ISINN32: Saw-Tooth Mass Dependence of Fission-Fragment Angular Momenta in the Spontaneous Fission of \(^{252}\)Cf

Abstract The mass dependence of fission-fragment angular momenta is investigated for the spontaneous fission of $^{252}\mathrm{Cf}$ within the dinuclear-system (DNS) model. After penetration of the fission barrier, the system evolves through an ensemble of touching fragment configurations in mass, charge, and deformation space, while the collective angular motion is treated quantum mechanically. The calculated fragment angular momenta reproduce well the experimentally observed mass-dependent trends and the pronounced minimum near $A\simeq132$. The saw-tooth structure persists after averaging over all charge partitions contributing to a given fragment mass, demonstrating that it is a robust property of the scission ensemble rather than a consequence of the particular isotope sequence selected experimentally. The results emphasize the central role of shell-dependent fragment deformation in the generation of fission-fragment angular momentum. The same scission ensemble also reproduces the observed anticorrelation between the total kinetic energy (TKE) and the total prompt-neutron multiplicity, further supporting the calculated scission configurations.