Semirelativistic 1s-2s Excitation of Atomic Hydrogen by Electron Impact

Abstract

In the framework of the first Born approximation, we present a semirelativistic theoretical study of the inelastic excitation (1s 1/2 −→ 2s 1/2 ) of hydrogen atom by electronic impact. The incident and scattered electrons are described by a free Dirac spinor and the hydrogen atom target is described by the Darwin wave function. Relativistic and spin effects are examined in the relativistic regime. A detailed study has been devoted to the nonrelativistic regime as well as the moderate relativistic regime. Some aspects of this dependence as well as the dynamic behavior of the differential cross-section in the relativistic regime have been addressed.

Spin Effects in Laser-Assisted Semirelativistic Excitation of Atomic Hydrogen by Electronic Impact

“…The spin-polarized differential cross sections dσ (n) /dΩ f are computed for the laser-assisted semirelativistic excitation of atomic hydrogen by electronic impact, where n denotes the number of photons absorbed or emitted. With a view to qualitative comparison with our previous work [14], kinematics and the geometry parameters are chosen in accordance with those used in Ref. [14].…”

“…With a view to qualitative comparison with our previous work [14], kinematics and the geometry parameters are chosen in accordance with those used in Ref. [14]. The direction of the laser field is chosen parallel to Oz axis.…”

“…In the present paper we have to extended our previous results [14] to the case of laser assisted inelastic excitation 1s to 2s of the atomic hydrogen by polarized electrons. Therefore, we have begun with the most basic results of our work using atomic units (a.u) in which one has (h = m e = e = 1), where m e is the electron mass at rest.…”