Transfer, sequential decay, and quasi-free reactions induced by 18-MeV He-6 beam on Li-6, Li-7, and C-12

The He-6 + Li-6,Li-7 and He-6 + C-12 scattering and reactions have been studied using an 18-MeV He-6 beam. Experimental results for the elastic scattering on all three targets are in fair agreement with optical model predictions, using the potentials found in the analysis of the Li-6 scattering on the same targets and at close beam energies. Several two-body exit channels show clear signatures of a direct reaction mechanism allowing extraction of spectroscopic information. The measured angular distribution for the He-6 + Li-6 --> alpha + Li-8 reaction indicated close similarity between the alpha + 2n configuration in He-6 and the alpha + d configuration in Li-6. The obtained results for alpha-particle pickup from both Li-6 and Li-7 give large values of a spectroscopic factors for some Be-10 states, indicating their well-developed alpha + He-6 cluster structure. The exotic two-proton pickup reaction (He-6, Be-8) was studied, as well as two-neutron and triton transfer reactions. Quasi-free scattering of He-6 on deuteron and a particle in Li-6 was also observed. The sequential decay reactions He-6 + Li-6 --> He-6 + alpha + d, He-6 + Li-6 --> 2 alpha + t + n, He-6 + Li-7 --> He-6 + alpha + t, and He-6 + C-12 --> Be-10 + 2 alpha were clearly seen, and alpha clustering of some states in Li-6,Li-7, Be8-10, and C-14 was thus studied. Several new spectroscopic results obtained for some Be-10 states support the existence of a molecule-like rotational band in Be-10 with a very large moment of inertia.