device for determining the content of short-lived fission products from a gas stream

摘要

945,304. Reactors. COMMISSARIAT A L'ENERGIE ATOMIQUE. May 17,1960 [May 19, 1959], No. 17428/60. Addition to 923, 083. Heading G6C. In a burst fuel element detector of the type described in the parent Specification the rotatable sampling drum is mounted in a gas-tight metal casing and is driven by a magnetic coupling which operates through a gas-tight portion which forms part of the casing. The nuclear reactor cooling gases pass through conduit A in the direction of arrows F. Positive ions in the gas stream are urged towards the surface 1a of drum 1 by a positively charged electrode and are adsorbed at the surface. Upon rotation, the drum presents the adsorbing surface to the scintillator 2 and photomultiplier 3. Drum 1 is mounted in gastight cavity E formed of metallic blocks 6, 7 and urged against 6 by screw 8. Gas-tightness between 6, 7 is effected by packing 11. Drum 1 is rotated by shaft 32 through pinion and gear 12, 4. 32 is turned by the inter-action of polepieces 15,18 through the non-magnetic cover 17. The poles 18 are rotatably mounted on shaft 17a fixed to 17 and are turned by an electric motor (not shown).