Speaker
Description
The neutron-rich Gadolinium isotopes around mass A=160 represent a critical region for understanding both nuclear structure and astrophysical nucleosynthesis. These nuclei exhibit large prolate deformations and lie along the freeze-out path of the rapid neutron capture process (r-process). Understanding their structure can give insight into the rare-earth abundance peak formation. The odd-mass isotope (N=97) provides a sensitive probe of the single-particle spectrum in this deformed region through its one-neutron excitation experiments relative to the well-studied even-even core. The low-lying single-neutron states have been probed via the ${}^{160}$Gd(d,p) reaction, and several Nilsson configurations were suggested. The study of the excited states via the neutron capture reaction provided very limited information on the gamma-ray decays, and the previous study by beta-decay placed only four transitions in the decay scheme. The present work reports new high-precision measurements of excited states following beta-decay of high-purity beams produced at the TRIUMF-ISAC facility. To avoid molecular and isobaric contamination, IGLIS(Ion Guide Laser Ion Source) was used along with the ISAC mass separator to greatly improve beam purity with two-step laser ionization selecting Eu isotopes only. Using the GRIFFIN high-efficiency gamma-ray spectrometer augmented with the PACES conversion electron spectrometer and beta-particle tagging with the Zero Degree Scintillator, this work has identified 87 new gamma-ray transitions and constructed a level scheme comprising 35 new excited states. The half-life has been remeasured with improved precision. An overview of the experiment and analysis will be provided with these results, providing stringent tests of the Nilsson model in the midshell region and delivering crucial nuclear structure inputs for r-process calculations.