Meteorological influences on the results of area dose rate measurements

摘要

The area dose rate (ADR) of the natural radiation is subject to strong fluctuations caused by meteorological influences. Rain in particular can strongly increase the local dose rate values on the earth's surface for a short time because radon progenies can be washed out of the atmosphere and accumulated on the Earth's surface. The Physikalisch-TechnischeBundesanstalt (PTB) has reference measuring facilities at its disposal which allow permanent measurement of the individual components of natural ambient radiation. Results of long-term measurements and their correlation to weather data, seasonal fluctuations, but also to solar activity, are presented. In addition to the quantification of the radiation level caused by photons, the contributions of the charged components of cosmic radiation (myons and electrons) as well as neutron radiation were measured. The terrestrial component of natural ambient radiation results from the radionuclides in the soil and in the air. In order to determine which nuclides cause the corresponding dose rate, the in-situ-gamma spectrometry method is especially suited. Measurements of the variation of the nuclide-specific photon flux as a function of the precipitation prove that the activity concentrations of radon progenies have an important influence on the local dose rate.