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Annette Röttger – One of the best experts on this subject based on the ideXlab platform.
Development of a transfer standard for the measurement of low Rn-222 Activity Concentration in air.Applied Radiation and Isotopes, 2013Co-Authors: Diana Linzmaier, Annette RöttgerAbstract:
Abstract A large volume transfer standard has been developed to calibrate commercial radon measurement devices in a homogeneous Rn-222 reference atmosphere. The transfer standard serves for the realization, maintenance and dissemination of the unit Bq/m3 below 1 kBq/m3. The transfer standard consists of a multi-wire impulse ionization chamber, electronic measurement equipment and the corresponding software. The multi-wire impulse ionization chamber is composed of two parallel printed boards. Between the boards, 478 vertical electrode wires are soldered in to include a volume of 10 L. In the dependency of the energy, the α-particles of Rn-222 and the decay products are detected in the active volume of the multi-wire impulse ionization chamber. By means of the measurement software an α-energy spectrum is produced. Via different algorithms, the Activity Concentration of the Rn-222 reference atmosphere is determined.
A primary standard for Activity Concentration of 220Rn (thoron) in air.Applied radiation and isotopes : including data instrumentation and methods for use in agriculture industry and medicine, 2010Co-Authors: Annette Röttger, Anja Honig, R. Dersch, Dirk ArnoldAbstract:
Due to the short half-life of Rn-220, a primary standard for Activity Concentration of Rn-220 (thoron) in air (i.e. a homogeneous reference atmosphere consisting of a certified Activity in a certified volume) has been considered unachievable in the past. Traceability of Rn-222 reference atmospheres is achievable using radon gas Activity standards (Picolo, 1996; Dersch, 1998) and standard volumes, and is an established method (Paul et al., 2002). For the short-lived radionuclide Rn-220 this procedure is not feasible, since no Rn-220 gas Activity standard with a reasonable Activity can be produced. This leads to a lack of traceability for measurements of Rn-220 Activity Concentration: only atmospheres monitored by reference instruments (i.e. secondary standards) are available. The new primary standard for the Activity Concentration of (220)Rn developed by PTB now closes this gap in radon metrology.
radon Activity Concentration a euromet and bipm supplementary comparisonApplied Radiation and Isotopes, 2006Co-Authors: Annette Röttger, Adam Honig, H. Buchröder, Gernot Butterweck, Ch. Schuler, F J Maringer, P Jachs, R Edelmaier, N MichielsenAbstract:
Abstract For the first time, a comparison of radon Activity Concentration in air has been performed within the scope of Euromet. In the project 657, ‘Comparison of calibration facilities for the radon Activity Concentration,’ 12 participants from 9 countries compared different radon reference atmospheres at 1, 3 and 10 kBq m−3 via a transfer standard. The comparison was listed as BIPM supplementary comparison EUROMET.RI(II)-S1. The results of most participants are correlated due to common traceability to one single radon gas standard producer. This makes a careful correlation analysis necessary to achieve an appropriate comparison reference value. The results of the comparison as well as the complex analysis of the correlated set of data is presented and discussed.
Lidia Fijalkowskalichwa – One of the best experts on this subject based on the ideXlab platform.
testing of 222rn application for recognizing tectonic events observed on water tube tiltmeters in underground geodynamic laboratory of space research centre at ksiąz the sudetes sw polandApplied Radiation and Isotopes, 2020Co-Authors: Tadeusz A. Przylibski, Lidia Fijalkowskalichwa, Marek Kaczorowski, Damia Kasza, Ryszard Zdunek, Roma WronowskiAbstract:
Abstract Research on relationships between variation in 222Rn Activity Concentration and tectonic events recorded using the instruments of the Geodynamic Laboratory of SRC PAS at Ksiąz (the Sudetes, SW Poland) had been conducted since 2014. The performed analyses of variation have demonstrated the spatial character of changes in 222Rn Activity Concentration. Their time-course is comparable in all parts of the underground laboratory. This means that gas exchange between the lithosphere and the atmosphere occurs not only through fault zones but also through all surfaces of the underground workings: the floors, the sidewalls and the roofs. Further, some relationships between 222Rn Activity Concentration and tectonic Activity of the orogen have been demonstrated with the use of Pearson’s linear correlation coefficient. The comparison between temporal distribution (times series) of radon Activity Concentration and water-tube tiltmeters (WTs) demonstrated that radon data have regular oscillations which can be approximated using the sine function with a 12 month cycle (seasonal changes) and amplitude in the range of 1000–1500 Bq/m3. To compare the collected radon signal data and tectonic Activity, we used linear function as the simplest method of trend assessment. Pearson’s correlation coefficient r cannot be accepted as appropriate for assessing the interdependencies between variables because they do not have a normal distribution, and the relationship between them is not linear. It was noted that each series of data, namely radon Activity Concentration and tectonic Activity determine the series of deviations above and below the trend function. Because of the non-fulfillment of the above assumptions, we used nonparametric equivalents such as Spearman’s rank correlation coefficient rs and Kendall’s tau. The obtained results showed that the value of the rs coefficient ranges from 0.38 to even 0.43. The best relationship at the level of rs = 0.43 was determined between the radon Activity Concentration recorded by detector no. 3 and the tectonic Activity of the rock mass registered on the WT-2 channel. Similar at the rs level of 0.37–0.38 between detector no. 5 and 4 and the WT-2 channel. A bit higher than rs = 0.39 between detector no. 3 and the WT-2 channel. In each case, these were positive correlations. The obtained Spearman’s rs coefficients indicate the correlation between 222Rn Activity Concentration and tectonic Activity of the rock mass. The t-statistic, which analyzes the significance of Spearman’s coefficient rs is a descriptive measure of the accuracy of regression matching to empirical data. It takes values in the range of percentage and provides informations about which part of the total variability of the radon Activity Concentration (Y) observed in the sample has been explained (determined) by regression in relation to tectonic Activity of the rock mass (X). In our case, approximately f 40% to more than 50% of the radon Activity Concentration (Y) was explained by regression in relation to the tectonic Activity of the rock mass. We obtained similar results with the use of Kendall’s tau coefficient. Precise description of the character of this relationship requires further, more detailed analyses, such as comparing characteristics of the distributions based on trend variation like Monte Carlo simulation, Multivariate Adaptive Regression Splines or neural networks.
short term radon Activity Concentration changes along the underground educational tourist route in the old uranium mine in kletno sudety mts sw polandJournal of Environmental Radioactivity, 2014Co-Authors: Lidia FijalkowskalichwaAbstract:
Abstract Short-term 222 Rn Activity Concentration changes along the Underground Educational Tourist Route in the Old Uranium Mine in Kletno were studied, based on continuous measurements conducted between 16 May 2008 and 15 May 2010. The results were analysed in the context of numbers of visitors arriving at the facility in particular seasons and the time per day spent inside by staff and visitors. This choice was based on partially published earlier findings ( Fijalkowska-Lichwa and Przylibski, 2011 ). Results for the year 2009 were analysed in depth, because it is the only period of observation covering a full calendar year. The year 2009 was also chosen for detailed analysis of short-term radon Concentration changes, because in each period of this year (hour, month, season) fluctuations of noted values were the most visible. Attention has been paid to three crucial issues linked to the occurrence and behaviour of radon and to the radiological protection of workers and visitors at the tourist route in Kletno. The object of study is a complex of workings in a former uranium mine situated within a metamorphic rock complex in the most radon-prone area in Poland. The facility has been equipped with a mechanical ventilation system, which is turned on after the closing time and at the end of the working day for the visitor service staff, i.e. after 6 p.m. Short-term radon Activity Concentration changes along the Underground Educational Tourist Route in the Old Uranium Mine in Kletno are related to the Activity of the facility’s mechanical ventilation. Its inActivity in the daytime results in the fact that the highest values of 222 Rn Activity Concentration are observed at the time when the facility is open to visitors, i.e. between 10 a.m. and 6 p.m. The improper usage of the mechanical ventilation system is responsible for the extremely unfavourable working conditions, which persist in the facility for practically all year. The absence of appropriate radiological protection (i.e. preventive measures like shortening working day, dosimetric measurements in the workplace) is a serious problem in the Kletno adit.
F. Gauthier-lafaye – One of the best experts on this subject based on the ideXlab platform.
Study on transfers of uranium, thorium and decay products from grain, water and soil to chicken meat and egg contentsJournal of Environmental Monitoring, 2012Co-Authors: M. Jeambrun, L. Pourcelot, C. Mercat, B. Boulet, J. Loyen, X. Cagnat, F. Gauthier-lafayeAbstract:
Activity Concentrations of the uranium and thorium series radionuclides were determined in chicken meat and eggs as well as in soil, water and other dietary intakes of poultry at five sites of the French territory. These data allow the calculation of transfer coefficients which enrich the database given by the technical report series no. 472 of the IAEA. In egg contents, the highest Activity Concentrations (in mBq kg-1 fresh weight) are for 226Ra, ranging between 136 and 190 and are much lower for uranium (between 0.51 and 1.30 for 238U). In chicken meat, 238U Activity Concentration is higher than in egg contents and ranges between 1.7 and 9.7. Concerning 232Th, its Activity Concentration is lower than uranium and ranges between 0.5 and 4.9. Daily ingested Activity Concentration by the animals was assessed taking into account the Activity Concentrations measured in the grains, in the soil and in the drinking water. The Activity Concentration in grains and the daily intakes allow the calculation of Concentration ratios and transfer coefficients for chicken meat and egg contents. In chicken meat the transfer coefficients (d kg-1) range between 0.0018 and 0.0073 for 238U and between 0.0008 and 0.0028 for 232Th. In egg contents they range from 0.00018 to 0.0018 for 238U and are much higher for radium isotopes (0.10-0.23 for 226Ra and 0.07-0.11 for 228Ra). © 2012 The Royal Society of Chemistry.