SPICA Mid-infrared Instrument

The SMI mid-IR spectrometer/camera covers the wavelength range from 12 to 36 µm with three separate channels: the low-resolution spectroscopy function LR, R=50-120, for the 17-36 µm range, the mid-resolution spectroscopy function MRS, R=1300-2300, for 18-36 μm, and the high-resolution spectroscopy function HR, R = 28000, in the 12-18 μm range. The SMI is composed of two main optics chains, one for LR and one for the MR/HR combination, each with their appropriate fore optics and rear optics. There are no moving parts except a shutter in the LR chain and a beam steering mirror in the MR/HR chains. The SMI fact sheet shows the full specifications for the baseline SMI with explanatory note.

SMI/LR: large area low resolution surveyor

SMI/MR: medium resolution mapper

  • 18 – 36 μm, R = 1200 – 2300
  • 1 slit (1’ long) echelle grating – 1K2 Si:Sb
  • Spectral mapping of galaxies

SMI/HR: high resolution spectrometer

  • 12 – 18 μm, R = 28,000
  • 1 slit (4″ long) echelle immersion grating – 1K2 Si:Sb
  • Molecular physics/kinematics