Details

Autor(en) / Beteiligte

• Sahagia, Maria
• Luca, Aurelian
• Antohe, Andrei
• Ioan, Mihail-Razvan

Titel

Absolute standardization of 57Co and analysis of the results obtained in two international comparisons

Ist Teil von

• Applied radiation and isotopes, 2018-10, Vol.140, p.146-150

Ort / Verlag

Elsevier Ltd

Erscheinungsjahr

2018

Quelle

Access via ScienceDirect (Elsevier)

Beschreibungen/Notizen

• The absolute standardization of Co-57 by the 4π(PC)-γ coincidence method, in efficiency extrapolation variant, is presented. An original, improved method, based on the use of the equivalent decay scheme, was applied; apart from the enhancement of efficiency, a diminution of extrapolation slope was obtained, lowering the extrapolation uncertainty. The results obtained in the participation at the supplementary comparison CCRI(II)-S6.Co-57 and at the key comparison code BIPM.RI(II)-K1.Co-57 are presented. The method allows to simplify the treatment of 56Co and 58Co impurities’ correction, which influences significantly the measurements in a CENTRONIC type ionization chamber. An example of treatment of this mixture, where the influence of impurities on results was analyzed, will be presented. •A solution of 57Co was standardized absolutely by the 4π(PC)-γ coincidence method.•The results of CCRI(II)-S6. Co-57 and BIPM.RI(II)-K1. Co-57 comparisons were contradictory.•This paper explains these differences, by the contribution of 58Co and 56Co impurities.