Allowance for the tunnel effect in the entrance channel of fusion–fission reactions

Journal Article · Sun May 15 04:00:00 EDT 2016 · Physics of Atomic Nuclei

DOI:https://doi.org/10.1134/S1063778816020113· OSTI ID:22612668

A two-stage model is developed in order to describe fusion–fission reactions. The process in the course of which colliding ions approach each other is simulated at the first stage, the deformations and relative orientations of the ions being taken into account. The first stage of the calculation is completed as soon as colliding nuclei touch each other. A continuous nuclear system (monosystem) is formed at this instant. The emerging distributions of the angular momenta of this system and of its potential and internal energies at the point of touching are used as input data that are necessary for triggering the second stage of the calculation. The evolution of collective coordinates that describe the shape of the monosystem is calculated at the second stage. The description of this evolution is terminated either at the instant of its fission or upon the release of a major part of its excess energy via particle and photon emission. In the latter case, the probability for the fission of the monosystem or a further decrease in its excitation energy becomes extremely small. The ion-collision process and the evolution of the monosystem formed after primary nuclei come into contact are simulated on the basis of stochastic Langevin equations. The quantities appearing in them (which include the potential energy and inertial and friction parameters) are determined with allowance for the shell structure of nuclei. The tunneling of colliding nuclei through the Coulomb barrier is taken into account, and the effect of this phenomenon on model predictions is studied.

• OSTI ID: 22612668
• Journal Information: Physics of Atomic Nuclei, Journal Name: Physics of Atomic Nuclei Journal Issue: 3 Vol. 79; ISSN 1063-7788; ISSN PANUEO
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
ANGULAR MOMENTUM
COMPUTERIZED SIMULATION
COORDINATES
COULOMB FIELD
DEFORMATION
EXCITATION
FISSION
HEAVY ION FUSION REACTIONS
ION COLLISIONS
IONS
LANGEVIN EQUATION
NUCLEI
ORIENTATION
PHOTON EMISSION
PHOTONS
POTENTIAL ENERGY
PROBABILITY
STOCHASTIC PROCESSES
TUNNEL EFFECT