https://doi.org/10.1140/epjp/s13360-026-07530-x
Regular Article
PMT charge uncertainty with artificial correlated pulses
1
Institute of High Energy Physics, 100049, Beijing, China
2
University of Chinese Academy of Sciences, 100049, Beijing, China
3
Zhengzhou University, 450001, Zhengzhou, Henan, China
a
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Received:
22
November
2025
Accepted:
3
March
2026
Published online:
1
June
2026
Abstract
Observing inverse beta decay (IBD) in reactor neutrino experiments requires precise detection of correlated prompt and delayed signals using photomultiplier tubes (PMTs). This study compares the performance of 20-inch microchannel plate (MCP) and dynode PMTs, investigating the impact of afterpulses and overshoot effects on measurement accuracy. An experimental setup using LED light sources simulated IBD-like signals with prompt with 
100 photoelectron (p.e.) and delayed with 10 p.e. components at time intervals from 0.5 to 25 
s. Analysis reveals that a “true charge” model for the delayed signal can be achieved by applying time interval cuts: over 5 s for MCP PMTs and over 3 s for dynode PMTs. This effectively mitigates afterpulse interference. Furthermore, the required cut length is correlated with the amplitude of the prompt pulse, as larger prompt signals tend to produce more significant afterpulsing. Extended 1 ms observations reveal fundamentally different afterpulse characteristics: MCP PMTs generate minimal but recognizable, rapidly decaying afterpulses, while dynode PMTs produce abundant, persistent afterpulses with rates higher to their pre-prompt dark counts, complicating late-time signal discrimination. The PMT types also exhibit distinct overshoot characteristics observable within a 500 ns window following the main pulse: MCP PMT exhibits a minor, long-tailed overshoot developing after 150 ns and decaying over time, while the dynode PMT displays a pronounced, high-amplitude overshoot peak (70–80 mV) at 50 ns, followed by secondary fluctuations. These findings provide essential criteria for PMT selection and signal processing optimization in precision timing applications for neutrino experiments.
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© The Author(s), under exclusive licence to Società Italiana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature 2026
Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.
