656 research outputs found

    Four-gap glass RPC as a candidate to a large area thin time-of-flight detector

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    A four-gap glass RPC with 0.3mm gap size was tested with hadron beam as a time-of-flight detector having a time resolution of ~ 100ps. A thickness of the detector together with front-end electronics is ~ 12mm. Results on time resolution dependently on a pad size are presented. This paper contains first result on the timing RPC (with ~ 100ps resolution) having a strip read-out. Study has been done within the HARP experiment (CERN-PS214) R&D work. A obtaned data can be useful if a design of a large area thin timing detector has to be done.Comment: 18 pages, 13 figure

    Lignosulfonate, anionic surfactants and their mixtures influence on water solutions surface tension and zinc concentrate pressure leaching

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    The formation of elemental sulfur during sulfide concentrate pressure leaching leads to the appearance of sulfur-sulfide granules, which significantly reduces zinc dissolution rate. The solution for this problem was the use of surfactants, which prevents the negative effect of molten sulfur, avoiding the granule formation during leaching. Lignosulfonates (waste from the woodworking industry) are most often used as reagents for sulfide concentrate pressure leaching. Influence of individual and mixtures of surfactants on surface tension of aqueous solutions, zinc extraction and size-grade distribution of cakes after sulfide zinc concentrate pressure leaching. Surface tension of aqueous solutions was analyzed by stalagmometric method. Leaching was performed in titanium autoclave in presence of lignosulfonate, sodium dodecylbenzenesulfonate and sodium dodecylsulfate. Solutions after leaching were analyzed on zinc by atomic absorption spectroscopy. Size-grade analysis of cakes after leaching was carried out by laser diffraction particle size analyzer. In this work, synergetic influence was observed of anionic surfactants and lignosulfonate on decreasing of aqueous solutions surface tension. The best results were obtained when LS-SDBS mixture was used, namely in the range of sodium dodecylbenzenesulfonate concentrations 400-600 mg / l. Usage of combined surfactants allowed to achieve high rates of zinc extraction and optimal particle size of cakes after leaching. At Ls and SDBS using zinc extraction was increased from 77,2 % up to 82,8 %, with the bulk of the cake (96,7%) having a particle size of-150 μm. Combined surfactants usage (lignosulfonate and sodium dodecylbenzenesulfonate) can be recommended for applying at pressure leaching of sulfide zinc concentrates. © Published under licence by IOP Publishing Ltd.Leaching experiments and grade size analysis were conducted at the expense of the Russian Science Foundation grant (project No. 18-19-00186)

    Revisiting the 'LSND anomaly' II: critique of the data analysis

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    This paper, together with a preceding paper, questions the so-called 'LSND anomaly': a 3.8 sigma excess of antielectronneutrino interactions over standard backgrounds, observed by the LSND Collaboration in a beam dump experiment with 800 MeV protons. That excess has been interpreted as evidence for the antimuonneutrino to antielectronneutrino oscillation in the \Deltam2 range from 0.2 eV2 to 2 eV2. Such a \Deltam2 range is incompatible with the widely accepted model of oscillations between three light neutrino species and would require the existence of at least one light 'sterile' neutrino. In a preceding paper, it was concluded that the estimates of standard backgrounds must be significantly increased. In this paper, the LSND Collaboration's estimate of the number of antielectronneutrino interactions followed by neutron capture, and of its error, is questioned. The overall conclusion is that the significance of the 'LSND anomaly' is not larger than 2.3 sigma.Comment: 30 pages, 16 figures, 6 table

    Reply to 'Corrections to the HARP-CDP Analysis of the LSND Neutrino Oscillation Backgrounds'

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    The alleged mistakes in recent papers that reanalyze the backgrounds to the 'LSND anomaly' do not exist. We maintain our conclusion that the significance of the 'LSND anomaly' is not 3.8 sigma but not larger than 2.3 sigma.Comment: 3 page

    Investigation into the Influence of Sodium Lignosulfonate, Anionic Surfactants, and Their Mixtures on the Copper Cementation Rate by Zinc

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    Abstract: This article is devoted to the influence of sodium lignosulfonate (SL), anionic surfactants (sodium dodecylsulfate (SDS), sodium dodecylbenzene sulfonate (SDBS)), and their mixtures on the copper cementation rate by zinc. The results demonstrated a copper cementation rate decreasing at LS and SDBS concentrations increasing. Excessive zinc consumption was also detected on copper-ion cementation due to LS and SDBS anion adsorption onto positively charged zinc cathodic areas and copper particles. This led to a decrease in the growth rate of nuclei of copper particles and energy consumption for the formation of new nucleation centers, as well as the creation of conditions for reducing the overvoltage of hydrogen evolution. At the same time, an increase in temperature led to zinc consumption decreasing in the presence of LS. The reagents under investigation could be ranked according to their degree of negative influence on copper cementation increasing in the following order: SDS < SDBS < LS. Testing LS and SDS mixtures showed their irregular influence on the copper cementation rate at different temperatures. In experiments with LS and SDBS mixtures, a linear decrease in the copper-ion cementation rate upon an increase in SDBS concentration and simultaneous zinc-consumption enhancement was fixed. Due to the negative influence of the investigated reagents, we offered a purification method from organic impurities through the use of multilayered alumosilicates modified by cationic surfactants. The results indicate the high effectiveness of removing organic impurities from solutions, which allowed us to increase the cementation rate in the presence of the LS and SDBS mixture by 50% while, at the same time, decreasing zinc consumption. © 2020, Allerton Press, Inc.This work was supported by the Russian Foundation for Basic Research as part of scientific project no. 18-38-00388

    Why the paper CERN-PH-EP-2009-015 (arXiv:0903.4762) is scientifically unacceptable

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    The paper CERN-PH-EP-2009-015 (arXiv:0903.4762) by A. Bagulya et al. violates standards of quality of work and scientific ethics on several counts. The paper contains assertions that contradict established detector physics. The paper falls short of proving the correctness of the authors' concepts and results. The paper ignores or quotes misleadingly pertinent published work. The paper ignores the fact that the authors' concepts and results have already been shown wrong in the published literature. The authors seem unaware that cross-section results from the 'HARP Collaboration' that are based on the paper's concepts and algorithms are in gross disagreement with the results of a second analysis of the same data, and with the results of other experiments.Comment: 8 pages, 3 figure

    Cross-sections of large-angle hadron production in proton- and pion-nucleus interactions VII: tin nuclei and beam momenta from \pm3 GeV/c to \pm15 GeV/c

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    We report on double-differential inclusive cross-sections of the production of secondary protons, charged pions, and deuterons, in the interactions with a 5% nuclear interaction length thick stationary tin target, of proton and pion beams with momentum from \pm3 GeV/c to \pm15 GeV/c. Results are given for secondary particles with production angles between 20 and 125 degrees. Cross-sections on tin nuclei are compared with cross-sections on beryllium, carbon, copper, tantalum and lead nuclei.Comment: 68 pages, 13 figure

    Comparison of Geant4 hadron generation with data from the interactions with beryllium nuclei of +8.9 GeV/c protons and pions, and of -8 GeV/c pions

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    Hadron generation in the Geant4 simulation tool kit is compared with inclusive spectra of secondary protons and pions from the interactions with beryllium nuclei of +8.9 GeV/c protons and pions, and of -8.0 GeV/c pions. The data were taken in 2002 at the CERN Proton Synchrotron with the HARP spectrometer. We report on significant disagreements between data and simulated data especially in the polar-angle distributions of secondary protons and pions.Comment: 15 pages, 13 figure

    Cross-Sections of Large-Angle Hadron Production in Proton- and Pion-Nucleus Interactions V: Lead Nuclei and Beam Momenta from +/-3 Gev/c to +/-15 Gev/c

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    We report on double-differential inclusive cross-sections of the production of secondary protons, charged pions, and deuterons, in the interactions with a 5% nuclear interaction length thick stationary lead target, of proton and pion beams with momentum from +/-3 GeV/c to +/-15 GeV/c. Results are given for secondary particles with production angles 20 to 125 degrees. Cross-sections on lead nuclei are compared with cross-sections on beryllium, copper, and tantalum nuclei.Comment: 67 pages, 13 figures, 47 table
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