IPAC2015 - List of Authors (Huang, X.)

Paper	Title	Page
MOPMA060	Impedance Measurement for the SPEAR3 Storage Ring	694
	X. Huang, J.J. Sebek SLAC, Menlo Park, California, USA
	We studied the transverse impedance of the SPEAR3 storage ring with tune shift vs. beam intensity, head-tail instability and transverse mode coupling instability measurements. By taking measurements under different machine conditions, we probed the frequency dependence of the impedance, from which an impedance model was built. This model is consistent with instability measurements and previous bunch lengthening results.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPMA060
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MOPMN001	Linear Optics and Coupling Correction with Turn-by-turn BPM Data	698
	X. Huang SLAC, Menlo Park, California, USA X. Yang BNL, Upton, Long Island, New York, USA
	We propose a method to measure and correct storage ring linear optics and coupling with turn-by-turn BPM data. The independent component analysis (ICA) is used to obtain the amplitudes and phase advances of the betatron normal modes, which are compared to their counterparts derived from the lattice model. By fitting the model to the data with quadrupole and skew quadrupole variables, the linear optics and coupling of the machine can be obtained. Simulation demonstrates that errors in the lattice and BPM parameters can be recovered with this method. Experiments on the NSLS-II storage ring show that it can find the same optics as the linear optics from closed orbit (LOCO) method.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPMN001
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TUPHA012	LOCO Application to NSLS2 SR Dispersion and Beta Beating Correction	1989
	X. Yang BNL, Upton, Long Island, New York, USA X. Huang, J.A. Safranek SLAC, Menlo Park, California, USA
	During the short run in early July, 2014, we made changes to the Matlab LOCO setup for NSLS-II and applied LOCO successfully to the machine. The MML setup was verified with I/O tests for all quadrupole families. The LOCO setup was further tested with an intentional quadrupole error. After the successful LOCO correction, the rms beta beat was reduced from the initial values of 5.5% x and 5.6% y, to 1.9% x and 1.0% y, respectively. The rms horizontal dispersion error was reduced from 21 mm to 6 mm. It is critical to keep the same closed orbit for LOCO correction to take effect. Because presently some correctors are nearly saturated, closed orbit cannot be controlled for additional iterations. We expect LOCO to achieve better optics correction after the orbit control is improved.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPHA012
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Paper

Title

Page

Impedance Measurement for the SPEAR3 Storage Ring

694

X. Huang, J.J. Sebek
SLAC, Menlo Park, California, USA

We studied the transverse impedance of the SPEAR3 storage ring with tune shift vs. beam intensity, head-tail instability and transverse mode coupling instability measurements. By taking measurements under different machine conditions, we probed the frequency dependence of the impedance, from which an impedance model was built. This model is consistent with instability measurements and previous bunch lengthening results.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPMA060

Export •

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

MOPMN001

Linear Optics and Coupling Correction with Turn-by-turn BPM Data

698

X. Huang
SLAC, Menlo Park, California, USA
X. Yang
BNL, Upton, Long Island, New York, USA

We propose a method to measure and correct storage ring linear optics and coupling with turn-by-turn BPM data. The independent component analysis (ICA) is used to obtain the amplitudes and phase advances of the betatron normal modes, which are compared to their counterparts derived from the lattice model. By fitting the model to the data with quadrupole and skew quadrupole variables, the linear optics and coupling of the machine can be obtained. Simulation demonstrates that errors in the lattice and BPM parameters can be recovered with this method. Experiments on the NSLS-II storage ring show that it can find the same optics as the linear optics from closed orbit (LOCO) method.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPMN001

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

TUPHA012

LOCO Application to NSLS2 SR Dispersion and Beta Beating Correction

1989

X. Yang
BNL, Upton, Long Island, New York, USA
X. Huang, J.A. Safranek
SLAC, Menlo Park, California, USA

During the short run in early July, 2014, we made changes to the Matlab LOCO setup for NSLS-II and applied LOCO successfully to the machine. The MML setup was verified with I/O tests for all quadrupole families. The LOCO setup was further tested with an intentional quadrupole error. After the successful LOCO correction, the rms beta beat was reduced from the initial values of 5.5% x and 5.6% y, to 1.9% x and 1.0% y, respectively. The rms horizontal dispersion error was reduced from 21 mm to 6 mm. It is critical to keep the same closed orbit for LOCO correction to take effect. Because presently some correctors are nearly saturated, closed orbit cannot be controlled for additional iterations. We expect LOCO to achieve better optics correction after the orbit control is improved.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPHA012

Export •

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