The new heterodyne receiver system for the ASTE radio telescope: three-cartridge cryostat with two cartridge-type superconducting receivers

Abstract

The ASTE (Atacama Submillimeter Telescope Experiment) is a 10-m submillimeter telescope located near the ALMA (Atacama Large Millimeter/submillimeter Array) site in Chile. Recently, the ASTE heterodyne receiver system has been upgraded with a new cryostat and two sub-mm-wave heterodyne receivers. The cryostat has three receiver ports. Its cooling capacity is improved with new design compared to a previous three-cartridge cryostat. The two new receivers are dual polarization Superconductor-Insulator-Superconductor (SIS) sideband-separating receivers in 345 GHz and 460 GHz bands. The 345 GHz band receiver has 55 GHz bandwidth. The single-sideband noise temperature TSSB measured in the laboratory is between 62 K and 440 K. The 460 GHz band receiver was originally an engineering qualification model of the ALMA Band 8 cartridge. The design of SIS mixer devices has been optimized for full coverage of ALMA Band 8 frequency (385-500 GHz). TSSB of the receiver is between 98 K and 257 K. The receiver system was installed on ASTE in March 2017. We have started to provide it for open-use observations after our CSV (Commissioning and Science Verification) activities.