Measurement of the bulk radioactive contamination of detector-grade silicon with DAMIC at SNOLAB
Abstrak
We present measurements of bulk radiocontaminants in the high-resistivity silicon CCDs from the DAMIC at SNOLAB experiment. We utilize the exquisite spatial resolution of CCDs to discriminate between $α$ and $β$ decays, and to search with high efficiency for the spatially-correlated decays of various radioisotope sequences. Using spatially-correlated $β$ decays, we measure a bulk radioactive contamination of $^{32}$Si in the CCDs of $140 \pm 30$ $μ$Bq/kg, and place an upper limit on bulk $^{210}$Pb of $< 160~μ$Bq/kg. Using similar analyses of spatially-correlated bulk $α$ decays, we set limits of $< 11$ $μ$Bq/kg (0.9 ppt) on $^{238}$U and of $< 7.3$ $μ$Bq/kg (1.8 ppt) on $^{232}$Th. The ability of DAMIC CCDs to identify and reject spatially-coincident backgrounds, particularly from $^{32}$Si, has significant implications for the next generation of silicon-based dark matter experiments, where $β$'s from $^{32}$Si decay will likely be a dominant background. This capability demonstrates the readiness of the CCD technology to achieve kg-scale dark matter sensitivity.
Topik & Kata Kunci
Penulis (31)
A. Aguilar-Arevalo
D. Amidei
D. Baxter
G. Cancelo
B. A. Cervantes Vergara
A. E. Chavarria
E. Darragh-Ford
J. C. D'Olivo
J. Estrada
F. Favela-Perez
R. Gaïor
Y. Guardincerri
T. W. Hossbach
B. Kilminster
I. Lawson
S. J. Lee
A. Letessier-Selvon
A. Matalon
P. Mitra
A. Piers
P. Privitera
K. Ramanathan
J. Da Rocha
Y. Sarkis
M. Settimo
R. Smida
R. Thomas
J. Tiffenberg
M. Traina
R. Vilar
A. L. Virto
Akses Cepat
- Tahun Terbit
- 2020
- Bahasa
- en
- Sumber Database
- arXiv
- Akses
- Open Access ✓