Far infrared astronomy

The research to develop a spectrometer to be used with a ground based telescope is described. Two liquid helium cooled infrared spectrometers were designed and built. The first, has a Cassegrain optical system and a variable focal length between 51.4 cm and 92.6 cm. It is capable of a resolution of 500. The second, has a focal length of 19.1 cm and has a resolution of 100. Both spectrometers have been operated at 10-30 microns. Sample spectra are included.