FIELD: mechanical engineering.
SUBSTANCE: invention relates to vacuum engineering and controlled thermonuclear fusion and is intended for pumping helium from a vacuum chamber of a thermonuclear reactor, said helium being a product of a nuclear reaction between hydrogen isotopes D and T. At the inlet of the device for pumping helium from the vacuum volume of the thermonuclear plant, comprising a general purpose pump that pumps out all the gases supplied to the exhaust of the thermonuclear plant, including hydrogen isotopes and helium, and selective pump, pumping only hydrogen isotopes, consisting of superpermeable membrane and generator of energetic hydrogen particles, there is a branch pipe having a length sufficient to block the exhaust mixture backflow from the selective pump location area and the general purpose pump into the thermonuclear plant vacuum volume, which is selected from the 
relationship, where d is the diameter of the branch pipe, expressed in cm, and JΣ is the total flow of particles (D2 and He), expressed in particles per second.
EFFECT: reduced dimensions and power of the required pumps, as well as elimination of problems of their arrangement in the reactor space due to reduction of the required speed of helium and D/T-mix pumping out by blocking of reverse flow of the exhaust mixture from the location area of the selective pump and the general-purpose pump to the vacuum volume of the thermonuclear plant.
1 cl, 1 dwg
