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In neuroimmune communication, the cholinergic system plays a key role in transmitting information vis-à-vis the peripheral immune status to the central nervous system and vice versa. Exposure to ionizing radiations (photons and charged particles) either for medical purposes (radiotherapy and radiodiagnostic) or during radiation accidents can affect the cholinergic system. As such, the administration of cholinergic medications, before or after exposure, can minimize the side effects of ionizing radiation on the cholinergic system. In literature, photon interaction parameters of cholinergic medications have been calculated. However, proton and alpha particle interactions parameters of cholinergic medications have not been investigated. This study, therefore, investigated the mass-stopping power (S(E)/ρ), effective atomic number (Zeff), and electron density (Neff) of 12 cholinergic medications, namely arecoline, carbachol, diisopropyl fluorophosphate, donepezil, malathion, parathion, physostigmine, pilocarpine, rivastigmine, sarin, soman, and tabun for proton and alpha particles interaction. To investigate the parameters of each of the cholinergic medications, a compact and comprehensible cross-platform computer software known as PAGEX was used to compute the S(E)/ρ, Zeff, and Neff for the proton and alpha particle interactions at an energy of 1 keV-10 GeV and 1 keV-1 GeV, respectively. The maximum value of the S(E)/ρ of the cholinergic medications occurred at lower energy regions of about 0.045 ≤ E ≤ 0.1 MeV and 0.5 ≤ E ≤ 0.75 MeV for proton and alpha particle interactions, respectively. Based on the S(E)/ρ, rivastigmine and parathion show the best and least radioprotective ability against proton and alpha particle radiations, respectively. Generally, it was observed that the medications with a lower Zeff have a higher S(E)/ρ than those with a higher Zeff. For both proton and alpha particle interactions, the variation of the Neff with the Zeff has been observed to be linear throughout the entire energy region. It is thought that the S(E)/ρ, Zeff, and Neff of the cholinergic medications for proton and alpha particle interactions investigated in this study will be useful in radiation dosimetry and will also be a buildup on future work that will focus on experimental findings on the radioprotective ability of the investigated medications against charged particle radiations. [ABSTRACT FROM AUTHOR]

Objective : Nuclear fragmentation generates a diverse dosimetric environment in the path of 12C ion beams. Concise parametrization of the beam's composition is paramount for determining key correction factors in clinical dosimetry. This study sets out to provide such a parametrization based on detailed Monte Carlo simulations of clinically relevant 12C beams. Special attention was paid to the products of nuclear fragmentations and their importance in determining the stopping power ratios. Approach : Using the Monte Carlo simulation package GATE, the spectral fluence of all primary and secondary particles in water were computed at different depths for selected clinically relevant incident energies. Collision-stopping power data was taken from the ICRU90, SRIM and MSTAR database, as well as from previous publications. Main results : The choice of stopping power data was shown to have a bigger impact on the resulting stopping power ratio than the choice of physics lists for the simulations. Significance : A comprehensive analysis of the relationship between fragmentation and dosimetric data has been provided. This study compared different methods for determining spectral fluence-based stopping power ratios, which is essential for accurate ion beam dosimetry. [ABSTRACT FROM AUTHOR]

Background: Electron backscattering coefficient and electron‐stopping power are essential concepts in many disciplines, from radiation to materials science, semiconductor manufacturing, and space exploration. They enable precise calculations, measurements, and simulations of electron interactions with matter, which contribute to advancing science, technology, and safety in a variety of applications. The availability of these data is fundamental to scientific research to validate hypotheses, conduct experiments, and explore new theories. A relatively novel machine learning approach has demonstrated notable success in enhancing data quality and completeness, significantly contributing to the facilitation of data discovery. Purpose: Using fundamental material property data, the stacking ensemble machine learning (EML) technique was established in this study to generate electron‐solid interaction parameters for any target material over a wide range of energies. The final stacking EML was built using the base and meta learners bagging regressor (BR), K‐nearest neighbors (k‐NN), random forest (RF), support vector regression (SVR), and eXtreme Gradient Boosting (XGB). Methods: In this study, two publicly available databases with a total of 4030 data points were used. Training datasets have 785 and 525 data points for electron backscattering coefficient and stopping power, respectively, whereas testing datasets contain 262 and 175 data points. Five features were used as input variables to train different individual algorithms and their combinations. On both the training and test datasets, the model was evaluated using different error metrics, including R‐squared (R2), mean‐absolute‐error (MAE), root‐mean‐squared‐error (RMSE), and mean‐absolute‐percentage‐error (MAPE). Results: Our model evaluation tests revealed that combining RF and XGB with a k‐NN meta‐learner outperformed other algorithms. The analysis of error metrics demonstrated a very close fit to all samples in each training dataset. Furthermore, predictions made by the model on unseen test data indicated accurate estimations of new backscattering and stopping power data. Conclusions: The developed model achieved high prediction accuracy for various target materials across the broad electron energy spectrum. The outcomes demonstrate the effectiveness of machine learning methodology and the chosen models' suitability for addressing substantial physics challenges. [ABSTRACT FROM AUTHOR]

To compute the stopping power, range, and stopping duration of electrons in CH3OH, CH2O, and CO2 throughout the energy range of 0.01 to 1000 MeV, the Bethe equation was used. The MATLAB software was used for the calculation of the findings. A fitting equation was identified. This signifies a strong concordance between the obtained findings and the outputs of the E-STAR and SRIM2013 programs. The correlation coefficient was computed and found to be 0.999, indicating that this relationship was identified. This study aims to provide the latest mass spectrometry (SPE) data, emphasizing the attributes of electron beam therapy (EBT), a therapeutic modality that directs electrons to the tumor location. [ABSTRACT FROM AUTHOR]

The determination of stopping power and the range of protons present in CH3OH, CH2O, and CO2 was accomplished within the energy range of 0.01–1,000 MeV by employing the Bethe equation and Ziegler equation. The latter two equations utilize quantum mechanics to derive an approximation of the stopping force formula, which applies to highly charged particles. The software MATLAB was utilized in the calculation of the results. A suitable equation for computing the halting power of protons in the range of 0.01–1,000 MeV has been identified. A correlation coefficient of 0.999 was determined, suggesting a high degree of concordance between the derived results and those of the SRIM 2013 and P-STAR programs. Proton stopping power analyses of this nature will aid the scientific community in selecting the optimal formulation of stopping power.

The present work focuses on the behavior of the stopping power of a polymer gel dosimetry system, known as PAGAT, infused with high atomic number nanoparticles formed by gold, with a 1 % mass concentration. The study is carried out for different energies of electron and proton beams within ranges of therapeutic applications, first by theoretical assessment, and then by simulation with Monte Carlo codes: PENELOPE in the case of electrons, and FLUKA in the case of protons. The results obtained analytically show promising behavior for gold nanoparticle infused tissue-equivalent systems, while the simulation results show better correspondence with models that consider the net path traveled, instead of models based on the thickness of the samples as typically done in experimental determinations.

In this paper we explore the possibility of boosting the reactivity of non-thermal proton-boron fusion triggered by an external proton beam in a plasma at densities near and lower than solid density and temperature characteristic to laser plasma interaction. Suprathermal protons generated by collisions with alpha particles, as well as energetic protons created by the beam protons that do not undergo fusion during the stopping down in the bulk plasma, are accounted for. In addition, we conduct calculations for non-neutral plasma, motivated by recent suggestion that the number of fusion events in such system may be increased. [ABSTRACT FROM AUTHOR]

In this research, the mass stopping powers, projected range, effective atomic numbers, effective electron density, radiation yield and stopping time of light and heavy charged particles such as electron, proton and alpha in the Rene alloys which consist of Rene N4, Rene N5, Rene 41, Rene 65, Rene 80, Rene 88, Rene 95 and Rene 104 were calculated for the first time. The calculations were performed by using the programs, which are called as ESTAR, SRIM and PAGEX codes. Moreover, all the results were compared with each other, and a comprehensive and comparative study of the theoretical results were presented. [ABSTRACT FROM AUTHOR]

The type of radiation that harms humans and living organisms is the ionizing type. In this type of radiation, radiation passing through the cell transfers energy to biological tissues and causes harmful biological effects along with chemical changes. Therefore, radiation exposure doses should be kept as low as possible and appropriate shielding materials should be used between radiation and living tissue. In this study, stopping power and range calculations of B-100 bone and C-552 air-equivalent plastic materials, which are International Commission on Radiation Units & Measurement (ICRU) materials, were performed for alpha particles in the energy range of 0.1 MeV - 10 MeV. The effective charge approach within the scope of Bethe-Bloch theory and Bohr stripping criterion was used in collision stopping power calculations. The Continuous Slowing-Down Approximation (CSDA) method and the 3/8 Simpson approximation were chosen for range calculations. The error rates were found to be less than 10% when the results were compared with the available literature data. [ABSTRACT FROM AUTHOR]

Simulation methods have received much attention across various fields in recent years. The rare-earth lutetium tantalate (LuTaO4) doped “Bismuth Oxide (Bi2O3) thin films were deposited onto polymer substrates using a SRIM program.” The SRIM program was used to calculate some physical characteristics of Bi2O3 films at energies between 1.0 MeV and 20 MeV. The “electronic and nuclear stopping powers” of LuTaO4, Bi2O3, C10H8O4, and LuTaO4/ Bi2O3/C10H8O4 samples were investigated. These findings show that rare earth doping may improve the performance of composite materials. The interaction of ion beams with matter can result in a wide variety of phenomena. The deposition of Bi2O3 films doped with LuTaO4 on C10H8O4 led to changes in the “electronic and nuclear stopping powers” and range in the materials. Published data were compared with the results obtained and the calculations parameters were provided. [ABSTRACT FROM AUTHOR]

Barium titanium borate glasses doped with ytterbium with the chemical composition of B2O3-TiO2-BaO-Yb2O3 are described as shields exhibiting excellent performance for β and γ applications. This study used the Phy-X and XCOM codes and the GEANT4 toolkit to calculate and simulate the gamma attenuation factors in a 0.02-MeV to 15-MeV range. From the linear attenuation coefficient and mass attenuation coefficient (MAC) values, the half-value layer (HVL), tenth value layer, mean free path (MFP), effective atomic number (Zeff), electronic cross-section, and atomic cross-section have been determined. In addition, the energy absorption build-up factors and exposure build-up factors values of glass samples were estimated for the energy spectrum spans from 0.02 MeV to 15 MeV and penetration depths up to 40 MFP. Additionally, we analyzed the heaviness (H%) of the selected samples, utilizing this crucial metric as a fundamental parameter to comprehend the distinctive properties of diverse materials. Furthermore, we determined the radiation protection efficiency (RPE), and observed that it is prominent at lower energies, gradually decreasing as the energy level rises. Incorporating Yb3O2 resulted in an augmentation of the RPE values, thereby enhancing the shielding capabilities of the glass system. The ESTAR program assessed the β-shielding action of the inspected glasses by determining the total stopping power (TSP) and the continuous slowing down approximation (CSDA) range. The findings indicate that the incorporation of ytterbium positively impacts the density, consequently enhancing the shielding proficiency, of the sample against β- and γ-rays. In BTBaY4 glass, the variant with the greatest concentration of Yb2O3 exhibits the greatest values for MAC, Zeff, and the most minimal HVL. Moreover, this type of glass has low concentrations of Yb2O3 and is free from lead materials, but shows good shielding properties. [ABSTRACT FROM AUTHOR]

Silicon carbide has been considered a material for use in the construction of advanced high-temperature nuclear reactors. However, one of the most important design issues for future reactors is the development of structural defects in SiC under a strong irradiation field at high temperatures. To understand how high temperatures affect radiation damage, SiC single crystals were irradiated at room temperature and after being heated to 800 °C with carbon and silicon ions of energies ranging between 0.5 and 21 MeV. The number of displaced atoms and the disorder parameters have been estimated by using the channeling Rutherford backscattering spectrometry. The experimentally determined depth profiles of induced defects at room temperature agree very well with theoretical calculations assuming its proportionality to the electronic and nuclear-stopping power values. On the other hand, a significant reduction in the number of crystal defects was observed for irradiations performed at high temperatures or for samples annealed after irradiation. Additionally, indications of saturation of the crystal defect concentration were observed for higher fluences and the irradiation of previously defected samples. [ABSTRACT FROM AUTHOR]

In this paper we explore the possibility of boosting the reactivity of non-thermal proton-boron fusion triggered by an external proton beam in a plasma at densities near and lower than solid density and temperature characteristic to laser plasma interaction. Suprathermal protons generated by collisions with alpha particles, as well as energetic protons created by the beam protons that do not undergo fusion during the stopping down in the bulk plasma, are accounted for. In addition, we conduct calculations for non-neutral plasma, motivated by recent suggestion that the number of fusion events in such system may be increased.

Stopping power, range, and time of proton in water, lung, bladder, and intestinal human tissues are calculated using density functional theory and Beth’s relativistic equation in range of proton energy (0.01–1,000 MeV). The experimental data extracted from SRIM-2013 program were used to proton to the same human tissues applied in the MATLAB-2021 program, and the mean ionization potential of water and the studied tissues is calculated using Gaussian 09W program. A good agreement has been found between our calculations for stopping power, range, and time of protons in the studied human body tissues and SRIM-2013 program calculations.

The discrete physics models available in the Geant4-DNA Monte Carlo toolkit are a subject of continuous evolution and improvement in order to meet the needs of state-of-the-art radiobiological research for medical and space applications. The current capabilities of Geant4-DNA for event-by-event electron transport extend up to 1 MeV. In this work, Geant4-DNA’s most accurate electron inelastic model for sub-keV energies is improved and extended up to 10 MeV via the Relativistic Plane Wave Born Approximation and other theoretical considerations. Benchmark simulations of the electronic stopping power and range of electrons in liquid water using the new model show almost excellent agreement (at the few % level) with the recommendations of the International Commission on Radiation Units and Measurements (ICRU) up to 10 MeV, offering notable improvement (by a factor of ~2) over the default Geant4-DNA inelastic model and an order-of-magnitude higher electron limit. The present development will allow Geant4-DNA users to perform electron track-structure simulations up to 10 MeV, thus, covering a wider range of radiotherapeutic applications (including FLASH-RT) as well as space applications involving MeV electrons which are not currently reachable.

In this study, the gamma-photon, neutron, and charged particle interaction quantities for SiO2–P2O5–CaO–Na2O–CaF2 bioactive glasses were evaluated with the objective of estimating the effect of CaF2 on the physical and radiation responses of the bioactive glasses involved. The physical features (e.g. glass density) were increased as the CaF2 increases in the samples. The gamma mass-attenuation coefficient (μ/ρ) of the glasses was estimated for photon energies 0.015–15 MeV using the XCOM database and the FLUKA Monte Carlo simulation procedure. The total stopping powers (TSP) and range of charged particles (electrons, protons, α-particles, and C6+ ions) were estimated with the aid of ESTAR (for electrons only) and the SRIM Monte Carlo code (for protons, α-particles, and C6 + ions). In addition, the fast (ΣR) and thermal (TN) neutron cross-sections were computed for the glasses using standard theoretical models. The μ/ρ values of the SPCNCF glasses were within 0.0216–8.7469, 0.0217–9.2151, 0.0219–10.0588 and 0.0222–11.1264 cm2/g for SPCNCF1, SPCNCF2, SPCNCF3 and SPCNCF4, respectively. The half-value layers had minimum values of 0.02936, 0.02767, 0.02499, and 0.02215 cm for SPCNCF1, SPCNCF2, SPCNCF3, and SPCNCF4, respectively, at 0.015 MeV. Analysis of the estimated photon interaction parameters showed that the gamma radiation attenuation prowess of the glasses improved with CaF2 content. The same trend was observed for charged particles. The TSP of electrons is maximum at 0.015 MeV with values of 12.82 for SPCNCF1 and SPCNCF2, 12.76 for SPCNCF3 and 12.71 MeV cm2/g for SPCNCF4. The values of ΣR were equal to 0.0896, 0.0896, 0.0897 and 0.0900 for SPCNCF1, SPCNCF2, SPCNCF3, and SPCNCF4, respectively. The increase in the weight proportion of CaF2 also improved the fast neutron removal and total thermal neutron interaction capacities of the SPCNCF glasses. The SPCNCF glasses showed better shielding competence compared to some conventional shields such as RS 253 and RS 253 G18 commercial shielding glasses, concrete samples, and polymers.

A theoretical description of reflection of hydrogen isotopes from a solid body based on data available in modern literature on the cross sections for elastic and inelastic scattering of ions is presented. The results of the analytical calculation are compared with the results of computer simulation and experimental data. The interaction of hydrogen isotopes with energies from 300 eV to 25 keV with materials in a wide range of atomic numbers, namely Be, C, Ti, Ni, W, Au, is considered. A critical review of existing analytical models of multiple scattering of light ions in solids is performed. [ABSTRACT FROM AUTHOR]

In the present investigation, we examined the efficacy of lithium calcium silicate glasses doped with nickel for various radiation shielding applications. Specifically, we estimated the mass attenuation coefficients (μm) for samples with the composition (11.5–x)CaO-23.5Li2O-(x)NiO-65SiO2 (x = 0, 2.87, 5.75, 8.63, 11.5 mol.%) using Monte Carlo simulation (GEANT4), Phy-X/PSD, and XCOM programs over an energy range of 0.015–15 MeV. The results demonstrate a strong correlation between the extracted μm magnitudes from the simulation and calculation results. Next, we estimated various other parameters, including the linear attenuation coefficients (μ), half-value layer (HVL), tenth-value layer (TVL), mean free path (MFP), effective atomic number (Zeff), fast neutron removal cross sections (ΣR), relative dose distribution (RDD) for gamma rays, energy absorption buildup factors (EABF), and exposure buildup factors (EBF). We also assessed the alpha and beta shielding characteristics of the glass samples by estimating the continuous slowing down approximation range (CSDA) and total stopping power (TSP) magnitudes. Our findings indicate that μm, μ, Zeff, and ΣR magnitudes increased as the ratio of NiO in the samples increased. In contrast, we observed that HVL, TVL, RDD, MFP, EABF, and EBF magnitudes decreased as the NiO ratio increased. A higher percentage of NiO in the samples resulted in the supply of beta and alpha particles with shorter ranges. Overall, we conclude that the lithium calcium silicate glass doped with nickel with an 11.5% NiO percentage is the optimal specimen for obtaining superior photon and charged particle shielding benefits. [ABSTRACT FROM AUTHOR]

Understanding and quantifying the electronic inelastic interactions of swift ions and electrons in metals is fundamental for many applications of charged particle beams. A common theoretical approach is moreover desirable for the case of both types of projectiles, as large numbers of secondary electrons arise as the result of ion interaction with metals. The electronic cross section, stopping power and energy-loss straggling resulting from the interaction of swift protons, alpha particles and electrons when moving through the metals aluminum, iron, copper, molybdenum, platinum and gold, are calculated theoretically for a wide energy range of the projectiles. The model is based on the dielectric formalism, which realistically accounts for the excitation spectrum of each metal through the Mermin Energy-Loss Function-Generalized Oscillator Strength (MELF-GOS) methodology. The impact of the complexity of the excitation spectrum of each metal (encompassing interband transitions and collective excitations), as well as the different sources of (sometimes conflicting) optical data is analysed in detail. Specific interactions are considered for each projectile, such as electron capture/loss and electron cloud polarisation for ions, and indistinguishability, exchange and low-energy corrections for electrons. An estimate of possible contributions of surface excitations to the interaction probabilities of low energy electrons is given. Comparison of our results with a large collection of available experimental data shows good agreement. As a practical and useful outcome of the work, we provide analytical expressions fitting all our calculated quantities, which can be applied for simulation or comparison purposes. [ABSTRACT FROM AUTHOR]

Understanding and quantifying the electronic inelastic interactions of swift ions and electrons in metals is fundamental for many applications of charged particle beams. A common theoretical approach is moreover desirable for the case of both types of projectiles, as large numbers of secondary electrons arise as the result of ion interaction with metals. The electronic cross section, stopping power and energy-loss straggling resulting from the interaction of swift protons, alpha particles and electrons when moving through the metals aluminum, iron, copper, molybdenum, platinum and gold, are calculated theoretically for a wide energy range of the projectiles. The model is based on the dielectric formalism, which realistically accounts for the excitation spectrum of each metal through the Mermin Energy-Loss Function–Generalized Oscillator Strength (MELF-GOS) methodology. The impact of the complexity of the excitation spectrum of each metal (encompassing interband transitions and collective excitations), as well as the different sources of (sometimes conflicting) optical data is analysed in detail. Specific interactions are considered for each projectile, such as electron capture/loss and electron cloud polarisation for ions, and indistinguishability, exchange and low-energy corrections for electrons. An estimate of possible contributions of surface excitations to the interaction probabilities of low energy electrons is given. Comparison of our results with a large collection of available experimental data shows good agreement. As a practical and useful outcome of the work, we provide analytical expressions fitting all our calculated quantities, which can be applied for simulation or comparison purposes.

In a fusion reactor, DT reactions produce huge amount of neutrons which hit the structure material and produce heat and damages. To understand the production of nuclear heating and material damages, study of double differential cross section (DDX), energy differential cross section (EDX), penetrating range of incident particles and stopping power of target element was calculated for 52Cr(n, p) and 52Cr(n, a) reactions. The calculated data have been compared with the suitable experimental data collected from EXFOR and other. The contribution of compound, pre-equilibrium and direct reaction processes has been analyzed for the entire cross section calculation. The emission of charged particles at different angles has been discussed based on the reaction processes. Parameter adjustment has been applied to fit the experimental data.

The investigation of PVC surface characteristics involved the utilization of Monte Carlo simulation software, TRIM, to replicate the interaction between ion beams and the PVC surface. TRIM is a widely employed tool for examining surface structure. The analysis centered on the interactions between PVC surfaces and ions of hydrogen, helium, argon, and krypton. The ion beam irradiation was carried out at varying angles 0°, 15°, 30°, 45°, 60°, and 75° relative to the sample's surface normal, and it encompassed two distinct incident ion energies 1 keV and 1 MeV. The interplay between ions and the PVC surface can result in diverse processes, including sputtering, emission, and ionization, contingent upon the mass, incident energy, and angle of incidence of the ions. The calculation of stopping power (both nuclear and electronic) and the range of projectiles can also be determined using the same set of incident ions (H, He, Ar, and Kr) but within different energy spectrums (from 10 eV to 10 MeV). The stopping range is contingent on the incident energy and mass of each incident ion, a crucial factor in the process of implantation. This procedure finds applications in doping semiconductors or other materials, with potential uses in catalysis, gas sensing, and various chemical applications.

Warm dense matter—an exotic, highly compressed state on the border between solid and plasma phases is of high current interest, in particular for compact astrophysical objects, high‐pressure laboratory systems, and inertial confinement fusion. For many applications, the interaction of quantum plasmas with energetic particles is crucial. Moreover, often the system is driven far out of equilibrium. In that case, there is high interest in time‐dependent simulations to understand the physics, in particular, during thermalization. Recently a novel many‐particle technique, the G1–G2 scheme was presented with reference to the study by Schlünzen et al. (2020) which allows for first‐principle simulations of the time evolution of interacting quantum systems. Here we apply this scheme to a spatially uniform dense quantum plasma [ABSTRACT FROM AUTHOR]

The stopping power of the target material is an essential variable for evaluating the effects of radiation. In this study, the stopping power for an electron that interacts with some components of human body tissues (H, C, N, O, Na, P, S, Cl, K, Ca, Fe, I) was calculated using two methods: The Beth formula and the ESTAR code, in the energy range 0.01–1000 MeV. The total stopping power of these elements was calculated by adding their collisional stopping power to their radiative stopping power. The results from both methods were in good agreement. A semiempirical formula was found to compute the total electron stopping power of electrons of these targets for a given electron energy. Our stopping power values show good agreement with ICRU 37 (1984). [ABSTRACT FROM AUTHOR]

In this research, the effect of deuterium beam energy distribution function resulting from TNSA and RPA mechanisms on the fast ignition of D/He3 fuel pellet has been investigated. The fuel is irradiated with a deuterium beam through a conical guide. The energy distribution function will be different in different mechanisms. Penetration depth and stopping power of ignitor beam with mono-energy, Maxwellian and Gaussian distribution of energy are calculated. Calculations show that the Maxwellian beam from TNSA mechanism, penetrates up to about 100 µm in the fuel and the height of deposition peak is still in plasma corona. The height of the peak has also increased about 25 times compared to the case where the Gaussian beam is considered. Also, the obtained results are shown that the energy deposit of the deuterium beam resulting the RPA mechanism will be completely localized and will be more concentrated in the dense fuel core. [ABSTRACT FROM AUTHOR]

Polycarbonate-bismuth oxide composite has been used as a beta-ray sensor in the previous works. Calculation of two main quantities namely stopping power and range of electrons in this material can be useful to evaluate the optimal thickness of the sensor. Thus, in this study, the range of electrons and stopping power of polycarbonate/bismuth oxide composite for several pure beta-emitters were estimated using the ESTAR program. Simulation findings indicated that the amount of concentration of the heavy metal oxide particles into the composite is an important factor to determine the range and stopping power of the electrons. Also, in the experimental phase, the response of the 50 wt% nanocomposite with thickness of 1 mm against the beta-rays of the P-32 source at the average energy of 695 keV in different activities was measured using an electrometer at a constant voltage of 800 V. Results showed that the response of the sample ranging from 4 to 6 mCi was linear with R² = 0.9757. [ABSTRACT FROM AUTHOR]

• Electron interactions in DNA material. • Geant4-DNA electron transport in DNA. • Electron stopping power in DNA. • Electron range in DNA. • Ionisation sampling method. In this study we are introducing an update of the Geant4-DNA physics constructor "option 6" including electron interactions with all constituents of the DNA molecule in addition to those already publicly available for liquid water. The new implementation is based on the interaction cross sections of electrons with the four DNA nucleobases, deoxyribose and phosphoric acid for elastic scattering, electronic excitation and ionisation in the 11 eV – 1 MeV energy range. An additional sampling method to estimate the transferred secondary electron energy produced by ionisation is also introduced and can be optionally activated instead of the classical interpolation method based on the differential cross section tables, thus eliminating the need to upload large data files. The implementation in Geant4-DNA was verified by calculating range and electronic stopping power in the various materials. Good agreement is observed with the data available in the literature, and calculations with the interpolation method and the sampling method showed less than 4% difference. No differences were observed in terms of computational cost. [ABSTRACT FROM AUTHOR]

The planning accuracy of charged particle therapy (CPT) is subject to the accuracy of stopping power (SP) estimation. In this study, we propose a method of deriving a pseudo-triple-energy CT (pTECT) that can be achievable in the existing dual-energy CT (DECT) systems for better SP estimation. In order to remove the direct effect of errors in CT values, relative CT values according to three scanning voltage settings were used. CT values of each tissue substitute phantom were measured to show the non-linearity of the values thereby suggesting the absolute difference and ratio of CT values as parameters for SP estimation. Electron density, effective atomic number (EAN), mean excitation energy and SP were calculated based on these parameters. Two of conventional methods were implemented and compared to the proposed pTECT method in terms of residuals, absolute error and root-mean-square-error (RMSE). The proposed method outperformed the comparison methods in every evaluation metrics. Especially, the estimation error for EAN and mean excitation using pTECT were converging to zero. In this proof-of-concept study, we showed the feasibility of using three CT values for accurate SP estimation. Our suggested pTECT method indicates potential clinical utility of spectral CT imaging for CPT planning.

We have measured for the first time simultaneously both the mean charge states and stopping powers of (35–280) MeV/u 208Pb ions in gases and solids with an accuracy of 1%. The existence at lower energies and disappearance at higher of density effects in the charge-state distribution and the corresponding stopping power are directly confirmed and comparisons with widely used theories and simulations for heavy ions demonstrate strong deviations of up to 27%. However, an unprecedented prediction power of better than 3% has been achieved for the energy loss when the measured mean charge-states are implemented in the Lindhard-Sørensen theory. Our present benchmark data contribute to an improved understanding of the basic atomic collision processes and to numerous applications in nuclear physics. Extending the GANIL data [1] to higher accuracy and energies, we can now answer at which velocities the Bohr-Lindhard density effect in stopping will vanish.

The invention of Chirped Pulse Amplification lasers along with the development of fast ignition methods have made fuels such as proton–boron-11 seem promising nuclear fusion energy sources because of their lack of high-energy neutrons and abundance of constituent isotopes. This paper investigates the transport of charged particles in proton–boron-11 fuel. In this study, the confinement parameter has been estimated as ρ R = 1 2 g/cm2 with the help of a proton driver in the fast ignition method for proton–boron-11 fuel pellets, with a ratio of boron-11 to proton = 0. 3. Subsequently, using the Li–Petrasso stopping-power model, the energy deposition coefficients of the accelerated proton-beam driver were calculated by the Target Normal Sheath Acceleration method with 1 MeV energy. The obtained results show that at a temperature of about 65 keV, the proton-beam driver with 1 MeV energy deposits about 85% of its energy in the hot spot area of 2.5 μ m depth from the surface of the fuel pellet to ignite the proton–boron-11 fuel pellet. [ABSTRACT FROM AUTHOR]

Data filtering is crucial for accurate relative stopping power (RSP) reconstruction in proton CT (pCT). In this work, we assess different filters and their performance for the US pCT collaboration prototype pCT system in Monte Carlo (MC) simulations. The potential of using the recently proposed [Formula: see text]-E filter for removing nuclear interactions that occurred in the energy/range detector of the pCT system is investigated. Full pCT scans were acquired with the TOPAS MC simulated version of the prototype scanner that comprises two tracking detectors and a five stage energy/range detector. An ideal water cylinder and a water cylinder with five tissue inserts were investigated. Before image reconstruction, a [Formula: see text] WEPL filter was applied as the only filter, or in addition to filters acting on the energy deposit in each of the energy detector stages, as done currently with the prototype. The potential of the [Formula: see text]-E filter that was recently proposed for helium imaging was assessed. The results were compared to simulations for which nuclear interactions were disabled representing ground truth. The [Formula: see text] WEPL filter alone was not sufficient to filter out all nuclear interaction events and systematic fluctuations in the form of ring artifacts were present in the pCT reconstructed images. Applying energy filters currently used with the device prior to the [Formula: see text] WEPL filter only slightly improved the image quality. A [Formula: see text] WEPL filter improved the mean RSP accuracy, but could not fully remove the systematic fluctuations. The [Formula: see text]-E filter in addition to the current reconstruction procedure efficiently removed the systematic fluctuations and the achieved RSP accuracy closely matched the simulation without nuclear interactions. This study demonstrates the dependence of the accuracy of the usual [Formula: see text] WEPL filter on uncertainties arising within the energy detector. By enabling to remove such uncertainties, the [Formula: see text]-E method proved to yield some potential for improving the accuracy of pCT.

Accurate electronic stopping power data is crucial for calculations of radiation-induced effects in a wide range of applications, from dosimetry and radiotherapy to particle physics. The data is dependent on the parameters of both the incident charged particle and the stopping medium. The existent Bethe theory can be used to calculate the stopping power of high-energy ions, but fails at lower energies, leaving incomplete and even contradictory experimental data, often expanded through extrapolations with fitting formula, as the only accessible resource. Moreover, the majority of the experimental data is available for elements only, further limiting the validity of fitting approaches for complex material compositions. A relatively novel machine learning methodology has been proven to be effective for exactly these types of problems. In this study, Stacking Ensemble Machine Learning (EML) algorithm was developed to predict electronic stopping power for any incident ion and target combination over a wide range of ion energies. For this purpose, five ML models, namely Bagging Regressor (BR), eXtreme Gradient Boosting (XGB), Adaptive Boosting (AdB), Gradient Boosting (GB), and Random Forest (RF), were selected as base and meta learners to construct the final Stacking EML. 40,044 experimental measurements, from 1928 to the present, available on the International Atomic Energy Agency (IAEA) website were used to train machine learning (ML) algorithms. This database consists of 593 various ion-target combinations across the energy range of 0.037 to 985 MeV. For model training, the eleven most important features were selected. The model evaluation was performed using several error metrics, including R-squared (R2), root-mean-squared-error (RMSE), mean-absolute-error (MAE), and mean-absolute-percentage-error (MAPE), on both the training and test datasets. Based on model performance evaluation tests, a stack of XGB and RF via BR meta -learner had the lowest error margin. The value of R2 = 0.9985 indicated a near-ideal fit to all samples in the training data across the entire range of stopping powers. R2 = 0.9955 for predictions made by the model on the unseen test data suggested that the model accurately predicted the test data. The developed model can serve as a universal tool to generate the eSP data in a wide range of cases, regardless of the availability of experimental data or reliable theoretical equations. Overall, the results of the developed tool testified to the power of machine learning approaches, and the suitability of the chosen models for solutions to practically important physics problems. [ABSTRACT FROM AUTHOR]

In this work, the projected range, the nuclear stopping power(Sn), electronic stopping power (Se), vacancies, replacement collisions, and total target damage of β-Ga2O3 by H, He and Ar ion bombardment are investigated by the Monte Carlo SRIM software. The ions were vertically incident on a 1-um β-Ga2O3 material, and their energies varied from 100 keV to 1 MeV. The results showed that the projected range increased for all three ions with increasing incident energies, with H ions having the largest projected range. The Sn for Se with incident energy of 0-1MeV in β-Ga2O3 is much greater than the Sn for H and He, while the Sn for Ar decreases gradually with the increase of incident ion energy, and the Se shows a gradual increasing trend. Compared with H and He, the number of vacancies induced by Ar were the largest at the same incident energy and thickness of β-Ga2O3. In addition, it is obvious that the total target damage of Ar on β-Ga2O3 material were much more serious than H and He. [ABSTRACT FROM AUTHOR]

Compression of fuel pellets in the degenerate state in inertial confinement fusion minimizes the energy required for compression. The increasing development of chirped pulse amplification lasers and the fast ignition method have made researchers to use advanced fuels such as deuterium-helium-3 and proton-boron-11. Proton-boron-11 is a promising source of nuclear fusion energy fuel due to its isotope abundance and purity. In this paper, the transport of charged particles is investigated in proton–11 degenerate fuel. In this study, the confinement parameter has been estimated as ρR = 20 g/cm2 with the help of a proton driver in the fast ignition method for the proton-boron-11 degenerate fuel pellet with the ratio of boron-11 to proton ε = 0.3 . The energy deposited coefficients of the accelerated proton beam driver, using the target normal sheath acceleration method with energy 1 MeV, have been calculated using the Li-Petrasso stopping power model. The results show that for the confinement parameter as ρR = 20 g/cm2, the temperature of the electrons falls below the Fermi temperature. Under these conditions, the proton driver with the optimal energy of 1 MeV at the ignition temperature of 550 eV penetrates the fuel pellet to a depth of 0.17 μm, it deposits approximately 65% of its energy in the ignition region. [ABSTRACT FROM AUTHOR]

Background: Dual-energy computed tomography (DECT) is a promising technique for estimating stopping-power ratio (SPR) for proton therapy planning. It is known, however,that deriving electron density (ED) and effective atomic number (EAN) from DECT data can cause noise amplification in the resulting SPR images. This can negate the benefits of DECT. Purpose: This work introduces a new algorithm for estimating SPR from DECT with noise suppression, using a pair of CT scans with spectral separation. The method is demonstrated using phantom measurements. Materials and methods: An iterative algorithm is presented, reconstructing ED and EAN with noise suppression, based on Prior Image Constrained Denoising (PIC-D). The algorithm is tested using a Siemens Definition AS+ CT scanner (Siemens Healthcare, Forchheim, Germany). Three phantoms are investigated: a calibration phantom (CIRS 062M), a QA phantom (CATPHAN 700), and an anthropomorphic head phantom (CIRS 731-HN). A task-transfer function (TTF) and the noise power spectrum are derived from SPR images of the QA phantom for the evaluation of image quality. Comparisons of accuracy and noise for ED, EAN, and SPR are made for various versions of the algorithm in comparison to a solution based on Siemens syngo.via Rho/Z software and the current clinical standard of a single-energy CT stoichiometric calibration. A gamma analysis is also applied to the SPR images of the head phantom and water-equivalent distance (WED) is evaluated in a treatment planning system for a proton treatment field. Results: The algorithm is effective at suppressing noise in both ED and EAN and hence also SPR. The noise is tunable to a level equivalent to or lower than that of the syngo.via Rho/Z software. The spatial resolution (10% and 50% frequencies in the TTF) does not degrade even for the highest noise suppression investigated, although the average spatial frequency of noise does decrease. The PIC-D algorithm showed better accuracy than syngo.via Rho/Z for low density materials. In the calibration phantom, it was superior even when excluding lung substitutes, with root-mean-square deviations for ED and EAN less than 0.3% and 2%, respectively, compared to 0.5% and 3%. In the head phantom, however, the SPR accuracy of the PIC-D algorithm was comparable (excluding sinus tissue) to that derived from syngo.via Rho/Z: less than 1% error for soft tissue, brain, and trabecular bone substitutes and 5-7% for cortical bone, with the larger error for the latter likely related to the phantom geometry. Gamma evaluation showed that PIC-D can suppress noise in a patient-like geometry without introducing substantial errors in SPR. The absolute pass rates were almost identical for PIC-D and syngo.via Rho/Z. In the WED evaluations no general differences were shown. Conclusions: The PIC-D DECT algorithm provides scanner-specific calibration and tunable noise suppression. It is vendor agnostic and applicable to any pair of CT scans with spectral separation. Improved accuracy to current methods was not clearly demonstrated for the complex geometry of a head phantom, but the suppression of noise without spatial resolution degradation and the possibility of incorporating constraints on image properties, suggests the usefulness of the approach. [ABSTRACT FROM AUTHOR]

In this study, the effects of ion beam (proton) on the PbO/SnO 2 /p-Si double interfacial layer MOS Schottky diode material were studied. The parameters of the ionizing radiation detection properties and radiation resistance of using double interfacial oxide layers were analyzed in MOS Schottky diodes. In the analysis, SRIM/TRIM software code was examined theoretically and modeled using simulation. The displacement per atom occurs more in the SnO 2 oxide layer than in the other interface layer. This can be explained by the concept of Bragg Curve Peak, which occurs as a result of ion beam induced doping effect. It has been observed that the electrical properties of the PbO/SnO 2 /p-Si double interface layer MOS Schottky diode structure in terms of sensing ionizing radiation change after ion beam induced doping and the interface states are affected. It has been shown that our double interface layer nano-MOS structure can be used as a ion beam based sensor on these results. In addition to the inelastic collision, without causing ionization NIEL values of PbO and SnO 2 layers were found to be 424.88 MeV. cm2/g and 524.9 MeV. cm2/g, respectively. These theoretical results were shown as graphs using the TRIM Monte Carlo simulation program and the behavior of the phonons in the layers was modeled. Additionally, LET values were calculated according to layers and compared with the simulation results of TRIM. While the LET value of the PbO layer was 889.3 MeV. cm2/g, the LET value of the SnO 2 layer was determined to be 1639 MeV cm2/g. The LET concept is visually presented with the TRIM software and it is seen that the displacement per atom is highest in the SnO 2 layer and the Bragg Curve reaches its maximum point. Thus, it can be seen that the SnO 2 layer produces more transient damage and oxide interface traps compared to the PbO layer as ionizing radiation propagates between the oxide layers. By studying the effects of the ion beam source on the MOS Schottky diode structure, it is shown that the double interface layer structure increases the oxide interface traps and the SnO 2 material is promising in terms of radiation sensing and detection properties. Moreover, MOS Schottky states that using a double interface layer instead of a single oxide layer in MOS structures positively increases the number of interface traps in the oxide layer for ion beam radiation detection. • The effects of gamma radiation on the PbO/SnO 2 interfacial layer were studied. • SRIM/TRIM software code was examined theoretically and modeled using simulation. • Electrical properties of double interface layer after gamma radiation and the interface states have been affected. • LET and NIEL values were calculated according to layers. [ABSTRACT FROM AUTHOR]

Accurate measurement of linear energy transfer (LET) is crucial in medical physics, particularly for proton therapy dosimetry. High atomic-number (Z e f f ) materials such as BaFBr and low- Z e f f materials such as A l 2 O 3 and water are commonly used in dosimeters. To evaluate the feasibility and accuracy of the use of various dosimetry materials (water, air, A l 2 O 3 , aluminum (Al), BaFBr, and oxygen) for measuring LET by comparing their stopping power (ratios) via the Bethe-Bloch theory and semiempirical models. Stopping power ratios were calculated via the PSTAR database for proton energies ranging from 0.01 MeV to 10,000 MeV. The Bethe-Bloch theory with density and shell corrections was used for high-energy protons, whereas a semiempirical model was applied for low-energy protons. Calculations validation involved comparing the computed stopping powers SRIM-2008 and PSTAR for materials such as water, aluminum, air, A l 2 O 3 , BaFBr, and oxygen. The stopping power water-to-air ratio remains stable, while the A l 2 O 3 -to-water and air-to-water ratios highlight their differing attenuation properties. The BaFBr-to-water ratio shows significant material-dependent differences, and the water-to- A l 2 O 3 ratio is particularly relevant for proton therapy dosimetry calculations in medical physics. These results demonstrate consistency across materials but do not inherently confirm the accuracy of LET measurements. However, a comparison of theoretical models with computed stopping powers SRIM-2008 and PSTAR showed strong agreement, particularly for high-energy protons where the Bethe-Bloch theory was applied, suggesting that the models reliably predict stopping power at these energy levels. This study confirms the feasibility of using high- Z e f f materials such as BaFBr and low- Z e f f materials such as A l 2 O 3 and water for the use of LET measurements in proton therapy. The results validate the use of the Bethe-Bloch theory, computed stopping powers and semiempirical models in dosimetric applications, enhancing the precision of LET measurements and contributing to improved radiation therapy outcomes. • Evaluation of dosimetry materials for accurate LET measurement. • Utilization of Bethe-Bloch theory with density and shell corrections for high-energy protons. • Application of a semi-empirical model for low-energy proton dosimetry calculations. • Validation of theoretical models with computed stopping powers from SRIM and PSTAR. • Findings support the use of high Z_eff materials and low Z_eff materials in proton therapy dosimetry. [ABSTRACT FROM AUTHOR]

An experiment to determine the range of Ni ions in matter consisting in the implantation of nickel ions into samples followed by the determination of the depth profile of the implanted ions by nuclear reaction resonance profiling was performed. The experimentally obtained ranges for Ni ions in Fe and Mo were compared with SRIM-2013 (www.srim.org) and TRIM-98 predictions. It was found that the ranges predicted by SRIM-2013 are significantly overestimated whereas the calculation results obtained with TRIM-98 modified to take into account radiation-enhanced diffusion are consistent with the experimental data. • An experiment to determine the range of Ni ions in matter was performed. • The depth profile of the implanted Ni ions was obtained by nuclear reaction resonance profiling. • A dramatic discrepancy between SRIM-2013 predictions and the experimental results for the Ni ranges in Mo and Fe was found. [ABSTRACT FROM AUTHOR]

Available experimental data on Mylar stopping powers (S P s) for heavy ions (HIs) at energies 0. 04 ⩽ E / A ⩽ 15 MeV/nucleon have been compared to different semi-empirical model calculations with the aim of probing their possible usage for the estimates of ranges for very heavy ions at E / A < 0. 5 MeV/nucleon, which are of practical interest. Significant deviations from the calculated S P values were found for fission fragments and lighter HIs at E / A < 1 MeV/nucleon. A new model parameterization for Mylar S P has been proposed. Range estimates obtained with any S P model calculation show a critical dependence of their mean values on the approximated electronic stopping powers and the nuclear (collisional) S P component. The last plays a crucial role at the end of the range and could only be obtained by calculations. Practical applicability of the results of investigation for very heavy evaporation residues (products of complete fusion reactions induced by HIs) implies the use of a thick catcher foil corresponding to the largest ranges derived in the estimates or the range measurements for these products. [ABSTRACT FROM AUTHOR]

In their paper the abnormal variation of the projectile range with the plasma density was found for fusion products, and some explanations were presented for the results. However, we could not find such abnormal behavior by the calculation of stopping powers under different models. And their explanations are not appropriate. Finally the revised results corresponding to figure 3 in their paper are presented.

Single-event ion imaging enables the direct reconstruction of the relative stopping power (RSP) information required for ion-beam therapy. Helium ions were recently hypothesized to be the optimal species for such technique. The purpose of this work is to investigate the effect of secondary fragments on the image quality of helium CT (HeCT) and to assess the performance of a prototype proton CT (pCT) scanner when operated with helium beams in Monte Carlo simulations and experiment. Experiments were conducted installing the U.S. pCT consortium prototype scanner at the Heidelberg Ion-Beam Therapy Center (HIT). Simulations were performed with the scanner using the TOPAS toolkit. HeCT images were reconstructed for a cylindrical water phantom, the CTP404 (sensitometry), and the CTP528 (line-pair) [Formula: see text] ® modules. To identify and remove individual events caused by fragmentation, the multistage energy detector of the scanner was adapted to function as a [Formula: see text] telescope. The use of the developed filter eliminated the otherwise arising ring artifacts in the HeCT reconstructed images. For the HeCT reconstructed images of a water phantom, the maximum RSP error was improved by almost a factor 8 with respect to unfiltered images in the simulation and a factor 10 in the experiment. Similarly, for the CTP404 module, the mean RSP accuracy improved by a factor 6 in both the simulation and the experiment when the filter was applied (mean relative error 0.40% in simulation, 0.45% in experiment). In the evaluation of the spatial resolution through the CTP528 module, the main effect of the filter was noise reduction. For both simulated and experimental images the spatial resolution was  ∼4 lp cm-1. In conclusion, the novel filter developed for secondary fragments proved to be effective in improving the visual quality and RSP accuracy of the reconstructed images. With the filter, the pCT scanner is capable of accurate HeCT imaging.