Domenic and Bob test fit Big Ben and the G10 collar into the cold bulkhead/optical bench, prior to inserting epoxy.
Big Ben and cold bench awaiting epoxy
Configuration before epoxying. Big Ben inverted on instrument cart.
Cold Bulkhead awaiting epoxy for G10 collar. Level is critical, so epoxy did not run out of the groove.
Domenic mixing epoxy
Using overhead crane to lower Big Ben into epoxy filled groove in cold bulkhead.
Epoxy bead is visible between the G10 collar (green) and the cold bulkhead (aluminum)
Side view of G10 collar that connects the warm to cold bulkheads. The collar wall thickness is about 1/4", permitting only about 9 Watts of heat to flow from the warm to cold zones in Mimir.
The LN2 ring fill and vent corregated tubes are almost three feet long, to reduce thermal conduction from the warm bulkhead to the cold interior of Mimir.
Domenic inspecting final epoxying of warm bulkhead to cold bulkhead. These two epoxy joints must support the full interior weight of the instrument (all optics as well as the filter box and cold bulkhead) without sag. Domenic once boasted that he was sure he could sit on the end of the cold optical bench and the G10 collar would allow less than 0.001" of sag. In the end, we believed him...
Stack of not-quite-finished filter cells, short, medium, and tall.
Similar picture. Just too neat to not capture... If you look closely, you can see the slots on the filter cell lips that engage the pins in the filter cell receptacles in the filter wheels, and the tapped holes in each filter cell to accept a tool for inserting them into their cells. In the end, careful fingers proved better tools than anything else, so the holes were unused.