Neutron-rich A~15 nuclei produced in fusion-evaporation reactions

NUCL 42

M. Wiedeking, MWiedeking@lbl.gov1, P. Fallon2, A. O. Macchiavelli2, L. W. Phair2, R. M. Clark1, M. Cromaz2, M-A. Deleplanque2, J. D. Gibelin1, I-Y. Lee2, M. A. McMahan2, L. G. Moretto2, E. Rodriguez-Vieitez2, L. A. Bernstein3, D. L. Bleuel, bleuel1@llnl.gov4, J. T. Burke3, B. F. Lyles4, and A. Volya5. (1) Nuclear Science Division, Lawrence Berkeley National Laboratory, One Cyclotron Rd, Berkeley, CA 94702, (2) LBNL, Berkeley, CA 94702, (3) LLNL, Livermore, CA 94550, CA, (4) Physics and Advanced Technologies, Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, CA 94551, (5) FSU, Tallahassee, FL 32306, Tallahassee, FL 32306
I will discuss our work on light neutron-rich nuclei and present new results on 18N (Z=7), which is relatively far from stability yet still within the reach of stable beam facilities. 18N was produced using the 9Be(11B,2p)18N fusion reaction at LBNL's 88-Inch Cyclotron and studied using STARS-LIBERACE, a large area segmented silicon ΔE-E detector telescope and six HPGe Compton suppressed Clover detectors. A key aspect of this experiment was to use the 2 proton reaction channel. The large Q-value for protons suppressed the evaporation of neutrons in conjunction with the 2p channel at the chosen beam energy, and the 2p tag cleanly selected the weak 18N products, allowing a direct measurement of the lifetimes and transition rates. Experimental and shell model results are compared. The n-p interaction, role of p3/2 proton holes, and onset of deformation is discussed. *Supported by the U.S. DoE, LBNL Contract No. DE-AC02-05CH11231 and LLNL Contract No. W-7405-Eng-48.
 

Nuclear Structure and Reactions in the Era of Radioactive Beams
8:10 AM-12:00 PM, Monday, August 20, 2007 Boston Park Plaza -- Lexington Room, Oral

Division of Nuclear Chemistry & Technology

The 234th ACS National Meeting, Boston, MA, August 19-23, 2007