Mean-field study of the nuclear partition function: application to level density and compound nucleus fission

Journal Article · Tue Sep 01 04:00:00 UTC 1981 · Phys. Rev. C; (United States)

DOI:https://doi.org/10.1103/PhysRevC.24.1029· OSTI ID:6146200

Kerman, A K; Levit, S

Functional integral formulation of the mean-field approximation for many-body systems is used to study the nuclear partition function. Both static and dynamic mean-field solutions with statistical occupations of the single particle wave functions are discussed. These correspond to different physical processes in the nuclear system. In the static case the effect of mean-field fluctuations on the nuclear level density is exhibited. This effect enters consistently along with the usual effects of temperature and chemical potential fluctuations. Together they account for generalized random phase approximation correlations and produce bosonlike terms in the nuclear entropy. Because of the self-consistency of the approach, no overcounting of the collective and single-particle degrees of freedom occurs. The effects of the single particle continuum are included in the discussion. In the low temperature limit a simple correction to the level density parameter is evaluated, which leads to an increase of its magnitude. Consequences of a possible multiplicity of static mean-field configurations are briefly discussed. Dynamical mean-field solutions are considered in relation to compound nucleus fission. They provide the extension of the mean-field description of spontaneous fission given recently. A microscopic expression for the energy dependence of the average fission width is presented. It combines both the dynamical and statistical features of the tunneling mean-field solution in the subbarrier region.

• Research Organization: Center for Theoretical Physics Laboratory for Nuclear Science and Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
• DOE Contract Number: AC02-76ER03069
• OSTI ID: 6146200
• Journal Information: Phys. Rev. C; (United States), Journal Name: Phys. Rev. C; (United States) Vol. 24:3; ISSN PRVCA
• Country of Publication: United States
• Language: English

Related Subjects

653001* -- Nuclear Theory-- Nuclear Structure
Moments
Spin
& Models
653003 -- Nuclear Theory-- Nuclear Reactions & Scattering
653006 -- Nuclear Theory-- Spontaneous & Induced Fission
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
COMPOUND-NUCLEUS REACTIONS
ENERGY LEVELS
FIELD THEORIES
FISSION
FUNCTIONS
HARTREE-FOCK METHOD
MANY-BODY PROBLEM
MATHEMATICAL MODELS
NUCLEAR REACTIONS
PARTICLE MODELS
PARTITION FUNCTIONS
RANDOM PHASE APPROXIMATION
SINGLE-PARTICLE MODEL
STATISTICAL MODELS
WAVE FUNCTIONS