Universal scaling law forK-vacancy production in heavy ion-atom single collisions

Abstract

New $K$-shell ionization cross sections are presented for symmetric and near-symmetric heavy-ion-atom single collisions ${Z}_{1}\ensuremath{\rightarrow}{Z}_{2}$, with $16\ensuremath{\le}({Z}_{1}, {Z}_{2})\ensuremath{\le}54$ and $0.4\ensuremath{\le}{E}_{1}\ensuremath{\le}225$ MeV. For $0.6\ensuremath{\lesssim}Q\ensuremath{\lesssim}1$, where $Q=\frac{{Z}_{L}}{{Z}_{H}}$, all data are unified by a simple scaling law, parametrized through the united-atom $2{p}_{\frac{1}{2}}$ binding energy. Existing models for $K$-vacancy production are shown to be inadequate.