STUDY OF THE TIME DEPENDENCE OF RADIOACTIVITY
In: Acta polytechnica: journal of advanced engineering, Band 53, Heft A, S. 524-527
ISSN: 1805-2363
The activity of a <sup>137</sup>Cs source was measured using a germanium detector installed deep underground in the Gran Sasso Laboratory. In total about 5100 energy spectra, one hour measuring time each, were collected and used to search for time variations of the decay constant with periods from a few hours to 1 year. No signal with amplitude larger than 9.6 × 10<sup>−5</sup> at 95% C.L. was detected. These limits are more than one order of magnitude lower than the values on the oscillation amplitude reported in the literature. The same data give a value of 29.96±0.08 years for the <sup>137</sup>Cs half life, which is in good agreement with the world mean value of 30.05 ± 0.08 years.