Electron correlation in an Auger process

Abstract

Coincident 205-eV electrons resulting from the double ionization of argon by electron impact have been measured for incident energies from 400 to 2200 eV. The two 205-eV electrons are produced by knockout of an argon 2{ital p} electron followed by 205-eV {ital LMM} Auger decay of the 2{ital p} vacancy. The cross section near threshold is an order of magnitude larger than at higher energies. In addition, an angular correlation is observed for low incident energies. The two electrons are emitted preferentially at a large angle to each other. The results suggest strong electron correlation in this process.