Design Of Cryogenic Infrared Target Simulation Optical System And Study Of Mirror Cooling Technology

Cryogenic Infrared Target Simulation System is mainly used for testing key indicators of infrared guidance system sensitivity through simulating targets of static or dynamic and vacuum cold background. As its core, cryogenic infrared target simulation optical system is the key to the development of the system, since the system operates at a low temperature, refrigerating of the mirror of the optical system has to be considered.Because the mirror surface temperature uniformity will directly affect the performance of optical systems.Based on the theory of cryogenic optics, heat transfer,finite element analysis and so on,this article desighed cryogenic infrared target simulation optical system and studied refrigerating technology of mirror.First, according to the application background of Cryogenic Infrared Target Simulation System,designed the optical system. In the design process, designed the overall layout of the Cryogenic Infrared Target Simulation System; By contrasting advantages and disadvantages of reflective and transmissive optical system,the form of optical system structure is determined as off-axis three-mirror optical system.In the process of the optical system designing, first solved initial system configuration parameters of coaxial three-mirror optical system and the off-axis quantity of aperture stop,then optimized the configuration parameters and the off-axis quantity,and completed the design of cryogenic infrared target simulation optical system.Secondly, studied mirror refrigeration technology.Combining several factors of affecting the mirror material selection, determined the reflector material as Al6061-T6.Desighed reflector structure on the basis of primary mirror structure parameters.In the process of desighing reflector structure, determined the formal structure of the mirror is concave shaped structure,the ratio of mirror diameter thickness and lightweight structural parameters,then finished the modeling of the mirror structure by mechanical design software. Studied mirrors refrigeration technology by cold beams,this method did not only improve refrigeration efficiency,but also made the mirror surface temperature uniformity better. Combining the actual working conditions of the mirror,improved mirrors refrigeration technology and proposed a new method of maintaining mirror refrigerating. By integrated opto-mechanical thermal analysis, analyzed and validated deformation of the mirror caused by refrigerated temperature uniformity, met the requirements of optical system.