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Angular correlation between autoionization electrons and scattered ions in 2000-eV He/sup +/-He collisions

Journal Article · · Phys. Rev., A; (United States)

Complex population amplitudes for the excitation of magnetic sublevels of He(2p/sup 2/) /sup 1/D and He(2s 2p) /sup 1/P states in 2-keV He/sup +/-He collisions have been determined by measuring the energy spectra of the corresponding autoionization electrons ejected at different angles in coincidence with the inelastically scattered ions. It was found that He(2p/sup 2/) /sup 1/D is excited with a relative probability of 97%. If the direction of the internuclear line at the distance of closest approach is taken as the z axis, we find that primarily the m=0 sublevel is populated and that the complete /sup 1/D excitation can be interpreted as due to pure m=0 excitations with respect to momentary internuclear lines at different points of the trajectory which are symmetric to the turning point. These results are discussed within the framework of the Fano-Lichten promotion model. Quantization along an axis perpendicular to the scattering plane shows an orientation of the excited /sup 1/D state. From this we find that the angular momentum L/sub y/ transferred from the motion of the heavy particles to the electron cloud has an expectation value of approx. =-h.

Research Organization:
Fakultaet fuer Physik der Universitaet Freiburg, D-7800 Freiburg/Br., Germany
OSTI ID:
5878414
Journal Information:
Phys. Rev., A; (United States), Journal Name: Phys. Rev., A; (United States) Vol. 20:3; ISSN PLRAA
Country of Publication:
United States
Language:
English