Multicluster accompanied fission

Abstract

In this process a heavy or superheavy nucleus spontaneously breaks into four, five, or six nuclei of which two are asymmetric or symmetric heavy fragments and the others are light clusters, e.g., $\ensuremath{\alpha}$ particles, ${}^{10}\mathrm{Be},{ }^{14}\mathrm{C},{ }^{20}\mathrm{O},$ or combinations of them. Examples are presented for the two-, three-, and four-cluster accompanied cold fission of ${}^{252}\mathrm{Cf}$ and ${}^{262}\mathrm{Rf},$ in which the emitted clusters are $2\ensuremath{\alpha},$ $\ensuremath{\alpha}{+}^{6}\mathrm{He},$ $\ensuremath{\alpha}{+}^{10}\mathrm{Be},$ $\ensuremath{\alpha}{+}^{14}\mathrm{C},$ $3\ensuremath{\alpha},$ $\ensuremath{\alpha}{+}^{6}\mathrm{He}{+}^{10}\mathrm{Be},$ $2\ensuremath{\alpha}{+}^{6}\mathrm{He},$ $2\ensuremath{\alpha}{+}^{8}\mathrm{Be},$ $2\ensuremath{\alpha}{+}^{14}\mathrm{C},$ and $4\ensuremath{\alpha}.$ A comparison is made with the recently observed ${}^{252}\mathrm{Cf}$ cold binary fission, and cold ternary (accompanied by $\ensuremath{\alpha}$ particle or by ${}^{10}\mathrm{Be}$ cluster). The strong shell effect corresponding to the doubly magic heavy fragment ${}^{132}\mathrm{Sn}$ is emphasized. The most favorable mechanism of such a decay mode should be the emission from an elongated neck formed between the two heavy fragments.