IPAC2019 - List of Keywords (storage-ring)

Paper	Title	Other Keywords	Page
MOZZPLS1	eRHIC Design Overview	electron, hadron, proton, luminosity	45
	C. Montag, G. Bassi, J. Beebe-Wang, J.S. Berg, M. Blaskiewicz, A. Blednykh, J.M. Brennan, S.J. Brooks, K.A. Brown, K.A. Drees, A.V. Fedotov, W. Fischer, D.M. Gassner, W. Guo, A. Hershcovitch, C. Hetzel, D. Holmes, H. Huang, W.A. Jackson, J. Kewisch, Y. Li, C. Liu, H. Lovelace III, Y. Luo, F. Méot, M.G. Minty, R.B. Palmer, B. Parker, S. Peggs, V. Ptitsyn, V.H. Ranjbar, G. Robert-Demolaize, S. Seletskiy, V.V. Smaluk, K.S. Smith, S. Tepikian, P. Thieberger, D. Trbojevic, N. Tsoupas, S. Verdú-Andrés, W.-T. Weng, F.J. Willeke, H. Witte, Q. Wu, W. Xu, A. Zaltsman, W. Zhang BNL, Upton, Long Island, New York, USA E. Gianfelice-Wendt Fermilab, Batavia, Illinois, USA Y. Hao FRIB, East Lansing, Michigan, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. The Electron-Ion Collider (EIC) is being envisioned as the next facility to be constructed by the DOE Nuclear Physics program. Brookhaven National Laboratory is proposing eRHIC, a facility based on the existing RHIC complex as a cost effective realization of the EIC project with a peak luminosity of 10³⁴ cm^-2 sec^-1. An electron storage ring with an energy range from 5 to 18 GeV will be added in the existing RHIC tunnel. A spin-transparent rapid-cycling synchrotron (RCS) will serve as a full-energy polarized electron injector. Recent design improvements include reduction of the IR magnet strengths to avoid the necessity for Nb₃Sn magnets, and a novel hadron injection scheme to maximize the integrated luminosity. We will provide an overview of this proposed project and present the current design status.
	Slides MOZZPLS1 [5.428 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOZZPLS1
About •	paper received ※ 14 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
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MOPGW001	Design Review of Bellows RF-Shielding Types and New Concepts for Sirius	shielding, wakefield, HOM, impedance	53
	H.O.C. Duarte, P.P.S. Freitas, A.R.D. Rodrigues, R.M. Seraphim, T.M. da Rocha LNLS, Campinas, Brazil
	Large amounts of bellows in an accelerator justify the importance of simplifying the machining and assembling processes of their RF shield. Such quantity also makes this component one of the main contributors for a machine impedance budget. On the other hand, low impedance designs tend to complicate the mechanical aspects. Applied to Sirius round vacuum chamber of 24 mm inner diameter, the omega-strip and comb-type bellows concepts are compared with new proposed designs. In such comparison, the aforementioned aspects, wakefield losses and prototyping experiences are presented in this work.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW001
About •	paper received ※ 16 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
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MOPGW003	Collective Instability Studies for Sirius	simulation, impedance, radiation, coupling	61
	F.H. de Sá LNLS, Campinas, Brazil
	In this work we will present the estimates of single and multi-bunch instability thresholds and current-dependent effects, such as tune-shifts and potential-well distortion for the Sirius storage ring. The results were obtained by tracking simulations and semi-analytic methods using the updated and detailed impedance budget of the machine, which includes contributions from all the in-vacuum components and the coherent synchrotron radiation (CSR) impedance.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW003
About •	paper received ※ 15 May 2019 paper accepted ※ 18 May 2019 issue date ※ 21 June 2019
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MOPGW007	Electromagnetic Impulse of Beam Density F(x, y)G(z)	factory, site, lattice, interaction-region	75
	S.R. Koscielniak TRIUMF, Vancouver, Canada
	We calculate the transverse impulse on a test particle as a bunch of charged particles beam passes by. It is often assumed, but seldom proven, that the EM field from a beam density distribution factored into transverse and longitudinal parts, F and G respectively, has also a factored form P(x, y)Q(z). This factorization is not possible for stationary charges. Contrastingly, it becomes increasingly accurate for ultra-relativistic particle beams. We give a general analysis, show how to develop the corrections in terms of integrals of F and derivatives of G. What is significant is that if we integrate over longitudinal coordinate z to find the transverse impulse on a witness charge, the correction terms integrate to zero leading to the impulse P(x, y)Integral[Q(z)] independent of bunch shape. If this result is already known, this paper serves as a reminder.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW007
About •	paper received ※ 15 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019
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MOPGW010	First Application of Online Particle Swarm Optimization at SOLEIL	injection, operation, controls, vacuum	82
	A. Bence, L.S. Nadolski SOLEIL, Gif-sur-Yvette, France J. Li HZB, Berlin, Germany
	First attempts of online optimisation of SOLEIL using Particle Swarm Optimisation (PSO) is reported with two major applications. This technique proves to be particularly suitable in a control room and could become a standard operation tool for tuning the accelerators in complement of other techniques. The first optimisation of the injection in the storage ring will be presented using the injection septa and the vertical correctors of the booster to storage ring transfer line. The second work will summarise the results obtained from the optimisation of the transverse on- and off-momentum dynamics in presence of insertion devices. Main results, the implementation and improvements will be presented and discussed thoroughly.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW010
About •	paper received ※ 19 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019
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MOPGW014	Developing Beam Optics for the BESSY VSR Project	optics, quadrupole, lattice, cavity	94
	F. Andreas, M. Abo-Bakr, F. Armborst, P. Goslawski HZB, Berlin, Germany
	At BESSY II due to the continuously increasing interest in short pulse operation, a major upgrade of the ring will enable simultaneous storage of long and short bunches. This Variable pulse-length Storage Ring (VSR) will be achieved by the installation of additional superconducting high gradient cavities. The cavities will be assembled into one cryomodule in one of the straights of the storage ring. As this module needs more space then initially assumed, one possible solution is to remove two quadrupoles to gain available installation length. The quadrupoles were switched off in simulations and the lattice was optimized with regard to the linear order. The best solution found was transferred to the storage ring, where storage of high current with reasonable injection efficiency and lifetime was possible. The proposed optics has to be further optimized in terms of nonlinear beam dynamics, but has shown that an available installation length can be increased.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW014
About •	paper received ※ 15 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
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MOPGW017	Feedback Design for Control of the Micro-Bunching Instability based on Reinforcement Learning	bunching, feedback, electron, controls	104
	T. Boltz, T. Asfour, M. Brosi, E. Bründermann, B. Härer, P. Kaiser, A.-S. Müller, C. Pohl, P. Schreiber, M. Yan KIT, Karlsruhe, Germany
	The operation of ring-based synchrotron light sources with short electron bunches increases the emission of coherent synchrotron radiation (CSR) in the THz frequency range. However, the micro-bunching instability resulting from self-interaction of the bunch with its own radiation field limits stable operation with constant intensity of CSR emission to a particular threshold current. Above this threshold, the longitudinal charge distribution and thus the emitted radiation vary rapidly and continuously. Therefore, a fast and adaptive feedback system is the appropriate approach to stabilize the dynamics and to overcome the limitations given by the instability. In this contribution, we discuss first efforts towards a longitudinal feedback design that acts on the RF system of the KIT storage ring KARA (Karlsruhe Research Accelerator) and aims for stabilization of the emitted THz radiation. Our approach is based on methods of adaptive control that were developed in the field of reinforcement learning and have seen great success in other fields of research over the past decade. We motivate this particular approach and comment on different aspects of its implementation.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW017
About •	paper received ※ 15 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019
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MOPGW018	Perturbation of Synchrotron Motion in the Micro-Bunching Instability	electron, bunching, synchrotron, radiation	108
	T. Boltz, M. Brosi, E. Bründermann, B. Härer, A.-S. Müller, P. Schreiber, P. Schönfeldt, M. Yan KIT, Karlsruhe, Germany
	Short electron bunches in a storage ring are subject to complex longitudinal dynamics due to self-interaction with their own CSR. Above a particular threshold current, this leads to the formation of dynamically changing micro-structures within the bunch, generally known as the micro-bunching instability. The longitudinal dynamics of this phenomenon can be simulated by solving the Vlasov-Fokker-Planck equation, where the CSR self-interaction can be added as a perturbation to the Hamiltonian. This contribution particularly focuses on the comprehension of synchrotron motion in the micro-bunching instability and how it relates to the formation of the occurring micro-structures. Therefore, we adopt the perspective of a single particle and comment on its implications for collective motion. We explicitly show how the shape of the parallel plates CSR wake potential breaks homogeneity in longitudinal phase space and propose a quadrupole-like mode as potential seeding mechanism of the micro-bunching instability. The gained insights are verified using the passive particle tracking method of the Vlasov-Fokker-Planck solver Inovesa.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW018
About •	paper received ※ 15 May 2019 paper accepted ※ 18 May 2019 issue date ※ 21 June 2019
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MOPGW021	Symplectic Tracking for the Robinson Wiggler	wiggler, dynamic-aperture, electron, linear-dynamics	120
	J. Li, J. Feikes, T. Mertens, Y. Petenev, M. Ries, A. Schälicke HZB, Berlin, Germany
	A Robinson wiggler (RW) is considered to be installed in the Metrology Light Source (MLS) to lengthen the bunch and improve the Touschek lifetime by manipulating the damping partitions. Symplectic tracking is crucial to study the impact of the nonlinear field components introduced by the Robinson wiggler. This paper introduces a tracking method based on an implicit symplectic integrator to solve the exact Hamiltonian equations of particle motion in the wiggler. In addition, a numerical generating function method is implemented as an approach to realize fast tracking.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW021
About •	paper received ※ 14 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
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MOPGW024	Measurements of the GSI Transfer Beam Lines Ion Optics	quadrupole, extraction, experiment, emittance	131
	M. Sapinski, O. Geithner, S. Reimann, P. Schütt, M. Vossberg, B. Walasek-Höhne GSI, Darmstadt, Germany C. Heßler CERN, Meyrin, Switzerland
	GSI High Energy Beam Transfer lines (HEST) link the SIS18 synchrotron with two storage rings (Experimental Storage Ring and Cryring) and six experimental caves. The recent upgrades to HEST beam instrumentation enables precise measurements of beam properties along the lines and allow for faster and more precise beams setup on targets. Preliminary results of some of the measurements performed during runs in 2018 and 2019 are presented here. The focus is on response matrix measurements and quadrupole scans performed on HADES beam line. The errors and future improvements are discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW024
About •	paper received ※ 15 May 2019 paper accepted ※ 19 May 2019 issue date ※ 21 June 2019
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MOPGW029	Preliminary Study of Bunch Compression in the Hefei Light Source	lattice, radiation, electron, synchrotron-radiation	151
	W. Li, Z.H. Bai, W. Li, J.G. Wang, D.R. Xu, Z. Zhao USTC/NSRL, Hefei, Anhui, People’s Republic of China
	Funding: This work was supported by the Fundamental Research Funds for the Central Universities (Grant No.WK2310000082 and WK2310000077), and the National Natural Science Foundation of China(GrantNo.11475167). Short electron bunch has interesting applications in the synchrotron radiation light sources, such as the production of powerful coherent THz radiation, time resolving spectrum analysis, etc. In this work, we are interested in acquiring the short bunch in the storage ring with a small circumference like Hefei Light Source. In this paper, we tried to approach the short bunch in two separate methods: by increasing the higher harmonic cavity voltage and by reducing the momentum compaction factor. The preliminary result and observations are shown and discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW029
About •	paper received ※ 16 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
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MOPGW044	Off-Energy Off-Axis Injection with Pulsed Multipole Magnet Into the HALS Storage Ring	injection, kicker, lattice, multipole	187
	G. Liu, Z.H. Bai, W. Li, L. Wang, P.N. Wang USTC/NSRL, Hefei, Anhui, People’s Republic of China
	As a future Diffraction-Limited Storage Ring (DLSR) at NSRL, the Hefei Advanced Light Source (HALS) has been proposed and has a great progress in the lattice optimization. The nonlinear dynamics is well designed and shows good performance, which makes it easier for beam injection and gives us more choices to design a more suitable injection scheme. In this paper, a new off-energy off-axis pulsed multipole injection scheme is proposed. The off-energy beam is off-axis injected into the acceptance of the storage ring with one or several pulsed multipole kickers and meanwhile the stored beam is almost unaffected during the injection. The injection acceptance of the storage ring is analyzed and the injection scheme is preliminary designed. A series of tracking simulations are carried out and the results are presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW044
About •	paper received ※ 15 May 2019 paper accepted ※ 17 May 2019 issue date ※ 21 June 2019
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MOPGW045	A Fast Method for Multi-Objective Nonlinear Dynamics Optimization of a Storage Ring	SRF, lattice, sextupole, dynamic-aperture	190
	J.J. Tan, Z.H. Bai, W. Li, L. Wang, P.H. Yang USTC/NSRL, Hefei, Anhui, People’s Republic of China
	Multi-objective evolutionary algorithms (MOEAs), including multi-objective genetic algorithm and particle swarm optimization algorithm, have been widely applied in the nonlinear dynamics optimization of storage ring light sources. In the optimization, the direct tracking of objectives, which are, for example, dynamic aperture (DA) and momentum aperture, is very time-consuming. We noticed that there is some positive correlation between on- and off-momentum nonlinear dynamics performances, which can be used to reduce the computation time when applying MOEAs. In this paper, a fast method is proposed, in which a strategy is introduced to speed up the process of optimizing nonlinear dynamics using MOEAs. Taking the SSRF storage ring as an example, on- and off-momentum DAs are optimized using MOEAs with and without the fast strategy, and then a comparison is made to demonstrate the fast method.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW045
About •	paper received ※ 15 May 2019 paper accepted ※ 18 May 2019 issue date ※ 21 June 2019
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MOPGW048	Design Study of an Electron Storage Ring for the Future Plan of Hiroshima Synchrotron Radiation Center.	synchrotron, radiation, emittance, synchrotron-radiation	200
	S. Matsuba, M. Katoh, K.S. Shimada HSRC, Higashi-Hiroshima, Japan K. Harada KEK, Ibaraki, Japan K. Kawase QST, Tokai, Japan
	Hiroshima synchrotron radiation center equips a 700 MeV electron storage ring nicknamed HiSOR. It has been operated for more than 20 years. The emittance of HiSOR is 400 nm, which is larger by one or more orders of magnitude than typical modern synchrotron light sources. Therefore, as the future plan of the facility, a new low emittance storage ring is desired. Several designs have been examined. In the newest version, we have selected the lattice structure similar to ASTRID 2 compact light source in Aarhus University, Denmark. The design goal is the energy of around 500 MeV, the circumference shorter than 50 m and the emittance smaller than 10 nm with straight sections for undulators more than 4. In this conference, we report the latest result from the design study.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW048
About •	paper received ※ 01 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019
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MOPGW058	Towards a Sextupole-Free Electron Storage Ring	electron, vacuum, impedance, feedback	217
	T.-Y. Lee, T. Ha PAL, Pohang, Kyungbuk, Republic of Korea
	This paper studies if it is possible to build an electron storage ring with no or a small number of sextupole mag-nets. If it is possible, the electron storage ring will be great-ly simplified. For the purpose, two methods are presented in the paper to handle head-tail instability: One is to use dielectric vacuum chamber made of such materials as ceramic or glass to reduce broadband impedance signifi-cantly. Then head-tail instability would be extremely weak. The other method is to install a bunch-by-bunch feedback system to suppress the already weak head-tail instability due to the dielectric vacuum chamber.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW058
About •	paper received ※ 15 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
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MOPGW066	Local Impedance Measurements Using the Orbit Bump Method at ALBA	impedance, betatron, simulation, vacuum	240
	Z. Martí, G. Benedetti, T.F.G. Günzel, U. Iriso ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
	The orbit bump technique has been used at the ALBA Storage Ring to characterize with good precision the impedance of single machine elements, like the in-vacuum undulators or the CLIC stripline kicker. The results are compared with theoretical studies, as well as impedance measurements done at ALBA using other methods like the turn by turn betatron phase or from the analysis of the detuning slopes of the Transverse Mode Coupling Instability.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW066
About •	paper received ※ 14 May 2019 paper accepted ※ 17 May 2019 issue date ※ 21 June 2019
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MOPGW096	Beam Dynamics in MBA Lattices with Different Chromaticity Correction Schemes	lattice, sextupole, emittance, betatron	346
	L. Hoummi, J. Resta-López, C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom L. Hoummi, J. Resta-López, C.P. Welsch The University of Liverpool, Liverpool, United Kingdom A. Loulergue, R. Nagaoka SOLEIL, Gif-sur-Yvette, France
	Ultra-low emittance lattices are being studied for the future upgrade of the 2.75 GeV SOLEIL storage ring. The candidate baseline lattice was inspired by the ESRF-EBS-type Multi-Bend-Achromat (MBA) lattice, introducing a (-I) transformation to compensate the nonlinear impact of sextupoles thanks to the lattice symmetry and tight control of the betatron phase advance between sextupoles. Whilst the final performance is still being optimized, other types of lattices are being considered for SOLEIL: This includes the so-called High-Order Achromat (HOA) lattice. Though the (-I) scheme provides a large on-momentum transverse dynamic aperture in 4D, its off-momentum performance is rather limited. 6D studies reveal intrinsic off-momentum transverse oscillations which are likely to result from a nonlinear increase in path length. This contribution presents the effects from the inhomogeneous sextupole distribution in the (-I) scheme and compares them with the HOA lattice.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW096
About •	paper received ※ 15 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019
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MOPGW098	Iterative Trajectory-Correction Scheme for the Early Commissioning of Diffraction-Limited Light Sources	MMI, lattice, feedback, simulation	353
	Ph. Amstutz, T. Hellert LBNL, Berkeley, USA
	The commissioning of diffraction-limited light sources will be significantly affected by the fact that typical lattice designs rely on very strong focussing elements in order to achieve the small emittance goals. Especially in the early-commissioning phase this can render procedures successfully used in the commissioning of existing third-generation light sources ill-suited for the application to these new machines. In this contribution we discuss an iterative approach to the early trajectory correction, based on the well-known pseudo-inversion of a trajectory-response matrix. Measuring this matrix during early commissioning can be cumbersome, so that an algorithm working with the model response matrix of the lattice is desirable. We discuss the stability of the iteration in the presence of lattice errors, resulting in differences between the actual and the model response matrix. Further, Tikhonov regularization is investigated as a means to trade off the RMS trajectory variation against the strength of the required corrector kicks.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW098
About •	paper received ※ 14 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019
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MOPGW104	Equilibria and Synchrotron Stability in Two Energy Storage Rings	electron, damping, simulation, focusing	364
	B. Dhital, J.R. Delayen, G.A. Krafft ODU, Norfolk, Virginia, USA J.R. Delayen, Y.S. Derbenev, D. Douglas, G.A. Krafft, F. Lin, V.S. Morozov, Y. Zhang JLab, Newport News, Virginia, USA
	In a dual energy storage ring, the electron beam passes through two loops at markedly different energies E_L, and E_H, i.e., energies for low energy loop and high energy loop respectively. These loops use a common beamline where a superconducting linac at first accelerates the beam from EL to EH and then decelerates the beam from EH to EL in the next pass. There are two basic solutions to the equilibrium problems possible, i.e., ’Storage Ring’ (SR) equilibrium and ’Energy Recovery Linac’ (ERL) equilibrium. SR equilibrium mode more resembles the usual single loop storage ring with strong synchrotron motion and ERL equilibrium mode is the case where RF in two beam passes nearly cancels. Calculations based on linear transfer matrix formalism show that longitudinal stability exists for both SR mode and ERL mode in two energy storage rings.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW104
About •	paper received ※ 14 May 2019 paper accepted ※ 18 May 2019 issue date ※ 21 June 2019
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MOPGW110	Study of the Beam Current Effects on the NSLS-II Storage Ring Optics Using Turn-by-Turn Data	lattice, optics, dipole, operation	375
	J. Choi, Y. Hidaka BNL, Upton, Long Island, New York, USA
	These days, the techniques using the turn-by-turn data are well developed in analyzing the accelerator optics. We compared the data for the low and high beam currents and studied the beam current effects on the storage ring lattice optics. Also, by comparing the local transfer matrices, we analyzed the amounts of the impacts on the linear optics around the ring.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW110
About •	paper received ※ 15 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
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MOPGW122	Beam-based Measurement of Broadband Longitudinal Impedance at NSLS-II	impedance, vacuum, simulation, diagnostics	400
	V.V. Smaluk, B. Bacha, G. Bassi, A. Blednykh BNL, Upton, Long Island, New York, USA
	Funding: Department of Energy Contract No. DE-SC0012704 Interaction of a particle beam with the vacuum chamber impedance is one of the main effects limiting the beam intensity in accelerators. Minimization of the impedance is an essential part of the vacuum chamber design for any new accelerator project. The impedance can be estimated experimentally by measuring beam dynamics effects caused by the beam-impedance interaction. Experience obtained at many accelerator facilities shows the beam-based measurements are often different from the pre-computed impedance budgets, the discrepancy of a factor of two or even more is not unusual. The measurements of broadband longitudinal impedance carried out at NSLS-II are discussed in comparison with the numerically simulated impedance budget.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW122
About •	paper received ※ 15 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019
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MOPGW125	Lossless Crossing of 1/2 Resonance Stopband by Synchrotron Oscillations	resonance, experiment, lattice, betatron	410
	G.M. Wang, Y. Li, J. Rose, T.V. Shaftan, V.V. Smaluk BNL, Upton, Long Island, New York, USA
	Funding: DOE under contract No.DE-AC02- 98CH10886 Modern high performance circular accelerators require sophisticated corrections of nonlinear lattices. The beam betatron tune footprint may cross many resonances, reducing dynamic aperture and causing particle loss. However, if particles cross a resonance reasonably fast, the beam deterioration may be minimized. In this paper, we present the experiments with the beam passing through a half-integer resonance stopband via chromatic tune modulation by exciting synchrotron oscillations. This is the first time that beam dynamics have been kept under precise control while the beam crosses a half-integer resonance. Our results convincingly demonstrate that particles can cross the half-integer resonance without being lost if the passage is reasonably fast and the resonance stopband is sufficiently narrow.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW125
About •	paper received ※ 13 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
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MOPRB005	Study of Higher-Order Achromat Lattice as an Alternative Option for the SOLEIL Storage Ring Upgrade	lattice, sextupole, octupole, injection	586
	R. Nagaoka, A. Bence, P. Brunelle, L. Hoummi, A. Loulergue, A. Nadji, L.S. Nadolski, M.-A. Tordeux, A. Vivoli SOLEIL, Gif-sur-Yvette, France A. Gamelin LAL, Orsay, France
	A ring composed of 20 symmetrical 7BA cells in which of a pair of chromaticity correcting sextupoles placed around horizontal dispersion bumps à la ESRF-EBS was developed as a baseline lattice for the SOLEIL storage ring upgrade (presented at IPAC2018). The strict phase relation between the two dispersion bumps provides an efficient way of optimizing the (on-momentum) nonlinear optics with a limited number of sextupoles. As an alternative, a scheme known as Higher-Order Achromat (HOA) develops a MBA (Multi-Bend Achromat) lattice where chromaticity correcting sextupoles are distributed in each M unit cell with a strict phase relation cell-wise such as to cancel basic geometric and chromatic resonance driving terms. The beam dynamics in a 20-fold 7BA HOA ring is compared with those of the baseline lattice, with focus on off-momentum properties such as Touschek lifetime, which are important for medium energy rings like SOLEIL. The robustness against errors, the reduction of the ring symmetry by introducing 4 longer straight sections, as well as a horizontal dispersion bump to cope with longitudinal on-axis injection scheme are also presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB005
About •	paper received ※ 22 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019
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MOPRB027	Progress of HEPS Accelerator System Design	cavity, booster, vacuum, lattice	633
	P. He, J.S. Cao, F.S. Chen, J. Chen, H. Dong, D.Y. He, Y. Jiao, W. Kang, C.H. Li, J.Y. Li, F. Long, H.H. Lu, X. Qi, Q. Qin, H. Qu, J.Q. Wang, G. Xu, J.H. Yue, J. Zhang, J.R. Zhang, P. Zhang IHEP, Beijing, People’s Republic of China
	The 4th generation ring-based light sources, HEPS (High Energy Photon Source) 7BA lattice has been de-veloped at IHEP. This is 6Gev, 200mA machine which has horizontal emittance Ɛh around 60pm.rad to gain the high brilliance photon beam. this compact lattice design bring so many engineering challenges for accelerator magnets, vacuum components, beam diagnotice, etc. This paper will present the noval lattice design and subsystem design progress.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB027
About •	paper received ※ 14 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
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MOPRB092	Symplectic and Exact Tracking of Low Energy 197Au⁷⁸⁺ in the Relativistic Heavy Ion Collider	electron, quadrupole, simulation, lattice	791
	Y. Luo, W. Fischer, F. Méot, G. Robert-Demolaize BNL, Upton, Long Island, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. In the coming RHIC low energy scan, the electron cooling technique is to be used to cool the ions 197Au⁷⁹⁺ with its energy range between 3.85~GeV/nucleon to 5.75~GeV/nucleon. To overlap the electron beam and the 197Au⁷⁹⁺ beam at the cooling section, a recombination monitor is to be used to detect the maximum flux of 197Au⁷⁸⁺ ions generated in the cooling section. In the previous studies, we tracked 197Au⁷⁸⁺ ions through the RHIC lattice defined with 197Au⁷⁹⁺ with an equivalent momentum deviation. In the article, we explode different symplectic ways to track 197Au⁷⁸⁺ ions exactly. We calculate and compare the trajectories and loss map of 197Au⁷⁸⁺ ions through the RHIC ring.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB092
About •	paper received ※ 14 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
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MOPRB093	eRHIC Electron Ring Design Status	polarization, electron, solenoid, radiation	794
	C. Montag, M. Blaskiewicz, C. Hetzel, D. Holmes, Y. Li, H. Lovelace III, V. Ptitsyn, K.S. Smith, S. Tepikian, F.J. Willeke, H. Witte, W. Xu BNL, Upton, Long Island, New York, USA E. Gianfelice-Wendt Fermilab, Batavia, Illinois, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. For the proposed electron-ion collider eRHIC, an electron storage ring will be installed in the existing RHIC tunnel. To reach the high luminosity of up to 10³⁴ cm^-2 sec^-1, beam currents up to 2.5A have to be stored. Besides high luminosity the physics program requires spin polarization levels of 70 percent, with both spin "up" and spin "down" orientations present in the fill. This is only feasible by using a full-energy spin polarized injector that replaces bunches faster than the depolarization rate. To limit the repetition rate of that injector to about one hertz, the polarization lifetime in the storage ring has to be maximized by proper spin matching and countermeasures for the machine misalignments. We will give an overview of the electron storage ring design.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB093
About •	paper received ※ 13 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019
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MOPRB104	A Parameter Study for Improving the Performance of the Production Target for the Fermilab Muon g-2 Experiment	target, simulation, experiment, proton	806
	D. Stratakis Fermilab, Batavia, Illinois, USA
	The target station of the Muon g-2 Experiment is one of the central pieces for the production of secondary pions which eventually will decay to the desired mu-ons. In this paper, we report adjustments made to opti-mize its performance. For instance, in the simulation we vary the size of the primary incoming beam and examine its impact on the downstream production. We then compare this with the actual measured beam size upstream of the target. In addition, we examine the sensitivity in performance with the strength of the lithium lens for pion capture and the distance between lens and target. We compare measured data with simu-lation results.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB104
About •	paper received ※ 13 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
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MOPTS004	2nd Order Optics Symmetrisation through Off-Energy Orbit Response Matrix Analysis	sextupole, optics, lattice, alignment	841
	D.K. Olsson, Å. Andersson, M. Sjöström MAX IV Laboratory, Lund University, Lund, Sweden
	The MAX IV 3 GeV storage ring lattice contains several strong sextupoles. In order to achieve nominal lattice performance it is important to be able to characterise and correct the higher order magnets and optics of the lattice. This has been done through the analysis of the Off-Energy Response Matrix (OEORM). Its approximate linearity in sextupole strength has been utilised to identify sextupole errors, as well as symmetrise the 2nd order optics. The symmetrisation was able to correct chromaticity, and increase horizontal acceptance by 50 %, compared to magnet settings based solely on rotating coil measurements. An approximate decrease of 10 % in vertical acceptance was detected. This work was inspired by similar investigations at ESRF.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS004
About •	paper received ※ 13 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
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MOPTS011	Spin Motion Perturbation Effect on the EDM Statistic in the Frequency Domain Method	betatron, polarization, dipole, lattice	861
	A.E. Aksentyev FZJ, Jülich, Germany A.E. Aksentyev MEPhI, Moscow, Russia A.E. Aksentyev, V. Senichev RAS/INR, Moscow, Russia
	The spin precession axis of a particle involved in betatron motion precesses about the invariant spin axis defined on the closed orbit (CO). This precession can be observed in polarization data as a rapid, small-amplitude oscillation on top of the major effect oscillation caused by the precession of spin about the CO axis. The frequency of this latter oscillation is used in the Frequency Domain (FD) methodology as the EDM observable. [] It is estimated by fitting polarimetry data by a sine function; the rapid oscillations, therefore, constitute a model specification error. This model error might introduce a bias into the frequency estimate. In the present work we investigate the effect of the spin precession axis motion on measurement data and fit quality, and conclude that it is not only insignificant (with regard to data perturbation) compared to spin tune variation, but is also controllable via the application of a Spin Wheel. [] Senichev Y, Aksentev A, Ivanov A, Valetov E. Frequency domain method of the search for the deuteron electric dipole moment in a storage ring with imperfections. arXiv:171106512. 2017 Nov 17
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS011
About •	paper received ※ 08 April 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
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MOPTS012	Spin Decoherence in the Frozen Spin Storage Ring Method of Search for a Particle EDM	sextupole, lattice, simulation, betatron	864
	A.E. Aksentyev FZJ, Jülich, Germany A.E. Aksentyev MEPhI, Moscow, Russia A.E. Aksentyev, V. Senichev RAS/INR, Moscow, Russia
	Spin coherence refers to a measure of preservation of polarization in an initially polarized beam. The spin vector of a particle injected into a storage ring starts to precess about the vertical magnetic field vector in accordance with the Thomas-BMT equation. The precession frequency is dependent on the equilibrium-level energy, which differs across the beam particles. This does not pose a problem when the initial polarization is vertical; however, the Frozen Spin Storage Ring EDM search method [] requires beam polarization along the momentum vector, i.e., in the horizontal plane. In the present work we analyze the source of decoherence, and investigate the way it can be suppressed in the horizontal plane in a perfectly aligned ring by means of sextupole fields. We also consider the case of an imperfect ring: transference of decoherence into the vertical plane induced by vertical plane spin precession, and the effect of sextupole fields. D. Anastassopoulos et al. AGS Proposal: Search for a permanent electric dipole moment of the deuteron nucleus at the 10 −29 e · cm level. BNL report, 2008.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS012
About •	paper received ※ 08 April 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
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MOPTS028	Search for Electric Dipole Moments at Cosy in Jülich - Spin-Tracking Simulations Using Bmad	simulation, dipole, experiment, alignment	914
	V. Poncza, A. Lehrach FZJ, Jülich, Germany A. Lehrach, V. Poncza RWTH, Aachen, Germany
	The observed matter-antimatter asymmetry in the universe cannot be explained by the Standard Model (SM) of particle physics. In order to resolve the matter dominance an additional CP violating phenomenon is needed. A candidate for physics beyond the SM is a non-vanishing Electric Dipole Moment (EDM) of subatomic particles. Since permanent EDMs violate parity and time reversal symmetries, they are also CP violating if the CPT -theorem is assumed. The JEDI (Jülich Electric Dipole moment Investigations) collaboration in Jülich is preparing a direct EDM measurement of protons and deuterons first at the storage ring COSY (COoler SYnchrotron) and later at a dedicated storage ring. In order to analyse the data and to disentangle the EDM signal from systematic effects spin tracking simulations are needed. Therefore a model of COSY was implemented using the software library Bmad. It includes the measured magnet misalignments of the latest survey and a simplified description of the RF-Wien Filter device that is used for the EDM measurement. The model was successfully benchmarked using analytical predictions of the spin behavior. A crucial point regarding the data analysis is the knowledge of the orientation of the invariant spin axis with vanishing EDM at the position of the RF-Wien Filter. Especially its radial component is unknown and spin tracking simulations can be used to determine this missing number. Tracking results as well as the algorithm to find the invariant spin axis will be presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS028
About •	paper received ※ 25 April 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
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MOPTS038	BEAM DYNAMICS OF HIGH CHROMATICITY LATTICE FOR IRANIAN LIGHT SOURCE FACILITY (ILSF) STORAGE RING	lattice, dynamic-aperture, resonance, optics	943
	F. Foroughi, S.M. Jazayeri IUST, Narmac, Tehran, Iran E. Ahmadi, S. Dastan, J. Rahighi ILSF, Tehran, Iran
	One of the limiting factors of electron beam lifetime in low emittance storage rings is Head-Tail (HT) insta-bility. Low emittance storage rings typically have a large negative natural chromaticity due to the strong quadru-poles. Above transition large negative natural chroma-ticity leads to large Head-Tail instability which limit the beam lifetime. Since the threshold current of HT insta-bility is directly related to linear chromaticity, increasing the linear chromaticity to slightly positive value is a solution to prevent HT instability. In this paper we in-creased the chromaticity of Iranian Light Source Facility (ILSF) to (+4, +4) and we will investigate the beam dy-namics of ILSF 3GeV storage ring in high chromaticity. For reaching this aim we have used two families of sex-tupoles for chromaticity correction and then optimized them to maximize the dynamic aperture and Touschek lifetime. The beam dynamics of high chromaticity lattice is presented in this paper. Foroughi.farangis@gmail.com
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS038
About •	paper received ※ 29 April 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
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MOPTS079	Design of 1.5 GeV Compact Storage Ring for the EUV and Soft X-rays	quadrupole, synchrotron, resonance, focusing	1028
	J.Y. Lee, I.G. Jeong Korea Atomic Energy Research Institute (KAERI), Daejeon, Republic of Korea P. Buaphad, Y.J. Joo, H.R. Lee University of Science and Technology of Korea (UST), Daejeon, Republic of Korea P. Buaphad, Y.J. Joo, Y. Kim, H.R. Lee, S. Lee KAERI, Jeongeup-si, Republic of Korea
	Recently, there has been discussions about the need for the next-generation synchrotron light source facility in Korea. The facility in consideration is composed of a super-conducting linear accelerator for the injector, a storage ring for the EUV and soft X-rays, and a main storage ring for hard X-rays. In this study, design concepts of the soft X-ray storage ring is presented. To effectively utilize the small space allocated for the soft X-ray storage ring, a compact storage ring is taken into account. The compact storage ring is a synchrotron accelerator of which diameter is shorter than the length of injector beamline. In this paper, we report design concepts and optimization of the compact storage ring for the EUV and soft X-ray users. The lattice of the storage ring is modelled by utilizing ELEGANT simulation code to optimize beam parameters and performance of the ring.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS079
About •	paper received ※ 24 May 2019 paper accepted ※ 24 May 2019 issue date ※ 21 June 2019
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MOPTS113	Sensitivity Analyses of All-Electric Storage Ring Designs	alignment, closed-orbit, proton, FEM	1148
	M.J. Syphers, A. Narayanan Northern Illinois University, DeKalb, Illinois, USA
	Funding: This work supported by the National Science Foundation Grant 1623691. Future searches of electric dipole moments (EDMs) of fundamental particles can require electrostatic storage rings operating at the particle’s "magic momentum" whereby spin precessions out of the plane of the particle motion would be governed in principle only by the presence of an EDM. An EDM search for the proton, for example, requires a momentum of approximately 700 MeV/c and thus implies a half-kilometer circumference, where relatively modest electric fields are assumed. As no all-electric ring on this scale has been constructed before, the ability to produce precise radial fields for establishing a central orbit and precise electrostatic focusing fields about that orbit requires attention. Results of initial investigations into the feasibility of designing a proper system and the sensitivities of such a system to placement, mis-powering errors and other requirements on realistic electrostatic elements will be presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS113
About •	paper received ※ 09 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
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MOPTS119	APS LINAC Interleaving Operation	linac, gun, operation, booster	1161
	Y. Sun, K. Belcher, J.C. Dooling, A. Goel, A.L. Hillman, R.T. Keane, A.F. Pietryla, H. Shang, A. Zholents ANL, Argonne, Illinois, USA
	Funding: Work supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02- 06CH11357. Three s-band RF guns are installed at the front end of the Advanced Photon Source (APS) linac: two thermionic cathode guns (RG2 and RG1), and one Photo-Cathode Gun (PCG). During normal operations, RG2 provides electron beams for the storage ring to generate x-rays for APS users. The PCG generates high brightness electron beams that can be accelerated through the APS linac and transported into the Linac Extension Area (LEA) for advanced accelerator technology and beam physics experiments. The alternating acceleration of the RG2 and PCG beam in the linac is possible, as most of the time, RG2 beam is only needed for ~20 seconds every two minutes. This mode of interleaving operation of RG2 and PCG beams through the APS linac requires some modifications/additions to several systems of the linac, including RF, magnets, controls and Access Control Interlock System etc. In this paper we report our interleaving design and present the commissioning results of the two beam interleaving operation.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS119
About •	paper received ※ 14 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019
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TUYPLM3	Status of the MAX IV Accelerators	electron, sextupole, linac, vacuum	1185
	P.F. Tavares, E. Al-Dmour, Å. Andersson, J. Breunlin, F.J. Cullinan, E. Mansten, S. Molloy, D.K. Olsson, D. Olsson, M. Sjöström, S. Thorin MAX IV Laboratory, Lund University, Lund, Sweden
	The MAX IV facility in Lund, Sweden, consists of three electron accelerators and their respective synchrotron radiation beamlines: a 3 GeV ring, which is the first implementation worldwide of a multi-bend achromat lattice, a 1.5 GeV ring optimized for soft X-Rays and UV radiation production and a 3 GeV linear accelerator that acts as a full-energy injector into both rings and provides electron pulses as short as 100 fs that produce X-rays by spontaneous emission in the undulators of the short-pulse facility (SPF). In this paper, we review the latest achieved accelerator performance and operational results.
	Slides TUYPLM3 [9.108 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUYPLM3
About •	paper received ※ 15 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019
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TUZPLS2	Beam Dynamics Study in the HEPS Storage Ring	lattice, emittance, photon, brightness	1203
	Y. Jiao, X. Cui, Z. Duan, Y.Y. Guo, P. He, X.Y. Huang, D. Ji, H.F. Ji, C. Li, J.Y. Li, X.Y. Li, C. Meng, Y.M. Peng, Q. Qin, S.K. Tian, J.Q. Wang, N. Wang, Y. Wei, G. Xu, H.S. Xu, F. Yan, C.H. Yu, Y.L. Zhao IHEP, Beijing, People’s Republic of China
	The High Energy Photon Source (HEPS) is the first high-energy diffraction-limited storage ring (DLSR) light source to be built in China, with a natural emittance of a few tens of pm rad and a circumference of 1360.4 m. After 10 years’ evolution, the accelerator physics design of the HEPS has been basically determined, with the ring consisting of 48 hybrid-7BAs with anti-bends and super-bends. This paper will discuss the accelerator physics studies of the HEPS storage ring, covering issues of lattice design, nonlinear optimization, collective effects, error correction, insertion devices, etc.
	Slides TUZPLS2 [9.517 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUZPLS2
About •	paper received ※ 15 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019
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TUZZPLS2	Beam Dynamics, Injection and Impedance Studies for the Proposed Single Pulsed Nonlinear Injection Kicker at the Australian Synchrotron	impedance, injection, kicker, synchrotron	1219
	R. Auchettl, R.T. Dowd, Y.E. Tan AS - ANSTO, Clayton, Australia
	The Australian Synchrotron are currently investigating the use of a single pulsed nonlinear injection kicker (NLK) to free floor space within the ring for future beamline development. The NLK has a zero and flat magnetic field at the stored beam to leave the stored beam undisturbed but has a maximum field off-axis where the injected beam is located. After the kick, the injected beam is stored. While NLKs have been prototyped at many facilities around the world, injection efficiency and heat loading have been the main impediment to deployment of the NLK. The wakefields that pass through the ceramic chamber aperture can cause severe heat loading and impedance. Despite achieving impressive injection efficiencies, a previous prototype at BESSY II * showed that strong interactions of the stored beam resulted in high heat load causing the thin 5µm Titanium coated ceramic chamber to reach temperatures > 500 °C and fail. To avoid beam induced heat loads, this paper presents studies of the wake impedance and thermal behaviour for our proposed NLK design. Injection simulations and future considerations for installation and operation at the Australian Synchrotron will be discussed. * T. Atkinson et al., "Development of a non-linear kicker system to facilitate a new injection scheme for the Bessy II storage ring", in Proc. IPAC’11, 2011, THPO024, pp. 3394-3396.
	Slides TUZZPLS2 [1.588 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUZZPLS2
About •	paper received ※ 15 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019
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TUPMP011	Storageless Resonant Converter for Accelerator Magnets	operation, resonance, controls, simulation	1248
	M. Cautero, T.N. Gucin Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
	Elettra Sincrotrone Trieste, a specialized research centre generating high quality synchrotron radiation, has been in operation since 1993 and was revised in 2009. Recently, Elettra has been funded for a complete renewal of the storage ring. For the new machine, it is planned to employ state of the art converters, mostly of which will be designed in-house. For this purpose, it has been decided to evaluate the performance of a storage-less resonant converter, pro-posed by Dr. Slobodan Ćuk, which is a step down DC/DC converter consisting of four switches, one resonant capac-itor and two resonant inductors. For this purpose, the voltage conversion ratio of the converter has been de-rived. The topology was confirmed with simulation and a PCB layout has been designed, which is still to be tested.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPMP011
About •	paper received ※ 08 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019
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TUPMP046	Improvement the Bending Magnet Power Supply Performance for TPS Storage Ring	power-supply, feedback, controls, photon	1353
	B.S. Wang, C.H. Huang, J.C. Huang, C.Y. Liu, K.-B. Liu, Y.S. Wong NSRRC, Hsinchu, Taiwan
	In the TPS (Taiwan Photon Source) facility, current stability of the electron beam depends on the bending magnet power supply and an orbit FOFB system to compensate the magnetic field. Due to the output current stability of the bending magnet power supply drifts with temperature so the orbit FOFB system should be applied to fine tune magnetic field and the photon beam should circulate in storage ring. In this paper, to stabilize the temperature of regulation circuit’s temperature box of the bending magnet power supply, the long-term output current stability is improve from ± 50ppm to ± 10ppm, and orbit FOFB system substantially reduce the tune X of beam position, effectively increasing the beam current stability and quality.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPMP046
About •	paper received ※ 12 April 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019
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TUPMP050	Conceptual Design of the Diamond-II Vacuum System	vacuum, photon, target, controls	1362
	M.P. Cox, C. Burrows, A.G. Day, J.A. Dymoke-Bradshaw, R.K. Grant, N.P. Hammond, X. Liu, A.G. Miller, H.S. Shiers, N. Warner DLS, Oxfordshire, United Kingdom
	The conceptual design of the vacuum system for the Diamond-II storage ring upgrade is described. Due to the small vessel cross section, typically 20 mm inside diameter (ID), and the consequent conductance limitation, distributed pumping is provided by non-evaporable getter (NEG) coating supplemented by ion pumps at high gas load locations. In-situ bakeout is incorporated to allow rapid recovery from both planned vacuum interventions and unplanned vacuum events. The vacuum vessels are constructed mainly from copper alloy while stainless steel is used in regions of AC magnets requiring low electrical conductivity. The proposed layout, engineering and build sequence of the vacuum system are described along with gas flow simulations confirming the vacuum performance advantages of NEG-coated vessels compared with uncoated vessels.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPMP050
About •	paper received ※ 14 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019
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TUPGW003	Sirius Status Update	booster, vacuum, alignment, controls	1381
	A.R.D. Rodrigues, F.C. Arroyo, J.F. Citadini, R.H.A. Farias, J.G.R.S. Franco, R. Junqueira Leão, L. Liu, S.R. Marques, R.T. Neuenschwander, C. Rodrigues, F. Rodrigues, R.M. Seraphim, O.H.V. Silva, F.H. de Sá LNLS, Campinas, Brazil
	Sirius is a 4th generation 3 GeV low emittance electron storage ring that is in its final installation phase at the Brazilian Center for Research in Energy and Materials (CNPEM) campus in Campinas, Brazil. Presently the injector installation is complete, and the storage ring installation is being finalized. Most subsystems are under test and tuning in real working conditions. Six beamlines are also under construction. In this paper we report on the Sirius main subsystems installation status.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW003
About •	paper received ※ 15 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019
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TUPGW005	Preparation of the EBS Beam Commissioning	SRF, MMI, controls, injection	1388
	S.M. Liuzzo, N. Carmignani, A. Franchi, T.P. Perron, K.B. Scheidt, E.T. Taurel, L. Torino, S.M. White ESRF, Grenoble, France
	In 2020 the ESRF storage ring will be upgraded to a Hybrid Multi Bend Achromat (HMBA) lattice. The commissioning of the new ring will require dedicated tools, either updated from the existing ones or newly developed. Most of the software and procedures were tested on the existing storage ring before its decommissioning. In particular we present experiments on first-turn steering and beam accumulation, check of magnet polarity and calibration, and injection tuning. The use of a control-system simulator proved to be crucial for the debugging of the software and the development of the new control system, as far as beam measurements and manipulations are concerned.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW005
About •	paper received ※ 26 April 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019
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TUPGW017	Superconducting Undulator Coils with Period Length Doubling	undulator, vacuum, FEM, operation	1426
	S. Casalbuoni, N. Glamann, A.W. Grau, T. Holubek, D. Saez de Jauregui KIT, Eggenstein-Leopoldshafen, Germany
	Funding: Work supported by the German government in the BMBF-project Superconducting ’Insertion Device Technologies for Ultra-Low-Emittance Light Sources’ (05K12CK1) Only since few years it has been demonstrated experimentally that NbTi based superconducting undulators (SCUs) have a higher peak field on axis for the same gap and period length in operation with electron beam with respect to permanent magnet undulators (even the ones in vacuum and cooled to cryogenic temperatures). Another advantage of NbTi based SCUs with respect to permanent magnet devices is radiation hardness, widely demonstrated for NbTi magnets, which is and will become an increasingly important issue with the small gaps in the newest machines as round beam storage rings and FELs. Moreover, SCU technology allows switching of the period length by changing the current direction in one of separately powered subset of winding packages of the superconducting coils. This feature further broadens the energy range of the emitted photons, required by the different beamlines. To this end 0.5 m long superconducting undulator coils with switchable period length between 17 mm and 34 mm have been developed. In this contribution we describe the design and report on the quench tests, as well as on the magnetic field measurements.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW017
About •	paper received ※ 25 April 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019
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TUPGW018	PETRA IV Study with Non-Interleaved Sextupole Scheme	sextupole, lattice, emittance, optics	1430
	H.C. Chao, R. Brinkmann, X.N. Gavaldà DESY, Hamburg, Germany
	This study is an attempt to design PETRA IV storage ring, which is an upgrade from PETRA III toward diffraction-limit synchrotron light source, based on the non-interleaved sextupole scheme. The lattice is constructed by mixing different types of cells. There are two basic building blocks. The double minus identity (DMI) cell dedicated for the chromaticity correction with non-interleaved sextupoles is tightly built up, while the combined function FODO cell with dispersion suppressors provides straights with small beta functions ideally for undulators. In addition, the hybrid section including a 10-m long super insertion device (ID) is custom-made to adapt to DESY’s current site plan. The beam dynamic behaviors are simulated and discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW018
About •	paper received ※ 18 April 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019
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TUPGW020	Non-Linear Features of the cSTART Project	quadrupole, sextupole, lattice, injection	1437
	B. Härer, E. Bründermann, A.B. Kaiser, A.-S. Müller, A.I. Papash, R. Ruprecht, J.M. Schaefer, M. Schuh KIT, Karlsruhe, Germany
	The compact storage ring for accelerator research and technology (cSTART) is being designed and will be realized at the Institute for Beam Physics and Technology (IBPT) of the Karlsruhe Institute of Technology (KIT). One important goal of the project is to demonstrate injection and storage of a laser wakefield accelerator (LWFA) beam in a storage ring. As a first stage the compact linear accelerator FLUTE will serve as an injector of 50 MeV bunches to test the ring’s performance. A highly non-linear lattice of DBA-FDF type was studied extensively. The specific features of ring optics are reported. A special transfer line from FLUTE to cSTART including bunch compressor and non-linear elements is presented that maintains the ultra-short bunch length of FLUTE.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW020
About •	paper received ※ 13 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019
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TUPGW024	Pulse Shaping Methods for Laser-Induced Generation of THz Radiation at the Delta Storage Ring	laser, radiation, electron, experiment	1453
	C. Mai, B. Büsing, A. Glaßl, S. Khan, D. Krieg, A. Meyer auf der Heide DELTA, Dortmund, Germany
	At DELTA, a 1.5-GeV electron storage ring operated as a synchrotron light source by the TU Dortmund University, a dedicated beamline is used for experiments with (sub-)THz radiation. Here, an interaction of short laser pulses with electron bunches to give rise to coherently emitted broadband as well as tunable narrowband radiation from 75 GHz to 5.6 THz. For the narrowband operation of the source, a laser pulse with periodic intensity modulation is used. An interferometric approach, the chirped-pulse beating technique, is routinely employed for this purpose. Recently, pulse shaping techniques using spatial light modulators are investigated to gain more flexible control of the laser pulse shape and the spectrotemporal properties of the resulting THz pulses.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW024
About •	paper received ※ 15 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019
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TUPGW035	A Highly Brilliant Compact 3 GeV Light Source Project in Japan	emittance, cavity, injection, linac	1478
	N. Nishimori National Institutes for Quantum and Radiological Science and Technology (QST), Sayo-cho, Japan H. Tanaka RIKEN SPring-8 Center, Hyogo, Japan T. Watanabe JASRI/SPring-8, Hyogo, Japan
	A highly brilliant compact 3 GeV light source project was proposed in Japan. The light source would be constructed in Sendai, north-east part of Japan. It provides brilliant soft X-ray beam to widely cover wavelengths ranging from EUV to hard X-ray in Japan together with SPring-8. The accelerator system is now mostly designed except for several linac components and so on. We have chosen a 4-bend achromat lattice to achieve a low emittance keeping a small circumference with a rather relaxed space issue. The number of cells is 16 and the ring circumference is about 350 m. Number of available beam lines are 26 including short straight sections for multi-pole wigglers. Horizontal emittance is expected to be around 1.1 nmrad, and the maximum brilliance may exceed 10²¹ at 1 - 3 keV region with a stored current of 400 mA. The designs of many components such as vacuum chambers, magnets and monitors are employed from those studied for SPring-8 upgrade project. A full energy injector linac equipped with a thermionic gun and C-band accelerating structures is employed to produce sufficiently low emittance beams for efficient beam injections. The C-band system is adopted from those developed for XFEL SACLA with some modifications. In the future, the injector would be upgraded as an electron driver for SXFEL. Details of the project and accelerator system will be presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW035
About •	paper received ※ 14 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
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TUPGW040	Study of Seven-Bend Achromat Lattices with Interleaved Dispersion Bumps for HALS	lattice, emittance, octupole, linear-dynamics	1495
	Z.H. Bai, W. Li, G. Liu, L. Wang, D.R. Xu, T. Zhang USTC/NSRL, Hefei, Anhui, People’s Republic of China
	Previously, we proposed a multi-bend achromat (MBA) lattice concept, called the MBA with interleav-ed dispersion bumps, which was then used to design a 7BA lattice for the Hefei Advanced Light Source (HALS) storage ring. Recently, such a 7BA lattice was further designed and optimized for the HALS by changing the number of lattice cells, scanning working point and employing octupoles. And two new HALS designs with such 7BA lattices have been made, one with 30 lattice cells and a natural emittance of 25 pm·rad and the other with 28 cells and 33 pm·rad. They had much better nonlinear dynamics perfor-mances than the previous design. The detailed study for these two HALS lattices will be presented in this paper.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW040
About •	paper received ※ 15 May 2019 paper accepted ※ 18 May 2019 issue date ※ 21 June 2019
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TUPGW041	Super-Period Locally Symmetric Lattices for Designing Diffraction-Limited Storage Rings	lattice, emittance, sextupole, quadrupole	1498
	Z.H. Bai, W. Li, G. Liu, L. Wang USTC/NSRL, Hefei, Anhui, People’s Republic of China Y. Li BNL, Upton, Long Island, New York, USA
	To achieve better nonlinear dynamics performance for a diffraction-limited storage ring, previously we proposed a locally symmetric multi-bend-achromat (MBA) lattice concept, where beta functions are locally symmetric about two mirror planes of each lattice cell. To have both high-beta long straight sections for beam injection and low-beta ones for higher brightness of insertion device radiation, many storage ring light sources use super-period lattices. The locally symmetric MBA lattice can be naturally extended to the super-period case. In the super-period locally symmetric (SP-LS) lattice, many nonlinear dynamics effects can be effectively cancelled out within one super-period lattice cell, and also there are many knobs to be used for further nonlinear optimization. As examples, two SP-LS lattices have been designed towards diffraction-limited emittances.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW041
About •	paper received ※ 20 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019
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TUPGW042	Study of the Intra-beam Scattering Effects in the HALS Storage Ring	emittance, damping, wiggler, lattice	1501
	W. Li, Z.H. Bai, W. Li, D.R. Xu, T. Zhang USTC/NSRL, Hefei, Anhui, People’s Republic of China
	Funding: This work was supported by the Fundamental Research Funds for the Central Universities (Grant No.WK2310000082 and WK2310000077). The Hefei Advanced Light Source (HALS) is designed to be a dedicated 4th generation diffraction limited light source. In 2018, the baseline lattice of the HALS storage ring has been proposed, with an ultra-low natural emittance of about 25 pm-rad. The preliminary study of intra-beam scattering effects on the beam emittance growth in the HALS storage ring has been performed with this baseline lattice. Due to the limited synchrotron radiation in this storage ring, damping wigglers are expected in this storage ring to reduce the damping time and reduce the emittance. In this paper, we will present the simulation results of the IBS effects, estimated effectiveness of damping wiggler and the corresponding linear optics calibration of the perturbation due to insertion device, and finally the estimated Touschek lifetime will be shown.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW042
About •	paper received ※ 13 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019
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TUPGW043	Simulation of Model Independent Analysis to HEPS Storage Ring	optics, simulation, quadrupole, betatron	1504
	D. Ji, Y. Jiao, H.Z. Ma, J.H. Yue IHEP, Beijing, People’s Republic of China
	Model Independent Analysis (MIA) is a beam analysis method applied for Turn-by-Turn (TBT) Beam Position Monitor (BPM) data. To develop the commissioning method of the HEPS storage ring, we simulate application of MIA on HEPS storage error model to measure and cor-rect the optics parameters. Difficulties and limitations of the MIA method are also discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW043
About •	paper received ※ 15 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019
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TUPGW045	Lattice Design for the Reversible SSMB	radiation, electron, emittance, bunching	1507
	C.L. Li SINAP, Shanghai, People’s Republic of China A. Chao SLAC, Menlo Park, California, USA C. Feng, B.C. Jiang Shanghai Advanced Research Institute, Pudong, Shanghai, People’s Republic of China
	Steady State Microbunching (SSMB) aiming at producing high average power radiation in the electron storage ring has been proposed by Ratner and Chao years ago. Reversible seeding scheme is one of the promising scenarios with less challenges on the storage ring lattice design. The key problem for reversible SSMB is the precise cancelation of the laser modulation which will allow producing turn-by-turn coherent radiation without spoiling the transverse emittances and energy spread. In this paper the lattice design for the microbunching generation and its cancelation will be presented. Also a storage ring lattice design will be shown.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW045
About •	paper received ※ 14 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019
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TUPGW046	Progress of Lattice Design and Physics Studies on the High Energy Photon Source	lattice, booster, photon, injection	1510
	Y. Jiao, X. Cui, Z. Duan, Y.Y. Guo, P. He, X.Y. Huang, D. Ji, C. Li, J.Y. Li, X.Y. Li, C. Meng, Y.M. Peng, Q. Qin, S.K. Tian, J.Q. Wang, N. Wang, Y. Wei, G. Xu, H.S. Xu, F. Yan, C.H. Yu, Y.L. Zhao IHEP, Beijing, People’s Republic of China
	The High Energy Photon Source (HEPS) is an ul-tralow-emittance, kilometer-scale storage ring light source to be built in China. In this paper we will introduce the progress of the physics design and related studies of HEPS over the past year, covering issues in storage ring lattice design, injection and injector design, insertion device effects, error study and lattice calibration, collective effects, etc.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW046
About •	paper received ※ 15 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019
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TUPGW048	Simulation of Injection Efficiency for the High Energy Photon Source	injection, booster, kicker, extraction	1514
	Z. Duan, J. Chen, Y.Y. Guo, D. Ji, Y. Jiao, C. Meng, Y.M. Peng, Xu. Xu IHEP, Beijing, People’s Republic of China
	Funding: Work supported by Natural Science Foundation of China (No.11605212). A ’high-energy accumulation’ scheme [1] was proposed to deliver the full charge bunches for the swap-out injec- tion of the High Energy Photon Source. In this scheme, the depleted storage ring bunches are recovered via merging with small charge bunches in the booster, before being refilled into the storage ring. In particular, the high charge bunches are transferred twice between the storage ring and the booster, and thus it is essential to maintain a near per- fect transmission efficiency in the whole process. In this paper, major error effects affecting the transmission efficiency are analyzed and their tolerances are summarized, injection simulations indicate a satisfactory transmission efficiency is achievable for the present baseline lattice. * Z. Duan, et al., "The swap-out injection scheme for the High Energy Photon Source", Proc. IPAC’18, THPMF052
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW048
About •	paper received ※ 15 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019
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TUPGW052	STUDY OF THE RAMPING PROCESS FOR HEPS BOOSTER	booster, damping, lattice, injection	1521
	Y.M. Peng, J.Y. Li, C. Meng, H.S. Xu IHEP, Beijing, People’s Republic of China
	The High Energy Photon Source (HEPS) is a 6-GeV, ul-tralow-emittance storage ring light source to be built in Huairou District, Beijing, China. The beam energy ramps from 500 MeV to 6 GeV in 400 ms, during which the RF voltage increases accordingly to keep the momentum acceptance large enough. The booster is designed to operate at 1 Hz repetition frequency. In this paper the energy ramping curve, RF choice, beam parameters changing curves and eddy current effect in HEPS booster will be presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW052
About •	paper received ※ 14 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019
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TUPGW053	Simulations of the Injection Transient Instabilities for the High Energy Photon Source	injection, feedback, simulation, lattice	1524
	Z. Duan, N. Wang, H.S. Xu IHEP, Beijing, People’s Republic of China
	Funding: Work supported by Natural Science Foundation of China (No.11605212). A "charge recovery in booster" scheme* was proposed to deliver the full charge bunches for the swap-out injection of the High Energy Photon Source. In this scheme, the booster is employed also as a full energy accumulator ring to capture the high charge bunch extracted from the storage ring via merging with the small charge bunch accelerated in the booster, after enough damping in the booster for about 20 ms, the recovered full charge bunch is re-injected into the storage ring. This scheme avoids the challenges to accelerate a bunch charge of ~ 15 nC, and is cost effective compared to building a dedicated 6 GeV accumulator ring. However, there will be a period of time during injection that one bunch is missing in the storage ring, which inevitably introduces some injection transients. Since "transparency" to the user experiments is a desired feature of injection schemes for next generation diffraction-limited storage rings, the injection transient effects are simulated for the proposed injection scheme, and how it would affect the user experiments are carefully evaluated. * Z. Duan, et al., "The swap-out injection scheme for the High Energy Photon Source", Proc. IPAC’18, THPMF052
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW053
About •	paper received ※ 15 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019
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TUPGW056	Comparison of Constrained Optimization Methods for Designing a Multi-Bend Achromat Lattice	lattice, emittance, sextupole, linear-dynamics	1535
	J.H. Xu, Z.H. Bai, W. Li, P.H. Yang USTC/NSRL, Hefei, Anhui, People’s Republic of China
	In the design of a multi-bend achromat (MBA) lattice for a diffraction-limited storage ring, there are usually many magnet parameters to be optimized and some stringent constraints to be satisfied. For example, to cancel out nonlinear dynamics effects, the phase advances between some sections are generally required to be set to certain values in the lattice design. For better designing a MBA lattice using an evolutionary algorithm, the handling of constraints will be important, because it is very hard to satisfy the constraints for most or even all of solutions in the early generations of the algorithm. This paper will first describe some methods for handling constraints, which are then applied to designing a hybrid 7BA lattice. The comparison of these methods shows that better lattice solutions can be obtained by including constraints into objective functions.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW056
About •	paper received ※ 23 April 2019 paper accepted ※ 19 May 2019 issue date ※ 21 June 2019
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TUPGW057	A Ten-Bend Achromat Lattice with Interleaved Dispersion Bumps for a Diffraction-Limited Storage Ring	lattice, emittance, sextupole, quadrupole	1538
	P.H. Yang, Z.H. Bai, J.J. Tan, L. Wang, J.H. Xu USTC/NSRL, Hefei, Anhui, People’s Republic of China
	Recently, a multi-bend achromat (MBA) lattice concept, called the MBA with interleaved dispersion bumps (IDB-MBA), was proposed to design the HALS storage ring, which presented better performance of both on- and off-momentum nonlinear dynamics. Since the beam emittance scales inversely with the third power of the number of bending magnets, in this paper we will study a new IDB-MBA lattice with more bending magnets. It is feasible to satisfy the requirement of the IDB-MBA concept in a 10BA lattice, and an IDB-10BA lattice is then designed for a storage ring light source with an energy of 2.4 GeV. The designed lattice has an ultra-low natural emittance of 81 pm·rad, and a dynamic aperture of about 6 mm and a large dynamic momentum aperture of 6% are achieved.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW057
About •	paper received ※ 24 April 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019
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TUPGW059	Studies of The Electron Beam Lifetime in Solaris Electron Storage Ring	electron, cavity, scattering, vacuum	1541
	R. Panas, A.M. Marendziak, A.I. Wawrzyniak, M. Wisniowski Solaris National Synchrotron Radiation Centre, Jagiellonian University, Kraków, Poland
	Solaris storage ring is a recently constructed and commissioned machine operated in decay mode. With total accumulated beam dose near to 1000 A.h the measured total lifetime has reached 16 h for 270mA of a stored current. In this paper, the beam lifetime studies are presented using measured residual gas analysis and vertical scraper position for tuned and detuned Landau cavities. It shows that for stable beam the lifetime is dominated by the interaction of the electron with residual gas (vacuum lifetime) and between electrons interaction within a bunch (Touschek lifetime). The estimated vacuum, Touschek and total beam lifetimes from theoretical analysis are also compared with the measured beam lifetime.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW059
About •	paper received ※ 15 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019
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TUPGW064	Trials of Beam-Based Sextupole Calibration through 2nd Order Dispersion	sextupole, optics, lattice, ECR	1551
	D.K. Olsson, Å. Andersson, M. Sjöström MAX IV Laboratory, Lund University, Lund, Sweden
	In order to achieve nominal performance in terms of the dynamic aperture and lifetime of a storage ring, it is important to be able to characterise and correct its second order optics. At the MAX IV 3 GeV storage ring in Lund, Sweden, the linearity of the 2nd order dispersion with chromatic sextupole field strengths has been utilised to investigate the sextupole circuits. The beating induced in the 2nd order dispersion when reducing the strength of a sextupole magnet can be compared to the beating in simulations. From this a beam-based sextupole calibration curve can be found. This work was inspired by similar work done at ESRF.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW064
About •	paper received ※ 13 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019
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TUPGW066	Exploring the Potential of the Swiss Light Source	emittance, operation, damping, cavity	1554
	M. Aiba, M. Böge, A. Citterio, M.M. Dehler, A. Lüdeke, C. Ozkan Loch, L. Stingelin, A. Streun PSI, Villigen PSI, Switzerland
	Swiss Light Source (SLS) has been on-line since 2001. Although its performance meets the specifications, it still has a potential to achieve better storage ring beam parameters. We explore two possible improvements. The first one is for the beam lifetime. There are 480 rf buckets while normally 390 bunches are stored. The gap in filing pattern (90 empty buckets) is held to suppress ion instability. After many years of operation, however, the vacuum condition is much better than that of the time when the SLS was turned on. Hence it is possible to shorten the gap. The beam lifetime can then be prolonged due to less bunch current while keeping the net beam current. The study may be also useful to predict possible filling patter in SLS2, which is the SLS upgrade planned. The second one is for the beam emittance. The nominal energy closed orbit coincides with the axes of quadrupole magnets. An off-momentum closed orbit is therefore off-centered through quadrupoles, resulting in a damping partition shift. The beam emittance can be decreased at the expense of a larger energy spread. This was successfully achieved in the ESRF booster. We study whether it is applicable to the SLS storage ring.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW066
About •	paper received ※ 13 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019
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TUPGW068	New Source for Bending Magnet Beam Lines at Ultra-Low-Emittance Ring	dipole, radiation, lattice, wiggler	1557
	M. Abbaslou, M. Sedaghatizadeh KNTU, Tehran, Iran S. Dastan, J. Rahighi, F. Saeidi ILSF, Tehran, Iran
	The Iranian Light Source Facility (ILSF) is a 3 GeV 3rd synchrotron radiation laboratory in the basic design phase. The Storage Ring (SR) is based on a five-bend achromat (5BA) lattice providing low horizontal emittance of 0.27 nm.rad. Due to the ILSF storage ring, straight section limits the use of the short length wigglers for hard X-ray generation is recommended. Which are removable in the lattice. In this article, the new design of the 3-pole wiggler is investigated and the main parameters of this 3-pole wiggler, by considering the ILSF storage ring characteristics, is modified. Also, the effect of the new 3-pole wiggler on the beam dynamics is investigated and the advantages of the new design are presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW068
About •	paper received ※ 28 April 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019
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TUPGW069	Insertion Devices for the Day-One Beamlines of ILSF	undulator, vacuum, wiggler, polarization	1561
	M. Hadad Shahid Beheshti University, Tehran, Iran S. Dastan, M. Hadad, J. Rahighi, M. Razazian, F. Saeidi, S. Yousefnejad ILSF, Tehran, Iran
	The Iranian Light Source Facility (ILSF) is a new 3 GeV synchrotron radiation laboratory with ultralow emittance of 270 pm-rad, which is in the design stage. Seven beamlines are planned to start operation with several different insertion devices installed in the storage ring either from "day one" or within the first year of operation. The most operational undulator for polarized radiations -Apple II- has been deliberated for the solid state electron spectroscopy, the Spectromicroscopy and the ARPES beamlines. The hybrid wigglers for the XPD and the EXAFS beamlines and in-vacuum undulators for Macromolecular Crystallography and SCD beamlines have been chosen too. The emission of these IDs covers a wide spectral range extending from hard X-rays to UV. Pre-design of the IDs were already done in ILSF. The main parameters of magnetic design as well as radiation parameters for the first phase of ILSF insertion devices have been described in this paper.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW069
About •	paper received ※ 15 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019
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TUPGW070	Multi-Bend Achromat Lattice Design for the Future of TPS Upgrade	lattice, emittance, dipole, dynamic-aperture	1564
	M.-S. Chiu, P.J. Chou, J.C. Huang NSRRC, Hsinchu, Taiwan S.-Y. Lee Indiana University, Bloomington, Indiana, USA
	We present a TPS upgrade option with the hybrid 7BA (H7BA) lattice. We also derive a simple formula on optimal dipole angle distribution among H7BA dipoles. The agreement is satisfactory. We also report preliminary results on the dynamic aperture (DA) optimization. Possible improvement on H7BA lattice is outlined.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW070
About •	paper received ※ 24 April 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019
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TUPGW071	Optimization and Measurements on the Double Mini-Betay Lattice in the TPS Storage Ring	lattice, betatron, injection, dynamic-aperture	1567
	M.-S. Chiu, B.Y. Chen, C.H. Chen, J.Y. Chen, Y.-S. Cheng, P.C. Chiu, P.J. Chou, T.W. Hsu, K.H. Hu, J.C. Huang, P.Y. Huang, C.-C. Kuo, T.Y. Lee, C.Y. Liao, W.Y. Lin, Y.-C. Liu, H.-J. Tsai, F.H. Tseng NSRRC, Hsinchu, Taiwan
	The Taiwan Photon Source (TPS) is capable of operat-ing in multi-bunch and single-bunch mode. To operate in a hybrid mode as requested by users, we developed a lattice with chromaticities of 0.8/2 (x/y) to provide higher single bunch currents. Beam dynamics simulations and lattice characterizations including dynamic aperture, frequency map analysis, tune shift with energy, tune shift with amplitude, and betatron coupling will be discussed in this report.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW071
About •	paper received ※ 30 April 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019
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TUPGW072	Design and Optimization of Full Energy Injector Linac for Siam Photon Source II	linac, injection, emittance, simulation	1570
	T. Chanwattana, P. Klysubun, T. Pulampong, P. Sudmuang SLRI, Nakhon Ratchasima, Thailand
	The new Thailand synchrotron light source, Siam Photon Source II (SPS-II), has been designed based on a 3 GeV storage ring with a Double-Triple Bend Achromat (DTBA) lattice and a full energy injector linac. The linac consists of an S-band photocathode RF gun, C-band accelerating structures and two magnetic chicanes. In addition to its main function as the storage ring injector, the linac is capable of producing sub-picosecond electron bunches for additional short-pulse beamlines at the end of the linac. The linac also has a potential to become a driver of a soft X-ray Free Electron Laser (FEL) operating adjacent to the storage ring. In this paper, start-to-end simulations of the full energy linac are presented. Optimization was performed in order to fulfil requirements for both storage ring injection and short pulse generation.
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TUPGW075	Towards a Diffraction Limited Storage Ring	lattice, optics, emittance, dynamic-aperture	1573
	J. Bengtsson DLS, Oxfordshire, United Kingdom P.F. Tavares MAX IV Laboratory, Lund University, Lund, Sweden
	A Lattice for a 500 m circ. Tunnel, based on First Principles & Best Practices is presented. Background: MAX-IV has made a "quantum leap" towards a Diffraction Limited Storage Ring (DLSR) by an Engineering-Science, i.e., Systems, Approach; leading to a Paradigm Shift(s): e.g. the Magnet Reference Radius is a Key Parameter, a Design Choice, that must be considered at an early stage for Robust Design. In addition, the pursuit of Systematic Benchmarks, MAX-I -> MAX-IV, has enabled the pursuit of Disruptive Technologies with Predictable Results. For example: Combined-Function Magnets (built-to-print) enabling an "IKEA Approach" (innovative, prompted by low-budget) like the use of Concrete Girders, Vacuum Requirements mitigated by NEG Coating, and Solid State Modulators providing a Reliable Injector by a Full-Energy Linac. Since "The Experiment" now has been done, Permanent Magnets, well understood for high-end Insertion Devices, provides another opportunity/step for a Next Generation. Besides, the Electricity Bill for Conventional Magnets is a significant part of the Operations Cost.
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About •	paper received ※ 20 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019
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TUPGW077	Impact of the DIAD Wiggler and ’Missing-sextupole’ Optics on the Diamond Storage Ring	wiggler, sextupole, optics, operation	1581
	I.P.S. Martin, R. Bartolini, B. Singh DLS, Oxfordshire, United Kingdom
	In order to generate space for a short, out-of-vacuum multipole wiggler for the DIAD beamline, a single sextupole was removed from one of the DBA arcs in the Diamond Storage Ring during June 2018. The removal of this sextupole presented a number of challenges to the operation of the storage ring, requiring a re-optimisation of the remaining sextupole strengths, a change in tune-point and modification of the orbit and coupling correction schemes. In this paper we describe the implementation of these changes, and provide an assessment of the impact that the installed wiggler has made on the storage ring parameters. B. Singh et al. ’Studies to Install a Multipole Wiggler by Removing a Chromatic Sextupole in Diamond Storage Ring’, Proc. IPAC 2016, Busan, Korea, paper THPMR050, (2016)
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About •	paper received ※ 15 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019
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TUPGW078	Harmonic Cavity Design Choice for Lifetime Increase in Diamond-II	cavity, simulation, beam-loading, lattice	1585
	T. Olsson, R. Bartolini, I.P.S. Martin DLS, Oxfordshire, United Kingdom
	The ongoing trend towards synchrotron light storage rings with ultralow emittance leads to a requirement for strong magnet gradients, which reduce the dynamic aperture and thus the Touschek lifetime of the machine. This is also the case for the planned upgrade of the Diamond Light Source. One option to increase the Touschek lifetime is to lengthen the electron bunches with a harmonic cavity operated close to a harmonic of the fundamental RF frequency. This paper presents studies of a harmonic cavity for Diamond-II with the focus on maximising the lifetime increase. It is foreseen that the ring will have to operate with a gap in the fill pattern to avoid instabilities and therefore multiparticle tracking was used to determine the effect on stability and lifetime for various cavity parameters taking into account transient beam loading.
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TUPGW082	Impedance of the Flange Joints With the RF Contact Spring in NSLS-II	impedance, vacuum, cavity, damping	1597
	A. Blednykh, B. Bacha, G. Bassi, C. Hetzel, B.N. Kosciuk, T.V. Shaftan, V.V. Smaluk, G.M. Wang BNL, Upton, Long Island, New York, USA
	Funding: This work was supported by Department of Energy Contract No. DE-SC0012704 Since the beginning of the NSLS-II commissioning, temperature of the vacuum components has been moni-tored by the Resistance Temperature Detectors located predominantly outside of the vacuum enclosure and at-tached to the chamber body. Temperature map helps us to control overheating of the vacuum components around the ring especially during the current ramp-up. The average current of 475mA has been achieved with two main 500MHz RF cavities and w/o harmonic cavities. Effect of the RF shielded flanges on local heat and on the longitu-dinal beam dynamics is discussed in details.
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Paper

Title

Other Keywords

Page

MOZZPLS1

eRHIC Design Overview

electron, hadron, proton, luminosity

45

C. Montag, G. Bassi, J. Beebe-Wang, J.S. Berg, M. Blaskiewicz, A. Blednykh, J.M. Brennan, S.J. Brooks, K.A. Brown, K.A. Drees, A.V. Fedotov, W. Fischer, D.M. Gassner, W. Guo, A. Hershcovitch, C. Hetzel, D. Holmes, H. Huang, W.A. Jackson, J. Kewisch, Y. Li, C. Liu, H. Lovelace III, Y. Luo, F. Méot, M.G. Minty, R.B. Palmer, B. Parker, S. Peggs, V. Ptitsyn, V.H. Ranjbar, G. Robert-Demolaize, S. Seletskiy, V.V. Smaluk, K.S. Smith, S. Tepikian, P. Thieberger, D. Trbojevic, N. Tsoupas, S. Verdú-Andrés, W.-T. Weng, F.J. Willeke, H. Witte, Q. Wu, W. Xu, A. Zaltsman, W. Zhang
BNL, Upton, Long Island, New York, USA
E. Gianfelice-Wendt
Fermilab, Batavia, Illinois, USA
Y. Hao
FRIB, East Lansing, Michigan, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
The Electron-Ion Collider (EIC) is being envisioned as the next facility to be constructed by the DOE Nuclear Physics program. Brookhaven National Laboratory is proposing eRHIC, a facility based on the existing RHIC complex as a cost effective realization of the EIC project with a peak luminosity of 10³⁴ cm^-2 sec^-1. An electron storage ring with an energy range from 5 to 18 GeV will be added in the existing RHIC tunnel. A spin-transparent rapid-cycling synchrotron (RCS) will serve as a full-energy polarized electron injector. Recent design improvements include reduction of the IR magnet strengths to avoid the necessity for Nb₃Sn magnets, and a novel hadron injection scheme to maximize the integrated luminosity. We will provide an overview of this proposed project and present the current design status.

Slides MOZZPLS1 [5.428 MB]

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MOPGW001

Design Review of Bellows RF-Shielding Types and New Concepts for Sirius

shielding, wakefield, HOM, impedance

53

H.O.C. Duarte, P.P.S. Freitas, A.R.D. Rodrigues, R.M. Seraphim, T.M. da Rocha
LNLS, Campinas, Brazil

Large amounts of bellows in an accelerator justify the importance of simplifying the machining and assembling processes of their RF shield. Such quantity also makes this component one of the main contributors for a machine impedance budget. On the other hand, low impedance designs tend to complicate the mechanical aspects. Applied to Sirius round vacuum chamber of 24 mm inner diameter, the omega-strip and comb-type bellows concepts are compared with new proposed designs. In such comparison, the aforementioned aspects, wakefield losses and prototyping experiences are presented in this work.

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paper received ※ 16 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

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MOPGW003

Collective Instability Studies for Sirius

simulation, impedance, radiation, coupling

61

F.H. de Sá
LNLS, Campinas, Brazil

In this work we will present the estimates of single and multi-bunch instability thresholds and current-dependent effects, such as tune-shifts and potential-well distortion for the Sirius storage ring. The results were obtained by tracking simulations and semi-analytic methods using the updated and detailed impedance budget of the machine, which includes contributions from all the in-vacuum components and the coherent synchrotron radiation (CSR) impedance.

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MOPGW007

Electromagnetic Impulse of Beam Density F(x, y)G(z)

factory, site, lattice, interaction-region

75

S.R. Koscielniak
TRIUMF, Vancouver, Canada

We calculate the transverse impulse on a test particle as a bunch of charged particles beam passes by. It is often assumed, but seldom proven, that the EM field from a beam density distribution factored into transverse and longitudinal parts, F and G respectively, has also a factored form P(x, y)Q(z). This factorization is not possible for stationary charges. Contrastingly, it becomes increasingly accurate for ultra-relativistic particle beams. We give a general analysis, show how to develop the corrections in terms of integrals of F and derivatives of G. What is significant is that if we integrate over longitudinal coordinate z to find the transverse impulse on a witness charge, the correction terms integrate to zero leading to the impulse P(x, y)Integral[Q(z)] independent of bunch shape. If this result is already known, this paper serves as a reminder.

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paper received ※ 15 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

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MOPGW010

First Application of Online Particle Swarm Optimization at SOLEIL

injection, operation, controls, vacuum

82

A. Bence, L.S. Nadolski
SOLEIL, Gif-sur-Yvette, France
J. Li
HZB, Berlin, Germany

First attempts of online optimisation of SOLEIL using Particle Swarm Optimisation (PSO) is reported with two major applications. This technique proves to be particularly suitable in a control room and could become a standard operation tool for tuning the accelerators in complement of other techniques. The first optimisation of the injection in the storage ring will be presented using the injection septa and the vertical correctors of the booster to storage ring transfer line. The second work will summarise the results obtained from the optimisation of the transverse on- and off-momentum dynamics in presence of insertion devices. Main results, the implementation and improvements will be presented and discussed thoroughly.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW010

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paper received ※ 19 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

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MOPGW014

Developing Beam Optics for the BESSY VSR Project

optics, quadrupole, lattice, cavity

94

F. Andreas, M. Abo-Bakr, F. Armborst, P. Goslawski
HZB, Berlin, Germany

At BESSY II due to the continuously increasing interest in short pulse operation, a major upgrade of the ring will enable simultaneous storage of long and short bunches. This Variable pulse-length Storage Ring (VSR) will be achieved by the installation of additional superconducting high gradient cavities. The cavities will be assembled into one cryomodule in one of the straights of the storage ring. As this module needs more space then initially assumed, one possible solution is to remove two quadrupoles to gain available installation length. The quadrupoles were switched off in simulations and the lattice was optimized with regard to the linear order. The best solution found was transferred to the storage ring, where storage of high current with reasonable injection efficiency and lifetime was possible. The proposed optics has to be further optimized in terms of nonlinear beam dynamics, but has shown that an available installation length can be increased.

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paper received ※ 15 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

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MOPGW017

Feedback Design for Control of the Micro-Bunching Instability based on Reinforcement Learning

bunching, feedback, electron, controls

104

T. Boltz, T. Asfour, M. Brosi, E. Bründermann, B. Härer, P. Kaiser, A.-S. Müller, C. Pohl, P. Schreiber, M. Yan
KIT, Karlsruhe, Germany

The operation of ring-based synchrotron light sources with short electron bunches increases the emission of coherent synchrotron radiation (CSR) in the THz frequency range. However, the micro-bunching instability resulting from self-interaction of the bunch with its own radiation field limits stable operation with constant intensity of CSR emission to a particular threshold current. Above this threshold, the longitudinal charge distribution and thus the emitted radiation vary rapidly and continuously. Therefore, a fast and adaptive feedback system is the appropriate approach to stabilize the dynamics and to overcome the limitations given by the instability. In this contribution, we discuss first efforts towards a longitudinal feedback design that acts on the RF system of the KIT storage ring KARA (Karlsruhe Research Accelerator) and aims for stabilization of the emitted THz radiation. Our approach is based on methods of adaptive control that were developed in the field of reinforcement learning and have seen great success in other fields of research over the past decade. We motivate this particular approach and comment on different aspects of its implementation.

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MOPGW018

Perturbation of Synchrotron Motion in the Micro-Bunching Instability

electron, bunching, synchrotron, radiation

108

T. Boltz, M. Brosi, E. Bründermann, B. Härer, A.-S. Müller, P. Schreiber, P. Schönfeldt, M. Yan
KIT, Karlsruhe, Germany

Short electron bunches in a storage ring are subject to complex longitudinal dynamics due to self-interaction with their own CSR. Above a particular threshold current, this leads to the formation of dynamically changing micro-structures within the bunch, generally known as the micro-bunching instability. The longitudinal dynamics of this phenomenon can be simulated by solving the Vlasov-Fokker-Planck equation, where the CSR self-interaction can be added as a perturbation to the Hamiltonian. This contribution particularly focuses on the comprehension of synchrotron motion in the micro-bunching instability and how it relates to the formation of the occurring micro-structures. Therefore, we adopt the perspective of a single particle and comment on its implications for collective motion. We explicitly show how the shape of the parallel plates CSR wake potential breaks homogeneity in longitudinal phase space and propose a quadrupole-like mode as potential seeding mechanism of the micro-bunching instability. The gained insights are verified using the passive particle tracking method of the Vlasov-Fokker-Planck solver Inovesa.

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paper received ※ 15 May 2019 paper accepted ※ 18 May 2019 issue date ※ 21 June 2019

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MOPGW021

Symplectic Tracking for the Robinson Wiggler

wiggler, dynamic-aperture, electron, linear-dynamics

120

J. Li, J. Feikes, T. Mertens, Y. Petenev, M. Ries, A. Schälicke
HZB, Berlin, Germany

A Robinson wiggler (RW) is considered to be installed in the Metrology Light Source (MLS) to lengthen the bunch and improve the Touschek lifetime by manipulating the damping partitions. Symplectic tracking is crucial to study the impact of the nonlinear field components introduced by the Robinson wiggler. This paper introduces a tracking method based on an implicit symplectic integrator to solve the exact Hamiltonian equations of particle motion in the wiggler. In addition, a numerical generating function method is implemented as an approach to realize fast tracking.

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MOPGW024

Measurements of the GSI Transfer Beam Lines Ion Optics

quadrupole, extraction, experiment, emittance

131

M. Sapinski, O. Geithner, S. Reimann, P. Schütt, M. Vossberg, B. Walasek-Höhne
GSI, Darmstadt, Germany
C. Heßler
CERN, Meyrin, Switzerland

GSI High Energy Beam Transfer lines (HEST) link the SIS18 synchrotron with two storage rings (Experimental Storage Ring and Cryring) and six experimental caves. The recent upgrades to HEST beam instrumentation enables precise measurements of beam properties along the lines and allow for faster and more precise beams setup on targets. Preliminary results of some of the measurements performed during runs in 2018 and 2019 are presented here. The focus is on response matrix measurements and quadrupole scans performed on HADES beam line. The errors and future improvements are discussed.

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MOPGW029

Preliminary Study of Bunch Compression in the Hefei Light Source

lattice, radiation, electron, synchrotron-radiation

151

W. Li, Z.H. Bai, W. Li, J.G. Wang, D.R. Xu, Z. Zhao
USTC/NSRL, Hefei, Anhui, People’s Republic of China

Funding: This work was supported by the Fundamental Research Funds for the Central Universities (Grant No.WK2310000082 and WK2310000077), and the National Natural Science Foundation of China(GrantNo.11475167).
Short electron bunch has interesting applications in the synchrotron radiation light sources, such as the production of powerful coherent THz radiation, time resolving spectrum analysis, etc. In this work, we are interested in acquiring the short bunch in the storage ring with a small circumference like Hefei Light Source. In this paper, we tried to approach the short bunch in two separate methods: by increasing the higher harmonic cavity voltage and by reducing the momentum compaction factor. The preliminary result and observations are shown and discussed.

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MOPGW044

Off-Energy Off-Axis Injection with Pulsed Multipole Magnet Into the HALS Storage Ring

injection, kicker, lattice, multipole

187

G. Liu, Z.H. Bai, W. Li, L. Wang, P.N. Wang
USTC/NSRL, Hefei, Anhui, People’s Republic of China

As a future Diffraction-Limited Storage Ring (DLSR) at NSRL, the Hefei Advanced Light Source (HALS) has been proposed and has a great progress in the lattice optimization. The nonlinear dynamics is well designed and shows good performance, which makes it easier for beam injection and gives us more choices to design a more suitable injection scheme. In this paper, a new off-energy off-axis pulsed multipole injection scheme is proposed. The off-energy beam is off-axis injected into the acceptance of the storage ring with one or several pulsed multipole kickers and meanwhile the stored beam is almost unaffected during the injection. The injection acceptance of the storage ring is analyzed and the injection scheme is preliminary designed. A series of tracking simulations are carried out and the results are presented.

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MOPGW045

A Fast Method for Multi-Objective Nonlinear Dynamics Optimization of a Storage Ring

SRF, lattice, sextupole, dynamic-aperture

190

J.J. Tan, Z.H. Bai, W. Li, L. Wang, P.H. Yang
USTC/NSRL, Hefei, Anhui, People’s Republic of China

Multi-objective evolutionary algorithms (MOEAs), including multi-objective genetic algorithm and particle swarm optimization algorithm, have been widely applied in the nonlinear dynamics optimization of storage ring light sources. In the optimization, the direct tracking of objectives, which are, for example, dynamic aperture (DA) and momentum aperture, is very time-consuming. We noticed that there is some positive correlation between on- and off-momentum nonlinear dynamics performances, which can be used to reduce the computation time when applying MOEAs. In this paper, a fast method is proposed, in which a strategy is introduced to speed up the process of optimizing nonlinear dynamics using MOEAs. Taking the SSRF storage ring as an example, on- and off-momentum DAs are optimized using MOEAs with and without the fast strategy, and then a comparison is made to demonstrate the fast method.

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MOPGW048

Design Study of an Electron Storage Ring for the Future Plan of Hiroshima Synchrotron Radiation Center.

synchrotron, radiation, emittance, synchrotron-radiation

200

S. Matsuba, M. Katoh, K.S. Shimada
HSRC, Higashi-Hiroshima, Japan
K. Harada
KEK, Ibaraki, Japan
K. Kawase
QST, Tokai, Japan

Hiroshima synchrotron radiation center equips a 700 MeV electron storage ring nicknamed HiSOR. It has been operated for more than 20 years. The emittance of HiSOR is 400 nm, which is larger by one or more orders of magnitude than typical modern synchrotron light sources. Therefore, as the future plan of the facility, a new low emittance storage ring is desired. Several designs have been examined. In the newest version, we have selected the lattice structure similar to ASTRID 2 compact light source in Aarhus University, Denmark. The design goal is the energy of around 500 MeV, the circumference shorter than 50 m and the emittance smaller than 10 nm with straight sections for undulators more than 4. In this conference, we report the latest result from the design study.

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paper received ※ 01 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

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MOPGW058

Towards a Sextupole-Free Electron Storage Ring

electron, vacuum, impedance, feedback

217

T.-Y. Lee, T. Ha
PAL, Pohang, Kyungbuk, Republic of Korea

This paper studies if it is possible to build an electron storage ring with no or a small number of sextupole mag-nets. If it is possible, the electron storage ring will be great-ly simplified. For the purpose, two methods are presented in the paper to handle head-tail instability: One is to use dielectric vacuum chamber made of such materials as ceramic or glass to reduce broadband impedance signifi-cantly. Then head-tail instability would be extremely weak. The other method is to install a bunch-by-bunch feedback system to suppress the already weak head-tail instability due to the dielectric vacuum chamber.

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MOPGW066

Local Impedance Measurements Using the Orbit Bump Method at ALBA

impedance, betatron, simulation, vacuum

240

Z. Martí, G. Benedetti, T.F.G. Günzel, U. Iriso
ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain

The orbit bump technique has been used at the ALBA Storage Ring to characterize with good precision the impedance of single machine elements, like the in-vacuum undulators or the CLIC stripline kicker. The results are compared with theoretical studies, as well as impedance measurements done at ALBA using other methods like the turn by turn betatron phase or from the analysis of the detuning slopes of the Transverse Mode Coupling Instability.

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MOPGW096

Beam Dynamics in MBA Lattices with Different Chromaticity Correction Schemes

lattice, sextupole, emittance, betatron

346

L. Hoummi, J. Resta-López, C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom
L. Hoummi, J. Resta-López, C.P. Welsch
The University of Liverpool, Liverpool, United Kingdom
A. Loulergue, R. Nagaoka
SOLEIL, Gif-sur-Yvette, France

Ultra-low emittance lattices are being studied for the future upgrade of the 2.75 GeV SOLEIL storage ring. The candidate baseline lattice was inspired by the ESRF-EBS-type Multi-Bend-Achromat (MBA) lattice, introducing a (-I) transformation to compensate the nonlinear impact of sextupoles thanks to the lattice symmetry and tight control of the betatron phase advance between sextupoles. Whilst the final performance is still being optimized, other types of lattices are being considered for SOLEIL: This includes the so-called High-Order Achromat (HOA) lattice. Though the (-I) scheme provides a large on-momentum transverse dynamic aperture in 4D, its off-momentum performance is rather limited. 6D studies reveal intrinsic off-momentum transverse oscillations which are likely to result from a nonlinear increase in path length. This contribution presents the effects from the inhomogeneous sextupole distribution in the (-I) scheme and compares them with the HOA lattice.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW096

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paper received ※ 15 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

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MOPGW098

Iterative Trajectory-Correction Scheme for the Early Commissioning of Diffraction-Limited Light Sources

MMI, lattice, feedback, simulation

353

Ph. Amstutz, T. Hellert
LBNL, Berkeley, USA

The commissioning of diffraction-limited light sources will be significantly affected by the fact that typical lattice designs rely on very strong focussing elements in order to achieve the small emittance goals. Especially in the early-commissioning phase this can render procedures successfully used in the commissioning of existing third-generation light sources ill-suited for the application to these new machines. In this contribution we discuss an iterative approach to the early trajectory correction, based on the well-known pseudo-inversion of a trajectory-response matrix. Measuring this matrix during early commissioning can be cumbersome, so that an algorithm working with the model response matrix of the lattice is desirable. We discuss the stability of the iteration in the presence of lattice errors, resulting in differences between the actual and the model response matrix. Further, Tikhonov regularization is investigated as a means to trade off the RMS trajectory variation against the strength of the required corrector kicks.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW098

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paper received ※ 14 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

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MOPGW104

Equilibria and Synchrotron Stability in Two Energy Storage Rings

electron, damping, simulation, focusing

364

B. Dhital, J.R. Delayen, G.A. Krafft
ODU, Norfolk, Virginia, USA
J.R. Delayen, Y.S. Derbenev, D. Douglas, G.A. Krafft, F. Lin, V.S. Morozov, Y. Zhang
JLab, Newport News, Virginia, USA

In a dual energy storage ring, the electron beam passes through two loops at markedly different energies E_L, and E_H, i.e., energies for low energy loop and high energy loop respectively. These loops use a common beamline where a superconducting linac at first accelerates the beam from EL to EH and then decelerates the beam from EH to EL in the next pass. There are two basic solutions to the equilibrium problems possible, i.e., ’Storage Ring’ (SR) equilibrium and ’Energy Recovery Linac’ (ERL) equilibrium. SR equilibrium mode more resembles the usual single loop storage ring with strong synchrotron motion and ERL equilibrium mode is the case where RF in two beam passes nearly cancels. Calculations based on linear transfer matrix formalism show that longitudinal stability exists for both SR mode and ERL mode in two energy storage rings.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW104

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paper received ※ 14 May 2019 paper accepted ※ 18 May 2019 issue date ※ 21 June 2019

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MOPGW110

Study of the Beam Current Effects on the NSLS-II Storage Ring Optics Using Turn-by-Turn Data

lattice, optics, dipole, operation

375

J. Choi, Y. Hidaka
BNL, Upton, Long Island, New York, USA

These days, the techniques using the turn-by-turn data are well developed in analyzing the accelerator optics. We compared the data for the low and high beam currents and studied the beam current effects on the storage ring lattice optics. Also, by comparing the local transfer matrices, we analyzed the amounts of the impacts on the linear optics around the ring.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW110

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paper received ※ 15 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

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MOPGW122

Beam-based Measurement of Broadband Longitudinal Impedance at NSLS-II

impedance, vacuum, simulation, diagnostics

400

V.V. Smaluk, B. Bacha, G. Bassi, A. Blednykh
BNL, Upton, Long Island, New York, USA

Funding: Department of Energy Contract No. DE-SC0012704
Interaction of a particle beam with the vacuum chamber impedance is one of the main effects limiting the beam intensity in accelerators. Minimization of the impedance is an essential part of the vacuum chamber design for any new accelerator project. The impedance can be estimated experimentally by measuring beam dynamics effects caused by the beam-impedance interaction. Experience obtained at many accelerator facilities shows the beam-based measurements are often different from the pre-computed impedance budgets, the discrepancy of a factor of two or even more is not unusual. The measurements of broadband longitudinal impedance carried out at NSLS-II are discussed in comparison with the numerically simulated impedance budget.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW122

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paper received ※ 15 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

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MOPGW125

Lossless Crossing of 1/2 Resonance Stopband by Synchrotron Oscillations

resonance, experiment, lattice, betatron

410

G.M. Wang, Y. Li, J. Rose, T.V. Shaftan, V.V. Smaluk
BNL, Upton, Long Island, New York, USA

Funding: DOE under contract No.DE-AC02- 98CH10886
Modern high performance circular accelerators require sophisticated corrections of nonlinear lattices. The beam betatron tune footprint may cross many resonances, reducing dynamic aperture and causing particle loss. However, if particles cross a resonance reasonably fast, the beam deterioration may be minimized. In this paper, we present the experiments with the beam passing through a half-integer resonance stopband via chromatic tune modulation by exciting synchrotron oscillations. This is the first time that beam dynamics have been kept under precise control while the beam crosses a half-integer resonance. Our results convincingly demonstrate that particles can cross the half-integer resonance without being lost if the passage is reasonably fast and the resonance stopband is sufficiently narrow.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW125

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paper received ※ 13 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

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MOPRB005

Study of Higher-Order Achromat Lattice as an Alternative Option for the SOLEIL Storage Ring Upgrade

lattice, sextupole, octupole, injection

586

R. Nagaoka, A. Bence, P. Brunelle, L. Hoummi, A. Loulergue, A. Nadji, L.S. Nadolski, M.-A. Tordeux, A. Vivoli
SOLEIL, Gif-sur-Yvette, France
A. Gamelin
LAL, Orsay, France

A ring composed of 20 symmetrical 7BA cells in which of a pair of chromaticity correcting sextupoles placed around horizontal dispersion bumps à la ESRF-EBS was developed as a baseline lattice for the SOLEIL storage ring upgrade (presented at IPAC2018). The strict phase relation between the two dispersion bumps provides an efficient way of optimizing the (on-momentum) nonlinear optics with a limited number of sextupoles. As an alternative, a scheme known as Higher-Order Achromat (HOA) develops a MBA (Multi-Bend Achromat) lattice where chromaticity correcting sextupoles are distributed in each M unit cell with a strict phase relation cell-wise such as to cancel basic geometric and chromatic resonance driving terms. The beam dynamics in a 20-fold 7BA HOA ring is compared with those of the baseline lattice, with focus on off-momentum properties such as Touschek lifetime, which are important for medium energy rings like SOLEIL. The robustness against errors, the reduction of the ring symmetry by introducing 4 longer straight sections, as well as a horizontal dispersion bump to cope with longitudinal on-axis injection scheme are also presented.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB005

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paper received ※ 22 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

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MOPRB027

Progress of HEPS Accelerator System Design

cavity, booster, vacuum, lattice

633

P. He, J.S. Cao, F.S. Chen, J. Chen, H. Dong, D.Y. He, Y. Jiao, W. Kang, C.H. Li, J.Y. Li, F. Long, H.H. Lu, X. Qi, Q. Qin, H. Qu, J.Q. Wang, G. Xu, J.H. Yue, J. Zhang, J.R. Zhang, P. Zhang
IHEP, Beijing, People’s Republic of China

The 4th generation ring-based light sources, HEPS (High Energy Photon Source) 7BA lattice has been de-veloped at IHEP. This is 6Gev, 200mA machine which has horizontal emittance Ɛh around 60pm.rad to gain the high brilliance photon beam. this compact lattice design bring so many engineering challenges for accelerator magnets, vacuum components, beam diagnotice, etc. This paper will present the noval lattice design and subsystem design progress.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB027

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paper received ※ 14 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

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MOPRB092

Symplectic and Exact Tracking of Low Energy 197Au⁷⁸⁺ in the Relativistic Heavy Ion Collider

electron, quadrupole, simulation, lattice

791

Y. Luo, W. Fischer, F. Méot, G. Robert-Demolaize
BNL, Upton, Long Island, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
In the coming RHIC low energy scan, the electron cooling technique is to be used to cool the ions 197Au⁷⁹⁺ with its energy range between 3.85~GeV/nucleon to 5.75~GeV/nucleon. To overlap the electron beam and the 197Au⁷⁹⁺ beam at the cooling section, a recombination monitor is to be used to detect the maximum flux of 197Au⁷⁸⁺ ions generated in the cooling section. In the previous studies, we tracked 197Au⁷⁸⁺ ions through the RHIC lattice defined with 197Au⁷⁹⁺ with an equivalent momentum deviation. In the article, we explode different symplectic ways to track 197Au⁷⁸⁺ ions exactly. We calculate and compare the trajectories and loss map of 197Au⁷⁸⁺ ions through the RHIC ring.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB092

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paper received ※ 14 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

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MOPRB093

eRHIC Electron Ring Design Status

polarization, electron, solenoid, radiation

794

C. Montag, M. Blaskiewicz, C. Hetzel, D. Holmes, Y. Li, H. Lovelace III, V. Ptitsyn, K.S. Smith, S. Tepikian, F.J. Willeke, H. Witte, W. Xu
BNL, Upton, Long Island, New York, USA
E. Gianfelice-Wendt
Fermilab, Batavia, Illinois, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
For the proposed electron-ion collider eRHIC, an electron storage ring will be installed in the existing RHIC tunnel. To reach the high luminosity of up to 10³⁴ cm^-2 sec^-1, beam currents up to 2.5A have to be stored. Besides high luminosity the physics program requires spin polarization levels of 70 percent, with both spin "up" and spin "down" orientations present in the fill. This is only feasible by using a full-energy spin polarized injector that replaces bunches faster than the depolarization rate. To limit the repetition rate of that injector to about one hertz, the polarization lifetime in the storage ring has to be maximized by proper spin matching and countermeasures for the machine misalignments. We will give an overview of the electron storage ring design.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB093

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paper received ※ 13 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019

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MOPRB104

A Parameter Study for Improving the Performance of the Production Target for the Fermilab Muon g-2 Experiment

target, simulation, experiment, proton

806

D. Stratakis
Fermilab, Batavia, Illinois, USA

The target station of the Muon g-2 Experiment is one of the central pieces for the production of secondary pions which eventually will decay to the desired mu-ons. In this paper, we report adjustments made to opti-mize its performance. For instance, in the simulation we vary the size of the primary incoming beam and examine its impact on the downstream production. We then compare this with the actual measured beam size upstream of the target. In addition, we examine the sensitivity in performance with the strength of the lithium lens for pion capture and the distance between lens and target. We compare measured data with simu-lation results.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB104

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paper received ※ 13 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

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MOPTS004

2nd Order Optics Symmetrisation through Off-Energy Orbit Response Matrix Analysis

sextupole, optics, lattice, alignment

841

D.K. Olsson, Å. Andersson, M. Sjöström
MAX IV Laboratory, Lund University, Lund, Sweden

The MAX IV 3 GeV storage ring lattice contains several strong sextupoles. In order to achieve nominal lattice performance it is important to be able to characterise and correct the higher order magnets and optics of the lattice. This has been done through the analysis of the Off-Energy Response Matrix (OEORM). Its approximate linearity in sextupole strength has been utilised to identify sextupole errors, as well as symmetrise the 2nd order optics. The symmetrisation was able to correct chromaticity, and increase horizontal acceptance by 50 %, compared to magnet settings based solely on rotating coil measurements. An approximate decrease of 10 % in vertical acceptance was detected. This work was inspired by similar investigations at ESRF.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS004

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paper received ※ 13 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

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MOPTS011

Spin Motion Perturbation Effect on the EDM Statistic in the Frequency Domain Method

betatron, polarization, dipole, lattice

861

A.E. Aksentyev
FZJ, Jülich, Germany
A.E. Aksentyev
MEPhI, Moscow, Russia
A.E. Aksentyev, V. Senichev
RAS/INR, Moscow, Russia

The spin precession axis of a particle involved in betatron motion precesses about the invariant spin axis defined on the closed orbit (CO). This precession can be observed in polarization data as a rapid, small-amplitude oscillation on top of the major effect oscillation caused by the precession of spin about the CO axis. The frequency of this latter oscillation is used in the Frequency Domain (FD) methodology as the EDM observable. [*] It is estimated by fitting polarimetry data by a sine function; the rapid oscillations, therefore, constitute a model specification error. This model error might introduce a bias into the frequency estimate. In the present work we investigate the effect of the spin precession axis motion on measurement data and fit quality, and conclude that it is not only insignificant (with regard to data perturbation) compared to spin tune variation, but is also controllable via the application of a Spin Wheel.
[*] Senichev Y, Aksentev A, Ivanov A, Valetov E. Frequency domain method of the search for the deuteron electric dipole moment in a storage ring with imperfections. arXiv:171106512. 2017 Nov 17

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS011

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paper received ※ 08 April 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

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MOPTS012

Spin Decoherence in the Frozen Spin Storage Ring Method of Search for a Particle EDM

sextupole, lattice, simulation, betatron

864

A.E. Aksentyev
FZJ, Jülich, Germany
A.E. Aksentyev
MEPhI, Moscow, Russia
A.E. Aksentyev, V. Senichev
RAS/INR, Moscow, Russia

Spin coherence refers to a measure of preservation of polarization in an initially polarized beam. The spin vector of a particle injected into a storage ring starts to precess about the vertical magnetic field vector in accordance with the Thomas-BMT equation. The precession frequency is dependent on the equilibrium-level energy, which differs across the beam particles. This does not pose a problem when the initial polarization is vertical; however, the Frozen Spin Storage Ring EDM search method [*] requires beam polarization along the momentum vector, i.e., in the horizontal plane. In the present work we analyze the source of decoherence, and investigate the way it can be suppressed in the horizontal plane in a perfectly aligned ring by means of sextupole fields. We also consider the case of an imperfect ring: transference of decoherence into the vertical plane induced by vertical plane spin precession, and the effect of sextupole fields.
* D. Anastassopoulos et al. AGS Proposal: Search for a permanent electric dipole moment of the deuteron nucleus at the 10 −29 e · cm level. BNL report, 2008.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS012

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paper received ※ 08 April 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

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MOPTS028

Search for Electric Dipole Moments at Cosy in Jülich - Spin-Tracking Simulations Using Bmad

simulation, dipole, experiment, alignment

914

V. Poncza, A. Lehrach
FZJ, Jülich, Germany
A. Lehrach, V. Poncza
RWTH, Aachen, Germany

The observed matter-antimatter asymmetry in the universe cannot be explained by the Standard Model (SM) of particle physics. In order to resolve the matter dominance an additional CP violating phenomenon is needed. A candidate for physics beyond the SM is a non-vanishing Electric Dipole Moment (EDM) of subatomic particles. Since permanent EDMs violate parity and time reversal symmetries, they are also CP violating if the CPT -theorem is assumed. The JEDI (Jülich Electric Dipole moment Investigations) collaboration in Jülich is preparing a direct EDM measurement of protons and deuterons first at the storage ring COSY (COoler SYnchrotron) and later at a dedicated storage ring. In order to analyse the data and to disentangle the EDM signal from systematic effects spin tracking simulations are needed. Therefore a model of COSY was implemented using the software library Bmad. It includes the measured magnet misalignments of the latest survey and a simplified description of the RF-Wien Filter device that is used for the EDM measurement. The model was successfully benchmarked using analytical predictions of the spin behavior. A crucial point regarding the data analysis is the knowledge of the orientation of the invariant spin axis with vanishing EDM at the position of the RF-Wien Filter. Especially its radial component is unknown and spin tracking simulations can be used to determine this missing number. Tracking results as well as the algorithm to find the invariant spin axis will be presented.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS028

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paper received ※ 25 April 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

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MOPTS038

BEAM DYNAMICS OF HIGH CHROMATICITY LATTICE FOR IRANIAN LIGHT SOURCE FACILITY (ILSF) STORAGE RING

lattice, dynamic-aperture, resonance, optics

943

F. Foroughi, S.M. Jazayeri
IUST, Narmac, Tehran, Iran
E. Ahmadi, S. Dastan, J. Rahighi
ILSF, Tehran, Iran

One of the limiting factors of electron beam lifetime in low emittance storage rings is Head-Tail (HT) insta-bility. Low emittance storage rings typically have a large negative natural chromaticity due to the strong quadru-poles. Above transition large negative natural chroma-ticity leads to large Head-Tail instability which limit the beam lifetime. Since the threshold current of HT insta-bility is directly related to linear chromaticity, increasing the linear chromaticity to slightly positive value is a solution to prevent HT instability. In this paper we in-creased the chromaticity of Iranian Light Source Facility (ILSF) to (+4, +4) and we will investigate the beam dy-namics of ILSF 3GeV storage ring in high chromaticity. For reaching this aim we have used two families of sex-tupoles for chromaticity correction and then optimized them to maximize the dynamic aperture and Touschek lifetime. The beam dynamics of high chromaticity lattice is presented in this paper.
Foroughi.farangis@gmail.com

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS038

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paper received ※ 29 April 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

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MOPTS079

Design of 1.5 GeV Compact Storage Ring for the EUV and Soft X-rays

quadrupole, synchrotron, resonance, focusing

1028

J.Y. Lee, I.G. Jeong
Korea Atomic Energy Research Institute (KAERI), Daejeon, Republic of Korea
P. Buaphad, Y.J. Joo, H.R. Lee
University of Science and Technology of Korea (UST), Daejeon, Republic of Korea
P. Buaphad, Y.J. Joo, Y. Kim, H.R. Lee, S. Lee
KAERI, Jeongeup-si, Republic of Korea

Recently, there has been discussions about the need for the next-generation synchrotron light source facility in Korea. The facility in consideration is composed of a super-conducting linear accelerator for the injector, a storage ring for the EUV and soft X-rays, and a main storage ring for hard X-rays. In this study, design concepts of the soft X-ray storage ring is presented. To effectively utilize the small space allocated for the soft X-ray storage ring, a compact storage ring is taken into account. The compact storage ring is a synchrotron accelerator of which diameter is shorter than the length of injector beamline. In this paper, we report design concepts and optimization of the compact storage ring for the EUV and soft X-ray users. The lattice of the storage ring is modelled by utilizing ELEGANT simulation code to optimize beam parameters and performance of the ring.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS079

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paper received ※ 24 May 2019 paper accepted ※ 24 May 2019 issue date ※ 21 June 2019

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MOPTS113

Sensitivity Analyses of All-Electric Storage Ring Designs

alignment, closed-orbit, proton, FEM

1148

M.J. Syphers, A. Narayanan
Northern Illinois University, DeKalb, Illinois, USA

Funding: This work supported by the National Science Foundation Grant 1623691.
Future searches of electric dipole moments (EDMs) of fundamental particles can require electrostatic storage rings operating at the particle’s "magic momentum" whereby spin precessions out of the plane of the particle motion would be governed in principle only by the presence of an EDM. An EDM search for the proton, for example, requires a momentum of approximately 700 MeV/c and thus implies a half-kilometer circumference, where relatively modest electric fields are assumed. As no all-electric ring on this scale has been constructed before, the ability to produce precise radial fields for establishing a central orbit and precise electrostatic focusing fields about that orbit requires attention. Results of initial investigations into the feasibility of designing a proper system and the sensitivities of such a system to placement, mis-powering errors and other requirements on realistic electrostatic elements will be presented.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS113

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paper received ※ 09 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

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MOPTS119

APS LINAC Interleaving Operation

linac, gun, operation, booster

1161

Y. Sun, K. Belcher, J.C. Dooling, A. Goel, A.L. Hillman, R.T. Keane, A.F. Pietryla, H. Shang, A. Zholents
ANL, Argonne, Illinois, USA

Funding: Work supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02- 06CH11357.
Three s-band RF guns are installed at the front end of the Advanced Photon Source (APS) linac: two thermionic cathode guns (RG2 and RG1), and one Photo-Cathode Gun (PCG). During normal operations, RG2 provides electron beams for the storage ring to generate x-rays for APS users. The PCG generates high brightness electron beams that can be accelerated through the APS linac and transported into the Linac Extension Area (LEA) for advanced accelerator technology and beam physics experiments. The alternating acceleration of the RG2 and PCG beam in the linac is possible, as most of the time, RG2 beam is only needed for ~20 seconds every two minutes. This mode of interleaving operation of RG2 and PCG beams through the APS linac requires some modifications/additions to several systems of the linac, including RF, magnets, controls and Access Control Interlock System etc. In this paper we report our interleaving design and present the commissioning results of the two beam interleaving operation.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS119

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paper received ※ 14 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019

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TUYPLM3

Status of the MAX IV Accelerators

electron, sextupole, linac, vacuum

1185

P.F. Tavares, E. Al-Dmour, Å. Andersson, J. Breunlin, F.J. Cullinan, E. Mansten, S. Molloy, D.K. Olsson, D. Olsson, M. Sjöström, S. Thorin
MAX IV Laboratory, Lund University, Lund, Sweden

The MAX IV facility in Lund, Sweden, consists of three electron accelerators and their respective synchrotron radiation beamlines: a 3 GeV ring, which is the first implementation worldwide of a multi-bend achromat lattice, a 1.5 GeV ring optimized for soft X-Rays and UV radiation production and a 3 GeV linear accelerator that acts as a full-energy injector into both rings and provides electron pulses as short as 100 fs that produce X-rays by spontaneous emission in the undulators of the short-pulse facility (SPF). In this paper, we review the latest achieved accelerator performance and operational results.

Slides TUYPLM3 [9.108 MB]

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paper received ※ 15 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

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TUZPLS2

Beam Dynamics Study in the HEPS Storage Ring

lattice, emittance, photon, brightness

1203

Y. Jiao, X. Cui, Z. Duan, Y.Y. Guo, P. He, X.Y. Huang, D. Ji, H.F. Ji, C. Li, J.Y. Li, X.Y. Li, C. Meng, Y.M. Peng, Q. Qin, S.K. Tian, J.Q. Wang, N. Wang, Y. Wei, G. Xu, H.S. Xu, F. Yan, C.H. Yu, Y.L. Zhao
IHEP, Beijing, People’s Republic of China

The High Energy Photon Source (HEPS) is the first high-energy diffraction-limited storage ring (DLSR) light source to be built in China, with a natural emittance of a few tens of pm rad and a circumference of 1360.4 m. After 10 years’ evolution, the accelerator physics design of the HEPS has been basically determined, with the ring consisting of 48 hybrid-7BAs with anti-bends and super-bends. This paper will discuss the accelerator physics studies of the HEPS storage ring, covering issues of lattice design, nonlinear optimization, collective effects, error correction, insertion devices, etc.

Slides TUZPLS2 [9.517 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUZPLS2

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TUZZPLS2

Beam Dynamics, Injection and Impedance Studies for the Proposed Single Pulsed Nonlinear Injection Kicker at the Australian Synchrotron

impedance, injection, kicker, synchrotron

1219

R. Auchettl, R.T. Dowd, Y.E. Tan
AS - ANSTO, Clayton, Australia

The Australian Synchrotron are currently investigating the use of a single pulsed nonlinear injection kicker (NLK) to free floor space within the ring for future beamline development. The NLK has a zero and flat magnetic field at the stored beam to leave the stored beam undisturbed but has a maximum field off-axis where the injected beam is located. After the kick, the injected beam is stored. While NLKs have been prototyped at many facilities around the world, injection efficiency and heat loading have been the main impediment to deployment of the NLK. The wakefields that pass through the ceramic chamber aperture can cause severe heat loading and impedance. Despite achieving impressive injection efficiencies, a previous prototype at BESSY II * showed that strong interactions of the stored beam resulted in high heat load causing the thin 5µm Titanium coated ceramic chamber to reach temperatures > 500 °C and fail. To avoid beam induced heat loads, this paper presents studies of the wake impedance and thermal behaviour for our proposed NLK design. Injection simulations and future considerations for installation and operation at the Australian Synchrotron will be discussed.
* T. Atkinson et al., "Development of a non-linear kicker system to facilitate a new injection scheme for the Bessy II storage ring", in Proc. IPAC’11, 2011, THPO024, pp. 3394-3396.

Slides TUZZPLS2 [1.588 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUZZPLS2

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paper received ※ 15 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

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TUPMP011

Storageless Resonant Converter for Accelerator Magnets

operation, resonance, controls, simulation

1248

M. Cautero, T.N. Gucin
Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy

Elettra Sincrotrone Trieste, a specialized research centre generating high quality synchrotron radiation, has been in operation since 1993 and was revised in 2009. Recently, Elettra has been funded for a complete renewal of the storage ring. For the new machine, it is planned to employ state of the art converters, mostly of which will be designed in-house. For this purpose, it has been decided to evaluate the performance of a storage-less resonant converter, pro-posed by Dr. Slobodan Ćuk, which is a step down DC/DC converter consisting of four switches, one resonant capac-itor and two resonant inductors. For this purpose, the voltage conversion ratio of the converter has been de-rived. The topology was confirmed with simulation and a PCB layout has been designed, which is still to be tested.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPMP011

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paper received ※ 08 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

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TUPMP046

Improvement the Bending Magnet Power Supply Performance for TPS Storage Ring

power-supply, feedback, controls, photon

1353

B.S. Wang, C.H. Huang, J.C. Huang, C.Y. Liu, K.-B. Liu, Y.S. Wong
NSRRC, Hsinchu, Taiwan

In the TPS (Taiwan Photon Source) facility, current stability of the electron beam depends on the bending magnet power supply and an orbit FOFB system to compensate the magnetic field. Due to the output current stability of the bending magnet power supply drifts with temperature so the orbit FOFB system should be applied to fine tune magnetic field and the photon beam should circulate in storage ring. In this paper, to stabilize the temperature of regulation circuit’s temperature box of the bending magnet power supply, the long-term output current stability is improve from ± 50ppm to ± 10ppm, and orbit FOFB system substantially reduce the tune X of beam position, effectively increasing the beam current stability and quality.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPMP046

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paper received ※ 12 April 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

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TUPMP050

Conceptual Design of the Diamond-II Vacuum System

vacuum, photon, target, controls

1362

M.P. Cox, C. Burrows, A.G. Day, J.A. Dymoke-Bradshaw, R.K. Grant, N.P. Hammond, X. Liu, A.G. Miller, H.S. Shiers, N. Warner
DLS, Oxfordshire, United Kingdom

The conceptual design of the vacuum system for the Diamond-II storage ring upgrade is described. Due to the small vessel cross section, typically 20 mm inside diameter (ID), and the consequent conductance limitation, distributed pumping is provided by non-evaporable getter (NEG) coating supplemented by ion pumps at high gas load locations. In-situ bakeout is incorporated to allow rapid recovery from both planned vacuum interventions and unplanned vacuum events. The vacuum vessels are constructed mainly from copper alloy while stainless steel is used in regions of AC magnets requiring low electrical conductivity. The proposed layout, engineering and build sequence of the vacuum system are described along with gas flow simulations confirming the vacuum performance advantages of NEG-coated vessels compared with uncoated vessels.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPMP050

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paper received ※ 14 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

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TUPGW003

Sirius Status Update

booster, vacuum, alignment, controls

1381

A.R.D. Rodrigues, F.C. Arroyo, J.F. Citadini, R.H.A. Farias, J.G.R.S. Franco, R. Junqueira Leão, L. Liu, S.R. Marques, R.T. Neuenschwander, C. Rodrigues, F. Rodrigues, R.M. Seraphim, O.H.V. Silva, F.H. de Sá
LNLS, Campinas, Brazil

Sirius is a 4th generation 3 GeV low emittance electron storage ring that is in its final installation phase at the Brazilian Center for Research in Energy and Materials (CNPEM) campus in Campinas, Brazil. Presently the injector installation is complete, and the storage ring installation is being finalized. Most subsystems are under test and tuning in real working conditions. Six beamlines are also under construction. In this paper we report on the Sirius main subsystems installation status.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW003

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paper received ※ 15 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

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TUPGW005

Preparation of the EBS Beam Commissioning

SRF, MMI, controls, injection

1388

S.M. Liuzzo, N. Carmignani, A. Franchi, T.P. Perron, K.B. Scheidt, E.T. Taurel, L. Torino, S.M. White
ESRF, Grenoble, France

In 2020 the ESRF storage ring will be upgraded to a Hybrid Multi Bend Achromat (HMBA) lattice. The commissioning of the new ring will require dedicated tools, either updated from the existing ones or newly developed. Most of the software and procedures were tested on the existing storage ring before its decommissioning. In particular we present experiments on first-turn steering and beam accumulation, check of magnet polarity and calibration, and injection tuning. The use of a control-system simulator proved to be crucial for the debugging of the software and the development of the new control system, as far as beam measurements and manipulations are concerned.

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paper received ※ 26 April 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

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TUPGW017

Superconducting Undulator Coils with Period Length Doubling

undulator, vacuum, FEM, operation

1426

S. Casalbuoni, N. Glamann, A.W. Grau, T. Holubek, D. Saez de Jauregui
KIT, Eggenstein-Leopoldshafen, Germany

Funding: Work supported by the German government in the BMBF-project Superconducting ’Insertion Device Technologies for Ultra-Low-Emittance Light Sources’ (05K12CK1)
Only since few years it has been demonstrated experimentally that NbTi based superconducting undulators (SCUs) have a higher peak field on axis for the same gap and period length in operation with electron beam with respect to permanent magnet undulators (even the ones in vacuum and cooled to cryogenic temperatures). Another advantage of NbTi based SCUs with respect to permanent magnet devices is radiation hardness, widely demonstrated for NbTi magnets, which is and will become an increasingly important issue with the small gaps in the newest machines as round beam storage rings and FELs. Moreover, SCU technology allows switching of the period length by changing the current direction in one of separately powered subset of winding packages of the superconducting coils. This feature further broadens the energy range of the emitted photons, required by the different beamlines. To this end 0.5 m long superconducting undulator coils with switchable period length between 17 mm and 34 mm have been developed. In this contribution we describe the design and report on the quench tests, as well as on the magnetic field measurements.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW017

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paper received ※ 25 April 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

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TUPGW018

PETRA IV Study with Non-Interleaved Sextupole Scheme

sextupole, lattice, emittance, optics

1430

H.C. Chao, R. Brinkmann, X.N. Gavaldà
DESY, Hamburg, Germany

This study is an attempt to design PETRA IV storage ring, which is an upgrade from PETRA III toward diffraction-limit synchrotron light source, based on the non-interleaved sextupole scheme. The lattice is constructed by mixing different types of cells. There are two basic building blocks. The double minus identity (DMI) cell dedicated for the chromaticity correction with non-interleaved sextupoles is tightly built up, while the combined function FODO cell with dispersion suppressors provides straights with small beta functions ideally for undulators. In addition, the hybrid section including a 10-m long super insertion device (ID) is custom-made to adapt to DESY’s current site plan. The beam dynamic behaviors are simulated and discussed.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW018

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paper received ※ 18 April 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

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TUPGW020

Non-Linear Features of the cSTART Project

quadrupole, sextupole, lattice, injection

1437

B. Härer, E. Bründermann, A.B. Kaiser, A.-S. Müller, A.I. Papash, R. Ruprecht, J.M. Schaefer, M. Schuh
KIT, Karlsruhe, Germany

The compact storage ring for accelerator research and technology (cSTART) is being designed and will be realized at the Institute for Beam Physics and Technology (IBPT) of the Karlsruhe Institute of Technology (KIT). One important goal of the project is to demonstrate injection and storage of a laser wakefield accelerator (LWFA) beam in a storage ring. As a first stage the compact linear accelerator FLUTE will serve as an injector of 50 MeV bunches to test the ring’s performance. A highly non-linear lattice of DBA-FDF type was studied extensively. The specific features of ring optics are reported. A special transfer line from FLUTE to cSTART including bunch compressor and non-linear elements is presented that maintains the ultra-short bunch length of FLUTE.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW020

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paper received ※ 13 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

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TUPGW024

Pulse Shaping Methods for Laser-Induced Generation of THz Radiation at the Delta Storage Ring

laser, radiation, electron, experiment

1453

C. Mai, B. Büsing, A. Glaßl, S. Khan, D. Krieg, A. Meyer auf der Heide
DELTA, Dortmund, Germany

At DELTA, a 1.5-GeV electron storage ring operated as a synchrotron light source by the TU Dortmund University, a dedicated beamline is used for experiments with (sub-)THz radiation. Here, an interaction of short laser pulses with electron bunches to give rise to coherently emitted broadband as well as tunable narrowband radiation from 75 GHz to 5.6 THz. For the narrowband operation of the source, a laser pulse with periodic intensity modulation is used. An interferometric approach, the chirped-pulse beating technique, is routinely employed for this purpose. Recently, pulse shaping techniques using spatial light modulators are investigated to gain more flexible control of the laser pulse shape and the spectrotemporal properties of the resulting THz pulses.

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paper received ※ 15 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019

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TUPGW035

A Highly Brilliant Compact 3 GeV Light Source Project in Japan

emittance, cavity, injection, linac

1478

N. Nishimori
National Institutes for Quantum and Radiological Science and Technology (QST), Sayo-cho, Japan
H. Tanaka
RIKEN SPring-8 Center, Hyogo, Japan
T. Watanabe
JASRI/SPring-8, Hyogo, Japan

A highly brilliant compact 3 GeV light source project was proposed in Japan. The light source would be constructed in Sendai, north-east part of Japan. It provides brilliant soft X-ray beam to widely cover wavelengths ranging from EUV to hard X-ray in Japan together with SPring-8. The accelerator system is now mostly designed except for several linac components and so on. We have chosen a 4-bend achromat lattice to achieve a low emittance keeping a small circumference with a rather relaxed space issue. The number of cells is 16 and the ring circumference is about 350 m. Number of available beam lines are 26 including short straight sections for multi-pole wigglers. Horizontal emittance is expected to be around 1.1 nmrad, and the maximum brilliance may exceed 10²¹ at 1 - 3 keV region with a stored current of 400 mA. The designs of many components such as vacuum chambers, magnets and monitors are employed from those studied for SPring-8 upgrade project. A full energy injector linac equipped with a thermionic gun and C-band accelerating structures is employed to produce sufficiently low emittance beams for efficient beam injections. The C-band system is adopted from those developed for XFEL SACLA with some modifications. In the future, the injector would be upgraded as an electron driver for SXFEL. Details of the project and accelerator system will be presented.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW035

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paper received ※ 14 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

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TUPGW040

Study of Seven-Bend Achromat Lattices with Interleaved Dispersion Bumps for HALS

lattice, emittance, octupole, linear-dynamics

1495

Z.H. Bai, W. Li, G. Liu, L. Wang, D.R. Xu, T. Zhang
USTC/NSRL, Hefei, Anhui, People’s Republic of China

Previously, we proposed a multi-bend achromat (MBA) lattice concept, called the MBA with interleav-ed dispersion bumps, which was then used to design a 7BA lattice for the Hefei Advanced Light Source (HALS) storage ring. Recently, such a 7BA lattice was further designed and optimized for the HALS by changing the number of lattice cells, scanning working point and employing octupoles. And two new HALS designs with such 7BA lattices have been made, one with 30 lattice cells and a natural emittance of 25 pm·rad and the other with 28 cells and 33 pm·rad. They had much better nonlinear dynamics perfor-mances than the previous design. The detailed study for these two HALS lattices will be presented in this paper.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW040

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paper received ※ 15 May 2019 paper accepted ※ 18 May 2019 issue date ※ 21 June 2019

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TUPGW041

Super-Period Locally Symmetric Lattices for Designing Diffraction-Limited Storage Rings

lattice, emittance, sextupole, quadrupole

1498

Z.H. Bai, W. Li, G. Liu, L. Wang
USTC/NSRL, Hefei, Anhui, People’s Republic of China
Y. Li
BNL, Upton, Long Island, New York, USA

To achieve better nonlinear dynamics performance for a diffraction-limited storage ring, previously we proposed a locally symmetric multi-bend-achromat (MBA) lattice concept, where beta functions are locally symmetric about two mirror planes of each lattice cell. To have both high-beta long straight sections for beam injection and low-beta ones for higher brightness of insertion device radiation, many storage ring light sources use super-period lattices. The locally symmetric MBA lattice can be naturally extended to the super-period case. In the super-period locally symmetric (SP-LS) lattice, many nonlinear dynamics effects can be effectively cancelled out within one super-period lattice cell, and also there are many knobs to be used for further nonlinear optimization. As examples, two SP-LS lattices have been designed towards diffraction-limited emittances.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW041

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paper received ※ 20 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

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TUPGW042

Study of the Intra-beam Scattering Effects in the HALS Storage Ring

emittance, damping, wiggler, lattice

1501

W. Li, Z.H. Bai, W. Li, D.R. Xu, T. Zhang
USTC/NSRL, Hefei, Anhui, People’s Republic of China

Funding: This work was supported by the Fundamental Research Funds for the Central Universities (Grant No.WK2310000082 and WK2310000077).
The Hefei Advanced Light Source (HALS) is designed to be a dedicated 4th generation diffraction limited light source. In 2018, the baseline lattice of the HALS storage ring has been proposed, with an ultra-low natural emittance of about 25 pm-rad. The preliminary study of intra-beam scattering effects on the beam emittance growth in the HALS storage ring has been performed with this baseline lattice. Due to the limited synchrotron radiation in this storage ring, damping wigglers are expected in this storage ring to reduce the damping time and reduce the emittance. In this paper, we will present the simulation results of the IBS effects, estimated effectiveness of damping wiggler and the corresponding linear optics calibration of the perturbation due to insertion device, and finally the estimated Touschek lifetime will be shown.

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paper received ※ 13 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

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TUPGW043

Simulation of Model Independent Analysis to HEPS Storage Ring

optics, simulation, quadrupole, betatron

1504

D. Ji, Y. Jiao, H.Z. Ma, J.H. Yue
IHEP, Beijing, People’s Republic of China

Model Independent Analysis (MIA) is a beam analysis method applied for Turn-by-Turn (TBT) Beam Position Monitor (BPM) data. To develop the commissioning method of the HEPS storage ring, we simulate application of MIA on HEPS storage error model to measure and cor-rect the optics parameters. Difficulties and limitations of the MIA method are also discussed.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW043

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paper received ※ 15 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

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TUPGW045

Lattice Design for the Reversible SSMB

radiation, electron, emittance, bunching

1507

C.L. Li
SINAP, Shanghai, People’s Republic of China
A. Chao
SLAC, Menlo Park, California, USA
C. Feng, B.C. Jiang
Shanghai Advanced Research Institute, Pudong, Shanghai, People’s Republic of China

Steady State Microbunching (SSMB) aiming at producing high average power radiation in the electron storage ring has been proposed by Ratner and Chao years ago. Reversible seeding scheme is one of the promising scenarios with less challenges on the storage ring lattice design. The key problem for reversible SSMB is the precise cancelation of the laser modulation which will allow producing turn-by-turn coherent radiation without spoiling the transverse emittances and energy spread. In this paper the lattice design for the microbunching generation and its cancelation will be presented. Also a storage ring lattice design will be shown.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW045

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paper received ※ 14 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019

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TUPGW046

Progress of Lattice Design and Physics Studies on the High Energy Photon Source

lattice, booster, photon, injection

1510

Y. Jiao, X. Cui, Z. Duan, Y.Y. Guo, P. He, X.Y. Huang, D. Ji, C. Li, J.Y. Li, X.Y. Li, C. Meng, Y.M. Peng, Q. Qin, S.K. Tian, J.Q. Wang, N. Wang, Y. Wei, G. Xu, H.S. Xu, F. Yan, C.H. Yu, Y.L. Zhao
IHEP, Beijing, People’s Republic of China

The High Energy Photon Source (HEPS) is an ul-tralow-emittance, kilometer-scale storage ring light source to be built in China. In this paper we will introduce the progress of the physics design and related studies of HEPS over the past year, covering issues in storage ring lattice design, injection and injector design, insertion device effects, error study and lattice calibration, collective effects, etc.

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paper received ※ 15 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

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TUPGW048

Simulation of Injection Efficiency for the High Energy Photon Source

injection, booster, kicker, extraction

1514

Z. Duan, J. Chen, Y.Y. Guo, D. Ji, Y. Jiao, C. Meng, Y.M. Peng, Xu. Xu
IHEP, Beijing, People’s Republic of China

Funding: Work supported by Natural Science Foundation of China (No.11605212).
A ’high-energy accumulation’ scheme [1] was proposed to deliver the full charge bunches for the swap-out injec- tion of the High Energy Photon Source. In this scheme, the depleted storage ring bunches are recovered via merging with small charge bunches in the booster, before being refilled into the storage ring. In particular, the high charge bunches are transferred twice between the storage ring and the booster, and thus it is essential to maintain a near per- fect transmission efficiency in the whole process. In this paper, major error effects affecting the transmission efficiency are analyzed and their tolerances are summarized, injection simulations indicate a satisfactory transmission efficiency is achievable for the present baseline lattice.
* Z. Duan, et al., "The swap-out injection scheme for the High Energy Photon Source", Proc. IPAC’18, THPMF052

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paper received ※ 15 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019

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TUPGW052

STUDY OF THE RAMPING PROCESS FOR HEPS BOOSTER

booster, damping, lattice, injection

1521

Y.M. Peng, J.Y. Li, C. Meng, H.S. Xu
IHEP, Beijing, People’s Republic of China

The High Energy Photon Source (HEPS) is a 6-GeV, ul-tralow-emittance storage ring light source to be built in Huairou District, Beijing, China. The beam energy ramps from 500 MeV to 6 GeV in 400 ms, during which the RF voltage increases accordingly to keep the momentum acceptance large enough. The booster is designed to operate at 1 Hz repetition frequency. In this paper the energy ramping curve, RF choice, beam parameters changing curves and eddy current effect in HEPS booster will be presented.

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paper received ※ 14 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

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TUPGW053

Simulations of the Injection Transient Instabilities for the High Energy Photon Source

injection, feedback, simulation, lattice

1524

Z. Duan, N. Wang, H.S. Xu
IHEP, Beijing, People’s Republic of China

Funding: Work supported by Natural Science Foundation of China (No.11605212).
A "charge recovery in booster" scheme* was proposed to deliver the full charge bunches for the swap-out injection of the High Energy Photon Source. In this scheme, the booster is employed also as a full energy accumulator ring to capture the high charge bunch extracted from the storage ring via merging with the small charge bunch accelerated in the booster, after enough damping in the booster for about 20 ms, the recovered full charge bunch is re-injected into the storage ring. This scheme avoids the challenges to accelerate a bunch charge of ~ 15 nC, and is cost effective compared to building a dedicated 6 GeV accumulator ring. However, there will be a period of time during injection that one bunch is missing in the storage ring, which inevitably introduces some injection transients. Since "transparency" to the user experiments is a desired feature of injection schemes for next generation diffraction-limited storage rings, the injection transient effects are simulated for the proposed injection scheme, and how it would affect the user experiments are carefully evaluated.
* Z. Duan, et al., "The swap-out injection scheme for the High Energy Photon Source", Proc. IPAC’18, THPMF052

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paper received ※ 15 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

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TUPGW056

Comparison of Constrained Optimization Methods for Designing a Multi-Bend Achromat Lattice

lattice, emittance, sextupole, linear-dynamics

1535

J.H. Xu, Z.H. Bai, W. Li, P.H. Yang
USTC/NSRL, Hefei, Anhui, People’s Republic of China

In the design of a multi-bend achromat (MBA) lattice for a diffraction-limited storage ring, there are usually many magnet parameters to be optimized and some stringent constraints to be satisfied. For example, to cancel out nonlinear dynamics effects, the phase advances between some sections are generally required to be set to certain values in the lattice design. For better designing a MBA lattice using an evolutionary algorithm, the handling of constraints will be important, because it is very hard to satisfy the constraints for most or even all of solutions in the early generations of the algorithm. This paper will first describe some methods for handling constraints, which are then applied to designing a hybrid 7BA lattice. The comparison of these methods shows that better lattice solutions can be obtained by including constraints into objective functions.

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paper received ※ 23 April 2019 paper accepted ※ 19 May 2019 issue date ※ 21 June 2019

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TUPGW057

A Ten-Bend Achromat Lattice with Interleaved Dispersion Bumps for a Diffraction-Limited Storage Ring

lattice, emittance, sextupole, quadrupole

1538

P.H. Yang, Z.H. Bai, J.J. Tan, L. Wang, J.H. Xu
USTC/NSRL, Hefei, Anhui, People’s Republic of China

Recently, a multi-bend achromat (MBA) lattice concept, called the MBA with interleaved dispersion bumps (IDB-MBA), was proposed to design the HALS storage ring, which presented better performance of both on- and off-momentum nonlinear dynamics. Since the beam emittance scales inversely with the third power of the number of bending magnets, in this paper we will study a new IDB-MBA lattice with more bending magnets. It is feasible to satisfy the requirement of the IDB-MBA concept in a 10BA lattice, and an IDB-10BA lattice is then designed for a storage ring light source with an energy of 2.4 GeV. The designed lattice has an ultra-low natural emittance of 81 pm·rad, and a dynamic aperture of about 6 mm and a large dynamic momentum aperture of 6% are achieved.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW057

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paper received ※ 24 April 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

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TUPGW059

Studies of The Electron Beam Lifetime in Solaris Electron Storage Ring

electron, cavity, scattering, vacuum

1541

R. Panas, A.M. Marendziak, A.I. Wawrzyniak, M. Wisniowski
Solaris National Synchrotron Radiation Centre, Jagiellonian University, Kraków, Poland

Solaris storage ring is a recently constructed and commissioned machine operated in decay mode. With total accumulated beam dose near to 1000 A.h the measured total lifetime has reached 16 h for 270mA of a stored current. In this paper, the beam lifetime studies are presented using measured residual gas analysis and vertical scraper position for tuned and detuned Landau cavities. It shows that for stable beam the lifetime is dominated by the interaction of the electron with residual gas (vacuum lifetime) and between electrons interaction within a bunch (Touschek lifetime). The estimated vacuum, Touschek and total beam lifetimes from theoretical analysis are also compared with the measured beam lifetime.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW059

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paper received ※ 15 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

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TUPGW064

Trials of Beam-Based Sextupole Calibration through 2nd Order Dispersion

sextupole, optics, lattice, ECR

1551

D.K. Olsson, Å. Andersson, M. Sjöström
MAX IV Laboratory, Lund University, Lund, Sweden

In order to achieve nominal performance in terms of the dynamic aperture and lifetime of a storage ring, it is important to be able to characterise and correct its second order optics. At the MAX IV 3 GeV storage ring in Lund, Sweden, the linearity of the 2nd order dispersion with chromatic sextupole field strengths has been utilised to investigate the sextupole circuits. The beating induced in the 2nd order dispersion when reducing the strength of a sextupole magnet can be compared to the beating in simulations. From this a beam-based sextupole calibration curve can be found. This work was inspired by similar work done at ESRF.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW064

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paper received ※ 13 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

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TUPGW066

Exploring the Potential of the Swiss Light Source

emittance, operation, damping, cavity

1554

M. Aiba, M. Böge, A. Citterio, M.M. Dehler, A. Lüdeke, C. Ozkan Loch, L. Stingelin, A. Streun
PSI, Villigen PSI, Switzerland

Swiss Light Source (SLS) has been on-line since 2001. Although its performance meets the specifications, it still has a potential to achieve better storage ring beam parameters. We explore two possible improvements. The first one is for the beam lifetime. There are 480 rf buckets while normally 390 bunches are stored. The gap in filing pattern (90 empty buckets) is held to suppress ion instability. After many years of operation, however, the vacuum condition is much better than that of the time when the SLS was turned on. Hence it is possible to shorten the gap. The beam lifetime can then be prolonged due to less bunch current while keeping the net beam current. The study may be also useful to predict possible filling patter in SLS2, which is the SLS upgrade planned. The second one is for the beam emittance. The nominal energy closed orbit coincides with the axes of quadrupole magnets. An off-momentum closed orbit is therefore off-centered through quadrupoles, resulting in a damping partition shift. The beam emittance can be decreased at the expense of a larger energy spread. This was successfully achieved in the ESRF booster. We study whether it is applicable to the SLS storage ring.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW066

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paper received ※ 13 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019

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TUPGW068

New Source for Bending Magnet Beam Lines at Ultra-Low-Emittance Ring

dipole, radiation, lattice, wiggler

1557

M. Abbaslou, M. Sedaghatizadeh
KNTU, Tehran, Iran
S. Dastan, J. Rahighi, F. Saeidi
ILSF, Tehran, Iran

The Iranian Light Source Facility (ILSF) is a 3 GeV 3rd synchrotron radiation laboratory in the basic design phase. The Storage Ring (SR) is based on a five-bend achromat (5BA) lattice providing low horizontal emittance of 0.27 nm.rad. Due to the ILSF storage ring, straight section limits the use of the short length wigglers for hard X-ray generation is recommended. Which are removable in the lattice. In this article, the new design of the 3-pole wiggler is investigated and the main parameters of this 3-pole wiggler, by considering the ILSF storage ring characteristics, is modified. Also, the effect of the new 3-pole wiggler on the beam dynamics is investigated and the advantages of the new design are presented.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW068

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paper received ※ 28 April 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

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TUPGW069

Insertion Devices for the Day-One Beamlines of ILSF

undulator, vacuum, wiggler, polarization

1561

M. Hadad
Shahid Beheshti University, Tehran, Iran
S. Dastan, M. Hadad, J. Rahighi, M. Razazian, F. Saeidi, S. Yousefnejad
ILSF, Tehran, Iran

The Iranian Light Source Facility (ILSF) is a new 3 GeV synchrotron radiation laboratory with ultralow emittance of 270 pm-rad, which is in the design stage. Seven beamlines are planned to start operation with several different insertion devices installed in the storage ring either from "day one" or within the first year of operation. The most operational undulator for polarized radiations -Apple II- has been deliberated for the solid state electron spectroscopy, the Spectromicroscopy and the ARPES beamlines. The hybrid wigglers for the XPD and the EXAFS beamlines and in-vacuum undulators for Macromolecular Crystallography and SCD beamlines have been chosen too. The emission of these IDs covers a wide spectral range extending from hard X-rays to UV. Pre-design of the IDs were already done in ILSF. The main parameters of magnetic design as well as radiation parameters for the first phase of ILSF insertion devices have been described in this paper.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW069

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paper received ※ 15 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

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TUPGW070

Multi-Bend Achromat Lattice Design for the Future of TPS Upgrade

lattice, emittance, dipole, dynamic-aperture

1564

M.-S. Chiu, P.J. Chou, J.C. Huang
NSRRC, Hsinchu, Taiwan
S.-Y. Lee
Indiana University, Bloomington, Indiana, USA

We present a TPS upgrade option with the hybrid 7BA (H7BA) lattice. We also derive a simple formula on optimal dipole angle distribution among H7BA dipoles. The agreement is satisfactory. We also report preliminary results on the dynamic aperture (DA) optimization. Possible improvement on H7BA lattice is outlined.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW070

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paper received ※ 24 April 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

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TUPGW071

Optimization and Measurements on the Double Mini-Betay Lattice in the TPS Storage Ring

lattice, betatron, injection, dynamic-aperture

1567

M.-S. Chiu, B.Y. Chen, C.H. Chen, J.Y. Chen, Y.-S. Cheng, P.C. Chiu, P.J. Chou, T.W. Hsu, K.H. Hu, J.C. Huang, P.Y. Huang, C.-C. Kuo, T.Y. Lee, C.Y. Liao, W.Y. Lin, Y.-C. Liu, H.-J. Tsai, F.H. Tseng
NSRRC, Hsinchu, Taiwan

The Taiwan Photon Source (TPS) is capable of operat-ing in multi-bunch and single-bunch mode. To operate in a hybrid mode as requested by users, we developed a lattice with chromaticities of 0.8/2 (x/y) to provide higher single bunch currents. Beam dynamics simulations and lattice characterizations including dynamic aperture, frequency map analysis, tune shift with energy, tune shift with amplitude, and betatron coupling will be discussed in this report.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW071

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paper received ※ 30 April 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

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TUPGW072

Design and Optimization of Full Energy Injector Linac for Siam Photon Source II

linac, injection, emittance, simulation

1570

T. Chanwattana, P. Klysubun, T. Pulampong, P. Sudmuang
SLRI, Nakhon Ratchasima, Thailand

The new Thailand synchrotron light source, Siam Photon Source II (SPS-II), has been designed based on a 3 GeV storage ring with a Double-Triple Bend Achromat (DTBA) lattice and a full energy injector linac. The linac consists of an S-band photocathode RF gun, C-band accelerating structures and two magnetic chicanes. In addition to its main function as the storage ring injector, the linac is capable of producing sub-picosecond electron bunches for additional short-pulse beamlines at the end of the linac. The linac also has a potential to become a driver of a soft X-ray Free Electron Laser (FEL) operating adjacent to the storage ring. In this paper, start-to-end simulations of the full energy linac are presented. Optimization was performed in order to fulfil requirements for both storage ring injection and short pulse generation.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW072

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paper received ※ 14 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

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TUPGW075

Towards a Diffraction Limited Storage Ring

lattice, optics, emittance, dynamic-aperture

1573

J. Bengtsson
DLS, Oxfordshire, United Kingdom
P.F. Tavares
MAX IV Laboratory, Lund University, Lund, Sweden

A Lattice for a 500 m circ. Tunnel, based on First Principles & Best Practices is presented. Background: MAX-IV has made a "quantum leap" towards a Diffraction Limited Storage Ring (DLSR) by an Engineering-Science, i.e., Systems, Approach; leading to a Paradigm Shift(s): e.g. the Magnet Reference Radius is a Key Parameter, a Design Choice, that must be considered at an early stage for Robust Design. In addition, the pursuit of Systematic Benchmarks, MAX-I -> MAX-IV, has enabled the pursuit of Disruptive Technologies with Predictable Results. For example: Combined-Function Magnets (built-to-print) enabling an "IKEA Approach" (innovative, prompted by low-budget) like the use of Concrete Girders, Vacuum Requirements mitigated by NEG Coating, and Solid State Modulators providing a Reliable Injector by a Full-Energy Linac. Since "The Experiment" now has been done, Permanent Magnets, well understood for high-end Insertion Devices, provides another opportunity/step for a Next Generation. Besides, the Electricity Bill for Conventional Magnets is a significant part of the Operations Cost.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW075

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paper received ※ 20 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

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TUPGW077

Impact of the DIAD Wiggler and ’Missing-sextupole’ Optics on the Diamond Storage Ring

wiggler, sextupole, optics, operation

1581

I.P.S. Martin, R. Bartolini, B. Singh
DLS, Oxfordshire, United Kingdom

In order to generate space for a short, out-of-vacuum multipole wiggler for the DIAD beamline, a single sextupole was removed from one of the DBA arcs in the Diamond Storage Ring during June 2018. The removal of this sextupole presented a number of challenges to the operation of the storage ring, requiring a re-optimisation of the remaining sextupole strengths*, a change in tune-point and modification of the orbit and coupling correction schemes. In this paper we describe the implementation of these changes, and provide an assessment of the impact that the installed wiggler has made on the storage ring parameters.
* B. Singh et al. ’Studies to Install a Multipole Wiggler by Removing a Chromatic Sextupole in Diamond Storage Ring’, Proc. IPAC 2016, Busan, Korea, paper THPMR050, (2016)

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW077

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paper received ※ 15 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

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TUPGW078

Harmonic Cavity Design Choice for Lifetime Increase in Diamond-II

cavity, simulation, beam-loading, lattice

1585

T. Olsson, R. Bartolini, I.P.S. Martin
DLS, Oxfordshire, United Kingdom

The ongoing trend towards synchrotron light storage rings with ultralow emittance leads to a requirement for strong magnet gradients, which reduce the dynamic aperture and thus the Touschek lifetime of the machine. This is also the case for the planned upgrade of the Diamond Light Source. One option to increase the Touschek lifetime is to lengthen the electron bunches with a harmonic cavity operated close to a harmonic of the fundamental RF frequency. This paper presents studies of a harmonic cavity for Diamond-II with the focus on maximising the lifetime increase. It is foreseen that the ring will have to operate with a gap in the fill pattern to avoid instabilities and therefore multiparticle tracking was used to determine the effect on stability and lifetime for various cavity parameters taking into account transient beam loading.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW078

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paper received ※ 14 May 2019 paper accepted ※ 18 May 2019 issue date ※ 21 June 2019

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TUPGW082

Impedance of the Flange Joints With the RF Contact Spring in NSLS-II

impedance, vacuum, cavity, damping

1597

A. Blednykh, B. Bacha, G. Bassi, C. Hetzel, B.N. Kosciuk, T.V. Shaftan, V.V. Smaluk, G.M. Wang
BNL, Upton, Long Island, New York, USA

Funding: This work was supported by Department of Energy Contract No. DE-SC0012704
Since the beginning of the NSLS-II commissioning, temperature of the vacuum components has been moni-tored by the Resistance Temperature Detectors located predominantly outside of the vacuum enclosure and at-tached to the chamber body. Temperature map helps us to control overheating of the vacuum components around the ring especially during the current ramp-up. The average current of 475mA has been achieved with two main 500MHz RF cavities and w/o harmonic cavities. Effect of the RF shielded flanges on local heat and on the longitu-dinal beam dynamics is discussed in details.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW082

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paper received ※ 15 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

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TUPGW088

Removal and Installation Planning for the Advanced Light Source - Upgrade Project

MMI, injection, vacuum, shielding

1609

D. Leitner, P.W. Casey, K. Chow, D.F. Fuller, M. Leitner, A.J. Lodge, M. Lopez, J. Niu, P. Novak, C. Steier, S.P. Virostek, W.L. Waldron
LBNL, Berkeley, California, USA

The ALS-U project is a proposed upgrade to the Advanced Light Source (ALS) at Berkeley Lab that aims to deliver diffraction limited performance in the soft x-ray range. By lowering the horizontal emittance to about 70 pm rad, the brightness for soft x-rays will increase two orders of magnitude compared to the current ALS. The design utilizes a nine-bend achromat lattice, with reverse bending magnets and on-axis swap-out injection utilizing an accumulator ring. This paper will describe the preliminary plans for the installation of the new three-bend achromat accumulator ring (AR) in the existing tunnel and for replacing the current storage ring with the new nine-bend achromat lattice. The AR will be installed during regular maintenance shutdowns while the ALS continues to operate. The SR will be replaced during a nine months installation period followed by three months of commissioning during the twelve darktime period.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW088

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paper received ※ 15 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019

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TUPGW092

Working Impedance Model and Its Effect on the Intensity Limitation of Petra-IV Storage Ring

impedance, cavity, feedback, emittance

1623

Y.-C. Chae
DESY, Hamburg, Germany

We made sufficient progress in modeling the imped-ance of the PETRA-IV storage ring. The result was ap-plied to estimate the impedance-based single and multi-bunch intensity limit. Due to the extremely small emit-tance of the beam the intrabeam scattering (IBS) effects will be significant unless they are reduced by bunch lengthening. The 3rd harmonic cavity was proposed to dilute the bunch density which resulted in the small syn-chrotron frequency with a large spread. Because of the complexity introduced by impedance and harmonic cavity we used broadband impedance up to 200 GHz to compute the parameters such as bunch length and energy spread at different currents. We found that the microwave instability started very early in current less than 0.5 mA. Even if it is small, the prediction by tracking simulation was consistent with another diffraction-limited storage ring (DLSR) when the Keil-Schnell criterion was used to predict one from the other. Then, we present the single-bunch current limit which had included the effect of geometric and resistive wall impedances of the NEG-coated chamber. Finally, we present the emittance and lifetime which can be realistically achieved in the ring with the above collective effects included.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW092

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paper received ※ 14 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

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TUPGW093

Compensation of Insertion Device Induced Emittance Variations in Ultralow Emittance Storage Rings by a Dispersion Bump in a Wiggler

emittance, wiggler, lattice, dipole

1627

F. Sannibale, M.P. Ehrlichman, T. Hellert, S.C. Leemann, D. Robin, C. Steier, C. Sun, M. Venturini
LBNL, Berkeley, California, USA

Funding: Work supported by the Director of the Office of Science of the US Department of Energy under Contract no. DEAC02-05CH11231.
Multi-bend achromat lattices allow for the design of extremely low emittance electron storage rings and hence for the realization of extremely high- brightness X-ray photon sources. In these new rings, the beam energy lost to radiation in the insertion devices (IDs) is often comparable to that lost in the ring dipole magnets. This implies that with respect to the typical 3rd generation light source, these new machines are more sensitive to the energy loss variations randomly occurring as the many users independently operate the gap of their IDs. The consequent induced variations in radiation damping time, equilibrium emittance, and transverse beam sizes at the radiation point sources can be significant and degrade the experimental performance in some of the beam-lines. In this paper we describe and discuss a possible method to compensate for such emittance variations by using a variable dispersion bump localized inside a fixed gap wiggler.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW093

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paper received ※ 13 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

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TUPGW094

First Attempts at Applying Machine Learning to ALS Storage Ring Stabilization

experiment, quadrupole, operation, emittance

1631

S.C. Leemann, Ph. Amstutz, M.P. Ehrlichman, T. Hellert, A. Hexemer, S. Liu, M. Marcus, C.N. Melton, H. Nishimura, G. Penn, F. Sannibale, D.A. Shapiro, C. Sun, D. Ushizima, M. Venturini
LBNL, Berkeley, USA

Funding: This research is funded by US Department of Energy (BES & ASCR Programs), and supported by the Director of the Office of Science of the US Department of Energy under Contract No. DEAC02-05CH11231.
The ALS storage ring operates multiple feedbacks and feed-forwards during user operations to ensure that various source properties such as beam position, beam angle, and beam size are maintained constant. Without these active corrections, strong perturbations of the electron beam would result from constantly varying ID gaps and phases. An important part of the ID gap/phase compensation requires recording feed-forward tables. While recording such tables takes a lot of time during dedicated machine shifts, the resulting compensation data is imperfect due to machine drift both during and after recording of the table. Since it is impractical to repeat recording feed-forward tables on a more frequent basis, we have decided to employ Machine Learning techniques to improve ID compensation in order to stabilize electron beam properties at the source points.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW094

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paper received ※ 14 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

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TUPGW095

Progress on a Novel 7BA Lattice for a 196-m Circumference Diffraction-Limited Soft X-Ray Storage Ring

lattice, emittance, sextupole, optics

1635

S.C. Leemann, F. Sannibale
LBNL, Berkeley, USA
M. Aiba, A. Streun
PSI, Villigen PSI, Switzerland
J. Bengtsson
DLS, Oxfordshire, United Kingdom
L.O. Dallin
CLS, Saskatoon, Saskatchewan, Canada

Funding: Work supported by the Director of the Office of Science of the US Department of Energy under Contract No. DEAC02-05CH11231.
The ALS Upgrade to a diffraction-limited soft x-ray storage ring calls for ultralow emittance in a very limited circumference. In this paper we report on progress with a lattice based on a 7BA with distributed chromatic correction. This lattice relies heavily on longitudinal gradient bends and reverse bending in order to suppress the emittance, so that, despite having only seven bends, ultralow emittance can be achieved in addition to large dynamic aperture and momentum acceptance. An initial alternate 7BA lattice has been revised to relax magnet requirements as well as further increase off-energy performance and resilience to machine imperfections. We now demonstrate ±2.5 mm dynamic aperture including errors and calculate the effect of IBS to show that this lattice achieves 6 hours Touschek lifetime (at 500 mA, including errors) and a brightness of roughly 3x10²¹ ph/s/mm²/mrad²/0.1%BW at 1 keV.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW095

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paper received ※ 14 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

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TUPGW097

Design Progress of ALS-U, the Soft X-ray Diffraction Limited Upgrade of the Advanced Light Source

emittance, lattice, cavity, vacuum

1639

C. Steier, Ph. Amstutz, K.M. Baptiste, P.A. Bong, E.S. Buice, P.W. Casey, K. Chow, S. De Santis, R.J. Donahue, M.P. Ehrlichman, J.P. Harkins, T. Hellert, M.J. Johnson, J.-Y. Jung, S.C. Leemann, R.M. Leftwich-Vann, D. Leitner, T.H. Luo, O. Omolayo, J.R. Osborn, G. Penn, G.J. Portmann, D. Robin, F. Sannibale, C. Sun, C.A. Swenson, M. Venturini, S.P. Virostek, W.L. Waldron, E.J. Wallén
LBNL, Berkeley, California, USA

Funding: This work was supported by the Director, Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.
The ALS-U project to upgrade the Advanced Light Source to a multi bend achromat lattice received CD-1 approval in 2018 marking the end of its conceptual design phase. The ALS-U design promises to deliver diffraction limited performance in the soft x-ray range by lowering the horizontal emittance to about 70 pm rad resulting in two orders of magnitude brightness increase for soft x-rays compared to the current ALS. The design utilizes a nine bend achromat lattice, with reverse bending magnets and on-axis swap-out injection utilizing an accumulator ring. This paper presents recent design progress of the accelerator, as well as new results of the mature R&D program.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW097

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paper received ※ 21 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

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TUPGW109

Conceptual Design of Vacuum Chamber for SPS-II Storage Ring

vacuum, photon, impedance, emittance

1666

T. Phimsen, S. Chaichuay, N. Juntong, P. Klysubun, S. Prawanta, P. Sudmuang, P. Sunwong
SLRI, Nakhon Ratchasima, Thailand
R. Deepan, A. Khamkham
Suranaree University of Technology, Nakhon Ratchasima, Thailand

The SPS-II is a 3 GeV ultralow emittance light source which is now under studied and designed by Thailand Synchrotron Light Research Institute (SLRI). The SPS-II storage ring is based on Double-Triple Bend Achromat (DTBA) cell with a circumference of 321.3 m aiming for horizontal emittance of less than 1 nm-rad. The compact lattice leaves narrow space for vacuum components. The small gap between poles of the magnets requires narrow vacuum chambers and limits the conductance of the chambers. The chambers will be made by stainless steel with a thickness of 1.5 mm. the cross section of beam duct is 40 mm × 16 mm elliptical shape. The bending chamber is designed as a long triangular chamber such that photon absorber can be installed as far from the light source as possible to lower the power density of the heat load. The overview of designed vacuum system for the SPS-II is presented.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW109

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paper received ※ 14 May 2019 paper accepted ※ 18 May 2019 issue date ※ 21 June 2019

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TUPGW110

Improvement of Touschek Lifetime by Higher Harmonic RF Cavity in the SPS Storage Ring

cavity, operation, synchrotron, scattering

1669

T. Phimsen, N. Juntong, P. Sudmuang
SLRI, Nakhon Ratchasima, Thailand
B.C. Jiang
Shanghai Advanced Research Institute, Pudong, Shanghai, People’s Republic of China
Z.T. Zhao
SSRF, Shanghai, People’s Republic of China

Siam Photon Source (SPS), located at Nakhon Ratchasima, Thailand, is a synchrotron light source with the beam energy of 1.2 GeV. User operation is performed in beam decay mode with the maximum current of 150 mA. Beam lifetime is about 12 hours at the beam current of 100 mA. Beam injection is carried out twice a day, and even with full energy, it takes roughly 30 minutes. Beam lifetime in the SPS storage ring is limited by Touschek scattering and strongly depends on operation conditions. Higher harmonic RF cavity is a proven method to increase the beam lifetime and suppressing coupled bunch instabilities through Landau damping effect. If the beam lifetime is increased for examples, to be double, only one injection per day would be needed. In this study, an improvement of Touschek lifetime by passive harmonic RF cavity is investigated.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW110

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paper received ※ 14 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

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TUPRB003

Virtual Shimming and Magnetic Measurements of two Long Period APPLE-II Undulators at the Canadian Light Source

MMI, undulator, polarization, multipole

1679

C.K. Baribeau, T.M. Pedersen, M.J. Sigrist
CLS, Saskatoon, Saskatchewan, Canada

Assembly and shimming have completed for a pair of long period APPLE-II type elliptically polarized undulators, QP-EPU180 and EPU142, at the Canadian Light Source. Both devices were shimmed using a weighted cost single-objective simulated annealing algorithm, with shims generated iteratively based on Hall probe and flipping coil data. In this paper we present detailed measurements on the two EPUs, including their magnetic and spectral performance across a wide range of gap and polarization operating points, as well as measured and predicted changes in field due to the virtual shimming.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB003

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paper received ※ 08 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

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TUPRB006

Effect of Electrostatic Deflectors and Fringe Fields on Spin for Hadron Electric Dipole Moment Measurements on Storage Rings

dipole, polarization, controls, vacuum

1691

J. Michaud, J.-M. De Conto, Y. Gómez Martínez
LPSC, Grenoble Cedex, France

The observed matter-antimatter asymmetry in the universe cannot be explained by the Standard Model. An explanation is a non-vanishing Electric Dipole Moment of subatomic particles. The JEDI (Jülich Electric Dipole moment Investigations) collaboration is preparing a direct EDM measurement of protons and deuterons first at the storage ring COSY (COoler SYnchrotron) and later at a dedicated storage ring. To achieve this, one needs a stable polarization, i.e. around 1000 seconds for spin coherence time. One source of decoherence are the electrostatic deflectors, and this must be quantified. We developed an analytical model for cylindrical deflectors, including fringe fields, and the associated beam and spin transfer functions, integrated over the deflector. All boundaries (including ground) are considered, giving a realistic, accurate field map up to any order. We get universal formulas, the only adjustable parameter being the deflector gap/radius ratio, all other terms being numerical. This has been implemented in BMAD. We present the mathematical, physical and numerical developments, as well as results for a proton storage ring.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB006

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paper received ※ 13 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

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TUPRB057

THz-Pump and UV-Probe Scheme Based on Storage Ring

laser, electron, radiation, bunching

1811

H.R. Zhang, Z.G. He, S.M. Jiang, W.X. Wang
USTC/NSRL, Hefei, Anhui, People’s Republic of China

We propose a THz-pump and UV-probe scheme based on storage ring for ultra-fast dynamics experiment. In which, two sequential laser pulses, one of which has a periodic intensity envelope, simultaneously interact with different parts of the long electron beam in a modulator; after a chicane, the part that interacts with the periodic pulse will bunch at THz domain and radiate through a bend magnet, another based on high-harmonic generation will bunch at UV domain and radiate at a radiator. The electron beam can be utilized circularly in the storage ring, which will increase its average power. The feasibility of this THz-pump and UV-probe scheme is verified in both theory and simulation.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB057

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paper received ※ 30 April 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

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TUPRB094

New Superconducting Undulator Magnetic Measurement System for the Advanced Photon Source Upgrade

GUI, undulator, photon, vacuum

1881

M. Kasa, E.R. Anliker, Y. Ivanyushenkov, Y. Shiroyanagi
ANL, Argonne, Illinois, USA

Funding: Work supported by the U.S. Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11357.
Magnetic measurements of existing superconducting undulators (SCUs) are performed under normal operating conditions after final assembly into the cryostat and before installation on the Advanced Photon Source (APS) storage ring. The SCU cryostat for the APS upgrade has been scaled in length from the current cryostat and will contain two SCUs. While some aspects of the current measurement system are desirable to retain, such as a room temperature measurement bore, scaling the current measurement techniques to the length required for the APS upgrade cryostat is not feasible. To address these challenges a unique system has been developed at the APS to allow measurements of the two SCU magnets in the long cryostat. The measurement system developed allows the magnets to be operated under normal operating conditions while maintaining the measurement equipment at room temperature and atmospheric pressure.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB094

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paper received ※ 14 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

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WEYYPLS1

Muon G-2: An Interplay between Beam Dynamics and a Muon Decay Experiment at the Precision Frontier

experiment, proton, detector, injection

2266

M.J. Syphers
Northern Illinois University, DeKalb, Illinois, USA

Funding: This work has been partially funded by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the U.S. Department of Energy, Office of Science, Office of High Energy Physics.
The Muon g-2 Experiment at Fermilab (E989) will use the higher proton flux delivered by the Fermilab accelerator complex and improvements to the experimental apparatus to measure the anomalous magnetic moment of the muon to unprecedented precision. In addition to the increased statistics beyond the most recent measurement, the experiment relies on detailed understanding of the beam dynamics in the experiment’s storage ring as well as the incoming muon beam properties for proper assessments of systematic errors in the data analysis. Modeling and measurements of beam and storage ring properties, from proton targeting to muon storage, produce a unique unification of particle beam physics with a high energy physics experiment. Here the beam dynamics issues and analysis techniques essential to the g-2 experiment are presented and discussed.

Slides WEYYPLS1 [12.990 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEYYPLS1

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paper received ※ 10 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

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WEPMP001

Proposed Nonlinear Injection Kicker for the Australian Synchrotron

kicker, injection, synchrotron, vacuum

2300

R. Auchettl, Y.E. Tan
AS - ANSTO, Clayton, Australia

Future beamline development at the Australian Synchrotron requires free floor space within the straights for a short undulator and relocation of diagnostics. Our current injection method uses a four-dipole kicker configuration that perturbs the stored beam during injection while also taking up approximately 4 meters of valuable space. To free this valuable space and provide transparent injections to the beamlines, a single pulsed nonlinear magnetic field kicker (NLK) will be deployed. The NLK has a flat and zero field at the stored beam but maximum field where the injected beam is located off-axis. NLKs deflect only the injected beam, leaving the stored beam undisturbed. NLKs have been extensively prototyped by many facilities around the world already and can produce injection efficiencies of 99 % (see e.g. *). This paper presents the preliminary magnet design for installation of a NLK at the Australian Synchrotron. We discuss the beam dynamics and thermal transfer constraints on kicker placement, field-flatness and the magnet and ceramic chamber design for adaptation to our 3 GeV beam. Installation plans and other constraints for future deployment are also outlined.
* T. Pulampong and R. Bartolini, "A Non-linear Injection Kicker for Diamond Light Source", in: Proc. IPAC’13, pp. 2268-2270.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPMP001

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paper received ※ 15 May 2019 paper accepted ※ 24 May 2019 issue date ※ 21 June 2019

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WEPMP015

Status of the R&D for HALS Injection System

kicker, injection, septum, vacuum

2335

L. Shang, W. Liu, Y. Lu, F.L. Shang, W.B. Song, Z.B. Sun
USTC/NSRL, Hefei, Anhui, People’s Republic of China

Hefei Advanced Light Source (HALS) is a diffraction-limited synchrotron radiation source proposed by the NSRL. A comprehensive R&D program funded by the local government was initiated in the end of 2017. The program focuses on the key technologies including the injection, magnets, vacuum, mechanics, RF, etc. The formal construction of HALS is estimated to begin in 2020. This paper presents the R&D of the injection system, including the fast kicker, nanosecond pulser, NLK (non-linear kicker) and the septum magnet. Test results of the prototype fast kicker, pulsed power and the NLK are given and discussed.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPMP015

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paper received ※ 16 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

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WEPMP017

A New Nonlinear Kicker Design and Measurement

kicker, injection, lattice, simulation

2342

W.B. Song, W. Liu, Y. Lu, F.L. Shang, L. Shang, Z.B. Sun
USTC/NSRL, Hefei, Anhui, People’s Republic of China

Funding: Work supported by The National Key Research and Development Program of China(2016YFA0402000) and Pre-research Project of Hefei Advanced Light Source
For the beam injection of HALS, a feasible injection scheme is proposed and a single-pulse nonlinear kicker has been designed for off-axis injection. The kicker has been improved on the basis of the previous designed one, and the structure of the kicker was simulated by OPERA, and the prototype has been processed and measured. The results showed that the kicker designed in this paper has less influence on stored beam and lower difficulty in location.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPMP017

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paper received ※ 26 April 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

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WEPMP042

Reduction of Stored Beam Oscillations During Injection at Diamond Light Source

kicker, injection, simulation, timing

2426

R.T. Fielder, M. Apollonio, R. Bartolini, C. Bloomer, I.P.S. Martin
DLS, Oxfordshire, United Kingdom

At Diamond injection is performed by means a of a four kicker off-axis system, relying on a perfect timing and amplitude setting to produce a closed bump. Ageing of some of the kicker vessel components has progressively spoiled the performance of the system, causing oscillations in the stored beam. Various schemes to control these oscillations have been considered including introducing an additional compensating kicker, and installing a non-linear injection kicker. Results of simulations analysing these schemes are presented, along with measurements taken in the storage ring using an existing pinger magnet. The effects of the reduction on the quality of beam seen by beamlines is also considered.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPMP042

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paper received ※ 14 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

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WEPMP043

Injection Studies for the Proposed Diamond-II Storage Ring

injection, booster, kicker, septum

2430

I.P.S. Martin, R. Bartolini, H. Ghasem, J.P. Kennedy, B. Singh
DLS, Oxfordshire, United Kingdom

The baseline design for the Diamond-II storage ring consists of a Modified-Hybrid 6-Bend Achromat, combining the ESRF-EBS low-emittance cell design with the DDBA mid-straight concept*,**. This cell design provides sufficient dynamic aperture to permit an off-axis injection scheme, provided the emittance of the injected beam is sufficiently low. In this paper we present simulations of an injection scheme using the anti-septum concept***, along with the design of an upgrade to the existing booster synchrotron. Alternate injection strategies are also discussed.
*ESRF Technical Design Study, ’The Orange Book’, (2014)
**R. Bartolini et al., PRAB 21, 050701, (2018)
***C. Gough, M. Aiba, Proc. IPAC 2017, Copenhagen, Denmark, paper MOPIK104, (2017)

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paper received ※ 15 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

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WEPMP051

Impedance Study of a New Septum Chamber of SPEAR3

impedance, septum, simulation, vacuum

2447

K. Tian, J. Langton, J.J. Sebek
SLAC, Menlo Park, California, USA

Funding: Work supported by US Department of Energy Contract DE-AC03-76SF00515.
A new Septum magnet and chamber has been designed for the storage ring as a part of the accelerator improvement plan for operating a lower emittance lattice in SPEAR3. Therefore it is necessary to analyze the impedance effects on the beam from the new Septum chamber. Due to the complex design at the downstream transition of the Septum chamber, the longitudinal impedance is particular of concern. In this paper, we will present numerical simulation results for this particular component as well as the general analysis for the impedance effects of the whole chamber.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPMP051

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paper received ※ 14 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

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WEPGW001

Characterising Injected Beam Dynamics in the Australian Synchrotron Storage Ring

kicker, synchrotron, injection, multipole

2458

P. Bennetto
ASCo, Clayton, Victoria, Australia

The injected beam trajectory at the Australian Synchrotron needs to be studied to assess the suitability of non-linear kicker installation. To achieve this, multiple diagnostics including cameras and radiochromic films were used to determine the position at several points inside the storage ring tunnels. This was used to infer the momentum data, and then simulated to model the new kicker installation.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPGW001

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paper received ※ 22 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

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WEPGW012

Vertical Beam Size Measurement Methods at the BESSY II Storage Ring and their Resolution Limits

diagnostics, electron, polarization, detector

2491

M. Koopmans, F. Armborst, J.G. Hwang, A. Jankowiak, P. Kuske, M. Ries, G. Schiwietz
HZB, Berlin, Germany

With the VSR upgrade for the BESSY II electron storage ring* bunch resolved diagnostics are required for machine commissioning and to ensure the long-term quality and stability of operation. For transverse beam size measurements we are going to use an interferometric method, which will be combined with a fast gated intensified CCD camera at a subsequent stage. A double-slit interferometer method has already been verified successfully at BESSY II**. In addition first 2D bunch resolved measurement tests have been performed at the dedicated diagnostics beamline for bunch length measurements. Measurements of the interferometer and X-ray pinholes as function of a vertical electron beam excitation are compared in this paper.
* A. Jankowiak et al., Germany, June 2015. DOI: 10.5442/R0001
** M. Koopmans et al., in Proc. IPAC’17, paper MOPAB032, 2017

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paper received ※ 09 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

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WEPGW016

Turn-by-Turn Horizontal Bunch Size and Energy Spread Studies at KARA

synchrotron, radiation, detector, synchrotron-radiation

2498

B. Kehrer, M. Brosi, E. Bründermann, S. Funkner, A.-S. Müller, G. Niehues, M.M. Patil, M. Schuh, J.L. Steinmann
KIT, Karlsruhe, Germany
L. Rota
SLAC, Menlo Park, California, USA

Funding: This work is funded by the BMBF under contract number: 05K16VKA
The energy spread is an important beam dynamics parameter. It can be derived from measurements of the horizontal bunch size. At the KIT storage ring KARA a fast-gated camera is routinely used for horizontal bunch size measurements with a single-turn resolution for a limited time span. To overcome the limits of the current camera setup in respect to resolution and time span, a high-speed line array with up to 10 Mfps, the KALYPSO system, is foreseen as a successor. The KALYPSO versions range from 256-pixel to 1024-pixel and allow unlimited turn-by-turn imaging of a single bunch at KARA. We successfully tested such a system at our visible light diagnostics port and present first results in this contribution.

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paper received ※ 15 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

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WEPGW017

Continuous Bunch-by-Bunch Reconstruction of Short Detector Pulses

detector, bunching, experiment, simulation

2501

J.L. Steinmann, M. Brosi, M. Caselle, B. Kehrer, M. Martin, A.-S. Müller, M.M. Patil, P. Schreiber
KIT, Karlsruhe, Germany

Funding: This work is funded by the BMBF contract number: 05K16VKA
The KAPTURE system (KArlsruhe Pulse Taking and Ultrafast Readout Electronics), developed at the Karlsruhe Institute of Technology (KIT), was designed to digitize detector pulses during multi-bunch operation at the KIT storage ring KARA (Karlsruhe Research Accelerator). KAPTURE provides digitization for pulses at rates of 500 MHz using up to 4 sampling points per pulse to record each bunch and each turn for potentially unlimited time. The new KAPTURE-2 system now provides eight sampling points per pulse, including baseline sampling between pulses, which allows improved reconstruction of the pulse shape. The advanced reconstruction of the pulse shape is realized with a highly parallelised implementation on GPU. The system will be used for the investigation on longitudinal beam dynamics e.g. by measuring instability induced CSR fluctuations or arrival time oscillations. This contribution will report on first results of the KAPTURE-2 system at KARA.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPGW017

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paper received ※ 15 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

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WEPGW027

Evaluation and Reduction of Influence of Filling Pattern on X-Ray Beam Position Monitors for SPring-8

space-charge, operation, electron, undulator

2526

H. Aoyagi, Y. Furukawa, S. Takahashi
JASRI/SPring-8, Hyogo, Japan

SPring-8 constantly provides various several-bunch mode operations, which combine single bunches and train bunches. Recently, influence of filling pattern on the accuracy of the XBPMs became apparent, so that we started a systematic evaluation. It was found that the influence was caused by suppression of current signal due to space charge effect, which could be quantified by observing a behaviour of the current signal while changing the voltage of photoelectron collecting electrodes. In order to mitigate the space charge effect, we examined some methods, such as, changing operation parameters of the XBPMs and the undulators. As a result, we successfully reduced the influence of filling pattern.
* H. Aoyagi et al., Proc. of PASJ2018 WEOL06
http://www.pasj.jp/web_publish/pasj2018/proceedings/PDF/WEOL/WEOL06.pdf
http://www.pasj.jp/web_publish/pasj2018/proceedings/PDF/WEOL/WEOL06_oral.pdf

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paper received ※ 10 May 2019 paper accepted ※ 17 May 2019 issue date ※ 21 June 2019

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WEPGW029

The Design of the Control System for the SACLA/SPring-8 Accelerator Complex to Use the LINAC of SACLA for a Full-Energy Injector of SPring-8

controls, database, operation, injection

2529

T. Fukui
RIKEN SPring-8 Center, Innovative Light Sources Division, Hyogo, Japan
T. Hara, N. Hosoda, T. Inagaki, H. Maesaka, T. Ohshima, H. Tanaka
RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan
T. Hasegawa, O. Morimoto, Y. Tajiri, S. Tanaka, M. Yoshioka
SES, Hyogo-pref., Japan
S. Matsubara, K. Okada
JASRI, Hyogo, Japan
M. Yamaga
JASRI/SPring-8, Hyogo-ken, Japan

At the SPring-8 site, the X-ray free electron laser facili-ty, SACLA, and the third-generation light source, SPring-8 storage ring, have been operated. On the SPring-8 up-grade project we have a plan to use the linac of SACLA as a full-energy injector of the storage ring. To achieve the SACLA’s user operation and the beam injection to the storage ring in parallel, it is necessary to control the beam energy and the peak current on a pulse by pulse. The demand for an injection occurs anytime during the top-up operation of the storage ring. For this purpose, two accel-erators should be controlled seamlessly and the SACLA has to provide the low emittance electron beam to gener-ate X-ray laser and to be an injector of the storage ring simultaneously. Because SACLA has to control the beam energy and peak current on a pulse by pulse, we are de-signing a system to meet these requirements. A master controller stores a pattern of parameters required for the low-level RF controllers. Each pattern consists of 60 rows which correspond to the parameters for one second with a beam repetition rate of the SACLA, 60Hz. The master sends the parameters to the controllers with reflective memory. We can select the pattern every second on de-mand and it is flexible enough for the top-up operation of the storage ring. Also the data of low-level RF and beam position monitor are stored into the database with a beam repetition rate. In this paper, we report the design of con-trol system for SACLA/SPring-8 to control the beam energy and the peak current on a pulse by pulse.

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WEPGW045

Application of Clustering by Fast Search and Find of Density Peaks to Beam Diagnostics at SSRF

SRF, GUI, diagnostics, electron

2581

R. Jiang, Y.B. Leng
SSRF, Shanghai, People’s Republic of China

With the increased technological complexity of accelera-tors, meeting the demand of beam diagnostics and opera-tion need more powerful and faster methods. And detect-ing the accuracy and stability of beam position moni-tors(BPMs) are important for all kinds of measurement systems and feedback systems in particle accelerator field. As an effective tool for data analysis and automa-tion, the machine learning methods had been used in accelerator physics field, recently. Among machine learn-ing methods, the clustering by fast search and find of density peaks as a typical unsupervised learning algo-rithms could be performed directly without training in arbitrary accelerator systems and could discover un-known patterns in the data. This paper used clustering by fast search and find of density peaks to detect faulty beam position monitor or monitoring beam orbit stability by analysis five typical parameters, that is beta oscilla-tion of X and Y direction(BetaX and BetaY), transverse oscillation of X and Y direction(AmpX and AmpY) and energy oscillation(AmpE). The results showed that cluster-ing by fast search and find of density peaks could classi-fy beam data into different clusters on the basis of their similarity. And that, aberrant run data points could be detected by decision graph. Morever, analysis results demonstrate the characteristic parameters AmpE, AmpX and BetaX amplitude have the same effect to distinguish the faulty BPMs and the AmpY and the BetaY amplitude are also.

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paper received ※ 15 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019

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WEPGW058

Orbit Correction With Machine Learning

lattice, closed-orbit, simulation, coupling

2608

D.J. Xiao, C.P. Chu, Y.S. Qiao
IHEP, Beijing, People’s Republic of China

Orbit correction is usually an important task in the operation of accelerators. In practice, due to various errors, many devices can not operate in ideal state. By correcting the errors of magnets with corrector magnets, the beam can return to the correct position to ensure the stable operation of the accelerator. In the process of orbit correction, inaccurate BPM output will lead to incorrect correction magnet strength setting, so that the orbit correction will be impacted. BPM may make mistakes in the process of signal acquisition and current conversion. A BPM anomaly detection and predict method based on machine learning and its using in orbit correction optimization is reported in this paper. This method does not need to observe the details of BPM system, electronics technology and so on. It can monitor and predict the BPM status directly by machine learning with the information of the beam inferred from BPM and others, and optimize the orbit correction.

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paper received ※ 15 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

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WEPGW061

Bunch Length Measurement Using Multi-Frequency Harmonic Analysis Method at SSRF

SRF, experiment, operation, framework

2616

Y.M. Zhou, B. Gao, Y.B. Leng, N. Zhang
SSRF, Shanghai, People’s Republic of China

Harmonics method in the frequency domain is an effective and inexpensive bunch length measurement method, which was implemented at the Shanghai Synchrotron Radiation Facility (SSRF). A multi-frequency bunch-bybunch length measurement system using an integrated RF conditioning module will be established to reduce the system noise and signal reflection, and to improve the bunch length measurement accuracy as well. The module consists of power splitters, band-pass filters, mixers and so on. The main function of the integrated RF conditioning module is to extract the beam signals at 500MHz, 1.5GHz, 2GHz, and 3GHz operating frequency. Raw data are acquired by a high-precision digitizer and analyzed by MATLAB code. The absolute bunch length can be obtained with a streak camera, which was used to calibrate the response coefficients of the system. Bunch-by-bunch length can be measured by the multi-frequency harmonic analysis method from the button BPM

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paper received ※ 15 May 2019 paper accepted ※ 18 May 2019 issue date ※ 21 June 2019

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WEPGW062

Synchrotron Light Diagnostic Beamline Design for HEPS Storage Ring

emittance, photon, diagnostics, lattice

2619

D.C. Zhu, J.S. Cao, Y.F. Sui, J.H. Yue
IHEP, Beijing, People’s Republic of China

Funding: National Nature Science Foundation of China(11605213)
High Energy Photon Source (HEPS) is a 6 GeV ul-tralow-emittance storage ring light source to be built in Beijing, China. With a multiple-bend achromat lattice design, the storage ring is expected to achieve an ul-tralow emittance of 34 pm.rad. The horizontal and verti-cal beam sizes will be in the sub-10 μm level. Beam emit-tance will be measured with x-ray diagnostic beamline at a low dispersion bending magnet source point. A visible light beamline will be designed to measure the bunch length and purity. In this paper, we will introduce the x-ray beamline, which combine with different techniques to resolve beam sizes and emittance.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPGW062

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paper received ※ 15 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

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WEPGW071

Evaluation of a New 500 MHz Digitizer at Elettra and Fermi

pick-up, interface, insertion, EPICS

2635

P. Leban, M. Žnidarčič
I-Tech, Solkan, Slovenia
S. Bassanese, G. Brajnik, R. De Monte
Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy

A new digitizer was evaluated in ELETTRA storage ring and FERMI linear accelerator. The A/D conversion is done with 14-bits at 500 MS/s. The sampling clock is hard-locked to the Master Oscillator and has a jitter of a maximum 10 ps. The AC coupled version has an analog bandwidth up to 2 GHz and was used to measure the fill pattern. The bunch flat-top is very narrow (10^-15 ps). To reach better stability, various external filtering components were used. Bunch-by-bunch beam position was calculated offline and compared to a standard BPM electronics. The DC coupled version was used to sample pulses from the fast current transformer at FERMI. A software interface can configure data acquisition length and fill buffer segments with pre-defined number of triggers. Native TANGO and EPICS interfaces allow for fast integration with CSS and other display tools.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPGW071

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paper received ※ 13 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019

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WEPGW085

Development of Operating Alarm System at TPS

operation, controls, vacuum, EPICS

2684

C.S. Huang, B.Y. Chen, C.K. Kuan, C.H. Kuo, T.Y. Lee, W.Y. Lin, S.Y. Perng, T.C. Tseng, H.S. Wang
NSRRC, Hsinchu, Taiwan

The Taiwan Photon Source (TPS) has many subsystems which includes magnet, power supply, vacuum, RF system, insertion device, control system, etc. Therefore, the operational and system check procedures are complex. In this paper, we summarize the routine operational procedures and propose an integrated operational alarm system that gathers machine information and sets high/low warning and fault limits for various signals which can help operators to quickly identify abnormal subsystems, thereby reducing machinery down time. The alarm system also has a wide range of applications, such as the event recording that helps the analysis after event. This new alarm system interface clearly indicates the machine status and improves operational efficiency.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPGW085

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paper received ※ 15 April 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019

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WEPGW101

A New Orbit Feedforward Table Generation Method for Insertion Devices

insertion-device, sextupole, insertion, ISOL

2724

Y. Hidaka, B.N. Kosciuk, B. Podobedov, J. Rank, T. Tanabe
BNL, Upton, Long Island, New York, USA

Funding: The study is supported by U.S. DOE under Contract No. DE-SC0012704.
A new method of orbit feedforward (FF) table generation for insertion devices (IDs) is proposed. The main purpose of the orbit FF table is to suppress orbit disturbance around a storage ring, caused by the gap/phase motion of an ID. A conventional procedure is to measure a closed orbit at a reference ID gap/phase state, and another one at a different state, with all types of orbit feedback (FB) systems disabled. Based on the difference orbit, the correction currents for the local ID correctors are estimated to cancel the global orbit distortion. The new method instead utilizes the orbit deviation at the beam position monitors within an ID straight section (ID BPMs) with respect to a dynamically changing orbit that is defined by the orbit at two BPMs bounding the ID straight. Correction currents are determined such that this orbit deviation at the ID BPMs is minimized. Being impervious to transverse kicks external to this bounded region, this measurement can be performed with a global orbit FB system turned on, which could allow parallel table generation for multiple IDs.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPGW101

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paper received ※ 17 May 2019 paper accepted ※ 18 May 2019 issue date ※ 21 June 2019

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WEPGW102

Investigation on Mysterious Long-Term Orbit Drift at NSLS-II

accumulation, operation, power-supply, quadrupole

2728

Y. Hidaka, W.X. Cheng, L. Doom, R.P. Fliller, G. Ganetis, J. Gosman, C. Hetzel, R.A. Hubbard, D. Padrazo Jr, B. Podobedov, J. Rose, T.V. Shaftan, S.K. Sharma, V.V. Smaluk, T. Tanabe, Y. Tian, G.M. Wang, C.H. Yu
BNL, Upton, Long Island, New York, USA

Funding: The study is supported by U.S. DOE under Contract No. DE-SC0012704.
Over a few months in 2018, we observed occasional episodes of relatively quick accumulation of correction strengths for the fast correctors (used by the fast orbit feedback) near Cell 4 (C04) region at NSLS-II Storage Ring. We immediately started investigating the problem, but the cause remained unclear. However, after coming back from the Fall shutdown, we experienced even faster drifts, at a rate of as much as 10 urad per day in terms of orbit kick angle accumulation. The risk of damage on the ring vacuum chambers by the continuing orbit drift without explanation eventually forced us to take emergency study shifts and temporarily lock out the C04 IVU beamline. After extensive investigation by many subsystem experts in Accelerator Division, ruling out many suspicious sources one by one, we were finally able to conclude the cause to be the localized ground motion induced by large temperature jumps of the utility tunnel right underneath the C04 straight section. We report the details of this incident.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPGW102

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paper received ※ 19 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

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WEPGW110

Feasibility Study of Beam Profile Measurements Using Interferometer and Diffractometer Techniques for ALS-U

electron, synchrotron, radiation, lattice

2752

C. Sun, S. De Santis, D. Filippetto, F. Sannibale, C. Steier
LBNL, Berkeley, California, USA

Funding: Work supported by the Director Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.
ALS-U is an ongoing upgrade of Advanced Light Source (ALS) at Lawrence Berkeley National Laboratory. The upgraded ALS will replace the existing Triple-Bend Achromat (TBA) storage ring lattice with a compact Multi-Bend Achromat (MBA) lattice. This MBA technology allows us to tightly focus electron beams down to about 10 μm to reach diffraction limit in a soft x-ray region. The beam size measurement is a challenging task for this tightly focused beam. The interferometer technique with visible light from synchrotron radiation has been developed in many facilities to measure their beam size at a micrometer-level accuracy. In this paper, we will present the feasibility study of this technique for the ALS-U storage ring beam size measurement.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPGW110

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paper received ※ 14 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019

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WEPGW111

Design of Booster-to-Accumulator Transfer Line for Advanced Light Source Upgrade

injection, quadrupole, optics, booster

2756

C. Sun, Ph. Amstutz, T. Hellert, J.-Y. Jung, S.C. Leemann, J.R. Osborn, M. Placidi, C. Steier, C.A. Swenson, M. Venturini, W. Wan
LBNL, Berkeley, California, USA

Funding: Work supported by the Director Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.
For the Advanced Light Source Upgrade, an on-axis swap-out injection is applied to exchange bunch trains between the storage ring and the accumulator ring. To replenish the accumulator ring before the swap-out injection, an electron beam from Linac is first injected into the ALS booster to ramp up the energy, and then transported to the accumulator through the Booster-to-Accumulator (BTA) transfer line. The design of the BTA transfer line is a challenging task as it has to fit within a tight space while accommodating the booster and accumulator rings at different elevations. Moreover, the BTA design needs to meet the optics boundary conditions and ideally minimize the size requirements of vacuum-chamber apertures. In this paper, we will present a design option of the BTA transfer line, which meets both space limitations and beam physics requirements.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPGW111

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paper received ※ 14 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

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WEPRB022

RF System Upgrade for Elettra 2.0

cavity, HOM, LLRF, klystron

2849

C. Pasotti, M. Bocciai, M. Rinaldi
Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy

The Elettra 2.0 low emittance light source project has triggered the review of the installed RF system’s performances and the analyses of the new machine requirement. This study includes the imperative revamp of the RF power sources. The trade off between the best theoretical RF system design and the available room for installation and budget for Elettra 2.0 has been translated into the operational plan reported here. The first planned step is the installation of 100 kW 500 MHz solid state based transmitters.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPRB022

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paper received ※ 13 May 2019 paper accepted ※ 18 May 2019 issue date ※ 21 June 2019

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WEPRB066

Utilizing the High Shunt Impedance TM020-Mode Cavity in the Double RF Systems for the Storage Ring of the Thailand New Light Source

cavity, impedance, coupling, damping

2972

N. Juntong, T. Phimsen
SLRI, Nakhon Ratchasima, Thailand
N. Chulakham, S. Malichan
Udon Thani Rajabhat University, Udon Thani, Thailand

The utilization of the TM020-mode cavity for the storage ring based light source was pioneered by SPring-8 with its high quality factor and hence its high shunt impedance. KEK-LS has also studied the possibility of using this type of cavity for their storage ring. The TM020-mode cavity has larger transverse dimension compared to the traditional TM010-mode cavity, but with its higher shunt impedance it can be designed to fit in the new low emittance storage ring regardless. The new storage ring based light source project in Thailand aims to optimum the low emittance beam in nano-meters region with the energy of 3 GeV. The TM020-mode cavity was considered as the main cavity and the harmonic cavity for the storage ring. They have been designed to have their pipe aperture fits the storage ring beam ducts. The main cavity has a high shunt impedance of 8.3 Mega Ohms with the 51,000 unloaded quality factor. The harmonic cavity has a high shunt impedance and an unloaded quality factor of 2.45 Mega Ohms and 36,000, respectively. The damping mechanism of the parasitic modes and the tuning mechanism of the operating mode of these cavities were also studied. There will be four main cavities and six harmonic cavities in the new storage ring. Detailed design and study of these cavities will be presented.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPRB066

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paper received ※ 29 April 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019

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WEPRB115

Development of RF Interlock and Diagnostics Systems in SOLARIS Storage Ring

network, cavity, synchrotron, betatron

3082

M.A. Knafel, M. Madura
Solaris National Synchrotron Radiation Centre, Jagiellonian University, Kraków, Poland
A.I. Wawrzyniak
SOLARIS, Kraków, Poland

The purpose of this document is to describe and asses the operation of various devices that have been developed, constructed and tested by RF team in NSRC SOLARIS . One of those devices is used as additional safety interlock for the tuning mechanism of main 100MHz active cavities. The other is a stripline feeding network, that in cooperation with BPM receiving network will excite the beam providing the diagnostics group with a new option for tune measurement. Each device shall have its principle of operation explained and construction details revealed. Finally, all devices will be assesed over their operational lifetime in our facility.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPRB115

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paper received ※ 15 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

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WEPRB116

X-ray Pinhole Camera for Emittance Measurements in Solaris Storage Ring

emittance, photon, radiation, diagnostics

3084

A. Kisiel, A.M. Marendziak, M. Ptaszkiewicz, A.I. Wawrzyniak
Solaris National Synchrotron Radiation Centre, Jagiellonian University, Kraków, Poland

X-ray pinhole camera is widely used system for the transverse beam profile measurement and emittance feedback. However this method is predominantly applied to the middle and high energy storage rings. At Solaris storage ring with the nominal energy of 1.5 GeV, the design of the beamline was modified to provide sufficient X-ray photon flux for proper imaging. The successful installation and commissioning of the X-ray pinhole beamline allows now to measure the emittance and helps in proper 3rd harmonic cavities tuning against the coupled bunch mode instabilities. The paper describes the design details, simulations and measurement results obtained during the beamline operation.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPRB116

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paper received ※ 14 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

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WEPTS015

Synchronous Measurements of Electron Bunches Under the Influence of the Microbunching Instability

synchrotron, radiation, bunching, simulation

3119

M. Brosi, T. Boltz, E. Bründermann, S. Funkner, B. Kehrer, A.-S. Müller, M.J. Nasse, G. Niehues, M.M. Patil, P. Schreiber, P. Schönfeldt, J.L. Steinmann
KIT, Karlsruhe, Germany

Funding: This work has been supported by the German Federal Ministry of Education and Research (Grant No. 05K16VKA). We acknowledge the support by the Helmholtz International Research School for Teratronics.
The microbunching instability is a longitudinal collective instability which occurs for short electron bunches in a storage ring above a certain threshold current. The instability leads to a charge modulation in the longitudinal phase space. The resulting substructures on the longitudinal bunch profile vary over time and lead to fluctuations in the emitted power of coherent synchrotron radiation (CSR). To study the underlying longitudinal dynamics on a turn-by-turn basis, the KIT storage ring KARA (Karlsruhe Research Accelerator) provides a wide variety of diagnostic systems. By synchronizing the single-shot electro-optical spectral decoding setup (longitudinal profile), the bunch-by-bunch THz detection systems (THz power) and the horizontal bunch size measurement setup (energy spread), three important properties of the bunch during this instability can be measured at every turn for long time scales. This allows a deep insight into the dynamics of the bunch under the influence of the microbunching instability. This contribution will discuss effects like the connection between the emitted CSR power and the deformations in the longitudinal bunch profile on the time scale of the instability.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPTS015

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paper received ※ 14 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

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WEPTS028

Transverse-Longitudinal Coupling for Harmonic Generation and Bunch Length Manipulation

emittance, bunching, coupling, lattice

3160

X.J. Deng, W.-H. Huang, C.-X. Tang, Y. Zhang
TUB, Beijing, People’s Republic of China
A. Chao
SLAC, Menlo Park, California, USA

A general harmonic generation and bunch length manipulation scheme using transverse-longitudinal coupling is presented. The method makes use of the freedom in projecting the three beam eigen-emittances into different physical dimensions. A realization of this coupling lattice, a PEHG variant, is given as an example. For the purpose of harmonic generation and bunch compression, this method is advantageous when the transverse emittance is small. The combination with sawtooth waveform modulation is proposed to boost the bunching further. Transverse-longitudinal coupling in storage rings are briefly discussed.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPTS028

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paper received ※ 15 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

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WEPTS053

Frequency Map Measurements at the TPS

resonance, dynamic-aperture, operation, MMI

3240

C.H. Chen, B.Y. Chen, J.Y. Chen, M.-S. Chiu, P.J. Chou, T.W. Hsu, B.Y. Huang, C.-C. Kuo, W.Y. Lin, Y.-C. Liu, H.-J. Tsai, F.H. Tseng
NSRRC, Hsinchu, Taiwan

Taiwan Photon Source (TPS) has been operated for several years since it’s first light in December 2014. TPS has achieved reliable routine operation at 500 mA with more than 10 hrs beam lifetime. The dynamic aperture measurements and associated Frequency Map Analyses (FMA) at TPS reveal the beam dynamics behavior with and without insertion devices. A preliminary measurement study by using the turn-by-turn BPMs and comparison with the model simulation results will be presented in this paper.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPTS053

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paper received ※ 30 April 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

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WEPTS060

Multi-objective Optimization of 3D Beam Tracking in Electrostatic Beamlines

simulation, experiment, quadrupole, lattice

3263

V. Rodin, J.R. Hunt, J. Resta-López, B. Veglia, C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom
J.R. Hunt, J. Resta-López, V. Rodin, B. Veglia, C.P. Welsch
The University of Liverpool, Liverpool, United Kingdom

Funding: *This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 721559.
After CERN’s Long Shutdown 2 (LS2) the Extra Low Energy Antiproton (ELENA) ring will begin providing extremely low energy (100 keV) antiproton beams to the antimatter experiments in the AD hall. To allow for simultaneous operation and guarantee maximum efficiency, all transfer lines will be based on electrostatic optics and short pulse (∼100 ns) deflectors. Currently, only a limited number of simulation codes allow a realistic representation of these elements, limiting the capabilities for beam quality optimization. In this contribution methods for modelling realistic electrostatic optical elements and perform 3D tracking studies through these are presented. A combination of finite element methods and experimental measurements are used along with a modified version of the G4Beamline and BMAD codes. Multi-objective optimization techniques are then applied to optimize beam transfer and beam quality at various points along the transfer lines.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPTS060

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paper received ※ 14 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019

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WEPTS101

A General Comparison on Impedance Theory and CST Simulation of Discontinuities

impedance, simulation, vacuum, coupling

3352

N. Khosravi, E. Ahmadi, M. Akhyani, S. Dastan, A.M. Mash’al
ILSF, Tehran, Iran
H. Karimi
Isfahan University of Technology, Isfahan, Iran

Inhomogeneity of vacuum chamber components is the main source of coupling impedance. Nowadays, wake potential is mostly predictable by 3D codes. Analytical prediction of impedance theories can be helpful as a side solution. On the other hand, some asymmetries in the geometry of components might make troubles and lead to imprecise numerical results in 3D simulations. Analytical approximation of discontinuities, holes, and grooves can give us an estimation of expected results and can be used as a benchmark in the case that we do not have any experimental data. To clarify the validity of theoretical expressions, general discontinuities are simulated in CST. The comparison of final results is presented here. At last, resistive wall impedance and some general discontinuities of components at ILSF storage ring are compared from the theoretical and simulation point of view.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPTS101

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paper received ※ 01 May 2019 paper accepted ※ 24 May 2019 issue date ※ 21 June 2019

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WEPTS103

Optimization of a Low-Alpha Lattice for the HLS-II Storage Ring

lattice, quadrupole, dynamic-aperture, sextupole

3360

S.W. Wang, Y.G. Wang, W. Xu, K. Xuan
USTC/NSRL, Hefei, Anhui, People’s Republic of China
J.Y. Li
IHEP, Beijing, People’s Republic of China

To generate terahertz radiation at HLS-II, a low-alpha lattice scheme is proposed. The new lattice can reduce the bunch length in the storage ring, thus enhancing the coherent synchrotron radiation in the THz region. In this paper, the design and optimization of a low-alpha lattice is reported. The new lattice preserves the symmetry of nominal lattice and reduces the first and second order momentum factor at the cost of increasing maximum beta function and natural emittance. The bunch length is tracked and the result shows that the low-alpha lattice can effectively compress bunches in the storage ring. The performance of this low-alpha lattice can be further studied and improved.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPTS103

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paper received ※ 29 April 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

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THYYPLM3

High-Charge Injector for on-Axis Injection Into A High-Performance Storage Ring Light Source

booster, injection, synchrotron, emittance

3423

K.C. Harkay, I.A. Abid, T.G. Berenc, W. Berg, M. Borland, A.R. Brill, D.J. Bromberek, J.M. Byrd, J.R. Calvey, J. Carvelli, J.C. Dooling, L. Emery, T. Fors, G.I. Fystro, A. Goel, D. Hui, R.T. Keane, R. Laird, F. Lenkszus, R.R. Lindberg, T.J. Madden, B.J. Micklich, L.H. Morrison, S.J. Pasky, V. Sajaev, N. Sereno, H. Shang, T.L. Smith, J.B. Stevens, Y. Sun, G.J. Waldschmidt, J. Wang, U. Wienands, K.P. Wootton, A. Xiao, B.X. Yang, Y. Yang, C. Yao
ANL, Argonne, Illinois, USA
A. Blednykh
BNL, Upton, Long Island, New York, USA
A.H. Lumpkin
Fermilab, Batavia, Illinois, USA

Funding: Work supported by U. S. Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11357.
Next-generation, high-performance storage ring light sources based on multibend achromat optics will require on-axis injection because of the extremely small dynamic aperture. Injectors will need to supply full-current bunch replacement in the ring with high single-bunch charge for swap-out. For upgrades of existing light sources, such as the Advanced Photon Source Upgrade (APS-U), it is economical to retain the existing injector infrastructure and make appropriate improvements. The challenges to these improvements include achieving high single-bunch charge in the presence of instabilities, beam loading, charge stability and reliability. In this paper, we discuss the rationale for the injector upgrades chosen for APS-U, as well as backup and potential alternate schemes. To date, we have achieved single-bunch charge from the injectors that doubles the original design value, and have a goal to achieve about three times the original design value.

Slides THYYPLM3 [1.499 MB]

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paper received ※ 15 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

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THPGW053

Exploiting the Potential of ISOLDE at CERN (the EPIC Project)

ISOL, experiment, target, proton

3706

R. Catherall, T.J. Giles, G. Neyens
CERN, Geneva, Switzerland

The ISOLDE Facility at CERN * is the world’s leading facility for the production of radioactive ion beams (RIBs) using the ISOL (Isotope Separation On-Line) method, providing RIBs at energies from 30 keV to 10 MeV/u for a wide variety of experiments. To improve on its capacity to deliver RIBs further from stability, the EPIC project takes full advantage of recent investments by CERN to upgrade the LHC injectors **. In particular, the new Linac4 and the PS Booster upgrade allow expanding the scope of ISOLDE by providing higher radioactive ion beam intensities further from stability. Sharing the proton-beam between two target stations that simultaneously feed the low-energy and high-energy beam lines will more than double the annual available beam time for experiments. To take further advantage of enhanced beam time, CERN and the ISOLDE collaboration also aims to studies installing a storage ring behind the HIE-ISOLDE post-accelerator to allow the storage of cooled exotic ion beams and thus opening up new possibilities in the fields of astrophysics, fundamental symmetry studies, atomic physics and nuclear physics.
* B. Jonson, K. Riisager (2010), Scholarpedia, 5(7):9742 doi:10.4249/scholarpedia.9742
** K. Hanke et al.DOI: 10.18429/JACoW-IPAC2017-WEPVA036

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paper received ※ 15 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

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THPRB001

Applications of Online Optimization Algorithms for Injection at the Australian Synchrotron

quadrupole, synchrotron, injection, optics

3795

R. Auchettl, R.T. Dowd
AS - ANSTO, Clayton, Australia

At the Australian Synchrotron, accelerator tuning predominantly occurs via manual optimization or traditional optimization techniques such as the Linear Optics from Closed Orbits (LOCO) algorithm. While we have had distinct success with the implementation of LOCO* and manual tuning, these strategies are not without their downsides. Some situations (such as the optimization of synchrotron beam dynamics) produce a design space too large and multifaceted for manual tuning while implementing LOCO can be computationally expensive. Also, without sufficient diagnostic systems, both LOCO and manual tuning do not necessarily guarantee that the optimal solution will be found. Motivated by the successful implementation of online optimization algorithms at SPEAR3**, this paper outlines the application of online optimization algorithms to improve the performance of the Australian Synchrotron injection system. We apply the efficient Robust Conjugate Direction Search (RCDS) Algorithm to reduce beam loss along the Booster-to-Storage ring (BTS) Transfer line and Storage Ring and compare against the LOCO method.
* R. Dowd et al. (2011), Phys. Rev. ST: AB, 14, 012804.
** X. Huang et al. (2013), Nucl. Instr. Meth. A., vol. 726, pp. 77-83.

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paper received ※ 08 April 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019

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THPRB034

Timing Synchronization System for Beam Injection from the SACLA Linac to the SPring-8 Storage Ring

timing, linac, injection, laser

3882

T. Ohshima, N. Hosoda, S. Matsubara
JASRI, Hyogo, Japan
N. Hosoda, H. Maesaka, T. Ohshima
RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan

We developed a timing synchronization system for beam injections from the linac of the X-ray free-electron laser (XFEL), SACLA, to the current SPring-8 storage ring. This injection scheme is beneficial for the next upgraded ring, SPring-8-II, where low emittance injection beams is required. The developed timing system aims at synchronizing the timing between the RF frequencies of the two accelerators which do not have a common subharmonic frequency. An important point is to keep the high performance of the current timing system which provides stable XFEL operation at SACLA. For this purpose, we designed and constructed a MicroTCA.4 system comprised of a high-speed ADC and an RF front-end for the synchronization. The RF signal of SACLA is digitized by the ADC whose clock is synchronized to SPring-8. A digital down-converter in the FPGA on the ADC module gives the phase difference instantaneously and a feedback logic applies a frequency modulation (FM) to the master oscillator of SACLA so as to synchronize SACLA with SPring-8. A bench test result showed that the timing jitter between the two frequency at injection timing was 1.2 ps rms, which was sufficient for the required value of 3 ps rms for the beam injection to the ring. In this presentation, we report an overview of the synchronization system, details of the developed electronics and the system performance obtained by a beam injection experiment from SACLA to SPring-8.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB034

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paper received ※ 30 April 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

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THPRB043

Design and Simulation of Thin Eddy-Current Septum for Injection of Diffraction Limited Storage Ring

septum, injection, simulation, HOM

3908

J. Tong, M. Gu, B. Liu, Y.F. Liu, R. Wang
SINAP, Shanghai, People’s Republic of China

Funding: Work supported by the National Key Research and Development Program of China(Grant No.2016YFA0402002)
Ultra-low emittance in Diffraction Limited Storage Ring (DLSR) usually has small Dynamic Aperture (DA), which makes the traditional off-axis injection inadequate. Fast kickers together with thin septum magnets or direct current lambertsons could support on-axis injection for closely-spaced bunches with small DA. Thin eddy-current septum prototype had been designed for injection with laminated silicon steel sheets as magnet core. Theoretical analysis and transient simulation had been carried out within OPERA software. Due to the minimum thickness of the septa is only 1 mm , several optimization approaches had been applied, such as shielding with strongly paramagnetic material and exciting with full cycle driving pulse, to satisfy the requirement that the leakage field is less than 0.1% with respect to the main one.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB043

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paper received ※ 29 April 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019

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THPRB059

Radiation Safety at SOLARIS 1.5 GeV Storage Ring

radiation, injection, electron, MMI

3940

M.B. Jaglarz
SOLARIS, Kraków, Poland
A.I. Wawrzyniak, J. Wikłacz
Solaris National Synchrotron Radiation Centre, Jagiellonian University, Kraków, Poland

Radiation measurements at Solaris are continuously performed by using 9 radiation monitor stations (RMS) located around the storage ring and the beamlines area. 4 of RMS are connected to the Personal Safety System and in case of exceeding alarm level dump the beam or close safety shutters. Moreover thermoluminescence dosimeters (TLDs) are used to registered doses in the classified areas according to the Polish regulation. Measurements are performed since 2015 when the commissioning of the storage ring has started. Since that time several improvements to the radiation shielding was done to fulfill the ALARA principle. Moreover the electron beam optimizations during the injection, ramping and operation were performed to decrease the electrons losses and the radiation level. This presentation will report on radiation measurements results obtained before and after the chopper installation. Additionally problems with radiation level while the beam current is increasing to the designed 500mA value will be presented.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB059

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paper received ※ 26 April 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

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THPRB071

Beam-Based Measurements on Two ±12.5 kV Inductive Adders, together with Striplines, for CLIC Damping Ring Extraction Kickers

kicker, flattop, extraction, damping

3970

J. Holma, M.J. Barnes, M. Carlà, N. Catalán Lasheras, Y. Papaphilippou
CERN, Geneva, Switzerland
U. Iriso, Z. Martí, F. Pérez, M. Pont
ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain

The CLIC study is investigating the technical feasibil-ity of an electron-positron linear collider with high lumi-nosity and a nominal centre-of-mass energy of 3 TeV. Pre-damping rings and damping rings (DRs) will produce ultra-low emittance beam with high bunch charge. The DR kicker systems, each of which consists of a set of striplines and two inductive adders, must provide ex-tremely stable field pulses. The DR extraction kicker system is the most demanding: specifications require a field uniformity within ±0.01% and pulses up to 900 ns flattop duration, at ±12.5 kV and 309 A, with ripple and droop of not more than ±0.02 % (±2.5 V), with respect to a reference waveform. Two prototype inductive adders have been designed and built at CERN, and have been tested with prototype striplines installed in the storage ring of the ALBA Synchrotron Light Source, in Spain. The stability of the kicker system, including the modulators, has been evaluated from the beam-based measure-ments and is reported in this paper.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB071

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paper received ※ 15 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

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THPRB088

Optimizing The Reliability of The Fire Alarm System in The Taiwan Photon Source

detector, radiation, controls, shielding

4026

W.S. Chan, F.-D. Chang, C.S. Chen, Y.F. Chiu, J.C. Liu, Z.-D. Tsai
NSRRC, Hsinchu, Taiwan

The fire alarm system plays a critical role for the safety of building occupants. However, in the past two years from 2016 to 2017, occasionally false alarms at the Taiwan Photon Source (TPS) occurred. Results of more detailed observations indicated that radiation and/or electromagnetic interference (EMI) of the TPS accelerator disturb smoke detectors and signal line circuits (SLCs). Lead shielding covers, adjusting of the detector alarm verification time and a laser-based aspi-rating smoke detector were used to reduce the probabil-ity that fire alarms become activated to less than 0.5 times per year.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB088

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paper received ※ 14 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

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THPRB092

Reduction of Beam Induced RF-Heating in the Horizontal Stripline Kicker at the TPS

kicker, impedance, feedback, damping

4035

P.J. Chou, C.K. Chan, C.-C. Chang, K.T. Hsu, K.H. Hu, C.K. Kuan, I.C. Sheng
NSRRC, Hsinchu, Taiwan

In preparation for 500 mA operation at the Taiwan Pho-ton Source (TPS), we redesigned the horizontal stripline kicker for the beam feedback system to gain a smaller loss factor with higher shunt impedance. We introduced ground fenders (see Fig. 1) to this new design which resulted in the reduction of the loss factor and substantial increase of the kicker shunt impedance. The transverse profile of the kicker electrodes was matched to the race-track beam pipe in the straight sections to minimize broadband impedance. The ground fenders can reduce the leakage of image currents through the gaps between the two strip line electrodes and also help to achieve a better impedance matching for the TEM modes in the transmission lines formed by the stripline electrodes and beam pipe in the kicker. The RF design and analysis of trapped resonant modes in the kicker were simulated by the 3-D electromagnetic code GdfidL [1]. Results of the RF design and analysis of trapped resonant modes will be discussed together with analytical estimates of coupled bunch instabilities at a beam current of 500 mA.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB092

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paper received ※ 17 April 2019 paper accepted ※ 19 May 2019 issue date ※ 21 June 2019

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THPRB099

Applications of Dimension-Reduction to Various Accelerator Physics Problems

dynamic-aperture, kicker, sextupole, synchrotron

4060

W.F. Bergan, I.V. Bazarov, C.J.R. Duncan, D.L. Rubin
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

Funding: DE-SC 0013571 DGE-1650441 OIA-1549132
Particle accelerators contain hundreds of magnets, making dimension-reduction techniques attractive when attempting to tune them. We apply this procedure to two different problems: correcting the orbit in the Cornell synchrotron and maximizing the dynamic aperture in the Cornell Electron Storage Ring (CESR). Cornell’s rapid cycling synchrotron accepts a 200 MeV beam from the linac and accelerates it to 6 GeV for injection into the CESR. ‘Kicker coils’ (dipole correctors) are used to correct for residual fields which would otherwise cause beam loss at the low energies. In such cases, it is usually advisable to measure and correct the orbit. However, one cannot measure the orbit without first getting the beam to circulate a few hundred times, by which point the low-energy orbit would already be mostly corrected. In order to speed up the process of empirical orbit tuning, we form knobs which have the largest effect on the global orbit error, so that the dimensionality of the space which must be searched may be greatly reduced. A small dynamic aperture in CESR will have adverse effects on beam lifetime and injection efficiency, and so ought to be maximized by tuning sextupoles. However, it is often unclear which sextupoles one ought to tune to alleviate the problem. Moreover, once the chromaticity is properly adjusted, it should not be changed. Since we expect resonance driving terms (RDTs) to have a large impact on the dynamic aperture, we develop sextupole knobs which change the RDTs as much as possible while leaving the chromaticity fixed.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB099

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paper received ※ 14 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

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THPRB104

Improvements in Long-Term Orbit Stability at NSLS-II

feedback, operation, photon, controls

4070

Y. Hidaka, A. Caracappa, Y. Hu, B. Podobedov, R.M. Smith, Y. Tian, G.M. Wang
BNL, Upton, Long Island, New York, USA

Funding: The study is supported by U.S. DOE under Contract No. DE-SC0012704.
We report our latest efforts to further improve long-term orbit stability at NSLS-II, on top of what is already provided by fast orbit feedback (FOFB) system. A DC local bump generation program, only utilizing RF beam position monitors (BPM) and compatible with FOFB, was first implemented and deployed in operation successfully, allowing on-demand fine adjustments of beamline source positions and angles. Then we introduced a simple feedback version that performs these bump corrections automatically as needed to maintain the sources within in 1 um/urad for select beamlines. In addition, an RF frequency feedback was also implemented to improve stability for 3-pole wigglers and bending magnet users. As a parallel effort, X-ray BPMs were included in a local feedback system to stabilize photon beam motion for several ID beamlines. However, this feedback scheme is not transparent to FOFB, and suspected to be the source of occasional saturation of fast corrector strength. As an alternative solution, the local bump program and its feedback version has been recently upgraded to include bumps with X-ray BPMs and in operation since April 2019.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB104

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paper received ※ 19 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

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THPTS002

Sirius Pre-alignment Results

alignment, booster, network, laser

4106

R. Junqueira Leão, H. Geraissate Paranhos de Oliveira, F. Rodrigues, G.R. Rovigatti de Oliveira, U.R. Sposito
LNLS, Campinas, Brazil

Sirius is a 4th generation synchrotron light source under final installation and beginning of commissioning phase in Brazil, with a bare emittance of 250 picometer rad. In order to fulfil stability requirements (magnets displacement caused by vibration of 6 nm) imposed to achieve expected performance, the mechanical assembly of supporting structures and magnets were designed without adjustment mechanisms. Yet, the misalignment errors of the magnets are the dominating source of dynamical aperture reduction, leading to a maximum permissible deviation of 40 micrometers between adjacent magnets. To this end, dimensional engineering was applied to conceive an alignment concept for magnets on a same girder based solely on the geometric characteristics of the parts. For the large volume positioning of girders in the storage ring tunnel, the applied methodology followed a strategy optimized to reduce measurement uncertainty, as described in the literature. This paper will present the complete measurement process that led to the alignment of Sirius, from the deployment and survey of reference networks to the final alignment of the machine. To express a consistent and unequivocal alignment result and assess the alignment quality considering the measurement uncertainty, an innovative metric described previously was employed. This work will show that the positioning of supports satisfies the requirement of 80 micrometer between girders. Also, the devices and mechanisms used for assembling will be detailed. Inspection of full girder set performed on a Coordinate measuring machine shows a maximum deviation of 30 micrometers for any pair of magnets on a common support.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPTS002

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paper received ※ 15 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

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THPTS004

The Sirius Heating System for the In-situ NEG Activation

controls, vacuum, power-supply, software

4109

P.H. Nallin, M. Bacchetti, F.G.R. Carrera, D.R. Cavalcante, R.O. Ferraz, P.P.S. Freitas, G.R. Gomes, J.G. Hidalgo, R.T. Neuenschwander, F.A.M. Pinto, A.R.D. Rodrigues, R.M. Seraphim
LNLS, Campinas, Brazil

Sirius is a 3 GeV fourth-generation synchrotron light source under commissioning in Brazil, with 518 m circumference and a bare lattice emittance of 0.25 nm.rad. This ultra-low emittance machine is based on approximately 700 magnets with 28 mm typical gap. The standard vacuum chamber, that makes up around 80% of the circumference, is a 26 mm external diameter copper tube. Due to the small conductance of the chambers and the limited space between the magnets, the vacuum pumping will be based on distributed concept and then non-evaporable getter (NEG) coating will be extensively used. To activate the NEG coating, the chambers must be heated at 200°C for about 24 hours. The solution for Sirius was the development of an ultra-thin heating tape, 0.4 mm thick, which allows an in-situ bake-out. The developed tapes are able to operate continuously at 220°C and have in their design a thermal shield that reduces the radiation heat loss to the magnets. This paper describes the development of the heating tape, its power supply, the control software and the operation of the system during the NEG activation at Sirius.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPTS004

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paper received ※ 15 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

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THPTS017

ILSF Ultralow Emittance Storage Ring Magnets

dipole, quadrupole, sextupole, multipole

4142

F. Saeidi, S. Dastan, J. Rahighi, M. Razazian
ILSF, Tehran, Iran

Iranian Light Source Facility (ILSF) is a 3 GeV synchro-tron which is in the basic design phase. The ILSF storage ring (SR) is based on a Five-Bend Achromat lattice providing a low horizontal beam emittance of 270 pm-rad. The ILSF storage ring consists of 100 combined di-pole magnets of 2 types, 240 quadrupoles in 5 families and also 320 sextupoles in 6 families. In this paper, we present some design features of the SR magnets and dis-cuss the detailed physical design of these electromagnets including electrical and cooling calculations. Using POISSON and OPERA codes [1,2], pole and yoke geome-try was developed for each magnet

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPTS017

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paper received ※ 30 April 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

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THPTS034

Design and Progress of Mechanical Support in HEPS

alignment, simulation, synchrotron, emittance

4180

C.H. Li, Y. Jiao, M.X. Li, H. Wang, Z. Wang, L. Wu, N. Zhou
IHEP, Beijing, People’s Republic of China

HEPS is a new generation synchrotron facility on construction with very low emittance. Stringent requirements are proposed to the design of mechanical support. The alignment error between girders should be less than 50μm. Based on that, the adjusting resolution of the girder are required to be less than 5μm in both transverse and vertical directions. Besides, the Eigen frequency of magnet & girder assembly should be higher than 54Hz to avoid the amplification of ground vibrations. To fulfill these requirements, studies on mechanical support design is now being carried out in HEPS. This paper will describe the design and progress of those work.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPTS034

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paper received ※ 14 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

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THPTS046

The Limited B-Field Integral of Superconducting Longitudinal Gradient Bend Magnet

simulation, emittance, synchrotron-radiation, radiation

4213

C. Chen, L. Wang, H.R. Zhang, T. Zhang
USTC/NSRL, Hefei, Anhui, People’s Republic of China

The National Synchrotron Radiation Laboratory (NSRL) is planning a fourth generation diffraction-limited light source–Hefei Advanced Light Source (HALS), it is based on a seven-bend achromat lattice providing an ultralow natural emittance of 34 pm rad. The emittance can be even lower with the use of longitudinal gradient bends (LGBs) and anti-bends (ABs). The designed energy for HALS is 2.4 GeV, superconducting LGB might be employed instead of normal bending magnet since it can improve radiated beam critical energy to hard x-ray regions without using up any straight sections. To get a peak field about 6 T and small B-field profile full width half maximum, SLS-2 type LGB is considered. In this paper, the limited B-field integral (along the beam path) is trying to be find with some restrictions.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPTS046

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paper received ※ 12 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019

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THPTS056

New Undulator and Front End for XAIRA Beamline at ALBA

undulator, photon, vacuum, synchrotron

4231

J. Campmany, J. Marcos, V. Massana
ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain

A new microfocus beamline for macromolecular crystallography, XAIRA, is being built at ALBA synchrotron light source. The light source for this new beamline is an in-vacuum undulator that can reach the spectrum range from 4 keV up to 20 keV. The in-vacuum undulator was terndered in 2018 and awarded to Kyma-RI consortium, and will be delivered to ALBA in November 2019. The Front End has been designed accordingly. It was tendered in 2018 and awarded to FMB. It will be delivered along second semester of 2019. In this paper we present the ID and FE designs.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPTS056

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paper received ※ 11 April 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

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THPTS057

New Small Diameter Rotating Coil Shaft for Characterizing New Generation of Multipolar Magnets

controls, alignment, quadrupole, data-acquisition

4234

J. Marcos, J. Campmany, V. Massana, R. Petrocelli, L.R.M. Ribó
ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain

The proliferation of ultimate-light source facilities around the world has yielded the need of accurate characterization of small gap magnets. This also applies to multipolar magnets. Clearance diameters down to 10 mm for quadrupoless and sextupoles become to be used and need to be accurately measured. At these small gaps, the high order multipoles influence on electron beam dynamics is high, and it should be well characterized in order to guarantee a feasible operation of the accelerator. To face this challenge, ALBA magnetics measurement laboratory has developed a new rotating coil shaft with a diameter of 10 mm able to be introduced inside narrow-gap multipolar magnets. In this paper we present the design as well as the first characterization of such a device.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPTS057

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paper received ※ 11 April 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

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THPTS059

Development of a 1.5 GHz, 1 KW Solid State Power Amplifier for 3rd Harmonic System of the Alba Storage Ring

cavity, network, ISOL, operation

4240

Z. Hazami, F. Pérez, A. Salom, P. Solans
ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain

ALBA is the Spanish third generation synchrotron light source, located near Barcelona, in operation since 2012. In order to improve the operation, a third harmonic system has been designed for the Storage Ring in order to stretch the bunch length, and so, improve the beam life time and increase the stability current thresholds. The design of the system consist of four Higher Order Mode (HOM) damped normal conductive active cavities at 1.5 GHz*, feed with 20 kW of RF power each cavity, in order to provide the voltage of 1 MV to the electron beam. The 20 kW RF power transmitter system is based on 250 W solid state power amplifier modules added in parallel by a tree combination technique. The selected combination tree divides the 20 kW overall power per cavity in twenty 1 kW crates. This paper presents the designs of the 250 W power amplifier modules, of the splitter and of the combiner, as well as the measurement results of a 1 kW prototype crate.
* HOM Damped Normal Conducting 1.5 GHz Cavity for the 3rd Harmonic System of the ALBA Storage Ring. IPAC 2019 proceedings

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPTS059

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paper received ※ 14 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

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THPTS075

Performance Tests of a Digital Low-Level Rf-System at the TPS

LLRF, beam-loading, cavity, controls

4292

F.Y. Chang, L.-H. Chang, M.H. Chang, S.W. Chang, L.J. Chen, F.-T. Chung, Y.T. Li, M.-C. Lin, Z.K. Liu, C.H. Lo, Ch. Wang, M.-S. Yeh, T.-C. Yu
NSRRC, Hsinchu, Taiwan

A digital low-level RF (DLLRF) control system for the cavity gap voltage is now common throughout the world. At the Taiwan Photon Source (TPS) we installed and operated a DLLRF in the booster ring in 2018 successfully and plan to install it also in the storage ring in 2019. Operational and beam loading tests of the DLLRF at the storage ring are ongoing. The performance of the DLLRF in the presence of a large number of 60 Hz harmonics and its stability for gap voltage and phase will be discussed.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPTS075

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paper received ※ 10 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

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