We report the first measurement of coherent elastic neutrino-nucleus scattering (CEvNS) on argon using a liquid argon detector at the Oak Ridge National Laboratory Spallation Neutron Source. Two ...independent analyses prefer CEvNS over the background-only null hypothesis with greater than 3σ significance. The measured cross section, averaged over the incident neutrino flux, is (2.2±0.7)×10^{-39} cm^{2}-consistent with the standard model prediction. The neutron-number dependence of this result, together with that from our previous measurement on CsI, confirms the existence of the CEvNS process and provides improved constraints on nonstandard neutrino interactions.
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The COHERENT Collaboration searched for scalar dark matter particles produced at the Spallation Neutron Source with masses between 1 and 220 MeV/c^{2} using a CsINa scintillation detector sensitive ...to nuclear recoils above 9 keV_{nr}. No evidence for dark matter is found and we thus place limits on allowed parameter space. With this low-threshold detector, we are sensitive to coherent elastic scattering between dark matter and nuclei. The cross section for this process is orders of magnitude higher than for other processes historically used for accelerator-based direct-detection searches so that our small, 14.6 kg detector significantly improves on past constraints. At peak sensitivity, we reject the flux consistent with the cosmologically observed dark-matter concentration for all coupling constants α_{D}<0.64, assuming a scalar dark-matter particle. We also calculate the sensitivity of future COHERENT detectors to dark-matter signals which will ambitiously test multiple dark-matter spin scenarios.
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4.
The RED-100 experiment Akimov, D.Yu; Alexandrov, I.S.; Alyev, R.R. ...
Journal of instrumentation,
11/2022, Volume:
17, Issue:
11
Journal Article
Peer reviewed
Open access
Abstract
The RED-100 two-phase xenon emission detector has been
deployed at 19-m distance from the reactor core of the Kalinin
Nuclear Power Plant (KNPP) in 2021–2022 for investigation of the
...possibility to observe reactor antineutrinos using the effect of
coherent elastic neutrino-nucleus scattering (CE
ν
NS). The
performance of the main systems of the RED-100 setup at operating
nuclear power plant is described. There is no correlation of the
radioactive background at the experimental setup site with ON and
OFF states of the reactor. The data taking run was carried out at
the beginning of the year 2022 and covered both the reactor OFF and
ON periods.
We present the first direct experimental confirmation of the fast component re-emission in liquid argon (LAr) doped with xenon (Xe). This effect was studied at various Xe concentrations up to ∼3000 ...ppm. The rate constant of energy transfer for the fast component was quantified. It was shown that LAr doped with a high concentration of Xe without TPB has a better Pulse Shape Discrimination (PSD) efficiency than pure LAr or Xe-doped LAr with TPB. The stability of LAr+Xe mixture was tested for the first time at high Xe concentration for long continuous runtimes.
Abstract
The RED-100 experiment with a liquid xenon target was
carried out at Kalinin Nuclear Power Plant. The goal of the
experiment is the detection and study of the coherent elastic
neutrino ...nucleus scattering process (CEνNS) for the low-energy
antineutrinos in close vicinity to a reactor core. A good
understanding of the external radioactive background is needed to
achieve this goal. This paper describes the external background
conditions for the RED-100 experiment at Kalinin Nuclear Power
Plant.
We report on the technical design and expected performance of a 592 kg heavy-water-Cherenkov detector to measure the absolute neutrino flux from the pion-decay-at-rest neutrino source at the ...Spallation Neutron Source (SNS) at Oak Ridge National Laboratory (ORNL). The detector will be located roughly 20 m from the SNS target and will measure the neutrino flux with better than 5% statistical uncertainty in 2 years. This heavy-water detector will serve as the first module of a two-module detector system to ultimately measure the neutrino flux to 2–3% at both the First Target Station and the planned Second Target Station of the SNS. This detector will significantly reduce a dominant systematic uncertainty for neutrino cross-section measurements at the SNS, increasing the sensitivity of searches for new physics.
Abstract
We present results of several measurements of CsINa
scintillation response to 3–60 keV energy nuclear recoils
performed by the COHERENT collaboration using tagged neutron elastic
scattering ...experiments and an endpoint technique. Earlier results,
used to estimate the coherent elastic neutrino-nucleus scattering
(CEvNS) event rate for the first observation of this process
achieved by COHERENT at the Spallation Neutron Source (SNS), have
been reassessed. We discuss corrections for the identified
systematic effects and update the respective uncertainty values. The
impact of updated results on future precision tests of CEvNS is
estimated. We scrutinize potential systematic effects that could
affect each measurement. In particular we confirm the response of
the H11934-200 Hamamatsu photomultiplier tube (PMT) used for the
measurements presented in this study to be linear in the relevant
signal scale region.
Abstract
We present the analysis and results of the first dataset
collected with the MARS neutron detector
deployed at the Oak Ridge National
Laboratory Spallation Neutron Source (SNS) for the ...purpose of
monitoring and characterizing the beam-related neutron (BRN) background
for the COHERENT collaboration. MARS was positioned
next to the COH-CsI coherent elastic neutrino-nucleus scattering detector
in the SNS basement corridor. This is the basement location of
closest proximity to the SNS target and thus, of highest neutrino flux,
but it is also well shielded from the BRN flux by infill concrete
and gravel. These data show the detector registered roughly one BRN per day.
Using MARS' measured detection efficiency, the incoming
BRN flux is estimated to be 1.20 ± 0.56 neutrons/m^2/MWh
for neutron energies above ∼3.5 MeV and up to a few tens of MeV.
We compare our results with previous BRN measurements in the SNS basement corridor
reported by other neutron detectors.
—
It is shown that the working volume of the RED-100 two-phase emission detector, which operates in a ground-based laboratory with liquid xenon used as a working substance, is a source of ...single-electron noise signals with a characteristic frequency of ~200 kHz. Possible mechanisms of generation of these noises and methods for their suppression are discussed.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
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