Structure Design and Key Parameter Analysis of CFETR Cryo-Pump Based on Monte Carlo Simulation

The stability of the vacuum environment is essential for the stable operation of the China FusionEngineering Experimental Reactor(CFETR). According to the vacuum requirements and operating environment ofthe fusion plasma reaction of the CFETR device,a 4.5 K high-speed cryogenic pump for the CFETR torus was de-signed. The Monte Carlo method was used to calculate the pumping probability and pipeline conductance,and itwas found that the internally opened valve structure can obtain a larger pipeline conductance as well as a largerpumping speed. Orthogonal experiments are used to simulate the influence of different shielding baffle structures onthe pumping probability,and the best inclination angle and plate spacing of the shielding baffle were investigated.The uniformity of gas adsorption on the cryopanels was explored. The results will provide a reference for the designof the torus cryopump in CFETR and the similar large cryopumps for other application cases.