IPAC2017 - List of Keywords (optics)

Paper	Title	Other Keywords	Page
MOOCB3	Intensity Interferometer to Measure Bunch Length at SPEAR3	photon, detector, electron, storage-ring	60
	W.J. Corbett SLAC, Menlo Park, California, USA T.M. Mitsuhashi KEK, Ibaraki, Japan
	Electron bunch length in a storage ring is typically measured with streak cameras, electro-optic devices or non-linear cross-correlation techniques with a range of system complexity, signal-to-noise ratios and cost. Another straight-forward method is to construct an 'intensity interferometer' utilizing a coincidence detector to record simultaneous photon arrival events. In this configuration, visible SR light is passed through a narrow bandpass filter followed by a small pinhole to generate a stream of single-mode monochromatic wavepackets. As the interferometer delay is scanned across an electron bunch, two-photon events occurring within the longitudinal coherence time of the light cause a reduction in the measured coincidence rate. The resulting autocorrelation of the optical pulse duration reveals the electron bunch length, independent of synchrotron oscillation motion. In this paper we comment on the theory and report on preliminary measurements carried out at SPEAR3.
	Slides MOOCB3 [2.606 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOOCB3
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MOPAB011	Impact on the HL-LHC Triplet Region and Experiments From Asynchronous Beam Dumps on Tertiary Collimators	proton, neutron, photon, interface	96
	A. Tsinganis, R. Bruce, F. Cerutti, A. Lechner CERN, Geneva, Switzerland
	Accidental beam impacts on the tertiary collimators (TCTs) can lead to significant energy deposition in the triplet region and to leakage of the induced particle shower towards the experimental cavern. In this work, carried out in the context of the planned High Luminosity Upgrade of the LHC, severe impacts from asynchronous beam dumps on the horizontal tertiary collimators in cells 4 and 6 of the CMS insertion were studied, with half or a full proton bunch impacting on a collimator jaw. The choice of jaw material is shown to be of great importance, with over a factor of 10 increase in peak energy density values in the triplet coils moving from tungsten (Inermet) to molybdenum graphite jaws. Nevertheless, although the quench limit is exceeded in at least one or more triplet magnets in all the evaluated scenarios, values remain well below the damage limit. Energy spectra of particles leaking into the experimental cavern have also been estimated and are presented here.
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MOPAB015	Optimization of a Skew Parametric Resonance Ionization Cooling Channel Using Genetic Algorithm	resonance, controls, dipole, collider	111
	Y. Bao UCR, Riverside, California, USA A. Afanasev GWU, Washington, USA Y.S. Derbenev, V.S. Morozov, A.V. Sy JLab, Newport News, Virginia, USA R.P. Johnson Muons, Inc, Illinois, USA
	Funding: This work is supported by Muons Inc. Skew Parametric-resonance Ionization Cooling (Skew PIC) is designed for the final 6D cooling of a high-luminosity muon collider. Tracking of muons in such a channel has been modeled in MADX and matter-dominated simulation tool G4beanline in previous studies. In this work, we developed an optimization code based on Genetic Algorithm (GA). We optimized the cooling channel and increased the acceptance of the channel by using the GA code.
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MOPAB021	Performance of OTR and Scintillator View Screens for the ARIEL Electron Linac	target, linac, radiation, scattering	117
	D.W. Storey, J.M. Abernathy, D. Karlen, M.O. Pfleger, P.R. Poffenberger Victoria University, Victoria, B.C., Canada P.S. Birney, P.E. Dirksen, S.R. Koscielniak, M. Lenckowski TRIUMF, Vancouver, Canada
	The ARIEL electron linac is a 0.3 MW CW accelerator, extensible to 0.5 MW, being installed at TRIUMF for radioactive beam production. To date, 17 view screen monitors have been installed along the beamline and have proven to be essential tools in the commissioning of e-linac systems. These are populated by two types of beam targets: P46 scintillator screens which provide diagnostics for low duty factor operation, while at locations with beam energies at and above 10 MeV, OTR foils using either Pyrolytic Graphite or Niobium foils are included to provide coverage up to 100's of μA average beam current. The design of the view screen is described including the image acquisition system and beam target selection. The performance thus far of the OTR foils under low duty factor commissioning is presented including quantification of the OTR emission distribution, thermal studies, and transmission of the beam through the linac after intercepting a foil.
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MOPAB040	Linear and Nonlinear Optics Measurements With Multiturn Data at PETRA III	kicker, operation, diagnostics, injection	170
	I.V. Agapov, M. Bieler, H. Ehrlichmann, J. Keil, J. Klute, G. Kube, G.K. Sahoo, F. Schmidt-Föhre, R. Wanzenberg DESY, Hamburg, Germany R. Tomás, A. Wegscheider CERN, Geneva, Switzerland
	At Petra III measuring multiturn beam response to pulsed and continuous excitations allows linear and nonlinear (e.g. frequency maps) optics parameter determination. We describe the measurement setup, approaches to optics parameter determination, and the measurement results for Petra III.
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MOPAB047	Electron Beam Phase Space Tomography at the European XFEL Injector	emittance, electron, quadrupole, FEL	196
	M. Scholz, B. Beutner DESY, Hamburg, Germany
	The FEL process is determined by the 6D phase space distribution of relativistic electron bunches. Experimental reconstructions of these distributions are therefore a step foreward to understand the beam dynamics and to optimize FEL operation. The reconstructions of the transverse phase spaces can be acieved with tomographic methods. In the injector of the European XFEL, measurements for the reconstruction of the phase spaces were carried out using phase advance scans with multiple quadrupoles. The beam sizes were kept optimized at the measurement screen. A transversely deflecting cavity (TDS) was used to streak the beam vertically. That allows to do longitudinally slice resolved measurements of the horizontal phase space. The horizontal streak required for the slice measurements in the vertical plane was achieved with a correlated linear energy spread and dispersion. In this paper, we present measurement results showing longitudinal slice resolved reconstructions of the transverse phase spaces taken in the European XFEL injector.
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MOPAB051	Progress in FLASH Optics Consolidation	undulator, emittance, gun, laser	211
	J. Zemella, M. Vogt DESY, Hamburg, Germany
	FLASH is the superconducting soft X-ray Free Electron Laser in Hamburg at DESY, Germany. A precise knowledge of the beam optics is a key aspect of the operation of a SASE FEL. A campaign of optics consolidation has started in 2013 when the second beam line FLASH2 was installed downstream of the FLASH linac. We give an update on progress of this effort and on recent results.
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MOPAB102	Fast Orbit Response Matrix Measurements at ALBA	storage-ring, linear-dynamics, non-linear-dynamics, data-acquisition	365
	Z. Martí, G. Benedetti, M. Carlà, J. Fraxanet, U. Iriso, J. Moldes, A. Olmos, R. Petrocelli ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
	At ALBA the standard orbit response matrix measurement with DC corrector magnet (CM) modulation is being upgraded with an AC excitation of the correctors combined with the synchronized beam position monitor (BPM) acquisition data rate at 10 kHz. Several types of excitation waveforms (sinusoidal vs square types) and frequencies have been tested and compared to optimize the measurement precision and repeatability. The data acquisition time of the ALBA response matrix (88 horizontal and 88 vertical correctors) with the new AC method takes 1 minute to complete instead of 7 minutes of the standard technique.
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MOPAB115	Transverse Beam Phase-Space Measurement Experience at CTF3	quadrupole, emittance, collider, linear-collider	393
	D. Gamba, B. Constance, R. Corsini, S. Döbert, L. Malina, T. Persson, J. Roberts, A.P. Rollings, P.K. Skowroński, F. Tecker CERN, Geneva, Switzerland L. Martin JAI, Oxford, United Kingdom A.L. Peirson Serratosa Oxford University, Physics Department, Oxford, Oxon, United Kingdom
	One of the objective of the CLIC Test Facility (CTF3) at CERN is to demonstrate the CLIC Drive Beam Recombination concept. An accurate control of the transverse beam parameters is necessary in order to succeed in preserving the beam quality after the recombination. During the activity of the facility we improved our tools and technique for characterising the transverse phase space of the beam before and after recombination. The common quadrupole scan technique was improved by performing constant-beam-size measurement and it was enriched by a tomographic reconstruction of the phase-space. Moreover studies have been performed in order to estimate and subtract the impact of dispersion on such a measurements. An overview of these techniques will be presented with actual measurements performed over the last year of operations of the facility.
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MOPAB130	Cross-Calibration of the LHC Transverse Beam-Profile Monitors	emittance, luminosity, proton, experiment	437
	R. Alemany-Fernández, F. Alessio, A. Alexopoulos, C. Barschel, F.S. Carlier, J.M. Coello de Portugal, M. Ferro-Luzzi, A. Garcia-Tabares, M. Hostettler, O. Karacheban, E.H. Maclean, R. Matev, T. Persson, P.K. Skowroński, R. Tomás, G. Trad, S. Vlachos, B. Würkner CERN, Geneva, Switzerland G.R. Coombs EPFL, Lausanne, Switzerland T.B. Hadavizadeh Oxford University, Physics Department, Oxford, Oxon, United Kingdom M. Hofer TU Vienna, Wien, Austria L. van Riesen-Haupt University of Oxford, Oxford, United Kingdom
	Calibration of a transverse beam profile monitor is of fundamental importance to guarantee the best possible accuracy and reliability of the instrument over time. In LHC the calibration standard for transverse-profile measurements are the wire scanners. Other profile monitors such as beam synchrotron light telescopes and interferometers are calibrated with respect to them. Additional information about single-bunch sizes can be obtained from beam-gas imaging in the LHCb vertex detector, from the transverse convolved beam sizes extracted from luminosity scans at the collision points, and from the evolution of the luminous-region parameters as reconstructed by ATLAS and CMS inner tracker detectors during such scans. For the first time in LHC, a dedicated cross-calibration of all the above-mentioned systems was carried out with beam in 2016. Additionally, dedicated optics measurements were also performed in order to determine with the highest possible accuracy the amplitude function at the interaction points and at the position of the profile monitors. Results of these measurements are presented in this paper.
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MOPAB138	Comparison of Optical Transition Radiation Simulations and Theory	radiation, diagnostics, simulation, electron	455
	J. Wolfenden, R.B. Fiorito, C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom M. Bergamaschi, P. Karataev, K.O. Kruchinin JAI, Egham, Surrey, United Kingdom M. Bergamaschi, P. Karataev, K.O. Kruchinin Royal Holloway, University of London, Surrey, United Kingdom M. Bergamaschi, R. Kieffer, T. Lefèvre CERN, Geneva, Switzerland R.B. Fiorito, C.P. Welsch, J. Wolfenden The University of Liverpool, Liverpool, United Kingdom
	The majority of optical diagnostics currently used will not stand up to the requirements of the next generation of particle accelerators. Current methodologies need innovation to be able to reach the sub-micrometre resolution and sensitivity that will be required. One technique that has the potential to meet these requirements is optical transition radiation (OTR) imaging. A new algorithm is proposed which incorporates OTR theory, optical effects and beam distribution. This algorithm takes an existing method used for beam imaging and pushes the limits resolution beyond that normally attainable. In doing so, it can provide a reliable and economical diagnostic for future accelerators. A discussion on further applications of the algorithm is also presented.
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MOPIK031	COSY Extraction Line Characterization and Modeling	quadrupole, extraction, proton, storage-ring	567
	B. Lorentz, M. Bai, Y. Dutheil, R. Tölle, C. Weidemann FZJ, Jülich, Germany
	COSY is a versatile racetrack-type synchrotron accelerating protons and deuterons in a range of rigidity between 1 T m and 11 T m. Circulating beam can be slowly extracted on a third order resonance and channeled towards different users. New users of the COSY beam have presented new challenges with specific requests, most notably in term of beam shape. This in turn drove a strong interest to develop and improve characterization and modeling methods in the COSY extraction beam line. In this contribution we will present the different beam characterization methods used and their limitations. We will then discuss the modeling of the line and the importance of an accurate and reliable model of the extraction line. Some of the latest beam measurements are presented and compared to modeled results.
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MOPIK056	On the Ariel Pre-Separator	dipole, target, emittance, ion	648
	S. Saminathan, R.A. Baartman TRIUMF, Vancouver, Canada
	Funding: Funded under a contribution agreement with NRC (National Research Council Canada) and Capital funding from CFI (Canada Foundation for Innovation). Two new independent target ion sources with dedicated pre-separators will be built in the ARIEL facility to triple the radioactive ion beam production at TRIUMF. A compact Nier-Johnson type of pre-separator has been designed to achieve a mass resolving power of 300 in order to minimize the undesired radioactive species contaminating the downstream beamlines. It consists of a 112 degree magnetic and a 90 degree toroidal electrostatic dipole with deflection in opposite direction. It also contains electrostatic quadrupole elements in between the dipoles. The electrostatic dipole compensates the energy dispersion of the magnetic dipole. This allows an achromatic mode of operation resulting in a high mass resolving power downstream to the electrostatic deflector even for beams with a high energy spread. We present the result of beam optics calculations for the ARIEL pre-separator.
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MOPIK066	COBEA - Optical Parameters From Response Matrices without Knowledge of Magnet Strengths	storage-ring, lattice, closed-orbit, betatron	676
	B. Riemann, S. Khan, S. Koetter, T. Weis DELTA, Dortmund, Germany
	This paper presents some results of Closed-Orbit Bilinear-Exponential Analysis (COBEA), an algorithm designed to decompose (coupled) response matrices into betatron tunes and other optical parameters at beam position monitor and corrector positions. The only additional information strictly required by the algorithm is the ordering of monitors and correctors along the storage ring beam path. The presented method is largely lattice-independent, as no magnet strengths or dimensions are needed, and converges in a reasonable time interval due to usage of gradient-based optimization. After describing key features of the algorithm, a set of COBEA results is compared to LOCO results for the storage rings of MLS and BESSY II. The paper is concluded by a brief discussion of further applications, limits and further development of the COBEA algorithm.
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MOPIK071	Dispersion and Beam Optic Parameter Measurements in the Transport Line (E-Weg) from DESY II to PETRA III	emittance, quadrupole, injection, synchrotron	692
	G.K. Sahoo, K. Balewski, H. Ehrlichmann, J. Keil, R. Wanzenberg DESY, Hamburg, Germany
	The transport line E-Weg extends from the extraction septum in DESY II to the injection septum in PETRA III, and transports electrons at a beam energy of 6.0 GeV. It consists of 3 parts. The first part is in DESY tunnel, the second part is a long drift space in a slanted tube and the third part is in PETRA III tunnel. The vertical plane difference between the tunnels is 1.28 m. The optics was derived from initial values at Transfer Point (UGP) from a previous optics. The total length of the transfer line is about 203 m. Ten screen monitors are used to estimate the profiles of the beam spot for the optics measurements, while 8 BPMs, mostly adjacent to the screens, are used to compare and control the orbits. Two scrapers are installed on either side of the long drift space to trim the beam dimensions in transverse plane. Two FCTs are used to measure the beam current and transfer efficiency. The transverse dispersion and beta functions are measured by extracting the beam from DESY at different energies and analysing the beam profiles at the screen as well as positions at BPMs. The details of such measurements are reported in this paper.
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MOPIK073	Calibration of Linear Optics of COSY Based on ORM Data	quadrupole, factory, dipole, sextupole	699
	C. Weidemann, M. Bai, Y. Dutheil, F. Hinder, B. Lorentz FZJ, Jülich, Germany
	The COoler SYnchrotron in Jülich is a well suited accelerator for a precursor experiment on the direct measurement of the Electric Dipole Moment (EDM) of the deuteron (see* and references within). It provides polarized and unpolarized proton and deuteron beams in the momentum range between 0.3 GeV/c and 3.65 GeV/c, allows for phase space cooling and is highly flexible with respect to ion-optical settings. Unfortunately, a model independent linear optics measurement is not possible and so far the existing MAD-X model of COSY does not provide an agreement with the actual machine parameters that is required by future experiments, such as the EDM experiment. Significant deviations with respect to the working point and linear optics have been reported*. As shown in**, a MAD-X based LOCO (Linear Optics from Closed Orbits) algorithm in a C++ program was successfully developed and carefully benchmarked. This contribution presents the application of the new program on measured ORM data and its capabilities in calibrating linear optics as well as reconstructing machine imperfections such as gradient errors of quadrupole magnets and calibration factors of BPMs and steerers. D. Eversmann et al., PRL 115, no. 9, 094801 (2015). R. Maier, NIM A 390, 1 (1997). * C. Weidemann et al., PRSTAB 18, 020101 (2015). ** D. Ji et al., IPAC16, doi:10.18429/JACoW-IPAC2016-TUPMR026. *** C. Weidemann et al., IPAC16, doi:10.18429/JACoW-IPAC2016-THPMB009.
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MOPIK081	Study of HEPS Performance with Error Model and Simulated Correction	quadrupole, sextupole, closed-orbit, simulation	721
	D. Ji, Z. Duan, S.K. Tian, Y. Wei IHEP, Beijing, People's Republic of China
	As an important component of physics study on High Energy Photon Source (HEPS), error modelling and simu-lated correction will provide the guideline to restrict the manufacture redundancy of the hardware and estimate the real machine performance. In this paper, we present some work on error effect evaluation and simulated commis-sioning based on a recent lattice design.
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MOPIK085	Linear Optics Calibration at the HLS-II Storage Ring Using Model Independent Analysis	storage-ring, lattice, experiment, operation	727
	G. Liu, L. Wang, F.F. Wu, K. Xuan USTC/NSRL, Hefei, Anhui, People's Republic of China
	Linear optics are the main lattice parameters characterizing the linear properties of storage rings. Especially for beta function and phase advance, they are the basic lattice functions which must be accurately calibrated to ensure high quality operation of the machine. Model Independent Analysis (MIA), which adopts mathematical statistical methods to extract the effective lattice information of storage rings by directly analyzing the turn-by-turn beam-position-monitor (BPM) measurements, has been applied at HLS-II to calibrate the linear optics model of the storage ring. The measurements of the turn-by-turn BPM data with all of the 32 BPMs are reported in this paper. The calibration results of the beta function using MIA are presented.
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MOPIK090	Beta Function Measurement in the SOLARIS Storage Ring	quadrupole, storage-ring, lattice, sextupole	736
	A. Kisiel, M.B. Jaglarz, M.P. Kopeć, S. Piela, M.J. Stankiewicz, A.I. Wawrzyniak Solaris, Kraków, Poland
	One of the most essential lattice function used for transverse beam dynamics studies of the storage rings is a beta function. It characterizes the linear properties of magnets layout and allows to optimize the compatibility of the model and the machine by reducing the beta-beating. Moreover, the calculation of other parameters like transverse beam emittance, dynamic aperture, energy spread and others, requires knowledge of the quantity of beta function along the ring. Various methods of measurement of this function used in Solaris will be presented.
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MOPIK100	Beam Delivery System Optimization for CLIC 380 GeV	luminosity, sextupole, lattice, quadrupole	764
	F. Plassard, A. Latina, E. Marín, D. Schulte, R. Tomás CERN, Geneva, Switzerland P. Bambade LAL, Orsay, France
	In the framework of the CLIC rebaselining, the Beam Delivery System (BDS) have been re-optimized for its initial stage at 380 GeV. Two BDS designs with L=4.3 meters and L=6 meters have been investigated. The optimization of the lattices and the beam parameters at the interaction point (IP) have been performed by taking into account their energy upgrade to 3 TeV and the tuning feasibility of the BDS in presence of static imperfections.
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MOPIK122	The Beam Optics of the FFAG Cell of the CBETA ERL Accelerator	quadrupole, electron, dipole, focusing	820
	N. Tsoupas, J.S. Berg, S.J. Brooks, G.J. Mahler, F. Méot, V. Ptitsyn, D. Trbojevic BNL, Upton, Long Island, New York, USA J.A. Crittenden Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA S.C. Tygier UMAN, Manchester, United Kingdom
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. The CBETA project[] is a prototype electron accelerator for the proposed eRHIC project[]. The electron accelerator is based on the Energy Recovery Linac (ERL) and the Fixed Field Alternating Gradient (FFAG) principles. The FFAG arcs and the straight section of the accelerator are comprised of one focusing and one defocusing quadrupoles which are designed as Halbach-type permanent dipole magnets with quadrupoles component[]. We will present the beam optics of the FFAG cell which is based on 3D field maps derived with the use of the OPERA computer code[*]. We will also present the electromagnetic design of the corrector magnets of the cell. http://arxiv.org/abs/1504.00588 http://arxiv.org/ftp/arxiv/papers/1409/1409.1633.pdf * K. Halbach, Nucl. Instrum. Meth. 169 (1980) pp. 1-10 **** http://www.scientificcomputing.com
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MOPIK123	Beam Dynamics Numerical Studies Regarding CBETA Cornell-BNL ERL	lattice, quadrupole, multipole, simulation	824
	F. Méot, S.J. Brooks, D. Trbojevic, N. Tsoupas BNL, Upton, Long Island, New York, USA S.C. Tygier UMAN, Manchester, United Kingdom
	Funding: Work supported by New York State Energy Research and Development Authority (NYSERDA) The Cornell-BNL Electron Test Accelerator CBETA is based on a 36 MeV superconducting linac and on a single 4-pass up/4-pass down linear FFAG return loop, for beam acceleration from 6 to 150 MeV and energy recovery. Numerical beam dynamics simulations have accompanied and eventually validated the quadrupole-doublet FFAG cell technology and parameters, and following that the complete return loop, all along the ERL lattice design process. They are key to assessing and validating the ERL optics and beam behavior over the whole acceleration/ER cycle, and in preparing future machine operation. This paper presents various of these beam dynamics studies, including start-to-end simulations.
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MOPIK125	Multi-frequency AC LOCO: A Fast and Precise Technique for Lattice Correction	lattice, quadrupole, power-supply, experiment	831
	X. Yang, K. Ha, V.V. Smaluk, Y. Tian, L. Yu BNL, Upton, Long Island, New York, USA
	We developed a novel technique to improve the precision and shorten the measurement time of the LOCO (Linear Optics from Closed Orbits) method at NSLS-II [1]. This technique named AC LOCO is based on a sine-wave (AC) beam excitation via fast correctors typically installed at synchrotron light sources for the fast orbit feedback. The beam oscillations are measured by beam position monitors. The narrow band used for the beam excitation and measurement not only allows us to suppress effectively the beam position noise and also makes simultaneously exciting multiple correctors at different frequencies (multi-frequency mode) possible. We demonstrated at NSLS-II that the new technique provides better lattice corrections and achieves two minutes measurement time in the thirty-frequency mode. [1] X. Yang et al., 'Fast and precise technique for magnet lattice correction via sine-wave excitation of fast correctors', Phys. Rev. Accel. Beams, vol. 20, p. 054001, 2017.
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MOPVA007	Simulations for Beam-Based Measurements in BERLinPro	cavity, simulation, diagnostics, gun	859
	M. McAteer, M. Abo-Bakr, J. Knedel, G. Kourkafas, B.C. Kuske, J. Völker HZB, Berlin, Germany
	BERLinPro is an energy recovery linac project whose goal is to establish the accelerator physics knowledge and technology needed to produce 50 MeV beams with high current, low normalized emittance, and low losses. Precise measurements of beam parameters are essential for demonstrating the achievement of performance goals. In this paper we present simulations for measurements of energy, energy spread, and bunch length using the tracking code Astra.
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MOPVA021	Optics Design of the Compact ERL Injector for 60 pC Bunch Charge Operation	cathode, laser, operation, gun	898
	T. Hotei Sokendai, Ibaraki, Japan R. Kato, T. Miyajima, N. Nakamura, M. Shimada KEK, Ibaraki, Japan
	EUV-FEL light source based on ERL has been designed at KEK for EUV lithography light source. The advantage of ERL is to accelerate high average current beam due to CW operation, and it is possible to drive high average power FEL. To generate the target EUV-FEL power, which is 10 kW, the bunch charge of 60 pC, the beam energy of 10.5 MeV and the bunch length of 1 ps are required at the end of the EUV-FEL injector. In order to demonstrate the target beam performance for the EUV-FEL accelerator, a high charge beam test was carried out at the cERL in KEK. We designed a new optics of the cERL injector prior to the high charge beam operation. To calculate beam dynamics more accurately, accelerator models corrected according to the condition of the actual cERL injector is used for the optics design. From results of the optics design that minimized the emittance and bunch length using the corrected accelerator models, the emittance and bunch length at the end of injector are 0.8 mm-mrad and 3.4 ps. Furthermore, based on the design optics, we carried out high bunch charge beam operation.
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MOPVA037	Development and Commissioning of the Doppler-Shift Unit for the Measurement of the Ion Species Fractions and Beam Energy of the ESS Proton Source	proton, coupling, linac, software	936
	C.A. Thomas, T.J. Shea ESS, Lund, Sweden J. Fils GSI, Darmstadt, Germany Y. Lussignol, P. Mattei CEA/DSM/IRFU, France Ø. Midttun University of Bergen, Bergen, Norway L. Neri INFN/LNS, Catania, Italy F. Senée, O. Tuske CEA/IRFU, Gif-sur-Yvette, France
	ESS proton source is in going to be soon delivered to the ESS project. In order to qualify the source, a series of beam instrumentation diagnostics have been designed and produced. In particular, a specific spectrograph dedicated to the fraction species measurement is currently commissioned. This instrument not only is capable of measuring the fraction species produced by the source, but also it can measure their energy and energy spread, the mass of the different species, and additional spectral rays coming from the gas species in presence in the vacuum chamber. We present in this paper the commissioning of this instrument, the Doppler Shift unit, dedicated to the measurement of the fraction species.
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TUOCB1	Progress in the Design of Beam Optics for FCC-ee Collider Ring*	quadrupole, collider, sextupole, emittance	1281
	K. Oide, K. Ohmi KEK, Ibaraki, Japan M. Benedikt, H. Burkhardt, B.J. Holzer, A. Milanese, J. Wenninger, F. Zimmermann CERN, Geneva, Switzerland A.P. Blondel, M. Koratzinos DPNC, Genève, Switzerland A.V. Bogomyagkov, E.B. Levichev, D.N. Shatilov BINP SB RAS, Novosibirsk, Russia M. Boscolo INFN/LNF, Frascati (Roma), Italy
	The beam optics for the FCC-ee collider has been updated: (a) the layout is adjusted to a new footprint of FCC-hh, (b) the design around the interaction point is refined considering a number of machine-detecor interface issues, (c) the arc lattice is refined taking realistic magnet designs into account, (d) the β^* and betatron tunes are re-optimized according to recent results of the beam-beam simulations, and more. These changes make the collider design more realistic without performance degradation.
	Slides TUOCB1 [4.891 MB]
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TUPAB104	Optimized Undulator to Generate Low Energy Photons From Medium to High Energy Accelerators	polarization, photon, undulator, radiation	1556
	T.Y. Chung, M.-S. Chiu, J.C. Huang, C.-S. Hwang, J.C. Jan, C.K. Yang NSRRC, Hsinchu, Taiwan H.W. Luo NTHU, Hsinchu, Taiwan
	While emitting low energy photons from a medium or high energy storage ring, the on-axis heat load on the beam line optics can become a critical issue. In addition, the heat load in the bending magnet chamber, especially in the vertical and circular polarization mode of operation may cause some concern. In this work, we compare the heat loads for the APPLE-II and the Knot-APPLE, both optimized to emit 10 eV photons from the 3 GeV TPS. Under this constraint the heat load analysis, synchrotron radiation performance and features in various polarization modes are presented. Additional consideration is given to beam dynamics effect.
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TUPAB134	Life Expectancy Studies for LCLS-II Permanent Magnet Undulators	undulator, radiation, permanent-magnet, electron	1640
	M. Santana-Leitner, D.E. Bruch, R.C. Field, D.S. Martinez-Galarce, B.D. McKee, H.-D. Nuhn, M. Rowen, S.W. Score SLAC, Menlo Park, California, USA
	Funding: Work supported by U.S. Department of Energy contract DE-AC02-76SF00515 LCLSII at SLAC National Accelerator Laboratory will add a 4 GeV superconducting Linac to the existing 20 GeV Cu structure. Electron beams from the two sources going through two new variable gap undulators [] will produce FEL ranging 200-5000 keV at up to 929 kHz, also reaching 20 keV at low frequency. Such performance will be achieved by hybrid design undulators with NdFeB magnet blocks until radiation-induced demagnetization exceeds 0.01%. This is a sizable challenge, as LCLS-II will carry 120 kW beams in both its soft (SXR) and hard (HXR) beam-lines. Even small fractional losses could result excessive if too frequent or not detected and aborted fast enough. A model of SXR undulator was set for FLUKA [] radiation transport, including segments, phase-shifters, quadrupoles, RFBPM, stands/pillars and interconnecting parts. Components were installed according to MAD files, which were also used to code the optics. Beam-loss/shower propagation was simulated for beam mis-steering, interception at wire scanners and gas-bremsstrahlung interactions. Results help set limits on shut-off times, uniform loss levels and wire scanner use, and to define placement for beam loss monitors. M. Leitner et al, Hard X-Ray and Soft X-Ray Undulator Segments for the Linear Coherent Light Source Upgrade (LCLS-II) Project, these proceedings ** A. Ferrari et al, The FLUKA Code: Developments and Challenges for High Energy and Medical Applications, Nuclear Data Sheets 120, 211-214 (2014)
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TUPIK059	Recent Progress of Dithering System at SuperKEKB	luminosity, feedback, background, electronics	1827
	Y. Funakoshi, H. Fukuma, T. Kawamoto, M. Masuzawa, S. Nakamura, K. Ohmi, T. Oki, S. Uehara KEK, Ibaraki, Japan P. Bambade, D. El Khechen, D. Jehanno, V. Kubytskyi, C. Rimbault LAL, Orsay, France A.S. Fisher SLAC, Menlo Park, California, USA U. Wienands ANL, Argonne, Illinois, USA
	Recent progress of the dithering system at SuperKEKB is described. Some details of the system layout are shown. Beam orbit and optics related issues are discussed. Preliminary tests of the some components in the Phase 1 beam commissioning or in the bench are described.
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TUPIK087	Phase Advance Interlocking Throughout the Whole LHC Cycle	quadrupole, kicker, software, operation	1901
	K. Fuchsberger, A. Calia, M.A. Galilée, G.H. Hemelsoet, M. Hostettler, D. Jacquet, J. Makai, M. Schaumann CERN, Geneva, Switzerland
	Each beam of CERN's Large Hadron Collider (LHC) stores 360 MJ at design energy and design intensity. In the unlikely event of an asynchronous beam dump, not all particles would be extracted immediately. They would still take one turn around the ring, oscillating with potentially high amplitudes. In case the beam would hit one of the experimental detectors or the collimators close to the interaction points, severe damage could occur. In order to minimize the risk during such a scenario, a new interlock system was put in place in 2016. This system guarantees a phase advance of zero degrees (within tolerances) between the extraction kicker and the interaction point. This contribution describes the motivation for this new system as well as the technical implementation and the strategies used to derive appropriate tolerances to allow sufficient protection without risking false beam dump triggers.
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TUPIK089	Studies on Luminous Region, Pile-up and Performance for HL-LHC Scenarios	luminosity, operation, simulation, detector	1908
	L.E. Medina Medrano, G. Arduini, R. Tomás CERN, Geneva, Switzerland L.E. Medina Medrano UGTO, Leon, Mexico
	Funding: Research supported by the HL-LHC project and the Beam project (CONACYT, Mexico). Studies on luminous region and pile-up density are of great interest for the experiments at the future High Luminosity LHC (HL-LHC) in order to optimize the detector performance. The evolution of these parameters at the two main interaction points of the HL-LHC along optimum physics fills is studied for the baseline and alternative operational scenarios with the latest set of parameters, including a refined description of the longitudinal bunch profile. Results are discussed in terms of a new figure-of-merit, the effective pile-up density.
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TUPIK119	Control of Intra-Bunch Vertical Instabilities at the SPS - Measurements and Technology Demonstration	feedback, controls, injection, kicker	2005
	J.D. Fox, J.E. Dusatko, C.H. Rivetta, O. Turgut SLAC, Menlo Park, California, USA H. Bartosik, W. Höfle, K.S.B. Li, E. Métral, B. Salvant, U. Wehrle CERN, Geneva, Switzerland S. De Santis LBNL, Berkeley, California, USA
	Funding: Work supported by the U.S. Department of Energy under contract # DOE-AC02-76SF00515, the US LHC Accelerator Research Program ( LARP), the FP7 High Luminosity LHC Project and the US-Japan Cooperative Program in High Energy Physics We present recent measurements demonstrating control of unstable beam motion in single bunch and bunch train configurations at the SPS. The work is motivated by anticipated intensity increases from the LIU and HL-LHC upgrade programs, and has included the development of a GHz bandwidth reconfigurable 4 GS/S signal processor with wideband kickers and associated amplifiers. The system was operated at 3.2GS/s with 16 samples across a 5 ns RF bucket (4.2 ns bunch at injection). The experimental results confirm damping of intra-bunch instabilities in both Q20 and Q26 optics configurations for intensities of 2x10¹¹ P/bunch. Instabilities with growth times of 200 turns are well-controlled from injection, consistent with the achievable gains for the 2 installed stripline kickers with 1 kW broadband power. Measurements from multiple studies in single-bunch and bunch train configurations show achieved damping rates, control of multiple intra-bunch modes, behavior of the system at injection and final damped noise floor. We present an analysis method to study the relative phase of slice motion during a transient to discriminate between TMCI and other types of Head-Tail instabilities.
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TUPVA002	Updates on the Optics of the Future Hadron-Hadron Collider FCC-hh	quadrupole, dipole, sextupole, hadron	2023
	A. Chancé, D. Boutin, B. Dalena CEA/IRFU, Gif-sur-Yvette, France B.J. Holzer, A. Langner, D. Schulte CERN, Geneva, 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 three options considered for the next generation accelerator in high-energy physics as recommended by the European Strategy Group. The layout of FCC-hh has been optimized to a more compact design following recommendations from civil engineering aspects. The updates on the first order and second order optics of the ring will be shown for collisions at the required centre-of-mass energy of 100 TeV. Special emphasis is put on the dispersion suppressors and general beam cleaning sections as well as first considerations of injection and extraction sections.
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TUPVA003	Advance on Dynamic Aperture at Injection for FCC-hh	dipole, injection, dynamic-aperture, target	2027
	B. Dalena, D. Boutin, A. Chancé CEA/IRFU, Gif-sur-Yvette, France B.J. Holzer, D. Schulte CERN, Geneva, Switzerland
	Funding: This Research and Innovation Action project submitted to call H2020-INFRADEV-1-2014-1 receives funding from the European Union's H2020 Framework Programme under grant agreement no. 654305. In the hadron machine option, proposed in the context of the Future Circular Colliders (FCC) study, the first evaluation of dipole field quality, based on the Nb3Sn technology, has shown a Dynamic Aperture at injection above the LHC target value. In this paper the effect of field imperfections on the dynamic aperture, using the updated lattice design, is presented. Tolerances on the main multipole components are evaluated including feed-down effect.
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TUPVA004	Synchrotron Radiation Backgrounds for the FCC-hh Experiments	photon, simulation, radiation, collider	2031
	F. Collamati INFN-Roma1, Rome, Italy M. Boscolo INFN/LNF, Frascati (Roma), Italy H. Burkhardt, R. Kersevan CERN, Geneva, Switzerland
	Funding: This work was supported by the HORIZON 2020 project EuroCirCol, grant agreement 654305. We present in this paper a detailed analysis of the synchrotron radiation emitted by the 50 TeV protons of the FCC-hh in the last bending and quadrupole magnets upstream the interaction region. We discuss the characteristics of this radiation in terms of power, flux, photon spectrum and fans in different running conditions such as, for example, with and without crossing angle. We mainly focus our study on the fraction of photons that may hit the detector, with a full tracking into GEANT4 that simulates their interaction within the central beam pipe.
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TUPVA009	Multiparametric Response of the LHC Dynamic Aperture in Presence of Beam-Beam Effects	emittance, simulation, luminosity, octupole	2051
	D. Pellegrini, F. Antoniou, S.D. Fartoukh, G. Iadarola, Y. Papaphilippou CERN, Geneva, Switzerland
	We performed extended simulations of LHC dynamic aperture (DA) in the presence of beam-beam effects in the weak-strong approximation, evaluating the contributions of parameters such as: tunes, optics, bunch intensity, crossing angle, emittance, chromaticity and current in the Landau octupoles. Here we present a summary of these studies, giving an overview of the amplitude of the LHC operational space and pointing out the remaining margins for mitigation of instabilities. These studies supported the actions deployed during the 2016 run of the LHC, which aimed at maximising its performances. Examples of such actions are the switch to lower emittance beams, the reduction of crossing angle and tune trims. More recently, DA scans have been used to help the definition of the operational scenarios for the 2017 run. Additional room for improvements, for instance by deploying crossing angle levelling, will be explained.
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TUPVA021	Impact of Collision Debris in the HL-LHC ATLAS and CMS Insertions	luminosity, proton, insertion, radiation	2093
	A. Tsinganis, F. Cerutti CERN, Geneva, Switzerland
	The High Luminosity upgrade of the LHC (HL-LHC) foresees the baseline operation of the accelerator at a 5 times higher peak luminosity (5.0x1034cm^-2s⁻¹). The impact of collision debris on the magnets and other equipment in the triplet region and matching section of the ATLAS and CMS insertions has been evaluated by means of detailed FLUKA models implementing the latest optics and layout version. Qualitative and quantitative differences between the vertical and horizontal beam crossing schemes are highlighted. With measures in place to mitigate the effects of the interruption of the beam screen in the triplet interconnections and the Q4 aperture reduction, peak dose values in the superconducting coils remain below 30MGy in the triplet-D1 and below 12MGy in the matching section magnets for an integrated luminosity of 3000fb-1. Peak power density values are lower than 3mW/cm³ and 1mW/cm³ in the triplet and matching section respectively. Total heat loads in magnets, collimators, masks and absorbers were also estimated, along with dose and particle fluence maps relevant for Radiation to Electronics (R2E) aspects. The effect of a displacement of the interaction point is also addressed.
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TUPVA022	Requirements for Crab Cavity System Availability in HL-LHC	luminosity, cavity, operation, proton	2097
	M. Valette, A. Apollonio, J.A. Uythoven, D. Wollmann CERN, Geneva, Switzerland
	Funding: Research supported by the HL-LHC project. Crab Cavities will be installed in the High Luminosity LHC in order to increase the effective peak luminosity through a partial compensation of the geometric factor. This will allow extending the levelling time resulting in an increased production of integrated luminosity. Based on the availability of the LHC during 2016 operation, the expected yearly-integrated luminosity of the future HL-LHC was estimated using a Monte Carlo model. Crab cavity faults were added to the observed failure distribu-tions and their impact on integrated luminosity produc-tion as a function of fault time and fault frequency was studied. This allows identifying a breakeven point in luminosity production and defining minimum system availability requirements for the crab cavities to reach the design goal of 250 fb-1 of integrated luminosity per year.
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TUPVA026	Beam-Beam Studies for FCC-hh	simulation, dynamic-aperture, luminosity, resonance	2109
	J. Barranco García, T. Pieloni, C. Tambasco EPFL, Lausanne, Switzerland X. Buffat, S.V. Furuseth, C. Tambasco CERN, Geneva, Switzerland S.V. Furuseth NTNU, Trondheim, Norway
	Funding: This works was performed in the framework of the European Circular 'Energy Fr'ontier Collider Study, H2020 Framework Programme under grant agreement no. 654305. We acknowledge support from the Swiss State Secretariat for Education, Research and Innovation SERI. The Future Circular Collider hadron-hadron (FCC-hh) design study is currently exploring different IR design possibilities including round and flat optics or different crossing schemes. The present study intends to evaluate each scenario from the beam-beam effects point of view. In particular the single particle long term stability to maximize beam lifetimes and luminosity reach is used to quantify the differences. The impact of strong head on interactions on the beam quality and lifetime is addressed by means of GPU accelerated simulations code featuring a weak-strong 6-dimensional beam-beam interaction.
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TUPVA027	Study of Beam-Beam Long Range Compensation with Octupoles	octupole, dynamic-aperture, resonance, beam-beam-effects	2113
	T. Pieloni, J. Barranco García, C. Tambasco EPFL, Lausanne, Switzerland X. Buffat, C. Tambasco CERN, Geneva, Switzerland
	Funding: The European Circular Energy-Frontier Collider Study (EuroCirCol), EU's Horizon 2020 grant No 654305. Long range beam-beam effects are responsible for particle losses and define fundamental operational parameters of colliders (i.e. crossing angles, intensities, emittances, β^*). In this study we propose octuple magnets as a possible scheme to efficiently compensate long-range beam-beam interactions with a global correction scheme. The impact and improvements on the dynamic aperture of colliding beams together with estimates of the luminosity potentials are discussed for the HL-LHC upgrade and extrapolations made for the FCC project. Results are compared to other compensating schemes.
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TUPVA030	Measurement of Beta-Beating Due to Strong Head-on Beam-Beam Interactions in the LHC	dipole, emittance, simulation, injection	2121
	P. Gonçalves Jorge, J. Barranco García, T. Pieloni EPFL, Lausanne, Switzerland X. Buffat, F.S. Carlier, J.M. Coello de Portugal, E. Fol, L.E. Medina Medrano, R. Tomás, A. Wegscheider CERN, Geneva, Switzerland
	The LHC operation relies on a good knowledge of the optics, usually corrected in absence of beam-beam interactions. In a near future, both the LHC and the HL-LHC will need to cope with large head-on beam-beam parameters, the impact on the optics needs to be understood and, if necessary, corrected. The results of a dedicated experiment performed at injection energy are discussed in this paper.
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TUPVA037	FCC-hh Final-Focus for Flat-Beams: Parameters and Energy Deposition Studies	luminosity, collider, quadrupole, hadron	2139
	J.L. Abelleira, E. Cruz Alaniz, A. Seryi, L. van Riesen-Haupt JAI, Oxford, United Kingdom M.I. Besana CERN, Geneva, Switzerland
	Funding: The European Circular Energy-Frontier Collider Study (EuroCirCol), EU's Horizon 2020 grant No 654305. The international Future Circular Collider (FCC) study comprises the study of a new scientific structure in a tunnel of 100 km. This will allow the installation of two accelerators, a 45.6'175 GeV lepton collider and a 100-TeV hadron collider. An optimized design of a final-focus system for the hadron collider is presented here. The new design is more compact and enables unequal β^* in both planes, whose choice is justified here. This is followed by energy deposition studies, where the total dose in the magnets as a consequence of the collision debris is evaluated.
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TUPVA039	Effect of Alignment Errors and Orbit Correctors on the Interaction Region of the FCC-hh	quadrupole, interaction-region, dipole, collider	2147
	E. Cruz Alaniz, J.L. Abelleira, A. Seryi, L. van Riesen-Haupt JAI, Oxford, United Kingdom J.L. Abelleira, L. van Riesen-Haupt University of Oxford, Oxford, United Kingdom
	Funding: European Union's Horizon 2020 research and innovation programme under grant No 654305. The Future Circular Collider (FCC) design study aims to develop the design of possible circular colliders in the LHC era. In particular the FCC-hh will aim to produce proton-proton collisions at a center of mass energy of 100 TeV. The interaction region has been designed to meet the requirements in terms of energy and luminosity. However, as it is the case in any real accelerator, misalignments in the magnets are likely to occur; the effect of these misalignments, if not properly compensated for, can jeopardize the performance of the machine. This study contemplates alignment and field errors in the interaction region in order to estimate the tolerance necessary to provide a good correction measured in terms of deviation of the orbit and strength of the correctors.
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TUPVA040	Overview of Design Development of FCC-hh Experimental Interaction Regions	luminosity, detector, dipole, experiment	2151
	A. Seryi, J.L. Abelleira, E. Cruz Alaniz, L.J. Nevay, L. van Riesen-Haupt JAI, Oxford, United Kingdom R.B. Appleby, H. Rafique UMAN, Manchester, United Kingdom R.B. Appleby Cockcroft Institute, Warrington, Cheshire, United Kingdom J. Barranco García, T. Pieloni EPFL, Lausanne, Switzerland M. Benedikt, M.I. Besana, X. Buffat, H. Burkhardt, F. Cerutti, A. Langner, R. Martin, W. Riegler, D. Schulte, R. Tomás CERN, Geneva, Switzerland M. Boscolo, F. Collamati INFN/LNF, Frascati (Roma), Italy M. Hofer TU Vienna, Wien, Austria L.J. Nevay Royal Holloway, University of London, Surrey, United Kingdom L. van Riesen-Haupt University of Oxford, Oxford, United Kingdom
	The experimental interaction region is one of the key areas that define the performance of the Future Circular Collider. In this overview we will describe the status and the evolution of the design of EIR of FCC-hh, focusing on design of the optics, energy deposition in EIR elements, beam-beam effects and machine detector interface issues.
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TUPVA041	Exploring the Triplet Parameter Space to Optimise the Final Focus of the FCC-hh	quadrupole, shielding, target, radiation	2155
	L. van Riesen-Haupt, J.L. Abelleira, E. Cruz Alaniz, A. Seryi JAI, Oxford, United Kingdom
	One of the main challenges when designing final focus systems of particle accelerators is maximising the beam stay clear in the strong quadrupole magnets of the inner triplet. Moreover it is desirable to keep the quadrupoles in the inner triplet as short as possible for space and costs reasons but also to reduce chromaticity and simplify corrections schemes. An algorithm that explores the triplet parameter space to optimise both these aspects was written. It uses thin lenses as a first approximation and MADX for more precise calculations. In cooperation with radiation studies, this algorithm was then applied to design an alternative triplet for the final focus of the Future Circular Collider.
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TUPVA042	K-Modulation Developments via Simultaneous Beam Based Alignment in the LHC	quadrupole, sextupole, closed-orbit, simulation	2159
	L. van Riesen-Haupt, A. Seryi JAI, Oxford, United Kingdom J.M. Coello de Portugal, E. Fol, R. Tomás, R. Tomás CERN, Geneva, Switzerland
	Funding: EuroCirCol A parasitic effect of k-modulation is that if the modulated quadrupole has an offset the modulation results in a dipole like kick forcing the beam on a new orbit. This paper presents a new method using the orthonormality of singular value decomposition that uses this new orbit to estimate the offset. This could be used to measure misalignments or crossing angles but could also help improve k-modulation \beta measurements by predicting the parasitic tune change caused by the new orbit not passing through the centre of the sextupoles.
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TUPVA045	Compensation of Head-on Beam-Beam Induced Resonance Driving Terms and Tune Spread in the Relativistic Heavy Ion Collider	electron, lattice, proton, resonance	2171
	W. Fischer, X. Gu, C. Liu, Y. Luo, A. Marusic, R.J. Michnoff, T.A. Miller, M.G. Minty, C. Montag, A.I. Pikin, G. Robert-Demolaize, V. Schoefer, P. Thieberger BNL, Upton, Long Island, New York, USA S.M. White ESRF, Grenoble, France
	Funding: Work supported by U.S. DOE under contract No DE-AC02-98CH10886 with the U.S. Department of Energy. A head-on beam-beam compensation scheme was implemented for operation in the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory. The compensation consists of a lattice for the minimization of beam-beam driven resonance driving terms, and electron lenses for the reduction of the beam-beam induced tune spread. We describe the implementations of the lattice and electron lenses, and report on measurements of lattice properties and the effect of the electron lenses on the hadron beam.
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TUPVA060	Upgrade of GSI HADES Beamline in Preparation for High Intensity Runs	quadrupole, target, beam-losses, dipole	2214
	M. Sapinski, P. Boutachkov, S. Damjanovic, K. Dermati, C.M. Kleffner, J. Pietraszko, T. Radon, S. Ratschow, S. Reimann, W. Sturm, B. Walasek-Höhne GSI, Darmstadt, Germany
	HADES is a fixed target experiment using SIS18 heavy-ion beams. It investigates the microscopic properties of matter formed in heavy-ion, proton and pion - induced reactions in the 1-3.5 GeV/u energy regime. In 2014 HADES used a secondary pion beam produced by interaction between high-intensity nitrogen primary beam and a beryllium target. In these conditions beam losses, generated by slow extraction and beam transport to the experimental area, led to activation of the beam line elements and triggered radiation alarms. The primary beam intensity had to be reduced and the beam optics modified in order to keep radiation levels within the allowed limits. Similar beam conditions are requested by HADES experiment for upcoming run in 2018 and in the following years. Therefore, a number of measures have been proposed to improve beam transmission and quality. These measures are: additional shielding, additional beam instrumentation, modification of beam optics and increase of vacuum chambers' apertures in critical locations. The optics study and preliminary results of FLUKA simulations for optimization of location of loss detectors are presented.
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TUPVA115	Progress with Long-Range Beam-Beam Compensation Studies for High Luminosity LHC	electron, simulation, cathode, proton	2358
	A. Rossi, O. Aberle, J. Albertone, A. Bertarelli, C.B. Boccard, F. Carra, G. Cattenoz, Y. Delaup, S.D. Fartoukh, G. Gobbi, J. Lendaro, Y. Papaphilippou, D. Perini, S. Redaelli, H. Schmickler, C. Zanoni CERN, Geneva, Switzerland A.M. Barnyakov, A.E. Levichev, D.A. Nikiforov BINP SB RAS, Novosibirsk, Russia M. Fitterer, A.S. Patapenka, G. Stancari, A. Valishev Fermilab, Batavia, Illinois, USA
	Long-range beam-beam (LRBB) interactions can be a source of emittance growth and beam losses in the LHC during physics and will become even more relevant with the smaller '* and higher bunch intensities foreseen for the High Luminosity LHC upgrade (HL-LHC), in particular if operated without crab cavities. Both beam losses and emittance growth could be mitigated by compensat-ing the non-linear LRBB kick with a correctly placed current carrying wire. Such a compensation scheme is currently being studied in the LHC through a demonstration test using current-bearing wires embedded into col-limator jaws, installed either side of the high luminosity interaction regions. For HL-LHC two options are considered, a current-bearing wire as for the demonstrator, or electron lenses, as the ideal distance between the particle beam and compensating current may be too small to allow the use of solid materials. This paper reports on the ongoing activities for both options, covering the progress of the wire-in-jaw collimators, the foreseen LRBB experiments at the LHC, and first considerations for the design of the electron lenses to ultimately replace material wires for HL-LHC.
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WEOAB2	Correction of Beta-Beating Due to Beam-Beam for the LHC and Its Impact on Dynamic Aperture	sextupole, quadrupole, dynamic-aperture, luminosity	2512
	L.E. Medina Medrano, J. Barranco García, X. Buffat, Y. Papaphilippou, T. Pieloni, R. Tomás CERN, Geneva, Switzerland J. Barranco García, T. Pieloni EPFL, Lausanne, Switzerland L.E. Medina Medrano UGTO, Leon, Mexico
	Funding: This work is supported by the European Circular Energy-Frontier Collider Study, H2020 programme under grant agreement no. 654305, by the Swiss State Secretariat for Education, Research and Innovation SERI, and by the Beam project (CONACYT, Mexico). Minimization of the beta-beating at the two main interaction points of the LHC arising from the head-on and long-range beam-beam interactions can be performed by adjusting the strength of quadrupole or sextupole correctors. This compensation scheme is applied to the current LHC optics where the results show a significant reduction of the peak and RMS beta-beating; and the impact on the dynamic aperture is computed. A proposal for a similar strategy to be adopted in the High Luminosity LHC is also discussed.
	Slides WEOAB2 [6.292 MB]
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WEPAB002	Pushing the MAX IV 3 GeV Storage Ring Brightness and Coherence Towards the Limit of its Magnetic Lattice	lattice, storage-ring, brightness, emittance	2557
	S.C. Leemann MAX IV Laboratory, Lund University, Lund, Sweden W.A. Wurtz CLS, Saskatoon, Saskatchewan, Canada
	The MAX IV 3 GeV storage ring is presently being commissioned and crucial parameters such as machine functions, emittance, and stored current have either already been reached or are approaching their design specifications. Once the baseline performance has been achieved, a campaign will be launched to further improve the brightness and coherence of this storage ring for typical x-ray users. During recent years, several such improvements have been designed. Common to these approaches is that they attempt to improve the storage ring performance using existing hardware provided for the baseline design. Such improvements therefore present more short-term upgrades. In this paper, however, we investigate medium-term improvements assuming power supplies can be exchanged in an attempt to push the brightness and coherence of the storage ring to the limit of what can be achieved without exchanging the magnetic lattice itself. We outline optics requirements, the optics optimization process, and summarize achievable parameters. WEPAB075 & WEPAB076 at IPAC17 ** MOPHO05 at PAC2013, TUPRI026 at IPAC'4, PRAB 19 060701 (2016)
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WEPAB006	Performance Improvements of the BESSY II Storage Ring by Optimizing the Phase Acceptance	injection, sextupole, resonance, storage-ring	2571
	P. Kuske, J. Li HZB, Berlin, Germany
	Linear optics modifications in order to improve injec-tion efficiency and for the installation of two IDs in one straight section demand an optimization of the sextupole correction scheme. Four harmonic sextupole families were sufficient with the earlier 8-fold symmetric lattice. Today there are ten families of harmonic sextupole mag-nets in addition to the three families of chromatic sextu-poles. This paper describes our experimental approach to find better settings for these harmonic sextupoles based on the direct optimization of the injection efficiency with a longitudinal phase offset between storage ring and the injector - in our case a booster synchrotron. As demon-strated in the paper, the resulting improvement of the phase acceptance of the ring leads to increased momen-tum acceptance by suppressing 3rd order non-systematic resonances. This increases not only the injection effi-ciency for long bunches but also the Touschek lifetime, the largest contribution to the overall lifetime of low emittance storage rings.
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WEPAB014	PETRA III Operation	operation, photon, timing, experiment	2589
	M. Bieler, I.V. Agapov, H. Ehrlichmann, J. Keil, G.K. Sahoo, R. Wanzenberg DESY, Hamburg, Germany
	At DESY the Synchrotron Light Source PETRA III offers scientists outstanding opportunities for experiments with hard X-rays of exceptionally high brilliance since 2009. This paper describes the challenges of daily operation, including different bunch patterns and their side effects, a procedure to clear spurious bunches, the operational statistics and the main contributions to down time.
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WEPAB046	New HMBA Lattice for PF-AR	lattice, injection, dynamic-aperture, emittance	2684
	N. Higashi, K. Harada, Y. Kobayashi, S. Nagahashi, N. Nakamura, A. Ueda KEK, Ibaraki, Japan
	Photon Factory Advanced Ring (PF-AR) has been operated for users about 30 years from 1987. The lattice and optics are not almost changed from the original one as the TRISTAN booster ring constructed in 1984. The lattice employs FODO structure and the horizontal emittance for the 6.5 GeV user run is about 300 nmrad. In order to improve the performance of PF-AR dramatically, the full replacement of the accelerator to the ESRF type HMBA (Hybrid multi bend achromat) lattice is examined. In order to geometrically fit the new lattice to the present PF-AR tunnel, the new ring consists of 12 cells with four long straight sections. The emittance is improved to about 500 pmrad at 3 GeV. With the present user experimental hall at the north half of the ring, at least eight undulator beam lines can be constructed. The simulated dynamic aperture is about 1.5 cm at the long straight section with reasonable magnetic errors and COD correction. The Touschek lifetime is about 6 hours. The beam injection with conventional injection system causes no problem and the beam lifetime is long enough.
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WEPAB050	Commissioning of SESAME Storage Ring	storage-ring, injection, sextupole, kicker	2694
	M. Attal, A.A. Abbadi, I.A. Abid, T.H. Abu-Hanieh, A. Al-Dalleh, H. Al-Mohammad, M.A. Al-Najdawi, D.S. Foudeh, A. Hamad, E. Huttel, A. Ismail, S.Kh. Jafar, K. Manukyan, I. Saleh, N.Kh. Sawai, M.M. Shehab SESAME, Allan, Jordan
	SESAME light source uses a 2.5GeV storage ring, designed to produce synchrotron light in the hard X-ray region. The 133.2 m circumference ring composed of 16 Double Bend Achromat cells with 16 dispersive straight sections, offers a maximum capacity of 25 beamlines. The storage ring is filled with electrons using an 800MeV injector of 1 Hz repetition rate. This article reports on the main results and first experience of storage ring commissioning and operation.
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WEPAB075	First Optics and Beam Dynamics Studies on the MAX IV 3 GeV Storage Ring	storage-ring, injection, emittance, synchrotron	2756
	S.C. Leemann, Å. Andersson, M. Sjöström MAX IV Laboratory, Lund University, Lund, Sweden
	We present results from beam commissioning of the MAX IV 3 GeV storage ring as well as a summary of the beam dynamics studies that have so for been carried out. We report on injection and accumulation using a single dipole kicker, top-up injection, slow orbit feedback, restoring the linear optics to design, effects of in-vacuum undulators with closed gaps, and adjusting nonlinear optics to achieve design chromaticity correction as well as dynamic aperture sufficient for high injection efficiency and good Touschek lifetime.
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WEPAB090	Developments in the CLARA FEL Test Facility Accelerator Design and Simulations	FEL, laser, undulator, simulation	2787
	P.H. Williams, D.J. Dunning, N. Thompson STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
	We present recent developments in the accelerator design of CLARA (Compact Linear Accelerator for Research and Applications), the proposed UK FEL test facility at Daresbury Laboratory. The requirement to co-propagate the beam with laser seeds of very different wavelengths has led to a redesign of the section preceding the undulators, with a dogleg being replaced by a chicane. Additional refinements of the facility design include the inter-undulator sections. With this finalised design we show start to FEL simulations for all beam modes envisaged.
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WEPAB114	Potential Performance Limit of Storage Rings	emittance, storage-ring, quadrupole, sextupole	2836
	X. Huang SLAC, Menlo Park, California, USA
	The next generation of storage ring light sources will have significantly higher performance as multi-bend achromat cell structures are made practical with strong quadrupole and sextupole magnets. In principle the natural emittance can be made ever smaller with stronger magnets and larger rings until it reaches the true diffraction limit for hard X-rays. By considering the scaling laws of linear optics and nonlinear beam dynamics of storage rings and technical challenges, we explore the potential performance limit of future storage rings. A similar discussion may be applicable to the limit of energy frontier heavy-ion storage ring colliders.
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WEPAB129	Study of Ionization Cooling with the MICE Experiment	emittance, solenoid, experiment, detector	2874
	C.T. Rogers STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
	The international Muon Ionization Cooling Experiment (MICE) will demonstrate the ionization cooling of muons; the only known technique that can provide high brightness muon beams suitable for applications such as a Neutrino Factory or Muon Collider. MICE is underway at the Rutherford Appleton Laboratory and has recently taken the data necessary to characterise the physical processes that underlie the ionization-cooling effect. Measurements of the change in normalised transverse amplitude are presented in two configurations. The measurements of the ionization-cooling effect are discussed.
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WEPAB133	A Wedge Absorber Experiment at MICE	emittance, collider, experiment, scattering	2888
	D.V. Neuffer Fermilab, Batavia, Illinois, USA T.A. Mohayai IIT, Chicago, Illinois, USA C.T. Rogers STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom P. Snopok Illinois Institute of Technology, Chicago, Illlinois, USA D.J. Summers UMiss, University, Mississippi, USA
	Emittance exchange mediated by wedge absorbers is required for longitudinal ionization cooling and for final transverse emittance minimization for a muon collider. A wedge absorber within the MICE beam line could serve as a demonstration of the type of emittance exchange needed for 6-D cooling, including the configurations needed for muon colliders, as well as configurations for low-energy muon sources. Parameters for this test are explored in simulation and possible experimental configurations with simulated results are presented.
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WEPIK007	Optics Design and Observation for the Beam Abort System in SuperKEKB HER	sextupole, injection, kicker, quadrupole	2922
	N. Iida, K. Egawa, Y. Enomoto, Y. Funakoshi, M. Kikuchi, T. Mimashi, Y. Ohnishi, K. Oide, Y. Suetsugu KEK, Ibaraki, Japan
	In the first commissioning of SuperKEKB, which is 'Phase 1', the new abort system is tested in the High Energy Ring (HER). There is a risk that aborted beams with low emittance and high current may destroy the window for extraction from beam pipe. In order to enlarge the aborted beam at the window, quadrupole field is applied only for the aborted beam. In the Low Energy Ring (LER), quadrupole pulsed magnets will be installed to enlarge the aborted beam, and in the HER, a pair of identical sextupole magnets is installed between the abort kickers and the extraction window. These sextrupole magnets are connected by I or 'I transformation to cancel the geometrical nonlinearity for the stored beam in the ring. This paper will report the optics design for the abort system of the HER as well as the observation of the aborted beam.
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WEPIK017	100 km CEPC Parameters and Lattice Design	luminosity, sextupole, collider, dynamic-aperture	2958
	D. Wang, T.J. Bian, X. Cui, J. Gao, H. Geng, Q. Qin, B. Sha, N. Wang, Y. Wang, C.H. Yu, J.Y. Zhai, C. Zhang, Y. Zhang IHEP, Beijing, People's Republic of China F. Su Institute of High Energy Physics (IHEP), People's Republic of China
	The 100km double ring configuration with shared su-perconducting RF system has been defined as baseline by the circular electron positron collider (CEPC) steering committee. Based on this new scheme, we will get higher luminosity for Higgs (+170%) keeping the beam power in preliminary conceptual design report (Pre-CDR) or to reduce the beam power (19 MW) while keeping same luminosity. CEPC will be compatible with W and Z ex-periment. The luminosity for Z is designed at the level of 1035 cm^-2s⁻¹. The requirement for the energy acceptance of Higgs has been reduced to 1.5% by enlarging the ring to 100 km. The optics of arc and final focus system (FFS) with crab sextupoles has been designed, and also some primary dynamic aperture (DA) results were introduced.
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WEPIK018	Optics Design for Cepc Double Ring Scheme	lattice, interaction-region, emittance, sextupole	2962
	Y. Wang, T.J. Bian, J. Gao, H. Geng, B. Sha, D. Wang, C.H. Yu, Y. Zhang IHEP, Beijing, People's Republic of China F. Su Institute of High Energy Physics (IHEP), People's Republic of China
	CEPC is a future Circular Electron and Positron Collider proposed by China to mainly study the Higgs boson. Its baseline scheme is double ring scheme and alternative scheme is partial double ring scheme. This paper will present the optics design for the main ring of double ring scheme. CEPC will also work as W and Z factories. Compatible optics design for W and Z mode will be presented as well.
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WEPIK030	Experimental Validation of the Achromatic Telescopic Squeezing Scheme at the LHC	collimation, insertion, injection, luminosity	2992
	S.D. Fartoukh, R. Bruce, F.S. Carlier, J.M. Coello de Portugal, A. Garcia-Tabares, E.H. Maclean, L. Malina, A. Mereghetti, D. Mirarchi, T. Persson, M. Pojer, L. Ponce, S. Redaelli, B. Salvachua, P.K. Skowroński, M. Solfaroli, R. Tomás, D. Valuch, A. Wegscheider, J. Wenninger CERN, Geneva, Switzerland
	The Achromatic Telescopic Squeezing (ATS) [1] scheme offers new techniques to deliver unprecedentedly small beam spot size at the interaction points of the ATLAS and CMS experiments of the LHC, while perfectly controlling the chromatic properties of the corresponding optics (linear and non-linear chromaticities, off-momentum beta-beating, spurious dispersion induced by the crossing bumps). The first series of beam tests with ATS optics were achieved during the LHC Run I (2011/2012) for a first validation of the basics of the scheme at small intensity. In 2016, a new generation of more performing ATS optics was developed and more extensively tested in the machine, still with probe beams for optics measurement and correction at β^=10 cm, but also with a few nominal bunches to establish first collisions at nominal β^ (40 cm) and beyond (33 cm), and to analysis the robustness of these optics in terms of collimation and machine protection. The paper will highlight the most relevant and conclusive results which were obtained during this second series of ATS tests. [1] S. Fartoukh , Phys. Rev. ST Accel. Beams 16, 111002
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WEPIK057	Transverse Resonance Island Buckets as Bunch Separation Scheme	injection, simulation, sextupole, operation	3059
	P. Goslawski, A. Jankowiak, F. Kramer, M. Ries, M. Ruprecht, G. Wüstefeld HZB, Berlin, Germany
	Funding: Supported by the BMBF Beam storage close to a tune resonance (Qx = 1/3,1/4) can generate transverse resonance island buckets in the x,x' phase space providing a second stable island orbit winding around the standard orbit. The two orbits are well separated, with good life time and stability. Successful user experiments have been conducted at BESSY II and the Metrology Light Source (MLS) ,* with such an operation mode. We discuss the required beam optics setup, the TopUp injection process and present successful measurements taken at photon beamlines at BESSY II. * THPMR017, P.Goslawski et al., IPAC2016, Busan, Korea ** MOPWA021, M.Ries et al., IPAC2015, Richmond, USA
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WEPIK068	Non-Linear Beam Dynamics Studies of the CLIC Damping Wiggler Prototype	wiggler, operation, storage-ring, damping	3087
	J. Gethmann, A. Bernhard, E. Blomley, E. Huttel, A.-S. Müller, A.I. Papash, M. Schedler KIT, Karlsruhe, Germany Y. Papaphilippou, P. Zisopoulos CERN, Geneva, Switzerland K. Zolotarev BINP SB RAS, Novosibirsk, Russia
	Funding: Julian Gethmann acknowledges the support by the DFG-funded Doctoral School Karlsruhe School of Elementary and Astroparticle Physics: Science and Technology First beam dynamics studies of a damping wiggler prototype for the CLIC damping rings have been carried out at the KIT storage ring. Effects of the 2.9 T superconducting wiggler on the electron beam in the 2.5 GeV standard operation mode have been measured and compared with theoretical predictions. Higher order multipole components were investigated using local orbit bump measurements. Based on these findings the simulation models for the storage ring optic have been adjusted. The refined optics model has been applied to the 1.3 GeV, low-operation case. This case will be used to experimentally benchmark beam dynamics simulations involving strong wiggler fields and dominant collective effects. We present these measurements, comparisons and the findings of the simulations with the updated low-mode optics model.
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WEPIK093	New Methods for Measurement of Nonlinear Errors in LHC Experimental IRs and Their Application in the HL-LHC	dipole, resonance, dynamic-aperture, collider	3155
	E.H. Maclean, F.S. Carlier, J.M. Coello de Portugal, A. Garcia-Tabares, M. Giovannozzi, L. Malina, T. Persson, P.K. Skowroński, R. Tomás CERN, Geneva, Switzerland
	Studies of nonlinear errors in LHC experimental insertions (IRs) during Run 1 were based upon feed-down to tune and coupling from the crossing angle orbit bumps. Useful for validating the magnetic model, this method alone is of limited use to understand discrepancies between magnetic and beam-based measurement. Feed-down from high-order multipoles is also difficult to observe. During Run 2 several alternative methods were tested in the LHC. This paper summarizes the results of these tests, and comments on their potential application to the High-Luminosity LHC upgrade.
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WEPVA040	Design of Imaginary Transition Gamma Booster Synchrotron for the Jefferson Lab EIC (JLEIC)	injection, ion, booster, lattice	3350
	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 U.S. Government retains a non- exclusive, world-wide license to publish or reproduce this manuscript, or allow others to do so, for U.S. Government purposes. Baseline design of the JLEIC booster synchrotron is presented. Its aim is to inject and accumulate heavy ions and protons at 285 MeV, to accelerate them to about 7 GeV, and finally to extract them into the ion collider ring. The Figure-8 ring features two 260 deg. achromatic arcs configured with negative momentum compaction lattices, designed to avoid transition crossing for all ion species during the course of acceleration. The arc optics is based on a lightly perturbed 90 deg. FODO, with missing dipoles every fourth half-cell, where the horizontal dispersion is driven partly negative for the inward bending arc leading to negative momentum compaction. The lattice also features a specialized high dispersion injection insert optimized to facilitate the transverse phase-space painting in both planes for multi-turn ion injection. Furthermore, the lattice has been optimized to mitigate magnet error sensitivity and to ease chromaticity correction with two families of sextupoles in each plane. The booster ring is configured with super-ferric, 3 Tesla bends. We are presently launching optimization of the booster synchrotron design to operate in the extreme space-charge dominated regime.
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WEPVA055	Pre Orbit Correction Based on Tunnel Level Measurement in SuperKEKB	alignment, coupling, factory, emittance	3385
	A. Morita, H. Koiso, Y. Ohnishi, H. Sugimoto KEK, Ibaraki, Japan
	The SuperKEKB accelerator tunnel has about 30mm displacement in the vertical direction. From the result of optics correction simulation with the tunnel displacement, it was decided that the beamline components align against the smoothed line of the measured tunnel level in order to save the alignment cost and time. In order to compensate the large tunnel displacement, the pre orbit correction based on the tunnel level measurement is applied at the beginning of the phase-1 commissioning, and the beam circulation is achieved with the small number of magnet adjustments. We report the result of the pre orbit correction.
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WEPVA061	High-Precision Pattern Power Supply of Kicker Magnet for Multi-Beamline Operation at SACLA	operation, power-supply, kicker, electron	3404
	C. Kondo, T. Fukui, T. Hara, T. Inagaki, Y. Otake, H. Tanaka RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan K. Fukami JASRI/SPring-8, Hyogo-ken, Japan H. Kawaguchi, Y. Kawaguchi Nichicon (Kusatsu) Corporation, Shiga, Japan S. Nakazawa SES, Hyogo-pref., Japan
	At the Japanese XFEL facility SACLA, two XFEL beamlines (BL2 and BL3) and an injection line to the SPring-8 storage ring are switched by a kicker magnet. This multi-beamline operation has been tested since February 2015, however, CSR effects at a dogleg beam transport to BL2 with a deflecting angle of 3 degree currently limit the peak current of the electron beam. In order to suppress and cancel out the CSR effects, new beam optics is introduced for the dogleg in January 2017. In the new optics, a deflecting angle of the first kicker magnet is increased to 1.5 degree, which is three times larger than that of the old optics. To drive the kicker magnet, a high-power pattern power supply has been developed. To achieve the maximum output of 300 A and 1 kV, SiC MOSFETs are used as switching modules. The newly developed power supply can generate bipolar trapezoidal current waveforms at 60 Hz, and the amplitude and polarity of each waveform are controlled from pulse to pulse according to the beam energy and destination. The target stability is 10 ppm (peak to peak). In this presentation, we report the design and operation results of the newly developed pattern power supply.
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THPAB049	Progress in the Understanding of the Performance Limitations in the CERN Low Energy Ion Ring	resonance, ion, sextupole, space-charge	3819
	A. Huschauer, H. Bartosik, S. Hancock, V. Kain CERN, Geneva, Switzerland
	The performance of heavy ion beams in the CERN Low Energy Ion Ring is mainly limited by beam loss occuring during the radio-frequency capture and the first part of acceleration. Since October 2015, the driving mechanism of these losses has been studied in detail and an interplay of direct space charge forces and excited betatron resonances was identified as the most plausible explanation of the phenomenon. In this paper we summarize the current understanding of the loss mechanism by presenting recent experimental and simulation studies. We discuss strategies to mitigate beam loss and further improve the performance of the accelerator in the future.
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THPAB090	Algorithm to Calculate Off-Plane Magnetic Field From an on-Plane Field Map	simulation, dipole, proton, extraction	3928
	N. Tsoupas, J.S. Berg, F. Méot, V. Ptitsyn, D. Trbojevic BNL, Upton, Long Island, New York, USA S.A. Kahn Muons, Inc, Illinois, USA S. Machida STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. We present an algorithm to calculate the off-plane components of the magnetic field from the on-plane components of the magnetic field which are measured on a grid of the plane. The algorithm, which is a general one and it is not restricted on a mid-plane symmetry, is based on the Taylor series expansion of the magnetic field components in terms of the normal to the plane location. The coefficients of the Taylor series expansion are expressed in terms of the on-plane derivatives of the field components which are generated by the measured magnetic field components on the grid of the plane. The algorithm is use in the RATRACE computer code[] and has been used[] on a dipole magnet with median plane symmetry. S.B. Kowalski and H.A. Enge The Ion-Optical Program Raytrace NIM A258 (1987) 407 ** N. Tsoupas et. al. Effects of Dipole Magnet Inhomogeneity on the Beam Ellipsoid NIM A258 (1987) 421-425
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THPVA015	Application of Modified KV-Distributions to Study the Phase Portrait Transformation of Intense Bunches in Magnetic Fields	emittance, cyclotron, electronics, multipole	4448
	H.Y. Barminova MEPhI, Moscow, Russia
	Modified KV-distribution functions are applied to study the intense bunch behavior in transverse magnetic fields. The functions used allow to consider both the emittance-dominated and charge-dominated bunches in 2D and 3D approximations. Peculiarities of the bunch phase portrait transformation in magnetic fields of achromatic structures are discussed. Particular case is proved to exist characterized by the absence of the emittance transfer.
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THPVA032	Space-Charge Simulation of Integrable Rapid Cycling Synchrotron	lattice, sextupole, space-charge, resonance	4501
	J.S. Eldred, A. Valishev Fermilab, Batavia, Illinois, USA
	Integrable optics is an innovation in particle accelerator design that enables strong nonlinear focusing without generating parametric resonances. We use a Synergia space-charge simulation to investigate the application of integrable optics to a high-intensity hadron ring that could replace the Fermilab Booster. We find that incorporating integrability into the design suppresses the beam halo generated by a mismatched KV beam. Our integrable rapid cycling synchrotron (iRCS) design includes other features of modern ring design such as low momentum compaction factor and harmonically canceling sextupoles. Experimental tests of high-intensity beams in integrable lattices will take place over the next several years at the Fermilab Integrable Optics Test Accelerator (IOTA) and the University of Maryland Electron Ring (UMER).
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THPVA079	First Optics Design and Beam Performance Simulation of PRAE: Platform for Research and Applications With Electrons at Orsay	electron, instrumentation, gun, detector	4637
	A. Faus-Golfe, S. Barsuk, B. Borgo, D. Douillet, M. El Khaldi, L. Garolfi, A. Gonnin, M. Langlet, P. Lepercq, M. Omeich, V. Puill, C. Vallerand LAL, Orsay, France P. Ausset, M. Ben Abdillah, S. Blivet, P. Duchesne, B. Genolini, M. Hoballah, G. Hull, R. Kunne, C. Le Galliard, J. Lesrel, D. Marchand, E. J-M. Voutier IPN, Orsay, France A. Hrybok, A. Pastushenko National Taras Shevchenko University of Kyiv, Radiophysical Faculty, Kiev, Ukraine A. Vnuchenko IFIC, Valencia, Spain
	The PRAE project aims at creating a multidisciplinary R&D facility in the Orsay campus gathering various scientific communities involved in radiobiology, subatomic physics, instrumentation and particle accelerators around an electron accelerator delivering a high-performance beam with energy up to 70 MeV and later 140 MeV, in order to perform a series of unique measurements and future challenging R&D. In addition PRAE will provide a major education and training asset for students and engineers yielding a regional instrument of advanced technology at the heart of the scientific, technological and academic complex of the Paris-Saclay University. In this paper we report the first optics design and performance evaluations of such a multidisciplinary machine, including a first description of future experiments and the required beam instrumentation.
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THPVA112	Progress of the Beamline and Energy Selection System for HUST Proton Therapy Facility	proton, cyclotron, dipole, scattering	4719
	B. Qin, Q.S. Chen, K. Fan, M. Fan, X.Y. Fang, D. Li, Z.K. Liang, K.F. Liu, X. Liu, P. Tan, J. Yang HUST, Wuhan, People's Republic of China W. Chen Huazhong University of Science and Technology, State Key Laboratory of Advanced Electromagnetic Engineering and Technology,, Hubei, People's Republic of China
	Funding: Work supported by The National Key Research and Development Program of China, with grant No. 2016YFC0105305 HUST proton therapy facility is a 5 years National Key Research and Development Program of China. This facil-ity is based on an isochronous superconducting cyclotron with two gantry treatment-rooms and one fixed beamline treatment station. The status for physical and technical design of the beamline and Energy Selection System (ESS) will be introduced in this paper.
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THPVA140	Superconducting Gantry Design for Proton Tomography	proton, dipole, quadrupole, linac	4795
	E. Oponowicz, H.L. Owen UMAN, Manchester, United Kingdom
	Precise proton therapy planning can be assisted by augmenting conventional medical imaging techniques with proton computed tomography (pCT). For adults this requires an incident proton energy up to around 330 MeV, requiring superconducting magnets if an imaging gantry is to replace a conventional 230-250 MeV gantry in the same space. Here we present optics considerations for a superconducting gantry to deliver 330 MeV protons within the context of the future Christie Hospital proton therapy centre, where it is proposed to increase the proton energy in the future with a booster linac.
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Paper

Title

Other Keywords

Page

MOOCB3

Intensity Interferometer to Measure Bunch Length at SPEAR3

photon, detector, electron, storage-ring

60

W.J. Corbett
SLAC, Menlo Park, California, USA
T.M. Mitsuhashi
KEK, Ibaraki, Japan

Electron bunch length in a storage ring is typically measured with streak cameras, electro-optic devices or non-linear cross-correlation techniques with a range of system complexity, signal-to-noise ratios and cost. Another straight-forward method is to construct an 'intensity interferometer' utilizing a coincidence detector to record simultaneous photon arrival events. In this configuration, visible SR light is passed through a narrow bandpass filter followed by a small pinhole to generate a stream of single-mode monochromatic wavepackets. As the interferometer delay is scanned across an electron bunch, two-photon events occurring within the longitudinal coherence time of the light cause a reduction in the measured coincidence rate. The resulting autocorrelation of the optical pulse duration reveals the electron bunch length, independent of synchrotron oscillation motion. In this paper we comment on the theory and report on preliminary measurements carried out at SPEAR3.

Slides MOOCB3 [2.606 MB]

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MOPAB011

Impact on the HL-LHC Triplet Region and Experiments From Asynchronous Beam Dumps on Tertiary Collimators

proton, neutron, photon, interface

96

A. Tsinganis, R. Bruce, F. Cerutti, A. Lechner
CERN, Geneva, Switzerland

Accidental beam impacts on the tertiary collimators (TCTs) can lead to significant energy deposition in the triplet region and to leakage of the induced particle shower towards the experimental cavern. In this work, carried out in the context of the planned High Luminosity Upgrade of the LHC, severe impacts from asynchronous beam dumps on the horizontal tertiary collimators in cells 4 and 6 of the CMS insertion were studied, with half or a full proton bunch impacting on a collimator jaw. The choice of jaw material is shown to be of great importance, with over a factor of 10 increase in peak energy density values in the triplet coils moving from tungsten (Inermet) to molybdenum graphite jaws. Nevertheless, although the quench limit is exceeded in at least one or more triplet magnets in all the evaluated scenarios, values remain well below the damage limit. Energy spectra of particles leaking into the experimental cavern have also been estimated and are presented here.

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MOPAB015

Optimization of a Skew Parametric Resonance Ionization Cooling Channel Using Genetic Algorithm

resonance, controls, dipole, collider

111

Y. Bao
UCR, Riverside, California, USA
A. Afanasev
GWU, Washington, USA
Y.S. Derbenev, V.S. Morozov, A.V. Sy
JLab, Newport News, Virginia, USA
R.P. Johnson
Muons, Inc, Illinois, USA

Funding: This work is supported by Muons Inc.
Skew Parametric-resonance Ionization Cooling (Skew PIC) is designed for the final 6D cooling of a high-luminosity muon collider. Tracking of muons in such a channel has been modeled in MADX and matter-dominated simulation tool G4beanline in previous studies. In this work, we developed an optimization code based on Genetic Algorithm (GA). We optimized the cooling channel and increased the acceptance of the channel by using the GA code.

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MOPAB021

Performance of OTR and Scintillator View Screens for the ARIEL Electron Linac

target, linac, radiation, scattering

117

D.W. Storey, J.M. Abernathy, D. Karlen, M.O. Pfleger, P.R. Poffenberger
Victoria University, Victoria, B.C., Canada
P.S. Birney, P.E. Dirksen, S.R. Koscielniak, M. Lenckowski
TRIUMF, Vancouver, Canada

The ARIEL electron linac is a 0.3 MW CW accelerator, extensible to 0.5 MW, being installed at TRIUMF for radioactive beam production. To date, 17 view screen monitors have been installed along the beamline and have proven to be essential tools in the commissioning of e-linac systems. These are populated by two types of beam targets: P46 scintillator screens which provide diagnostics for low duty factor operation, while at locations with beam energies at and above 10 MeV, OTR foils using either Pyrolytic Graphite or Niobium foils are included to provide coverage up to 100's of μA average beam current. The design of the view screen is described including the image acquisition system and beam target selection. The performance thus far of the OTR foils under low duty factor commissioning is presented including quantification of the OTR emission distribution, thermal studies, and transmission of the beam through the linac after intercepting a foil.

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MOPAB040

Linear and Nonlinear Optics Measurements With Multiturn Data at PETRA III

kicker, operation, diagnostics, injection

170

I.V. Agapov, M. Bieler, H. Ehrlichmann, J. Keil, J. Klute, G. Kube, G.K. Sahoo, F. Schmidt-Föhre, R. Wanzenberg
DESY, Hamburg, Germany
R. Tomás, A. Wegscheider
CERN, Geneva, Switzerland

At Petra III measuring multiturn beam response to pulsed and continuous excitations allows linear and nonlinear (e.g. frequency maps) optics parameter determination. We describe the measurement setup, approaches to optics parameter determination, and the measurement results for Petra III.

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MOPAB047

Electron Beam Phase Space Tomography at the European XFEL Injector

emittance, electron, quadrupole, FEL

196

M. Scholz, B. Beutner
DESY, Hamburg, Germany

The FEL process is determined by the 6D phase space distribution of relativistic electron bunches. Experimental reconstructions of these distributions are therefore a step foreward to understand the beam dynamics and to optimize FEL operation. The reconstructions of the transverse phase spaces can be acieved with tomographic methods. In the injector of the European XFEL, measurements for the reconstruction of the phase spaces were carried out using phase advance scans with multiple quadrupoles. The beam sizes were kept optimized at the measurement screen. A transversely deflecting cavity (TDS) was used to streak the beam vertically. That allows to do longitudinally slice resolved measurements of the horizontal phase space. The horizontal streak required for the slice measurements in the vertical plane was achieved with a correlated linear energy spread and dispersion. In this paper, we present measurement results showing longitudinal slice resolved reconstructions of the transverse phase spaces taken in the European XFEL injector.

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MOPAB051

Progress in FLASH Optics Consolidation

undulator, emittance, gun, laser

211

J. Zemella, M. Vogt
DESY, Hamburg, Germany

FLASH is the superconducting soft X-ray Free Electron Laser in Hamburg at DESY, Germany. A precise knowledge of the beam optics is a key aspect of the operation of a SASE FEL. A campaign of optics consolidation has started in 2013 when the second beam line FLASH2 was installed downstream of the FLASH linac. We give an update on progress of this effort and on recent results.

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MOPAB102

Fast Orbit Response Matrix Measurements at ALBA

storage-ring, linear-dynamics, non-linear-dynamics, data-acquisition

365

Z. Martí, G. Benedetti, M. Carlà, J. Fraxanet, U. Iriso, J. Moldes, A. Olmos, R. Petrocelli
ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain

At ALBA the standard orbit response matrix measurement with DC corrector magnet (CM) modulation is being upgraded with an AC excitation of the correctors combined with the synchronized beam position monitor (BPM) acquisition data rate at 10 kHz. Several types of excitation waveforms (sinusoidal vs square types) and frequencies have been tested and compared to optimize the measurement precision and repeatability. The data acquisition time of the ALBA response matrix (88 horizontal and 88 vertical correctors) with the new AC method takes 1 minute to complete instead of 7 minutes of the standard technique.

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MOPAB115

Transverse Beam Phase-Space Measurement Experience at CTF3

quadrupole, emittance, collider, linear-collider

393

D. Gamba, B. Constance, R. Corsini, S. Döbert, L. Malina, T. Persson, J. Roberts, A.P. Rollings, P.K. Skowroński, F. Tecker
CERN, Geneva, Switzerland
L. Martin
JAI, Oxford, United Kingdom
A.L. Peirson Serratosa
Oxford University, Physics Department, Oxford, Oxon, United Kingdom

One of the objective of the CLIC Test Facility (CTF3) at CERN is to demonstrate the CLIC Drive Beam Recombination concept. An accurate control of the transverse beam parameters is necessary in order to succeed in preserving the beam quality after the recombination. During the activity of the facility we improved our tools and technique for characterising the transverse phase space of the beam before and after recombination. The common quadrupole scan technique was improved by performing constant-beam-size measurement and it was enriched by a tomographic reconstruction of the phase-space. Moreover studies have been performed in order to estimate and subtract the impact of dispersion on such a measurements. An overview of these techniques will be presented with actual measurements performed over the last year of operations of the facility.

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MOPAB130

Cross-Calibration of the LHC Transverse Beam-Profile Monitors

emittance, luminosity, proton, experiment

437

R. Alemany-Fernández, F. Alessio, A. Alexopoulos, C. Barschel, F.S. Carlier, J.M. Coello de Portugal, M. Ferro-Luzzi, A. Garcia-Tabares, M. Hostettler, O. Karacheban, E.H. Maclean, R. Matev, T. Persson, P.K. Skowroński, R. Tomás, G. Trad, S. Vlachos, B. Würkner
CERN, Geneva, Switzerland
G.R. Coombs
EPFL, Lausanne, Switzerland
T.B. Hadavizadeh
Oxford University, Physics Department, Oxford, Oxon, United Kingdom
M. Hofer
TU Vienna, Wien, Austria
L. van Riesen-Haupt
University of Oxford, Oxford, United Kingdom

Calibration of a transverse beam profile monitor is of fundamental importance to guarantee the best possible accuracy and reliability of the instrument over time. In LHC the calibration standard for transverse-profile measurements are the wire scanners. Other profile monitors such as beam synchrotron light telescopes and interferometers are calibrated with respect to them. Additional information about single-bunch sizes can be obtained from beam-gas imaging in the LHCb vertex detector, from the transverse convolved beam sizes extracted from luminosity scans at the collision points, and from the evolution of the luminous-region parameters as reconstructed by ATLAS and CMS inner tracker detectors during such scans. For the first time in LHC, a dedicated cross-calibration of all the above-mentioned systems was carried out with beam in 2016. Additionally, dedicated optics measurements were also performed in order to determine with the highest possible accuracy the amplitude function at the interaction points and at the position of the profile monitors. Results of these measurements are presented in this paper.

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MOPAB138

Comparison of Optical Transition Radiation Simulations and Theory

radiation, diagnostics, simulation, electron

455

J. Wolfenden, R.B. Fiorito, C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom
M. Bergamaschi, P. Karataev, K.O. Kruchinin
JAI, Egham, Surrey, United Kingdom
M. Bergamaschi, P. Karataev, K.O. Kruchinin
Royal Holloway, University of London, Surrey, United Kingdom
M. Bergamaschi, R. Kieffer, T. Lefèvre
CERN, Geneva, Switzerland
R.B. Fiorito, C.P. Welsch, J. Wolfenden
The University of Liverpool, Liverpool, United Kingdom

The majority of optical diagnostics currently used will not stand up to the requirements of the next generation of particle accelerators. Current methodologies need innovation to be able to reach the sub-micrometre resolution and sensitivity that will be required. One technique that has the potential to meet these requirements is optical transition radiation (OTR) imaging. A new algorithm is proposed which incorporates OTR theory, optical effects and beam distribution. This algorithm takes an existing method used for beam imaging and pushes the limits resolution beyond that normally attainable. In doing so, it can provide a reliable and economical diagnostic for future accelerators. A discussion on further applications of the algorithm is also presented.

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MOPIK031

COSY Extraction Line Characterization and Modeling

quadrupole, extraction, proton, storage-ring

567

B. Lorentz, M. Bai, Y. Dutheil, R. Tölle, C. Weidemann
FZJ, Jülich, Germany

COSY is a versatile racetrack-type synchrotron accelerating protons and deuterons in a range of rigidity between 1 T m and 11 T m. Circulating beam can be slowly extracted on a third order resonance and channeled towards different users. New users of the COSY beam have presented new challenges with specific requests, most notably in term of beam shape. This in turn drove a strong interest to develop and improve characterization and modeling methods in the COSY extraction beam line. In this contribution we will present the different beam characterization methods used and their limitations. We will then discuss the modeling of the line and the importance of an accurate and reliable model of the extraction line. Some of the latest beam measurements are presented and compared to modeled results.

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MOPIK056

On the Ariel Pre-Separator

dipole, target, emittance, ion

648

S. Saminathan, R.A. Baartman
TRIUMF, Vancouver, Canada

Funding: Funded under a contribution agreement with NRC (National Research Council Canada) and Capital funding from CFI (Canada Foundation for Innovation).
Two new independent target ion sources with dedicated pre-separators will be built in the ARIEL facility to triple the radioactive ion beam production at TRIUMF. A compact Nier-Johnson type of pre-separator has been designed to achieve a mass resolving power of 300 in order to minimize the undesired radioactive species contaminating the downstream beamlines. It consists of a 112 degree magnetic and a 90 degree toroidal electrostatic dipole with deflection in opposite direction. It also contains electrostatic quadrupole elements in between the dipoles. The electrostatic dipole compensates the energy dispersion of the magnetic dipole. This allows an achromatic mode of operation resulting in a high mass resolving power downstream to the electrostatic deflector even for beams with a high energy spread. We present the result of beam optics calculations for the ARIEL pre-separator.

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MOPIK066

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

storage-ring, lattice, closed-orbit, betatron

676

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

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

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MOPIK071

Dispersion and Beam Optic Parameter Measurements in the Transport Line (E-Weg) from DESY II to PETRA III

emittance, quadrupole, injection, synchrotron

692

G.K. Sahoo, K. Balewski, H. Ehrlichmann, J. Keil, R. Wanzenberg
DESY, Hamburg, Germany

The transport line E-Weg extends from the extraction septum in DESY II to the injection septum in PETRA III, and transports electrons at a beam energy of 6.0 GeV. It consists of 3 parts. The first part is in DESY tunnel, the second part is a long drift space in a slanted tube and the third part is in PETRA III tunnel. The vertical plane difference between the tunnels is 1.28 m. The optics was derived from initial values at Transfer Point (UGP) from a previous optics. The total length of the transfer line is about 203 m. Ten screen monitors are used to estimate the profiles of the beam spot for the optics measurements, while 8 BPMs, mostly adjacent to the screens, are used to compare and control the orbits. Two scrapers are installed on either side of the long drift space to trim the beam dimensions in transverse plane. Two FCTs are used to measure the beam current and transfer efficiency. The transverse dispersion and beta functions are measured by extracting the beam from DESY at different energies and analysing the beam profiles at the screen as well as positions at BPMs. The details of such measurements are reported in this paper.

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MOPIK073

Calibration of Linear Optics of COSY Based on ORM Data

quadrupole, factory, dipole, sextupole

699

C. Weidemann, M. Bai, Y. Dutheil, F. Hinder, B. Lorentz
FZJ, Jülich, Germany

The COoler SYnchrotron in Jülich is a well suited accelerator for a precursor experiment on the direct measurement of the Electric Dipole Moment (EDM) of the deuteron (see* and references within). It provides polarized and unpolarized proton and deuteron beams in the momentum range between 0.3 GeV/c and 3.65 GeV/c**, allows for phase space cooling and is highly flexible with respect to ion-optical settings***. Unfortunately, a model independent linear optics measurement is not possible and so far the existing MAD-X model of COSY does not provide an agreement with the actual machine parameters that is required by future experiments, such as the EDM experiment. Significant deviations with respect to the working point and linear optics have been reported****. As shown in*****, a MAD-X based LOCO (Linear Optics from Closed Orbits) algorithm in a C++ program was successfully developed and carefully benchmarked. This contribution presents the application of the new program on measured ORM data and its capabilities in calibrating linear optics as well as reconstructing machine imperfections such as gradient errors of quadrupole magnets and calibration factors of BPMs and steerers.
* D. Eversmann et al., PRL 115, no. 9, 094801 (2015).
** R. Maier, NIM A 390, 1 (1997).
*** C. Weidemann et al., PRSTAB 18, 020101 (2015).
**** D. Ji et al., IPAC16, doi:10.18429/JACoW-IPAC2016-TUPMR026.
***** C. Weidemann et al., IPAC16, doi:10.18429/JACoW-IPAC2016-THPMB009.

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MOPIK081

Study of HEPS Performance with Error Model and Simulated Correction

quadrupole, sextupole, closed-orbit, simulation

721

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

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

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MOPIK085

Linear Optics Calibration at the HLS-II Storage Ring Using Model Independent Analysis

storage-ring, lattice, experiment, operation

727

G. Liu, L. Wang, F.F. Wu, K. Xuan
USTC/NSRL, Hefei, Anhui, People's Republic of China

Linear optics are the main lattice parameters characterizing the linear properties of storage rings. Especially for beta function and phase advance, they are the basic lattice functions which must be accurately calibrated to ensure high quality operation of the machine. Model Independent Analysis (MIA), which adopts mathematical statistical methods to extract the effective lattice information of storage rings by directly analyzing the turn-by-turn beam-position-monitor (BPM) measurements, has been applied at HLS-II to calibrate the linear optics model of the storage ring. The measurements of the turn-by-turn BPM data with all of the 32 BPMs are reported in this paper. The calibration results of the beta function using MIA are presented.

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MOPIK090

Beta Function Measurement in the SOLARIS Storage Ring

quadrupole, storage-ring, lattice, sextupole

736

A. Kisiel, M.B. Jaglarz, M.P. Kopeć, S. Piela, M.J. Stankiewicz, A.I. Wawrzyniak
Solaris, Kraków, Poland

One of the most essential lattice function used for transverse beam dynamics studies of the storage rings is a beta function. It characterizes the linear properties of magnets layout and allows to optimize the compatibility of the model and the machine by reducing the beta-beating. Moreover, the calculation of other parameters like transverse beam emittance, dynamic aperture, energy spread and others, requires knowledge of the quantity of beta function along the ring. Various methods of measurement of this function used in Solaris will be presented.

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MOPIK100

Beam Delivery System Optimization for CLIC 380 GeV

luminosity, sextupole, lattice, quadrupole

764

F. Plassard, A. Latina, E. Marín, D. Schulte, R. Tomás
CERN, Geneva, Switzerland
P. Bambade
LAL, Orsay, France

In the framework of the CLIC rebaselining, the Beam Delivery System (BDS) have been re-optimized for its initial stage at 380 GeV. Two BDS designs with L*=4.3 meters and L*=6 meters have been investigated. The optimization of the lattices and the beam parameters at the interaction point (IP) have been performed by taking into account their energy upgrade to 3 TeV and the tuning feasibility of the BDS in presence of static imperfections.

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MOPIK122

The Beam Optics of the FFAG Cell of the CBETA ERL Accelerator

quadrupole, electron, dipole, focusing

820

N. Tsoupas, J.S. Berg, S.J. Brooks, G.J. Mahler, F. Méot, V. Ptitsyn, D. Trbojevic
BNL, Upton, Long Island, New York, USA
J.A. Crittenden
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
S.C. Tygier
UMAN, Manchester, United Kingdom

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
The CBETA project[*] is a prototype electron accelerator for the proposed eRHIC project[**]. The electron accelerator is based on the Energy Recovery Linac (ERL) and the Fixed Field Alternating Gradient (FFAG) principles. The FFAG arcs and the straight section of the accelerator are comprised of one focusing and one defocusing quadrupoles which are designed as Halbach-type permanent dipole magnets with quadrupoles component[***]. We will present the beam optics of the FFAG cell which is based on 3D field maps derived with the use of the OPERA computer code[****]. We will also present the electromagnetic design of the corrector magnets of the cell.
* http://arxiv.org/abs/1504.00588
** http://arxiv.org/ftp/arxiv/papers/1409/1409.1633.pdf
*** K. Halbach, Nucl. Instrum. Meth. 169 (1980) pp. 1-10
**** http://www.scientificcomputing.com

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MOPIK123

Beam Dynamics Numerical Studies Regarding CBETA Cornell-BNL ERL

lattice, quadrupole, multipole, simulation

824

F. Méot, S.J. Brooks, D. Trbojevic, N. Tsoupas
BNL, Upton, Long Island, New York, USA
S.C. Tygier
UMAN, Manchester, United Kingdom

Funding: Work supported by New York State Energy Research and Development Authority (NYSERDA)
The Cornell-BNL Electron Test Accelerator CBETA is based on a 36 MeV superconducting linac and on a single 4-pass up/4-pass down linear FFAG return loop, for beam acceleration from 6 to 150 MeV and energy recovery. Numerical beam dynamics simulations have accompanied and eventually validated the quadrupole-doublet FFAG cell technology and parameters, and following that the complete return loop, all along the ERL lattice design process. They are key to assessing and validating the ERL optics and beam behavior over the whole acceleration/ER cycle, and in preparing future machine operation. This paper presents various of these beam dynamics studies, including start-to-end simulations.

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MOPIK125

Multi-frequency AC LOCO: A Fast and Precise Technique for Lattice Correction

lattice, quadrupole, power-supply, experiment

831

X. Yang, K. Ha, V.V. Smaluk, Y. Tian, L. Yu
BNL, Upton, Long Island, New York, USA

We developed a novel technique to improve the precision and shorten the measurement time of the LOCO (Linear Optics from Closed Orbits) method at NSLS-II [1]. This technique named AC LOCO is based on a sine-wave (AC) beam excitation via fast correctors typically installed at synchrotron light sources for the fast orbit feedback. The beam oscillations are measured by beam position monitors. The narrow band used for the beam excitation and measurement not only allows us to suppress effectively the beam position noise and also makes simultaneously exciting multiple correctors at different frequencies (multi-frequency mode) possible. We demonstrated at NSLS-II that the new technique provides better lattice corrections and achieves two minutes measurement time in the thirty-frequency mode.
[1] X. Yang et al., 'Fast and precise technique for magnet lattice correction via sine-wave excitation of fast correctors', Phys. Rev. Accel. Beams, vol. 20, p. 054001, 2017.

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MOPVA007

Simulations for Beam-Based Measurements in BERLinPro

cavity, simulation, diagnostics, gun

859

M. McAteer, M. Abo-Bakr, J. Knedel, G. Kourkafas, B.C. Kuske, J. Völker
HZB, Berlin, Germany

BERLinPro is an energy recovery linac project whose goal is to establish the accelerator physics knowledge and technology needed to produce 50 MeV beams with high current, low normalized emittance, and low losses. Precise measurements of beam parameters are essential for demonstrating the achievement of performance goals. In this paper we present simulations for measurements of energy, energy spread, and bunch length using the tracking code Astra.

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MOPVA021

Optics Design of the Compact ERL Injector for 60 pC Bunch Charge Operation

cathode, laser, operation, gun

898

T. Hotei
Sokendai, Ibaraki, Japan
R. Kato, T. Miyajima, N. Nakamura, M. Shimada
KEK, Ibaraki, Japan

EUV-FEL light source based on ERL has been designed at KEK for EUV lithography light source. The advantage of ERL is to accelerate high average current beam due to CW operation, and it is possible to drive high average power FEL. To generate the target EUV-FEL power, which is 10 kW, the bunch charge of 60 pC, the beam energy of 10.5 MeV and the bunch length of 1 ps are required at the end of the EUV-FEL injector. In order to demonstrate the target beam performance for the EUV-FEL accelerator, a high charge beam test was carried out at the cERL in KEK. We designed a new optics of the cERL injector prior to the high charge beam operation. To calculate beam dynamics more accurately, accelerator models corrected according to the condition of the actual cERL injector is used for the optics design. From results of the optics design that minimized the emittance and bunch length using the corrected accelerator models, the emittance and bunch length at the end of injector are 0.8 mm-mrad and 3.4 ps. Furthermore, based on the design optics, we carried out high bunch charge beam operation.

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MOPVA037

Development and Commissioning of the Doppler-Shift Unit for the Measurement of the Ion Species Fractions and Beam Energy of the ESS Proton Source

proton, coupling, linac, software

936

C.A. Thomas, T.J. Shea
ESS, Lund, Sweden
J. Fils
GSI, Darmstadt, Germany
Y. Lussignol, P. Mattei
CEA/DSM/IRFU, France
Ø. Midttun
University of Bergen, Bergen, Norway
L. Neri
INFN/LNS, Catania, Italy
F. Senée, O. Tuske
CEA/IRFU, Gif-sur-Yvette, France

ESS proton source is in going to be soon delivered to the ESS project. In order to qualify the source, a series of beam instrumentation diagnostics have been designed and produced. In particular, a specific spectrograph dedicated to the fraction species measurement is currently commissioned. This instrument not only is capable of measuring the fraction species produced by the source, but also it can measure their energy and energy spread, the mass of the different species, and additional spectral rays coming from the gas species in presence in the vacuum chamber. We present in this paper the commissioning of this instrument, the Doppler Shift unit, dedicated to the measurement of the fraction species.

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TUOCB1

Progress in the Design of Beam Optics for FCC-ee Collider Ring*

quadrupole, collider, sextupole, emittance

1281

K. Oide, K. Ohmi
KEK, Ibaraki, Japan
M. Benedikt, H. Burkhardt, B.J. Holzer, A. Milanese, J. Wenninger, F. Zimmermann
CERN, Geneva, Switzerland
A.P. Blondel, M. Koratzinos
DPNC, Genève, Switzerland
A.V. Bogomyagkov, E.B. Levichev, D.N. Shatilov
BINP SB RAS, Novosibirsk, Russia
M. Boscolo
INFN/LNF, Frascati (Roma), Italy

The beam optics for the FCC-ee collider has been updated: (a) the layout is adjusted to a new footprint of FCC-hh, (b) the design around the interaction point is refined considering a number of machine-detecor interface issues, (c) the arc lattice is refined taking realistic magnet designs into account, (d) the β^* and betatron tunes are re-optimized according to recent results of the beam-beam simulations, and more. These changes make the collider design more realistic without performance degradation.

Slides TUOCB1 [4.891 MB]

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TUPAB104

Optimized Undulator to Generate Low Energy Photons From Medium to High Energy Accelerators

polarization, photon, undulator, radiation

1556

T.Y. Chung, M.-S. Chiu, J.C. Huang, C.-S. Hwang, J.C. Jan, C.K. Yang
NSRRC, Hsinchu, Taiwan
H.W. Luo
NTHU, Hsinchu, Taiwan

While emitting low energy photons from a medium or high energy storage ring, the on-axis heat load on the beam line optics can become a critical issue. In addition, the heat load in the bending magnet chamber, especially in the vertical and circular polarization mode of operation may cause some concern. In this work, we compare the heat loads for the APPLE-II and the Knot-APPLE, both optimized to emit 10 eV photons from the 3 GeV TPS. Under this constraint the heat load analysis, synchrotron radiation performance and features in various polarization modes are presented. Additional consideration is given to beam dynamics effect.

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TUPAB134

Life Expectancy Studies for LCLS-II Permanent Magnet Undulators

undulator, radiation, permanent-magnet, electron

1640

M. Santana-Leitner, D.E. Bruch, R.C. Field, D.S. Martinez-Galarce, B.D. McKee, H.-D. Nuhn, M. Rowen, S.W. Score
SLAC, Menlo Park, California, USA

Funding: Work supported by U.S. Department of Energy contract DE-AC02-76SF00515
LCLSII at SLAC National Accelerator Laboratory will add a 4 GeV superconducting Linac to the existing 20 GeV Cu structure. Electron beams from the two sources going through two new variable gap undulators [*] will produce FEL ranging 200-5000 keV at up to 929 kHz, also reaching 20 keV at low frequency. Such performance will be achieved by hybrid design undulators with NdFeB magnet blocks until radiation-induced demagnetization exceeds 0.01%. This is a sizable challenge, as LCLS-II will carry 120 kW beams in both its soft (SXR) and hard (HXR) beam-lines. Even small fractional losses could result excessive if too frequent or not detected and aborted fast enough. A model of SXR undulator was set for FLUKA [**] radiation transport, including segments, phase-shifters, quadrupoles, RFBPM, stands/pillars and interconnecting parts. Components were installed according to MAD files, which were also used to code the optics. Beam-loss/shower propagation was simulated for beam mis-steering, interception at wire scanners and gas-bremsstrahlung interactions. Results help set limits on shut-off times, uniform loss levels and wire scanner use, and to define placement for beam loss monitors.
* M. Leitner et al, Hard X-Ray and Soft X-Ray Undulator Segments for the Linear Coherent Light Source Upgrade (LCLS-II) Project, these proceedings
** A. Ferrari et al, The FLUKA Code: Developments and Challenges for High Energy and Medical Applications, Nuclear Data Sheets 120, 211-214 (2014)

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TUPIK059

Recent Progress of Dithering System at SuperKEKB

luminosity, feedback, background, electronics

1827

Y. Funakoshi, H. Fukuma, T. Kawamoto, M. Masuzawa, S. Nakamura, K. Ohmi, T. Oki, S. Uehara
KEK, Ibaraki, Japan
P. Bambade, D. El Khechen, D. Jehanno, V. Kubytskyi, C. Rimbault
LAL, Orsay, France
A.S. Fisher
SLAC, Menlo Park, California, USA
U. Wienands
ANL, Argonne, Illinois, USA

Recent progress of the dithering system at SuperKEKB is described. Some details of the system layout are shown. Beam orbit and optics related issues are discussed. Preliminary tests of the some components in the Phase 1 beam commissioning or in the bench are described.

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TUPIK087

Phase Advance Interlocking Throughout the Whole LHC Cycle

quadrupole, kicker, software, operation

1901

K. Fuchsberger, A. Calia, M.A. Galilée, G.H. Hemelsoet, M. Hostettler, D. Jacquet, J. Makai, M. Schaumann
CERN, Geneva, Switzerland

Each beam of CERN's Large Hadron Collider (LHC) stores 360 MJ at design energy and design intensity. In the unlikely event of an asynchronous beam dump, not all particles would be extracted immediately. They would still take one turn around the ring, oscillating with potentially high amplitudes. In case the beam would hit one of the experimental detectors or the collimators close to the interaction points, severe damage could occur. In order to minimize the risk during such a scenario, a new interlock system was put in place in 2016. This system guarantees a phase advance of zero degrees (within tolerances) between the extraction kicker and the interaction point. This contribution describes the motivation for this new system as well as the technical implementation and the strategies used to derive appropriate tolerances to allow sufficient protection without risking false beam dump triggers.

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TUPIK089

Studies on Luminous Region, Pile-up and Performance for HL-LHC Scenarios

luminosity, operation, simulation, detector

1908

L.E. Medina Medrano, G. Arduini, R. Tomás
CERN, Geneva, Switzerland
L.E. Medina Medrano
UGTO, Leon, Mexico

Funding: Research supported by the HL-LHC project and the Beam project (CONACYT, Mexico).
Studies on luminous region and pile-up density are of great interest for the experiments at the future High Luminosity LHC (HL-LHC) in order to optimize the detector performance. The evolution of these parameters at the two main interaction points of the HL-LHC along optimum physics fills is studied for the baseline and alternative operational scenarios with the latest set of parameters, including a refined description of the longitudinal bunch profile. Results are discussed in terms of a new figure-of-merit, the effective pile-up density.

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TUPIK119

Control of Intra-Bunch Vertical Instabilities at the SPS - Measurements and Technology Demonstration

feedback, controls, injection, kicker

2005

J.D. Fox, J.E. Dusatko, C.H. Rivetta, O. Turgut
SLAC, Menlo Park, California, USA
H. Bartosik, W. Höfle, K.S.B. Li, E. Métral, B. Salvant, U. Wehrle
CERN, Geneva, Switzerland
S. De Santis
LBNL, Berkeley, California, USA

Funding: Work supported by the U.S. Department of Energy under contract # DOE-AC02-76SF00515, the US LHC Accelerator Research Program ( LARP), the FP7 High Luminosity LHC Project and the US-Japan Cooperative Program in High Energy Physics
We present recent measurements demonstrating control of unstable beam motion in single bunch and bunch train configurations at the SPS. The work is motivated by anticipated intensity increases from the LIU and HL-LHC upgrade programs, and has included the development of a GHz bandwidth reconfigurable 4 GS/S signal processor with wideband kickers and associated amplifiers. The system was operated at 3.2GS/s with 16 samples across a 5 ns RF bucket (4.2 ns bunch at injection). The experimental results confirm damping of intra-bunch instabilities in both Q20 and Q26 optics configurations for intensities of 2x10¹¹ P/bunch. Instabilities with growth times of 200 turns are well-controlled from injection, consistent with the achievable gains for the 2 installed stripline kickers with 1 kW broadband power. Measurements from multiple studies in single-bunch and bunch train configurations show achieved damping rates, control of multiple intra-bunch modes, behavior of the system at injection and final damped noise floor. We present an analysis method to study the relative phase of slice motion during a transient to discriminate between TMCI and other types of Head-Tail instabilities.

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TUPVA002

Updates on the Optics of the Future Hadron-Hadron Collider FCC-hh

quadrupole, dipole, sextupole, hadron

2023

A. Chancé, D. Boutin, B. Dalena
CEA/IRFU, Gif-sur-Yvette, France
B.J. Holzer, A. Langner, D. Schulte
CERN, Geneva, 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 three options considered for the next generation accelerator in high-energy physics as recommended by the European Strategy Group. The layout of FCC-hh has been optimized to a more compact design following recommendations from civil engineering aspects. The updates on the first order and second order optics of the ring will be shown for collisions at the required centre-of-mass energy of 100 TeV. Special emphasis is put on the dispersion suppressors and general beam cleaning sections as well as first considerations of injection and extraction sections.

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TUPVA003

Advance on Dynamic Aperture at Injection for FCC-hh

dipole, injection, dynamic-aperture, target

2027

B. Dalena, D. Boutin, A. Chancé
CEA/IRFU, Gif-sur-Yvette, France
B.J. Holzer, D. Schulte
CERN, Geneva, Switzerland

Funding: This Research and Innovation Action project submitted to call H2020-INFRADEV-1-2014-1 receives funding from the European Union's H2020 Framework Programme under grant agreement no. 654305.
In the hadron machine option, proposed in the context of the Future Circular Colliders (FCC) study, the first evaluation of dipole field quality, based on the Nb3Sn technology, has shown a Dynamic Aperture at injection above the LHC target value. In this paper the effect of field imperfections on the dynamic aperture, using the updated lattice design, is presented. Tolerances on the main multipole components are evaluated including feed-down effect.

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TUPVA004

Synchrotron Radiation Backgrounds for the FCC-hh Experiments

photon, simulation, radiation, collider

2031

F. Collamati
INFN-Roma1, Rome, Italy
M. Boscolo
INFN/LNF, Frascati (Roma), Italy
H. Burkhardt, R. Kersevan
CERN, Geneva, Switzerland

Funding: This work was supported by the HORIZON 2020 project EuroCirCol, grant agreement 654305.
We present in this paper a detailed analysis of the synchrotron radiation emitted by the 50 TeV protons of the FCC-hh in the last bending and quadrupole magnets upstream the interaction region. We discuss the characteristics of this radiation in terms of power, flux, photon spectrum and fans in different running conditions such as, for example, with and without crossing angle. We mainly focus our study on the fraction of photons that may hit the detector, with a full tracking into GEANT4 that simulates their interaction within the central beam pipe.

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TUPVA009

Multiparametric Response of the LHC Dynamic Aperture in Presence of Beam-Beam Effects

emittance, simulation, luminosity, octupole

2051

D. Pellegrini, F. Antoniou, S.D. Fartoukh, G. Iadarola, Y. Papaphilippou
CERN, Geneva, Switzerland

We performed extended simulations of LHC dynamic aperture (DA) in the presence of beam-beam effects in the weak-strong approximation, evaluating the contributions of parameters such as: tunes, optics, bunch intensity, crossing angle, emittance, chromaticity and current in the Landau octupoles. Here we present a summary of these studies, giving an overview of the amplitude of the LHC operational space and pointing out the remaining margins for mitigation of instabilities. These studies supported the actions deployed during the 2016 run of the LHC, which aimed at maximising its performances. Examples of such actions are the switch to lower emittance beams, the reduction of crossing angle and tune trims. More recently, DA scans have been used to help the definition of the operational scenarios for the 2017 run. Additional room for improvements, for instance by deploying crossing angle levelling, will be explained.

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TUPVA021

Impact of Collision Debris in the HL-LHC ATLAS and CMS Insertions

luminosity, proton, insertion, radiation

2093

A. Tsinganis, F. Cerutti
CERN, Geneva, Switzerland

The High Luminosity upgrade of the LHC (HL-LHC) foresees the baseline operation of the accelerator at a 5 times higher peak luminosity (5.0x1034cm^-2s⁻¹). The impact of collision debris on the magnets and other equipment in the triplet region and matching section of the ATLAS and CMS insertions has been evaluated by means of detailed FLUKA models implementing the latest optics and layout version. Qualitative and quantitative differences between the vertical and horizontal beam crossing schemes are highlighted. With measures in place to mitigate the effects of the interruption of the beam screen in the triplet interconnections and the Q4 aperture reduction, peak dose values in the superconducting coils remain below 30MGy in the triplet-D1 and below 12MGy in the matching section magnets for an integrated luminosity of 3000fb-1. Peak power density values are lower than 3mW/cm³ and 1mW/cm³ in the triplet and matching section respectively. Total heat loads in magnets, collimators, masks and absorbers were also estimated, along with dose and particle fluence maps relevant for Radiation to Electronics (R2E) aspects. The effect of a displacement of the interaction point is also addressed.

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TUPVA022

Requirements for Crab Cavity System Availability in HL-LHC

luminosity, cavity, operation, proton

2097

M. Valette, A. Apollonio, J.A. Uythoven, D. Wollmann
CERN, Geneva, Switzerland

Funding: Research supported by the HL-LHC project.
Crab Cavities will be installed in the High Luminosity LHC in order to increase the effective peak luminosity through a partial compensation of the geometric factor. This will allow extending the levelling time resulting in an increased production of integrated luminosity. Based on the availability of the LHC during 2016 operation, the expected yearly-integrated luminosity of the future HL-LHC was estimated using a Monte Carlo model. Crab cavity faults were added to the observed failure distribu-tions and their impact on integrated luminosity produc-tion as a function of fault time and fault frequency was studied. This allows identifying a breakeven point in luminosity production and defining minimum system availability requirements for the crab cavities to reach the design goal of 250 fb-1 of integrated luminosity per year.

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TUPVA026

Beam-Beam Studies for FCC-hh

simulation, dynamic-aperture, luminosity, resonance

2109

J. Barranco García, T. Pieloni, C. Tambasco
EPFL, Lausanne, Switzerland
X. Buffat, S.V. Furuseth, C. Tambasco
CERN, Geneva, Switzerland
S.V. Furuseth
NTNU, Trondheim, Norway

Funding: This works was performed in the framework of the European Circular 'Energy Fr'ontier Collider Study, H2020 Framework Programme under grant agreement no. 654305. We acknowledge support from the Swiss State Secretariat for Education, Research and Innovation SERI.
The Future Circular Collider hadron-hadron (FCC-hh) design study is currently exploring different IR design possibilities including round and flat optics or different crossing schemes. The present study intends to evaluate each scenario from the beam-beam effects point of view. In particular the single particle long term stability to maximize beam lifetimes and luminosity reach is used to quantify the differences. The impact of strong head on interactions on the beam quality and lifetime is addressed by means of GPU accelerated simulations code featuring a weak-strong 6-dimensional beam-beam interaction.

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TUPVA027

Study of Beam-Beam Long Range Compensation with Octupoles

octupole, dynamic-aperture, resonance, beam-beam-effects

2113

T. Pieloni, J. Barranco García, C. Tambasco
EPFL, Lausanne, Switzerland
X. Buffat, C. Tambasco
CERN, Geneva, Switzerland

Funding: The European Circular Energy-Frontier Collider Study (EuroCirCol), EU's Horizon 2020 grant No 654305.
Long range beam-beam effects are responsible for particle losses and define fundamental operational parameters of colliders (i.e. crossing angles, intensities, emittances, β^*). In this study we propose octuple magnets as a possible scheme to efficiently compensate long-range beam-beam interactions with a global correction scheme. The impact and improvements on the dynamic aperture of colliding beams together with estimates of the luminosity potentials are discussed for the HL-LHC upgrade and extrapolations made for the FCC project. Results are compared to other compensating schemes.

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TUPVA030

Measurement of Beta-Beating Due to Strong Head-on Beam-Beam Interactions in the LHC

dipole, emittance, simulation, injection

2121

P. Gonçalves Jorge, J. Barranco García, T. Pieloni
EPFL, Lausanne, Switzerland
X. Buffat, F.S. Carlier, J.M. Coello de Portugal, E. Fol, L.E. Medina Medrano, R. Tomás, A. Wegscheider
CERN, Geneva, Switzerland

The LHC operation relies on a good knowledge of the optics, usually corrected in absence of beam-beam interactions. In a near future, both the LHC and the HL-LHC will need to cope with large head-on beam-beam parameters, the impact on the optics needs to be understood and, if necessary, corrected. The results of a dedicated experiment performed at injection energy are discussed in this paper.

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TUPVA037

FCC-hh Final-Focus for Flat-Beams: Parameters and Energy Deposition Studies

luminosity, collider, quadrupole, hadron

2139

J.L. Abelleira, E. Cruz Alaniz, A. Seryi, L. van Riesen-Haupt
JAI, Oxford, United Kingdom
M.I. Besana
CERN, Geneva, Switzerland

Funding: The European Circular Energy-Frontier Collider Study (EuroCirCol), EU's Horizon 2020 grant No 654305.
The international Future Circular Collider (FCC) study comprises the study of a new scientific structure in a tunnel of 100 km. This will allow the installation of two accelerators, a 45.6'175 GeV lepton collider and a 100-TeV hadron collider. An optimized design of a final-focus system for the hadron collider is presented here. The new design is more compact and enables unequal β^* in both planes, whose choice is justified here. This is followed by energy deposition studies, where the total dose in the magnets as a consequence of the collision debris is evaluated.

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TUPVA039

Effect of Alignment Errors and Orbit Correctors on the Interaction Region of the FCC-hh

quadrupole, interaction-region, dipole, collider

2147

E. Cruz Alaniz, J.L. Abelleira, A. Seryi, L. van Riesen-Haupt
JAI, Oxford, United Kingdom
J.L. Abelleira, L. van Riesen-Haupt
University of Oxford, Oxford, United Kingdom

Funding: European Union's Horizon 2020 research and innovation programme under grant No 654305.
The Future Circular Collider (FCC) design study aims to develop the design of possible circular colliders in the LHC era. In particular the FCC-hh will aim to produce proton-proton collisions at a center of mass energy of 100 TeV. The interaction region has been designed to meet the requirements in terms of energy and luminosity. However, as it is the case in any real accelerator, misalignments in the magnets are likely to occur; the effect of these misalignments, if not properly compensated for, can jeopardize the performance of the machine. This study contemplates alignment and field errors in the interaction region in order to estimate the tolerance necessary to provide a good correction measured in terms of deviation of the orbit and strength of the correctors.

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TUPVA040

Overview of Design Development of FCC-hh Experimental Interaction Regions

luminosity, detector, dipole, experiment

2151

A. Seryi, J.L. Abelleira, E. Cruz Alaniz, L.J. Nevay, L. van Riesen-Haupt
JAI, Oxford, United Kingdom
R.B. Appleby, H. Rafique
UMAN, Manchester, United Kingdom
R.B. Appleby
Cockcroft Institute, Warrington, Cheshire, United Kingdom
J. Barranco García, T. Pieloni
EPFL, Lausanne, Switzerland
M. Benedikt, M.I. Besana, X. Buffat, H. Burkhardt, F. Cerutti, A. Langner, R. Martin, W. Riegler, D. Schulte, R. Tomás
CERN, Geneva, Switzerland
M. Boscolo, F. Collamati
INFN/LNF, Frascati (Roma), Italy
M. Hofer
TU Vienna, Wien, Austria
L.J. Nevay
Royal Holloway, University of London, Surrey, United Kingdom
L. van Riesen-Haupt
University of Oxford, Oxford, United Kingdom

The experimental interaction region is one of the key areas that define the performance of the Future Circular Collider. In this overview we will describe the status and the evolution of the design of EIR of FCC-hh, focusing on design of the optics, energy deposition in EIR elements, beam-beam effects and machine detector interface issues.

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TUPVA041

Exploring the Triplet Parameter Space to Optimise the Final Focus of the FCC-hh

quadrupole, shielding, target, radiation

2155

L. van Riesen-Haupt, J.L. Abelleira, E. Cruz Alaniz, A. Seryi
JAI, Oxford, United Kingdom

One of the main challenges when designing final focus systems of particle accelerators is maximising the beam stay clear in the strong quadrupole magnets of the inner triplet. Moreover it is desirable to keep the quadrupoles in the inner triplet as short as possible for space and costs reasons but also to reduce chromaticity and simplify corrections schemes. An algorithm that explores the triplet parameter space to optimise both these aspects was written. It uses thin lenses as a first approximation and MADX for more precise calculations. In cooperation with radiation studies, this algorithm was then applied to design an alternative triplet for the final focus of the Future Circular Collider.

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TUPVA042

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

quadrupole, sextupole, closed-orbit, simulation

2159

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

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

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TUPVA045

Compensation of Head-on Beam-Beam Induced Resonance Driving Terms and Tune Spread in the Relativistic Heavy Ion Collider

electron, lattice, proton, resonance

2171

W. Fischer, X. Gu, C. Liu, Y. Luo, A. Marusic, R.J. Michnoff, T.A. Miller, M.G. Minty, C. Montag, A.I. Pikin, G. Robert-Demolaize, V. Schoefer, P. Thieberger
BNL, Upton, Long Island, New York, USA
S.M. White
ESRF, Grenoble, France

Funding: Work supported by U.S. DOE under contract No DE-AC02-98CH10886 with the U.S. Department of Energy.
A head-on beam-beam compensation scheme was implemented for operation in the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory. The compensation consists of a lattice for the minimization of beam-beam driven resonance driving terms, and electron lenses for the reduction of the beam-beam induced tune spread. We describe the implementations of the lattice and electron lenses, and report on measurements of lattice properties and the effect of the electron lenses on the hadron beam.

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TUPVA060

Upgrade of GSI HADES Beamline in Preparation for High Intensity Runs

quadrupole, target, beam-losses, dipole

2214

M. Sapinski, P. Boutachkov, S. Damjanovic, K. Dermati, C.M. Kleffner, J. Pietraszko, T. Radon, S. Ratschow, S. Reimann, W. Sturm, B. Walasek-Höhne
GSI, Darmstadt, Germany

HADES is a fixed target experiment using SIS18 heavy-ion beams. It investigates the microscopic properties of matter formed in heavy-ion, proton and pion - induced reactions in the 1-3.5 GeV/u energy regime. In 2014 HADES used a secondary pion beam produced by interaction between high-intensity nitrogen primary beam and a beryllium target. In these conditions beam losses, generated by slow extraction and beam transport to the experimental area, led to activation of the beam line elements and triggered radiation alarms. The primary beam intensity had to be reduced and the beam optics modified in order to keep radiation levels within the allowed limits. Similar beam conditions are requested by HADES experiment for upcoming run in 2018 and in the following years. Therefore, a number of measures have been proposed to improve beam transmission and quality. These measures are: additional shielding, additional beam instrumentation, modification of beam optics and increase of vacuum chambers' apertures in critical locations. The optics study and preliminary results of FLUKA simulations for optimization of location of loss detectors are presented.

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TUPVA115

Progress with Long-Range Beam-Beam Compensation Studies for High Luminosity LHC

electron, simulation, cathode, proton

2358

A. Rossi, O. Aberle, J. Albertone, A. Bertarelli, C.B. Boccard, F. Carra, G. Cattenoz, Y. Delaup, S.D. Fartoukh, G. Gobbi, J. Lendaro, Y. Papaphilippou, D. Perini, S. Redaelli, H. Schmickler, C. Zanoni
CERN, Geneva, Switzerland
A.M. Barnyakov, A.E. Levichev, D.A. Nikiforov
BINP SB RAS, Novosibirsk, Russia
M. Fitterer, A.S. Patapenka, G. Stancari, A. Valishev
Fermilab, Batavia, Illinois, USA

Long-range beam-beam (LRBB) interactions can be a source of emittance growth and beam losses in the LHC during physics and will become even more relevant with the smaller '* and higher bunch intensities foreseen for the High Luminosity LHC upgrade (HL-LHC), in particular if operated without crab cavities. Both beam losses and emittance growth could be mitigated by compensat-ing the non-linear LRBB kick with a correctly placed current carrying wire. Such a compensation scheme is currently being studied in the LHC through a demonstration test using current-bearing wires embedded into col-limator jaws, installed either side of the high luminosity interaction regions. For HL-LHC two options are considered, a current-bearing wire as for the demonstrator, or electron lenses, as the ideal distance between the particle beam and compensating current may be too small to allow the use of solid materials. This paper reports on the ongoing activities for both options, covering the progress of the wire-in-jaw collimators, the foreseen LRBB experiments at the LHC, and first considerations for the design of the electron lenses to ultimately replace material wires for HL-LHC.

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WEOAB2

Correction of Beta-Beating Due to Beam-Beam for the LHC and Its Impact on Dynamic Aperture

sextupole, quadrupole, dynamic-aperture, luminosity

2512

L.E. Medina Medrano, J. Barranco García, X. Buffat, Y. Papaphilippou, T. Pieloni, R. Tomás
CERN, Geneva, Switzerland
J. Barranco García, T. Pieloni
EPFL, Lausanne, Switzerland
L.E. Medina Medrano
UGTO, Leon, Mexico

Funding: This work is supported by the European Circular Energy-Frontier Collider Study, H2020 programme under grant agreement no. 654305, by the Swiss State Secretariat for Education, Research and Innovation SERI, and by the Beam project (CONACYT, Mexico).
Minimization of the beta-beating at the two main interaction points of the LHC arising from the head-on and long-range beam-beam interactions can be performed by adjusting the strength of quadrupole or sextupole correctors. This compensation scheme is applied to the current LHC optics where the results show a significant reduction of the peak and RMS beta-beating; and the impact on the dynamic aperture is computed. A proposal for a similar strategy to be adopted in the High Luminosity LHC is also discussed.

Slides WEOAB2 [6.292 MB]

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WEPAB002

Pushing the MAX IV 3 GeV Storage Ring Brightness and Coherence Towards the Limit of its Magnetic Lattice

lattice, storage-ring, brightness, emittance

2557

S.C. Leemann
MAX IV Laboratory, Lund University, Lund, Sweden
W.A. Wurtz
CLS, Saskatoon, Saskatchewan, Canada

The MAX IV 3 GeV storage ring is presently being commissioned and crucial parameters such as machine functions, emittance, and stored current have either already been reached or are approaching their design specifications*. Once the baseline performance has been achieved, a campaign will be launched to further improve the brightness and coherence of this storage ring for typical x-ray users. During recent years, several such improvements have been designed**. Common to these approaches is that they attempt to improve the storage ring performance using existing hardware provided for the baseline design. Such improvements therefore present more short-term upgrades. In this paper, however, we investigate medium-term improvements assuming power supplies can be exchanged in an attempt to push the brightness and coherence of the storage ring to the limit of what can be achieved without exchanging the magnetic lattice itself. We outline optics requirements, the optics optimization process, and summarize achievable parameters.
* WEPAB075 & WEPAB076 at IPAC17
** MOPHO05 at PAC2013, TUPRI026 at IPAC'4, PRAB 19 060701 (2016)

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WEPAB006

Performance Improvements of the BESSY II Storage Ring by Optimizing the Phase Acceptance

injection, sextupole, resonance, storage-ring

2571

P. Kuske, J. Li
HZB, Berlin, Germany

Linear optics modifications in order to improve injec-tion efficiency and for the installation of two IDs in one straight section demand an optimization of the sextupole correction scheme. Four harmonic sextupole families were sufficient with the earlier 8-fold symmetric lattice. Today there are ten families of harmonic sextupole mag-nets in addition to the three families of chromatic sextu-poles. This paper describes our experimental approach to find better settings for these harmonic sextupoles based on the direct optimization of the injection efficiency with a longitudinal phase offset between storage ring and the injector - in our case a booster synchrotron. As demon-strated in the paper, the resulting improvement of the phase acceptance of the ring leads to increased momen-tum acceptance by suppressing 3rd order non-systematic resonances. This increases not only the injection effi-ciency for long bunches but also the Touschek lifetime, the largest contribution to the overall lifetime of low emittance storage rings.

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WEPAB014

PETRA III Operation

operation, photon, timing, experiment

2589

M. Bieler, I.V. Agapov, H. Ehrlichmann, J. Keil, G.K. Sahoo, R. Wanzenberg
DESY, Hamburg, Germany

At DESY the Synchrotron Light Source PETRA III offers scientists outstanding opportunities for experiments with hard X-rays of exceptionally high brilliance since 2009. This paper describes the challenges of daily operation, including different bunch patterns and their side effects, a procedure to clear spurious bunches, the operational statistics and the main contributions to down time.

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WEPAB046

New HMBA Lattice for PF-AR

lattice, injection, dynamic-aperture, emittance

2684

N. Higashi, K. Harada, Y. Kobayashi, S. Nagahashi, N. Nakamura, A. Ueda
KEK, Ibaraki, Japan

Photon Factory Advanced Ring (PF-AR) has been operated for users about 30 years from 1987. The lattice and optics are not almost changed from the original one as the TRISTAN booster ring constructed in 1984. The lattice employs FODO structure and the horizontal emittance for the 6.5 GeV user run is about 300 nmrad. In order to improve the performance of PF-AR dramatically, the full replacement of the accelerator to the ESRF type HMBA (Hybrid multi bend achromat) lattice is examined. In order to geometrically fit the new lattice to the present PF-AR tunnel, the new ring consists of 12 cells with four long straight sections. The emittance is improved to about 500 pmrad at 3 GeV. With the present user experimental hall at the north half of the ring, at least eight undulator beam lines can be constructed. The simulated dynamic aperture is about 1.5 cm at the long straight section with reasonable magnetic errors and COD correction. The Touschek lifetime is about 6 hours. The beam injection with conventional injection system causes no problem and the beam lifetime is long enough.

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WEPAB050

Commissioning of SESAME Storage Ring

storage-ring, injection, sextupole, kicker

2694

M. Attal, A.A. Abbadi, I.A. Abid, T.H. Abu-Hanieh, A. Al-Dalleh, H. Al-Mohammad, M.A. Al-Najdawi, D.S. Foudeh, A. Hamad, E. Huttel, A. Ismail, S.Kh. Jafar, K. Manukyan, I. Saleh, N.Kh. Sawai, M.M. Shehab
SESAME, Allan, Jordan

SESAME light source uses a 2.5GeV storage ring, designed to produce synchrotron light in the hard X-ray region. The 133.2 m circumference ring composed of 16 Double Bend Achromat cells with 16 dispersive straight sections, offers a maximum capacity of 25 beamlines. The storage ring is filled with electrons using an 800MeV injector of 1 Hz repetition rate. This article reports on the main results and first experience of storage ring commissioning and operation.

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WEPAB075

First Optics and Beam Dynamics Studies on the MAX IV 3 GeV Storage Ring

storage-ring, injection, emittance, synchrotron

2756

S.C. Leemann, Å. Andersson, M. Sjöström
MAX IV Laboratory, Lund University, Lund, Sweden

We present results from beam commissioning of the MAX IV 3 GeV storage ring as well as a summary of the beam dynamics studies that have so for been carried out. We report on injection and accumulation using a single dipole kicker, top-up injection, slow orbit feedback, restoring the linear optics to design, effects of in-vacuum undulators with closed gaps, and adjusting nonlinear optics to achieve design chromaticity correction as well as dynamic aperture sufficient for high injection efficiency and good Touschek lifetime.

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WEPAB090

Developments in the CLARA FEL Test Facility Accelerator Design and Simulations

FEL, laser, undulator, simulation

2787

P.H. Williams, D.J. Dunning, N. Thompson
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom

We present recent developments in the accelerator design of CLARA (Compact Linear Accelerator for Research and Applications), the proposed UK FEL test facility at Daresbury Laboratory. The requirement to co-propagate the beam with laser seeds of very different wavelengths has led to a redesign of the section preceding the undulators, with a dogleg being replaced by a chicane. Additional refinements of the facility design include the inter-undulator sections. With this finalised design we show start to FEL simulations for all beam modes envisaged.

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WEPAB114

Potential Performance Limit of Storage Rings

emittance, storage-ring, quadrupole, sextupole

2836

X. Huang
SLAC, Menlo Park, California, USA

The next generation of storage ring light sources will have significantly higher performance as multi-bend achromat cell structures are made practical with strong quadrupole and sextupole magnets. In principle the natural emittance can be made ever smaller with stronger magnets and larger rings until it reaches the true diffraction limit for hard X-rays. By considering the scaling laws of linear optics and nonlinear beam dynamics of storage rings and technical challenges, we explore the potential performance limit of future storage rings. A similar discussion may be applicable to the limit of energy frontier heavy-ion storage ring colliders.

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WEPAB129

Study of Ionization Cooling with the MICE Experiment

emittance, solenoid, experiment, detector

2874

C.T. Rogers
STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom

The international Muon Ionization Cooling Experiment (MICE) will demonstrate the ionization cooling of muons; the only known technique that can provide high brightness muon beams suitable for applications such as a Neutrino Factory or Muon Collider. MICE is underway at the Rutherford Appleton Laboratory and has recently taken the data necessary to characterise the physical processes that underlie the ionization-cooling effect. Measurements of the change in normalised transverse amplitude are presented in two configurations. The measurements of the ionization-cooling effect are discussed.

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WEPAB133

A Wedge Absorber Experiment at MICE

emittance, collider, experiment, scattering

2888

D.V. Neuffer
Fermilab, Batavia, Illinois, USA
T.A. Mohayai
IIT, Chicago, Illinois, USA
C.T. Rogers
STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
P. Snopok
Illinois Institute of Technology, Chicago, Illlinois, USA
D.J. Summers
UMiss, University, Mississippi, USA

Emittance exchange mediated by wedge absorbers is required for longitudinal ionization cooling and for final transverse emittance minimization for a muon collider. A wedge absorber within the MICE beam line could serve as a demonstration of the type of emittance exchange needed for 6-D cooling, including the configurations needed for muon colliders, as well as configurations for low-energy muon sources. Parameters for this test are explored in simulation and possible experimental configurations with simulated results are presented.

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WEPIK007

Optics Design and Observation for the Beam Abort System in SuperKEKB HER

sextupole, injection, kicker, quadrupole

2922

N. Iida, K. Egawa, Y. Enomoto, Y. Funakoshi, M. Kikuchi, T. Mimashi, Y. Ohnishi, K. Oide, Y. Suetsugu
KEK, Ibaraki, Japan

In the first commissioning of SuperKEKB, which is 'Phase 1', the new abort system is tested in the High Energy Ring (HER). There is a risk that aborted beams with low emittance and high current may destroy the window for extraction from beam pipe. In order to enlarge the aborted beam at the window, quadrupole field is applied only for the aborted beam. In the Low Energy Ring (LER), quadrupole pulsed magnets will be installed to enlarge the aborted beam, and in the HER, a pair of identical sextupole magnets is installed between the abort kickers and the extraction window. These sextrupole magnets are connected by I or 'I transformation to cancel the geometrical nonlinearity for the stored beam in the ring. This paper will report the optics design for the abort system of the HER as well as the observation of the aborted beam.

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WEPIK017

100 km CEPC Parameters and Lattice Design

luminosity, sextupole, collider, dynamic-aperture

2958

D. Wang, T.J. Bian, X. Cui, J. Gao, H. Geng, Q. Qin, B. Sha, N. Wang, Y. Wang, C.H. Yu, J.Y. Zhai, C. Zhang, Y. Zhang
IHEP, Beijing, People's Republic of China
F. Su
Institute of High Energy Physics (IHEP), People's Republic of China

The 100km double ring configuration with shared su-perconducting RF system has been defined as baseline by the circular electron positron collider (CEPC) steering committee. Based on this new scheme, we will get higher luminosity for Higgs (+170%) keeping the beam power in preliminary conceptual design report (Pre-CDR) or to reduce the beam power (19 MW) while keeping same luminosity. CEPC will be compatible with W and Z ex-periment. The luminosity for Z is designed at the level of 1035 cm^-2s⁻¹. The requirement for the energy acceptance of Higgs has been reduced to 1.5% by enlarging the ring to 100 km. The optics of arc and final focus system (FFS) with crab sextupoles has been designed, and also some primary dynamic aperture (DA) results were introduced.

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WEPIK018

Optics Design for Cepc Double Ring Scheme

lattice, interaction-region, emittance, sextupole

2962

Y. Wang, T.J. Bian, J. Gao, H. Geng, B. Sha, D. Wang, C.H. Yu, Y. Zhang
IHEP, Beijing, People's Republic of China
F. Su
Institute of High Energy Physics (IHEP), People's Republic of China

CEPC is a future Circular Electron and Positron Collider proposed by China to mainly study the Higgs boson. Its baseline scheme is double ring scheme and alternative scheme is partial double ring scheme. This paper will present the optics design for the main ring of double ring scheme. CEPC will also work as W and Z factories. Compatible optics design for W and Z mode will be presented as well.

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WEPIK030

Experimental Validation of the Achromatic Telescopic Squeezing Scheme at the LHC

collimation, insertion, injection, luminosity

2992

S.D. Fartoukh, R. Bruce, F.S. Carlier, J.M. Coello de Portugal, A. Garcia-Tabares, E.H. Maclean, L. Malina, A. Mereghetti, D. Mirarchi, T. Persson, M. Pojer, L. Ponce, S. Redaelli, B. Salvachua, P.K. Skowroński, M. Solfaroli, R. Tomás, D. Valuch, A. Wegscheider, J. Wenninger
CERN, Geneva, Switzerland

The Achromatic Telescopic Squeezing (ATS) [1] scheme offers new techniques to deliver unprecedentedly small beam spot size at the interaction points of the ATLAS and CMS experiments of the LHC, while perfectly controlling the chromatic properties of the corresponding optics (linear and non-linear chromaticities, off-momentum beta-beating, spurious dispersion induced by the crossing bumps). The first series of beam tests with ATS optics were achieved during the LHC Run I (2011/2012) for a first validation of the basics of the scheme at small intensity. In 2016, a new generation of more performing ATS optics was developed and more extensively tested in the machine, still with probe beams for optics measurement and correction at β^*=10 cm, but also with a few nominal bunches to establish first collisions at nominal β^* (40 cm) and beyond (33 cm), and to analysis the robustness of these optics in terms of collimation and machine protection. The paper will highlight the most relevant and conclusive results which were obtained during this second series of ATS tests.
[1] S. Fartoukh , Phys. Rev. ST Accel. Beams 16, 111002

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WEPIK057

Transverse Resonance Island Buckets as Bunch Separation Scheme

injection, simulation, sextupole, operation

3059

P. Goslawski, A. Jankowiak, F. Kramer, M. Ries, M. Ruprecht, G. Wüstefeld
HZB, Berlin, Germany

Funding: Supported by the BMBF
Beam storage close to a tune resonance (Qx = 1/3,1/4) can generate transverse resonance island buckets in the x,x' phase space providing a second stable island orbit winding around the standard orbit. The two orbits are well separated, with good life time and stability. Successful user experiments have been conducted at BESSY II and the Metrology Light Source (MLS) *,** with such an operation mode. We discuss the required beam optics setup, the TopUp injection process and present successful measurements taken at photon beamlines at BESSY II.
* THPMR017, P.Goslawski et al., IPAC2016, Busan, Korea
** MOPWA021, M.Ries et al., IPAC2015, Richmond, USA

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WEPIK068

Non-Linear Beam Dynamics Studies of the CLIC Damping Wiggler Prototype

wiggler, operation, storage-ring, damping

3087

J. Gethmann, A. Bernhard, E. Blomley, E. Huttel, A.-S. Müller, A.I. Papash, M. Schedler
KIT, Karlsruhe, Germany
Y. Papaphilippou, P. Zisopoulos
CERN, Geneva, Switzerland
K. Zolotarev
BINP SB RAS, Novosibirsk, Russia

Funding: Julian Gethmann acknowledges the support by the DFG-funded Doctoral School Karlsruhe School of Elementary and Astroparticle Physics: Science and Technology
First beam dynamics studies of a damping wiggler prototype for the CLIC damping rings have been carried out at the KIT storage ring. Effects of the 2.9 T superconducting wiggler on the electron beam in the 2.5 GeV standard operation mode have been measured and compared with theoretical predictions. Higher order multipole components were investigated using local orbit bump measurements. Based on these findings the simulation models for the storage ring optic have been adjusted. The refined optics model has been applied to the 1.3 GeV, low-operation case. This case will be used to experimentally benchmark beam dynamics simulations involving strong wiggler fields and dominant collective effects. We present these measurements, comparisons and the findings of the simulations with the updated low-mode optics model.

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WEPIK093

New Methods for Measurement of Nonlinear Errors in LHC Experimental IRs and Their Application in the HL-LHC

dipole, resonance, dynamic-aperture, collider

3155

E.H. Maclean, F.S. Carlier, J.M. Coello de Portugal, A. Garcia-Tabares, M. Giovannozzi, L. Malina, T. Persson, P.K. Skowroński, R. Tomás
CERN, Geneva, Switzerland

Studies of nonlinear errors in LHC experimental insertions (IRs) during Run 1 were based upon feed-down to tune and coupling from the crossing angle orbit bumps. Useful for validating the magnetic model, this method alone is of limited use to understand discrepancies between magnetic and beam-based measurement. Feed-down from high-order multipoles is also difficult to observe. During Run 2 several alternative methods were tested in the LHC. This paper summarizes the results of these tests, and comments on their potential application to the High-Luminosity LHC upgrade.

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WEPVA040

Design of Imaginary Transition Gamma Booster Synchrotron for the Jefferson Lab EIC (JLEIC)

injection, ion, booster, lattice

3350

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 U.S. Government retains a non- exclusive, world-wide license to publish or reproduce this manuscript, or allow others to do so, for U.S. Government purposes.
Baseline design of the JLEIC booster synchrotron is presented. Its aim is to inject and accumulate heavy ions and protons at 285 MeV, to accelerate them to about 7 GeV, and finally to extract them into the ion collider ring. The Figure-8 ring features two 260 deg. achromatic arcs configured with negative momentum compaction lattices, designed to avoid transition crossing for all ion species during the course of acceleration. The arc optics is based on a lightly perturbed 90 deg. FODO, with missing dipoles every fourth half-cell, where the horizontal dispersion is driven partly negative for the inward bending arc leading to negative momentum compaction. The lattice also features a specialized high dispersion injection insert optimized to facilitate the transverse phase-space painting in both planes for multi-turn ion injection. Furthermore, the lattice has been optimized to mitigate magnet error sensitivity and to ease chromaticity correction with two families of sextupoles in each plane. The booster ring is configured with super-ferric, 3 Tesla bends. We are presently launching optimization of the booster synchrotron design to operate in the extreme space-charge dominated regime.

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WEPVA055

Pre Orbit Correction Based on Tunnel Level Measurement in SuperKEKB

alignment, coupling, factory, emittance

3385

A. Morita, H. Koiso, Y. Ohnishi, H. Sugimoto
KEK, Ibaraki, Japan

The SuperKEKB accelerator tunnel has about 30mm displacement in the vertical direction. From the result of optics correction simulation with the tunnel displacement, it was decided that the beamline components align against the smoothed line of the measured tunnel level in order to save the alignment cost and time. In order to compensate the large tunnel displacement, the pre orbit correction based on the tunnel level measurement is applied at the beginning of the phase-1 commissioning, and the beam circulation is achieved with the small number of magnet adjustments. We report the result of the pre orbit correction.

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WEPVA061

High-Precision Pattern Power Supply of Kicker Magnet for Multi-Beamline Operation at SACLA

operation, power-supply, kicker, electron

3404

C. Kondo, T. Fukui, T. Hara, T. Inagaki, Y. Otake, H. Tanaka
RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan
K. Fukami
JASRI/SPring-8, Hyogo-ken, Japan
H. Kawaguchi, Y. Kawaguchi
Nichicon (Kusatsu) Corporation, Shiga, Japan
S. Nakazawa
SES, Hyogo-pref., Japan

At the Japanese XFEL facility SACLA, two XFEL beamlines (BL2 and BL3) and an injection line to the SPring-8 storage ring are switched by a kicker magnet. This multi-beamline operation has been tested since February 2015, however, CSR effects at a dogleg beam transport to BL2 with a deflecting angle of 3 degree currently limit the peak current of the electron beam. In order to suppress and cancel out the CSR effects, new beam optics is introduced for the dogleg in January 2017. In the new optics, a deflecting angle of the first kicker magnet is increased to 1.5 degree, which is three times larger than that of the old optics. To drive the kicker magnet, a high-power pattern power supply has been developed. To achieve the maximum output of 300 A and 1 kV, SiC MOSFETs are used as switching modules. The newly developed power supply can generate bipolar trapezoidal current waveforms at 60 Hz, and the amplitude and polarity of each waveform are controlled from pulse to pulse according to the beam energy and destination. The target stability is 10 ppm (peak to peak). In this presentation, we report the design and operation results of the newly developed pattern power supply.

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THPAB049

Progress in the Understanding of the Performance Limitations in the CERN Low Energy Ion Ring

resonance, ion, sextupole, space-charge

3819

A. Huschauer, H. Bartosik, S. Hancock, V. Kain
CERN, Geneva, Switzerland

The performance of heavy ion beams in the CERN Low Energy Ion Ring is mainly limited by beam loss occuring during the radio-frequency capture and the first part of acceleration. Since October 2015, the driving mechanism of these losses has been studied in detail and an interplay of direct space charge forces and excited betatron resonances was identified as the most plausible explanation of the phenomenon. In this paper we summarize the current understanding of the loss mechanism by presenting recent experimental and simulation studies. We discuss strategies to mitigate beam loss and further improve the performance of the accelerator in the future.

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THPAB090

Algorithm to Calculate Off-Plane Magnetic Field From an on-Plane Field Map

simulation, dipole, proton, extraction

3928

N. Tsoupas, J.S. Berg, F. Méot, V. Ptitsyn, D. Trbojevic
BNL, Upton, Long Island, New York, USA
S.A. Kahn
Muons, Inc, Illinois, USA
S. Machida
STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
We present an algorithm to calculate the off-plane components of the magnetic field from the on-plane components of the magnetic field which are measured on a grid of the plane. The algorithm, which is a general one and it is not restricted on a mid-plane symmetry, is based on the Taylor series expansion of the magnetic field components in terms of the normal to the plane location. The coefficients of the Taylor series expansion are expressed in terms of the on-plane derivatives of the field components which are generated by the measured magnetic field components on the grid of the plane. The algorithm is use in the RATRACE computer code[*] and has been used[**] on a dipole magnet with median plane symmetry.
* S.B. Kowalski and H.A. Enge The Ion-Optical Program Raytrace NIM A258 (1987) 407
** N. Tsoupas et. al. Effects of Dipole Magnet Inhomogeneity on the Beam Ellipsoid NIM A258 (1987) 421-425

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THPVA015

Application of Modified KV-Distributions to Study the Phase Portrait Transformation of Intense Bunches in Magnetic Fields

emittance, cyclotron, electronics, multipole

4448

H.Y. Barminova
MEPhI, Moscow, Russia

Modified KV-distribution functions are applied to study the intense bunch behavior in transverse magnetic fields. The functions used allow to consider both the emittance-dominated and charge-dominated bunches in 2D and 3D approximations. Peculiarities of the bunch phase portrait transformation in magnetic fields of achromatic structures are discussed. Particular case is proved to exist characterized by the absence of the emittance transfer.

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THPVA032

Space-Charge Simulation of Integrable Rapid Cycling Synchrotron

lattice, sextupole, space-charge, resonance

4501

J.S. Eldred, A. Valishev
Fermilab, Batavia, Illinois, USA

Integrable optics is an innovation in particle accelerator design that enables strong nonlinear focusing without generating parametric resonances. We use a Synergia space-charge simulation to investigate the application of integrable optics to a high-intensity hadron ring that could replace the Fermilab Booster. We find that incorporating integrability into the design suppresses the beam halo generated by a mismatched KV beam. Our integrable rapid cycling synchrotron (iRCS) design includes other features of modern ring design such as low momentum compaction factor and harmonically canceling sextupoles. Experimental tests of high-intensity beams in integrable lattices will take place over the next several years at the Fermilab Integrable Optics Test Accelerator (IOTA) and the University of Maryland Electron Ring (UMER).

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THPVA079

First Optics Design and Beam Performance Simulation of PRAE: Platform for Research and Applications With Electrons at Orsay

electron, instrumentation, gun, detector

4637

A. Faus-Golfe, S. Barsuk, B. Borgo, D. Douillet, M. El Khaldi, L. Garolfi, A. Gonnin, M. Langlet, P. Lepercq, M. Omeich, V. Puill, C. Vallerand
LAL, Orsay, France
P. Ausset, M. Ben Abdillah, S. Blivet, P. Duchesne, B. Genolini, M. Hoballah, G. Hull, R. Kunne, C. Le Galliard, J. Lesrel, D. Marchand, E. J-M. Voutier
IPN, Orsay, France
A. Hrybok, A. Pastushenko
National Taras Shevchenko University of Kyiv, Radiophysical Faculty, Kiev, Ukraine
A. Vnuchenko
IFIC, Valencia, Spain

The PRAE project aims at creating a multidisciplinary R&D facility in the Orsay campus gathering various scientific communities involved in radiobiology, subatomic physics, instrumentation and particle accelerators around an electron accelerator delivering a high-performance beam with energy up to 70 MeV and later 140 MeV, in order to perform a series of unique measurements and future challenging R&D. In addition PRAE will provide a major education and training asset for students and engineers yielding a regional instrument of advanced technology at the heart of the scientific, technological and academic complex of the Paris-Saclay University. In this paper we report the first optics design and performance evaluations of such a multidisciplinary machine, including a first description of future experiments and the required beam instrumentation.

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THPVA112

Progress of the Beamline and Energy Selection System for HUST Proton Therapy Facility

proton, cyclotron, dipole, scattering

4719

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

Funding: Work supported by The National Key Research and Development Program of China, with grant No. 2016YFC0105305
HUST proton therapy facility is a 5 years National Key Research and Development Program of China. This facil-ity is based on an isochronous superconducting cyclotron with two gantry treatment-rooms and one fixed beamline treatment station. The status for physical and technical design of the beamline and Energy Selection System (ESS) will be introduced in this paper.

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THPVA140

Superconducting Gantry Design for Proton Tomography

proton, dipole, quadrupole, linac

4795

E. Oponowicz, H.L. Owen
UMAN, Manchester, United Kingdom

Precise proton therapy planning can be assisted by augmenting conventional medical imaging techniques with proton computed tomography (pCT). For adults this requires an incident proton energy up to around 330 MeV, requiring superconducting magnets if an imaging gantry is to replace a conventional 230-250 MeV gantry in the same space. Here we present optics considerations for a superconducting gantry to deliver 330 MeV protons within the context of the future Christie Hospital proton therapy centre, where it is proposed to increase the proton energy in the future with a booster linac.

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