Balloon-based measurements of the cosmic background radiation. [with Far IR spectrometer

We have developed and flown a balloon-borne liquid-heliumcooled spectrometer to measure the cosmic background radiation in the 3 -18-cm/sup -1/ region. It features a cooled horn antenna, a polarizing Michelson interferometer, and a germanium bolometer. These design features and the performance of the instrument are discussed.