Angular Distribution Research Articles

Exploring the Efficiency of Caprylic Acid and Quaternary Ammonium Salt-Based Deep Eutectic Solvents for Separation of CO2 and H2S from Gas Mixtures Using Molecular Dynamics Simulations and COSMO-RS

In the present study, quaternary ammonium salts (QAS) and caprylic acid based deep eutectic solvents (DES) were employed for the separation of CO2 and H2S from natural gas (NG). To understand the extraction mechanisms of H2S from NG, we utilized MD simulations to understand intermolecular interactions between the gases and the eutectic solvents. Our detailed analysis for better understanding of QAS absorption capability in H2S extractions included combined distribution functions (CDFs), which encompass radial distribution functions (RDFs), angular distribution functions (ADFs), hydrogen-bonding networks, density profiles, spatial distribution functions (SDFs), and the non-bond energies between H2S and the DES components, all measured at 310 K. Additionally, we calculated the solubility of H2S and CO2 gases as well as the solubility selectivity and diffusivity selectivity parameters to evaluate the performance of the QAS-based DES in sweetening processes of NG. The results represent that eutectic solvents based on quaternary ammonium chloride are effective for H2S adsorption and show selectivity for H2S in gas mixtures. Furthermore, the COSMO-RS model was used to predict the solubility of various gases (H2S/CO2) in the QAS-based DES, providing further insights into their effectiveness.

Tau polarization effects in ντ/ν¯τ -tungsten interactions at the LHC energies

Recent studies have demonstrated that the tau produced in charged current neutrino deeply inelastic interactions at the GeV-TeV neutrino energy range is not fully polarized. In this paper we investigate the impact of the tau polarization on the pions generated in its decay. In particular, we consider tau neutrino-tungsten interactions at the LHC energies and estimate the associated pion momentum, energy, and angular distributions. The contribution of the F5 is also investigated. Our results indicate that the pion properties are sensitive to the tau polarization state as well as to the magnitude of F5. Published by the American Physical Society 2024

Electron-impact ionization of water molecules at low impact energies.

The electron-impact ionization of water molecules at low impact energies is investigated using a theoretical approach named M3CWZ. In this model, which considers exchange effects and post-collision interaction, the continuum electrons (incident, scattered, and ejected) are all described by a Coulomb wave that corresponds to distance-dependent charges generated from the molecular target properties. Triple differential cross-sections for low impact energy ionization of either the 1b1 or 3a1 orbitals are calculated for several geometrical and kinematical configurations, all in the dipole regime. The M3CWZ model is thoroughly tested with an extensive comparison with available theoretical results and COLTRIMS measurements performed at projectile energies of Ei = 81eV [Ren et al., Phys. Rev. A 95, 022701 (2017)] and Ei = 65eV [Zhou et al., Phys. Rev. A 104, 012817 (2021)]. Similar to other theoretical models, an overall good agreement with both sets of measured data is observed for the angular distributions. Our calculated cross-sections' magnitudes are also satisfactory when compared to the other theoretical results, as well as to the cross-normalized relative scale data at 81eV impact energy. The 65eV set of data, measured on an absolute scale, offers a further challenging task for theoretical descriptions, and globally the M3CWZ performs fairly well and comparably to other theories. The proposed approach with variable charges somehow allows to capture the main multicenter distortion effects while avoiding high computational costs.

Application of partial wave analysis in multiphoton pair production

Electron-positron pair production is investigated in the multiphoton regime under polarized fields. Partial wave analysis can be applied to reveal the momentum spectral structure and identify the positions of valleys/peaks of the multiphoton rings by combining with CP conservation. Moreover, considering the spin states of created pairs in partial wave analysis, the particle orbital angular momentum associated with the valleys/peaks can also be identified from multiphoton rings. It is found that the approximate analytical treatments for angular distribution by using partial wave analysis are consistent with those of the numerical calculation using the Dirac-Heisenberg-Wigner formalism. The results are helpful for understanding the angular momentum information in momentum spectra, and they also have an implication for revealing the vortex structure near the valleys where the amplitude nearly vanishes. Published by the American Physical Society 2024

Polarization study of the P-wave charmonium radiative decay into a light vector meson at e+e- collider experiment

Abstract In this work, a formalism is presented for the helicity amplitude analysis of the decays ψ(2S) →γ1χcJ, χcJ→γ2V (V=ρ0, Φ, ω) (the subscript 1,2 is used to distinguish the two radiative photons), and the polarization expressions of the P-wave charmonia χcJ and the vector mesons ρ0, Φ, ω for experimental measurements at Electron-Positron Collider. In addition, we derive the formulae of the angular distributions of the χc1,2→γV to extract the degree of transverse polarization PT of e+e- pairs with symmetric beam energy as well as the ratios of two helicity amplitudes x (in χc1 decays) and x, y (in χc2 decays) representing the relative magnitudes of transverse to longitudinal polarization amplitude, and validate it by performing the Monte Carlo simulation. Finally, the statistical sensitivity of PT, x and y are estimated based on the large ψ(2S) data samples collected at the current and proposed future e+e- collider experiment.Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must main tain attribution to the author(s) and the title of the work, journal citation and DOI. Article funded by SCOAP3 and published under licence by Chinese Physical Society and the Institute of High Energy Physics of the Chinese Academy of Sciences and the Institute of Modern Physics of the Chinese Academy of Sciences and IOP Publishing Ltd

A comprehensive study of nonuniformity properties of the LiCoO2 thin-film cathode fabricated by RF sputtering

The influence of nonuniformity properties of the LiCoO2 cathode film deposited by magnetron sputtering on the capacity of all-solid-state thin-film lithium-ion batteries (ASSLib) was studied. It was found that the film nonuniformity corresponds to the magnetron plasma density distribution and the angular distribution of sputtered particles. The capacity distribution of the ASSLib with LiCoO2 cathode depending on the distance to the substrate center was studied. The maximum capacity corresponded to the dense part of the toroidal region of the magnetron plasma. It was determined that the main causes of batteries capacity decline in the central part and on the edge of the substrate are the impurity phase of lithium cobaltate and the smaller thickness of the cathode layer, respectively.

Transverse momentum dependence of the T -even hadronic structure functions in the Drell-Yan process

We present detailed analysis of the T-even lepton angular distribution in the Drell-Yan process including γ/Z0 gauge boson exchange and using perturbative QCD based on the collinear factorization scheme at leading order in the αs expansion. We focus on the study of the transverse momentum QT dependence of the corresponding hadronic structure functions and angular coefficients up to next-to-next-to-leading order in the QT2/Q2 expansion. We analyze QT dependence numerically and compare T-even angular coefficients integrated over rapidity with available data of the ATLAS Collaboration at LHC. Additionally, we present our results for the forward-backward asymmetry and compare it with data. Published by the American Physical Society 2024

Apostle–Auriga: Effects of stellar feedback subgrid models on the evolution of angular momentum in disc galaxies

Abstract Utilizing the Apostle–Auriga simulations, which start from the same zoom-in initial conditions of Local Group-like systems but run with different galaxy formation subgrid models and hydrodynamic solvers, we study the impact of stellar feedback models on the evolution of angular momentum in disc galaxies. At z = 0, auriga disc galaxies tend to exhibit higher specific angular momenta compared to their cross-matched apostle counterparts. By tracing the evolution history of the Lagrangian mass tracers of the in-situ star particles in the z = 0 galaxies, we find that the specific angular momentum distributions of the gas tracers from the two simulations at the halo accretion time are relatively similar. The present-day angular momentum difference is mainly driven by the physical processes occurring inside dark matter haloes, especially galactic fountains. Due to the different subgrid implementations of stellar feedback processes, auriga galaxies contain a high fraction of gas that has gone through recycled fountain (∼65 per cent) which could acquire angular momentum through mixing with the high angular momentum circumgalactic medium (CGM). In apostle, however, the fraction of gas that has undergone the recycled fountain process is significantly lower (down to ∼20 per cent for Milky Way-sized galaxies) and the angular momentum acquisition from the CGM is marginal. As a result, the present-day auriga galaxies overall have higher specific angular momenta.

Vetoing all the Higgs imposters in H→ℓ-ℓ+Z\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$H\\rightarrow \\ell ^-\\ell ^+ Z$$\\end{document}

We develop an effective and methodical algorithm for the construction of general covariant four-point HℓℓZ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$H\\ell \\ell Z$$\\end{document} vertices, accommodating leptons ℓ=e,μ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\ell =e, \\mu $$\\end{document}, and designed to handle a boson H of any integer spin, not merely confined to spins up to 2. While our numerical analysis assumes the H-boson mass to be mH=125GeV\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$m_H=125\\,\ extrm{GeV}$$\\end{document}, the analytical framework we propose is versatile, enabling the examination of various mass as well as spin scenarios. These meticulously devised general covariant four-point HℓℓZ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$H\\ell \\ell Z$$\\end{document} vertices are pivotal in vetoing all the imposters of the Standard Model Higgs boson holding the spin-0 and even-parity quantum numbers, especially in one of its primary decay channels, the three-body decay process H→ℓ-ℓ+Z\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$H\\rightarrow \\ell ^-\\ell ^+ Z$$\\end{document}, observable at the Large Hadron Collider. Our innovative strategy encompasses the analysis of all the effectively allowed scenarios, extending beyond the limitations of previous investigations on the Higgs spin and parity determinations in the decay H→ℓ-ℓ+Z\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$H \\rightarrow \\ell ^-\\ell ^+ Z$$\\end{document}. Based on the significantly expanded scheme, we demonstrate that the Higgs boson imposter of any spin and parity can be definitively vetoed by leveraging angular and invariant mass distributions focusing on threshold effects. Even though achieving such conclusive results in practical and exhaustive analyses may necessitate high event rates, especially in the spin-0 contact-interaction case.

Mass and spin measurements of black hole and neutron stars X-ray binaries through axisymmetric oscillation modes of thick torus

Abstract This paper examines the oscillatory behaviour of relativistic, non-self-gravitating, charged-fluid toroidal structures within the context of the Kerr metric. The primary objective is to explore how thick accretion discs influence the mass and spin measurements of black holes and neutron stars in Low-Mass X-ray Binaries (LMXBs) through Quasi-Periodic Oscillations (QPOs) models. To achieve this, we conduct a local analysis within a general relativistic framework, determining the radial epicyclic and orbital frequencies in a perfect fluid disk. The tori are modelled using a non-Keplerian distribution of specific angular momentum, and we analyse how the oscillation properties depend on the model’s angular momentum distribution parameters. Subsequently, we connect these oscillatory frequencies to high-frequency QPOs observed in low-mass X-ray binaries, enabling us to calculate the optimal mass and spin values for each studied source.

Photoelectron momentum distribution in structured strong fields

Abstract In this study, a reaction microscope is used to explore the behavior of electrons in shaped beams under strong field conditions. Photoelectron momentum spectra indicate that the inclusion of orbital angular momentum (OAM) of light does not significantly impact the available electron angular momentum states. However, the distinctive donut shape of the beam plays a crucial role in determining the observed Photoelectron Angular Distributions (PADs). TDSE simulations, incorporating focal volume averaging indicates that the geometric properties of the focal region of the OAM and the Gaussian beams affect the photoelectron spectra differently. By averaging the spectra across different intensity regions, we have provided a qualitative explanation for the variations in photoelectron spectra resulting from the shapes of the individual beams. This result shows that the transfer of OAM in ultrashort light pulses cannot be detected in gas ensembles due to the ionization being overwhelmed by atoms in the most intense region with minimal spatial phase variation within the laser field. We demonstrate that the differences in the momentum spectra arising from shaped beams can be qualitatively explained using models that incorporate the spatial averaging of the beam, rather than focusing on the OAM content.

Study of lepton flavor universality and angular distributions in D→KJ∗(→Kπ)ℓνℓ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$D\\rightarrow K^*_{J} (\\rightarrow K\\pi )\\ell \ u _{\\ell }$$\\end{document}

The decay of the D meson into multibody final states is a complex process that provides valuable insights into the fundamental interactions within the Standard Model of particle physics. This study focuses on the decay cascade D+→KJ∗ℓ+ν→K±π∓ℓ+ν\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$D^{+}\\rightarrow K^{*}_{J} \\ell ^{+}\ u \\rightarrow K^{\\pm }\\pi ^{\\mp } \\ell ^{+}\ u $$\\end{document} where the KJ∗\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$K^*_J$$\\end{document} resonance encompasses the K∗(892),K∗(1410),K0∗(1430)\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$K^*(892),K^{*}(1410),K^{*}_0(1430)$$\\end{document} states. We employ the helicity amplitude technique to derive the angular distributions for the decay chain, enabling the extraction of one-dimensional and two-dimensional distributions. Utilizing form factors for the D→K∗\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$D\\rightarrow K^*$$\\end{document} transition derived from the quark model, we calculate the differential and integrated partial decay widths, explicitly considering the electron and muon masses. Decay branching fractions are calculated, the ratios of the branching fractions are found to be Br(D+→K∗(892)(→K-π+)μ+νμ)Br(D+→K∗(892)(→K-π+)e+νe)=0.975\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\frac{\\mathcal {B}r(D^{+}\\rightarrow K^{*}(892)(\\rightarrow K ^{-}\\pi ^{+}) \\, \\mu ^{+}\ u _{\\mu })}{\\mathcal {B}r(D^{+}\\rightarrow K^{*}(892)(\\rightarrow K ^{-}\\pi ^{+}) \\, e^{+}\ u _{e})} = 0.975$$\\end{document}, Br(D+→K∗(1410)(→K-π+)μ+νμ)Br(D+→K∗(1410)(→K-π+)e+νe)=0.714\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\frac{\\mathcal {B}r(D^{+}\\rightarrow K^{*}(1410)(\\rightarrow K ^{-}\\pi ^{+}) \\, \\mu ^{+}\ u _{\\mu })}{\\mathcal {B}r(D^{+}\\rightarrow K^{*}(1410)(\\rightarrow K ^{-}\\pi ^{+}) \\, e^{+}\ u _{e})} = 0.714$$\\end{document} and Br(D+→K0∗(1430)(→K+π-)μ+νμ)Br(D+→K0∗(1430)(→K+π-)e+νe)=0.774\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\frac{\\mathcal {B}r(D^{+}\\rightarrow K^{*}_{0}(1430)(\\rightarrow K ^{+}\\pi ^{-}) \\, \\mu ^{+}\ u _{\\mu })}{\\mathcal {B}r(D^{+}\\rightarrow K^{*}_{0}(1430)(\\rightarrow K ^{+}\\pi ^{-}) \\, e^{+}\ u _{e})} = 0.774$$\\end{document}. Results in this work will serve a calibration for the study of c→s\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$c \\rightarrow s $$\\end{document} in D meson decays in future and provide useful information towards the understanding of the properties of the K∗\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$K^{*}$$\\end{document} meson, as well as Kπ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$K \\pi $$\\end{document} system.

Dynamics of hydride anion and acetyloxyl radical production by electron attachment to acetic acid.

We investigate the dynamics and site-selectivity in the dissociation of transient anions formed upon attachment of low energy electrons to acetic acid by anion fragment momentum imaging experiments. The resonances at 6.7 and 7.7eV are confirmed to dissociate exclusively by the O-H bond, while a third resonance at 9.1eV dissociates primarily by both C-H break and O-H break. A fourth resonance near 10eV is found to dissociate by O-H break. For each resonance, the measured kinetic energy release indicates two-body dissociation produces a neutral radical in the ground electronic state, for all four resonances. The measured angular distributions are consistent with all four resonances having A' symmetry.

Generation of ultrarelativistic vortex leptons with large orbital angular momenta

We put forward a novel method for generating ultrarelativistic vortex positrons and electrons with intrinsic orbital angular momenta (OAM) through nonlinear Breit-Wheeler (NBW) scattering of vortex γ photons. A complete angular momentum-resolved scattering theory has been formulated, introducing angular momenta of laser photons and vortex particles into the conventional NBW scattering framework. We find that vortex positron (electron) can be produced when the outgoing electron (positron) is generated along the collision axis. By unveiling the angular momentum transfer mechanism, we clarify that the OAM of the γ photon and the large angular momenta due to multiple laser photons are entirely transferred to the generated vortex leptons. Furthermore, the cone opening angle and superposition state of the vortex γ photon can be determined via the angular distribution of created pairs in NBW processes. Published by the American Physical Society 2024

Hard jet substructure in a multistage approach

We present predictions and postdictions for a wide variety of hard jet-substructure observables using a multistage model within the framework. The details of the multistage model and the various parameter choices are described in []. A novel feature of this model is the presence of two stages of jet modification: a high-virtuality phase [modeled using the modular all twist transverse-scattering elastic-drag and radiation model ()], where modified coherence effects diminish medium-induced radiation, and a lower virtuality phase [modeled using the linear Boltzmann transport model ()], where parton splits are fully resolved by the medium as they endure multiple scattering induced energy loss. Energy-loss calculations are carried out on event-by-event viscous fluid dynamic backgrounds constrained by experimental data. The uniform and consistent descriptions of multiple experimental observables demonstrate the essential role of modified coherence effects and the multistage modeling of jet evolution. Using the best choice of parameters from [], and with no further tuning, we present calculations for the medium modified jet fragmentation function, the groomed jet momentum fraction zg and angular separation rg distributions, as well as the nuclear modification factor of groomed jets. These calculations provide accurate descriptions of published data from experiments at the Large Hadron Collider. Furthermore, we provide predictions from the multistage model for future measurements at the BNL Relativistic Heavy Ion Collider. Published by the American Physical Society 2024

Orientation Distribution of Crystalline β-Sheet Domains in Bombyx mori Silk Fiber Studied with Vibrational Sum Frequency Generation Spectroscopy.

Silk fibers have good biocompatibility and mechanical properties, which make them attractive in biomaterial applications as well as textile industries. It is believed that the superior mechanical property is associated with the crystalline β-sheet structure in the fiber; but a deeper understanding of the structure-property relationship is still needed for full exploitation of its physical properties. Especially, accurate information on hydrogen-bonding interactions within β-sheet domains at the nanoscale and their spatial distributions at the mesoscale are critically needed. In this study, we demonstrate the selective detection of crystalline β-sheet domains in Bombyx mori silk fiber using sum frequency generation (SFG) spectroscopy and its use to determine the angular distribution of the β-sheet crystallites with respect to the fiber axis. Numerical simulations of the SFG signal of the amide-I band were carried out using tensors based on the B2 symmetry of the D2 point group and compared with experimental data. This comparison found that the crystalline β-sheet domains are aligned along the fiber axis with a standard deviation of ∼27° and parallel to the fiber surface with a standard deviation of ∼5°. It was also found that the amide bands in the SFG spectra cannot be fully explained with the assumption that the crystalline β-sheet vibrations can be described with the D2 point group. Being able to monitor the amide group vibrations sensitive to both interchain hydrogen bonding and crystallite orientations, SFG analysis has a potential to unveil the structure-mechanical property relationship that may not be readily assessable with other characterization techniques.

On the Shift of the Maximum of the Polar Angular Distribution of Sputtered Atoms in the MD Model of the (001) Ni Face Sputtering

Using an up-to-date full molecular dynamics model of sputtering of single crystals, taking into account the incidence of ions on the surface, the peculiarities and mechanisms of atom sputtering during bombardment of the (001) Ni face with 200 eV Ar ions are studied for two target temperatures. It is shown for the first time that with an increase in the energy of sputtered atoms, not only the maximum of their polar angular distribution in the azimuthal direction toward the Wehner spots, but also the maximum of the polar angular distribution integrated over the azimuthal angles shifts first toward the normal to the surface, and then in the opposite direction. The polar distribution integrated over the azimuthal angle is formed by atoms ejecting from the surface at much larger polar angles than in the final (observed) distribution. Both effects are explained in terms of the surface mechanism of single crystal sputtering.

Determination of the Ion—Solid Interaction Potential from the Experiment and Its Influence on the Profiles of Implanted Particles

Based on the analysis of the angular distributions of particles passing through thin gold films, the parameters of the potential that best describes the experiment are obtained. The resulting potential differs from the potential describing collisions in the gaseous phase by a noticeable change in the screening constant. The influence of the collision energy, the choice of potential, and the model of electron bremsstrahlung on the depth distribution of implanted particles is analyzed.

Multimode light generation in an injection semiconductor laser based on a chiral AlAs/(Al, Ga)As/GaAs microcavity

Experimental investigations of chiral injection AlAs/(Al, Ga)As/GaAs vertical-cavity surface-emitting lasers in the multimode generation regime are performed. A high circular polarization degree 70% of different generation modes measured with a high spectral resolution, is demonstrated. Detailed maps of spatial and angular distribution of laser radiation intensity were constructed.

Exploration of drag on the thin film of micropolar fluid flow within a permeable medium

Advances in thin film acquired many industrial applications because of their use in several products like electronic devices, magnetic recording media, LED, optical coating, etc. Additionally, thin film has an extensive role in the study of multiferroic materials and superlattices in quantum phenomena. Therefore, it is an urge to predict the importance of drag employing Darcy-Forchheimer on the thin film flow of micropolar liquid through an expanding plate embedding with a permeable medium. Moreover, the current model enriches by incorporating the impact of Soret because of the cross-diffusion process and the radiative heat. By using the appropriate transformed variables, the designed problem is distorted, and further, these sets of equations are handled numerically employing Runge-Kutta shooting technique. The computation is carried out by deploying in-house built-in function bvp4c in MATLAB. The significant operational behavior of the manipulated quantities is accessible graphically and deliberated in the discussion section. The important findings are elaborated as; the angular velocity distribution shows a greater deceleration for the increasing microrotation and the inertial drag effect. Further, the thermo-diffusion due to Soret also attenuates the concentration profile and the solutal thickness became thinner for the higher heavier species.