Levels of 188Re nucleus populated in thermal neutron capture reaction

Levels of 188Re populated in thermal neutron capture reaction with enriched 187Re targets have been studied. Single γ-ray spectrum of 188Re, measured with the high-resolution crystal diffraction spectrometer GAMS5, as well as γγ-coincidence experiments performed with high efficiency Ge detectors, allowed to develop model-independent level scheme of the doubly-odd 188Re nucleus up to ∼1.5MeV excitation energy. Analysis of the established 188Re level scheme in terms of the quasiparticle-plus-rotor model indicates coexistence of axially-deformed and triaxial structures in the energy range above 400 keV.