Karlsruhe 2011 – wissenschaftliches Programm
SYDI 1.3: Hauptvortrag
Dienstag, 29. März 2011, 09:30–10:00, 30.95: 001
New anchorpoints for the mass surface in the rare-earth region with TRIGA-TRAP — •Jens Ketelaer — Max-Planck-Institut für Kernphysik, Heidelberg
High-precision mass measurements play an important role in understanding nuclear structure since nuclear masses reflect all interactions present in the nucleus. Many masses of the presently known nuclides have not been measured directly but are determined by a variety of links, such as nuclear reaction energies. To this end, more anchorpoints for the mass surface are required, linking nuclides to the atomic-mass standard carbon. 15 stable nuclides in the rare-earth region have been investigated at the Penning-trap mass spectrometer TRIGA-TRAP, leading to a shift of the mass surface on the order of a few keV. In the setup which has been installed and commissioned in Mainz, singly-charged particles of the desired species are stored in a superposition of magnetic and electric fields and their characteristic eigenfrequencies are measured to determine the mass. The implementation of the new measurements into the Atomic-Mass Evaluation will be discussed as well as nuclear structure effects discovered by calculating mass differences in the the rare-earth region. Considering the valence nucleons the so-called δ Vpn-values exhibit a behavior similar to the Wigner effect in N∼ Z nuclei.