Break-up fusion studies in heavy ion reactions at low energies

In heavy ion interactions, both the complete fusion (CF) as well as break up fusion (BUF) reactions has been observed from energies close to the Coulomb barrier to well above it. The relative contribution of these processes depends not only on the projectile energy and on the nature of projectile-target combination but on various other entrance channel parameters as well. In order study the BUF reactions and to study its influence on various entrance channel parameters at low energies, we have undertaken a programme for the measurement and analysis of excitation functions (EF) and forward recoil range distributions (RRD), for both neutron emission as well as alpha-emission channels, in heavy ion interactions. Complementary measurements for various systems have been obtained. Analysis of EF data has indicated that neutron emitting channels are populated via complete fusion process however, a significantly large contribution of incomplete fusion process in the alpha emitting channels has been observed. The results of EF data has been confirmed by the direct measurement of recoil range distributions. The spin distribution measurements reveal the peripheral nature of ICF reactions. The results of a large number of projectile-target combinations has been used to develop systematic for incomplete fusion processes that may be useful for the development of a theoretical model for such reactions at low energies. The details will be presented. (author)