Spectral unmixing applied to fast identification of γ-emitting radionuclides using NaI(Tl) detectors

H Paradis; C Bobin; J Bobin; J Bouchard; V Lourenço; C Thiam; R André; L Ferreux; A de Vismes Ott; M Thévenin

doi:10.1016/j.apradiso.2020.109068

Spectral unmixing applied to fast identification of γ-emitting radionuclides using NaI(Tl) detectors

Appl Radiat Isot. 2020 Apr:158:109068. doi: 10.1016/j.apradiso.2020.109068. Epub 2020 Feb 1.

Authors

H Paradis¹, C Bobin², J Bobin³, J Bouchard¹, V Lourenço¹, C Thiam¹, R André¹, L Ferreux⁴, A de Vismes Ott⁵, M Thévenin⁶

Affiliations

¹ CEA, LIST, Laboratoire National Henri Becquerel, (LNE-LNHB), 91191, Gif-sur-Yvette Cedex, France.
² CEA, LIST, Laboratoire National Henri Becquerel, (LNE-LNHB), 91191, Gif-sur-Yvette Cedex, France. Electronic address: christophe.bobin@cea.fr.
³ CEA, IRFU, Laboratoire de cosmologie et statistiques, 91191, Gif-sur-Yvette Cedex, France.
⁴ IRSN, Laboratoire de mesures Nucléaires, 78116, Le Vésinet Cedex, France.
⁵ IRSN, Laboratoire de métrologie de la radioactivité dans l'environnement, 91400, Orsay, France.
⁶ CEA, IRAMIS, Service de physique de l'état condensé, 91191, Gif-sur-Yvette Cedex, France.

PMID: 32174369
DOI: 10.1016/j.apradiso.2020.109068

Abstract

Spectral unmixing was investigated for fast spectroscopic identification in γ-emitter mixtures at low-statistics in the case of measurements performed to prevent illegal nuclear material trafficking or for in situ environmental analysis following a radiological or nuclear accident. For that purpose, a multiplicative update algorithm based on full-spectrum analysis was tested in the case of a 3″x3″ NaI(Tl) detector. Automatic decision-making was addressed using Monte Carlo calculations of decision thresholds and detection limits. The first results obtained with a portable instrument equipped with a 3″x3″ NaI(Tl) detector designed for the control of food samples by non-expert users following a radiological or nuclear accident, are also presented.

Keywords: Automatic decision-making; Environmental analysis; Inverse problem; Multiplicative update algorithm; NaI(Tl) detector; Spectral unmixing; Spectroscopic measurements.