Valence and core electron capture in proton-alkali atom collisions

2016

Can. J. Phys.

Inelastic collisions of protons with rubidium atoms are treated for the first time within the framework of the three channel coupled static, and frozen core approximations. The method is used for calculating partial and total cross sections with the assumption that only three channels (elastic; non-excited hydrogen, 1s-state; and excited hydrogen, 2s-state) are open. We have used the Lipmann-Schwinger equation and the Green's functions iterative numerical method technique to solve the derived coupled integro-differential equations to obtain the computer code. The present results for total hydrogen formation cross sections are in agreement with results of other available ones in a wide range of incident energy. Résumé: Une étude des collisions inélastiques de protons sur des atomes de rubidium est présentée pour la première fois dans le cadre des approximations des trois canaux couplés-statiques et du coeur figé. La méthode est utilisée pour calculer les sections efficaces partielles et totale en supposant que seuls trois canaux sont ouverts : élastique, hydrogène dans le fondamental 1s et excité 2s. Nous utilisons l'équation de Lipmann-Schwinger et la technique numérique itérative des fonctions de Green pour solutionner les équations couplées intégro-différentielles dérivées afin d'obtenir le code d'ordinateur. Nos résultats pour les sections efficaces totales de formation d'hydrogène sont en accord avec d'autres résultats disponibles sur une large bande de l'énergie incidente. [Traduit par la Rédaction]Mots-clés : collision inélastique, proton-rubidium, formation d'hydrogène, formation d'hydrogène excité.

Section: Resultsmentioning

confidence: 90%

Section: Introductionmentioning

confidence: 99%

Formation of ground and excited hydrogen atoms in proton–rubidium inelastic scattering

2016

Can. J. Phys.

“…According to (2), the binding energy of the valence electron of the target is determined by E Cs(6s) ϭ ͗⌽ Cs(6s) (r)|H T |⌽ Cs(6s) (r)͘ (6) The total Hamiltonian of the first channel, elastic channel, (in Rydberg units and frozen core approximation) has the following form:…”

Section: Theoretical Formalismmentioning

confidence: 99%

“…Banyard and Shirtcliffe [5] used the continuumdistorted wave method to calculate cross sections for protons scattered from atomic lithium. Ferrante et al [6] calculated total cross sections for hydrogen formation in proton scattering with alkali atoms using the Oppenheimer-Brinkman-Kramers approximation. Daniele et al [7] calculated total cross sections of proton scattering by alkali atoms using the eikonal approximation treatment, developed previously within the framework of the time-dependent impact parameter method for high-energy charge transfer.…”

Section: Introductionmentioning

confidence: 99%

Formation of ground and excited hydrogen atoms in proton–caesium inelastic scattering

2015

Can. J. Phys.

The inelastic scattering of a proton with a caesium atom is treated for the first time as a three-channel problem within the framework of the improved coupled static approximation with the assumption that the ground (1s state) and excited (2s state) hydrogen formation channels are open for seven values of the total angular momentum, ℓ ͑0 ≤ ℓ ≤ 6͒ at energies between 50 and 500 keV. The Green's function iterative numerical method is used to obtain the computer code to calculate iterative partial cross sections. This can be done through calculating the reactance matrix at different values of considered energies to obtain the transition matrix that gives partial and total cross sections. Present results give reasonable agreement with previous results. PACS Nos.: 34.80.Dp, 34.80.Gs, 34.80.Ht. Résumé :Pour la première fois, la diffusion inélastique de protons sur des atomes de Cs est traitée comme un problème à trois canaux dans le cadre de l'approximation améliorée du couplage statique sous l'hypothèse que les canaux de formation d'hydrogène dans les états fondamental (état 1s) et excité (état 2s) sont ouverts pour sept valeurs du moment cinétique orbital, ℓ ͑0 ≤ ℓ ≤ 6͒, à des énergies entre 50 et 500 keV. Nous utilisons la méthode numérique itérative pour la fonction de Green afin d'obtenir le code source pour calculer itérativement les sections efficaces partielles. Ceci est fait via le calcul de la matrice de réactance à différentes valeurs d'énergie pour obtenir la matrice de transition qui donne les sections efficaces partielles et totale. Nos résultats sont en accord raisonnable avec des résultats antérieurs. [Traduit par la Rédaction]

“…A procedure for determining the effective screening of the target nucleus by the uncaptured "passive" electrons is discussed, and the sensitivity of the cross-sections with respect to such screening is examined. Ferrante et al [3] reported the capture crosssections into ground and excited hydrogen states by protons colliding with alkali atoms. By means of simple models, the capture of both valence and core electrons is considered.…”

Section: Introductionmentioning

confidence: 99%

Effect of Polarization Potential on Proton–Sodium Inelastic Scattering

2014

Braz J Phys

Inelastic collisions of protons with sodium atoms are treated for the first time within the framework of the coupled static and frozen core approximations. The method is used for calculating partial and total cross-sections with the assumption that only two channels (elastic and hydrogen formation in 2s-state) are open. The calculations are carried out, in each case, for seven values of the total angular momentum ℓ (0≤ ℓ ≤6). In the second channel, the effect of "switching on" the polarization potential of hydrogen (in 2s-state) on the coupled static cross-sections is investigated. Although the resulting hydrogen (in 2s-state) formation cross-sections are smaller than the elastic ones, their large values should draw the attention of experimental and theoretical physicists to the field of proton-alkali atom collisions. Our results for the total hydrogen (2s-state) formation cross-sections and those determined by previous authors are in reasonable agreement.