Status and Performance of the Balanced Superconductor-insulator-superconductor Receivers for the Leighton Chajnantor Telescope

Abstract In this paper, we report on the current status and performance of the balanced superconductor-insulator-superconductor (SIS) receiver suite developed for the Leighton Chajnantor Telescope (LCT). Currently, Shanghai Normal University (ShNU) together with Caltech and Universidad de Concepción are collaborating on the LCT program, which aims to relocate the Caltech Submillimeter Observatory (CSO) telescope from Mauna Kea, Hawaii to the Chajnantor Plateau in Chile. A suite of balanced SIS receivers exhibiting excellent sensitivity, covering the 180–720 GHz atmospheric windows, will be deployed as first-light instruments to facilitate high-resolution spectral line observations. The 230/460 GHz receiver pair was previously commissioned and operated at the CSO until its closure. In contrast, the 345/650 GHz receiver pairs had not been commissioned or tested prior to this work. Recently, these balanced SIS receivers were assembled and characterized for the first time in the submillimeter laboratory at ShNU. This paper presents a comprehensive overview of the receiver system and discusses the detailed experimental results obtained from these characterization measurements.