Possibilities for synthesis of new isotopes of superheavy nuclei in cold fusion reactions

In order to find a way to produce superheavy nuclei (SHN), which appear in the gap between the SHN synthesized by cold fusion and those by hot fusion, or those so far not yet been produced in the laboratory, we tried to make use of a set of projectile isotopic chains, to use a radioactive beam projectile, and to test symmetric fusion reactions for gaining more neutrons to synthesize neutron-richer SHN based on the dinuclear system (DNS) model via cold fusion reactions. It is found that the nuclei ${}^{265}\mathrm{Mt},{}^{268,272}\mathrm{Ds},{}^{273}\mathrm{Rg}$, and ${}^{274,275,276}\mathrm{Cn}$ may be produced with the detectable evaporation residual cross sections. The intensities of radioactive beams are significantly less than those of the stable beams, therefore using a stable beam is predicted to be the most favorable method for producing SHN. From the symmetric reaction system ${}^{136}\mathrm{Xe}+{}^{136}\mathrm{Xe}$, no fusion event was found.

Figure 1

Comparison of predictions of $P_{\text{CN}}$ for $Z=107–113$ cold fusion reactions.

Figure 2

Isospin dependence of the maximal ERCS from the cold fusion reactions (a) ${}^X\text{Fe}$ + ${}^{208}\mathrm{Pb}$, (b) ${}^X\text{Fe}$ + ${}^{209}\mathrm{Bi}$, (c) ${}^X\text{Ni}$ + ${}^{208}\mathrm{Pb}$, (d) ${}^X\text{Ni}$ + ${}^{209}\mathrm{Bi}$, and (e) ${}^X\text{Zn}$ + ${}^{208}\mathrm{Pb}$, as functions of the mass number $A$ of the residue compound nucleus, for the $1n$ emission channels.