171 research outputs found

    Improving the Fermilab Booster Notching Efficiency, Beam Losses and Radiation Levels

    Full text link
    Currently a fast vertical 1.08-m long kicker (notcher) located in the Fermilab Booster Long-5 straight section is used to remove 3 out of 84 circulating bunches after injection to generate an abort gap. With magnetic field of 72.5 Gauss it removes only 87% of the 3-bunch intensity at 400 MeV, with 75% loss on pole tips of the focusing Booster magnets, 11% on the Long-6 collimators, and 1% in the rest of the ring. We propose to improve the notching efficiency and reduce beam loss in the Booster by using two horizontal kickers in the Long-12 section. The STRUCT calculations show that using such horizontal notchers, one can remove up to 99% of the 3-bunch intensity at 400-700 MeV, directing 96% of it to a new beam dump at the Long-13 section. This fully decouples notching and collimation. The beam dump absorbs most of the impinging proton energy in its jaws. The latter are encapsulated into an appropriate radiation shielding that reduces impact on the machine components, personnel and environment to the tolerable levels. The MARS simulations show that corresponding prompt and residual radiation levels can be reduced ten times compared to the current ones.Comment: 4 pp. 3rd International Particle Accelerator Conference (IPAC 2012) 20-25 May 2012. New Orleans, Louisian

    Measurement of xF3xF_3 and F2F_2 Structure Functions in Low Q2Q^2 Region with the IHEP-JINR Neutrino Detector

    Full text link
    The isoscalar structure functions xF3xF_3 and F2F_2 are measured as functions of xx averaged over all Q2Q^2 permissible for the range of 6 to 28 GeV of incident neutrino (anti-neutrino) energy at the IHEP-JINR Neutrino Detector. The QCD analysis of xF3xF_3 structure function provides ΛMSˉ(4)=(411±200)\Lambda_{\bar{MS}}^{(4)} = (411 \pm 200) MeV under the assumption of QCD validity in the region of low Q2Q^2. The corresponding value of the strong interaction constant αS(MZ)=0.1230.013+0.010\alpha_S (M_Z) = 0.123^{+0.010}_{-0.013} agrees with the recent result of the CCFR collaboration and with the combined LEP/SLC result.Comment: 11 pages, 1 Postscript figure, LaTeX. Talk given at the 7th International Workshop on Deep Inelastic Scattering and QCD (DIS 99), Zeuthen, Germany, 19-23 Apr 199

    Сравнительное изучение взаимодействия флуоресцентных красителей К-35 и К7-1045 с белками сыворотки крови крыс

    Get PDF
    Using the fluorescent spectroscopy, gel chromatography and electrophoresis in polyacrylamide gel methods interaction of fluorescent dyes K-35 and К7-1045 with rat serum proteins has been studied in the work in comparative aspect. It has been established that in serum K-35 and К7-1045 dyes bound mainly with albumin. It has been shown that K-35 dye may be used for estimating degree of rat serum albumin fullness by different ligands.В работе методами флуоресцентной спектроскопии, гель-хроматографии и электрофореза в полиакриламидном геле изучено в сравнительном аспекте взаимодействие флуоресцентных красителей К-35 и К7-1045 с белками сыворотки крови крыс. Установлено, что в сыворотке красители К-35 и К7-1045 главным образом связываются с альбумином. Показано, что краситель К-35 может быть применен для оценки степени нагруженности сывороточного альбумина крысы лигандами различного происхождения

    Determination of the high-twist contribution to the structure function xF3νNxF^{\nu N}_3

    Get PDF
    We extract the high-twist contribution to the neutrino-nucleon structure function xF3(ν+νˉ)NxF_3^{(\nu+\bar{\nu})N} from the analysis of the data collected by the IHEP-JINR Neutrino Detector in the runs with the focused neutrino beams at the IHEP 70 GeV proton synchrotron. The analysis is performed within the infrared renormalon (IRR) model of high twists in order to extract the normalization parameter of the model. From the NLO QCD fit to our data we obtained the value of the IRR model normalization parameter Λ32=0.69±0.37 (exp)±0.16 (theor) GeV2\Lambda^2_{3}=0.69\pm0.37~({\rm exp})\pm0.16~({\rm theor})~{\rm GeV}^2. We also obtained Λ32=0.36±0.22 (exp)±0.12 (theor) GeV2\Lambda^2_{3}=0.36\pm0.22~({\rm exp})\pm0.12~({\rm theor})~{\rm GeV}^2 from a similar fit to the CCFR data. The average of both results is Λ32=0.44±0.19 (exp) GeV2\Lambda^2_{3}=0.44\pm0.19~({\rm exp})~{\rm GeV}^2.Comment: preprint IHEP-01-18, 7 pages, LATEX, 1 figure (EPS

    Study of KS KL Coupled Decays and KL -Be Interactions with the CMD-2 Detector at VEPP-2M Collider

    Full text link
    The integrated luminosity about 4000 inverse nanobarn of around phi meson mass ( 5 millions of phi mesons) has been collected with the CMD-2 detector at the VEPP-2M collider. A latest analysis of the KS KL coupled decays based on 30 % of available data is presented in this paper. The KS KL pairs from phi meson decays were reconstructed in the drift chamber when both kaons decayed into two charged particles. From a sample of 1423 coupled decays a selection of candidates to the CP violating KL into pi+ pi- decay was performed. CP violating decays were not identified because of the domination of events with a KL regenerating at the Be beam pipe into KS and a background from KL semileptonic decays. The regeneration cross section of 110 MeV/c KL mesons was found to be 53 +- 17 mb in agreement with theoretical expectations. The angular distribution of KS mesons after regeneration and the total cross section of KL for Be have been measured.Comment: 14 pages, 8 figure

    New precise determination of the \tau lepton mass at KEDR detector

    Full text link
    The status of the experiment on the precise τ\tau lepton mass measurement running at the VEPP-4M collider with the KEDR detector is reported. The mass value is evaluated from the τ+τ\tau^+\tau^- cross section behaviour around the production threshold. The preliminary result based on 6.7 pb1^{-1} of data is mτ=1776.800.23+0.25±0.15m_{\tau}=1776.80^{+0.25}_{-0.23} \pm 0.15 MeV. Using 0.8 pb1^{-1} of data collected at the ψ\psi' peak the preliminary result is also obtained: ΓeeBττ(ψ)=7.2±2.1\Gamma_{ee}B_{\tau\tau}(\psi') = 7.2 \pm 2.1 eV.Comment: 6 pages, 8 figures; The 9th International Workshop on Tau-Lepton Physics, Tau0

    The Atmospheric Chemistry Suite (ACS) of Three Spectrometers for the ExoMars 2016 Trace Gas Orbiter

    Get PDF
    The Atmospheric Chemistry Suite (ACS) package is an element of the Russian contribution to the ESA-Roscosmos ExoMars 2016 Trace Gas Orbiter (TGO) mission. ACS consists of three separate infrared spectrometers, sharing common mechanical, electrical, and thermal interfaces. This ensemble of spectrometers has been designed and developed in response to the Trace Gas Orbiter mission objectives that specifically address the requirement of high sensitivity instruments to enable the unambiguous detection of trace gases of potential geophysical or biological interest. For this reason, ACS embarks a set of instruments achieving simultaneously very high accuracy (ppt level), very high resolving power (>10,000) and large spectral coverage (0.7 to 17 μm—the visible to thermal infrared range). The near-infrared (NIR) channel is a versatile spectrometer covering the 0.7–1.6 μm spectral range with a resolving power of ∼20,000. NIR employs the combination of an echelle grating with an AOTF (Acousto-Optical Tunable Filter) as diffraction order selector. This channel will be mainly operated in solar occultation and nadir, and can also perform limb observations. The scientific goals of NIR are the measurements of water vapor, aerosols, and dayside or night side airglows. The mid-infrared (MIR) channel is a cross-dispersion echelle instrument dedicated to solar occultation measurements in the 2.2–4.4 μm range. MIR achieves a resolving power of >50,000. It has been designed to accomplish the most sensitive measurements ever of the trace gases present in the Martian atmosphere. The thermal-infrared channel (TIRVIM) is a 2-inch double pendulum Fourier-transform spectrometer encompassing the spectral range of 1.7–17 μm with apodized resolution varying from 0.2 to 1.3 cm−1. TIRVIM is primarily dedicated to profiling temperature from the surface up to ∼60 km and to monitor aerosol abundance in nadir. TIRVIM also has a limb and solar occultation capability. The technical concept of the instrument, its accommodation on the spacecraft, the optical designs as well as some of the calibrations, and the expected performances for its three channels are described

    Measurement of the ϕ\phi meson parameters with CMD-2 detector at VEPP-2M Collider

    Full text link
    About 300 000 e+eϕKL0KS0e^+e^-\to \phi\to K^0_L K^0_S events in the center of mass energy range from 984 to 1040 MeV were used for the measurement of the ϕ\phi meson parameters. The following results have been obtained: σ0=(1367±15±21)nb,mϕ=(1019.504±0.011±0.033)MeV/c2,Γϕ=(4.477±0.036±0.022)MeV,Γe+eB(ϕKL0KS0)=(4.364±0.048±0.065)104\sigma_0 = (1367 \pm 15 \pm 21) nb, m_{\phi}=(1019.504 \pm 0.011 \pm 0.033) MeV/c^2, \Gamma_\phi=(4.477 \pm 0.036 \pm 0.022) MeV, \Gamma_{e^+e^-}\cdot B(\phi\to K^0_L K^0_S) = (4.364 \pm 0.048 \pm 0.065)\cdot 10^{-4} MeV.Comment: 13 pages, 5 figures, 5 table

    New precision measurement of the J/ψJ/\psi- and ψ\psi' -meson masses

    Full text link
    A new high precision measurement of the J/ψJ/\psi- and ψ\psi'-meson masses has been performed at the VEPP-4M collider using the KEDR detector. The resonant depolarization method has been employed for the absolute calibration of the beam energy. The following mass values have been obtained: MJ/ψ=3096.917±0.010±0.007M_{J/\psi} = 3096.917 \pm 0.010 \pm 0.007 MeV, Mψ=3686.111±0.025±0.009M_{\psi'} = 3686.111 \pm 0.025 \pm 0.009 MeV. The relative measurement accuracy has reached 4.1064. 10^{-6} for J/ψJ/\psi and 7.1067. 10^{-6} for ψ\psi', approximately 3 times better than in the previous precise experiments.Comment: 12 pages, 4 tables, 10 figure
    corecore