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https://doi.org/10.18429/JACoW-NAPAC2019-FRXBA4
Title Maximizing 2-D Beam Brightness Using the Round to Flat Beam Transformation in the Ultralow Charge Regime
Authors
  • F.W. Cropp V, P.E. Denham, J. Giner Navarro, E.T. Liu, P. Musumeci
    UCLA, Los Angeles, USA
  • N. Burger, L. Phillips
    PBPL, Los Angeles, USA
  • A.L. Edelen, C. Emma
    SLAC, Menlo Park, California, USA
Abstract We seek to maximize the 2-D beam brightness in an RF photoinjector operating in an ultralow charge (<1 pC) regime by implementing the FBT. Particle tracking simulations suggest that in one dimension, normalized projected emittances smaller than 5 nm can be obtained at the UCLA Pegasus facility with up to 100 fC beam charge. A tunable magnetic field is put on the cathode. Three skew quadrupoles are used to block-diagonalize the beam matrix and recover the vastly different eigenemittances as the projected emittances. Emittance measurement routines, including grid-based, pepperpot-based and quad scan routines, have been developed for on-line calculation of the 4-D beam matrix and its eigenemittances. Preliminary measurements are in agreement with simulations and indicate emittance ratios larger than 10 depending on the laser spot size on the cathode. Fine tuning the quadrupole gradients for the FBT has a significant effect on the 2-D beam brightness. We have made concrete steps toward computer minimization and machine learning optimization of the quadrupole gradients in order to remove the canonical angular momentum from the beam and achieve the target normalized projected emittances.
Funding This work is supported by the United States National Science Foundation award PHY-1549132 (the Center for Bright Beams)
Paper download FRXBA4.PDF [0.649 MB / 4 pages]
Slides download FRXBA4_TALK.PDF [3.059 MB]
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Conference NAPAC2019
Series North American Particle Accelerator Conference (4th)
Location Lansing, MI, USA
Date 01-06 September 2019
Publisher JACoW Publishing, Geneva, Switzerland
Editorial Board Yoshishige Yamazaki (MSU, East-Lansing, MI, USA); Tor Raubenheimer (SLAC, Stanford, CA, USA); Amy McCausey (FRIB, East-Lansing, MI, USA); Volker RW Schaa (GSI, Darmstadt, Germany)
Online ISBN 978-3-95450-223-3
Online ISSN 2673-7000
Received 28 August 2019
Accepted 05 December 2019
Issue Date 08 October 2019
DOI doi:10.18429/JACoW-NAPAC2019-FRXBA4
Pages 986-989
Copyright
Creative Commons CC logoPublished by JACoW Publishing under the terms of the Creative Commons Attribution 3.0 International license. Any further distribution of this work must maintain attribution to the author(s), the published article's title, publisher, and DOI.