The Thermal and Heat Leak Analyses of Dewar

Dewar is an important component of the astronomical observation. CCD should be cooled to low temperature by Dewar, because of the noise and dark current. This paper investigates the thermal dynamics of nitrogen Dewar with finite element at the aim avoid problems in optimizing the design of Dewar. By analising the ways of thermal conducting of nitrogen Dewar, we computes the heat leak of Dewar.