Located at the TRIUMF laboratory in Vancouver, the Isotope Separator and Accelerator or the ISAC facility is one of the world’s most advanced isotope separator on-line facilities providing high-intensity and high-purity radioactive ion beams for a wide variety of science programmes. ISAC-I’s γ-ray spectroscopy programme for studying nuclear structure, nuclear astrophysics and tests of fundamental symmetries is using the GRIFFIN γ-ray spectrometer for β- and β-delayed γ-ray spectroscopy experiments with low-energy beams to study nuclei located far from the line of beta stability. Such studies provide information about the shell evolution far from stability, can provide input for modern state-of-the-art calculations of the nuclear force and for astrophysics processes such as the rapid neutron capture process that is responsible for the creation of elements heavier than iron.
GRIFFIN, short for Gamma-Ray Infrastructure For Fundamental Interactions in Nuclei, consists of up to 16 Compton-suppressed high purity Germanium clover detectors augmented with special ancillary detectors for coincidence measurements and particle selection leading to comprehensive spectroscopy studies of exotic nuclei.
In this talk I will present recent results from the nuclear structure studies around the shell closures that confer extra stability to nuclear matter. I will focus on the example of Ge-80 (element 32; neutron number 48), which is located close to Ni-78 (element 28, neutron number 50), in which shape coexistence at low energies was not confirmed as previously reported in another experiment and how we solved this interesting puzzle by teaming up with shell-model theory experts.