Location via proxy:   [ UP ]  
[Report a bug]   [Manage cookies]                
  • Open Access

Crossing integer spin resonance with conservation of beam polarization

A. K. Barladyan, A. Yu. Barnyakov, V. E. Blinov, S. A. Glukhov, S. E. Karnaev, E. B. Levichev, S. A. Nikitin, I. B. Nikolaev, I. N. Okunev, P. A. Piminov, A. G. Shamov, and A. N. Zhuravlev
Phys. Rev. Accel. Beams 22, 112804 – Published 20 November 2019
PDFHTMLExport Citation
Abstract
Authors
Article Text
  • MOTIVATION
  • ISSUES OF FAST/SLOW CROSSING
  • SPIN KINEMATICS AT KEDR DETECTOR FIELD…
  • COMBINATION SPIN RESONANCES
  • RADIATIVE DEPOLARIZATION RATE DURING…
  • COMPENSATION OF BETATRON COUPLING FROM…
  • TOUSCHEK POLARIMETER
  • EXPERIMENTAL RESULTS
  • DISCUSSION
    • References

    Abstract

    A method proposed to preserve the electron beam polarization at the VEPP-4M collider during acceleration with crossing the integer (imperfection) spin resonance at energy E=1763  MeV has been successfully applied. It is based on full decompensation of the 0.6×3.3  Tesla×meter integral of the KEDR detector longitudinal magnetic field due to the antisolenoid being “switched off.”

    • Figure
    • Figure
    • Figure
    • Figure
    • Figure
    • Figure
    • Figure
    2 More
    • Received 3 July 2019

    DOI:https://doi.org/10.1103/PhysRevAccelBeams.22.112804

    Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI.

    Published by the American Physical Society

    Physics Subject Headings (PhySH)

    1. Research Areas
    Beam polarization
    Accelerators & Beams

    Authors & Affiliations

    A. K. Barladyan1, A. Yu. Barnyakov1,2, V. E. Blinov1,2,3, S. A. Glukhov1, S. E. Karnaev1, E. B. Levichev1,3, S. A. Nikitin1,*, I. B. Nikolaev1,2,†, I. N. Okunev1, P. A. Piminov1, A. G. Shamov1,2, and A. N. Zhuravlev1,2

    • 1Budker Institute of Nuclear Physics, 11, Lavrentiev prospect, Novosibirsk, 630090, Russia
    • 2Novosibirsk State University, 2, Pirogova street, Novosibirsk, 630090, Russia
    • 3Novosibirsk State Technical University, 20, Karl Marx prospect, Novosibirsk, 630092, Russia

    • *S.A.Nikitin@inp.nsk.su
    • †I.B.Nikolaev@inp.nsk.su

    Article Text

    Click to Expand

    References

    Click to Expand
    Issue

    Vol. 22, Iss. 11 — November 2019

    Reuse & Permissions
    Author publication services for translation and copyediting assistance advertisement

    Authorization Required

    Log In
    Other Options
    ×

    Images

    • Figure 1
      Figure 1

      Scheme of the VEPP-4 complex from the point of view of polarization experiments. ITP is the internal target setup based on the use of a jet of polarized deuterium atoms from the Atomic Beam Source (ABS).

      Reuse & Permissions
    • Figure 2
      Figure 2

      Diagram of energy points in the experiment.

      Reuse & Permissions
    • Figure 3
      Figure 3

      Two cases of the spin kinematics at ν=integer. (a) There is no preferable direction of the spin polarization in an ideal storage ring with a flat orbit. (b) There is a dynamically stable vector n→, the periodical precession axis, when an arbitrary solenoid is introduced.

      Reuse & Permissions
    • Figure 4
      Figure 4

      Spin tune shift in the energy units vs the beam energy in the cases of no and full decompensation of the KEDR detector field integral of 0.6×3.3  Tesla×meter.

      Reuse & Permissions
    • Figure 5
      Figure 5

      The calculated radiative depolarization time vs the beam energy under the influence of 0.6 T KEDR field decompensation. The separate point shows the measured value at an energy of 1806 MeV (estimated value of 1407 s).

      Reuse & Permissions
    • Figure 6
      Figure 6

      The calculated change in the degree of polarization relative to the initial one in the course of beam acceleration at a rate characterized by the parameter dE/dt in the case of complete decompensation of the KEDR field. The separate point with the error bars presents the generalized experimental data.

      Reuse & Permissions
    • Figure 7
      Figure 7

      The scheme (depicted not to scale) of compensation of the betatron coupling caused by the KEDR main solenoid field with the help of two skew quadrupoles (SQ+ and SQ−) located near the final focus lenses. The antisolenoids are off. Above is a view of normal betatron modes in the X-Z plane at different distances from the center of the detector.

      Reuse & Permissions
    • Figure 8
      Figure 8

      Depolarization jumps in two typical scans of the depolarizer frequency: at the advance energy 1655 MeV (a), i.e., before acceleration, and at the target energy 1809 MeV after acceleration with a rate of 2.4  MeV/s (b). In the second case, before scanning, the compensatory solenoid field was restored in 385 s. Each graph additionally shows the values of the measured depolarization jump and the beam energy, as well as the corresponding errors.

      Reuse & Permissions
    • Figure 9
      Figure 9

      The process of beam polarization relaxation following the acceleration from the advance energy up to 1806 MeV with a rate of 5  MeV/s. The compensatory solenoids remain switched off. In the time diagram of the ratio of the IBS rates in the polarized bunch and unpolarized one, differing in the number of particles, two stages are clearly distinguished.

      Reuse & Permissions
    ×

    Sign up to receive regular email alerts from Physical Review Accelerators and Beams

    Reuse & Permissions

    It is not necessary to obtain permission to reuse this article or its components as it is available under the terms of the Creative Commons Attribution 4.0 International license. This license permits unrestricted use, distribution, and reproduction in any medium, provided attribution to the author(s) and the published article's title, journal citation, and DOI are maintained. Please note that some figures may have been included with permission from other third parties. It is your responsibility to obtain the proper permission from the rights holder directly for these figures.

    ×

    Log In

    Cancel
    ×

    Search

    Article Lookup

    Paste a citation or DOI
    Enter a citation
    ×