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Monitoring of the anthropogenic radionuclides (90Sr, 135Cs and 137Cs) in different components such as spinach, milk, meat, soil and the grass is important for the environmental radiological survey. Nuclear weapons testing in the atmosphere, nuclear power plant accidents and leaks from the nuclear fuel cycle are the main sources of these radionuclides. The amounts of 90Sr/90Y detected in the environment are mostly due to fallout from nuclear weapons testing. Because of its long physical (28.5 years) and biological half-lives (approximately 12 years) and high fission yield, the measurement of 90Sr is also necessary for radiation protection purposes. It accumulates in bone tissue when ingested by humans through the food chain, and 90Y, a daughter nuclide of 90Sr, emits high-energy beta particles, raising the risk of bone cancer. Strontium has been widely measured in milk samples by using various classical methods. In this study, the procedure we used is based on the separation of 90Y by HDEHP extraction and counting the Cherenkov radiation using a liquid scintillation spectrometer, Quantulus 1220. Prior to analyses, spiked milk samples were dried and prepared as milk powder. The microwave ashing programme was optimised, and recovery of the radiochemical separation steps was tested for spiked milk powder samples before routine analysis. This method is found to be applicable for the routine analysis of 90Sr in milk samples after validation of the method by measuring IRMM milk powder samples, too. A lower limit of detection of about 0.02 Bq.kg−1 was obtained for samples in the case of 84–99% Y chemical yield, 1.45 cpm reagent blank, 4 × 60 minutes counting time and about 83.5 ± 2.1% counting efficiency. [ABSTRACT FROM AUTHOR]

In this study, we selected the Japanese red fox (Vulpes vulpes japonica) as a representative mid-size mammal from the forests near the spent nuclear fuel reprocessing plant at Rokkasho. A fox voxel phantom was constructed based on magnetic resonance imaging of a female red fox caught in Rokkasho. This phantom consisted of 264 × 321 × 383 voxels (each voxel size: 0.78 × 0.78 × 2 mm) with internal organs. The external radiation dose rate to the voxel phantom by beta and gamma rays from environmental radionuclides was estimated using a Monte Carlo code (EGS4 and UCPIXEL). We estimated the dose rates to the phantom on the ground and in an average fox burrow in the Rokkasho forest, which were 11 and 27 nGy h−1, respectively. Assuming that the animal on the ground was irradiated by cosmic rays of 27 nGy h−1, the total external dose rate was evaluated to be 38 nGy h−1. Based on the assumption that the fox lives on the ground for 12 h and in the burrow for 12 h, the dose rate was estimated to be 33 nGy h−1. [ABSTRACT FROM AUTHOR]

Background: Combining the sharp dose fall off feature of beta‐emitting 106Ru/106Rh radionuclide with larger penetration depth feature of photon‐emitting125I radionuclide in a bi‐radionuclide plaque, prescribed dose to the tumor apex can be delivered while maintaining the tumor dose uniformity and sparing the organs at risk. The potential advantages of bi‐radionuclide plaque could be of interest in context of ocular brachytherapy. Purpose: The aim of the study is to evaluate the dosimetric advantages of a proposed bi‐radionuclide plaque for two different designs, consisting of indigenous 125I seeds and 106Ru/106Rh plaque, using Monte Carlo technique. The study also explores the influence of other commercial 125I seed models and presence or absence of silastic/acrylic seed carrier on the calculated dose distributions. The study further included the calculation of depth dose distributions for the bi‐radionuclide eye plaque for which experimental data are available. Methods: The proposed bi‐radionuclide plaque consists of a 1.2‐mm‐thick silver (Ag) spherical shell with radius of curvature of 12.5 mm, 20 µm‐thick‐106Ru/106Rh encapsulated between 0.2 mm Ag disk, and a 0.1‐mm‐thick Ag window, and water‐equivalent gel containing 12 symmetrically arranged 125I seeds. Two bi‐radionuclide plaque models investigated in the present study are designated as Design I and Design II. In Design I, 125I seeds are placed on the top of the plaque, while in Design II 106Ru/106Rh source is positioned on the top of the plaque. In Monte Carlo calculations, the plaque is positioned in a spherical water phantom of 30 cm diameter. Results: The proposed bi‐radionuclide eye plaque demonstrated superior dose distributions as compared to 125I or 106Ru plaque for tumor thicknesses ranges from 5 to 10 mm. Amongst the designs, dose at a given voxel for Design I is higher as compared to the corresponding voxel dose for Design II. This difference is attributed to the higher degree of attenuation of 125I photons in Ag as compared to beta particles. Influence of different 125I seed models on the normalized lateral dose profiles of Design I (in the absence of carrier) is negligible and within 5% on the central axis depth dose distribution as compared to the corresponding values of the plaque that has indigenous 125I seeds. In the presence of a silastic/acrylic seed carrier, the normalized central axis dose distributions of Design I are smaller by 3%–12% as compared to the corresponding values in the absence of a seed carrier. For the published bi‐radionuclide plaque model, good agreement is observed between the Monte Carlo‐calculated and published measured depth dose distributions for clinically relevant depths. Conclusion: Regardless of the type of 125I seed model utilized and whether silastic/acrylic seed carrier is present or not, Design I bi‐radionuclide plaque offers superior dose distributions in terms of tumor dose uniformity, rapid dose fall off and lesser dose to nearby critical organs at risk over the Design II plaque. This shows that Design I bi‐radionuclide plaque could be a promising alternative to 125I plaque for treatment of tumor sizes in the range 5 to 10 mm. [ABSTRACT FROM AUTHOR]

10.1119/5.0218373.1 We describe a simplified experiment that can be used to verify the relativistic energy-momentum relationship for beta particles emitted from a 204Tl source. The experiment makes use of an exempt radioactive source and is therefore ideal for institutions that do not maintain a Nuclear Regulatory Commission (or state) license. The relativistic beta particles are injected into a uniform magnetic field and the maximum radius of the trajectories is determined. Comparing this radius to the relativistic and non-relativistic predictions demonstrates that only the relativistic equations are consistent with the data. The simplicity of the experiment and analysis makes this project ideal for inclusion in a sophomore-level modern physics course. [ABSTRACT FROM AUTHOR]

Semiconductor materials play an important role as transmitters of electrical energy in betavoltaic batteries. Optimal selection will increase the efficiency of these batteries. In this study, based on common semiconductors and relying on increasing the maximum efficiency of betavoltaic batteries and the possibility of using ³H, 63Ni, and 147Pm beta sources, the indicators and criteria for optimal selection of semiconductor materials were determined. Evaluation criteria include backscattering coefficient of beta particles from semiconductors, efficiency of electron-hole pairs generation, electronic specifications and properties, radiation damage threshold, radiation yield, stopping power and penetration of beta particles in semiconductors, physical characteristics, and temperature tolerance, accessibility, and fabrication were considered. Based on these criteria and compared with silicon semiconductors, conventional semiconductors have been quantitatively evaluated. Ten semiconductors including β-B, Diamond, 2H-SiC, 3C-SiC, 4H-SiC, 6H-SiC, c-BN, AlN, MgO, B4C with effective atomic number less than 14 and bandgap above 1.12 eV at room temperature (300K) compared to silicon semiconductors were evaluated. Considering the results of evaluation indicators, Diamond, c-BN, and 4H-SiC were selected as more suitable semiconductors in terms of efficiency. Based on the experiments performed in this study, a betavoltaic semiconductor type junction for Schottky diamond with 147pm radioisotope, for 4H-SiC semiconductors with 63Ni or ³H radioisotopes, and for three-dimensional structures of betavoltaic batteries, Si combination with 147pm or 63Ni radioisotopes is recommended for planar batteries. [ABSTRACT FROM AUTHOR]

Image plates (IPs), or phosphor storage screens, are a technology employed frequently in inertial confinement fusion (ICF) and high energy density plasma (HEDP) diagnostics because of their sensitivity to many types of radiation, including, x rays, protons, alphas, beta particles, and neutrons. Prior studies characterizing IPs are predicated on the signal level remaining below the scanner saturation threshold. Since the scanning process removes some signal from the IP via photostimulated luminescence, repeatedly scanning an IP can bring the signal level below the scanner saturation threshold. This process, in turn, raises concerns about the signal response of IPs after an arbitrary number of scans and whether such a process yields, for example, a constant ratio of signal between the nth and n + 1st scan. Here, the sensitivity of IPs is investigated when scanned multiple times. It is demonstrated that the ratio of signal decay is not a constant with the number of scans and that the signal decay depends on the x-ray energy. As such, repeatedly scanning an IP with a mixture of signal types (e.g., x ray, neutron, and protons) enables ICF and HEDP diagnostics employing IPs to better isolate a particular signal type. [ABSTRACT FROM AUTHOR]

With low background radiation, tritiate compounds exclusively emit intense beta particles without structural changes. This makes them a useful tool in the drug discovery arsenal. Thanks to the recent rapid progress in tritium chemistry, the preparation and analysis of tritium-labeled compounds are now much easier, simpler, and cheaper. Pharmacokinetics, autoradiography, and protein binding studies have been much more efficient with the employment of tritium-labeled compounds. This review provides a comprehensive overview of tritium-labeled compounds regarding their properties, synthesis strategies, and applications. [ABSTRACT FROM AUTHOR]

In recent years, there has been a rapid growth in new technologies within nuclear medicine and PET diagnostics, particularly in the field of radiopharmaceutical dose preparation. These advancements are driven by the integration of automatic algorithms into the process. This evolution has brought about significant improvements in the efficiency and accuracy of radiopharmaceutical dose preparation. These automatic algorithms utilize state-of-the-art technologies to streamline the process and ensure precise and tailored doses for patients. The integration of these advanced technologies has revolutionized the field, allowing for more effective and personalized treatment options in nuclear medicine and PET diagnostics. By employing automatic radiopharmaceutical dose dispensers (ARDDs), radiation exposure to technologists is minimized while also mitigating the risk of potential infections for patients. Ionization chambers are currently the most used detectors to measure the activity of radiopharmaceuticals in ARDDs. However, they present certain limitations, including size constraints. This study is part of an international endeavor to develop a new approach for evaluating radiopharmaceutical activity in an ARDD named KARl100. A new approach was used to develop a scintillation detector by linking a PVT detector to a SiPMs array consisting of four elements, each having an active surface of 6 × 6 mm with a bias voltage of 30 V. The detection system's amplified output was then fed to a single-channel analyzer called Enviro, developed by Tema Sinergie S.p.A in Italy. The counts per second (CPS) detected by the detector were studied using WinTAM software allowing for the radionuclide's activity concentration to be read out at run-time. Three widely used medical radioisotopes, 18F, 11C and 68Ga, were used to evaluate the performance of the detector in terms of linearity and repeatability of the measurements. Half-life and linear response were evaluated over a wide range of activities with different decay schemes. Data analysis was conducted, resulting in half-lives of the 18F, 11C and 68Ga radioisotopes of 109.75 ± 0.35, 20.62 ± 0.34 and 67.82 ± 0.25 min, respectively, with calculated deviations of 0.0167%, 1.00% and 0.29% from expected values. The linear response of the detector over the entire range of desired activity concentrations was confirmed after data correction for the detector dead time. Calibration of the detector combined with the dispenser system was carried out in parallel investigations to provide the required device properties for reference applications in nuclear medicine. Furthermore, Monte Carlo simulations using FLUKA code were performed to investigate the contribution of beta particles in addition to gamma radiations to assess the influence of beta particles on the calibration factors. For better accuracy, a shielding was designed to prevent any beta particles from reaching the detector. [ABSTRACT FROM AUTHOR]

When interacting with absorption materials, beta rays, which are emitted by isotopes, are harmful because bremsstrahlung (braking) radiation is produced. Therefore, the efficiency of a shielding material can be improved by considering the bremsstrahlung radiation generated by the material's beta ray absorption. In this study, to determine the risk of bremsstrahlung radiation produced by beta rays, the fractions of beta energy transformed into bremsstrahlung radiation were calculated for beta emitters in the energy ranges of 0.0026-0.1734, 0.205-0.694, and 0.9345-2.640 MeV, using five different absorption materials (13Al, 26Fe, 48Cd, 74W, and 82Pb). The relationship between the fractions of beta energy transformed into bremsstrahlung radiation by the five shielding materials and the maximum energies of some beta emitters was studied to determine the most suitable beta-ray shielding materials to effectively minimize bremsstrahlung radiation. The results showed that the fractions of beta energy transformed into bremsstrahlung radiation increased as the beta energy and the atomic number of the shielding material increased. The fraction of beta energy transformed into bremsstrahlung radiation in 13Al < 26Fe < 48Cd < 74W < 82Pb. Therefore, beta ray shields should be made with low atomic number materials to reduce the generation of bremsstrahlung radiation. Practically, beta shields made from materials with atomic numbers greater than 13 are rarely employed; notably, aluminum successfully decreased the production of bremsstrahlung radiation. However, it is also necessary to use materials with medium and high atomic numbers as secondary beta shields to reduce the effect of the bremsstrahlung radiation photons formed by the interaction between beta rays and shielding materials. [ABSTRACT FROM AUTHOR]

Background: In radiopharmaceutical therapies (RPT) involving beta emitters, absorbed dose (Dabs) calculations often employ the use of dose voxel kernels (DVK). Such methods are faster and easier to implement than Monte Carlo (MC) simulations. Using DVK methods implies a non‐stochastic distribution of particles. This is a valid assumption for betas where thousands to tens of thousands of particles traversing the cell nucleus are required to achieve cell kill. However, alpha particles have linear energy transfers (LET) that are ∼500 times higher than LETs of betas. This results in a significant probability of killing a cell from even a single traversal through its nucleus. Consequently, the activity used for therapy involving alphas is very low, and the use of DVKs for estimating Dabs will generate results that may be erroneous. Purpose: This work aims at illustrating how use of DVKs affect the resulting Dabs in small tumors when irradiated with clinically relevant amounts of beta‐ and alpha‐emitters. The results are compared with those from using a Monte Carlo method where the energy deposition from individual tracks is simulated. Methods: To illustrate the issues associated with DVK for alpha radiopharmaceutical therapies at the microscale, a tumor cluster model was used to compare beta (177Lu) and alphas (211At, 225Ac, and 227Th) irradiations. We used 103 beta particles and 20 alpha particles per cell, which is within the range of the required number of particle traversals through its nucleus to sterilize a cell. Results from using both methods were presented with Dabs histograms, dose volume histograms, and Dabs error maps. Results: For beta‐emitter (177Lu) irradiating the modeled tumor cluster, resulting Dabs was similar for both DVK and MC methods. For all alpha emitters, the use of DVK led to an overestimation of Dabs when compared to results generated using a MC approach. Conclusions: Our results demonstrate that the use of DVK methods for alpha emitters can lead to an overestimation in the calculated Dabs. The use of DVKs for therapies involving alpha emitters may therefore not be appropriate when only referring to the mean Dabs metric. [ABSTRACT FROM AUTHOR]

High-energy beta-ray sources generate bremsstrahlung photons in the building materials, generated by the radioactive nuclides inside the nuclear reactor buildings emitted by the Fukushima Daiichi nuclear reactor accident. Therefore, evaluating the bremsstrahlung dose subjected to the workers in the building is crucial for radiation protection. The precision for assessing the bremsstrahlung dose was investigated by comparing the Particle and Heavy Ion Transport code System (PHITS) and the GEometry ANd Tracking (GEANT4) simulation code results. Behind various shielding plates (lead, copper, aluminum, glass, and polyethylene with multiple thicknesses), the water cylinder was set to obtain the absorbed dose and the deposited energy spectrum by the bremsstrahlung photons. In comparing the deposited energy spectrum, the spectral shapes have consistent trends. Below several tens of keV, a peak is observed in the PHITS spectrum for lead. While comparing the absorbed dose, most of the results from both codes correlate within an ~10% difference for 2.280 MeV beta-ray sources and an ~20% difference for 0.5459 MeV beta-ray sources, except for ~30% for 20 mm thick lead. Although some differences occurred, the evaluation results of both codes correlated well with the above precision. [ABSTRACT FROM AUTHOR]

Introduction: This article presents data on the ecological situation of agricultural territories where small cattle are raised, focusing on the exposure dose rate, radon concentration in residential and social buildings, and the density of alpha and beta particle flux. The study also examines the levels of heavy metals (Pb, Cd, As, Hg) and radionuclides Cs-137 and Sr-90 in raw meat from ecologically unfavorable areas, as well as the effects of heat treatment on reducing the content of these harmful substances. Methods: The research involved analyzing raw meat samples from the Abai district near the former Semipalatinsk Nuclear Test Site in Semey, Kazakhstan. The levels of heavy metals and radionuclides were measured before and after heat treatment to assess the effectiveness of cooking in reducing these contaminants. Radioecological measurements were also conducted in residential and social buildings to evaluate radon concentration and alpha and beta particle flux. Results and discussion: The results of the study showed a significant decrease in the levels of lead, cadmium, arsenic, Cs-137, and Sr-90 in meat after heat treatment. Prolonged cooking or quenching led to the most significant reductions in toxicity and radionuclides. These findings suggest that heat treatment can be an effective method for reducing the levels of harmful substances in meat from ecologically compromised areas. Further research is needed to explore other potential strategies for mitigating the impact of environmental contamination on food safety in agricultural regions. [ABSTRACT FROM AUTHOR]

Radiation hardness tests were conducted on a silicon detector and preamplifier to develop a reactor coolant leakage monitoring system, which detects high-energy beta particles from 16N in the primary reactor coolant of nuclear power plants. Monte Carlo simulations were used to calculate the doses that would be absorbed on components over a 60-year design lifetime. The components were exposed to a 60Co gamma source with an activity of 2.4 kCi for 54 hours. The absorbed doses accumulated during the test were determined to be 0.99 kGy for the detector and 1.37 kGy for the preamplifier. During the test, the alpha count from a check source in the high-channel range disappeared in a high-dose-rate environment, and the gross gamma count decreased as the accumulated dose increased. The performance degradation of the detector and preamplifier was evaluated by comparing the alpha signals and background noise before and after irradiation. The energy resolution of the alpha signals in the high-channel range exhibited slight changes, whereas the electronic noise in the low-channel range increased by approximately 773 % for the irradiated detector and 17 % for the irradiated pre-amp. A method employing various low-level discriminator channels is proposed to miti-gate noise effects in the monitoring system. [ABSTRACT FROM AUTHOR]

Scandium (Sc) isotopes have recently attracted significant attention in the search for new radionuclides with potential uses in personalized medicine, especially in the treatment of specific cancer patient categories. In particular, Sc-43 and Sc-44, as positron emitters with a satisfactory half-life (3.9 and 4.0 h, respectively), are ideal for cancer diagnosis via Positron Emission Tomography (PET). On the other hand, Sc-47, as an emitter of beta particles and low gamma radiation, may be used as a therapeutic radionuclide, which also allows Single-Photon Emission Computed Tomography (SPECT) imaging. As these scandium isotopes follow the same biological pathway and chemical reactivity, they appear to fit perfectly into the "theranostic pair" concept. A step-by-step description, initiating from the moment of scandium isotope production and leading up to their preclinical and clinical trial applications, is presented. Recent developments related to the nuclear reactions selected and employed to produce the radionuclides Sc-43, Sc-44, and Sc-47, the chemical processing of these isotopes and the main target recovery methods are also included. Furthermore, the radiolabeling of the leading chelator, 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA), and its structural analogues with scandium is also discussed and the advantages and disadvantages of scandium complexation are evaluated. Finally, a review of the preclinical studies and clinical trials involving scandium, as well as future challenges for its clinical uses and applications, are presented. [ABSTRACT FROM AUTHOR]

Background: Diffusing alpha‐emitters radiation therapy (DaRT) is a novel brachytherapy technique that leverages the diffusive flow of 224Ra progeny within the tumor volume over the course of the treatment. Cell killing is achieved by the emitted alpha particles that have a short range in tissue and high linear energy transfer. The current proposed absorbed dose calculation method for DaRT is based on a diffusion‐leakage (DL) model that neglects absorbed dose from beta particles. Purpose: This work aimed to couple the DL model with dose point kernels (DPKs) to account for dose from beta particles as well as to consider the non‐local deposition of energy. Methods: The DaRT seed was modeled using COMSOL multiphysics and the DL model was implemented to extract the spatial information of the diffusing daughters. Using Monte–Carlo (MC) methods, DPKs were generated for 212Pb, 212Bi, and their progenies since they were considered to be the dominant beta emitters in the 224Ra radioactive decay chain. A convolution operation was performed between the integrated number densities of the diffusing daughters and DPKs to calculate the total absorbed dose over a 30‐day treatment period. Both high‐diffusion and low‐diffusion cases were considered. Results: The calculated DPKs showed non‐negligible energy deposition over several millimeters from the source location. An absorbed dose >10 Gy was deposited within a 1.8 mm radial distance for the low diffusion case and a 2.2 mm radial distance for the high diffusion case. When the DPK method was compared with the local energy deposition method that solely considered dose from alpha particles, differences above 1 Gy were found within 1.3 and 1.8 mm radial distances from the surface of the source for the low diffusion and high diffusion cases, respectively. Conclusions: The proposed method enhances the accuracy of the dose calculation method used for the DaRT technique. [ABSTRACT FROM AUTHOR]

A study of the dead layer thickness and quenching factor of a plastic scintillator for use in ultracold neutron (UCN) experiments is described. Alpha spectroscopy was used to determine the thickness of a thin surface dead layer to be 630 ± 110 nm. The relative light outputs from the decay of 241Am and Compton scattering of electrons were used to extract Birks' law coefficient, yielding a kB value of 0.087 ± 0.003 mm/MeV, consistent with some previous reports for other polystyrene-based scintillators. The results from these measurements are incorporated into the simulation to show that an energy threshold of (∼9 keV) can be achieved for the UCNProBe experiment. This low threshold enables high beta particle detection efficiency and the indirect measurement of UCN. The ability to make the scintillator deuterated, accompanied by its relatively thin dead layer, gives rise to unique applications in a wide range of UCN experiments, where it can be used to trap UCN and detect charged particles in situ. [ABSTRACT FROM AUTHOR]

In this study, the graphene field-effect transistor (FET) has been created by depositing a film-forming suspension of reduced graphene oxide (RGO) on the silicon substrate with a SiO2 layer and air-drying at room temperature. The possibility of using the obtained FET for ionizing radiation detection was investigated. The electrical characteristics of the radiation sensor based on the RGO film were studied in modes of direct current and alternating current. The dependencies of the drain current and the resistance of the RGO film on the gate voltage of the obtained FET were analyzed. Linear sections on the dependence of the drain current on the gate voltage, the positions of which are determined by the sign of the drain-source voltage, were detected. A decrease in the conductivity of the FET based on the RGO film near the point of charge neutrality due to irradiation from the 226Ra isotope was established. An increase in resistance and a decrease in capacitance of the investigated FET have been found in the frequency range of 25 Hz – 1 MHz caused by the joint action of alpha and beta particles and gamma quanta. A linear dependence of the electrical characteristics of the proposed sensor on the adsorbed dose determined by the irradiation duration was discovered. Possible mechanisms of the ionizing radiation influence on the conductivity of the obtained structure based on the RGO film are considered. The generation of electron-hole pairs in the silicon substrate and the formation of radiation defects in the insulator layer are probably the main factors affecting the electrical characteristics of the RGO based FET under the action of ionizing radiation. The obtained results expand the perspective of using graphene FETs to create a new type of radiation detectors and diametric devices. [ABSTRACT FROM AUTHOR]

Background: In time‐of‐flight PET, image quality and accuracy can be enhanced by improving the annihilation photon pair coincidence time resolution, which is the variation in the arrival time difference between the two annihilation photons emitted from each positron decay in the patient. Recent studies suggest direct detection of ionization tracks and their resulting modulation of optical properties, instead of scintillation, can improve the CTR significantly, potentially down to less than 10 ps CTR. However, the arrival times of the 511 keV photons are not predictable, leading to challenges in the spatiotemporal localization characterization of the induced charge carriers in the detector crystal. Purpose: To establish an optimized experimental setup for measuring ionization induced modulation of optical properties, it is critical to develop a versatile simulation algorithm that can handle multiple detector material properties and time‐resolved charge carrier dynamics. Methods: We expanded our previous algorithm and simulated ionization tracks, cascade time and induced charge carrier density over time in different materials. For designing a proof‐of‐concept experiment, we simulated ultrafast electrons and free‐electron x‐ray photons for timing characterization along with alpha and beta particles for higher spatial localization. Results: With 3 MeV ultrafast electrons, by reducing detector crystal thickness, we can effectively reduce the ionization cascade time to 0.79 ps and deposited energy to 198.5 keV, which is on the order of the desired 511 keV energy. Alpha source simulations produced a cascade time of 2.45 ps and charge carrier density of 6.39 × 1020 cm−3. Compared to the previous results obtained from 511 keV photon‐induced ionization track simulations, the cascade time displayed similar characteristics, while the charge density was found to be higher. These findings suggest that alpha sources have the potential to generate a stronger ionization‐induced signal using the modulation of optical properties as the detection mechanism. Conclusions: This work provides a guideline to understand, design and optimize an experimental platform that is highly sensitive and temporally precise enough to detect single 511 keV photon interactions with a goal to advance CTR for ToF‐PET. [ABSTRACT FROM AUTHOR]

The article presents the results of the development of a universal radiometric device for measuring the activities of alpha, beta, and gamma radiation and the volumetric activity of radon in soil, air, and water. The structure of a multichannel radiometric device with software, a diagram of a microcontroller unit with a signal conditioner, and the operation of electronic units are presented. The data of monitoring the volumetric activity of radon alpha particles and the activities of beta and gamma radiation in the soil air are given. The monitoring results showed that activities vary depending on temperature, humidity, and time of day. The device is compact, mobile, and universal and can be used both stationary and in the field. The developed RMI V1.7 program allows for long-term, real-time monitoring, and all measurements are displayed on a computer monitor. [ABSTRACT FROM AUTHOR]

Purifying aqueous solutions from radioactive contamination is an extremely relevant scientific topic today. Many organic and inorganic adsorbents can be recommended for the adsorption of heavy metal ions and radionuclides from aqueous solutions, or as carriers for storage and disposal of radioactive waste. Since radionuclides are sources of ionizing radiation, the radiation resistance of the adsorbent is an important characteristic. These studies aim to investigate the titanium silicate behavior and its adsorption properties' changes or their invariability in the field of intense β-radiation. Experimental techniques describe the synthesis of titanium silicate adsorbent by sol-gel method and the study of its adsorption capacity toward Ba2+ cations. The adsorption of Ba2+ cations was investigated under batch conditions with neutral pH of the solution. Initial and residual concentrations of Ba2+ cations were controlled by direct complexometric titration with Na-EDTA with Eriochrom Black T as an indicator. The study of the radiation resistance of the adsorbent to high-energy β-radiation was performed using a 90Sr-90Y β- - source “Sirius” installed in the Microtron Laboratory of the Uzhhorod National University. The distance from the source to the adsorbent samples was 20 cm. The flux of electrons at this distance was 108 el/cm2 ‧per second. The maximum energy of beta particles was 0.456 MeV for 90Sr and 2.28 MeV for 90Y. The maximum duration of exposure was 21 days, which corresponds to 1310 Gy. Raman spectroscopy of irradiated and nonirradiated samples of TiSi was performed using a Raman spectrometer XploRA PLUS installed in the Center for Collective Use of Scientific Equipment “Laboratory of Experimental and Applied Physics” of Uzhhorod National University. Results consist of kinetic of Ba2+ adsorption by titanium silicate and irradiated titanium silicate; isotherm of Ba2+ adsorption and Raman spectrum of nonirradiated, irradiated titanium silicate (TiSi) and TiSi after Ba2+ adsorption. Results showed that the value of the maximal adsorption was 140.5±9.2 mg/g (6.55 %) under a confidence level of 95 %. The adsorption values of barium ions by irradiated and non-irradiated titanium silicate coincide. This indicates that the adsorption properties of this adsorbent do not change under the influence of such a radiation dose. The Raman spectra of irradiated and non-irradiated titanium silicate coincide, while they do not identify free radicals, or ionic formations, which would indicate a change in the properties of the adsorbent under the influence of beta radiation. It can be argued that this adsorbent is radiation-resistant to beta-radioactivity, with a radiation dose of 1310 Gy. The main conclusion of the present work is that the studied sample of titanium silicate is radiation-resistant. It can withstand a radiation dose of 1310 Gy without changing its adsorption properties. Titanium silicate can be used for the adsorption of strontium radionuclides, it can be a carrier for the disposal of radioactive waste. [ABSTRACT FROM AUTHOR]

This study investigated the thermoluminescence properties of undoped CaF2 nanoparticles synthesized via co-precipitation with ethanol. X-ray diffraction revealed pure CaF2 nanoparticles with a complete cubic structure and an average crystallite size of 36.5 nm. Scanning electron microscopy confirmed the nanoscale size, averaging 51.23 nm. Electron dispersive spectroscopy analysis showed that the sample mainly consists of Ca and F, with oxygen potentially introducing defects in the crystal structure. Synthesized nanoparticles TL glow curves exposed to 7 mGy of 90Sr beta rays exhibited a prominent peak at 205 oC in thermoluminescence glow curves, likely due to oxygen-induced defects that act as thermoluminescence activators. The thermoluminescence activating energy and the frequency factor of the CaF2 nanoparticles were determined using initial rise methods of approximately 0.83 eV and 5.99 x 10-19, respectively. [ABSTRACT FROM AUTHOR]

INTRODUCTION On November 8, 1895, Wilhelm Conrad Roentgen discovered x-rays. Recent developments in imaging technology have led to a rapid increase in the use of ionizing radiation in medicine, which has potential for resolving a variety of clinical problems (1,2). The application of medical radiation in the diagnosis of disease, various procedures, and the surgical management of patients is increasing day by day. Radiation is defined as a moving form of energy (3). We use both ionizing and non-ionizing radiation commonly in our day-to-day practice (4). According to its effects on the substance, radiation is divided into two groups: ionizing and non-ionizing radiation (5). Different types of radiation: 1) Ionizing radiation: Ionizing radiation is divided into direct and indirect? Direct ionizing radiation includes alpha particles and beta particles.? Indirect ionizing radiation includes X-rays, gamma rays, and UV rays. 2) Non-ionizing radiation Radiation accidents have enabled the study of the effects of high levels of radiation. The first x-ray machine was introduced in India at the Madras Medical College in 1900. New setups are being established, and radiation workers are constantly being produced through various academic programs. A worker typically wears the personnel monitoring equipment for three months. The employer registers the dosage recorded by the personnel monitoring equipment, which is subsequently forwarded to the dosimetry service provider for evaluation in order to determine the radiation exposure level (6). [ABSTRACT FROM AUTHOR]

α-particle targeted radionuclide therapy has shown promise for optimal cancer management, an exciting new era for brachytherapy. Alpha-emitting nuclides can have significant advantages over gamma- and beta-emitters due to their high linear energy transfer (LET). While their limited path length results in more specific tumor 0kill with less damage to surrounding normal tissues, their high LET can produce substantially more lethal double strand DNA breaks per radiation track than beta particles. Over the last decade, the physical and chemical attributes of Actinium-225 (225Ac) including its half-life, decay schemes, path length, and straightforward chelation ability has peaked interest for brachytherapy agent development. However, this has been met with challenges including source availability, accurate modeling for standardized dosimetry for brachytherapy treatment planning, and laboratory space allocation in the hospital setting for on-demand radiopharmaceuticals production. Current evidence suggests that a simple empirical approach based on 225Ac administered radioactivity may lead to inconsistent outcomes and toxicity. In this review article, we highlight the recent advances in 225Ac source production, dosimetry modeling, and current clinical studies. [ABSTRACT FROM AUTHOR]

Background: In radionuclide therapy, to enhance therapeutic efficacy, an intriguing alternative is to ensure the simultaneous implementation of low- and high-LET radiation emitted from a one radionuclide. In the present study, we introduce the concept of utilizing 109Pd (T1/2 = 13.7 h) in the form of a 109Pd/109mAg in vivo generator. In this system, 109Pd emits beta particles of medium energy, while 109mAg releases a cascade of conversion and Auger electrons. 109Pd was utilized in the form of 15 nm gold nanoparticles, which were coated with a monolayer of 109Pd. In this system, the 109Pd atoms are on the surface of the nanoparticle, while the 109mAg atoms generated in the decay reaction possess the capability for unhindered emission of Auger electrons. Results: 109Pd, obtained through neutron irradiation of natural palladium, was deposited onto 15-nm gold nanoparticles, exceeding a efficiency rate of 95%. In contrast to previously published data on in vivo generators based on chelators, where the daughter radionuclide diffuses away from the molecules, daughter radionuclide 109mAg remains on the surface of gold nanoparticles after the decay of 109Pd. To obtain a radiobioconjugate with an affinity for HER2 receptors, polyethylene glycol chains and the monoclonal antibody trastuzumab were attached to the Au@Pd nanoparticles. The synthesized bioconjugate contained an average of 9.5 trastuzumab molecules per one nanoparticle. In vitro cell studies indicated specific binding of the Au@109Pd-PEG-trastuzumab radiobioconjugate to the HER2 receptor on SKOV-3 cells, resulting in 90% internalization. Confocal images illustrated the accumulation of Au@109Pd-PEG-trastuzumab in the perinuclear area surrounding the cell nucleus. Despite the lack of nuclear localization, which is necessary to achieve an effective cytotoxic effect of Auger electrons, a substantial cytotoxic effect, significantly greater than that of pure β− and pure Auger electron emitters was observed. We hypothesize that in the studied system, the cytotoxic effect of the Auger electrons could have also occurred through the damage to the cell's nuclear membrane by Auger electrons emitted from nanoparticles accumulated in the perinuclear area. Conclusion: The obtained results show that trastuzumab-functionalized 109Pd-labeled nanoparticles can be suitable for the application in combined β−—Auger electron targeted radionuclide therapy. Due to both components decay (β− and conversion/Auger electrons), the 109Pd/109mAg in vivo generator presents unique potential in this field. Despite the lack of nuclear localization, which is highly required for efficient Auger electron therapy, an adequate cytotoxic effect was attained. [ABSTRACT FROM AUTHOR]

While some evidence of an effect of radiation exposure on respiratory disease at low dose levels has now emerged, there is heterogeneity in the risks between different studies and countries. In this paper, we aim to show the effect of radiation on three different sub-types of respiratory disease mortality through the analysis of the NRRW cohort in UK. The NRRW cohort consisted of 174,541 radiation workers. Doses to the surface of the body were monitored using individual film badges. Most of the doses are associated with X-rays and gamma rays and to a less extent of beta and neutron particles. The overall mean 10-year lagged lifetime external dose was 23.2 mSv. Some workers were potentially exposed to alpha particles. However, doses from internal emitters were not available for the NRRW cohort. 25% of male workers and 17% of female workers were identified as being monitored for internal exposure. The Poisson regression methods for grouped survival data with a stratified baseline hazard function were used to describe the dependence of the risk on cumulative external radiation dose. The disease was analyzed by the following subgroups: Pneumonia (1066 cases including 17 cases of influenza), COPD and allied disease (1517 cases) and other remaining respiratory diseases (479 cases). There was very little radiation effect on pneumonia mortality, but evidence of a reduction in mortality risk for COPD and allied disease (ERR/Sv= −0.56, 95%CI: −0.94, −0.06; p =.02) and an increase in risk for other respiratory disease mortality (ERR/Sv = 2.30, 95%CI: 0.67, 4.62; p =.01) with increasing cumulative external dose were observed. The effects of radiation were more prominent amongst workers monitored for internal exposure. The reduction in mortality risk of COPD and allied disease per cumulative external dose was statistically significant for the radiation workers monitored for internal exposure (ERR/Sv= −0.59, 95%CI: −0.99, −0.05; p =.017) but not significant among the workers who were not monitored (ERR/Sv= −0.43, 95%CI: −1.20, 0.74; p =.42). A statistically significant increased risk was observed for other respiratory diseases among monitored radiation workers (ERR/Sv = 2.46, 95%CI: 0.69, 5.08; p =.019), but not among unmonitored workers (ERR/Sv = 1.70, 95%CI: −0.82, 5.65; p =.25). The effects of radiation exposure can be different depending on the type of respiratory disease. No effect was seen in pneumonia; a reduction in mortality risk of COPD, and increased mortality risk of other respiratory diseases were observed with cumulative external radiation dose. More studies are needed to verify these findings. [ABSTRACT FROM AUTHOR]

Uncertainty evaluation for unknown distribution data is a key problem to be solved in uncertainty evaluation theory. To evaluate the measurement uncertainty of data with unknown distributions, a novel uncertainty evaluation method based on the particle filter (PF) and beta distribution is proposed in this paper. A beta distribution with wide adaptability was adopted as the distribution type of measurement results, the parameters of the beta distribution were taken as the parameters to be estimated, and a state-space model was established. The PF method, suitable for non-Gaussian data, was utilized to obtain the estimates of the parameters of the beta distribution according to the measurement results. Finally, the best estimates of the measurement results and their uncertainty were calculated using the beta distribution parameters. Simulation results show that the proposed method is adaptive to accurately evaluate the measurement uncertainties of data, especially for non-Gaussian distribution data or asymmetrically distributed data. Multiple evaluation results show that the method has good robustness. The experimental results for the drift errors of a laser interferometer show that the uncertainty result of the proposed method is consistent with the Monte Carlo method. This method is suitable for a variety of distribution types that can be characterized through beta distribution and can solve the optimal estimation and uncertainty evaluation of most measurement results with unknown distribution types. [ABSTRACT FROM AUTHOR]

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Although nuclear power plants produce about 20% of India's power, the risk posed by radioactive leakage is considerable. Radiation leakage detection devices must be installed in all nuclear power plants to ensure that avoidable catastrophes never occur again and that the loss of human life is prevented. A safe atmosphere for inhabitants and workers may be ensured by keeping a consistent radiation level in all applications that use radioactive material. Complementary Metal-Oxide Semiconductor technology, or CMOS, uses complementary and symmetrical MOSFETS for logic-based functions in various applications, such as analog circuits (CMOS sensors). The Internet of Things (IoT) extends the power of the Internet beyond computing devices to a multitude of other things, processes, and environments. The main objective of this paper is to find a better and more creative solution for radioactive leakage detection techniques over present-day techniques. In this paper, the Authors aim to integrate CMOS and IOT applications for radioactive leakage detection methods on an industrial level. Within this paper, we have given brief descriptions of CMOS and IoT with their types, functions, methodology, and applications. CMOS is considered to be the most sophisticated and precise technology that can be employed to measure radiation leaks of all types (alpha rays, beta rays, gamma rays, and neutrons). With the help of IOT, massive disasters can be averted using complex alert systems. A well-coordinated combination of the two technologies has the potential to vastly increase leak detection potential and consistency. The study's major goal is to develop new and improved technology for detecting released radiation in the industry in order to obtain real-time information about the material leaked, as well as the location of the leak and the quantity of leakage that occurred, in order to reduce the danger of a natural catastrophe. [ABSTRACT FROM AUTHOR]

Background: Vertebroplasty is a minimally invasive outpatient procedure to stabilize compression fractures in the spine. This procedure involves injecting bone cement into the vertebrae that have been cracked or broken, typically due to osteoporosis. The cement hardens inside the bones, providing stability to the fractures and supporting the spine. Additionally, radioactive bone cement and brachytherapy sources have been utilized to suppress tumor growth in the vertebral body. Objective: We present a novel brachytherapy technique for treating vertebral body metastases using a liquid form of radioactive sources, Phosphorus-32 and Lutetium-177, separately mixed with bone cement and injected into vertebral body bone prostheses. We also investigated the dose distribution of the radioactive bone cement by theoretically calculating it using GEANT4 Monte Carlo and measuring it using TLD dosimeters for Phosphorus-32 and Lutetium-177 loaded in vertebral bodies. Material and methods: CT-scanned images of each vertebral body (L2 and L3) were imported into GEANT4 for simulation purposes. Two simulations were performed to evaluate the possibility of using PLA prostheses in ex vivo measurements, using bone and PLA material as a bone substitute for brachytherapy of Lutetium-177 and Phosphorus-32. The simulations calculated the dose distribution, dose rates, and deposited dose to the spinal cord and aorta. Next, 3D-printed bone prostheses were drilled and separately filled with bone cement, including PMMA-P32 and PMMA-Lu177, in liquid form using the Vertebroplasty technique. The dose to regions of interest was measured using Thermoluminescence dosimeters. Conclusions: When comparing the simulated and measured results of dose rates, it was observed that P32 delivers higher doses to normal organs such as the spinal cord and aorta. At the same time, Lu177 has better sparing in these regions of interest. Therefore, while P32 and Lu177 are suitable for radioactive bone cement treatment, Lu177 delivers relatively lower doses to vital organs such as the spinal cord and aorta. Additionally, Lu177 has characteristics such as a shorter range and lower energies of beta particles in tissue and the presence of gamma rays that make it a better choice for the same treatments. It also provides the possibility of SPECT imaging. [ABSTRACT FROM AUTHOR]

Background: Recent developments in alpha and beta emitting radionuclide therapy highlight the importance of developing efficient methods for patient‐specific dosimetry. Traditional tabulated methods such as Medical Internal Radiation Dose (MIRD) estimate the dose at the organ level while more recent numerical methods based on Monte Carlo (MC) simulations are able to calculate dose at the voxel level. A precalculated MC (PMC) approach was developed in this work as an alternative to time‐consuming fully simulated MC. Once the spatial distribution of alpha and beta emitters is determined using imaging and/or numerical methods, the PMC code can be used to achieve an accurate voxelized 3D distribution of the deposited energy without relying on full MC calculations. Purpose: To implement the PMC method to calculate energy deposited by alpha and beta particles emitted from the Ra‐224 decay chain. Methods: The GEANT4 (version 10.7) MC toolkit was used to generate databases of precalculated tracks to be integrated in the PMC code as well as to benchmark its output. In this regard, energy spectra of alpha and beta particles emitted by the Ra‐224 decay chain were generated using GAMOS (version 6.2.0) and imported into GEANT4 macro files. Either alpha or beta emitting sources were defined at the center of a homogeneous phantom filled with various materials such as soft tissue, bone, and lung where particles were emitted either mono‐directionally (for database generation) or isotropically (for benchmarking). Two heterogeneous phantoms were used to demonstrate PMC code compatibility with boundary crossing events. Each precalculated database was generated step‐by‐step by storing particle track information from GEANT4 simulations followed by its integration in a PMC code developed in MATLAB. For a user‐defined number of histories, one of the tracks in a given database was selected randomly and rotated randomly to reflect an isotropic emission. Afterward, deposited energy was divided between voxels based on step length in each voxel using a ray‐tracing approach. The radial distribution of deposited energy was benchmarked against fully simulated MC calculations using GEANT4. The effect of the GEANT4 parameter StepMax on the accuracy and speed of the code was also investigated. Results: In the case of alpha decay, primary alpha particles show the highest contribution (>99%) in deposited energy compared to their secondary particles. In most cases, protons act as the main secondary particles in the deposition of energy. However, for a lung phantom, using a range cutoff parameter of 10 µm on primary alpha particles yields a higher contribution of secondary electrons than protons. Differences between deposited energy calculated by PMC and fully simulated MC are within 2% for all alpha and beta emitters in homogeneous and heterogeneous phantoms. Additionally, statistical uncertainties are less than 1% for voxels with doses higher than 5% of the maximum dose. Moreover, optimization of the parameter StepMax is necessary to achieve the best tradeoff between code accuracy and speed. Conclusions: The PMC code shows good performance for dose calculations deposited by alpha and beta emitters. As a stand‐alone algorithm, it is suitable to be integrated into clinical treatment planning systems. [ABSTRACT FROM AUTHOR]

Hard bremsstrahlung produced during the deceleration of fission-product beta rays in nuclear fuel is proposed as a source of delayed photoneutrons (PNs) in heavy water reactors. Electron Gamma Shower (EGS5) code simulations of coupled electron-photon transport in seven fuel element geometries immersed in an infinite heavy water medium confirm high-energy beta rays produce sufficient bremsstrahlung yields with photon energies greater than the D(γ,n)1H reaction threshold such that the beta-ray contribution to an isotopic PN yield can be comparable to or greater than yields from hard gamma rays emitted during the isomeric transition of the daughter, especially for some short-lived fission products with high-intensity direct-to-ground-state beta transitions where the beta ray and antineutrino carry away the majority of the Q-value. Some fission products that do not have hard gamma rays in their decay schemes are in fact PN precursors due to the beta-ray-bremsstrahlung contribution. The lack of evaluated nuclear data for many short-lived fission products, data reliability issues of fission products with decay scheme data, cross-section library effects, and possible decay-chain/parent-feeding phenomenon are affecting the accuracy of PN group parameters derived from a small number of legacy experiments. The reanalysis of two legacy PN experiments supports the existence of a very-short-lived direct-delayed neutron group. [ABSTRACT FROM AUTHOR]

هذه الدراسة تقوم بفحص تأثير المصادر اإلشعاعية على السالمونيال تايفي، وهي بكتيريا معوية متحركة ، سالبة لصبغة الجرام، ذات شكل عصوي الهوائية اختيارية، غير منتجة للسبورات، وتصيب مجموعة متنوعة من أنواع الخاليا بما في . السالمونيال تنتشر أساسًا من خالل الطعام الملوث، والذي يكون غالبًا ملوثً ذلك الخاليا الطالئية ، الجذعية ، والبلعمية ا بالفضالت البشرية أو الحيوانية. في هذه البحث، تم استخدام 50 عينة من السالمونيال تايفي من مرضى مختلفين في مستشفى بغداد. تضمنت الطريقة تحديد البكتيريا باستخدام 2Viteck، وزراعتها على مرق غذائي وغراء غذائي، ثم تعريضها لمصادر إشعاعية متنوعة: 23Na و 60CO( µCi 1 و µCi 10 60CO). استُخدمت أطباق بيتري تحتوي على غراء غذائي لزرع العينات، تلتها فترة حضانة لمدة 24 ساعة عند 37 درجة مئوية. أظهرت النتائج أن التعرض ألشعة بيتا وجاما الناتجة عن 23Na بمستوى نشاط 10 µCi أدى إلى زيادة في مستويات اإلشعاع مع الزمن. بدون ألمونيوم، كانت جرعات اإلشعاع لفترات الساعة الواحدة، والساعتين، والثالث ساعات 9.64 ميلي سيفرت، و19.29 ميلي سيفرت، و28.93 ميلي سيفرت على التوالي، مما أدى إلى تغير في عدد الخاليا القابلة للنجاة. مع األلمونيوم، كانت الجرعات لنفس الفترات أقل بشكل ملحوظ، مع وجود أقل عدد من الخاليا القابلة للنجاة. بالمثل، أدى التعرض لـ 60CO (µCi 1 (إلى مستويات متغيرة من اإلشعاع وعدد متغير من الخاليا القابلة للنجاة، مما يشير إلى اتجاه مماثل بوجود أو عدم وجود ألمونيوم. أظهر (µCi 10 (60CO أيضًا زيادة في جرعات اإلشعاع مع مرور الوقت، وعرض تأثي ًرا على عدد الخاليا القابلة للنجاة. يستنتج البحث أن اإلشعاع الناتج عن مصادر الصوديوم والكوبالت كان فعاًال في القضاء على السالمونيال تايفي بنسبة مباشرة إلى زيادة وقت التعرض والجرعة. يسلط هذا البحث الضوء على إمكانية تأثير مصادر اإلشعاع على قابلية البقاء لخاليا السالمونيال تايفي. [ABSTRACT FROM AUTHOR]

The mass attenuation coefficient of lead nitrate (Pb(NO3)2)-filled polycarbonate (PC) composite films were determined both computationally (using Baltakmen's and Thummel empirical formulae) and experimentally using 204Tl and 90Sr-90Y radio-isotopes for films at different filler levels 0, 5, 15, 25, 35 and 50 weight percent (Wt.%). In comparison with Thummel empirical formula, the values obtained from Baltakmen's empirical formula is in good agreement with the experiment. The percentage decrease of half value layer values were (52 ± 8) and (60 ± 10)% for 204Tl and 90Sr-90Y, on comparing the values for 0 and 50 Wt.% films, and so the prepared composite films shield the beta particles effectively. The PC that used to shield the low-energy beta particles of 90Sr-90Y can also moderate the higher energy beta particles; the plot of end point energy of 90Sr-90Y versus thickness of PC exhibits a decreasing trend, which confirms that PC acts as an electron moderator. [ABSTRACT FROM AUTHOR]

Background: The [177Lu]Lu-DOTA-TATE mediated peptide receptor radionuclide therapy (PRRT) of neuroendocrine tumors (NETs) is sometimes leading to treatment resistance and disease recurrence. An interesting alternative could be the somatostatin antagonist, [177Lu]Lu-DOTA-JR11, that demonstrated better biodistribution profile and higher tumor uptake than [177Lu]Lu-DOTA-TATE. Furthermore, treatment with alpha emitters showed improvement of the therapeutic index of PRRT due to the high LET offered by the alpha particles compared to beta emitters. Therefore, [225Ac]Ac-DOTA-JR11 can be a potential candidate to improve the treatment of NETs (Graphical abstract). DOTA-JR11 was radiolabeled with [225Ac]Ac(NO3)3 and [177Lu]LuCl3. Stability studies were performed in phosphate buffered saline (PBS) and mouse serum. In vitro competitive binding assay has been carried out in U2OS-SSTR2 + cells for natLa-DOTA-JR11, natLu-DOTA-JR11 and DOTA-JR11. Ex vivo biodistribution studies were performed in mice inoculated with H69 cells at 4, 24, 48 and 72 h after injection of [225Ac]Ac-DOTA-JR11. A blocking group was included to verify uptake specificity. Dosimetry of selected organs was determined for [225Ac]Ac-DOTA-JR11 and [177Lu]Lu-DOTA-JR11. Results: [225Ac]Ac-DOTA-JR11 has been successfully prepared and obtained in high radiochemical yield (RCY; 95%) and radiochemical purity (RCP; 94%). [225Ac]Ac-DOTA-JR11 showed reasonably good stability in PBS (77% intact radiopeptide at 24 h after incubation) and in mouse serum (~ 81% intact radiopeptide 24 h after incubation). [177Lu]Lu-DOTA-JR11 demonstrated excellent stability in both media (> 93%) up to 24 h post incubation. Competitive binding assay revealed that complexation of DOTA-JR11 with natLa and natLu did not affect its binding affinity to SSTR2. Similar biodistribution profiles were observed for both radiopeptides, however, higher uptake was noticed in the kidneys, liver and bone for [225Ac]Ac-DOTA-JR11 than [177Lu]Lu-DOTA-JR11. Conclusion: [225Ac]Ac-DOTA-JR11 showed a higher absorbed dose in the kidneys compared to [177Lu]Lu-DOTA-JR11, which may limit further studies with this radiopeptide. However, several strategies can be explored to reduce nephrotoxicity and offer opportunities for future clinical investigations with [225Ac]Ac-DOTA-JR11. [ABSTRACT FROM AUTHOR]

Fluid-fueled molten-salt reactors (MSRs) are actively being developed by several companies, with plans to deploy them internationally. The current IAEA inspection tools are largely incompatible with the unique design features of liquid fuel MSRs (e.g., the complex fuel chemistry, circulating fuel inventory, bulk accountancy, and high radiation environment). For these reasons, safeguards for MSRs are seen as challenging and require the development of new techniques. This paper proposes one such technique through the observation of the reactor's off-gas. Any reactor design using low-enriched uranium will build up plutonium as the fuel undergoes burnup. Plutonium has different fission product yields than uranium. Therefore, a shift in fission product production is expected with fuel evolution. The passive removal of certain gaseous fission products to the off-gas tank of an MSR provides a valuable opportunity for analysis without significant modifications to the design of the system. Uniquely, due to the gaseous nature of the isotopes, beta particle emissions are available for observation. The ratios of these fission product isotopes can, thus, be traced back to the relative amount and types of fissile isotopes in the core. This proposed technique represents an effective safeguards tool for bulk accountancy which, while avoiding being onerous, could be used in concert with other techniques to meet the IAEA's timeliness goals for the detection of a diversion. [ABSTRACT FROM AUTHOR]

The approaches for predicting output parameters of betavoltaic batteries are reviewed. The need to develop a strategy for predicting these parameters with sufficient accuracy for the optimization of betavoltaic cell design without using the simple trial and error approach is discussed. The strengths and weaknesses of previously proposed approaches for the prediction are considered. Possible reasons for the difference between the calculated and measured parameters are analyzed. The depth dependencies of beta particles deposited energy for Si, SiC, GaN, and Ga2O3 and 20% purity 63Ni and titanium tritide as radioisotope sources are simulated using the Monte Carlo algorithm taking into account the full beta energy spectrum, the isotropic angular distribution of emitted electrons and the self-absorption inside the radioisotope source for homogeneously distributed emitting points. The maximum short circuit current densities for the same semiconductors and radioisotope sources are calculated. The methodology allowing the prediction of betavoltaic cell output parameters with accuracy no worse than 30% is described. The results of experimental and theoretical investigations of the temperature dependence of betavoltaic cell output parameters are briefly discussed. The radiation damage by electrons with the subthreshold energy and the need to develop models for its prediction is considered. [ABSTRACT FROM AUTHOR]

This is the story of how one man's life's work allowed for Iodine-131 (I-131) to become a therapy for hyperthyroidism and thyroid cancer. What is now a standard in our times arose from Saul Hertz's rather challenging and humble beginnings. Thyroid lobectomy and total thyroidectomy were therapeutic mainstays for thyroid disease until Hertz treated his first patient with radioactive iodine (RAI) ablation therapy at Massachusetts General Hospital (MGH) on March 31, 1941. His concepts for using beta particle emission from RAI to ablate thyroid tissue were revolutionary. Hertz's RAI therapy translated to research with thyroid cancer by the mid-1940s. The high-energy beta particles produced cytolethal effects on remnant thyroid tissue left behind by total thyroidectomy, thereby accomplishing completion thyroidectomy in some patients. Progressive surgeons from the Hertz era incorporated RAI into their practice. MGH surgery resident Francis Moore took sabbatical from clinical training to do translational research with RAI and other radioisotopes. Irving Ariel of New York became known as a nuclear surgeon in the wake of Hertz's work. George Crile Jr of Cleveland became an RAI advocate for the surgical community, implementing several paradigm-changing concepts in thyroid disease along the way. Hertz was a visionary who sparked this movement, predicting many of the molecular dilemmas with RAI-tumor avidity that clinical researchers continue to navigate today. This timely history for surgical oncologists and endocrine surgeons traces the development of RAI therapy through the life of Saul Hertz, a biographical window influenced by social stigma, political controversy, and mainstream media. [ABSTRACT FROM AUTHOR]

Purpose: To update and extend version 2 of the Carleton Laboratory for Radiotherapy Physics (CLRP) TG-43 dosimetry database (CLRP_TG43v2) for high-energy (HE, ≥ 50 keV) brachytherapy sources (1 169Yb, 23 192Ir, 5 137Cs, and 4 60Co) using egs_brachy, an open-source EGSnrc application. A comprehensive dataset of TG-43 parameters is compiled, including detailed source descriptions, dose-rate constants, radial dose functions, 1D and 2D anisotropy functions, along-away dose-rate tables, Primary and Scatter Separated (PSS) dose tables,and mean photon energies escaping each source.The database also documents the source models which are freely distributed with egs_brachy. Acquisition and Validation Methods: Datasets are calculated after a recoding of the source geometries using the egs++ geometry package and its egs_brachy extensions. Air kerma per history is calculated in a 10 × 10 × 0.05 cm³ voxel located 100 cm from the source along the transverse axis and then corrected for the lateral and thickness dimensions of the scoring voxel to give the air kerma on the central axis at a point 100 cm from the source’s mid-point. Full-scatter water phantoms with varying voxel resolutions in cylindrical coordinates are used for dose calculations. Most data (except for 60Co) are based on the assumption of charged particle equilibrium and ignore the potentially large effects of electron transport very close to the source and dose from initial beta particles. These effects are evaluated for four representative sources. For validation, data are compared to those from CLRP_TG43v1 and published data. Data Format and Access: Data are available at https://physics.carleton. ca/clrp/egs_brachy/seed_database_v2 or http://doi.org/10.22215/clrp/tg43v2 including in Excel (.xlsx) spreadsheets, and are presented graphically in comparisons to previously published data for each source. Potential Applications: The CLRP_TG43v2 database has applications in research, dosimetry, and brachytherapy planning. This comprehensive update provides the medical physics community with more precise and in some cases more accurate Monte Carlo (MC) TG-43 dose calculation parameters, as well as fully benchmarked and described source models which are distributed with egs_brachy. [ABSTRACT FROM AUTHOR]

Background: Internal dosimetry has an increasing role in the planning and verification of nuclear medicine therapies with radiopharmaceuticals. Dose Point Kernels (DPKs), quantifying the energy deposition all around a point source, in a homogenous medium, are extensively used for 3D dosimetry and nowadays are mostly evaluated by Monte Carlo (MC) simulation. To our knowledge, DPK for beta emitters is estimated neglecting the continuous photon emission due to the Internal Bremsstrahlung (IB), whose contribution to the absorbed dose can be relevant beyond the maximum range of betas, as evidenced in recent works. Purpose: Aim of this study was to investigate and quantify, by means of MC simulations, the contribution of IB photons to DPK calculated for 90Y and provide the updated 90Y DPK. Methods: The overall radiation due to the decay of a 90Y point source, placed at the centre of concentric water shells of increasing radii from 0.02 cm to 20 cm, was simulated with GAMOS, including the IB source term whose spectral distribution was described by an analytical model. Energy deposition was scored in the shells as a function of the distance from the source, R, and DPK was estimated in terms of the scaled absorbed dose fraction, F(R/X90), where X90 is the range within which the beta particles deposit 90% of their energy. Results: A comparison between the two simulated absorbed dose distributions, calculated with or without IB, clearly shows that the latter (incomplete) choice is consistent with the findings of other Authors and systematically underestimates the absorbed dose imparted to the tissue. 90Y DPK values currently used are underestimated by 20%-34% for R>2X90. Conclusions: The revised values provided in this work suggest that the inclusion of IB emission in DPK evaluations is advisable for pure beta emitters. [ABSTRACT FROM AUTHOR]

Er3+-doped calcium fluoride (CaF2:Er3+) nanoparticles (NPs) have been synthesized by a chemical co-precipitation method. A solution of water ethanol in a 1:1 ratio was used as a solvent. X-ray diffraction and scanning electron microscopy (SEM) results indicated that the fabricated material had a cubic crystal structure and a characteristic cubic shape of Caionscrystals. The main grain size calculated from Scherer's formula was about 30 nm. The photoluminescence (PL) spectrum of the material showed the specific emissions of Er3+ ion in the CaF2 host lattice and the highest emission intensity was obtained at 2 mol% Er3+ ion. Under a 980 nm laser excitation, the up-conversion luminescence spectra with predominance of red emission were recorded. The thermoluminescence (TL) characteristics of the material were also studied. The obtained CaF2:Er3+ nanocrystals exhibit a high TL sensitivity and linearity to beta (β) radiation doses. The main TL peak is located at 235°C (508 K) and the kinetic parameters corresponding to the trap have been determined by TLAnal software These properties make the phosphor useful for application to estimate exposures of beta rays. [ABSTRACT FROM AUTHOR]

The thermoluminescence (TL) dosimetric properties of metaphosphate glass system were investigated. The glass system of (Er2O3)1-(SrO)24-(B2O3)25-(P2O5)50 was prepared using a melt quenching technique. The glass system was characterized using different techniques. The internal structure of the system was probed with XRD and FTIR technique was used to identify the types of bonds between the involved atoms. The analysis of TL glow curve was studied by different methods and was found to be composed of six trap peaks at energies 0.817, 0.846, 0.958, 1.190, 1.248, and 1.347 eV. The TL dose–response signal was found to be linear in the range of 0.22–55 Gy. The activation energies were determined by three methods: glow curve deconvolution (CGCD), Tmax-Tstop method and Peak shape (PS) methods. The results of the three methods exhibited a good agreement with each other. Highlights The thermoluminescence properties of metaphosphate glass were investigated. The glass samples were irradiated to different doses of beta particles. The deconvolution indicated the presence of six overlapping glow peaks. The activation energies were determined by three methods and the results of all the methods exhibited a good agreement. [ABSTRACT FROM AUTHOR]

The β− emitter, rhenium-188 (188Re), has long been recognized as an attractive candidate for targeted cancer radionuclide therapy (TRNT). This transition metal shares chemical similarities with its congener element technetium, whose nuclear isomer technetium-99m (99mTc) is the current workhorse of diagnostic nuclear medicine. The differences between these two elements have a significant impact on the radiolabelling methods and should always receive critical attention. This review aims to highlight what needs to be considered to design a successful radiopharmaceutical incorporating 118Re. Some of the most effective strategies for preparing therapeutic radiopharmaceuticals with 188Re are illustrated and rationalized using the concept of the inorganic functional group (core) and a simple ligand field theoretical model combined with a qualitative definition of frontiers orbitals. Of special interest are the Re(V) oxo and Re(V) nitrido functional groups. Suitable ligands for binding to these cores are discussed, successful clinical applications are summarized, and a prediction of viable future applications is presented. Rhenium-188 decays through the emission of a high energy beta particle (2.12 MeV max energy) and a half-life of 16.9 h. An ideal biological target would therefore be a high-capacity target site (transporters, potential gradients, tumour microenvironment) with less emphasis on saturable targets such as overexpressed receptors on smaller metastases. [ABSTRACT FROM AUTHOR]