Investigating the fission dynamics of the following neutron shell closed nuclei within a stochastic dynamical approach: 210Po, 212Rn, and 213Fr

Abstract

Dissipative dynamics of nuclear fission is a well confirmed phenomenon described either by a Kramers-modified statistical model or by a dynamical model employing the Langevin equation. Though dynamical models as well as statistical models incorporating fission delay are found to explain the measured fission observables in many studies, it nonetheless shows conflicting results for shell closed nuclei in the mass region 200. Analysis of recent data for neutron shell closed nuclei in excitation energy range 40$-$80 MeV failed to arrive at a satisfactory description of the data and attributed the mismatch to shell effects and/or entrance channel effects, without reaching a definite conclusion. In the present work we show that a well established stochastic dynamical code simultaneously reproduces the available data of pre-scission neutron multiplicities, fission and evaporation residue excitation functions for neutron shell closed nuclei ${}^{210}$Po and ${}^{212}$Rn and their isotopes ${}^{206}$Po and ${}^{214,216}$Rn without the need for including any extra shell or entrance channel effects. The calculations are performed by using a phenomenological universal friction form factor with no ad-hoc adjustment of model parameters. However, we note significant deviation, beyond experimental errors, in some cases of Fr isotopes.

References in corpus (18)

• Nuclear Ground-State Masses and Deformations
• Brownian shape motion on five-dimensional potential-energy surfaces: Nuclear fission-fragment mass distributions
• Unified description of fission in fusion and spallation reactions
• Statistical Model of Heavy-Ion Fusion-Fission Reactions
• Fission-fragment mass distributions from strongly damped shape evolution
• Fission Hindrance in hot 216Th: Evaporation Residue Measurements
• Prescission neutron multiplicity and fission probability from Langevin dynamics of nuclear fission
• Transient effects in fission evidenced from new experimental signatures
• Fission Decay Widths for Heavy-Ion Fusion-Fission Reactions
• First experiment on fission transients in highly fissile spherical nuclei produced by fragmentation of radioactive beams
• Thermal fission rates with temperature dependent fission barriers
• Evaporation residue cross-sections as a probe for nuclear dissipation in the fission channel of a hot rotating nucleus
• Fission barrier, damping of shell correction and neutron emission in the fission of A$\sim$200
• Quest for consistent modelling of statistical decay of the compound nucleus
• Influence of fusion dynamics on fission observables: A multi-dimensional analysis
• Isoscaling of the Fission Fragments with Langevin Equation
• Fission fragment mass distribution in ${}^{210}$Po and ${}^{213}$At
• Modeling survival probabilities of superheavy nuclei at high excitations