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1

Magnetic susceptibility and gamma ray spectrometry in the Tré Maroua section (Tithonian/Berriasian, SE France) - terrigenous input and comparison with Tethyan record

Grabowski Jacek, Frau Camille, Schnabl Petr, Svobodová Andrea

Volumina Jurassica

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2022

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Vol. 20

47--58

EN

Field magnetic susceptibility (MS) and gamma ray spectrometry (GRS) measurements were performed in the Jurassic/Cretaceous boundary interval in the Tré Maroua section (SE France). The 24 m thick section covers the interval from the upper Tithonian magnetozone M20n (Chitinoidella Zone) to the lower Berriasian M17r magnetozone (Calpionella elliptica Subzone). The micritic limestones reveal a very low content of terrigenous impurities (0.0-0.2% K and 0.2-2.0 ppm Th) and low MS values (-5 to 15 × 10-6 SI). Despite low intensity of both MS and GRS signal, a consistent trend of terrigenous input is observed: decreasing values in the upper Tithonian and increasing tendency in the upper part of the lower Berriasian. The long-term trends are quite similar to those documented in some Western Tethyan sections and the Polish Basin, indicating that variations of terrigenous input might be controlled by large-scale palaeoclimatic variations and relative sea-level changes. Decrease of Conusphaera and increase of Nannoconus frequencies fall in the lower part of M19n2n in the uppermost Tithonian. These events correlate with large decrease of terrigenous input and widespread oligotrophication in the Western Tethyan domain.

2

The impact of the oil and gas industry on NORMs of groundwater and their annual efective dose in Ma’rib, central Yemen

Ali Mohsen M. M., Zhao Hongtao, Li Zhigang, Ahmed O. M. H., Alfasatleh Ibrahim, Maglas Najeeb N. M.

Acta Geophysica

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2020

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Vol. 68, no. 5

1421--1431

EN

The gamma-ray spectrum equipped with a high-purity germanium detector was used to measure the naturally occurring radioactive materials of groundwater samples resources from the petroleum-producing communities of Ma’rib Province-Yemen. Thirty-fve samples were collected from diferent sites. The 40K, 232Th, and 226Ra activity concentrations of groundwater samples for oil and non-oil communities were measured. The annual efective doses due to 40K, 232Th, and 226Ra were calculated and did not show a signifcant health impact. These results can contribute to building a database and provide a general background of the detectable TENORMs for studied areas, which will be useful in any radiological emergency. Signifcantly, the Ma’rib region is rich in oil and gas.

3

Np-237 incineration study in various beams in ADS setup QUINTA

Kilim S., Strugalska-Gola E., Szuta M., Bielewicz M., Tyutyunnikov S. I., Furman W. I., Adam J., Stegailov V. I.

Nukleonika

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2018

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Vol. 63, No. 1

17--22

EN

Neptunium-237 samples were irradiated in a spallation neutron fi eld produced in accelerator-driven system (ADS) setup QUINTA. Five experiments were carried out on the accelerators at the JINR in Dubna – one in carbon (C6+), three in deuteron, and one in a proton beam. The energy in carbon was 24 GeV, in deuteron 2, 4 and 8 GeV, respectively, and 660 MeV in the proton beam. The incineration study method was based on gamma-ray spectrometry. During the analysis of the spectra several fi ssion products and one actinide were identifi ed. Fission product activities yielded the number of fi ssions. The actinide (Np-238), a result of neutron capture by Np-237, yielded the number of captures. The main goal of this work was to fi nd out if and how the incineration rate depended on parameters of the accelerator beam.

4

Study of radon flux and natural radionuclides (226Ra, 232Th and 40K) in the Main Boundary Thrust region of Garhwal Himalaya

Kandari T., Prasad M., Pant P., Semwal P., Bourai A. A., Ramola R. C.

Acta Geophysica

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2018

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Vol. 66, no. 5

1243--1248

EN

The Himalayan region is subdivided lithologically into four regions in which the junction between the lower Himalaya and Shivalik is known as the Main Boundary Thrust (MBT). It is well known that the environmental radon concentration depends upon various geological factors including faults, thrust, cracks and the composition of the soil. Radon gas eventually comes out from the fault/thrust zones having radium as its prominent source. Hence, it is important to study the behaviour of emission of radon present inside the earth crust as well as the levels of natural radionuclides in soil. In this study, the levels of natural radionuclides and exhalation rates of radon in the soil of MBT region of Garhwal Himalaya, India, were determined by using gamma ray spectrometer and scintillation detector-based Smart Radon Monitor, respectively. The average activities of 226Ra, 232Th and 40K were found 71.9, 88.2 and 893.6 Bq Kg-1, respectively. The measured radon surface flux was found to vary from 13.08 to 1626.4 Bq m-2 h-1 with a mean value of 256.5 Bq m-2 h-1. The measured activity levels were used to assess the doses associated with the contaminated soil.

5

Pomiar zawartości toru, uranu i potasu w próbkach z rdzeni wiertniczych

Zych M.

Przegląd Elektrotechniczny

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2017

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R. 93, nr 9

142--145

PL

Ciągły pomiar zawartości toru, uranu i potasu w otworze wiertniczym (profilowanie gamma), jak i laboratoryjne badanie próbek skalnych z wydobytych rdzeni jest jedną ze standardowych metod, które służą do rozróżniania litologii formacji skalnych. Oznaczenie Th, U i K wiąże się z szeregiem problemów, które są wynikają z innego układu geometrycznego oraz objętości i masy skały wpływających na wynik pomiaru w otworze i w laboratorium. Próbki z rdzeni wiertniczych mają masy nie przekraczające 40 g. Objętość i masa skały dostarczające informacji o formacji w czasie profilowania w otworze zależą od pionowej rozdzielczości i zasięgu radialnego sond pomiarowych. Wymienione czynniki wpływają na dokładność wyznaczenia koncentracji pierwiastków. Artykuł przedstawia metodykę pomiaru laboratoryjnego opracowaną w Katedrze Geofizyki Wydziału Geologii Geofizyki i Ochrony Środowiska AGH.

EN

Continuous measurement of thorium, uranium and potassium content in borehole (Gamma Ray log) and laboratory investigations of rock samples from the drilling cores are the standard methods used to distinguish rock formations in lithology. The is a number of problems is related to the Th, U and K determination in aspect of different borehole and laboratory geometry and volume of rock mass in investigations. Samples from drilling cores have a mass not exceeding 40 g. Volume and mass of rock providing the information in well logging depends and vertical resolution and radius of investigation of borehole devices. The mentioned factors affect the accuracy of determining the concentration of chemical elements. The article presents the methodology of measurement developed at the Department of Geophysics of the Faculty of Geology Geophysics and Environmental Protection at the AGH-UST.

6

Measurement of anthropogenic radionuclides in post-Fukushima Pacific seawater samples

Lutter G., Tzika F., Hult M., Aoyama M., Hamajima Y., Marissens G., Stroh H.

Nukleonika

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2015

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Vol. 60, No. 3, part 2

545--550

EN

Following the accident at the Daiichi Fukushima nuclear power plant in 2011, a vast number of Pacific seawater samples from many locations far from Fukushima have been collected by Japanese investigators. Due to dilution, the activities of radionuclides from North Pacifi c seawater samples are very low, which calls for extraordinary measures when being measured. This study focuses on the metrological aspects of the gamma-ray spectrometry measurements performed on such samples in two underground laboratories; at HADES (by JRC- -IRMM in Belgium), and at Ogoya (by Kanazawa University in Japan). Due to many samples and long measurement times, all available HPGe detectors needed to be employed. In addition to single coaxial detectors, this involved multidetector systems and well detectors. Optimization of detection limits for different radionuclides and detectors was performed using Monte Carlo simulations.

7

Cosmogenic radionuclides in the Sołtmany (L6) meteorite

Laubenstein M., Giampaoli A., Janowski P., Mietelski J. W.

Meteorites

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2012

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Vol. 2, No. 1-2

45--51

EN

Cosmogenic radionuclides were measured in two specimens of the Sołtmany chondrite (L6) that fell on April 30, 2011. The first fragment (154.9 g) was measured 12 days after the fall and the second piece (120 g), 53 days after the fall. Both fragments were measured by means of non-destructive gamma ray spectroscopy. The first specimen was examined with an ultra-low background high purity germanium (HPGe) detector in a deep underground laboratory. A standard low-background HPGe detector was used to examine the second fragment in a ground level laboratory. Twelve cosmogenic nuclides were detected in the activity range of 0.030 m・Bq g–1 until 1.5 m・Bq g–1 Their activities place constraints on the exposure history of the meteorite and reflect the effect of solar modulation of galactic cosmic rays during the solar maximum. On the activities of expected radionuclides 60 Co (< 0.0075 m・Bq g–1) and 44 Ti (< 0.023 m・Bq g–1) only upper limits could be given. Sołtmany is part of a group of only 14 meteorites where 52 Mn (5.591 d half life) could be determined.

8

Gamma-Ray Spectrometry Laboratory for high-precision measurements of radionuclide concentrations in environmental samples

Jodłowski P., Kalita S. J.

Nukleonika

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2010

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Vol. 55, No. 2

143-148

EN

The paper outlines the methodology used in the Gamma-Ray Spectrometry Laboratory for high-precision measurements of radionuclide activity concentrations in environmental samples. The Laboratory equipment includes a semiconductor detector HPGe with a 42% relative efficiency. The detector is placed in a Pb housing made of bricks 10 cm in thickness. Three measurement geometries are considered: Marinelli beakers 710 cm3 in volume and two cylindrical geometries 121 and 48 cm3 in volume. In the efficiency calibration (E = 32 division sign 1836 keV) mixed gamma standard solutions were used. Obtained experimental efficiency values epsilon were fitted with two quadratic functions. The junction point is that equivalent to 200 keV. Uncertainty of the calibration curve is 2% for E > 200 keV. The relationship between the total efficiency and the energy epsilon t(E) was also found for energies E = 33 division sign 1250 keV. Self-absorption correction factors Cs are calculated by the method proposed by K. Debertin, the uncertainty level being 1 division sign 2% for E > 100 keV. These correction factors are calculated by an original computer program. Coincidence summing correction factors Cc for the selected nuclides are derived using the ETNA computer program, basing on the relationships epsilon(E) and epsilon t(E). Minimum detectable activity (MDA) for selected nuclides encountered in environmental samples was determined for the water matrix. The methodology used was successfully verified in the course of international intercomparison measurements.

9

Self-absorption correction in gamma-ray spectrometry of environmental samples - an overview of methods and correction values obtained for the selected geometries

Jodłowski P.

Nukleonika

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2006

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Vol. 51,suppl.2

21-25

EN

Of major concern are the self-absorption correction factors Cs in precise gamma-ray spectrometry of environmental samples. The overview of Cs determination methods (experimental, Monte Carlo calculations, analytical function application) is presented. Among several available methods, the author chose the one proposed by Debertin where the uncertainty level of Cs correction factor is 1÷2%. The point-like detector model is assumed whilst its efficiency is taken to be proportional to the weighted sum (integral) of the number of photons coming from sample volume elements. Computer program was developed to support the computation of Cs by the Debertin's method for samples in cylindrical geometries and Marinelli beakers. The input data are sample dimensions, density and the mass attenuation coefficient. The Cs uncertainty due to an arbitrarily chosen position of a point-like detector would not exceed 1% for the considered photon energies and the sample density range. Utilising this computer program, the relationships Cs(E,ń) were obtained for the applied geometries and a SiO2 matrix to support routine measurements. The SiO2 matrix is widely encountered in environmental spectrometry. This relationship was derived by fitting the computed data with the function Cs(E,ń) in the form proposed by Bolivar. It was shown that while handling this function to samples with the H2O matrix, the error involved in estimations would not exceed 3%.

10

Gamma-ray spectrometry across the Upper Devonian basin succession at Kowala in the Holy Cross Mountains (Poland)

Bond D., Zatoń M.

Acta Geologica Polonica

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2003

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Vol. 53, nr 2

93-99

EN

The Upper Devonian sequence at Kowala in the Holy Cross Mountains was logged using gamma-ray spectrometry, for investigating the changes of oxygenation level in the Late Devonian basin. The Th/U ratio indicates that oxygen levels were low throughout the Late Frasnian interval, with low peaks during the Kellwasser Events showing anoxic conditions in the basin. The F-F boundary interval was also oxygen deficient, but there may have been a brief reoxygenation at the boundary itself. By the Famennian crepida Zone, the basin gradually began to reoxygenate, but in the trachytera Zone another anoxic event, the Annulata Event occurred, causing a bloom rather than extinction of specially adapted taxa such as Guerichia. Thus the gamma-ray spectrometry data suggests that basinal anoxia prevailed through much of the Late Frasnian. The F-F extinction might have been the result of prolonged stresses imposed on the ecosystem, particularly during the euxinic Upper Kellwasser Event.

11

Reference peak method for the analysis of doublets in gamma-ray spectrometry used in neutron activation analysis

Wasek M., Sterliński S., Dybczyński R., Cichowlas A.

Chemia Analityczna

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2000

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Vol. 45, No. 5

689-698

EN

A simple algebraic method for the quantitative analysis of doublets in gamma-ray spectra from HPGe detectors is presented. The calculation algorithm is accomplished using the Microsoft Excel program. The method does not require any assumptions regarding the shape of the peaks in the spectrum. The possibilities of quantitative analysis of doublets of various intensity ratio and separation of its components are discussed in detail. The practical examples proved the usefulness of the method also for the analysis of the closed doublets.

PL

Zaprezentowano prostą metodę algebraiczną przeznaczoną do ilościowej analizy dubletów w widmach promieniowania gamma, mierzonych detektorami HPGe. Algorytm obliczeniowy zrealizowano przy użyciu programu komputerowego Microsoft Excel. Metoda nie wymaga żadnych założeń co do kształtu pików w widmie. Bardzo szczegółowo przeanalizowano możliwości ilościowej analizy dubletów o różnym stosunku natężeń i rozdzieleniu jego składników. Przedstawione przykłady praktyczne potwierdzaj ą przydatność tej metody również do analizy dubletów zamkniętych.