IPAC2018 - List of Authors (Gavaldà, X.N.)

Paper	Title	Page
THPAF028	Multi-Objectives Genetic Algorithms (MOGA) Optimization of PETRA IV Scenarios	3015
	X.N. Gavaldà, J. Keil, R. Wanzenberg DESY, Hamburg, Germany
	This paper reports the application of Multi-Objective Genetic Algorithms (MOGA) to optimize the linear and nonlinear beam dynamics of the different PETRA IV scenarios to transform PETRA III storage ring in a diffracted limited one. As it is well known, the dynamic aperture and momentum acceptance of these kinds of lattices are dramatically reduced due to the increase of the sextupoles strengths to compensate its strong focusing. The reduction of the dynamic aperture jeopardizes the current off-axis injection system and lower beam lifetimes increase the beam instabilities and the radiation safety concerns of the storage ring. MOGA searches the best settings of quadrupoles and sextupoles in a multi-dimensional parameter space taking into account the dynamic properties and the natural emittance as objectives at the level of ten picometers. The lattices studied are the so-called 'Twist lattice' based in a phase space exchange lattice, a solution based in the ESRF-Hybrid Multi-bend Achromat (HMA) design and finally the 'double 'I' lattice combining a non-interleaved sextupoles cell with an ESRF-HMA cell.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAF028
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THPAF030	PETRA III Storage Ring Performance Improvement Based on Multi-Objective Genetic Algorithms (MOGA)	3018
	X.N. Gavaldà, J. Keil, G.K. Sahoo, R. Wanzenberg DESY, Hamburg, Germany
	The performance of the 3th generation light sources relies on the beam lifetime and the injection efficiency, both related with the beam dynamic properties of the storage ring as momentum acceptance and dynamic aperture, respectively. High values of beam lifetime and injection efficiency are desirable to reduce the storage ring instabilities during injection, the radiation losses and the energy consumption of the facility. This paper reports the first application of Multi-Objective Genetic Algorithms (MOGA) to optimize the linear and non-linear beam dynamics of PETRA III storage ring. Genetic algorithms are a heuristic search that mimics the process of natural evolution to optimize problems with a high level of complexity, as in the case of PETRA III storage ring composed by hundreds of magnets. This computational method uses hundreds of CPUs. MOGA is used to maximize the dynamic aperture and the momentum acceptance finding new combinations of quadrupole and sextupole settings in a multi-dimensional parameter space maintaining the solutions in the level of ten picometers.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAF030
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THPAF031	A PETRA IV Lattice based on Hybrid Seven Bend Achromats	3021
	J. Keil, I.V. Agapov, R. Brinkmann, X.N. Gavaldà, R. Wanzenberg DESY, Hamburg, Germany
	For the PETRA IV project at DESY it is planned to convert the 6 GeV synchrotron light source PETRA III into a diffraction limited storage ring with ultra-low emittances. PETRA IV should provide a natural emittance two orders of magnitude smaller as now. The energy and the current of 100 mA should be unchanged. Currently different lattice options are investigated to achieve an emittance in the range of 10-30 pm*rad. As one candidate for a lattice of PETRA IV a ring based on the concept of hybrid multi-bend achromats (HMBA) has been studied in detail. Due to the unique layout of PETRA III with long straight sections it is possible to use damping wigglers to reduce the emittance further. While this helps to mitigate intrabeam scattering it has the disadvantage of an increased energy spread. The linear and nonlinear parameters of this HMBA-based lattice and the influence of damping wigglers on beam parameters are discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAF031
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Paper

Title

Page

Multi-Objectives Genetic Algorithms (MOGA) Optimization of PETRA IV Scenarios

3015

X.N. Gavaldà, J. Keil, R. Wanzenberg
DESY, Hamburg, Germany

This paper reports the application of Multi-Objective Genetic Algorithms (MOGA) to optimize the linear and nonlinear beam dynamics of the different PETRA IV scenarios to transform PETRA III storage ring in a diffracted limited one. As it is well known, the dynamic aperture and momentum acceptance of these kinds of lattices are dramatically reduced due to the increase of the sextupoles strengths to compensate its strong focusing. The reduction of the dynamic aperture jeopardizes the current off-axis injection system and lower beam lifetimes increase the beam instabilities and the radiation safety concerns of the storage ring. MOGA searches the best settings of quadrupoles and sextupoles in a multi-dimensional parameter space taking into account the dynamic properties and the natural emittance as objectives at the level of ten picometers. The lattices studied are the so-called 'Twist lattice' based in a phase space exchange lattice, a solution based in the ESRF-Hybrid Multi-bend Achromat (HMA) design and finally the 'double 'I' lattice combining a non-interleaved sextupoles cell with an ESRF-HMA cell.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAF028

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

THPAF030

PETRA III Storage Ring Performance Improvement Based on Multi-Objective Genetic Algorithms (MOGA)

3018

X.N. Gavaldà, J. Keil, G.K. Sahoo, R. Wanzenberg
DESY, Hamburg, Germany

The performance of the 3th generation light sources relies on the beam lifetime and the injection efficiency, both related with the beam dynamic properties of the storage ring as momentum acceptance and dynamic aperture, respectively. High values of beam lifetime and injection efficiency are desirable to reduce the storage ring instabilities during injection, the radiation losses and the energy consumption of the facility. This paper reports the first application of Multi-Objective Genetic Algorithms (MOGA) to optimize the linear and non-linear beam dynamics of PETRA III storage ring. Genetic algorithms are a heuristic search that mimics the process of natural evolution to optimize problems with a high level of complexity, as in the case of PETRA III storage ring composed by hundreds of magnets. This computational method uses hundreds of CPUs. MOGA is used to maximize the dynamic aperture and the momentum acceptance finding new combinations of quadrupole and sextupole settings in a multi-dimensional parameter space maintaining the solutions in the level of ten picometers.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAF030

Export •

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

THPAF031

A PETRA IV Lattice based on Hybrid Seven Bend Achromats

3021

J. Keil, I.V. Agapov, R. Brinkmann, X.N. Gavaldà, R. Wanzenberg
DESY, Hamburg, Germany

For the PETRA IV project at DESY it is planned to convert the 6 GeV synchrotron light source PETRA III into a diffraction limited storage ring with ultra-low emittances. PETRA IV should provide a natural emittance two orders of magnitude smaller as now. The energy and the current of 100 mA should be unchanged. Currently different lattice options are investigated to achieve an emittance in the range of 10-30 pm*rad. As one candidate for a lattice of PETRA IV a ring based on the concept of hybrid multi-bend achromats (HMBA) has been studied in detail. Due to the unique layout of PETRA III with long straight sections it is possible to use damping wigglers to reduce the emittance further. While this helps to mitigate intrabeam scattering it has the disadvantage of an increased energy spread. The linear and nonlinear parameters of this HMBA-based lattice and the influence of damping wigglers on beam parameters are discussed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAF031

Export •

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