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., August 02, 2012, at 3:00 p.m. (refreshments at 2:40 p.m.)

New techniques for study of N=Z nuclei

David Jenkins, University of York
Building 6008 Conference Room

The N=Z line between 56-Ni and 100-Sn is a fascinating laboratory for study of a wide range of Physics from nuclear structure to nuclear astrophysics. This talk will focus on the region around A=70 which is one of rapidly changing nuclear shape. We have probed shape coexistence in this region through Coulomb excitation with accelerated radioactive beams from the REX-ISOLDE facility at CERN. Results will be presented for 70-Se and on-line spectra for Coulomb excitation of N=Z, 72-Kr obtained with an accelerated beam of only around 500 pps in May 2012. We have also developed a new technique of recoil-beta-tagging at the University of Jyvaskyla where exotic proton-rich nuclei can be studied using fusion-evaporation reactions. Evaporation residues are separated using the RITU gas-filled recoil separator and implanted in the focal plane of the great spectrometer. Their subsequent beta-decay is recorded using a silicon detector and plastic scintillator as a deltaE-E telescope. Residues with fast and high energy beta decay are selected and correlated with gamma rays recorded at the target position. In this manner, new information is obtained on N=Z 74-Rb, while the structure of 78-Y and N=Z-2 nucleus, 66Se is investigated for the first time. This new data allows us to discriminate between different models for shape coexistence in this region. Perspectives for the future development of this programme with new apparatus to improve sensitivity will be discussed.

Alfredo Galindo-Uribarri 574-6124