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The Rooppur Nuclear Power Plant (RNPP), the first nuclear power plant in Bangladesh with a capacity of 2.4 GWe, is under construction on the bank of the river Padma, at Rooppur in Bangladesh. Measurement of background radioactivity in the natural environment adjacent to RNPP finds great importance for future perspectives. Soil and sediment samples collected from upstream and downstream positions of the Padma River (adjacent to RNPP) were collected and analyzed by HPGe gamma-ray spectrometry for primordial radionuclides. The average activity concentrations (in Bqkg−1) of 226Ra, 232Th and 40K radionuclides in soil samples were found to be 44.99 ± 3.89, 66.28 ± 6.55 and 553 ± 82.17 respectively. Respective values in sediment samples were found to be 44.59 ± 4.58, 67.64 ± 7.93, 782 ± 108. Relevant radiation hazard indices and dosimetric parameters were calculated and compared with the world average data recommended by US-EPA. Analytical results show non-negligible radiation hazards to the surrounding populace. Measured data will be useful to monitor any change of background radioactivity in the surrounding environment of RNPP following its operation for the generation of nuclear energy.

The aim of this study was to determine the activity of post-Chernobyl 137Cs in Slovak bilberry (Vaccinium myrtillus L.) from selected locations of Slovakia depending upon: the season, location and the soil-plant transfer factor (TF). The 137Cs activity was determined in samples of forest soil and bilberry bushes (stems, leaves and fruits) growing on the soil in three locations: Arboretum Mlyňany (1), Hodruša-Hámre (2) and Javorníky (3). Altogether we collected 35 samples; namely 15 samples from Arboretum Mlyňany, 10 samples from Hodruša-Hámre and 10 from Javorníky. The samples of soil were examined also for the activity of 40K. The samples were collected in the spring, summer and autumn in the years 2019 and 2020 and were analysed by a gamma-ray spectrometry method. The highest levels of 137Cs activity concentrations were determined in Hodruša-Hámre in September where they reached 161 ± 13 Bq.kg−1 in the soil, 3.95 ± 1.07 Bq.kg−1 in the stems and 14.7 ± 4.26 Bq.kg−1 in the leaves. The lowest levels were determined in the Arboretum Mlyňany in October where the 137Cs activity in the soil reached 13.1 ± 1 15 Bq.kg−1, while in the stems, leaves and fruits it was lower than the minimum detectable level. In the latter location, we also determined the highest activity of 40K, the radioactive isotope physiologically and metabolically similar to 137Cs. The mass activity of 137Cs in all samples of bilberries were lower than the minimum detectable activity (MDA). The comparison of the results obtained in this study with the limit for total mass activity of radiocaesium (134Cs + 137Cs) in the food (600 Bq.kg−1) allowed us to conclude that the fruits, stems and leaves of Slovak bil-berries present neither health nor environmental risk.

Impact assessment of building materials is a focused topic in the field of radioecology. A radiological survey has conducted to monitor radioactivity of most common building materials in Semnan Province, Iran, and assess the radiation risk. Activity concentrations of 226Ra, 232Th, and 40K were measured in 29 samples including nine commonly used building materials that were collected from local suppliers and manufacturers, using a high purity germanium gamma-ray detector. The activity concentrations of 226Ra, 232Th, and 40K varied from 6.7±1 to 43.6±9, 5.9±1 to 60±11, and 28.5±3 to 1085±113 Bq kg−1 with averages of 26.8±5, 22.7±4, and 322.4±4 Bq kg−1, respectively. By applying multivariate statistical approach (Pearson correlation, cluster, and principal component analyses (PCA)), the radiological health hazard parameters were analyzed to obtain similarities and correlations between the various samples. The Pearson correlation showed that the 226Ra distribution in the samples is controlled by changing the 232Th concentration. The variance of 95.58% obtained from PCA resulted that the main radiological health hazard parameters exist due to the concentration of 226Ra and 232Th. The resulting dendrogram of cluster analysis also shows a well coincidence with the correlation analysis.

This study was performed to identify and interpret airborne geophysical responses and landform features of the Cabeça de Sapo Structure (CSS), a 6 km-diameter circular structure located in northeastern Brazil, SW of the Maranhão State, suspected of having been formed by the impact of a solid body. The application of processing techniques addressed to enhance the images from the remotely sensed data (gamma-ray spectrometry, magnetic, Sentinel 2B and ALOS PALSAR) enabled the identification of two airborne geophysical responses (ring-shaped magnetic anomaly and radiometric patterns) and five landform features ("A", "B", "C","D" and "E"). The ring-shaped magnetic anomaly is related to a 5.4 km-diameter well-defined circular structure and the depth of its magnetic sources is estimated in 300 m. Those sources are unknown, but they probably occur due to layers of dolerite sills. The radiometric patterns identified seem to be related to the "A" and "D" landform features. Feature "A" is an elevated area at the center of CSS. The radiometric response (high eTh, eU, and low K) at the top of this area possibly reflects the weathering effect, while the radiometric response (high K and low eTh, eU) at the hillside is possibly from the lithotypes that have supported this elevation. Feature “D” is a 6 km – diameter circular elevated area that corresponds to the outer boundary of CSS. This boundary is characterized by increased eU counts, which may happen due to weathering-resistant mineral content (e.g. zircon) present in eolian sandstones. Features “C” and “E” are outside of CSS. The first is interpreted as plateau-shaped residual relief formed by differential erosion of basaltic rocks and sandstones and the second is interpreted as a flat-relief dominated by eolian sandstones. This flat-relief may represent the landscape that has not been affected by the formation process of CSS, while the affected internal region may be represented by feature “B”. The interpretations also have revealed that CSS shows some similarities with typical features of impact structures, namely: disruption of the magnetic field by a ring-shaped magnetic anomaly; central elevation surrounded by a raised outer rim; local control of drainage and; differences in the relief pattern of internal and external parts of the structure. Those similarities reinforce the possibility of an exogenous origin of CSS, but new studies are required to confirm or refuse such possibility.

The activity concentrations of main naturally occurring radionuclides were determined with the aim of assessing the radiation hazards in the Northeastern part of Burkina Faso. Soil samples were taken and analyzed by the gamma-ray spectrometry method. The ranges of specific activity of 238U, 232Th and40K are $$15.25 \pm 2.59 \, \text{Bq} \cdot {\text{kg}^{-1}}$$ 15.25 ± 2.59 Bq · kg - 1 to $$109.57 \pm 3.21 \, \text{Bq} \cdot {\text{kg}^{-1}}$$ 109.57 ± 3.21 Bq · kg - 1 , $$19.56 \pm 1.65 \, \text{Bq} \cdot {\text{kg}^{-1}}$$ 19.56 ± 1.65 Bq · kg - 1 to $$44.88 \pm 2.49 \text{Bq} \cdot {\text{kg}^{-1}}$$ 44.88 ± 2.49 Bq · kg - 1 and $$125.74 \pm 4.40 \, \text{Bq} \cdot {\text{kg}^{-1}}$$ 125.74 ± 4.40 Bq · kg - 1 to $$705.85 \pm 10.79 \, \text{Bq} \cdot {\text{kg}^{-1}}$$ 705.85 ± 10.79 Bq · kg - 1 respectively. Three high background radioactivity areas have been identified for Uranium, Thorium and Potassium on different places in the study area. The radiological hazards indices vary from $$62.87 \, \text{Bq} \cdot {\text{kg}^{-1}}$$ 62.87 Bq · kg - 1 to $$189.47 \, \text{Bq} \cdot {\text{kg}^{-1}}$$ 189.47 Bq · kg - 1 for the Radium equivalent activity ($$Ra_{eq}$$ R a eq ), $$29.5 \, \eta \text{Gy} \cdot {\text{h}^{-1}}$$ 29.5 η Gy · h - 1 to $$86.65 \, \eta \text{Gy} \cdot {\text{h}^{-1}}$$ 86.65 η Gy · h - 1 for the absorbed dose rate ($$D_R$$ D R ), $$0.18 \, \text{mSv} \cdot {\text{y}^{-1}}$$ 0.18 mSv · y - 1 to $$0.53 \, \text{mSv} \cdot {\text{y}^{-1}}$$ 0.53 mSv · y - 1 for the annual effective dose rate (AEDE), 0.21 to 0.81 for the internal hazard index ($$H_{in}$$ H in ), 0.17 to 0.51 for the external hazard index ($$H_{ex}$$ H ex ), $$1.27 \times 10^{-4}$$ 1.27 × 10 - 4 to $$3.73 \times 10^{-4}$$ 3.73 × 10 - 4 for the Excess Lifetime Cancer Risk (ELCR) and $$209.01{\mkern 1mu} \mu \, 0.18{\mkern 1mu} Sv \cdot y^{{ - 1}}$$ 209.01 μ 0.18 S v · y - 1 to $$594.21 \, \mu \text{Sv} \cdot {\text{y}^{-1}}$$ 594.21 μ Sv · y - 1 for the annual gonadal dose equivalent. The average values of indices are well below their permissible limit. However, at Niapsi the obtained values for absorbed dose rate, annual effective dose rate and excess lifetime cancer risk are little above their permissible limit.

This paper presents the results of analyses of radionuclide content in the samples of the surrounding soil and clayey material of ?Zbegovi? open-pit mine in Donje Crniljevo, Serbia. Samples from 78 sites were collected and prepared. The activity concentrations were determined for radionuclides: 238U, 232Th, 40K, 226Ra, and 137Cs. The mean values obtained are as follows: 23 Bqkg?1, 89 Bqkg?1, 372 Bqkg?1, 56 Bqkg?1, and 11 Bqkg?1, respectively. Concentrations of 238U, 40K, and 226Ra in the studied area do not deviate from the values obtained for the soil in Serbia. The concentration of 232Th in the studied area is slightly higher relative to average values for soil, and slightly lower compared to similar deposits of clayey material in the world. Measurements performed showed that the open-pit mine of clayey material is completely uncontaminated surface as far as 137Cs is concerned, while there are sites where measured 137Cs concentrations are significantly higher, which is due to topographic differences and inhomogeneous surface contamination of land after the Chernobyl accident. To assess the radiological risks in the observed area, the following indices were determined: absorbed dose rate, annual outdoor effective dose, absorbed dose for biota, excess lifetime cancer risk outdoors as well as external radiation hazard index. The mean value of the estimated absorbed dose rate in the given area amounts to 80.1 nGyh?1, and the annual outdoor effective dose ranges from 46.9 to 134 Sv. Absorbed dose rate for biota in the studied area is 1.31 10?4 Gyd?1. The mean excess lifetime cancer risk outdoors for the population is 3.8 10?4, and t he mean value of the external radiation hazard index obtained in this study is 0.48, which is consistent with the world average. A low dose of radiation will not pose a risk to the population and biota in the studied area.

In the past decades, particulate matter (PM) measurements have been used extensively in atmospheric sciences, as it allows studying the evolution of tracers for different atmospheric processes and the effects of atmospheric pollution on human health. However, measuring PM mass requires a constant control of the laboratory conditions due to its capacity to absorb humidity. For this reason, this study was focused on developing a novel, simple and precise methodology to determine the corrections of the filter mass due to humidity changes. The control and corrections are possible using a “control filter”, which is always adapted to the environmental conditions of the laboratory. To check the consistency of this method, it was proved that the mass of any problem filter and that of the control filter behave in a very similar way. This allows quantifying the mass changes of any problem filter by using the control filter, where the problem filters and the control filter must have the same chemical composition and dimensions. To validate this methodology, a comparison was made between the methodology proposed in this study (Method-1) and the one proposed by the EPA (Method-2), which is generally applied. The particulate matter mass (m) was obtained for a problem filter for different weights, achieving similar values using both methods. However, Method-1 still provided reliable mass measurements for relative humidities very different from 50%, even as low as 18%. It was also proved that the adsorption or loss of water by the particulate matter can be neglected, since m is much smaller than the blank filter mass. Method-1 was also employed in several samplings carried out using three PM10 samplers to determine contaminants, such as 7Be and 210Pb, obtaining a good agreement between all particulate masses and activities measured by the three samplers for all samplings., This research has partially funded by the projects of the Regional Government of Andalusia called “Basic processes regulating the fractionations and enrichments of natural radionuclides under acid mine drainage conditions” (Ref.: UHU-1255876), and “Treatment of acid leachates from phosphogypsum piles located at Huelva, and transport modelling of the released radionuclides” (Ref.: P20_00096), the project funded by the Spanish Ministry of Science, Innovation and Universities’ Research Agency “Development and optimization of a process for removing natural radionuclides in phosphogypsum leachates” (Ref.: PID2020-116461RB-C21), and the Project for Novel Principal Investigators “Quantitative study of the variables involved in the radon exhalation rate for granular solids; application to rafts of granular solid phosphogypsum” (Ref.: UHUPJ-00005-632). The authors acknowledge the funding for open access charge provided by Universidad de Huelva / CBUA. The authors would like to thank A.M. Padilla for his great help provided in order to make this study possible.

Radiometric measurement of building materials is very important to assess the internal and external exposure caused by the ionizing radiation emitted from terrestrial radionuclides in building materials. The activity concentrations of 226Ra, 232Th, and 40K in fifty-eight samples of fifteen different structural and covering building materials commonly used in Osmaniye province located in the Mediterranean region of Turkey were measured by using gamma-ray spectroscopy. The activity concentrations of 226Ra, 232Th and 40K varied from 2.5 ± 0.1 (marble) to 145.7 ± 4.4 (clay brick), 1.3 ± 0.1 (marble) to 154.3 ± 4.1 (marble) and 8.6 ± 0.2 (sand) to 1044.1 ± 70.3 (granite), respectively. Radiological parameters (activity concentration index, alpha index, indoor absorbed gamma dose rate and the corresponding annual effective dose rate, and excess lifetime cancer risk) were estimated to evaluate the health hazards associated with these building materials. Since the estimated values of these parameters are within the recommended safety limits or criteria values, the use of the studied building materials in the construction of dwellings can be considered to be safe for the residents of the region.

This study reports the natural radioactivity of characteristic rocks found in the historic Jeroným Mine of the Czech Republic as measured under the laboratory conditions. The rocks analyzed included granites and schists weathered to varying degrees and collected from different levels of the underground workings of the Jeroným Mine. The mine itself has been subject to metal extraction (mainly tin and tungsten) since the 16th century and has recently been developed as a cultural and scientific attraction open to the public. Activity concentrations of 40K, 232Th and 238U were measured from nine rock samples using gamma-ray spectrometry. The activity concentrations of 40K varied from 595 Bq kg− 1 to 1244 Bq kg− 1, while 232Th varied from 25 Bq kg− 1 to 55 Bq kg− 1. The activities associated with 238U ranged from 46 Bq kg− 1 to 386 Bq kg− 1. The measured activities were used to estimate two radiation hazard indices typically applied to building materials, the activity concentration index I and the external hazard index Hex. Mean respective values of 1.02 and 0.77 for I and Hex indicate that the rocks found in the Jeroným Mine meet radiological safety standards for building materials and do not pose a risk to potential tourists and staff.

A new gamma-ray sensor, which could be employed in harsh underwater conditions, was developed using YAlO3(Ce) single crystal and carbon nanotube reinforced polyetheretherketone (CNT/PEEK). The sensor is compact, highly sensitive and stable, by providing real-time gross counts and an accumulated spectrum for fresh, saline, or contaminated water conditions. The sensor was tested in a water tank for quantification of the limit of detections. The Φ51 × 51 mm2 YAlO3(Ce) crystal exhibits a nearly perfect proportionality with a correlation of over 0.999 in terms of light yield per energy and possesses a high energy resolution. The chemically stable CNT/PEEK window material further enhances the detection efficiency by minimizing the background counts from penetrating gamma-rays. Data timeliness was obtained for regulation-based minimum detectable activity targets within 300 s. For a source-detector distance of up to 300 mm in water, the gross counts demonstrate the existence of radionuclides (Cs-137 and Co-60), owing to their higher efficiency (max. ~15 times) than those of the photopeak counts. Such differences between efficiency values are more likely in water than in air because of the high density of water, resulting in an increased build-up of scattered photons. The proposed sensor is suitable for autonomous underwater systems.

Climate change forecasts and modelling for south-east Australia, where irrigated cotton growing occurs, suggest hotter conditions and reduced rainfall with less water for evapotranspiration. There are also ever increasing and competing demands for water from environment, mining and domestic applications. To improve soil-water management, knowledge on soil-water dynamics and soil properties which influence water holding capacity in cotton growing areas is required at the field, farm and district level. Given the heavy-clay nature of the soil (i.e., Vertosols), detailed characterization of soil moisture is a challenging task. Recently, apparent soil electrical conductivity (ECa) data, measured by electromagnetic (EM) induction instruments, is increasingly being used with inversion modelling to understand the dynamics in volumetric soil moisture content (theta). This is because it is non-invasive, quick and inexpensive. In this thesis, electromagnetic conductivity images (EMCI), generated by inverting ECa data, has been used to map the spatial and temporal variations of theta along an irrigated cotton field located near Narrabri, New South Wales, Australia. Furthermore, EMCI was applied to create 2-dimensional maps of different soil properties in order to identify more permeable prior stream channels along a 4km section of a farm supply channel and to better understand how soil physical (e.g., clay, silt and sand) and chemical properties (e.g., ECe and CEC) influence soil water holding capacity. In addition, the use of additional sources of digital data (i.e., gamma-ray spectrometry) was examined to understand spatial variation of available water content (AWC) at the field scale and landscape units across larger spatial scales, in concert with other digital data (i.e., ECa and DEM). The results showed that the collection of ECa and its inversion to produce estimates of s is a useful tool to create digital soil maps (DSM) of q and soil physical (e.g., clay, sand) and chemical (e.g., ECe and CEC) properties using machine learning modelling (i.e., support vector machine) with good accuracy (Lin’s Concordance > 0.8). Moreover, it was evident that DSM of AWC and soil profile classes can be created using ECa in combination with gamma-ray spectrometry data. It was concluded that DSM techniques using easy and cheap to acquire digital data such as ECa and gamma-ray spectrometry data can aid precision irrigation and agriculture by providing quantitative information and digital maps of soil properties for the farmers and decision makers.

JOURNAL OF CURRENT SCIENCE AND TECHNOLOGY, 11, 1, 40-50

The results of the gamma-spectrometric measurements in a 16500 ha large region of south-western Serbia, are presented. Activity concentrations of 40K, 137Cs, and 210Pb in different deciduous and evergreen trees in the region are investigated. For all the investigated isotopes, there is a tendency that, on average, the lowest activity concentrations were found in tree stems, then in leaves, while the highest ones were in the soil. Statistical analysis did not show any differences between activity concentrations of leaves and needles, showing that both leaves and needles could be equally well used as a biomonitors.

Sepiolite is a naturally occurring clay mineral of sedimentary origin and is a magnesium hydrosilicate. Sepiolite has been widely used as an additive raw material in ceramics and cement industry, pharmaceutical, cleaning-detergent, paper, paint, cosmetic agriculture, fertilizer, etc. In this study, the natural radioactivity levels, radon emanation coefficients and radon exhalation rates of 30 sepiolite samples collected from open three sepiolite quarries (Beylikova, Polath and Sivrihisar) in Central Anatolia region of Turkey were determined by using a gamma-ray spectrometry with an HPGe detector. The average absorbed gamma dose rates directly measured in Beylikova, Polath and Sivrihisar open three sepiolite quarries located in Central Anatolia region of Turkey were found as 59, 65, and 64 nGyh?1, respectively. The average activity concentrations of 226Ra, 232Th, and 40K in 30 sepiolite samples collected from those quarries were found as 38.6, 12.4, and 67.4 Bqkg?1, respectively. The average emanation coefficient and exhalation rate of radon of sepiolite samples were determined as 22 % and 0.065 Bqkg?1h?1, respectively. Also, radiological parameters (outdoor absorbed gamma dose rate, annual effective dose rate, external and internal index) were estimated to evaluate the use of sepiolite samples as additive raw materials in the building sector.

The integration of geological data obtained through fieldwork, remote sensing and airborne geophysics has been shown to be efficient in creation of precise geological maps. The Vieirópolis region, sited in the west of the Rio Grande do Norte Subprovince of the Borborema Province, is characteristically made up of rocks intensely deformed by transcurrent shear zones and late brittle structures which control the mineralization of gemmological and industrial minerals. ASTER GDEM and airborne geophysical images (magnetometry and gamma-ray spectrometry) were used in order to enhance the geological knowledge of this region and to facilitate the identification and delimitation of structures and lithologies mapped during stages of fieldwork. Thus, a geological map on a scale of 1:50,000 was achieved, made up of six main lithological units and three new shear zones (Vieirópolis, Lastro and São Pedro), as well as the NE-SW-trending Portalegre Shear Zone. Within the newly mapped structures, the Vieirópolis Shear Zone stands out due to its expressiveness. Aeromagnetometry data suggest that this zone originated on the edge of the Brejo das Freiras Subbasin, part of the Portalegre Shear Zone System. NW-SE, ESE-WNW and E-W lineaments were correlated to lesser extent brittle structures which sometimes transversely cut the regional foliation, allowing pegmatite fluids to rise. The RGB ternary composition map (K, eTh, eU) also corroborates the presence of these structures, besides helping to determine lithological units. In this case study, the integration of direct and indirect data showed to be essential for the understanding and producing of local geological map.

A study of the environmental radioactivity in the Kopački Rit Nature Park, Croatia, is presented. This wildlife reserve is part of the Middle Danube River Basin, and it is exposed to various pollutants due to a number of human activities in the surroundings, where there is a nuclear power plant and also urban centres and areas of intense agricultural production. Results for the activity concentrations of soil and surface water samples do not indicate any elevated radioactivity level, which is confirmed by on-site measurements of ambient dose rate equivalent. An assessment of the radiological load on the local biota, carried out using the ERICA tool, implies an overall low radiological risk even if conservative values of the risk quotient are used. Therefore, human activities do not have a significant effect on the radiological load on the Kopački Rit area. A similar conclusion might be made with regard to numerous similar environments in the Middle Danube River Basin.

Neptunium-237 samples were irradiated in a spallation neutron field 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 fission products and one actinide were identified. Fission product activities yielded the number of fissions. 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 find out if and how the incineration rate depended on parameters of the accelerator beam.

This work estimates and discusses the effects of the rainforest on the airborne gamma-spectrometric surveys, taking as case study an area in the center of the Rondônia State, Amazonia, northern Brazil, where wooded and deforested areas are frequently juxtaposed. The control of the wooded areas is made using Landsat satellite images, by the calculation of the Normalized Difference Vegetation Index (NDVI), which allows distinguishing between areas with low and high concentration of green leaves. The results show that, compared to the NDVI values for non-vegetated areas, there is an attenuation of the mean signal of this index in the rainforest areas corresponding up to 36% of the Total Count of Radiation (TC), 12% of potassium (K), 37% of equivalent thorium (eTh), and 29% of the equivalent uranium (eU) concentrations. In our interpretation, part of this effect might be caused by the radiation shielding of the biomass in rainforest areas. However, as a secondary effect for the gamma-spectrometry data processing, the canopy trees are considered on the Digital Elevation Model being used as a surface to calculate the distance between the source of radiation and the sensor, which causes a bias in the processing, underestimating the real flight height to the ground surface. This last effect could have been avoided if there were a Digital Terrain Model available for the area, which should be considered for the data processing. Improving the understanding about this phenomenon, an increase in the quality of the signal-to-noise ratio of airborne gamma-spectrometric data used for the quantitative land modeling may be achieved for regions where the presence of rainforests is significant such as the Amazon region northern Brazil.

The investigation of radioactivity in samples is an application of gamma-ray spectrometry dealing with low and very low level gamma-ray activities of different isotopes. Gamma-ray spectrometry performed in the framework of radiological environmental monitoring may be done after selective sampling processes or after a chemical purification of a sample. Both cases imply that only some specific radionuclides should contribute to the obtained spectrum. Gamma-ray spectrometry performed with medium energy resolution detectors may allow the possible distinction of their photopeaks. Therefore, a cerium bromide (CeBr3) detector can be particularly attractive for routine tasks in radiological environmental monitoring as it has a high efficiency, medium energy resolution and it can work at room temperature. This study describes the conditions under which a CeBr3 detector can serve for some routine analysis in radiological analysis of samples collected in the environment or collected by air-samplers in environmental radiological monitoring programmes.

To study the runaway electron (RE) dynamics during plasma discharge and develop scenarios for disruption mitigation, a hard X-ray (HXR) spectrometric system has been developed and commissioned at the ASDEX Upgrade tokamak (AUG). The diagnostic system consists of two high-performance spectrometers based on LaBr3(Ce) scintillation detectors supplied with advanced electronics and analysis algorithms. These spectrometers view the AUG tokamak chamber quasi-radially at the equatorial plane. The measurements were carried out in the RE beam generation regimes by injecting argon into a deuterium plasma. In the interaction of a developed RE beam with a heavy gas target, powerful bremsstrahlung flux is induced, reaching energy close to 20 MeV. The electron energy distributions were reconstructed from the measured HXR spectra by deconvolution methods. The experimentally obtained maximum RE energies at different discharge stages were compared with relativistic test particle simulations that include the effect of toroidal electric field, plasma collisional drag force, synchrotron deceleration force. It was observed that the electrons attain their maximum energies within 50-100 ms after the gas injection. It gradually decreases due to the drop in loop voltage, energy loss due to synchrotron radiation emission and collisions dissipation of energy with the background plasma. HXR measurements at the discharge with multiple deuterium pellet injections allowed observing the effects of plasma cooling and argon ion recombination after the pellet injections. Argon density in AUG plasma after massive gas injection was estimated using HXR measurements.

International audience; Palladium-103 is a radioisotope of interest in medical applications which is used in brachytherapy implants for the treatment of prostate cancer. It decays through electron capture to excited levels of $^{103}$Rh, and especially to the 39.756 keV metastable state. The half-life of $^{103}$Pd was measured by gamma-ray spectrometry on a HPGe detector on an aliquot of the diluted solution, for 50 days. The absolute photon emission intensities were obtained by gamma-ray spectrometry using a solution whose mass activity was obtained by liquid scintillation, using the TDCR method. The full-energy peak efficiency of the detectors were previously calibrated with LNE-LNHB standard sources. The 357-keV photon emission intensity per 100 disintegrations obtained is 0.02464(16), in perfect agreement with the tabulated data (0.0246 (6)), and with a reduced uncertainty. In addition, the emission intensities of five other gamma-rays was also derived with a significant reduction of the uncertainties.

International audience; The hypothesis that seasonal changes in proximity to the Sun cause variation of decay constants at permille level has been tested for radionuclides disintegrating through electron capture and beta plus decay. Activity measurements of Na-22, Mn-54, Fe-55, Co-57, Zn-65, Sr82+85, Sr-90, Cd-109, Sb-124, Ba-133, Eu-152, and Bi-207 sources were repeated over periods from 200 d up to more than four decades at 14 laboratories across the globe. Residuals from the exponential nuclear decay curves were inspected for annual oscillations. Systematic deviations from a purely exponential decay curve differ from one data set to another and appear attributable to instabilities in the instrumentation and measurement conditions. Oscillations in phase with Earth's orbital distance to the sun could not be observed within 10(-4)-10(-5) range precision. The most stable activity measurements of beta(+) and EC decaying sources set an upper limit of 0.006% or less to the amplitude of annual oscillations in the decay rate. There are no apparent indications for systematic oscillations at a level of weeks or months.

Radium ((226)Ra) contamination derived from military, industrial, and pharmaceutical products can be found at a number of historical sites across the world posing a risk to human health. The analysis of spectral data derived using gamma-ray spectrometry can offer a powerful tool to rapidly estimate and map the activity, depth, and lateral distribution of (226)Ra contamination covering an extensive area. Subsequently, reliable risk assessments can be developed for individual sites in a fraction of the timeframe compared to traditional labour-intensive sampling techniques: for example soil coring. However, local heterogeneity of the natural background, statistical counting uncertainty, and non-linear source response are confounding problems associated with gamma-ray spectral analysis. This is particularly challenging, when attempting to deal with enhanced concentrations of a naturally occurring radionuclide such as (226)Ra. As a result, conventional surveys tend to attribute the highest activities to the largest total signal received by a detector (Gross counts): an assumption that tends to neglect higher activities at depth. To overcome these limitations, a methodology was developed making use of Monte Carlo simulations, Principal Component Analysis and Machine Learning based algorithms to derive depth and activity estimates for (226)Ra contamination. The approach was applied on spectra taken using two gamma-ray detectors (Lanthanum Bromide and Sodium Iodide), with the aim of identifying an optimised combination of detector and spectral processing routine. It was confirmed that, through a combination of Neural Networks and Lanthanum Bromide, the most accurate depth and activity estimates could be found. The advantage of the method was demonstrated by mapping depth and activity estimates at a case study site in Scotland. There the method identified significantly higher activity (3 Bq g(-1)) occurring at depth (0.4m), that conventional gross counting algorithms failed to identify. It was concluded that the method could easily be employed to identify areas of high activity potentially occurring at depth, prior to intrusive investigation using conventional sampling techniques.

Proceedings of the 20th International Conference on Radionuclide Metrology and its Applications (ICRM), 8-11 June 2015, Vienna, Austria. Organizer TU Wien. Editors Franz-Josef Maringer, Dirk Arnold, Uwe Wätjen.; International audience; Photon emission intensities of Pb-210 have been determined using sources prepared from a standard solution, whose activity was measured by liquid scintillation counting. The absolute gamma-ray and X-ray emission intensity was measured by conventional gamma-ray spectrometry. Complementary measurements of the L X-ray spectrum were performed using a cryogenic detector, characterized by very high energy resolution and constant detection efficiency. As a result, precise emission intensities of the individual X-ray lines were obtained taking into account the presence of satellite lines.

For the future JET deuterium-tritium (DT) campaigns numerous gamma-ray diagnostics, in particular the JET Gamma-ray Camera (GC) and the JET Gamma-ray Spectrometer (GS), were upgraded in the last few years. The upgrade of GC and GS included replacement of detector modules in order to allow operation at expected high count rate of ∼0.5 Mcps on the scintillator front surface of 506 mm2 for each GC crystal and 7 squared inches for GS as well as to improve energy resolution to equal or better than 5% at gamma-ray energy above 1.1 MeV for both diagnostics. Within the JET4 Enhancements Project, performance of a number of photodetectors including multi-pixel photon counter (MPPC), PIN diode and photomultiplier tube (PMT) connected to scintillators was investigated. Upgraded detector modules are based on fast scintillators with a decay time of about 20 ns, LaBr3:Ce and CeBr3, coupled to MPPC and PMT for GC and GS, respectively. Results on energy resolution obtained with upgraded diagnostics, already installed at JET, are presented and compared to those collected in laboratory conditions.

The γ-radiation emitted by building materials is calculated from the activity indices for 232Th, 226Ra and 40K and expressed as the activity concentration index (ACI). Gamma spectroscopy is a non-destructive technique frequently used to simultaneously determine the indices for several radionuclides. Spectral interpretation poses a number of challenges, including identification of γ-lines subject to summing-in effects, interference from other γ-ray emitting radionuclides and the time required to reach secular equilibrium. These challenges are not fully addressed by Canberra Industries’ Genie 2000, the software used by many laboratories to analyse samples. This article describes a Microsoft Excel workbook that exploits Genie 2000 flexibility to program applications with Visual Basic using Canberra's Nuclear Data Access Library and batch procedure tools. The workbook determines 40K activity concentration after correcting for 228Ac interference and 226Ra activity directly from the γ-peak at 186.5 keV. The method proposed was tested by participating in 13 national and international scale inter-comparison exercises. The results were statistically indistinguishable from the reference values at a coverage factor of k = 3 and no statistically significant differences were identified between the respective means by a Student's t pairwise comparison., This study was funded by the Spanish Ministry of the Economy, Industry and Competitiveness under project BIA2016-77252-P.

It is well known that monitoring of radioactivity released from nuclear medicine departments is necessary to ensure the radiological safety of patients and personnel. Unfortunately, equipment for air sampling is often expensive, loud and is not suitable to use in hospitals. Our goal was to find cheap and simple system for passive monitoring of 131I activity concentration in the air of nuclear medicine departments. Medical activated charcoal tablets were used, because charcoal is excellent material for 131I trapping and tablets are readily available. Our proposed sampling protocol contains tablets preparation, exposure and measurements using HPGe detector. Different methods of tablets preparation (drying, impregnation with KI or NaOH) were tested while an experimental chamber was prepared for estimating 131I (released from Na131I, similar to that used in therapy) trapping efficiency of tablets in different conditions. Finally, tablets were placed in plastic holders and tested in nuclear medicine facilities.

A method is presented for calculating the expected number of counts in peaks that have a large relative peak area uncertainty and appear in measured gamma-ray spectra. The method was applied to calculations of the correction factors for peaks occurring in the spectra of radon daughters. It was shown that the factors used for correcting the calculated peak areas to their expected values decrease with an increasing relative peak-area uncertainty. The accuracy of taking the systematic influence inducing the correction factors into account is given by the dispersion of the correction factors corresponding to specific peaks. It was shown that the highest accuracy is obtained in the peak analyses with the GammaVision and Gamma-W software. 21st International Conference on Radionuclide Metrology and itsApplications (ICRM), Argentinian Comis Nacl Energia Atomica, BuenosAires, ARGENTINA, MAY 15-19, 2017

The background radiation of the areas was collected at random for each point using a rados survey meter. The detectors (two rados survey meter were used) were placed 1 meter above the ground with the operator positioned a few meters away. Three (3) readings were taking from each detector in other to reduce error or reach accuracy in obtaining the background readings from each randomly selected point where soil samples were later collected. In the current study, the concentration levels of naturally occurring radioactive materials (NORMs) of 40K, 232Th, and 238U in the surface soil samples of selected areas in kigo road new extension Kaduna north, Kaduna in Nigeria were studied. The collected soil samples were analyzed by means of gamma-ray spectrometry. The mean activity concentrations of the natural occurring radionuclides of 226Ra, 232Th and 40K in the soil samples were estimated to be 62, 78.35, 227.17 Bq/kg respectively for kigo road new extension respectively. Radium equivalent activity, absorbed dose rate, annual effective dose equivalent were also calculated for assessment of radiological risk. External hazard value (Hex) is between 0.3163 and 0.9557 and Internal hazard value is between 0.4462 and 1.1618. The worldwide average activity concentrations of 226Ra, 232Th and 40K in soil samples from various studies around the world have values of 37, 30 and 400 Bq/kg respectively [UNSCEAR, 2000]. The values compared well with published data from UNSCEAR shows Ra-226, Th-232 from the location are well above the standards while K-40 below the risk value.

Major elements concentrations (Na, K, Ca, Mg) and the activity concentrations of 226, 228Ra, 234, 238U, 210Po, 210Pb, 40K and 137Cs in northern and eastern Croatian thermal and mineral waters, collected directly from springs (or wells), are presented herein with total effective doses assessed for those waters that are considered as drinking “cures” and are available for consumption. The methods used for radionuclide determination included alpha- particle spectrometry, gas-proportional counting and gamma-ray spectrometry, while the major element composition was determined by ICP-MS. The activity concentrations of all of the radionuclides were found to be below the guidance levels set by the WHO and EC Directive, with the exception of one water sample that measured 0.26 Bq L–1 of 228Ra. The effective ingestion dose assessment for the consumption of the so-called water “cures” during one, two or four weeks’ time period throughout one year was well below the recommended 0.1 mSv for drinking water.

Active charcoal detectors are used for testing the concentration of radon in dwellings. The method of measurement is based on radon adsorption on coal and measurement of gamma radiation of radon daughters. The contributions to the final measurement uncertainty are identified, based on the equation for radon activity concentration calculation. Different methods for setting the region of interest for gamma spectrometry of canisters were discussed and evaluated. The obtained radon activity concentration and uncertainties do not depend on peak area determination method. (C) 2013 Elsevier Ltd. All rights reserved.

Proceedings of the 19th International Conference on Radionuclide Metrology and its Applications 17–21 June 2013, Antwerp, Belgium; International audience; Commercial digital signal-processing modules have been tested for their applicability to gamma-ray spectrometry. The tests were based on the same n-type high purity germanium detector. The spectrum quality was studied in terms of energy resolution and peak area versus shaping parameters, using a Eu-152 point source. The stability of a reference peak count rate versus the total count rate was also examined. The reliability of the quantitative results is discussed for their use in measurement at the metrological level.

The ISOCS calibration, when utilized for a BEGe detector with a small angled collimator, produces inaccuracies of about 19% for gamma rays with energies greater than 0.4 MeV. Such a discrepancy is caused by the collimator algorithms currently utilized in the ISOCS software which, originally developed for HPGe detectors, are less suited for BEGe detectors. ISOCS's errors are due to the different crystal configurations of broad energy detectors compared to coaxial detectors, i.e. to a different importance of the active area portion obscured by the collimator. This work proposes some solutions for the problem, either using the ISOCS software or implementing a stochastic calibration procedure. In particular, the present work considers a virtual collimator that, maintaining its angular aperture, is capable of continuously enlarging its bottom collimator's aperture cone radius, to expose growing active area portions. In such a way two goals may be achieved: the mathematical characterization of ISOCS’ errors and the minimization of observed errors by means of the stochastic calibration procedure. Different reference set-ups are considered in order to test source geometry effects, source materials and different detectors. In particular, a 220 L drum, a 2 m 3 box filled with uniformly contaminated cellulose or PVC, and small BE3825 and large BE5030 Canberra detectors are considered. Detection efficiencies calculated by ISOCS software are compared against a completely stochastic MCNPX simulation procedure, that is unaffected by any algorithmic correction. MCNPX simulations demonstrate, when widening collimators’ cone but maintaining the angular aperture unchanged, that ISOCS and MCNPX difference percentage between efficiency data points reduces, depending on energy, by more than 50%. This happens as far as the shadow-shielded portion of detector's active area reduces.

The study of spatial distribution of activity concentration of 238U, 226Ra, 210Pb, 232Th, 40K, and 137Cs radionuclides in the surface soil samples (n = 42) collected in the vicinity of four coal-fired power plants in Serbia is presented. Radioactivity measurements in soils performed by gamma-ray spectrometry showed values [Bqkg-1] in the range: 15-117 for 238U, 21-115 for 226Ra, 33-65 for 210Pb, 20-69 for 232Th, 324-736 for 40K, and 2-59 for 137Cs. Surface soil radio-activity that could have resulted from deposition of radionuclides from airborne discharges or resuspension of ash from disposal sites showed no enhanced levels. It was found that variation of soil textural properties, pH values, and carbonate content influenced activity levels of natural radionuclides while radiocesium activities were associated with soil organic matter content. Modification of some soil properties was observed in the immediate vicinity (

This paper addresses the noticeable increase of 137Cs activity concentrations in soil and fallout in the area surrounding Zagreb (Croatia) that occurred at the time of the 2011 Fukushima accident. This topic is important for public health as 137Cs is highly toxic due to its long half-life of radioactive decay and chemical similarity to potassium. 137Cs concentrations in fallout were much greater than in soil, but remained present longer in the latter. While being detectable in our measurements, 137Cs did not spread through the food chain in amounts exceeding the maximum allowed level of radioactive food contamination. However, more thorough and consistent measurements need to be done in order to establish the precise activity trends of 137Cs in Zagreb soil and fallout.

La Xarxa de Vigilància Radiològica Ambiental de la Generalitat de Catalunya està constituïda per diversos tipus de detectors per a la mesura automàtica en continu i en temps real de la radiació ambiental. Entre ells destaquen els monitors d’espectrometria gamma amb detectors d’escintil•lació de NaI (Tl) i LaBr3 (Ce). Les mesures ambientals registrades amb monitors d'espectrometria gamma en temps real no tenen significat radiològic fins que se sotmeten a processos d'adequació. Aquests processos comprenen l'estabilització d'espectres, els calibratges del monitor en energia, resolució i eficiència i la sostracció del fons intrínsec del detector. En aquest estudi es presenta el procés d'adequació d'espectres per a un monitor d'aigua amb detector de LaBr3 (Ce). Els espectres gamma estabilitzats i calibrats poden ser sotmesos a processos d'anàlisi de dades. A partir dels espectres es pot obtenir l'equivalent de dosi ambiental H*(10) o la concentració d'activitat dels isòtops escollits. L'equivalent de dosi ambiental H*(10) és la magnitud que s'usa en la legislació relacionada amb el límit de dosis del públic. Es presenta un mètode per al càlcul del H*(10) obtingut a partir d'espectres gamma ambientals basat en mètodes de Montecarlo amb el codi EGS5. Els valors obtinguts de les dades espectromètriques d'un monitor amb detector de LaBr3(Ce) es comparen amb els proporcionats per un comptador Geiger Muller calibrat en H*(10). Finalment, es presenta un mètode d'anàlisi d'espectres gamma per regions espectrals per a la monitorització automàtica i en temps real de la concentració d'activitat d'isòtops naturals i artificials. El mètode soluciona el solapament de pics i elimina la contribució addicional causada per la presència de radiació natural dins de cada regió. Es presenten resultats de mesures de laboratori per isòtops artificials (Cs-137 i I-131) i naturals (Bi-124 i Pb-214)., La Red de Vigilancia Radiológica Ambiental de la Generalitat de Catalunya está constituida por varios tipos de detectores para la medida automática en continuo y en tiempo real de la radiación ambiental. Entre ellos destacan los monitores de espectrometría gamma con detectores de centelleo de NaI(Tl) y LaBr3(Ce). Las medidas ambientales registradas con monitores de espectrometría gamma en tiempo real carecen de significado radiológico hasta que se someten a procesos de adecuación. Estos procesos comprenden la estabilización de espectros, las calibraciones del monitor en energía, resolución y eficiencia y la sustracción del fondo intrínseco del detector. En este estudio se presenta el proceso de adecuación de espectros para un monitor de agua con detector de LaBr3(Ce). Los espectros gamma estabilizados y calibrados pueden ser sometidos a procesos de análisis de datos. A partir de los espectros se puede obtener el equivalente de dosis ambiental H*(10) o la concentración de actividad de isótopos escogidos. El equivalente de dosis ambiental H*(10) es la magnitud usada en la legislación relacionada con las dosis del público. Se presenta un método para el cálculo del H*(10) obtenido a partir de espectros gamma ambientales basado en métodos de Montecarlo con el código EGS5. Los valores obtenidos de los datos espectrométricos de un monitor con detector de LaBr3(Ce) se comparan con los proporcionados por un contador Geiger Muller calibrado en H*(10). Por último, se presenta un método de análisis de espectros gamma por regiones espectrales para la monitorización automática y en tiempo real de la concentración de actividad de isótopos naturales y artificiales. El método solventa el solapamiento de picos y elimina la contribución adicional causada por la presencia de radiación natural dentro de cada región. Se presentan resultados de medidas de laboratorio para isótopos artificiales (Cs-137 y I-131) y naturales (Bi-124 y Pb-214)., The Environmental Radiological Surveillance Network implemented in Catalonia consists of several types of detectors for real time automatic measurement of the environmental radiation. Among these are the gamma spectrometry monitors using NaI (Tl) and LaBr3 (Ce) scintillation detectors. Environmental measurements measured with real-time gamma-ray spectrometry monitors are not significant until they are adequately processed. These processes include spectrum stabilisation, energy, resolution and efficiency calibrations and subtraction of the detector's intrinsic background. This study presents the process of spectra adequacy for a water monitor with LaBr3(Ce) detector. Stabilised and calibrated spectra can be subjected to data analysis processes. Form spectra, the ambient dose equivalent H*(10) or the activity concentration of isotopes can be obtained. The ambient dose equivalent H*(10) is the quantity used in legislation related to limits on dose to public exposure. We present a method for the calculation of H*(10) obtained from environmental gamma spectra based on Monte Carlo simulations with the EGS5 code. The values obtained from the spectrometric data registered by a monitor with a LaBr3(Ce) detector are compared with those provided by a Geiger Muller counter calibrated in H*(10). Finally, a spectral regions analysis method of gamma spectra is presented for the automatic and real-time monitoring of the activity concentrations of natural and artificial isotopes. The method solves peak overlapping and eliminates the additional contribution caused by the presence of natural radiation within each region. Results of laboratory measurements for artificial (Cs-137 and I-131) and natural (Bi-124 and Pb-214) isotopes are presented.

A measurement station dedicated for quantitative radiological characterisation of naturally occurring radio-nuclides in a metallurgical company and based on gamma-ray spectrometry was developed. The station is intended for performing quality control of final non-ferrous metal products and for radiological checks of incoming materials. A low-background point-contact HPGe-detector was used and the signal was split in two branches to enable collecting simultaneously spectra with high amplification (for gamma-ray energies below 250 keV) and low amplification. This work was supported by the EMRP joint research project 'Metrology for processing materials with high natural radioactivity' (MetroNORM, JRP IND57) which has received funding from the European Union on the basis of Decision No 912/2009/EC. The EMRP is jointly funded by the EMRP participating countries within EURAMET and the European Union.

The aim of this paper is to present information about currently used standard and routine methods for radon analysis in drinking waters. An overview is given about the current situation and the performance of different measurement methods based on literature data. The following parameters are compared and discussed: initial sample volume and sample preparation, detection systems, minimum detectable activity, counting efficiency, interferences, measurement uncertainty, sample capacity and overall turnaround time. Moreover, the parametric levels for radon in drinking water from the different legislations and directives/guidelines on radon are presented.

In the presented paper analysis of sensitivity of self-attenuation correction C s to the accuracy of chemical composition analysis is presented. The analyses were done by means of Monte Carlo simulation for cylindrical samples and for four sample materials: peat, water, ash and soil. For each of these materials the major elements were selected whose determination in the analysed material is necessary. For the remaining elements threshold levels of their concentration were determined—if expected element concentration in a sample exceeds this value, its determination is indispensable, assuming the accuracy of C s determination at 3 %.

We develop a simple and widely applicable method for determining the self-attenuation correction in gamma-ray spectrometry on environmental samples. The method relies on measurements of the transmission of photons over the matrices of a calibration standard and an analysed sample. Results of this experiment are used in subsequent Monte Carlo simulations in which we first determine the linear attenuation coefficients () of the two matrices and then the self-attenuation correction for the analysed sample. The method is validated by reproducing, over a wide energy range, the literature data for the  of water. We demonstrate the use of the method on a sample of sand, for which we find that the correction is considerable below ~400 keV, where many naturally occurring radionuclides emit gamma rays. At the lowest inspected energy (~60 keV), one measures an activity that is by a factor of ~1.8 smaller than its true value.

In situ gamma-ray measurements were taken at eight locations in the Gran Sasso National Laboratory (Italy). Count rates for gamma radiation within the energy range of 7–2,734 keV varied from 8 to 60 c s-1. The arithmetic mean was 49 c s-1 for measurements taken without a collimator. The average gamma flux inside the Lab was 0.25 c cm-2 s-1. The sedimentary rocks surrounding the Lab are characterized by low activity concentrations of uranium and thorium, equal to 1.7 and 1.4 Bq kg-1, respectively.

Materials containing radionuclides of natural origin, which is modified by human made processes and being subject to regulation because of their radioactivity are known as NORM. We present a brief review of the main categories of non-nuclear industries together with the levels of activity concentration in feed raw materials, products and waste, including mechanisms of radioisotope enrichments. The global management of NORM shows a high level of complexity, mainly due to different degrees of radioactivity enhancement and the huge amount of worldwide waste production. The future tendency of guidelines concerning environmental protection will require both a systematic monitoring based on the ever-increasing sampling and high performance of gamma ray spectroscopy. On the ground of these requirements a new low background fully automated high-resolution gamma-ray spectrometer MCA_Rad has been developed. The design of Pb and Cu shielding allowed to reach a background reduction of two order of magnitude with respect to laboratory radioactivity. A severe lowering of manpower cost is obtained through a fully automation system, which enables up to 24 samples to be measured without any human attendance. Two coupled HPGe detectors increase the detection efficiency, performing accurate measurements on sample volume (180 cc) with a reduction of sample transport cost of material. Details of the instrument calibration method are presented. MCA_Rad system can measure in less than one hour a typical NORM sample enriched in U and Th with some hundreds of Bq/kg, with an overall uncertainty less than 5%. Quality control of this method has been tested. Measurements of certified reference materials RGK-1, RGU-2 and RGTh-1 containing concentrations of K, U and Th comparable to NORM have been performed, resulting an overall relative discrepancy of 5% among central values within the reported uncertainty., 21 pages, 4 figures, 6 tables

Gamma-ray spectrometry has been widely used in various environmental and natural sciences by its ability to determine the concentrations of each radionuclide of the samples, and also because of the easiness in sample preparation and measurement procedures. Recently, its applicability is being extended for Quaternary geochronology, by providing information on the rate of energy absorbed by phosphor minerals (i.e. dose rate) used in trapped charge dating methods. To measure the radionuclides emitting low energy gamma ray (particularly, 210 Pb and 234 Th), which are subjected to be easily absorbed by detector-cryostat materials and sample itself, various HPGe detectors have been developed, because these detectors have high resolution capacity and are relatively easy for maintenance. In this paper, we review the characteristics of p-type coaxial HPGe, well-type HPGe and broad energy HPGe (BEGe) gamma-ray detector, and these are compared with each other, particularly with a view to establishing the most appropriate measurement procedure for estimating the dose rate for trapped charge dating methods. Also various calibration factors to analyse the low-level environmental samples are discussed. Especially self-absorption correction method using sample weight is suggested.

The gamma-ray spectrometer JET EP2 (Joint European Torus enhancement project 2) project aims to perform high-resolution gamma spectroscopy at very high count rate (up to few MHz). Traditional analogue electronic has count rate and pulse processing limitations (long dead-time, pile-up challenge). Digital pulse processing (DPP) systems have been shown to have better performance than analogue ones for processing neutrons or/and gamma-ray signals. DPP can synthesize almost any pulse response shape without the signal degradation associated to complex analogue paths. High-speed transient recorders (TR) with auto-trigger functionality are used to digitize and store the detailed shape of pulses. The data acquisition (DAQ) system provides sophisticated analysis/data reduction based on real time algorithms, implemented in field programmable gate arrays (FPGA), for Pulse Height Analysis (PHA) while resolving pulse pile-up of digitized pulses. This paper describes a new DAQ system for real-time pulse analysis. The system is based on the Advanced Telecommunications Computing Architecture (TM) (ATCA (TM)) and contains an ix86-based processor blade with up to 40 GFLOPS and a TR module interconnected through PCI Express (PCIe) links. TR module features: (i) 8 channels of 13 bit resolution with accuracy equal or higher than 11 bit to cope with the expected signal-to-noise ratio (SNR) of the input pulses; (ii) up to 500 MSamples/s sampling rate with the possibility to achieve 1 GSamples/s; and (iii) 2 or 4 GB of local memory. The core of the TR module is two FPGAs able to perform real-time processing algorithms such as PHA and pile-up resolution. This will allow data reduction by a factor of at least 6 and eventually spectra output in real-time. (c) 2007 Elsevier B.V. All rights reserved.

The paper describes the procedure of adapting a coaxial high-precision germanium detector to a device with numerical calibration. The procedure includes the determination of detector dimensions and establishing the corresponding model of the system. In order to achieve a successful calibration of the system without the usage of standard sources, Monte Carlo simulations were performed to determine its efficiency and pulse-height response function. A detailed Monte Carlo model was developed using the MCNP-5.0 code. The obtained results have indicated that this method represents a valuable tool for the quantitative uncertainty analysis of radiation spectrometers and gamma-ray detector calibration, thus minimizing the need for the deployment of radioactive sources.

In forthcoming deuterium-tritium (DT) experiments on JET a significant population of alpha-particles will be produced. For operating alpha-particle diagnostics at high DT neutron fluxes, specific improvements have to be made. Proposed new detectors for gamma-ray measurements will be based on CeBr3 and LaBr3:Ce scintillators. They are characterized by a good energy resolution, a relatively high detection efficiency for a few MeV gamma-rays and a fast response time. An overview of scintillator parameters is presented. A description of the properties of photodetectors is given to indicate optimal setups. Results of measurements, using gamma-ray sources with energies up to a few MeV, are discussed with relation to the DT campaign requirements.

In this article, the X-ray and gamma-ray coincidence summing effect in Eu-152 is studied. Coincidence summing corrections and peak and total efficiencies of point and volume sources were determined using the direct matrices multiplication (DMM) method. The theoretically evaluated peak count rates were found to be in good agreement with the experimentally obtained values. Validation was performed by comparing the calculated efficiency curves and the corresponding correction factors with the results obtained using GESPECOR 4.2 software. (C) 2015 Elsevier Ltd. All rights reserved.

The concentration of 238 U, 232 Th and 40 K in 13 building materials obtained from factories and collected in field in Cameroon were investigated by γ -ray spectrometry. The activity ranged from 1.76 to 49.84 Bq kg - 1 , 0.32 to 147 Bq kg - 1 and 18 to 1226 Bq kg - 1 for 238 U, 232 Th and 40 K, respectively. The highest 238 U activity was found in compressed red soil brick type I ( 49.6 ± 0.3 Bq kg - 1 ) produced by a local manufacturer while the highest 232 Th ( 139 ± 13 Bq kg - 1 ) and 40 K ( 1162 ± 108 Bq kg - 1 ) activities were found in gravel collected from an exploitation site in Logbadjeck. The activities are compared with available data from other investigations and with the world average value for soils. The radium equivalent activity Ra eq , the external hazard index H ex , the indoor absorbed dose rate D ˙ in air and the annual effective dose equivalent E ˙ were evaluated to assess the radiation hazard for people living in dwellings made of the materials studied. All building materials have shown Ra eq (range from 10 to 313 Bq kg - 1 ) lower than the limit of 370 Bq kg - 1 set in the Organization for Economic Cooperation and Development [OECD, 1979. Exposure to radiation from the natural radioactivity in building materials. OECD, Paris] report which is equivalent to a γ -dose of 1.5 mSv yr - 1 . Except for the gravel from Logbadjeck, all the materials examined are acceptable for use as building materials as defined by the OECD criterion.

In order to identify radon-prone areas and evaluate radon risk level, a soil gas radon survey combined with gamma-ray spectrometry measurements was carried out in Shenzhen City, south China. Meanwhile, the statistical analysis was applied to evaluate the distribution of measured results. This paper presents the methodology of the radon risk assessment. A radon risk map was accomplished based on a combination of soil gas radon concentration (RC), soil air permeability (Perm.) and uranium (238U) concentration. The results showed that the distribution of soil gas RC and radon-prone areas were closely related to geologic distribution of uranium (238U) and local lithology.

International audience; Soil erosion studies, based on the 137Cs technique, require a lot of time-consuming cores to determine soil loss or gain. We show that portable HP-Ge spectrometer can be used to determine the content and the distribution in the soil of natural and artificial radionuclides. Simulations of gamma-rays transport throughout the soil profile used a Monte Carlo code. The methodology requires a unique undisturbed coring site to build the models, calibrate the spectrometer readings and derive soil denudation or accumulation thickness.