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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.
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 $alpha$ and $beta$ decays, and to search with high
The General AntiParticle Spectrometer (GAPS) is an Antarctic balloon-borne detector designed to measure low-energy cosmic antinuclei (< 0.25 GeV/n), with a specific focus on antideuterons, as a distinctive signal from dark matter annihilation or deca
We report on a measurement of the attenuation length for the scintillation light in the tonne size liquid argon target of the ArDM dark matter experiment. The data was recorded in the first underground operation of the experiment in single-phase oper
A measurement of the absolute fluorescence yield of the 337 nm nitrogen band, relevant to ultra-high energy cosmic ray (UHECR) detectors, is reported. Two independent calibrations of the fluorescence emission induced by a 120 GeV proton beam were emp
Low-noise, position-sensitive Silicon Drift Detectors (SDDs) are particularly useful for experiments in which a good energy resolution combined with a large sensitive area is required, as in the case of X-ray astronomy space missions and medical appl