Ternary-fission mass distribution ofCf252: A level-density approach

Abstract

We study here the ternary-fission mass distribution of the 252 Cf nucleus for a fixed third fragment 48 Ca using the level-density approach within the framework of statistical theory. For the evaluation of nuclear level densities, the single-particle energies of the finite-range droplet model are used. Our results for temperatures T = 1 and 2 MeV reproduce qualitatively the experimental expectation of ternary fragmentation of 132 Sn + 72 Ni + 48 Ca. In addition, different possible ternary-fission modes are highlighted.

Relative mass distributions of neutron-rich thermally fissile nuclei within a statistical model

“…The possible binary fragments of the considered nucleus is obtained by equating the charge to mass ratio of the parent nucleus to the fission fragments as [17]:…”

Ternary Fission Mass Distributions of Superheavy Nuclei Within a Statistical Model

“…Theoretically, Manimaran and Balasubramaniam found that the fragments 34,36,38 Si, 46,48 Ar and 48,50 Ca associated fragmentations are the most favoured for the ternary fission of 252 Cf within the three-cluster model [30]. In addition, the combination Sn + Ni + Ca is the most favourable from the statistical studies [34] and also from the three-centre shell model potential calculations [48]. So, from the experimental and theoretical studies, the neutron-rich Ni or/and Ca isotopes associated fragmentations are the most preferred ternary breakup.…”

“…In our earlier fission studies [34,36], we have considered the arbitrary temperatures T = 1 and 2 MeV for all the fragmentations. This arbitrary temperature consideration is valid only for a particular fragmentation.…”

“…In addition, the relative cross-section of ternary to binary spontaneous fission is much higher in SHN than that in the actinide region. Further, the calculated ternary fragmentation of 298 Fl is always accompanied with the closed-shell fragments such as 139 I + 20 O + 139 I, 132 Sn + 34 Si + 132 Sn because many nucleons will be outside the closed shell (Z = 50, N = 82) in the nascent binary fragmentation of SHN. Hence, there exists a possibility of the third fragment with proton or neutron magic number.…”

“…Rajasekaran and Devanathan [33] applied the level density approach to study the binary mass distributions of heavy nuclei 236 U, 258 Fm and 240 Pu. This approach was further extended by Balasubramaniam et al [34] to study the ternary mass distributions of 252 Cf nucleus for a fixed third fragment 48 Ca. Using the single-particle energies of the finite range droplet model (FRDM), they have reported the double closure fragment combination Sn + Ni + Ca as the most favoured ternary fragmentation at a higher temperature (T = 2 MeV).…”