"Prospects in reaction studies with weakly and tightly bound nuclei at near and above barrier energies ”

Weakly bound nuclei are interesting candidates for reaction studies due to their low breakup threshold energies. The driving force, for studies with these nuclei, has been to investigate the effect of their breakup on different reaction channels. Suppression of complete fusion cross-sections as compared to coupled-channels calculations, breakup threshold anomaly in the elastic scattering, large inclusive alpha cross-sections as compared to reaction cross-sections, and large transfer cross-sections, have been observed in reactions carried out using weakly bound stable 6,7Li and 9Be nuclei on different targets. Recent investigations, to probe the mechanism of the breakup of these nuclei, have observed transfer induced breakup to be the dominant mode rather than the direct breakup of these nuclei. Thus it is of interest to determine the cross-sections of breakup via each mode. An outlook on these will be presented in the talk.

Reactions studies with tightly bound heavy projectiles also present interesting challenges, especially in investigations of the fusion-fission process. With increasing charge of the projectile, suppression of the total fusion cross-section is observed. In other words, the survival of the compound nucleus, formed in such processes, is hindered. This is thought to be due to the onset of dissipative processes like transfer induced fission, quasi-fission, etc. Thus, such investigations play a crucial role in choosing the projectile-target combination, in an attempt to form heavier compound nuclei (Z>100). Very recent studies show transfer induced fission to be increasing with an increase in the projectile charge. Thus, measurement of cross-sections for such dissipative processes is is of immediate requirement. An overview of the studies in this field will be presented.