The prototype optics consist in a set of custom made lenses as close as possible to the final design lenses (at the time of the lenses order, December 2016), differing only for the absence of the AR coating, not performed for schedule and cost issues.
The prototypemechanical structure is equivalent to the TOU final structure, in terms of thermal behavior (to mimic the relative movements of the lenses when going from “warm” to “cold” conditions)and interfaces to the FPA.
The TOU prototype main goals are:
- Testing the TOU integration and alignment procedures designed by INAF, to identify strength and criticality’s in view of the industrial AIV processes
- Testing the warm/cold TOU system performance over the whole field of view.