Speaker
Description
A Kinetic Inductance Phonon-Mediated (KIPM) Detector is a microcalorimeter that leverages kinetic inductance detectors (KID) to read out phonon signals from the device substrate. They are an attractive architecture for low-threshold rare-event searches. We have established a consortium comprising university and national lab groups dedicated to advancing the state of the art in these detectors. The ultimate goal of this consortium is to deploy a detector of kg-scale target mass and sub-eV energy threshold for direct detection of dark matter with masses below 10 MeV$/c^2$, necessitating meV-scale energy resolution. While these detectors have yet to achieve the resolution attained by transition-edge sensors (TES), our consortium has recently demonstrated a sensor resolution (i.e., resolution in the quasiparticle channel) of 2.1 eV, the current record for such devices. The meV-scale energy resolution can be achieved in KIPM detectors by: (1) reducing the intrinsic detector noise including the two-level-system (TLS) noise, amplifier noise, and generation-recombination (GR) noise; and (2) improving total efficiency to $\approx30\%$, as demonstrated with TES-based detectors, limited by the phonon pair breaking efficiency. Both low noise and high efficiency can be achieved by implementing quasiparticle trapping with aluminum absorbers and low-$T_c$ inductors. Our consortium brings together experts in KID design, phonon and quasiparticle dynamics, and noise modeling, along with specialized fabrication facilities, test platforms, and unique calibration capabilities. In this talk, I will provide an overview of the consortium and its capabilities, discuss recent results from our member groups focusing on our observed pulse shapes and phonon dynamics, and present projections for realizing our goal.
