Radioactive Sources Research Articles

On the Internal Bremsstrahlung accompanying β-decay and its potential relevance in the application of radioactive sources.

An in-depth analysis of the decay process for β-emitting radionuclides highlights, for some of them, the existence of high-order effects usually not taken into account in literature as considered negligible in terms of energy and yield, and referred to as Internal Bremsstrahlung (IB). This set of β-radionuclides presents, besides their β spectrum, a continuous γ emission due to the Coulomb field braking action on the emitted electron following the decaying nucleus. 
In this work, we review the theoretical and experimental studies on the IB process focusing on its actual importance for the pure β emitters. It emerges that there is no satisfactory model able to reproduce the experimental IB distribution for most of the investigated beta emitters and the several measurements are sometimes at odds with each other. Moreover, as recently demonstrated, the IB process can give a relevant contribution to the physics of beta emitters thus requiring its inclusion in the physics of the beta decay.
A discussion on the importance of considering the IB process in both applicative fields such as nuclear medicine, industrial applications, and research or calibration laboratories, and in other relevant fields of particle physics or astrophysics, such as the research on dark matter or neutrino mass, is presented.

A Novel Anthropometric Phantom for Rapid Radiological Triage: A Quick Sort Triage Solution

Abstract Rapidly identifying individuals who have received internal radiation exposure above action guidelines is crucial for mitigating health risks and addressing public concerns immediately following a radiological event involving the dispersal of radioactive materials. This study describes a novel triage method using a conventional Geiger-Mueller (GM) detector to select those individuals from the large group of persons who may have received an intake of radioactive material at levels corresponding to one Clinical Decision Guide (CDG). The triage method involves placing a portable GM detector against the lower anterior torso of a sitting person as they bend over to surround the detector with their body. The response of the GM detector is evaluated using a new, specially designed anthropometric phantom that simulates combined tissues of the lower thorax and gastrointestinal (GI) tract and is fabricated with a tissue substitute material that matches the overall radiological properties of human tissue present in this body region. The phantom has four separate layers of tissue substitute material with ports to accommodate a single GM detector at the center and one or more sealed radioactive sources that can be arranged to characterize the detector response for a variety of source distributions, including a “hot spot.” In this study, the response of a Ludlum Model 133-4 GM detector was evaluated using sealed sources of 232Th and 137Cs to determine the measurement efficiency for a quantity of activity present in the abdomen within a few hours post-intake equivalent to 1 CDG. Results demonstrate that the Quick Sort triage procedure using a single GM detector placed against the abdomen of a person can reliably detect internal deposition resulting from an intake equivalent to 1 CDG for 232Th or a significantly lower activity of 137Cs within a few hours following a radiological incident. The evaluation was performed over a wide range of photon energies, so the Quick Sort triage procedure is expected to be suitable for most fission products distributed uniformly within the abdomen or as a single “hot spot.”

Output performance analysis of a piezoelectric micro nuclear battery powered by radioisotopes

Abstract This paper investigates the output performance (output voltage, electrical energy output, power output) of a piezoelectric micro nuclear battery powered by radioisotopes. The theoretical formulations are base on Euler-Bernoulli beam theory and include the effects of load nonlinearity due to radioactive source. By employing extended Hamilton’s principle, the nonlinear electromechanical Lagrange equations are derived then solved by using Runge-Kutta method to obtain the dynamic output response. The results based on present electromechanical dynamic model are validated through direct comparisons with the results in the open literatures. The effects of initial gap, length of the piezoelectric layer, thickness of the collector and load impedance on the output voltage, energy output and power output of the piezoelectric micro nuclear battery are discussed in detail.

Three-dimensional source position verification in image-guided high-dose-rate brachytherapy using an XCT-based gel dosimeter.

Comprehensive quality assurance (QA) for a seamless workflow of high-dose-rate brachytherapy, from imaging to planning and irradiation, is uncommon, and QA of the source dwell position is performed in one- or two-dimensions. Gel dosimetry using magnetic resonance imaging (MRI) is effective in verifying the three-dimensional distribution of doses for image-guided brachytherapy (IGBT). However, MRI scanners are not readily accessible, and MRI scanning is time-consuming. Nevertheless, X-ray computed tomography (XCT) is available for IGBT planning. In this study, we designed and developed an efficient method for QA for a seamless workflow of IGBT with a new commercially available XCT-based polymer gel dosimeter. To enable direct insertion of brachytherapy applicators, the gelatinizing agent of the dosimeter was modified. A cylindrical polyvinyl chloride jar was filled with the modified gel dosimeter, which was subsequently used to determine the reproducibility of source dwell positions, detectability of source positional errors from intentionally introduced catheter length offsets, effect of looped source transfer tubes on the average displacement, extent of inter-observer variation, and gel robustness following multiple needle-insertions. Three ProGuide sharp needles were inserted into the jar. The dwell time at each point was determined to identify the irradiated volume with a diameter of approximately 10mm on XCT images. All the times were the same. The plan was delivered using an afterloader with an Ir-192 radioactive source, and the irradiated gel dosimeter was scanned using an XCT scanner. The subtracted images were generated from pre- and post-irradiated images. Volumes with incremented Hounsfield units were manually identified and contoured. The centroid of the volume was defined as the measured source dwell position. Subsequently, planned source dwell positions were extracted from the DICOM file of the plan. Finally, the source dwell positions in plan and irradiated gel were compared in three axes. The hardness of the dosimeter was 1250% greater than that of the previously reported gel dosimeter. Source dwell positions were visually identified in the XCT image. Testing of CT acquisition, planning, irradiation, and analysis was completed in approximately 1h. In the reproducibility test of source dwell positions, created by inserting three needles (each with three source dwell positions), the average displacements of the source positions from the first source dwell position were within 0.5mm in all three directions. In the detectability test, displacements were less than 1mm in the x-y plane but greater than 1mm in the z-axis, which was the source path direction. When errors of 1-3mm were intentionally introduced, the measured displacement was within 0.7mm of the median (range: 0.21-1.65mm) of intentional errors. When the transfer tube was looped, the source dwell position displaced by approximately 1mm. After 20 needle-insertions, the source dwell position displacement was within 1mm. The maximum inter-observer variation of contouring was 0.57mm. The XCT-based gel dosimeter enabled verification of three-dimensional source dwell positions for a seamless workflow of IGBT with high precision and efficiency.

A 90SrHfO3-based betavoltaic/beta-photovoltaic dual-effect integrated nuclear battery

In this paper, the secondary conversion idea is used to reduce the self-absorption effect of the radioactive source by combining the radioactive source with the scintillation material, so as to enhance the energy conversion efficiency of the battery. A theoretical model of a dual-effect integrated nuclear battery based on 90SrHfO3 doped with Ce is proposed. The emission photon and electron spectra of the β-luminescent integrated radioactive source 90SrHfO3 have been calculated by GEANT4. The average outgoing electron energy of SrHfO3 was calculated, and the thickness of the energy reducing material was determined. The effect of structural parameters of GaAs materials on the dual-effect integrated nuclear battery was analyzed to obtain the optimal output performance according to theoretical calculation. From the perspective of conversion efficiency, the activity density and thickness of 90SrHfO3 are determined to be 1.6 Ci/cm2 and 53.6 μm. At this time, the thickness of SrHfO3 is 1.28 mm. The total maximum output power density of the optimized dual-effect integrated nuclear battery is 9.31 μ W/cm2, and the energy conversion efficiency is 0.18 %. At this point, the doping concentrations of GaAs are Na = 1.26 × 1017 cm−3 and Nd = 6.31 × 1018 cm−3, and xj is 0.05 μm. Compared with nonintegrated batteries, the output performance is significantly improved.

Performance study of GaN-based betavoltaic nuclear batteries with 3D interfaces

This study presents a design of a 3D interface simulation model featuring an inverted pyramid structure. Our objective is to forecast the performance of GaN-based betavoltaic nuclear batteries with the PN junction 3D interface structures comparing a practical machining process. Initially, we computed the electron-hole pairs (EHPs) generation rate in GaN materials irradiated by both 63Ni and 147Pm sources using Geant4. Furthermore, we employed COMSOL Multiphysics, a finite element analysis software, to simulate the EHPs transport phenomena within the battery and investigate the influence of structural parameters on the output performance. Despite maintaining thicknesses of the P- and N-regions and consistent doping concentrations (Hp-GaN, Hn-GaN, Na, and Nd) as constants, the simulation results revealed notable disparities in the short-circuit current density (Jsc), open-circuit voltage (Voc), and maximum output power density (Pmax) among batteries irradiated with various radioactive sources. Subsequently, we investigated the output performance of the nuclear battery by altering parameters such as the number of inverted pyramid structures, junction depth, and type of radioactive source. Our investigation revealed that selecting 63Ni as the radioactive source, with Na at 1017 cm−3, Nd at 1014 cm−3, a junction depth of 0.1 μm, and inverted pyramid structures of 25, resulted in the following battery performance parameters: a short-circuit current density (Jsc) of 0.648 μA/cm2, an open-circuit voltage (Voc) of 2.3481 V, and a maximum output power density (Pmax) of 1.2949 μW/cm2. Substituting the radioactive source with 147Pm, the average short-circuit current density, Jsc, increased to 56.865 μA/cm2, and the maximum output power density, Pmax, increased to 94.975 μW/cm2, It's a significant enhancement in output performance.

Simplified efficiency calibration methods for scintillation detectors used in nuclear remediation

Our study introduces innovative methods to address waste reduction and enhance resource efficiency in nuclear cleanup processes. We focus on sustainable nuclear technology, aligning with goals for cleaner production and environmental protection. We developed two novel methods, termed “oversimplified” and “simplified,” for easily determining the photopeak efficiency of NaI(Tl) scintillation detectors. These methods, along with a “general” solution method, were validated with calibrated radioactive sources such as 241Am, 57Co, 133Ba, 137Cs, and 60Co, and were used to commission a NaI(Tl) scintillation detector system at Chalk River Laboratories (CRL) for nuclear remediation. The system demonstrated high accuracy, making it suitable for screening unstable isotopes at contaminated sites. This screening tool significantly reduces the number of soil samples requiring detailed characterization, thereby lowering operational costs. The NaI(Tl) detector system was calibrated for near-contact geometry, which is commonly used at CRLs. Detection limits were established for this configuration. By improving the efficiency calibration of scintillation detectors, our study advances sustainable nuclear remediation practices, promoting environmental sustainability and cleaner production processes.

Optimizing neutron shielding: A specialised container approach for Disused Sealed Radioactive Sources and orphan neutron emitters

Shielding Disused Sealed Radioactive Sources (DSRSs) and orphan neutron sources, such as 252Cf, pose challenges due to the high penetration of neutrons, induced radioactivity in shielding materials, and the limited availability of compact, effective shielding materials. This study addresses these challenges by proposing a specialized container for the safe transport, conditioning, and disposal of neutron-emitting DSRSs and orphan sources. The computational tool that was used in this study is the Monte Carlo N-Particle (MCNP). The investigation begins with an examination of moderation materials, including high-density polyethylene (HDPE), paraffin, and water-extended polyester (WEP). Subsequently, four concrete types, namely Ordinary, Barite, Portland, and Serpentine Concrete, are scrutinized. Employing a comprehensive methodology, the design of the container is optimized to effectively moderate and absorb neutron emissions. The findings of this study demonstrate that the designed compact container can safely handle activities exceeding those studied, effectively managing up to 10 μg (about 0.2 GBq) 252Cf without exceeding 25 μSv/h at the outer container contact. This suggests a promising solution for the secure management of high-activity neutron-emitting sources.

Gaussian process-based online sensor selection for source localization

This paper addresses the sensor selection problem for source localization within cyber–physical systems (CPSs). While recent machine learning and reinforcement learning approaches aim to optimize sensor selection and placement within the Area of Interest (AoI), their need for intensive data collection and training precludes online operation. Furthermore, these methods often require prior knowledge of the unknown source’s characteristics and lack adaptability to the dynamic nature of CPSs, leading to inefficiencies in unseen environments. This paper addresses these shortcomings using Gaussian process Optimization coupled with an active sensor selection mechanism to locate the unknown source within the AoI. The proposed approach first builds a probabilistic model of the environment, which is discretized into a grid, without prior training using a Gaussian Process surrogate model. Next, the model iteratively and systematically learns the underlying spatial phenomenon using Gaussian Process optimization. Concurrently, the approach selects a subset of sensors by optimizing a fitness function that advocates selecting informative and energy-efficient sensors. Next, the probabilistic model, having accurately learned the environment, directs the algorithm to the unknown source by identifying the cell with the highest likelihood of containing it. Finally, a peak refinement step is performed, which computes the exact location of the source within the designated cell. The proposed method’s efficacy is validated through experiments in radioactive source localization, validation studies, and adaptability assessments across various environments. In terms of quality of localization (QoL), it outperforms recent localization benchmarks, such as a reinforcement learning-based approach and DANS, by around 18% and 100%, respectively.

A study on in-situ characterization technology development for clearance verification of radioactive waste from nuclear decommissioning

Although the clearance level of every radioactive nuclide was published by the IAEA to promote the recycling and reuse of decontaminated radioactive waste worldwide, technical and regulatory issues have always been raised around the application of the criteria. Therefore, several countries are developing in-situ characterization equipment or apparatus for on-site verification to check if the clearance criteria is met.In this study authors developed a pilot radiation detection and measurement system using in-situ characterization technology to solve the issues, which consists of a 3D scanning camera system and a built-in Monte Carlo simulation program. Measurement results show that MDA (Minimum Detectable Activity) of the current design was indisputably below the clearance level and built-in Monte Carlo simulation package closely predicts the measurements results with the error of less than 5%. This implicates that it can determine with enough margin whether the radioactivity level of decontaminated metallic components meets the clearance criteria at decommissioning site or not.Practically when we measure the radioactivity from gamma ray source mass attenuation always takes place during the photon transports through the medium. In fact, the reduction depends on the material, shapes, and radioactive sources. In this study the reduction factors were experimentally examined according to the influencing parameters and the results were saved as DCF (Density Correction Factor) in the data base. As expected, it turned out that the factor is somewhat affected by medium material and radioactive sources, but it is basically proportional to the distance of gamma ray passage.It is expected that upgraded design with more accurate and reliable instruments can make it easier for regulators to accept the application of the in-situ characterization technology on-site.

A radioactive source-seeking method based on angle constraint and particle diffusion

The deployment of mobile robots to conduct search for radioactive sources plays a crucial role in preventing radiation pollution and safeguarding public health. And it is a significant challenge to accurately locate radioactive sources in unknown environments. Herein, a particle filter based on mobile robot search method is proposed to localize radiation sources. By applying an angle constraint technique, the complexity of this algorithm is reduced, the high accuracy of source estimation is maintained, and the range of search is expanded. Additionally, a particle diffusion technology is applied to address particle loss that occurs during filtering. Furthermore, an adaptive gradient descent strategy is adopted to enhance the search efficiency. Experimental results demonstrate that this method achieves a success rate of over 95 % within a rectangular area (e.g., 40m by 40m), outperforming traditional methods, and it could perform effectively in dual radioactive source search tasks.

New readout system of the FATIMA detectors based on Silicon Photomultipliers arrays

We present a new readout system based on large area Silicon Photomultipliers arrays coupled with cylindrical 1.5 × 2” LaBr3(Ce) FATIMA-type crystals. This achieves the fast-timing capabilities of such crystals coupled to the usual Photomultiplier Tubes. Energy calibration was measured with 137Cs and 152Eu standard radioactive sources, while the timing performances were investigated with a 60Co radioactive source. We benchmark our results against the corresponding results obtained with the fast R9779 Photomultiplier tubes and highlight the importance of achieving similar energy and timing performances for nuclear structure experiments. The FWHM energy resolution for the 1.5 × 2” LaBr3(Ce) crystal coupled with the SiPM and PMT was found to be 3.31(2)% and 3.85(1)%, respectively, for the 661.6 keV transition of the 137Cs source. The timing resolution was measured between a conical crystal known for its fast response and a cylindrical crystal coupled to a SiPM or PMT readout. We obtain values of FWHM = 230(1) ps and 232(1) ps, respectively, between the 1173.2-1332.5 keV transitions of the 60Co source. In addition, a temperature effect compensation circuit was developed to maintain a good stability of the gain during long measurements, typical for in-beam/off-beam experiments in nuclear physics.

Development of a large NaI(Tl) detection system

A large NaI(Tl) detection system was developed to address the increasing demand for high detection efficiency and high energy resolution detectors across various applications. Through Geant4 simulation and experimental research, critical characteristics of the detector prototype were examined, encompassing energy response, energy nonlinearity, and energy resolution. Given the substantial impact of variations in Tl concentration and the complex process of photon propagation on the detection performance of large NaI(Tl) crystals, the detection efficiency and energy resolution with the radioactive source placed at different incident spots were studied to evaluate its spatial response uniformity. The results demonstrate that the detector's energy response range spans from 50 keV to 3 MeV with an energy nonlinearity of 1.5%. The developed large NaI(Tl) detection system achieved an overall energy resolution of 7.93%, along with excellent uniformity in its resolution and detection efficiency, satisfying the application requirements for large dimensions and high detection efficiency.

The Medium Energy Electron Telescope (MEET): Instrument Fabrication and Testing

AbstractThis manuscript is a follow up study to Hogan et al., (2024, https://doi.org/10.1029/2023JA032221) which describes the science motivation and development of the Medium Energy Electron Telescope (MEET). Medium Energy Electron Telescope is a 1U instrument optimized to measure 30–400 keV electrons in the inner radiation belt with fine energy resolution to resolve dynamics of these populations which are not well understood. Here we present the fabrication and testing of MEET to certify its performance in preparation for in‐space measurements. Assembly of an engineering model is shown. This unit has undergone vibration testing and these results are discussed. The electronics of the instrument are tested after these environmental tests including electron measurements with pulse injection and a radioactive source. Test results indicate the instrument is viable for flight on a potential mission by satisfying noise requirements and reproduction of an input flux spectrum. The noise of expected input signals is quantified to be <∼6 keV allowing for <20% dE/E for 30 keV electrons. Strontium‐90 radioactive source tests were conducted. Using measured count rates from MEET's electron energy channels, we reproduce the strontium‐90 spectrum proving the instrument's ability to measure flux of 30–800 keV electrons with fine nominal energy resolution (<20% dE/E for <60 keV, and <10% for >60 keV electrons). These results demonstrate MEET's performance in a relevant environment via ground testing. Medium Energy Electron Telescope is available for future missions to provide novel electron measurements in the inner radiation belt.

Development of a charged particle-[formula omitted] coincidence system for nuclear structure and reaction studies at TIFR

A new detector system for measurements of charged particles and γ-rays in coincidence has been developed at TIFR Mumbai, by coupling an annular double-sided segmented Si detector with an array of Compton-suppressed clover HPGe detectors. Digital data acquisition system has been configured for the setup, which has been calibrated and tested using the 229Th radioactive source that emits α-particles along with γ-rays. The functionality and performance of the coincidence apparatus for Doppler correction of γ-transitions emitted during the in-flight de-excitation of the projectile and the target in the 30Si + 197Au Coulomb excitation experiment have been demonstrated.

Overproduction Of Fibrinolysis Enzyme Produced By Mutant Pseudomonas Aeruginosa Compared To Wild Type Pseudomonas Aeruginosa

Objective: The aim of the study is to increase the production of fibrinolytic enzyme produced by pseudomonas aeruginosa after mutagenesis with physical mutagens compared to the wild type. Study design: Cross-sectional in descriptive study design and case–control in analytical study design. Backgrounds: P. aeruginosa is a ubiquitous gram-negative aerobe. Its opportunistic pathogen that infects patients with cystic fibrosis, burn, wounds, immunodeficiency, chronic obstructive pulmonary disorder (COPD), cancer. Fibrinolytic enzyme is a factor that lysis fibrin clots. This fibrinolytic factor has prospective use totreat cardiovascular diseases such as stroke and heart attack. Thrombotic disorders are the main cause of death world. Methodology: Study patients, specimens, collection of bacterial isolates. Plasma agar plate assay, Skim milk agar assay, Radial caseinolytic assay, Preparing magnetizing Water. Exposure P. aeruginosa to radioactive sources, lasers and magnetic water. Determination of optimal bacterial isolate for the fibrinolytic enzyme production. Results: Increased when P. aeruginosa were exposed to Na23 at an efficiency of 10 µci. Also exposed to 10 ml of magnetic water during 48 hr., then exposed to a cobalt radioactive source during 3 hr., another radioactive source is Cs137, Co60 and Sr90 in 1 hr. during 48 hours with exposure to laser and magnetized water. Conclusion: Conclude that the overproduction of fibrinolytic enzyme (clot-dissolving enzyme) increased when P. aeruginosa were exposed to Na23, Cs137, Co60 and Sr90 with exposed to laser and magnetized water in certain period.

Development of [formula omitted]/[formula omitted]/[formula omitted] discrimination with the phoswich detector using improved charge comparison method

Both pulse shape discrimination methods based on temporal difference characteristic and phoswich detectors are well-known and effective for particles discrimination, so the combination and further improvement are significant for better performance. In this paper, a phoswich detector combining YAG(Ce) and CsI(Tl) was constructed for α/β/γ discrimination using various techniques including two machine learning algorithms and an improved charge comparison method that further exploited the difference in the decay rate of pulse tail. The detector was designed with Geant4, simulating the suitable sizes of scintillators, and a high-speed digitizer was used for the collection of pulses that were from three radioactive sources. The results among the α (β) and γ rays had the figure of merit values greater than 2, simultaneously with an optimal 1.68 of the improved method that had more than twice the performance comparing the original 0.69 for α/β identification, which showed the detector is able to discriminate α, β and γ rays in mixed radiation field effectively.

Rapid and efficient separation of radioactive cesium ion/other radioactive ions by reduced graphene oxide membrane

Separation of cesium ions from other radioactive ions is of great significance for recycling and utilization of radioactive sources, facilitating the management of highly radioactive liquid waste (HLW), as well as for environmental protection. We achieved a highly selective and efficient separation of binary mixtures of 137Cs/60Co, Cs+/Co2+, Cs+/Ni2+, and Cs+/Zn2+ using amino-hydrothermal reduced graphene oxide membranes. The separation factor for non-radioactive binary mixtures is up to 4290, with a water permeance of 50.8 L m−2 h−1 bar−1. The separation factor for radioactive 137Cs/60Co is 623, which is somewhat underestimated due to the detection limit of the high-purity germanium spectrometer. The rGO membranes has the high water permeance of 72.4 L m−2 h−1 bar−1, with a thickness of ∼300 nm. The rGO membrane achieved effective separation of cesium and cobalt ions over a wide range of cesium-to-cobalt ion concentration ratios, with the best results achieved at a concentration ratio of 100:1 for cesium and cobalt. In addition, the rGO membranes showed outstanding stability. The superior performance is attributed to the amino hydrothermal treatment, which reduced oxygen functional groups and directly inserted nitrogen atoms into the GO lattice, ultimately forming stable narrow nanochannels conducive to the size-sieving effect. The findings show that the rGO membranes have excellent separation performance due to their size-sieving effect, and this work has great potential for rapid and efficient treatment of radioactive liquid waste.

Validation of GAMOS Monte Carlo simulation for 131Cs brachytherapy source in water and dosimetric characterization of solid water, bone, and brain tissues

PurposeThe treatment of brain tumours using permanently implanted 131Cs has become more frequent since GammaTile brachytherapy platform was cleared by the U.S. Food and Drug Administration (FDA). Current treatment planning systems (TPS) (BrachyVision v11.0.47, Varian Medical Systems, Palo Alto, CA, USA) used clinically do not account for anatomical heterogeneities. GAMOS Monte Carlo simulation was validated for the dose deposited by 131Cs in water and used to accurately determine the dose deposited in simulated human tissues, including bone and brain tissue, as well as in Solid Water (SW) phantom material. MethodGAMOS was validated and benchmarked for dose deposited by 131Cs (CS-1 Rev2) in water. The evaluation performed included air-kerma strength, radial dose function, anisotropy function, and dose rate constant based on the recommendation of TG-43U1S2 protocol. Dosimetric simulation of the 131Cs brachytherapy source was also performed in SW, bone, and brain tissue using GAMOS. Conversion factors were calculated by the ratio of the dose rate constant from water to SW, bone, and brain tissue, respectively. ResultResults for dose in water were benchmarked with MCNP simulation and experiential data published in the TG-43U1S2. The dose rate constant in water was 1.039 ± 0.017 cGy h−1 U−1 which is consistent with the results used to determine the TG-43U1S2 consensus data. The conversion factor of water to SW, water to the bone, and water to brain tissue were 0.936, 1.15, and 0.964, respectively. ConclusionOther Monte Carlo (MC) simulation codes, such as MCNP, have been previously used in the literature to determine the dose deposited by 131Cs. In this work, doses deposited by 131Cs radioactive sources were successfully simulated using GAMOS MC simulation. To our knowledge, this is the first time that GAMOS was used to simulate the dose deposited by 131Cs seed. MC simulation of dose for brachytherapy sources is especially important to accurately estimate the dose deposited in high Z materials such as skull bone, which may be widely different than the dose calculated by the TG-43U1S2 formalism.

Development of electron detectors for the BRAND experiment

The BRAND experiment employs detectors that utilize gas ionization and plastic scintillators, integrated with custom-designed front-end electronics, aimed at measuring the correlation coefficients in neutron beta decay. This article focuses on the characterization and performance of a newly developed electron detector prototype featuring custom-designed front-end electronics. The characterization results indicate an weak gain dependency of the scintillator when exposed to a radioactive source, varying along its length and width.