红外冷光学用杜瓦静态真空维持及其漏热机理分析

介绍了所研制的红外冷光学真空系统,并对红外冷光学真空杜瓦进行了静态真空维持试验。结果表明,静态真空维持4 h后,未烘烤除气的杜瓦内部真空度由8.6 E-3 Pa回升至12.5 Pa,光学镜组最大温升为17℃;经100℃烘烤除气48 h的杜瓦内部真空度由4.1 E-3 Pa回升至2.5 Pa,光学镜组最大温升为14.9℃;经100℃烘烤除气120 h的杜瓦内部真空度由3.0 E-3 Pa回升至1.5 Pa,光学镜组最大温升为14.7℃。通过分析杜瓦漏热机理,可知杜瓦内部材料出气是导致静态真空维持能力下降、杜瓦漏热增加的根本原因。

Analysis on the static vacuum maintenance and heat leakage mechnism of the dewar used in infrared cold optical system

An infrared cold optical vacuum system was introduced in this paper.The static vacuum maintenance capacity of the dewar used in this infrared cold optical vacuum system was tested.The test results show that after static vacuum is maintained for 4 hours,the internal vacuum of dewar without baking and degassing rises from 8.6 E-3 Pa to 12.5 Pa,the maximum temperature of optical lens group rises to 17℃;the dewar intermal vacuum after 100℃baking and degassing for 48 hours increases from 4.1 E-3 Pa to 2.5 Pa,the maximum temperature of optical lens group rises to 14.9℃;the dewar intermal vacuum after 100℃baking and degassing for 120 hours increases from 3.0 E-3 Pa to 1.5 Pa,the maximum temperature of optical lens group rises to 14.7℃.The materials outgassing in dewar is the primary cause that leads the static vacuum maintenance ability to be decreased and the heat leakage to be increased through analysing the mechanism of dewar heat leakage.