Study of various ground state decay mechanisms of Actinide nuclei

Abstract：

The special property of the actinide mass region is that nuclei belonging to this group are radioactive and undergo different ground state processes, such as alpha decay, cluster radioactivity (CR), heavy particle radioactivity (HPR), and spontaneous fission (SF). In this study, the probable radioactive decay modes of the heavy mass region ( Z= 89−102) are studied within the framework of the preformed cluster model (PCM). In the PCM, the radioactive decay modes are explored in terms of the preformation probability ( $ P_0 $ ) and penetration probability ( P) at the turning point $ R_a $ , where the penetration of fragments is initiated [ R $ _a $ = R $ _T $ (touching state) + $ \Delta R $ (neck length parameter)]. First, the alpha decay half-lives are calculated for light and heavy nuclei, and $ R_a $ points are obtained by optimizing the neck length parameter. These $ R_a $ points are further employed to fix the Q-value dependent turning point ( $ R_a $ ( Q)). Then, using the ( $ R_a $ ( Q)) relation, the decay half-lives are computed, and the calculated results are compared with the available theoretical and experimental data. The isotopical trend of $ P_0 $ and Pis studied with respect to the mass number of the parent and daughter nucleus, respectively. The CR and HPR channels are also explored, and a comparison of calculated data is conducted with the available literature. Comparative analysis of the fragmentation potential and preformation probability is carried out for alpha decay and SF. The mass distribution of the nuclei is studied as a function of fragment mass ( A $ _2 $ ) by considering the spherical and hot-compact deformation of the decaying fragments. Finally, the most probable fission fragments are identified using the fragmentation structure, and the corresponding fission fragment total kinetic energy of the identified fragments is calculated and compared with available data, wherever applicable.