Maximum detector sizes required for orphan source detection

Ziock, Klaus-Peter; Nelson, K.

doi:10.1016/j.nima.2007.04.061

Cited by 27 publications

(11 citation statements)

References 4 publications

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“…3. The results presented here are thus in line with those of Ziock and Nelson (2007), who argued that a semiconductor system will out perform a scintillation-based system of comparable size, given that spectroscopy can be used to limit the background (which is the case in this work).…”

Section: Discussionsupporting

confidence: 90%

A deviation display method for visualising data in mobile gamma-ray spectrometry

Kock

Finck

Nilsson

et al. 2010

Applied Radiation and Isotopes

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A real time visualisation method, to be used in mobile gamma-spectrometric search operations using standard detector systems is presented. The new method, called Deviation Display, uses a modified waterfall display to present relative changes in spectral data over energy and time. Using unshielded 137 Cs and 241 Am point sources and different natural background environments, the behaviour of the Deviation Displays is demonstrated and analysed for two standard detector types (NaI(Tl) and HPGe). The Deviation Display enhances positive significant changes while suppressing the natural background fluctuations. After an initialisation time of about 10 minutes this technique leads to a homogeneous display dominated by the background colour, where even small changes in spectral data are easy to discover. As this paper shows, the Deviation Display method works well for all tested gamma energies and natural background radiation levels and with both tested detector systems.

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Section: Discussionsupporting

confidence: 90%

A deviation display method for visualising data in mobile gamma-ray spectrometry

Kock

Finck

Nilsson

et al. 2010

Applied Radiation and Isotopes

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“…The generative model smooths out the most extreme observations, but expected counts in the 10 th , 50 th , and 90 th percentiles align fairly well with the empirical distribution. As a result, the simulation environment reflects significant variation in local background intensity, which is an important element of the threat detection problem in the real world [28,26].…”

Section: Resultsmentioning

confidence: 99%

“…Searching for nuclear and radiological threats with mobile radiation detectors remains problematic. In typical search operations, the environment is cluttered with benign nuisance radiation sources and large fluctuations in the natural radiation background [26]. Detecting sources of interest through this clutter requires discrimination.…”

Section: Introductionmentioning

confidence: 99%

Evaluation of coded aperture radiation detectors using a Bayesian approach

Miller

Huggins

Labov

et al. 2016

Nuclear Instruments and Methods in Physics Research Section A:

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Introduction. We investigate the utility of coded aperture (CA) for roadside radiation threat detection applications. With coded aperture, information in the form of photon quantity is traded for directional information.Whether and in what scenarios this trade-off is beneficial is the focus of this study. We quantify the impact of a masking approach by comparing performance with an unmasked approach in terms of both detection and localization of a roadside nuclear threat. We simulate many instances of a drive-by scenario via Monte Carlo using empirical observations from the RadMAP project [1] to obtain background photons and synthetic injection of threat source. Simulation results suggest that at 0.1%false positive rate (FPR) the masked detector suffers 20-50% loss of detection probability for weak sources, but only 1-1.5% for moderate source intensities. The masked approach also demonstrates consistent improvement in localization performance ranging from 0.7-2.2m across all source intensities investigated.

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“…Toward this end, various vehicle-borne, large area detector systems have been designed and tested in recent years [1][2][3][4]. However, the problem of detecting illicit radioactive sources is confounded by the non-Poissonian background fluctuations commonly encountered in operational environments, which greatly limit the capabilities of these systems [5][6][7][8]. These fluctuations are caused by variations in the environment through which the vehicle is moving, but the exact radiological properties and geometric configuration of materials around the vehicle are seldom known well enough to predict or even understand these changes.…”

Section: Introductionmentioning

confidence: 99%