Spin polarization and cross sections of electrons elastically scattered from heavy alkaline-earth atoms

Kumar, Pradeep; Jain, Arvind Kumar; Tripathi, A. N.; Nahar, Sultana N.

doi:10.1007/bf01426064

Cited by 3 publications

(15 citation statements)

References 14 publications

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“…However, the present work with OPMD has a rough qualitative agreement with the work of Kelemen et al [20] at energies 1 and 2 eV, as observed from figures 1(a) and (b). It can be noticed from figure 1(e) that the OPMD calculations have also qualitative agreement with Kumar et al [16] for 10 eV incident energy. Furthermore, for 100 eV collision energy, OPMD and [16] produce similar cross sections both in trend and magnitude ( figure 3(c)).…”

Section: Dcs and Total Cross Sectionssupporting

confidence: 84%

“…It can be noticed from figure 1(e) that the OPMD calculations have also qualitative agreement with Kumar et al [16] for 10 eV incident energy. Furthermore, for 100 eV collision energy, OPMD and [16] produce similar cross sections both in trend and magnitude ( figure 3(c)). As seen in the figure 1(f), the three predictions produce a good qualitative agreement with differences in the cross-section values, except for the low angles where a good agreement in trend and magnitude of DCS is noticeable.…”

Section: Dcs and Total Cross Sectionssupporting

confidence: 84%

“…In figure 5, we present our results of TCS, MTCS, IECS, VCS and INCS for e-Sr scattering in the range of energy E i =1-1000 eV in comparison with the available experimental data and other calculations. The results using the OPMD and OPMS calculations for TCS are compared in figure 5(a) with the experimental data of Romanyuk et al [8] and the theoretical calculations of Adibzadeh and Theodosiou [19], Kelemen et al [20], Kumar et al [16] and Yuan [14]. The above mentioned six calculations almost follow the same trend of energy variation with differences in magnitude of the cross-sections.…”

Section: Dcs and Total Cross Sectionsmentioning

confidence: 58%

“…In figures 1-4, we present the differential cross sections (DCSs) for e-Sr elastic scattering in the range of incident energies E i =1-1000 eV, obtained from the OPMD and OPMS methods. There is no experimental work on DCS for e-Sr elastic scattering, and so we compare our predictions with the available theoretical works of Kelemen et al [20] for energies 1.0 and 2.0 eV, Kumar et al [16] for 10.0 and 100 eV and Adibzadeh and Theodosiou [19]. To the best of our knowledge, the present work is the first one to predict the DCS at energies E i =60, 150, 250, 600, 800 and 900 eV.…”

Section: Dcs and Total Cross Sectionsmentioning

confidence: 80%

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Elastic scattering of electrons by Sr atom: a study of critical minima and spin polarization

et al. 2019

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Within the framework of the complex optical potential, the critical minima (CM) in the differential cross sections and the spin polarization in the elastic scattering of electrons by the Sr atom are studied in the energy range E i =1-1000 eV using the Dirac and Schrödinger partial wave methods. The two methods are, respectively, termed as the optical potential method of Dirac (OPMD) and optical potential method of Schrödinger (OPMS). The differential cross sections (DCSs), total cross sections (TCSs), momentum transfer cross sections (MTCSs), integral elastic cross sections (IECSs), viscosity cross sections (VCSs) and inelastic cross sections (INCSs) for e-Sr scattering are also calculated for the same energy range. In OPMD, the complex optical potential is composed of the static, exchange, polarization and absorption potentials. The OPMS potential, on the other hand, comprises the static, local exchange, polarization, spin-orbit, and absorption components. The number of CM points has been found to be respectively 7 and 5 with OPMD and OPMS methods in the DCSs of e-Sr scattering. The number of maximum spin polarization points observed is 13 and 10 for the OPMD and OPMS respectively. The energy dependence of TCS, MTCS, IECS, VCS, and INCS, studied in this work, show a non-monotonous pattern for energies beyond about 50 eV. So far as we are concerned, this is the first work for the study of CM in the DCSs of the e-Sr scattering as there are neither experimental nor theoretical studies published in the literature for the same.The strontium (Sr), with Z=38 , is one of the six alkaline earth metals with electron valence configuration 5s 2 . The scattering of electrons from Sr atom has drawn considerable interest due to the presence of low-lying shape resonance (SR) structures and the existence of its negative ion Sr − [7]. To the best of our knowledge, there is no extensive experimental or theoretical study on DCS and other cross sections for e-Sr scattering in the literature. However, we found two experimental works on the total cross section (TCS) by Romanyuk et al [8] and Kazakov et al [9] for a narrow electron energy interval 1-10 eV that agree with the two-state close-coupling (CC2) theoretical calculations of Fabrikant [10]. In their work, Romanyuk et al [8] observed a sharp increase of TCS as the scattering energy decreases to 0.1 eV. Kazakov et al [9] found a d-wave shape resonance at 1.2 eV by studying the structure of electron spectra for the scattering of electrons by the Sr atom, but they also attributed a minimum structure in 0.3-0.4 eV.Szmytkowski and Sienkiewicz [11] have done theoretical calculations on TCS using the relativistic polarized orbital approximation for the elastic electron scattering by Sr in the energy range 0.2-10 eV. They calculated the static part of their interaction potential by solving the Dirac-Hartree-Fock (DHF) equations for the isolated target while the polarization potential was obtained by solving the coupled DHF equations for the target perturbed by an electric field prod...

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Section: Dcs and Total Cross Sectionssupporting

confidence: 84%

Section: Dcs and Total Cross Sectionssupporting

confidence: 84%

Section: Dcs and Total Cross Sectionsmentioning

confidence: 58%

Section: Dcs and Total Cross Sectionsmentioning

confidence: 80%

See 2 more Smart Citations

Elastic scattering of electrons by Sr atom: a study of critical minima and spin polarization

et al. 2019

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“…Spin polarization of electrons elastically scattered from alkaline-earth-metal atoms was given by Dzuba et al. [3,6], Yuan and Zhang [5], and Kumar et al [8].…”

Section: Introductionmentioning

confidence: 99%

Intra-atomic relativistic effects on the spin polarization in low-energy electron scattering from Ca, Sr, Ba, and Yb atoms

Yuan

1995

Phys. Rev. A

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The influence of intratarget relativistic effects on electron spin polarization is studied for low-energy electron scattering from Ca, Sr, Ba, and Yb atoms, for which a low-lying d-wave shape resonance is predicted. The motion of the scattering electron is described by solving the continuous-state Dirac-Fock equations plus a parameter-free correlation-polarization potential. The targets are represented using Dirac-Fock, Cowan's quasirelativistic Hartree-Fock, and nonrelativistic Hartree-jock wave functions, in which the intra-atomic (also called the indirect) relativistic effects are incorporated in varying degrees. It is shown that the intra-atomic relativistic effects, in particular the spin dependence of the Dirac-Fock one-electron orbitals, create apparent quantitative changes in the spin polarization parameters around the d-wave shape resonances.PACS number(s): 34.80.Bm, 34.80.Nz the intra-atomic relativistic effects in the collisions. Most recently, the R-matrix method for the Breit-Pauli Hamiltonian [12] and the relativistic R-matrix method for oneelectron alkali-metal atoms of Thumm and Norcross [13] were applied to the very-low-energy electron collision with the Cs atom, where the author [12] found somewhat surprising discrepancies of the spin polarization parameters between their results [12,13] and suspected that it was due to Address to which correspondence should be sent.the Breit-Pauli approach to treat the relativistic effects. In the scheme of Thumm and Norcross [13],the closed core of the target was approximated with a model potential and the spin dependence of the core electron orbitals was not taken into account either. Electron scattering by neutral Hg atoms was studied by Wijesundera, Grant, and Norrington [14] using the Dirac R-matrix method based on the same relativistic Hamiltonian for both bound and continuous electrons, and

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A study of critical minima and spin polarization in the e±–Ba elastic scattering

et al. 2020

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Spin polarization and cross sections of electrons elastically scattered from heavy alkaline-earth atoms

Cited by 3 publications

References 14 publications

Elastic scattering of electrons by Sr atom: a study of critical minima and spin polarization

Elastic scattering of electrons by Sr atom: a study of critical minima and spin polarization

Intra-atomic relativistic effects on the spin polarization in low-energy electron scattering from Ca, Sr, Ba, and Yb atoms

A study of critical minima and spin polarization in the e±–Ba elastic scattering

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