Cold Box and Detectors (FPCA)

© AIRBUS D&S

The cold box will be cooled by an active machine at a temperature of around 75°K.
It comprises:

• Cold optics that defines the field and the pupil. These optics employ pupil imaging (enabled by the field compensation) to make the instrument less sensitive to imperfections in the spatial response of the detectors. The cold optics also enable the signal to be seperated into 4 different spectral bands.

• Four sealed detection boxes closed by lenses with an anti-reflective coating. The B1 band is based on "multistrip" photoconductor detectors (authorized by the quality of the pupil imaging). For the B2, B3 and B4 bands the detectors come from classical photovoltaic techniques. The use of mono-element detectors working as a flux sensor (radiometer) is possible thanks to the field compensation. They are equally perfectly adapted to path difference sampling.