dc.contributor |
Universitat de Barcelona |
dc.contributor.author |
Salvat Gavaldà, Francesc |
dc.date |
2009-10-06T10:48:32Z |
dc.date |
2009-10-06T10:48:32Z |
dc.date |
2003 |
dc.identifier.citation |
1050-2947 |
dc.identifier.citation |
529865 |
dc.identifier.uri |
http://hdl.handle.net/2445/9587 |
dc.format |
17 p. |
dc.format |
application/pdf |
dc.language.iso |
eng |
dc.publisher |
The American Physical Society |
dc.relation |
Reproducció digital del document publicat en format paper, proporcionada per PROLA i http://dx.doi.org/10.1103/PhysRevA.68.012708 |
dc.relation |
Physical Review A, 2003, vol. 68, núm. 1, p. 012708. |
dc.relation |
http://dx.doi.org/10.1103/PhysRevA.68.012708 |
dc.rights |
(c) The American Physical Society, 2003 |
dc.rights |
info:eu-repo/semantics/openAccess |
dc.subject |
Dispersió (Física nuclear) |
dc.subject |
Electrons |
dc.subject |
Scattering (Physics) |
dc.subject |
Electrons |
dc.title |
Optical-model potential for electron and positron elastic scattering by atoms |
dc.type |
info:eu-repo/semantics/article |
dc.type |
info:eu-repo/semantics/publishedVersion |
dc.description.abstract |
An optical-model potential for systematic calculations of elastic scattering of electrons and positrons by atoms and positive ions is proposed. The electrostatic interaction is determined from the Dirac-Hartree-Fock self-consistent atomic electron density. In the case of electron projectiles, the exchange interaction is described by means of the local-approximation of Furness and McCarthy. The correlation-polarization potential is obtained by combining the correlation potential derived from the local density approximation with a long-range polarization interaction, which is represented by means of a Buckingham potential with an empirical energy-dependent cutoff parameter. The absorption potential is obtained from the local-density approximation, using the Born-Ochkur approximation and the Lindhard dielectric function to describe the binary collisions with a free-electron gas. The strength of the absorption potential is adjusted by means of an empirical parameter, which has been determined by fitting available absolute elastic differential cross-section data for noble gases and mercury. The Dirac partial-wave analysis with this optical-model potential provides a realistic description of elastic scattering of electrons and positrons with energies in the range from ~100 eV up to ~5 keV. At higher energies, correlation-polarization and absorption corrections are small and the usual static-exchange approximation is sufficiently accurate for most practical purposes. |