Effect of the finite range of the nuclear force on the dynamics of fission and heavy-ion collisions

Journal Article · Thu Sep 01 04:00:00 EDT 1977 · Phys. Rev., C; (United States)

DOI:https://doi.org/10.1103/PhysRevC.16.1048· OSTI ID:7082011

Sierk, A J; Nix, J R

We study the effect on dynamical calculations of fission and heavy-ion collisions of replacing the surface energy of the liquid-drop model with a modification that takes into account the lowering of the nuclear macroscopic energy due to the finite range of the nuclear force. This energy is calculated by performing a two-dimensional volume integral over the nuclear density of a two-body attractive Yukawa potential, in analogy with the calculation of the electrostatic energy of a charge distribution. The kinetic energy of the nuclear liquid drop is calculated for incompressible, nearly irrotational hydrodynamical flow by use of the Werner-Wheeler method. The dissipation of collective energy into internal, single-particle excitation energy is neglected. In the case of fission, the liquid-drop model and finite-range model give similar results, although the liquid-drop model predicts a somewhat larger fission-fragment excitation energy. In the case of heavy-ion collisions, the surface energy of the liquid-drop model causes a large coupling of energy from relative center-of-mass motion into higher-order collective motion. This increases the energy over the one-dimensional interaction barrier that is needed to cause compound-nucleus formation in head-on collisions for symmetric systems. For an A = 250 compound system, the predicted energy over the barrier is about 170 MeV in the liquid-drop model, as compared to about 40 MeV in the finite-range model. We conclude that the effect of the finite range of the nuclear force is small in calculations of fission, but that it must be included in calculations of heavy-ion collisions.

• Research Organization: W. K. Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, California 91125
• OSTI ID: 7082011
• Journal Information: Phys. Rev., C; (United States), Journal Name: Phys. Rev., C; (United States) Vol. 16:3; ISSN PRVCA
• Country of Publication: United States
• Language: English

Related Subjects

651815* -- Nuclear Properties & Reactions
A=150-189
Theoretical-- Nuclear Reactions & Scattering-- (-1987)
652016 -- Nuclear Properties & Reactions
A=220 & above
Theoretical-- Spontaneous & Induced Fission-- (-1987)
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ACTINIDE ISOTOPES
ACTINIDE NUCLEI
ALPHA DECAY RADIOISOTOPES
ANGULAR MOMENTUM
CHARGED-PARTICLE REACTIONS
COMPOUND-NUCLEUS REACTIONS
DISTANCE
ENERGY
EVEN-EVEN NUCLEI
FISSION
HEAVY ION REACTIONS
HEAVY NUCLEI
HYDRODYNAMIC MODEL
INTERACTION RANGE
ISOTOPES
LIQUID DROP MODEL
MATHEMATICAL MODELS
NEODYMIUM 150 REACTIONS
NEODYMIUM 150 TARGET
NUCLEAR FORCES
NUCLEAR MODELS
NUCLEAR POTENTIAL
NUCLEAR REACTIONS
NUCLEI
PARTICLE MODELS
RADIOISOTOPES
STATISTICAL MODELS
TARGETS
THERMODYNAMIC MODEL
URANIUM 236
URANIUM ISOTOPES
YEARS LIVING RADIOISOTOPES
YUKAWA POTENTIAL