On the recent claim of correlation between radioactive decay rates and space weather
- PDF / 1,085,410 Bytes
- 8 Pages / 595.276 x 790.866 pts Page_size
- 16 Downloads / 140 Views
Regular Article - Experimental Physics
On the recent claim of correlation between radioactive decay rates and space weather S. Pomméa , K. Pelczar European Commission, Joint Research Centre (JRC), Geel, Belgium
Received: 8 August 2020 / Accepted: 13 November 2020 / Published online: 26 November 2020 © The Author(s) 2020
Abstract In recent literature, several authors have challenged the validity of the exponential-decay law, based on observed variations in radioactive decay rate measurements beyond statistical accuracy. Tentative explanations have been sought in external interferences influencing the decay process, such as interactions of the nuclei with solar and cosmic neutrinos. Given the important implications of such statements on theoretical and practical level, one would expect that they are backed up with radionuclide metrology of the highest quality. In reality, they share the common traits of using poor metrology and incomplete uncertainty analysis with respect to the stability of the measurement technique. In this paper, new claims of correlations between decay rates and space weather are questioned.
1 Introduction The exponential-decay law is a cornerstone of nuclear physics, the common measurement system of radioactivity, and numerous applications derived from it, including radiometric dating and nuclear dosimetry. It follows directly from quantum theory, which predicts invariable transition rate coefficients λ in most practical conditions, and its validity has been amply confirmed by experiment [1–3] with the most accurate measurement techniques used for primary [4] and secondary [5] standardisation of activity. As a result, international equivalence of radioactivity standards can be demonstrated at the 0.1% uncertainty level regardless of the time of measurement. Applying rigour in measurement conditions and data analysis [6,7], laboratories can reach consistency in half-life measurements at levels below 0.1–0.01%, as recently demonstrated in the case of 55 Fe [8,9] and 99m Tc [10]. Repeated activity measurements with the most stable instruments show absence of cyclic perturbations down to 0.023–0.00023% in amplitude [3,11], when excluding the a e-mail:
susceptibility of the instrument to environmental conditions and using appropriate significance criteria [11,12]. In spite of the arguments in favour of the exponential-decay law, some authors have questioned the invariability of the decay constants [13–30]. Summaries of their claims and refutations by others have already been published in detail [3,31–34]. The most important class of experimental evidence pertains to activity measurements of beta emitters showing seasonal fluctuations of the order of 0.3%, with a periodicity of 1 year [13,16–19]. Whereas susceptibility of the measurement instrument to variations in temperature, humidity or radon concentration are plausible causes of the instabilities [32,35,36], the authors chose to make strong claims about decay being induced by solar or cosmic neutrinos interacting with the nuclei. Overwhelming
Data Loading...
