Study of Dissipation Role in Fusion–fission Reaction Dynamics in Mass Region A>190 Via Fission Time

In the present work, fission times have been calculated for systems with wide range of fissility using statistical model code JOANNE2. Fission time is a direct indicator of the dissipation strength of the compound nucleus and higher the fission time, more will be the hindrance in the evolution path of the compound nucleus (CN). So, in order to understand the dissipation effects in CN, it becomes important to calculate the fission time ( τ _tot ). Role of excitation energy, shell effects and entrance channel mass effects are also studied for these systems. Effect of entrance channel on τ _tot has been studied for ^216 Ra, ^197 Tl, ^210 Po and ^213 Fr. Radon isotopes have τ _tot in the range (60–80 ± 10) × 10^-21 secs whereas for Francium isotopes, the total fission time is found to be as high as ( 130 ± 10 ) × 10^-21 secs. ^213 Fr having neutron shell enclosure has τ _tot lower than other Fr isotopes.