Measurements and data-based predictions for Δn=1 resonance and intercombination transitions in the Be and Ne sequences

Earlier studies of line strengths for ${\mathit{ns}}^2$ ${}_{}{}^1{}_{}{}^{}$ ${\mathit{S}}_0$–nsn’p ${}_{}{}^{1,3}{}_{}{}^{}$ ${\mathit{P}}_1$ resonance and intercombination transitions for intrashell (n’=n) cases have revealed isoelectronic regularities that have been used to make accurate predictions along the sequence. Although lifetime data exist for intershell (n’>n) cases, the lack of branching ratio measurements has until now prevented similar analyses. Through new lifetime measurements, a critical evaluation of the available data, and determinations of branching fractions from a differential measurement and from calculational considerations, we have extended these methods to systematize and predict line strengths for Δn=1 resonance and intercombination transitions in the Be and Ne sequences.