Is there a radiometric term for the quantity (power emitted per unit volume per unit solid angle)?
Since power per solid angle [W/sr] is "Intensity", I suspect you are thinking of 'intensity density'? It has a nice rhythm, at least....
Which volume are you referring to? That of the emitter?
emitter volume. For a gas or plasma.
For a receiving surface external to an emitting object, usually only the power per unit area and/or solid angle are considered as that is what the receiving surface "sees." As such, I'm not sure how the volume of the emitter can be taken into account, especially if there is nonuniform power generated throughout.
How would one include the opacity of the medium, I wonder? The inner regions of a volume of gas would not necessarily have the same effect as the outer regions. Take the example of s Star, for instance. That's an extreme example but worth while thinking about.
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