Focal Plane Instruments (FPI) of the IRTS

Japanese / English
There were 4 instruments at the focus of the IRTS telesocpe.

FPI side view FPI bottom view

Focal Plane Instruments of the IRTS

NIRS (Near Infrared Spectrometer)

The NIRS is a grating spectrometer with two 12 element InSb linear arrays. The wavelength coverage ranges from1.4 micron to 4.0 micron with a spectral resolution of 0.12 micron. The field of view is 8 arcmin X 8 arcmin.

MIRS (Mid Infrared Spectrometer)

The MIRS is also a grating spectrometer with 32 Si:Bi photoconductors. The wavelength coverage ranges from 4.5 micron to 11.7 micron, with a spectral resolution of 0.23 to 0.36 micron. The field of view is 8 arcmin X 8 arcmin.

FILM (Far-Infrared Line Mapper) (in Japanese)

The FILM is a grating spectrometer designed to simultaneously measure [CII] 158 micron line and [OI] 63 micron line intensities and cotinuum emission near the [CII] line with spatial resolution of 13 arcmin X 8 arcmin. The detectors are unstressed and stressed Ge:Ga photoconductors.

FIRP (Far-Infrared Photometer)

The FIRP provides absolute photometry in four bands centered at 150, 250, 400, and 700 micron with spectral resolution of 3 and spatial resolution 0.5 degree. High sensitivity is achieved by using bolometric detectors operated at 300 mK in an AC bridge circuit . The closed-cycle 3He refrigerator were recycled three times in orbit.
The IRTS was designed for diffuse IR radiation.

[Fig] IRTS sensitivity

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