Abstract: | The study of excited 55Mn levels with the 52Cr(α, pγ) reaction was extended to levels up to 3161 keV. With a Ge(Li) detector, DSA measurements in gold-backed targets were made, as well as angular correlations; both of these experiments were done in coincidence with protons detected near 180°. A multiple-detector NaI(Tl) array was also used in the same reaction geometry for better γ-ray detection efficiency. Mean lifetimes of 12 levels from 2727 to 3161 keV are reported. Spins and sometimes parities of the following levels were deduced from the angular-correlation analyses and lifetime results: 1885 keV, ?; 2199 keV, (?); 2311 keV, (); 2366keV, ?; 2727 keV, ; 2823 keV, . Multipole mixing ratios and M1 and E2 transition rates of the radiations from these and from the 1292 keV level are presented. The similarity of the low-lying level structure and of interlevel transitions in 55Mn to those in certain other f3 nuclei is examined. |