A high-efficiency HPGe coincidence system for environmental analysis. (August 2015)

• Record Type: Journal Article
• Authors: Britton, R.; Davies, A.V.; Burnett, J.L.; Jackson, M.J.
• Is Part Of: Journal of environmental radioactivity. Volume 146(2015:Aug.)
• Page Start: 1
• Page End: 5
• Publication Date: 2015-08
• Subjects: CTBT -- Gamma spectroscopy -- MDA -- Coincidence measurements -- List-mode; Radioactivity -- Periodicals; Radiation, Background -- Periodicals; Radioecology -- Periodicals; Radioactive pollution -- Periodicals; Environmental Pollutants -- Periodicals; Radioactive Pollutants -- Periodicals; Radioactivity -- Periodicals; Radioécologie -- Périodiques; Pollution radioactive -- Périodiques; Fond de rayonnement -- Périodiques; 539.752
• DOI: 10.1016/j.jenvrad.2015.03.033
• Languages: English
• ISSNs: 0265-931X

Abstract

Abstract: The Comprehensive Nuclear–Test–Ban Treaty (CTBT) is supported by a network of certified laboratories which must meet certain sensitivity requirements for CTBT relevant radionuclides. At the UK CTBT Radionuclide Laboratory (GBL15), a high-efficiency, dual–detector gamma spectroscopy system has been developed to improve the sensitivity of measurements for treaty compliance, greatly reducing the time required for each sample. Utilising list–mode acquisition, each sample can be counted once, and processed multiple times to further improve sensitivity. For the 8 key radionuclides considered, Minimum Detectable Activities (MDA's) were improved by up to 37% in standard mode (when compared to a typical CTBT detector system), with the acquisition time required to achieve the CTBT sensitivity requirements reduced from 6 days to only 3. When utilising the system in coincidence mode, the MDA for 60 Co in a high–activity source was improved by a factor of 34 when compared to a standard CTBT detector, and a factor of 17 when compared to the dual–detector system operating in standard mode. These MDA improvements will allow the accurate and timely quantification of radionuclides that decay via both singular and cascade γ emission, greatly enhancing the effectiveness of CTBT laboratories. Highlights: New high-sensitivity, high-resolution gamma spectroscopy system developed. Data collected in list-mode with all events time stamped for offline coincidence analysis. MDA's improved for a range of CTBT relevant radionuclides in singles mode. MDA's substantially improved by detecting multiple gammas in coincidence.