Nuclear structure studies of the heaviest actinides and super-heavy elements with the CAGRA array at the JAEA Tandem

The search for the “island of stability” (IoS) and the production of super-heavy elements is one of the main goals of nuclear research. Different models disagree on the location and extent of the spherical IoS, and a way to obtain information on the single-particle orbitals near the IoS is to study well-deformed, lighter nuclei around fermium and nobelium, which are poorly known. The deformation causes in fact the spherical single-particle states to split and states originating from high-lying spherical orbitals come close to the Fermi surface in these systems.

The exceptional availability of a radioactive ²⁵⁴Es target at the JAEA Tandem Accelerator in Tokai, Japan, provides an excellent opportunity to investigate the structure of these nuclei. By irradiating ²⁵⁴Es with heavy-ion beams, via Coulex and multi-nucleon transfer reactions, the γ-ray spectroscopy of neutron-rich isotopes of einsteinium (Z=99), fermium (Z=100), mendelevium (Z=101) and nobelium (Z=102) will be attempted. The γ-rays emitted by these isotopes will be detected using a compact array of 8 clover detectors from the CAGRA collaboration.