Low energy backgrounds and excess noise in a two-channel low-threshold calorimeter
We describe observations of low energy excess (LEE) events, background events observed in all light dark matter direct detection calorimeters, and noise in a transition edge sensor based two-channel silicon athermal phonon detector with 375 meV baseline energy resolution. We measure two distinct LEE populations: “shared” multichannel events with a pulse shape consistent with substrate athermal phonon events and sub-eV events that couple nearly exclusively to a single channel with a significantly faster pulse shape. These “singles” are consistent with events occurring within the aluminum athermal phonon collection fins. Similarly, our measured detector noise is higher than the theoretical expectation. Measured noise can be split into an uncorrelated component, consistent with shot noise from small energy depositions within the athermal phonon sensor itself, and a correlated component, consistent with shot noise from energy depositions within the silicon substrate's phonon system.
Authors
- R. Mahapatra (ORCID: https://orcid.org/0000-0003-0286-1114)
- J. Lin (ORCID: https://orcid.org/0000-0002-9970-8150)
- Yunying Qi
- V. Velan
- S. L. Watkins
- P. Sorensen (ORCID: https://orcid.org/0000-0001-7290-2175)
- Robin Anthony-Petersen (ORCID: https://orcid.org/0000-0001-7261-0885)
- Mark Platt (ORCID: https://orcid.org/0000-0002-9195-7216)
- G. Wang (ORCID: https://orcid.org/0000-0003-1385-3806)
- B. Serfass (ORCID: https://orcid.org/0000-0003-4681-4109)
- D. N. McKinsey
- M. W. Reed (ORCID: https://orcid.org/0000-0001-9615-1388)
- S. A. Hertel
- W. Matava (ORCID: https://orcid.org/0000-0002-9939-7786)
- R. K. Romani (ORCID: https://orcid.org/0000-0002-9556-1876)
- P. K. Patel
- B. Suerfu (ORCID: https://orcid.org/0000-0003-0259-7392)
- M. Williams (ORCID: https://orcid.org/0000-0002-6540-436X)
- Y. Wang
- B. Sadoulet
- M. Pyle (ORCID: https://orcid.org/0000-0002-3490-6754)
- Xinran Li (ORCID: https://orcid.org/0000-0003-3133-3660)
- Luke Chaplinsky (ORCID: https://orcid.org/0000-0003-4887-0657)
- M. Lisovenko (ORCID: https://orcid.org/0000-0002-2946-3944)
- B. Penning (ORCID: https://orcid.org/0000-0001-9020-9112)
- C. W. Fink (ORCID: https://orcid.org/0000-0003-3946-4809)
- C. L. Chang (ORCID: https://orcid.org/0000-0002-6311-0448)
- Wei Guo (ORCID: https://orcid.org/0000-0002-9466-3213)
- Y.-Y. Chang (ORCID: https://orcid.org/0000-0002-6441-980X)
- I. Rydstrom (ORCID: https://orcid.org/0009-0000-5969-368X)
- D. Z. Osterman
- M. Garcia-Sciveres (ORCID: https://orcid.org/0000-0002-5800-4210)
Institutions
- Argonne National Laboratory (US)
- Florida A&M University - Florida State University College of Engineering (US)
- Los Alamos National Laboratory (US)
- High Energy Accelerator Research Organization (JP)
- Lawrence Berkeley National Laboratory (US)
- University of Zurich (CH)
- University of Massachusetts Amherst (US)
- University of Chicago (US)
- National High Magnetic Field Laboratory (US)
- International Center for Quantum-field Measurement Systems for Studies of the Universe and Particles
- Texas A&M University (US)
- University of California, Berkeley (US)
Publication Details
- Journal
- Applied Physics Letters
- Published
- 2025-03-01
- DOI
- https://doi.org/10.1063/5.0247343
- Citations
- 8
- Primary Topic
- Dark Matter and Cosmic Phenomena
- Type
- article
- Field-Weighted Citation Impact
- 13.09
Funders
- National Science Foundation
- U.S. Department of Energy
- National Nuclear Security Administration
- Argonne National Laboratory
- Lawrence Berkeley National Laboratory