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James Webb Space Telescope
MIRI Filters

MIRI has an 18 position filter wheel (filter wheel schematic) located in the imager module. There are 10 filters for imaging, 4 filter and diaphragm combinations for the coronagraphy, 1 neutral density filter, 1 ZnS-Ge double prism for the LRS mode, 1 opaque position for darks and 1 for a lens for ground test purposes. The instrument control electronics (ICE) moves the filter wheel when commanded by the MIRI flight software (FSW). The ICE can measure the absolute position of the filter wheel before and/or after movement of the filter wheel. The ICE can move the filter wheel to the next adjacent position in either direction.

The table below lists all the MIRI filters.

λ(μm) Δλ(μm)Comment
F560W 5.6 1.2 Broad Band
F770W 7.7 2.2
F1000W 10 2 Silicate, Broad Band
F1130W 11.3 0.7 PAH, Broad Band
F1280W 12.8 2.4 Broad Band
F1500W 15 3 Broad Band
F1800W 18 3 Silicate, Broad Band
F2100W 21 5 Broad Band
F2550W 25.5 4 Broad Band
F2550WR25.5 4 Redundant Filter, Risk Reduction
FND Neutral Density For Coron. Acquis.
F1065C 10.65 0.53 Phase mask, NH3, silicate
F1140C 11.4 0.57 Phase mask, cont. or PAH
F1550C 15.5 0.78 Phase mask, cont.
F2300C 23 4.6 Focal Plane Mask, Debris Disk
OPAQUE Blackened BlankN/A For Darks