Thanks for all of your help. We ended up going with spun aluminum hemispheres. The radiometers have portals for them to look through with a low loss dieletric foam (closed cell) covering/plugging the holes.
We had test flights in Dec 2001 and just a few weeks ago in June 2002. The foam worked...
I am on the APMIR team at the Naval Research Lab in Washington DC.<br>
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I have the need for at least one pair of hemispheres of 36 to 42 inches in diameter, having a thickness of between 3/16 to 3/8. I had envisioned using aluminum as the material, but am open to other materials. <br>
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I...
