Examination of effects of weak transfer channels on quasi elastic barrier distribution measurement

Abstract

This thesis is based on the quasi-elastic (QE) scattering and transfer channels cross-section measurements performed at Inter UniversityAccelerator Centre (IUAC), New Delhi. The motivation behind these experiments was to investigate the effect of channel couplings, i.e., relative motion between the projectile and target coupled to the intrinsic degrees of freedom, in heavy-ion fusion reactions through QE-measurements. These couplings are experimentally observed as the sub-barrier fusion enhancement and leads to the distribution of the barrier (known as barrier distribution (BD)) instead of a single peak barrier. These various degrees of freedom includes the static or dynamic deformations, the inelastic excitations, break up channels, transfer processes etc. Primarily for this thesis work,effect of nuclear structure and weakly coupled transfer channel has been studied.To have a deeper insight to these effects, barrier distribution study is proven quite useful. The BDs can be extracted from the fusion cross-sections as well as from QE-excitation function. On a theoretical front,coupled channel calculations has been performed using code CCFULL as well as the CCQUEL to extract and fit the experimental BD. The purpose of this thesis to understand and gain information about the role of nuclear structure and transfer channels in the heavy-ion fusion reactions from the quasi-elastic BD measurements. newline