345 GHz array receiver for the Heinrich Hertz Telescope

In this paper, we present the design and construction of DesertSTAR, a seven pixel heterodyne receiver for the 345 GHz atmospheric window for operation on the Heinrich Hertz Telescope located at Mt. Graham, Arizona. The seven beams are arranged in a hexagonal close-packed pattern with one beam spacing. The instrument uses fixed tuned split-block, half-height waveguide mixers with Nb SIS junctions. The mixers have an instantaneous bandwidth of 2 GHz, centered on 5 GHz. The cryostat uses a NRAO Joule-Thompson refrigerator to cool the mixers, isolators, amplifiers and optics to 4 K. The computer controlled bias system allows automated bias optimization and monitoring both locally and remotely. The instrument will take full advantage of the good 345 GHz weather at the HHT and dramatically increase scientific throughput. We expect to have first operations with seven pixels in November, 2000.