Lifetimes of the 2s2p¹PLevel in Be-Like NIV and OV Obtained from Beam-Foil Experiments and Extensive Cascade Analyses

Lifetime measurements using the beam-foil method are reported for the 2 s 2 p 1 P level in Be-like N IV and O V. The results, 0.425 ± 0.015 ns in N IV and 0.338 ± 0.015 ns in O V, are in excellent agreement with the majority of recent theoretical results. The existing systematic discrepancy between theory and experiments in this sequence is thereby removed for these two ions. It is shown that this agreement is possible only when the most prominent cascades that repopulate the 2 s 2 p 1 P level, are explicitly included in the analysis through the application of the ANDC method. Lifetimes of these cascading levels are also reported and are found to be in good agreement with previous experimental and theoretical results.