Elastic electron scattering by mercury atoms

Zeitschrift für Physik A Hadrons and nuclei - The cross section and Mott asymmetry function of elastic electron scattering by mercury atoms have been calculated for energies of 46, 79, 100,...     

Elastic scattering of positrons by helium and lithium

We present differential and integrated cross-sections for elastic scattering of positrons by helium and lithium at intermediate and high energies, calculated using the two-potential eikonal approach. The present calculations are compared with the available theoretical results.     

Elastic electron deuteron scattering

Measurements of the ratio of the deuteron to proton electric form factors were made for low q. The rms radius of the deuteron structure factor was found to be 1.9635 ± 0.0045 fm, yielding an rms charge radius of 2.095 ± 0.006 fm.     

Elastic constants of lithium thallium tartrate measured by Brillouin scattering

All components of the elastic stiffness tensor of lithium thallium tartrate at room temperature have been measured by Brillouin scattering techniques using two different scattering configurations. Refractive indices have been determined independently by optical measurement. The results are compared with previous work on lithium thallium tartrate and lithium ammonium tartrate.     

Elastic scattering of a photon by a neon-like ion

The differential cross sections of anomalous elastic scattering of a linearly polarized x-ray photon by a neon-like Si ion in the energy range near the K-and KL ₂₃-ionization thresholds are calculated. The calculation results are predictive.     

Elastic scattering of an electron on the Coulomb potential with a cut-off

The partial-wave method is used to study the elastic scattering of electrons on the Coulomb potential with a cut-off. There is considerable discrepancy between the present results and those obtained by means of the Born approximation and the classical method. At a given specific energy, the cross section exhibits a maximum. This due to the appearance of maxima in the differential cross section in both the forward and the backward direction.     

Elastic electron scattering in an intense field and two-photon emission

The elastic scattering amplitude, taking into account the mass correction to the propagation function, is found for electrons interacting with an intense electromagnetic field characteristic of non-linear quantum electrodynamics. The probability for two-photon emission e → e2γ, the mass correction to the probability for one-photon emission and the mass correction to the anomalous field-dependent magnetic moment of the electron are found with the aid of the amplitude.     

Elastic electron scattering from 19F

The form factors for elastic scattering from ¹⁹F have been calculated with a projected Hartree-Fock function obtained from a calculation in which the B1 force of Brink and Boeker was used as two-body interaction. Good agreement was obtained with the experimental data, both for the charge and for the magnetic form factor. A detailed analysis of the results shows that the agreement depends in an essential way on the amount of 0d component in the wave function of the valence nucleons.     

Elastic electron scattering from C and O

Electron scattering cross sections for carbon and oxygen between q = 1 fm⁻¹ and 4 fm⁻¹ are given. The data are analysed in terms of a phenomenological charge distribution and new information concerning the tail and the center of the charge distribution are obtained. The presence of dispersion effects appears to be necessary to explain the cross sections in the first diffraction minimum. The effect of a finite potential and short range correlations on the form factor are discussed.     

Elastic electron scattering on Zr and Mo

Elastic electron scattering on ⁹⁰Zr and ⁹²Mo has been measured at 200 and 300 MeV up to 2 fm⁻¹ momentum transfer. Data analysis led us to adopt the parabolic Gaussian shape as a valuable charge distribution for these nuclei. For ⁹⁰Zr, we have compared this model with charge distributions given by recent Hartree-Fock calculations.     

Inelastic electron scattering and energy-selective negative ion reactions in molecular films on silicon surfaces

Careful control of plasma chemistry, particularly the negative ion production and reaction channels, could lead to nanoscale patterning, growth, and etching strategies. Since the energies of anion and electron surface collisions are relatively low (<10 eV) in plasmas, these interactions are essentially damage free with respect to the buried interface and subsurface region. Thus, renewed interest has arisen that takes advantage of negative ion surface chemistry in film deposition and nanopatterning. We review (i) the transient negative ion states such as shape and dissociative electron attachment resonances produced during electron molecule scattering, (ii) the many body interactions and substrate-effects on the resonance energies, widths and cross sections and (iii) examples of post-dissociation interactions of the reactive fragments and anions that may lead to controlled etching or growth. Specifically, we summarize past and recent studies on electron scattering with gas- and condensed-phase H₂O, CF₄, SiCl₄ and O₂ targets. We then discuss recent examples of energy selective oxidation and fluorination of hydrogen terminated silicon surfaces and comment on the general applicability of low-energy electrons and negative ion surface chemistry in film deposition, nanopatterning and growth strategies.     

Eikonal expansion in electron scattering: I. Elastic scattering

A systematic eikonal expansion for the scattering of high-energy electrons from nuclei is derived which starts from the iterated Dirac equation. The resulting scattering amplitude is written in an impact parameter representation depending on eikonal phases which are proportional to inverse powers of the energy. The first two correction terms to the leading Glauber-Baker amplitude are calculated. For a Coulomb potential they agree with a sinθ-expansion of the relativistic Coulomb scattering amplitude. In the case of scattering from an extended charge distribution at sufficiently high energies numerical partial wave calculations are accurately reproduced.     

Elastic electron scattering from the isotones Ca and K

The nuclear charge distributions of ⁴⁰Ca and ³⁹K have been extracted from elastic electron scattering cross sections. The difference of the distributions shows a concentration of charge in a single peak at 4.1 fm. Comparisons with models are made.     

Elastic scattering amplitude of a polarized electron in an arbitrary plane wave field

The elastic scattering amplitude of a polarized electron in an arbitrary plane wave electromagnetic field is obtained by using the method of dispersion relations. Superposition of a constant crossed field and a plane monochromatic wave of elliptic polarization is considered a particular case of giving the field. An anomalous magnetic moment is obtained for the electron in the mentioned field as are also relative contributions to the anomalous magnetic moment due to the transition into the intermediate state with and without spin turnover.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 10, pp. 69–75, October, 1990.     

Differential cross sections for electron scattering by polar molecules. Elastic scattering and vibrational excitation

By use of the effective range theory for electron scattering by polar molecules differential cross sections for elastic scattering by HCN and LiF molecules and for vibrational excitation of water molecules are calculated.     

Elastic and total cross-sections for electron scattering by acetylene in the intermediate energy range

We present a joint theoretical-experimental study on electron scattering by C₂H₂ in the intermediate energy range. We report calculated elastic differential, integral, and momentum-transfer as well as total (elastic + inelastic) and absorption cross-sections at impact energies ranging from 10 to 500 eV. Also, experimental absolute elastic cross-sections are reported in the (50-500)-eV energy range. A complex optical potential is used to represent the electron-molecule interaction dynamics. The iterative Schwinger variational method, combined with the distorted-wave approximation, is used to solve the scattering equations. Experimentally, the angular distributions of the scattered electrons are converted to absolute cross-sections using the relative flow technique. The comparison of our calculated with our measured results, as well as with other experimental and theoretical data available in the literature, is encouraging.Received: 26 August 2004, Published online: 5 October 2004PACS: 34.80.Bm Elastic scattering of electrons by atoms and molecules     

Elastic differential cross sections of electron scattering by CF_4 at intermediate energies

The elastic differential cross sections(DCS)for electron scattering from CF 4 are calculated at six impact energies(in 100—700 eV)employing the independent atom model(IAM)with partial waves. The atoms are presented by a model complex optical potential which is composed of static, exchange, polarization, and absorption terms. The electron density function ρ(r) is obtained by a fitting procedue to the Dirac Hartree Fock Slater sef consistent data. Compared with available experimental data, the presen...     

Elastic electron scattering from 40Ar

Cross sections for elastic electron scattering from ⁴⁰Ar have been measured for the momentum transfer range from 0.59 to 1.31 fm^?1. We have analyzed with the Fourier-Bessel ansatz our data as well as the data of former experiments. The rms charge radius we have found is 3.423(14) fm. The results are in excellent agreement with latest muonic data. Furthermore, we have reanalyzed former ⁴⁰Ca data and have discussed the ⁴⁰Ca- ⁴⁰Ar charge distribution.     

Elastic differential cross sections of electron scattering by CF_4 at intermediate energies

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