Analysis of Beta-Decay Rates for Ag108, Ba133, Eu152, Eu154, Kr85, Ra226 And Sr90, Measured at the Physikalisch-Technische Bundesanstalt from 1990 to 1996

Peter A. Sturrock, Ephraim Fischbach, Jere Jenkins

Published 2014-08-13, updated 2014-10-10Version 2

We present the results of an analysis of measurements of the beta-decay rates of Ag108, Ba133, Eu152, Eu154, Kr85, Ra226, and Sr90 acquired at the Physikalisch-Technische Bundesanstalt from 1990 through 1995. Although the decay rates vary over a range of 165 to 1 and the measured detector current varies over a range of 19 to 1, the detrended and normalized current measurements exhibit a sinusoidal annual variation with amplitude in the small range 0.068% to 0.088% (mean 0.081%, standard deviation 0.0072%, an 11{\sigma} rejection of the zero-amplitude hypothesis) and phase-of-maximum in the small range 0.062 to 0.083 (January 23 to January 30). In comparing these results with those of other related experiments that yield different results, it may be significant that this experiment, at a standards laboratory, seems to be unique in using a 4{\pi} detector. These results are compatible with a solar influence, and appear not to be compatible with an experimental or environmental influence. It is possible that Ba133 measurements are subject also to a non-solar (possibly cosmic) influence.