Inner-shell ionization during α decay of superheavy isotopes from the tennessine Ts117293 and oganesson Og118294 chains

Abstract

Presented here are calculations of probabilities of the $K$-, $L$-, and $M$-shell ionization during $\ensuremath{\alpha}$ decay of superheavy isotopes $_{117}^{293}\mathrm{Ts}$, $_{115}^{289}\mathrm{Mc}$, and $_{113}^{285}\mathrm{Nh}$ involved in the tennessine decay chain as well as $_{118}^{294}\mathrm{Og}$, $_{116}^{290}\mathrm{Lv}$, and $_{114}^{286}\mathrm{Fl}$ involved in the new oganesson decay chain. The ionization probabilities are of importance for handling data obtained by methods of the combined $\ensuremath{\alpha}$, $\ensuremath{\gamma}$, and conversion-electron spectroscopy used in the superheavy element synthesis analysis. Relativistic calculations are based on the quantum mechanical model. Electron wave functions are determined by the Dirac-Fock method. The $\ensuremath{\alpha}$-particle tunneling through the atomic Coulomb barrier is taken into account. Peculiarities of the $K$-, $L$-, and $M$-shell ionization are considered. Results demonstrate that the effect of tunneling through the Coulomb barrier for the $L$ and $M$ shells is of no significance as distinct from the $K$ shell, where the inclusion of the tunneling leads to a considerable decrease of the ionization probability. The probability of ionization from higher shells is larger than that from inner shells. However, the change from the $K$ shell to $L$ shell is much more significant than the change from the $L$ shell to $M$ shell. It has been found that only monopole and dipole terms of the radiative field $L=0,1$ make a contribution to the $K$- and ${L}_{1}$-shell ionization probabilities while contributions of all multipoles $L\ensuremath{\le}4$ may be important for the ${L}_{2}$, ${L}_{3}$, and particularly for ${M}_{1}\ensuremath{-}{M}_{5}$ subshells.