Asymmetric fission of sup 149 Tb sup * from the finite-range, rotating-liquid-drop model: Mean total kinetic energies for binary fragmentation

Journal Article · Fri May 01 00:00:00 EDT 1992 · Physical Review, C (Nuclear Physics); (United States)

DOI:https://doi.org/10.1103/PhysRevC.45.2185· OSTI ID:7301138

Carjan, N ^[1]; Kaplan, M ^[2]

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1. Centre d'Etudes Nucleaires de Bordeaux-Gradignan, 33170 Gradignan (France)
2. Department of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213 (United States)

We have used the finite-range, rotating-liquid-drop model to calculate the conditional saddle-point shapes, fission barriers, and moments of inertia of the nucleus {sup 149}Tb as functions of mass asymmetry (or fragment charge {ital Z}) and angular momentum. A strong motivation in the present work is the potentiality for predicting total kinetic energies (TKE) in asymmetric fission, which may be compared with measurements of intermediate-mass fragments (IMF's) produced in heavy-ion reactions. From the conditional saddle points, we estimate the TKE in the limit of no post-saddle dissipation, yielding, in effect, upper limits for the TKE's. Clearly the nuclear shapes at scission will produce lower limits for the TKE's, and we propose two methods for determining the characteristics of such scission configurations. The first involves a linear extrapolation along the fission normal mode at the conditional saddle point, and the second employs Swiatecki's scaling rule to determine the effect of dissipation on the nuclear elongation at scission. In comparison to experimental TKE results for IMF's, corrected for light particle evaporation, we find that the predictions from saddle-point shapes are in rather good agreement with the data over a wide range of mass asymmetry. The calculated estimates from nondissipative scission-point configurations also agree fairly well with the data, but tend to underpredict the TKE's significantly for the heavier IMF's. This is not a serious concern, as the calculations have not included any prescission damping. The estimates from fully dissipative scission-point shapes are systematically low, falling appreciably below the data over the whole range studied.

• OSTI ID: 7301138
• Journal Information: Physical Review, C (Nuclear Physics); (United States), Vol. 45:5; ISSN 0556-2813
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
TERBIUM 149
BINARY FISSION
ANGULAR MOMENTUM
COLLECTIVE MODEL
FINITE-RANGE INTERACTIONS
FISSION FRAGMENTS
LIQUID DROP MODEL
MOMENT OF INERTIA
SCISSION-POINT MODEL
YUKAWA POTENTIAL
ALPHA DECAY RADIOISOTOPES
BETA DECAY RADIOISOTOPES
BETA-PLUS DECAY RADIOISOTOPES
ELECTRON CAPTURE RADIOISOTOPES
FISSION
HOURS LIVING RADIOISOTOPES
INTERACTIONS
INTERMEDIATE MASS NUCLEI
ISOTOPES
MATHEMATICAL MODELS
MINUTES LIVING RADIOISOTOPES
NUCLEAR FRAGMENTS
NUCLEAR MODELS
NUCLEAR POTENTIAL
NUCLEAR REACTIONS
NUCLEI
ODD-EVEN NUCLEI
POTENTIALS
RADIOISOTOPES
RARE EARTH NUCLEI
663470* - Fission- (1992-)