Microscopic self-consistent description of induced fission dynamics: Finite-temperature effects

Scientific paper - Original scientific paper

• Author: Jie Zhao
• Author: Tamara Nikšić; MBZ: 234533
• Author: Dario Vretenar; MBZ: 9570
• Author: Shan-Gui Zhou
• Author's institution: University of Zagreb; Faculty of Science; (Department of Physics)
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Physics

Abstract (english)

The dynamics of induced fission of 226Th is investigated in a theoretical framework based on the finite-temperature time-dependent generator coordinate method (TDGCM) in the Gaussian overlap approximation (GOA). The thermodynamical collective potential and inertia tensor at temperatures in the interval T=0–1.25 MeV are calculated using the self-consistent multidimensionally constrained relativistic mean-field (MDC-RMF) model, based on the energy density functional DD-PC1. Pairing correlations are treated in the BCS approximation with a separable pairing force of finite range. Constrained RMF+BCS calculations are carried out in the collective space of axially symmetric quadrupole and octupole deformations for the asymmetric fissioning nucleus 226Th. The collective Hamiltonian is determined by the temperature-dependent free energy surface and perturbative cranking inertia tensor, and the TDGCM+GOA is used to propagate the initial collective state in time. The resulting charge and mass fragment distributions are analyzed as functions of the internal excitation energy. The model can qualitatively reproduce the empirical triple-humped structure of the fission charge and mass distributions already at T=0, but the precise experimental position of the asymmetric peaks and the symmetric-fission yield can only be accurately reproduced when the potential and inertia tensor of the collective Hamiltonian are determined at finite temperature, in this particular case between T=0.75 MeV and T=1 MeV.

• Keywords (english): induced fission; nuclear energy density functional; finite temperature
• Language: english
• Publication type: Scientific paper - Original scientific paper
• Publication status: Published
• Peer review: Peer review - international
• Publication version: Published version
• Journal title: Physical Review C
• Numbering: vol. 99, no. 1, 014618
• p-ISSN: 2469-9985
• DOI: https://doi.org/10.1103/physrevc.99.014618
• URN:NBN: urn:nbn:hr:217:297554
• Publication: 2019
• Document URL: https://journals.aps.org/prc/abstract/10.1103/PhysRevC.99.014618
• Type of resource: Text
• Access conditions: Open access
• Public note: © 2019 American Physical Society. Received 16 September 2018. Published 22 January 2019.
• Created on: 2020-03-01 19:25:23