IPAC2017 - List of Authors (Yu, L.)

Paper	Title	Page
MOPIK125	Multi-frequency AC LOCO: A Fast and Precise Technique for Lattice Correction	831
	X. Yang, K. Ha, V.V. Smaluk, Y. Tian, L. Yu BNL, Upton, Long Island, New York, USA
	We developed a novel technique to improve the precision and shorten the measurement time of the LOCO (Linear Optics from Closed Orbits) method at NSLS-II [1]. This technique named AC LOCO is based on a sine-wave (AC) beam excitation via fast correctors typically installed at synchrotron light sources for the fast orbit feedback. The beam oscillations are measured by beam position monitors. The narrow band used for the beam excitation and measurement not only allows us to suppress effectively the beam position noise and also makes simultaneously exciting multiple correctors at different frequencies (multi-frequency mode) possible. We demonstrated at NSLS-II that the new technique provides better lattice corrections and achieves two minutes measurement time in the thirty-frequency mode. [1] X. Yang et al., 'Fast and precise technique for magnet lattice correction via sine-wave excitation of fast correctors', Phys. Rev. Accel. Beams, vol. 20, p. 054001, 2017.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPIK125
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WEPIK122	Applying Square Matrix to Optimize Storage Ring Nonlinear Lattice	3241
	Y. Li, L. Yu BNL, Upton, Long Island, New York, USA
	Funding: Supported by US DOE Contract No. DE-AC02-98CH10886 and DE-SC0012704. A new method of using linear algebra technique to analyze periodical nonlinear beam dynamics is presented. For a given dynamical system, a square upper triangular transfer matrix is constructed out of a one turn Taylor transfer map. First we separate the matrix into different low dimensional invariant subspaces according to their eigenvalues. Then a stable Jordan transformation can be obtained on each subspace. The transformation provides an excellent action-angle approximation to the solution of the nonlinear dynamics. And the deviation of the new action from constancy provides a measure of the nonlinearity of the motions, which provides a novel method to optimize the nonlinear dynamic system. We applied this method to optimize various rings, such as NSLS-II, SPEAR3, and APS-U lattice, the promising dynamic aperture have been achieved from both tracking simulation and experimental measurements.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-WEPIK122
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Paper

Title

Page

Multi-frequency AC LOCO: A Fast and Precise Technique for Lattice Correction

831

X. Yang, K. Ha, V.V. Smaluk, Y. Tian, L. Yu
BNL, Upton, Long Island, New York, USA

We developed a novel technique to improve the precision and shorten the measurement time of the LOCO (Linear Optics from Closed Orbits) method at NSLS-II [1]. This technique named AC LOCO is based on a sine-wave (AC) beam excitation via fast correctors typically installed at synchrotron light sources for the fast orbit feedback. The beam oscillations are measured by beam position monitors. The narrow band used for the beam excitation and measurement not only allows us to suppress effectively the beam position noise and also makes simultaneously exciting multiple correctors at different frequencies (multi-frequency mode) possible. We demonstrated at NSLS-II that the new technique provides better lattice corrections and achieves two minutes measurement time in the thirty-frequency mode.
[1] X. Yang et al., 'Fast and precise technique for magnet lattice correction via sine-wave excitation of fast correctors', Phys. Rev. Accel. Beams, vol. 20, p. 054001, 2017.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPIK125

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPIK122

Applying Square Matrix to Optimize Storage Ring Nonlinear Lattice

3241

Y. Li, L. Yu
BNL, Upton, Long Island, New York, USA

Funding: Supported by US DOE Contract No. DE-AC02-98CH10886 and DE-SC0012704.
A new method of using linear algebra technique to analyze periodical nonlinear beam dynamics is presented. For a given dynamical system, a square upper triangular transfer matrix is constructed out of a one turn Taylor transfer map. First we separate the matrix into different low dimensional invariant subspaces according to their eigenvalues. Then a stable Jordan transformation can be obtained on each subspace. The transformation provides an excellent action-angle approximation to the solution of the nonlinear dynamics. And the deviation of the new action from constancy provides a measure of the nonlinearity of the motions, which provides a novel method to optimize the nonlinear dynamic system. We applied this method to optimize various rings, such as NSLS-II, SPEAR3, and APS-U lattice, the promising dynamic aperture have been achieved from both tracking simulation and experimental measurements.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-WEPIK122

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)