Lifetime measurements in multiply ionized atoms using beam-foil<i>–</i>laser excitation

Abstract

We have applied the recently proposed beam-foil--laser method to determine lifetimes in multiply ionized atoms. The lifetimes of two levels in multiply ionized carbon have been measured. The results are, for C iii 2s3d $^{1}D$, 0.15\ifmmode\pm\else\textpm\fi{}0.01 ns and for C iv 3s $^{2}S$, 0.21\ifmmode\pm\else\textpm\fi{}0.02 ns. These values are in good agreement with the theoretical predictions. We have also determined these lifetimes using the classical (nonselective) beam-foil method. These latter lifetime results are in agreement with the beam-foil results reported previously but \ensuremath{\approxeq}20% longer than the beam-foil--laser values. The factors limiting the accuracy of the lifetime determinations by the beam-foil--laser method are discussed.