Low-, medium-, and high-spin states in the N=Z+1 nucleus 63Ga

The fusion-evaporation reaction 28Si+40Ca at 122 MeV beam energy was used to populate excited states in the N=Z+1 nucleus 63Ga. With the combination of the Gammasphere spectrometer and the Microball CsI(Tl) charged-particle detector array, the level scheme of 63Ga was extended by more than a factor of two in terms of number of γ-ray transitions and excited states, excitation energy (Ex>30 MeV), and angular momentum (I>30 ℏ). Nine regular sequences of states were newly established in the high-spin part of the level scheme. The majority of these rotational band structures could be connected to the previously known part of the level scheme by high-energy γ-ray transitions in the energy range Eγ=4–6 MeV. Low-spin states were assessed by shell-model calculations. The high-spin rotational bands were interpreted and classified by means of cranked Nilsson-Strutinsky calculations.