{
  "abstract": "The T0 detector provides the event start time for the HIRFL-CSR external-target experiment, and its multi-channel readout signals also contain 2D position information of incident particles. In the CEE experiment, the dedicated beam-profile detector has a rate capability of only ~1 kHz, far below the beam event rate of up to 1 MHz, so it cannot provide real-time beam-spot monitoring under high-rate data-taking or an event time reference. To fill this gap, this work studies a CNN-based position reconstruction method that enables the T0 detector to provide both start time and beam-spot information. The over-threshold times and time-over-threshold (TOT) values from 32 SiPM channels are reorganized into a geometry-preserving input tensor. Time features are corrected by event-wise mean-time subtraction, and TOT features are normalized by an event-wise trimmed mean before feature standardization. A customized CNN directly regresses the incident coordinates. Training and validation samples are built with Geant4 simulation and waveform digitization, and the method is evaluated using a pulsed-laser scanning data set with known position labels. On independent test sets, the residual standard deviations for uniformly distributed planar simulation data are about 1.11 and 1.04 mm in x and y. For the discrete laser-scanning geometry, the resolutions are about 2.36 and 1.34 mm in simulation and 2.42 and 1.41 mm in experiment. The trained model is applied to CEE zero-field beam data collected at the Institute of Modern Physics, Lanzhou, in January 2026, and a 2D beam-spot distribution is reconstructed. These results show the T0 detector's potential as a high-rate beam-spot monitor while retaining its role as an event start-time detector.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.12969",
  "author_total": 5,
  "authors": [
    {
      "name": "Shuai-Ke Lv"
    },
    {
      "name": "D Hu"
    },
    {
      "name": "M Shao"
    },
    {
      "name": "Yingjie Zhou"
    },
    {
      "name": "Yiding Zhao"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/em8mb75hzaqa7.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.12969",
  "fulltext_url": null,
  "id": "em8mb75hzaqa7",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.12969",
  "language": null,
  "licence": "CC-BY-NC-ND-4.0",
  "licence_label": "CC BY-NC-ND 4.0",
  "licence_source": "article",
  "licence_url": "http://creativecommons.org/licenses/by-nc-nd/4.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "physics.ins-det"
    ],
    [
      "openalex",
      "3106|Particle Detector Development and Performance"
    ]
  ],
  "openalex": "W7221534345",
  "pdf_url": "https://arxiv.org/pdf/2610.12969",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-09",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/em8mb75hzaqa7.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:28:36Z",
      "native_id": "2610.12969",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.12969"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:physics.ins-det",
      "subfield": "applied-instrumentation"
    }
  ],
  "title": "CNN-based Position Reconstruction for the T0 Detector in the HIRFL-CSR External-target Experiment",
  "title_text": "CNN-based Position Reconstruction for the T0 Detector in the HIRFL-CSR External-target Experiment",
  "type": "preprint",
  "updated_at": "2026-10-30T12:28:36Z",
  "url": "https://research.draconitic.com/paper/em8mb75hzaqa7",
  "venue": "arXiv",
  "versions": []
}