AN (E,2E) INVESTIGATION OF INNER-SHELL IONIZATION IN ARGON

New experimental results are presented of relative triple differential cross sections for ionization of the 2p orbital in argon. Coplanar as ymmetric kinematics were employed in the measurements; with an inciden t electron energy of around 1000 eV and ejected electron energies well below the binding energy of the 2p orbital. The results indicate the presence of a dominant recoil structure in the cross section. A compar ison is made with distorted-wave Born approximation calculations and t he theoretical results are found to be in very good agreement with the experimental data.