DANSS is a highly segmented 1 m3 plastic scintillator detector. Its 2500 one meter long scintillator strips have a Gd-loaded reflective cover. The DANSS detector is placed under an industrial 3.1 ...GWth reactor of the Kalinin Nuclear Power Plant 350 km NW from Moscow. The distance to the core is varied on-line from 10.7 m to 12.7 m. The reactor building provides about 50 m water-equivalent shielding against the cosmic background. DANSS detects almost 5000 ν˜e per day at the closest position with the cosmic background less than 3%. The inverse beta decay process is used to detect ν˜e. Sterile neutrinos are searched for assuming the 4ν model (3 active and 1 sterile ν). The exclusion area in the Δm142,sin22θ14 plane is obtained using a ratio of positron energy spectra collected at different distances. Therefore results do not depend on the shape and normalization of the reactor ν˜e spectrum, as well as on the detector efficiency. Results are based on 966 thousand antineutrino events collected at three different distances from the reactor core. The excluded area covers a wide range of the sterile neutrino parameters up to sin22θ14<0.01 in the most sensitive region.
The R&D results of new tellurium loaded liquid scintillators based on linear alkylbenzene are presented in this work. For the first time, diphenyltellurium dicarboxylates (dipivalate, diisovalerate, ...di-2-ethylhexanoate) are used as tellurium-containing additives. The optical properties (transparency, light yield) of the scintillator have been studied depending on the tellurium concentration, comprehensive studies have been carried out to optimize the composition of the scintillator, the effect of the secondary scintillation solvent on the light yield has been studied, and the long-term stability of Te-LS has been finally established.
•A liquid scintillator based on linear alkylbenzene with a loading of 1% Te has been developed.•The influence of tellurium addition on scintillation properties is investigated.•A new tellurium-loaded liquid scintillator has been proposed for use in large-scale experiments to search for neutrinoless double β-decay.
The DANSS detector is located directly under the nuclear reactor at the Kalinin nuclear power plant. Such a position ensures about 50 m.w.e. shielding from cosmic rays in the vertical direction; as a ...result, the detector occupies an intermediate position between surface and underground detectors in the shielding from cosmic rays. The sensitive volume of the detector consisting of a 1-m
3
plastic scintillator is surrounded by the multilayer passive shielding and muon veto. The main aim of the DANSS experiment is to measure the antineutrino spectrum at various distances from the source. To this end, the detector is placed on a lifting platform in order to record data at three positions of 10.9, 11.9, and 12.9 m from the reactor core. The detector can reconstruct muon tracks passing through its sensitive volume. The pressure, temperature, and decay coefficients for muons in various regions of the zenith angle
have been determined from the muon data collected during four years using the effective generation level method.
Abstract
The paper is aimed to analyse the labour mobility in the region using GIS services. Within the framework of the project, a methodology for continuous automatic collection and accumulation of ...information on the state of the transport network and weather conditions was developed, tested and implemented. Based on this information, it is possible to analyse the important factors of the regional economy: temporary and financial losses of residents of the Moscow Region on the home-to-work paths, as well as identify patterns of traffic congestion from various factors. The first results of the analysis of the accumulated data are presented, which demonstrate the commuting effects in the regional transport network.
The DANSS detector (Alekseev et al. in JINST 11:P11011, 2016) is located directly below a commercial reactor core at the Kalinin Nuclear Power Plant. Such a position provides an overburden about 50 ...m.w.e. in vertical direction. In terms of the cosmic rays it occupies an intermediate position between surface and underground detectors. The sensitive volume of the detector is a cubic meter of plastic scintillator with fine segmentation and combined PMT and SiPM readout, surrounded by multilayer passive and active shielding. The detector can reconstruct muon tracks passing through its sensitive volume. The main physics goal of the DANSS experiment implies the antineutrino spectra measurements at various distances from the source. This is achieved by means of a lifting platform so that the data is taken in three positions – 10.9, 11.9 and 12.9 meters from the reactor core. The muon data were collected for nearly four calendar years. The overburden parameters
⟨
E
thr
cos
θ
⟩
and
⟨
E
thr
⟩
, as well as the temperature and barometric correlation coefficients are evaluated separately for the three detector positions and, in each position, in three ranges of the zenith angle – for nearly vertical muons with
cos
θ
>
0.9
, for nearly horizontal muons with
cos
θ
<
0.36
, and for the whole upper hemisphere.
Based on the studies of data for the Moscow region for 2001–2014, this paper proposes a method for assessing the long-term dynamics of labor commuting according to the dynamics of its key factors, ...including the population’s income, the cost of housing, and the cost of intraregional travels. It has been shown that these parameters did not undergo radical changes in the studied period: this indicates the stability of the structure and dynamics of labor commuting in the Moscow region. The forecast for the development of the situation in the near future has been discussed.
A possible right-handed component affecting electron-neutrino helicity is probed using a Compton polarimeter. Compared to previous experiments of this kind, the systematic uncertainty is ...significantly reduced by independently calibrating the polarimeter efficiency. The electron-neutrino helicity is measured as
in agreement with previous measurements. The bigger than expected total error on
H
largely arises from the relatively low efficiency of the polarimeter. In connection with this, one should reanalyze the results of previous experiments.
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