Angular correlation studies of the low-lying levels of 57Co

Abstract

Proton-gamma angular correlations and gamma-ray branching ratios were measured for the first nine excited states of 57Co using the 54Fe(α, pγ) reaction. In contradiction to earlier reports, the 1.754 and 2.127 MeV states were found to be single, well isolated states, and the 1.687 MeV state was observed to have a large gamma-ray branch (44 %) to the ground state. From the data obtained here and in previous experiments, J π values were deduced for the following levels whose energies are shown in MeV: 1.222, 9 2 −( 5 2 −) ; 1.375, 3 2 −; 1.502, 1 2 −; 1.687 ( 11 2 −, ( 7 2 − 5 2 −); 1.754, 3 2 −; 1.894, 7 2 −; 1.917, 5 2 −; 2.127, 5 2 − and 2307, 7 2 −( 5 2 −) . Possible, but less probable, assignments have been enclosed in parentheses.