NAPAC2019 - List of Keywords (feedback)

Paper	Title	Other Keywords	Page
TUPLM11	Beam-Beam Damping of the Ion Instability	electron, simulation, storage-ring, damping	391
	M. Blaskiewicz BNL, Upton, New York, USA
	Funding: Work Supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. Beam-Beam damping of the Ion Instability The electron storage ring of the proposed electron ion collider at BNL has bunch charges as large as 50 nC and bunch spacings as small as 10 ns. For molecules like CO a dangerous buildup of positive ions is possible and a significant fraction of these ions can survive allowable clearing gaps. The instability is thus multi-turn and the weak damping required to stop the ion instabilty with an ideal clearing gap is ineffective here. The beam-beam force is highly nonlinear and a potent source of tune spread. Simulations employing several macro-particles per electron bunch and several ion macroparticles are used to estimate maximum gas densities for some common molecules. A simplified model is introduced and compared with simulations.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-TUPLM11
About •	paper received ※ 26 August 2019 paper accepted ※ 02 September 2019 issue date ※ 08 October 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPLS09	Precision Insertion Device Control and Simultaneous Monochromator Fly Scanning for NSLS-II	controls, insertion-device, insertion, photon	471
	D.A. Hidas, P.L. Cappadoro, T.M. Corwin, J. Escallier, A. Hunt, M. Musardo, J. Rank, C. Rhein, J. Sinsheimer, T. Tanabe, I. Waluyo BNL, Upton, New York, USA
	Funding: Department of Energy Office of Science DE-SC0012704 Beginning in January of 2019, 8 of the 10 In-Vacuum Undulators installed in the NSLS-II storage ring underwent in-house in-situ control system upgrades allowing for control of the magnetic gap during motion down to the 50 nanometer level with an in-position accuracy of nearly 5 nanometers. Direct linking of Insertion Devices and beamline monochromators is achieved via a fiber interface allowing precise, simultaneous, nonlinear motion of both devices and providing a fast hardware trigger for real-time accurate insertion device and monochromator fly scanning. This presentation will detail the accuracy of motion and its effect on the produced spectra as well as the variation of flux when both insertion device and monochromator are in simultaneous motion.
	Poster TUPLS09 [0.668 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-TUPLS09
About •	paper received ※ 28 August 2019 paper accepted ※ 01 September 2019 issue date ※ 08 October 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEXBB1	Adaptive Machine Learning and Automatic Tuning of Intense Electron Bunches in Particle Accelerators	FEL, electron, controls, target	609
	A. Scheinker LANL, Los Alamos, New Mexico, USA
	Machine learning and in particular neural networks, have been around for a very long time. In recent years, thanks to growth in computing power, neural networks have reshaped many fields of research, including self driving cars, computers playing complex video games, image identification, and even particle accelerators. In this tutorial, I will first present an introduction to machine learning for beginners and will also touch on a few aspects of adaptive control theory. I will then introduce some problems in particle accelerators and present how they have been approached utilizing machine learning techniques as well as adaptive machine learning approaches, for automatically tuning extremely short and high intensity electron bunches in free electron lasers.
	Slides WEXBB1 [58.913 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-WEXBB1
About •	paper received ※ 28 August 2019 paper accepted ※ 06 September 2019 issue date ※ 08 October 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPLM05	Continuous Monitoring of Spectral Features of Electron Beam Orbit Motion at NSLS-II	operation, undulator, controls, cavity	673
	B. Podobedov, A.A. Derbenev, K. Ha, T.V. Shaftan BNL, Upton, New York, USA
	NSLS-II ring is equipped with state-of-the art beam position monitors (BPMs) which are indispensable in all aspects of machine studies and operations. Among other data, they can provide, on demand, up to 10 seconds of fast-acquisition (FA) data, sampled at ~10 kHz. Analysis of these data in time, frequency and spatial domains provides valuable insights into orbit stability, locations of residual noise sources, performance of feedback systems, etc. In addition, changes in FA signal spectral features are often the earliest indicators of potential equipment problems. This is why we recently implemented an Input / Output Controller (IOC) software that runs during regular user operation, and, once a minute, acquires 10 second buffers of FA data from 180 BPMs around the ring. These buffers are processed to determine the amplitudes and frequencies of the strongest spectral peaks as well as some other measures of fast beam orbit noise. Processed results can be monitored in real time and are also archived for offline analysis and troubleshooting. In this paper we discuss the implementation of this system and the insights we gained from it over about two years of operations.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-WEPLM05
About •	paper received ※ 31 August 2019 paper accepted ※ 02 September 2019 issue date ※ 08 October 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPLM11	Closed Loop Modeling of the APS-U Orbit Feedback System	controls, power-supply, vacuum, simulation	683
	P.S. Kallakuri, A.R. Brill, J. Carwardine, N. Sereno ANL, Lemont, Illinois, USA
	Funding: Work supported by the U.S. Department of Energy, Office of Science, under Contract No. DE-ACO₂-O6CH11357. Orbit stabilization to 10% of the expected small beam sizes for Advanced Photon Source Upgrade (APS-U) requires pushing the state of the art in fast orbit feedback (FOFB) control, both in the spatial domain and in dynamical performance. We are building a Matlab/Simulink fast orbit feedback system model to guide decisions about APS-U fast orbit feedback system implementation and to provide a test bench for optimal-control methodologies and orbit correction algorithms applicable to the APS-U. A transfer function model was built from open-loop frequency-response and step-response measurements of the present APS and subsequently validated against closed-loop measurements. A corresponding model for APS-U fast orbit feedback was generated by substituting measured responses of APS-U prototype corrector magnets and power supplies into this same model. Stabilizing PID gains are designed using model, and simulated dynamic performance of the new controller is validated through experiments.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-WEPLM11
About •	paper received ※ 27 August 2019 paper accepted ※ 19 November 2019 issue date ※ 08 October 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Other Keywords

Page

TUPLM11

Beam-Beam Damping of the Ion Instability

electron, simulation, storage-ring, damping

391

M. Blaskiewicz
BNL, Upton, New York, USA

Funding: Work Supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
Beam-Beam damping of the Ion Instability The electron storage ring of the proposed electron ion collider at BNL has bunch charges as large as 50 nC and bunch spacings as small as 10 ns. For molecules like CO a dangerous buildup of positive ions is possible and a significant fraction of these ions can survive allowable clearing gaps. The instability is thus multi-turn and the weak damping required to stop the ion instabilty with an ideal clearing gap is ineffective here. The beam-beam force is highly nonlinear and a potent source of tune spread. Simulations employing several macro-particles per electron bunch and several ion macroparticles are used to estimate maximum gas densities for some common molecules. A simplified model is introduced and compared with simulations.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-TUPLM11

About •

paper received ※ 26 August 2019 paper accepted ※ 02 September 2019 issue date ※ 08 October 2019

Export •

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

TUPLS09

Precision Insertion Device Control and Simultaneous Monochromator Fly Scanning for NSLS-II

controls, insertion-device, insertion, photon

471

D.A. Hidas, P.L. Cappadoro, T.M. Corwin, J. Escallier, A. Hunt, M. Musardo, J. Rank, C. Rhein, J. Sinsheimer, T. Tanabe, I. Waluyo
BNL, Upton, New York, USA

Funding: Department of Energy Office of Science DE-SC0012704
Beginning in January of 2019, 8 of the 10 In-Vacuum Undulators installed in the NSLS-II storage ring underwent in-house in-situ control system upgrades allowing for control of the magnetic gap during motion down to the 50 nanometer level with an in-position accuracy of nearly 5 nanometers. Direct linking of Insertion Devices and beamline monochromators is achieved via a fiber interface allowing precise, simultaneous, nonlinear motion of both devices and providing a fast hardware trigger for real-time accurate insertion device and monochromator fly scanning. This presentation will detail the accuracy of motion and its effect on the produced spectra as well as the variation of flux when both insertion device and monochromator are in simultaneous motion.

Poster TUPLS09 [0.668 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-TUPLS09

About •

paper received ※ 28 August 2019 paper accepted ※ 01 September 2019 issue date ※ 08 October 2019

Export •

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

WEXBB1

Adaptive Machine Learning and Automatic Tuning of Intense Electron Bunches in Particle Accelerators

FEL, electron, controls, target

609

A. Scheinker
LANL, Los Alamos, New Mexico, USA

Machine learning and in particular neural networks, have been around for a very long time. In recent years, thanks to growth in computing power, neural networks have reshaped many fields of research, including self driving cars, computers playing complex video games, image identification, and even particle accelerators. In this tutorial, I will first present an introduction to machine learning for beginners and will also touch on a few aspects of adaptive control theory. I will then introduce some problems in particle accelerators and present how they have been approached utilizing machine learning techniques as well as adaptive machine learning approaches, for automatically tuning extremely short and high intensity electron bunches in free electron lasers.

Slides WEXBB1 [58.913 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-WEXBB1

About •

paper received ※ 28 August 2019 paper accepted ※ 06 September 2019 issue date ※ 08 October 2019

Export •

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

WEPLM05

Continuous Monitoring of Spectral Features of Electron Beam Orbit Motion at NSLS-II

operation, undulator, controls, cavity

673

B. Podobedov, A.A. Derbenev, K. Ha, T.V. Shaftan
BNL, Upton, New York, USA

NSLS-II ring is equipped with state-of-the art beam position monitors (BPMs) which are indispensable in all aspects of machine studies and operations. Among other data, they can provide, on demand, up to 10 seconds of fast-acquisition (FA) data, sampled at ~10 kHz. Analysis of these data in time, frequency and spatial domains provides valuable insights into orbit stability, locations of residual noise sources, performance of feedback systems, etc. In addition, changes in FA signal spectral features are often the earliest indicators of potential equipment problems. This is why we recently implemented an Input / Output Controller (IOC) software that runs during regular user operation, and, once a minute, acquires 10 second buffers of FA data from 180 BPMs around the ring. These buffers are processed to determine the amplitudes and frequencies of the strongest spectral peaks as well as some other measures of fast beam orbit noise. Processed results can be monitored in real time and are also archived for offline analysis and troubleshooting. In this paper we discuss the implementation of this system and the insights we gained from it over about two years of operations.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-WEPLM05

About •

paper received ※ 31 August 2019 paper accepted ※ 02 September 2019 issue date ※ 08 October 2019

Export •

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

WEPLM11

Closed Loop Modeling of the APS-U Orbit Feedback System

controls, power-supply, vacuum, simulation

683

P.S. Kallakuri, A.R. Brill, J. Carwardine, N. Sereno
ANL, Lemont, Illinois, USA

Funding: Work supported by the U.S. Department of Energy, Office of Science, under Contract No. DE-ACO₂-O6CH11357.
Orbit stabilization to 10% of the expected small beam sizes for Advanced Photon Source Upgrade (APS-U) requires pushing the state of the art in fast orbit feedback (FOFB) control, both in the spatial domain and in dynamical performance. We are building a Matlab/Simulink fast orbit feedback system model to guide decisions about APS-U fast orbit feedback system implementation and to provide a test bench for optimal-control methodologies and orbit correction algorithms applicable to the APS-U. A transfer function model was built from open-loop frequency-response and step-response measurements of the present APS and subsequently validated against closed-loop measurements. A corresponding model for APS-U fast orbit feedback was generated by substituting measured responses of APS-U prototype corrector magnets and power supplies into this same model. Stabilizing PID gains are designed using model, and simulated dynamic performance of the new controller is validated through experiments.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-WEPLM11

About •

paper received ※ 27 August 2019 paper accepted ※ 19 November 2019 issue date ※ 08 October 2019

Export •

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