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 Jyväskylä, 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 the h11/2 orbit. [ABSTRACT FROM AUTHOR]