Magnetic Moment of the Fragmentation-Aligned ⁶¹Fe (9/2⁺) Isomer

We report on the g factor measurement of an isomer in the neutron-rich ₂₆⁶¹Fe (E^*=861  keV and T_1/2=239(5)  ns). The isomer was produced and spin aligned via a projectile-fragmentation reaction at intermediate energy, the time dependent perturbed angular distribution method being used for the measurement of the g factor. For the first time, due to significant improvements of the experimental technique, an appreciable residual alignment of the nuclear spin ensemble has been observed, allowing a precise determination of its g factor, including the sign: g=-0.229(2). In this way we open the possibility to study moments of very neutron-rich short-lived isomers, not accessible via other production and spin-orientation methods.