Elastic scattering of electrons by calcium atoms

Abstract

The differential, total, and momentum transfer cross sections along with the minima in the differential cross sections (DCSs) and the Sherman function S() for the elastic scattering of electrons by calcium atoms have been calculated. These calculations are done within the framework of complex electron-atom optical potential and relativistic dynamics, in the energy range 1-2000 eV. The results obtained are in good agreement with the available experimental data and are better than the previous calculations in overall assessment. In the DCSs, the energies and angular positions of five critical minima have been confirmed. In the vicinity of these critical minima, nine maximum polarization points have been found within the range −0.90 ≤ S() ≤ +0.73. Near the critical minima, a strong energy dependence of maximum polarization points is found. PACS Nos.: 41.75.Fr, 34.80.Bm. Résumé : Nous avons calculé les sections efficaces différentielle, totale et de transfert de quantité de mouvement, ainsi que les minima dans les sections efficaces différentielles (DCSs) et la fonction de Sherman S(), pour la diffusion élastique d'électrons sur des atomes de calcium. Ces calculs ont été faits en dynamique relativiste avec un potentiel optique complexe électron-atome, pour des énergies allant de 1 à 2000 eV. Les résultats obtenus sont en accord avec les données expérimentales et globalement meilleurs que les calculs antérieurs. Nous confirmons l'énergie et la position angulaire de cinq minima critiques des DCSs. Dans le voisinage de ces minima critiques, nous avons trouvé neuf points de polarisation maximale dans le domaine −0.90 ≤ S() ≤ +0.73. Nous observons une forte dépendance en énergie des points de polarisation maximale près des minima critiques. [Traduit par la Rédaction]

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

“…This happens also in figure 8(f), where two extremum values of S(θ) lies between +0.991 1 at 126°and −0.997 3 at 127°in the vicinity of 126.5°. These results agree with the work of Hasan et al [48] where they found the variation of S(θ) from +0.54 at 120.5°to −0.75 at 121°for e-Ca scattering at 139.5 eV and from +0.64 at 120.5°to −0.75 at 121°f or 140 eV. This result profoundly reveals the success of OPMD calculations in determining the CM in DCSs for e-Sr scattering.…”

Relativistic calculations for spin-polarization of elastic electron—mercury scattering

“…The real part, on the other hand, includes the static [30], the exchange [31] and the polarization [32] potentials. In our calculations of e --atom scattering [33][34][35], we chose a global polarization potential that was a combination of the long-range Buckingham potential and shortrange local-density approximation (LDA) correlation potential. In the present study, instead of Buckingham potential, a parameter free potential due to Sun et al [36] is used as the long-range part of the polarization potential, which allows us to obtain better results of spin-polarization over a wide energy range of 1 eV E 2 keV i   .…”

Comprehensive Study of Properties of a Endohedrally Confined Ca Atom using Relativistic Many-body Methods

“…see Refs. [15,27,28]), we also employ the DFCP method in our calculations to demonstrate differences between the results from this method and the RCC theory by introducing the CP potential (V cp (r)) in the interaction potential as V (r) = V st (r) + V ex (r) + V cp (r) − ιV ab (r). Here V st (r) and V ex (r) are determined using ρ(r) from the DF method.…”

“…The results are reported for differential cross-sections (DCSs) and integrated cross-sections (ICSs). We compare our results for the free Ca atom with the available experimental data [14] and other reported calculations using the DFCP method [15] in order to gauge accuracies of the results for the confined atom.…”