Marouli M, Pommé S, Van Ammel R, García-Toraño E, Crespo T, Pierre S
European Commission, Joint Research Centre, Directorate for Nuclear Safety and Security, Retieseweg 111, B-2440 Geel, Belgium.
European Commission, Joint Research Centre, Directorate for Nuclear Safety and Security, Retieseweg 111, B-2440 Geel, Belgium.
Appl Radiat Isot. 2017 Jul;125:196-202. doi: 10.1016/j.apradiso.2017.04.029. Epub 2017 Apr 27.
High-resolution alpha-particle spectrometry was performed to determine the main alpha-particle emission probabilities in the decay of Ra. Thin, homogeneous sources were prepared by electrodeposition on stainless steel disks. Alpha spectra with an energy resolution of 20keV were obtained in three laboratories and analysed with different deconvolution algorithms. In two set-ups, a magnet system was used to deflect conversion electrons to avoid their coincidental detection with the alpha particles. Spectra taken at close range without a magnet system yielded biased results which cannot be fully compensated by statistical corrections for coincidence summing. The derived emission probabilities of the three main alpha decays are 94.07 (1)%, 5.93 (1)%, and 0.0059 (15)%, respectively. They are in excellent agreement with calculated values derived from the P(γ+ce) decay scheme balance, which solves the existing discrepancy problem with two previous direct measurements published in literature.
采用高分辨率α粒子能谱法测定镭衰变过程中的主要α粒子发射概率。通过电沉积在不锈钢圆盘上制备了薄的均匀源。在三个实验室获得了能量分辨率为20keV的α能谱，并使用不同的解卷积算法进行分析。在两种装置中，使用磁体系统使转换电子偏转，以避免它们与α粒子同时被探测到。在近距离且没有磁体系统的情况下采集的能谱产生了有偏差的结果，这种偏差无法通过对符合相加的统计校正来完全补偿。三种主要α衰变的推导发射概率分别为94.07(1)%、5.93(1)%和0.0059(15)%。它们与从P(γ+ce)衰变方案平衡推导的计算值非常吻合，解决了文献中之前发表的两次直接测量中存在的差异问题。
