Investigation of the N=127 nucleus $^{217}$Th*

The evolution of the N=126 neutron shell is interesting, since it can be compared to large-scale shell model calculations and the structure of heavy-proton-rich nuclei exhibit a number of interesting structural phenomena. The recoil decay tagging technique, which provides an extremely clean method for channel selection, is the key to the investigation of heavy nuclei near N=126. Here we report on results of an experiment performed with the gas-filled recoil separator SASSYER which attempted, for the first time, in-beam gamma-ray spectroscopy of the nucleus $^{217}$Th with one neutron above the 126-neutron shell.