JACoW logo

Joint Accelerator Conferences Website

The Joint Accelerator Conferences Website (JACoW) is an international collaboration that publishes the proceedings of accelerator conferences held around the world.


https://doi.org/10.18429/JACoW-IPAC2018-WEPAF041
Title Use of Dimension-Reduction Techniques With Multi-Objective Genetic Algorithms to Improve the Vertical Emittance and Orbit at CESR
Authors
  • W.F. Bergan, I.V. Bazarov, C.J. Duncan, D. L. Rubin
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
  • D. Liarte, J.P. Sethna
    Cornell University, Ithaca, New York, USA
Abstract In order to reduce the vertical emittance at the Cornell Electron Storage Ring (CESR), we first measure and correct the vertical orbit, dispersion, and coupling. However, due to the finite resolution of our optics measurements, we still retain a significant residual emittance. In order to correct this further, we made use of the theory of sloppy models, according to which certain high-dimensionality systems can be modeled with significantly fewer "eigenparameters" that still contain most of the effect on the desired objective, in this case, the emittance.* However, we noted that using these knobs for tuning often resulted in increased vertical orbit errors. In an attempt to constrain these, we have applied multi-objective genetic algorithms to this problem. We have found that it can be more efficient to run such algorithms using our eigenparameters as the genes to be varied, as opposed to the raw magnet values. When running with the first 8 such knobs as genes, we can get either orbits or beam sizes as good as we obtain with our regular emittance-tuning algorithm which uses all the corrector magnets.
Footnotes & References *K.S. Brown and J.P. Sethna, Phys. Rev. E 68, 021904 (2003).
Funding DOE DE-SC0013571 NSF DGE-1650441
Paper download WEPAF041.PDF [0.232 MB / 4 pages]
Export download ※ BibTeX ※ LaTeX ※ Text/Word ※ RIS ※ EndNote
Conference IPAC2018, Vancouver, BC, Canada
Series International Particle Accelerator Conference (9th)
Proceedings Link to full IPAC2018 Proccedings
Session MC6 Poster Session
Date 02-May-18   09:00–12:00
Main Classification 06 Beam Instrumentation, Controls, Feedback, and Operational Aspects
Sub Classification T33 Online Modeling and Software Tools
Keywords emittance, storage-ring, simulation, lattice, electron
Publisher JACoW Publishing, Geneva, Switzerland
Editors Shane Koscielniak (TRIUMF, Vancouver, BC, Canada); Todd Satogata (JLab, Newport News, VA, USA); Volker RW Schaa (GSI, Darmstadt, Germany); Jana Thomson (TRIUMF, Vancouver, BC, Canada)
ISBN 978-3-95450-184-7
Published June 2018
Copyright
Copyright © 2018 by JACoW, Geneva, Switzerland     CC-BY Creative Commons License
cc Creative Commons Attribution 3.0