IPAC2017 - List of Keywords (closed-orbit)

Paper	Title	Other Keywords	Page
MOPAB085	Introduction of Beam Position Monitor System in the HLS II Storage Ring	storage-ring, feedback, quadrupole, brilliance	319
	F.F. Wu, L. Lin, X.Y. Liu, P. Lu, B.G. Sun, L.L. Tang, J.G. Wang, J.H. Wei, K. Xuan, Y.L. Yang, T.Y. Zhou, Z.R. Zhou USTC/NSRL, Hefei, Anhui, People's Republic of China
	Funding: Supported by the National Key Research and Development Program of China (No. 2016YFA0402000) Supported by the National Science Foundation of China (11575181, 11605202) Beam position monitor(BPM) system for the HLS II storage ring were designed in the HLS II upgrade project. This system is composed of BPM, BPM processor embedded with IOC and OPI. Every component of BPM system is introduced in this paper. BPM processors have different modes of data, such as ADC data, turn-by-turn(TBT) data, fast acquirement(FA) data and slow acquirement(SA) data. Different modes of data are used to different applications. Two applications based on SA data of the BPM system, such as BBA for quadrupole magnet center measurement and beam closed orbit feedback, are described in detail. The result of BBA shows that most magnetic centers of quadrupole magnets are in the range of [-1 mm, 1 mm] with respect to BPM electric centers. The result of beam closed orbit feedback shows that beam orbit stability when the closed orbit feedback system is on is far better than that when the closed orbit feedback system is off.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPAB085
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPAB127	A New Method for Emittance Reconstruction Using a Scraper in a Dispersive Region of a Low Energy Storage Ring	emittance, simulation, storage-ring, antiproton	429
	J.R. Hunt, J. Resta-López, C.P. Welsch The University of Liverpool, Liverpool, United Kingdom C. Carli CERN, Geneva, Switzerland J.R. Hunt, J. Resta-López, C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom
	Funding: Science and Technology Funding Council, UK CERN Beam scraping is a standard method for beam emittance measurements at low energies and will be applied at the Extra Low ENergy Antimatter (ELENA) ring. However, in ELENA, as in many other low energy storage rings, the scraper is located in a position of finite dispersion which poses a unique challenge when reconstructing the emittance from beam intensity data. A new algorithm for ELENA and other machines that use a scraper in a dispersive region has been developed. It combines data obtained by scraping the beam from opposite sides with information on the storage ring lattice. In this contribution, the new algorithm is presented, tested using simulations and compared with alternate methods for emittance reconstruction.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPAB127
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPIK065	Status of the Development of a BE-Model-Based Program for Orbit Correction at the Electron Storage Ring DELTA	storage-ring, hardware, operation, synchrotron	673
	S. Koetter, B. Riemann, T. Weis DELTA, Dortmund, Germany
	A new program for orbit correction is currently being developed at the electron storage ring DELTA. Based upon the standard approach of utilizing the linear response of a closed orbit to dipole-field-strength variations, proposed features include a live-updated orbit-response-matrix model and the integration of the Closed-Orbit-Bilinear-Exponential-Analysis algorithm (COBEA) to clean measured orbit-response matrices from noise. This work focuses on the current status of development of the aforementioned program. After an assessment of the situation at DELTA, first measurements are shown along with numerical convergence studies.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPIK065
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPIK066	COBEA - Optical Parameters From Response Matrices without Knowledge of Magnet Strengths	storage-ring, optics, lattice, betatron	676
	B. Riemann, S. Khan, S. Koetter, T. Weis DELTA, Dortmund, Germany
	This paper presents some results of Closed-Orbit Bilinear-Exponential Analysis (COBEA), an algorithm designed to decompose (coupled) response matrices into betatron tunes and other optical parameters at beam position monitor and corrector positions. The only additional information strictly required by the algorithm is the ordering of monitors and correctors along the storage ring beam path. The presented method is largely lattice-independent, as no magnet strengths or dimensions are needed, and converges in a reasonable time interval due to usage of gradient-based optimization. After describing key features of the algorithm, a set of COBEA results is compared to LOCO results for the storage rings of MLS and BESSY II. The paper is concluded by a brief discussion of further applications, limits and further development of the COBEA algorithm.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPIK066
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPIK081	Study of HEPS Performance with Error Model and Simulated Correction	optics, quadrupole, sextupole, simulation	721
	D. Ji, Z. Duan, S.K. Tian, Y. Wei IHEP, Beijing, People's Republic of China
	As an important component of physics study on High Energy Photon Source (HEPS), error modelling and simu-lated correction will provide the guideline to restrict the manufacture redundancy of the hardware and estimate the real machine performance. In this paper, we present some work on error effect evaluation and simulated commis-sioning based on a recent lattice design.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPIK081
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPIK082	First Turn Around Strategy for HEPS	quadrupole, lattice, accumulation, dipole	724
	Y.L. Zhao, Z. Duan, D. Ji, Y. Jiao, C. Li IHEP, Beijing, People's Republic of China
	The High Energy Photon Source (HEPS) is a 6-GeV, kilometer-scale, quasi-diffraction limited storage ring light source to be built in China[1]. Getting the first turn and approaching the closed orbit is very important in accelerator commissioning. In order to make first turn beam commissioning efficiently, we develop a MATLAB tool based on AT for automatic beam correction and closed orbit searching. The algorithm and simulation results are presented in this paper.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPIK082
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPIK045	Closed Orbit Feedback for FAIR - Prototype Tests at SIS18	controls, software, feedback, distributed	1784
	B.R. Schlei, H. Liebermann, D. Ondreka, P.J. Spiller, R.J. Steinhagen GSI, Darmstadt, Germany
	A new steering software for cycle-to-cycle closed orbit as well as trajectory control is currently under development for FAIR's planned control system. It has been successfully tested with beam at the SIS18 in 2016. COAT (i.e., Controlling Orbits And Trajectories) has been realized as a distributed, Java-based application. It consists of a background daemon process that handles the actual beam-based feedback logic, and independent clients that provide visualization and various user-interaction capabilities. Built on top of the LSA settings management system, code-shared and also used at CERN, the system is kept generic. Furthermore, it is designed to support multiple accelerators, transfer lines and users in parallel. In particular, it can handle continuously changing optics and other in advance known changing beam parameters. The COAT computer program is part of a set of newly developed beam-based feedback tools* for FAIR. Preliminary results of our proof-of-concept prototype studies indicate, e.g., in view of the observed SIS18 machine reproducibility, that such a cycle-to-cycle feedback control scheme may be adequate also for the other FAIR accelerators and transfer lines. *see separate contribution by R. J. Steinhagen et al.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPIK045
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPIK050	COSY Slow Orbit Feedback System	controls, EPICS, feedback, dipole	1802
	M. Simon, M. Bai, C. Böhme, F. Hinder, B. Lorentz, C. Weidemann FZJ, Jülich, Germany J. Bobnar, J. Malec, R. Modic, K. Žagar Cosylab, Ljubljana, Slovenia A. Marusic BNL, Upton, Long Island, New York, USA
	The Cooler Synchrotron (COSY) at Forschungszentrum Jülich is currently carrying out the preparation for a direct measurement of the electric Dipole Moment (EDM) of the deuteron using an RF Wien filter,. In a magnetic storage ring with the spin vector aligned along the direction of motion, the EDM manifests in a buildup of the vertical spin component. Besides this signal, radial magnetic fields due to a distortion of the vertical closed orbit can produce a similar signal. This signal is a systematic limit of the proposed measurement procedure. Based on simulation studies*, a vertical closed orbit distortion with a RMS smaller than 0.1 mm is required to achieve a sensitivity of 10^-19 e.cm or better. In order to accomplish this challenging goal, a slow orbit feedback system was proposed and recently commissioned at COSY. The design and commissioning results will be presented, and the future plan will also be discussed. A. Lehrach et. al, arXiv:1201.5773 [hep-ex]. W. M. Morse, Y. F. Orlov and Y. K. Semertzidis, PRSTAB 16, no.11, 114001 (2013). * M. Rosenthal, Ph.D. thesis, RWTH Aachen University, 2016, available from http://collaborations.fz-juelich.de/ikp/jedi/public_files/theses/Thesis_MRosenthal.pdf
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPIK050
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPIK064	Application of Smoothing Analysis in the Alignment and Installation Process of Particle Accelerator	alignment, storage-ring, software, Windows	1839
	W. Wang, X.Y. He, L. Lin, F.F. Wu, Q. Zhang USTC/NSRL, Hefei, Anhui, People's Republic of China
	With the development of technology and theory of particle accelerator, the new particle accelerators will be built in the near future. Comparing with the running accelerators, higher efficiency and accuracy of installation and alignment are required. It is necessary for all the storage ring magnets to be placed with a high relative accuracy to meet the stringent demands of accelerator physics. Smoothing analysis is a practical method considering both relative accuracy and work efficiency. This article mainly introduces the principle and application of smoothing analysis.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPIK064
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPVA042	K-Modulation Developments via Simultaneous Beam Based Alignment in the LHC	quadrupole, optics, sextupole, simulation	2159
	L. van Riesen-Haupt, A. Seryi JAI, Oxford, United Kingdom J.M. Coello de Portugal, E. Fol, R. Tomás, R. Tomás CERN, Geneva, Switzerland
	Funding: EuroCirCol A parasitic effect of k-modulation is that if the modulated quadrupole has an offset the modulation results in a dipole like kick forcing the beam on a new orbit. This paper presents a new method using the orthonormality of singular value decomposition that uses this new orbit to estimate the offset. This could be used to measure misalignments or crossing angles but could also help improve k-modulation \beta measurements by predicting the parasitic tune change caused by the new orbit not passing through the centre of the sextupoles.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPVA042
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPVA081	An MDM Spin Transparent Quadrupole for Storage Ring Based EDM Search	quadrupole, lattice, storage-ring, dipole	2264
	Y. Dutheil, M. Bai FZJ, Jülich, Germany D. Sagan Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
	A storage ring provides an attractive option for directly measuring the electric dipole moment (EDM) of charged particles. To reach a sensitivity of 10²⁹ e.cm, it is critical to mitigate the systematic errors from all sources. This daunting task is pushing the precision frontier of accelerator science and technology beyond its current state of the art. Here, we present a unique idea of a magnetic dipole moment (MDM) spin transparent quadrupole that can significantly reduce the systematic errors due to the transverse electric and magnetic fields that particle encounters.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPVA081
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPVA083	Analysis of Closed-Orbit Deviations for a First Direct Deuteron Electric Dipole Moment Measurement at the Cooler Synchrotron COSY	dipole, power-supply, quadrupole, simulation	2271
	V. Schmidt, A. Lehrach FZJ, Jülich, Germany
	This presentation investigates closed orbit influencing effects focusing on transverse orbit deviations. Using a model of the Cooler Synchrotron COSY at the Forschungszentrum Jülich implemented in the Methodical Accelerator Design program, several magnet misalignments are simulated and analyzed. A distinction is made between magnet displacements along the axes and rotations around them. Results are always analyzed for the uncorrected as well as for the orbit after the application of an orbit correction. Furthermore, the effect of displaced beam position monitors is simulated and a constraint resolution of their readout is considered. Besides magnet misalignments also field variations resulting from residual power supply oscillations are quantified for all types of magnets.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPVA083
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEOCA1	Performance of SOLARIS Storage Ring	storage-ring, injection, electron, photon	2490
	A.I. Wawrzyniak, P.B. Borowiec, M.B. Jaglarz, A. Kisiel, P.M. Klimczyk, M.A. Knafel, M.P. Kopeć, A.M. Marendziak, S. Piela, P. Sagało, M.J. Stankiewicz, K. Wawrzyniak, M. Zając Solaris National Synchrotron Radiation Centre, Jagiellonian University, Kraków, Poland
	After one year of the Solaris storage ring commission-ing excellent performance has been achieved. The optics was corrected close to the design values. However, some minor adjustments are still needed. The commissioning of the Solaris 1.5 GeV storage ring required a big effort in machine parameters optimization. Performance of posi-tion monitoring devices has proven essential for the suc-cessful optimization of beam parameters such as: closed orbit, tune, chromaticity, and dispersion. Now, the effort is focused on fine-tuning the machine by implementing the linear optics from orbit correction (LOCO) and reduc-ing the disparity between model and measured results revealed by the phase advance analysis and dispersion measurement. Moreover, during daily operation the main task is to maintain long-term stability of the circulating electron beam allowing for beamlines commissioning. Within this presentation the current status of the Solaris facility and the commissioning results will be reported.
	Slides WEOCA1 [13.180 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-WEOCA1
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPIK023	Sawtooth Effect in CEPC	synchrotron, synchrotron-radiation, radiation, lattice	2971
	H. Geng, J. Gao, B. Sha, D. Wang, Y. Wang, C.H. Yu, Y. Zhang IHEP, Beijing, People's Republic of China
	Funding: This work was supported by National Natural Science Foundation of China, under contract NO. 11405188. CEPC is a circular electron and positron machine designed to study the property of the Higgs boson. The beam energy for CEPC is thus chosen to be 120GeV. At such a high energy, synchrotron radiation has pronounced effect on the beam behavior. In this paper, we will show the synchrotron radiation effect in the CEPC single ring design, namely, the closed orbit, linear optics and dynamic aperture. Analytical analysis will be given trying to explain the phenomenon.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-WEPIK023
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPIK061	Lattice Tuning and Error Setting in Accelerator Toolbox	lattice, dipole, quadrupole, multipole	3067
	S.M. Liuzzo, N. Carmignani, L. Farvacque, B. Nash ESRF, Grenoble, France
	New lattice designs need to be studied in the presence of magnetic and alignment errors and appropriate lattice tuning procedures. For this reason a set of tools to perform a commissioning-like sequence has been developed for the ESRF-EBS* upgrade in Accelerator Toolbox (AT)* and is now generalized to be used for other accelerators lattice design. The functions presented here allow to correct first turn trajectory, orbit, tune, chromaticity, optics and coupling, in any order. A set of functions to define errors is introduced to address, among others, the issues of: misalignment of magnets modeled by several slices, multiple errors setting on the same magnet and spatially recursive errors along the lattice. * J.C. Biasci et al. ,A low emittance lattice for the ESRF, Synchrotron Radiation News, vol. 27, Iss.6, 2014. ESRF upgrade programme phase II, ESRF, December 2014. * Nash, B. et al.. New functionality for beam dynamics in Accelerator Toolbox (AT) IPAC'15.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-WEPIK061
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPAB042	Long-Range Beam-Beam Orbit Effects in LHC, Simulations and Observations From Machine Operation in 2016	luminosity, simulation, operation, emittance	3799
	A.A. Gorzawski, K. Fuchsberger, M. Hostettler, T. Pieloni, J. Wenninger CERN, Geneva, Switzerland
	To limit the number of head on collisions to only one at the interaction point in the Large Hadron Collider (LHC), two beams are colliding with a non zero crossing angle. Under the presence of such angle the closed orbits of the individual bunches in the bunch train varies due to the long-range beam-beam effects. These variations leave a signature as a non zero transverse offset at the collision points visible in the front and trail of the bunch train. When operation team aims for the optimised beam orbit and therefore maximised luminosity, those front and tail bunches due to the overall offset experience reduced luminosity. This paper describes an overview of the existing tool for simulating these effects and compares to operational data. The effects of different operational scenarios (i.e. beam brightness, reduced or asymmetric crossing angles between the interaction points etc.) are simulated and discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-THPAB042
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPAB058	PyZgoubi Simulations of the CBETA Lattice	lattice, electron, dipole, framework	3847
	S.C. Tygier UMAN, Manchester, United Kingdom C.E. Mayes Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA F. Méot, N. Tsoupas BNL, Upton, Long Island, New York, USA
	Funding: Work supported by New York State Energy Research and Development Authority (NYSERDA) The Cornell-BNL Electron Test Accelerator CBETA is a 4 pass up, 4 pass down energy recovery linac using Fixed-Field Alternating-Gradient (FFAG) recirculation arcs with a top energy of 150 MeV. We present lattice implemented in the tracking code pyZgoubi, with both hard edge and field map magnet versions. We also describe the recent developments in pyZgoubi such as importing lattice tables from other tracking codes.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-THPAB058
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPAB146	Investigation of the Remanent Field of the SPS Main Dipoles and Possible Solutions for Machine Operation	dipole, operation, extraction, proton	4069
	F.M. Velotti, H. Bartosik, J. Bauche, M.C.L. Buzio, K. Cornelis, M.A. Fraser, V. Kain CERN, Geneva, Switzerland
	The CERN Super Proton Synchrotron (SPS) provides different types of beams at different extraction energies. The main magnets of the SPS are regulated with a current loop, but it has turned out that hysteresis effects from the main dipoles have a significant impact on reproducibility and hence efficiency and availability. Beam and machine parameters were found to depend on the programmed sequence of magnetic cycles - the so-called super cycle - representing the production of the different beams. The scientific program of the SPS requires frequent changes of the supercycle composition and the effect of the main magnet hysteresis has to be understood, modelled and used in accelerator control system. This paper summarises the first main field measurements carried out with the currently available systems during operational conditions as well as measurements of vital machine and beam parameters as a function of the super cycle composition. Finally, ideas will be presented to provide reproducibility by automatically correcting different parameters taking the magnetic history of the main magnets into account.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-THPAB146
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPVA037	Injection of a Self-Consistent Beam at the Spallation Neutron Source	injection, simulation, space-charge, target	4516
	J.A. Holmes, S.M. Cousineau, T.V. Gorlov, M.A. Plum ORNL, Oak Ridge, Tennessee, USA
	Funding: ORNL is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. Department of Energy. This research was supported by the DOE Office of Science, Basic Energy Science. We plan to demonstrate the injection of a self-consistent beam into the Spallation Neutron Source (SNS). Self-consistent beams are defined to be ellipsoidal distributions with uniform density and to retain these properties under all linear transformations. Self-consistent distributions may generate very little halo if realized in practice. Some may also be manipulated to generate flat beams. Self-consistent distributions involve very special relationships between the phase space coordinates, making them difficult to realize experimentally. One self-consistent distribution, the 2D rotating distribution, can be painted into the SNS ring, with slight modification of the lattice. However, it is unknown how robust self-consistent distributions will be under real world transport in the presence of nonlinearities and other collective effects. This paper studies these issues and the mitigation of unwanted effects by applying realistic detailed computational models to the simulation of the injection of rotating beams into SNS. The result is a feasible prescription for the injection of a rotating self-consistent distribution into the SNS ring.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-THPVA037
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Other Keywords

Page

MOPAB085

Introduction of Beam Position Monitor System in the HLS II Storage Ring

storage-ring, feedback, quadrupole, brilliance

319

F.F. Wu, L. Lin, X.Y. Liu, P. Lu, B.G. Sun, L.L. Tang, J.G. Wang, J.H. Wei, K. Xuan, Y.L. Yang, T.Y. Zhou, Z.R. Zhou
USTC/NSRL, Hefei, Anhui, People's Republic of China

Funding: Supported by the National Key Research and Development Program of China (No. 2016YFA0402000) Supported by the National Science Foundation of China (11575181, 11605202)
Beam position monitor(BPM) system for the HLS II storage ring were designed in the HLS II upgrade project. This system is composed of BPM, BPM processor embedded with IOC and OPI. Every component of BPM system is introduced in this paper. BPM processors have different modes of data, such as ADC data, turn-by-turn(TBT) data, fast acquirement(FA) data and slow acquirement(SA) data. Different modes of data are used to different applications. Two applications based on SA data of the BPM system, such as BBA for quadrupole magnet center measurement and beam closed orbit feedback, are described in detail. The result of BBA shows that most magnetic centers of quadrupole magnets are in the range of [-1 mm, 1 mm] with respect to BPM electric centers. The result of beam closed orbit feedback shows that beam orbit stability when the closed orbit feedback system is on is far better than that when the closed orbit feedback system is off.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPAB085

Export •

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

MOPAB127

A New Method for Emittance Reconstruction Using a Scraper in a Dispersive Region of a Low Energy Storage Ring

emittance, simulation, storage-ring, antiproton

429

J.R. Hunt, J. Resta-López, C.P. Welsch
The University of Liverpool, Liverpool, United Kingdom
C. Carli
CERN, Geneva, Switzerland
J.R. Hunt, J. Resta-López, C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom

Funding: Science and Technology Funding Council, UK CERN
Beam scraping is a standard method for beam emittance measurements at low energies and will be applied at the Extra Low ENergy Antimatter (ELENA) ring. However, in ELENA, as in many other low energy storage rings, the scraper is located in a position of finite dispersion which poses a unique challenge when reconstructing the emittance from beam intensity data. A new algorithm for ELENA and other machines that use a scraper in a dispersive region has been developed. It combines data obtained by scraping the beam from opposite sides with information on the storage ring lattice. In this contribution, the new algorithm is presented, tested using simulations and compared with alternate methods for emittance reconstruction.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPAB127

Export •

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

MOPIK065

Status of the Development of a BE-Model-Based Program for Orbit Correction at the Electron Storage Ring DELTA

storage-ring, hardware, operation, synchrotron

673

S. Koetter, B. Riemann, T. Weis
DELTA, Dortmund, Germany

A new program for orbit correction is currently being developed at the electron storage ring DELTA. Based upon the standard approach of utilizing the linear response of a closed orbit to dipole-field-strength variations, proposed features include a live-updated orbit-response-matrix model and the integration of the Closed-Orbit-Bilinear-Exponential-Analysis algorithm (COBEA) to clean measured orbit-response matrices from noise. This work focuses on the current status of development of the aforementioned program. After an assessment of the situation at DELTA, first measurements are shown along with numerical convergence studies.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPIK065

Export •

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

MOPIK066

COBEA - Optical Parameters From Response Matrices without Knowledge of Magnet Strengths

storage-ring, optics, lattice, betatron

676

B. Riemann, S. Khan, S. Koetter, T. Weis
DELTA, Dortmund, Germany

This paper presents some results of Closed-Orbit Bilinear-Exponential Analysis (COBEA), an algorithm designed to decompose (coupled) response matrices into betatron tunes and other optical parameters at beam position monitor and corrector positions. The only additional information strictly required by the algorithm is the ordering of monitors and correctors along the storage ring beam path. The presented method is largely lattice-independent, as no magnet strengths or dimensions are needed, and converges in a reasonable time interval due to usage of gradient-based optimization. After describing key features of the algorithm, a set of COBEA results is compared to LOCO results for the storage rings of MLS and BESSY II. The paper is concluded by a brief discussion of further applications, limits and further development of the COBEA algorithm.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPIK066

Export •

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

MOPIK081

Study of HEPS Performance with Error Model and Simulated Correction

optics, quadrupole, sextupole, simulation

721

D. Ji, Z. Duan, S.K. Tian, Y. Wei
IHEP, Beijing, People's Republic of China

As an important component of physics study on High Energy Photon Source (HEPS), error modelling and simu-lated correction will provide the guideline to restrict the manufacture redundancy of the hardware and estimate the real machine performance. In this paper, we present some work on error effect evaluation and simulated commis-sioning based on a recent lattice design.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPIK081

Export •

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

MOPIK082

First Turn Around Strategy for HEPS

quadrupole, lattice, accumulation, dipole

724

Y.L. Zhao, Z. Duan, D. Ji, Y. Jiao, C. Li
IHEP, Beijing, People's Republic of China

The High Energy Photon Source (HEPS) is a 6-GeV, kilometer-scale, quasi-diffraction limited storage ring light source to be built in China[1]. Getting the first turn and approaching the closed orbit is very important in accelerator commissioning. In order to make first turn beam commissioning efficiently, we develop a MATLAB tool based on AT for automatic beam correction and closed orbit searching. The algorithm and simulation results are presented in this paper.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPIK082

Export •

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

TUPIK045

Closed Orbit Feedback for FAIR - Prototype Tests at SIS18

controls, software, feedback, distributed

1784

B.R. Schlei, H. Liebermann, D. Ondreka, P.J. Spiller, R.J. Steinhagen
GSI, Darmstadt, Germany

A new steering software for cycle-to-cycle closed orbit as well as trajectory control is currently under development for FAIR's planned control system. It has been successfully tested with beam at the SIS18 in 2016. COAT (i.e., Controlling Orbits And Trajectories) has been realized as a distributed, Java-based application. It consists of a background daemon process that handles the actual beam-based feedback logic, and independent clients that provide visualization and various user-interaction capabilities. Built on top of the LSA settings management system, code-shared and also used at CERN, the system is kept generic. Furthermore, it is designed to support multiple accelerators, transfer lines and users in parallel. In particular, it can handle continuously changing optics and other in advance known changing beam parameters. The COAT computer program is part of a set of newly developed beam-based feedback tools* for FAIR. Preliminary results of our proof-of-concept prototype studies indicate, e.g., in view of the observed SIS18 machine reproducibility, that such a cycle-to-cycle feedback control scheme may be adequate also for the other FAIR accelerators and transfer lines.
*see separate contribution by R. J. Steinhagen et al.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPIK045

Export •

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

TUPIK050

COSY Slow Orbit Feedback System

controls, EPICS, feedback, dipole

1802

M. Simon, M. Bai, C. Böhme, F. Hinder, B. Lorentz, C. Weidemann
FZJ, Jülich, Germany
J. Bobnar, J. Malec, R. Modic, K. Žagar
Cosylab, Ljubljana, Slovenia
A. Marusic
BNL, Upton, Long Island, New York, USA

The Cooler Synchrotron (COSY) at Forschungszentrum Jülich is currently carrying out the preparation for a direct measurement of the electric Dipole Moment (EDM) of the deuteron using an RF Wien filter*,**. In a magnetic storage ring with the spin vector aligned along the direction of motion, the EDM manifests in a buildup of the vertical spin component. Besides this signal, radial magnetic fields due to a distortion of the vertical closed orbit can produce a similar signal. This signal is a systematic limit of the proposed measurement procedure. Based on simulation studies***, a vertical closed orbit distortion with a RMS smaller than 0.1 mm is required to achieve a sensitivity of 10^-19 e.cm or better. In order to accomplish this challenging goal, a slow orbit feedback system was proposed and recently commissioned at COSY. The design and commissioning results will be presented, and the future plan will also be discussed.
* A. Lehrach et. al, arXiv:1201.5773 [hep-ex].
** W. M. Morse, Y. F. Orlov and Y. K. Semertzidis, PRSTAB 16, no.11, 114001 (2013).
*** M. Rosenthal, Ph.D. thesis, RWTH Aachen University, 2016, available from http://collaborations.fz-juelich.de/ikp/jedi/public_files/theses/Thesis_MRosenthal.pdf

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPIK050

Export •

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

TUPIK064

Application of Smoothing Analysis in the Alignment and Installation Process of Particle Accelerator

alignment, storage-ring, software, Windows

1839

W. Wang, X.Y. He, L. Lin, F.F. Wu, Q. Zhang
USTC/NSRL, Hefei, Anhui, People's Republic of China

With the development of technology and theory of particle accelerator, the new particle accelerators will be built in the near future. Comparing with the running accelerators, higher efficiency and accuracy of installation and alignment are required. It is necessary for all the storage ring magnets to be placed with a high relative accuracy to meet the stringent demands of accelerator physics. Smoothing analysis is a practical method considering both relative accuracy and work efficiency. This article mainly introduces the principle and application of smoothing analysis.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPIK064

Export •

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

TUPVA042

K-Modulation Developments via Simultaneous Beam Based Alignment in the LHC

quadrupole, optics, sextupole, simulation

2159

L. van Riesen-Haupt, A. Seryi
JAI, Oxford, United Kingdom
J.M. Coello de Portugal, E. Fol, R. Tomás, R. Tomás
CERN, Geneva, Switzerland

Funding: EuroCirCol
A parasitic effect of k-modulation is that if the modulated quadrupole has an offset the modulation results in a dipole like kick forcing the beam on a new orbit. This paper presents a new method using the orthonormality of singular value decomposition that uses this new orbit to estimate the offset. This could be used to measure misalignments or crossing angles but could also help improve k-modulation \beta measurements by predicting the parasitic tune change caused by the new orbit not passing through the centre of the sextupoles.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPVA042

Export •

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

TUPVA081

An MDM Spin Transparent Quadrupole for Storage Ring Based EDM Search

quadrupole, lattice, storage-ring, dipole

2264

Y. Dutheil, M. Bai
FZJ, Jülich, Germany
D. Sagan
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

A storage ring provides an attractive option for directly measuring the electric dipole moment (EDM) of charged particles. To reach a sensitivity of 10²⁹ e.cm, it is critical to mitigate the systematic errors from all sources. This daunting task is pushing the precision frontier of accelerator science and technology beyond its current state of the art. Here, we present a unique idea of a magnetic dipole moment (MDM) spin transparent quadrupole that can significantly reduce the systematic errors due to the transverse electric and magnetic fields that particle encounters.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPVA081

Export •

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

TUPVA083

Analysis of Closed-Orbit Deviations for a First Direct Deuteron Electric Dipole Moment Measurement at the Cooler Synchrotron COSY

dipole, power-supply, quadrupole, simulation

2271

V. Schmidt, A. Lehrach
FZJ, Jülich, Germany

This presentation investigates closed orbit influencing effects focusing on transverse orbit deviations. Using a model of the Cooler Synchrotron COSY at the Forschungszentrum Jülich implemented in the Methodical Accelerator Design program, several magnet misalignments are simulated and analyzed. A distinction is made between magnet displacements along the axes and rotations around them. Results are always analyzed for the uncorrected as well as for the orbit after the application of an orbit correction. Furthermore, the effect of displaced beam position monitors is simulated and a constraint resolution of their readout is considered. Besides magnet misalignments also field variations resulting from residual power supply oscillations are quantified for all types of magnets.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPVA083

Export •

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

WEOCA1

Performance of SOLARIS Storage Ring

storage-ring, injection, electron, photon

2490

A.I. Wawrzyniak, P.B. Borowiec, M.B. Jaglarz, A. Kisiel, P.M. Klimczyk, M.A. Knafel, M.P. Kopeć, A.M. Marendziak, S. Piela, P. Sagało, M.J. Stankiewicz, K. Wawrzyniak, M. Zając
Solaris National Synchrotron Radiation Centre, Jagiellonian University, Kraków, Poland

After one year of the Solaris storage ring commission-ing excellent performance has been achieved. The optics was corrected close to the design values. However, some minor adjustments are still needed. The commissioning of the Solaris 1.5 GeV storage ring required a big effort in machine parameters optimization. Performance of posi-tion monitoring devices has proven essential for the suc-cessful optimization of beam parameters such as: closed orbit, tune, chromaticity, and dispersion. Now, the effort is focused on fine-tuning the machine by implementing the linear optics from orbit correction (LOCO) and reduc-ing the disparity between model and measured results revealed by the phase advance analysis and dispersion measurement. Moreover, during daily operation the main task is to maintain long-term stability of the circulating electron beam allowing for beamlines commissioning. Within this presentation the current status of the Solaris facility and the commissioning results will be reported.

Slides WEOCA1 [13.180 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-WEOCA1

Export •

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

WEPIK023

Sawtooth Effect in CEPC

synchrotron, synchrotron-radiation, radiation, lattice

2971

H. Geng, J. Gao, B. Sha, D. Wang, Y. Wang, C.H. Yu, Y. Zhang
IHEP, Beijing, People's Republic of China

Funding: This work was supported by National Natural Science Foundation of China, under contract NO. 11405188.
CEPC is a circular electron and positron machine designed to study the property of the Higgs boson. The beam energy for CEPC is thus chosen to be 120GeV. At such a high energy, synchrotron radiation has pronounced effect on the beam behavior. In this paper, we will show the synchrotron radiation effect in the CEPC single ring design, namely, the closed orbit, linear optics and dynamic aperture. Analytical analysis will be given trying to explain the phenomenon.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-WEPIK023

Export •

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

WEPIK061

Lattice Tuning and Error Setting in Accelerator Toolbox

lattice, dipole, quadrupole, multipole

3067

S.M. Liuzzo, N. Carmignani, L. Farvacque, B. Nash
ESRF, Grenoble, France

New lattice designs need to be studied in the presence of magnetic and alignment errors and appropriate lattice tuning procedures. For this reason a set of tools to perform a commissioning-like sequence has been developed for the ESRF-EBS* ** upgrade in Accelerator Toolbox (AT)*** and is now generalized to be used for other accelerators lattice design. The functions presented here allow to correct first turn trajectory, orbit, tune, chromaticity, optics and coupling, in any order. A set of functions to define errors is introduced to address, among others, the issues of: misalignment of magnets modeled by several slices, multiple errors setting on the same magnet and spatially recursive errors along the lattice.
* J.C. Biasci et al. ,A low emittance lattice for the ESRF, Synchrotron Radiation News, vol. 27, Iss.6, 2014.
** ESRF upgrade programme phase II, ESRF, December 2014.
*** Nash, B. et al.. New functionality for beam dynamics in Accelerator Toolbox (AT) IPAC'15.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-WEPIK061

Export •

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

THPAB042

Long-Range Beam-Beam Orbit Effects in LHC, Simulations and Observations From Machine Operation in 2016

luminosity, simulation, operation, emittance

3799

A.A. Gorzawski, K. Fuchsberger, M. Hostettler, T. Pieloni, J. Wenninger
CERN, Geneva, Switzerland

To limit the number of head on collisions to only one at the interaction point in the Large Hadron Collider (LHC), two beams are colliding with a non zero crossing angle. Under the presence of such angle the closed orbits of the individual bunches in the bunch train varies due to the long-range beam-beam effects. These variations leave a signature as a non zero transverse offset at the collision points visible in the front and trail of the bunch train. When operation team aims for the optimised beam orbit and therefore maximised luminosity, those front and tail bunches due to the overall offset experience reduced luminosity. This paper describes an overview of the existing tool for simulating these effects and compares to operational data. The effects of different operational scenarios (i.e. beam brightness, reduced or asymmetric crossing angles between the interaction points etc.) are simulated and discussed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-THPAB042

Export •

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

THPAB058

PyZgoubi Simulations of the CBETA Lattice

lattice, electron, dipole, framework

3847

S.C. Tygier
UMAN, Manchester, United Kingdom
C.E. Mayes
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
F. Méot, N. Tsoupas
BNL, Upton, Long Island, New York, USA

Funding: Work supported by New York State Energy Research and Development Authority (NYSERDA)
The Cornell-BNL Electron Test Accelerator CBETA is a 4 pass up, 4 pass down energy recovery linac using Fixed-Field Alternating-Gradient (FFAG) recirculation arcs with a top energy of 150 MeV. We present lattice implemented in the tracking code pyZgoubi, with both hard edge and field map magnet versions. We also describe the recent developments in pyZgoubi such as importing lattice tables from other tracking codes.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-THPAB058

Export •

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

THPAB146

Investigation of the Remanent Field of the SPS Main Dipoles and Possible Solutions for Machine Operation

dipole, operation, extraction, proton

4069

F.M. Velotti, H. Bartosik, J. Bauche, M.C.L. Buzio, K. Cornelis, M.A. Fraser, V. Kain
CERN, Geneva, Switzerland

The CERN Super Proton Synchrotron (SPS) provides different types of beams at different extraction energies. The main magnets of the SPS are regulated with a current loop, but it has turned out that hysteresis effects from the main dipoles have a significant impact on reproducibility and hence efficiency and availability. Beam and machine parameters were found to depend on the programmed sequence of magnetic cycles - the so-called super cycle - representing the production of the different beams. The scientific program of the SPS requires frequent changes of the supercycle composition and the effect of the main magnet hysteresis has to be understood, modelled and used in accelerator control system. This paper summarises the first main field measurements carried out with the currently available systems during operational conditions as well as measurements of vital machine and beam parameters as a function of the super cycle composition. Finally, ideas will be presented to provide reproducibility by automatically correcting different parameters taking the magnetic history of the main magnets into account.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-THPAB146

Export •

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

THPVA037

Injection of a Self-Consistent Beam at the Spallation Neutron Source

injection, simulation, space-charge, target

4516

J.A. Holmes, S.M. Cousineau, T.V. Gorlov, M.A. Plum
ORNL, Oak Ridge, Tennessee, USA

Funding: ORNL is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. Department of Energy. This research was supported by the DOE Office of Science, Basic Energy Science.
We plan to demonstrate the injection of a self-consistent beam into the Spallation Neutron Source (SNS). Self-consistent beams are defined to be ellipsoidal distributions with uniform density and to retain these properties under all linear transformations. Self-consistent distributions may generate very little halo if realized in practice. Some may also be manipulated to generate flat beams. Self-consistent distributions involve very special relationships between the phase space coordinates, making them difficult to realize experimentally. One self-consistent distribution, the 2D rotating distribution, can be painted into the SNS ring, with slight modification of the lattice. However, it is unknown how robust self-consistent distributions will be under real world transport in the presence of nonlinearities and other collective effects. This paper studies these issues and the mitigation of unwanted effects by applying realistic detailed computational models to the simulation of the injection of rotating beams into SNS. The result is a feasible prescription for the injection of a rotating self-consistent distribution into the SNS ring.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-THPVA037

Export •

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