Statistical fission parameters for nuclei at high excitation and angular momenta

Journal Article · Sun Aug 01 04:00:00 EDT 1982 · Phys. Rev. C; (United States)

DOI:https://doi.org/10.1103/PhysRevC.26.472· OSTI ID:6698085

Blann, M; Komoto, T A

Experimental fusion/fission excitation functions are analyzed by the statistical model with modified rotating liquid drop model barriers and with single particle level densities modeled for deformation for ground state (a/sub ..nu../) and saddle point nuclei (a/sub f/). Values are estimated for the errors in rotating liquid drop model barriers for the different systems analyzed. These results are found to correlate well with the trends predicted by the finite range model of Krappe, Nix, and Sierk, although the discrepancies seem to be approximately 1 MeV greater than the finite range model predictions over the limited range tested. The a priori values calculated for a/sub f/ and a/sub ..nu../ are within +- 2% of optimum free parameter values. Analyses for barrier decrements explore the importance of collective enhancement on level densities and of nuclear deformation in calculating transmission coefficients. A calculation is performed for the /sup 97/Rh nucleus for which a first order angular momentum scaling is used for the J = 0 finite range corrections. An excellent fit is found for the fission excitation function in this approach. Results are compared in which rotating liquid drop model barriers are decremented by a constant energy, or alternatively multiplied by a constant factor. Either parametrization is shown to be capable of satisfactorily reproducing the data although their J = 0 extrapolated values differ markedly from one another. This underscores the dangers inherent in arbitrary barrier extrapolations.

• Research Organization: E Division, Lawrence Livermore National Laboratory, Livermore, California 94550
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 6698085
• Journal Information: Phys. Rev. C; (United States), Journal Name: Phys. Rev. C; (United States) Vol. 26:2; ISSN PRVCA
• Country of Publication: United States
• Language: English

Related Subjects

653006* -- Nuclear Theory-- Spontaneous & Induced Fission
653007 -- Nuclear Theory-- Nuclear Models-- (-1987)
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ANGULAR MOMENTUM
BETA DECAY RADIOISOTOPES
BETA-PLUS DECAY RADIOISOTOPES
CROSS SECTIONS
DEFORMATION
ENERGY LEVELS
ENERGY-LEVEL DENSITY
EXCITATION FUNCTIONS
FINITE-RANGE INTERACTIONS
FISSION
FISSION BARRIER
FUNCTIONS
FUSION REACTIONS
INTERACTIONS
INTERMEDIATE MASS NUCLEI
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
LIQUID DROP MODEL
MATHEMATICAL MODELS
MINUTES LIVING RADIOISOTOPES
NUCLEAR DEFORMATION
NUCLEAR MODELS
NUCLEAR POTENTIAL
NUCLEAR REACTIONS
NUCLEI
ODD-EVEN NUCLEI
PARTICLE MODELS
POTENTIALS
RADIOISOTOPES
RHODIUM 97
RHODIUM ISOTOPES
SECONDS LIVING RADIOISOTOPES
SINGLE-PARTICLE MODEL
STATISTICAL MODELS