Mass measurements on neutron-rich fission products and actinoids at Triga-Trap

The double Penning trap mass spectrometer Triga-Trap has been installed at the research reactor Triga Mainz to perform high-precision mass measurements on neutron-rich fission products and actinoids. Masses of these nuclides are important for nuclear structure studies of heavy elements, tests of mass models, and nucleosynthesis calculations of the astrophysical r-process. Ions of many stable isotopes as well as carbon clusters for calibration purposes can be produced by a non-resonant laser ablation ion source, allowing off-line mass measurements independently from the research reactor. Besides the physics program, Triga-Trap serves as a test bench for the development of new ion detection techniques, which will enable mass measurements on single stored singly-charged ions with a half-life in the order of one second. To this end, a unique combination of the commonly used destructive time-of-flight technique and the non-destructive image current detection method is employed here in an on-line mass spectrometer for short-lived nuclides. First time-of-flight mass measurements on rare earth elements and actinoids are reported.