(e,2e) studies of processes involving inner-shell ionization

The (e,2e) technique has been applied to the problem of direct outer shell ionization for many years, with considerable success. In recent years an increasing number of groups have explored the process of inner shell ionization, with a view to obtaining information on the dynamics of the process. In this paper, the existing theoretical and experimental studies of this process are discussed. Our recent measurements of the triple differential cross section for 2p ionization in argon, performed at lower energies than have been used previously, are presented.