Absolute (e,2e) cross sections measured for the2porbital of argon

The absolute ($e$, $2e$) triply differential cross sections measured in coplanar nonsymmetric conditions are reported for the intermediate $2p$ orbital of Ar, at an incident energy of 8.4 keV. The data are made absolute by integrating over all ejection directions and comparing with the corresponding doubly differential cross section. The latter is also measured in a separate experiment and is made absolute by use of the Bethe sum rule. Preliminary calculations using first-order theories indicate very large discrepancies between experiment and theory, at the relatively low energy of the outgoing electron: 150 eV.