The HIRMES Spectrometer: Science and Technical Details

The HIgh Resolution Mid-infrared Spectrometer - HIRMES is the 3rd generation instrument that will fly on SOFIA in early 2020. HIRMES primary science is to investigate protoplanetary disk physics with a focus on the evolution of distribution of oxygen, water ice, water vapor and molecular hydrogen during planet formation. Science is achieved through background limited detection of spectral lines at resolving powers (RP) of 10^5 or velocity resolution of 3 km/s. The high velocity resolution enables us to use Kepler's law to locate the radial distributions of the emitting species. HIRMES addresses the spectral range from 25 um to 122 um, and in addition to our Hi-Res mode has a Mid-Res mode (RP ~ 10,000), a Low-Res imaging spectroscopy mode (RP ~ 2000) and a long-slit grating spectrometer mode (RP ~ 600). The Hi-Res, Mid-Res, and Low-Res modes are achieved through a series of 8 fully scanning cryogenic Fabry-Perot interferometers (FPI). I intend to give a brief introduction on HIRMES science, and to then focus on some of the more interesting technical details of the instrument including the mechanics and operation of the FPI series and sensitivity calculations.