Resonance parameters of /sup 60/Ni+n from measurements of transmission and capture yields from 1 to 450 keV

Journal Article · Wed Jun 01 04:00:00 EDT 1983 · Phys. Rev. C; (United States)

DOI:https://doi.org/10.1103/PhysRevC.27.2556· OSTI ID:5820654

Perey, C M; Harvey, J A; Macklin, R L; Perey, F G; Winters, R R

High-resolution transmission and capture measurements of /sup 60/Ni-enriched targets have been made 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 452 keV were analyzed with a multilevel R-matrix code which uses Bayes' theorem for the fitting process. This code provides the energies and neutron widths of the resonances inside the 1- to 452-keV region as well as a possible parametrization for outside resonances to describe the smooth cross section in this region. The capture data were analyzed from 2.5 to 452 keV with a least-squares fitting code using the Breit-Wigner formula. 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-bar/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 correlation coefficient rho between GAMMA/sub n//sup 0/ and GAMMA/sub ..gamma../ is equal to 0.53 +- 0.18. 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.

• Research Organization: Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830
• OSTI ID: 5820654
• Journal Information: Phys. Rev. C; (United States), Journal Name: Phys. Rev. C; (United States) Vol. 27:6; ISSN PRVCA
• Country of Publication: United States
• Language: English

Related Subjects

651625* -- Nuclear Properties & Reactions
A=59-89
Experimental-- Nuclear Reactions & Scattering-- (-1987)
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
BARYON REACTIONS
CAPTURE
CROSS SECTIONS
DIPOLES
ELECTRIC DIPOLES
ELECTROMAGNETIC RADIATION
ENERGY LEVELS
ENERGY RANGE
EVEN-ODD NUCLEI
FERMI GAS MODEL
FUNCTIONS
GAMMA RADIATION
GIANT RESONANCE
HADRON REACTIONS
INTERMEDIATE MASS NUCLEI
IONIZING RADIATIONS
ISOTOPES
KEV RANGE
MATHEMATICAL MODELS
MATRICES
MULTIPOLES
NEUTRON REACTIONS
NICKEL 60 TARGET
NICKEL 61
NICKEL ISOTOPES
NUCLEAR MODELS
NUCLEAR REACTIONS
NUCLEI
NUCLEON REACTIONS
R MATRIX
RADIATIONS
RESONANCE
S MATRIX
STABLE ISOTOPES
STRENGTH FUNCTIONS
TARGETS
TOTAL CROSS SECTIONS
TRANSMISSION