The Design of Public Aerating System

Abstract

Microwave receiver system is signal receiving equipment in radio astronomical observation. Through refrigeration, we can greatly reduce the noise temperature of receiver, but the dewar has more than 200 K temperature difference between inside and outside, and the vapor will freeze on the surface of vacuum window to effect observation. The aerating system is a pneumatic control system, it supplies dry air and exhausts old for dry air cavity of receiver. Three cryogenic receivers of Nanshan 26 m radio telescope were equipped with aerating systems, but they were independent each other. The public aerating system could not only realize to supply dry air for three cavities, but also had a simpler structure with only one inflator. Compared with the test results of original systems, the public aerating system could make the pressure of each cavity more stable, and keep dry for each vacuum window of cryogenic receivers very well.