Published October 18, 2024 | Published
Journal Article

Performance of a phonon-mediated kinetic inductance detector at the NEXUS cryogenic facility

Abstract

Microcalorimeters that leverage microwave kinetic inductance detectors to read out phonon signals in the particle-absorbing target, referred to as kinetic inductance phonon-mediated (KIPM) detectors, offer an attractive detector architecture to probe dark matter (DM) down to the fermionic thermal relic mass limit. A prototype KIPM detector featuring a single aluminum resonator patterned onto a 1-gram silicon substrate was operated in the Northwestern EXerimental Underground Site (NEXUS) low-background facility at Fermilab for characterization and evaluation of this detector architecture’s efficacy for a DM search. An energy calibration was performed by exposing the bare substrate to a pulsed source of 470-nm photons, resulting in a baseline resolution on the energy absorbed by the phonon sensor of 2.1±0.2 eV, a factor of two better than the current state of the art, enabled by quasiparticle lifetimes extending up to 6.5 ms. However, due to the subpercent phonon collection efficiency, the resolution on energy deposited in the substrate is limited to 𝜎𝐸=318±29 eV. We further model both the signal pulse shape as a function of device temperature to extract quasiparticle lifetimes, and the observed noise spectra.

Copyright and License

© 2024 American Physical Society.

Acknowledgement

The authors would like to thank Bruce Bumble of the Jet Propulsion laboratory for his guidance and expertise in fabricating the KIPM device studied in this work. Additional thanks are due to Ryan Linehan for useful discussions of quasiparticle and phonon dynamics. This manuscript has been authored by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the U.S. Department of Energy, Office of Science, Office of High Energy Physics. Primary funding for this project was furnished by the FNAL Laboratory Directed Research and Development (LDRD) program award number LDRD2020-040. This work was supported by the US Department of Energy, Office of Science, National Quantum Information Science Research Centers, Quantum Science Center and the US Department of Energy, Office of Science, High-Energy Physics Program Office. OW was also supported by NASA fellowship NSTGRO80NSSC20K1223.

Contributions

DJT commissioned the KIPMD data acquisition system, collected the data, performed the analysis, and drafted the manuscript. OW fabricated the device under test in this work, using funds provided by SG. OW and KR motivated the physical interpretation of the two-component signal model, and in conjunction with SG, contributed expertise in phonon and quasiparticle dynamics and MKID operation. LH led the management and supervision of this project. NK conceived of this project on the original LDRD award and participated in the RF upgrade of NEXUS. SL and DBo participated in the RF upgrade of NEXUS. DBa led the QSC project which supported this work following conclusion of the initial project funding (LDRD). EF-F led the management of the NEXUS facility. MH, CJ, and PL contributed to the management and operation of the NEXUS facility. RC, KK, and RR contributed to the operation of the NEXUS facility. VN and BS contributed to the management, upgrade and operation of the NEXUS facility, and led the work to characterize the radiogenic background present at this facility. CB contributed to the design and simulation of the magnetic shield at NEXUS.

Additional details

Created:
October 22, 2024
Modified:
November 8, 2024