DWBA-G calculations of electron impact ionization of noble gas atoms

Abstract

We perform calculations of electron impact ionization of noble gas atoms within the distorted wave Born approximation (DWBA) corrected by the Gamow factor (G) to account for the post-collision interaction. We make an extensive comparison with experimental data on He 1s2, Ne 2s2, 2p6 and Ar 3p6 under kinematics characterized by large energy transfer and close to minimum momentum transfer from the projectile to the target. For all atoms, good agreement between theory and experiment is achieved. In the case of Ar, the disagreement of experimental data with theory reported earlier by Catoire et al (2006 J. Phys. B: At. Mol. Opt. Phys. 39 2827) is reconciled.

Low-energy electron-impact ionization of argon: Three-dimensional cross section

“…With this approximation, the electron-electron repulsion factors out of the integral, and the net effect is to multiply the DWBA amplitude by the Gamow factor. Kheifets et al [16] recently showed that approximating the Coulomb interaction by the Gamow factor significantly improved agreement between experiment and theory for high-energy ionization of inert gases particularly at larger scattering angles. Ward and Macek [18] proposed a low-energy approximation, keeping the hypergeometric function but evaluating it for an average separation between the electrons.…”

“…These are based upon the distorted-wave Born approximation (DWBA) [12][13][14][15][16] for both the projectile and the ejected electron, or a hybrid approach where the scattering of the (slow) ejected electron with the residual ion is treated via a close-coupling expansion while the projectile-target interaction is again treated perturbatively up to second order [17]. Some of the models also attempt to account for the final-state post-collision interaction, either through an asymptotically correct wavefunction in the matrix elements [14], or, much simpler, via the so-called Gamow factor [16,18].…”

“…[15][16][17]. On the other hand, puzzling discrepancies remain in particular outside the scattering plane [9,19].…”

Energy dependence of the (e,2e) recoil peak to binary peak ratio across He (2p2)1deHarak1, Bartschat2, Martin3 2014Phys. Rev. A3010View full textAdd to dashboardCite

“…It can also serve as a benchmark for testing state-of-the-art theoretical approaches. Thus experimental and theoretical studies of He, Ne, and Ar [3,4], carried out for a fixed scattering angle θ sc = 6 • and scatteredelectron energy of 500 eV, found recoil to binary ratios (R RB ) that were pronounced functions of ejected-electron energy. For He, the recoil peak was generally much smaller than the binary peak, and R RB was <0.2 for ejected-electron energies >20 eV.…”

Triply Differential Ionization Cross Sections of atomic and molecular targets by single electron impact

“…In 2012 Sahlaoui and Bouamoud [6] compared analytical TDCSs calculated within the FBA framework using Slatertype functions to these experimental data. Their work aimed at proposing an improvement of the FBA to model postcollision interactions by multiplying the TDCS equation with the Gamow factor [12]. We consider the results of these studies and compare them to our TDCSs for the ionization of the hydrogen atom.…”