Jenkins J H, Fischbach E, Javorsek D, Lee R H, Sturrock P A
School of Nuclear Engineering, Purdue University, West Lafayette, IN 47907, USA.
Appl Radiat Isot. 2013 Apr;74:50-5. doi: 10.1016/j.apradiso.2012.12.010. Epub 2012 Dec 31.
The decay rates of eight nuclides ((85)Kr, (90)Sr, (108)Ag, (133)Ba, (137)Cs, (152)Eu, (154)Eu, and (226)Ra) were monitored by the standards group at the Physikalisch-Technische Bundesanstalt (PTB), Braunschweig, Germany, over the time frame June 1999 to November 2008. We find that the PTB measurements of the decay rate of (137)Cs show no evidence of an annual oscillation, in agreement with the recent report by Bellotti et al. However, power spectrum analysis of PTB measurements of a (133)Ba standard, measured in the same detector system, does show such evidence. This result is consistent with our finding that different nuclides have different sensitivities to whatever external influences are responsible for the observed periodic variations.
德国不伦瑞克市物理技术联邦研究所（PTB）的标准小组在1999年6月至2008年11月期间监测了8种核素（氪-85、锶-90、银-108、钡-133、铯-137、铕-152、铕-154和镭-226）的衰变率。我们发现，PTB对铯-137衰变率的测量没有显示出年度振荡的迹象，这与贝洛蒂等人最近的报告一致。然而，在同一探测器系统中对钡-133标准进行的PTB测量的功率谱分析确实显示出了这样的迹象。这一结果与我们的发现一致，即不同的核素对导致观测到的周期性变化的任何外部影响具有不同的敏感性。
