Probability of Double Jumps in X-Ray Spectra

By a suitable perturbation method, two-electron transition probabilities are computed for a number of double jumps, such as $2p$, $4s\to 1s$, $3s$ and $2p$, $3d\to 1s$, $3s$, in Na and Cu atoms. It is found that these probabilities are too small to account for the observed intensities of the x-ray satellites $K{\alpha }_{3,4}$. As a more general argument against the correctness of the double-jump hypothesis for the origin of the short wave-length x-ray satellites it is pointed out that the line structure due to two-electron transitions of the kind considered would consist of a symmetrical grouping of faint lines about the parent line, the stronger components being on the long wave-length side.