Diagnosing and Correcting Double Pulsing Effects in Measured Neutron Multiplicity Rates

Passive neutron coincidence and multiplicity counters are inevitably subject to certain non-ideal instrument behaviour, such as double pulsing and dead time. Previous research has shown that double pulsing can be identified in a Rossi-alpha distribution or time interval distribution, but not so readily identified using traditional Multiplicity Shift Register analysis. In this work, we use high-fidelity Monte Carlo simulations accompanied by experimental measurements to study the effects of double pulsing on multiplicity rates—that is, the promotion of singles to doubles and so forth. Extracting information about the character of the double pulsing from a tell-tale signature peak observable in the Rossi-alpha distribution, the double pulsing fraction can be determined. In this paper, we present algebraic correction terms for the individual multiplicity rates that are functions of the double pulsing fraction. Additionally, we discuss the role and significance.