Neutron ionization chamber

An improved variant of the ionization chamber, designed for measurement and control of neutron flux density in the range from 0.1 upto 1011 neutronxcm-2xs-1 is suggested. The chamber consists of a box and positive, collecting and negative electrodes, which form working and compensating volumes. All electrodes have plane shape and are installed in parallel to each other. Continuity of neutron flux density measurement over the whole indicated range is ensured by the holes made in the collecting electrode the diameter of each of them not exceeding the thickness of the collecting electrode, and their number is determined by the expression m=ksub(n)/ksub (1), where ksub(n) - the proportionality factor between sensitivity of pulse characteristics of the chamber working and compensation volumes, ksub(1) - the efficiency of fission fragment passing through one hole. The presence of the holes results in the fact, that a part of fission fragments gets from the working volume into compensating one, where they also ionize gas and create current pulse. The conclusion is made, that the use of the suggested chamber design in the nuclear reactor control systems permits to reduce the volume of the equipment used by a factor of 3