Dynamics of Different Fission Mechanisms Using Fragmentation Approach

Abstract

The fusion-fission mechanism is a complex process which consists a collective motion of nucleons at compound nucleus stage and its subsequent segregation in the fission channel. Significant progress on experimental and theoretical front has helped immensely to understand this intricate process. The main emphasis in this thesis is to investigate the dynamics of different fission mechanisms. The work is committed to the study of several compound nucleus (CN) and non-compound nucleus (nCN) fission mechanisms of light and heavy nuclei formed in nuclear reactions, which involve different type of projectiles, e.g., light particles, loosely bound nuclei and heavy ions. This investigation is performed by utilizing the collective clusterization technique of “dynamical clusterdecay model (DCM)”, thereby the contribution of light particles in the decay process is also investigated along with the fission process. The collective fragmentation potential is calculated using macro-microscopic method, which in turn helps to estimate the mass fragmentation and related cross-section yields in the decay channel. Here, the structural information of fissioning nuclei is obtained by calculating the preformation probability (P0) of the nascent fragments. Current study includes the temperature (T) and angular momentum (ℓ) effects, which have decisive impact on fission process. Besides this, the deformation and orientation effects of decaying fragments are also incorporated via the radius vector. The calculated results for different fission mechanisms compare nicely with the experimental data, and some predictions are made which can be verified via future experiments. Besides induced fission, spontaneous fission (SF) occurring at the end of α-decay chains of superhavey nuclei (SHN) is also explored in this thesis.