| Summary: | The structure of the neutron-deficient nuclides 168Os and 166W has been investigated in experiments using the JUROGAM γ-ray spectrometer and GREAT spectrometer in conjunction with RITU separator at the Accelerator Laboratory of the University of Jyväskylä. The excitation level scheme for 168Os has been extended and the lifetimes of excited states in 166W have been measured using the DPUNS differential plunger and the recoil distance Doppler-shift method. These states were produced using by a fusion-evaporation reaction using a 92Mo target and a 78Kr beam. This thesis addresses the anomalous B(E2;4+ → 2+)/B(E2;2+ → 0+) ratios measured for these neutron-deficient N = 92 isotones. The extended level scheme of 168Os has revealed several new features. These features were investigated in a model using the Bateman equations and based on the differential decay curve method to provide possible explanations for the anomalous B(E2)4+/2+ ratios in 168Os extracted from recent lifetime measurements by Grahn et al [1]. In a complementary experiment, the lifetimes of the 2+, 4+, 6+, 12+ and 14+ excited states in 166W have been measured for the first time using recoil gated γ- γ-coincidence spectra. The measured reduced transition probabilities revealed a B(E2; 4+ →2+)/B(E2; 2+ → 0+) ratio less than unity. The B(E2) value for the transitions between high-spin states provides evidence for a weak interaction strength at the ground-Stockholm band crossing.
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