Examples of X-ray fluorescence spectra

Spin-orbit coupling decreases as the orbital angular momentum quantum number f increases. This is illustrated by the fact that the Pj and P3 transitions, split by only about 70 eV, are not resolved. 

For elements with lower nuclear charges than tin, the aj-a2 splitting is smaller because of the reduced spin-orbit coupling. For example for calcium, with Z = 20, the splitting is only about 3 eV and usually unresolved. 

There are two further effects on K emission XRF which become more important with decreasing nuclear charge. One is the appearance of weak satellite transitions, to lower wavelengths of the main transitions, occurring in the small proportion of doubly ionized atoms which may be produced by the initial X-ray bombardment. The other is a tendency for some transitions to be broadened into bands, rather than the usual sharp lines, due to the 

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