Lifetimes and Oscillator Strengths for the Resonance Transitions in Cu-Like Iodine, I XXV

Using the beam-foil time-of-flight technique we have measured decay curves for 4 s 2 S 1/2 -4 p 2 P 1/2, 3/2 and 4 p 2 P 1/2, 3/2 -4 d 2 D 3/2, 5/2 transitions in Cu-like iodine, I XXV. Accurate experimental lifetimes of the 4 p levels have been obtained after careful cascade corrections using the ANDC technique. The results are 46.7 ± 2 ps ( 2 P 1/2 ) and 23.1 ± 1 ps ( 2 P 3/2 ). These values are in good agreement with relativistic Hartree-Fock calculations. An up-to-date comparison between experimental and theoretical oscillator strengths is given for the whole copper sequence.