Kossert Karsten, Marganiec-Gałązka Justyna, Mougeot Xavier, Nähle Ole J
Physikalisch-Technische Bundesanstalt (PTB), Bundesallee 100, 38116 Braunschweig, Germany.
Physikalisch-Technische Bundesanstalt (PTB), Bundesallee 100, 38116 Braunschweig, Germany.
Appl Radiat Isot. 2018 Apr;134:212-218. doi: 10.1016/j.apradiso.2017.06.015. Epub 2017 Jun 15.
The activity concentration of a Co solution was measured by means of two 4πβ-γ coincidence counting systems using a liquid scintillation counter and a proportional counter (PC) in the beta channel, respectively. Additional liquid scintillation measurements were carried out and CIEMAT/NIST efficiency tracing as well as the triple-to-double coincidence ratio (TDCR) methods were applied to analyse the data. The last two methods require computed beta spectra to determine the counting efficiencies. The results of both 4πβ-γ coincidence counting techniques are in very good agreement and yield a robust reference value. The initial activity concentration determined with liquid scintillation counting was found to be significantly lower than the results from 4πβ-γ coincidence counting. In addition, the results from TDCR and CIEMAT/NIST show some inconsistency. The discrepancies were resolved by applying new beta spectrum calculations for the dominant allowed beta transition of Co. The use of calculations which take screening effects as well as the atomic exchange effect into account leads to good agreement between all four methods; the combination of these techniques delivers an important validation of beta spectra.
通过两个4πβ-γ符合计数系统分别使用液体闪烁计数器和β通道中的正比计数器（PC）来测量钴溶液的活度浓度。进行了额外的液体闪烁测量，并应用CIEMAT/NIST效率追踪以及三对双符合比（TDCR）方法来分析数据。后两种方法需要计算β能谱来确定计数效率。两种4πβ-γ符合计数技术的结果非常一致，并产生了可靠的参考值。发现用液体闪烁计数法测定的初始活度浓度明显低于4πβ-γ符合计数法的结果。此外，TDCR和CIEMAT/NIST的结果显示出一些不一致性。通过对钴的主要允许β跃迁应用新的β能谱计算解决了这些差异。考虑屏蔽效应以及原子交换效应的计算方法的使用导致所有四种方法之间具有良好的一致性；这些技术的结合对β能谱进行了重要验证。
