Experimental study of single- and double-electron transfer in slow Ne8++Hecollisions using photon and electron spectroscopy

Single- and double-electron transfer from He to the Ne8+(ls(2))S-0(1) ion h as been studied at 80 keV by extreme ultraviolet (EUV) spectroscopy and zer o-degree electron spectroscopy. Signals originating from the stabilization after two-electron capture are identified in the photon data. This gives in formation on the stabilization of two electrons on the projectile. Single-e lectron capture signals originating from n = 9 states are observed, and the absolute emission cross section is determined. The presented experimental data have unprecedented resolution. The analysis is supported by extensive theoretical calculations of the (3,3), (3,4), and (4,4) doubly excited stat es in Be-like neon. Decay from triplet states due to spin exchange is obser ved in the spectra. [S1050-2947(99)09809-1].