658 research outputs found

    Особливості змісту права громадян на екологічну безпеку

    Get PDF
    В статье сделан анализ содержания права граждан на экологическую безопасность, определяется момент, с которого право на экологическую безопасность считается нарушенным

    Particle detection experiment for Applications Technology Satellite 1 /ATS-1/ Final report

    Get PDF
    Applications technology satellite particle detection experiment for measuring energy spectra of earth magnetic fiel

    Spin tune mapping as a novel tool to probe the spin dynamics in storage rings

    Get PDF
    Precision experiments, such as the search for electric dipole moments of charged particles using storage rings, demand for an understanding of the spin dynamics with unprecedented accuracy. The ultimate aim is to measure the electric dipole moments with a sensitivity up to 15 orders in magnitude better than the magnetic dipole moment of the stored particles. This formidable task requires an understanding of the background to the signal of the electric dipole from rotations of the spins in the spurious magnetic fields of a storage ring. One of the observables, especially sensitive to the imperfection magnetic fields in the ring is the angular orientation of stable spin axis. Up to now, the stable spin axis has never been determined experimentally, and in addition, the JEDI collaboration for the first time succeeded to quantify the background signals that stem from false rotations of the magnetic dipole moments in the horizontal and longitudinal imperfection magnetic fields of the storage ring. To this end, we developed a new method based on the spin tune response of a machine to artificially applied longitudinal magnetic fields. This novel technique, called \textit{spin tune mapping}, emerges as a very powerful tool to probe the spin dynamics in storage rings. The technique was experimentally tested in 2014 at the cooler synchrotron COSY, and for the first time, the angular orientation of the stable spin axis at two different locations in the ring has been determined to an unprecedented accuracy of better than 2.8μ2.8\murad.Comment: 32 pages, 15 figures, 7 table

    Phase Measurement for Driven Spin Oscillations in a Storage Ring

    Get PDF
    This paper reports the first simultaneous measurement of the horizontal and vertical components of the polarization vector in a storage ring under the influence of a radio frequency (rf) solenoid. The experiments were performed at the Cooler Synchrotron COSY in J\"ulich using a vector polarized, bunched 0.97GeV/c0.97\,\textrm{GeV/c} deuteron beam. Using the new spin feedback system, we set the initial phase difference between the solenoid field and the precession of the polarization vector to a predefined value. The feedback system was then switched off, allowing the phase difference to change over time, and the solenoid was switched on to rotate the polarization vector. We observed an oscillation of the vertical polarization component and the phase difference. The oscillations can be described using an analytical model. The results of this experiment also apply to other rf devices with horizontal magnetic fields, such as Wien filters. The precise manipulation of particle spins in storage rings is a prerequisite for measuring the electric dipole moment (EDM) of charged particles

    Transverse-target-spin asymmetry in exclusive ω\omega-meson electroproduction

    Get PDF
    Hard exclusive electroproduction of ω\omega mesons is studied with the HERMES spectrometer at the DESY laboratory by scattering 27.6 GeV positron and electron beams off a transversely polarized hydrogen target. The amplitudes of five azimuthal modulations of the single-spin asymmetry of the cross section with respect to the transverse proton polarization are measured. They are determined in the entire kinematic region as well as for two bins in photon virtuality and momentum transfer to the nucleon. Also, a separation of asymmetry amplitudes into longitudinal and transverse components is done. These results are compared to a phenomenological model that includes the pion pole contribution. Within this model, the data favor a positive πω\pi\omega transition form factor.Comment: DESY Report 15-14

    Evidence for a New Resonance from Polarized Neutron-Proton Scattering

    Get PDF
    Exclusive and kinematically complete high-statistics measurements of quasifree polarized np\vec{n}p scattering have been performed in the energy region of the narrow resonance structure dd^* with I(JP)=0(3+)I(J^P) = 0(3^+), MM \approx 2380 MeV/c2c^2 and Γ\Gamma \approx 70 MeV observed recently in the double-pionic fusion channels pndπ0π0pn \to d\pi^0\pi^0 and pndπ+πpn \to d\pi^+\pi^-. The experiment was carried out with the WASA detector setup at COSY having a polarized deuteron beam impinged on the hydrogen pellet target and utilizing the quasifree process dpnp+pspectator\vec{d}p \to np + p_{spectator}. That way the npnp analyzing power AyA_y was measured over a large angular range. The obtained AyA_y angular distributions deviate systematically from the current SAID SP07 NN partial-wave solution. Incorporating the new AyA_y data into the SAID analysis produces a pole in the 3D33G3^3D_3 - ^3G_3 waves as expected from the dd^* resonance hypothesis

    Phase locking the spin precession in a storage ring

    Get PDF
    This letter reports the successful use of feedback from a spin polarization measurement to the revolution frequency of a 0.97 GeV/cc bunched and polarized deuteron beam in the Cooler Synchrotron (COSY) storage ring in order to control both the precession rate (121\approx 121 kHz) and the phase of the horizontal polarization component. Real time synchronization with a radio frequency (rf) solenoid made possible the rotation of the polarization out of the horizontal plane, yielding a demonstration of the feedback method to manipulate the polarization. In particular, the rotation rate shows a sinusoidal function of the horizontal polarization phase (relative to the rf solenoid), which was controlled to within a one standard deviation range of σ=0.21\sigma = 0.21 rad. The minimum possible adjustment was 3.7 mHz out of a revolution frequency of 753 kHz, which changes the precession rate by 26 mrad/s. Such a capability meets a requirement for the use of storage rings to look for an intrinsic electric dipole moment of charged particles

    Cross section ratio and angular distributions of the reaction p + d -> 3He + eta at 48.8 MeV and 59.8 MeV excess energy

    Full text link
    We present new data for angular distributions and on the cross section ratio of the p + d -> 3He + eta reaction at excess energies of Q = 48.8 MeV and Q = 59.8 MeV. The data have been obtained at the WASA-at-COSY experiment (Forschungszentrum J\"ulich) using a proton beam and a deuterium pellet target. While the shape of obtained angular distributions show only a slow variation with the energy, the new results indicate a distinct and unexpected total cross section fluctuation between Q = 20 MeV and Q = 60 MeV, which might indicate the variation of the production mechanism within this energy interval.Comment: 9 pages, 9 figure
    corecore