P. Zambon, J. J. P. Peters, L. Jones
We devised a novel non-paralyzable counting strategy, an evolution of the instant retrigger technology, that has the potential to extend by several times the count rate capabilities of current X-ray and electron detectors. Based on the same working principle – counting the time-over-threshold of piled-up signals in multiples of a predefined and selectable retrigger time – thedynamic retriggerfeatures a variable retrigger time which is adjusted dynamically upon consecutive re-evaluations of the piled-up signal, in an accelerating fashion. The rationale is to boost the recorded count rate in regimes of heavy signal pile-up, where even the standard retrigger suffers from count losses. In this work, we provide the statistical foundation for the dynamic retrigger concept and operation, based on the relationship between the rate of incoming events and the length of piled-up signals. Monte Carlo simulations are used to qualify the analytical model, to compute the resulting count rate behavior and to provide heuristic optimizations to the sequence of retrigger times obtained by theoretical means. We show that the dynamic retrigger strategy improves the count rate performance, with respect to the standard retrigger, by a factor 4.75 for ideal rectangular signals and by a factor 3.05 for a more realistic signal shape. Furthermore, the model is validated through a semi-empirical approach using experimental pulse parameters from a HAADF detector illuminated with 300 keV electrons. This hardware-grounded validation confirms a count rate enhancement of a factor 1.84, demonstrating the model’s robustness under real-world operating conditions.