Neutron transmission and capture measurements and analysis of /sup 60/Ni from 1 to 450 keV [electronic resource].
- Oak Ridge, Tenn. : Oak Ridge National Laboratory, 1982. and Oak Ridge, Tenn. : Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy.
- Physical Description:
- Pages: 76 : digital, PDF file
- Additional Creators:
- Oak Ridge National Laboratory and United States. Department of Energy. Office of Scientific and Technical Information
- Restrictions on Access:
- Free-to-read Unrestricted online access
- High-resolution transmission and capture measurements of /sup 60/Ni-enriched targets have been made at the Oak Ridge Electron Linear Accelerator (ORELA) from a few eV to 1800 keV in transmission and from 2.5 keV to 5 MeV in capture . The transmission data from 1 to 450 keV were analyzed with a multi-level R-matrix code which uses the Bayes' theorem for the fitting process. This code provides the energies and neutron widths of the resonances inside the 1- to 450-keV region as well as a possible parameterization for outside resonances to describe the smooth cross section in this region. The capture data were analyzed with a least-squares fitting code using the Breit-Wigner formula. From 2.5 to 450 keV, 166 resonances were seen in both sets of data. Correspondence between the energy scales shows a discontinuity around 300 keV which makes the matching of resonances at higher energies difficult. Eighty-nine resonances were seen in the capture data only. Average parameters for the 30 observed s-wave resonances were deduced. The average level spacing D/sub 0/ was found to be equal to 15.2 +- 1.5 keV, the strength function, S/sub 0/, equal to (2.2 +- 0.6) x 10/sup -4/ and the average radiation width, GAMMA/sub ..gamma../, equal to 1.30 +- 0.07 eV. The staircase plot of the reduced level widths and the plot of the Lorentz-weighted strength function averaged over various energy intervals show possible evidence for doorway states. The level densities calculated with the Fermi-gas model for l = 0 and for l > 0 resonances were compared with the cumulative number of observed resonances, but the analysis is not conclusive. The average capture cross section as a function of the neutron incident energy is compared to the tail of the giant electric dipole resonance prediction.
- Published through SciTech Connect., 11/01/1982., "ornl-5893", " endf-330", "DE83003190", and Harvey, J.A.; Macklin, R.L.; Winters, R.R.; Perey, F.G.; Perey, C.M.
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