IPAC2015 - List of Authors (Garcia-Bonilla, A.C.)

Paper	Title	Page
MOPWA004	Reformulation of the Action and Phase Jump Method to Obtain Magnetic Errors in the LHC IRs	80
	A.C. García-Bonilla, J.F. Cardona UNAL, Bogota D.C, Colombia
	Funding: Fundación Para la Promoción de la Investigación y la Tecnología del Banco de la República and Division de Investigación Bogotá (DIB). One of the major problems when doing the commissioning of an accelerator is to identify and correct the linear components of magnetic errors. The Action and Phase Jump Technique is one of the available methods to perform this task. For this method to work, it is necessary to have one BPM measurement at the IR, the region where the magnetic error is evaluated. In some cases, this BPM measurement become the biggest source of uncertainty when the action and phase jump technique is used. In this paper, a new formulation based on this method is presented. This new formulation doesn't make any use of BPM measurements at the IR, thereby allowing more robust error estimations. Quadrupole errors in the LHC lattice are estimated with this new formulation, using both, simulated data and LHC experimental data. A comparison with the previous formulation is included. The results on simulated data show that the reformulation leads to a reduction in the uncertainty, while for the experimental case, the reduction is not so clear. Explanations for this behavior and possible remedies will also be discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPWA004
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MOPWA005	Comparison between Digital Filters and Singular Value Decomposition to Reduce Noise in LHC Orbits used for Action and Phase Jump Analysis	83
	A.C. García-Bonilla, J.F. Cardona UNAL, Bogota D.C, Colombia
	Funding: Fundación Para la Promoción de la Investigación y la Tecnología del Banco de la República and DIB (División de Investigación de Bogotá). One of the initial difficulties to apply the Action and Phase Jump (APJ) analysis to LHC orbits was the high level of noise present in the BPM measurements. On the other hand, the unprecedented number of turns for LHC allows us to use all sort of filters. In this paper, we evaluate the effectiveness of digital filters like the band-pass filter and compare them with a filter based on Singular Value Decomposition, when magnetic error estimations are made using a recent version of the APJ method. First, mainly results on simulated orbits with noise are presented, and then, plots and results are shown for the filters effect on experimental data. The analysis indicates that a combination of filters leads to measurements with the least uncertainty.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPWA005
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Reformulation of the Action and Phase Jump Method to Obtain Magnetic Errors in the LHC IRs

80

A.C. García-Bonilla, J.F. Cardona
UNAL, Bogota D.C, Colombia

Funding: Fundación Para la Promoción de la Investigación y la Tecnología del Banco de la República and Division de Investigación Bogotá (DIB).
One of the major problems when doing the commissioning of an accelerator is to identify and correct the linear components of magnetic errors. The Action and Phase Jump Technique is one of the available methods to perform this task. For this method to work, it is necessary to have one BPM measurement at the IR, the region where the magnetic error is evaluated. In some cases, this BPM measurement become the biggest source of uncertainty when the action and phase jump technique is used. In this paper, a new formulation based on this method is presented. This new formulation doesn't make any use of BPM measurements at the IR, thereby allowing more robust error estimations. Quadrupole errors in the LHC lattice are estimated with this new formulation, using both, simulated data and LHC experimental data. A comparison with the previous formulation is included. The results on simulated data show that the reformulation leads to a reduction in the uncertainty, while for the experimental case, the reduction is not so clear. Explanations for this behavior and possible remedies will also be discussed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPWA004

Export •

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

MOPWA005

Comparison between Digital Filters and Singular Value Decomposition to Reduce Noise in LHC Orbits used for Action and Phase Jump Analysis

83

A.C. García-Bonilla, J.F. Cardona
UNAL, Bogota D.C, Colombia

Funding: Fundación Para la Promoción de la Investigación y la Tecnología del Banco de la República and DIB (División de Investigación de Bogotá).
One of the initial difficulties to apply the Action and Phase Jump (APJ) analysis to LHC orbits was the high level of noise present in the BPM measurements. On the other hand, the unprecedented number of turns for LHC allows us to use all sort of filters. In this paper, we evaluate the effectiveness of digital filters like the band-pass filter and compare them with a filter based on Singular Value Decomposition, when magnetic error estimations are made using a recent version of the APJ method. First, mainly results on simulated orbits with noise are presented, and then, plots and results are shown for the filters effect on experimental data. The analysis indicates that a combination of filters leads to measurements with the least uncertainty.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPWA005

Export •

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