Beta decay of $^{66}$Mn to the $N = 40$ nucleus $^{66}$Fe
Résumé
The low energy structure of 66Fe was studied by means of γ- and fast-timing spectroscopy at the ISOLDE/CERN facility. The level scheme of 66Fe populated following the ${\beta }^{-}$ decay of 66Mn was established. It confirms and further expands the level scheme from recent publications. The β-delayed neutron emission branch was measured and γ rays in 65Fe were observed following the β–n decay for the first time. The half lives of the ${2}_{1}^{+}$ state and four other states of 66Fe were measured using the advanced time-delayed $\beta \gamma \gamma $(t) method. These results are compared with large-scale shell-model calculations based on the Lenzi–Nowacki–Poves–Sieja interaction. The β-decay of 66Mn to 66Fe has been calculated as well, and log(ft) values derived. Spin and parity assignments are proposed based on the experimental information and the new calculations.