PCI effects in resonant processes of photo double electron emission near the Ne 1s threshold

Abstract

Resonant double photoionization of neon in the vicinity of the 1s threshold is studied with a focus on a two-step decay of the inner vacancy. Firstly, an Auger decay 1s−1 → 2s−12p−1Ep leads to ejection of a fast Auger electron and creation of an intermediate state with two vacancies: 2s and 2p. Post-collision interaction (PCI) results in the capture of the slow photoelectron into a discrete state of the doubly charged ion. In this way an autoionizing decay 2s−12p−1np → 2p−2El becomes possible with the ejection of the second electron. A quantum-mechanical approach to the description of the process is developed. It allows us to calculate the spectrum of the emitted electrons as well as the total cross section. The results of the calculations are in reasonable agreement with experimental data.