Speaker
Description
The $^{48}$Ca + $^{208}$Pb reaction is distinguished by its unique combination of advantages in heavy-ion fusion studies, as both interacting partners are doubly magic nuclei. Moreover, the $^{208}$Pb target provides a cold fusion pathway, while the neutron-rich $^{48}$Ca projectile provides a significant neutron excess, favoring the formation of neutron-rich compound nuclei.
The survival probability of a superheavy nucleus in heavy-ion fusion reactions is directly related to its fission barrier magnitude. In transuranium elements, the fission barrier is predominantly due to shell effects, while the liquid-drop contribution is minimal [1]. The present work aims to investigate the characteristics of the mass-total kinetic energy (M-TKE) distribution of binary reaction products from the $^{48}$Ca + $^{208}$Pb reaction, to conduct a detailed examination of this reaction system, and to obtain an experimental estimate of the fission barriers for $^{256}$No nucleus.
The experiments were carried out using the U400 cyclotron at the Flerov Laboratory of Nuclear Reactions, Dubna, Russia. Beams of $^{48}$Ca with energies of 208–281 MeV bombarded isotopically enriched thin targets of $^{208}$Pb to populate the $^{256}$No$^*$ compound nucleus at different excitation energies. The binary reaction products were detected in coincidence using the double-arm time-of flight (ToF-ToF) spectrometer CORSET [2]. A detailed analysis of the mass–total kinetic energy distributions of fission-like fragments from the $^{48}$Ca + $^{208}$Pb reaction has been performed, and fission cross sections were obtained. From a combined analysis of the fission cross section and evaporation residue cross sections for 1–3 neutron channels [3–5], the fission barrier of the $^{256}$No nucleus has been estimated.
References
[1] M. G. Itkis et al., Phys. Rev. C 65, 044602 (2002).
[2] E. M. Kozulin et al., Instrum. Exp. Tech. 51, 44 (2008).
[3] Yu. Ts. Oganessian et al., Phys. Rev. C 64,054606 (2001).
[4] A. V. Belozerov et al., Eur. Phys. J A 16, 447 (2003).
[5] H. W. G ̈aggeler et al., Nucl. Phys. A 502, 561 (1989).
