IBIC2023 - Classification: 08 Feedback Systems and Beam Stability

Paper	Title	Page
MO2I02	Fast Orbit Feedback for Diamond-II	1
	I. Kempf, M.G. Abbott, L. Bobb, G.B. Christian DLS, Harwell, United Kingdom S. Duncan University of Oxford, Oxford, United Kingdom G. Rehm HZB, Berlin, Germany
	Funding: Diamond Light Source and Engineering and Physical Sciences Research Council The electron beam stability is critical for 4th generation light sources. As opposed to 10% of beam size up to 140 Hz at Diamond, advances in detector speed and resolution at Diamond-II increase the stability requirements to 3% up to 1 kHz. This paper presents a novel control methodology for the fast orbit feedback at Diamond-II, which will stabilise the beam using two arrays of 252 slow and 144 fast correctors and 252 beam position monitors at 100 kHz. In contrast to existing approaches that separate slow and fast feedback loops, our approach is based on a two-matrix factorisation called the generalised singular value decomposition (GSVD), which decouples the system into 144 two-input modes controlled by slow and fast magnets and 108 modes controlled by slow magnets only. The GSVD-based controller is implemented in the existing Diamond storage ring using a centralised communication architecture, such as planned for Diamond-II. We present results from the Diamond storage ring and simulation, which confirm that the proposed approach meets the target specification for Diamond-II.
	Slides MO2I02 [3.686 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-IBIC2023-MO2I02
About •	Received ※ 06 September 2023 — Revised ※ 07 September 2023 — Accepted ※ 11 September 2023 — Issue date ※ 18 September 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MO2C03	Coupled Bunch Mode Zero Correction within the Orbit Feedback Bandwidth	7
	P.S. Kallakuri, A.R. Brill, J. Carwardine, L. Emery, N. Sereno ANL, Lemont, Illinois, USA
	Funding: Work supported by U. S. Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11357. The fast orbit feedback (FOFB) bandwidth for Advanced photon source upgrade (APS-U) will be DC-1 kHz and the synchrotron frequency will be between 100-560 Hz. This frequency overlap places coupled bunch mode 0 (CBM0) induced horizontal orbit motion inside the orbit feedback bandwidth, potentially affecting our ability to achieve beam stability goals. Longitudinal feedback kicker is not strong enough to damp CBM0 oscillations. We developed new beam-based feedback method to suppress CBM0 oscillations with low level RF phase as actuator. It uses existent FOFB framework with no changes to the feedback algorithm. Effectiveness of this method is verified using present APS operations lattice where synchrotron frequency is outside orbit feedback bandwidth. In the present work, low alpha lattice is created to emulate APS-U setting where synchrotron frequency is inside the orbit feedback bandwidth. Experiments with this lattice successfully demonstrated CBM0 correction within FOFB bandwidth. Combined operation of orbit feedback and CBM0 correction is stable, and CBM0 oscillations are damped. We achieved better orbit motion suppression and corrector drive efforts are reduced as well. P. Kallakuri et al., ’Coupled bunch mode zero correction using orbit measurements and RF system phase feedback’, doi:10.1103/PhysRevAccelBeams.25.082801
	Slides MO2C03 [1.326 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-IBIC2023-MO2C03
About •	Received ※ 14 July 2023 — Revised ※ 07 September 2023 — Accepted ※ 13 September 2023 — Issue date ※ 25 September 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MO2C04	SOLEIL New Platform for Fast Orbit Feedback	11
	R. Bronès, A. Bence, J. Bisou, N. Hubert, D. Pédeau, G. Pichon SOLEIL, Gif-sur-Yvette, France
	SOLEIL is upgrading its Fast Orbit Feedback platform to withstand coming obsolescence of electronic BPM and future evolutions of the machine. This new platform has to be compatible with current boundary devices such as BPM electronics or corrector power supplies, but it also shall evolve to interface future versions of these systems. A MTCA based platform was designed and installed. It is integrated in the control system by mean of a OPCUA server, and care has been taken to seamlessly toggle the closing of the feedback loop on the former or new FOFB platform. This paper will present the first tests and results conducted to commission this new system.
	Slides MO2C04 [30.176 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-IBIC2023-MO2C04
About •	Received ※ 06 September 2023 — Revised ※ 09 September 2023 — Accepted ※ 26 September 2023 — Issue date ※ 01 October 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOP036	A New Approach for Canadian Light Source Future Orbit Correction System Driven by Neural Network	102
	S. Saadat, M.J. Boland CLS, Saskatoon, Saskatchewan, Canada M.J. Boland University of Saskatchewan, Saskatoon, Canada
	The Orbit Correction System (OCS) of the CLS comprises 48 sets of BPMs. Each BPM has the ability to measure the position of the beam in both the X-Y directions and can record data at a rate of 900 times per second. The Inverse Response Matrix is utilized to determine the optimal strength of the 48 sets of orbit correctors in both the X-Y directions, in order to ensure that the beam follows its desired path. The Singular Value Decomposition function is replaced by a neural network algorithm to serve as the brain of the orbit correction system in this study. The training model’s design includes three hidden layers, and within each layer, there are 96 nodes. The neural network’s outputs for regular operations in CLS exhibit a Mean Square Error of 10^-7. Various difficult scenarios were created to test the OCS at 8.0 mA, using offsets in different sections of the storage ring. However, the new model was able to produce the necessary Orbit Correctors signals without any trouble.
	Poster MOP036 [1.438 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-IBIC2023-MOP036
About •	Received ※ 14 July 2023 — Revised ※ 09 September 2023 — Accepted ※ 28 September 2023 — Issue date ※ 30 September 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOP037	Tune Feedback at the Canadian Light Source	106
	W.A. Wurtz, C.K. Baribeau, A.M. Duffy CLS, Saskatoon, Saskatchewan, Canada
	In order to maintain good injection efficiency for top-up operation at the Canadian Light Source, we must keep the betatron tunes constant even as changes in insertion device fields cause the tunes to vary. To meet this requirement, we implemented a tune feedback system. We measure the tunes at a rate of 1 Hz using Dimtel bunch-by-bunch systems. The transverse feedback function of the bunch-by-bunch systems provides tune measurements without disturbing the electron beam. We adjust two quadrupole families at a rate of 0.25 Hz to control the horizontal and vertical tunes. In this article we describe the tune feedback system, its development and its performance. The system has proven to be very robust, enabling reliable top-up operation.
	Poster MOP037 [1.284 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-IBIC2023-MOP037
About •	Received ※ 24 August 2023 — Revised ※ 07 September 2023 — Accepted ※ 14 September 2023 — Issue date ※ 21 September 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOP038	Development of an Active Beam-Stabilization System for Electrofission Experiments at the S-Dalinac	111
	D. Schneider, M. Arnold, U. Bonnes, A. Brauch, M. Dutine, R. Grewe, L.E. Jürgensen, N. Pietralla, F. Schließmann, G. Steinhilber TU Darmstadt, Darmstadt, Germany
	Funding: Work supported by DFG (GRK 2128), BMBF (05H21RDRB1), the State of Hesse within the Research Cluster ELEMENTS (Project ID 500/10.006) and the LOEWE Research Group Nuclear Photonics. The r-process fission cycle terminates the natural synthesis of heavy elements in binary neutron-star mergers. Fission processes of transuranium nuclides will be studied in electrofission reactions at the S-DALINAC. Due to the minuscule fissile target, the experimental setup requires an active electron-beam-stabilization system with high accuracy and a beam position resolution in the submillimeter range. In this contribution, requirements and concepts of this system regarding beam-diagnostic elements, feedback control and readout electronics are presented. The usage of a beam position monitor cavity and optical transition radiation targets to monitor the required beam parameters will be discussed in detail. Additionally, various measurements performed at the S-DALINAC to assess requirements and limits for the beam-stabilization system will be presented. Finally, the option of using advanced machine learning methods such as neural networks and agent-based reinforcement learning will be discussed. N. Pietralla, Nuclear Physics News, Vol. 28, No. 2, 4 (2018)
	Poster MOP038 [1.526 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-IBIC2023-MOP038
About •	Received ※ 06 September 2023 — Revised ※ 07 September 2023 — Accepted ※ 14 September 2023 — Issue date ※ 23 September 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOP039	Transverse Multi-Bunch Feedback Detector Electronics Using Direct Sampling Analog-to-Digital Converters for the Synchrotron Radiation Source PETRA IV	115
	S. Jabłoński, H.T. Duhme, U. Mavrič, S. Pfeiffer, H. Schlarb DESY, Hamburg, Germany
	PETRA IV, a new fourth generation synchrotron radiation source planned at DESY, will require a transverse multi-bunch feedback (T-MBFB) system to damp transverse instabilities and keep the beam emittance low. The critical part of the T-MBFB is a detector that must measure bunch-by-bunch, i.e. every 2 ns, beam position variations with the resolution not worse than 1 ¿m for the dynamic beam range of ±1 mm. In this paper, we present the conceptual design of the T-MBFB detector from the beam position pickups to the direct sampling ADCs. We analyse the noise sources limiting the detector resolution and present measurement results based on the evaluation modules.
DOI •	reference for this paper ※ doi:10.18429/JACoW-IBIC2023-MOP039
About •	Received ※ 01 September 2023 — Revised ※ 08 September 2023 — Accepted ※ 12 September 2023 — Issue date ※ 01 October 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOP041	Modified Fast Orbit Feedback Controller for Disturbance Attenuation in Long Straights for Diamond-II	119
	S. Banerjee, M.G. Abbott, L. Bobb, I. Kempf DLS, Harwell, United Kingdom I. Kempf University of Oxford, Oxford, United Kingdom
	At Diamond Light Source, the fast orbit feedback (FOFB) uses one array of correctors and the controller is designed using the internal model control (IMC) structure. The Diamond-II upgrade will introduce an additional array of fast correctors and a new controller that is designed using the generalised modal decomposition, increasing the overall closed-loop bandwidth from 140 Hz to 1 kHz. Although simulation results have shown that the resulting beam displacement is within specification in all straights, they have also shown that the performance on long straights is limited, particularly in the vertical plane. In this paper, the controller is tuned in order to increase the FOFB performance in long straights by introducing a mode-by-mode regularisation parameter. The performance of the controller beyond 1 kHz is assessed using new disturbance data and a new measurement noise model, showing that the Diamond-II performance criteria are met, even in the presence of measurement noise.
DOI •	reference for this paper ※ doi:10.18429/JACoW-IBIC2023-MOP041
About •	Received ※ 07 September 2023 — Revised ※ 09 September 2023 — Accepted ※ 13 September 2023 — Issue date ※ 16 September 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOP043	Using Lag Compensator in Orbit Feedback	123
	I. Pinayev BNL, Upton, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy Growing demand on the beam orbit stability requires higher loop gain within the operational bandwidth. Increasing the gain leads to the increase of the unity gain frequency and creates problems with systems stability due to the additional phase shifts caused by the trims (power supplies, eddy currents in vacuum chambers, etc.) and filtering of beam position data. Conventionally employed systems have 20 dB/decade slope near the unity gain providing 90 degrees phase shift which is sufficient for stability. Utilizing one or more lag compensators allows to increase the gain at low frequencies while keeping phase margin acceptable. The paper provides more details on the proposed solution as well as simulations of how the transients will be modified.
	Poster MOP043 [0.230 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-IBIC2023-MOP043
About •	Received ※ 25 August 2023 — Revised ※ 08 September 2023 — Accepted ※ 13 September 2023 — Issue date ※ 23 September 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Fast Orbit Feedback for Diamond-II

1

I. Kempf, M.G. Abbott, L. Bobb, G.B. Christian
DLS, Harwell, United Kingdom
S. Duncan
University of Oxford, Oxford, United Kingdom
G. Rehm
HZB, Berlin, Germany

Funding: Diamond Light Source and Engineering and Physical Sciences Research Council
The electron beam stability is critical for 4th generation light sources. As opposed to 10% of beam size up to 140 Hz at Diamond, advances in detector speed and resolution at Diamond-II increase the stability requirements to 3% up to 1 kHz. This paper presents a novel control methodology for the fast orbit feedback at Diamond-II, which will stabilise the beam using two arrays of 252 slow and 144 fast correctors and 252 beam position monitors at 100 kHz. In contrast to existing approaches that separate slow and fast feedback loops, our approach is based on a two-matrix factorisation called the generalised singular value decomposition (GSVD), which decouples the system into 144 two-input modes controlled by slow and fast magnets and 108 modes controlled by slow magnets only. The GSVD-based controller is implemented in the existing Diamond storage ring using a centralised communication architecture, such as planned for Diamond-II. We present results from the Diamond storage ring and simulation, which confirm that the proposed approach meets the target specification for Diamond-II.

Slides MO2I02 [3.686 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-IBIC2023-MO2I02

About •

Received ※ 06 September 2023 — Revised ※ 07 September 2023 — Accepted ※ 11 September 2023 — Issue date ※ 18 September 2023

Cite •

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

MO2C03

Coupled Bunch Mode Zero Correction within the Orbit Feedback Bandwidth

7

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

Funding: Work supported by U. S. Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11357.
The fast orbit feedback (FOFB) bandwidth for Advanced photon source upgrade (APS-U) will be DC-1 kHz and the synchrotron frequency will be between 100-560 Hz. This frequency overlap places coupled bunch mode 0 (CBM0) induced horizontal orbit motion inside the orbit feedback bandwidth, potentially affecting our ability to achieve beam stability goals. Longitudinal feedback kicker is not strong enough to damp CBM0 oscillations. We developed new beam-based feedback method to suppress CBM0 oscillations with low level RF phase as actuator. It uses existent FOFB framework with no changes to the feedback algorithm. Effectiveness of this method is verified using present APS operations lattice where synchrotron frequency is outside orbit feedback bandwidth*. In the present work, low alpha lattice is created to emulate APS-U setting where synchrotron frequency is inside the orbit feedback bandwidth. Experiments with this lattice successfully demonstrated CBM0 correction within FOFB bandwidth. Combined operation of orbit feedback and CBM0 correction is stable, and CBM0 oscillations are damped. We achieved better orbit motion suppression and corrector drive efforts are reduced as well.
* P. Kallakuri et al., ’Coupled bunch mode zero correction using orbit measurements and RF system phase feedback’, doi:10.1103/PhysRevAccelBeams.25.082801

Slides MO2C03 [1.326 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-IBIC2023-MO2C03

About •

Received ※ 14 July 2023 — Revised ※ 07 September 2023 — Accepted ※ 13 September 2023 — Issue date ※ 25 September 2023

Cite •

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

MO2C04

SOLEIL New Platform for Fast Orbit Feedback

11

R. Bronès, A. Bence, J. Bisou, N. Hubert, D. Pédeau, G. Pichon
SOLEIL, Gif-sur-Yvette, France

SOLEIL is upgrading its Fast Orbit Feedback platform to withstand coming obsolescence of electronic BPM and future evolutions of the machine. This new platform has to be compatible with current boundary devices such as BPM electronics or corrector power supplies, but it also shall evolve to interface future versions of these systems. A MTCA based platform was designed and installed. It is integrated in the control system by mean of a OPCUA server, and care has been taken to seamlessly toggle the closing of the feedback loop on the former or new FOFB platform. This paper will present the first tests and results conducted to commission this new system.

Slides MO2C04 [30.176 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-IBIC2023-MO2C04

About •

Received ※ 06 September 2023 — Revised ※ 09 September 2023 — Accepted ※ 26 September 2023 — Issue date ※ 01 October 2023

Cite •

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

MOP036

A New Approach for Canadian Light Source Future Orbit Correction System Driven by Neural Network

102

S. Saadat, M.J. Boland
CLS, Saskatoon, Saskatchewan, Canada
M.J. Boland
University of Saskatchewan, Saskatoon, Canada

The Orbit Correction System (OCS) of the CLS comprises 48 sets of BPMs. Each BPM has the ability to measure the position of the beam in both the X-Y directions and can record data at a rate of 900 times per second. The Inverse Response Matrix is utilized to determine the optimal strength of the 48 sets of orbit correctors in both the X-Y directions, in order to ensure that the beam follows its desired path. The Singular Value Decomposition function is replaced by a neural network algorithm to serve as the brain of the orbit correction system in this study. The training model’s design includes three hidden layers, and within each layer, there are 96 nodes. The neural network’s outputs for regular operations in CLS exhibit a Mean Square Error of 10^-7. Various difficult scenarios were created to test the OCS at 8.0 mA, using offsets in different sections of the storage ring. However, the new model was able to produce the necessary Orbit Correctors signals without any trouble.

Poster MOP036 [1.438 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-IBIC2023-MOP036

About •

Received ※ 14 July 2023 — Revised ※ 09 September 2023 — Accepted ※ 28 September 2023 — Issue date ※ 30 September 2023

Cite •

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

MOP037

Tune Feedback at the Canadian Light Source

106

W.A. Wurtz, C.K. Baribeau, A.M. Duffy
CLS, Saskatoon, Saskatchewan, Canada

In order to maintain good injection efficiency for top-up operation at the Canadian Light Source, we must keep the betatron tunes constant even as changes in insertion device fields cause the tunes to vary. To meet this requirement, we implemented a tune feedback system. We measure the tunes at a rate of 1 Hz using Dimtel bunch-by-bunch systems. The transverse feedback function of the bunch-by-bunch systems provides tune measurements without disturbing the electron beam. We adjust two quadrupole families at a rate of 0.25 Hz to control the horizontal and vertical tunes. In this article we describe the tune feedback system, its development and its performance. The system has proven to be very robust, enabling reliable top-up operation.

Poster MOP037 [1.284 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-IBIC2023-MOP037

About •

Received ※ 24 August 2023 — Revised ※ 07 September 2023 — Accepted ※ 14 September 2023 — Issue date ※ 21 September 2023

Cite •

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

MOP038

Development of an Active Beam-Stabilization System for Electrofission Experiments at the S-Dalinac

111

D. Schneider, M. Arnold, U. Bonnes, A. Brauch, M. Dutine, R. Grewe, L.E. Jürgensen, N. Pietralla, F. Schließmann, G. Steinhilber
TU Darmstadt, Darmstadt, Germany

Funding: Work supported by DFG (GRK 2128), BMBF (05H21RDRB1), the State of Hesse within the Research Cluster ELEMENTS (Project ID 500/10.006) and the LOEWE Research Group Nuclear Photonics.
The r-process fission cycle terminates the natural synthesis of heavy elements in binary neutron-star mergers. Fission processes of transuranium nuclides will be studied in electrofission reactions at the S-DALINAC*. Due to the minuscule fissile target, the experimental setup requires an active electron-beam-stabilization system with high accuracy and a beam position resolution in the submillimeter range. In this contribution, requirements and concepts of this system regarding beam-diagnostic elements, feedback control and readout electronics are presented. The usage of a beam position monitor cavity and optical transition radiation targets to monitor the required beam parameters will be discussed in detail. Additionally, various measurements performed at the S-DALINAC to assess requirements and limits for the beam-stabilization system will be presented. Finally, the option of using advanced machine learning methods such as neural networks and agent-based reinforcement learning will be discussed.
*N. Pietralla, Nuclear Physics News, Vol. 28, No. 2, 4 (2018)

Poster MOP038 [1.526 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-IBIC2023-MOP038

About •

Received ※ 06 September 2023 — Revised ※ 07 September 2023 — Accepted ※ 14 September 2023 — Issue date ※ 23 September 2023

Cite •

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

MOP039

Transverse Multi-Bunch Feedback Detector Electronics Using Direct Sampling Analog-to-Digital Converters for the Synchrotron Radiation Source PETRA IV

115

S. Jabłoński, H.T. Duhme, U. Mavrič, S. Pfeiffer, H. Schlarb
DESY, Hamburg, Germany

PETRA IV, a new fourth generation synchrotron radiation source planned at DESY, will require a transverse multi-bunch feedback (T-MBFB) system to damp transverse instabilities and keep the beam emittance low. The critical part of the T-MBFB is a detector that must measure bunch-by-bunch, i.e. every 2 ns, beam position variations with the resolution not worse than 1 ¿m for the dynamic beam range of ±1 mm. In this paper, we present the conceptual design of the T-MBFB detector from the beam position pickups to the direct sampling ADCs. We analyse the noise sources limiting the detector resolution and present measurement results based on the evaluation modules.

DOI •

reference for this paper ※ doi:10.18429/JACoW-IBIC2023-MOP039

About •

Received ※ 01 September 2023 — Revised ※ 08 September 2023 — Accepted ※ 12 September 2023 — Issue date ※ 01 October 2023

Cite •

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

MOP041

Modified Fast Orbit Feedback Controller for Disturbance Attenuation in Long Straights for Diamond-II

119

S. Banerjee, M.G. Abbott, L. Bobb, I. Kempf
DLS, Harwell, United Kingdom
I. Kempf
University of Oxford, Oxford, United Kingdom

At Diamond Light Source, the fast orbit feedback (FOFB) uses one array of correctors and the controller is designed using the internal model control (IMC) structure. The Diamond-II upgrade will introduce an additional array of fast correctors and a new controller that is designed using the generalised modal decomposition, increasing the overall closed-loop bandwidth from 140 Hz to 1 kHz. Although simulation results have shown that the resulting beam displacement is within specification in all straights, they have also shown that the performance on long straights is limited, particularly in the vertical plane. In this paper, the controller is tuned in order to increase the FOFB performance in long straights by introducing a mode-by-mode regularisation parameter. The performance of the controller beyond 1 kHz is assessed using new disturbance data and a new measurement noise model, showing that the Diamond-II performance criteria are met, even in the presence of measurement noise.

DOI •

reference for this paper ※ doi:10.18429/JACoW-IBIC2023-MOP041

About •

Received ※ 07 September 2023 — Revised ※ 09 September 2023 — Accepted ※ 13 September 2023 — Issue date ※ 16 September 2023

Cite •

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

MOP043

Using Lag Compensator in Orbit Feedback

123

I. Pinayev
BNL, Upton, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy
Growing demand on the beam orbit stability requires higher loop gain within the operational bandwidth. Increasing the gain leads to the increase of the unity gain frequency and creates problems with systems stability due to the additional phase shifts caused by the trims (power supplies, eddy currents in vacuum chambers, etc.) and filtering of beam position data. Conventionally employed systems have 20 dB/decade slope near the unity gain providing 90 degrees phase shift which is sufficient for stability. Utilizing one or more lag compensators allows to increase the gain at low frequencies while keeping phase margin acceptable. The paper provides more details on the proposed solution as well as simulations of how the transients will be modified.

Poster MOP043 [0.230 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-IBIC2023-MOP043

About •

Received ※ 25 August 2023 — Revised ※ 08 September 2023 — Accepted ※ 13 September 2023 — Issue date ※ 23 September 2023

Cite •

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