Differential Cross Sections For Electron Research Articles

Correction to: Predicting differential cross sections of electron scattering from N2 using DCMe method

Correction to: Predicting differential cross sections of electron scattering from N2 using DCMe method

Predicting differential cross sections of electron scattering from N2 using DCMe method

The e + N2 scattering system is usually a typical testing model in electron scattering from molecule. The accurate resonant and the non-resonant differential cross sections (DCSs), integral cross sections (ICSs) and momentum transfer cross sections (MTCSs) of electron scattering from N2 molecule are studied using limited experimental DCSs and the difference converging method for electron scattering (DCMe) proposed in our previous work. The DCMe results well represent those known experimental data and obtain all unknown ones at given energies. It supplies a theoretical alternative to correctly predict the DCSs those may be experimentally unknown or hard to have quantum mechanically. This study shows that.

Critical positions and spin polarisation for electrons scattered by potassium atoms

ABSTRACT The critical points were calculated using the Dirac equation and real optical potential model, in addition to calculating differential, integrated elastic, transfer momentum and viscosity cross sections, and Sherman function for elastic scattering of Potassium atoms at the range 4 to 150 eV and in the angular range θ = 0–180°. We obtained two critical positions (38.1 eV, 141.1°) and (128.1 eV, 120.2°) at these positions we obtained the highest polarisation of spin, and the amplitude of the spin–flip is greater than the amplitude of the direct scattering. This study is considered the first calculation of the critical points in the differential cross sections for electron scattering by potassium atom.

Triply differential cross sections for electron and positron impact on methane.

We here report theoretical triply differential cross sections (TDCS) for 250eV electron and positron impact ionization of the methane molecule calculated within the second-order distorted-wave Born approximation (DWBA2) for various momentum transfer conditions. The experimental data taken from Işık et al. [J. Phys. B: At., Mol. Opt. Phys. 49, 065203 (2016)] will be compared with the current theoretical predictions as well as molecular three body distorted wave (M3DW) approximation and generalized Sturmian function (GSF) theoretical models in a non-coplanar geometry. In the low analyzer scattering plane, the results obtained within the DWBA2 theory show better agreement with the experimental results compared to the GSF results. The M3DW results also exhibit agreement with the experimental results, in particular in the perpendicular plane geometry. Furthermore, significant differences between electron and positron TDCS were observed.

Resonance signatures in DCS and spin polarization for positron scattering with C60 and rare gas endohedrals

We present a comparative study of differential cross sections (DCSs) and spin polarizations for positron scattering from C60 and A@C60, elucidating the role of encapsulation of rare gas atoms inside the giant C60 cage. A comparison is provided with the earlier work for elastic positron-C60 scattering. We find a very good agreement even when a model potential is used for the positron-C60 interaction. Also, we evaluate similarities and differences between the positron and electron DCSs and spin polarizations, both from bare and endohedral targets. To mark resonance features on the scattering dynamics, DCSs and spin polarizations are calculated at resonant energies, which showcase different characteristics compared to the cases where the positron energy is non-resonant. In order to account for a complete picture of the scattering process, an absorption potential is included in the total scattering field. For the sake of illustrating the impact of individual interactions and their interplay as a whole, DCSs and spin polarizations are reported including several scattering interactions alternatively.

Scattering of low energy neutrinos and antineutrinos by atomic electrons

Studies of neutrino mixing and oscillations, solar neutrinos as background in dark matter searches involving electron detection, detection of sterile neutrino warm dark matter, and of possible electromagnetic properties of neutrinos, have generated interest in the low energy O(10 keV) scattering of electron neutrinos and antineutrinos by atomic electrons where the binding of the atomic electron cannot be ignored. Of particular interest is the ionization of atoms by neutrinos and antineutrinos. Most existing calculations are based on modifications of the free electron differential cross section, which destroy the relationship between the neutrino helicities and the orbital and spin angular momenta of the atomic electrons. The present calculations maintain the full collision dynamics by formulating the scattering in configuration space using the Bound Interaction Picture, rather than the usual formulation in the Interaction Picture in momentum space as appropriate to scattering by free electrons. Energy spectra of ionization electrons produced by scattering of neutrinos and antineutrinos with energies of 5, 10, 20, and 30 keV by hydrogen, helium and neon have been calculated using Dirac central field eigenfunctions and are presented as ratios to the spectra for scattering by free electrons. Binding effects increase strongly with atomic number, are largest for low neutrino energy and, for each neutrino energy, greatest at the high electron energy end of the spectrum. The most extreme effects of binding are for 5 keV scattering by Ne where the ratios are less than 0.1. The energy spectra are calculated for both a Coulombic final electron state and a free final electron state. The results indicate that the binding effects from the continuum state of the final electron are significant and can be comparable to those arising from the bound initial electron state.

Implications of PREX-2 data on the electron-neutrino opacity in dense matter

Motivated by the recent measurement of the neutron distribution radius of ${}^{208}$Pb from the PREX--2 data, I study the effects of the new G3(M) parameter set constrained by PREX--2 data on the electron--neutrino scattering in dense matter using the extended relativistic mean field (E--RMF) model. I employ the G3(M) parameter set to describe the nuclear matter. The obtained equation of state for the G3(M) parameter set has an excellent agreement with experimental data and the chiral effective field theory calculation with N$^3$LO 3N forces. I analyze both differential cross section of electron--neutrino and electron--neutrino mean free path to observe their sensitivity to the G3(M) parameter set. One finds that the differential cross sections of electron--neutrino for different baryon densities have higher values compared with that obtained for the TM1e and FSU Garnet parameter sets. The higher cross section decreases the electron--neutrino mean free path.

Low energy electron scattering from pyridine using a Surko trap and beam

This paper presents measurements of low energy electron scattering from pyridine. The low energy positron beamline at the Australian National University was used for these measurements, with a change in operational parameters allowing for the measurement of electron scattering processes. We have collected data for the low energy total cross section for electron scattering, as well as measurements of the differential cross sections for electrons up to 3 eV impact energy. The operation of the beamline will be briefly outlined and data are compared to R-matrix and Schwinger multichannel theoretical calculations, as well as previous experimental data.

Elastic Electron Scattering from Methane Molecule in the Energy Range from 50-300 eV.

Electron interaction with methane molecule and accurate determination of its elastic cross-section is a demanding task for both experimental and theoretical standpoints and relevant for our better understanding of the processes in Earth’s and Solar outer planet atmospheres, the greenhouse effect or in plasma physics applications like vapor deposition, complex plasma-wall interactions and edge plasma regions of Tokamak. Methane can serve as a test molecule for advancing novel electron-molecule collision theories. We present a combined experimental and theoretical study of the elastic electron differential cross-section from methane molecule, as well as integral and momentum transfer cross-sections in the intermediate energy range (50–300 eV). The experimental setup, based on a crossed beam technique, comprising of an electron gun, a single capillary gas needle and detection system with a channeltron is used in the measurements. The absolute values for cross-sections are obtained by relative-flow method, using argon as a reference. Theoretical results are acquired using two approximations: simple sum of individual atomic cross-sections and the other with molecular effect taken into the account.

Theoretical investigation of the elastic scattering of by the ions of nitrogen isonuclear series

This work reports on differential, integrated and momentum transfer cross sections for the elastic scattering of electrons and positrons off the ions of nitrogen isonuclear series (N+ - N7+) over the energy range 1–500 eV. Calculations of these observable quantities involve the solution of Dirac relativistic wave equation employing a pure Coulomb potential and a short range potential. The latter comprises static, exchange, polarization and absorption potentials. Effects of these individual potentials on angular distribution of elastically scattered electrons are investigated throughout this ionic series. Differential cross sections for electron and positron scattering are compared with each other to demonstrate the difference of their collision dynamics. A satisfactory agreement between our predictions and other available data, experimental and theoretical, is observed.

Differential cross sections for ionisation of helium by proton impact

SynopsisA wave-packet convergent close-coupling approach is applied to study differential ionisation in proton-helium collisions. The fully differential cross sections for electrons ejected with energy of 5.4 eV are investigated in 75 keV proton-helium collisions. We also study the doubly differential cross sections for electrons ejected with energies up to 65 eV at intermediate projectile energies (50-150 keV). The results are converged regarding the number of pseudostates included and are in fairly good agreement with the available experimental data.

Electron impact excitation of the 4 1S0-4 1P1 state of Zn atom

SynopsisThe electron impact excitation total and differential cross sections, Stokes parameters, and coherence pa-rameters of Zn atom from the ground state 41S0 to the excited state 41P1 were systematically calculated using the fully relativistic distorted wave method. The calculated results are compared with the experimental data and other theoretical results, good agreement is obtained.

Effect of dynamic screening on the electron capture process in nonideal plasma

In this paper, the process of electron capture in nonideal plasma has been investigated. For this goal the Bohr-Lindhard method has been applied to obtain the electron capture cross section. All calculations have been done in the framework of the trajectories of incident electron near hydrogen ion (proton) obtained by the numerical simulation of the equations of motion. The effective interaction potential, which takes into account the static or dynamic screening effects at large distances and quantum diffraction effects at short distances, was used. The results of numerical calculations of the electron capture radius, differential and total cross section for different values of the density parameter and velocity are presented. It is shown that dynamic charge screening increases the capture cross sections in comparison with static screening.

Calculation of electron scattering cross sections for Anthracene, Pyridine and Warfarin molecules over energy range 10–30000 eV

This paper reports electron impact total cross section, total elastic, total inelastic and differential cross sections for molecules Anthracene, Pyridine and Warfarin having been computed using the independent atom model with screening-corrected additivity rule over an incident energy range of 10–30000 eV. The calculations are performed with relativistic (Dirac) partial-wave for scattering by applying a local central interaction potential V(r). A model spherical complex optical potential is used for calculations. Good agreement is achieved in intermediate and high-energy zones.

Low energy differential elastic electron scattering from acetonitrile (CH3CN).

Measurements of elastic differential cross sections for electron scattering from acetonitrile (CH3CN) have been performed utilizing a crossed electron-molecular beam experiment and with the relative flow method, for the incident electron energy range of 0.7 eV-30 eV and the scattering angle range of 10°-130°. These differential cross sections have been used to calculate the elastic integral and momentum-transfer cross sections, revealing a π * resonance located around 3 eV. The elastic differential cross sections are compared with available theoretical models using the R-matrix method and the Schwinger multichannel method.

Elastic electron differential cross sections for argon atom in the intermediate energy range from 40 eV to 300 eV

Measurements and calculations for electron elastic differential cross sections (DCS) of argon atom in the energy range from 40 to 300 eV are presented. DCS have been measured in the crossed beam arrangement of the electron spectrometer with an energy resolution of 0.5 eV and angular resolution of 1.5∘ in the range of scattering angles from 20∘ to 126∘. Both angular behaviour and energy dependence of DCS are obtained in a separate sets of experiments, while the absolute scale is achieved via relative flow method, using helium as a reference gas. All data is corrected for the energy transmission function, changes of primary electron beam current and target pressure, and effective path length (volume correction). DCSs are calculated in relativistic framework by expressing the Mott’s cross sections in partial wave expansion. Our results are compared with other available data.

The 3D differential cross sections of electron scattering on fluorine atom

У рамках методу R -матриці з B- сплайнами (БСР) розраховані диференціальні перерізи (ДП) розсіяння електронів на атомі фтору в області енергій до 110 еВ. Розклад сильного зв‘язку включав 39 зв‘язаних станів атома F. Отримані енергетично-кутові залежності ДП і побудовані відповідні 3D-поверхні для перерізів пружного розсіяння та збудження п’яти нижчих станів атома F. Обговорено зв’язок енергетично-кутових 3D-залежностей ДП від типу спектральних переходів у атомі F.

DWBA double differential ionization cross sections for positron and electron impact on argon

The ionization of the 3p orbital of argon by 100 eV incident electrons and positrons is studied with the DWBA-WM approximation. The variation of our double differential ionization cross sections with the angles of the ejected electrons is found to be in reasonable agreement with the experiment. We found that the inclusion of the post-collision interaction in the theoretical model is necessary to obtain the size of the difference between the experimental double differential cross sections for electron and positron impact ionization.

Elastic Differential Cross Sections for Electron Scattering with Dichloromethane

SynopsisIn the present study joint experimental and theoretical elastic differential cross sections for electron scattering from dichloromethane in the incident electron energy region 7 to 50eV are discussed.

Predicting differential cross sections of electron scattering from tetrahydrofuran

A difference algebraic converging method for electron scattering from molecule (DACMe) is suggested based on the recently proposed difference converging method (DCM) to predict unknown differential cross sections (DCSs). The applications of the DACMe to electron scattering from tetrahydrofuran (THF) molecule at energies below 20 eV show that: (1) the DACMe DCSs excellently reproduce all the available experimental data; (2) the DACMe method correctly predicts unknown DCSs that may not be given experimentally; (3) the DACMe can be used as an economic and useful alternative method to predict the correct DCSs where such scattering data are required; (4) the DACMe method does not depend on the size and the stereochemistry structure of a scattering molecule; (5) the algebraic modification to the DCM enhances the computational efficiency of the DCM theoretical study by at least 110 times.