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

Brightness analysis of an electron beam with a complex profile

Hirokazu Maesaka, Toru Hara, Kazuaki Togawa, Takahiro Inagaki, and Hitoshi Tanaka
Phys. Rev. Accel. Beams 21, 050703 – Published 29 May 2018
PDFHTMLExport Citation
Abstract
Authors
Article Text
  • INTRODUCTION
  • BRIGHTNESS CALCULATION
  • APPLICATION TO ELECTRON BEAM FOR XFEL
  • DISCUSSION
  • CONCLUSIONS
  • APPENDICES
    • References

    Abstract

    We propose a novel analysis method to obtain the core bright part of an electron beam with a complex phase-space profile. This method is beneficial to evaluate the performance of simulation data of a linear accelerator (linac), such as an x-ray free electron laser (XFEL) machine, since the phase-space distribution of a linac electron beam is not simple, compared to a Gaussian beam in a synchrotron. In this analysis, the brightness of undulator radiation is calculated and the core of an electron beam is determined by maximizing the brightness. We successfully extracted core electrons from a complex beam profile of XFEL simulation data, which was not expressed by a set of slice parameters. FEL simulations showed that the FEL intensity was well remained even after extracting the core part. Consequently, the FEL performance can be estimated by this analysis without time-consuming FEL simulations.

    • Figure
    • Figure
    • Figure
    • Figure
    • Figure
    • Figure
    • Figure
    8 More
    • Received 23 March 2018

    DOI:https://doi.org/10.1103/PhysRevAccelBeams.21.050703

    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 code development & simulation techniques
    1. Physical Systems
    Free-electron lasers
    Accelerators & Beams

    Authors & Affiliations

    Hirokazu Maesaka*, Toru Hara, Kazuaki Togawa, Takahiro Inagaki, and Hitoshi Tanaka

    • RIKEN SPring-8 Center, Kouto, Sayo, Hyogo 679-5148, Japan

    • *maesaka@spring8.or.jp

    Article Text

    Click to Expand

    References

    Click to Expand
    Issue

    Vol. 21, Iss. 5 — May 2018

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

    Authorization Required

    Log In
    Other Options
    ×

    Images

    • Figure 1
      Figure 1

      Phase space distributions of the XFEL simulation data sets A (upper figures) and B (lower figures). The left, center and right figures show the horizontal, vertical and longitudinal phase spaces, respectively. The Twiss parameters from the brightness analysis and the conventional rms calculation are plotted as blue ellipses and red ones, respectively, for horizontal and vertical phase-space plots.

      Reuse & Permissions
    • Figure 2
      Figure 2

      Beam current (upper) and sliced brightness (lower) histograms of XFEL simulation data. The data sets A and B are plotted in left and right figures, respectively. The beam current histograms of core bright parts with the cut threshold of 5 stds. are also shown in the orange histograms.

      Reuse & Permissions
    • Figure 3
      Figure 3

      Survived charge of the data sets A (solid) and B (dashed) as functions of the cut threshold on a std. basis.

      Reuse & Permissions
    • Figure 4
      Figure 4

      Normalized emittance of the data sets A (solid) and B (dashed) as functions of the cut threshold on a std. basis. The horizontal (vertical) emittances are shown by the blue (red) curves.

      Reuse & Permissions
    • Figure 5
      Figure 5

      Brightness (left) and the ratio of the dropped brightness to the total brightness, 1−B/Bmax, (right) as functions of the cut threshold on a std. basis. The data set A (B) is shown in the solid (dashed) lines.

      Reuse & Permissions
    • Figure 6
      Figure 6

      Phase space distributions of the core bright part in the XFEL simulation data sets A (upper figures) and B (lower figures). The left, center and right figures show the horizontal, vertical and longitudinal phase-space distributions, respectively. The Twiss parameters from the brightness analysis are plotted as blue ellipses for horizontal and vertical phase-space plots.

      Reuse & Permissions
    • Figure 7
      Figure 7

      FEL pulse energy dependent on the survived charge for the electron beam data set A (left) and B (right).

      Reuse & Permissions
    • Figure 8
      Figure 8

      FEL gain curves of the data set A (left) and B (right). The results from the original particle data are shown in solid lines and those from Gaussian transverse profiles are in dashed lines. Blue (red) curves correspond to the entire electrons (the core bright part).

      Reuse & Permissions
    • Figure 9
      Figure 9

      Phase space distributions of the Gaussian data. The left (right) figure shows horizontal (vertical) phase space. The Twiss parameters from the analysis is plotted by blue ellipses.

      Reuse & Permissions
    • Figure 10
      Figure 10

      Survived charge as a function of the cut threshold on a std. basis.

      Reuse & Permissions
    • Figure 11
      Figure 11

      Normalized emittance as a function of the cut threshold on a std. basis. The mean value of horizontal and vertical emittances is plotted, since both emittances are almost identical.

      Reuse & Permissions
    • Figure 12
      Figure 12

      Brightness (left) and the ratio of the dropped brightness to the total brightness, 1−B/Bmax, (right) as functions of the cut threshold N.

      Reuse & Permissions
    • Figure 13
      Figure 13

      FEL pulse energy from the Gaussian input data as a function of the survived charge. Open circles are the simulation results and dashed line shows the linear fit result below 85 pC.

      Reuse & Permissions
    • Figure 14
      Figure 14

      Simulated FEL profiles of the data set B around the end of the exponential growth region (left: z=48.0  m) and at the end of the undulator beamline (right: z=109.5  m).

      Reuse & Permissions
    • Figure 15
      Figure 15

      Sliced FEL profiles of the data set B around the end of the exponential growth region. The longitudinal position is different for the two figures (left: s=−0.4  μm, right: s=+1.2  μm), where s is the position within a electron bunch.

      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
    ×