Armengaud, E., Arnaud, Q., Augier, C. et al. (60 more authors) (2017) Performance of the EDELWEISS-III experiment for direct dark matter searches. Journal of Instrumentation, 12. P08010. ISSN 1748-0221
Abstract
We present the results of measurements demonstrating the efficiency of the EDELWEISS-III array of cryogenic germanium detectors for direct dark matter searches. The experimental setup and the FID (Fully Inter-Digitized) detector array is described, as well as the efficiency of the double measurement of heat and ionization signals in background rejection. For the whole set of 24 FID detectors used for coincidence studies, the baseline resolutions for the fiducial ionization energy are mainly below 0.7 keV$_{ee}$ (FHWM) whereas the baseline resolutions for heat energies are mainly below 1.5 keV$_{ee}$ (FWHM). The response to nuclear recoils as well as the very good discrimination capability of the FID design has been measured with an AmBe source. The surface $\beta$- and $\alpha$-decay rejection power of $R_{\rm surf} < 4 \times 10^{-5}$ per $\alpha$ at 90% C.L. has been determined with a $^{210}$Pb source, the rejection of bulk $\gamma$-ray events has been demonstrated using $\gamma$-calibrations with $^{133}$Ba sources leading to a value of $R_{\gamma{\rm -mis-fid}} < 2.5 \times 10^{-6}$ at 90% C.L.. The current levels of natural radioactivity measured in the detector array are shown as the rate of single $\gamma$ background. The fiducial volume fraction of the FID detectors has been measured to a weighted average value of $(74.6 \pm 0.4)\%$ using the cosmogenic activation of the $^{65}$Zn and $^{68,71}$Ge isotopes. The stability and uniformity of the detector response is also discussed. The achieved resolutions, thresholds and background levels of the upgraded EDELWEISS-III detectors in their setup are thus well suited to the direct search of WIMP dark matter over a large mass range.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2017 IOP Publishing Ltd and Sissa Medialab. This is an author produced version of a paper subsequently published in Journal of Instrumentation. Uploaded in accordance with the publisher's self-archiving policy. |
Keywords: | Dark Matter detectors (WIMPs, axions, etc.); Cryogenic detectors; Solid state detectors; Large detector-systems performance |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Science (Sheffield) > Department of Physics and Astronomy (Sheffield) |
Funding Information: | Funder Grant number SCIENCE AND TECHNOLOGY FACILITIES COUNCIL ST/H000917/1 Science and Technology Facilities Council ST/N000277/1 |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 09 Jun 2017 11:54 |
Last Modified: | 16 Aug 2018 00:38 |
Published Version: | https://doi.org/10.1088/1748-0221/12/08/P08010 |
Status: | Published |
Publisher: | IOP Publishing |
Refereed: | Yes |
Identification Number: | 10.1088/1748-0221/12/08/P08010 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:117516 |