Fission cross sections of heavy nuclei as a probe of nuclear dissipation

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

“…A detailed description of the theoretical aspects of the model can be found elsewhere [36,38]. The dynamical part of the model is analyzed with a 1D Langevin equation of motion governed by a driving potential that is determined by the free energy F(q, T), as in recent studies [39][40][41][42][43][44]. The free energy, as derived from the Fermi gas model, is related to the deformation dependent level density parameter a(q, A) as F(q, T) = V(q) -a(q, A) , where T is the nuclear temperature; q is a dimensionless deformation coordinate, which is defined as the ratio of half the distance between the center of masses of future fission fragments to the radius of the CN; and is the nuclear potential energy obtained from the finite-range liquid drop model [45,46].…”

“…[49]. B (q) is the dimensionless functional of the surface energy [34,38,43,50], which is expressed as a ratio of the surface energy of the composite system to that of a sphere.…”

“…Further, considering only symmetric fission, the mass asymmetry parameter of the shape evolution is set to α=0 [36,38,50]. The dimensionless fission coordinate (q) is given by q(c, h)= ( )(1+ [2h+ ]c ), where c and h define the elongation and neck degree of freedom of the fissioning nucleus, respectively [36,43,53,54].…”

“…Notably, following the fission dynamics through the full Langevin dynamical calculation is quite time consuming. Similar to previous Langevin studies [31,36,[39][40][41][42][43], a computationally less intensive approach is adopted in the present study, and herein, the dynamical stage is coupled with a statistical model. In the present calculations, the emission of light particles from the ground state to the scission configuration along the Langevin trajectories is treated as a discrete process.…”

“…[36] and later incorporated in Refs. [34,[40][41][42][43]. The emission width of a particle of type ν (n, p, α) is given as follows [55]:…”