skip to main content

DOE PAGESDOE PAGES

Title: Measurement of low energy ionization signals from Compton scattering in a charge-coupled device dark matter detector [Measurement of low energy ionization signals from Compton scattering in a CCD dark matter detector]

In this paper, an important source of background in direct searches for low-mass dark matter particles are the energy deposits by small-angle scattering of environmental γ rays. We report detailed measurements of low-energy spectra from Compton scattering of γ rays in the bulk silicon of a charge-coupled device (CCD). Electron recoils produced by γ rays from 57Co and 241Am radioactive sources are measured between 60 eV and 4 keV. The observed spectra agree qualitatively with theoretical predictions, and characteristic spectral features associated with the atomic structure of the silicon target are accurately measured for the first time. A theoretically motivated parametrization of the data that describes the Compton spectrum at low energies for any incident γ-ray flux is derived. The result is directly applicable to background estimations for low-mass dark matter direct-detection experiments based on silicon detectors, in particular for the DAMIC experiment down to its current energy threshold.
Authors:
 [1] ;  [2] ;  [1] ;  [1] ;  [2] ;  [1] ;  [1] ;  [1] ;  [3] ;  [3] ;  [4]
  1. The Univ. of Chicago, Chicago, IL (United States)
  2. Univ. of Michigan, Ann Arbor, MI (United States)
  3. Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
  4. Univ. Nacional de Asuncion, Asuncion (Paraguay)
Publication Date:
Report Number(s):
FERMILAB-PUB-17-221-AE; arXiv:1706.06053
Journal ID: ISSN 2470-0010; PRVDAQ; 1605730
Grant/Contract Number:
AC02-07CH11359
Type:
Accepted Manuscript
Journal Name:
Physical Review D
Additional Journal Information:
Journal Volume: 96; Journal Issue: 4; Journal ID: ISSN 2470-0010
Publisher:
American Physical Society (APS)
Research Org:
Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
Sponsoring Org:
USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)
Country of Publication:
United States
Language:
English
Subject:
79 ASTRONOMY AND ASTROPHYSICS; 46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
OSTI Identifier:
1459593

Ramanathan, K., Kavner, A., Chavarria, A. E., Privitera, P., Amidei, D., Chou, T. -L., Matalon, A., Thomas, R., Estrada, J., Tiffenberg, J., and Molina, J.. Measurement of low energy ionization signals from Compton scattering in a charge-coupled device dark matter detector [Measurement of low energy ionization signals from Compton scattering in a CCD dark matter detector]. United States: N. p., Web. doi:10.1103/PhysRevD.96.042002.
Ramanathan, K., Kavner, A., Chavarria, A. E., Privitera, P., Amidei, D., Chou, T. -L., Matalon, A., Thomas, R., Estrada, J., Tiffenberg, J., & Molina, J.. Measurement of low energy ionization signals from Compton scattering in a charge-coupled device dark matter detector [Measurement of low energy ionization signals from Compton scattering in a CCD dark matter detector]. United States. doi:10.1103/PhysRevD.96.042002.
Ramanathan, K., Kavner, A., Chavarria, A. E., Privitera, P., Amidei, D., Chou, T. -L., Matalon, A., Thomas, R., Estrada, J., Tiffenberg, J., and Molina, J.. 2017. "Measurement of low energy ionization signals from Compton scattering in a charge-coupled device dark matter detector [Measurement of low energy ionization signals from Compton scattering in a CCD dark matter detector]". United States. doi:10.1103/PhysRevD.96.042002. https://www.osti.gov/servlets/purl/1459593.
@article{osti_1459593,
title = {Measurement of low energy ionization signals from Compton scattering in a charge-coupled device dark matter detector [Measurement of low energy ionization signals from Compton scattering in a CCD dark matter detector]},
author = {Ramanathan, K. and Kavner, A. and Chavarria, A. E. and Privitera, P. and Amidei, D. and Chou, T. -L. and Matalon, A. and Thomas, R. and Estrada, J. and Tiffenberg, J. and Molina, J.},
abstractNote = {In this paper, an important source of background in direct searches for low-mass dark matter particles are the energy deposits by small-angle scattering of environmental γ rays. We report detailed measurements of low-energy spectra from Compton scattering of γ rays in the bulk silicon of a charge-coupled device (CCD). Electron recoils produced by γ rays from 57Co and 241Am radioactive sources are measured between 60 eV and 4 keV. The observed spectra agree qualitatively with theoretical predictions, and characteristic spectral features associated with the atomic structure of the silicon target are accurately measured for the first time. A theoretically motivated parametrization of the data that describes the Compton spectrum at low energies for any incident γ-ray flux is derived. The result is directly applicable to background estimations for low-mass dark matter direct-detection experiments based on silicon detectors, in particular for the DAMIC experiment down to its current energy threshold.},
doi = {10.1103/PhysRevD.96.042002},
journal = {Physical Review D},
number = 4,
volume = 96,
place = {United States},
year = {2017},
month = {8}
}