IPAC2021 - List of Keywords (distributed)

Paper	Title	Other Keywords	Page
MOPAB288	Real-Time Edge AI for Distributed Systems (READS): Progress on Beam Loss De-Blending for the Fermilab Main Injector and Recycler	network, real-time, operation, FPGA	912
	K.J. Hazelwood, M.R. Austin, M.A. Ibrahim, V.P. Nagaslaev, A. Narayanan, D.J. Nicklaus, A.L. Saewert, B.A. Schupbach, K. Seiya, R.M. Thurman-Keup, N.V. Tran Fermilab, Batavia, Illinois, USA H. Liu, S. Memik, R. Shi, M. Thieme Northwestern University, Evanston, Illinois, USA A. Narayanan Northern Illinois University, DeKalb, Illinois, USA
	The Fermilab Main Injector enclosure houses two accelerators, the Main Injector and Recycler. During normal operation, high intensity proton beams exist simultaneously in both. The two accelerators share the same beam loss monitors (BLM) and monitoring system. Beam losses in the Main Injector enclosure are monitored for tuning the accelerators and machine protection. Losses are currently attributed to a specific machine based on timing. However, this method alone is insufficient and often inaccurate, resulting in more difficult machine tuning and unnecessary machine downtime. Machine experts can often distinguish the correct source of beam loss. This suggests a machine learning (ML) model may be producible to help de-blend losses between machines. Work is underway as part of the Fermilab Real-time Edge AI for Distributed Systems Project (READS) to develop a ML empowered system that collects streamed BLM data and additional machine readings to infer in real-time, which machine generated beam loss.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB288
About •	paper received ※ 19 May 2021 paper accepted ※ 29 July 2021 issue date ※ 13 August 2021
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TUPAB117	Eigenmode Decomposition for Free-Electron Lasers Using Bayesian Analysis	optics, laser, FEL, simulation	1666
	P. Liu, W. Li, Y.K. Wu, J. Yan FEL/Duke University, Durham, North Carolina, USA
	Funding: This work is supported in part by the US DOE grant no. DE-FG02-97ER41033. Laser beams from an optical cavity, such as free-electron laser (FEL) resonators, are typically a mixture of the cavity’s eigenmodes, such as the Hermite-Gaussian (HG) modes or Laguerre-Gaussian (LG) modes. Robust evaluation of the eigenmode spectrum of a multimode laser beam has various applications in laser development, research, and utilization. In this work, a general eigenmode decomposition method for a multimode laser beam has been developed based on Bayesian analysis. This problem is transformed into a linear system and then solved using a Gaussian probabilistic model. Using Bayesian analysis, prior knowledge about the mode content is further incorporated into the solution to improve the results for laser beams contaminated with complex disturbances. The decomposition of the beam image from the incoherent intensity addition of HG modes is discussed with different types of noise or disturbances. The simulation results have been used to show the robustness of this method. This method can be straightforwardly extended into other cases such as the wavefront decomposition into the coherent superposition of HG and LG modes.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB117
About •	paper received ※ 18 May 2021 paper accepted ※ 15 June 2021 issue date ※ 01 September 2021
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TUPAB257	Analysis of Multibunch Spectrum for an Uneven Bunch Distribution in a Storage Ring	electron, impedance, collider, storage-ring	2058
	R. Li, F. Marhauser JLab, Newport News, Virginia, USA
	Funding: This work is supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics under contract DE-AC05-06OR23177. Modern storage-ring designs often require an uneven bunch distribution pattern. An uneven bunch fill pattern can result in complex structures for the beam current spectra. Particularly at high average beam currents, these complex current spectra need to be taken into account in concern of beam-dynamical effects. In this study, we analyze a beam current spectrum for various filling patterns with bunch trains and gaps. The characteristics of the resulting beam current spectra are illustrated and discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB257
About •	paper received ※ 21 June 2021 paper accepted ※ 28 June 2021 issue date ※ 12 August 2021
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WEPAB031	Frequency Dependence of Plasma Cascade Amplification	electron, plasma, simulation, hadron	2672
	G. Wang, V. Litvinenko, J. Ma BNL, Upton, New York, USA V. Litvinenko Stony Brook University, Stony Brook, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. A new type of amplifier, plasma cascade amplifier (PCA) has been proposed for a coherent electron cooling (CeC) system. Previously, the 1D model for PCA assumes that the transverse distribution of the density perturbation in the electrons is uniform and consequently, the plasma frequency does not depend on the wavelength of the perturbation. This assumption is valid if the longitudinal wavelength of the beam frame is much shorter than the transverse width of perturbation. In this work, we explore the PCI gain at a long wavelength by assuming the perturbation in the electron density has a non-uniform transverse profile. Specifically, we solve the 3D Poisson equation for given charge distribution (longitudinal sinusoidal, transversely Gaussian, or Beer-can), average the electric field over the transverse plane, and then apply it to 1D Vlasov equation. Similar to the previous calculation, the Vlasov equation can be reduced to a Hill’s equation but the plasma frequency now depends on the longitudinal wavelength of the density perturbation in the electrons. By numerically solving Hill’s equation, we obtain the gain of a PCA and compare it with the results from 3D SPACE simulations.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB031
About •	paper received ※ 20 May 2021 paper accepted ※ 23 June 2021 issue date ※ 27 August 2021
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WEPAB226	Investigation of Vlasov Systems with a Certain Class of Linearly-Collective Hamiltonians	bunching, simulation, collective-effects, linear-dynamics	3157
	Ph. Amstutz, M. Vogt DESY, Hamburg, Germany
	In many cases the Vlasov equation cannot be solved exactly due its inherent non-linearity arising from collective terms in the Hamiltonian. Based on the analysis of the Hamiltonian’s dependence on the phase-space density and the requirement for self-consistency in this contribution a class of Hamiltonians is defined and characterized. For members of this class the corresponding expansion of the Vlasov equation terminates. The new, potentially non-autonomous, Hamiltonian of the resulting Liouville equation depends only on the initial condition of the phase-space density. Prominent members of this class are Poisson-type kick-Hamiltonians, which we show as an example. We expect these investigations to be a potential starting point for the analysis and conception of operator-splitting schemes or splitting-free methods for beam-dynamics simulation codes.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB226
About •	paper received ※ 18 May 2021 paper accepted ※ 01 July 2021 issue date ※ 17 August 2021
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WEPAB294	LLRF Control and Synchronization System of the ARES Facility	LLRF, gun, laser, experiment	3347
	S. Pfeiffer, J. Branlard, F. Burkart, M. Hoffmann, T. Lamb, F. Ludwig, H. Schlarb, S. Schulz, B. Szczepanski, M. Titberidze DESY, Hamburg, Germany
	The linear accelerator ARES (Accelerator Research Experiment at SINBAD) is a new research facility at DESY. Electron bunches with a maximum repetition rate of 50 Hz are accelerated up to 155 MeV. The facility aims for ultra-stable sub-femtosecond arrival-times and high peak-currents at the experiment, placing high demands on the reference distribution and field regulation of the S-band RF structures. In this paper, we report on the current status of the RF reference generation, facility-wide distribution, and the LLRF systems of the RF structures.
	Poster WEPAB294 [2.394 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB294
About •	paper received ※ 18 May 2021 paper accepted ※ 05 July 2021 issue date ※ 20 August 2021
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPAB298	Design of an Accurate LLRF System for an Array of Two-Gap Resonators	controls, LLRF, FPGA, Ethernet	3360
	D.A. Liakin, S.V. Barabin, T. Kulevoy, A.Y. Orlov ITEP, Moscow, Russia
	A particle accelerator based on an array of two-gap resonators requires a control system, which is responsible for precise setup and stabilization of the phase and magnitude of the electromagnetic field in resonators. We develop a cost-effective LLRF system for the array of more than 80 resonators and three different operating frequencies. The design is based on proved solution used for 5-resonators accelerator HILAC (project NICA, Dubna). This paper gives an overview of the basic structure and some specific features of the developing LLRF control system.
	Poster WEPAB298 [0.355 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB298
About •	paper received ※ 18 May 2021 paper accepted ※ 23 June 2021 issue date ※ 30 August 2021
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THPAB201	A Machine Learning Technique for Dynamic Aperture Computation	network, dynamic-aperture, simulation, hadron	4172
	B. Dalena, M. Ben Ghali CEA-IRFU, Gif-sur-Yvette, France
	Currently, dynamic aperture calculations of high-energy hadron colliders are performed through computer simulations, which are both a resource-heavy and time-costly processes. The aim of this study is to use a reservoir computing machine learning model in order to achieve a faster extrapolation of dynamic aperture values. A recurrent echo-state network (ESN) architecture is used as a basis for this work. Recurrent networks are better fitted to extrapolation tasks while the reservoir echo-state structure is computationally effective. Model training and validation is conducted on a set of "seeds" corresponding to the simulation results of different machine configurations. Adjustments in the model architecture, manual metric and data selection, hyper-parameters tuning and the introduction of new parameters enabled the model to reliably achieve good performance on examining testing sets.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB201
About •	paper received ※ 14 May 2021 paper accepted ※ 22 July 2021 issue date ※ 02 September 2021
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Other Keywords

Page

Real-Time Edge AI for Distributed Systems (READS): Progress on Beam Loss De-Blending for the Fermilab Main Injector and Recycler

network, real-time, operation, FPGA

912

K.J. Hazelwood, M.R. Austin, M.A. Ibrahim, V.P. Nagaslaev, A. Narayanan, D.J. Nicklaus, A.L. Saewert, B.A. Schupbach, K. Seiya, R.M. Thurman-Keup, N.V. Tran
Fermilab, Batavia, Illinois, USA
H. Liu, S. Memik, R. Shi, M. Thieme
Northwestern University, Evanston, Illinois, USA
A. Narayanan
Northern Illinois University, DeKalb, Illinois, USA

The Fermilab Main Injector enclosure houses two accelerators, the Main Injector and Recycler. During normal operation, high intensity proton beams exist simultaneously in both. The two accelerators share the same beam loss monitors (BLM) and monitoring system. Beam losses in the Main Injector enclosure are monitored for tuning the accelerators and machine protection. Losses are currently attributed to a specific machine based on timing. However, this method alone is insufficient and often inaccurate, resulting in more difficult machine tuning and unnecessary machine downtime. Machine experts can often distinguish the correct source of beam loss. This suggests a machine learning (ML) model may be producible to help de-blend losses between machines. Work is underway as part of the Fermilab Real-time Edge AI for Distributed Systems Project (READS) to develop a ML empowered system that collects streamed BLM data and additional machine readings to infer in real-time, which machine generated beam loss.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB288

About •

paper received ※ 19 May 2021 paper accepted ※ 29 July 2021 issue date ※ 13 August 2021

Export •

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

TUPAB117

Eigenmode Decomposition for Free-Electron Lasers Using Bayesian Analysis

optics, laser, FEL, simulation

1666

P. Liu, W. Li, Y.K. Wu, J. Yan
FEL/Duke University, Durham, North Carolina, USA

Funding: This work is supported in part by the US DOE grant no. DE-FG02-97ER41033.
Laser beams from an optical cavity, such as free-electron laser (FEL) resonators, are typically a mixture of the cavity’s eigenmodes, such as the Hermite-Gaussian (HG) modes or Laguerre-Gaussian (LG) modes. Robust evaluation of the eigenmode spectrum of a multimode laser beam has various applications in laser development, research, and utilization. In this work, a general eigenmode decomposition method for a multimode laser beam has been developed based on Bayesian analysis. This problem is transformed into a linear system and then solved using a Gaussian probabilistic model. Using Bayesian analysis, prior knowledge about the mode content is further incorporated into the solution to improve the results for laser beams contaminated with complex disturbances. The decomposition of the beam image from the incoherent intensity addition of HG modes is discussed with different types of noise or disturbances. The simulation results have been used to show the robustness of this method. This method can be straightforwardly extended into other cases such as the wavefront decomposition into the coherent superposition of HG and LG modes.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB117

About •

paper received ※ 18 May 2021 paper accepted ※ 15 June 2021 issue date ※ 01 September 2021

Export •

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

TUPAB257

Analysis of Multibunch Spectrum for an Uneven Bunch Distribution in a Storage Ring

electron, impedance, collider, storage-ring

2058

R. Li, F. Marhauser
JLab, Newport News, Virginia, USA

Funding: This work is supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics under contract DE-AC05-06OR23177.
Modern storage-ring designs often require an uneven bunch distribution pattern. An uneven bunch fill pattern can result in complex structures for the beam current spectra. Particularly at high average beam currents, these complex current spectra need to be taken into account in concern of beam-dynamical effects. In this study, we analyze a beam current spectrum for various filling patterns with bunch trains and gaps. The characteristics of the resulting beam current spectra are illustrated and discussed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB257

About •

paper received ※ 21 June 2021 paper accepted ※ 28 June 2021 issue date ※ 12 August 2021

Export •

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

WEPAB031

Frequency Dependence of Plasma Cascade Amplification

electron, plasma, simulation, hadron

2672

G. Wang, V. Litvinenko, J. Ma
BNL, Upton, New York, USA
V. Litvinenko
Stony Brook University, Stony Brook, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
A new type of amplifier, plasma cascade amplifier (PCA) has been proposed for a coherent electron cooling (CeC) system. Previously, the 1D model for PCA assumes that the transverse distribution of the density perturbation in the electrons is uniform and consequently, the plasma frequency does not depend on the wavelength of the perturbation. This assumption is valid if the longitudinal wavelength of the beam frame is much shorter than the transverse width of perturbation. In this work, we explore the PCI gain at a long wavelength by assuming the perturbation in the electron density has a non-uniform transverse profile. Specifically, we solve the 3D Poisson equation for given charge distribution (longitudinal sinusoidal, transversely Gaussian, or Beer-can), average the electric field over the transverse plane, and then apply it to 1D Vlasov equation. Similar to the previous calculation, the Vlasov equation can be reduced to a Hill’s equation but the plasma frequency now depends on the longitudinal wavelength of the density perturbation in the electrons. By numerically solving Hill’s equation, we obtain the gain of a PCA and compare it with the results from 3D SPACE simulations.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB031

About •

paper received ※ 20 May 2021 paper accepted ※ 23 June 2021 issue date ※ 27 August 2021

Export •

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

WEPAB226

Investigation of Vlasov Systems with a Certain Class of Linearly-Collective Hamiltonians

bunching, simulation, collective-effects, linear-dynamics

3157

Ph. Amstutz, M. Vogt
DESY, Hamburg, Germany

In many cases the Vlasov equation cannot be solved exactly due its inherent non-linearity arising from collective terms in the Hamiltonian. Based on the analysis of the Hamiltonian’s dependence on the phase-space density and the requirement for self-consistency in this contribution a class of Hamiltonians is defined and characterized. For members of this class the corresponding expansion of the Vlasov equation terminates. The new, potentially non-autonomous, Hamiltonian of the resulting Liouville equation depends only on the initial condition of the phase-space density. Prominent members of this class are Poisson-type kick-Hamiltonians, which we show as an example. We expect these investigations to be a potential starting point for the analysis and conception of operator-splitting schemes or splitting-free methods for beam-dynamics simulation codes.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB226

About •

paper received ※ 18 May 2021 paper accepted ※ 01 July 2021 issue date ※ 17 August 2021

Export •

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

WEPAB294

LLRF Control and Synchronization System of the ARES Facility

LLRF, gun, laser, experiment

3347

S. Pfeiffer, J. Branlard, F. Burkart, M. Hoffmann, T. Lamb, F. Ludwig, H. Schlarb, S. Schulz, B. Szczepanski, M. Titberidze
DESY, Hamburg, Germany

The linear accelerator ARES (Accelerator Research Experiment at SINBAD) is a new research facility at DESY. Electron bunches with a maximum repetition rate of 50 Hz are accelerated up to 155 MeV. The facility aims for ultra-stable sub-femtosecond arrival-times and high peak-currents at the experiment, placing high demands on the reference distribution and field regulation of the S-band RF structures. In this paper, we report on the current status of the RF reference generation, facility-wide distribution, and the LLRF systems of the RF structures.

Poster WEPAB294 [2.394 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB294

About •

paper received ※ 18 May 2021 paper accepted ※ 05 July 2021 issue date ※ 20 August 2021

Export •

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

WEPAB298

Design of an Accurate LLRF System for an Array of Two-Gap Resonators

controls, LLRF, FPGA, Ethernet

3360

D.A. Liakin, S.V. Barabin, T. Kulevoy, A.Y. Orlov
ITEP, Moscow, Russia

A particle accelerator based on an array of two-gap resonators requires a control system, which is responsible for precise setup and stabilization of the phase and magnitude of the electromagnetic field in resonators. We develop a cost-effective LLRF system for the array of more than 80 resonators and three different operating frequencies. The design is based on proved solution used for 5-resonators accelerator HILAC (project NICA, Dubna). This paper gives an overview of the basic structure and some specific features of the developing LLRF control system.

Poster WEPAB298 [0.355 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB298

About •

paper received ※ 18 May 2021 paper accepted ※ 23 June 2021 issue date ※ 30 August 2021

Export •

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

THPAB201

A Machine Learning Technique for Dynamic Aperture Computation

network, dynamic-aperture, simulation, hadron

4172

B. Dalena, M. Ben Ghali
CEA-IRFU, Gif-sur-Yvette, France

Currently, dynamic aperture calculations of high-energy hadron colliders are performed through computer simulations, which are both a resource-heavy and time-costly processes. The aim of this study is to use a reservoir computing machine learning model in order to achieve a faster extrapolation of dynamic aperture values. A recurrent echo-state network (ESN) architecture is used as a basis for this work. Recurrent networks are better fitted to extrapolation tasks while the reservoir echo-state structure is computationally effective. Model training and validation is conducted on a set of "seeds" corresponding to the simulation results of different machine configurations. Adjustments in the model architecture, manual metric and data selection, hyper-parameters tuning and the introduction of new parameters enabled the model to reliably achieve good performance on examining testing sets.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB201

About •

paper received ※ 14 May 2021 paper accepted ※ 22 July 2021 issue date ※ 02 September 2021

Export •

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