Gamma-ray studies of the odd-parity states in Zn isotopes. II. Levels below 2.0 MeV in excitation energy in67Zn

Abstract

For pt.I see ibid., vol.4, p.755 (1978). The techniques of gamma -ray spectroscopy have been employed to investigate the structure of levels below 2.0 MeV in excitation energy in 67Zn populated in the 64Ni( alpha ,n)67Zn reaction. Gamma-gamma coincidences have been recorded at several alpha -particle beam energies. Gamma-ray angular distributions and linear polarisations have been measured using an escape-suppressed spectrometer and a three-Ge(Li) Compton polarimeter respectively. The gamma -ray decay modes of the levels have been deduced. Spin and parity assignments have been made. Multipole mixing ratios have been obtained for many of the transitions. The lifetimes of 11 levels have been measured using the Doppler-shift attenuation method. The electromagnetic multipole transition strengths deduced show moderate E2 enhancements. The results have been compared with the particle-vibration coupling model, the Alaga model and the shell model with reasonable agreement in each case.