{
  "abstract": "Strong thermal gradients in tungsten plasma-facing components can bias the migration of irradiation-induced defects and thereby alter their redistribution, interaction, and retention. Here, we extend an atomistic jump-statistics framework previously developed for hydrogen to quantify the thermomigration of a single vacancy and interstitial He$_1$--He$_4$ clusters in body-centered-cubic tungsten. Non-equilibrium molecular-dynamics simulations performed over several thermal gradients are used to determine the directional jump ratio, while geometrically derived projected jump lengths convert the fitted directional-bias coefficient into the heat-of-transport coefficient $Q^*=αkT^2$, where $k$ is the Boltzmann constant, $T$ the temperature, and $α$ a constant. All investigated defects exhibit negative values of $α$, corresponding to net migration toward the hot region. He$_4$ has the largest response, $α=-2.2457\\times10^{-2}$ K$^{-1}$, followed closely by the vacancy, whereas He$_3$ exhibits the weakest response despite its intermediate cluster size. Independent constant-temperature simulations over 1000--1600 K show that He$_3$ is also the least mobile cluster and has the largest effective migration energy, $E_m^{\\mathrm{eff}}=0.271$ eV. In contrast, He$_4$ is more mobile than He$_3$ and has the smallest effective migration energy, 0.087 eV. Agreement between the He$_3$ concentration profile predicted from the jump statistics and that obtained from a long molecular-dynamics trajectory provides an independent validation of the method. These results show that thermomigration cannot be inferred from cluster size, diffusivity, or migration energy alone and provide defect-specific heat-of-transport parameters for higher-length-scale models of tungsten under fusion-relevant thermal gradients.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.26667",
  "author_total": 2,
  "authors": [
    {
      "name": "Sanad Alturk"
    },
    {
      "name": "Enrique Martinez"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/ft7dxq47n7en6.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.26667",
  "fulltext_url": null,
  "id": "ft7dxq47n7en6",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.26667",
  "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",
      "cond-mat.mtrl-sci"
    ],
    [
      "arxiv",
      "physics.plasm-ph"
    ],
    [
      "openalex",
      "2505|Fusion materials and technologies"
    ]
  ],
  "openalex": "W7223052000",
  "pdf_url": "https://arxiv.org/pdf/2610.26667",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-19",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/ft7dxq47n7en6.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:30:52Z",
      "native_id": "2610.26667",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.26667"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:cond-mat.mtrl-sci",
      "subfield": "condensed-matter"
    },
    {
      "field": "physics",
      "origin": "arxiv:physics.plasm-ph",
      "subfield": "plasma"
    }
  ],
  "title": "Vacancy and Helium-Cluster Thermomigration in Tungsten",
  "title_text": "Vacancy and Helium-Cluster Thermomigration in Tungsten",
  "type": "preprint",
  "updated_at": "2026-10-30T12:33:41Z",
  "url": "https://research.draconitic.com/paper/ft7dxq47n7en6",
  "venue": "arXiv",
  "versions": []
}