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arXiv · 2606.24574

Anomalously long-delayed afterpulses in large-area photomultipliers

Nikita Ushakov·Bayarto Lubsandorzhiev·Arslan Lukanov·Andrei Sidorenkov·Dmitrii Voronin
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Abstract

We report the observation of anomalously long-delayed afterpulses in photomultipliers of the Baksan Large Neutrino Telescope project$~-$ 10-inch R7081-100, 8-inch R5912-100, 20-inch R12860 photomultipliers produced by Hamamatsu Photonics, and 20-inch N6205 photomultipliers produced by NNVT. The mean delay times relative to the main pulses are approximately $85~\mu$s, $73~\mu$s, $260~\mu$s, and $90~\mu$s, respectively. The probability of such afterpulses does not exceed 0.1% per photoelectron, and their amplitudes are strictly confined to the single-photoelectron level, regardless of the amplitude of the main pulse. The delay time of these afterpulses shows no significant dependence on the PMT operating voltage.

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Nikita Ushakov, Bayarto Lubsandorzhiev, Arslan Lukanov, Andrei Sidorenkov, Dmitrii Voronin. 2026-06-23. Anomalously long-delayed afterpulses in large-area photomultipliers. https://arxiv.org/abs/2606.24574

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