Atomic Processes Accompanying Alpha Decay of Superheavy Nuclei

Processes involving the ionization of atomic shells and x-ray transitions in daughter nuclei and accompanying alpha decay of superheavy isotopes are considered. The probabilities for $N$-shell ionization during the decay of isotopes entering into the tennessine (${}_{117}^{294}$Ts) and oganesson (${}_{118}^{294}$Og) alpha-decay chains are calculated. The Dirac–Fock method is used, and all multipole transitions and alpha-particle tunneling through the atomic Coulomb barrier are taken into account. The results of these calculations are analyzed and are compared with the $K$-, $L$-, and $M$-shell ionization probabilities. The energies of the x-ray $K_{{\alpha }_{1,2}}$ lines are calculated for superheavy elements appearing as products of alpha decay in the ${}_{117}^{294}$Ts and ${}_{118}^{294}$Og chains. The Breit interaction and higher order electrodynamic corrections are taken into account. It is found that the energy of the $K_{{\alpha }_1}$ line of the meitnerium isotope ${}_{109}^{268}$Mt agrees within 0.01 keV with the results of earlier calculations. This indicates that the line observed at the GSI laboratory (Darmstadt) at an energy that is higher than the respective theoretical value by 3.2 keV does not admit an identification with the $K_{{\alpha }_1}$ line of ${}_{109}^{268}$Mt.