search

tschoonj / xraylib

A library for X-ray matter interaction cross sections for X-ray fluorescence applications
https://github.com/tschoonj/xraylib/wiki
Other
120 stars 54 forks source link

Question about KL1_LINE #19

Closed yandaikang closed 9 years ago

yandaikang commented 9 years ago

Hello,

I have a question about KL1_LINE: according to transition selection rule, K-->L1, K-->M1, K-->N1 transitions are forbidden, which however are listed in the "X-ray fluorescence line macros". Also the corresponding energies could be given calling the "LineEnergy" function.

I am thinking if this fluorescence database is directly deviated from the absorption energies, by subtracting different energy levels, without considering whether the transition would really happen...?

Thanks!

tschoonj commented 9 years ago

Hi

You are indeed correct: the _LINE macros correspond to all transitions based on the differences of two edge energies. Although cases like K → L1 are typically called forbidden transitions that doesn't mean that they are really impossible, just that they have a very, very low probability. Try for example RadRate(82, L1M1_LINE) and you will not get zero...