关键词: CFETR, 偏滤器, 流导, 有效抽速, 低温泵

Abstract: CFETR has put forward the concept of hybrid divertor-blanket. The lower part of the divertor is occupied by the breeding blanket. The divertor pumping channel is designed in the breeding blanket to meet the engineering design requirements that the effective extraction flow of the divertor is 250Pa·m³ ·s^-1 . Based on the vacuum flow conductance calculation theory, the divertor cryo-pump pumping system is designed, and the flow conductance of the divertor cryo-pump pumping system and the effective pumping speed of a single cryo-pump at the inlet of the divertor pumping channel under different section shapes are calculated and compared. It is more reasonable to design a square section pumping channel in the breeding blanket, which can meet both the exclude impurities requirements and the strength requirements of the breeding blanket. When the square section size is 350mm×350mm, the flow conductance of the divertor cryo-pump pumping system is 12.08m³ ·s^-1 , the effective pumping speed of a single cryo-pump at the inlet of the divertor pumping channel is 9.905m³ ·s^-1 , 26 cryo-pumps can meet the exclude impurities requirements, and if one lower window is equipped with 2 cryo-pumps, the cryo-pumps occupy altogether 13 lower windows. Based on the theoretical formula, the cryo-pump pumping system of the divertor is designed and the exclude impurities ability of the divertor is evaluated, which provides a theoretical basis and reference for the subsequent optimization of the divertor pumping channel and evaluation of the effective pumping speed of CFETR. 

Key words:  CFETR, Divertor, Flow conductance, Effective pumping speed, Cryo-pump