{
  "abstract": "Rare-event search experiments demand ever-lower backgrounds, and the resulting radio-pure materials and suppressive shielding make related background simulations computationally expensive without event biasing. We present a method for optimising the widely used importance splitting and Russian roulette technique for rare-event searches, in which a whole number of equal-width importance layers fill the shielding geometry. Balancing relative uncertainty against execution time, we optimise the layer thickness for both $γ$-rays and neutrons, and across different shielding materials and thicknesses. Expressed as a multiple of the primary particle's mean free path, the optimal thickness generalises across energies for a given particle type and yields a physics-based prediction applicable to any shielding design. The same trend reveals that over-biasing is possible, with relative uncertainty worsening at high layer counts for fixed execution time. The optimal configuration gives an $\\mathcal{O}$(20) gain in computational efficiency over the unbiased case.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.03822",
  "author_total": 3,
  "authors": [
    {
      "name": "P. Knights"
    },
    {
      "name": "L. J. Milligan"
    },
    {
      "name": "K. Nikolopoulos"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/byh9hrpr5021e.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.03822",
  "fulltext_url": null,
  "id": "byh9hrpr5021e",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.03822",
  "language": null,
  "licence": "CC-BY-SA-4.0",
  "licence_label": "CC BY-SA 4.0",
  "licence_source": "article",
  "licence_url": "http://creativecommons.org/licenses/by-sa/4.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "hep-ex"
    ],
    [
      "arxiv",
      "physics.comp-ph"
    ],
    [
      "arxiv",
      "physics.ins-det"
    ],
    [
      "openalex",
      "3106|Neutrino Physics Research"
    ]
  ],
  "openalex": "W7208743824",
  "pdf_url": "https://arxiv.org/pdf/2609.03822",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-03",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/byh9hrpr5021e.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:18:31Z",
      "native_id": "2609.03822",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.03822"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:physics.ins-det",
      "subfield": "applied-instrumentation"
    },
    {
      "field": "physics",
      "origin": "arxiv:physics.comp-ph",
      "subfield": "computational"
    },
    {
      "field": "physics",
      "origin": "arxiv:hep-ex",
      "subfield": "high-energy"
    }
  ],
  "title": "Optimisation of importance sampling implementation in rare-event shielding simulations using Geant4",
  "title_text": "Optimisation of importance sampling implementation in rare-event shielding simulations using Geant4",
  "type": "preprint",
  "updated_at": "2026-10-30T12:18:31Z",
  "url": "https://research.draconitic.com/paper/byh9hrpr5021e",
  "venue": "arXiv",
  "versions": []
}