Photodetachment of He- in the vicinity of the two-electron escape threshold -: art. no. 013002

Recording the yield of He(1snl(3)L) Rydberg states for n=11-14, we measure the photodetachment cross sections of metastable He-(1s2s2p(4)P(o)) ions in the vicinity of the two-electron escape threshold. We observe a large number of double Rydberg He- quartet state resonances and report energies and widths of intrashell states in the n=13-15 manifolds. Sharp thresholds are measured at He(P-3(o)) and He(D-3(e)) Rydberg states with preference for population of the former, whereas the He(S-3(e)) states are not populated, in agreement with qualitative theoretical arguments.