNNL has designed, fabricated, and field-tested several prototype assay sensor packages in an effort to demonstrate proof-of-principle for the hybrid assay approach, quantify the expected assay precision for various categories of cylinder contents, and assess the potential for unattended deployment of the technology in a portal-monitor form factor. We refer to recent sensor-package prototypes as the Hybrid Enrichment Verification Array (HEVA). The report provides an overview of the assay signatures and summarizes the results of several HEVA field measurement campaigns on populations of Type 30B UF 6 cylinders containing low-enriched uranium (LEU), natural uranium (NU), and depleted uranium (DU). Approaches to performance optimization of the assay technique via radiation transport modeling are briefly described, as are spectroscopic and data-analysis algorithms.v

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