The Key Technology Research Of Cryogenic Optical Integration System

It is one of the most effective measures to reduce the background thermal noise and improve the infrared detection sensitivity by using cryogenic integrated technology to cool the infrared optical components.Based on the space payload cryogenic optical system and the airborne platform cold optical system,some key technologies research work of cryogenic system integration are carried out.The feasibility and accuracy of cryogenic system integrated thermal design and thermal analysis are verified by special and system level tests and compared with the measured data on orbit.In order to realize the demand of 200 K working temperature of space infrared load cryogenic optical system,as well as the requirements of long life and low vibration,the radiant cooler is selected as the cold source,cryogenic channel heat pipe and flexible thermal link are used as the heat transmission unit to solve the requirement of the seperation layout of radiant cooler and cryogenic optical components and the demand for flexible heat transmission.the cooling and heat transmission scheme of ?radiantor cooler,ethane grooved cryogenic heat pipe and flexible thermal link? integrated thermal design and thermal analysis are carried out.Based on the working environment and working characteristics of the cryogenic optical system on the airborne platform,to solve the problem of the cooling of cryogenic optical components and flexible heat transmission between cold source and the cryogenic optical components with the working temperature of 100 K.the cooling and heat transmission scheme of ? cryogenic cold box,flexible thermal link? and the related work of cryogenic integrated thermal design and thermal analysis are also carried out.The thermal sensitivity analysis was carried out with the space payload cryogenic optical system as an example.The temperature field distribution of the cryogenic optical system under different working conditions and the sensitivity of the input thermal parameters were obtained,that can provide basis for the optimization design of the optical machine structure.By seting up the thermal simulation model,according to the thermal boundry conditions,the distribution of the temperature field and the demand for the cooling capacity of cyogenic optical system working on airborne platform at different ambient temperatures are analyzed and calculated,which provides the basis for the selection of the cryogenic refrigeration system and the design of the heat transmission unit.In order to study the cooling characteristics of the airborne platform cryogenic optical components,the theoretical analysis of the cooling time prediction of the cold optical components is carried out,and the corresponding formulas are derived.In order to analyze the influence of the change of the optical mirror position on the optical properties due to the thermal deformation at low temperature,the airborne platform cryogenic optical system with lower working temperature was used as the research object,and the thermal-structure-optical integrated analysis and optimization design of optical and structure were carried out.The analysis results show that the optical transfer function(MTF)of the cryogenic optical system working at 100 K low temperature is close to the diffraction limit.The validity and rationality of the cryogenic integrated thermal design is proved theoretically.In order to verify the effectiveness of cryogenic integrated design and the accuracy of thermal analysis,some special experiments were carried out,which include cooling capacity of radiantor cooler,the heat transfer performance test of ethane grooved cryogenic heat pipe under different working temperature and different heat load conditions is carried out.Through these two special tests,it is proved that the cooling capacity of the radiantor cooler and the heat transmission performance of the cryogenic heat pipe are consistent with the design target.After the integrated of atmospheric vetical detector,the cooling and heat transmission performance,temperature distribution and precision temperature control effect test of the 200 K cryogenic optical integrated system are carried out.The influence factors of temperature distribution of the cryogenic cryogenic integrated system are analyzed,which can be as data support for the orbit performance prediction.The characteristics of temperature cooling and temperature distribution of the cryogenic optical integrated system are analyzed by carrying out the performance test of the cryogenic optical system working on airborne platform,which provides the parameter basis for the analysis of the temperature characteristics of the airborne flight test.