The very strong Coster-Kronig transition 1s2s [right arrow] 1s2p3l, which depopulates the 2s spectator state very fast, further reduces any possible 2s spectator contributions to the spectrum [13,67].
This is not surprising in view of the fast depopulation of the 3s vacancies by Coster-Kronig transitions. Similarly, no indication of contributions from the 3p spectator transitions were found for K[beta], though a very small contribution, ~0.5% of the total intensity, to the K[alpha] spectrum may be possible.
The additional outer vacancies may result from Coster-Kronig transitions or shake-off mechanisms.
The transition rate of non-radiative Coster-Kronig transitions [f.sub.ij], where i and j are two subshells within the same energy level, is not permitted for all elements.