Abstract:
. Recent experimental studies have shown the presence of pre-compound emission component in heavy
ion reactions at low projectile energy ranging from 4 to 7 MeV/nucleons. In earlier measurements strength of
the pre-compound component has been estimated from the di↵erence in forward-backward distributions of
emitted particles. Present measurement is a part of an ongoing program on the study of reaction dynamics of
heavy ion interactions at low energies aimed at investigating the e↵ect of momentum transfer in compound, precompound,
complete and incomplete fusion processes in heavy ion reactions. In the present work on the basis
of momentum transfer the measurement of the recoil range distributions of heavy residues has been used to decipher
the components of compound and pre-compound emission processes in the fusion of 16O projectile with 159Tb and 169Tm targets. The analysis of recoil range distribution measurements show two distinct linear momentum
transfer components corresponding to pre-compound and compound nucleus processes are involved.
In order to obtain the mean input angular momentum associated with compound and pre-compound emission
processes, an online measurement of the spin distributions of the residues has been performed. The analysis
of spin distribution indicate that the mean input angular momentum associated with pre-compound products
is found to be relatively lower than that associated with compound nucleus process. The pre-compound components
obtained from the present analysis are consistent with those obtained from the analysis of excitation
functions.
