Four-dimensional Langevin approach to fission with Cassini shape parameterization

¹ Department of Pure and Applied Physics, Kansai University, 564-8680 Suita, Osaka, Japan
² Joint Institute for Nuclear Research, 141980 Dubna, Moscow Region, Russia
³ Horia Hulubei - National Institute for Nuclear Physics and Engineering, P.O.Box MG-6, RO-76900, Bucharest, Romania

^* e-mail: k319244@kansai-u.ac.jp
^** e-mail: wadataka@kansai-u.ac.jp
^*** e-mail: carjan@cenbg.in2p3.fr

Published online: 26 May 2023

Abstract

We apply the Cassini shape parameterization to the dynamical study of actinide fission using the multi-dimensional Langevin equation. The fragment mass distributions for fission of ²³⁶U and ^{256, 258} Fm are calculated with the 4D Langevin equation. The 4D collective space is formed by adding either α₃ or α₆ to the basic 3D {α, α₁, α₄} space. We investigate the role of α₃ and α₆ by comparing the results of 4D (α₃ or α₆) with that of 3D. For 236U and 256Fm, where asymmetric fission is predominant, the fragment mass distributions calculated in the 4D (α₃) space are in good agreement with experimental data. On the other hand, for ²⁵⁸Fm, which is characterized by symmetric fission, 4D (α₆) is effective for describing the shape of compact symmetric fragments. We demonstrate the advantages of the Cassini shape parameterization for the dynamical study of actinide fission.