Inner-shell ionization cross sections of atoms by positron impact

The relativistic binary-encounter-Bethe model with Wannier-type threshold law is employed to obtain the inner-shell ionization cross sections of multi-electron atoms (Ni, Cu, Y, Ag, Au, Yb, Ta, and Pb) for positron impact energies from the thresholds up to $10^{5}$ keV. Good agreement between the present calculations and experimental data is obtained. The constant in the acceleration term derived from the Wannier law is determined to be $0.2$ and $0.5$ for the K- and L-shells, respectively.