{
  "abstract": "In large-scale liquid scintillator detectors such as the Jiangmen Underground Neutrino Observatory (JUNO), high-intensity events like cosmic muons induce photomultiplier tube (PMT) afterpulses that can interfere with the analysis of delayed physics signals. To systematically evaluate this instrumental background, we present a dedicated measurement of long-delayed afterpulses in two types of JUNO 20-inch PMTs: a dynode-based PMT and a microchannel-plate (MCP) PMT. The afterpulse time profiles were first characterized within a direct 1.8~ms waveform window and were further extended to 20~ms using a sliding-window readout strategy. Distinct long-delayed components are observed, revealing a strong dependence on the PMT multiplication structure. The dynode PMT exhibits a broad afterpulse component peaking at approximately 260~$μ$s, whereas the MCP-PMT shows a pronounced peak around 90~$μ$s, an additional component around 550~$μ$s, and a much smaller, broadly distributed millisecond-scale component. For the microsecond-scale components, the afterpulse yield per primary photoelectron is at the $10^{-3}$ level in the selected delayed windows and increases approximately linearly with the primary light intensity. The accumulated delayed activity can therefore become non-negligible following high-intensity events. These quantitative findings provide critical inputs for PMT response characterization and for the accurate modeling of delayed correlated backgrounds in high-precision neutrino experiments.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2608.01943",
  "author_total": 12,
  "authors": [
    {
      "name": "Xiaojie Luo"
    },
    {
      "name": "Cailian Jiang"
    },
    {
      "name": "Haojie Dong"
    },
    {
      "name": "Yuduo Guan"
    },
    {
      "name": "Gaosong Li"
    },
    {
      "name": "Zhonghua Qin"
    },
    {
      "name": "Zhenning Qu"
    },
    {
      "name": "Junyu Shao"
    },
    {
      "name": "Mingxia Sun"
    },
    {
      "name": "Liangjian Wen"
    },
    {
      "name": "Zeyuan Yu"
    },
    {
      "name": "Boyi Zheng"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/4bc4yq5gxzhxd.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2608.01943",
  "fulltext_url": null,
  "id": "4bc4yq5gxzhxd",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2608.01943",
  "language": null,
  "licence": "LicenseRef-arXiv-nonexclusive-1.0",
  "licence_label": "arXiv licence",
  "licence_source": "article",
  "licence_url": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "hep-ex"
    ],
    [
      "openalex",
      "3106|Particle Detector Development and Performance"
    ]
  ],
  "openalex": "W7172424489",
  "pdf_url": "https://arxiv.org/pdf/2608.01943",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-14",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/4bc4yq5gxzhxd.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:29:31Z",
      "native_id": "2608.01943",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2608.01943"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:hep-ex",
      "subfield": "high-energy"
    }
  ],
  "title": "Long-Delayed Afterpulse Measurement of JUNO 20-inch Photomultiplier Tubes",
  "title_text": "Long-Delayed Afterpulse Measurement of JUNO 20-inch Photomultiplier Tubes",
  "type": "preprint",
  "updated_at": "2026-10-30T12:29:31Z",
  "url": "https://research.draconitic.com/paper/4bc4yq5gxzhxd",
  "venue": "arXiv",
  "versions": []
}