An 800 GHz NbN phonon-cooled hot-electron bolometer mixer receiver

We describe a heterodyne receiver developed for astronomical applications t o operate in the 350 mu m atmospheric window. The waveguide receiver employ s a superconductive NbN phonon-cooled hot-electron bolometer mixer. The dou ble sideband receiver noise temperature closely follows 1 K GHz(-1) across 780-870 GHz, with the intermediate frequency centered at 1.4 GHz. The conve rsion loss is about 15 dB. The receiver was installed for operation at the University of Arizona/Max Planck Institute for Radio Astronomy Submillimete r Telescope facility. The instrument was successfully used to conduct test observations of a number of celestial sources in a number of astronomically important spectral lines.