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1 Tomsk Polytechnic University, Tomsk, Russian Federation;

1 Tomsk Polytechnic University, Tomsk, Russian Federation; 2 Institute of Monitoring of Climatic and Ecological Systems SB RAS, Tomsk, RF ; 3 Kamchatkan Branch Geophysical service, RAS, Petropavlovsk- Kamchatsky , RF.

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1 Tomsk Polytechnic University, Tomsk, Russian Federation;

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  1. 1Tomsk Polytechnic University, Tomsk, Russian Federation; 2Institute of Monitoring of Climatic and Ecological Systems SB RAS, Tomsk, RF; 3Kamchatkan Branch Geophysical service, RAS, Petropavlovsk-Kamchatsky, RF First results of multifactor experiment on radon transport in the lithosphere-atmosphere system Valentina S. Yakovleva1, Artem V. Vukolov1, Ivan I. Ippolitov1,2, Mikhail V. Kabanov2, Vladimir D. Karataev1, Peter M. Nagorsky1,2, Sergey V. Smirnov1,2,Pavel P. Firstov3 The work was fulfilled with financial supportof FAP № 02.740.11.0738 and project of SB RAS № VII.63.1.1 Russian Federation

  2. First results of multifactor experiment on radon transport in the lithosphere-atmosphere system Natural background radiation is one of the most important elements of atmosphere, and its variations are closely connected with the change of weather parameters of atmosphere, its chemical and aerosol composition. Registration and further analysis of ionizing radiation fields in the atmosphere is carried out by one radiation type – γ-radiation. Monitoring of β-radiation in the atmosphere is practically absent.

  3. First results of multifactor experiment on radon transport in the lithosphere-atmosphere system β- and γ-background in the surface atmosphere is caused by one and the same sources: soil radionuclides and atmosphere decay products of radon and thoron. Taking this fact into account, one should expect similar behavior of β- и γ-radiation fields in the surface atmosphere. However, due to large differences in their penetrating power, a legal question arose: how agreed the variations of different types of natural ionizing radiation are.

  4. First results of multifactor experiment on radon transport in the lithosphere-atmosphere system It is known, that time variability of atmosphere β- and γ-radiation is mainly caused by the influence of RFD from the ground surface. The attempts to determine RFD value by the γ-dose rate value are known [Szegvary, 2007]. It was found that space variations of γ-background coincide with RFD variations by 60%. There, it was also found that time variations of γ-background and RFD are in good agreement with each other.

  5. First results of multifactor experiment on radon transport in the lithosphere-atmosphere system • Thus, two problems arose: • comparative evaluation of spectrum-time parameters of β- and γ-radiation fields and detection of their interactions with atmosphere-electrical values of the surface layer. • detection of interactions between β- and γ-radiation fields and radon field, with the objective to further research the possibility to investigate radon transport in the “lithosphere-atmosphere” system by β-, γ-radiation.

  6. First results of multifactor experiment on radon transport in the lithosphere-atmosphere system • Tomsk measuring-experimental complex: • The monitoring is performed via automated information measuring system: • atmosphere temperature – T, • pressure – p, • relative humidity – h, • wind velocity and direction, • surface temperature and subsurface temperatures at some depths. • β-, γ- and α-field characteristics. • Additionally it includes: • the detectors of atmosphere electric field intensity E «Field-2», • polar electroconductivitiesL-, L+ of atmosphere air «Electroconductivity-2» • gamma radiation dose rate. • pyranometerKipp & Zonen SM-11 and photometer NILU-UV-6T to measure incoming solar radiation Pr. • The measurements are continuous with 1 minute time step.

  7. First results of multifactor experiment on radon transport in the lithosphere-atmosphere system Since March 2007 the measurements of electrical, weather and actinometrical values have been transferred to a specially equipped monitoring platform, situated at the IMCES SB RAS building mezzanine at the height of 24 m.

  8. Scheme of the multifactor experiment in Tomsk А– meteo- and actinometrical sensors; B – sensors of electrical parameters; I – scintillation ZnSα-detector; II – scintillation NaI(Tl) γ-detector; III – STS-6 gas counter of β-radiation; IV – SBT-10 end-window counter of β-radiation; V – line of gas counters of γ-radiation; VI – DGDK-100V semiconducting coaxial germanium detector of γ-radiation, put into Dewar vessel; VII – automated accumulative chamber for radon flux density measurement; APM 2200 – radon decay products radiometer (SARAD GmbH, Germany).

  9. First results of multifactor experiment on radon transport in the lithosphere-atmosphere system Initial procedure of monitoring of ionizing radiations, meteorological and atmospheric-electric parameters were created to analyze the influence of upper soil layer and ground atmosphere state and dynamics: on radon and thoron fluxes from the ground surface; distribution of radon, thoron and their decay products; vertical distribution of α-, β- and γ-radiation fluxes in the air; ion generation rate due to radon and its decay products.

  10. First results of multifactor experiment on radon transport in the lithosphere-atmosphere system At the height of 25 m in a standard weather booth there are two gas counters of β+γ-radiation (type STS-6), one of which is worn in aluminum casing for beta-radiation delay. Thus, one counter registers β+γ-radiation and the other one – only γ-radiation. Pure β-background is obtained by registration difference. Data pickup cycle is 2 minutes.

  11. In some periods a good synchronism was found in dynamics of α- and β-radiation measured at different height and depth. First results of multifactor experiment on radon transport in the lithosphere-atmosphere system β+γ-radiation at 10 m; β+γ-radiation at 5 m; β-radiation at 0 m; α-radiation at 0 m; β-radiation at -0.5 m; β-radiation at -1 m; Air temperature, ºC; Relative humidity, %; Incoming solar radiation

  12. In some periods a good synchronism was found in dynamics of β-radiation at 0.5 m depth and atmosphere temperature. β+γ-radiation β+γ-radiation

  13. β+γ-radiation at 5 m

  14. Synchronous spikes were found inγ-radiation dose time series measured at different height andposition (indoor or outdoor). First results of multifactor experiment on radon transport in the lithosphere-atmosphere system γ-radiation at 25 m (gas discharge counter-outdoor); γ-radiation at 24 m (scintillation detector-indoor); γ-radiation at 24 m (line of gas discharge counters-indoor); β+γ-radiation at 10 m -outdoor; β+γ-radiation at 5 m -outdoor; Horizontal speed of wind, m/s; Vertical speed of wind, m/s; Atmosphere air density, kg/m3; Atmosphere temperature, ºС.

  15. First results of multifactor experiment on radon transport in the lithosphere-atmosphere system Preliminary results of monitoring data analysis allow to make a conclusion that contributions of β- and γ-radiation into the total level of background atmosphere radiation depend on different meteorological factors and one type of radiation correlates with others not always. Some examples follow further…

  16. Typical time variations of β- and γ-radiation in summer atmosphere γ-dose rate, µSv/h β-flux, m-2 c-1 γ-dose rate, µSv/h β-flux, m-2 c-1 August, 2009

  17. First results of multifactor experiment on radon transport in the lithosphere-atmosphere system August, 2009

  18. First results of multifactor experiment on radon transport in the lithosphere-atmosphere system γ-dose rate, µSv/h β-flux density, m-2 c-1 Pressure

  19. On time scales from synoptic to annual the variations of γ–background are appeared to be connected with air pressure change. For instance, air pressure decrease leads to the increase of γ–background level (and vice versa). γ-dose rate, µSv/h β-flux density Pressure

  20. First results of multifactor experiment on radon transport in the lithosphere-atmosphere system γ-dose rate, µSv/h β-flux density, m-2 c-1

  21. γ– background variations with diurnal period are expressed weakly in comparison with similar β-background variations, however there are intervals, when they are expressed rather vividly. γ-dose rate, µSv/h β-flux density, m-2 c-1

  22. Beta-background variations appeared to be closely connected with diurnal variations of atmosphere conductivity, its temperature and humidity. γ-dose rate β-flux density

  23. First results of multifactor experiment on radon transport in the lithosphere-atmosphere system γ-dose rate, µSv/h β-flux density, m-2 c-1

  24. First results of multifactor experiment on radon transport in the lithosphere-atmosphere system γ-dose rate, µSv/h β-flux density, m-2 c-1

  25. Beta-background variations appeared to be closely connected with diurnal variations of atmosphere temperature and density.

  26. First results of multifactor experiment on radon transport in the lithosphere-atmosphere system Connection between variations of γ- and β-radiation fieldson different time scale Winter of2008and2009-2010 Summer of2009and2010 Variations with 2 hours–2 days periods (all data) Regressionrelation of variations with 2 days and more periods

  27. Normalized crosscorrelation function (NICF) between low-frequency variations of β- and γ-radiations Summer (4.06.09 – 28.08.09) Winter (21.12.09 – 16.03.10) X-axis - day number of year (beginning from 1.01.2009), Y-axis– time shift (hours).

  28. Results analysis and Experimental Platform modernization • Conclusion • It has been found that: • Variations of beta- and gamma-radiations are weakly connected between each other, however, within some periods of the synoptic scale the correlation between them can be rather high; • The estimations of radon flux variations based only on variations of gamma-radiation can appear to be incorrect; • Beta-background variations appeared to be comparatively weakly connected with variations of synoptic scale pressure and closely connected with diurnal variations of atmosphere conductivity, its temperature, density and steam pressure.

  29. After the first results analysis it was decided to complicate the scheme of the multifactor experiment, adding 6 gas counters to the existing ones.

  30. Thank you very much for your attention! Tomsk, Siberia, Russian Federation

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