Performance of a Kinetic Inductance Phonon-Mediated Detector at the NEXUS Cryogenic Facility

• DOI: 10.48550/arxiv.2402.04473
• Publication Date: 2024-02-06
• Authors: Dylan Temples; Osmond Wen; Karthik Ramanathan; T. Aralis; Y.-Y. Chang; S. R. Golwala; L. Hsu; Corey Bathurst; D. Baxter; D. Bowring; Ran Chen; E. Figueroa‐Felic...; M. Hollister; Christopher James; K. T. Kennard; Noah Kurinsky; Samantha M. Lewis; P. Lukens; V. Novati; R. Ren; B. Schmidt
• Keywords: Kinetic inductance

Microcalorimeters that leverage microwave kinetic inductance detectors to read out phonon signals in the particle-absorbing target, referred as phonon-mediated (KIPM) detectors, offer an attractive detector architecture probe dark matter (DM) down fermionic thermal relic mass limit. A prototype KIPM featuring a single aluminum resonator patterned onto 1-gram silicon substrate was operated NEXUS low-background facility at Fermilab for characterization and evaluation of this architecture's efficacy search. An energy calibration performed by exposing bare pulsed source 470 nm photons, resulting baseline resolution on absorbed sensor $2.1\pm0.2$ eV, factor two better than current state-of-the-art, enabled millisecond-scale quasiparticle lifetimes. However, due sub-percent collection efficiency, deposited is limited $\sigma_E=318 \pm 28$ eV. We further model signal pulse shape function device temperature extract lifetimes, well observed noise spectra, both which impact sensor.