A Log N and Period Amplifier Utilizing Statistical Fluctuation Signals from a Neutron Detector

A novel approach to the logarithmic measurement of neutron level and period in a nuclear reactor is described, in which the statistical fluctuations in the output of a neutron detector are utilized rather than the individual pulses or the d-c component. This approach is shown to overcome some of the limitations that are inherent in the usual log n and period amplifier systems. A system using a fission chamber as detector and all solid-state circuitry is shown which covers a six-decade range of neutron level between the limits of 103 and 1010 nv without the need for low level d-c amplification.