Visualization Of Dead-time Behaviour Of 3He Neutron Coincidence Counters Using List Mode Recorders

Visualization of dead-time behaviour of 3He neutron coincidence counters using list mode recorders: Neutron multiplicity counting using 3He neutron detectors is a widely used technique in safeguards for the determination of mass of fissile material. Unfortunately, these neutron detectors suffer from dead-time loss, which - if uncorrected - will lead to a bias in fissile material mass assay. Although several techniques for correction exist, correction for high count-rates is still a topic of research. During the last decades, a new technique for high count-rate correction, making use of multi-channel list mode recorders, has been developed at the Joint Research Centre Karlsruhe in collaboration with Los Alamos National Laboratory. Based on this technique, a visualization tool is developed, allowing visualization of dead-time behaviour of the pre-amplifiers in a neutron detector. This tool, which shall be presented here, allows the visualization of correction for dead-time behaviour for any multiplicity (Singles, Doubles, Triples, Quads, ⋯) and for the related multiplicity histograms. Dead-time behaviour of the single pre-amplifier can be visualized as well as that of the whole detector system. For quality control purposes also the time-line can be visualized. Although this tool has been developed for 3He counters, it can also be deployed with, and adapted for, other neutron detection systems with similar characteristics and data acquisition architecture.