A study of the neutron-deficient isotope66Ge

Abstract

The neutron-deficient isotope 66Ge has been studied using gamma-ray spectroscopy techniques. States in 66Ge were populated using the 58Ni(10B,pn gamma )66Ge reaction at bombarding energies of 28.5, 29 and 30 MeV. A decay scheme has been established from the results of gamma-gamma and neutron-gamma coincidence experiments performed at a beam energy of 28.5 MeV. Angular distributions were measured at beam energies of 28.5, 29 and 30 MeV, and linear polarisations were measured at 28.5 MeV. The analysis of these data yields spin-parity assignments of 1694 keV (2+), 2175 keV (4+), 3686 keV (4+,5-), 4208 keV (6+,7-) and a probable 6+ assignment to the 3657 keV level. Spin restrictions are also placed on several other levels. The lifetimes of the 958, 1694 and 4208 keV levels are deduced from a recoil-distance-method experiment, performed at a beam energy of 29 MeV, to be 5.3+or-1.0 ps, 6.5+or-2.5 ps and 295+or-40 ps respectively. A limit of less than 3 ps has also been placed on the lifetime of the 2175 keV level.