A new type of electron spectroscopy for the investigation of gas-phase targets has been developed. Based on electron-ion coincidence measurements using synchrotron radiation the method for the first time allows an electron spectrum to be split into the different final charge states. These spectra give deep insight into different, in part spin-dependent, multiple photoionization mechanisms, which is demonstrated for atomic samarium and europium in the photon energy range of the 4d giant resonances.

• Received 26 December 1995

DOI:https://doi.org/10.1103/PhysRevLett.76.4320