Transfer-type products accompanying cold fusion reactions

Production of nuclei heavier than the target is treated for projectile-target combinations used in cold fusion reactions leading to superheavy nuclei. These products are related to transfer-type or to asymmetry-exit-channel quasifission reactions. The production of isotopes in the transfer-type reactions emitting of α particles with large energies is discussed.

Figure 1

Calculated cross sections of the isotopes of nuclei with $Z=84\text{−}94$ produced in the reactions ${}^{66,68,70}\mathrm{Zn}$+${}^{208}\mathrm{Pb}$ at $E_{c.m.}=251$, 254, and 255 MeV, respectively. The order of the indicated mass numbers of the isotopes is in accordance with the decrease of their cross sections.

Figure 2

The same as in Fig. 1, but for the reactions ${}^{74,76}\mathrm{Ge}$+${}^{208}\mathrm{Pb}$ at $E_{c.m.}=271.3$ and 272.3 MeV, respectively.

Figure 3

The same as in Fig. 1, but for the reactions ${}^{70,72}\mathrm{Ge}$+${}^{208}\mathrm{Pb}$ at $E_{c.m.}=267.3$ and 270.3 MeV, respectively.

Figure 4

Resulting cross sections $\sigma (Z,N,t)$ at $t=2\mu$s for the nuclei produced in the reactions ${}^{66,68,70}\mathrm{Zn}$+${}^{208}\mathrm{Pb}$ are presented by open triangles, circles, and squares, respectively, versus the energies of α particles emitted from these nuclei for $E_{\alpha }\ge 8.5$ MeV.