Prompt gamma ray-spectroscopy of N = 50 fission fragments

Excited states in the nuclei 83As and 84,86Se have been studied via prompt γ-ray spectroscopy. The nuclei were produced by the proton-induced fission of a 238U target, at the accelerator of the University of Jyväskylä. The JUROGAM-II array was used to detect prompt γ-rays and a triple-γ coincidence analysis performed. A comparison of the N = 50 nuclei with shell-model calculations reproduces the low-lying states in 83As and 84Se well. The inclusion of particle-hole excitations is necessary to correctly describe the states above ∼ 3.5 MeV.