IPAC2019 - List of Keywords (optics)

Paper	Title	Other Keywords	Page
MOPGW006	Long Range Beam Beam: Towards Faster Computations	interaction-region, closed-orbit, lattice, betatron	72
	S.R. Koscielniak TRIUMF, Vancouver, Canada
	We outline some features of a program of study toward faster computation of the cumulative effect of a sequence of beam-beam interactions across the interaction region.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW006
About •	paper received ※ 23 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019
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MOPGW012	Study of Fringe Fields Effects from Final Focus Quadrupoles on Beam Based Measured Quantities	quadrupole, multipole, dynamic-aperture, simulation	90
	T. Pugnat, B. Dalena CEA-IRFU, Gif-sur-Yvette, France L. Bonaventura, A. Simona Politecnico di Milano, Milano, Italy R. De Maria, V.K.B. Olsen CERN, Geneva, Switzerland
	Accelerator physics needs advanced modeling and simulation techniques, in particular for beam stability studies. A deeper understanding of the effects of magnetic fields non-linearities will greatly help in the improvement of future colliders design and performance. In , a new tracking method was proposed to study the effect of the longitudinal dependency of the harmonics on the beam dynamics. In this paper, the study will focus on the effects on observable quantities in beam based measurements, for the case of HL-LHC Inner Triplet and with possible tests in LHC. T. Pugnat et al., "Accurate and Efficient Tracking in Electromagnetic Quadrupoles", in Proc. IPAC’18, Vancouver, Canada, June 2018, paper THPAK004, pp. 3207.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW012
About •	paper received ※ 14 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019
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MOPGW014	Developing Beam Optics for the BESSY VSR Project	quadrupole, storage-ring, 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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MOPGW019	Beam-Beam Blowup Issue After Low Emittance Tuning for FCC-ee	emittance, lattice, simulation, coupling	112
	D. El Khechen, K. Oide, F. Zimmermann CERN, Geneva, Switzerland K. Oide KEK, Ibaraki, Japan
	FCC-ee (Future Circular Collider) is a 100 km electron-positron circular collider with two foreseen experiments, aiming to run at four energies for precision studies of the Z, W, and Higgs boson and the top quark. The FCC-ee is a challenging machine from different points of view. In particular the beam-beam effects are of great importance. For the FCC-ee high-luminosity operation, the beam-beam effects impose profound constraints on the operating point in betatron tune space. In addition, taking into account different sources of machine nonlinearities, a tracking simulation with beam-beam elements revealed a strong beam blowup, especially in the vertical plane. Such a blowup is a potential obstacle to achieving and maintaining a high luminosity; therefore it needs to be carefully studied. In this paper, we present a general overview of simulation results on the FCC-ee beam-beam blowup with realistic machine errors.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW019
About •	paper received ※ 10 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
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MOPGW020	Numerical Calculation of Micro Bunching in BERLinPro Due to Space Charge and CSR Effects	bunching, space-charge, linac, emittance	116
	B.C. Kuske, A. Meseck HZB, Berlin, Germany
	Funding: Work supported by the German Bundesministerium für Bildung und Forschung, Land Berlin and grants of the Helmholtz Association BERLinPro is an Energy Recovery Linac Project, currently being set up at the Helmholtz-Zentrum Berlin für Materialien und Energie, Berlin, Germany. BERLinPro is a small demonstrator for ERL technology and applications. Due to the low energy of 50, resp. 32MeV, space charge plays a dominant role in the beam dynamics. Micro-bunching, due to unavoidable shot noise from the cathode in combination with space charge, is seen in the merger as well as in the recirculator. Coherent synchrotron radiation (CSR) can amplify this bunching, as well as micro-bunching can enhance CSR losses. With the release of OPAL 2.0** in May 2018, for the first time, an open source, highly parallel tracking code is available, that is capable of numerically calculating both effects, space charge and CSR, simultaneously. The calculations are compared to earlier results, that used analytical formulas on tracked, space charge dominated bunches. "On space charge driven microbunching instability in BERLinPro", PhD thesis, S.D.Rädel, Humboldt Universität zu Berlin, 2017 ** http://amas.web.psi.ch/docs/opal/opal_user_guide-2.0.0.pdf
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW020
About •	paper received ※ 13 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
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MOPGW022	Achromatic Isochronous Mode of the ESR at GSI	sextupole, experiment, detector, emittance	124
	S.A. Litvinov, M. Steck GSI, Darmstadt, Germany
	The isochronous optics of the ESR is a unique ion-optical setting in which the ring is operated as a Time-of-Flight Mass-Spectrometer and is used for direct mass measurements of short-lived exotic nuclei. The present isochronous optics had been performed only making a negative dispersion in the straight sections of the ESR of about -7 m. This negative dispersion makes the injection into the ESR very complicated and strict the transmission of the ions in the ring. Moreover, the non-achromatism of the ESR brings a supplementary uncorrectable first-order transverse contribution to the revolution time. In order to make the ESR achromatic, to improve injection and the isochronicity a new achromatic isochronous optics has been calculated and will be presented here in details.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW022
About •	paper received ※ 15 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019
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MOPGW026	Transfer Line Optics Design Using Machine Learning Techniques	target, simulation, quadrupole, operation	139
	D.M. Vilsmeier IAP, Frankfurt am Main, Germany M. Bai, M. Sapinski GSI, Darmstadt, Germany
	Optimization of transfer line optics is essential for delivering high quality beams to the experimental areas. This type of optimization is usually done by hand and relies on the experience of operators. The nature of this task is repetitive though highly complex. Besides optimizing the beam quality at the experiments this task is often accompanied by secondary objectives or requirements such as keeping the beam losses below an acceptable threshold. In the past years Deep Learning algorithms have experienced a rapid development and gave rise to various advanced software implementations which allow for straightforward usage of corresponding techniques, such as automatic differentiation and gradient backpropagation. We investigate the applicability and performance of these techniques in the field of transfer line optics optimization, specifically for the HADES beamline at GSI, in form of gradient-based differentiable simulators. We test our setup on results obtained from MADX simulations and compare our findings to different gradient-free optimization methods. Successfully employing such methods relieves operators from the tedious optimization tasks.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW026
About •	paper received ※ 15 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
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MOPGW031	Analysis and Correction for the Effect of Multipoles with Skewed Errors on IP Beam Dynamics in SuperKEKB	luminosity, coupling, MMI, betatron	159
	K. Hirosawa Sokendai, Ibaraki, Japan Y. Funakoshi, H. Koiso, A. Morita, K. Ohmi, Y. Ohnishi, H. Sugimoto, D. Zhou KEK, Ibaraki, Japan
	The beam dynamics at the interaction point (IP) in the accelerators which has the nano-beam scheme like as SuperKEKB is extremely sensitive for skewed error of final focusing magnets (QCS). As proceeding the beta squeezing in the interaction region (IR), the effect of optics aberrations at IP is enhanced. In the SuperKEKB Phase-2 commissioning, there was the problem come from skewed quadrupole fields in IR. The dominant skew parameters ‘‘R" for this problem is very hard to see directly by using beam position monitors, thus it was corrected by scanning R parameters. In the next commissioning Phase-3 which is just before the operation with the Belle II experiment, it is planned that the IP beta squeezing is going forward to design parameters which is smaller than it achieved in Phase-2 by the factor of 4 (for horizontal beta) and 10 (for vertical beta). Hence the effect of skew error will be considerable larger and it is estimated that skew sextupoles will emerge as a serious cause for the aberration from the orbit. This report is the study of analysis and correction results for the effect of QCS skewed errors in the SuperKEKB commissioning.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW031
About •	paper received ※ 19 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
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MOPGW041	Transverse Profile Shaping of a Charged-Particle Beam using Multipole Magnets - Formation of Hollow Beams -	octupole, target, multipole, radiation	184
	Y. Yuri, T. Yuyama QST/Takasaki, Takasaki, Japan M. Fukuda RCNP, Osaka, Japan
	The use of multipole magnets enables us to shape the transverse profile of a charged-particle beam into various ones that can never be realized through linear beam optics. To date, the formation of a large-area beam with a uniform transverse intensity distribution has been actually realized using octupole magnets in several accelerator facilities. In this presentation, we demonstrate the formation of different beam profiles using multipole magnets rather than existing rectangular uniform beams. Results of tracking simulations and beam-formation experiments will be shown on the formation of clear-cut beams with different cross-sectional shapes, depending on the order and strength of applied multipole magnets. The dynamic behavior of a beam focused with multipole magnets is also investigated theoretically to better understand the numerical and experimental results.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW041
About •	paper received ※ 19 April 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
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MOPGW069	Recent Beam Performance Achievements with the Pb-Ion Beam in the SPS for LHC Physics Runs	injection, target, luminosity, flattop	250
	H. Bartosik, R. Alemany-Fernández, T. Argyropoulos, T. Bohl, H. Damerau, V. Kain, G. Papotti, G. Rumolo, A. Saá Hernández, E.N. Shaposhnikova CERN, Meyrin, Switzerland
	In the SPS, which is the last accelerator in the LHC ion injector chain, multiple injections of the Pb-ion beam have to be accumulated. On this injection plateau the beam suffers from considerable degradation such as emittance growth and losses. This paper summarises the achievements on improving the beam parameters and maximising the performance of the Pb-ion beam for the LHC physics run in 2018. The results are discussed in view of the target beam parameters of the LHC injectors upgrade project, which is being deployed during the presently ongoing long shutdown.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW069
About •	paper received ※ 12 May 2019 paper accepted ※ 17 May 2019 issue date ※ 21 June 2019
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MOPGW072	Reconfiguration of SPS Landau Octupole Circuits to Minimise Second Order Chromaticity	octupole, operation, target, acceleration	262
	H. Bartosik, M. Carlà, K. Cornelis CERN, Meyrin, Switzerland
	In the SPS Q20 optics presently used for LHC beams, the Landau octupole families of the SPS (LOF and LOD circuits) generate large second order chromaticity due to the relatively high dispersion at their locations. Since the induced second order chromaticity results in enhanced losses due to the large incoherent tune spread, these octupoles cannot be used for mitigating transverse instabilities for LHC beams. A new cabling scheme was proposed, exploiting additional octupoles that were already installed in the machine but not used, which allows minimizing the induced second order chromaticity in both the Q20 optics used for LHC beams, as well as the original SPS optics used for fixed target beams. This paper summarises the optics calculations as well as the experimental verification of the reduced chromatic detuning of the new octupole scheme.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW072
About •	paper received ※ 12 May 2019 paper accepted ※ 17 May 2019 issue date ※ 21 June 2019
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MOPGW080	Optics Measurements in the CERN PS Booster Using Turn-by-Turn BPM Data	injection, MMI, booster, software	285
	A. Garcia-Tabares, P.K. Skowroński, R. Tomás CERN, Geneva, Switzerland A. Garcia-Tabares Universidad Complutense Madrid, Madrid, Spain
	As part of the LHC Injector Upgrade Project the injection of the CERN PS Booster will be changed to increase intensity and brightness of the delivered beams. The new injection scheme is likely to give rise to beta beating above the required level of 5\% and new measurements are required. Achieving accurate optics measurements in PSB lattice is a challenging task that has involved several improvements in both hardware and software. This paper summarizes all the improvements that have been performed in the optics measurement acquisition system together with a brief summary of the first results obtained.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW080
About •	paper received ※ 11 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
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MOPGW088	A Two-Mode Model to Study the Effect of Space Charge on TMCI in the "Long-Bunch" Regime	coupling, space-charge, impedance, simulation	316
	E. Métral CERN, Geneva, Switzerland
	Using a two-mode approach for the Transverse Mode-Coupling Instability (TMCI) in the ’short-bunch’ regime (where the mode-coupling takes place between the modes 0 and -1, such as in the CERN LHC), both a reactive damper (ReaD) and Space Charge (SC) are expected to be beneficial: the ReaD would shift the mode 0 up while SC would shift the mode -1 down, but in both cases the coupling (and related instability) would occur at higher intensities. However, the situation is more involved in the ’long-bunch’ regime (where the mode-coupling takes place between higher-order modes, such as in the CERN SPS). As the ReaD modifies only the (main) mode 0 and not the others, it is expected to have no effect for the main mode-coupling. As concerns SC, it modifies all the modes except the mode 0, and the result has been a subject of discussion for two decades. A two-mode approach is discussed in detail in this contribution for the case of a single bunch interacting with a broad-band resonator impedance in the ’long-bunch’ regime. This model reveals in particular that in the presence of space charge, the intensity threshold can only be similar to or lower than that in the absence of space charge.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW088
About •	paper received ※ 23 April 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019
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MOPGW090	Alignment of a Magnetic Lattice Based on Particle Tracking	alignment, lattice, controls, sextupole	324
	K.P. Nesteruk, C. Calzolaio, J.M. Schippers PSI, Villigen PSI, Switzerland
	In calculations based on particle tracking in 3D magnetic field maps alignment of the components of a magnetic lattice is essential to obtain desired properties of beam optics. In this contribution we propose a method to control and correct misalignments during the process of the beam optics design. These misalignments would result from overlapping fringe fields of different field maps. The 3D field maps are obtained from the software for electromagnetic calculations OPERA. The full 3D map is saved in the tracking coordinate system and a ROOT (An Object Oriented Data Analysis Framework) ntuple is then created for analysis. The trajectory of the reference particle is calculated by means of OPAL - open source code developed at the Paul Scherrer Institut (PSI). The transverse magnetic field profiles allow possible misalignments to be precisely determined and the corresponding corrections to be calculated. Moreover, the multipole content in discrete locations along the lattice can be controlled by performing a polynomial fit, which calculates the magnetic field harmonics with respect to the reference track. This method was used at PSI for a design of a model of the magnetic lattice for a superconducting gantry for proton therapy with a large momentum acceptance. *An Object Oriented Data Analysis Framework - http://root.cern.ch
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW090
About •	paper received ※ 13 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
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MOPGW093	Optics Calibration for Routine Operations In Taiwan Photon Source	lattice, quadrupole, operation, coupling	335
	F.H. Tseng, C.H. Chen, P.J. Chou NSRRC, Hsinchu, Taiwan
	To ensure a stable performance of Taiwan Photon Source (TPS), we perform the calibration of accelerator optics using LOCO (Linear Optics from Closed Orbit) technique every month. After the optics and coupling corrections, the rms beta beatings in both planes are reduced to less than 1%. The emittance coupling ratio is also restored to within the design value.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW093
About •	paper received ※ 06 May 2019 paper accepted ※ 18 May 2019 issue date ※ 21 June 2019
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MOPGW095	Beam Dynamics Simulations with Crab Cavities in the SPS Machine	multipole, cavity, simulation, luminosity	342
	A. Alekou, A. Alekou, H. Bartosik, H. Bartosik, M. Carlà, Y. Papaphilippou, Y. Papaphilippou, Y. Papaphilippou CERN, Meyrin, Switzerland A. Alekou, A. Alekou, R.B. Appleby, R.B. Appleby UMAN, Manchester, United Kingdom R.B. Appleby Cockcroft Institute, Warrington, Cheshire, United Kingdom
	The LHC Upgrade, called High Luminosity LHC, aims to increase the integrated luminosity by a factor of 10. To achieve this, the project relies on a number of key innovative technologies, including the use of superconducting Crab Cavities with ultra-precise phase control for beam rotation. A set of prototype Crab Cavities has been recently installed in the second largest machine of CERN, the Super Proton Synchrotron (SPS), that operated as a test-bed from May to November of 2018. The tight LHC constraints call for axially non-symmetric cavity designs that introduce high order multipole components. Furthermore, the Crab Cavities in the presence of SPS non-linearities can affect the long term stability of the beam. This paper presents how the SPS dynamic aperture is affected for different cavity, machine and beam configurations.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW095
About •	paper received ※ 06 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
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MOPGW100	Bypass Design for Testing Optical Stochastic Cooling at the Cornell Electron Storage Ring (CESR)	sextupole, radiation, wiggler, damping	360
	W.F. Bergan, M.B. Andorf, M.P. Ehrlichman, V. Khachatryan, D.L. Rubin, S. Wang Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
	Funding: NSF-1734189 DGE-1650441 Optical Stochastic Cooling (OSC) is a promising method for cooling very dense stored particle beams through the interference of radiation created in an upstream ’pickup’ wiggler and a downstream ’kicker’ wiggler. By correlating a particle’s path length via a bypass between the two wigglers with its betatron coordinates in the pickup, the particle will receive a kick in energy which, through coupling introduced by non-zero horizontal dispersion in the kicker, can reduce its betatron amplitude, thus cooling the beam. A proof-of-principle test of this technique is being planned at the Cornell Electron Storage Ring (CESR). In addition to maintaining standard requirements such as a large dynamic aperture and acceptable lattice functions throughout the ring, the design of the bypass is guided by the mutually competing goals of maximizing the cooling rate while maintaining a sufficiently large cooling acceptance with properly-corrected nonlinearities. We present a design of such a bypass and ring optics so as to best achieve these objectives.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW100
About •	paper received ※ 14 May 2019 paper accepted ※ 19 May 2019 issue date ※ 21 June 2019
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MOPGW105	Preliminary Lattice Studies for the Single-Invariant Optics Experiment at the University of Maryland	lattice, experiment, octupole, resonance	367
	L. Dovlatyan, T.M. Antonsen, B.L. Beaudoin, I. Haber, D.B. Matthew UMD, College Park, Maryland, USA K.J. Ruisard ORNL, Oak Ridge, Tennessee, USA
	Funding: This work is supported through DOE-HEP Award DESC0010301 and NSF Award PHY1414681. A novel approach to transverse resonance suppression in next generation high-intensity accelerators is the use of nonlinear optical elements to induce large tune spreads which result in reduced responses to resonance driving perturbations. In order to test this theory, we have built and characterized an octupole channel insert for use in the University of Maryland Electron Ring (UMER). This paper presents experimental lattice studies using a low space-charge intensity beam at an energy of 10keV with a beam current of ~150uA, tune depression < 0.005, and unnormalized RMS emittance of 4.3 mm-mr. We apply beam based measurement techniques in order to evaluate the quality of our single-invariant lattice and better understand the nonlinearities created by the octupole channel. V. Danilov and S. Nagaitsev, Nonlinear accelerator lattices with one and two analytic invariants, PRSTAB, 13, 084002, 2010.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW105
About •	paper received ※ 11 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
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MOPGW107	Study of Integrable and Quasi-Integrable Sextupole Lattice	sextupole, resonance, focusing, lattice	371
	L. Gupta, Y.K. Kim University of Chicago, Chicago, Illinois, USA S. Baturin Enrico Fermi Institute, University of Chicago, Chicago, Illinois, USA S. Nagaitsev Fermilab, Batavia, Illinois, USA
	Funding: Funded through Center for Bright Beams, NSF award PHY-1549132 In order to maximize beam lifetime in circular particle accelerators, the nonlinear beam optics are optimized to maximize the dynamic aperture of the beam. The dynamic aperture (DA), which is a 6-D phase space volume of stable trajectories, depends on the strength of the nonlinearities in the machine, and is calculated via particle tracking. Current DA optimization processes include multi-objective genetic algorithm optimizers, and relies on minimizing the magnitudes of resonance driving terms (RDT), which are calculated from the nonlinear contribution to the one-turn-map. The process of searching through the parameter space for an ideal combination that maximizes DA is computationally strenuous. By setting up the sextupole channel such that it is resembles a symplectic integrator of a smooth Hamiltonian, with only a few sextupoles we are able to closely reproduce phase space trajectories of a smooth Hamiltonian up to the hyperbolic point. No chaos and resonances are observed if phase advance per one sextupole magnet in the channel does not exceed ~0.12x2 pi. Therefore, an important property of the suggested approach is the intrinsic elimination of the resonances, and minimization of corresponding RDTs.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW107
About •	paper received ※ 13 May 2019 paper accepted ※ 23 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, storage-ring, 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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MOPGW112	Design of a Bunch Compressor with CSR Suppression to Achieve Hundreds of kA Peak Current	emittance, electron, site, dipole	382
	Y.C. Jing, V. Litvinenko BNL, Upton, Long Island, New York, USA V. Litvinenko Stony Brook University, Stony Brook, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. A four dipole magnetic chicane is usually used to compress electron bunch to very short in modern accelerators which requires electron beams to have high peak current. The coherent synchrotron radiation (CSR) originated from the strong bending magnets in the chicane could greatly degrade the quality of the electron beam. In this paper, we present our design for a bunch compressing system with 30 to 100 fold in bunch length reduction and at the mean time suppress the effect of CSR on the e-beam’s quality. We discuss and detail the performance of such a compressor for potential FACET-II upgrade.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW112
About •	paper received ※ 15 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
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MOPGW113	Experimental Demonstration of the Henon-Heiles Quasi-Integrable System at IOTA	octupole, experiment, lattice, alignment	386
	N. Kuklev, Y.K. Kim University of Chicago, Chicago, Illinois, USA S. Nagaitsev, A.L. Romanov, A. Valishev Fermilab, Batavia, Illinois, USA
	Funding: Work supported by National Science Foundation award PHY-1549132, the Center for Bright Beams. Fermi Research Alliance operates Fermilab under Contract DE-AC02-07CH11359 with the US Dept. of Energy. The Integrable Optics Test Accelerator is a research electron and proton storage ring recently commissioned at the Fermilab Accelerator Science and Technology facility. Its research program is focused on testing novel techniques for improving beam stability and quality, notably the concept of non-linear integrable optics. In this paper, we report the first results of experimental investigation of a quasi-integrable transverse focusing system with one invariant of motion, a Henon-Heiles type system implemented with octupole magnets. Good agreement with simulations is demonstrated on key parameters of achievable tune spread and dynamic aperture preservation. Resilience to perturbations and imperfections in the lattice is explored. We conclude by outlining future research plans and discussing applicability to future high intensity accelerators.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW113
About •	paper received ※ 15 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019
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MOPGW114	Bayesian Approach for Linear Optics Correction	quadrupole, lattice, GUI, distributed	390
	Y. Li, W.X. Cheng, R.S. Rainer BNL, Upton, Long Island, New York, USA
	With a Bayesian approach, the linear optics correction algorithm for storage rings is revisited. In modern ring-based accelerators, optics corrections are determined from repetitive measurements which help identify systematic and random quadrupole errors in presence of various measurement noises. This process is a multivariate nonlinear regression problem driven by either a completed lattice model or a Jacobian matrix. Starting from the Bayes’ theorem, ’likelihood functions’ and ’prior probability’ distributions are extracted from a complete linear optics model. Under some assumptions, the least square algorithm and then the Jacobian matrix approach can be re-derived. The coherence of the correction algorithm is ensured through specifying a self-consistent regularization coefficient to prevent overfitting. Optimal weights for different correction objectives are obtained based on their measurement noise level. A new technique has been developed to resolve degenerated quadrupole errors when observed at a few select BPMs. A necessary condition of being distinguishable is that their optics response vectors seen at these specific BPMs should be near-orthogonal.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW114
About •	paper received ※ 18 April 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
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MOPGW115	A Cross-Cell Interleaved Nonlinear Lattice for Potential NSLS-II Upgrade	lattice, emittance, sextupole, dynamic-aperture	393
	Y. Li, A. He, B.N. Kosciuk, T.V. Shaftan, V.V. Smaluk BNL, Upton, Long Island, New York, USA Z.H. Bai, L. Wang USTC/NSRL, Hefei, Anhui, People’s Republic of China
	An interleaved sextupole scheme using cross-cell betatron phase cancellation technique is adopted as a candidate for the future NSLS-II upgrade lattice. The lattice uses as many NSLS-II installed magnets as possible, including 30 dipoles, to compose a triple bend achromat lattice. A 300 pm.rad horizontal beam emittance is achieved. The emittance can be further reduced to around 200 pm rad with damping wigglers. Various design concepts used in modern 4th-generation light sources, such as adopting longitudinal gradient dipoles and anti-bend scheme, are incorporated into the design as well. The betatron phase-advance between sextupoles is designed to have a cross-cell interleaving cancellation pattern in the transverse planes. The dynamic aperture is big enough for the conventional off-axis top-off injection. At the same time, a large energy acceptance looks promising to ensure a sufficiently long beam lifetime.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW115
About •	paper received ※ 12 April 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
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MOPGW123	Electromagnetic Study and Measurements of the iRCMS Cell	focusing, quadrupole, proton, extraction	403
	N. Tsoupas, P.N. Joshi, F. Méot, D. Trbojevic BNL, Upton, Long Island, New York, USA D.T. Abell RadiaSoft LLC, Boulder, Colorado, USA V.L. Bailey, J.P. Lidestri Best Medical International, Springfield, USA M. Sinnott Everson Tesla Inc., Nazareth, Pennsylvania, USA
	Funding: BNL Contract TSA-NF-18-80 The ion Rapid Cycle Medical Synchrotron (iRCMS) * will provide proton and C ion bunches with maximum energy 270 MeV and 450 MeV/u respectively at a frequency of 15 Hz for treating cancerous tumors. One of the six cells of the iRCMS has been designed, built and magnetic field measurements have been performed. We will present results from the static and AC electromagnetic study of the iRCMS cell and compare the measured magnetic fields with those calculated using the OPERA computer code . In addition the beam optics of the cell will be calculated based on the experimental fields using the zgoubi computer code * and compared with the designed beam optics. * D. Trbojevic, iRCMS Magnet Review, BNL, Sept. 6, 2012 (unpublished) OPERA computer code https://operafea.com/ * The zgoubi computer code https://www.bnl.gov/isd/documents/79375.pdf
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW123
About •	paper received ※ 15 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
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MOPMP004	Consolidated Lattice of the Collider FCC-hh	dipole, quadrupole, injection, insertion	428
	A. Chancé, D. Boutin, B. Dalena CEA-IRFU, Gif-sur-Yvette, France W. Bartmann, M. Hofer, R. Martin, D. Schulte CERN, Meyrin, Switzerland
	Funding: The European Circular Energy-Frontier Collider Study (EuroCirCol) project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant No 654305. The FCC-hh (Future Hadron-Hadron Circular Collider) is one of the options considered for the next generation accelerator in high-energy physics as recommended by the European Strategy Group. The latest changes brought to the lattice of the FCC-hh collider are commented: impact of the new intra-beam distance, efforts to increase the beam stay clear in the dispersion suppressors, tuning procedures, and updates on the insertions.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP004
About •	paper received ※ 14 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
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MOPMP019	High Luminosity LHC Optics and Layout HLLHCV1.4	luminosity, operation, experiment, cavity	468
	R. De Maria, R. Bruce, D. Gamba, M. Giovannozzi, F. Plassard CERN, Geneva, Switzerland
	The goal of the High Luminosity Project is the upgrade of the LHC to deliver an integrated luminosity of at least 250 \rm fb^-1 per year in each of the two high-luminosity, general-purpose detectors ATLAS and CMS. This article presents the latest layout design and the corresponding optics features, which comprise optimisation of the orbit corrector and crab cavity systems, and new estimates of the performance reach thanks to the new concept of fully remote alignment. In addition, the new optics version incorporates improvements required by beam instrumentation, dump system, and collimation system, as well as low-beta solutions for the LHCb experiment.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP019
About •	paper received ※ 17 April 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
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MOPMP020	Smooth and Beta-Beating-Free Optics Transitions for HL-LHC	injection, quadrupole, insertion, operation	472
	R. De Maria, M. Solfaroli CERN, Geneva, Switzerland
	In the CERN LHC, optics transitions are mainly required to control the beam size at the four experimental interaction points. The current method, based on linearly-interpolated optics functions over a small set of matched optics and parabolic time-domain segments, introduces non-zero beta-beating and it is not optimal in time. This contribution presents an alternative approach, based on continuously-matched optics solutions distributed in time domain by using a realistic model of the superconducting circuits, which optimises the overall process duration. This method requires a change in the paradigm used in the control system and it is proposed for the future High Luminosity LHC (HL-LHC) runs.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP020
About •	paper received ※ 18 April 2019 paper accepted ※ 17 May 2019 issue date ※ 21 June 2019
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MOPMP022	K-Modulation in Future High Energy Colliders	quadrupole, luminosity, collider, power-supply	476
	M. Hofer, F.S. Carlier, R. Tomás CERN, Geneva, Switzerland
	K-Modulation of the quadrupoles closest to the interaction point (IP) has been an indispensable tool to accurately measure the beta-function in the interaction point (β^) in the Large Hadron Collider (LHC) at CERN. K-Modulation may become even more important to control the lower β^ and reach the design luminosities in the High-Luminosity LHC (HL-LHC) and the Future Circular Collider (FCC). K-Modulation results also provide important input for the luminosity calibration and help in the identification and correction of errors in the machines. This paper presents a method for determining β^* using K-Modulation adapted to the characteristic layout of both colliders. Using the latest models for the HL-LHC and the FCC-hh, estimated uncertainties on the measurements are presented. The results are compared to the accuracy of an alternative modulation scheme using a different powering scheme.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP022
About •	paper received ※ 06 May 2019 paper accepted ※ 18 May 2019 issue date ※ 21 June 2019
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MOPMP026	HE-LHC Optics Design Options	dipole, lattice, quadrupole, hadron	492
	J. Keintzel, M.P. Crouch, M. Hofer, T. Risselada, R. Tomás, F. Zimmermann CERN, Geneva, Switzerland M. Hofer, J. Keintzel TU Vienna, Wien, Austria L. van Riesen-Haupt University of Oxford, Oxford, United Kingdom L. van Riesen-Haupt JAI, Oxford, United Kingdom
	The High Energy Large Hadron Collider (HE-LHC), a possible successor of the High Luminosity Large Hadron Collider (HL-LHC) aims at reaching a centre-of-mass energy of about 27 TeV using basically the same 16 T dipoles as for the hadron-hadron Future Circular Collider FCC-hh. Designing the HE-LHC results in a trade off between energy reach, beam stay clear as well as geometry offset with respect to the LHC. In order to best meet the requirements, various arc cell and dispersion suppressor options have been generated and analysed, before concluding on two baseline options, which are presented in this paper. Merits of each design are highlighted and possible solutions for beam stay clear minima are presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP026
About •	paper received ※ 02 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019
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MOPMP027	Second Order Dispersion Measurements in LHC	dipole, coupling, quadrupole, betatron	496
	J. Keintzel, M. Hofer TU Vienna, Wien, Austria J.M. Coello de Portugal, J. Dilly, E. Fol, A. Garcia-Tabares, M. Hofer, J. Keintzel, E.H. Maclean, L. Malina, T.H.B. Persson, R. Tomás, A. Wegscheider CERN, Geneva, Switzerland
	The quadratic dependence of the orbit on the relative momentum offset, also known as second order dispersion, is analysed for the first time for the LHC. In this paper, the measurement and analysis procedure are described. Results and implications on future optics are discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP027
About •	paper received ※ 02 May 2019 paper accepted ※ 17 May 2019 issue date ※ 21 June 2019
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MOPMP033	LHC Run 2 Optics Commissioning Experience in View of HL-LHC	luminosity, coupling, simulation, experiment	508
	R. Tomás, F.S. Carlier, J.M. Coello de Portugal, J. Dilly, S.D. Fartoukh, E. Fol, D. Gamba, A. Garcia-Tabares, M. Giovannozzi, M. Hofer, E.H. Maclean, L. Malina, T.H.B. Persson, P.K. Skowroński, M. Solfaroli, M.L. Spitznagel, A. Wegscheider, J. Wenninger, D.W. Wolf CERN, Geneva, Switzerland
	LHC Run 2 has achieved a beta lower than a factor 2 below design. This has significantly challenged optics measurement and correction techniques in the linear and non-linear regimes, leading to the development of new approaches. Furthermore, experimenting with a large variety of optics has allowed facing the difficulties of future optics and gaining understanding of the machine imperfections. A summary of these aspects is given in view of their implications for the HL-LHC Project.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP033
About •	paper received ※ 07 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
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MOPMP052	Numerical Simulations of the DC Wire Prototypes in LHC for Enhancing the HL-LHC Performances	experiment, simulation, luminosity, resonance	566
	A. Poyet Université Grenoble Alpes, Grenoble, France S.D. Fartoukh, N. Karastathis, Y. Papaphilippou, K. Skoufaris, G. Sterbini CERN, Geneva, Switzerland
	For the last 15 years, the compensation of the Beam-Beam Long-Range (BBLR) interaction in colliders using DC wires has been studied. In 2015, in the frame of the HL-LHC project, it has been shown that a compensation of all the Resonance Driving Terms (RDTs) generated by the BBLR interaction is possible using wires with constraints on their transverse and longitudinal positions. In 2017, an experimental campaign has been launched in the present LHC, with wires installed in sub-optimal positions due to integration constraints. The aim of this paper is therefore to apply the formalism developped for HL-LHC to the LHC case and to compare the experimental results to the numerical tracking studies of the compensation using wires.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP052
About •	paper received ※ 06 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, storage-ring, 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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MOPTS017	Status of Operation With Negative Momentum Compaction at KARA	operation, injection, quadrupole, sextupole	878
	P. Schreiber, T. Boltz, M. Brosi, B. Härer, A. Mochihashi, A.-S. Müller, A.I. Papash, M. Schuh KIT, Karlsruhe, Germany
	Funding: We are supported by the DFG-funded ’Karlsruhe School of Elementary and Astroparticle Physics: Science and Technology’ and European Union’s Horizon 2020 research and innovation programme (No 730871) For future synchrotron light source development novel operation modes are under investigation. At the Karlsruhe Research Accelerator (KARA) an optics with negative momentum compaction has been proposed, which is currently under commissioning. In this context, the collective effects expected in this regime are studied with an initial focus on the head-tail instability and the micro-bunching instability resulting from CSR self-interaction. In this contribution, we will present the proposed optics and the status of implementation for operation in the negative momentum compaction regime as well as a preliminary discussion of expected collective effects.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS017
About •	paper received ※ 14 May 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	storage-ring, lattice, dynamic-aperture, resonance	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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MOPTS087	Transverse Emittance Studies at Extraction of the CERN PS Booster	emittance, operation, booster, injection	1058
	F. Antoniou, S.C.P. Albright, F. Asvesta, H. Bartosik, G.P. Di Giovanni, V. Forte, M.A. Fraser, A. Garcia-Tabares, A. Huschauer, B. Mikulec, T. Prebibaj, A. Santamaría García, P.K. Skowroński CERN, Meyrin, Switzerland F. Asvesta NTUA, Athens, Greece T. Prebibaj National Technical University of Athens, Zografou, Greece
	Transverse emittance discrepancy in the beam transfer between the Proton Synchrotron Booster (PSB) and the Proton Synchrotron (PS) is observed in operational conditions for the LHC beams at CERN. The ongoing LHC Injectors Upgrade (LIU) project requires a tight budget for beam degradation along the injector chain and therefore the reason for this emittance discrepancy needs to be understood. Systematic measurements have been performed for various beam characteristics (beam intensity, transverse and longitudinal emittance). In this paper, a comparison between the emittance measurements using all available beam instrumentation with different emittance computation algorithms is presented. The results are compared to measurements at PS injection. Furthermore, the impact on the LIU project requirements for the emittance preservation along the LHC Injectors Complex is discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS087
About •	paper received ※ 14 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019
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MOPTS100	Transverse Emittance Measurement in the CERN Proton Synchrotron in View of Beam Production for the High-Luminosity LHC	emittance, brightness, proton, betatron	1106
	E. Senes, J. Emery, V. Forte, M.A. Fraser, A. Guerrero, A. Huschauer, F. Roncarolo, J.L. Sirvent, P.K. Skowroński, F. Tecker CERN, Geneva, Switzerland
	In the framework of the LHC Injectors Upgrade project the improvements required to achieve the parameters of the future beams for the High-Luminosity LHC are being studied and implemented. In order to deliver high brightness beams, control over the beam intensity and emittance is fundamental. Therefore, a highly accurate and reliable transverse emittance measurement is essential. Presently at the CERN Proton Synchrotron, the only operationally available emittance monitors not impacting the facility beam production are the flying wire scanners used to measure the circulating beam profile. The wire scanners will be replaced with a new generation in the next two years and a prototype is already installed. The prototype has been commissioned with beams featuring a wide range of intensities and emittances. This paper evaluates the performance of the prototype with respect to the present system via beam-based measurements. The transverse emittance measurement is discussed, considering the different potential error contributions to the measurement, such as knowledge of the machine optics and the dispersive contribution to the beam size.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS100
About •	paper received ※ 02 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
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MOPTS102	Linear and Non-Linear Optics Measurements in PS using Turn-by-Turn BPM Data	injection, coupling, sextupole, betatron	1114
	P.K. Skowroński, M. Giovannozzi, A. Huschauer CERN, Meyrin, Switzerland
	For the first time, the optics of the CERN Proton Synchrotron (PS) was measured using turn-by-turn BPM data of forced betatron oscillations excited with an AC dipole. We report results of phase advance and beta beating measurements. Linear coupling was globally minimized along the machine by measuring and correcting coupling resonance driving terms. Finally, non-linear properties of the ring were probed looking at third and fourth order resonance driving terms and amplitude detuning.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS102
About •	paper received ※ 07 May 2019 paper accepted ※ 19 May 2019 issue date ※ 21 June 2019
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MOPTS120	Commissioning of the New Experimental FODO Line at the SNS Beam Test Facility	rfq, emittance, MMI, simulation	1164
	A.V. Aleksandrov, S.M. Cousineau, K.J. Ruisard, V. Tzoganis, A.P. Zhukov ORNL, Oak Ridge, Tennessee, USA Z.L. Zhang UTK, Knoxville, Tennessee, USA
	The SNS Beam Test Facility consists of a 2.5MeV proton accelerator and a beam line with various diagnostics for high intensity beam dynamics study. A FODO line consisting of 19 quadrupole magnets and a large dynamic range emittance monitor has been added recently. The new setup is design for experimental study of mechanisms of halo formation in mismatched high intensity beams. We present results of the new beam line commissioning with beam.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS120
About •	paper received ※ 07 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019
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TUZPLM2	Optics Measurements at SuperKEKB Using Beam Based Calibration for BPM and BBA	quadrupole, betatron, emittance, coupling	1198
	H. Sugimoto, H. Koiso, K. Mori, A. Morita, Y. Ohnishi, M. Tejima KEK, Ibaraki, Japan
	The beam-based calibration(BBC) technique for Beam-Position-Monitor(BPM) is applied in order to establish reliable optics measurement. In the BBC, a response model between beam position, charge and output signals of the BPM electrodes are introduced to calibrate the relative gain of the BPM electrodes. The gains are adjusted by total squares fitting so that the model reproduces the measured BPM signals. The Beam-Based Alignment(BBA) is also performed to determine the magnetic center of a quadrupole. Using BBC and BBA, the performance of the BPM system and optics correction are successfully improved. This talk presents what we experienced during the beam commissioning focusing on beam optics measurement and some details on the beam-based calibration scheme for BPM system.
	Slides TUZPLM2 [15.911 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUZPLM2
About •	paper received ※ 15 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019
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TUPGW013	Tune and Chromaticity Optimization at Bessy II for the Transverse Resonant Island Bucket Optics	simulation, photon, resonance, emittance	1411
	F. Armborst, P. Goslawski, A. Jankowiak HZB, Berlin, Germany
	Funding: Federal Ministry of Education and Research Transverse Resonant Island Buckets (TRIBs ) correspond to a second stable orbit, longitudinally winding around the core orbit in the transverse x-x^′-phasespace. The exploitation possibilities for stable TRIBs are under investigation at the third generation light source BESSY II in Berlin. The applicability for bunch separation is a main subject of these studies. Stable operation of TRIBs optics with a single or few bunches on the second orbit and a multibunch train on the main orbit has been shown . Photons emitted on the second orbit are well separated from those of the main orbit at all beamlines. This provides the possibility of bunch separation by beamline adjustment for the timing community without significant impact on the average brightness for other users. Simulations based on linear optics from closed orbits (LOCO) and on nonlinear optics derived from the measured chromaticity and tune shift with action (TSWA) predict this separation well. Friendly user experiments in 2018 confirmed these results. The scheduled upgrade BESSY VSR ** features simultaneously stored long and short bunches. Then TRIBs optics would in principle enable the separation of the different bunches at every beamline offering unique possibilities to our users. Simulations and measurements aiming to investigate further possible optimization of the TRIBs optics are presented. * F. Armborst, P. Goslawski et al, DOI: 10.18429/JACoW-IPAC2018-TUPML052 P. Goslawski, F. Armborst et al. DOI: 10.18429/JACoW-IPAC2017-WEPIK057 * A. Jankowiak et al., DOI: 10.5442/R0001
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW013
About •	paper received ※ 14 May 2019 paper accepted ※ 18 May 2019 issue date ※ 21 June 2019
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TUPGW016	New Operation Regimes at the Storage Ring KARA at KIT	lattice, operation, injection, simulation	1422
	A.I. Papash, E. Blomley, T. Boltz, M. Brosi, E. Bründermann, S. Casalbuoni, J. Gethmann, E. Huttel, B. Kehrer, A. Mochihashi, A.-S. Müller, R. Ruprecht, M. Schuh, J.L. Steinmann KIT, Karlsruhe, Germany
	The storage ring Karlsruhe Research Accelerator (KARA) at KIT operates in a wide energy range from 0.5 to 2.5 GeV. Initially, the ring was designed to serve as a Light Source for synchrotron radiation facility ANKA. Since then different operation modes have been implemented at KARA: in particular, the double bend achromat (DBA) lattice with non-dispersive straight sections, the theoretical minimum emittance (TME) lattice with distributed dispersion, and different versions of low compaction factor optics with highly stretched dispersion function. Short bunches of a few ps pulse width are available at KARA. Low alpha optics have been tested and implemented in a wide operational range of the ring and are now routinely used at 1.3 GeV for studies of CSR-induced beam dynamics and THz bursting in the micro-bunching instability. Different non-linear effects, in particular, residual high order components of magnetic fields generated in insertion devices have been studied and cured. A new operation mode at high vertical tune implemented at KARA essentially improves beam performance during user operation as well as at low alpha regimes.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW016
About •	paper received ※ 23 April 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019
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TUPGW018	PETRA IV Study with Non-Interleaved Sextupole Scheme	sextupole, lattice, emittance, storage-ring	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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TUPGW023	Incorporation of a MESA Linac Modules into BERLinPro	linac, operation, HOM, cavity	1449
	B.C. Kuske, W. Anders, A. Jankowiak, A. Neumann HZB, Berlin, Germany K. Aulenbacher IKP, Mainz, Germany K. Aulenbacher HIM, Mainz, Germany F. Hug, T. Stengler, C.P. Stoll KPH, Mainz, Germany
	Funding: Work supported by the German Bundesministerium für Bildung und Forschung, Land Berlin, grants of the Helmholtz Association and grants of Helmholtz Association and the DFG within GRK 2128 BERLinPro is an Energy Recovery Linac (ERL) project, currently being set up at the Helmholtz-Zentrum Berlin für Materialien und Energie, Berlin, Germany. BERLinPro is designed as - and for - experiments in accelerator physics and as a test bed for novel ERL components. MESA is an ERL project under construction at the Johannes Gutenberg-Universität, Mainz, Germany. MESA is designed as a user facility to perform experiments in dark matter physics and precision measurements of natural constants. Despite the diverse goals, the main linac, providing the larger part of the particles energy, is fairly compatible. It is planned to test and run the MESA linac module in BERLinPro, prior to its usage in MESA. The goals and benefits of this unique cooperation for both projects are outlined in this paper. The necessary adaptions in BERLinPro, including hardware aspects, the new optics, and the scope of performance are described.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW023
About •	paper received ※ 30 April 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019
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TUPGW025	The DELTA Short-Pulse Source: Upgrade Plans from CHG to EEHG	laser, electron, undulator, radiation	1457
	A. Meyer auf der Heide, B. Büsing, S. Khan, D. Krieg, C. Mai, F. Teutenberg DELTA, Dortmund, Germany
	At the synchrotron light source DELTA operated by the TU Dortmund University, coherent harmonic generation (CHG) is employed to provide ultrashort pulses in the vacuum ultraviolet and terahertz (THz) regime. Here, a modulation of the electron energy induced by an interaction of an ultrashort laser pulse with an electron bunch is transformed into a density modulation by a magnetic chicane. This results in coherent emission at harmonics of the laser wavelength as well as THz radiation. With the planned upgrade towards echo-enabled harmonic generation (EEHG), much higher harmonics can be achieved by adding a second laser-electron interaction. The necessary major modifications of the DELTA storage ring and investigations of the laser-electron interaction will be presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW025
About •	paper received ※ 15 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019
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TUPGW037	Systematic Measurements of the Coherent THz Spectra by Magnetic Bunch Compression at the Compact ERL	electron, radiation, sextupole, linac	1486
	M. Shimada, Y. Honda, R. Kato, T. Miyajima, N. Nakamura, T. Obina, T. Uchiyama KEK, Ibaraki, Japan T. Hotei Sokendai, Ibaraki, Japan
	Short electron bunch beam is one of the key elements of a Free Electron Laser (FEL) or intense THz coherent light source. The Energy Recovery Linac (ERL) has the strong advantage of operation of such an electron bunch at high repetition rate and is expected to increase the photon flux. At the Compact ERL in KEK site, we have demonstrated the magnetic bunch compression at the 180-degree return arc and measured the THz spectra of the Coherent Transition Radiation (CTR). This paper reports the revamped THz beamline and the improvement of the beam tuning as well as the systematic measurements of the THz spectra by magnetic bunch compression.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW037
About •	paper received ※ 15 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019
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TUPGW039	Error Study and Correction of Hefei Advanced Light Source	lattice, quadrupole, closed-orbit, coupling	1492
	D.R. Xu, Z.H. Bai, W. Li USTC/NSRL, Hefei, Anhui, People’s Republic of China
	Hefei Advanced Light Source (HALS) is a future diffraction limited storage ring. The machine performance under all kinds of magnet errors is a vital component in physical design. In this paper, we present our work on the closed orbit correction, the linear beam optics compensation and the coupling control in HALS. After correction, the dynamical aperture can suffice the injection scheme.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW039
About •	paper received ※ 23 April 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	simulation, quadrupole, storage-ring, 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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TUPGW054	Design of a Hybrid Seven-Bend-Achromat Lattice for a High-Energy Diffraction-Limited Storage Ring Using a New Optimization Method	lattice, linear-dynamics, emittance, sextupole	1528
	P.H. Yang, Z.H. Bai, J.J. Tan, L. Wang, J.H. Xu USTC/NSRL, Hefei, Anhui, People’s Republic of China
	Recently, we proposed a new optimization method, with nonlinear dynamics indicators considered in the linear optics design, for designing hybrid multi-bend-achromat (MBA) lattices. With this method, two hybrid MBA lattices for medium-low-energy diffraction limited storage rings (DLSRs) have been designed, showing remarkable effectiveness in improving nonlinear dynamic performance. In this paper, we will apply this optimization method to the design of a hybrid 7BA lattice for a 6 GeV DLSR with the same circumference as that of HEPS. In the design, the strengths and arrangement of magnets of this lattice also meet the engineering requirement for HEPS. The designed lattice has a natural emittance of 34 pm·rad. The nonlinear dynamic performance is satisfactory, with a dynamic aperture of about 6 mm and 3 mm in the horizontal and vertical directions, respectively, and a dynamic momentum aperture of larger than 5%, which also shows the power of our optimization method.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW054
About •	paper received ※ 14 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019
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TUPGW055	Comparison of Optimization Methods for Hybrid Seven-Bend-Achromat Lattice Design	lattice, linear-dynamics, sextupole, emittance	1532
	P.H. Yang, Z.H. Bai, J.J. Tan, L. Wang, J.H. Xu USTC/NSRL, Hefei, Anhui, People’s Republic of China
	Generally, for a hybrid multi-bend-achromat (MBA) lattice with fixed linear optics, there is little potential to further optimize the nonlinear dynamics due to limited free knobs. To obtain a hybrid MBA lattice with better nonlinear dynamics performance, it is better to consider some indicators of nonlinear dynamics as objective functions in designing the linear optics using an optimization algorithm. In this paper, integral strengths of sextupoles and natural chromaticities are used as the nonlinear dynamics indicators, and different optimization methods with both or either of the two indicators are carried out and compared. As an example, a hybrid 7BA lattice with an energy of 2.4 GeV is designed towards an emittance of less than 70 pm·rad.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW055
About •	paper received ※ 18 April 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019
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TUPGW061	First Study for an Upgrade of the ALBA Lattice	lattice, emittance, injection, dipole	1544
	G. Benedetti, U. Iriso, Z. Martí, F. Pérez ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
	ALBA has started a study that will produce the design of a new lattice for a diffraction limited photon source. The baseline lattice should preserve the present circumference and energy, and keep the insertion device beamline source points as much as possible unchanged. The first solution is a 16-fold periodic ring based on a 7BA cell with dispersion bump, paired sextupoles and anti-bends. An emittance of 155 pm·rad would be reached without longitudinal gradient in the dipole magnets.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW061
About •	paper received ※ 14 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019
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TUPGW064	Trials of Beam-Based Sextupole Calibration through 2nd Order Dispersion	sextupole, storage-ring, 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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TUPGW075	Towards a Diffraction Limited Storage Ring	lattice, storage-ring, 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.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW075
About •	paper received ※ 20 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019
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TUPGW076	Early Commissioning Simulation of the Diamond Storage Ring Upgrade	MMI, simulation, quadrupole, closed-orbit	1577
	H. Ghasem, M. Apollonio, R. Bartolini, J.P. Kennedy, I.P.S. Martin DLS, Oxfordshire, United Kingdom
	A low beam emittance lattice has been designed for up-grade of the Diamond storage ring. Due to the use of strong focusing elements and rather small vacuum cham-ber and considering the required short dark time, commis-sioning of the designed storage ring becomes very chal-lenging. This paper briefly explains the progress of early commissioning simulations of the storage ring, gives the required engineering tolerances, presents the first simula-tion results and discusses the non-linear beam dynamics (NLBD) issues after successful commissioning with and without insertion devices (IDs).
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW076
About •	paper received ※ 13 May 2019 paper accepted ※ 22 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, storage-ring, 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)
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW077
About •	paper received ※ 15 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019
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TUPGW079	Exploratory Lattice Design Studies for Diamond-II	lattice, controls, emittance, dynamic-aperture	1589
	B. Singh, R. Bartolini, J. Bengtsson, H. Ghasem, I.P.S. Martin DLS, Oxfordshire, United Kingdom R. Bartolini JAI, Oxford, United Kingdom
	We pursue Robust Design of a Ring-Based Synchrotron Light Source as a System. In particular, the Design Phi-losophy is based on: ’ To Control the Nonlinear Dynamics: Control the Linear Optics. In particular, by: ’ Optimal Control of Natural Chromaticity. ’ ’-I Transformer’ between Chromatic Sextupoles for Unit Cell. ’ Higher-Order-Achromat for Super Period. In addition, by pushing the Requirements for Robust & Efficient Injection ’Upstream’, i.e., by considering On-Axis Injection, and by utilizing Reverse Bends (to trans-cend the reductionist Theoretical Minimum Emittance Cell), either: ’ the Natural Emittance can be reduced further, ’ or the Touschek Lifetime can be improved. Bottom line, a Design Choice.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW079
About •	paper received ※ 15 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019
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TUPGW080	Alternative Lattice Design for Diamond-II	lattice, emittance, sextupole, dipole	1593
	M. Korostelev Oxford University, Physics Department, Oxford, Oxon, United Kingdom B. Singh DLS, Oxfordshire, United Kingdom
	Plans for upgrade of the Diamond Light Source aim to reduce beam emittance by a factor of 20 or better. This is motivated by demand for photon flux with significantly high brightness and transverse coherence. The baseline lattice design for the Diamond-II upgrade has been recently proposed, however alternative design are under investigation to reduce the emittance even further. This paper presents a new lattice design based on implementation of bending magnets with transverse field gradient only.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW080
About •	paper received ※ 15 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019
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TUPGW084	Multi-pass ERL in a ’Dogbone’ Topology	linac, cavity, dipole, focusing	1601
	S.A. Bogacz JLab, Newport News, Virginia, USA
	Funding: Work has been authored by Jefferson Science Associates, LLC under Contract No. DE-AC05-06OR23177 with the U.S. Department of Energy. The main thrust of a multi-pass RLA is its very efficient usage of expensive linac structures. That efficiency can be further enhanced by configuring an RLA in a ’dogbone’ topology, which further boosts the RF efficiency by factor of two (compare to a corresponding racetrack). However, the ’dogbone’ configuration requires the beam to traverse the linac in both directions, while being accelerated. This can be facilitated by a special ’bisected’ linac Optics. Here, the quadrupole gradients scale up with momentum to maintain periodic FODO structure for the lowest energy pass in the first half of the linac and then the quadrupole strengths are mirror reflected in the second linac half. The virtue of this optics is the appearance of distinct nodes in the beta beat-wave at the ends of each pass (where the droplet arcs begin), which limits the growth of initial betas at the beginning of each subsequent droplet arc. Furthermore, ‘bisected’ linac optics naturally supports energy recovery in the ’dogbone’ topology. In this paper, we present a-proof-of-principle lattice design of a multi-pass ’dogbone’ ERL.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW084
About •	paper received ※ 08 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, storage-ring	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.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW095
About •	paper received ※ 14 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019
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TUPRB113	Dynamic Aperture of JLEIC Electron Collider Ring with Errors and Correction	alignment, electron, multipole, quadrupole	1920
	Y.M. Nosochkov, Y. Cai SLAC, Menlo Park, California, USA F. Lin, V.S. Morozov, Y. Zhang JLab, Newport News, Virginia, USA
	Funding: * This work is supported by the U.S. Department of Energy, Office of Science, and Office of Nuclear Physics under Contracts DE-AC05-06OR23177, DE-AC02-06CH11357, and DE-AC02-76SF00515. Design of the Jefferson Lab Electron-Ion Collider (JLEIC) includes low-beta Interaction Region (IR) and spin rotator optics for high luminosity and polarization. Magnet errors, especially in the high-beta final focus quadrupoles, result in optics perturbations which need to be corrected in order to attain sufficient dynamic aperture (DA). We present design of orbit correction system for the electron ring and evaluate its performance. The DA is then studied including misalignment, magnet strength errors, non-linear field errors, and corrections.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB113
About •	paper received ※ 16 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019
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WEYYPLM1	Status of Early SuperKEKB Phase-3 Commissioning	MMI, detector, operation, luminosity	2255
	A. Morita KEK, Ibaraki, Japan
	SuperKEKB is an asymmetric energy electron-positron collider for B-meson physics experiment. The beam collision with 3mm vertical beta function at the interaction point is confirmed during prior beam commissioning until July 2018. The next beam commissioning with the inner silicon vertex detectors so called "phase-3 commissioning" will start in March 2019. In the early part of next phase-3 commissioning, we plan to try the collision operation with over 1A stored beam current in order to exceed 1 x 10³⁴ cm^-2 s^-1 luminosity. We will report the preliminary results of the early stage of the SuperKEKB phase-3 commissioning.
	Slides WEYYPLM1 [2.570 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEYYPLM1
About •	paper received ※ 15 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
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WEYYPLM2	The 2018 Heavy-Ion Run of the LHC	luminosity, heavy-ion, experiment, proton	2258
	J.M. Jowett, C. Bahamonde Castro, W. Bartmann, C. Bracco, R. Bruce, J.M. Coello de Portugal, J. Dilly, S.D. Fartoukh, E. Fol, N. Fuster-Martínez, A. Garcia-Tabares, M. Hofer, E.B. Holzer, M.A. Jebramcik, J. Keintzel, A. Lechner, E.H. Maclean, L. Malina, T. Medvedeva, A. Mereghetti, T.H.B. Persson, B.Aa. Petersen, S. Redaelli, B. Salvachua, M. Schaumann, C. Schwick, M. Solfaroli, M.L. Spitznagel, H. Timko, R. Tomás, A. Wegscheider, J. Wenninger, D. Wollmann CERN, Geneva, Switzerland D. Mirarchi The University of Manchester, The Photon Science Institute, Manchester, United Kingdom
	The fourth one-month Pb-Pb collision run brought LHC Run 2 to an end in December 2018. Following the tendency to reduce dependence on the configuration of the preceding proton run, a completely new optics cycle with the strongest ever focussing at the ALICE and LHCb experiments was designed and rapidly implemented, demonstrating the maturity of the collider’s operating modes. Beam-loss monitor thresholds were carefully adjusted to provide optimal protection from the multiple loss mechanisms in heavy-ion operation. A switch from a basic bunch-spacing of 100 ns to 75 ns was made as the beam became available from the injector chain. A new record luminosity, 6 times the original design and close to the operating value proposed for HL-LHC, provided validation of the strategy for mitigating quenches due to bound-free pair production (BFPP) at the interaction points of the ATLAS and CMS experiments. Most of the beam parameters of the HL-LHC Pb-Pb upgrade were attained during this run and the integrated luminosity goals for the first 10 years of LHC operation were substantially exceeded.
	Slides WEYYPLM2 [10.884 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEYYPLM2
About •	paper received ※ 08 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019
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WEPMP025	Matching Studies Between CERN PSB and PS Through Multi-Turn Beam Profile Acquisitions	emittance, injection, betatron, operation	2367
	M.A. Fraser, Y. Dutheil, V. Forte, A. Guerrero, A. Huschauer, A. Oeftiger, S. Ogur, F. Roncarolo, E. Senes, F. Tecker CERN, Geneva, Switzerland
	In the framework of the LHC Injectors Upgrade (LIU) project, the investigation and quantification of the optics mismatch between the CERN Proton Synchrotron Booster (PSB) and PS is a crucial step in understanding the source of horizontal emittance growth between the two machines. Extensive studies were carried out to estimate the mismatch from single-pass measurements in the transfer line and to rematch the transfer line to reduce the dispersive mismatch at PS injection while keeping the betatron matching unaltered. This paper presents the results of the data analysis of more recent multi-turn measurements, which profited from a new turn-by-turn beam profile monitor in the PS ring, to assess the achieved level of matching and corresponding emittance growth. The results confirm the improved matching and demonstrate the feasibility of the multi-turn technique as a fundamental tool that will be important for the recommissioning of the renovated transfer line after Long Shutdown 2.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPMP025
About •	paper received ※ 14 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
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WEPMP029	Systematic Optics Studies for the Commissioning of the AWAKE Beamline	electron, plasma, experiment, quadrupole	2383
	C. Bracco, B. Goddard, I. Gorgisyan, M. Turner, F.M. Velotti, L. Verra CERN, Geneva, Switzerland M. Aiba PSI, Villigen PSI, Switzerland
	The commissioning of the AWAKE electron beam line was successfully completed in 2018. Despite a modest length of about 15 m, this low-energy line is quite complex and several iterations were needed before finding satisfactory agreement between the model and the measurements. The work allowed to precisely predict the size and positioning of the electron beam at the merging point with the protons inside the plasma cell, where no direct measurement is possible. All the key aspects and corrections which had to be included in the model, precautions and systematic checks to apply for the correct setup of the line are presented. The sensitivity of the ~18 MeV electron beam to various perturbations, like different initial optics parameters and beam conditions, energy jitter and drifts, earth’s magnetic field etc., is described.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPMP029
About •	paper received ※ 10 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019
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WEPMP032	Tracking Simulations of Shadowing Electrostatic Septum Wires by Means of Bent Crystals	simulation, extraction, septum, experiment	2395
	F.M. Velotti, M.A. Fraser, B. Goddard, V. Kain, L.S. Stoel CERN, Meyrin, Switzerland
	The Super Proton Synchrotron (SPS) slow extraction is a third integer resonant extraction and hence suffers from high losses at the electrostatic septum (ZS). This is one of the main limiting factors for the maximum number of Protons On Target (POT) deliverable from the SPS to the North Area (NA). A concept to significantly reduce the extraction losses via shadowing of the electrostatic septum wires using an upstream bent crystal has been proposed in , predicting a loss reduction of up to 50% for the prototype system installed in 2018. Following the successful experimental demonstration of the concept with beam , detailed tracking simulations have been performed to fully understand the results obtained. Further insights, such as the effective ZS width and its alignment, could be deduced by exploiting the response of the extraction loss as a function of the two degrees of freedom of the crystal (position and angle). In this paper, the beam dynamics simulations are discussed together with the implementation of the bent crystal into the simulation framework. A comparison with measurements is presented before proposals for new configurations and parameters are discussed. F.M. Velotti, et al., "Reduction of Resonant Slow Extraction Losses…", IPAC’18. ** F.M. Velotti, M.A. Fraser, et al., "Experimental SPS Slow Extraction Loss Reduction…", this conf.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPMP032
About •	paper received ※ 15 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
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WEPMP038	Combined MCNP/Turtle Simulation of the SINQ Beam Line at PSI-HIPA	simulation, target, proton, scattering	2410
	D. Reggiani, D.C. Kiselev, M. Seidel, V. Talanov, M. Wohlmuther PSI, Villigen PSI, Switzerland
	With a nominal beam power of nearly 1.4 MW, the PSI High Intensity Proton Accelerator (HIPA) complex is currently at the forefront of the high intensity frontier of particle accelerators. A key issue of such facilities is the minimization of beam losses that could lead to excessive activation of beam line components. At HIPA, the SINQ beam line is particularly subject to relatively large losses since it receives the highly divergent beam scattered off a 40 or 60 mm thick muon production graphite target (TE). So far, for HIPA, beam line simulations have been carried out only by means of the matrix multiplication codes TRANSPORT and TURTLE. Although very efficient, such tools do not allow a precise determination of beam losses whenever targets and collimators are substantially affecting the beam optics. A true understanding of how beam halo and the low momentum tail contribute to the measured losses can only be achieved by complementing the traditional simulations techniques by a tool that can transport beam particles in different materials and, at the same time, handle complex geometries like the ones of collimators situated in the beam line. Moreover, such an improved beam line simulation would give a significant contribution in evaluating the feasibility of the SINQ beam rotation system currently under study. In this paper we present a simulation of the SINQ beam line combining MCNP models of TE and collimator sections with the TURTLE computation of the magnetic channel.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPMP038
About •	paper received ※ 15 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019
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WEPMP041	Damping Bunch Oscillations Due to Off-Axis Injection	injection, wiggler, damping, radiation	2422
	F. Zimmermann, O. Etisken, N. Mounet, A. Oeftiger, S. Ogur, Y. Papaphilippou, B. Salvant CERN, Geneva, Switzerland K. Oide KEK, Ibaraki, Japan
	Funding: This work was supported by the European Commission under the HORIZON 2020 project ARIES, grant agreement no. 730871. In the FCC-ee pre-injector complex, a slightly modified SPS can serve as pre-booster. The baseline design foresees injecting the low-emittance electron and positron bunches off-axis into the SPS, and deploying strong wigglers to greatly enhance the radiation damping at the injection energy. We here compare the damping of large injection oscillations by means of radiation damping with the effect of other possible damping mechanisms such as a fast bunch-by-bunch feedback system and/or head-tail damping via nonzero chromaticity. As a by-product, we investigate the transverse beam stability.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPMP041
About •	paper received ※ 10 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019
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WEPMP049	Simulations of Beam Shaping for Dark Matter Experiments at LCLS-II	electron, experiment, FEL, quadrupole	2443
	Y.M. Nosochkov, C. Hast, T.W. Markiewicz, L.Y. Nicolas, T.O. Raubenheimer, M. Santana-Leitner SLAC, Menlo Park, California, USA
	Funding: * Work supported by the U.S. DOE Contract DE-AC02-76SF00515. A new transfer beamline, called S30XL, and an experimental facility are proposed to be built at SLAC, taking advantage of the LCLS-II free electron laser (FEL) under construction. The S30XL will operate parasitically to the FEL by extracting the unused low intensity 4-GeV LCLS-II bunches into the existing A-line and the End Station-A (ESA). This provides a unique capability of multi-GeV nearly continuous electron beam for a variety of HEP experiments, in particular the dark matter search experiments. The latter require a very low beam current ranging from pA to micro-A, as well as a large beam spot at the detector. The necessary beam shaping will be performed using spoilers and collimators in the A-line, and by optimizing the optics. FLUKA and elegant codes are used to generate and track the beam into the ESA.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPMP049
About •	paper received ※ 16 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
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WEPGW081	Unsupervised Machine Learning for Detection of Faulty Beam Position Monitors	simulation, ISOL, MMI, ECR	2668
	E. Fol, J.M. Coello de Portugal, R. Tomás CERN, Meyrin, Switzerland
	Unsupervised learning includes anomaly detection techniques that are suitable for the detection of unusual events such as instrumentation faults in particle accelerators. In this work we present the application of decision trees-based algorithm to faulty BPMs detection at the LHC. This method achieves significant improvements in quality of optics measurements and allows to identify relevant signal properties that contribute to fault detection.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPGW081
About •	paper received ※ 14 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019
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WEPGW099	Development of a Beam Halo Monitor	radiation, synchrotron-radiation, synchrotron, electron	2721
	V.G. Dudnikov, R.P. Johnson, M. Popovic Muons, Inc, Illinois, USA M.A. Cummings Northern Illinois University, DeKalb, Illinois, USA R.M. Thurman-Keup Fermilab, Batavia, Illinois, USA
	Our innovative approach is to design the Beam Halo Monitor, where beam induced synchrotron radiation will be used to monitor the beam Halo. This involves an original scheme of light collection using a coronograph for measuring beam halo.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPGW099
About •	paper received ※ 15 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019
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Paper

Title

Other Keywords

Page

MOPGW006

Long Range Beam Beam: Towards Faster Computations

interaction-region, closed-orbit, lattice, betatron

72

S.R. Koscielniak
TRIUMF, Vancouver, Canada

We outline some features of a program of study toward faster computation of the cumulative effect of a sequence of beam-beam interactions across the interaction region.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW006

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

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MOPGW012

Study of Fringe Fields Effects from Final Focus Quadrupoles on Beam Based Measured Quantities

quadrupole, multipole, dynamic-aperture, simulation

90

T. Pugnat, B. Dalena
CEA-IRFU, Gif-sur-Yvette, France
L. Bonaventura, A. Simona
Politecnico di Milano, Milano, Italy
R. De Maria, V.K.B. Olsen
CERN, Geneva, Switzerland

Accelerator physics needs advanced modeling and simulation techniques, in particular for beam stability studies. A deeper understanding of the effects of magnetic fields non-linearities will greatly help in the improvement of future colliders design and performance. In *, a new tracking method was proposed to study the effect of the longitudinal dependency of the harmonics on the beam dynamics. In this paper, the study will focus on the effects on observable quantities in beam based measurements, for the case of HL-LHC Inner Triplet and with possible tests in LHC.
* T. Pugnat et al., "Accurate and Efficient Tracking in Electromagnetic Quadrupoles", in Proc. IPAC’18, Vancouver, Canada, June 2018, paper THPAK004, pp. 3207.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW012

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

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MOPGW014

Developing Beam Optics for the BESSY VSR Project

quadrupole, storage-ring, 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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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW014

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

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MOPGW019

Beam-Beam Blowup Issue After Low Emittance Tuning for FCC-ee

emittance, lattice, simulation, coupling

112

D. El Khechen, K. Oide, F. Zimmermann
CERN, Geneva, Switzerland
K. Oide
KEK, Ibaraki, Japan

FCC-ee (Future Circular Collider) is a 100 km electron-positron circular collider with two foreseen experiments, aiming to run at four energies for precision studies of the Z, W, and Higgs boson and the top quark. The FCC-ee is a challenging machine from different points of view. In particular the beam-beam effects are of great importance. For the FCC-ee high-luminosity operation, the beam-beam effects impose profound constraints on the operating point in betatron tune space. In addition, taking into account different sources of machine nonlinearities, a tracking simulation with beam-beam elements revealed a strong beam blowup, especially in the vertical plane. Such a blowup is a potential obstacle to achieving and maintaining a high luminosity; therefore it needs to be carefully studied. In this paper, we present a general overview of simulation results on the FCC-ee beam-beam blowup with realistic machine errors.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW019

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

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MOPGW020

Numerical Calculation of Micro Bunching in BERLinPro Due to Space Charge and CSR Effects

bunching, space-charge, linac, emittance

116

B.C. Kuske, A. Meseck
HZB, Berlin, Germany

Funding: Work supported by the German Bundesministerium für Bildung und Forschung, Land Berlin and grants of the Helmholtz Association
BERLinPro is an Energy Recovery Linac Project, currently being set up at the Helmholtz-Zentrum Berlin für Materialien und Energie, Berlin, Germany. BERLinPro is a small demonstrator for ERL technology and applications. Due to the low energy of 50, resp. 32MeV, space charge plays a dominant role in the beam dynamics. Micro-bunching, due to unavoidable shot noise from the cathode in combination with space charge, is seen in the merger as well as in the recirculator. Coherent synchrotron radiation (CSR) can amplify this bunching, as well as micro-bunching can enhance CSR losses. With the release of OPAL 2.0** in May 2018, for the first time, an open source, highly parallel tracking code is available, that is capable of numerically calculating both effects, space charge and CSR, simultaneously. The calculations are compared to earlier results*, that used analytical formulas on tracked, space charge dominated bunches.
* "On space charge driven microbunching instability in BERLinPro", PhD thesis, S.D.Rädel, Humboldt Universität zu Berlin, 2017
** http://amas.web.psi.ch/docs/opal/opal_user_guide-2.0.0.pdf

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW020

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

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MOPGW022

Achromatic Isochronous Mode of the ESR at GSI

sextupole, experiment, detector, emittance

124

S.A. Litvinov, M. Steck
GSI, Darmstadt, Germany

The isochronous optics of the ESR is a unique ion-optical setting in which the ring is operated as a Time-of-Flight Mass-Spectrometer and is used for direct mass measurements of short-lived exotic nuclei. The present isochronous optics had been performed only making a negative dispersion in the straight sections of the ESR of about -7 m. This negative dispersion makes the injection into the ESR very complicated and strict the transmission of the ions in the ring. Moreover, the non-achromatism of the ESR brings a supplementary uncorrectable first-order transverse contribution to the revolution time. In order to make the ESR achromatic, to improve injection and the isochronicity a new achromatic isochronous optics has been calculated and will be presented here in details.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW022

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

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MOPGW026

Transfer Line Optics Design Using Machine Learning Techniques

target, simulation, quadrupole, operation

139

D.M. Vilsmeier
IAP, Frankfurt am Main, Germany
M. Bai, M. Sapinski
GSI, Darmstadt, Germany

Optimization of transfer line optics is essential for delivering high quality beams to the experimental areas. This type of optimization is usually done by hand and relies on the experience of operators. The nature of this task is repetitive though highly complex. Besides optimizing the beam quality at the experiments this task is often accompanied by secondary objectives or requirements such as keeping the beam losses below an acceptable threshold. In the past years Deep Learning algorithms have experienced a rapid development and gave rise to various advanced software implementations which allow for straightforward usage of corresponding techniques, such as automatic differentiation and gradient backpropagation. We investigate the applicability and performance of these techniques in the field of transfer line optics optimization, specifically for the HADES beamline at GSI, in form of gradient-based differentiable simulators. We test our setup on results obtained from MADX simulations and compare our findings to different gradient-free optimization methods. Successfully employing such methods relieves operators from the tedious optimization tasks.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW026

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

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MOPGW031

Analysis and Correction for the Effect of Multipoles with Skewed Errors on IP Beam Dynamics in SuperKEKB

luminosity, coupling, MMI, betatron

159

K. Hirosawa
Sokendai, Ibaraki, Japan
Y. Funakoshi, H. Koiso, A. Morita, K. Ohmi, Y. Ohnishi, H. Sugimoto, D. Zhou
KEK, Ibaraki, Japan

The beam dynamics at the interaction point (IP) in the accelerators which has the nano-beam scheme like as SuperKEKB is extremely sensitive for skewed error of final focusing magnets (QCS). As proceeding the beta squeezing in the interaction region (IR), the effect of optics aberrations at IP is enhanced. In the SuperKEKB Phase-2 commissioning, there was the problem come from skewed quadrupole fields in IR. The dominant skew parameters ‘‘R" for this problem is very hard to see directly by using beam position monitors, thus it was corrected by scanning R parameters. In the next commissioning Phase-3 which is just before the operation with the Belle II experiment, it is planned that the IP beta squeezing is going forward to design parameters which is smaller than it achieved in Phase-2 by the factor of 4 (for horizontal beta) and 10 (for vertical beta). Hence the effect of skew error will be considerable larger and it is estimated that skew sextupoles will emerge as a serious cause for the aberration from the orbit. This report is the study of analysis and correction results for the effect of QCS skewed errors in the SuperKEKB commissioning.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW031

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

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MOPGW041

Transverse Profile Shaping of a Charged-Particle Beam using Multipole Magnets - Formation of Hollow Beams -

octupole, target, multipole, radiation

184

Y. Yuri, T. Yuyama
QST/Takasaki, Takasaki, Japan
M. Fukuda
RCNP, Osaka, Japan

The use of multipole magnets enables us to shape the transverse profile of a charged-particle beam into various ones that can never be realized through linear beam optics. To date, the formation of a large-area beam with a uniform transverse intensity distribution has been actually realized using octupole magnets in several accelerator facilities. In this presentation, we demonstrate the formation of different beam profiles using multipole magnets rather than existing rectangular uniform beams. Results of tracking simulations and beam-formation experiments will be shown on the formation of clear-cut beams with different cross-sectional shapes, depending on the order and strength of applied multipole magnets. The dynamic behavior of a beam focused with multipole magnets is also investigated theoretically to better understand the numerical and experimental results.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW041

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

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MOPGW069

Recent Beam Performance Achievements with the Pb-Ion Beam in the SPS for LHC Physics Runs

injection, target, luminosity, flattop

250

H. Bartosik, R. Alemany-Fernández, T. Argyropoulos, T. Bohl, H. Damerau, V. Kain, G. Papotti, G. Rumolo, A. Saá Hernández, E.N. Shaposhnikova
CERN, Meyrin, Switzerland

In the SPS, which is the last accelerator in the LHC ion injector chain, multiple injections of the Pb-ion beam have to be accumulated. On this injection plateau the beam suffers from considerable degradation such as emittance growth and losses. This paper summarises the achievements on improving the beam parameters and maximising the performance of the Pb-ion beam for the LHC physics run in 2018. The results are discussed in view of the target beam parameters of the LHC injectors upgrade project, which is being deployed during the presently ongoing long shutdown.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW069

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paper received ※ 12 May 2019 paper accepted ※ 17 May 2019 issue date ※ 21 June 2019

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MOPGW072

Reconfiguration of SPS Landau Octupole Circuits to Minimise Second Order Chromaticity

octupole, operation, target, acceleration

262

H. Bartosik, M. Carlà, K. Cornelis
CERN, Meyrin, Switzerland

In the SPS Q20 optics presently used for LHC beams, the Landau octupole families of the SPS (LOF and LOD circuits) generate large second order chromaticity due to the relatively high dispersion at their locations. Since the induced second order chromaticity results in enhanced losses due to the large incoherent tune spread, these octupoles cannot be used for mitigating transverse instabilities for LHC beams. A new cabling scheme was proposed, exploiting additional octupoles that were already installed in the machine but not used, which allows minimizing the induced second order chromaticity in both the Q20 optics used for LHC beams, as well as the original SPS optics used for fixed target beams. This paper summarises the optics calculations as well as the experimental verification of the reduced chromatic detuning of the new octupole scheme.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW072

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paper received ※ 12 May 2019 paper accepted ※ 17 May 2019 issue date ※ 21 June 2019

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MOPGW080

Optics Measurements in the CERN PS Booster Using Turn-by-Turn BPM Data

injection, MMI, booster, software

285

A. Garcia-Tabares, P.K. Skowroński, R. Tomás
CERN, Geneva, Switzerland
A. Garcia-Tabares
Universidad Complutense Madrid, Madrid, Spain

As part of the LHC Injector Upgrade Project the injection of the CERN PS Booster will be changed to increase intensity and brightness of the delivered beams. The new injection scheme is likely to give rise to beta beating above the required level of 5\% and new measurements are required. Achieving accurate optics measurements in PSB lattice is a challenging task that has involved several improvements in both hardware and software. This paper summarizes all the improvements that have been performed in the optics measurement acquisition system together with a brief summary of the first results obtained.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW080

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paper received ※ 11 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

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MOPGW088

A Two-Mode Model to Study the Effect of Space Charge on TMCI in the "Long-Bunch" Regime

coupling, space-charge, impedance, simulation

316

E. Métral
CERN, Geneva, Switzerland

Using a two-mode approach for the Transverse Mode-Coupling Instability (TMCI) in the ’short-bunch’ regime (where the mode-coupling takes place between the modes 0 and -1, such as in the CERN LHC), both a reactive damper (ReaD) and Space Charge (SC) are expected to be beneficial: the ReaD would shift the mode 0 up while SC would shift the mode -1 down, but in both cases the coupling (and related instability) would occur at higher intensities. However, the situation is more involved in the ’long-bunch’ regime (where the mode-coupling takes place between higher-order modes, such as in the CERN SPS). As the ReaD modifies only the (main) mode 0 and not the others, it is expected to have no effect for the main mode-coupling. As concerns SC, it modifies all the modes except the mode 0, and the result has been a subject of discussion for two decades. A two-mode approach is discussed in detail in this contribution for the case of a single bunch interacting with a broad-band resonator impedance in the ’long-bunch’ regime. This model reveals in particular that in the presence of space charge, the intensity threshold can only be similar to or lower than that in the absence of space charge.

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

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MOPGW090

Alignment of a Magnetic Lattice Based on Particle Tracking

alignment, lattice, controls, sextupole

324

K.P. Nesteruk, C. Calzolaio, J.M. Schippers
PSI, Villigen PSI, Switzerland

In calculations based on particle tracking in 3D magnetic field maps alignment of the components of a magnetic lattice is essential to obtain desired properties of beam optics. In this contribution we propose a method to control and correct misalignments during the process of the beam optics design. These misalignments would result from overlapping fringe fields of different field maps. The 3D field maps are obtained from the software for electromagnetic calculations OPERA. The full 3D map is saved in the tracking coordinate system and a ROOT (An Object Oriented Data Analysis Framework) ntuple is then created for analysis. The trajectory of the reference particle is calculated by means of OPAL - open source code developed at the Paul Scherrer Institut (PSI). The transverse magnetic field profiles allow possible misalignments to be precisely determined and the corresponding corrections to be calculated. Moreover, the multipole content in discrete locations along the lattice can be controlled by performing a polynomial fit, which calculates the magnetic field harmonics with respect to the reference track. This method was used at PSI for a design of a model of the magnetic lattice for a superconducting gantry for proton therapy with a large momentum acceptance.
*An Object Oriented Data Analysis Framework - http://root.cern.ch

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

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MOPGW093

Optics Calibration for Routine Operations In Taiwan Photon Source

lattice, quadrupole, operation, coupling

335

F.H. Tseng, C.H. Chen, P.J. Chou
NSRRC, Hsinchu, Taiwan

To ensure a stable performance of Taiwan Photon Source (TPS), we perform the calibration of accelerator optics using LOCO (Linear Optics from Closed Orbit) technique every month. After the optics and coupling corrections, the rms beta beatings in both planes are reduced to less than 1%. The emittance coupling ratio is also restored to within the design value.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW093

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paper received ※ 06 May 2019 paper accepted ※ 18 May 2019 issue date ※ 21 June 2019

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MOPGW095

Beam Dynamics Simulations with Crab Cavities in the SPS Machine

multipole, cavity, simulation, luminosity

342

A. Alekou, A. Alekou, H. Bartosik, H. Bartosik, M. Carlà, Y. Papaphilippou, Y. Papaphilippou, Y. Papaphilippou
CERN, Meyrin, Switzerland
A. Alekou, A. Alekou, R.B. Appleby, R.B. Appleby
UMAN, Manchester, United Kingdom
R.B. Appleby
Cockcroft Institute, Warrington, Cheshire, United Kingdom

The LHC Upgrade, called High Luminosity LHC, aims to increase the integrated luminosity by a factor of 10. To achieve this, the project relies on a number of key innovative technologies, including the use of superconducting Crab Cavities with ultra-precise phase control for beam rotation. A set of prototype Crab Cavities has been recently installed in the second largest machine of CERN, the Super Proton Synchrotron (SPS), that operated as a test-bed from May to November of 2018. The tight LHC constraints call for axially non-symmetric cavity designs that introduce high order multipole components. Furthermore, the Crab Cavities in the presence of SPS non-linearities can affect the long term stability of the beam. This paper presents how the SPS dynamic aperture is affected for different cavity, machine and beam configurations.

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paper received ※ 06 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

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MOPGW100

Bypass Design for Testing Optical Stochastic Cooling at the Cornell Electron Storage Ring (CESR)

sextupole, radiation, wiggler, damping

360

W.F. Bergan, M.B. Andorf, M.P. Ehrlichman, V. Khachatryan, D.L. Rubin, S. Wang
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

Funding: NSF-1734189 DGE-1650441
Optical Stochastic Cooling (OSC) is a promising method for cooling very dense stored particle beams through the interference of radiation created in an upstream ’pickup’ wiggler and a downstream ’kicker’ wiggler. By correlating a particle’s path length via a bypass between the two wigglers with its betatron coordinates in the pickup, the particle will receive a kick in energy which, through coupling introduced by non-zero horizontal dispersion in the kicker, can reduce its betatron amplitude, thus cooling the beam. A proof-of-principle test of this technique is being planned at the Cornell Electron Storage Ring (CESR). In addition to maintaining standard requirements such as a large dynamic aperture and acceptable lattice functions throughout the ring, the design of the bypass is guided by the mutually competing goals of maximizing the cooling rate while maintaining a sufficiently large cooling acceptance with properly-corrected nonlinearities. We present a design of such a bypass and ring optics so as to best achieve these objectives.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW100

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paper received ※ 14 May 2019 paper accepted ※ 19 May 2019 issue date ※ 21 June 2019

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MOPGW105

Preliminary Lattice Studies for the Single-Invariant Optics Experiment at the University of Maryland

lattice, experiment, octupole, resonance

367

L. Dovlatyan, T.M. Antonsen, B.L. Beaudoin, I. Haber, D.B. Matthew
UMD, College Park, Maryland, USA
K.J. Ruisard
ORNL, Oak Ridge, Tennessee, USA

Funding: This work is supported through DOE-HEP Award DESC0010301 and NSF Award PHY1414681.
A novel approach to transverse resonance suppression in next generation high-intensity accelerators is the use of nonlinear optical elements to induce large tune spreads which result in reduced responses to resonance driving perturbations*. In order to test this theory, we have built and characterized an octupole channel insert for use in the University of Maryland Electron Ring (UMER). This paper presents experimental lattice studies using a low space-charge intensity beam at an energy of 10keV with a beam current of ~150uA, tune depression < 0.005, and unnormalized RMS emittance of 4.3 mm-mr. We apply beam based measurement techniques in order to evaluate the quality of our single-invariant lattice and better understand the nonlinearities created by the octupole channel.
* V. Danilov and S. Nagaitsev, Nonlinear accelerator lattices with one and two analytic invariants, PRSTAB, 13, 084002, 2010.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW105

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paper received ※ 11 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

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MOPGW107

Study of Integrable and Quasi-Integrable Sextupole Lattice

sextupole, resonance, focusing, lattice

371

L. Gupta, Y.K. Kim
University of Chicago, Chicago, Illinois, USA
S. Baturin
Enrico Fermi Institute, University of Chicago, Chicago, Illinois, USA
S. Nagaitsev
Fermilab, Batavia, Illinois, USA

Funding: Funded through Center for Bright Beams, NSF award PHY-1549132
In order to maximize beam lifetime in circular particle accelerators, the nonlinear beam optics are optimized to maximize the dynamic aperture of the beam. The dynamic aperture (DA), which is a 6-D phase space volume of stable trajectories, depends on the strength of the nonlinearities in the machine, and is calculated via particle tracking. Current DA optimization processes include multi-objective genetic algorithm optimizers, and relies on minimizing the magnitudes of resonance driving terms (RDT), which are calculated from the nonlinear contribution to the one-turn-map. The process of searching through the parameter space for an ideal combination that maximizes DA is computationally strenuous. By setting up the sextupole channel such that it is resembles a symplectic integrator of a smooth Hamiltonian, with only a few sextupoles we are able to closely reproduce phase space trajectories of a smooth Hamiltonian up to the hyperbolic point. No chaos and resonances are observed if phase advance per one sextupole magnet in the channel does not exceed ~0.12x2 pi. Therefore, an important property of the suggested approach is the intrinsic elimination of the resonances, and minimization of corresponding RDTs.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW107

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paper received ※ 13 May 2019 paper accepted ※ 23 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, storage-ring, 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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MOPGW112

Design of a Bunch Compressor with CSR Suppression to Achieve Hundreds of kA Peak Current

emittance, electron, site, dipole

382

Y.C. Jing, V. Litvinenko
BNL, Upton, Long Island, New York, USA
V. Litvinenko
Stony Brook University, Stony Brook, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
A four dipole magnetic chicane is usually used to compress electron bunch to very short in modern accelerators which requires electron beams to have high peak current. The coherent synchrotron radiation (CSR) originated from the strong bending magnets in the chicane could greatly degrade the quality of the electron beam. In this paper, we present our design for a bunch compressing system with 30 to 100 fold in bunch length reduction and at the mean time suppress the effect of CSR on the e-beam’s quality. We discuss and detail the performance of such a compressor for potential FACET-II upgrade.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW112

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

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MOPGW113

Experimental Demonstration of the Henon-Heiles Quasi-Integrable System at IOTA

octupole, experiment, lattice, alignment

386

N. Kuklev, Y.K. Kim
University of Chicago, Chicago, Illinois, USA
S. Nagaitsev, A.L. Romanov, A. Valishev
Fermilab, Batavia, Illinois, USA

Funding: Work supported by National Science Foundation award PHY-1549132, the Center for Bright Beams. Fermi Research Alliance operates Fermilab under Contract DE-AC02-07CH11359 with the US Dept. of Energy.
The Integrable Optics Test Accelerator is a research electron and proton storage ring recently commissioned at the Fermilab Accelerator Science and Technology facility. Its research program is focused on testing novel techniques for improving beam stability and quality, notably the concept of non-linear integrable optics. In this paper, we report the first results of experimental investigation of a quasi-integrable transverse focusing system with one invariant of motion, a Henon-Heiles type system implemented with octupole magnets. Good agreement with simulations is demonstrated on key parameters of achievable tune spread and dynamic aperture preservation. Resilience to perturbations and imperfections in the lattice is explored. We conclude by outlining future research plans and discussing applicability to future high intensity accelerators.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW113

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

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MOPGW114

Bayesian Approach for Linear Optics Correction

quadrupole, lattice, GUI, distributed

390

Y. Li, W.X. Cheng, R.S. Rainer
BNL, Upton, Long Island, New York, USA

With a Bayesian approach, the linear optics correction algorithm for storage rings is revisited. In modern ring-based accelerators, optics corrections are determined from repetitive measurements which help identify systematic and random quadrupole errors in presence of various measurement noises. This process is a multivariate nonlinear regression problem driven by either a completed lattice model or a Jacobian matrix. Starting from the Bayes’ theorem, ’likelihood functions’ and ’prior probability’ distributions are extracted from a complete linear optics model. Under some assumptions, the least square algorithm and then the Jacobian matrix approach can be re-derived. The coherence of the correction algorithm is ensured through specifying a self-consistent regularization coefficient to prevent overfitting. Optimal weights for different correction objectives are obtained based on their measurement noise level. A new technique has been developed to resolve degenerated quadrupole errors when observed at a few select BPMs. A necessary condition of being distinguishable is that their optics response vectors seen at these specific BPMs should be near-orthogonal.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW114

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paper received ※ 18 April 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

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MOPGW115

A Cross-Cell Interleaved Nonlinear Lattice for Potential NSLS-II Upgrade

lattice, emittance, sextupole, dynamic-aperture

393

Y. Li, A. He, B.N. Kosciuk, T.V. Shaftan, V.V. Smaluk
BNL, Upton, Long Island, New York, USA
Z.H. Bai, L. Wang
USTC/NSRL, Hefei, Anhui, People’s Republic of China

An interleaved sextupole scheme using cross-cell betatron phase cancellation technique is adopted as a candidate for the future NSLS-II upgrade lattice. The lattice uses as many NSLS-II installed magnets as possible, including 30 dipoles, to compose a triple bend achromat lattice. A 300 pm.rad horizontal beam emittance is achieved. The emittance can be further reduced to around 200 pm rad with damping wigglers. Various design concepts used in modern 4th-generation light sources, such as adopting longitudinal gradient dipoles and anti-bend scheme, are incorporated into the design as well. The betatron phase-advance between sextupoles is designed to have a cross-cell interleaving cancellation pattern in the transverse planes. The dynamic aperture is big enough for the conventional off-axis top-off injection. At the same time, a large energy acceptance looks promising to ensure a sufficiently long beam lifetime.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW115

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paper received ※ 12 April 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

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MOPGW123

Electromagnetic Study and Measurements of the iRCMS Cell

focusing, quadrupole, proton, extraction

403

N. Tsoupas, P.N. Joshi, F. Méot, D. Trbojevic
BNL, Upton, Long Island, New York, USA
D.T. Abell
RadiaSoft LLC, Boulder, Colorado, USA
V.L. Bailey, J.P. Lidestri
Best Medical International, Springfield, USA
M. Sinnott
Everson Tesla Inc., Nazareth, Pennsylvania, USA

Funding: BNL Contract TSA-NF-18-80
The ion Rapid Cycle Medical Synchrotron (iRCMS) * will provide proton and C ion bunches with maximum energy 270 MeV and 450 MeV/u respectively at a frequency of 15 Hz for treating cancerous tumors. One of the six cells of the iRCMS has been designed, built and magnetic field measurements have been performed. We will present results from the static and AC electromagnetic study of the iRCMS cell and compare the measured magnetic fields with those calculated using the OPERA computer code **. In addition the beam optics of the cell will be calculated based on the experimental fields using the zgoubi computer code *** and compared with the designed beam optics.
* D. Trbojevic, iRCMS Magnet Review, BNL, Sept. 6, 2012 (unpublished)
** OPERA computer code https://operafea.com/
*** The zgoubi computer code https://www.bnl.gov/isd/documents/79375.pdf

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW123

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

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MOPMP004

Consolidated Lattice of the Collider FCC-hh

dipole, quadrupole, injection, insertion

428

A. Chancé, D. Boutin, B. Dalena
CEA-IRFU, Gif-sur-Yvette, France
W. Bartmann, M. Hofer, R. Martin, D. Schulte
CERN, Meyrin, Switzerland

Funding: The European Circular Energy-Frontier Collider Study (EuroCirCol) project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant No 654305.
The FCC-hh (Future Hadron-Hadron Circular Collider) is one of the options considered for the next generation accelerator in high-energy physics as recommended by the European Strategy Group. The latest changes brought to the lattice of the FCC-hh collider are commented: impact of the new intra-beam distance, efforts to increase the beam stay clear in the dispersion suppressors, tuning procedures, and updates on the insertions.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP004

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

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MOPMP019

High Luminosity LHC Optics and Layout HLLHCV1.4

luminosity, operation, experiment, cavity

468

R. De Maria, R. Bruce, D. Gamba, M. Giovannozzi, F. Plassard
CERN, Geneva, Switzerland

The goal of the High Luminosity Project is the upgrade of the LHC to deliver an integrated luminosity of at least 250 \rm fb^-1 per year in each of the two high-luminosity, general-purpose detectors ATLAS and CMS. This article presents the latest layout design and the corresponding optics features, which comprise optimisation of the orbit corrector and crab cavity systems, and new estimates of the performance reach thanks to the new concept of fully remote alignment. In addition, the new optics version incorporates improvements required by beam instrumentation, dump system, and collimation system, as well as low-beta solutions for the LHCb experiment.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP019

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paper received ※ 17 April 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

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MOPMP020

Smooth and Beta-Beating-Free Optics Transitions for HL-LHC

injection, quadrupole, insertion, operation

472

R. De Maria, M. Solfaroli
CERN, Geneva, Switzerland

In the CERN LHC, optics transitions are mainly required to control the beam size at the four experimental interaction points. The current method, based on linearly-interpolated optics functions over a small set of matched optics and parabolic time-domain segments, introduces non-zero beta-beating and it is not optimal in time. This contribution presents an alternative approach, based on continuously-matched optics solutions distributed in time domain by using a realistic model of the superconducting circuits, which optimises the overall process duration. This method requires a change in the paradigm used in the control system and it is proposed for the future High Luminosity LHC (HL-LHC) runs.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP020

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

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MOPMP022

K-Modulation in Future High Energy Colliders

quadrupole, luminosity, collider, power-supply

476

M. Hofer, F.S. Carlier, R. Tomás
CERN, Geneva, Switzerland

K-Modulation of the quadrupoles closest to the interaction point (IP) has been an indispensable tool to accurately measure the beta-function in the interaction point (β^*) in the Large Hadron Collider (LHC) at CERN. K-Modulation may become even more important to control the lower β^* and reach the design luminosities in the High-Luminosity LHC (HL-LHC) and the Future Circular Collider (FCC). K-Modulation results also provide important input for the luminosity calibration and help in the identification and correction of errors in the machines. This paper presents a method for determining β^* using K-Modulation adapted to the characteristic layout of both colliders. Using the latest models for the HL-LHC and the FCC-hh, estimated uncertainties on the measurements are presented. The results are compared to the accuracy of an alternative modulation scheme using a different powering scheme.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP022

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paper received ※ 06 May 2019 paper accepted ※ 18 May 2019 issue date ※ 21 June 2019

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MOPMP026

HE-LHC Optics Design Options

dipole, lattice, quadrupole, hadron

492

J. Keintzel, M.P. Crouch, M. Hofer, T. Risselada, R. Tomás, F. Zimmermann
CERN, Geneva, Switzerland
M. Hofer, J. Keintzel
TU Vienna, Wien, Austria
L. van Riesen-Haupt
University of Oxford, Oxford, United Kingdom
L. van Riesen-Haupt
JAI, Oxford, United Kingdom

The High Energy Large Hadron Collider (HE-LHC), a possible successor of the High Luminosity Large Hadron Collider (HL-LHC) aims at reaching a centre-of-mass energy of about 27 TeV using basically the same 16 T dipoles as for the hadron-hadron Future Circular Collider FCC-hh. Designing the HE-LHC results in a trade off between energy reach, beam stay clear as well as geometry offset with respect to the LHC. In order to best meet the requirements, various arc cell and dispersion suppressor options have been generated and analysed, before concluding on two baseline options, which are presented in this paper. Merits of each design are highlighted and possible solutions for beam stay clear minima are presented.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP026

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paper received ※ 02 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

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MOPMP027

Second Order Dispersion Measurements in LHC

dipole, coupling, quadrupole, betatron

496

J. Keintzel, M. Hofer
TU Vienna, Wien, Austria
J.M. Coello de Portugal, J. Dilly, E. Fol, A. Garcia-Tabares, M. Hofer, J. Keintzel, E.H. Maclean, L. Malina, T.H.B. Persson, R. Tomás, A. Wegscheider
CERN, Geneva, Switzerland

The quadratic dependence of the orbit on the relative momentum offset, also known as second order dispersion, is analysed for the first time for the LHC. In this paper, the measurement and analysis procedure are described. Results and implications on future optics are discussed.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP027

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paper received ※ 02 May 2019 paper accepted ※ 17 May 2019 issue date ※ 21 June 2019

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MOPMP033

LHC Run 2 Optics Commissioning Experience in View of HL-LHC

luminosity, coupling, simulation, experiment

508

R. Tomás, F.S. Carlier, J.M. Coello de Portugal, J. Dilly, S.D. Fartoukh, E. Fol, D. Gamba, A. Garcia-Tabares, M. Giovannozzi, M. Hofer, E.H. Maclean, L. Malina, T.H.B. Persson, P.K. Skowroński, M. Solfaroli, M.L. Spitznagel, A. Wegscheider, J. Wenninger, D.W. Wolf
CERN, Geneva, Switzerland

LHC Run 2 has achieved a beta lower than a factor 2 below design. This has significantly challenged optics measurement and correction techniques in the linear and non-linear regimes, leading to the development of new approaches. Furthermore, experimenting with a large variety of optics has allowed facing the difficulties of future optics and gaining understanding of the machine imperfections. A summary of these aspects is given in view of their implications for the HL-LHC Project.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP033

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paper received ※ 07 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

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MOPMP052

Numerical Simulations of the DC Wire Prototypes in LHC for Enhancing the HL-LHC Performances

experiment, simulation, luminosity, resonance

566

A. Poyet
Université Grenoble Alpes, Grenoble, France
S.D. Fartoukh, N. Karastathis, Y. Papaphilippou, K. Skoufaris, G. Sterbini
CERN, Geneva, Switzerland

For the last 15 years, the compensation of the Beam-Beam Long-Range (BBLR) interaction in colliders using DC wires has been studied. In 2015, in the frame of the HL-LHC project, it has been shown that a compensation of all the Resonance Driving Terms (RDTs) generated by the BBLR interaction is possible using wires with constraints on their transverse and longitudinal positions. In 2017, an experimental campaign has been launched in the present LHC, with wires installed in sub-optimal positions due to integration constraints. The aim of this paper is therefore to apply the formalism developped for HL-LHC to the LHC case and to compare the experimental results to the numerical tracking studies of the compensation using wires.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP052

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paper received ※ 06 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, storage-ring, 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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MOPTS017

Status of Operation With Negative Momentum Compaction at KARA

operation, injection, quadrupole, sextupole

878

P. Schreiber, T. Boltz, M. Brosi, B. Härer, A. Mochihashi, A.-S. Müller, A.I. Papash, M. Schuh
KIT, Karlsruhe, Germany

Funding: We are supported by the DFG-funded ’Karlsruhe School of Elementary and Astroparticle Physics: Science and Technology’ and European Union’s Horizon 2020 research and innovation programme (No 730871)
For future synchrotron light source development novel operation modes are under investigation. At the Karlsruhe Research Accelerator (KARA) an optics with negative momentum compaction has been proposed, which is currently under commissioning. In this context, the collective effects expected in this regime are studied with an initial focus on the head-tail instability and the micro-bunching instability resulting from CSR self-interaction. In this contribution, we will present the proposed optics and the status of implementation for operation in the negative momentum compaction regime as well as a preliminary discussion of expected collective effects.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS017

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paper received ※ 14 May 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

storage-ring, lattice, dynamic-aperture, resonance

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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MOPTS087

Transverse Emittance Studies at Extraction of the CERN PS Booster

emittance, operation, booster, injection

1058

F. Antoniou, S.C.P. Albright, F. Asvesta, H. Bartosik, G.P. Di Giovanni, V. Forte, M.A. Fraser, A. Garcia-Tabares, A. Huschauer, B. Mikulec, T. Prebibaj, A. Santamaría García, P.K. Skowroński
CERN, Meyrin, Switzerland
F. Asvesta
NTUA, Athens, Greece
T. Prebibaj
National Technical University of Athens, Zografou, Greece

Transverse emittance discrepancy in the beam transfer between the Proton Synchrotron Booster (PSB) and the Proton Synchrotron (PS) is observed in operational conditions for the LHC beams at CERN. The ongoing LHC Injectors Upgrade (LIU) project requires a tight budget for beam degradation along the injector chain and therefore the reason for this emittance discrepancy needs to be understood. Systematic measurements have been performed for various beam characteristics (beam intensity, transverse and longitudinal emittance). In this paper, a comparison between the emittance measurements using all available beam instrumentation with different emittance computation algorithms is presented. The results are compared to measurements at PS injection. Furthermore, the impact on the LIU project requirements for the emittance preservation along the LHC Injectors Complex is discussed.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS087

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

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MOPTS100

Transverse Emittance Measurement in the CERN Proton Synchrotron in View of Beam Production for the High-Luminosity LHC

emittance, brightness, proton, betatron

1106

E. Senes, J. Emery, V. Forte, M.A. Fraser, A. Guerrero, A. Huschauer, F. Roncarolo, J.L. Sirvent, P.K. Skowroński, F. Tecker
CERN, Geneva, Switzerland

In the framework of the LHC Injectors Upgrade project the improvements required to achieve the parameters of the future beams for the High-Luminosity LHC are being studied and implemented. In order to deliver high brightness beams, control over the beam intensity and emittance is fundamental. Therefore, a highly accurate and reliable transverse emittance measurement is essential. Presently at the CERN Proton Synchrotron, the only operationally available emittance monitors not impacting the facility beam production are the flying wire scanners used to measure the circulating beam profile. The wire scanners will be replaced with a new generation in the next two years and a prototype is already installed. The prototype has been commissioned with beams featuring a wide range of intensities and emittances. This paper evaluates the performance of the prototype with respect to the present system via beam-based measurements. The transverse emittance measurement is discussed, considering the different potential error contributions to the measurement, such as knowledge of the machine optics and the dispersive contribution to the beam size.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS100

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paper received ※ 02 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

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MOPTS102

Linear and Non-Linear Optics Measurements in PS using Turn-by-Turn BPM Data

injection, coupling, sextupole, betatron

1114

P.K. Skowroński, M. Giovannozzi, A. Huschauer
CERN, Meyrin, Switzerland

For the first time, the optics of the CERN Proton Synchrotron (PS) was measured using turn-by-turn BPM data of forced betatron oscillations excited with an AC dipole. We report results of phase advance and beta beating measurements. Linear coupling was globally minimized along the machine by measuring and correcting coupling resonance driving terms. Finally, non-linear properties of the ring were probed looking at third and fourth order resonance driving terms and amplitude detuning.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS102

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paper received ※ 07 May 2019 paper accepted ※ 19 May 2019 issue date ※ 21 June 2019

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MOPTS120

Commissioning of the New Experimental FODO Line at the SNS Beam Test Facility

rfq, emittance, MMI, simulation

1164

A.V. Aleksandrov, S.M. Cousineau, K.J. Ruisard, V. Tzoganis, A.P. Zhukov
ORNL, Oak Ridge, Tennessee, USA
Z.L. Zhang
UTK, Knoxville, Tennessee, USA

The SNS Beam Test Facility consists of a 2.5MeV proton accelerator and a beam line with various diagnostics for high intensity beam dynamics study. A FODO line consisting of 19 quadrupole magnets and a large dynamic range emittance monitor has been added recently. The new setup is design for experimental study of mechanisms of halo formation in mismatched high intensity beams. We present results of the new beam line commissioning with beam.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS120

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paper received ※ 07 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019

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TUZPLM2

Optics Measurements at SuperKEKB Using Beam Based Calibration for BPM and BBA

quadrupole, betatron, emittance, coupling

1198

H. Sugimoto, H. Koiso, K. Mori, A. Morita, Y. Ohnishi, M. Tejima
KEK, Ibaraki, Japan

The beam-based calibration(BBC) technique for Beam-Position-Monitor(BPM) is applied in order to establish reliable optics measurement. In the BBC, a response model between beam position, charge and output signals of the BPM electrodes are introduced to calibrate the relative gain of the BPM electrodes. The gains are adjusted by total squares fitting so that the model reproduces the measured BPM signals. The Beam-Based Alignment(BBA) is also performed to determine the magnetic center of a quadrupole. Using BBC and BBA, the performance of the BPM system and optics correction are successfully improved. This talk presents what we experienced during the beam commissioning focusing on beam optics measurement and some details on the beam-based calibration scheme for BPM system.

Slides TUZPLM2 [15.911 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUZPLM2

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

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TUPGW013

Tune and Chromaticity Optimization at Bessy II for the Transverse Resonant Island Bucket Optics

simulation, photon, resonance, emittance

1411

F. Armborst, P. Goslawski, A. Jankowiak
HZB, Berlin, Germany

Funding: Federal Ministry of Education and Research
Transverse Resonant Island Buckets (TRIBs *) correspond to a second stable orbit, longitudinally winding around the core orbit in the transverse x-x^′-phasespace. The exploitation possibilities for stable TRIBs are under investigation at the third generation light source BESSY II in Berlin. The applicability for bunch separation is a main subject of these studies. Stable operation of TRIBs optics with a single or few bunches on the second orbit and a multibunch train on the main orbit has been shown **. Photons emitted on the second orbit are well separated from those of the main orbit at all beamlines. This provides the possibility of bunch separation by beamline adjustment for the timing community without significant impact on the average brightness for other users. Simulations based on linear optics from closed orbits (LOCO) and on nonlinear optics derived from the measured chromaticity and tune shift with action (TSWA) predict this separation well. Friendly user experiments in 2018 confirmed these results. The scheduled upgrade BESSY VSR *** features simultaneously stored long and short bunches. Then TRIBs optics would in principle enable the separation of the different bunches at every beamline offering unique possibilities to our users. Simulations and measurements aiming to investigate further possible optimization of the TRIBs optics are presented.
* F. Armborst, P. Goslawski et al, DOI: 10.18429/JACoW-IPAC2018-TUPML052
** P. Goslawski, F. Armborst et al. DOI: 10.18429/JACoW-IPAC2017-WEPIK057
*** A. Jankowiak et al., DOI: 10.5442/R0001

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW013

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

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TUPGW016

New Operation Regimes at the Storage Ring KARA at KIT

lattice, operation, injection, simulation

1422

A.I. Papash, E. Blomley, T. Boltz, M. Brosi, E. Bründermann, S. Casalbuoni, J. Gethmann, E. Huttel, B. Kehrer, A. Mochihashi, A.-S. Müller, R. Ruprecht, M. Schuh, J.L. Steinmann
KIT, Karlsruhe, Germany

The storage ring Karlsruhe Research Accelerator (KARA) at KIT operates in a wide energy range from 0.5 to 2.5 GeV. Initially, the ring was designed to serve as a Light Source for synchrotron radiation facility ANKA. Since then different operation modes have been implemented at KARA: in particular, the double bend achromat (DBA) lattice with non-dispersive straight sections, the theoretical minimum emittance (TME) lattice with distributed dispersion, and different versions of low compaction factor optics with highly stretched dispersion function. Short bunches of a few ps pulse width are available at KARA. Low alpha optics have been tested and implemented in a wide operational range of the ring and are now routinely used at 1.3 GeV for studies of CSR-induced beam dynamics and THz bursting in the micro-bunching instability. Different non-linear effects, in particular, residual high order components of magnetic fields generated in insertion devices have been studied and cured. A new operation mode at high vertical tune implemented at KARA essentially improves beam performance during user operation as well as at low alpha regimes.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW016

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

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TUPGW018

PETRA IV Study with Non-Interleaved Sextupole Scheme

sextupole, lattice, emittance, storage-ring

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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TUPGW023

Incorporation of a MESA Linac Modules into BERLinPro

linac, operation, HOM, cavity

1449

B.C. Kuske, W. Anders, A. Jankowiak, A. Neumann
HZB, Berlin, Germany
K. Aulenbacher
IKP, Mainz, Germany
K. Aulenbacher
HIM, Mainz, Germany
F. Hug, T. Stengler, C.P. Stoll
KPH, Mainz, Germany

Funding: Work supported by the German Bundesministerium für Bildung und Forschung, Land Berlin, grants of the Helmholtz Association and grants of Helmholtz Association and the DFG within GRK 2128
BERLinPro is an Energy Recovery Linac (ERL) project, currently being set up at the Helmholtz-Zentrum Berlin für Materialien und Energie, Berlin, Germany. BERLinPro is designed as - and for - experiments in accelerator physics and as a test bed for novel ERL components. MESA is an ERL project under construction at the Johannes Gutenberg-Universität, Mainz, Germany. MESA is designed as a user facility to perform experiments in dark matter physics and precision measurements of natural constants. Despite the diverse goals, the main linac, providing the larger part of the particles energy, is fairly compatible. It is planned to test and run the MESA linac module in BERLinPro, prior to its usage in MESA. The goals and benefits of this unique cooperation for both projects are outlined in this paper. The necessary adaptions in BERLinPro, including hardware aspects, the new optics, and the scope of performance are described.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW023

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

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TUPGW025

The DELTA Short-Pulse Source: Upgrade Plans from CHG to EEHG

laser, electron, undulator, radiation

1457

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

At the synchrotron light source DELTA operated by the TU Dortmund University, coherent harmonic generation (CHG) is employed to provide ultrashort pulses in the vacuum ultraviolet and terahertz (THz) regime. Here, a modulation of the electron energy induced by an interaction of an ultrashort laser pulse with an electron bunch is transformed into a density modulation by a magnetic chicane. This results in coherent emission at harmonics of the laser wavelength as well as THz radiation. With the planned upgrade towards echo-enabled harmonic generation (EEHG), much higher harmonics can be achieved by adding a second laser-electron interaction. The necessary major modifications of the DELTA storage ring and investigations of the laser-electron interaction will be presented.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW025

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

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TUPGW037

Systematic Measurements of the Coherent THz Spectra by Magnetic Bunch Compression at the Compact ERL

electron, radiation, sextupole, linac

1486

M. Shimada, Y. Honda, R. Kato, T. Miyajima, N. Nakamura, T. Obina, T. Uchiyama
KEK, Ibaraki, Japan
T. Hotei
Sokendai, Ibaraki, Japan

Short electron bunch beam is one of the key elements of a Free Electron Laser (FEL) or intense THz coherent light source. The Energy Recovery Linac (ERL) has the strong advantage of operation of such an electron bunch at high repetition rate and is expected to increase the photon flux. At the Compact ERL in KEK site, we have demonstrated the magnetic bunch compression at the 180-degree return arc and measured the THz spectra of the Coherent Transition Radiation (CTR). This paper reports the revamped THz beamline and the improvement of the beam tuning as well as the systematic measurements of the THz spectra by magnetic bunch compression.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW037

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

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TUPGW039

Error Study and Correction of Hefei Advanced Light Source

lattice, quadrupole, closed-orbit, coupling

1492

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

Hefei Advanced Light Source (HALS) is a future diffraction limited storage ring. The machine performance under all kinds of magnet errors is a vital component in physical design. In this paper, we present our work on the closed orbit correction, the linear beam optics compensation and the coupling control in HALS. After correction, the dynamical aperture can suffice the injection scheme.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW039

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paper received ※ 23 April 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

simulation, quadrupole, storage-ring, 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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TUPGW054

Design of a Hybrid Seven-Bend-Achromat Lattice for a High-Energy Diffraction-Limited Storage Ring Using a New Optimization Method

lattice, linear-dynamics, emittance, sextupole

1528

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

Recently, we proposed a new optimization method, with nonlinear dynamics indicators considered in the linear optics design, for designing hybrid multi-bend-achromat (MBA) lattices. With this method, two hybrid MBA lattices for medium-low-energy diffraction limited storage rings (DLSRs) have been designed, showing remarkable effectiveness in improving nonlinear dynamic performance. In this paper, we will apply this optimization method to the design of a hybrid 7BA lattice for a 6 GeV DLSR with the same circumference as that of HEPS. In the design, the strengths and arrangement of magnets of this lattice also meet the engineering requirement for HEPS. The designed lattice has a natural emittance of 34 pm·rad. The nonlinear dynamic performance is satisfactory, with a dynamic aperture of about 6 mm and 3 mm in the horizontal and vertical directions, respectively, and a dynamic momentum aperture of larger than 5%, which also shows the power of our optimization method.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW054

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

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TUPGW055

Comparison of Optimization Methods for Hybrid Seven-Bend-Achromat Lattice Design

lattice, linear-dynamics, sextupole, emittance

1532

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

Generally, for a hybrid multi-bend-achromat (MBA) lattice with fixed linear optics, there is little potential to further optimize the nonlinear dynamics due to limited free knobs. To obtain a hybrid MBA lattice with better nonlinear dynamics performance, it is better to consider some indicators of nonlinear dynamics as objective functions in designing the linear optics using an optimization algorithm. In this paper, integral strengths of sextupoles and natural chromaticities are used as the nonlinear dynamics indicators, and different optimization methods with both or either of the two indicators are carried out and compared. As an example, a hybrid 7BA lattice with an energy of 2.4 GeV is designed towards an emittance of less than 70 pm·rad.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW055

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paper received ※ 18 April 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

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TUPGW061

First Study for an Upgrade of the ALBA Lattice

lattice, emittance, injection, dipole

1544

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

ALBA has started a study that will produce the design of a new lattice for a diffraction limited photon source. The baseline lattice should preserve the present circumference and energy, and keep the insertion device beamline source points as much as possible unchanged. The first solution is a 16-fold periodic ring based on a 7BA cell with dispersion bump, paired sextupoles and anti-bends. An emittance of 155 pm·rad would be reached without longitudinal gradient in the dipole magnets.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW061

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

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TUPGW064

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

sextupole, storage-ring, 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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TUPGW075

Towards a Diffraction Limited Storage Ring

lattice, storage-ring, 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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TUPGW076

Early Commissioning Simulation of the Diamond Storage Ring Upgrade

MMI, simulation, quadrupole, closed-orbit

1577

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

A low beam emittance lattice has been designed for up-grade of the Diamond storage ring. Due to the use of strong focusing elements and rather small vacuum cham-ber and considering the required short dark time, commis-sioning of the designed storage ring becomes very chal-lenging. This paper briefly explains the progress of early commissioning simulations of the storage ring, gives the required engineering tolerances, presents the first simula-tion results and discusses the non-linear beam dynamics (NLBD) issues after successful commissioning with and without insertion devices (IDs).

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW076

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paper received ※ 13 May 2019 paper accepted ※ 22 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, storage-ring, 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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paper received ※ 15 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

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TUPGW079

Exploratory Lattice Design Studies for Diamond-II

lattice, controls, emittance, dynamic-aperture

1589

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

We pursue Robust Design of a Ring-Based Synchrotron Light Source as a System. In particular, the Design Phi-losophy is based on: ’ To Control the Nonlinear Dynamics: Control the Linear Optics. In particular, by: ’ Optimal Control of Natural Chromaticity. ’ ’-I Transformer’ between Chromatic Sextupoles for Unit Cell. ’ Higher-Order-Achromat for Super Period. In addition, by pushing the Requirements for Robust & Efficient Injection ’Upstream’, i.e., by considering On-Axis Injection, and by utilizing Reverse Bends (to trans-cend the reductionist Theoretical Minimum Emittance Cell), either: ’ the Natural Emittance can be reduced further, ’ or the Touschek Lifetime can be improved. Bottom line, a Design Choice.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW079

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

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TUPGW080

Alternative Lattice Design for Diamond-II

lattice, emittance, sextupole, dipole

1593

M. Korostelev
Oxford University, Physics Department, Oxford, Oxon, United Kingdom
B. Singh
DLS, Oxfordshire, United Kingdom

Plans for upgrade of the Diamond Light Source aim to reduce beam emittance by a factor of 20 or better. This is motivated by demand for photon flux with significantly high brightness and transverse coherence. The baseline lattice design for the Diamond-II upgrade has been recently proposed, however alternative design are under investigation to reduce the emittance even further. This paper presents a new lattice design based on implementation of bending magnets with transverse field gradient only.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW080

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

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TUPGW084

Multi-pass ERL in a ’Dogbone’ Topology

linac, cavity, dipole, focusing

1601

S.A. Bogacz
JLab, Newport News, Virginia, USA

Funding: Work has been authored by Jefferson Science Associates, LLC under Contract No. DE-AC05-06OR23177 with the U.S. Department of Energy.
The main thrust of a multi-pass RLA is its very efficient usage of expensive linac structures. That efficiency can be further enhanced by configuring an RLA in a ’dogbone’ topology, which further boosts the RF efficiency by factor of two (compare to a corresponding racetrack). However, the ’dogbone’ configuration requires the beam to traverse the linac in both directions, while being accelerated. This can be facilitated by a special ’bisected’ linac Optics. Here, the quadrupole gradients scale up with momentum to maintain periodic FODO structure for the lowest energy pass in the first half of the linac and then the quadrupole strengths are mirror reflected in the second linac half. The virtue of this optics is the appearance of distinct nodes in the beta beat-wave at the ends of each pass (where the droplet arcs begin), which limits the growth of initial betas at the beginning of each subsequent droplet arc. Furthermore, ‘bisected’ linac optics naturally supports energy recovery in the ’dogbone’ topology. In this paper, we present a-proof-of-principle lattice design of a multi-pass ’dogbone’ ERL.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW084

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paper received ※ 08 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, storage-ring

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

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TUPRB113

Dynamic Aperture of JLEIC Electron Collider Ring with Errors and Correction

alignment, electron, multipole, quadrupole

1920

Y.M. Nosochkov, Y. Cai
SLAC, Menlo Park, California, USA
F. Lin, V.S. Morozov, Y. Zhang
JLab, Newport News, Virginia, USA

Funding: * This work is supported by the U.S. Department of Energy, Office of Science, and Office of Nuclear Physics under Contracts DE-AC05-06OR23177, DE-AC02-06CH11357, and DE-AC02-76SF00515.
Design of the Jefferson Lab Electron-Ion Collider (JLEIC) includes low-beta Interaction Region (IR) and spin rotator optics for high luminosity and polarization. Magnet errors, especially in the high-beta final focus quadrupoles, result in optics perturbations which need to be corrected in order to attain sufficient dynamic aperture (DA). We present design of orbit correction system for the electron ring and evaluate its performance. The DA is then studied including misalignment, magnet strength errors, non-linear field errors, and corrections.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB113

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paper received ※ 16 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

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WEYYPLM1

Status of Early SuperKEKB Phase-3 Commissioning

MMI, detector, operation, luminosity

2255

A. Morita
KEK, Ibaraki, Japan

SuperKEKB is an asymmetric energy electron-positron collider for B-meson physics experiment. The beam collision with 3mm vertical beta function at the interaction point is confirmed during prior beam commissioning until July 2018. The next beam commissioning with the inner silicon vertex detectors so called "phase-3 commissioning" will start in March 2019. In the early part of next phase-3 commissioning, we plan to try the collision operation with over 1A stored beam current in order to exceed 1 x 10³⁴ cm^-2 s^-1 luminosity. We will report the preliminary results of the early stage of the SuperKEKB phase-3 commissioning.

Slides WEYYPLM1 [2.570 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEYYPLM1

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

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WEYYPLM2

The 2018 Heavy-Ion Run of the LHC

luminosity, heavy-ion, experiment, proton

2258

J.M. Jowett, C. Bahamonde Castro, W. Bartmann, C. Bracco, R. Bruce, J.M. Coello de Portugal, J. Dilly, S.D. Fartoukh, E. Fol, N. Fuster-Martínez, A. Garcia-Tabares, M. Hofer, E.B. Holzer, M.A. Jebramcik, J. Keintzel, A. Lechner, E.H. Maclean, L. Malina, T. Medvedeva, A. Mereghetti, T.H.B. Persson, B.Aa. Petersen, S. Redaelli, B. Salvachua, M. Schaumann, C. Schwick, M. Solfaroli, M.L. Spitznagel, H. Timko, R. Tomás, A. Wegscheider, J. Wenninger, D. Wollmann
CERN, Geneva, Switzerland
D. Mirarchi
The University of Manchester, The Photon Science Institute, Manchester, United Kingdom

The fourth one-month Pb-Pb collision run brought LHC Run 2 to an end in December 2018. Following the tendency to reduce dependence on the configuration of the preceding proton run, a completely new optics cycle with the strongest ever focussing at the ALICE and LHCb experiments was designed and rapidly implemented, demonstrating the maturity of the collider’s operating modes. Beam-loss monitor thresholds were carefully adjusted to provide optimal protection from the multiple loss mechanisms in heavy-ion operation. A switch from a basic bunch-spacing of 100 ns to 75 ns was made as the beam became available from the injector chain. A new record luminosity, 6 times the original design and close to the operating value proposed for HL-LHC, provided validation of the strategy for mitigating quenches due to bound-free pair production (BFPP) at the interaction points of the ATLAS and CMS experiments. Most of the beam parameters of the HL-LHC Pb-Pb upgrade were attained during this run and the integrated luminosity goals for the first 10 years of LHC operation were substantially exceeded.

Slides WEYYPLM2 [10.884 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEYYPLM2

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

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WEPMP025

Matching Studies Between CERN PSB and PS Through Multi-Turn Beam Profile Acquisitions

emittance, injection, betatron, operation

2367

M.A. Fraser, Y. Dutheil, V. Forte, A. Guerrero, A. Huschauer, A. Oeftiger, S. Ogur, F. Roncarolo, E. Senes, F. Tecker
CERN, Geneva, Switzerland

In the framework of the LHC Injectors Upgrade (LIU) project, the investigation and quantification of the optics mismatch between the CERN Proton Synchrotron Booster (PSB) and PS is a crucial step in understanding the source of horizontal emittance growth between the two machines. Extensive studies were carried out to estimate the mismatch from single-pass measurements in the transfer line and to rematch the transfer line to reduce the dispersive mismatch at PS injection while keeping the betatron matching unaltered. This paper presents the results of the data analysis of more recent multi-turn measurements, which profited from a new turn-by-turn beam profile monitor in the PS ring, to assess the achieved level of matching and corresponding emittance growth. The results confirm the improved matching and demonstrate the feasibility of the multi-turn technique as a fundamental tool that will be important for the recommissioning of the renovated transfer line after Long Shutdown 2.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPMP025

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

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WEPMP029

Systematic Optics Studies for the Commissioning of the AWAKE Beamline

electron, plasma, experiment, quadrupole

2383

C. Bracco, B. Goddard, I. Gorgisyan, M. Turner, F.M. Velotti, L. Verra
CERN, Geneva, Switzerland
M. Aiba
PSI, Villigen PSI, Switzerland

The commissioning of the AWAKE electron beam line was successfully completed in 2018. Despite a modest length of about 15 m, this low-energy line is quite complex and several iterations were needed before finding satisfactory agreement between the model and the measurements. The work allowed to precisely predict the size and positioning of the electron beam at the merging point with the protons inside the plasma cell, where no direct measurement is possible. All the key aspects and corrections which had to be included in the model, precautions and systematic checks to apply for the correct setup of the line are presented. The sensitivity of the ~18 MeV electron beam to various perturbations, like different initial optics parameters and beam conditions, energy jitter and drifts, earth’s magnetic field etc., is described.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPMP029

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paper received ※ 10 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

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WEPMP032

Tracking Simulations of Shadowing Electrostatic Septum Wires by Means of Bent Crystals

simulation, extraction, septum, experiment

2395

F.M. Velotti, M.A. Fraser, B. Goddard, V. Kain, L.S. Stoel
CERN, Meyrin, Switzerland

The Super Proton Synchrotron (SPS) slow extraction is a third integer resonant extraction and hence suffers from high losses at the electrostatic septum (ZS). This is one of the main limiting factors for the maximum number of Protons On Target (POT) deliverable from the SPS to the North Area (NA). A concept to significantly reduce the extraction losses via shadowing of the electrostatic septum wires using an upstream bent crystal has been proposed in *, predicting a loss reduction of up to 50% for the prototype system installed in 2018. Following the successful experimental demonstration of the concept with beam **, detailed tracking simulations have been performed to fully understand the results obtained. Further insights, such as the effective ZS width and its alignment, could be deduced by exploiting the response of the extraction loss as a function of the two degrees of freedom of the crystal (position and angle). In this paper, the beam dynamics simulations are discussed together with the implementation of the bent crystal into the simulation framework. A comparison with measurements is presented before proposals for new configurations and parameters are discussed.
* F.M. Velotti, et al., "Reduction of Resonant Slow Extraction Losses…", IPAC’18.
** F.M. Velotti, M.A. Fraser, et al., "Experimental SPS Slow Extraction Loss Reduction…", this conf.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPMP032

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

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WEPMP038

Combined MCNP/Turtle Simulation of the SINQ Beam Line at PSI-HIPA

simulation, target, proton, scattering

2410

D. Reggiani, D.C. Kiselev, M. Seidel, V. Talanov, M. Wohlmuther
PSI, Villigen PSI, Switzerland

With a nominal beam power of nearly 1.4 MW, the PSI High Intensity Proton Accelerator (HIPA) complex is currently at the forefront of the high intensity frontier of particle accelerators. A key issue of such facilities is the minimization of beam losses that could lead to excessive activation of beam line components. At HIPA, the SINQ beam line is particularly subject to relatively large losses since it receives the highly divergent beam scattered off a 40 or 60 mm thick muon production graphite target (TE). So far, for HIPA, beam line simulations have been carried out only by means of the matrix multiplication codes TRANSPORT and TURTLE. Although very efficient, such tools do not allow a precise determination of beam losses whenever targets and collimators are substantially affecting the beam optics. A true understanding of how beam halo and the low momentum tail contribute to the measured losses can only be achieved by complementing the traditional simulations techniques by a tool that can transport beam particles in different materials and, at the same time, handle complex geometries like the ones of collimators situated in the beam line. Moreover, such an improved beam line simulation would give a significant contribution in evaluating the feasibility of the SINQ beam rotation system currently under study. In this paper we present a simulation of the SINQ beam line combining MCNP models of TE and collimator sections with the TURTLE computation of the magnetic channel.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPMP038

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

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WEPMP041

Damping Bunch Oscillations Due to Off-Axis Injection

injection, wiggler, damping, radiation

2422

F. Zimmermann, O. Etisken, N. Mounet, A. Oeftiger, S. Ogur, Y. Papaphilippou, B. Salvant
CERN, Geneva, Switzerland
K. Oide
KEK, Ibaraki, Japan

Funding: This work was supported by the European Commission under the HORIZON 2020 project ARIES, grant agreement no. 730871.
In the FCC-ee pre-injector complex, a slightly modified SPS can serve as pre-booster. The baseline design foresees injecting the low-emittance electron and positron bunches off-axis into the SPS, and deploying strong wigglers to greatly enhance the radiation damping at the injection energy. We here compare the damping of large injection oscillations by means of radiation damping with the effect of other possible damping mechanisms such as a fast bunch-by-bunch feedback system and/or head-tail damping via nonzero chromaticity. As a by-product, we investigate the transverse beam stability.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPMP041

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

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WEPMP049

Simulations of Beam Shaping for Dark Matter Experiments at LCLS-II

electron, experiment, FEL, quadrupole

2443

Y.M. Nosochkov, C. Hast, T.W. Markiewicz, L.Y. Nicolas, T.O. Raubenheimer, M. Santana-Leitner
SLAC, Menlo Park, California, USA

Funding: * Work supported by the U.S. DOE Contract DE-AC02-76SF00515.
A new transfer beamline, called S30XL, and an experimental facility are proposed to be built at SLAC, taking advantage of the LCLS-II free electron laser (FEL) under construction. The S30XL will operate parasitically to the FEL by extracting the unused low intensity 4-GeV LCLS-II bunches into the existing A-line and the End Station-A (ESA). This provides a unique capability of multi-GeV nearly continuous electron beam for a variety of HEP experiments, in particular the dark matter search experiments. The latter require a very low beam current ranging from pA to micro-A, as well as a large beam spot at the detector. The necessary beam shaping will be performed using spoilers and collimators in the A-line, and by optimizing the optics. FLUKA and elegant codes are used to generate and track the beam into the ESA.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPMP049

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

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WEPGW081

Unsupervised Machine Learning for Detection of Faulty Beam Position Monitors

simulation, ISOL, MMI, ECR

2668

E. Fol, J.M. Coello de Portugal, R. Tomás
CERN, Meyrin, Switzerland

Unsupervised learning includes anomaly detection techniques that are suitable for the detection of unusual events such as instrumentation faults in particle accelerators. In this work we present the application of decision trees-based algorithm to faulty BPMs detection at the LHC. This method achieves significant improvements in quality of optics measurements and allows to identify relevant signal properties that contribute to fault detection.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPGW081

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

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WEPGW099

Development of a Beam Halo Monitor

radiation, synchrotron-radiation, synchrotron, electron

2721

V.G. Dudnikov, R.P. Johnson, M. Popovic
Muons, Inc, Illinois, USA
M.A. Cummings
Northern Illinois University, DeKalb, Illinois, USA
R.M. Thurman-Keup
Fermilab, Batavia, Illinois, USA

Our innovative approach is to design the Beam Halo Monitor, where beam induced synchrotron radiation will be used to monitor the beam Halo. This involves an original scheme of light collection using a coronograph for measuring beam halo.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPGW099

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

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WEPGW103

Synchrotron Radiation Beam Diagnostics at IOTA - Commissioning Performance and Upgrade Efforts

electron, radiation, experiment, detector

2732

N. Kuklev, Y.K. Kim
University of Chicago, Chicago, Illinois, USA
J.D. Jarvis, A.L. Romanov, J.K. Santucci, G. Stancari
Fermilab, Batavia, Illinois, USA

Funding: Work supported by National Science Foundation award PHY-1549132, the Center for Bright Beams. Fermi Research Alliance operates Fermilab under Contract DE-AC02-07CH11359 with the US Dept. of Energy.
The Integrable Optics Test Accelerator is a research electron and proton storage ring recently commissioned at the Fermilab Accelerator Science and Technology facility. A key part of its beam diagnostics suite are synchrotron radiation monitors, used for measuring transverse beam profile, position, and intensity. In this paper, we report on the performance and uses of this system during the year 1 run. We demonstrate sub-100nm statistical beam position uncertainty and high dynamic range from 10⁹ electrons down to a single electron. Commissioning challenges and operational issues are discussed. We conclude by outlining current upgrade efforts, including improved modularity, small emittance measurements, and a multi-anode photomultiplier system for turn-by-turn acquisition.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPGW103

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paper received ※ 15 May 2019 paper accepted ※ 19 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, storage-ring, 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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WEPGW116

LHC Optics Measurement and Correction Software Progress and Plans

software, coupling, MMI, GUI

2773

R. Tomás, F.S. Carlier, J.M. Coello de Portugal, J. Dilly, E. Fol, A. Garcia-Tabares, M. Hofer, E.H. Maclean, L. Malina, T.H.B. Persson, P.K. Skowroński, M.L. Spitznagel, A. Wegscheider, J. Wenninger
CERN, Geneva, Switzerland
J.F. Cardona, Y. Rodriguez
UNAL, Bogota D.C, Colombia
F.S. Carlier
NIKHEF, Amsterdam, The Netherlands
D. Esperante Pereira, J. Fuster, D. Gonzalez-Iglesias
IFIC, Valencia, Spain
R. Hoekstra
KVI, Groningen, The Netherlands

LHC Optics Measurements and Corrections (OMC) require efficient on-line software applications to acquire and analyze data and to compute the necessary corrections. During Run 2 various measurement and correction techniques have been merged to yield unprecedented optics quality, increasing the required number of steps to finalize the optics commissioning and the size of the software project. In turn, this calls for a higher level of automation, where machine learning techniques are being implemented. During the Long Shutdown 2 a large refactoring of the codes will be in place to improve performance, maintainability and extensibility. A description of the current status of the software and future plans is given.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPGW116

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paper received ※ 07 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019

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WEPGW121

Update on the JLEIC Electron Collider Ring Design

electron, collider, quadrupole, solenoid

2780

F. Lin, V.S. Morozov, Y. Zhang
JLab, Newport News, Virginia, USA
Y. Cai, Y.M. Nosochkov
SLAC, Menlo Park, California, USA

Funding: This material is based upon work supported by the U.S. Department of Energy, Office of Science, and Office of Nuclear Physics under Contracts DE-AC05-06OR23177 and DE-AC02-76SF00515.
The design concept of electron collider ring in the Jefferson Lab Electron-Ion Collider (JLEIC) is based on a small beam size at the interaction point (IP) to boost the luminosity. With a chosen beta-star at the IP, electron beam size is determined by the equilibrium emittance obtained from the linear optics design. In this paper, we present an update on the lattice design of the electron ring considering not only preservation of low beam emittance, but also optimization of geometric arrangement. In particular, recent development of the lattice design has been focused on incorporating the vertical dogleg, which brings the electron beam to the ion beam plane for collisions, in the spin rotator design. The vertical dogleg is designed with no horizontal emittance growth, controlled vertical emittance and no first-order effect on the electron polarization.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPGW121

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

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WEPRB106

Simulation of the Transition Radiation Transport Through an Optic System

radiation, simulation, electron, diagnostics

3059

M. Marongiu, A. Mostacci, L. Palumbo
Sapienza University of Rome, Rome, Italy
F.G. Bisesto, E. Chiadroni, G. Di Pirro, G. Franzini, A. Giribono, V. Shpakov, A. Stella, A. Variola
INFN/LNF, Frascati, Italy
A. Cianchi
Università di Roma II Tor Vergata, Roma, Italy
A. Mostacci, L. Palumbo
INFN-Roma, Roma, Italy

Optical Transition Radiation (OTR) screens are widely used for beam profile measurements. The radiation is emitted when a charged particle beam crosses the boundary between two media with different optical properties. The main advantages of OTR are the instantaneous emission process allowing fast single shot measurements (i.e. bunch by bunch measurements in a multi bunch machine), and the good linearity with the beam charge (if coherent effects can be neglected). Furthermore, OTR angular distribution strongly depends on beam energy. Since OTR screens are typically placed in several positions along the Linac to monitor beam envelope, one may perform a distributed energy measurement along the machine: this will be useful, for instance, during the commissioning phase of a machine. This paper deals with the studies of an algorithm to optimize the generation and the transport of the transition radiation through an optic system using the simulation tool Zemax. The algorithm, in combination with a particle tracking code (i.e. Elegant), will allow to simulate the radiation generated by a beam and, so, to take into account beam divergence and energy spread or chromatic effects in the optic system.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPRB106

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

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WEPTS039

Momentum Slip-Stacking in CERN SPS for the Ion Beams

simulation, cavity, operation, emittance

3184

T. Argyropoulos, T. Bohl, A. Lasheen, G. Papotti, D. Quartullo, E.N. Shaposhnikova
CERN, Geneva, Switzerland

The LHC Injectors Upgrade (LIU) project at CERN aims at doubling the total intensity of the lead ion beam for the High-Luminosity (HL) LHC. Achieving this goal requires using momentum slip-stacking in the SPS, the LHC injector. Slip-stacking will be applied on an intermediate energy plateau to interleave two batches, reducing the bunch spacing from 100 ns to 50 ns and thus increasing the total number of bunches injected into the LHC. Realistic macro-particle simulations, with the present SPS impedance model are used to study and design this complicated beam manipulation. Slip-stacking can be tested experimentally only after the upgrade of the SPS 200 MHz RF system, in 2021. Preliminary, slip-stacking related beam measurements were performed at the end of 2018. In this paper both macro-particle simulations and beam measurements are reported with emphasis given on optimisation of the process, crucial to achieve the required HL-LHC parameters (bunch lengths, beam losses).

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPTS039

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

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WEPTS041

Coupling and Space Charge Studies at the CERN PSB

resonance, coupling, emittance, space-charge

3192

F. Asvesta
NTUA, Athens, Greece
F. Antoniou, H. Bartosik, G.P. Di Giovanni, Y. Papaphilippou
CERN, Meyrin, Switzerland

In the nominal optics of the CERN PS-Booster (PSB), the fourth order coupling resonance is excited by space charge (Montague resonance) due to the same integer tune values. This resonance can be avoided by changing the tunes to different integers. A new PSB optics is presented and emittance measurements crossing the coupling resonance for the nominal and the new optics are shown.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPTS041

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paper received ※ 17 April 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

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WEPTS056

Can a Paul Ion Trap Be Used to Investigate Nonlinear Quasi-Integrable Optics?

octupole, lattice, experiment, quadrupole

3251

L. Martin, S.L. Sheehy
JAI, Oxford, United Kingdom
D.J. Kelliher
STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom

Here we describe the design of an experimental setup using the IBEX Paul trap to test nonlinear quasi-integrable optics, an accelerator lattice design to create stable high intensity beams. In 2010 Danilov and Nagaitsev found a realisable nonlinear potential which can create integrable optics in an accelerator when embedded in a linear lattice that provides round beams. This concept will be tested in the IOTA ring at Fermilab. It is important to further test this concept over a wide parameter range, preferably in a simplified experimental setup such as IBEX. The IBEX Paul trap is capable of replicating the transverse dynamics of a high intensity accelerator without dispersion or chromaticity.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPTS056

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

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WEPTS068

A Novel S-Based Symplectic Algorithm for Tracking With Space Charge

space-charge, simulation, resonance, proton

3279

J.P. Edelen, D.T. Abell, D.L. Bruhwiler, N.M. Cook, C.C. Hall, S.D. Webb
RadiaSoft LLC, Boulder, Colorado, USA

Funding: This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of High Energy Physics under Award Number DE-SC0011340
Traditional finite-difference particle-in-cell methods for modeling self-consistent space charge introduce non-Hamiltonian effects that make long-term tracking in storage rings unreliable. Foremost of these is so-called grid heating. Particularly for studies where the Hamiltonian invariants are critical for understanding the beam dynamics, such as nonlinear integrable optics, these spurious effects make interpreting simulation results difficult. To remedy this, we present a novel symplectic spectral space charge algorithm that is free of non-Hamiltonian numerical effects and, therefore, suitable for long-term tracking studies. Results presented here include a detailed study of the solver’s performance under a range of conditions. First, we show benchmarking and convergence studies for different particle shapes and different particle distributions. Then we demonstrate the solver’s ability to preserve Hamiltonian structure by studying the formation of space-charge driven resonances using both our algorithm and traditional PIC.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPTS068

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

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WEPTS070

First Measurements of Nonlinear Decoherence in the IOTA Ring

lattice, kicker, experiment, damping

3286

C.C. Hall, D.L. Bruhwiler, J.P. Edelen
RadiaSoft LLC, Boulder, Colorado, USA
N. Kuklev
University of Chicago, Chicago, Illinois, USA
A.L. Romanov, A. Valishev
Fermilab, Batavia, Illinois, USA

Funding: This work has been supported by the U.S. Department of Energy Office of Science, Office of High Energy Physics under Award No. DE-SC00111340
The Integrable Optics Test Accelerator (IOTA), at Fermi National Laboratory is aimed at testing nonlinear optics for the next generation of high intensity rings. Through use of a special magnetic element the ring is designed to induce a large tune spread with amplitude while maintaining integrable motion. This will allow for the suppression of instabilities in high-intensity beams without significant reduction in dynamic aperture. One important aspect of this is the nonlinear decoherence that occurs when a beam is injected off axis or receives a transverse kick while circulating in the ring. This decoherence has been studied in detail, with simulations, for protons in IOTA both with and without space-charge. However, it has yet to be demonstrated experimentally. During the first phase of the IOTA experimental program, the ring is operated with 100 MeV electrons, allowing for the study of nonlinear optics without the complications introduced by space charge. Here we present measurements taken during the IOTA commissioning, and an analysis of the results.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPTS070

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

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WEPTS102

Helical Wiggler Model for Fast Tracking

wiggler, radiation, electron, undulator

3356

W.F. Bergan, V. Khachatryan, D.L. Rubin
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

Funding: NSF-1734189 DGE-1650441
In order to test the process of Optical Stochastic Cooling (OSC) at the Cornell Electron Storage Ring (CESR), we plan to use helical wigglers as both the pickup and kicker, since the required radiation wavelength of 800nm can be achieved with lower magnetic field strength in helical as compared to planar wigglers. In order to simulate the lattice with such wigglers, it is useful to be able to model the effect of the wiggler on the optics without resorting to direct tracking, which is time-consuming and so ill-suited for the repeated evaluations necessary in running an optimizer. We generate a Taylor map to third order for this element using analytic field expressions, enabling easy determination of the effects of such an element on linear and nonlinear optics. This model is compared with the results of direct tracking and shows good agreement.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPTS102

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

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WEPTS107

Designing the European Spallation Source Tuning Dump Beam Imaging System

proton, radiation, target, linac

3374

M.G. Ibison, C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom
E. Adli, G. Christoforo, H. Gjersdal
University of Oslo, Oslo, Norway
M.G. Ibison, C.P. Welsch
The University of Liverpool, Liverpool, United Kingdom
T.J. Shea, C.A. Thomas
ESS, Lund, Sweden

Funding: In-Kind Agreement, ESS/Norway
The first section of the European Spallation Source (ESS) to receive high-energy protons when live operation begins will be the Tuning Dump beam-line. The dump line will be used during accelerator commissioning to tune the linac, and must accept the full range of ESS energies up to 2 GeV, from 5µs probe pulse to full 2.86ms pulse length, and beam sizes up to the 250 mm limit of the physical aperture, although the allowed pulse rate will be restricted by the thermal capacity of the dump. An imaging system has been developed to view remotely the transverse beam profile in the section immediately before the dump entrance, using insertable scintillator screens. This contribution presents the principal design parameters for this system, with particular reference to the techniques used in assessing the radiation and thermal environments and their impact on the selection of locations for the imaging cameras, and the specification of the mechanical screen actuators. The predicted optical performance of the system is also summarised.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPTS107

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

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THXXPLM2

Demonstration of Loss Reduction Using a Thin Bent Crystal to Shadow an Electrostatic Septum During Resonant Slow Extraction

extraction, operation, septum, experiment

3399

F.M. Velotti, P. Bestmann, M.E.J. Butcher, M. Calviani, M. Di Castro, M. Donzé, L.S. Esposito, M.A. Fraser, M. Garattini, S.S. Gilardoni, B. Goddard, V. Kain, J. Lendaro, A. Masi, D. Mirarchi, M. Pari, J. Prieto, S. Redaelli, R. Rossi, W. Scandale, R. Seidenbinder, P. Serrano Galvez, L.S. Stoel, C. Zamantzas, V. Zhovkovska
CERN, Meyrin, Switzerland
F.M. Addesa, F. Iacoangeli
INFN-Roma, Roma, Italy
A.G. Afonin, Y.A. Chesnokov, A.A. Durum, V.A. Maisheev, Yu.E. Sandomirskiy, A.A. Yanovich
IHEP, Moscow Region, Russia
J.E. Borg, M. Garattini, G. Hall, T. James, M. Pesaresi
Imperial College of Science and Technology, Department of Physics, London, United Kingdom
A.S. Denisov, Y. Gavrikov, Yu.M. Ivanov, M.A. Koznov, L.G. Malyarenko, V. Skorobogatov
PNPI, Gatchina, Leningrad District, Russia
F. Galluccio
INFN-Napoli, Napoli, Italy
F. Murtas
INFN/LNF, Frascati, Italy

A proof-of-principle experiment demonstrating the feasibility of using a thin, bent crystal aligned upstream of an extraction septum (ES) to increase the efficiency of the third-integer resonant slow extraction process has been carried out at the CERN Super Proton Synchrotron (SPS). With the primary aim of reducing the beam loss and induced radio-activation of the SPS, the crystal was aligned to both the beam and the septum to reduce by up to 40% the beam intensity impinging the ES and increase the intensity entering the external transfer line. In this contribution, we introduce the concept and the prototype system that was installed in 2018 before reporting in detail on the dedicated program of machine development studies carried out to characterise its performance and demonstrate operational feasibility. The performance reach and compatibility with other loss reduction techniques proposed to further increase the extraction efficiency, such as phase space folding with octupoles, is discussed in view of future high intensity operation.

Slides THXXPLM2 [1.397 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THXXPLM2

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paper received ※ 15 May 2019 paper accepted ※ 28 May 2019 issue date ※ 21 June 2019

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THPMP002

Optics Design and Beam Dynamics Simulation for a VHEE Radiobiology Beam Line at PRAE Accelerator

linac, gun, radiation, electron

3444

A. Faus-Golfe, B. Bai, Y. Han, C. Vallerand
LAL, Orsay, France
R. Delorme, Y. Prezado
IMNC, Orsay, France
M. Dosanjh
CERN, Meyrin, Switzerland
P. Duchesne
IPN, Orsay, France
V. Favaudon, C. Fouillade, P.M. Poortmans, F. Pouzoulet
Institut Curie - Centre de Protonthérapie d’Orsay, Orsay, France

The Platform for Research and Applications with Electrons (PRAE) is a multidisciplinary R&D facility gathering subatomic physics, instrumentation, radiobiology and clinical research around a high-performance electron accelerator with beam energies up to 70 MeV. In this paper we report the complete optics design and performance evaluation of a Very High Energy Electron (VHEE) innovative radiobiology study, in particular by using Grid mini-beam and FLASH methodologies, which could represent a major breakthrough in Radiation Therapy (RT) treatment modality.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPMP002

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paper received ※ 27 April 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

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THPMP011

Optics and Commissioning of the CNAO Experimental Beam Line

experiment, radiation, proton, MMI

3472

S. Savazzi, E. Bressi, L. Falbo, V. Lante, C. Priano, M.G. Pullia
CNAO Foundation, Pavia, Italy
P. Meliga
University of Pavia, Pavia, Italy

CNAO (National Centre for Oncological Hadronthera-py) in Pavia is one of the six centres worldwide in which hadrontherapy is administered with both protons and carbon ions. The main accelerator is a 25 m diameter synchrotron designed to accelerate carbon ions up to an energy of 400 MeV/u and protons up to an energy of 250 MeV. It was designed with three treatment rooms and an ’experimental room’ where research can be carried out. The room itself was built since the beginning, but the beam line was planned to be installed in a second moment in order to give priority to treatments. The beam line of the experimental room (XPR) is designed to be "general purpose", for research activities in different fields. In October 2018 the installation phase of the line was started and it ended in January 2019. In this paper a short description of the optics layout and commissioning strategy is given.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPMP011

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

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THPMP017

Design and Development of the Beamline System for a Proton Therapy Facility

dipole, kicker, proton, quadrupole

3488

B. Qin, Q.S. Chen, M. Fan, K.F. Liu, X. Liu, J. Yang, Z.F. Zhao
HUST, Wuhan, People’s Republic of China
W.J. Han, D. Li, Z.K. Liang
Huazhong University of Science and Technology, State Key Laboratory of Advanced Electromagnetic Engineering and Technology,, Hubei, People’s Republic of China

Funding: This work was supported by The National Key Research and Development Program of China, with grant No. 2016YFC0105305; and by National Natural Science Foundation of China (11375068).
A proton therapy facility with multiple treatment rooms based on superconducting cyclotron scheme is under development in HUST (Huazhong University of Science and Technology). Design features and overview of development progress for the beamline system will be presented in this paper, which mainly focuses on prototype beamline magnets, a kicker magnet for fast beam switch, and the gantry beamline using image optics.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPMP017

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

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THPMP020

Single-Shot Cascade High Energy Electron Radiography based on Strong Permanent Magnet Quadrupole Composed Imaging Lens

electron, experiment, simulation, quadrupole

3491

Z. Zhou, Y.-C. Du, W.-H. Huang
TUB, Beijing, People’s Republic of China

High energy electron imaging, an extension of conventional transmission electron microscopy, is suitable for imaging of thicker objects and expected to be a promising tool for diagnostics of high energy density physics (HEDP). A cascade high energy electron imaging system using two-stage imaging lenses based on strong permanent magnet quadrupoles is designed, optimized and finally installed at Tsinghua university. Encouraging result of 1.6-μm space resolution is obtained in our primary experiments, along with the clear imaging of a spherical capsule as a substitute of the targets used in inertial confinement fusion. Successful implement of cascade high energy electron imaging system is necessary for reaching better resolving power of the imaging system, and well matching of design, simulation with experimental results paves the way to high energy electron microscopy to provide full capacities for diagnostics of HEDP with sub-um and picosecond spatiotemporal resolutions.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPMP020

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paper received ※ 07 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019

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THPMP050

Progress on the Optics Modeling of BMI’s Ion Rapid-Cycling Medical Synchrotron at BNL

dipole, focusing, GUI, simulation

3561

F. Méot, P.N. Joshi, N. Tsoupas
BNL, Upton, Long Island, New York, USA
J.P. Lidestri
Best Medical International, Springfield, USA

Funding: A project funded by Best Medical International, in the framework of a Technical Services Agreement (No. TSA-NF-18-50) with Brookhaven National Laboratory.
The Brookhaven National Laboratory continues to provide technical support and guidance to Best Medical International to build and test a 60 degree magnetic arc of a rapid-cycling ion synchrotron for cancer treatment. The 60 degree magnetic sector on its guirder has undergone field measurements, including the production of partial 3D field maps. Concurrently, OPERA field map computations as well as lattice and beam dynamics simulations have been performed, aimed at both preparing and analyzing the field measurements. Contingency responses aimed at adapting to non-ideal orbit and optics have been devised. These works and their outcomes are summarized here.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPMP050

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

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THPGW029

Crucial Transverse Beam Dynamics of the Racetrack-shape Fixed Field Induction Accelerator for Giant Cluster Ions

acceleration, injection, induction, space-charge

3643

T. Taufik
BATAN, Yogyakarta, Indonesia
T. Adachi, K. Takayama, M. Wake
KEK, Ibaraki, Japan

A racetrack-shape fixed field induction accelerator (RAFFIA) for high energy giant cluster ion acceleration was proposed in 2015*. The RAFFIA employs 4 bending magnets with gradient in the main pole face and reverse field strip at its front side which generate strong focusing in both planes. Beam dynamics properties of the RAFFIA of 140 MeV for C-60 have been evaluated by linear optics. The result has been confirmed with a help of 3D macro-particle computer simulation**. It is identified that the issue of COD generated from field non-uniformity associated with a finite size of the bending magnet is inherent. The programmed COD correction by steering magnets are discussed as well as the importance of uniformity in the magnet field profile. So far it has been unknown what beam current is acceptable in the RAFFIA. In order to estimate space-charge effects in the RAFFIA under design, the 2D core (σ) evolution equation has been derived from the envelope equation perturbed by space-charge fields. Resonant structures and chaotic motion in the phase space of (σ,σ’) have been clarified as a function of beam current. Those results were justified by macro-particle tracking based on a renormalized transfer matrix approach***. As a result, it turns out that the 8+ C-60 beam of 200 uA is acceptable.
* K.Takayama, et. al, Phys. Rev. ST Accel. Beams 18, 050101 (2015).
** Taufik, et. al, sub. to Phys. Rev. AB (2018).
*** Taufik, K.Takayama, and T. Adachi, sub. Phys. Rev. AB (2019).

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPGW029

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

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THPGW049

Fabrication of On-Line Test Facility of Li-8 Beam at KOMAC

target, ion-source, proton, linac

3697

J.J. Dang, Y.-S. Cho, H.S. Kim, H.-J. Kwon, P. Lee, Y.G. Song
Korea Atomic Energy Research Institute (KAERI), Gyeongbuk, Republic of Korea

Funding: This work has been supported through KOMAC operation fund of KAERI by MSIT and the NRF of Korea grant funded by the Korea government (MSIT) (No. NRF-2017M2A2A6A02071070).
A Li-8 beam facility has been developed at KOMAC. A target/ion source (TIS) was fabricated, and heating experiment of a target heater and a surface ion source was conducted at off-line test site. Also, beam optics components were developed. They are utilized in Li-8 beam line that electrostatic steerers to adjust misalignment of the beam, Einzel lens to focus beam and Wien filter to separate Li-8. Furthermore, a high-energy beta-ray telescope detector was developed as a dedicated beta-decay spectrometer for diagnostics of the Li-8 beam. The TIS, the beam optics and the beam diagnostics are installed in a target room (TR104) of the 100-MeV proton linac. An experiment of the proton beam transportation into TR10⁴ and the TIS heating experiment were conducted separately. Finally, the on-line test of TIS has been conducted to generate Li-8 beam and examine the beam optics and the diagnostics.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPGW049

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

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THPGW062

The New CERN East Area Primary and Secondary Beams

target, secondary-beams, radiation, proton

3730

E. Montbarbon, D. Banerjee, J. Bernhard, D. Brethoux, M. Brugger, B.D. Carlsen, N. Charitonidis, A. Ebn Rahmoun, S. Evrard, L. Gatignon, A. Gerbershagen, E. Harrouch, M. Lazzaroni, B. Rae, M.S. Rosenthal, M.W.U. Van Dijk
CERN, Geneva, Switzerland

The East Area is one of the intensely used facilities at CERN, now serving for over 56 years beams to more than 20 user teams and experiments for about 200 days of running each year. Besides primary proton and ion beams for the irradiation facilities IRRAD and CHARM, mixed secondary beams of hadrons, electrons and muons within a range of 0.5 GeV/c to 12 GeV/c are provided. The CERN management approved an upgrade and renovation of the full facility to meet reliably future beam test and physics requirements. We present new, flexible beam optics that will assure better purity of the secondary beams, even with the new possibility of highly pure electron, hadron or muon beams. The upgrade also includes a pulsed powering scheme with energy recovering power supplies and new laminated magnets that will reduce both power and cooling requirements. The renovation phase started already and first beams in the new facility will be delivered from 2021 on.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPGW062

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paper received ※ 03 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

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THPGW063

The "Physics Beyond Colliders" Projects for the CERN M2 Beam

experiment, radiation, hadron, detector

3734

D. Banerjee, J. Bernhard, M. Brugger, N. Charitonidis, L. Gatignon, A. Gerbershagen, E. Montbarbon, B. Rae, M.S. Rosenthal, M.W.U. Van Dijk, B. Veit, V. de Jesus
CERN, Geneva, Switzerland
S. Cholak
Taras Shevchenko National University of Kyiv, Kyiv, Ukraine
G. D’Alessandro
JAI, Egham, Surrey, United Kingdom

Physics Beyond Colliders is an exploratory study aimed at exploiting the full scientiﬁc potential of CERN’s accelerator complex up to 2040 and its scientiﬁc infrastructure through projects complementary to the existing and possible future colliders. Within the Conventional Beam Working Group (CBWG), several pro-jects for the M2 beam line in the CERN North Area were proposed, such as a successor for the COMPASS experiment, a muon programme for NA64 dark sector physics, and the MuonE proposal aiming at investigating the hadronic contribution to the vacuum polarisation. We present integration and beam optics studies for 100-160 GeV/c muon beams as well as an outlook for improvements on hadron beams, which include RF-separated options and low-energy antiproton beams and radiation studies for high intensity beams. In addition, necessary beam instrumentation upgrades for beam particle identiﬁcation and momentum measurements are discussed.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPGW063

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

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THPGW069

Implementation of CERN Secondary Beam Lines T9 and T10 in BDSIM

target, secondary-beams, simulation, software

3746

G. D’Alessandro, S.T. Boogert, S.M. Gibson, L.J. Nevay, W. Shields
JAI, Egham, Surrey, United Kingdom
J. Bernhard, A. Gerbershagen, M.S. Rosenthal
CERN, Geneva, Switzerland

CERN has a unique set of secondary beam lines, which deliver particle beams extracted from the PS and SPS accelerators after their interaction with a target, reaching energies up to 400 GeV. These beam lines provide a crucial contribution for test beam facilities and host several fixed target experiments. A correct operation of the beam lines requires precise simulations of the beam optics and studies on the beam-matter interaction, radiation protection, beam equipment survival etc. BDSIM combines tracking studies with energy deposition and beam-matter interaction simulations within one software framework. This paper presents studies conducted on secondary beams with BDSIM for the beam lines T9 and T10. We report the tracking analysis and the energy deposition along the beam line. Tracking analysis validation is demonstrated via comparison to existing code.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPGW069

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paper received ※ 30 April 2019 paper accepted ※ 21 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, storage-ring

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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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB001

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

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THPRB020

A Feedback System to Minimize the Electron Bunch Arrival-Time Jitter Between Femtosecond Laser Pulses and Electron Bunches for Laser-Driven Plasma Wakefield Accelerators

laser, plasma, electron, feedback

3843

S. Mattiello, A. Penirschke
THM, Friedberg, Germany
H. Schlarb
DESY, Hamburg, Germany

Funding: The work of S. Mattiello is supported by the German Federal Ministry of Education and Research (BMBF) within the Project MAKE-PWA.
In a laser driven plasma based particle accelerator a stable synchronization of the electron bunch and of the plasma wake field in the range of less than 2 fs is necessary in order to optimize the acceleration. For this purpose we are developing a new shot to shot feedback system with a time resolution of less than 1 fs*. We plane to generate stable THz pulses by optical rectification of a fraction of the plasma generating high energy laser pulses in a nonlinear lithium niobate crystal. With these pulses we will energy modulate the electron bunches shot to shot before the plasma to achieve the time resolution. In this contribution we will focus on realization aspects of the shot to shot feedback system and the lithium niobate crystal itself. Here we compare different approximations for the modeling of the generation dynamics (second order or first order calculation) and of the dielectric function (influence of the dispersion relation, of the free carries generated by the pump adsorption and their saturation, depletion of the pump) in order to investigate the importance of a detailed description of the optical properties for the THz generation.
*The feedback system will be tested at the Accelerator R&D facility SINBAD (Short Innovative Bunches and Accelerators at DESY).

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB020

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

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THPRB031

Operational Performance of the Machine Protection Systems of the Large Hadron Collider During Run 2 and Lessons Learnt for the LIU/HL-LHC Era

operation, machine-protect, injection, experiment

3875

M. Zerlauth, A. Antoine, W. Bartmann, C. Bracco, E. Carlier, Z. Charifoulline, R. Denz, B. Goddard, A. Lechner, N. Magnin, C. Martin, R. Mompo, S. Redaelli, I. Romera, B. Salvachua, R. Schmidt, J.A. Uythoven, A.P. Verweij, J. Wenninger, C. Wiesner, D. Wollmann, C. Zamantzas
CERN, Geneva, Switzerland

The Large Hadron Collider (LHC) has successfully completed its second operational run of four years length in December 2018. Operation will be stopped during two years for maintenance and upgrades. To allow for the successful completion of the diverse physics program at 6.5 TeV, the LHC has been routinely operating with stored beam energies close to 300 MJ per beam during high intensity proton runs as well as being frequently reconfigured to allow for special physic runs and important machine developments. No significant damage has incurred to the protected accelerator equipment throughout the run thanks to the excellent performance of the various machine protection systems, however a number of important observations and new failure scenarios have been identified, which were studied experimentally as well as through detailed simulations. In this contribution, we provide an overview of the performance of the machine protection systems throughout Run 2 as well as the important lessons learnt that will impact consolidation actions and the upgrade of the machine protection systems for the LIU/HL-LHC era.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB031

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

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THPRB077

Optics Corrections Using Machine Learning in the LHC

network, quadrupole, simulation, controls

3990

E. Fol, J.M. Coello de Portugal, R. Tomás
CERN, Meyrin, Switzerland
G. Franchetti
GSI, Darmstadt, Germany

Optics corrections in the LHC are based on a response matrix approach between available correctors and observables. Supervised learning has been applied to quadrupole error prediction at the LHC giving promising results in simulations and surpassing the performance of the traditional approach. A comparison of different algorithms is given and it is followed by the presentation of further possible concepts to obtain optics corrections using machine learning.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB077

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

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THPTS021

Magnets for Elettra 2.0

quadrupole, sextupole, ion-effects, lattice

4152

D. Castronovo, E. Karantzoulis
Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy

After 25 years of faithfully serving the user community with excellent results, Elettra need a major upgrade with a new compact latice that will replace the existing double bend achromat for the reducing of the horizontal emittance and the increasing of the brilliance and coherence of the X-ray beam. This paper report the magnetic design development and optimisations carried out in order to satisfy the layout feasibility and the magnet strengths.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPTS021

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

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