Looping variation observed in environmental gamma-ray measurement due to atmospheric radon daughters

Analysis of environmental influences in nuclear half-life measurements exhibiting time-dependent decay rates

“…We next turn to the possible contributions from background radiation of cosmic and terrestrial origins, such as the 222 Rn variations considered by Siegert, et al [5], and Schrader [10] as the cause of the annual variation of the 226 Ra measurements. Although 222 Rn concentrations do exhibit seasonal as well as diurnal variations [13,14,15,16,17,18,19,20], the actual activities are quite small, on the order of 15-90 Bq/m 3 , which are far below the activities of the sources being measured. Specifically, an analysis performed by Abbady, et al in Hannover, Germany [18] (which is ∼60 km from the PTB in Braunschweig), measured indoor concentrations of 222 Rn inside the Centre for Radiation Protection and Radioecology (ZSR) at Hannover University.…”

Remote On-line Calibration of a Particulate-Iodine Monitor of a Real-Time Radiological Network

“…For that, the Channel A and B count rates (in c. p. s.) for the alpha and beta emissions are registred over the longest sampling period that is technically viable (typically from six to twelve hours). Nevertheless, it is well-know that the Rn/Th decay product content of aerosols undergoes diverse periodic-type variations, so that there is a significant modification of the recorded count rates, varying seasonally, daily, and even during the course of a Single day [5,11,12,13]. However, when the calibrated parameters are obtained from the local procedure, they are fixed during six or twelve months until a new local procedure calibration is performed.…”

Monte carlo calculation of gamma-ray flux density due to atmospheric radon daughters.

“…One of the main causes of the natural variation in the environmental r-ray intensity is the transport of radon daughters from the upper air to the ground surface by precipita-tion<'l-<•l. Another one is the change of the atmospheric radon daughter content due to various meteorological conditions<•l- (6). Others have usually only small effect on the environmental r-ray intensity, and have a rather long characteristic time length.…”