LIFETIME MEASUREMENTS OF EXCITED-LEVELS IN V-II AND V-III BY BEAM-FOIL EXPERIMENTS

Using the beam-foil excitation method we have measured lifetimes for s everal displaced terms and singly-excited levels in C II-III, some of which are of astrophysical interest. The Lifetimes were determined acc urately by means of the ANDC:CANDY method wherever possible. Our resul ts agree very well with the predictions of the close-coupling approxim ations except for the 2s2p4f(2)F terms. We observe that, in general, t he replacement of calculated wavelengths by the observed ones in the t ransition probability of the concerned channel improves the agreement further. The transition probabilities have been computed wherever poss ible.