CHANNEL ARRANGEMENT TO MEASURE FLUX OF NEUTRONS (VERSIONS) Russian patent published in 1997 - IPC

FIELD: nuclear technology. SUBSTANCE: invention is meant for measurement of flux of neutrons by primary converter based on unit of ionization chambers used in control and protection system of nuclear reactor, critical assembly and other sources of neutrons. Channel arrangement to measure flux of neutrons incorporates primary converter which includes two neutron-sensitive columes with electrically insulated signal electrodes where material with amounts of nuclei n₁ and n₂<n₁, emitting charge particles in reaction with neutrons is placed and electron unit having two paths of measurement of rate of reaction pulse count. Their inputs are connected by electric coupling line to individual signal electrodes of sensitive volumes with amounts of nuclei n₁ and n₂ and path of measurement of electric current. In this case χ/D≅n₂/n₁= K₂/K₁≅δ•Q•D•N_min/(χ•I_b), where is coefficient of overlapping of linear sections under modes of measurement of rate of reaction pulse count and of electric current; δ is relative deviation of load characteristic from linear one; D = N_max/N_min is range of loading of path of measurement of rate of reaction pulse count; N_min is minimal load of path of measurement of rate of reaction pulse count; N_max is maximal load of path of measurement of rate of reaction pulse count; Q is average charge formed by one reaction of nuclide with neutrons in first sensitive colume; I_b is inherent background current in first sensitive volume; K₂/K₁ is relation of sensitives of second and first columes to neutrons. Input of path of measurement of electric current is connected to signal electrode of first sensitive volume with amount of nuclide n₁. In compliance with second version of channel arrangement primary converter has third neutron-sensitive volume. Relation α of inherent background current in it to inherent background current of first sensitive volume is less than relation b of their sensitives to neutrons. In this case c/D≅n₂/n₁= K₂/K₁≅δ•Q•D•N_min/(α•χ•I_b), where and input of path of measurement of electric current is connected to signal electrode of third neutron-sensitive volume. EFFECT: enhanced functional reliability. 4 cl, 4 dwg