We find evidence from measurements of Ag108, Ba133, Eu152, Eu154, Ra226 and Sr90 (Physikalisch-Technische Bundesanstalt, Germany), Rn222 (Geological Survey of Israel), Co60, Pu239, and Sr90 (Lomonosov Moscow State University, Russia), Cl36 and Si32 (Brookhaven National Laboratory, USA) and Mn54 (Purdue University, USA) that beta-decay rates tend to be variable, and that the Sun is responsible for some - perhaps all - of the variability. One variation is an annual oscillation with amplitude about 0.1% and maximum in January or February, presumably related to the annually varying Sun-Earth distance. We also find evidence for two rotational modulations, one with a measured (synodic) frequency of about 12.5 year-1 (an absolute, sidereal frequency of 13.5 year-1), due perhaps to processes in the radiative zone, and another with a synodic frequency of about 11 year-1 (12 year-1 sidereal), due perhaps to processes in an inner tachocline between the core and the radiative zone. A steep gradient in angular velocity (as in a tachocline) is known to be unstable and generate r-mode oscillations. These may be detectable as Rieger-type oscillations in the outer tachocline, and to similar oscillations (with correspondingly lower frequencies, in proportion to the sidereal rotation frequencies) in the inner tachocline. We find evidence for such r-mode oscillations not only in beta-decay data, but also in solar diameter data. A possible explanation of the apparent beta-decay variability is that decays may be stimulated by neutrinos. Since the flavor composition of the neutrino flux can be modified by the Sun’s internal magnetic field (via Resonant Spin Flavor Precession), magnetohydrodynamic processes in the deep solar interior may be detectable on Earth as neutrino-stimulated beta-decay fluctuations. Experiments suggest that a nuclide such as 32Si has a beta-decay-equivalent-cross-section of order 10-25 cm2, larger than the neutrino-equivalent-cross-section of an electron or proton by about 1019. If this proves to be correct, then less than 1 picogram of 32Si would yield the same solar-neutrino-induced event rate as the Super-Kamiokande Observatory.
American Astronomical Society Meeting Abstracts #224
- Pub Date:
- June 2014