Atomic lifetimes and transition probabilities in boron-like (Na VII) and beryllium-like (Na VIII) sodium ions

Spectra and decay curves of boron-like (Na VII) and beryllium-like (Na VIII ) sodium lolls produced by Learn-foil excitation have been recorded in the 30-60 nm spectral range and the radiative lifetimes of seven n = 2 levels h ave been measured. The experimental results are compared with the available theoretical values and with with results obtained in the framework of two theoretical approaches: the Relativistic Hartree-Fock approximation and the Multiconfiguration Dirac-Fock; method. Corroborated Ly the fair agreement of the new theory data with experiment, a new set of accurate transition pr obabilities for the 2s(2)2p-2s2p(2) and 2s2p(2)-2p(3) transitions of Na VII is presented.