IPAC2017 - List of Authors (Hidaka, Y.)

Paper	Title	Page
MOPIK124	A New Method to Tune the Nonlinear Lattice Online	828
	W. Guo, Y. Hidaka, X. Yang BNL, Upton, Long Island, New York, USA
	Most nonlinear lattice tuning methods use only part of the optimization constraints, for example, part of the driving terms, nonlinear detuning, lifetime or injection efficiency. Even though some of the nonlinear properties can be improved, it is not guaranteed the nonlinear lattice is fully optimized. In this paper we propose to optimize the nonlinear lattice by correcting the betatron phase advance and detuning of the off-orbit lattices. It is shown that all the leading order optimization constraints are restored in this approach. One advantage of this new method is that the measurement is independent of BPM calibration errors. We succeed in both simulation and experiment in identifying the intentionally added sextupole errors.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPIK124
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TUPAB140	Analysis and Correction of in-Vacuum Undulator Misalignment Effects in a Storage Ring Synchrotron Radiation Source	1663
	O.V. Chubar, T.A. Caswell, Y. Chen-Wiegart, A. Fluerasu, Y. Hidaka, D.A. Hidas, C.A. Kitegi, M.S. Rakitin, T. Tanabe, J. Thieme, L. Wiegart, G. Williams BNL, Upton, Long Island, New York, USA
	Funding: Work was partially supported by US DOE SBIR grants DE-SC0006284 and DE-SC0011237. In-vacuum undulators (IVU) are currently very extensively used at different light source facilities, and in particular in medium-energy storage rings, for the production of high-brightness and high-flux hard X-rays. The relatively small (~5 mm or less) vertical magnetic gaps used in these planar undulators make them, however, rather sensitive to the accuracy of alignment of magnet arrays with respect to electron orbit in the vertical plane. Based on results of commissioning of a number of IVUs at hard X-ray beamlines of NSLS-II, their eventual misalignment with respect to the electron orbit was found to be among frequent reasons of spectral underperformance of the beamlines. We will present results of simulations of different IVU misalignment effects on magnetic fields seen by electron beam and on the emitted undulator radiation spectra. The simulations show e.g. that an impact of angular misalignment of an IVU on the radiation spectrum can be minimized if the IVU elevation is selected to make the electron orbit to pass through the IVU magnetic center. Experimental results of spectrum-based alignment of IVUs at hard X-ray beamlines will be presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB140
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Paper

Title

Page

A New Method to Tune the Nonlinear Lattice Online

828

W. Guo, Y. Hidaka, X. Yang
BNL, Upton, Long Island, New York, USA

Most nonlinear lattice tuning methods use only part of the optimization constraints, for example, part of the driving terms, nonlinear detuning, lifetime or injection efficiency. Even though some of the nonlinear properties can be improved, it is not guaranteed the nonlinear lattice is fully optimized. In this paper we propose to optimize the nonlinear lattice by correcting the betatron phase advance and detuning of the off-orbit lattices. It is shown that all the leading order optimization constraints are restored in this approach. One advantage of this new method is that the measurement is independent of BPM calibration errors. We succeed in both simulation and experiment in identifying the intentionally added sextupole errors.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPIK124

Export •

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

TUPAB140

Analysis and Correction of in-Vacuum Undulator Misalignment Effects in a Storage Ring Synchrotron Radiation Source

1663

O.V. Chubar, T.A. Caswell, Y. Chen-Wiegart, A. Fluerasu, Y. Hidaka, D.A. Hidas, C.A. Kitegi, M.S. Rakitin, T. Tanabe, J. Thieme, L. Wiegart, G. Williams
BNL, Upton, Long Island, New York, USA

Funding: Work was partially supported by US DOE SBIR grants DE-SC0006284 and DE-SC0011237.
In-vacuum undulators (IVU) are currently very extensively used at different light source facilities, and in particular in medium-energy storage rings, for the production of high-brightness and high-flux hard X-rays. The relatively small (~5 mm or less) vertical magnetic gaps used in these planar undulators make them, however, rather sensitive to the accuracy of alignment of magnet arrays with respect to electron orbit in the vertical plane. Based on results of commissioning of a number of IVUs at hard X-ray beamlines of NSLS-II, their eventual misalignment with respect to the electron orbit was found to be among frequent reasons of spectral underperformance of the beamlines. We will present results of simulations of different IVU misalignment effects on magnetic fields seen by electron beam and on the emitted undulator radiation spectra. The simulations show e.g. that an impact of angular misalignment of an IVU on the radiation spectrum can be minimized if the IVU elevation is selected to make the electron orbit to pass through the IVU magnetic center. Experimental results of spectrum-based alignment of IVUs at hard X-ray beamlines will be presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB140

Export •

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