"Direct mass measurements above uranium"
Enrique Minaya Ramírez, GSI Darmstadt, Helmholtz-Institut Mainz
(id #114)
Seminar: NoPoster: Yes
Invited talk: No
For the SHIPTRAP Collaboration
The masses of the nuclides 255No and 255-256Lr have been measured with high accuracy using the Penning trap mass spectrometer SHIPTRAP at GSI Darmstadt. The radionuclides were produced in fusion-evaporation reactions and separated by the velocity-filter SHIP from the primary beam. Lawrencium 256 is the nuclide with the lowest yield measured with a Penning trap. Moreover, until now, the two Lawrencium masses were only estimated from the extrapolation of systematic trends of the Atomic Mass Evaluation (AME2003). These new results represent a further step towards the exploration of the Island of stability. These investigation continue our pioneering experiments started in 2008 at SHIPTRAP with the first direct mass measurements of three nobelium isotopes 252-254No. In addition, during this last experiment, the uncertainty of 252No and 254No masses was further improved. The future objective of this study is to measure nuclides in the region of Z = 104-105 in order to fix the endpoints of α-decay chains starting from superheavy nuclei in the vicinity of the predicted island of stability. Furthermore, the knowledge of nuclear masses enables the direct determination of the binding energy of the nucleus. This quantity allows exploring the shell structure and consequently it is another way to determine the stability of a nucleus.
The masses of the nuclides 255No and 255-256Lr have been measured with high accuracy using the Penning trap mass spectrometer SHIPTRAP at GSI Darmstadt. The radionuclides were produced in fusion-evaporation reactions and separated by the velocity-filter SHIP from the primary beam. Lawrencium 256 is the nuclide with the lowest yield measured with a Penning trap. Moreover, until now, the two Lawrencium masses were only estimated from the extrapolation of systematic trends of the Atomic Mass Evaluation (AME2003). These new results represent a further step towards the exploration of the Island of stability. These investigation continue our pioneering experiments started in 2008 at SHIPTRAP with the first direct mass measurements of three nobelium isotopes 252-254No. In addition, during this last experiment, the uncertainty of 252No and 254No masses was further improved. The future objective of this study is to measure nuclides in the region of Z = 104-105 in order to fix the endpoints of α-decay chains starting from superheavy nuclei in the vicinity of the predicted island of stability. Furthermore, the knowledge of nuclear masses enables the direct determination of the binding energy of the nucleus. This quantity allows exploring the shell structure and consequently it is another way to determine the stability of a nucleus.
