{
  "abstract": "Massive cryogenic calorimeters read out by transition-edge sensors (TES) can reach eV-scale baseline resolution, but the single-channel dc-SQUID readout conventionally used in rare-event searches, with one amplifier chain and several wires per detector, limits practical arrays to a few tens of channels. We propose to apply microwave SQUID multiplexing ($μ$MUX), developed for fast X-ray and neutrino-mass microcalorimeters, to massive BGO (Bi$_4$Ge$_3$O$_{12}$) calorimeters operated at $\\simeq 20$~mK; sapphire and TeO$_2$ absorbers are covered by the same framework. Using the established thermal and noise model for massive TES calorimeters, we derive a noise model for the multiplexed readout, including the HEMT, two-level-system and SQUID contributions, and its scaling with the multiplexing factor $N_{\\rm mux}$. Since the slow thermal signals require only about a kHz of sampling per channel, the limiting requirement is not bandwidth but an input-coil sensitivity of $( 0.1$ to $1)\\,μ$A$/Φ_0$, a factor of $10$ to $30$ beyond current $μ$MUX devices, matched to the detector current noise of ($9$ to $10$)~pA$/\\sqrt{\\rm Hz}$, which is independent of the absorber mass. With a total flux noise of $\\simeq$$1.2\\,μΦ_0/\\sqrt{\\rm Hz}$, the readout degrades the baseline resolution by less than $2\\%$ up to $N_{\\rm mux}=1000$, negligible compared with the TES-limited resolution. These results are implemented in a single-tower design: 52 BGO crystals of 100~g each and one HEMT amplifier. The tower is the unit of a multi-tower array of several kilograms aimed at CE$ν$NS and dark matter searches.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2608.27556",
  "author_total": 13,
  "authors": [
    {
      "name": "N. Ferreiro Iachellini"
    },
    {
      "name": "P. Szypryt"
    },
    {
      "name": "L. Canonica"
    },
    {
      "name": "W. B. Doriese"
    },
    {
      "name": "M. Durkin"
    },
    {
      "name": "A. Giachero"
    },
    {
      "name": "J. A. B. Mates"
    },
    {
      "name": "A. Nucciotti"
    },
    {
      "name": "L. Pattavina"
    },
    {
      "name": "S. Quitadamo"
    },
    {
      "name": "C. Shiu"
    },
    {
      "name": "J. N. Ullom"
    },
    {
      "name": "M. R. Vissers"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/098vcjq3mx610.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2608.27556",
  "fulltext_url": null,
  "id": "098vcjq3mx610",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2608.27556",
  "language": null,
  "licence": "LicenseRef-arXiv-nonexclusive-1.0",
  "licence_label": "arXiv licence",
  "licence_source": "article",
  "licence_url": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "astro-ph.CO"
    ],
    [
      "arxiv",
      "hep-ex"
    ],
    [
      "arxiv",
      "physics.ins-det"
    ],
    [
      "openalex",
      "3103|Superconducting and THz Device Technology"
    ]
  ],
  "openalex": "W7204791808",
  "pdf_url": "https://arxiv.org/pdf/2608.27556",
  "pmcid": null,
  "pmid": null,
  "published": "2026-08-27",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/098vcjq3mx610.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:22Z",
      "native_id": "2608.27556",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2608.27556"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.CO",
      "subfield": "cosmology"
    },
    {
      "field": "physics",
      "origin": "arxiv:physics.ins-det",
      "subfield": "applied-instrumentation"
    },
    {
      "field": "physics",
      "origin": "arxiv:hep-ex",
      "subfield": "high-energy"
    }
  ],
  "title": "A microwave SQUID multiplexing concept for macro-cryogenic calorimeter arrays",
  "title_text": "A microwave SQUID multiplexing concept for macro-cryogenic calorimeter arrays",
  "type": "preprint",
  "updated_at": "2026-10-30T12:17:22Z",
  "url": "https://research.draconitic.com/paper/098vcjq3mx610",
  "venue": "arXiv",
  "versions": []
}