K-shell ionization duringαdecay

Quantum-mechanical calculations of the probability of $K$-shell ionization in the $\alpha$ decay of Po and in $\alpha +\mathrm{Pb}$ collisions are made. The initial and final electronic wave functions are approximated by Dirac hydrogenic wave functions centered on the Pb nucleus. Also, we include the contribution from the part of the trajectory where the $\alpha$ particle tunnels through the Coulomb barrier. The contribution from tunneling is small except at small $\alpha$-particle velocities.