Beam-foil spectroscopy of the Cu I and Zn I isoelectronic sequences

Abstract

A summary is presented of recent investigations of the Cu I and Zn I isoelectronic sequences. A discussion is given of the 4s4d 1D term, with a provisional energy assignment being made for Se V. Two other Se V terms and five As V terms are also assigned. Lifetimes are presented for the 4p, 4d and 5s levels of the Ge IV, As V and Se VI members of the Cu I sequence, the 4p results being obtained from ANDC analyses using decay curve data the 4s-4p, 4p-5s and 4p-4d transitions. The multiplet ƒ-values derived for the 4s-4p transition are in excellent agreement with theoretical predictions. Lifetimes are also given for the 4s4p 1P 0, 4p 2 1D 2, 4s4d 1D 2 and 4s5s 1S 0 levels of the Ge III, AS IV and Se V members of the Zn I sequence, the 4s4p 1P 0 results again coming from ANDC or constrained-fitting analyses. The agreement with theoretical values here is good up to As IV, but for higher series members the theoretical ƒ-values are significantly higher than the experimental values. Possible reasons for this discrepancy are discussed.