Exploring the role of entrance channel magicity on fusion fission dynamics

Understanding the role of entrance channel magicity of the target projectile combination on the fusion fission dynamics will help in the best selection of the target projectile combination for super heavy element synthesis. The fission fragment mass distributions of the actinide compound nucleus ²²⁴Th was experimentally studied by populating the compound nucleus at similar excitation energies through two channels ^16O + ²⁰⁸Pb (both target and projectile doubly magic) and ¹⁹F + ²⁰⁵TI (both target and projectile are non-magic). The charge product (Z_pZ_T) of the target projectile combination chosen in this set of reactions is less than 800, hence admixture of quasi-fission in the fission fragment mass distribution is not expected. The fission fragment mass distribution of the compound nucleus ²²⁴Th was measured by the time of flight difference technique using two MWPC gas detectors. The system was populated through the two entrance channels ^160+208Pb and ¹⁹p + ²⁰⁵TI with excitation energies between 30 MeV to 65 MeV. The beam energies were so chosen such that the compound nucleus formed were at the similar excitation energies. A possible influence of the entrance channel magicity was seen in this experimental data. This may indicate a possible influence of the entrance channel magicity on the potential energy surface (PES), which governs the fusion fission dynamics of the actinide compound nucleus ²²⁴Th. (author)