Report
Measurement of radioactive contamination in the high-resistivity silicon CCDs of the DAMIC experiment
| العنوان: | Measurement of radioactive contamination in the high-resistivity silicon CCDs of the DAMIC experiment |
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| المؤلفون: | Aguilar-Arevalo, A., Amidei, D., Bertou, X., Bole, D., Butner, M., Cancelo, G., Vázquez, A. Castañeda, Chavarria, A. E., Neto, J. R. T. de Mello, Dixon, S., D'Olivo, J. C., Estrada, J., Moroni, G. Fernandez, Torres, K. P. Hernández, Izraelevitch, F., Kavner, A., Kilminster, B., Lawson, I., Liao, J., López, M., Molina, J., Moreno-Granados, G., Pena, J., Privitera, P., Sarkis, Y., Scarpine, V., Schwarz, T., Haro, M. Sofo, Tiffenberg, J., Machado, D. Torres, Trillaud, F., You, X., Zhou, J. |
| المصدر: | JINST 10 (2015) P08014 |
| سنة النشر: | 2015 |
| المجموعة: | Astrophysics High Energy Physics - Experiment Physics (Other) |
| مصطلحات موضوعية: | Astrophysics - Instrumentation and Methods for Astrophysics, High Energy Physics - Experiment, Physics - Instrumentation and Detectors |
| الوصف: | We present measurements of radioactive contamination in the high-resistivity silicon charge-coupled devices (CCDs) used by the DAMIC experiment to search for dark matter particles. Novel analysis methods, which exploit the unique spatial resolution of CCDs, were developed to identify $\alpha$ and $\beta$ particles. Uranium and thorium contamination in the CCD bulk was measured through $\alpha$ spectroscopy, with an upper limit on the $^{238}$U ($^{232}$Th) decay rate of 5 (15) kg$^{-1}$ d$^{-1}$ at 95% CL. We also searched for pairs of spatially correlated electron tracks separated in time by up to tens of days, as expected from $^{32}$Si-$^{32}$P or $^{210}$Pb-$^{210}$Bi sequences of $\beta$ decays. The decay rate of $^{32}$Si was found to be $80^{+110}_{-65}$ kg$^{-1}$ d$^{-1}$ (95% CI). An upper limit of $\sim$35 kg$^{-1}$ d$^{-1}$ (95% CL) on the $^{210}$Pb decay rate was obtained independently by $\alpha$ spectroscopy and the $\beta$ decay sequence search. These levels of radioactive contamination are sufficiently low for the successful operation of CCDs in the forthcoming 100 g DAMIC detector. Comment: 18 pages, 20 figures |
| نوع الوثيقة: | Working Paper |
| DOI: | 10.1088/1748-0221/10/08/P08014 |
| URL الوصول: | http://arxiv.org/abs/1506.02562 |
| رقم الانضمام: | edsarx.1506.02562 |
| قاعدة البيانات: | arXiv |
| DOI: | 10.1088/1748-0221/10/08/P08014 |
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