Not scientific -- but a search of google images for "alumina
transmission" indicates that you can get pretty much any profile you
want (Include transparent sapphires, of course), and that the actual
profiles vary wildly.
One would thus have to characterize the ceramic actually used, and
then calculate the power (as Goat & Jones suggested) based on a
mixture of transmitting and conducting.
I think that this could be modelled as a radiating cylinder enclosed
by a transmitting/conducting cylinder, but you'd have to know ALL the
parameters to do it. Complicated by the fins, of course.
I'm still inclined to say that the quantitative numbers are suspect.
We really shouldn't have to look at un-annotated photos to figure out
how even the coloring is.
