Study on Stray Radiation Suppression of Vacuum Cryogenic Infrared Radiation Measurement System

In this paper, the method of stray radiation suppression in infrared radiation measurement in vacuum and cryogenic environment is introduced. The stray radiation suppression structure of a vacuum cryogenic infrared radiation measurement system is designed, and the stray radiation received by the detector of the system is simulated and analyzed. The vacuum cryogenic infrared radiation measurement system is mainly composed of blackbody radiation source, cryogenic optical system, medium wave(3 mu m similar to 5 mu m)/long wave(8 mu m similar to 12 mu m) detector, signal processing system and stray radiation suppression system. First, the hood retaining ring is designed. according to the system design requirements and structure, the cylindrical blocking ring of the cylindrical mask is designed. Secondly, the number of stray lights entering the system with or without the blocking ring is simulated and analyzed. The stray radiation of the key components in the system is analyzed, and the signal-to-clutter ratio of the target radiation to the stray radiation received by the detector at different ambient temperatures is analyzed. The simulation results of stray radiation received by medium-wave and long-wave infrared detectors at different ambient temperatures are given respectively.