Lifetimes of 55Co excited levels

Gamma-rays deexciting 55CO levels have been studied in coincidence with deuterons detected in a particle telescope, in the 54Fe(3He,dγ)55Co reaction. Excitation energies, relative γ-ray intensities, and Doppler-shift attenuations of 12 levels have been measured. Mean lifetimes and transition strengths are reported. The Doppler-shifted line shape of the 2164→0-keV transition has been analyzed and has been found consistent with the assumption of a single level. Lifetimes of selected levels are: 2164 keV, 125+25/sub -//sub 2//sub 0/ fs; 3301 keV, 50+20/sub -//sub 1//sub 5/ fs; 3322 keV, 45+15/sub -//sub 1//sub 0/ fs; 3641 keV, 300+150/sub -//sub 1//sub 0//sub 0/ fs; 4163 keV, 30+15/sub -//sub 1//sub 0/ fs; 4714 keV, 300+200/sub -//sub 1//sub 5//sub 0/ fs; 4719 keV, <30 fs; and 5172 keV, 10+10/sub -//sub 5/ fs