Theoretical study on the production of neutron-rich transuranium nuclei with radioactive beams in multinucleon transfer reactions

The production of neutron-rich transuranium nuclei with $Z=93–98$ in multinucleon transfer reactions induced by radioactive beams ${}^{92}\mathrm{Kr}, {}^{132}\mathrm{Sn}$, and ${}^{144}\mathrm{Xe}$ with actinide target ${}^{238}\mathrm{U}$ is investigated within the dinuclear system model with decay code gemini$++$. The isotopic distributions for reactions ${}^{136}\mathrm{Xe}+{}^{248}\mathrm{Cm}$ and ${}^{136}\mathrm{Xe}+{}^{249}\mathrm{Cf}$ are calculated and compared with the available experimental data. Theoretical calculations can reproduce the experimental results well. Both the $N/Z$ ratio equilibration mechanism and driving potential dominate the transfer process of nucleons. Reaction ${}^{132}\mathrm{Sn}+{}^{238}\mathrm{U}$ is an optimal projectile-target combination to obtain large production cross sections of neutron-rich isotopes with $Z=93–98$. The corresponding optimal incident energy is also explored. The production cross sections of 41 unknown neutron-rich transuranium isotopes with cross sections greater than 1 nb are predicted. The reaction ${}^{132}\mathrm{Sn}+{}^{238}\mathrm{U}$ at $E_{\mathrm{c}.\mathrm{m}.}=521.3$ MeV shows huge advantages in producing neutron-rich transuranium nuclei with $Z=93–98$.

Figure 1

The final isotopic production cross sections distributions of Pu, Am, Cm, Bk, Cf, and Es in MNT reactions ${}^{136}\mathrm{Xe}+{}^{248}\mathrm{Cm}$ ($E_{\mathrm{c}.\mathrm{m}.}=533$ MeV) and ${}^{136}\mathrm{Xe}+{}^{249}\mathrm{Cf}$ ($E_{\mathrm{c}.\mathrm{m}.}=526$ MeV). The black solid lines and red dashed lines denote the calculation results of ${}^{136}\mathrm{Xe}+{}^{248}\mathrm{Cm}$ and ${}^{136}\mathrm{Xe}+{}^{249}\mathrm{Cf}$, respectively. The experimental data taken from Refs. [24, 25] are marked by black solid squares and red solid circles, respectively.

Figure 2

The final isotopic production cross section distributions of Np, Pu, Am, Cm, Bk, and Cf in MNT reactions ${}^{92}\mathrm{Kr}+{}^{238}\mathrm{U}$ (black solid lines), ${}^{132}\mathrm{Sn}+{}^{238}\mathrm{U}$ (red dashed lines), and ${}^{144}\mathrm{Xe}+{}^{238}\mathrm{U}$ (blue dash-dotted lines) at $E_{\mathrm{c}.\mathrm{m}.}=1.10 V_B$.

Figure 3

The values of the driving potential which need to overcome ($\mathrm{\Delta }U$) during the transfer of nucleons as a function of the number of transferred nucleons in reactions ${}^{92}\mathrm{Kr}+{}^{238}\mathrm{U}, {}^{132}\mathrm{Sn}+{}^{238}\mathrm{U}$, and ${}^{144}\mathrm{Xe}+{}^{238}\mathrm{U}$. (a) and (b) denote the pure neutron stripping channel and pure proton stripping channel, respectively.

Figure 4

The final isotopic production cross section distributions of Np, Pu, Am, Cm, Bk, and Cf in the ${}^{132}\mathrm{Sn}+{}^{238}\mathrm{U}$ reaction at $E_{\mathrm{c}.\mathrm{m}.}=1.10 V_B$, 1.20 $V_B$, and 1.30 $V_B$, respectively. The dashed, solid, and dash-dotted lines indicate different incident energies.

Figure 5

The production cross sections of TLFs with $Z=93–98$ for reaction ${}^{132}\mathrm{Sn}+{}^{238}\mathrm{U}$ at $E_{\mathrm{c}.\mathrm{m}.}=521.3$ MeV. The empty circles denote the unknown neutron-rich nuclei with cross sections greater than 1 nb.