Session BH: Nuclei far from Stability

7:00 PM–9:00 PM, Monday, September 19, 2005
Ritz-Carlton Hotel - Plantation 1

Sponsoring Units: DNP JPS
Chair: Michael Thoennessen, Michigan State University

Abstract: BH.00008 : Measurement of the absolute B(E2;0$^+ _1 \rightarrow$2$^+ _1$) strength in the $^{106-110}$Sn isotopes via intermediate-energy Coulomb excitation.

8:45 PM–9:00 PM

Preview Abstract

Authors:

  C. Vaman
  D. Bazin
  A. Becerril
  A. Chester
  J. Cook
  A. Gade
  D. Galaviz
  T. Glasmacher
  V. Moeller
  W. Mueller
  T. Russ
  A. Schiller
  K. Starosta
    (NSCL, Michigan State University)

  C. Andreoiu
    ( University of Guelph, Canada)

Sn isotopes at Z=50 provide the longest shell-to-shell chain of semi-magic nuclei investigated to date in nuclear spectroscopy. The nearly constant energy of the first excited 2$^+ _1$ states for isotopes between N=50 and N=82 is attributed to the fact that the valence nucleons of one kind outside the doubly magic core do not affect the near-spherical nuclear shape. Except for the stable Sn isotopes, the B(E2, 0$^+ _1\rightarrow$ 2$^+ _1$) values are sparsely known. An intermediate energy Coulomb excitation experiment was performed at the NSCL to study the first excited 2$^+ _1$ states in the $^{106-110}$Sn isotopes. The Sn isotopes beams obtained following the fragmentation of $^{124}$Xe and selection with the A1900 fragment analyzer, impinged on a 212 mg/cm2 thick Au target at an energy of 140 MeV/nucleon. Gamma rays were observed using the highly segmented high purity SeGA Ge array. The particle identification and the determination of the scattering angles were performed with the detector system of the high-resolution S800 spectrograph. This talk presents the results of the B(E2, 0$^+ _1 \rightarrow$ 2$^+ _1$) excitation strength measurements and a comparison with the shell model predictions for $^{106-110}$Sn isotopes.