We calculate beta spectrum of Ce-Pr-144 taking into account several types of corrections. The result is compared with the experimental data obtained at NRC Kurchatov Institute. Using this comparison ...we estimate the reliability of theoretical calculations for electron and antineutrino spectra from beta decay.
We report a reanalysis of the reactor antineutrino energy spectra based on the new relative measurements of the ratio R = eS5/eS9 between cumulative β spectra from 235 U and 239 Pu , performed at a ...research reactor in National Research Centre Kurchatov Institute (KI). A discrepancy with the β spectra measured at Institut Laue-Langevin (ILL) was observed, indicating a steady excess of the ILL ratio by the factor of 1.054 ± 0.002. We find a value of the ratio between inverse beta decay cross section per fission for 235U and 239Pu: (5σf/9σf) KI = 1.45 ± 0.03 , and then we reevaluate the converted antineutrino spectra for 235U and 238U. We conclude that the new predictions are consistent with the results of Daya Bay and STEREO experiments.
We present new results based on the entire CHOOZ (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) data sample. We find (at 90% confidence level) no evidence for neutrino oscillations in the
ν
̄
e
disappearance mode, for the parameter region given by approximately
δm
2>7·10
−4
eV
2
for maximum mixing, and sin
22
θ=0.10 for large
δm
2. Lower sensitivity results, based only on the comparison of the positron spectra from the two different-distance nuclear reactors, are also presented; these are independent of the absolute normalization of the
ν
̄
e
flux, the cross section, the number of target protons and the detector efficiencies.
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.
Abstract The stability of a dark matter detector on the timescale of a few years is a key requirement due to the large exposure needed to achieve a competitive sensitivity. It is especially crucial ...to enable the detector to potentially detect any annual event rate modulation, an expected dark matter signature. In this work, we present the performance history of the DarkSide-50 dual-phase argon time projection chamber over its almost three-year low-radioactivity argon run. In particular, we focus on the electroluminescence signal that enables sensitivity to sub-keV energy depositions. The stability of the electroluminescence yield is found to be better than 0.5%. Finally, we show the temporal evolution of the observed event rate around the sub-keV region being consistent to the background prediction.
The iDREAM (industrial Detector for reactor antineutrino monitoring) project is aimed at remote monitoring of the operating modes of the atomic reactor on nuclear power plant to ensure a technical ...support of IAEA non-proliferation safeguards. The detector is a scintillator spectrometer. The sensitive volume (target) is filled with a liquid organic scintillator based on linear alkylbenzene where reactor antineutrinos will be detected via inverse beta-decay reaction. We present first results of laboratory tests after physical launch. The detector was deployed at sea level without background shielding. The number of calibrations with radioactive sources was conducted. All data were obtained by means of a slow control system which was put into operation.
A prototype of the calibration system for the Liquid Scintillator Veto (LSV) and for the Water Cherenkov Veto (WCV) of the DarkSide detector have been developed. The instrument consists of a fast ...double output flasher which can be configured and controlled via USB, the appropriate application software. UV, visible or combination of both LEDs could be installed. Flashes amplitude, repetition rate and delay time between two continuous pulses are adjustable. High -OH silica fibers are used to minimize intensity losses on the delivery path. X shape splitter is used to combine two LED's pigtailed output and then to split the sum of the signals. One output feeds calibration path to the detector, while the second is used for pulse-to-pulse measurement of the flash intensity with compatible photodiode in combination with Flash ADC. The instrument allows to simulate point-like physical events in very wide energy range from a few hundred keV up to several dozen of MeV. Additional studies (pile-up analysis, spatial reconstruction, quenching as a function of position and wavelength) can be performed due to double-LEDs scheme and possibility of fast replacement of diodes.
The 2nd International Conference on Particle Physics and Astrophysics (ICPPA-2016) was held in Moscow, Russia, from October 10 to 14, 2016. The conference is organized by the National Research ...Nuclear University "MEPhI". The aim of the Conference is to promote contacts between scientists and to develop new ideas in fundamental research. We bring together experts and young scientists working on experimental and theoretical aspects of nuclear, particle and astroparticle physics and cosmology. The conference covers a wide range of topics such as accelerator physics, (astro) particle physics, cosmic rays, cosmology and methods of experimental physics: detectors and instruments. These directions are unified by development of the Standard Model which is evidently not complete. There are deviations from the Standard Model: neutrino oscillations, the dark matter existence. Together with strong interactions they are main subjects of the Conference. New results from leading high energy physics collaborations are discussed. Main LHC experiments (ATLAS, CMS, ALICE) presented their results and detector upgrade prospects on the conference. Various aspects of Standard Model testing and search for new phenomena are main subjects of the conference. Among them: flavor physics at B factories, precision multi-boson production measurements, dark matter searches. Electroweak interaction was discussed in the talks given by participants of neutrino physics experiments (Borexino, Neutrino-4, SOX, T2K and others). Enigmatic properties of neutrinos such as their tiny masses, oscillations between different neutrino types, cannot be explained in frame of the modern theory and require new approaches. Properties of neutrinos influenced the formation of the large-scale structure of the Universe and may be neutrinos are partially responsible for the excess of matter over anti-matter. Also our current challenge is the nature of the Dark matter. Many opportunities arise with the development of neutrino detection technologies comprising: measurements of neutrinos from the Sun, measurements of geo-neutrino from the deep interior of the Earth, detecting neutrino fluxes from supernovae and different astrophysical sources. They were the subject of discussion which have been held at the conference. Neutrino physics experiments make huge demands to technologies like ultra-high precision measurements, huge detector size, excellent reliability and ultra-low radioactive background. Acknowledgments We are thankful to Anotonova M M, Buzhan P Zh, Gurov Yu B, Vdovkina S S, Zherebtsova E S, Esipova E A, Kovylyaeva A A, Kozlov E S, Koshelenko D D, Matveev N A, Mayorov A G, Nigmatkulov G A, Novikov A S, Svadkovsky I V, Smirnov Yu S, Voronov S A and Yurin K O for the assistance in organizing the conference and heavy work on proceedings. Conference organizers would like to express their gratitude to the TFT company (supply and maintenance of CAEN equipment, delivery of equipment and components for scientific research) for their support.
Reactor antineutrino detector iDREAM Gromov, M B; Lukyanchenko, G A; Novikova, G J ...
Journal of physics. Conference series,
09/2017, Letnik:
888, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Industrial Detector for Reactor Antineutrino Monitoring (iDREAM) is a compact (≈ 3.5m2) industrial electron antineutrino spectrometer. It is dedicated for remote monitoring of PWR reactor operational ...modes by neutrino method in real-time. Measurements of antineutrino flux from PWR allow to estimate a fuel mixture in active zone and to check the status of the reactor campaign for non-proliferation purposes. LAB-based gadolinium doped scintillator is exploited as a target. Multizone architecture of the detector with gamma-catcher surrounding fiducial volume and plastic muon veto above and below ensure high efficiency of IBD detection and background suppression. DAQ is based on Flash ADC with PSD discrimination algorithms while digital trigger is programmable and flexible due to FPGA. The prototype detector was started up in 2014. Preliminary works on registration Cerenkov radiation produced by cosmic muons were established with distilled water inside the detector in order to test electronic and slow control systems. Also in parallel a long-term measurements with different scintillator samples were conducted.
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