K, L, M electron transitions, x-ray emission lines, conflicting information

[ApeXaviour]

So the basic understanding I have of electron transitions for EDX, XES and other x-ray fluorescence techniques is that a transition from:
L to K shell is named K\alpha
M to K shell is K\beta
N to K shell is K\gamma
M to L shell is K\alpha
etc.

Grand, easy... google leads me to multiple diagrams explaining it like this. But now I have a feeling that's a bit woolly and the real story is more convoluted. The http://xdb.lbl.gov/Section1/Sec_1-2.html" which shows L\beta _{2} being an N to L transition and K\beta _{2} being an N to K transition...

Can anyone explain to me why this is? Is there a physical logic to it or is it just from historical labeling of lines observed?

Also the last number, say L\beta _{2}, what does the 2 refer to? Is it the intensity of the line? The energy position?

Cheers

 

[JeffKoch]

http://en.wikipedia.org/wiki/K-alpha

It's confusing historical notation but people continue to use it anyway. I think in practice the 1, 2, etc. refers to the wavelength ordering of distinct lines, which I believe corresponds to different delta-J values but I won't swear that this is always the case.