IPAC2017 - List of Authors (Yang, X.)

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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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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WEPAB120	Reproducibility Issues of NSLS-II Storage Ring and Modeling of the Lattice	2851
	J. Choi, W. Guo, T.V. Shaftan, X. Yang BNL, Upton, Long Island, New York, USA
	Funding: DOE Contract No: DE-SC0012704 As other facilities, in operating NSLS-II, we develop the lattices based on theoretical and simulation studies. Then the lattice is applied and the machine is optimized to have the desired design parameters. This process is very typical and works well and, furthermore, there is a general understanding that a model with the field measurement data is not realized as it is. However, it is evident that if the model represents the real machine close enough, there are lots of advantages we can take. One of them can be producing the lattice with changing environments. In this paper, we discuss the NSLS-II reproducibility status and efforts to construct the faithful realistic model.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-WEPAB120
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WEPAB121	Database for NSLS-II Accelerator Operation	2854
	J. Choi, R.I. Farnsworth, T.V. Shaftan, G.J. Weiner, X. Yang BNL, Upton, Long Island, New York, USA
	Funding: DOE Contract No: DE-SC0012704 NSLS-II is employing a database and corresponding user interfaces which are used for the accelerator data sharing and management. The database include operation related information such as beam optics parameters, magnet measurement data, survey data and operation summary. To improve the usability, other functionalities are also being added. However, due to the limited scope, the general expectation of the overall facility cannot not be met and, in order to solve the issue, we are in the process of adopting Component Database (ComponentDB) developed at Advanced Photon Source (APS). This paper shows the current status of the process.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-WEPAB121
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THPVA095	Storage Ring Injection Kickers Alignment Optimization in NSLS-II	4683
	G.M. Wang, W.X. Cheng, J. Choi, T.V. Shaftan, X. Yang BNL, Upton, Long Island, New York, USA
	The National Synchrotron Light Source II (NSLS-II) is a state of the art 3 GeV third generation light source at Brookhaven National Laboratory. The SR is designed to work in top-off injection mode. The injection straight includes a septum and four fast kicker magnets with independent amplitude and timing control. Ideally, fast kickers formed a local bump, which is transparent to stored beam during top off injection. Due to mismatch of kicker voltage, timing or waveform, there is residual betatron oscillation and impact normal operation. This paper will present the injection kicker waveform measurement with beam, local and global alignment optimization to in improve top off injection transition.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-THPVA095
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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)

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

WEPAB120

Reproducibility Issues of NSLS-II Storage Ring and Modeling of the Lattice

2851

J. Choi, W. Guo, T.V. Shaftan, X. Yang
BNL, Upton, Long Island, New York, USA

Funding: DOE Contract No: DE-SC0012704
As other facilities, in operating NSLS-II, we develop the lattices based on theoretical and simulation studies. Then the lattice is applied and the machine is optimized to have the desired design parameters. This process is very typical and works well and, furthermore, there is a general understanding that a model with the field measurement data is not realized as it is. However, it is evident that if the model represents the real machine close enough, there are lots of advantages we can take. One of them can be producing the lattice with changing environments. In this paper, we discuss the NSLS-II reproducibility status and efforts to construct the faithful realistic model.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-WEPAB120

Export •

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

WEPAB121

Database for NSLS-II Accelerator Operation

2854

J. Choi, R.I. Farnsworth, T.V. Shaftan, G.J. Weiner, X. Yang
BNL, Upton, Long Island, New York, USA

Funding: DOE Contract No: DE-SC0012704
NSLS-II is employing a database and corresponding user interfaces which are used for the accelerator data sharing and management. The database include operation related information such as beam optics parameters, magnet measurement data, survey data and operation summary. To improve the usability, other functionalities are also being added. However, due to the limited scope, the general expectation of the overall facility cannot not be met and, in order to solve the issue, we are in the process of adopting Component Database (ComponentDB) developed at Advanced Photon Source (APS). This paper shows the current status of the process.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-WEPAB121

Export •

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

THPVA095

Storage Ring Injection Kickers Alignment Optimization in NSLS-II

4683

G.M. Wang, W.X. Cheng, J. Choi, T.V. Shaftan, X. Yang
BNL, Upton, Long Island, New York, USA

The National Synchrotron Light Source II (NSLS-II) is a state of the art 3 GeV third generation light source at Brookhaven National Laboratory. The SR is designed to work in top-off injection mode. The injection straight includes a septum and four fast kicker magnets with independent amplitude and timing control. Ideally, fast kickers formed a local bump, which is transparent to stored beam during top off injection. Due to mismatch of kicker voltage, timing or waveform, there is residual betatron oscillation and impact normal operation. This paper will present the injection kicker waveform measurement with beam, local and global alignment optimization to in improve top off injection transition.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-THPVA095

Export •

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