Gamma Spectroscopy of Neutron-deficient Nuclei Close to \(^{70}\)Br Using the EAGLE Array and Ancillary Detectors at the Heavy Ion Laboratory in Warsaw

The \(A=70\), \(T=1\) isobaric multiplet exhibits an anomalous Coulomb energy difference (CED) behavior, with the \(^{70}\)Br/\(^{70}\)Se pair showing a decrease in CED with increasing spin, contrary to the typical trend observed in other \(pf\)-shell nuclei. To investigate this phenomenon, a dedicated experiment was carried out at the Heavy Ion Laboratory of the University of Warsaw using an 88 MeV \(^{32}\)S beam impinging on a \(^{40}\)Ca target. Excited states in \(A \approx 70\) neutron-deficient nuclides were populated in fusion–evaporation reactions. Gamma rays were measured with the EAGLE spectrometer, whereas the reaction channel identification was provided by the combined set of neutron — NEDA and charged particle — DIAMANT detectors. Preliminary data analysis shows the satisfactory performance of the setup, which will allow for in-depth studies of the structure of the nuclei of interest. Abstract Published by the Jagiellonian University 2026 authors