A Transistorized Reactivity Measurement System

An all-transistor system has been developed to be used in measuring the reactivity of the reactor in the Sandia Engineering Reactor Facility. In operation, the system triggers a pulsed neutron source (PNS) in the reactor and counts the resulting neutron flux, thus giving a measure of the time constant of the reactor. The counting is done in eleven time-sequenced counting channels. The reactor time constant is a measure of the reactor reactivity.