In-beam spectroscopy with Gammasphere and Argonne Gas-Filled Analyzer*

Search for super-heavy nuclei is one of the frontiers of nuclear physics. Super-heavy nuclei owe their existence to shell corrections which overcome the Coulomb repulsion. However, spectroscopy of the heaviest known nuclei is limited to their alpha and fission decay properties. On the other hand, trans-fermium nuclei near the Z=100, N=152 closed deformed shells are produced with much larger cross sections and can be studied in more detail using various spectroscopic methods. The combination of the Gammasphere array of Ge detectors and the Argonne Gas-Filled Analyzer (AGFA) is a powerful tool for in-beam gamma-ray studies of trans-fermium nuclei.  It can be used to determine rotational properties of nuclei near Z=100, N=152 in order to learn about deformation, sequence of single-nucleon orbitals near the Fermi surface  and pairing correlations in these heavy nuclei. This information can aid in extrapolating existing nuclear models to the heaviest known nuclei and, among others, in pinning down the location of the so-called “island of stability” of super-heavy nuclei. During the talk, recent results obtained with Gammasphere and AGFA will be presented and future prospects for in-beam studies of more neutron-deficient nuclei at the fission limit and of heavier nuclei towards the Z=108, N=162 closed deformed shells will be discussed.