METHOD AND DEVICE FOR REMOVING HELIUM AND HYDROGEN ISOTOPES FROM VACUUM SPACE OF FUSION POWER PLANT Russian patent published in 2000 - IPC

FIELD: controlled nuclear fusion. SUBSTANCE: method involves maintaining vacuum by means of built-in cryopump and removing difficult-to-condense components by means of external cryopumping unit. Helium and hydrogen jets are introduced using re- condensation effect in cryocondensation pumping unit wherein hydrogen isotopes are condensed at temperature lower than that of cryopanel of built-in cryopump. Helium isotopes are compressed and further pumped out by traditional method, primarily by means of cold steam diffusion pump. Mentioned operations are made by varying temperature gradient along gas flow due to reducing pressure above liquid helium and using enthalpy of exit steam. Device implementing this method has at least two filler cryopumps, cold steam diffusion pump, and annular vacuum water pump. All pumps are installed in tandem and separated from each other by means of vacuum seals; annular vacuum water pump is parallel-connected to each cryopump and to helium and hydrogen isotope recipients. After device is disconnected, from fusion power plant, it is subjected to stepped heating. EFFECT: improved efficiency. 4 cl, 1 dwg