Selected properties of nuclei at the magic shell closures from the studies of E1, M1 and E2 transition rates

Using the Advanced Time‐Delayed method we have studied transition rates in several neutron‐rich nuclei at the magic shell closures. These include the heavy Co and Fe nuclei just below the Z = 28 shell closure at the point of transition from spherical to collective structures. Of particular interest is 63Fe located exactly at the point of transition at N = 37. A substantial increase in the information on this nucleus was obtained from a brief fast timing study conducted at ISOLDE. The new results indicate that 63Fe seems to depart from a simple shell model structure observed for heavier N = 37 isotones of 65Ni and 67Zn.Another region of interest are the heavy Cd and Sn nuclei at N = 72, 74 and the properties of negative parity quasi‐particle excitations. These experiments, performed at the IGISOL separator at Jyvaskyla, revealed interesting properties of the E2 rates in the sequence of E2 transitions connecting the 10+, 8+, 6+, 4+, 2+ and 0+ members of the multiplet of levels in 122Sn due to neutrons in th...