Investigation of valence inter-multiplet Auger transitions in Ne following 1s photoelectron recapture

We employ a novel technique in which highly excited Rydberg states of Ne⁺ 2p⁴ⁿp are populated via PCI-induced recapture of the near-threshold 1s photoelectron (De Fanis et al 2004 Phys. Rev. A 70 040702) to investigate valence inter-multiplet Auger transitions. The following series of the transitions have been observed: Ne⁺ 2p⁴( ¹D)np ²L → Ne²⁺ 2p^{4 3}P_J, Ne⁺ 2p⁴(¹S)np ²P →Ne²⁺ 2p^{4 3}P_J and Ne⁺ 2p⁴(¹S)np ²P →Ne ²⁺ 2p^{4 1}D. Their energy positions, quantum defects and the anisotropy parameters of the Auger electron emission have been determined. Experimental results are in good agreement with multi-configuration Dirac-Fock calculations carried out as a part of this study. The importance of interference effects for decays via naturally overlapping fine-structure components of the intermediate state is discussed.