{
  "abstract": "The ultralow transverse emittance of diffraction-limited electron storage rings leads to high beam densities, making direct space-charge effects increasingly relevant despite their relativistic suppression at high energy. In this work, we investigate the impact of direct space charge on transverse coupled-bunch instabilities, using PETRA-IV as a representative example. A Vlasov solver, multi-bunch particle tracking, and analytical calculations in normalized phase space are combined to study the coupled-bunch mode spectrum, the nonlinear incoherent tune spread, and the associated Landau damping. Particle-tracking simulations show that the space-charge-induced tune spread can provide sufficient Landau damping to stabilize higher-order head-tail modes. Landau stability diagrams constructed from the analytical tune spread of a frozen bi-Gaussian beam predict the stabilization of these higher-order modes, in agreement with the tracking simulations. These results demonstrate the important role of direct space charge in transverse coupled-bunch dynamics. The analysis framework developed here can also be extended to collective-instability studies in both electron and hadron accelerators.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.03771",
  "author_total": 1,
  "authors": [
    {
      "name": "Chao Li"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/a3dcq4g9142nh.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.03771",
  "fulltext_url": null,
  "id": "a3dcq4g9142nh",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.03771",
  "language": null,
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "http://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "physics.acc-ph"
    ],
    [
      "openalex",
      "2202|Particle accelerators and beam dynamics"
    ]
  ],
  "openalex": "W7208764031",
  "pdf_url": "https://arxiv.org/pdf/2609.03771",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-03",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/a3dcq4g9142nh.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:18:31Z",
      "native_id": "2609.03771",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.03771"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:physics.acc-ph",
      "subfield": "applied-instrumentation"
    }
  ],
  "title": "Effects of the Direct Space Charge on Transverse Coupled-Bunch Instabilities",
  "title_text": "Effects of the Direct Space Charge on Transverse Coupled-Bunch Instabilities",
  "type": "preprint",
  "updated_at": "2026-10-30T12:18:31Z",
  "url": "https://research.draconitic.com/paper/a3dcq4g9142nh",
  "venue": "arXiv",
  "versions": []
}