Industrial Detector of REactor Antineutrinos for Monitoring (iDREAM) is a 1 ton Gd-doped liquid scintillator detector mounted in the Kalinin nuclear power plant (Russia), 20 m from the 3 GW
VVER type ...commercial reactor. Antineutrinos are detected via inverse beta decay on protons. Beginning in 2021, the detector is collecting data both in reactor ON and OFF modes. The first iDREAM antineutrino results are presented, showing no doubt on the proper operation of the detector as a counting device.
This final article about the CHOOZ experiment presents a complete description of the \(\bar{\nu}_e\) source and detector, the calibration methods and stability checks, the event reconstruction ...procedures and the Monte Carlo simulation. The data analysis, systematic effects and the methods used to reach our conclusions are fully discussed. Some new remarks are presented on the deduction of the confidence limits and on the correct treatment of systematic errors.
A Passive Shield for the RED-100 Neutrino Detector Akimov, D. Yu; Aleksandrov, I. S.; Belov, V. A. ...
Instruments and experimental techniques (New York),
03/2021, Volume:
64, Issue:
2
Journal Article
Peer reviewed
Open access
—
A combined passive shield of the RED-100 two-phase emission neutrino detector has been developed and built for suppressing the background of external γ rays and neutrons. The shield is composed of ...a 5‑cm-thick copper layer (the inner layer is adjacent to the detector) and a water layer with a total thickness of approximately 70 cm (including the water inside the copper shield). The Monte Carlo simulation of the shielding efficiency has been performed. The obtained attenuation factor of the copper shield for the γ-ray background has been experimentally verified in a laboratory test using a NaI(Tl) scintillator detector. The γ‑ray background rejection factor of the full shield has also been calculated.
Initial results are presented from CHOOZ
1
The CHOOZ experiment is named after the new nuclear power station operated by Électricité de France (EdF) near the village of Chooz in the Ardennes region ...of France.
1
, a long-baseline reactor-neutrino vacuum-oscillation experiment. The data reported here were taken during the period March to October 1997, when the two reactors ran at combined power levels varying from zero to values approaching their full rated power of 8.5
GW
(thermal). Electron antineutrinos from the reactors were detected by a liquid scintillation calorimeter located at a distance of about 1
km
. The detector was constructed in a tunnel protected from cosmic rays by a 300
MWE
rock overburden. This massive shielding strongly reduced potentially troublesome backgrounds due to cosmic-ray muons, leading to a background rate of about one event per day, more than an order of magnitude smaller than the observed neutrino signal. From the statistical agreement between detected and expected neutrino event rates, we find (at 90% confidence level) no evidence for neutrino oscillations in the
ν
e
disappearance mode for the parameter region given approximately by
Δm
2>0.9
10
−3
eV
2
for maximum mixing and sin
22
θ>0.18 for large
Δm
2.
—
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.
The technology of preparing a linear-alkylbenzene-based gadolinium-doped liquid organic scintillator (Gd-LOS) as a target material in reactor antineutrino detectors has been developed. Results of ...longterm measurements of the light yield of Gd-LOS in contact with acryl and stainless steel are presented, which confirm the compatibility of Gd-LOS with these materials. The measurements were performed for two otherwise identical LOS detectors only differing in wall materials of the sensitive volume: acryl versus stainless steel. The results of measurements over about one year showed almost the same, relatively small decreases in the light yield of both detectors. It is concluded that both structural materials can be used in detector parts contacting with Gd-doped scintillator. Such a long-term parallel comparative test was carried out for the first time.
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