Quasiparticle alignment in the most deformed krypton isotope 74Kr

High-spin states in 74Kr were studied using the 58Ni(19F,p2n)74Kr reaction at 62 MeV. States up to (14+) in the ground state band and a number of states in three side bands were placed in the level scheme. The level scheme of 74Kr closely resembles those of 76Kr and 78Kr. Quasiparticle alignment occurs at ℎω∼0.65 MeV in agreement with a recent calculation. There is no evidence for an alignment at lower frequency as was previously reported. Mean lifetimes were measured for six states in the ground state band of 74Kr using the Doppler shift attenuation and recoil-distance methods. The lifetimes imply transition quadrupole moments of 3.2-3.3 eb, the highest known among Kr isotopes. The corresponding axial deformation is β2∼0.41