Correlations in electron-atom collisions involving polarised electrons and photons

More sophisticated experimental methods to study inelastic electron–atom collisions include polarisation-correlation measurements such as electron–photon (e, eγ) and electron–electron (e, 2e) coincidence studies or stepwise electron–photon (eγ, γ) correlations. Electron correlations and spin effects can be explored on the most fundamental level in such experiments. In this paper recent (e, eγ) studies with Hg and Xe, (eγ, γ) studies with Ne and (e, 2e) studies with Xe using polarised electrons and/or polarised photons are reviewed.