L-Shell Ionization during the Alpha Decay of Superheavy Nuclei from 117294Ts Tennessine Decay Chain and the Alpha Decay of the Polonium Isotope 84210Po

Abstract

The probabilities for L-shell ionization following the alpha decay of ₁₁₇²⁹⁴Ts, ₁₁₃²⁸⁶Nh, ₁₀₉²⁷⁸Mt, and ₁₀₅²⁷⁰Db superheavy nuclei from the decay chain of tennessine, which was synthesized at the Joint Institute for Nuclear Research (JINR Dubna), and the alpha decay of the isotope ₈₄²¹⁰Po are calculated and analyzed. The respective calculations rely on a quantum-mechanical model that takes into account alpha-particle tunneling through the Coulomb barrier of an atom. The relativistic electron wave functions obtained by the Dirac-Fock method were employed. The probabilities for L-shell ionization that were calculated here for the isotope ₈₄²¹⁰Po are in better agreement with experimental data than the results of earlier calculations. In contrast to what we have for K-shell ionization, where monopole transitions make a dominant contribution to the ionization probability, a significant contribution to the probability for L-shell ionization also comes from dipole and quadrupole transitions. The results of the present study will be of use in interpreting superheavy-element spectra obtained by methods of combined alpha, gamma, and electron-conversion spectroscopy.