9 research outputs found
Skipper-CCD sensors for the Oscura experiment: requirements and preliminary tests
Oscura is a proposed multi-kg skipper-CCD experiment designed for a dark matter (DM) direct detection search that will reach unprecedented sensitivity to sub-GeV DM-electron interactions with its 10 kg detector array. Oscura is planning to operate at SNOLAB with 2070 m overburden, and aims to reach a background goal of less than one event in each electron bin in the 2-10 electron ionization-signal region for the full 30 kg-year exposure, with a radiation background rate of 0.01 dru.[1 dru (differential rate unit) corresponds to 1 event/kg/day/keV.] In order to achieve this goal, Oscura must address each potential source of background events, including instrumental backgrounds. In this work, we discuss the main instrumental background sources and the strategy to control them, establishing a set of constraints on the sensors' performance parameters. We present results from the tests of the first fabricated Oscura prototype sensors, evaluate their performance in the context of the established constraints and estimate the Oscura instrumental background based on these results
Searching for millicharged particles with 1 kg of Skipper-CCDs using the NuMI beam at Fermilab
Oscura is a planned light-dark matter search experiment using Skipper-CCDs with a total active mass of 10 kg. As part of the detector development, the collaboration plans to build the Oscura Integration Test (OIT), an engineering test with 10% of the total mass. Here we discuss the early science opportunities with the OIT to search for millicharged particles (mCPs) using the NuMI beam at Fermilab. mCPs would be produced at low energies through photon-mediated processes from decays of scalar, pseudoscalar, and vector mesons, or direct Drell-Yan productions. Estimates show that the OIT would be a world-leading probe for mCPs in the ∼MeV mass range
Search for coherent elastic neutrino-nucleus scattering at a nuclear reactor with CONNIE 2019 data
The Coherent Neutrino-Nucleus Interaction Experiment (CONNIE) is taking data
at the Angra 2 nuclear reactor with the aim of detecting the coherent elastic
scattering of reactor antineutrinos with silicon nuclei using charge-coupled
devices (CCDs). In 2019 the experiment operated with a hardware binning applied
to the readout stage, leading to lower levels of readout noise and improving
the detection threshold down to 50 eV. The results of the analysis of 2019 data
are reported here, corresponding to the detector array of 8 CCDs with a
fiducial mass of 36.2 g and a total exposure of 2.2 kg-days. The difference
between the reactor-on and reactor-off spectra shows no excess at low energies
and yields upper limits at 95% confidence level for the neutrino interaction
rates. In the lowest-energy range, 50-180 eV, the expected limit stands at 34
(39) times the standard model prediction, while the observed limit is 66 (75)
times the standard model prediction with Sarkis (Chavarria) quenching factors.Comment: 23 pages, 14 figure
Skipper-CCD Sensors for the Oscura Experiment: Requirements and Preliminary Tests
Oscura is a proposed multi-kg skipper-CCD experiment designed for a dark
matter (DM) direct detection search that will reach unprecedented sensitivity
to sub-GeV DM-electron interactions with its 10 kg detector array. Oscura is
planning to operate at SNOLAB with 2070 m overburden, and aims to reach a
background goal of less than one event in each electron bin in the 2-10
electron ionization-signal region for the full 30 kg-year exposure, with a
radiation background rate of 0.01 dru. In order to achieve this goal, Oscura
must address each potential source of background events, including instrumental
backgrounds. In this work, we discuss the main instrumental background sources
and the strategy to control them, establishing a set of constraints on the
sensors' performance parameters. We present results from the tests of the first
fabricated Oscura prototype sensors, evaluate their performance in the context
of the established constraints and estimate the Oscura instrumental background
based on these results
Early Science with the Oscura Integration Test
Oscura is a planned light-dark matter search experiment using Skipper-CCDs
with a total active mass of 10 kg. As part of the detector development, the
collaboration plans to build the Oscura Integration Test (OIT), an engineering
test experiment with 10% of the Oscura's total mass. Here we discuss the early
science opportunities with the OIT to search for millicharged particles (mCPs)
using the NuMI beam at Fermilab. mCPs would be produced at low energies through
photon-mediated processes from decays of scalar, pseudoscalar, and vector
mesons, or direct Drell-Yan productions. Estimates show that the OIT would be a
world-leading probe for low-mass mCPs.Comment: 21 pages, 13 figure
Skipper-CCD sensors for the Oscura experiment: Requirements and preliminary tests
Oscura collaboration: et al.Oscura is a proposed multi-kg skipper-CCD experiment designed for a dark matter (DM) direct detection search that will reach unprecedented sensitivity to sub-GeV DM-electron interactions with its 10 kg detector array. Oscura is planning to operate at SNOLAB with 2070 m overburden, and aims to reach a background goal of less than one event in each electron bin in the 2–10 electron ionization-signal region for the full 30 kg-year exposure, with a radiation background rate of 0.01 dru.[1 dru (differential rate unit) corresponds to 1 event/kg/day/keV.] In order to achieve this goal, Oscura must address each potential source of background events, including instrumental backgrounds. In this work, we discuss the main instrumental background sources and the strategy to control them, establishing a set of constraints on the sensors' performance parameters. We present results from the tests of the first fabricated Oscura prototype sensors, evaluate their performance in the context of the established constraints and estimate the Oscura instrumental background based on these results.This document was prepared by members of the Oscura collaboration using the resources of the Fermi National Accelerator Laboratory (Fermilab), a U.S. Department of Energy, Office of Science, HEP User Facility. Fermilab is managed by Fermi Research Alliance, LLC (FRA), acting under Contract No. DE-AC02-07CH11359. Also, part of this work was performed at the Center for Nanoscale Materials, a U.S. Department of Energy Office of Science User Facility, and was supported by the U.S. DOE, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357.Peer reviewe
SENSEI: First Direct-Detection Results on sub-GeV Dark Matter from SENSEI at SNOLAB
International audienceWe present the first results from a dark matter search using six Skipper-CCDs in the SENSEI detector operating at SNOLAB. With an exposure of 534.9 gram-days from well-performing sensors, we select events containing 2 to 10 electron-hole pairs. After aggressively masking images to remove backgrounds, we observe 55 two-electron events, 4 three-electron events, and no events containing 4 to 10 electrons. The two-electron events are consistent with pileup from one-electron events. Among the 4 three-electron events, 2 appear in pixels that are likely impacted by detector defects, although not strongly enough to trigger our "hot-pixel" mask. We use these data to set world-leading constraints on sub-GeV dark matter interacting with electrons and nuclei
SENSEI: First Direct-Detection Results on sub-GeV Dark Matter from SENSEI at SNOLAB
International audienceWe present the first results from a dark matter search using six Skipper-CCDs in the SENSEI detector operating at SNOLAB. With an exposure of 534.9 gram-days from well-performing sensors, we select events containing 2 to 10 electron-hole pairs. After aggressively masking images to remove backgrounds, we observe 55 two-electron events, 4 three-electron events, and no events containing 4 to 10 electrons. The two-electron events are consistent with pileup from one-electron events. Among the 4 three-electron events, 2 appear in pixels that are likely impacted by detector defects, although not strongly enough to trigger our "hot-pixel" mask. We use these data to set world-leading constraints on sub-GeV dark matter interacting with electrons and nuclei
Searching for millicharged particles with 1 kg of Skipper-CCDs using the NuMI beam at Fermilab
Abstract Oscura is a planned light-dark matter search experiment using Skipper-CCDs with a total active mass of 10 kg. As part of the detector development, the collaboration plans to build the Oscura Integration Test (OIT), an engineering test with 10% of the total mass. Here we discuss the early science opportunities with the OIT to search for millicharged particles (mCPs) using the NuMI beam at Fermilab. mCPs would be produced at low energies through photon-mediated processes from decays of scalar, pseudoscalar, and vector mesons, or direct Drell-Yan productions. Estimates show that the OIT would be a world-leading probe for mCPs in the ∼MeV mass range