QUaD Secondary Support Foam Cone


For on axis polarimeter conventional feedlegs cause problems
In addition wish to keep mirrors warm to prevent snow accumulation

Material Zotefoam PPA30 is legendary in the field for its transparency at these wavelengths
Polypropylene copolymer expanded using dry nitrogen
Used for cryostat windows...

But manufactured only in 6x3' flat sheets
How to make a 9' base diameter cone?