IBIC2023 - Classification: 07 Machine Parameter Measurements

Paper	Title	Page
MOP044	"Instantaneous" Lifetime Measurement in Storage Ring with Top-Up Injection	125
	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 Top-up operation becomes routine in the light sources. The goal of the top-up operation is to keep the current of the circulating beam stable to avoid variations of the heat load on the beamline optics. It is also considered for the electron-ion collider to maintain the polarization of the electron beam. Frequent re-injection makes measurement of the beam lifetime very difficult if possible. Since, only part of the bunch train is refreshed during the injection cycle then the distribution of the bunch charges in the train has a characteristic saw-tooth distribution. The slope of saw tooth and step in the bunch charge distribution is defined by the lifetime and filling frequency. Both parameters can be used for the measurement. The data for processing can be obtained either from fast current transformer or from the raw ADC signal from beam position monitor. In this paper we present the theoretical considerations as well as experimental data from NSLS-II storage ring.
	Poster MOP044 [0.284 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-IBIC2023-MOP044
About •	Received ※ 25 August 2023 — Revised ※ 10 September 2023 — Accepted ※ 13 September 2023 — Issue date ※ 18 September 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOP045	Robust Emittance Measurements	127
	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 The quadrupole scan is commonly used for measurement of beam emittance. The found dependence of the beam size vs. quadrupole strength is fitted with parabola, which coefficients are used for emittance calculations. The measurement errors can cause substantial variations in the emittance value. Sometimes the fitted parabola has negative minimum value, making impossible emittance calculation. We propose more robust data processing using weighted fit for parabola or modifying the quadrupole scan procedure. The experimental results are presented.
	Poster MOP045 [0.255 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-IBIC2023-MOP045
About •	Received ※ 25 August 2023 — Revised ※ 11 September 2023 — Accepted ※ 13 September 2023 — Issue date ※ 28 September 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOP046	Measurement of Slice Emittance with Deflecting Cavity and Slit	129
	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 Coherent Electron Cooling experiment carried out at RHIC requires small slice emittance of 15 MeV electron beam with high peak current. In this paper we describe the system for slice emittance measurement utilizing transverse deflecting cavity and slit. The image of the beam passing through the slit is used to measure slice intensity and angular divergence. Beam size at slit location is measured using scan of the beam across the slit with trim. The angular kick by the trim is taken into the account during calculations. Data processing and the experimental results are presented.
	Poster MOP046 [0.997 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-IBIC2023-MOP046
About •	Received ※ 28 August 2023 — Revised ※ 11 September 2023 — Accepted ※ 14 September 2023 — Issue date ※ 19 September 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEP014	Measuring Electromagnet Polarity Using Magnetic Remanence	354
	K.P. Wootton ANL, Lemont, Illinois, USA
	Funding: This research used resources of the Advanced Photon Source, operated for the U.S. Department of Energy Office of Science by Argonne National Laboratory under Contract No. DE-AC02-06CH11357. Large accelerator systems typically include many individually powered electromagnets. An important activity prior to commissioning with beam is verifying that the polarity of the installed magnets matches the design lattice. In the present work, we motivate the measurement of magnet polarity in a manner that is electrically safe, by measuring the magnetic remanence of iron yokes of normal conducting electromagnets. This has been used to confirm the polarities of iron-dominated dipole and quadrupole electromagnets at the Linac Extension Area at the Advanced Photon Source.
	Poster WEP014 [0.504 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-IBIC2023-WEP014
About •	Received ※ 24 July 2023 — Revised ※ 08 September 2023 — Accepted ※ 14 September 2023 — Issue date ※ 29 September 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEP033	A Schottky Tune Meter for the Fermilab Mu2E Delivery Ring	425
	V.E. Scarpine, B.J. Fellenz, A. Semenov, D. Slimmer Fermilab, Batavia, Illinois, USA
	Funding: This work was supported by the U.S. Department of Energy under contract No. DE-AC02-07CH11359. The Mu2E experiment will measure the ratio of the rate of the neutrinoless, coherent conversion of muons into electrons as a measure of Charged Lepton Flavor Violation. As part of the Mu2E experiment, a proton storage ring, called the Delivery Ring, will utilize resonant extraction to slow-spill protons to the experiment. To regulate and optimize the Delivery Ring resonant extraction process, a fast tune measurement scheme will be required. This Mu2E tune meter will measure the average tune and the tune spectrum, in multiple time slices, through the entire resonant extraction cycle of nominally 43 msec. The Mu2E tune meter utilizes vertical and horizontal 21.4 MHz Schottky detector resonant pickups, taken from the decommissioned Tevatron, as well as its receiver electronics. This paper will present the design of this Schottky tune meter as well as tune measurements from the Mu2E Delivery Ring.
	Poster WEP033 [2.011 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-IBIC2023-WEP033
About •	Received ※ 12 September 2023 — Revised ※ 14 September 2023 — Accepted ※ 29 September 2023 — Issue date ※ 29 September 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEP034	Effect of Longitudinal Beam-Coupling Impedance on the Schottky Spectrum of Bunched Beams	428
	C. Lannoy, D. Alves, K. Łasocha, N. Mounet CERN, Meyrin, Switzerland C. Lannoy, T. Pieloni EPFL, Lausanne, Switzerland
	Schottky spectra can be strongly affected by collective effects, in particular those arising from beam-coupling impedance when a large number of bunch charges are involved. In such conditions, the direct interpretation of the measured spectra becomes difficult, which prevents the extraction of beam and machine parameters in the same way as is usually done for lower bunch charges. Since no theory is yet directly applicable to predict the impact of impedance on such spectra, we use here time-domain, macro-particle simulations and apply a semi-analytical method to compute the Schottky spectrum for various machine and beam conditions, such as the ones found at the Large Hadron Collider. A simple longitudinal resonator-like impedance model is introduced in the simulations and its effect studied in different configurations, allowing preliminary interpretations of the impact of longitudinal impedance on Schottky spectra.
	Poster WEP034 [1.237 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-IBIC2023-WEP034
About •	Received ※ 05 September 2023 — Revised ※ 10 September 2023 — Accepted ※ 14 September 2023 — Issue date ※ 22 September 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEP035	Statistical Properties of Schottky Spectra	433
	C. Lannoy, D. Alves, K. Łasocha, N. Mounet CERN, Meyrin, Switzerland C. Lannoy, T. Pieloni EPFL, Lausanne, Switzerland
	Schottky signals are used for non-invasive beam diagnostics as they contain information on various beam and machine parameters. The instantaneous Schottky signal is, however, only a single realisation of a random process, implicitly depending on the discrete distribution of synchrotron and betatron amplitudes and phases among the particles. To estimate the expected value of the Schottky power spectrum, and reveal the inner structure of the Bessel satellites described by the theory, the averaging of instantaneous Schottky spectra is required. This study describes this procedure quantitatively by analysing the statistical properties of the Schottky signals, including the expected value and variance of Schottky power spectra. Furthermore, we investigate how these quantities evolve with the number of particles in the bunch, the observed harmonic of the revolution frequency, the distribution of synchrotron oscillation amplitudes, and the bunch profile. The theoretical findings are compared against macro-particle simulations as well as Monte Carlo computations.
	Poster WEP035 [3.908 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-IBIC2023-WEP035
About •	Received ※ 05 September 2023 — Accepted ※ 14 September 2023 — Issue date ※ 29 September 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEP036	Study of Non-destructive BPM-Based Energy Measurement of the Canadian Light Source Linac	438
	H. Shaker, A. Bertwistle, E.J. Ericson, Y. Yousefi Sigari CLS, Saskatoon, Saskatchewan, Canada E. Soltan, Y. Yousefi Sigari University of Saskatchewan, Saskatoon, Canada
	There is a plan in the Canadian Light Source (CLS) to replace the current Linac with a new one from Research Instruments GmbH in mid-2024. The first straight section of LTB (Linac-To-Booster) was upgraded to have two BPMs with a 4.79m drift between them, and two phosphor screens were replaced by YAG screens. A new BPM and a YAG-based screen station upgraded the following 90-degree achromat beamline. These upgrades help us to measure the current and future Linac beam parameters, including the beam twiss parameters, energy, and energy spread. In this paper, we discussed how we could use these three BPMs for non-destructive energy measurement, which will be a part of the active energy correction system.
DOI •	reference for this paper ※ doi:10.18429/JACoW-IBIC2023-WEP036
About •	Received ※ 29 August 2023 — Revised ※ 09 September 2023 — Accepted ※ 27 September 2023 — Issue date ※ 28 September 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEP037	Design and Simulation of the High-Sensitivity Tune Measurement System Based on Diode Detection at HIAF
	N.Y. Na, L.F. Lin, Z.S. Zhang SCNU, Guangzhou, People’s Republic of China Y.Y. Wang, Y.L. Yang, Z.L. Zhao, G. Zhu IMP/CAS, Lanzhou, People’s Republic of China
	A high-sensitivity tune measurement system have been developed for the Booster Ring (BRing) and Spectrometer Ring (SRing) of the High-Intensity heavy-ion Accelerator Facility (HIAF). The beam signal induced by the BPM bipolar plate is amplified by the measurement system via a preamplifier, and then fed through the direct diode detection circuit to the spectrometer for Fourier analysis to calculate the tune fraction. Simulation results show a signal-to-noise ratio of approximately 50 dB without beam excitation. The new system is more sensitive to the detection of tuned fractions than conventional electronic storage ring tuning measurement systems and is simple and does not require beam excitation. This paper presents the design of HIAF tune measurement system, especially on front-end electronics design and the simulation results.
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WEP038	Development of the Prototype for Measuring Beam Position and Orbit Tilt Based on Cavity BPM for the SHINE
	J. Chen, F.Z. Chen SSRF, Shanghai, People’s Republic of China S.S. Cao SARI-CAS, Pudong, Shanghai, People’s Republic of China Y.B. Leng USTC/NSRL, Hefei, Anhui, People’s Republic of China
	In recent decades, the high-gain free-electron lasers (FELs) based on linear accelerator has been successfully developed around the world. Advanced beam diagnostics and feedback technology is one of the key factors to further improve the performance of such facilities. Both the beam position deviation and orbit tilt will weaken the interaction between electron beam and photon beam in the undulator, and affected the FEL radiation performance severely. According to the physical requirements of the SHINE, this paper proposes a method based on the measurement results of a single cavity BPM, which can simultaneously achieve the in-suit measurement of beam position deviation and orbit tilt, thus opening up a new way to improve the efficiency of FEL radiation. The working principle, the development of the verification prototype and the preliminary beam experiments will also be presented in this paper. Under the bunch charge of 100 pC, the beam experiment results show that the prototype has a resolution of better than 13.3¿rad for the beam orbit tilt measurement, which can be applied to the SHINE after optimization.
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WEP039	Operation Performance Evaluation of Accelerator Based on Cluster Analysis of Bunch-by-Bunch Diagnostic Data
	X. Yang SINAP, Shanghai, People’s Republic of China Y.B. Leng USTC/NSRL, Hefei, Anhui, People’s Republic of China Y.M. Zhou SARI-CAS, Pudong, Shanghai, People’s Republic of China
	In order to improve the operating performance of the particle accelerator, it is better to develop a toolkits to monitor and analyze the sub-health state of the facility in addition to ensuring the stability of basic parameters such as beam current, life, transverse size, longitudinal length and orbit. The 3D bunch-by-bunch position measurement system combined with cluster analysis is a feasible solution for this requirement. HOTCAP is a general solution, which is based on high-speed oscilloscope and developed by SSRF, can deliver charge and absolute 3D position information bunch-by-bunch. Clustering analysis is a method for multidimensional data with complex structure. The data can be aggregated and discover the dependencies between data items. After the SSRF bunch-by-bunch measurement system is put into operation, the data of injection and steady-state operation are continuously accumulated. From it, many information including 3D positions, 3D tunes, filling pattern, refilled charge and the 3D damping times can be extracted. In this paper, based on the operational data of SSRF and the cluster analysis, operational status of the storage ring and injector is evaluated.
	Poster WEP039 [0.502 MB]
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TH2I01	6D and High Dynamic Range Measurements of Hadron Beam Phase-Space
	A.V. Aleksandrov ORNL, Oak Ridge, Tennessee, USA
	Over last several years, the SNS Beam Instrumentation Group has made significant progress in developing instrumentation to measure and characterize hadron beam distribution with accuracy and resolution sufficient for model-based understanding and mitigation of beam loss in high power hadron linacs. This includes measurement of the beam distribution in high dimensional phase-space to provide realistic initial conditions for particle tracking, and high dynamic range to measure the beam halo. This presentation will describe the latest results from the SNS Beam test facility: measurement of the 6-dimensional phase space with dynamic range sufficient to reveal features not previously observed; 2-dimensional phase-space measurements with 10⁶ dynamic showing emergence of the beam halo; and, in between, the 5-dimensional measurements with sufficient dynamic range and resolution to generate realistic distribution of 10-100 million particles for tracing codes.
	Slides TH2I01 [11.296 MB]
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TH2C02	Machine Learning-Assisted Beam Operation at SuperKEKB and Linac at KEK
	G. Mitsuka, N. Iida, S.K. Kato, T. Natsui, M. Satoh KEK, Ibaraki, Japan
	Hundreds to thousands of tuning parameters must be optimized for each operating condition to obtain the best performance from an accelerator. In the past, experts made decisions based on their experience on which tuning parameters contributed the most to the performance and adjusted them sequentially. On the other hand, accelerator tuning approaches based on machine learning, which has become much easier to handle, have been studied intensively in recent years. We have been developing a beam-tuning tool based on Bayesian optimization for boosting the SuperKEKB accelerator. In this presentation, we will report on the latest status of the beam test of the positron-beam-yield maximization and dispersion tuning at the KEK injector as the first development step.
	Slides TH2C02 [2.902 MB]
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TH2C03	Analysis of the Transverse Schottky Signals in the LHC	462
	K. Łasocha, D. Alves CERN, Meyrin, Switzerland
	Schottky-based diagnostics are remarkably useful tools for the non-invasive monitoring of hadron beam and machine characteristics such as the betatron tune and the chromaticity. In this contribution recent developments in the analysis of the transverse Schottky signals measured at the Large Hadron Collider will be reported. A fitting-based technique, where the measured spectra are iteratively compared with theoretical predictions, will be presented and benchmarked with respect to the previously known methods and alternative diagnostic.
	Slides TH2C03 [4.054 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-IBIC2023-TH2C03
About •	Received ※ 06 September 2023 — Revised ※ 08 September 2023 — Accepted ※ 13 September 2023 — Issue date ※ 19 September 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

"Instantaneous" Lifetime Measurement in Storage Ring with Top-Up Injection

125

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
Top-up operation becomes routine in the light sources. The goal of the top-up operation is to keep the current of the circulating beam stable to avoid variations of the heat load on the beamline optics. It is also considered for the electron-ion collider to maintain the polarization of the electron beam. Frequent re-injection makes measurement of the beam lifetime very difficult if possible. Since, only part of the bunch train is refreshed during the injection cycle then the distribution of the bunch charges in the train has a characteristic saw-tooth distribution. The slope of saw tooth and step in the bunch charge distribution is defined by the lifetime and filling frequency. Both parameters can be used for the measurement. The data for processing can be obtained either from fast current transformer or from the raw ADC signal from beam position monitor. In this paper we present the theoretical considerations as well as experimental data from NSLS-II storage ring.

Poster MOP044 [0.284 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-IBIC2023-MOP044

About •

Received ※ 25 August 2023 — Revised ※ 10 September 2023 — Accepted ※ 13 September 2023 — Issue date ※ 18 September 2023

Cite •

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

MOP045

Robust Emittance Measurements

127

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
The quadrupole scan is commonly used for measurement of beam emittance. The found dependence of the beam size vs. quadrupole strength is fitted with parabola, which coefficients are used for emittance calculations. The measurement errors can cause substantial variations in the emittance value. Sometimes the fitted parabola has negative minimum value, making impossible emittance calculation. We propose more robust data processing using weighted fit for parabola or modifying the quadrupole scan procedure. The experimental results are presented.

Poster MOP045 [0.255 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-IBIC2023-MOP045

About •

Received ※ 25 August 2023 — Revised ※ 11 September 2023 — Accepted ※ 13 September 2023 — Issue date ※ 28 September 2023

Cite •

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

MOP046

Measurement of Slice Emittance with Deflecting Cavity and Slit

129

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
Coherent Electron Cooling experiment carried out at RHIC requires small slice emittance of 15 MeV electron beam with high peak current. In this paper we describe the system for slice emittance measurement utilizing transverse deflecting cavity and slit. The image of the beam passing through the slit is used to measure slice intensity and angular divergence. Beam size at slit location is measured using scan of the beam across the slit with trim. The angular kick by the trim is taken into the account during calculations. Data processing and the experimental results are presented.

Poster MOP046 [0.997 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-IBIC2023-MOP046

About •

Received ※ 28 August 2023 — Revised ※ 11 September 2023 — Accepted ※ 14 September 2023 — Issue date ※ 19 September 2023

Cite •

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

WEP014

Measuring Electromagnet Polarity Using Magnetic Remanence

354

K.P. Wootton
ANL, Lemont, Illinois, USA

Funding: This research used resources of the Advanced Photon Source, operated for the U.S. Department of Energy Office of Science by Argonne National Laboratory under Contract No. DE-AC02-06CH11357.
Large accelerator systems typically include many individually powered electromagnets. An important activity prior to commissioning with beam is verifying that the polarity of the installed magnets matches the design lattice. In the present work, we motivate the measurement of magnet polarity in a manner that is electrically safe, by measuring the magnetic remanence of iron yokes of normal conducting electromagnets. This has been used to confirm the polarities of iron-dominated dipole and quadrupole electromagnets at the Linac Extension Area at the Advanced Photon Source.

Poster WEP014 [0.504 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-IBIC2023-WEP014

About •

Received ※ 24 July 2023 — Revised ※ 08 September 2023 — Accepted ※ 14 September 2023 — Issue date ※ 29 September 2023

Cite •

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

WEP033

A Schottky Tune Meter for the Fermilab Mu2E Delivery Ring

425

V.E. Scarpine, B.J. Fellenz, A. Semenov, D. Slimmer
Fermilab, Batavia, Illinois, USA

Funding: This work was supported by the U.S. Department of Energy under contract No. DE-AC02-07CH11359.
The Mu2E experiment will measure the ratio of the rate of the neutrinoless, coherent conversion of muons into electrons as a measure of Charged Lepton Flavor Violation. As part of the Mu2E experiment, a proton storage ring, called the Delivery Ring, will utilize resonant extraction to slow-spill protons to the experiment. To regulate and optimize the Delivery Ring resonant extraction process, a fast tune measurement scheme will be required. This Mu2E tune meter will measure the average tune and the tune spectrum, in multiple time slices, through the entire resonant extraction cycle of nominally 43 msec. The Mu2E tune meter utilizes vertical and horizontal 21.4 MHz Schottky detector resonant pickups, taken from the decommissioned Tevatron, as well as its receiver electronics. This paper will present the design of this Schottky tune meter as well as tune measurements from the Mu2E Delivery Ring.

Poster WEP033 [2.011 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-IBIC2023-WEP033

About •

Received ※ 12 September 2023 — Revised ※ 14 September 2023 — Accepted ※ 29 September 2023 — Issue date ※ 29 September 2023

Cite •

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

WEP034

Effect of Longitudinal Beam-Coupling Impedance on the Schottky Spectrum of Bunched Beams

428

C. Lannoy, D. Alves, K. Łasocha, N. Mounet
CERN, Meyrin, Switzerland
C. Lannoy, T. Pieloni
EPFL, Lausanne, Switzerland

Schottky spectra can be strongly affected by collective effects, in particular those arising from beam-coupling impedance when a large number of bunch charges are involved. In such conditions, the direct interpretation of the measured spectra becomes difficult, which prevents the extraction of beam and machine parameters in the same way as is usually done for lower bunch charges. Since no theory is yet directly applicable to predict the impact of impedance on such spectra, we use here time-domain, macro-particle simulations and apply a semi-analytical method to compute the Schottky spectrum for various machine and beam conditions, such as the ones found at the Large Hadron Collider. A simple longitudinal resonator-like impedance model is introduced in the simulations and its effect studied in different configurations, allowing preliminary interpretations of the impact of longitudinal impedance on Schottky spectra.

Poster WEP034 [1.237 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-IBIC2023-WEP034

About •

Received ※ 05 September 2023 — Revised ※ 10 September 2023 — Accepted ※ 14 September 2023 — Issue date ※ 22 September 2023

Cite •

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

WEP035

Statistical Properties of Schottky Spectra

433

C. Lannoy, D. Alves, K. Łasocha, N. Mounet
CERN, Meyrin, Switzerland
C. Lannoy, T. Pieloni
EPFL, Lausanne, Switzerland

Schottky signals are used for non-invasive beam diagnostics as they contain information on various beam and machine parameters. The instantaneous Schottky signal is, however, only a single realisation of a random process, implicitly depending on the discrete distribution of synchrotron and betatron amplitudes and phases among the particles. To estimate the expected value of the Schottky power spectrum, and reveal the inner structure of the Bessel satellites described by the theory, the averaging of instantaneous Schottky spectra is required. This study describes this procedure quantitatively by analysing the statistical properties of the Schottky signals, including the expected value and variance of Schottky power spectra. Furthermore, we investigate how these quantities evolve with the number of particles in the bunch, the observed harmonic of the revolution frequency, the distribution of synchrotron oscillation amplitudes, and the bunch profile. The theoretical findings are compared against macro-particle simulations as well as Monte Carlo computations.

Poster WEP035 [3.908 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-IBIC2023-WEP035

About •

Received ※ 05 September 2023 — Accepted ※ 14 September 2023 — Issue date ※ 29 September 2023

Cite •

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

WEP036

Study of Non-destructive BPM-Based Energy Measurement of the Canadian Light Source Linac

438

H. Shaker, A. Bertwistle, E.J. Ericson, Y. Yousefi Sigari
CLS, Saskatoon, Saskatchewan, Canada
E. Soltan, Y. Yousefi Sigari
University of Saskatchewan, Saskatoon, Canada

There is a plan in the Canadian Light Source (CLS) to replace the current Linac with a new one from Research Instruments GmbH in mid-2024. The first straight section of LTB (Linac-To-Booster) was upgraded to have two BPMs with a 4.79m drift between them, and two phosphor screens were replaced by YAG screens. A new BPM and a YAG-based screen station upgraded the following 90-degree achromat beamline. These upgrades help us to measure the current and future Linac beam parameters, including the beam twiss parameters, energy, and energy spread. In this paper, we discussed how we could use these three BPMs for non-destructive energy measurement, which will be a part of the active energy correction system.

DOI •

reference for this paper ※ doi:10.18429/JACoW-IBIC2023-WEP036

About •

Received ※ 29 August 2023 — Revised ※ 09 September 2023 — Accepted ※ 27 September 2023 — Issue date ※ 28 September 2023

Cite •

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

WEP037

Design and Simulation of the High-Sensitivity Tune Measurement System Based on Diode Detection at HIAF

N.Y. Na, L.F. Lin, Z.S. Zhang
SCNU, Guangzhou, People’s Republic of China
Y.Y. Wang, Y.L. Yang, Z.L. Zhao, G. Zhu
IMP/CAS, Lanzhou, People’s Republic of China

A high-sensitivity tune measurement system have been developed for the Booster Ring (BRing) and Spectrometer Ring (SRing) of the High-Intensity heavy-ion Accelerator Facility (HIAF). The beam signal induced by the BPM bipolar plate is amplified by the measurement system via a preamplifier, and then fed through the direct diode detection circuit to the spectrometer for Fourier analysis to calculate the tune fraction. Simulation results show a signal-to-noise ratio of approximately 50 dB without beam excitation. The new system is more sensitive to the detection of tuned fractions than conventional electronic storage ring tuning measurement systems and is simple and does not require beam excitation. This paper presents the design of HIAF tune measurement system, especially on front-end electronics design and the simulation results.

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

WEP038

Development of the Prototype for Measuring Beam Position and Orbit Tilt Based on Cavity BPM for the SHINE

J. Chen, F.Z. Chen
SSRF, Shanghai, People’s Republic of China
S.S. Cao
SARI-CAS, Pudong, Shanghai, People’s Republic of China
Y.B. Leng
USTC/NSRL, Hefei, Anhui, People’s Republic of China

In recent decades, the high-gain free-electron lasers (FELs) based on linear accelerator has been successfully developed around the world. Advanced beam diagnostics and feedback technology is one of the key factors to further improve the performance of such facilities. Both the beam position deviation and orbit tilt will weaken the interaction between electron beam and photon beam in the undulator, and affected the FEL radiation performance severely. According to the physical requirements of the SHINE, this paper proposes a method based on the measurement results of a single cavity BPM, which can simultaneously achieve the in-suit measurement of beam position deviation and orbit tilt, thus opening up a new way to improve the efficiency of FEL radiation. The working principle, the development of the verification prototype and the preliminary beam experiments will also be presented in this paper. Under the bunch charge of 100 pC, the beam experiment results show that the prototype has a resolution of better than 13.3¿rad for the beam orbit tilt measurement, which can be applied to the SHINE after optimization.

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WEP039

Operation Performance Evaluation of Accelerator Based on Cluster Analysis of Bunch-by-Bunch Diagnostic Data

X. Yang
SINAP, Shanghai, People’s Republic of China
Y.B. Leng
USTC/NSRL, Hefei, Anhui, People’s Republic of China
Y.M. Zhou
SARI-CAS, Pudong, Shanghai, People’s Republic of China

In order to improve the operating performance of the particle accelerator, it is better to develop a toolkits to monitor and analyze the sub-health state of the facility in addition to ensuring the stability of basic parameters such as beam current, life, transverse size, longitudinal length and orbit. The 3D bunch-by-bunch position measurement system combined with cluster analysis is a feasible solution for this requirement. HOTCAP is a general solution, which is based on high-speed oscilloscope and developed by SSRF, can deliver charge and absolute 3D position information bunch-by-bunch. Clustering analysis is a method for multidimensional data with complex structure. The data can be aggregated and discover the dependencies between data items. After the SSRF bunch-by-bunch measurement system is put into operation, the data of injection and steady-state operation are continuously accumulated. From it, many information including 3D positions, 3D tunes, filling pattern, refilled charge and the 3D damping times can be extracted. In this paper, based on the operational data of SSRF and the cluster analysis, operational status of the storage ring and injector is evaluated.

Poster WEP039 [0.502 MB]

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TH2I01

6D and High Dynamic Range Measurements of Hadron Beam Phase-Space

A.V. Aleksandrov
ORNL, Oak Ridge, Tennessee, USA

Over last several years, the SNS Beam Instrumentation Group has made significant progress in developing instrumentation to measure and characterize hadron beam distribution with accuracy and resolution sufficient for model-based understanding and mitigation of beam loss in high power hadron linacs. This includes measurement of the beam distribution in high dimensional phase-space to provide realistic initial conditions for particle tracking, and high dynamic range to measure the beam halo. This presentation will describe the latest results from the SNS Beam test facility: measurement of the 6-dimensional phase space with dynamic range sufficient to reveal features not previously observed; 2-dimensional phase-space measurements with 10⁶ dynamic showing emergence of the beam halo; and, in between, the 5-dimensional measurements with sufficient dynamic range and resolution to generate realistic distribution of 10-100 million particles for tracing codes.

Slides TH2I01 [11.296 MB]

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TH2C02

Machine Learning-Assisted Beam Operation at SuperKEKB and Linac at KEK

G. Mitsuka, N. Iida, S.K. Kato, T. Natsui, M. Satoh
KEK, Ibaraki, Japan

Hundreds to thousands of tuning parameters must be optimized for each operating condition to obtain the best performance from an accelerator. In the past, experts made decisions based on their experience on which tuning parameters contributed the most to the performance and adjusted them sequentially. On the other hand, accelerator tuning approaches based on machine learning, which has become much easier to handle, have been studied intensively in recent years. We have been developing a beam-tuning tool based on Bayesian optimization for boosting the SuperKEKB accelerator. In this presentation, we will report on the latest status of the beam test of the positron-beam-yield maximization and dispersion tuning at the KEK injector as the first development step.

Slides TH2C02 [2.902 MB]

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TH2C03

Analysis of the Transverse Schottky Signals in the LHC

462

K. Łasocha, D. Alves
CERN, Meyrin, Switzerland

Schottky-based diagnostics are remarkably useful tools for the non-invasive monitoring of hadron beam and machine characteristics such as the betatron tune and the chromaticity. In this contribution recent developments in the analysis of the transverse Schottky signals measured at the Large Hadron Collider will be reported. A fitting-based technique, where the measured spectra are iteratively compared with theoretical predictions, will be presented and benchmarked with respect to the previously known methods and alternative diagnostic.

Slides TH2C03 [4.054 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-IBIC2023-TH2C03

About •

Received ※ 06 September 2023 — Revised ※ 08 September 2023 — Accepted ※ 13 September 2023 — Issue date ※ 19 September 2023

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