Low-Energy Elastic Electron Scattering from Helium Atoms

Robert P Mceachran,Kathryn R Hamilton,Klaus Bartschat

doi:10.3390/atoms9040082

Abstract

We reinvestigate a key process in electron-atom collision physics, the elastic scattering of electrons from helium atoms. Specifically, results from a special-purpose relativistic polarized-orbital method, which is designed to treat elastic scattering only, are compared with those from a very extensive, fully ab initio, general-purpose B-spline R-matrix (close-coupling) code.

Highlights

One of the most-frequently investigated collision problems in atomic physics has been the elastic scattering of electrons from helium atoms
In addition to comparing with the results of Wan et al [1], we show representative data obtained by Nesbet [9] using his early benchmark variational approach for elastic scattering as well as extensive multi-channel close-coupling calculations, the momentum-space convergence close-coupling (CCC) approach of Fursa and Bray [10] and the coordinate-space R-matrix with pseudostates (RMPS) method used by Hudson et al [11]
We compared results for elastic electron scattering from helium atoms obtained in a number of special-purpose and general-purpose approaches

Summary

Introduction

One of the most-frequently investigated collision problems in atomic physics has been the elastic scattering of electrons from helium atoms. For example, that Equation (1) of Wan et al [1] contains a model potential with an approximate form of a local dipole-polarization potential Both the cut-off radius and the actual form of the cut-off function, while known to be working well, are not based on first principles. As pointed out by those authors themselves, going from an infinite nuclear mass to the proper reduced mass will change the results, and so will relativistic and even quantum electrodynamic effects. In addition to such inaccuracies based on the omission of some known (or even unknown) physics in a model, the numerical accuracy of any computational method is limited as well

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