X-rays are emitted when high velocity electrons in an X-ray tube collide with a metal target. Some high velocity electrons on collision with the metal atoms cause an inner electron of an atom to be ejected, creating a vacancy in the inner shell of that atom. Outer electrons fill up this vacancy and emit an X-ray photon (corresponding to characteristic X-rays).
Most explanations I have found say so much. My question is, is it certain that the inner electron is ejected completely out of the atom, and not to another vacant, higher energy level? In calculation of characteristic K$_\alpha$ ray frequencies for instance, I have always taken the difference of the energies of an ionised atom in the two states when an electron is lost from a K shell, and when it is lost from the L shell of that atom. The only difference, of course, in the situation I propose is where the excited electron finally ends up - whether it becomes free of the atom, or makes a transition to a higher energy level. Will the prediction of characteristic X-ray frequencies differ if the electron is assumed to be excited to a higher level - or is the difference too minimal to matter (the energy difference between the K and L shell energy levels for an electron is hardly affected by outer electrons anyway)? And does that electron, in reality, actually become free of the atom, or can it also move to a higher level energy state?