Picosecond lifetime measurements in 109Cd and 110Cd

170 S. Harissopulos et al. / Nuclear Physics A 683 (2001) 157–181
Fig. 7. Same as Fig. 6 for the 8 + 2 ,10+ 1 and 12+ 1 states of 110 Cd.
at E x = 3187 keV, which is deexcited by the 707 keV γ -line: in case the latter feeder had
been taken into account in the analysis, one would have obtained a slightly shorter mean
lifetime τ for the 6 + 1
state. Such a decrease in τ of this state however would not have
changed the final conclusions concerning this level.
The mean lifetime determined in the present work for the 10 + 1
state (τ = 670(25) ps) do
not justify the findings of the measurement reported in [28], where a longer mean lifetime
(τ = 800(40) ps) was reported. However, a reanalysis of the data of the latter measurement
yielded according to [31] a mean lifetime τ = 670(35) ps, which is in excellent agreement
with our result, with which the findings of [32] (τ = 650(144) ps) also agree. The mean
lifetime of the 12 + 1
state measured in our work (τ = 11.4(6) ps) is statistically in agreement
with the respective mean lifetime reported in [28] (τ = 12.0(6) ps). For the 14 + 1
and the
10 + 2
levels only upper limits of τ 4psandτ 5 ps, respectively, could be determined in
the present work, since the decay curves of their precursor states could not be measured.
These upper limits have been determined by fitting a single exponential function to the
decay curves of the 854 keV and 802 keV γ -transitions, respectively. Here, it has to be
pointed out that the 637 keV γ -ray, which according to [28], deexcites the 10 + 2
level and
feeds the 8 + 3 level at E x = 3440 keV (see Fig. 5) was not present in our γ -spectra.
No DDCM analysis could be performed for the 7 − state since the 467 keV γ -ray feeder
from the 9 − level is a doublet and therefore no decay curve could be derived for the
precursor 9 − state. The fitting of a single exponential function to the decay curve of the 7 −