Study of the dependence of 198Au half-life on source geometry

Abstract

We report the results of an experiment to determine whether the half-life of \Au{198} depends on the shape of the source. This study was motivated by recent suggestions that nuclear decay rates may be affected by solar activity, perhaps arising from solar neutrinos. If this were the case then the $\beta$-decay rates, or half-lives, of a thin foil sample and a spherical sample of gold of the same mass and activity could be different. We find for \Au{198}, $(T_{1/2}{)}_{\mathrm{foil}}/(T_{1/2}{)}_{\mathrm{sphere}}=0.999\pm 0.002$, where $T_{1/2}$ is the mean half-life. The maximum neutrino flux at the sample in our experiments was several times greater than the flux of solar neutrinos at the surface of the Earth. We show that this increase in flux leads to a significant improvement in the limits that can be inferred on a possible solar contribution to nuclear decays.

5 pages, 1 figure

References in corpus (4)

• Evidence for Correlations Between Nuclear Decay Rates and Earth-Sun Distance
• Perturbation of Nuclear Decay Rates During the Solar Flare of 13 December 2006
• Searching for modifications to the exponential radioactive decay law with the Cassini spacecraft
• Analysis of environmental influences in nuclear half-life measurements exhibiting time-dependent decay rates

Cited by in corpus (5)

• Additional experimental evidence for a solar influence on nuclear decay rates
• Absence of a self-induced decay effect in 198Au
• Anomalies in Radioactive Decay Rates: A Bibliography of Measurements and Theory
• Upper limit on the cross section for reactor antineutrinos changing 22Na decay rates
• Sensitivity of reactor experiments to nonstandard neutrino interactions in beta decay rates