Radiative lifetimes have been measured for two excited levels of Ce IV using the time-resolved laser-induced fluorescence technique. ${\mathrm{Ce}}^{3+}$ ions were produced in a laser-induced plasma. In the measurements, a suitable magnetic field was applied to reduce the recombination between electrons and the ions and thus the background light from the recombination, and special care was exercised to avoid flight-out-of-view effects on the lifetime measurements for the high-velocity ions. The experimental lifetime results, $\tau =30\mathrm{}\left(2\right)\mathrm{ns}$ for the level $49737{\mathrm{cm}}^{-1\mathrm{}}$ and $\tau =30\mathrm{}\left(3\right)\mathrm{ns}$ for the level $52226{\mathrm{cm}}^{-1\mathrm{}}$, were compared with relativistic Hartree-Fock calculations ( $\tau =30.5\mathrm{}$ and 30.0 ns) indicating a particularly excellent agreement.

• Received 7 February 2001

DOI:https://doi.org/10.1103/PhysRevLett.87.273001