Identification of mixed sources with an organic scintillator-based radiation portal monitor

Marc Paff, Angela Di Fulvio, Yoann Altmann, Shaun Clarke, Sarah A. Pozzi

Research output: Contribution to conferencePaper

Abstract

We have developed radionuclide identification algorithms for radiation portal monitor applications. One algorithm uses a spectral angle mapper to match the power spectral density of modified cumulative distribution functions of measured pulse height distributions to reference spectra, while the other rely on the decomposition of the observed spectrum as a linear mixture of known radionuclide spectra. Three algorithms were then tested for their ability to perform on-the-fly radionuclide identification on datasets acquired with a liquid organic scintillator-based pedestrian radiation portal monitor on moving special nuclear material and industrial radiological sources, as well as common medical isotopes. We quantified and compared the relative efficacies of the algorithms considered using F-score analysis. Measured radiation sources included 51 g of highly enriched uranium, 6.6 g of weapons grade plutonium, 241Am, 133Ba, 57Co and 137Cs sources with activities of several hundred kBq, as well as 260 kBq liquid solution samples of the medical isotopes 99mTc, 111In, 67Ga, 123I, 131I, and 201Tl. We achieved 100% positive identification, for three-second measurements of single sources moving at a source-transit speed of 1.2 m/s. For mixed sources with strongest and weakest sources having no more than a 3:1 ratio of detected counts, encouraging positive identification results were achieved with the un-mixing algorithms. Current radiation portal monitor designs suffer from a high incidence rate of nuisance radiation alarms caused in radiation portal monitors by recent nuclear medicine patients and cargo containing large amounts of naturally occurring radioactive materials. Integrating reliable on-the-fly radionuclide identification into the radiation portal monitors could lower the number of nuisance alarms requiring time-consuming secondary inspections.
Original languageEnglish
Publication statusPublished - Jul 2017
EventInstitute of Nuclear Materials Management 58th Annual Meeting - Indian Wells, United States
Duration: 16 Jul 201720 Jul 2018

Conference

ConferenceInstitute of Nuclear Materials Management 58th Annual Meeting
CountryUnited States
CityIndian Wells
Period16/07/1720/07/18

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scintillation counters
monitors
radioactive isotopes
radiation
warning systems
isotopes
radioactive materials
nuclear medicine
cargo
organic liquids
weapons
plutonium
pulse amplitude
transit
radiation sources
uranium
inspection
grade
incidence
distribution functions

Cite this

Paff, M., Di Fulvio, A., Altmann, Y., Clarke, S., & Pozzi, S. A. (2017). Identification of mixed sources with an organic scintillator-based radiation portal monitor. Paper presented at Institute of Nuclear Materials Management 58th Annual Meeting, Indian Wells, United States.
Paff, Marc ; Di Fulvio, Angela ; Altmann, Yoann ; Clarke, Shaun ; Pozzi, Sarah A. . / Identification of mixed sources with an organic scintillator-based radiation portal monitor. Paper presented at Institute of Nuclear Materials Management 58th Annual Meeting, Indian Wells, United States.
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abstract = "We have developed radionuclide identification algorithms for radiation portal monitor applications. One algorithm uses a spectral angle mapper to match the power spectral density of modified cumulative distribution functions of measured pulse height distributions to reference spectra, while the other rely on the decomposition of the observed spectrum as a linear mixture of known radionuclide spectra. Three algorithms were then tested for their ability to perform on-the-fly radionuclide identification on datasets acquired with a liquid organic scintillator-based pedestrian radiation portal monitor on moving special nuclear material and industrial radiological sources, as well as common medical isotopes. We quantified and compared the relative efficacies of the algorithms considered using F-score analysis. Measured radiation sources included 51 g of highly enriched uranium, 6.6 g of weapons grade plutonium, 241Am, 133Ba, 57Co and 137Cs sources with activities of several hundred kBq, as well as 260 kBq liquid solution samples of the medical isotopes 99mTc, 111In, 67Ga, 123I, 131I, and 201Tl. We achieved 100{\%} positive identification, for three-second measurements of single sources moving at a source-transit speed of 1.2 m/s. For mixed sources with strongest and weakest sources having no more than a 3:1 ratio of detected counts, encouraging positive identification results were achieved with the un-mixing algorithms. Current radiation portal monitor designs suffer from a high incidence rate of nuisance radiation alarms caused in radiation portal monitors by recent nuclear medicine patients and cargo containing large amounts of naturally occurring radioactive materials. Integrating reliable on-the-fly radionuclide identification into the radiation portal monitors could lower the number of nuisance alarms requiring time-consuming secondary inspections.",
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Paff, M, Di Fulvio, A, Altmann, Y, Clarke, S & Pozzi, SA 2017, 'Identification of mixed sources with an organic scintillator-based radiation portal monitor' Paper presented at Institute of Nuclear Materials Management 58th Annual Meeting, Indian Wells, United States, 16/07/17 - 20/07/18, .

Identification of mixed sources with an organic scintillator-based radiation portal monitor. / Paff, Marc; Di Fulvio, Angela; Altmann, Yoann; Clarke, Shaun; Pozzi, Sarah A. .

2017. Paper presented at Institute of Nuclear Materials Management 58th Annual Meeting, Indian Wells, United States.

Research output: Contribution to conferencePaper

TY - CONF

T1 - Identification of mixed sources with an organic scintillator-based radiation portal monitor

AU - Paff, Marc

AU - Di Fulvio, Angela

AU - Altmann, Yoann

AU - Clarke, Shaun

AU - Pozzi, Sarah A.

PY - 2017/7

Y1 - 2017/7

N2 - We have developed radionuclide identification algorithms for radiation portal monitor applications. One algorithm uses a spectral angle mapper to match the power spectral density of modified cumulative distribution functions of measured pulse height distributions to reference spectra, while the other rely on the decomposition of the observed spectrum as a linear mixture of known radionuclide spectra. Three algorithms were then tested for their ability to perform on-the-fly radionuclide identification on datasets acquired with a liquid organic scintillator-based pedestrian radiation portal monitor on moving special nuclear material and industrial radiological sources, as well as common medical isotopes. We quantified and compared the relative efficacies of the algorithms considered using F-score analysis. Measured radiation sources included 51 g of highly enriched uranium, 6.6 g of weapons grade plutonium, 241Am, 133Ba, 57Co and 137Cs sources with activities of several hundred kBq, as well as 260 kBq liquid solution samples of the medical isotopes 99mTc, 111In, 67Ga, 123I, 131I, and 201Tl. We achieved 100% positive identification, for three-second measurements of single sources moving at a source-transit speed of 1.2 m/s. For mixed sources with strongest and weakest sources having no more than a 3:1 ratio of detected counts, encouraging positive identification results were achieved with the un-mixing algorithms. Current radiation portal monitor designs suffer from a high incidence rate of nuisance radiation alarms caused in radiation portal monitors by recent nuclear medicine patients and cargo containing large amounts of naturally occurring radioactive materials. Integrating reliable on-the-fly radionuclide identification into the radiation portal monitors could lower the number of nuisance alarms requiring time-consuming secondary inspections.

AB - We have developed radionuclide identification algorithms for radiation portal monitor applications. One algorithm uses a spectral angle mapper to match the power spectral density of modified cumulative distribution functions of measured pulse height distributions to reference spectra, while the other rely on the decomposition of the observed spectrum as a linear mixture of known radionuclide spectra. Three algorithms were then tested for their ability to perform on-the-fly radionuclide identification on datasets acquired with a liquid organic scintillator-based pedestrian radiation portal monitor on moving special nuclear material and industrial radiological sources, as well as common medical isotopes. We quantified and compared the relative efficacies of the algorithms considered using F-score analysis. Measured radiation sources included 51 g of highly enriched uranium, 6.6 g of weapons grade plutonium, 241Am, 133Ba, 57Co and 137Cs sources with activities of several hundred kBq, as well as 260 kBq liquid solution samples of the medical isotopes 99mTc, 111In, 67Ga, 123I, 131I, and 201Tl. We achieved 100% positive identification, for three-second measurements of single sources moving at a source-transit speed of 1.2 m/s. For mixed sources with strongest and weakest sources having no more than a 3:1 ratio of detected counts, encouraging positive identification results were achieved with the un-mixing algorithms. Current radiation portal monitor designs suffer from a high incidence rate of nuisance radiation alarms caused in radiation portal monitors by recent nuclear medicine patients and cargo containing large amounts of naturally occurring radioactive materials. Integrating reliable on-the-fly radionuclide identification into the radiation portal monitors could lower the number of nuisance alarms requiring time-consuming secondary inspections.

M3 - Paper

ER -

Paff M, Di Fulvio A, Altmann Y, Clarke S, Pozzi SA. Identification of mixed sources with an organic scintillator-based radiation portal monitor. 2017. Paper presented at Institute of Nuclear Materials Management 58th Annual Meeting, Indian Wells, United States.