Orateur
Description
Yoshihiro Aritomo$^{1}$, Kosuke Kawa$^{1}$i, Kohta Nakajima$^{1}$, Shinya Takagi$^{2}$, Akira Yumikura$^{1}$
$^{1}$ Graduate School of Science and Engineering, Kindai University, Osaka, 577-8502, Japan
$^{2}$ RIKEN Center for Computational Science, Kobe, 650-0047, Japan
Currently, investigations into the synthesis of superheavy elements are pursued with two principal objectives. The first is the extension of the periodic table toward higher atomic numbers, and the second is the experimental approach to the predicted “island of stability,” corresponding to the next doubly magic nucleus. The periodic table has been extended up to element 118, oganesson (Og) [1], and ongoing experimental efforts are directed toward the synthesis of element 119 as the next undiscovered element. Recently, a successful synthesis experiment, $^{54}\mathrm{Cr} + ^{238}\mathrm{U} \rightarrow ^{292-x}\mathrm{Lv} $ has been reported employing a chromium beam [2].
In this work, we discuss methods employing secondary beams of neutron-rich nuclei. In such approaches, a key concern is whether measurable evaporation-residue cross sections can be achieved, given the inherently low beam intensities.
However, theoretical analyses indicate that relatively large evaporation-residue cross sections may be achieved, owing to both the fusion mechanism associated with neutron-rich beams and the decay properties of the resulting nuclei. These advantages are expected to sufficiently compensate for the limitation imposed by the low beam intensity. In this study, we elucidate and examine these mechanisms and discuss the feasibility of synthesizing new elements using secondary beams.
Dynamical and statistical models are employed to describe the formation of compound nuclei in the neutron-rich region, their subsequent decay processes, and to evaluate the corresponding evaporation-residue cross sections. The production of neutron-rich compound nuclei, together with future experimental prospects, including the advantages associated with enhanced survival probabilities, is discussed [3]. Furthermore, the potential for the synthesis of new elements through the exploitation of the “dynamical effects of shell structure” is examined.
References
[1] Yu. Ts. Oganessian, et al.,“Results from the first 249Cf+48Ca experiment”. JINR Communication (JINR, Dubna) (2002)
[2] Yu. Ys. Oganessian, et al., Phys. Rev. C 112, 014603 (2025).
[3] Y. Aritomo, Phys. Rev. C 75, 024602 (2007).