Beam-laser lifetime measurements for four resonance levels of Yb II

Laser excitation of a fast beam of Yb + ions has been used to determine the lifetimes of the Yb II levels at 27062 cm -1 (8.10+or-0.13 ns), 33654 cm -1 (37.7+or-0.5 ns), 34575 cm -1 (28.6+or-0.4 ns) and 44941 cm -1 (20.3+or-0.3 ns). These results are compared with previous measurements and with the extensive calculation of Fawcett and Wilson (1991), with whom fair agreement is found for the level at 27062 cm -1 but marked disagreement is found for the other three levels.