This study presents the third consecutive assessment of ¹³⁷Cs activity concentrations in the same 50 moss (7 species) and lichen (2 species) sampling points in Ordu province, Türkiye, one of the most heavily contaminated areas following the Chernobyl accident. Samples were collected from exactly the same locations used in the 1997 and 2007 studies and analyzed by high‑resolution gamma spectrometry. In 2025, detectable ¹³⁷Cs was found in 14 of 30 moss sites (47%) and 3 of 20 lichen sites (15%). For samples below the minimum detectable activity (MDA), a value of MDA/2 (0.93 Bq kg⁻¹) was substituted for lichens, while moss samples below the MDA were excluded from regression. The ecological half‑life (Teco) for the 2007-2025 period was 4.38 ± 1.05 years for mosses and 4.18 ± 0.61 years for lichens. For mosses, this is nearly identical to the 1997-2007 mean (4.4 years), while for lichens it decreased from 5.6 to 4.18 years, suggesting a slight acceleration in environmental removal. All Teco values remain far shorter than the physical half‑life of ¹³⁷Cs (30 years), confirming that environmental removal processes dominate over radioactive decay. Residual ¹³⁷Cs is concentrated in higher‑altitude areas, reflecting the original deposition pattern and slower removal in cooler, more humid microenvironments. Nearly 39 years after the accident, the radiological risk posed by residual trace levels is negligible. This 28‑year dataset provides one of the longest continuous records of ¹³⁷Cs in epiphytic bioindicators and serves as a valuable baseline for future contamination events.

The increasing use of ionizing radiation in medical, industrial, and nuclear applications necessitates the development of advanced and environmentally friendly shielding materials. In this study, the gamma-ray shielding performance of BaO-modified magnesium borophosphate glasses with compositions xBaO-30MgO-10P2O5-(50-x)B2O3-10Na2O (x = 0-35 mol%) was theoretically investigated. The radiation attenuation properties were evaluated over a wide photon energy range (59.54-2000 keV) using the WinXCOM database and Monte Carlo simulations based on the EGS4 code. Key shielding parameters, including mass attenuation coefficient (mu/rho), half-value layer (HVL), mean free path (MFP), effective atomic number (Zeff), radiation protection efficiency (RPE), and gamma-ray kerma coefficients, were determined. The results indicate that increasing BaO content enhances the attenuation capability of the glass system, particularly in the low and medium photon energy regions, due to increased density and effective atomic number. A good agreement between WinXCOM and EGS4 results confirms the reliability of the applied theoretical approaches. These findings suggest that BaO-modified magnesium borophosphate glasses are promising candidates for radiation shielding applications.

Abstract True coincidence summing (TCS) effects in gamma-ray spectrometry introduce significant systematic uncertainties in activity determinations, particularly for radionuclides with complex decay schemes such as 214 Bi. This study presents a comprehensive Monte Carlo investigation of TCS correction factors (CFs) for seven major gamma-ray lines of 214 Bi. The primary contribution of this study is the systematic decoupling of detector geometry effects: nine distinct HPGe detector configurations were simulated with varying crystal dimensions, dead layers, and hole geometries, followed by an isolated analysis of crystal radius versus crystal length contributions for both point and extended source geometries. The decay scheme of 214 Bi was meticulously modeled using Nucleide 2000 data, incorporating all beta branches, gamma transitions, internal conversion coefficients, and cascade probabilities to ensure high-fidelity representation of the decay scheme. Results demonstrate that crystal radius exerts a substantially stronger influence on TCS CFs than crystal length, with point source values at 609.3 keV increasing by 18.2% across the radius range of 2.1–4.5 cm, compared to only 3.7% variation across the length range of 3–11 cm. Extended source geometries reduce TCS CFs by 5%–11% compared to point sources across all configurations, highlighting the mitigating effect of distributed sources. Energy-dependent behavior is also evident: the 609.3 keV line exhibits strong summing-in (CF > 1.3 for large detectors), while the 1377.7 keV line shows dominant summing-out (CF < 0.86). These findings provide gamma-ray spectrometrists with insight into the relative importance of detector dimensions for TCS effects, suggesting that crystal radius is the primary geometric parameter influencing coincidence summing corrections. The observed trends illustrate how TCS corrections vary with detector dimensions, offering spectrometrists a basis for understanding the relative sensitivity of these corrections to different geometric parameters.

This study presents a comprehensive assessment of natural radioactivity levels and associated radiological hazards in rock samples collected from Mastra and Hazine Ma & gbreve;ara mining sites in the G & uuml;m & uuml;& scedil;hane province, T & uuml;rkiye. The concentrations of primordial radionuclides (226Ra, 232Th, and 40K) were measured in samples of andesite, granite, and limestone using a High Purity Germanium (HPGe) detector. Complementary whole-rock geochemical analysis (XRF and ICP-MS) was conducted to understand the geochemical controls on radioactivity concentrations. The results reveal significant heterogeneity in activity concentrations both within and between the two sites. For 226Ra, the Hazine Ma & gbreve;ara site exhibited a wider range (2.44-22.57 Bq kg-1) with a higher maximum value compared to Mastra (2.65-13.96 Bq kg-1). Similarly, 232Th and 40K activity concentrations showed considerable variability, often linked to the presence of specific accessory minerals like zircon, monazite, and K-feldspar. Geochemical data indicated that element concentrations (K, U, Th) were generally lowest in limestone and highest in granite, showing a strong correlation with the measured activity concentration values. Radiological risk indices, including radium equivalent activity, absorbed dose rate, annual effective dose equivalent, and excess lifetime cancer risk, were calculated. While values remain below international public health safety limits, localized anomalies were identified. Multivariate statistical methods were used to determine the relationship between the 226Ra, 232Th, 40K, Raeq (Bq/kg), Ig, Hex, D (nGy/h), AEDE (mu Sv/y), AGDE (mu Sv/y), and ELCR (& times;10-5). The study concludes that despite these localized anomalies, both mining areas pose an overall minimum environmental radiation risk, underscoring the necessity for site-specific assessments to ensure safe resource utilization and radiation protection.

The radionuclide 152Eu presents a significant challenge in gamma-ray spectrometry due to its complex decay scheme and significant true coincidence summing (TCS) effects, especially in close-measurement geometries. This study presents a comprehensive investigation into TCS correction factors for the principal gamma-ray lines of 152Eu using tripartite methodology: a custom Monte Carlo (MC) simulation based on the EGS4 system, an established analytical method, and direct experimental measurements. The MC simulation explicitly models the complete decay process, including branching ratios, gamma emissions, internal conversion, and subsequent X-ray emissions for both decay branches (beta-minus to 152Gd and EC to 152Sm). Experimentally, correction factors were derived using a well-characterized point source measured at multiple distances with a coaxial HPGe detector. The analytical, method based on probabilistic analysis of the decay scheme, served as an examination. Results demonstrate that the analytical method underestimated the TCS correction factors, particularly for low-energy lines such as 121.78 keV, where it predicted a mere 0.78% correction compared to 25.5 and 23.5 % from MC and experiment, respectively. This discrepancy is attributed to the analytical method’s neglect of gamma-X ray coincidences and the internal conversion effects. In contrast, the MC simulation showed remarkable agreement with experimental results across all energies, validating its capability to accurately model the full complexity of TCS effects. The study concludes that while analytical methods offer rapid estimates, MC simulations, especially when experimentally validated, are essential for achieving metrological accuracy in the gamma-ray spectrometric analysis of complex radionuclides like 152Eu.

CsPbBr3 single-crystals were synthesized using a hydrobromic acid-based temperature-lowering method, and their structural and optical properties were confirmed by XRD, DSC, and UV-Vis analyses. A solubility curve was established to optimize growth conditions, enabling enlargement of the seeded crystals. The radiation detection potential of CsPbBr3 was evaluated using EGS4 Monte Carlo simulations across photon energies ranging from 10 keV to 1 MeV. Simulated full-energy peak efficiencies and resolution values were compared with conventional detectors (Si(Li), NaI, and HPGe) and with alternative perovskite derivatives (CH3NH3PbBr3, Cs4PbBr6, CsPb2Br5). CsPbBr3 exhibited efficiency scaling with detector volume and resolution behavior consistent with the statistical 1/root E dependence typical of direct-gap semiconductors. While HPGe maintained superior intrinsic resolution, CsPbBr3 offered promising room-temperature performance without cryogenic requirements. These results demonstrate that the temperature-lowering method provides a viable route to scalable CsPbBr3 single-crystals and confirm their potential as cost-effective, high-Z semiconductor detectors for X- and gamma-ray applications. The findings establish a foundation for the further optimization of perovskite-based radiation detection technologies.

Accurate assessment of external radiation dose rates from 137 Cs is essential for evaluating radiological risk in environmental and occupational settings. This study refines dose conversion coefficient calculations by incorporating depth-dependent soil density and addressing limitations in conventional methods that assume constant soil density. We calculated dose conversion coefficients for 137 Cs in soil, considering both exponential and Gaussian distributions of activity concentration. Using two models, one with constant density and another with variable density as a function of depth, we compared dose rates to quantify the effect of soil density variations. Results indicate that dose rates are consistently higher when depth-dependent density is applied. The effect is more pronounced when 137 Cs activity is distributed over larger depths (i.e., greater relaxation lengths) or when broader Gaussian distributions are considered. This suggests that assuming constant soil density may lead to underestimations of dose rates, especially in heterogeneous or compacted soils. Our findings emphasize the importance of accounting for density variability in dose calculations to enhance radiological risk assessments for areas contaminated with 137 Cs.

High Purity Germanium (HPGe) detectors are essential instruments in gamma-ray spectrometry, offering high sensitivity and exceptional energy resolution. The full-energy-peak (FEP) efficiency is a critical parameter that influences the accuracy of activity concentration measurements of radionuclides. This study examines the FEP efficiency of a coaxial HPGe detector, focusing on variations in crystal length, crystal radius, and crystal hole dimensions. For varying crystal lengths, the efficiency values show negligible differences at low energy (50 keV) but significant increases at higher energies, indicating that longer crystal lengths enhance efficiency. Similarly, the efficiency increases with larger crystal radii across all energy levels suggesting substantial efficiency gains even at low energies. However, variations in crystal hole radius and depth, exhibit minimal impact on FEP efficiency across all tested energy levels. These findings highlight that optimizing crystal length and radius is more crucial for changing detector efficiency compared to modifying hole dimensions, providing valuable insights for optimising Monte Carlo models and detector design.

This study introduces a novel, physics-informed, and calibration-friendly hybrid machine learning framework for the rapid and accurate prediction of the Full Energy Peak (FEP) efficiency in High-Purity Germanium (HPGe) detectors. To overcome the limitations of conventional “black-box” models, our two-stage approach first represents the FEP efficiency curve using a physically interpretable logarithmic polynomial. Subsequently, machine learning models were trained to predict the polynomial coefficients directly from the detector geometric parameters using a comprehensive dataset generated via Monte Carlo simulations. Among the various algorithms tested, the Generalized Linear Model yielded superior performance, achieving R2 values of 0.975–0.992 for the coefficients. While raw model predictions showed expected variability, a key feature of our framework (a single-point calibration protocol using one known efficiency value) dramatically improved accuracy, reducing the mean absolute percentage error by an average of 80

In this paper, Grover's quantum search algorithm is analyzed using a classical computer by calculating the amplitudes and the probabilities of finding a single marked state for n=5, 10, 15, 20, 25, and 27 qubit states. The calculations show that the marked state can be found in O(root N) iterations, where N = 2(n) is the number of items. The possibility of improving Grover's search algorithm to find a single item in N search elements is discussed by calculating the amplitudes and hence the probabilities of finding a single marked state for n=5, 10, 15, 20, 25, 30, 35, 40, 45, and 50 qubit states. The calculations showed that the marked state could be found with sufficiently high probability in (ln(N)) iterations. This is quite a remarkable speed-up that can be achieved to find a single marked element in an unsorted N search element.

The geometrical parameters which affect the suppression factor for an HPGe (High Purity Germanium)-NaI Compton suppression spectrometer were studied by a Monte Carlo simulation with the EGS4 system. The spectrums were crated for 5 energy values ranging from 200 keV to 2 MeV. Compton suppression factors (CSFs), the parameters characterizing the system performance, were calculated for different HPGe crystal parameters. It was observed that to obtain better Compton suppressed factors, a laboratory must choose as small HPGe crystal as possible for energy values up to 400 keV. However, for higher energies up to 2 MeV, larger HPGe crystals provide better Compton suppression systems. These findings suggest that the choice of HPGe crystal size can significantly impact the performance of a Compton suppression spectrometer and should be carefully considered in its design and optimization.

As well known, High Purity Germanium (HPGe) detectors have a wide range of applications in every area where radiation detection and measurements are involved. One of the most important parameters in this respect is the determination of the full energy peak (FEP) efficiency. There are certain parameters affecting the so-called FEP efficiency. Perhaps the most important one is the thickness of dead layers of the crystal itself. In the current study, we investigated the effects of the thickness of front, lateral and back dead layer thicknesses of the detector crystal on the FEP efficiencies for the energy range 30 keV–5 MeV using EGS4 Monte Carlo simulation package. It was shown that the change in the thickness of the front dead layer has significant effect on the efficiency values for the energy interval 30–400 keV. The change in the thickness of the lateral and back dead layer was shown to have significant effects on the efficiencies for the energy intervals 2–3 MeV and 3–5 MeV, respectively. The results were checked using GEANT4 and a good agreement was observed.

In this paper, we propose two protocols for the transfer of quantum information carried by one particle onto another particle by using the path-spin hybrid and hyper entangled states as the quantum resources. It has been shown that the double slit arrangement with a spin flipper at one of its openings can be used for the generation of path-spin hybrid and hyper entangled states. By using such path-spin entangled states as the quantum resource, the quantum information encoded in one particle is transferred to another particle via spin and path measurements.

In quantum teleportation, the sender must interact her/his qubit to one of the qubits in a maximally entangled Bell/Bell-type state and as a result, a joint state is obtained. This joint state has to be rearranged in terms of the appropriate number of Bell/Bell-type states. Then the sender measures her/his qubits and sends the results via a classical channel to the receiver. According to the outcome of the measurement results, the receiver applies appropriate gates to the qubits in her/his share to recover the teleported state. Perhaps the most important step in this protocol is to be able to rewrite the joint state in terms of the appropriate number of Bell-type states. An efficient way to produce Bell-type states for quantum teleportation of an arbitrary n-qubit state is proposed. Quantum teleportation of an arbitrary three-qubit state is studied as an example.

The aim of the study is to determine the ambient radiation level in Gumushane province. With this aim, the gamma dose ratios absorbed in the air were surveyed by a portable gamma detector. The activity concentrations of 226Ra, 232Th, 40K, and 137Cs in soil samples have been measured by the gamma spectrometric analysis system. The gross alpha and beta activity concentrations in drinking water were also determined by the alpha and beta counting system. By considering the geological structure, the soil samples have been obtained from 62 different spots. In addition, 77 samples of natural and tap water have been collected from different points of the province. The samples were analyzed at the Cekmece Nuclear Research and Training Center in Turkey. Absorbed gamma dose rates in the air were measured in 338 different points in the studied area.

We have carried out 48 in situ measurements on radioactivities of 238U, 232Th and 40K isotopes at the Gümüşhane granitoid plutons employing gamma-ray spectrometer with a NaI(Tl) scintillation detector. The radionuclide activity concentrations of 40K, 238U and 232Th ranged from 62.6 to 1680.8 Bq kg−1, 2.5 to 119.9 Bq kg−1 and 3.3 to 92.4 Bq kg−1, respectively. The mean concentration of natural radionuclides (40K, 238U and 232Th) was found to be 638.5 ± 421.6 Bq kg−1, 40.8 ± 27.4 Bq kg−1 and 33.5 ± 25.5 Bq kg−1, respectively. The mean values of the radium equivalent and the external hazard index were 137.9 ± 80.6 Bq kg−1 and 0.37 ± 0.22, respectively. The value of annual effective dose equivalent value (81.8 μSv year−1) is lower on average than in the world average of 460 μSv year−1. The external hazard index acquired in this study did not exceed the international safety standard levels, which means that Gümüşhane pluton does not produce any radiation hazards to the dwellers.

We have carried out 48 in situ measurements on radioactivities of 238 U, 232 Th and 40 K isotopes at the Gümüşhane granitoid plutons employing gamma-ray spectrometer with a NaI(Tl) scintillation detector. The radionuclide activity concentrations of 40 K, 238 U and 232 Th ranged from 62.6 to 1680.8 Bq kg −1 , 2.5 to 119.9 Bq kg −1 and 3.3 to 92.4 Bq kg −1 , respectively. The mean concentration of natural radionuclides ( 40 K, 238 U and 232 Th) was found to be 638.5 ± 421.6 Bq kg −1 , 40.8 ± 27.4 Bq kg −1 and 33.5 ± 25.5 Bq kg −1 , respectively. The mean values of the radium equivalent and the external hazard index were 137.9 ± 80.6 Bq kg −1 and 0.37 ± 0.22, respectively. The value of annual effective dose equivalent value (81.8 μSv year −1 ) is lower on average than in the world average of 460 μSv year −1 . The external hazard index acquired in this study did not exceed the international safety standard levels, which means that Gümüşhane pluton does not produce any radiation hazards to the dwellers.