Structure of inert gases from the (e, 2e) reaction

Abstract

The ($e, 2e$) reaction is used to investigate the binding energies and angular correlations for electrons ejected from the $4p$ and $4s$ orbitals of krypton. Configuration interaction in the ion eigenstates is the dominant feature in the ejection of a $4s$ electron. Only (30±3)% of the strength of the $4s$ hole state is contained in the ion eigenstate with the dominant configuration $4s4p^6{}_{}{}^2{}_{}{}^{}S_{\frac{1}{2}}^{}{}_{}{}^{}$. The angular correlations calculated with the distorted-wave off-shell impulse approximation, and using the Hartree-Fock wave functions of Froese-Fischer, agree very well with the observed angular correlations. In addition, relative to a $4p^{-1\mathrm{}}$ spectroscopic factor of unity, the $4s^{-1\mathrm{}}$ spectroscopic factors for the various excited ion eigenstates sum to 0.99 ± 0.08. Data are also presented on the binding energies of electrons ejected from the outer $s$ and $p$ orbitals in neon and argon, and the role of configuration interaction in the $s^{-1\mathrm{}}$ states is discussed. Incident electron energies are approximately 200, 400, and 800 eV.