dc.contributor.author |
Van Wyngaardt, WM
|
en_US |
dc.contributor.author |
Simpson, BRS
|
en_US |
dc.date.accessioned |
2007-02-07T06:01:49Z |
en_US |
dc.date.accessioned |
2007-06-07T10:01:59Z |
|
dc.date.available |
2007-02-07T06:01:49Z |
en_US |
dc.date.available |
2007-06-07T10:01:59Z |
|
dc.date.issued |
2006-10 |
en_US |
dc.identifier.citation |
Van Wyngaardt, WM and Simpson, BRS. 2006. Absolute activity measurement of the electron-capture-based radionuclides Ce-139, I-125, Ir-192 and Zn-65 by liquid scintillation coincidence counting. Applied Radiation and Isotopes, vol. 64, 11 October, pp 1454-1458 |
en_US |
dc.identifier.issn |
0969-8043 |
en_US |
dc.identifier.uri |
http://hdl.handle.net/10204/1570
|
en_US |
dc.identifier.uri |
http://hdl.handle.net/10204/1570
|
|
dc.description.abstract |
Four radionuclides with electron-capture-based decay schemes have been directly measured by a liquid scintillation coincidence extrapolation technique. The advantage of using (LS) counting in the 4p channel is that self-absorption does not occur, leading to Auger electrons being detected with relatively high efficiency; I-125, Ir-192 and Zn-65 were measured as part of international key comparisons held under the auspices of the International Bureau of Weights and Measures (BIPM). The Ce-139 measurements formed part of a regional comparison organized by the Asia Pacific Metrology Programme (APMP). Since Ce-139 decays simply by electron-capture to the 166 keV excited state of 139La. This state de-excites through the emission of conversion electrons and g-rays. The detection efficiency analysis is based on a counting source being viewed by two phototubes in coincidence, with a single NaI(Tl) crystal detecting the g-rays this technique is a viable technique for the absolute activity measurement of electron-capture-based radionuclides. The efficiency data can generally be fitted with a linear function, particularly in the high-efficiency region, or by a low-order polynomial expression, giving rise to reliable extrapolated activity values. However the application of the method to 125I is more difficult due to the requirement of a proper background correction to the sum peak area. It is surmised that a NaI detector with improved resolution that better separates the sum peak will reduce the discrepancy observed in the more recent activity measurement |
en_US |
dc.format.extent |
164754 bytes |
en_US |
dc.format.mimetype |
application/pdf |
en_US |
dc.language.iso |
en |
en_US |
dc.publisher |
Elsevier Science Ltd |
en_US |
dc.rights |
Copyright: 2006 Elsevier Science Ltd |
en_US |
dc.subject |
Liquid scintillations |
en_US |
dc.subject |
Coincidence extrapolation technique |
en_US |
dc.subject |
Radionuclides |
en_US |
dc.subject |
BIPM |
en_US |
dc.subject |
International bureau of weights measures |
en_US |
dc.subject |
APMP |
en_US |
dc.subject |
Asian pacific metrology programme |
en_US |
dc.subject |
Inorganic nuclear sciences |
en_US |
dc.title |
Absolute activity measurement of the electron-capture-based radionuclides Ce-139, I-125, Ir-192 and Zn-65 by liquid scintillation coincidence counting |
en_US |
dc.type |
Article |
en_US |
dc.identifier.apacitation |
Van Wyngaardt, W., & Simpson, B. (2006). Absolute activity measurement of the electron-capture-based radionuclides Ce-139, I-125, Ir-192 and Zn-65 by liquid scintillation coincidence counting. http://hdl.handle.net/10204/1570 |
en_ZA |
dc.identifier.chicagocitation |
Van Wyngaardt, WM, and BRS Simpson "Absolute activity measurement of the electron-capture-based radionuclides Ce-139, I-125, Ir-192 and Zn-65 by liquid scintillation coincidence counting." (2006) http://hdl.handle.net/10204/1570 |
en_ZA |
dc.identifier.vancouvercitation |
Van Wyngaardt W, Simpson B. Absolute activity measurement of the electron-capture-based radionuclides Ce-139, I-125, Ir-192 and Zn-65 by liquid scintillation coincidence counting. 2006; http://hdl.handle.net/10204/1570. |
en_ZA |
dc.identifier.ris |
TY - Article
AU - Van Wyngaardt, WM
AU - Simpson, BRS
AB - Four radionuclides with electron-capture-based decay schemes have been directly measured by a liquid scintillation coincidence extrapolation technique. The advantage of using (LS) counting in the 4p channel is that self-absorption does not occur, leading to Auger electrons being detected with relatively high efficiency; I-125, Ir-192 and Zn-65 were measured as part of international key comparisons held under the auspices of the International Bureau of Weights and Measures (BIPM). The Ce-139 measurements formed part of a regional comparison organized by the Asia Pacific Metrology Programme (APMP). Since Ce-139 decays simply by electron-capture to the 166 keV excited state of 139La. This state de-excites through the emission of conversion electrons and g-rays. The detection efficiency analysis is based on a counting source being viewed by two phototubes in coincidence, with a single NaI(Tl) crystal detecting the g-rays this technique is a viable technique for the absolute activity measurement of electron-capture-based radionuclides. The efficiency data can generally be fitted with a linear function, particularly in the high-efficiency region, or by a low-order polynomial expression, giving rise to reliable extrapolated activity values. However the application of the method to 125I is more difficult due to the requirement of a proper background correction to the sum peak area. It is surmised that a NaI detector with improved resolution that better separates the sum peak will reduce the discrepancy observed in the more recent activity measurement
DA - 2006-10
DB - ResearchSpace
DP - CSIR
KW - Liquid scintillations
KW - Coincidence extrapolation technique
KW - Radionuclides
KW - BIPM
KW - International bureau of weights measures
KW - APMP
KW - Asian pacific metrology programme
KW - Inorganic nuclear sciences
LK - https://researchspace.csir.co.za
PY - 2006
SM - 0969-8043
T1 - Absolute activity measurement of the electron-capture-based radionuclides Ce-139, I-125, Ir-192 and Zn-65 by liquid scintillation coincidence counting
TI - Absolute activity measurement of the electron-capture-based radionuclides Ce-139, I-125, Ir-192 and Zn-65 by liquid scintillation coincidence counting
UR - http://hdl.handle.net/10204/1570
ER -
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en_ZA |