Phenomenological critical interaction distance from elastic scattering measurements on a 208Pb target

.We have surveyed a series of elastic scattering measurements from the literature involving tightly bound (Li-9, Be-10, C-12, O-16, F-19), weakly bound (Li-6, Li-7, Li-8, He-8, Be-9, F-17), and exotic (He-6 and Li-11) nuclei on a Pb-208 target at energies close to the Coulomb barrier. The corresponding data were then converted and analyzed in terms of the interaction distance, where critical-interaction and strong-absorption distances were extracted. Larger values were obtained for the exotic He-6 and Li-11 nuclei, as compared with both weakly bound and tightly bound projectiles. The influence of long-range nuclear interactions and Coulomb dipole polarizability are discussed. A correlation between the critical interaction distance and binding energy for a given configuration is observed.