Systematic study of projectile structure effect on fusion barrier distribution

TL;DR

This study systematically investigates how projectile and target structures influence fusion barrier distributions using quasielastic excitation measurements across different systems, revealing the importance of inelastic states and charge product effects.

Contribution

It provides a comprehensive analysis of fusion barrier distributions for various systems, highlighting the role of target and projectile structures in coupled channel calculations.

Findings

Couplings due to target states suffice for $^{4}$He, $^{12}$C, and $^{16}$O + $^{232}$Th systems.

Inelastic states of $^{19}$F are necessary alongside target couplings for $^{19}$F + $^{232}$Th.

Barrier distribution width exhibits transition behavior related to charge product.

Abstract

Quasielastic excitation function measurement has been carried out for the $^{4}$He + $^{232}$Th system at $\theta_{lab}$=160$^\circ$ with respect to the beam direction, to obtain a representation of the fusion barrier distribution. Using the present data along with previously measured barrier distribution results on $^{12}$C, $^{16}$O, and $^{19}$F + $^{232}$Th systems a systematic analysis has been carried out to investigate the role of target and/or projectile structures on fusion barrier distribution. It is observed that for $^{4}$He, $^{12}$C, and $^{16}$O + $^{232}$Th, reactions the couplings due to target states only are required in coupled channel fusion calculations to explain the experimental data, whereas for the $^{19}$F+ $^{232}$Th system along with the coupling of target states, inelastic states of $^{19}$F are also required to explain the experimental results on fusion-barrier distribution. The width of the barrier distribution shows interesting transition behavior when plotted with respect to the target-projectile charge product for the above systems.