Production of unknown transactinides in asymmetry-exit-channel quasifission reactions

Possibilities of production of new isotopes of superheavy nuclei with charge numbers 104–108 in asymmetry-exit-channel quasifission reactions are studied for the first time. The optimal conditions for the synthesis are suggested in this type of reaction. The products of suggested reactions can fill a gap of unknown isotopes between the isotopes of heaviest nuclei obtained in cold and hot complete fusion reactions.

Figure 1

The DNS potential energies at $R_m$ and $J=0$ as functions of Z of heavy nucleus are presented by dotted, dashed, and solid curves for the reactions ${}^{48}\mathrm{Ca}+{}^{244,246,248}\mathrm{Cm}$, respectively. The arrow indicates the initial DNS. For the ${}^{48}\mathrm{Ca}+{}^{248}\mathrm{Cm}$ reaction, the barriers $B_{{\eta }_{\mathrm{sym}}}(Z_i=20,N_i=48)$ and $B_R(Z=102,N=160)$ are indicated. The $\times$ notates $U(R_b,Z=102,N=160,J=0)$. The potential energies refer to the energies of corresponding compound nuclei.

Figure 2

The calculated primary yields $Y_{Z,N}$ (lower part) and evaporation residue cross sections ${\sigma }_{\mathrm{ER}}$ (middle and upper parts) are shown by triangles, circles, and squares for the reactions ${}^{48}\mathrm{Ca}+{}^{244,246,248}\mathrm{Cm}$ ($E_{c.m.}=207,205.5,\text{and}204\text{MeV}$), respectively. The heavy fragments after 1n evaporation are indicated in the upper part of the figure. The results obtained with Eqs. (2) and (3) and with Eq. (6) are indicated by closed and open symbols, respectively.