Oak Ridge National Laboratory

Physics Division

Physics Division Seminars

Physics Division Seminars bring us speakers on a variety of physics related subjects. Usually these are held in the Building 6008 large Conference Room, at 3:00 pm on the chosen day, but times and locations may vary. For more information, contact our seminar chairman,

Alfredo Galindo-Uribarri
Tel (Office): (865) 574-6124  (FAX): (865) 574-1268

Thu., October 19, 2006, at 3:00 p.m. (refreshments at 2:40 p.m.)

Mass Measurements at the Extremes: An input for astrophysical calculations

Milan Matoš, NSCL, Michigan State University, & Joint Institute of Nuclear Astrophysics (JINA)
Building 6008 Conference Room

Nuclear masses play an important role in nuclear physics and nuclear astrophysics. Numerous mass measurement techniques offer various possibilities; from high precision mass measurements of nuclei close to the line of stability to the mass measurements of very exotic species. The latter ones struggle with very short half-lives and difficulties associated with production of the ions. The most exotic nuclei are accessed by time-of-flight techniques at radioactive beam facilities. In general, a TOF mass measurement can be provided with a rate of 0.01 particle/s. On the contrary, the Penning trap measurements with the best precision require at least 100 particle/s. The NSCL facility offers ideal opportunities for TOF mass measurements of very exotic ions. We have recently implemented a TOF-Br technique and performed a mass measurement of neutron-rich nuclides in the Fe region. Mass values of neutron rich nuclei are important for r-process calculations, and for calculations of processes occurring in the crust of accreting neutron stars.

Details of the TOF mass measurement experimental techniques (at NSCL, GSI, etc.) will be presented. Preliminary results from the experiment at NSCL and their importance for nuclear astrophysics will be discussed.