Wyniki wyszukiwania - Biblioteka Nauki

1

Calibration standard for use in gamma spectrometry and luminescence dating

100%

Oczkowski H. L.

Geochronometria

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2001

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tom Vol. 20

31-38

EN

In our TL dating laboratory the dose rates are determined from high-resolution gamma spectrometry measurements. A Canberra spectrometer with HPGe detector and Marinelli geometry (0.5 l capacity) is used. Spectral analysis is based on the Sampo90 computer program. The users have to supply the program with the detector efficiency as a function of gamma ray energy. Long-term changes in sensitivity of gamma-ray detectors lead to a drift in detector efficiency over a period of time. A uranium pitchblende source is investigated here for use in the system calibration. This calibrated source is a tempting alternative, especially for TL dating procedure, because of its long half-life and wide range of gamma-ray energies. Moreover, for a standard geometry (Marinelli) and matrix (quartz), the self-absorption and coincidence corrections for the calibrated and measured samples are comparable. The numerical deconvolution of spectral multiplets from the uranium pitchblende source with strongly overlapping peaks is verified experimentally. Several multiplets are used in the calibration procedure.

2

Interlaboratory comparison material homogeneity testing

80%

Pantelić G. K. , Todorović D. J. , Nikolić J. D. , Rajačić M. M.

Open Chemistry

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2015

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tom 13

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nr 1

EN

The homogeneity of fertilizer samples for interlaboratory γ-ray spectrometry comparison was tested by determination of the total γ count rate and the count rates for two 238U γ lines, one 40K line and one common 235U and 226Ra line. Homogeneity testing was accomplished by determination of the minimum, maximum, mean and standard deviation for each parameter and comparison of their standard deviations with predefined tolerances, by Cochran’s test, and by a one-way ANOVA. The standard deviations were all less than these tolerances. All samples passed Cochran’s test and the one-way ANOVA test for homogeneity.

3

Self-absorption correction and efficiency calibration for radioactivity measurement of environmental samples by gamma-ray spectrometry

80%

Misiak R. , Hajduk R. , Stobiński M. , Bartyzel M. , Szarłowicz K. , Kubica B.

Nukleonika

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2011

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tom Vol. 56, No. 1

23-28

EN

In this work empirical functions which relate the full-energy peak efficiency with sample height, energy, matrix composition and bulk density for voluminal samples in a cylindrical counting geometry were found. Accurate determination of the radioactivity of gamma-emitting radionuclides in environmental samples requires taking into account self-absorption. For the obtained self-absorption correction factor, a direct transmission method was chosen. Finally, this paper proposes a simple correlation between the self-absorption correction factor and the bulk density and height of the measured sample for a given energy.

4

High-resolution stratigraphy of the Lower Badenian deposits in selected cores of the Carpathian Foredeep

80%

Hracek D.

Geology, Geophysics and Environment

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2015

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tom Vol. 41, no. 1

88

EN

Drill cores from IK-1 Iváň and LOM-1 Lomnice u Tišnova (Lower Badenian) was evaluated by several various proxy methods (X-ray fluorescence spektrometry XRF, gammaspectrometry, grain size analysis, RTG diffraction and chemical analysis) in order to obtain data about paleoclimatic and paleogeographic conditions of sedimentation as well as to veryficate applications of these methods on monitored Neogenous sediments. Both wells are situated in the southern part of the Karpathian Foredeep in the Czech Republic. IK-1 is situated in the central area of the basin while LOM-1 lies on the western border of it. According to the biostratigraphic data, both of the observed wells belong to the NN5 zone (Tomanová Petrová & Švábenická 2007). Facial and litologic studies (Nehyba et al. 2007) point to similar sedimentary conditions (shallow-sea sediments of inner and outer shelf) and similar source of clastic material settling in the basin. Results from the X-ray fluorescence spectrometry were used as proxy date for grain size, weathring, oxide-reductive ratios and changes of high of sea-level. For the study, chemical elements were used, especially those which has been confirmed as reliable for given methods, specifically Al, Si, S, K, Ti, Mn, Fe, Rb and Zr. On the other hand, elements showing higher deviations during measuring were excluded, for example Cr, V, T or Ni. According to the results of grain analysis, the sediments can be classified as clay silts and, in only a fraction of cases, silt clays. Medium size of Mz grain (Folk & Ward 1957) was counted and was used to confirm grain proxies. Chosen ratios Si/Al, Ti/Al and Zr/Al (Ver Straeten et al. 2011) were used as grain proxies. Mutual correlations were insignificant, only in case of LOM-1 higher correlation between Mz and Ti/Al was proved. Therefore, the grain proxies cannot be considered reliable. Proxies for weathering show the effects of chemical weathering, which is also proved by high values of the CIA index. For surface-level changes, we used proxy Fe/Al (Clarkson et al. 2014). In IK-1, the results were compared with ratio of plankton and bentos (Nehyba et al. 2007) and stronger similarity of trends was established. To sum it up, proxy data of studied sediments can be considered partially reliable.

5

Evaluation of the coal combustion input to the 226Ra ground-level air concentration in the Lodz city, Poland

80%

Bem H. , Olszewski M. , Bysiek M. , Gluba T.

Nukleonika

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2004

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tom Vol. 49, nr 4

167-171

EN

The network of high volume aerosol samplers type ASS-500 in Poland, established mainly for monitoring radionuclides of artificial origin, offers also a unique opportunity for measuring natural radionuclide concentrations in ground-level air. Recounting of the closed (sealed) filters after a one month period, necessary for establishing radioactive equilibrium between 226Ra and 222Rn, as well as its short-lived decay products, remarkably improves the accuracy of 226Ra determination. The Currie's average detection and determination limits (with 10% relative accuracy) calculated for 226Ra for 160,000 s counting time and combined with the average filtered air volume of 60,000 m3 were 0.3 and 1.2 mi Bq/m3, respectively. The observed 226Ra concentrations in air in Lodz during the half year collection period, including parts of winter and summer seasons, were always above the detection limit and ranged from 0.76 to 2.75 mi Bq/m3. 226Ra, present in the ground level air mainly as a result of resuspension from the top layer of soil and fly ash emissions from coal burning, was used for rough estimation of the contribution of the coal combustion to the total suspended particulate matter. On the basis of available data for 226Ra content in the soil and fly ashes for the Lodz region of Poland, the calculated coal combustion input to the total air suspended particulate matter ranged from 8 to 39%.

6

Gamma spectrometry in thermoluminescence dating

80%

Oczkowski H. L. , Przegiętka K. R. , Lankauf K. R. , Szmańda J. B.

Geochronometria

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2000

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tom Vol. 18

57-62

EN

The aim of this paper is to present in detail a method, adopted in our laboratory, for the determination of annual dose. In particular, an analysis is focused on the thermoluminescence dating of eolian sediments from Kępa Kujawska. The advantage of the presented method is that partial matrix doses for alfa, beta and gamma radiation are determined simultaneously from the high resolution gamma spectrometry measurements.

7

Radioactivity of the Baszkówka meteorite

80%

Biernacka M. , Isajenko K. , Lipiński P. , Żak A.

Geological Quarterly

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2001

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tom Vol. 45, No 3

327-330

EN

In January 1996 a fragment, and in May 1996 a cut slab of the Baszkówka meteorite, were delivered for the radioactivity analysis to the Dosimetry Department of the Central Laboratory for Radiological Protection (CLOR) in Warsaw. The measurement method was gamma spectrometry using HPGe (High Purity Germanium) detectors. The CLOR prepared volume calibration source identical to the cut slab of the meteorite delivered for analyses. The presence of 40K and the cosmogenic radionuclides such as 54Mn and 22Na was detected in the Baszkówka meteorite. The results and measurement method are discussed.

8

Pomiary izotopów gamma promieniotwórczych w trynitytach

80%

Tymiński Z. , Burakowska A. , Tymińska K. , Kołakowska E. , Saganowski P. , Ziemek T. , Dziel T. , Kotowiecki A.

Acta Societatis Metheoriticae Polonorum

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2018

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tom 9

150-157

EN

Trynitite is a material in form of a glass created as a result of a nuclear explosion close to ground. The mechanism of its formation is similar to the formation of impact glasses and tektites, although the material usually contains trapped bubble voids, much more water and it is radioactive. High resolution non-destructive gamma spectrometry technique was used to measure rdionuclides in the chips of trinitities. The signals were detected for 137Cs, 152Eu, 226Ra, 241Am and 133Ba. The most extreme concentration was found for cesium 137Cs which the specific activity reached the level of 2317 mBq/g. Much lower values were obtained for 241Am – 722 mBq/g, 152Eu – 211 mBq/g, 226Ra – 451 mBq/g and 133Ba – 94 mBq/g.

9

Gamma spectrometry for OSL and TL dating of loess deposits at Dybawka and Tarnawce (SE Poland)

80%

Poręba G. , Fedorowicz S.

Geochronometria

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2005

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tom Vol. 24

27-32

EN

This article presents a comparison of results from the activity measurements of loess samples obtained with two methods in two laboratories. The methods are semiconductor gamma radiation spectrometry and gamma radiation scintillation spectrometry. Various measurement geometries and various sets of radioactivity standards were applied. Samples were collected from two loess profiles, namely Dybawka and Tarnawce. The results of activity measurements for natural radioisotopes of uranium, thorium and potassium obtained in the Gliwice and Gdańsk laboratories are in good agreement. Additionally, the activity of 235U was measured in the analysed samples.

10

Review of international normatives for natural radioactivity determination in building materials

70%

Mossini E. , Macerata E. , Giola M. , Mariani M.

Nukleonika

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2015

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tom Vol. 60, No. 3, part 2

597--602

EN

Anthropogenic activities, such as high-altitude flights and living in buildings, have enhanced the public exposure to natural radiation. In particular, 40K and radionuclides belonging to 232Th and 238U decay chains are present even in building materials, and they may be considered as partially responsible for the effective dose coming from natural radioactivity. Scientists and governments have devoted great attention to the evaluation of the effects produced on the public by naturally occurring radionuclides. In this context, to evaluate the building materials acceptability, accurate and reliable methods for the measurement of the specific activity of natural radioactive isotopes in building materials have been developed. This paper aims to provide a clear and exhaustive review on natural radionuclide measurement procedures. Several standard national normatives (Dutch NEN 5697, Italian UNI 10797, Polish ITB 455), based on gamma spectrometry, have been considered and some critical issues were identified regarding the preparation and the radiometric measuring of the samples. Therefore, the direct measurement of 238U and 232Th by ICP-MS spectrometry as well as the extrapolation of the specific activities without waiting for secular equilibrium have been considered as two promising alternative approaches.

11

Precise determination of HPGe detector efficiency for gamma spectrometry measurements of environmental samples with variable geometry and density

70%

Barrera M. , Casas-Ruiz M. , Alonso J. J. , Vidal J.

Nukleonika

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2017

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tom Vol. 62, No. 1

47--59

EN

A methodology to determine the full energy peak efficiency (FEPE) for precise gamma spectrometry measurements of environmental samples with high-purity germanium (HPGe) detector, valid when this efficiency depends on the energy of the radiation E, the height of the cylindrical sample H, and its density ρ is introduced. The methodology consists of an initial calibration as a function of E and H and the application of a self-attenuation factor, depending on the density of the sample ρ, in order to correct for the different attenuation of the generic sample in relation to the measured standard. The obtained efficiency can be used in the whole range of interest studied, E = 120–2000 keV, H = 1–5 cm, and ρ = 0.8–1.7 g/cm3, being its uncertainty below 5%. The efficiency has been checked by the measurement of standards, resulting in a good agreement between experimental and expected activities. The described methodology can be extended to similar situations when samples show geometric and compaction differences.

12

Radiological and health hazards resulting from radioactivity and elemental composition of some soil samples

70%

Al-Khawlany A. H. , Khan A. R. , Pathan J. M.

Polish Journal of Medical Physics and Engineering

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2020

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tom Vol. 26, Iss. 2

97--110

EN

Inspection of the radioactivity level in the soil is very important for human health and environmental protection. This study aims at evaluating the radiological hazards and pollution risks related to natural radionuclides and elements in the selected soil samples. Ten samples of soil were collected from different sites of Aurangabad-India and the level of radioactivity was measured using gamma-ray spectrometry with NaI (Tl) detector. Furthermore, the Physico-chemical properties such as pH, organic matter, electrical conductivity, moisture, soil texture, etc., and elemental composition of soils have been decided on using various standard techniques. The mean concentrations of 226Ra, 232Th, and 40K were 8.178, 17.408, and 96.496 Bq/kg, respectively, which are lower than the global average values of 35, 30, and 400 Bq/kg, respectively (UNSCEAR, 2000). The radiological hazard indices such as radium equivalent, absorbed dose, annual effective dose, internal index, external index, gamma index, excess lifetime cancer risk, etc., were calculated to assess the radiation hazards and compared with internationally recommended values which found to be lower than the permissibility limits.

13

A sedimentation study of St. Ana Lake (Romania) applying the 210 Pb and 137 Cs dating methods.

70%

Begy R. C. , Timar-Gabor A. , Somlai J. , Cosma C.

Geochronometria

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2011

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tom Vol. 38, no. 2

93-100

EN

The biggest problem with most lakes that have no contact with other water sources and are being charged by precipitation is the massive eutrophication. The aim of this work was to determine the sedimentation rate in order to evaluate the progress of eutrophication for St. Ana Lake (Ciomad Mountain near the Băile Tuşnad in Harghita County (Romania)). The concentration of 210 Pb was determined by means of high resolution gamma spectrometry as well as derived from 210 Po activity which was measured through alpha spectrometry; values obtained are in good agreement. For the excess 210 Pb activity values between 4.0š0.5 Bq/kg and 218š20 Bq/kg have been found. As an alternative method, the 137 Cs dating method was applied as well. Calculated mass sedimentation rates are in the range of 0.06š0.01 to 0.32š0.05 g/cm 2 year with a mean of value of 0.15š0.02 g/cm 2 year. Linear sedimentation rates yielded much higher sedimentation values (between 0.5š0.1 and 7.9š0.7 cm/year with a mean of 2.4š0.6 cm/year), due to the predominant organic matter composition and the long suspension time of the sediment. This is an indication for the process of eutrophication which will probably lead to the transformation of the lake into a peat bog.

14

Radionuclides 137Cs and 40K in the soils of the Tatra National Park (TPN, Poland)

70%

Kubica B. , Skiba S. , Drewnik M. , Stobiński M. , Kubica M. , Gołaś J. , Misiak R.

Nukleonika

|

2010

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tom Vol. 55, No. 3

377-386

EN

The paper presents the results of radioactivity determination of artificial 137Cs and natural 40K in soil samples taken from the Tatra Mountains in Poland (Tatra National Park – TPN). Soil samples were collected as the cores of 10 cm in diameter and 10 cm in depth. These cores were divided into 3 slices. It has been found that the content of 137Cs was the highest at the sites of the altitude over 1300 m a.s.l. The values of 137Cs concentration in the soils examined varied – from 55.8 Bqźkg–1 (dry mass) (417.8 Bqźm–2) for the Tomanowa Pass (1685 m a.s.l.) to 5111 Bqźkg–1 (dry mass) (8400 Bqźm–2) for the Krzyzne Pass (2112 m a.s.l.). In most cases, the values were lower than the average radiocaesium concentration established for Poland.

15

A Whole-Body Spectrometer (WBS) at the Institute of Nuclear Physics, Kraków : design and results for Polish citizens visiting Japan during the Fukushima accident

70%

Mietelski J. W. , Janowski P. , Kierepko R. , Hajduk R. , Bogacz J. , Jurkowski J. , Ochab E.

Nukleonika

|

2013

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tom Vol. 58, No. 4

519--525

EN

The first Polish whole-body spectrometer (WBS) with scintillation detectors was constructed in Łódź in the early sixties of the last century and was operating there for more than 30 years. In 2008, the 19th century steel shield of this instrument was transported from Łódź to Kraków, where it was re-equipped with a modern gamma spectrometric system. Design and construction of this modernized spectrometer is presented along with the results for in-body contamination measurements of four Polish inhabitants who returned to Poland from Japan after the Fukushima accident compared with the results for typical Polish inhabitants, the volunteers from the Institute of Nuclear Physics (IFJ, Kraków) workers. Although, a clear signal from the Fukushima fallout was noticed for three of four persons who returned from Japan, the calculated doses were negligible. No traces of Fukushima-originating radionuclides were noticed for the examined people who have not traveled to Japan.

16

Numerical model of thyroid counter

70%

Szuchta M. , Ośko J.

Nukleonika

|

2016

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tom Vol. 61, No. 1

45--47

EN

The aim of this study was to develop a numerical model of spectrometric thyroid counter, which is used for the measurements of internal contamination by in vivo method. The modeled detector is used for a routine internal exposure monitoring procedure in the Radiation Protection Measurements Laboratory of National Centre for Nuclear Research (NCBJ). This procedure may also be used for monitoring of occupationally exposed nuclear medicine personnel. The developed model was prepared using Monte Carlo code FLUKA 2011 ver. 2b.6 Apr-14 and FLAIR ver. 1.2-5 interface. It contains a scintillation NaI(Tl) detector, the collimator and the thyroid water phantom with a reference source of iodine 131I. The geometry of the model was designed and a gamma energy spectrum of iodine 131I deposited in the detector was calculated.

17

Implication and hazard of radiation level in the building materials

70%

Kekur B. , Rajeshwari T. , Siddanna R. , Kumar A.

Acta Geophysica

|

2013

|

tom Vol. 61, no. 4

1046--1056

EN

The natural radioactivity due to radium, thorium, and potassium in building material samples contribute to the radiation dose received by human beings significantly. It is essential to evaluate the activity levels of these nuclides for the assessment of natural radiation dose. Activity concentrations of the gamma emitting primordial radionuclides 232Th, 226Ra, and 40K were measured using high resolution gamma spectrometry technique with high purity germanium (HPGe) detector in building materials: sand, brick, granite, cement and rock, collected from various areas of Gulbarga and Koppal districts. The standard ASTM procedure was followed for the sample preparation. The distribution of radionuclides and variation in activity concentration depend upon the rock formation and the geological properties of the region. The activity of the three radionuclides, 232Th, 226Ra, and 40K, were found to be in the range of 3.1-227.1, 1.6-111, and 23.2-1505 Bq/kg, respectively. The dose related radiological parameters were also calculated for all the samples and the observations show that the activity concentrations of the radionuclides are well within the UNSCEAR limits.

18

Characterization of some modern scintillators recommended for use on large fusion facilities in γ-ray spectroscopy and tomographic measurements of γ-emission profiles

60%

Sibczynski P. , Broslawski A. , Gojska A. , Kiptily V. , Korolczuk S. , Kwiatkowski R. , Mianowski S. , Moszyński M. , Rzadkiewicz J. , Swiderski L. , Szydlowski A. , Zychor I.

Nukleonika

|

2017

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tom Vol. 62, No. 3

223--228

EN

LaBr3:Ce,CeBr3 and GAGG:Ce scintillators were investigated and the determined characteristics were compared with those obtained for the well-known and widely used CsI:Tl and NaI:Tl crystals. All the detectors were of the same size of 10 × 10 × 5 mm3. The aim of this test study was to single out scintillation detectors most suitable for γ-ray spectrometry and γ -ray emission radial profile measurements in high-temperature plasma experiments. Decay time, energy resolution, non-proportionality and full energy peak detection efficiency were measured for γ -ray energies up to 1770 keV. Due to their good energy resolution, short decay time and high detection efficiency for MeV gamma rays, LaBr3:Ce and CeBr3 scintillators are proposed as the best candidates for use especially under conditions of high count rates, which are expected in the forthcoming DT experiments.

19

Levels of natural radioactivity in mineral and thermal waters of Bosnia and Herzegovina

60%

Kasić A. , Adrović F. , Kasumović A. , Hankić E.

Nukleonika

|

2015

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tom 60

|

nr 3

503-508

EN

With gamma spectrometric method 23 samples of mineral and thermal waters of Bosnia and Herzegovina were analyzed. Activity concentrations of the investigated radionuclides were in the range 12–346 mBq·L−1 for 40K, 1.1–791 mBq·L−1 for 226Ra, 0.2–221 mBq·L−1 for 228Ra, 13–367 mBq·L−1 for 238U, and 0.6–17 mBq·L−1 for 235U. For all investigated radionuclides annual effective dose was estimated. The estimated total annual committed effective dose received by population as a result of ingestion of water was in the range 0.11–2.51 μSv·y−1 for thermal water and in the range 0.11–38.8 μSv·y−1 for mineral water. Measurement of activity concentrations of natural radionuclides in the examined samples was carried out with a gamma-spectrometer with high-purity germanium (HPGe) detector, having a relative efficiency of 70%.

20

Thoron emanation and exhalation of Slovenian soils determined by a PIC detector-equipped radon monitor

60%

Jónás J. , Sas Z. , Vaupotic J. , Kocsis E. , Somlai J. , Kovács T.

Nukleonika

|

2016

|

tom Vol. 61, No. 3

379--384

EN

The health risk from thoron (Rn-220) is usually ignored owing to its short half-life (55.6 s), but the generated thoron decay products can cause a significant dose contribution. In this study, altogether 51 Slovenian soil samples were investigated using an accumulation chamber technique to obtain information about thoron exhalation features. The obtained (massic) thoron exhalation results varied between 6.9 and 149 mBq•kg–1•s–1 (average: 55.2 mBq•kg –1•s–1). The Th-232 content was determined using HPGe gamma spectrometry. The Th-232 activity concentration ranged between 9.3 and 161.7 Bq•kg–1 (average: 64.6 Bq•kg –1). The thoron emanation features were also calculated from the obtained results (2.9 to 21.2% with an average of 8.6%). The thoron exhalation and emanation properties were compared with the radon exhalation and emanation features determined in a previous study. It was found that there was no correlation between the radon and thoron emanation features, according to the obtained data. This can be explained by the different Ra-224 and Ra-226 distributions in the soil grains. As a result, the thoron emanation factor cannot be predicted from radon emanation and vice versa.