Design study of pumping system for tokamak fusion power reactor

Design study of the pumping system for tokamak fusion power reactor has been carried out. The reactor is pumped through twelve pumping ports. It is assumed that the partial pressures of DT and He at 1000 K in the reactor should be maintained less than 3.33 x 10-4 Torr and 1.67 x 10-5 Torr respectively. The main pump is liquid helium cooled cryopump containing sorption panel for helium pumping. The pumping speeds for DT and He are 1.65 x 106 l.sec-1 and 9.98 x 105 l.sec-1 respectively. The conductance between the reactor and the cryopump should be more than 7.8 x 105 l.sec-1 for DT. To satisfy this condition, inlet diameter of pumping duct should be extended to 2.5 m and the configuration of cooling pipes in pumping duct should be changed from original design. Auxiliary pumping system contains turbo-molecular pump, clean roots pump, mechanical booster pump and diaphragm pump. The mechanical booster pump and the diaphragm pump of auxiliary pumping system are also used as recovery pumping system. (auth.)