Photon-ion angular correlations for He+ + He and He+ + Ne collisions

Detailed information about scattering amplitudes of inelastic atomic collision processes is obtained by simultaneous detection of a scattered particle and a photon emitted from from a scattered particle. Channels of neighbouring excitation energy, which are difficult to distinguish by optical or energy loss spectroscopy, are demonstrated to be separable making use of a difference in radiative lifetimes and of the resulting different response to an external magnetic field. The results are discussed in the framework of a quasi-molecular description of the collision pair. For the He+ + He system, a complete picture of the process is obtained by modifying models discussed previously. Qualitative conclusions are drawn for the He+ + Ne system. (orig.)