Fully differential cross sections for singly ionizing 1-MeV p +He collisions at small momentum transfer: Beyond the first Born approximation

Abstract

We present calculations of the electron angular distributions in the single ionization of helium by 1-MeV proton impact at momentum transfer of 0.75 a.u. and ejected-electron energy of 6.5 eV. The results using the first and second Born approximations and the 3C model with different trial helium functions are compared to the experimental data. A good agreement between theory and experiment is found in the case of the 3C final state and a strongly correlated helium wave function. The electron-electron correlations in the He atom are found to influence the ratio of the binary and recoil peak intensities.

Fully differential cross sections for the single ionization of helium by fast ions: Classical model calculations

“…In Fig. 5 for 1-MeV proton impact we compare the result obtained by the latter model with the experimental data [2] and the predictions of quantummechanical models: the FBA and CDW-EIS-NN model of Voitkiv [7] and the 3C-SPM model of Chuluunbaatar et al [9]. In CDW-EIS-NN the label "NN" refers to the inclusion of the internuclear interaction.…”

“…In 3C-SPM the meaning of "SPM" is the same as in the present CTMC work: the authors of Ref. [9] applied the Silverman-Platas-Matsen function [34] for [2] (closed circles) and the predictions of quantum-mechanical models: the FBA and CDW-EIS-NN model of Voitkiv [7] (dashed and solid line, respectively) and the 3C-SPM model of Chuluunbaatar et al [9] (dashed-dotted line). The experimental data are normalized to CDW-EIS-NN at the maximum of the binary peak.…”

“…Unlike in the present work and that of Ref. [9], Voitkiv [7] expressed the FDCS as differential with respect to the transverse momentum vector Q and electron momentum vector k. We applied the following transformation between the two forms of FDCS:…”

“…Chuluunbaatar et al [9] performed FDCS calculations beyond PWFBA in order to clarify the role of higher-order collision mechanisms. For this purpose they used the planewave second Born approximation (PWSBA) and the 3C approaches.…”

Differential Study of Projectile Coherence Effects on Double Capture Processes in p + Ar Collisions

“…As a result, couplings between different eigenstates in the final state, which can be very important especially at small collision velocities, are completely ignored. Furthermore, in practice, the power series has to be truncated after some term and to the best of our knowledge no calculations beyond second order have been published yet, e.g., [11][12][13]. Some of these shortcomings are circumvented in distorted wave approaches, e.g., [14][15][16].…”