Abstract:
The entrance channel effect on the onset and strength of incomplete fusion (icf) has
been studied in the present work. Several inclusive experiments have been performed to measure
the icf strength function in 12C,16O+169Tm systems at near and above barrier energies. Data
obtained in these experiments suggest the existence of icf even at slightly above barrier energies
where complete fusion (cf) is supposed to be the sole contributor, and conclusively demonstrate
strong projectile structure and energy dependence of icf. The incomplete fusion strength
functions for 16O,12,13C+159Tb and 16O,12,13C+181Ta systems are analyzed as a function of
projectile α-Q-value at a constant νrel = 0.053c. It has been found that one neutron (1n)
excess projectile 13C (as compared to 12C) results in less incomplete fusion contribution due
to its relatively large negative α-Q-value. In order to understand the onset of icf at such
low energies, the driving input angular momenta ( ) involved in the production of different
evaporation residues have been deduced from the analysis of experimentally measured spindistributions for the same projectile-target combinations at the same incident energies. Higher
-values, imparted into the system in non-central interactions, are found to be responsible for
low energy icf. The icf-αxn/2αxn channels display involvement of higher -values than that
observed in cf-xn/pxn/αxn/2αxn channels at the very same projectile energies. It has been
observed that the mean value of increases with successively opened icf channels and incident
energy
