English

No correlation between Solar flares and the decay rate of several $\beta$-decaying isotopes

Nuclear Experiment 2018-10-24 v2 Solar and Stellar Astrophysics

Abstract

We report on finding no correlation between the two strongest observed Solar flares in September 2017 and the decay rates of 60^{60}Co, 44^{44}Ti and 137^{137}Cs sources, which are continuously measured by two independent NaI(Tl) detector setups. We test for variations in the number of observed counts with respect to the number of expected counts over multiple periods with timescales varying from 1 to 109 hours around the Solar flare. No excess or deficit exceeds the 2σ\sigma global significance. We set a conservative lower limit on the decay rate deviation over an 84-hour period around the two correlated Solar flares in September 2017 to 0.044%0.044\% with 2σ\sigma confidence. A fractional change of  0.1%~0.1\% in the decay rate of 54^{54}Mn over a period of 84 hours was claimed with 7σ\sigma significance during multiple Solar flares in December 2006. We exclude such an effect at 4.7σ\sigma significance.

Keywords

Cite

@article{arxiv.1806.03202,
  title  = {No correlation between Solar flares and the decay rate of several $\beta$-decaying isotopes},
  author = {J. R. Angevaare and L. Baudis and P. A. Breur and A. Brown and A. P. Colijn and R. F. Lang and A. Massafferri and J. C. P. Y. Nobelen and R. Perci and C. Reuter and M. Schumann},
  journal= {arXiv preprint arXiv:1806.03202},
  year   = {2018}
}

Comments

Corrected typos, revised table values, results unchanged Will be published in Astroparticle Physics, Volume 103, December 2018, Pages 62-66 9 pages, 2 figures and 1 table. Keywords: Solar Flares, Radioactivity, Beta Decays, Neutrinos, Global Significance