Effect of preequilibrium spin distribution on Ti48 +n cross sections

D. Dashdorj, T. Kawano, P. E. Garrett, J. A. Becker, U. Agvaanluvsan, L. A. Bernstein, M. B. Chadwick, M. Devlin, N. Fotiades, G. E. Mitchell, R. O. Nelson, and W. Younes
Phys. Rev. C 75, 054612 – Published 18 May 2007

Abstract

Nuclear model calculations of discrete γ-ray production cross sections produced in Ti48(n,n'γi)Ti48 and Ti48(n,2nγi)Ti47 reactions were made as a function of incident neutron energy from En=1 MeV to 35 MeV and compared with new experimental results using the large-scale Compton-suppressed germanium array for neutron induced excitations (GEANIE) at LANSCE. The Hauser-Feshbach reaction code GNASH, incorporating the spin distribution for the preequilibrium process calculated with the Feshbach-Kerman-Koonin (FKK) quantum-mechanical preequilibrium theory, was used to calculate partial γ-ray transition cross sections. The comparisons of calculated and experimental data demonstrate that, the FKK model for preequilibrium leads a better overall reproduction of the experimental data above En=10 MeV, where preequilibrium processes are important. The FKK calculation predicts a strong reduction in the high-spin state population in Ti48 by inelastic scattering. Population of low-spin states was also affected, however the change in the low-lying 983.5-keV (2+) state production is small because almost all γ-ray decay cascades feed this transition. In addition, the FKK calculation has a significant impact on the partial γ-ray transition cross sections for the (n,2n) reaction above En=15 MeV. The calculated cross sections for high-spin states in Ti47 are reduced, and those from the low-spin states are enhanced, in agreement with the experimental cross section data.

  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
6 More
  • Received 1 March 2007

DOI:https://doi.org/10.1103/PhysRevC.75.054612

©2007 American Physical Society

Authors & Affiliations

D. Dashdorj1,2,3,*, T. Kawano4, P. E. Garrett3,5, J. A. Becker3, U. Agvaanluvsan3, L. A. Bernstein3, M. B. Chadwick4, M. Devlin4, N. Fotiades4, G. E. Mitchell1,2, R. O. Nelson4, and W. Younes3

  • 1North Carolina State University, Raleigh, North Carolina 27695, USA
  • 2Triangle Universities Nuclear Laboratory, Durham, North Carolina 27708, USA
  • 3Lawrence Livermore National Laboratory, Livermore, California 94551, USA
  • 4Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
  • 5Department of Physics, University of Guelph, Guelph, Ontario N1G2W1, Canada

  • *Electronic address: dashdorj1@llnl.gov

Article Text (Subscription Required)

Click to Expand

References (Subscription Required)

Click to Expand
Issue

Vol. 75, Iss. 5 — May 2007

Reuse & Permissions
Access Options

Authorization Required


×
×

Images

×

Sign up to receive regular email alerts from Physical Review C

Log In

Cancel
×

Search


Article Lookup

Paste a citation or DOI

Enter a citation
×