Nuclear levels in 190Ir studied with the 192Os(p,3nγ) and 192Os(d,4ne−) reactions

Nuclear levels in 190Ir have been investigated with the 192Os(p,3nγ) and 192Os(d,4ne−) reactions using beams of 18–31 MeV protons and 27.8 MeV deuterons. A series of measurements, including excitation functions, γγ and e−e−coincidences, and life time measurements, was performed. From the singles measurements, a total of 140 γ rays were assigned as belonging to the 192Os(p,3n)190Ir channel. The results of the coincidence measurements show that many of these lines are multiplets. Using information from a previous isomer study and single-nucleon transfer reactions, a level scheme is proposed comprising of 112 γ rays placed between 76 levels. It is shown that most of the γ intensity arises from bands having Kπ≥4+. Several negative-parity bands are also proposed. Calculations performed using values of ϵ and γ characteristic of the region reproduce qualitatively some aspects of the level scheme.