Gamma-ray Spectrometer Research Articles

Effective doses received by the gastrointestinal tract compartments of adults due to food intake in Egypt

226Ra, 232Th, and 40K levels in various foods frequently consumed by Egyptians were determined using a gamma-ray spectrometer based on the germanium detector (HPGe). Activity concentrations of 226Ra, 232Th, and 40K were in the range of < 0.10 to 0.79 ± 0.07, < 0.09 to 0.42 ± 0.04, and < 1.96 to 89.73 ± 2.96 Bq/kg, respectively. The gastrointestinal tract (GIT) model was employed to estimate the effective doses received by the different parts of the adult’s gastrointestinal tract, i.e., stomach (ST), small intestine (SI), upper large intestine (ULI), and lower large intestine (LLI), due to the ingestion of the analyzed foods. This estimation was based on mathematical calculations of the energy absorbed by organs due to transformations of ingested radionuclides. The effective doses (μSv/y) received by each compartment were 8.86 (ST), 8.76 (SI), 66.90 (ULI), and 176.76 (LLI). The results do not exceed the safe thresholds set by global organizations UNSCEAR and WHO, 290 and 250–400 μSv/y, respectively. Therefore, radionuclide intakes due to investigated food consumption do not pose any significant radiological impact.

Assessment of radioactivity in soil samples from Wolaita Sodo town, Ethiopia: implications for environmental and public health.

This study assesses the activity concentrations of the radionuclides 238U, 232Th, and 40K in soil samples collected from Wolaita Sodo town, located in the Southern Nations, Nationalities, and Peoples' (SNNP) Region, Ethiopia. A gamma-ray spectrometer equipped with a NaI(Tl) detector was used for the measurements. The concentrations of 238U, 232Th, and 40K varied from 3.25±1.5 to 13.84±2.2Bq.kg-1, 0.4±0.9 to 85.12±3.4Bq.kg-1, and 34.43±2.7 to 748.07±5.9Bq.kg-1, respectively. The average activity concentrations were 7.83±1.9Bq.kg-1, 40.74±2.7Bq.kg-1, and 161.63±3.9Bq.kg-1 for 238U, 232Th, and 40K, respectively. The average radium equivalent activity was 192.25Bq.kg-1, well below the recommended safety limit of 370Bq.kg-1. The average gamma dose rate, and annual effective dose rate were 35.68 nGy.h-1, and 0.18mSv.y-1, respectively. The internal and external indexes are below the recommended limit set by UNSCEAR and ICRP. However, the estimated excess lifetime cancer risk and indoor radon concentrations are slightly higher. Despite this, the overall radiological impact on the environment and public health in the study area remains negligible. This study provides valuable baseline data for radiation protection and informs urban and environmental policy in the region.

A gamma-ray spectrometer based on MAPD-3NM-2 and LaBr3(ce) and LSO scintillators for hydrogen detection on planetary surfaces

The presented work is dedicated to the detection of hydrogen, using detectors based on a MAPD (Micropixel Avalanche Photodiode) array based on new MAPD-3NM-2 type photodiodes and two different scintillators (LaBr3(Ce) and LSO(Ce)). The physical parameters of the MAPD photodiode used in the study and the intrinsic background of the scintillators were investigated. For the 2.223 MeV energy gamma-ray indicating the presence of hydrogen, the energy resolution was 6.89% with the MAPD array and LSO scintillator-based detector, and the number of events corresponding to this energy was 4817. With the MAPD array and LaBr3(Ce) scintillator, the energy resolution for the 2.223 MeV gamma-ray was 3.55%, and the number of events corresponding to this energy was 3868. The LSO scintillator-based detector allowed for the detection of 24.5% more 2.223 MeV energy gamma-rays compared to the LaBr3(Ce) scintillator. For the 2.223 MeV gamma-ray associated with hydrogen, the energy resolution with the LaBr3(Ce) scintillator was 48.5% better than with the LSO scintillator. The lower energy resolution compared to the LSO is due to the higher light output of LaBr3(Ce). The obtained results experimentally demonstrate that it is possible to obtain information about the presence of hydrogen in the target using both detectors.

The Surface Heat Flow of Mars at the Noachian–Hesperian Boundary

The time period around the Noachian–Hesperian boundary, 3.7 billionyears ago, was an epoch when great geodynamical and environmental changes occurred on Mars. Currently available remote sensing data are crucial for understanding the Martian heat loss pattern and its global thermal state in this transitional period. We here derive surface heat flows in specific locations based on the estimations of the depth of five large thrust faults in order to constrain both surface and mantle heat flows. Then, we use heat-producing element (HPE) abundances mapped from orbital measurements by the Gamma-Ray Spectrometer (GRS) onboard the Mars Odyssey 2001 spacecraft and geographical crustal thickness variations to produce a global model for the surface heat flow. The heat loss contribution of large mantle plumes beneath the Tharsis and Elysium magmatic provinces is also considered in our final model. We thus obtain a map of the heat flow variation across the Martian surface at the Noachian–Hesperian boundary. Our model also predicts an average heat flow between 32 and 50 mW m−2, which implies that the heat loss of Mars at that time was lower than the total radioactive heat production of the planet, which has profound implications for the thermal history of Mars.

Assessment of Radiological Safety of Ceramic Tiles Commonly Used in Polish Buildings.

The concentration of natural radionuclides 226Ra, 232Th and 40K in ceramic tiles manufactured in Poland is presented in this paper. The concentration of natural radioactive isotopes in the tested samples was determined using a low-level digital gamma ray spectrometer equipped with an HPGe semiconductor detector. The mean concentrations of 226Ra, 232Th and 40K in the analyzed samples were found to be 48 ± 3 Bq∙kg-1, 49 ± 3 Bq∙kg-1 and 476 ± 23 Bq∙kg-1, respectively. The world mean concentrations of these radionuclides (50 Bq·kg-1, 50 Bq·kg-1 and 500 Bq·kg-1, respectively) were not exceeded. Furthermore, in order to ascertain the level of gamma radiation exposure, fundamental radiation protection parameters were established: radioactivity concentration indicator/gamma ray indicator (Iγ), indoor dose rate (Din) and annual indoor effective dose (Ein). In the case of the investigated ceramic tiles, it was established that the parameters were not higher than the limit values, except the indoor gamma radiation dose rate which was found to be 1.5 times higher than the world average. Therefore, the findings of this study indicate that the utilization of the examined ceramic tiles in constructions should be approached with a degree of caution.

Ground-Based Gamma-Ray Spectrometer Application on Drone-Borne: Suitability and Height Attenuation

Rapid development in the use of unmanned aerial vehicles (UAVs) in many applications, such as topographic mapping, agricultural management, marine monitoring, and others, has also brought the radiometric mapping application to this drone-borne application. Before the application, several corrections are performed to the data, including stripping corrections obtained from calibration results and height attenuation corrections. This study aims to determine the effectiveness and the height attenuation of the ground-based spectrometer attached to the drone. The method is carried out to determine the optimal altitude and conduct direct testing in the field of a small detector of 0.1 l of RS-125 gamma-ray spectrometer using drone-borne radiometric applications. In ideal conditions without obstacles in the flying path, 15 m is considered the ideal height, proportional to the detector size. Based on the results of field measurements at a drone height of 24 m, the comparison of drone and ground data is acceptable for dose rate, thorium, and potassium concentration with Pearson correlation of 0.67, 0.49, and 0.45, respectively. The drone measurement result is less acceptable for uranium data, with a Pearson correlation of 0.05 to the ground measurement. In conclusion, the RS-125 gamma-ray spectrometer is generally suitable for drone-borne radiometric applications.

Addressing challenges of high-energy atmospheric physics in Europe

Thunderstorm-induced gamma radiation phenomena, including terrestrial gamma-ray flashes (TGFs) and thunderstorm ground enhancements (TGEs), have emerged as key areas in high-energy atmospheric physics due to their potential radiation effects in the atmosphere. The interaction of high-energy photons and relativistic electrons with the air can lead to complex radiation processes, influencing local and global atmospheric radiation fields. Developing specialized gamma-ray spectrometers is essential in regions like Central Europe, where environmental and technical challenges differ from those in Japan or Asian high-altitude areas. This paper describes the necessary adaptations for gamma spectrometry in such environments, focusing on sensitivity to high-energy photon detection, rapid event timing, and integration into distributed measurement networks. Results from field deployments at high-altitude observatories and thunderstorm chase events provide new insights into the radiation dynamics of TGEs, contributing to a better understanding of radiation effects in the air during thunderstorms in continental climates.

Studies of GAGG:Ce scintillators for space missions dedicated to Terrestrial Gamma-Ray Flashes and Gamma-Ray Bursts observation

Fast Gamma ray Spectrometer (FGS) is an on-going detector development for the observation of transient gamma ray events such as Terrestrial Gamma ray Flashes (TGFs) produced in Earth’s thunderstorms and Gamma Ray Bursts (GRBs) produced in the far Universe. In this work, we compare different Cerium-doped Gadolinium Aluminium Gallium Garnet (GAGG:Ce) scintillators, associated with Silicon Photo-Multipliers (SiPMs), quantifying their performances at atmospheric pressure and under vacuum, with different surface conditions. We also study their afterglow following proton irradiation, similar to what will be observed in space environment. Our measurements with GAGG:Ce scintillators after proton irradiation confirm that GAGG:Ce can be used in space.

Comparison between carrier transport property and crystal quality of TlBr semiconductors

Thallium bromide (TlBr) semiconductor detectors are being developed as promising candidates for high-detection-efficiency, high-energy-resolution, and room-temperature gamma-ray spectrometers. This study presents methods for evaluating TlBr crystal quality and carrier transport characteristics using neutron Bragg-dip imaging and the time-of-flight method for pulsed-laser-induced carriers, respectively. Neutron Bragg-dip imaging effectively determines the crystal orientation distribution, revealing crystal imperfections and grain boundaries. Time-of-flight measurements provide a spatial distribution of carrier mobility. In this study, two samples obtained from both the upstream and downstream region in the crystal ingot were evaluated. Although both samples show similar crystal quality, the upstream sample showed high carrier mobility across all areas, whereas the downstream sample exhibits low mobility in some areas. These findings suggest that, at least within the range of carrier mobility currently obtained, the effect of crystal integrity on carrier mobility is less significant than that of impurities. In conclusion, combining neutron Bragg-dip imaging with carrier mobility measurements offers a comprehensive approach to evaluating and improving TlBr detectors.

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.

Comparison of two gamma-ray datasets measured with different methods and assessment of their performance to predict soil properties

ABSTRACT Terrain mobility is directly dependent on soil properties, i.e. stoniness, soil particle size and peat depth. Gamma-ray spectrometry has been widely used in soil mapping as gamma-rays can penetrate up to 50 cm of soil. The method has proven to be effective in gathering information on various soil properties, such as clay and silt content, organic carbon content, soil pH, and soil stoniness. The intensity of gamma radiation decreases with increasing soil moisture content, which is important when assessing the load-bearing capacity of forest terrain, which affects the quality and planning of mechanized wood harvesting. In this study, we compared two gamma-ray datasets that were acquired from the same plots but measured with different methods: airborne gamma-ray spectrometry and a handheld gamma-ray spectrometer. Regression analyses were used to examine whether the gamma-ray datasets have significant similarities. Linear discriminant analysis was then used to study the performance of the two gamma-ray datasets when predicting different soil properties (stoniness index classes (SIC), soil depth, and peat depth). Our correlation analysis produced R2 values of 0.18–0.29 and root mean square error (RMSE%) values of 0.48–0.55. Prediction of SIC was 67.1% accurate with ground gamma and 45.9% accurate with air gamma. For soil depth predictions, the accuracies were 64.7–70.0% for ground gamma and 61.7–63.5% for air gamma. Our findings showed that ground gamma-ray spectrometry is better at predicting soil properties than air gamma-ray spectrometry.

Measurement of radioactivity and hazard index of Gonadal dose in selected Cement samples in Iraq.

Given the importance of cement as a basic material in construction, this study was undertaken to evaluate the level of radioactivity in a selected group of cement samples most used in construction to determine whether they are safe for human health. In this investigative study, nine samples of cement, both domestic and imported, that are often used in construction projects in Iraq were gathered. A NaI (Tl) gamma-ray spectrometer (3"x3") was used to measure the radioactivity in the samples. The average specific activity levels in the tested cement samples were 11.373±0.522, 5.795 ± 0.230, and 179.123±2.207 Bq/Kg, respectively. Also calculated was the average of the radium, which was equivalent to 33.449±1.022 Bq/kg. As for the risk indicators, the internal risk coefficient was 0.121±0.004 and external risk coefficient was 0.090 ±0.002. While studying the radiation doses, the values of effective annual internal dose was 0.080 mSv/y, external dose rates were 0.020 mSv/y, absorbed dose ratio was 16.321±0.476 nGy/h, and gamma index was 0.253±0.007. In the end, and depending on what was studied from various variables, with an average of 115.59 Sv/y, the annual gonadal equivalent dose risk (AGED) was calculated. The world average values were used to compare all the results. Finally, it was discovered that the radiation parameter levels of none of the samples had a detrimental effect on human health.

Radioactivity Levels, Spatial Distribution, and Radiological Risk Assessment of 226Ra, 228Ra, 40K, and 3H in Water Samples from Dhaka City and Savar, Bangladesh.

This investigation was conducted to measure the radioactivity levels of 226Ra, 228Ra, 40K, and 3H in the 13 most popular branded bottled mineral water (BMW), 12 groundwater sources consumed in Dhaka city, Bangladesh, and six water samples collected from the nuclear object site at Savar, adjacent to Dhaka. The activity of 3H was measured by using a liquid scintillation counter, and a gamma-ray spectrometer with an HPGe detector was used to measure the activity of other radionuclides. The average activity concentrations of 226Ra, 228Ra, 40K, and 3H in BMW samples and groundwater were found to be 1.81 ± 0.43, 1.74 ± 0.40, 43.08 ± 6.23, 2.42 ± 0.16, and 1.61 ± 0.51, 1.69 ± 0.45, 57.42 ± 3.16, and 3.02 ± 0.19 Bq/L, respectively. In addition, the activity concentrations of identified radionuclides in water samples collected from Savar were found to be 1.59 ± 0.43, 1.53 ± 0.50, 99.83 ± 3.05, and 2.95 ± 0.20 Bq/L. With the exception of 3H, the activity concentration and the annual effective dose of 40K, 226Ra, and 228Ra surpassed the acceptable thresholds of the WHO. The combined activity of radium (Rac) also exceeds the USEPA recommended maximum permissible limit of 0.185 Bq/L. The excess lifetime cancer risk results were below the permissible threshold of 10-3 for radiological risks. Groundwater was subjected to an AAS analysis for common metals (Na, Mg, and Ca) and heavy metals (Fe, Cr, Cu, and Pb). The results showed that the heavy metals were below the detection limit. Radionuclide contents in groundwater of Dhaka city were mapped spatially using a GIS technique. Statistical analyses such as one-way ANOVA, one sample t test, and Pearson's correlation analysis were also performed. According to Pearson's correlation analysis, 228Ra is mostly responsible for radiation risk in BMW and groundwater.

First results of a newly-built hard-X-ray/soft-Gamma spectrometer imaging system: on the aspect of plasma disruptions

Abstract A new Hard X-ray and soft gamma-ray spectrometer imaging System (HXS) has been built for the 2-Dimensional measurements of plasma emitted photons on the Experimental Advanced Superconducting Tokamak (EAST). The system uses a 2-D Cadmium Zinc Telluride (CZT) detector and an integrated electronics, which is as a whole shielded by a tungsten box with a pinhole and is tangential to the toroidal field. Three classes of typical energy spectra have been summarized in differently experimental scenarios over the past campaigns. After performing tomography calculations, the local emissivity contours have been obtained in different energy ranges which obviously show the asymmetry on the plasma cross section. The spatial perturbation structure is similar to the magnetohydrodynamics (MHD) modes with low mode numbers. In particular, the runaway island found by an infrared camera [R. Jaspers et al, Phys. Rev. Lett. 72, 4093 (1994)] is also measured by the HXS. There exists a reversal population on the energy spectra in both slide-away and strong neutral beam injection (NBI) shots. It is consistently observed that the count rate is increased in the low energy range before the plasma disruptions. Calculations in phase space indicate that the accelerated momentum flux can be deflected back to the low energy region by the large pitch-angle scattering. In the post-disruption phase the plasma current is not replaced by runaway electrons due to tearing modes or transiently bursting instabilities. This paper constructs the basics for the proper use of HXS for Hard X-ray and Soft Gamma-ray measurements in future investigations of plasma disruptions.

Radon exhalation and emanation assessments in the Transdanubian Central Mountain in Hungary

ObjectiveTo determine the radium-226 activity concentration, the massic radon exhalation rate and emanation factor of 55 soil samples from the Central Transdanubian Mountains in Hungary as well as possible radon exhalation hotspots in the sampling area were determined. Further indoor measurements are planned to investigate the possible exposure to radon of the inhabitants. MethodsThe radium-226 activity concentration measurements were carried out with a semiconductor HPGe gamma-ray spectrometer. The massic radon exhalation rate and emanation factor were determined by measuring the radon activity concentrations using the accumulation method with a system developed by our department based on an AlphaGUARD DF2000 portable radon monitor. ResultsThe activity concentrations of radium-226 were between (11.4 ​± ​2.5) and (118.2 ​± ​3.0) Bq/kg, while their average was 39.51 Bq/kg. The massic radon exhalation rates were between (1.02 ​± ​3.64) mBq⋅kg−1⋅h−1 and (275.63 ​± ​4.05) mBq⋅kg−1⋅h−1, while their average was 39.51 mBq⋅kg−1⋅h−1. Finally, the emanation factors were between (0.01 ​± ​0.04) and (0.80 ​± ​0.03) with an average of 0.30. ConclusionsIn our study, the results recorded from the bedrock at the sampling sites were analyzed. 9 samples were taken from sites comprised of limestone bedrock, moreover, the average radium-226 activity concentrations and massic radon exhalation rates at these sampling sites were higher than average. It was also concluded that although no regional correlation can be seen from the results, a possible smaller radon hotspot was identified from our measurements where further sampling will be carried out.

Characterization of a typical urban soil in terms of natural radionuclide content. The case study of a university campus

A first comprehensive survey was carried out in a university campus in Italy in order to investigate in terms of natural elements an area where medium-high values of natural radiation are expected because of its peculiar geological features. The content of terrestrial radionuclides in 20 topsoil samples from the campus was determined with the aim to provide an important database of the soil characteristics.226Ra, 232Th, and 40K concentrations were analysed by High Purity Germanium (HPGe) gamma-ray spectrometer in order to determine the background levels of natural radionuclides characteristics of the original area. The mean concentrations of radionuclides in the investigated soil samples ranged from 58.95 ± 4.20 to 158.05 ± 19.95 Bq kg−1 for 226Ra, from 72.28 ± 7.61 to 146.00 ± 22.27 Bq kg−1 for 232Th and, for 40K, from 550.76 ± 33.24 to 1367.50 ± 18.73 Bq kg−1. The radiological hazard indices, including radium equivalent activity, external hazard index, annual effective dose, absorbed dose rate, lifetime excess cancer risk, were also evaluated and compared with global averages, revealing values above the worldwide ones. Finally, a spatial modelling methodology of the site-specific radionuclides levels as graphical tool for the monitoring of the potential land redevelopment of urban soils was proposed.

The GRB221009A gamma-ray burst as revealed by the gamma-ray spectrometer onboard the KPLO (Danuri)

The strongest gamma-ray burst (GRB) of the century, GRB20221009A, has been detected by the Korean Pathfinder Lunar Orbiter Gamma-ray Spectrometer (KGRS) instrument onboard the Korean Pathfinder Lunar Orbiter (KPLO). KGRS uses a LaBr3 detector to measure GRB counts with five energy bins in the energy range from 30 keV to 12 MeV. KGRS detected GRB221009A at a distance of 1.508 million kilometers from the Earth. The full duration of the main burst was recorded between 13:20 and 13:26 on October 9, 2022 with peak counts of over 1000 times background. The dead time of KGRS reached as high as 50%, and the intrinsic gamma-ray spectrum of LaBr3 was significantly altered.

Accessing the Characteristics of Nuclear Reactions: A Radioactive Decay and Half-Life Measurement Study

This study investigates the impact of external environmental factors, specifically electromagnetic fields and pressure variations, on the decay constants and half-lives of three radioactive isotopes: 60Co, 137Cs, and 226Ra. By conducting controlled laboratory experiments, the research aimed to quantify the extent to which these factors influence decay rates, challenging the traditional assumption of invariant half-lives. The isotopes were exposed to varying levels of electromagnetic fields (0-100 Gauss) and pressure (1-10 atm), with decay rates measured using high-resolution gamma-ray spectrometers. The results revealed that while 137Cs exhibited the most significant sensitivity, with a 13.04% increase in decay constant under extreme conditions, 60Co and 226Ra showed moderate and minimal changes, respectively. These findings have important implications for fields such as nuclear medicine, radiometric dating, and nuclear waste management, where precise knowledge of decay rates is crucial. The study contributes to a deeper understanding of nuclear decay processes and highlights the need for further research on the effects of other environmental factors, such as temperature and chemical composition, on radioactive decay.

A compact and portable gamma-ray spectrometer (GRASP) for inertial confinement fusion and basic science experiments.

A compact and portable gamma-ray spectrometer has been designed to diagnose different components of the inertial confinement fusion-relevant γ-ray spectrum with energies between ∼3.7-17.9MeV. The system is designed to be as compact as possible for convenient transportation and fielding in diagnostic ports on the OMEGA laser, the National Ignition Facility, and other photon-source facilities. The system consists of a conversion foil for Compton scattering in front of four magnetic spectrometer "arms," each covering a different energy range and constructed out of cylindrical permanent magnet Halbach arrays. Monte Carlo simulations have been used to optimize and assess the performance of the conversion foil, and COSY INFINITY ion-optical simulations have been used to optimize the spectrometer magnets. The performance of the design is assessed for a simulated direct-drive γ-ray spectrum. Spanning its total γ-ray energy bandwidth and using a 1.7mm thick boron conversion foil, the system's total energy resolution and efficiency are ∼15.8%-4.5% and 5.4 × 10-7-3.7 × 10-7e-/γ, respectively, with room for improvement. Spectral γ-ray measurements will provide guidance to the inertial confinement fusion program toward achieving high-energy gain relevant to inertial fusion energy and enable new measurement capabilities for basic discovery science.

Investigation of the Capabilities of a Xenon Gamma-Ray Spectrometer to Assess the Activity of an Isotope 60Co

Investigation of the Capabilities of a Xenon Gamma-Ray Spectrometer to Assess the Activity of an Isotope 60Co