Isthmus connecting mainland and island of stability of superheavy nuclei

For the ${}^{48}\mathrm{Ca}$ 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.

Figure 1

The calculated (lines) excitation functions for $xn$-evaporation channels of the indicated complete fusion reactions. The mass table of Ref. [15] is used in the calculations. The black triangles at the energy axis indicate the excitation energy $E_{CN}^{*}$ of the CN at bombarding energy corresponding to the Coulomb barrier for the sphere-side orientation. The blue diamonds, green squares, red circles, and gray pentagons represent the experimental data [3] with error bars for $2n$-, $3n$-, $4n$-, and $5n$-evaporation channels, respectively. The symbols with the arrow indicate the upper limits of evaporation residue cross sections.

Figure 2

The same as in Fig. 1, but for $xn$-evaporation channels of the indicated complete fusion reaction.

Figure 3

The same as in Fig. 1, but for $xn$-evaporation channels of the indicated complete fusion reactions. The experimental data are from Ref. [33].