Interaction Of Charged Particles Research Articles

Simulation of deflection and photon emission of ultra-relativistic electrons and positrons in a quasi-mosaic bent silicon crystal

Abstract A comprehensive numerical investigation has been conducted on the angular distribution and spectrum of radiation emitted by 855 MeV electron and positron beams while traversing a ‘quasi-mosaic’ bent silicon (111) crystal. This interaction of charged particles with a bent crystal gives rise to various phenomena such as channeling, dechanneling, volume reflection, and volume capture. The crystal’s geometry, emittance of the collimated particle beams, as well as their alignment with respect to the crystal, have been taken into account as they are essential for an accurate quantitative description of the processes. The simulations have been performed using a specialized relativistic molecular dynamics module implemented in the MBN Explorer package. The angular distribution of the particles after traversing the crystal has been calculated for beams of different emittances as well as for different anticlastic curvatures of the bent crystals. For the electron beam, the angular distributions of the deflected particles and the spectrum of radiation obtained in the simulations are compared with the experimental data collected at the Mainz Microtron facility. For the positron beam such calculations have been performed for the first time. We predict significant differences in the angular distributions and the radiation spectra for positrons versus electrons.

Quantum number conservation: a tool in the design and analysis of high energy experiments

The Clifford Unification algebra Cl 7,7 is shown to provide a unified description of all the elementary fermions and hadrons in terms of seven binary quantum numbers. Four of these are defined in existing theories, namely spin-direction, fermion/anti-fermion pairing and the two commuting generators in the SU(3) description of quark colour. A Cl 3,3 sub-algebra integrates the Cl 1,3 space-time and Dirac algebras providing a new definition of time direction and identifying parity as a new quantum number. A further two quantum numbers are related to the commuting generators of an SU(3) description of fermion generations. All seven are conserved in the decays and interactions of charged particles, suggesting that quantum number conservation provides a useful tool in the design and interpretation of high energy experiments. This is especially relevant when neutral particles and parity are involved.

Evaluation of Scale-dependent Kurtosis with HelioSwarm

Plasma turbulence involves complex, nonlinear interactions of electromagnetic fields and charged particles across multiple scales. Studying these phenomena in space plasmas, like the solar wind, is facilitated by the intrinsic scale separations and the availability of in situ spacecraft observations. However, the single-point or single-scale configurations of current spacecraft limit our understanding of many properties of the turbulent solar wind. To overcome these limitations, multipoint measurements spanning a range of characteristic scales are essential. This Letter prepares for the enhanced measurement capabilities of upcoming multispacecraft missions by demonstrating that higher-order statistics, specifically kurtosis, as a baseline for intermittency can be accurately measured. Using synthetic turbulent fields with adjustable intermittency levels, we achieve scale separations analogous to those in the solar wind and apply these techniques to the planned trajectories of the HelioSwarm mission. This approach promises significant advancements in our understanding of plasma turbulence.

Efficacy of barium and calcium additives in lithium silicate glasses for nuclear shielding applications

This study presents a detailed investigation into the nuclear radiation shielding capabilities of lithium silicate (Li2O-SiO2) glass systems, specifically examining the impact of doping with barium oxide (BaO) and calcium oxide (CaO). Utilizing advanced simulation tools, including PAGEX and SRIM for charged particle interactions, and Phy-X/PSD for gamma-ray attenuation analysis, the radiation shielding effectiveness of BaO-based and CaO-based lithium silicate glasses were systematically compared. The gamma attenuation parameters (LAC, MAC, TVL, HVL, EBF, EABF, MFP, Zeff, Neff, FNRCS, and Zeq) of investigated glass samples were computed via the Phy-X/PSD program (15 keV-15 MeV energy). The HVL values vary between 0.007–14.203 cm, and the TVL values vary between 0.054–47.182 cm for all samples in the selected energy range. The highest and lowest values of FNRCS were observed for samples BaO20 and CaO5, with the values 0.093 and 0.1 cm−1, respectively. KERMAs were calculated using PAGEX software between the 1.5 keV and 20 MeV energy range, with the highest KERMA obtained for the BaO20 sample at 0.05 MeV and the lowest KERMA obtained for the CaO5 sample at the lowest density. The mass stopping power quantities were computed between 1 keV-10 GeV energy with PAGEX. The projected range values were calculated with SRIM codes. The lowest projected range values for both alpha particles and protons were obtained for the BaO20 sample with maximum density (3.391 g cm−3). The sample with BaO20 code showed better shielding potential for alpha and proton particles with lower values of projected range and mass stopping power. Findings reveal that the Li2O-BaO-SiO2 glass composition exhibits superior gamma-ray attenuation properties compared to its CaO-doped counterpart, with the BaO20 sample demonstrating particularly enhanced performance.

Skin dose investigations on a 0.5 T parallel rotating biplanar linac-MR using Monte Carlo simulations and measurements.

The Alberta rotating biplanar linac-MR has a 0.5 T magnetic field parallel to the beamline. When developing a new linac-MR system, interactions of charged particles with the magnetic field necessitate careful consideration of skin dose and tissue interface effects. To investigate the effect of the magnetic field on skin dose using measurements and Monte Carlo (MC) simulations. We develop an MC model of our linac-MR, which we validate by comparison with ion chamber measurements in a water tank. Additionally, MC simulation results are compared with radiochromic film surface dose measurements on solid water. Variations in surface dose as a function of field size are measured using a parallel plate ion chamber in solid water. Using an anthropomorphic computational phantom with a 2mm-thick skin layer, we investigate dose distributions resulting from three beam arrangements. Magnetic field on and off scenarios are considered for all measurements and simulations. For a 20×20cm2 field size, (the minimum dose to the hottest contiguous 0.2 cc volume) for the top 2mm of a simple water phantom is 72% when the magnetic field is on, compared to 34% with magnetic field off (values are normalized to the central axis dose maximum). Parallel plate ion chamber measurements demonstrate that the relative increase in surface dose due to the magnetic field decreases with increasing field size. For the anthropomorphic phantom, (minimum skin dose in the hottest 1×1×1 cm3 cube) shows relative increases of 20%-28% when the magnetic field is on compared to when it is off. With magnetic field off, skin is 71%, 56%, and 21% for medial-lateral tangents, anterior-posterior beams, and a five-field arrangement, respectively. For magnetic field on, the corresponding skin values are 91%, 67%, and 25%. Using a validated MC model of our linac-MR, surface doses are calculated in various scenarios. MC-calculated skin dose varies depending on field sizes, obliquity, and the number of beams. In general, the parallel linac-MR arrangement results in skin dose enhancement due to charged particles spiraling along magnetic field lines, which impedes lateral motion away from the central axis. Nonetheless, considering the results presented herein, treatment plans can be designed to minimize skin dose by, for example, avoiding oblique beams and using a larger number of fields.

Dynamics of electron capture in positron‐hydrogen scattering under dense semi‐classical plasmas

AbstractThe scattering dynamics of electron capture in ‐H(1 s) scattering under dense semi‐classical plasma (DSCP) environments has been investigated theoretically. Coupled multi‐channel two‐body Lippmann‐Schwinger equations have been solved by retaining +H(1 s) and p + Ps(1 s) channels to calculate the cross sections (CS) of the electron capture process at intermediate and high incident energies. The effective interaction of the plasma charged particles is modelled by a pseudopotential which is a function of two parameters, namely the plasma screening strength and the de Broglie wavelength. A detailed study is made to explore the changes in the CSs of the above‐mentioned process with respect to the variation in the plasma screening strength and de Broglie wavelength. Significant changes are found to take place, when the screening strength and the de Broglie wavelength are varied. Specifically, the sharp minimum in the differential CS moves toward the forward direction with increasing de Broglie wavelength at a given screening strength.

Experimental modeling of atmospheric discharge phenomena and charged dust particle interactions

Experimental modeling of atmospheric discharge phenomena and charged dust particle interactions

Plasmonic excitations in double-walled carbon nanotubes

The interactions of charged particles moving paraxially in multi-walled carbon nanotubes may excite electromagnetic modes. This wake effect has recently been proposed as a potential novel method of short-wavelength high-gradient particle acceleration and for obtaining brilliant radiation sources. In this work, the excitation of wakefields in double-walled carbon nanotubes is studied by means of the linearized hydrodynamic theory. General expressions have been derived for the excited longitudinal and transverse wakefields and related to the resonant wavenumbers which can be obtained from the dispersion relation. In the absence of friction, the stopping power of the wakefield driver, modelled here as a charged macroparticle, can be written solely as a function of these resonant wavenumbers. The dependencies of the wakefields on the radii of the double-walled carbon nanotubes and the driving velocity have been studied. Double-walled carbon nanotubes with inter-wall distances much smaller than the internal radius may be a potential option to obtain higher wakefields for particle acceleration compared to single-walled carbon nanotubes.

Nonstandard Finite Difference Time Domain Methodology to Simulate Light Propagation in Nonlinear Materials

We extend the nonstandard (NS) finite difference time domain (FDTD) methodology, originally developed to solve Maxwell’s equations in linear materials, to nonlinear ones. We validate it by computing harmonics generation in a nonlinear dielectric and comparing with theory. The methodology also applies to the quantum electrodynamics that describes the interaction of charged particles with electromagnetic fields, and also to the Ginzburg-Landau model of superconductivity.

Search for Wormhole Candidates: Accreting Wormholes with Monopole Magnetic Fields

The existence of even the simplest magnetized wormholes may lead to observable consequences. In the case where both the wormhole and the magnetic field around its mouths are static and spherically symmetric, and gas in the region near the wormhole falls radially into it, the former’s spectrum contains bright cyclotron or synchrotron lines due to the interaction of charged plasma particles with the magnetic field. At the same time, due to spherical symmetry, the radiation is non-polarized. The emission of this just-described exotic type (non-thermal, but non-polarized) may be a wormhole signature. Also, in this scenario, the formation of an accretion disk is still quite possible at some distance from the wormhole, but a monopole magnetic field could complicate this process and lead to the emergence of asymmetrical and one-sided relativistic jets.

Examining the reliability of selected materials for the Indonesian small satellite by electron beam machine

The interaction of charged particles and satellites can result in partial or total loss, leading to the satellite’s inoperable. Charging on the satellite is the dominant cause of malfunctions and failures of satellite components. Damage mitigation can be done through a series of experiments in which materials and satellite components are bombarded with high- energy electrons. In this study, electrons are generated and accelerated using an electron beam machine (EBM). The test material and electronic components are placed beneath the EBM’s beam window, where a 300 keV electron beam bombards them uniformly. The experimental results show that the electron beam can penetrate all the test materials used as shields within 20 s, and the absorbance levels range between 67% and 98%. The penetration depths span between 0.16 and 0.46 mm and agree with the Kanaya-Okayama calculation. The values of stopping power for most materials show the ineffectiveness of materials for shielding. However, increasing the thickness, such as in the MLI case, can reduce the level of electron radiation absorption. This experiment provides recommendations on the selection of materials used for equatorial satellite shielding, particularly the next Indonesian LEO equatorial satellite, both in terms of material and size.

Preface

The International Summer School on Vacuum, Electron and Ion Technologies (VEIT) has been organized biennially since 1978, when the series of VEIT Schools was launched by the Institute of Electronics, Bulgarian Academy of Sciences, with the aim to act as a forum for exchange and dissemination of knowledge and ideas on the latest developments in electron-, ion-, and plasma-assisted technologies. The organizers of the 2023 edition of the event were the Institute of Electronics, Bulgarian Academy of Sciences, Sofia, Bulgaria and the Dutch Institute for Fundamental Energy Research, Eindhoven, The Netherlands. The School is a major scientific event and a meeting place for young scientists involved in research and development associated with high-tech industries. Many former School participants went on to become successful scientists in their field of research in leading institutions and companies all over the world. The School Proceedings have been published in special issues of the international journals Vacuum, Plasma Processes and Polymers, Journal of Physics: Conference Series.The twenty-third edition of VEIT was held in the Black Sea resort Sozopol, Bulgaria, from 18 to 22 September 2023. It was attended by 108 participants (33 students and young researchers) from 16 countries on two continents: Belgium, Bulgaria, Czech Republic, Estonia, France, Germany, Japan, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, The Netherlands, Ukraine, UK.The School Program covered a large spectrum of fundamental problems of the nanotechnologies, the interaction of charged particles with solid surfaces, the deposition and characterization of thin films, which were balanced out by reports on a wide range of significant high-technology applications – from equipment for deposition of hard coatings or thin optical/protective films to nanostructures prepared via evaporation, sputtering or irradiation. By their subjects, the lectures and reports were grouped for presentation and discussion in three sessions, each of them including oral presentations at plenary sessions and posters.List of Chairs of the School, International Advisory Committee, Local Organizing Committee, Invited Speakers, Participants are available in the pdf.

Solvent Effects on the Catalyst Ink and Layer Microstructure for Anion Exchange Membrane Fuel Cells.

Understanding the complex solvent effects on the microstructures of ink and catalyst layer (CL) is crucial for the development of high-performance anion exchange membrane fuel cells (AEMFCs). Herein, we study the solvent effects within the binary solvent ink system composed of water, isopropyl alcohol (IPA), commercial anion exchange ionomer, and Pt/C catalyst. The results show that the Pt/C particles and ionomer tend to form large aggregates wrapped with a thick ionomer layer in IPA-rich ink and promote the formation of large mesopores within the CL. With the increase of the water content in the ink, Pt/C particles are more likely to bridge to each other through wrapped FAA to form a well-connected three-dimensional network. The CL fabricated using water-rich ink shows smaller pores, higher porosity, and a more homogeneous ionomer network without the formation of large aggregates. Based on these results, we propose that the properties of the solvent mixture, including dielectric constant (ε) and solubility parameter (δ), affect the coulomb interaction of charged particles and surface tension at interfaces, which in turn affects the microstructure of ink and CL. By leveraging the solvent effects, we optimize the CL microstructures and improve the performance of AEMFC. These results may guide the rational design and fabrication of AEMFCs.

Investigation of charged particles interaction with CeBr3 scintillator by Monte Carlo simulation programs

This work aims to investigate the interaction of charged particles (alpha and proton) with the CeBr3 scintillator by using Monte Carlo simulation. The total mass stopping power (TMSP), projected range, ion distributions, and ion ranges in the CeBr3 at an energy range of 0.01 - 10,000 , were computed by SRIM and FLUKA programs. The simulation results show that the TMSP of CeBr3 obtained by both programs is in good agreement. The alpha particle has a higher TMSP of the CeBr3 than the proton. The projected range of alpha and proton particles increases with increasing energy. The projected range of the proton is higher than that of the alpha particle when compared at the same energy. Finally, the 2D visualization of ion distributions and ion ranges for alpha and proton particles was reported.
 
 

The science case for an intermediate energy advanced and novel accelerator linear collider facility

It is widely accepted that the next lepton collider beyond a Higgs factory would require center-of-mass energy of the order of up to 15 TeV. Since, given reasonable space and cost restrictions, conventional accelerator technology reaches its limits near this energy, high-gradient advanced acceleration concepts are attractive. Advanced and novel accelerators (ANAs) are leading candidates due to their ability to produce acceleration gradients on the order of 1–100 GV/m, leading to compact acceleration facilities. However, intermediate energy facilities (IEF) are required to test the critical technology elements on the way towards multi-TeV-class collliders. Here a science case for a 20–100 GeV center-of-mass energy ANA-based lepton collider that can be a candidate for an intermediate energy facility is presented. The IEF can provide numerous opportunities for high energy physics studies including precision Quantum Chromodynamics and Beyond the Standard Model physics measurements, investigation of charged particle interactions with extreme electromagnetic fields, and exploring muon and proton beam acceleration. Possible applications of this collider include the studies of γγ and electron beam-fixed target/beamdump collider designs. Thus, the goal of the proposed IEF is to both carry out particle physics measurements in the 20-100 GeV ranges as well as to serve as an ANA demonstrator facility.

Excitation of wakefields in carbon nanotubes: a hydrodynamic model approach

The interactions of charged particles with carbon nanotubes (CNTs) may excite electromagnetic modes in the electron gas produced in the cylindrical graphene shell constituting the nanotube wall. This wake effect has recently been proposed as a potential novel method of short-wavelength high-gradient particle acceleration. In this work, the excitation of these wakefields is studied by means of the linearized hydrodynamic model. In this model, the electronic excitations on the nanotube surface are described treating the electron gas as a 2D plasma with additional contributions to the fluid momentum equation from specific solid-state properties of the gas. General expressions are derived for the excited longitudinal and transverse wakefields. Numerical results are obtained for a charged particle moving within a CNT, paraxially to its axis, showing how the wakefield is affected by parameters such as the particle velocity and its radial position, the nanotube radius, and a friction factor, which can be used as a phenomenological parameter to describe effects from the ionic lattice. Assuming a particle driver propagating on axis at a given velocity, optimal parameters were obtained to maximize the longitudinal wakefield amplitude.

Guiding as a General Consequence of the Charged Particle Interaction with the Inner Surface of an Insulator Capillary—Guiding of 1 MeV Proton Microbeam through Polytetrafluoroethylene Macrocapillary

The transmission of energetic, 1 MeV proton microbeam through a single, cylindrical shaped, macrometer-sized polytetrafluoroethylene capillary was studied experimentally. The capillary axis was tilted with respect to the axis of the incident ion beam. The tilting, the aspect ratio of the capillary and the small beam divergence disabled the geometrical transmission of the beam through the target. The intensity, energy, deflection and charge state of the transmitted beam were investigated. We found that the pure guided transmission of a MeV/amu energy ion beam is observable. We clearly identified three completely different stages during the guiding process according to the measured energy distribution of transmitted particles. At the beginning the transmission intensity was low and only inelastic contributions with energy lower than 1 MeV were found in the spectrum. Later, in the second stage, the elastic peak appeared and became more and more significant. Finally, when the stable transmission evolved, only the elastic peak was present and the inelastic area was totally absent as a direct consequence of the ion guiding and as a result of the charged particle interaction with a charged inner surface of the insulator capillary.

Physical, microstructural, and radiation energy absorption properties of recycled CRT-screen glass doped with Bi2O3

In this study, pristine TV-CRT screen glass (TVS) and those doped with 10% (TVS-Bi10) and 20% (TVS-Bi20) by weight of Bi2O3 were prepared and analyzed for their physical, microstructural, radiation dosimetry quantities, and shielding features. The glass samples were fabricated using the cold isostatic press method. The surface microstructure and the chemical composition of the glass ceramics were probed with the aid of the scanning electron microscopy-energy dispersive X-ray (SEM-EDX) system. Photon absorption and scattering quantities were estimated using standard procedures. The mean density values determined by Archimedes principle were calculated as 2.614, 2.788, and 3.056 gr/cm3 for the TVS, TVS-Bi10, and TVS-Bi20 samples, respectively. SEM images of samples showed that the increase in bismuth content increased sample crystallization and surface pores. The estimated mass energy absorption coefficients of the samples varied from 0.0177 to 11.7578 cm2/g for TVS, 0.0182–14.5218 cm2/g for TVS-Bi10, and 0.0187–17.7615 cm2/g for TVS-Bi20 for photon energies between 15 keV and 15 MeV. At 1 mm glass thickness and for 100 keV gamma rays, the dose rate was 13 MR/h, 17 MR/h, and 22 MR/h for TVS, TVS-Bi10, and TVS-Bi20, respectively. The mass stopping powers of electrons at 15 keV have values of 12.37 MeV cm2/g 12.21 MeV cm2/g, and 12.03 MeV cm2/g for TVS, TVS-Bi10, and TVS-Bi20, respectively. Generally, the ranges of the CPs were such that those of TVS > TVS-Bi10>TVS-Bi20. Bi2O3 increases the electron, proton, alpha particle, and carbon ion absorbing features of the TVS-BiX samples. Bi2O3 suppresses photon scattering, makes the TVS glass more sensitive to photon and charged particle interaction and absorption. The investigated glasses are useful for gamma-radiation, light, and heavy ion absorption and protection technology.

Investigation of the nuclear radiation parameters of some Ti alloys for biomedical applications

This study investigates the nuclear radiation parameters of selected Ti alloys with potential biomedical applications. The compatibility with nuclear radiation is essential for these alloys in biomedical applications. To understand the nuclear radiation compatibility for this selected alloy, the gamma rays, neutrons, and charged particle interaction parameters were estimated using EpiXS, NGCal, ESTAR, and SRIM. The gamma rays, neutrons, and charged particle interaction parameters of selected Ti alloys relative to the cortical bone were studied. The Zeff of selected alloys relative to the cortical bone reaches unity in the lower photon energy region. Similar values of energy absorption buildup factor for selected alloys and cortical bone when the gamma energy region lies between 200 keV and 3 MeV. For neutron interaction at incident energy of thermal neutron at 25.4 meV and fast neutron 4 MeV, significant differences exist between selected alloys and cortical bone. From the estimated data, it is observed that among selected alloys, Ti-6Al-4V and Ti-6Al-4V-2.5Cu are comparable with cortical bone in terms of gamma rays and charged particle interactions. The results indicate that Ti-6Al-4V and Ti-6Al-4V-2.5Cu are the most suitable alloys for biomedical applications such as knee, hip, and elbow joints.

Nuclear data for space exploration

Understanding the harmful effects of galactic cosmic rays (GCRs) on space exploration requires a substantial amount of nuclear data. Specifically, the interaction of energetic GCR charged particles with spacecraft materials generates secondary radiations that, through energy deposition, can harm astronauts and electronic systems. By identifying the gaps in our knowledge of the relevant nuclear data—such as interaction cross sections—and identifying ways to fill those gaps—with measurements, compilations, evaluations, dissemination, reaction modeling, sensitivity studies, and uncertainty quantification—the safety and viability of space exploration can be improved. This work surveys the state of the art in this interdisciplinary field and identifies promising collaborative research topics that have significant potential to advance our understanding of the effects of the space radiation environment on space exploration.