Isthmus connecting mainland and island of stability of superheavy nuclei

For the Ca-48 and Ra/actinide-based complete fusion reactions, the excitation functions for the production of isotopes of superheavy nuclei with charge numbers 108-116 are calculated and compared to the available experimental data. The calculated production cross sections clearly indicate the border nucleus Ds between the island of stability of superheavy nuclei and the mainland with a relatively large number of neutrons.