Double ionisation of Ar atoms by single electron impact

Abstract

With the aid of translational energy spectroscopy the authors have studied the double ionisation of Ar by single electron impact at collision energies between threshold and 600 eV. On the one hand the authors have determined the total cross section for double ionisation, sigma _t, and on the other hand they have measured, for the first time, apparent partial cross sections for production of Ar²⁺ in specific long-lived states: ³P, ¹D₂, ¹S₀, ⁵D^degrees ₄ and ³F^degrees ₄. The experimental setup, the principle of the applied method and the evaluation procedure are described. Where possible the results are compared with other experimental results, yielding rather good agreement.