Study of one-step and two-step neutron transfer in the reaction $^{6}$Li + $^{9}$Be

The paper presents the results of experiments on measuring the cross sections for elastic scattering and nucleon transfer channels in the $^{6}$Li + $^{9}$Be reaction at an incident energy of 68 MeV: $^{9}$Be($^{6}$Li,$^{6}$Li)$^{9}$Be, $^{9}$Be($^{6}$Li,$^{7}$Li)$^{8}$Be, $^{9}$Be($^{6}$Li,$^{7}$Li)$^{8}$Be$_{2+}$, $^{9}$Be($^{6}$Li,$^{8}$Li)$^{7}$Be, $^{9}$Be($^{6}$Li,$^{7}$Be)$^{8}$Li. The aim is to reveal the manifestation of the cluster structure of $^{9}$Be. Theoretical analysis of the contributions of one-step and two-step neutron transfer mechanisms is performed using the distorted wave Born approximation method with the Fresco code. Good agreement between the calculations and the experimental data was obtained for the channels of elastic scattering $^{9}$Be($^{6}$Li,$^{6}$Li)$^{9}$Be, neutron $^{9}$Be($^{6}$Li,$^{7}$Li)$^{8}$Be and proton transfer $^{9}$Be($^{6}$Li,$^{7}$Be)$^{8}$Li, as well as the transfer of two neutrons $^{9}$Be($^{6}$Li,$^{8}$Li)$^{7}$Be. It is shown that the dineutron cluster transfer mechanism makes a dominant contribution to the $^{9}$Be($^{6}$Li,$^{8}$Li)$^{7}$Be reaction channel at forward angles.