Polarization of Lyman-αemission in proton-hydrogen collisions studied using a semiclassical two-center convergent close-coupling approach

Abstract

The semiclassical convergent close-coupling approach to ion-atom collisions has been extended to include electron-transfer channels. The approach has been applied to study the excitation and the electron-capture processes in proton-hydrogen collisions. The integral alignment parameter A20 for polarization of Lyman-α emission as well as the cross sections for excitation and electron-capture into the lowest excited states have been calculated in a wide range of the proton impact energies from 1 keV to 1 MeV. The results are in good agreement with experimental measurements.

Proton impact on ground and excited states of atomic hydrogen

“…Although the cross section curves from the CTMC calculations [8] have similar structures as the other results, quantitative differences in the intermediate [14]. Theory: AOCC-PS, CTMC and TDL [8]; Sturmian-CC [4]; SC-CCC [5]; WP-CCC [9]; AOCC-GTO [10]; and present TC-BGM.…”

“…Results of the nl excitation cross sections for p-H(1s) and p-H(2s) collisions are displayed in figure 2. For H(1s) collisions, the present cross sections are compared with several previous theoretical results based on the TDL method from [2,8], close-coupling approaches based on a large Sturmian basis (Sturmian-CC) from [4], single-center convergent close-coupling (SC-CCC) calculations by Avazbaev et al [5], and the AOCC-GTO analysis by Agueny et al [10]. Note that the uncertainty bars shown from the AOCC-GTO results are estimates of the convergence of the cross sections [10].…”

“…Among all the cross sections that were compared, discrepancies with those approaches are mainly evident in the ionization results. Considering that these discrepancies are of some concern, the results produced by the TC-BGM should be viewed as a notable achievement since fewer pseudostates are needed to reach a similar level of accuracy compared to the convergent close-coupling approaches [5,9,17] which uses a significantly larger basis.…”

“…The classic problem of proton scattering from ground-state hydrogen has often been used as a benchmark system for theoretical models [1][2][3][4][5]. Cross sections of electronic processes (e.g., capture, excitation, and ionization) for this prototypical system have important applications in plasma physics.…”

Proton-beam stopping in hydrogen

“…The single-centre CCC approach has previously been applied to the calculation of stopping cross sections for antiproton collisions with atoms and molecules [17][18][19] and to the calculation of scattering cross sections for antiproton-hydrogen collisions [20,21]. Additionally, the two-centre CCC approach has been applied to the calculation of scattering cross sections for proton-hydrogen collisions [22][23][24]. Preliminary results of the protonhydrogen stopping cross section using the two-centre CCC approach have been reported in Ref.…”