Low energy backgrounds and excess noise in a two-channel low-threshold calorimeter
Abstract
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.
Article Details
Journal Info
Applied Physics Letters
American Institute of Physics
Authors (32)
R. Anthony-Petersen
University of California Berkeley, Department of Physics 1 , Berkeley, California 94720,
C. L. Chang
Argonne National Laboratory 1 , 9700 S Cass Ave, Lemont, Illinois 60439,
Y.-Y. Chang
Department of Physics, University of California Berkeley 4 , 366 LeConte Hall 7300, Berkeley, California 94720,
L. Chaplinsky
University of Massachusetts, Amherst Center for Fundamental Interactions and Department of Physics 5 , Amherst, Massachusetts 01003-9337,
C. W. Fink
University of California Berkeley, Department of Physics 1 , Berkeley, California 94720,
M. Garcia-Sciveres
W. Guo
S. A. Hertel
University of Massachusetts, Amherst Center for Fundamental Interactions and Department of Physics 9 , 101 Stockbridge Hall, 80 Campus Center Way, Amherst, Massachusetts 01003-9337,
X. Li
J. Lin
M. Lisovenko
Argonne National Laboratory 1 , 9700 S Cass Ave, Lemont, Illinois 60439,
R. Mahapatra
Department of Physics and Astronomy, Texas A&M University 10 , 4242 TAMU, 578 University Dr., College Station, Texas 77843-4242,
W. Matava
Department of Physics, University of California Berkeley 4 , 366 LeConte Hall 7300, Berkeley, California 94720,
D. N. McKinsey
Department of Physics, University of California Berkeley 4 , 366 LeConte Hall 7300, Berkeley, California 94720,
D. Z. Osterman
University of Massachusetts, Amherst Center for Fundamental Interactions and Department of Physics 5 , Amherst, Massachusetts 01003-9337,
P. K. Patel
University of Massachusetts, Amherst Center for Fundamental Interactions and Department of Physics 9 , 101 Stockbridge Hall, 80 Campus Center Way, Amherst, Massachusetts 01003-9337,
B. Penning
Department of Physics, University of Zurich 11 , Winterthurerstrasse 190, 8057 Zurich,
M. Platt
Department of Physics and Astronomy, Texas A&M University 10 , 4242 TAMU, 578 University Dr., College Station, Texas 77843-4242,
M. Pyle
Department of Physics, University of California Berkeley 4 , 366 LeConte Hall 7300, Berkeley, California 94720,
Y. Qi
M. Reed
Department of Physics, University of California Berkeley 4 , 366 LeConte Hall 7300, Berkeley, California 94720,
I. Rydstrom
Department of Physics, University of California Berkeley 4 , 366 LeConte Hall 7300, Berkeley, California 94720,
R. K. Romani
Department of Physics, University of California Berkeley 4 , 366 LeConte Hall 7300, Berkeley, California 94720,
B. Sadoulet
Department of Physics, University of California Berkeley 4 , 366 LeConte Hall 7300, Berkeley, California 94720,
B. Serfass
Department of Physics, University of California Berkeley 4 , 366 LeConte Hall 7300, Berkeley, California 94720,
P. Sorensen
Lawrence Berkeley National Laboratory 5 , 1 Cyclotron Rd., Berkeley, California 94720,
B. Suerfu
International Center for Quantum-Field Measurement Systems for Studies of the Universe and Particles (QUP, WPI), High Energy Accelerator Research Organization (KEK) 6 , Oho 1-1, Tsukuba, Ibaraki 305-0801,
V. Velan
Lawrence Berkeley National Laboratory 5 , 1 Cyclotron Rd., Berkeley, California 94720,
G. Wang
Y. Wang
S. L. Watkins
University of California Berkeley, Department of Physics 1 , Berkeley, California 94720,
M. R. Williams
Lawrence Berkeley National Laboratory 5 , 1 Cyclotron Rd., Berkeley, California 94720,