The JWST MIRI Double-Prism, Design and Science Drivers

We present how it is achieved to mount a double prism in the filter wheel of MIRIM - the imager of JWST’s Mid
Infrared Instrument. In order to cope with the extreme conditions of the prisms’ surroundings, the low resolution
double prism assembly (LRSDPA) design makes high demands on manufacturing accuracy. The design and the
manufacturing of the mechanical parts are presented here, while ’Manufacturing and verification of ZnS and Ge
prisms for the JWST MIRI imager’ are described in a second paper [1]. We also give insights on the astronomical
possibilities of a sensitive MIR spectrometer. Low resolution prism spectroscopy in the wavelength range from
5-10 microns will allow to spectroscopically determine redshifts of objects close to/at the re-ionization phase of
the universe.