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1
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van Wyngaardt WM, Bowan AHH, Clark EL, Keevers CMB, Smith ML, Zarifi M, Stopic A. Cross-validation of standardisation techniques at ANSTO using cobalt-60 and learnings from the presence and identification of non-gamma-ray emitting impurities. Appl Radiat Isot 2023; 201:111027. [PMID: 37748217 DOI: 10.1016/j.apradiso.2023.111027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 08/26/2023] [Accepted: 09/11/2023] [Indexed: 09/27/2023]
Abstract
To fulfil the technical requirements for accreditation to ISO/IEC 17025, the end-to-end validation of all processes associated with standardising 60Co, including gravimetric source dispensing, primary standardisation by the 4π(LS)β-γ coincidence and live-timed anti-coincidence extrapolation techniques, and impurity determination were performed and documented. Pure-beta-emitting impurities in a 60Co stock solution were identified. The impact of such impurities on measurement by liquid scintillation counting and comparison in the ESIR are discussed. A fresh 60Co source was produced, standardised, and compared using the SIR.
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Affiliation(s)
- W M van Wyngaardt
- Australian Nuclear Science and Technology Organisation, New Illawarra Rd, Lucas Heights, 2234 NSW, Australia.
| | - A H H Bowan
- Australian Nuclear Science and Technology Organisation, New Illawarra Rd, Lucas Heights, 2234 NSW, Australia
| | - E L Clark
- Australian Nuclear Science and Technology Organisation, New Illawarra Rd, Lucas Heights, 2234 NSW, Australia
| | - C M B Keevers
- Australian Nuclear Science and Technology Organisation, New Illawarra Rd, Lucas Heights, 2234 NSW, Australia
| | - M L Smith
- Australian Nuclear Science and Technology Organisation, New Illawarra Rd, Lucas Heights, 2234 NSW, Australia
| | - M Zarifi
- Australian Nuclear Science and Technology Organisation, New Illawarra Rd, Lucas Heights, 2234 NSW, Australia
| | - A Stopic
- Australian Nuclear Science and Technology Organisation, New Illawarra Rd, Lucas Heights, 2234 NSW, Australia
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2
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Heranudin, Smith ML, van Wyngaardt WM, Guatelli S, Li E, Rosenfeld A. Characterisation of a well-type NaI(Tl) detector by means of a Monte Carlo simulation for radionuclide metrology application. Appl Radiat Isot 2021; 176:109889. [PMID: 34375816 DOI: 10.1016/j.apradiso.2021.109889] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 07/14/2021] [Accepted: 08/02/2021] [Indexed: 11/29/2022]
Abstract
A well-type NaI(Tl) detector was modelled and characterised by means of a Monte Carlo simulation, as part of a project to develop a 4πβ (Plastic Scintillator)-4πγ instrument to be used for the primary standardisation of radionuclides at ANSTO. The simulation based on GEANT4 was used to characterise the 4πγ detector in terms of potential dead layer/inactive materials, full energy peak efficiency, coincidence-summing correction, and energy resolution. An excellent agreement was obtained between the simulation results and the experimental measurements.
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Affiliation(s)
- Heranudin
- Centre for Medical Radiation Physics, University of Wollongong, NSW, Australia; Radionuclide Metrology, Australian Nuclear Science and Technology Organisation, NSW, Australia; National Nuclear Energy Agency of Indonesia, Tangerang, Indonesia.
| | - M L Smith
- Centre for Medical Radiation Physics, University of Wollongong, NSW, Australia; Radionuclide Metrology, Australian Nuclear Science and Technology Organisation, NSW, Australia
| | - W M van Wyngaardt
- Radionuclide Metrology, Australian Nuclear Science and Technology Organisation, NSW, Australia
| | - S Guatelli
- Centre for Medical Radiation Physics, University of Wollongong, NSW, Australia
| | - E Li
- Centre for Medical Radiation Physics, University of Wollongong, NSW, Australia
| | - A Rosenfeld
- Centre for Medical Radiation Physics, University of Wollongong, NSW, Australia
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van Wyngaardt WM, Tobin SM, Lee S, Smith ML, Jackson TW, Ilter J, Howe B, Sarbutt A. Primary standardisation of technetium-99m by liquid scintillation coincidence counting. Appl Radiat Isot 2020; 156:108935. [PMID: 31675614 DOI: 10.1016/j.apradiso.2019.108935] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 09/26/2019] [Accepted: 10/09/2019] [Indexed: 11/18/2022]
Abstract
Technetium-99m was standardised by the 4π(LS)ce-γ coincidence extrapolation method. Sensitivity of the 4π(LS) channel to two types of radiation, namely conversion electrons and γ-rays, resulted in incorrect activity values being obtained when this was not adequately accounted for. Measurements were more robust when the LS detection efficiency was optimised, and when a γ-window setting was used that monitored the combined LS efficiency for conversion electrons and γ-rays. The primary standard was internationally compared through participation in the BIPM.RI(II)-K4.Tc99m key comparison.
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Affiliation(s)
- W M van Wyngaardt
- Australian Nuclear Science and Technology Organisation, New Illawarra Rd, Lucas Heights, 2234, NSW, Australia.
| | - S M Tobin
- Australian Nuclear Science and Technology Organisation, New Illawarra Rd, Lucas Heights, 2234, NSW, Australia
| | - S Lee
- Australian Nuclear Science and Technology Organisation, New Illawarra Rd, Lucas Heights, 2234, NSW, Australia
| | - M L Smith
- Australian Nuclear Science and Technology Organisation, New Illawarra Rd, Lucas Heights, 2234, NSW, Australia
| | - T W Jackson
- Australian Nuclear Science and Technology Organisation, New Illawarra Rd, Lucas Heights, 2234, NSW, Australia
| | - J Ilter
- Australian Nuclear Science and Technology Organisation, New Illawarra Rd, Lucas Heights, 2234, NSW, Australia
| | - B Howe
- Australian Nuclear Science and Technology Organisation, New Illawarra Rd, Lucas Heights, 2234, NSW, Australia
| | - A Sarbutt
- Australian Nuclear Science and Technology Organisation, New Illawarra Rd, Lucas Heights, 2234, NSW, Australia
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