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Polymers are often used in medical applications, therefore, some novel polymers and their interactions with photons have been studied. The gamma-ray shielding parameters for Polymethylpentene (PMP), Polybutylene terephthalate (PBT), Polyoxymethylene (POM), Polyvinylidenefluoride (PVDF), and Polychlorotrifluoroethylene (PCTFE) polymers were determined using the Geant4 simulation and discussed in the current work. The mass attenuation coefficients (μ/ρ) were simulated at low and high energies between 0.059 and 1.408 MeV using different radionuclides. The accuracy of the Geant4 simulated results were checked with the XCOM software. The two different methods had good agreement with each other. Exposure buildup factor (EBF) was calculated and discussed in terms of polymers under study and photon energy. Effective atomic number (Zeff) and electron density (Neff) were calculated and analyzed at different energies. Additionally, the half-value layer (HVL) of the polymers was evaluated, and the results of this parameter showed that PCTFE had the highest probability of interaction with gamma photons compared to those of the other tested polymers.

Rice straw is considered an agricultural waste harmful to the environment, which is abundant in most parts of the world. From this point, the present study is devoted to preparing new composites of two types of glue based on rice straw as a plentiful, low-cost matrix. Straw glue samples were prepared by mixing 20% wt. of rice straw with 80% wt. of animal glue (RS-An) and polyvinyl acetate (RS-PVA C ) at different thicknesses of 1, 2, and 3 cm. The chemical composition of the prepared samples was identified by energy dispersive X-ray analysis and their morphology was examined using a scanning electron microscope. The mechanical test explored that RS-An and RS-PVA C respectively required a stress of 25.2 and 25.5 MPa before reaching the breaking point. γ-ray shielding performance was analyzed and determined at numerous photon energies from 0.059 to 1.408 MeV emitted from five-point γ-rays sources using NaI (Tl). Linear attenuation coefficient was calculated by obtaining the area under the peak of the energy spectrum observed from Genie 2000 software in the presence and absence of the sample. The experimental results of mass attenuation coefficient were compared with theoretical data of XCOM software with relative deviation ranging from 0.10 to 2.99%. Geant4 Monte Carlo simulation code was also employed to validate the experimental results. The relative deviation of XCOM and Geant4 outcomes was 0.09–1.77%, which indicates a good agreement between them. Other radiation shielding parameters such as half value layer (HVL), tenth value layer, and mean free path were calculated in three ways: experimentally, theoretically from the XCOM database, and by simulation using Geant4 code. Additionally, effective atomic number (Z eff ), effective atomic number (N eff ), equivalent atomic number (Z eq ), and buildup factors were evaluated. It was confirmed that the γ-ray shielding properties were further boosted by mixing rice straw with the animal glue compared to the synthetic one.

The ASPECT-BET project, or An sdd-SPECTrometer for BETa decay studies, aims to develop a novel technique for the precise measurement of forbidden beta spectra in the 10 keV–1 MeV range. This technique employs a Silicon Drift Detector (SDD) as the main spectrometer with the option of a veto system to reject events exhibiting only partial energy deposition in the SDD. A precise understanding of the spectrometer’s response to electrons is crucial for accurately reconstructing the theoretical shape of the beta spectrum. To compute this response, GEANT4 simulations optimized for low-energy electron interactions are used and validated with a custom-made electron gun. In this article we present the performance of these simulations in reconstructing the electron spectra measured with SDDs of a 109Cd monochromatic source, both in vacuum and in air. The allowed beta spectrum of a 14C source was also measured and analyzed, proving that this system is suitable for the application in ASPECT-BET.

This paper examines the potential of using a fast neutron technique called defectoscopy with a compact and efficient deuterium-deuterium (D-D) neutron generator and plastic scintillator. The paper describes the design of the apparatus and the methodology for obtaining images. In order to correctly interpret the results of the experiments, it is necessary to simulate the expected outcomes. For this purpose, simulations were performed using the Monte Carlo method in the GEANT4 code. A mockup of a printed circuit heat exchanger was modeled, and simulations were performed using multiple structural defects. The initial findings of our research are presented: GEANT4-simulated images and their processing for defects identification in combination with unidirectional surface sources. The results demonstrate the functionality and potential of our setup for fast neutron defectoscopy using a D-D generator.

This paper examines the potential deployment of a 10 mm × 10 mm × 1 mm cadmium telluride detector for strontium-90 measurement in groundwater boreholes at nuclear decommissioning sites. Geant4 simulation was used to model the deployment of the detector in a borehole monitoring contaminated groundwater. It was found that the detector was sensitive to strontium-90, yttrium-90, caesium-137, and potassium-40 decay, some of the significant beta emitters found at Sellafield. However, the device showed no sensitivity to carbon-14 decay, due to the inability of the weak beta emission to penetrate both the groundwater and the detector shielding. The limit of detection for such a sensor when looking at solely strontium-90 decay was calculated as 323 BqL−1 after a 1-h measurement and 66 BqL−1 after a 24-h measurement. A gallium-arsenide (GaAs) sensor with twice the surface area, but 0.3% of the thickness was modelled for comparison. Using this sensor, sensitivity was increased, such that the limit of detection for strontium-90 was 91 BqL−1 after 1 h and 18 BqL−1 after 24 h. However, this sensor sacrifices the potential to identify the present radionuclides by their end-point energy. Additionally, the feasibility of using flexible detectors based on solar cell designs to maximise the surface area of detectors has been modelled.

We present a Geant4-based simulation study of the electromagnetic sampling calorimeter (ECAL) foreseen in the LUXE experiment. The ECAL will enable precise measurement of the number and energy spectrum of positrons and electrons. The electromagnetic shower response, energy resolution, and linearity—properties that are essential for physics research—are studied. The Geant4 simulation model provides a good description of the data from the literature, and the stochastic energy resolution is comparable to the state-of-the-art resolution for a Si-W calorimeter. The simulated ECAL model consists of layers of solid-state sensors interspersed between tungsten plates, with the sensors divided into pads. The advantage of these detectors is their high active layer density, which facilitates the construction of more compact devices. A detailed description of the sensor response using MC simulations is fundamental to detector design and predicting energy measurement performance. We collected simulated data using electron beams in the energy range of 2 to 18 GeV, with a step of 2 GeV. The signal size distribution measured in the test beam campaign is well reproduced by the Geant4 simulation, confirming the accuracy of the simulation approach. The analysis described in this paper focuses on electromagnetic shower reconstruction and characterizes the ECAL response to electrons in terms of energy resolution and linearity.

Bioluminescence imaging (BLI) is a widely used technique in preclinical scientific research, particularly in the development of mRNA-based medications and non-invasive tumor diagnostics. It has become an essential tool in current science. However, the current state of bioluminescence imaging is primarily qualitative, making it challenging to obtain quantitative measurements and to draw accurate conclusions. This fact is caused by the unique properties of optical photons and tissue interactions. In this paper, we propose an experimental setup and Geant4-simulations to gain a better understanding of the optical properties and processes involved in bioluminescence imaging. Our goal is to advance the field towards more quantitative measurements. We will discuss the details of our experimental setup, the data we collected, the outcomes of the Geant4-simulations, and additional information on the underlying physical processes.

Auger-emitting radionuclides have potential application in targeted radiotherapy, particularly for metastatic cancers. This possibility, especially, is stemmed from their characteristic short-range (a few μm) in biological systems allowing localization of high dose within small tumours. To explore this potential application, a Geant4 Monte Carlo toolkit has been employed to simulate the energy deposition of different radionuclides in a water model. The Geant4 Monte Carlo toolkit has model packages to simulate the interaction of radiation with matter and with diverse applications such as studies in science and medicine. In this study, the Geant4-DNA package was used to simulate the radiolytic yields induced by some Auger electron-emitting (AE) radionuclides including; I-131, I-125 and Pd-103, In-111, Ru-97 and Rh-103 m in water model. The results showed that the transient yield of the radiolytic species is characterized by the kinetic energies of the emitted electrons. It was observed that almost all the radionuclides, except I-131, deposited more energy in their proximity thereby inducing a high density of spurs to interact in a short time. It is, therefore, important to consider the kinetic energies of the emitted particles in choosing a radionuclide for specified targeted radiotherapy. This means that apart from their toxicity, compatibility with chelator and carrier molecules, and method of production, we can predict radionuclides such as In-111, Ru-97, Pb-103 m and I-125 could be relevant for targeted radiotherapy for the treatment of metastasis lesions, or tiny tumours at the cellular level, and tumours after surgical resection.

The Chasing All Transients Constellation Hunters (CATCH) space mission is an intelligent constellation consisting of 126 micro-satellites in three types (A, B, and C), designed for X-ray observation with the objective of studying the dynamic universe. Currently, we are actively developing the first Pathfinder (CATCH-1) for the CATCH mission, specifically for type-A satellites. CATCH-1 is equipped with Micro Pore Optics (MPO) and a 4-pixel Silicon Drift Detector (SDD) array. To assess its scientific performance, including the effective area of the optical system, on-orbit background, and telescope sensitivity, we employ the Monte Carlo software Geant4 for simulation in this study. The MPO optics exhibit an effective area of 41 cm 2 at the focal spot for 1 keV X-rays, while the entire telescope system achieves an effective area of 29 cm 2 at 1 keV when taking into account the SDD detector’s detection efficiency. The primary contribution to the background is found to be from the Cosmic X-ray Background. Assuming a 625 km orbit with an inclination of 29 ∘ , the total background for CATCH-1 is estimated to be 8.13 × 10 - 2  counts s - 1 in the energy range of 0.5–4 keV. Based on the background within the central detector and assuming a Crab-like source spectrum, the estimated ideal sensitivity could achieve 1.9 × 10 - 12  erg cm - 2  s - 1 for an exposure of 10 4  s in the energy band of 0.5–4 keV. Furthermore, after simulating the background caused by low-energy charged particles near the geomagnetic equator, we have determined that there is no need to install a magnetic deflector.

In order to meet the requirement of radiation shielding caused by medical isotopes, nuclear reactors, and industrial facilities, gamma shielding effect of epoxy resin base added with Gd 2 O 3 /Bi 2 O 3 particles was studied by Monte Carlo simulation platform Geant4 in this paper. Firstly, the shielding effects of functional filler with different ratios of Gd 2 O 3 and Bi 2 O 3 particles showed that both the Gd 2 O 3 and Bi 2 O 3 fillers have almost identical shielding effects. Then, the shielding effects of the epoxy resin composites under different ranges of on γ-ray were studied. We found the γ-ray intensities decreased rapidly with the depth. From 10 to ~ 100 keV, the γ-ray intensities revealed a decreased trend with the gamma energy except two upshifts at 50.50 keV and 91.00 keV. We also found that the shielding effect increases with decreasing the particle size at the γ-ray energy lower than 100 keV, above 500 keV, the effect can be ignored; the arrangement of the filler greatly affects the γ-ray shielding performance, the filler arrangement with a larger projected area will have a better γ-ray shielding effect due to a serious collision between gamma rays and filler particles.