Scission Deformation of the Cd120/Sn132 …

We report on a study of the radiative decay of fission fragments populated via neutronless fission of ²⁵²Cf(sf). Applying the double-energy method a perfect mass identification is achieved for these rare events. In the specific case of the ¹²⁰Cd/¹³²Sn cold fragmentation, we find that ¹³²Sn is produced in its ground state. We can therefore directly measure the excitation energy of the complementary fragment, ¹²⁰Cd. The reproduction of the γ-ray spectrum, measured in coincidence with the neutronless fission events, is sensitive to the angular momentum distribution of the studied primary fragment. The latter estimated using a time-dependent collective Hamiltonian model, allows us to constrain for the first time the deformation (β₂0.4) of the studied fission fragment at scission. The present work demonstrates the high potential of the understudied neutronless fission channel for extracting detailed information on both fission fragments and process.