Observations of the relationship between directionality and decay rate of radon in a confined experiment
Geological Survey of Israel, Jerusalem, Israel
a e-mail: Steinitz@gsi.gov.il
Received: 10 February 2015
Revised: 23 April 2015
Published online: 10 June 2015
Radon (222Rn) is a radioactive inert gas with an accepted half life of 3.8235 days. Its unique, systematic and complex variation in the geological environment and in simulation experiments combined with lack of understanding of the underlying drivers lead us to conduct tests of its apparent half life. A primary test took into account experimental observations indicating anisotropy of the gamma radiation from radon in air, which is related to global orientation. Using a goniometric configuration radon diffuses into two identical cylinders oriented along Earth axis of rotation and in a vertical and perpendicular direction to the latter. Detectors placed on cylinder ends measure gamma radiation sub parallel to these directions. At steady state and confined conditions different patterns of daily signals are observed in the two directions. Isolating the cylinders from the source leads to an exponential decrease on which similar daily signals are superimposed, having amplitudes proportional to the level of the remaining radon. The indicated apparent half-lives are in significant difference from the accepted value: 0.861 ± 0.003 days in the pole direction and 2.308 ± 0.008 days in the vertical direction. The outcome is in conformity with observations on radon signals in confined conditions and their different manifestation at different directions.
© EDP Sciences, Springer-Verlag, 2015