Role of compact and elongated configurations in the spontaneous fission of heavy and superheavy nuclei

The spontaneous fission analysis of even mass ($^{230}\mathrm{U}$ to $^{264}\mathrm{Hs}$) nuclei is carried out using the quantum mechanical fragmentation theory (QMFT) based preformed cluster model (PCM). The effect of deformations and orientations is investigated in view of the spontaneous fission of the considered nuclei. The PCM treats the spontaneous emission in terms of the barrier tunneling process where the fragments are preformed with a relative probability within the QMFT framework. The addition of deformation effects, i.e., ${\ensuremath{\beta}}_{2}$ (elongated)-deformed and ${\ensuremath{\beta}}_{2}$ (compact)-deformed, considerably modify the fragmentation potential, penetration path, and related barrier characteristics, resulting in significant change in the mass and charge of emitting fragments. The half-life time calculated using compact ${\ensuremath{\beta}}_{2}$ deformed fragments find better comparison with experimental data. For this configuration, the transition from asymmetric fission to nearly symmetric fission takes place with an increase in the mass/charge number of the considered nuclei. The effect of deformations on the decay of $A=230--264$ parent nuclei is also analyzed in terms of barrier characteristics such as barrier height, barrier position, and fissility parameter, and the most probable fragments operating in spontaneous fission process are identified. In addition to this, the substructure of fission fragments and the isobaric behavior is analyzed within the collective clusterization approach.