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James Webb Space Telescope
MIRI Instrument Design

MIRI optics module.
Figure 1: The MIRI optics module.

MIRI will provide imaging and spectroscopy over the 5-28.3 µm wavelength range. Its design consists of two main modules, an imager and a medium resolution spectrograph (MRS).

The MIRI imager will provide broad and narrow-band imaging, phase-mask coronagraphy, Lyot coronagraphy, and prism low-resolution (R ~ 100) slit spectroscopy from 5 to 10 µm. The imaging module will use a single 1024 x 1024 pixels Si:As sensor chip assembly. The imager will be diffraction limited at 7 µm with a pixel scale of ~0.11" and a field of view of 79" x 113".

The medium resolution spectrograph will obtain simultaneous spectral and spatial data on a relatively compact region of sky. Its design uses four integral field units, implemented as four simultaneous fields of view, ranging from 3.7" x 3.7" to 7.7" x 7.7" with increasing wavelength, with pixel sizes ranging from 0.2" to 0.65". The spectroscopy has a resolution of R~3000 over the 5-27 µm wavelength range. The spectrograph uses two 1024 x 1024 pixels Si:As sensor chip assemblies.

MIRI CAD rendering
Figure 2: The MIRI CAD rendering.

MIRI will be developed by NASA and a consortium of European partners sponsored by the European Space Agency (ESA). Each Agency will contribute about half of the required resources. The science team overseeing the construction of MIRI is led by Dr. George Rieke, University of Arizona. Dr. Gillian Wright, UK Astronomy Technology Centre, is the European PI. NASA has selected the Jet Propulsion Lab (JPL) in Pasadena, California as the lead center for implementing the MIRI. Mike Ressler (JPL) is the Project Scientist.