Thermal Design and Evaluation of Cryopump: A Simulation and Experimental Study

The temperature field and heat flow, from cooling-down to steady state in the newly-developed cryopump comprising the 1^st and 2^nd cryo-cooling arrays, were empirically approximated, mathematically modeled, theoretically analyzed, numerically simulated and experimentally measured with the lab-built test platform equipped with DN400 cryopump for thermal design optimization.The influence of the rather complicated cooling-down conditions, including but not limited to the 1^st cryo-cooling array structure, thermal rod setting, radiation shield thickness, operating modes, thermal properties of components materials and large temperature ranges involved, on the refrigeration and time evolution of temperature distribution of the newly-designed cryopump was investigated.The simulated and tested results were found to be in good agreement.For example, when it comes to the cool-down time, the discrepancy between the simulation and measurement was about 7%.