With regard to reconstructing the gamma background dose rate, existing models are either empirical with limited applicability or have many unknown input parameters, which complicates their application in practice. Due to this, there is a need to search for a new approach and build a convenient, easily applicable and universal model. The paper proposes a mathematical model for reconstructing the temporal evolution of the ambient equivalent γ-radiation dose rate during rain episodes, depending on the density of radon flux from the soil surface, as well as the duration and intensity of rain. The efficiency of the model is confirmed by the high coefficient of determination (R2 = 0.81–0.99) between the measured and reconstructed ambient equivalent dose rate during periods of rain, the simulation of which was performed using Wolfram Mathematica. An algorithm was developed for restoring the dynamics of the ambient equivalent γ-radiation dose rate during rainfall. Based on the results obtained, assumptions were made where the washout of radionuclides originates. The influence of the radionuclides ratio on the increase in the total γ-radiation dose rate was investigated.

The features of the atmospheric γ-background reaction to liquid atmospheric precipitation in the form of bursts is investigated, and various forms of them are analyzed. A method is described for interpreting forms of the measured γ-background response with the determination of the beginning and ending time of precipitation, the distinctive features of changes in the intensity of precipitation and the number of single (separate) events that form one burst. It is revealed that a change in the intensity of precipitation in one event leads to a change in the γ-radiation dose rate increase speed (time derivative). A method of estimating the average value of the intensity and amount of precipitation for one event, reconstructing the intensity spectrum from experimental data on the dynamics of the measured dose rate of γ-radiation, is developed. The method takes into account the radioactive decay of radon daughter products in the atmosphere and on the soil surface during precipitation, as well as the purification of the atmosphere from radionuclides. Recommendations are given for using the developed method to correct for changes (daily variations) in radon flux density from the ground surface, which lead to variations in radon in the atmosphere. Experimental verification of the method shows good agreement between the values of the intensity of liquid atmospheric precipitation, calculated and measured with the help of shuttle and optical rain precipitation gauges.

No abstract

No abstract

В работе представлены результаты исследования гамма-фона от объектов техносферы в городской среде г. Томска, Россия, с помощью высокочувствительных детекторов БДКГ-03. Было замечено, что в радиусе 1 м от некоторых объектов техносферы поглощенная доза была на 1.5–4.4 выше, чем предел дозы, рекомендованный НКДАР ООН. Максимальная зарегистрированная мощность дозы на расстоянии 50 см от объектов техносферы составила 0.204 мкЗв/ч, что соответствует среднегодовой эффективной дозе внешнего облучения 0.31 мЗв и риску радиационно-индуцированного рака в течение жизни 1.09·10-3. Диапазон изменения мощности амбиентного эквивалента дозы гамма-излучения в г. Томске составил от 0.058 мкЗв/ч до 0.39 мкЗв/ч. The paper presents the results of a study of the gamma background from technosphere objects in the urban environment of Tomsk, Russia, using high-sensitivity detectors BDKG-03. It was noted that within a radius of 1 m from some objects of the technosphere, theabsorbed dose was 1.5–4.4 higher than the dose limit recommended by UNSCEAR. The maximum recorded dose rate at a distance of 50 cm from the objects of the technosphere was 0.204 mSv/h, which corresponds to an average annual effective dose of external radiation of 0.31 mSv and a lifetime risk of radiation-induced cancer of 1.09 ·10-3. The variation range of the ambient dose equivalent rate of gamma radiation in Tomsk was from 0.058 mSv/h to 0.39 mSv/h.