Ternary fission of superheavy elements

Ternary fission of superheavy nuclei is studied within the three-cluster model potential energy surfaces (PESs). Due to shell effects, the stability of superheavy nuclei has been predicted to be associated with $Z=114$, 120, and 126 for protons and $N=184$ for neutrons. Taking some representative nuclei we have extended the ternary fission studies to superheavy nuclei. We adopted two minimization procedures to minimize the potential and considered different arrangements of the fragments. The PES from one-dimensional minimization reveals a strong cluster region favoring various ternary breakups for an arrangement in which the lightest fragment is kept at the center. The PES obtained from two-dimensional minimization reveals strong preference of ternary fragmentation in the true ternary fission region. Though the dominant decay mode of superheavy nuclei is $\alpha$ decay, the $\alpha$-accompanied ternary breakup is found to be a nonfavorable one. Further, the prominent ternary combinations are found to be associated with the neutron magic number.

Figure 1

Ternary fragmentation potential of ${}_{114}{}^{298}\text{X}$ as a function of fragment mass number $A_2$ for three different arrangements.

Figure 2

Same as Fig. 1, but for ${}_{120}{}^{304}\text{X}$.

Figure 3

Same as Fig. 1, but for the parent nucleus ${}_{126}{}^{310}\text{X}$.

Figure 4

Potential energy surfaces of proton-minimized ternary fission fragments at touching configuration for the arrangements (a) Case I (upper) and (b) Case II (lower) in the ternary fission of ${}_{114}{}^{298}\text{X}$.

Figure 5

Potential energy surfaces of proton-minimized ternary fission fragments at touching configuration for the arrangement Case I in the fission of (a) ${}_{120}{}^{304}\text{X}$ (upper) and (b) ${}_{126}{}^{310}\text{X}$ (lower).

Figure 6

Potential energy surfaces of neutron-minimized ternary fission fragments at touching configuration for the arrangements (a) Case I (upper) and (b) Case II (lower) in the ternary fission of ${}_{114}{}^{298}\text{X}$.

Figure 7

Potential energy surfaces of neutron-minimized ternary fission fragments at touching configuration for the arrangement Case I in the fission of (a) ${}_{120}{}^{304}\text{X}$ (upper) and (b) ${}_{126}{}^{310}\text{X}$ (lower).

Figure 8

Potential energy surfaces of ternary fission fragments at touching configuration for the triangular geometry in the fission of ${}_{114}{}^{298}\text{X}$ corresponding to (a) proton minimization and (b) neutron minimization.