Analog and Digital Dynamic Compensation Techniques for Delayed Self-Powered Neutron Detectors

Analog and digital methods have been developed to compensate for the time delay associated with rhodium self-powered neutron detector signals. This delay is caused by the decay of the neutron-activated rhodium and results in a current signal with unfavorable time response characteristics. The compensating analog method is based on the use of lead-lag networks to eliminate undesirable poles and zeros. The digital method takes digitized signals and numerically solves the inverse kinetics equation that relates reactor flux to the detector current at all earlier times. These methods were tested in a realistic reactor environment, and the results illustrate the accuracy achieved using each method.