{
  "abstract": "We present the design methodology, implementation, and data products of the Energetic Particle Detector (EPD) instrument on-board the Electron Losses and Fields Investigation (ELFIN) dual SmallSat mission. ELFIN was designed to study the time-evolution of energetic particle distributions in Earth's magnetosphere, having operated in polar Low Earth Orbit (LEO) from 2018 to 2022. Each satellite's instrument payload contained a pair of detector heads to sense differential-directional fluxes of 50 keV to $\\sim$5 MeV electrons (EPDE), and 50 keV to $\\sim$2 MeV atomic ions (EPDI), with an energy resolution better than 50% ($ΔE/E<0.5$). The satellites were spinning with a nominal period of 2.8 s in a plane containing Earth's background magnetic field, with particle counting intervals subdivided into 16 consecutive spin sectors. Each EPD was paired with a three-axis Fluxgate Magnetometer (FGM) sampled at 80 Hz for local pitch-angle determination. Each detector head operated on the principle of pulse-height analysis (PHA) in solid state media, collimated by a rectangular 22.5$^\\circ$ field of view and entrance aperture. The EPDE contained a stack of 6 silicon detectors (0.7 cm total thickness) with 0.15 cm$^2$ str geometric factor, with ion contamination mitigated by an aperture foil and digital coincidence logic. The EPDI contained a stack of 2 silicon detectors (0.1 cm total thickness) with 0.03 cm$^2$ str geometric factor, with electron contamination mitigated by a magnetic broom stage and digital anti-coincidence logic. The total assembled mass, volume, and power required for the EPD detector heads and circuit boards were 939 g, 10$\\times$9.8$\\times$8.4 cm$^3$, and 2.3 W, respectively. We describe each EPD design element alongside instrument data products and processing.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.18628",
  "author_total": 27,
  "authors": [
    {
      "name": "Colin Wilkins"
    },
    {
      "name": "Ryan Caron"
    },
    {
      "name": "Ethan Tsai"
    },
    {
      "name": "Chris Shaffer"
    },
    {
      "name": "Patrick Cruce"
    },
    {
      "name": "Maxwell Chung"
    },
    {
      "name": "Andrei Runov"
    },
    {
      "name": "Jiang Liu"
    },
    {
      "name": "Drew Turner"
    },
    {
      "name": "Yuri Shprits"
    },
    {
      "name": "Wen Li"
    },
    {
      "name": "Michael Lawson"
    },
    {
      "name": "Emmanuel Masongsong"
    },
    {
      "name": "Cindy Russell"
    },
    {
      "name": "Eric Grimes"
    },
    {
      "name": "Jiashu Wu"
    },
    {
      "name": "Matthew Allen"
    },
    {
      "name": "Jessica Artinger"
    },
    {
      "name": "Alex Flemming"
    },
    {
      "name": "Brayden Hesford"
    },
    {
      "name": "Laura Iglesias"
    },
    {
      "name": "James King"
    },
    {
      "name": "Austin Norris"
    },
    {
      "name": "Carter Pedersen"
    },
    {
      "name": "Daniel Thomlinson"
    },
    {
      "name": "Wynne Turner"
    },
    {
      "name": "Vassilis Angelopoulos"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/3xs7pc8kq39vh.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.18628",
  "fulltext_url": null,
  "id": "3xs7pc8kq39vh",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.18628",
  "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.ins-det"
    ],
    [
      "arxiv",
      "physics.space-ph"
    ],
    [
      "openalex",
      "3103|Ionosphere and magnetosphere dynamics"
    ]
  ],
  "openalex": "W7221824721",
  "pdf_url": "https://arxiv.org/pdf/2610.18628",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-13",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/3xs7pc8kq39vh.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:29:11Z",
      "native_id": "2610.18628",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.18628"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:physics.space-ph",
      "subfield": "stellar"
    },
    {
      "field": "physics",
      "origin": "arxiv:physics.ins-det",
      "subfield": "applied-instrumentation"
    }
  ],
  "title": "The Energetic Particle Detector Instrument on ELFIN",
  "title_text": "The Energetic Particle Detector Instrument on ELFIN",
  "type": "preprint",
  "updated_at": "2026-10-30T12:29:11Z",
  "url": "https://research.draconitic.com/paper/3xs7pc8kq39vh",
  "venue": "arXiv",
  "versions": []
}