Gamma Spectrometry Research Articles

Detection of potential hydrocarbon micro-seepage accumulations along radioactive profiles in the Syrian desert area (Area-1) Syria, using the airborne gamma-ray spectrometry technique

Detection of potential hydrocarbon micro-seepage accumulations along radioactive profiles in the Syrian desert area (Area-1) Syria, using the airborne gamma-ray spectrometry technique

Assessment of natural radioactivity levels in rice samples and their implications for radiological protection

ABSTRACT This study investigates the levels of natural and artificial radioactivity in rice samples collected from various local markets in Islamabad, Pakistan. The 226Ra, 232Th, and 40K activity concentrations were measured through gamma-ray spectrometry with a NaI(Tl) detector. The average activity concentrations were 1.67 ± 1.19 Bq kg−1 for 226Ra, 3.31 ± 1.83 Bq kg−1 for 232Th, and 88.51 ± 11.65 Bq kg−1 for 40K. Calculated radium equivalent (Raeq) values ranged from 7.35 to 18.08 Bq kg−1, with a mean value of 11.11 Bq kg−1, all below the permissible maximum of 370 Bq kg−1. The absorbed dose rates ranged from 6.85 to 16.39 nGy h−1, with an average of 10.64 nGy h−1, falling below the acceptable limit of 51 nGy h−1. The outdoor and indoor radiation hazard indices (Hex and Hin) had mean values of 0.03, both below the threshold value of one. The external and internal hazard indices (Iγ and Iα ) were both 0.088, also below the critical value of one. The excess lifetime cancer risk (ELCR) ranged from 0.28 to 0.11, with a mean value of 0.18, which is less than the critical value of one. Overall, the radioactivity levels in the analyzed rice samples are within the acceptable limits set by the International Commission on Radiological Protection and are below global averages. These results offer important insights into the radiological safety of rice consumption in the study area.

Natural radioactivity and technological properties of kaolinized granite from the Motajica mine, Bosnia and Herzegovina

For the production of ceramic tiles, it is necessary to use high-quality and economical raw materials, which will optimize the properties of the final product and meet the prescribed standards. For this reason, it is necessary to examine the properties of each potential raw material. This paper examines radioactivity and technological properties of kaolinized granite from the Motajica mine, in Bosnia and Herzegovina. Chemical analysis, X-ray diffraction (XRD), and thermal analysis (DTA) were carried out. In order to examine the technological (ceramic) properties of this raw material, ignition tests of the composite obtained by introducing kaolinized granite (with a content of 25 %) into the standard factory series of ceramic tiles were conducted at four selected temperatures (1050, 1100, 1120, and 1150 ℃). Total linear shrinkage, flexural strength, and water absorption were determined for the produced biscuit. Using gamma spectrometry, the activity concentrations of radionuclides 226Ra, 232Th and, 40K were measured, and then the radiation risk for external exposure of workers in the industry was assessed using hazard indices and doses. The radiation risk from the use of manufactured unglazed ceramic tiles in houses was also assessed. Statistical analysis of radionuclides for 100 samples of kaolinized granite was performed using descriptive statistics and hierarchical cluster analysis (HCA). It was observed that the average values of 226Ra, 232Th, and 40K are above the average for building materials in the world and amount respectively to 122 Bq kg−1, 96 Bq kg−1, and 1068 Bq kg−1. All other obtained values indicate that it is a quality raw material that, despite having an increased content of radioactive elements compared to the world average, does not represent a radiological hazard for workers and people who stay indoors on an annual basis. The tested raw material satisfies all technological criteria for further use and can be considered a desirable ingredient of ceramic composites because it can partially or completely replace feldspar.

Prompt gamma rays of lanthanum and praseodymium produced by inelastic scattering of fission neutrons

AbstractEmission of prompt gamma rays in lanthanum and praseodymium nuclei triggered by (n,n’γ) inelastic scattering reactions of fission neutrons was investigated with the instrument FaNGaS (Fast Neutron-induced Gamma-ray Spectrometry) at Heinz Maier-Leibnitz Zentrum (MLZ). We identified 125 gamma lines (54 for lanthanum and 71 for praseodymium), for which we give the relative intensities and production cross sections. Presence of oxygen and chlorine in the samples was exploited to verify previous measurements. Our results are consistent with available literature data but also enhance it as we detect new lines and recognize a few false assignments. In addition, for a counting time of 12 h we estimated the detection limits of lanthanum and praseodymium as 0.6 and 0.4 mg, respectively.

Geophysical Monitoring Technologies for the Entire Life Cycle of CO2 Geological Sequestration

Geophysical monitoring of CO2 geological sequestration represents a critical technology for ensuring the long-term safe storage of CO2 while verifying its characteristics and dynamic changes. Currently, the primary geophysical monitoring methods employed in CO2 geological sequestration include seismic, fiber optic, and logging technologies. Among these methods, seismic monitoring techniques encompass high-resolution P-Cable three-dimensional seismic systems, delayed vertical seismic profiling technology, and four-dimensional distributed acoustic sensing (DAS). These methods are utilized to monitor interlayer strain induced by CO2 injection, thereby indirectly determining the injection volume, distribution range, and potential diffusion pathways of the CO2 plume. In contrast, fiber optic monitoring primarily involves distributed fiber optic sensing (DFOS), which can be further classified into distributed acoustic sensing (DAS) and distributed temperature sensing (DTS). This technology serves to complement seismic monitoring in observing interlayer strain resulting from CO2 injection. The logging techniques utilized for monitoring CO2 geological sequestration include neutron logging methods, such as thermal neutron imaging and pulsed neutron gamma-ray spectroscopy, which are primarily employed to assess the sequestration volume and state of CO2 plumes within a reservoir. Seismic monitoring technology provides a broader monitoring scale (ranging from dozens of meters to kilometers), while logging techniques operate at centimeter to meter scales; however, their results can be significantly affected by the heterogeneity of a reservoir.

A comprehensive review of radiation shielding concrete: Properties, design, evaluation, and applications

AbstractThis review paper provides a comprehensive analysis of radiation shielding concrete, covering its properties, design, evaluation, and applications. It begins with an introduction, stating the objective and scope. The paper explores radiation shielding basics, including ionizing radiation, shielding principles, and materials used for shielding. Concrete's properties relevant to shielding, radiation attenuation mechanisms, and factors affecting its efficiency are discussed. Different types of radiation shielding concrete are examined, along with their applications. The design and formulation of shielding concrete, including mix proportions, optimization techniques, and quality control, are presented. Evaluation methods and standards are discussed. Lastly, challenges, future directions, and emerging technologies are outlined. This review paper serves as a valuable resource for professionals involved in radiation shielding. The review on radiation shielding concrete highlighted its effectiveness in attenuating ionizing radiation, emphasizing material composition, density, and thickness as key design factors. Evaluation methods, such as gamma spectroscopy and Monte Carlo simulations, are discussed, demonstrating its versatile applications in nuclear facilities, healthcare, and space exploration.

Determination of natural radioactivity levels in soil samples from irrigated vegetable farming land in and around Addis Ababa, Ethiopia.

Soil samples were collected from vegetable agricultural areas in and around Addis Ababa, and their levels of radioactivity were measured. Gamma spectrometry with high-purity germanium detector was used to quantify radioactivity level. The average concentration of 226Ra, 232Th, and 40K were 32.8±2.1, 62.4±4.4, and 544.3±23.3Bqkg-1 respectively. The mean values of 232Th and 40K are higher, whereas the value of 226Ra is comparable with world average values. Radiological hazard indices, including radium equivalent activity (Raeq), absorbed dose rate (Dr), outdoor annual effective dose equivalent (Deff), external hazard index (Hex), internal hazard index (Hin), and gamma radiation representative level index (Iγ), were calculated based on the activity concentration of 226Ra, 232Th and 40K. The mean values were 163.9Bqkg-1, 78.7 nGy h-1, 0.10mSv y-1, 0.44, 0.53, and 0.60 respectively. All indices are lower than global recommended limit values. These results revealed that radiation hazard due to radionuclides in the soil of the study area is insignificant.

Assessment of radiological contamination due to gold mining in soil and food crops of Babban Tsauni, Gwagwalada, Nigeria.

This work assessed the activity concentrations of 238U(226Ra), 232Th, and 40K and their associated radiological risks due to exposure to soil and consumption of food crops in Babban Tsauni artisanal gold mine, Gwagwalada, Nigeria, using the gamma spectrometry technique. The mean activity concentrations of 226Ra, 232Th, and 40K in the mine soil were 60.2±9.9, 161.4±16.2, and 664.6±138.2, while they were 46.4±4.9, 79.9±39.3, 266.4±185.4 for tubers and 46.9±15.7, 100.5±35.8, 311.4±132.7 (Bq/kg) for grains, respectively. The results reveal that the activity concentrations of radionuclides in all samples exceeded the recommended values set by United Nations Scientific Committee on the Effects of Atomic Radiation (33, 45, and 420 Bq/kg) except 40K, which fell within the acceptable limit in all food crop sample types. Estimated results for radiological hazard parameters, radium equivalent, annual effective dose due to ingestion, and excess life cancer risk were within safe limits, while the annual effective dose due to external gamma radiation in soil and annual gonadal equivalent dose were significantly high in all investigated samples; these call for constant radiological monitoring.

Searching accretion-enhanced dark matter annihilation signals in the Galactic Centre

This study reanalyzes the detection prospects of dark matter (DM) annihilation signals in the Galactic Center, focusing on velocity-dependent dynamics within a spike density near the supermassive black hole (Sgr A⋆). We investigate three annihilation processes — p-wave, resonance, and forbidden annihilation — under semi-relativistic velocities, leveraging gamma-ray data from Fermi and DAMPE telescopes. Our analysis integrates a fermionic DM model with an electroweak axion-like particle (ALP) portal, exploring annihilation into two or four photons. Employing a comprehensive six-dimensional integration, we precisely calculate DM-induced gamma-ray fluxes near Sgr A⋆, incorporating velocity and positional dependencies in the annihilation cross-section and photon yield spectra. Our findings highlight scenarios of resonance and forbidden annihilation, where the larger ALP-DM-DM coupling constant Caχχ can affect spike density, potentially yielding detectable gamma-ray line spectra within Fermi and DAMPE energy resolution. We set upper limits for Caχχ across these scenarios, offering insights into the detectability and spectral characteristics of DM annihilation signals from the Galactic Center.

Intrinsic scintillation performance & europium concentration effects in RbSr2I5 and RbSr2Br5 scintillators

Scintillators play crucial roles in homeland security applications like gamma ray spectroscopy and high energy X-ray radiography. For promising new scintillators, fine-tuning the luminescent dopant concentration is one avenue to further improve their performance and tailor their properties. In this work, the effects of europium dopant concentrations on the crystal growth, luminescence and scintillation properties of RbSr2Br5 and RbSr2I5 crystals was investigated. Nine transparent 7 mm diameter single crystals were grown via the Vertical Bridgman method. The optical band gap of RbSr2Br5 was 5.9 eV and that of RbSr2I5 was 4.7 eV. High scintillation performance was achieved with a relatively low europium concentration of 1 mol%. For both RbSr2Br5:Eu and RbSr2I5:Eu crystals, light yield of 60–90,000 ph/MeV, energy resolution 2.8–4.0 % at 662 keV, and X-ray afterglow 0.79–1.5 % at 2 ms were obtained.

Radionuclides distribution in soils and radon level assessment in dwellings of Mungo and Nkam Divisions, Cameroon.

Radionuclide and radon levels have been investigated in soil samples and residential environments within the Mungo and Nkam Divisions of the Littoral Region. These analyses employed gamma spectrometry facilitated by a NaI (Tl) detector for soil samples, yielding average activity concentrations of 226Ra, 232Th, and 40K at 23.8, 72, and 105Bqkg-1, respectively. Various radiological parameters were calculated to evaluate radiological hazards. Additionally, the indoor radon concentrations were quantified utilizing the CR-39 solid-state nuclear track detector (Radtrack), revealing an average concentration of 25Bqm-3 and an associated inhalation dose of 0.66mSv y-1. Risk assessments for lung cancer attributable to indoor radon exposure incorporated models such as the Harley model. An observed moderate correlation between indoor radon levels and external 226Ra concentrations implies that radon intrusion indoors might be substantially influenced by the 226Ra present in the subjacent soil, considering the construction of residential structures directly upon these terrains.

Radiation Monitoring for Volatilized Zinc Contamination Using Gamma-Ray Imaging and Spectroscopy

Abstract Gamma-ray imaging is a tool that has grown in importance in the applications of non-destructive assay (NDA) for radioactive survey and analysis of nuclear facilities. Imaging techniques have shown great promise in providing valuable information involving radioactive waste management and contamination prevention. For the application studied in this work, 65Zn has been identified as a radioactive contaminant during tritium extraction. Due to the volatile nature of 65Zn under the pressure and temperature changes during extraction operations, 65Zn can easily travel through components of the extraction system as vapor, making it difficult to trap. Previous research involving the development of a filtration system showed that the 65Zn can be trapped, mitigating product contamination. However, during the extraction process, direct analysis of the equipment to confirm that zinc contamination is trapped in the filter and has not spread to other components is impractical. In this situation, the need to assay the location of the contamination with little-to-no interference with operations is vital. In this work, we demonstrate the use of a commercialized 3D position-sensitive CdZnTe (CZT) gamma-ray imaging spectrometer to provide analysis of the 65Zn contamination. Onsite measurements during an extraction process are studied to assess the location and migration of the 65Zn. The results obtained from real-time glovebox monitoring demonstrate the feasibility of gamma-ray imaging for localizing the contamination and providing a preliminary qualitative assessment that is intended to be used in future work quantifying the contamination build-up and activity over time.

Radionuclides determination by alpha (210Po, 228,230,232Th) and gamma (226,228Ra, 137Cs, 40K) spectrometry in children's food in Croatia with assessment of cumulative ingestion dose for infants

This work presents comprehensive results of alpha (210Po, 228,230,232Th) and gamma (40K, 226,228Ra, 137Cs) radioactivity measurements in selected food typically consumed by infants (< 1 year) in Croatia. The samples of readily available infant’s food on Croatian market were categorized according to the growth of an infant, from their first nourishment: adapted powdered milk, to their first solid food. The aim was to estimate ingestion doses and the potential radiological risks for infants. In addition to anthropogenic radionuclides, the study focused on naturally occurring radionuclides often underrepresented in similar researches. 40K prevails in activity concentrations in all types of samples. 210Po was determined in all sample types reaching up to 502 mBq/kg. Maximum values of activity concentrations for 228Ra, 226Ra and Th isotopes were 230 mBq/kg, 1.29 Bq/kg and 52 mBq/kg, respectively. The most important contributors to the annual effective dose were 40K, 226Ra, 210Po and 228Ra contributing with 29 % 28 %, 24 % and 17 %, respectively. Th isotopes contributed with less than 2 %, while the contribution of anthropogenic radionuclides 137Cs and 90Sr were negligible (less than 1 %). Cumulative effective ingestion dose for infants was calculated to be 0.69 mSv/y, which is below the recommended limiting dose of 1 mSv/y. Largest proportion comes from the intake of fruit (33 %), followed by the intake of vegetables 19 %) and cereals 19 %). Although national radioactivity monitoring programs usually focus on anthropogenic radionuclides, this study highlights that naturally occurring radionuclides are dominant contributors to the cumulative effective ingestion dose in infants. Overall, the estimated cumulative effective ingestion dose for infants from consuming food available in Croatia is below recommended dose limits and therefore does not present a radiological concern.

Patterns distribution, concentrations and sources of radioactive elements from black sand in the Red Sea coast, Egypt

In Egypt, the distribution of black sand in various coastal regions has been readily apparent by thorough research. Unfortunately, these investigations did not measure radioactivity in black sand, particularly in the vicinity of the Red Sea. Gamma-ray spectroscopy was used to detect the naturally occurring radioactivity from 238U, 232Th, 40K, and 226Ra in black sand samples from eight locations along the Red Sea coast: Ras Elbehar, Gemsa, Hurghada Elahiaa, Hurghada Titanic, Safaga, Qusier Elsharm Alqbly, Gabal Alrosass, and Marsa Alam. The resultant data were interpolated to represent the spatial distribution. Additionally, the potential rocks sources of radionuclides were geologically mapped to elucidate the relationship between rock components and radioactivity. The results showed that 226Ra, 232Th and238U were higher at samples collected from Ras Elbehar, Hurghada Elahiaa and Hurghada Titanic compared to the other sites. On the other hand, 40K showed the lowest mean value (75.3 ± 3.8 Bq/kg) in Hurghada Titanic samples, while it peaked (563 ± 28 Bq/kg) in Qusier Elsharm Alqbly samples. The interpolated results show notable differences in radioactive amounts between the north and south, which are indicative of several environmental conditions and human activities. Alkaline syenite, syenogranite, older granites (tonalite and granodiorite), and minor acidic volcanic/metavolcanic rocks make up the upstream area of the basin area draining into, for example, the Ras Elbehar locality (highest activity concentrations for 238U (1596 ± 80 Bq/kg) and 226Ra (886 ± 44 Bq/kg)), while alkali-feldspar granite, schist, and shale rocks make up the mid-stream area. The findings provide a basis for scientific forecasting on the impact of synthetic or naturally occurring radioactive isotopes introduced into aquatic environments.

Estimation of soil-to-plant transfer factor across six local government areas of Kwara state, Nigeria

Transfer factors (TFs) are among the necessary parameter values for the mathematical modeling of radiological pollution's environmental impact. In this study, 238U, 232Th, and 40K activity concentrations and TFs were estimated in 48 soil and plant samples through gamma-ray spectrometry NaI(Tl) in six selected areas of local governments in Kwara State, Nigeria. The findings revealed that the soil and plant samples' 238U and 232Th activity concentrations were within the radiological safety limits. The TFs of soil to plant fell within the worldwide ranges. A set of statistical tests were applied to verify the validity of the data, such as descriptive analysis, the analysis of variance (ANOVA) test, frequency distribution, and Spearman's correlation. The study reveals a skewed distribution in data. Spearman correlation coefficient analysis indicates a moderately negative correlation between 238U, 232Th, and 40K's activity concentrations and their respective TFs (TFU, TFTh, and TFK). In terms of future research in the study area, it is hoped that the data from this study will contribute to improved scientific knowledge.

Determination of a standard efficiency using the ISOCS uncertainty estimator for calculating the activity concentration of 226Ra, 232Th, and 40K in concrete

The Activity Concentration Index (ACI) requires knowledge of the activity concentrations of 226Ra, 232Th (212Pb), and 40K, typically determined through gamma spectrometry. The inherent heterogeneity of concrete makes the determination of gamma counting efficiency a complex problem. For this reason, this study employed the ISOCS Uncertainty Estimator (IUE), which allows for probabilistic calculations based on variations in parameters affecting counting efficiency, such as dimensions, density, and composition. The IUE enabled the estimation of a representative efficiency for a standard concrete configuration applicable to concrete specimens and samples from existing structures. The results obtained with the proposed efficiency for natural radionuclides of the uranium and thorium series, along with 40K, compared to the classical material grinding method, showed no significant differences in the mean and variance. The maximum differences observed when applying regression analysis were less than 16 %, thus validating the representative efficiency obtained with the IUE.

Experimental measurements and theoretical calculations of excitation functions of 103Rh(α,xn)106m,105g,104gAg and 103Rh(α,αxn)101m,102gRh reactions up to 40 MeV

Activation cross sections of 103Rh(α,xn)106m,105g,104gAg and 103Rh(α,αxn)101m,102gRh radionuclides were measured at energies ranging from their respective threshold energies up to 40 MeV. Standard stacked foil activation technique was employed for irradiation. Residual activity was assayed using high-resolution gamma-ray spectrometry. Excitation functions were also theoretically calculated using TALYS nuclear reaction model to reproduce the experimental cross section data. The present data are compared with the available literature data, TENDL-2023 data using default values as well as the theoretical data calculated by TALYS-1.96. The shape and amplitude of the experimentally obtained excitation functions were well reproduced theoretically for all the studied radionuclides except for 105gAg, for which magnitude of the cross sections was not reproduced. The integral yields were also deduced using the measured cross sections and the stopping power of natural Rh from 40 MeV down to their threshold energies for these radionuclides, and compared with the experimental yield data available in the literature.

Low-level ionizing radiation-induced DNA responses in the Asian green mussel Perna viridis

Cesium-137 (Cs-137) is a radioactive isotope present in marine environments due to the operation of nuclear power plants and weapons testing. Radiocesium poses a potential risk to marine life due to its long half-life and bioaccumulation. This study evaluated the genotoxicity of low doses of Cs-137 in the Asian green mussel Perna viridis, a sentinel species for marine pollution monitoring, by performing the comet assay and micronucleus test on hemolymph samples. Genotoxicity was assessed after exposing mussels to Cs-137 at dose rates of 0, 5, 10, and 15 μGy/h for 48 h. Cs-137's organ-specific distribution was also determined using HPGe gamma spectrometry. Even at low radiation doses, Cs-137 was found to exert genotoxic effects. Significant increases in DNA strand breaks (%Tail DNA) and micronucleus formation (MNF) were observed at all tested dose rates compared with the levels in controls, with dose-dependent responses. Cs-137 predominantly accumulated in the soft tissues, specifically the gills and digestive gland. The findings support the recommended safety level of 10 μGy/h for aquatic organisms, suggesting its appropriateness as a fundamental criterion for developing the national marine water quality standard for Cs-137 in Thailand.

Use GIS Technical to map Natural Radioactivity in Soil Samples for the University of Kufa, Iraq

GIS "Geographic Information System" technology was used to map the specific activity (S.A.) of primordial radionuclides 238U, 232Th, and 40K in selected soil samples for twelve locations at the University of Kufa, Iraq. S.A. values were determined using gamma spectrometry type NaI(Tl) with volume “3×3”. Also, the values of radiological parameters such as Raeq“radium equivalent”, Hex “external hazard index”, Iγr “representative gamma risk index”, Dr “Absorbed Dose rate, AEDEoutdoor “Annual Effective Dose Equivalent in outdoor”, and ELCR “Excess Lifetime Cancer Risk” were determined. The average value of S.A. for 238U, 232Th, and 40K was 10.35±0.9 Bq/kg, 7.31±1.8 Bq/kg, and 256.19±55.7 Bq/kg, respectively. While, the average values of Raeq (Bq/kg), Hex, Iγr, Dr (nGy/h), AEDEoutdoor (mSv/y), and ELCR were 48.00, 0.130, 0.373, 23.70, 0.029, and 0.102×10-3, respectively. The results of S.A. and each radiological parameter of the study area locations were low according to acceptable level reports by UNSCEAR, ICRP, and OCDE. Therefore, it can be concluded that the soil samples of the University of Kufa were safe.

Gamma Spectroscopy of Nanometer Layers of Gadolinium in the Mode of Resonantly Enhanced Standing Neutron Waves

Gamma Spectroscopy of Nanometer Layers of Gadolinium in the Mode of Resonantly Enhanced Standing Neutron Waves