Transport coefficients for modeling fission dynamics

Abstract

Transport coefficients are important ingredients in dynamical investigations of a nuclear fission process, which determine the dynamical evolution of the fissioning system. The inertia (mass) and friction (dissipation) tensors influence substantially on different observables. The proper calculation of these tensors is a necessary condition for correct modeling of the fission process. The calculation of the inertia and friction tensors is presented for a large variety of nuclear shapes generated by a {c,h,α} parametrization. The inertia tensor is calculated within the Werner-Wheeler approximation for incompressible irrotational flow. The friction tensor is calculated within the one-body and two-body mechanisms of nuclear dissipation. A numerical code is made available, which calculates all these quantities. Program summaryProgram Title: Mass_DissCPC Library link to program files:https://doi.org/10.17632/rcndf6sbns.1Licensing provisions: CC BY NC 3.0Programming language: C++Nature of problem: The modeling of the nuclear fission within dynamical consideration requires calculation of the inertia and friction coefficients. This calculation should be performed for a large variety of the nuclear shapes, which describe the evolution of the shape of compound nucleus from the ground state till the separated fission fragments.Solution method: The inertia tensor is calculated within the Werner-Wheeler approximation for incompressible irrotational flow. The friction tensor is calculated within the one-body and two-body mechanisms of the nuclear dissipation. The shape of the fissioning nucleus is described by the {c,h,α} parametrization. This parametrization determines the axially symmetric shapes in cylindrical coordinates. The inertia and friction tensors are calculated using numerical integration procedure as a function of the three shape parameters. All subroutines, which define the nuclear shape, are separated from the code, which calculates the inertia and friction tensors. Thus, the program could be adopted for any other shape parameterization in case if it is given in cylindrical coordinates.