Asymmetric fission study in the lead-island region

Moumita Maiti (Indian Institute of Technology Roorkee)

Asymmetric mass splits observed in the extremely neutron-deficient sub-lead nuclei have generated keen interest in exploring the A < 200 mass region. Although some experiments have been performed using β-delayed fission and heavy-ion induced reactions, the role of proton and neutron shells on asymmetric fission in this region remains to be tested and requires further investigation. In view of this fact, we have experimentally explored the fission fragment mass distributions and associated fission fragment properties of Pt and Hg isotopes at multiple excitation energies. Further, available experimental mass distributions have been compared with the theory to test its prediction efficiency. The structure observed in the middle section of the mass distribution confirms the presence of asymmetric mode(s) in addition to the symmetric mode, highlighting the relevance of deformed proton shells. We have analyzed the fission data of neutron-deficient lead-island nuclei from Hg, Pt, Au, Pb, and Po. The details of our observations will be discussed during the talk.