Spectrum processing method for measuring low levels of specific activity of 137Cs with a NaI(Tl) detector in the presence of natural radionuclides

When measuring low levels of 137Cs in soil samples using spectrometers with a NaI(Tl) detector, identification of the 137mBa peak (the 662 keV gamma line of the daughter radionuclide) is difficult due to the influence of natural radionuclides, the peaks of which fall within the 137mBa detection regi...

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Main Authors: V. S. Repin, K. A. Sednev
Format: Article
Language:English
Published: Saint-Petersburg Research Institute of Radiation Hygiene after Professor P.V. Ramzaev 2023-01-01
Series:Радиационная гигиена
Subjects:
Online Access:https://www.radhyg.ru/jour/article/view/919
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author V. S. Repin
K. A. Sednev
author_facet V. S. Repin
K. A. Sednev
author_sort V. S. Repin
collection DOAJ
description When measuring low levels of 137Cs in soil samples using spectrometers with a NaI(Tl) detector, identification of the 137mBa peak (the 662 keV gamma line of the daughter radionuclide) is difficult due to the influence of natural radionuclides, the peaks of which fall within the 137mBa detection region. To identify and estimate the area under the peak of 137mBa, it is necessary to know the contribution of the background component to this area and the contribution of each natural radionuclide. When using such approach, the accuracy of estimating the 137mBa photopeak area depends on the accuracy with which the levels of natural radionuclides are determined. The article proposes a method of spectrum decomposition based on the taking into account individual parameters of the spectrometer and a more accurate determination of specific activities of natural radionuclides. The method involves the modeling the spectral regions for each natural radionuclide in the area of 137mBa peak and subtracting the simulated regions and the background spectrum from the total spectrum under the peak of 137mBa. The use of this approach allows to measure with a 63×63 NaI(Tl) detector the specific activity of 137Cs at a level of 0.7–1 Bq/kg with an uncertainty of 30-50% in the Marinelly geometry with a volume of 1 liter and with the measurement time of 6 hours.
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spelling doaj.art-ef29cade885d49539037e63d3b493d6d2023-03-13T09:47:12ZengSaint-Petersburg Research Institute of Radiation Hygiene after Professor P.V. RamzaevРадиационная гигиена1998-426X2023-01-0115414214810.21514/1998-426X-2022-15-4-142-148778Spectrum processing method for measuring low levels of specific activity of 137Cs with a NaI(Tl) detector in the presence of natural radionuclidesV. S. Repin0K. A. Sednev1Санкт-Петербургский научно-исследовательский институт радиационной гигиены имени профессора П.В. Рамзаева, Федеральная служба по надзору в сфере защиты прав потребителей и благополучия человекаСанкт-Петербургский научно-исследовательский институт радиационной гигиены имени профессора П.В. Рамзаева, Федеральная служба по надзору в сфере защиты прав потребителей и благополучия человекаWhen measuring low levels of 137Cs in soil samples using spectrometers with a NaI(Tl) detector, identification of the 137mBa peak (the 662 keV gamma line of the daughter radionuclide) is difficult due to the influence of natural radionuclides, the peaks of which fall within the 137mBa detection region. To identify and estimate the area under the peak of 137mBa, it is necessary to know the contribution of the background component to this area and the contribution of each natural radionuclide. When using such approach, the accuracy of estimating the 137mBa photopeak area depends on the accuracy with which the levels of natural radionuclides are determined. The article proposes a method of spectrum decomposition based on the taking into account individual parameters of the spectrometer and a more accurate determination of specific activities of natural radionuclides. The method involves the modeling the spectral regions for each natural radionuclide in the area of 137mBa peak and subtracting the simulated regions and the background spectrum from the total spectrum under the peak of 137mBa. The use of this approach allows to measure with a 63×63 NaI(Tl) detector the specific activity of 137Cs at a level of 0.7–1 Bq/kg with an uncertainty of 30-50% in the Marinelly geometry with a volume of 1 liter and with the measurement time of 6 hours.https://www.radhyg.ru/jour/article/view/919гамма-спектрометриядекомпозиция спектрацезий-137природные радионуклидыградуировка спектрометра
spellingShingle V. S. Repin
K. A. Sednev
Spectrum processing method for measuring low levels of specific activity of 137Cs with a NaI(Tl) detector in the presence of natural radionuclides
Радиационная гигиена
гамма-спектрометрия
декомпозиция спектра
цезий-137
природные радионуклиды
градуировка спектрометра
title Spectrum processing method for measuring low levels of specific activity of 137Cs with a NaI(Tl) detector in the presence of natural radionuclides
title_full Spectrum processing method for measuring low levels of specific activity of 137Cs with a NaI(Tl) detector in the presence of natural radionuclides
title_fullStr Spectrum processing method for measuring low levels of specific activity of 137Cs with a NaI(Tl) detector in the presence of natural radionuclides
title_full_unstemmed Spectrum processing method for measuring low levels of specific activity of 137Cs with a NaI(Tl) detector in the presence of natural radionuclides
title_short Spectrum processing method for measuring low levels of specific activity of 137Cs with a NaI(Tl) detector in the presence of natural radionuclides
title_sort spectrum processing method for measuring low levels of specific activity of 137cs with a nai tl detector in the presence of natural radionuclides
topic гамма-спектрометрия
декомпозиция спектра
цезий-137
природные радионуклиды
градуировка спектрометра
url https://www.radhyg.ru/jour/article/view/919
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AT kasednev spectrumprocessingmethodformeasuringlowlevelsofspecificactivityof137cswithanaitldetectorinthepresenceofnaturalradionuclides