Relations Between Transition Probabilities, Absorption Coefficient, and Line Strength

7 Relations Between Transition Probabilities, Absorption Coefficient, and Line Strength 

In this section we will summarize important relations between the different quantities discussed so far. 

The absorption coefficient a(co) for a transition between levels i) and k) with population densities Nj and Nk and statistical weights gi, gk is related to the absorption cross section (Ji] (jo) by 

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