Facets of reaction mechanism in 6Li+181Ta system

Abstract

More focused investigations are required to better understand the different modes of fusion phenomena in weakly bound projectiles. In order to comprehend the reaction mechanism of weakly bound projectiles, a new measurement of the evaporation residue cross sections from the $^6$Li induced reaction on $^{181}$Ta in the 4.5 -- 7.1 MeV/nucleon energy range has been reported in this article. The $\gamma$--ray spectrometry has been employed to identify the $^{183m,g}$Os, $^{182}$Os, $^{183}$Re, and $^{183,182m2,180}$Ta residues produced in the reaction via different evaporation channels. The \textsc{EMPIRE-3.2.2} code, which houses both the equilibrium (EQ) and pre-equilibrium (PEQ) models in its framework, and \textsc{PACE4} have been tasked to analyze the measured excitation functions. Out of the two, \textsc{EMPIRE-3.2.2} demonstrates better agreement with the data. A systematic analysis of the measured data and theoretical background indicates that the complete and incomplete fusion (ICF) of $^6$Li contribute to the residual cross sections. Thus, the strength of the partial fusion has been inferred. Further, the neutron transfer channels have been found to contribute significantly to the reaction dynamics; hence they are investigated using the coupled reaction channel (CRC) calculations and discussed in detail. The isomeric cross section ratio obtained from the measured residual cross sections of the isomeric pair of $^{183}$Os highlights the significance of angular momentum and relative spins of the ground and isomeric states as a function of projectile incident energy.