IPAC2018 - List of Keywords (quadrupole)

Paper	Title	Other Keywords	Page
MOPMF010	Measurement and Simulation of Betatron Coupling Beam Transfer Function in RHIC	coupling, betatron, simulation, experiment	99
	Y. Luo, W. Fischer, A. Marusic, M.G. Minty BNL, Upton, Long Island, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. Transfer function measurements are important for characterizing betatron tunes, betatron coupling, and beam spectrum in the routine operation of the Relativistic Heavy Ion Collider (RHIC). To counteract the linear betatron coupling, we developed a technique to continuously measure the betatron coupling coefficient with a base band phase lock loop tune meter in 2006. Based on this technique, we demonstrated and built a robust tune/coupling feedback in RHIC. In this article, we revisit the BTF measurement with betatron coupling to benchmark our BTF simulation code. We also compared the values of eigenmode projection ratios from BTF with those calculated with the single particle model.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMF010
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MOPMF023	Updates on the Optic Corrections of FCC-hh	coupling, injection, dipole, interaction-region	133
	D. Boutin, A. Chancé, B. Dalena CEA/IRFU, Gif-sur-Yvette, France B.J. Holzer, D. Schulte CERN, Geneva, Switzerland
	The FCC-hh (Future Hadron-Hadron Circular Collider) is one of the options considered for the next generation accelerator in high-energy physics as recommended by the European Strategy Group, and the natural evolution of existing LHC. The evaluation of the various magnets mechanical error and field error tolerances in the arc sections of FCC-hh, as well as an estimation of the correctors strengths necessary to perform the error corrections, are important aspects of the collider design. In this study recommended values for the mechanical errors, dipole and quadrupole field errors tolerances are proposed, with the possible consequences on the correctors technological choice and on the beam screen design. Advanced correction schemes of the linear coupling (with skew quadrupoles) and of the beam tunes (with normal quadrupoles) are discussed. Also a combined correction scheme including the interaction regions is tested.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMF023
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MOPMF025	Overview of Arc Optics of FCC-hh	dipole, optics, insertion, sextupole	141
	A. Chancé, B. Dalena CEA/IRFU, Gif-sur-Yvette, France D. Boutin CEA/DRF/IRFU, Gif-sur-Yvette, France B.J. Holzer, 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 options considered for the next generation accelerator in high-energy physics as recommended by the European Strategy Group. In this overview the status and the evolution of the design of optics integration of FCC-hh are described, focusing on design of the arcs, alternatives, and tuning procedures.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMF025
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MOPMF063	Asynchronous Beam Dump Tests at LHC	proton, extraction, beam-losses, operation	265
	C. Wiesner, W. Bartmann, C. Bracco, E. Carlier, L. Ducimetière, M.I. Frankl, M.A. Fraser, B. Goddard, C. Heßler, T. Kramer, A. Lechner, N. Magnin, V. Senaj, D. Wollmann CERN, Geneva, Switzerland
	The detailed understanding of the beam-loss pattern in case of an asynchronous beam dump is essential for the safe operation of the future High Luminosity LHC (HL-LHC) with nearly twice the nominal LHC beam intensity, leading to correspondingly higher energy deposition on the protection elements. An asynchronous beam dump is provoked when the rise time of the extraction kickers is not synchronized to the 3 us long particle-free abort gap. Thus, particles that are not absorbed by dedicated protection elements can be lost on the machine aperture. Since asynchronous beam dumps are among the most critical failure cases of the LHC, experimental tests at low intensity are performed routinely. This paper reviews recent asynchronous beam dump tests performed in the LHC. It describes the test conditions, discusses the beam-loss behaviour and presents simulation and measurement results. In particular, it examines a test event from May 2016, which led to the quench of four superconducting magnets in the extraction region and which was studied by a dedicated beam experiment in December 2017.
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MOPMF088	Preparation Activity for the Siddharta-2 Run at DAΦNE	experiment, luminosity, controls, feedback	334
	C. Milardi, D. Alesini, S. Bini, O.R. Blanco-García, M. Boscolo, B. Buonomo, S. Cantarella, S. Caschera, A. D'Uffizi, A. De Santis, G.O. Delle Monache, D.G.C. Di Giulio, G. Di Pirro, A. Drago, L.G. Foggetta, A. Gallo, R. Gargana, A. Ghigo, S. Guiducci, S. Incremona, F. Iungo, C. Ligi, M. Maestri, A. Michelotti, L. Pellegrino, R. Ricci, U. Rotundo, L. Sabbatini, C. Sanelli, G. Sensolini, A. Stecchi, A. Stella, A. Vannozzi, M. Zobov INFN/LNF, Frascati (Roma), Italy G. Castorina INFN-Roma1, Rome, Italy J. Chavanne, G. Le Bec, P. Raimondi ESRF, Grenoble, France
	DAΦNE, the Frascati lepton collider working at the c.m. energy of the F resonance, continues to be a very suitable infrastructure to realize experiments aimed at studying elementary particles and nuclear physics. The motivations of this long lasting interest are related to the DAΦNE ability of increasing its performances in terms of luminosity thanks to the innovative Crab-Waist collision scheme. In this framework, a new run for the SIDDHARTA-2 experiment has been planned in the year 2019. The detector presently installed in the interaction region, KLOE-2, will be removed and a new low-beta session, equipped with new permanent magnets quadrupoles, will be installed. Diagnostics tools will be improved especially the ones used to keep under control the beam-beam interaction. The horizontal feedback in the positron ring will be potentiated in order to achieve a higher positron current. The design and development work done in view of the SIDDHARTA-2 run is presented and discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMF088
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MOPMK001	Optics for RF Acceleration Section for the High Energy Large Hadron Collider	optics, cavity, dipole, instrumentation	345
	L. van Riesen-Haupt, J.L. Abelleira University of Oxford, Oxford, United Kingdom J.L. Abelleira, E. Cruz Alaniz, P. Martinez Mirave, A. Seryi JAI, Oxford, United Kingdom M. Hofer, F. Zimmermann CERN, Geneva, Switzerland D. Zhou KEK, Ibaraki, Japan
	Funding: Work supported by the Horizon 2020 project EuroCirCol, grant 654305 and by the Science and Technology Facilities Council As part of the FCC study, the design of the High Energy LHC (HE-LHC) is addressed. A proposed layout for the interaction region for the containing the radio frequency (RF) cavities and various beam instrumentation will be discussed. The higher energy requires more RF cavities, which strongly restricts the space available for optics and instrumentation. Another challenge arises because the beam rigidity increases whilst the LHC geometry has to be conserved. To this end, next generation dipoles have to be used in order to achieve sufficient beam to beam separation. A design that provides enough beam stay clear (BSC) in all the magnets will be presented. The design introduces an additional quadrupole on either side of the RF region to be used for phase advance adjustments that can increase the dynamic aperture.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMK001
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MOPMK003	Energy Deposition Studies and Luminosity Evolution for the Alternative FCC-hh Triplet	optics, luminosity, radiation, dipole	352
	J.L. Abelleira, E. Cruz Alaniz, A. Seryi, L. van Riesen-Haupt JAI, Oxford, United Kingdom J.L. Abelleira, E. Cruz Alaniz, L. van Riesen-Haupt University of Oxford, Oxford, United Kingdom
	Funding: Work supported by EuroCircol, EU's Horizon 2020 grant No 654305 & STFC grant to the John Adams Institute The international Future Circular Collider (FCC) study comprises the development of a new scientific structure in a tunnel of 100 km. This will allow the installation of a proton collider with a centre of mass energy of 100 TeV, called FCC-hh. An alternative design of the final focus triplet for the FCC-hh has been developed in parallel to the alternative one, and adapted to the constraint of a free length (L*) of 40 m. We discuss in this paper the energy deposition issues as well as the luminosity evolution for two different optics choices: round and flat beams.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMK003
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MOPMK005	HE-LHC Final Focus: Flat Beam Parameters and Energy Deposition Studies	optics, luminosity, cavity, dipole	356
	J.L. Abelleira, E. Cruz Alaniz, A. Seryi, L. van Riesen-Haupt JAI, Oxford, United Kingdom J.L. Abelleira, E. Cruz Alaniz, L. van Riesen-Haupt University of Oxford, Oxford, United Kingdom
	Funding: Work supported by EuroCircol, EU's Horizon 2020 grant No 654305 & STFC grant to the John Adams Institute The High Energy LHC (HE-LHC) project is studying the feasibility of a new proton-proton collider with a beam energy of 13.5 TeV. The nominal optics features a β^* of 0.25 m and crab-cavities. Here we present a flat-beam optics that can be used with a non-zero crossing angle, in the absence of crab cavities. This is followed by energy deposition studies for the superconducting quadrupoles and dipole separators. The total dose in these magnets coming from the collision debris is evaluated.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMK005
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MOPMK006	Experimental Interaction Region Optics for the High Energy LHC	optics, dipole, shielding, dynamic-aperture	360
	L. van Riesen-Haupt, J.L. Abelleira University of Oxford, Oxford, United Kingdom J.L. Abelleira, E. Cruz Alaniz, A. Seryi JAI, Oxford, United Kingdom M.P. Crouch, F. Zimmermann CERN, Geneva, Switzerland D. Zhou KEK, Ibaraki, Japan
	Funding: Work supported by the Horizon 2020 project EuroCirCol, grant 654305 and by the Science and Technology Facilities Council The High Energy LHC (HE-LHC) is one option for a next generation hadron collider explored in the FCC-hh program. The core concept of the HE-LHC is to install FCC-hh technology magnets in the LHC tunnel. The higher beam rigidity and the increased radiation debris, however, impose severe challenges on the design of the triplet for the low beta insertions. In order to achieve 25 cm β^* optics and survive a lifetime integrated luminosity of 10 ab-1 a new longer triplet was designed that provides sufficient shielding and enough beam stay clear. This triplet has been designed using complimentary radiation studies to optimise the shielding that will also be presented. The optics for the rest of the interaction region had to be adjusted in order to host this more rigid beam and longer triplet whilst leaving enough room for crab cavities. Moreover, the effects non-linear errors in this triplet have on the dynamic aperture will be outlined.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMK006
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MOPMK007	An Optimised Triplet for the Final Focus of the FCC-HH with a 40m Final Drift	optics, luminosity, collider, injection	364
	L. van Riesen-Haupt, J.L. Abelleira University of Oxford, Oxford, United Kingdom J.L. Abelleira, E. Cruz Alaniz, A. Seryi JAI, Oxford, United Kingdom
	Funding: Work supported by the Horizon 2020 project EuroCirCol, grant 654305 and by the Science and Technology Facilities Council The sizes of the beta functions in the final focus triplet of a synchrotron collider have a great impact on the chromaticity and dynamic aperture of the machine. These beta functions are proportional to the square of the length of the final drift so it is desirable to keep it as short as possible whilst leaving enough room for the experiment. In the latest design of the FCC-hh this drift was reduced from 45 m to 40 m. In the following an alternative final focus for this new design will be presented. The effects this change has on the interaction region will examined and discussed.
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MOPMK012	Electron Cloud Studies in FCC-ee	electron, collider, simulation, vacuum	374
	E. Belli Sapienza University of Rome, Rome, Italy P. Costa Pinto, G. Rumolo, T.F. Sinkovits, M. Taborelli CERN, Geneva, Switzerland M. Migliorati INFN-Roma1, Rome, Italy
	Electron cloud effects are one of the most critical aspects for the LHC and the future circular colliders. In the frame of the electron-positron collider FCC-ee, an estimation of the electron cloud build up in the machine will be discussed in this paper. A preliminary evaluation of the heat load in the arc components and interaction region magnets will be presented, together with possible mitigation strategies.
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MOPML039	Comparison of Two Types of Steerers Applied in Proton Therapy Gantry	proton, simulation, superconductivity, radiation	488
	Z.F. Zhao, Q.S. Chen, S. Hu, X. Liu, B. Qin, W. Wei 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
	A proton therapy project HUST-PTF (HUST Proton Therapy Facility) based on a 250MeV isochronous superconducting cyclotron is under development in Huazhong University of Science and Technology (HUST). Based on the optics design of the gantry, the steering magnets need to be placed in a compact structure, as well as meet the magnetic field requirement with a maximum deflection angle of ±5mrad@250MeV. In the paper, two types of steerers (O-shape and H-shape) were introduced and discussed in detail. The magnetic fringe field interference effects between quadrupoles and steerers were studied by using OPERA/TOSCA code. The result based on the contrastive analysis will give us a valuable reference to choose suitable steerers for proton therapy beamline.
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TUPAF028	Energy Deposition Studies and Analysis of the Quench Behavior in the Case of Asynchronous Dumps During 6.5 TeV LHC Proton Beam Operation	simulation, superconducting-magnet, proton, kicker	736
	M.I. Frankl, W. Bartmann, M. Bednarek, C. Bracco, A. Lechner, A.P. Verweij, C. Wiesner, D. Wollmann CERN, Geneva, Switzerland
	The CERN LHC beam dumping system comprises a series of septa and fast-pulsed kicker magnets for extracting the stored proton beams to the external beam dumps. Different absorbers in the extraction region protect superconducting magnets and other machine elements in case of abnormal beam aborts, where bunches are swept across the machine aperture. During Run 2 of the LHC, controlled beam loss experiments were carried out at 6.5 TeV probing the particle leakage from protection devices under realistic operation conditions. This paper presents particle shower simulations analyzing the energy deposition in superconducting coils and assessing if the observed magnet quenches are compatible with the presently known quench limits.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAF028
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TUPAF032	Beam Transfer Line Design to the SPS Beam Dump Facility	target, proton, experiment, extraction	751
	Y. Dutheil, J. Bauche, M. Calviani, L.A. Dougherty, M.A. Fraser, B. Goddard, C. Heßler, J. Kurdej, E. Lopez Sola CERN, Geneva, Switzerland
	Studies for the SPS Beam Dump Facility (BDF) are ongoing within the scope of the Physics Beyond Collider project. The BDF is a proposed fixed target facility to be installed in the SPS North Area, to accommodate the SHiP experiment (Search for Hidden Particles), which is most notably aiming at studying hidden sector particles. This experiment requires a high intensity slowly extracted 400 GeV proton beam with 4·10¹³ protons per 1 s spill to achieve 4·10¹⁹ protons on target per year. The extraction and transport scheme will make use of the first 600 m of the existing North Area extraction line. In this paper, we will present the design of the additional 600 m of transfer line towards BDF branching off from the existing line and discuss the detailed design of the BDF beam line, its components and optics. We present the latest results on the study and design of a new laminated Lambertson splitter magnet to provide fast switch between the current North Area experiments and the BDF. The latest specification of a dipole dilution system used to reduce the local peak power of the beam on the target is also presented.
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TUPAF035	Observations of SPS Slow-Extracted Spill Quality Degradation and Possible Improvements	extraction, power-supply, simulation, experiment	761
	F.M. Velotti, H. Bartosik, K. Cornelis, M.A. Fraser, B. Goddard, S. Hirlaender, V. Kain, O. Michels, M. Pari CERN, Geneva, Switzerland
	The SPS delivers slow extracted proton and heavy ion spills of several seconds to the North Area fixed target experiments with a very high duty factor. Reduced machine reproducibility due to magnetic history and power supply ripples on the main circuits lead however to frequent degradation of the spill duty factor. In this paper, the measured effect of the SPS magnetic history on spill quality and principal machine parameters is presented. Another detailed measurement campaign was aimed at characterising the frequency content and response of the spill to noise on the main power supplies ripples. The main findings of this study will also be reported. Finally, simulations of possible improvements based on the data acquired are discussed, as well as an extrapolation to the possible spill quality after the implementation of the improvements.
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TUPAF050	Beam Dynamics Simulations of the Effect of Power Converter Ripple on Slow Extraction at the CERN SPS	extraction, emittance, sextupole, experiment	818
	J. Prieto, M.A. Fraser, B. Goddard, V. Kain, L.S. Stoel, F.M. Velotti CERN, Geneva, Switzerland
	The SPS provides slowly extracted protons at 400 GeV/c to CERN's North Area Fixed Target experiments over spills of duration from 1-10 seconds. Low frequency ripple on the current in the main magnets originating from their power converters is a common issue that degrades the slow-extracted spill quality. In order to better understand how the stability of the power converters affects losses, beam emittance and spill quality, particle tracking simulations were carried out using MAD-X and compared to measurements, with the impact of each magnet circuit investigated systematically. The implications for the performance of the SPS slow extraction are discussed.
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TUPAF077	Beam Optics Measurements in Medium Energy Beam Transport at PIP-II Injector Test Facility	optics, rfq, beam-transport, emittance	909
	A. Saini, J.-P. Carneiro, B.M. Hanna, L.R. Prost, A.V. Shemyakin Fermilab, Batavia, Illinois, USA V.L. Sista BARC, Mumbai, India
	Funding: This manuscript has been authored by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the U.S. Department of Energy, Office of Science, Office of High Energy Physics The Proton Improvement Plan-II Injector Test (PIP2IT) is an accelerator test facility under construction at Fermilab that will provide a platform to demonstrate critical technologies and concept of the front-end of the PIP-II linear accelerator (linac). The PIP2IT warm front-end comprises a H⁻ ion source capable of delivering 15 mA, 30 keV DC or pulsed beam, a Low Energy Beam Transport (LEBT), a 162.5 MHz, CW Radio Frequency Quadrupole (RFQ) that accelerates the beam to 2.1 MeV and, a 14 m medium energy beam transport (MEBT). Presently, beamline up to the MEBT has been commissioned and operates routinely at the PIP2IT facility. In this paper, we discuss beam measurements performed at the MEBT to analyze beam emittance and its RMS sizes along the MEBT. In addition, beam based calibration of the beamline elements using differential trajectory measurement is also presented.
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TUPAF080	Final Design of the FoS Alvarez-Cavity-Section for the Upgraded UNILAC	cavity, DTL, operation, simulation	920
	M. Heilmann, X. Du, L. Groening, M. Kaiser, S. Mickat, C. Mühle, A. Rubin, V. Srinivasan GSI, Darmstadt, Germany A. Seibel IAP, Frankfurt am Main, Germany
	The final design describes the First-of-Series (FoS) Alvarez-Cavity-section of the first tank being part of the new post-stripper DTL of the UNILAC. The FoS-cavity has an input energy of 1.358 MeV/u with 11 drift tubes (including quadrupole singlets) in a total length of 1.9 m and a diameter of 2 m with an operation frequency of 10⁸.4 MHz. The drift tubes will have a new shape profile at the end plates. The single layered quadruple singlets inside the drift tubes are pulsed with 10 Hz and will have a maximum field gradient of 51 T/m. The new drift tube design combines the new shape profile with the transverse and longitudinal installation space of the magnet. The FoS Alvarez-cavity will be part of the first section of the new Alvarez DTL. It shall be operated at nominal RF- and magnetic fields prior to procurement of the series.
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TUPAK001	Progress of the Modulated 325 MHz Ladder RFQ	rfq, linac, proton, operation	952
	M. Schuett, U. Ratzinger, M. Syha IAP, Frankfurt am Main, Germany
	Funding: BMBF 05P15RFRBA Based on the positive results of the unmodulated 325 MHz Ladder-RFQ prototype from 2013 to 2016, we developed and designed a modulated 3.3 m Ladder-RFQ. The unmodulated Ladder-RFQ features a very constant voltage along the axis. It accepted 3 times the operating power of which is needed in operation. That level corresponds to a Kilpatrick factor of 3.1 with a pulse length of 200 μs. The 325 MHz RFQ is designed to accelerate protons from 95 keV to 3.0 MeV according to the design parameters of the proton linac within the FAIR project. This particular high frequency creates difficulties for a 4-ROD type RFQ, which triggered the development of a Ladder RFQ with its high symmetry. The results of the unmodulated prototype have shown, that the Ladder-RFQ is a suitable candidate for that frequency. The duty cycle is suitable up to 5%. The basic design and tendering of the RFQ has been successfully completed in 2016. Manufacturing will be completed in May 2018. We will show the latest results of manufacturing, beam dynamics simulations for the matching between LEBT and RFQ. Journal of Physics: Conf. Series 874 (2017) 012048 **Proceedings of LINAC2016, East Lansing, TUPLR053
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TUPAK016	Commissioning of the Diagnostic Beam Line for the Muon RF Acceleration with H⁻ Ion Beam Derived from the Ultraviolet Light	acceleration, diagnostics, experiment, MMI	997
	Y. Nakazawa, H. Iinuma Ibaraki University, Ibaraki, Japan N. Kawamura, T. Mibe, M. Otani, T. Yamazaki KEK, Ibaraki, Japan R. Kitamura University of Tokyo, Tokyo, Japan Y. Kondo JAEA/J-PARC, Tokai-mura, Japan N. Saito J-PARC, KEK & JAEA, Ibaraki-ken, Japan Y. Sue Nagoya University, Graduate School of Science, Chikusa-ku, Nagoya, Japan
	Funding: This work is supported by JSPS KAKENHI Grant Numbers JP15H03666, JP16H03987, and JP16J07784. A muon LINAC is under development for a precise measurement of muon g-2 / EDM at J-PARC. We conducted an experiment of a muon RF acceleration on October and December 2017. The surface muon beam is irradiated to a metal degrader to generate slow negative muonium. The slow negative muoniums are accelerated to 90 keV with an electrostatic accelerator and an RFQ. Prior to muon RF acceleration, we conducted a commissioning of the diagnostic beam line consisting of two quadrupole magnets and a bending magnet. The ultraviolet light is irradiated to an aluminum foil and H⁻ ion is generated. It simulates a negative muonium and is accelerated with an electrostatic accelerator. This system allowed us to check operation for the diagnostic beam line, which is essential task for transportation and momentum selection of the negative muonium. In this paper, I would like to report the performance evaluation of the diagnostic beam line by H⁻ ions.
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TUPAK018	Study on the Collimation Method for a Future Proton-Proton Collider	collimation, proton, insertion, superconducting-magnet	1004
	J.Q. Yang, Y. Bao, J.Y. Tang, J.Y. Tang, Y. Zou IHEP, Beijing, People's Republic of China
	As the second phase of CEPC-SPPC project, SPPC (Super Proton-Proton Collider) is to explore new physics beyond the standard model in the energy frontier with a center-of-mass energy of 75 TeV. In order to handle extremely-high stored energy in beam, the collimation system of extremely high efficiency is required for safe operation. SPPC has been studying a collimation method which arranges both the transverse and momentum collimations in one long straight section. In this way, the downstream momentum collimation section can clean those particles related to the single diffractive effect in the transverse collimation section thus eliminate beam losses in the arc section. In addition, one more collimation stage is obtained with use of special superconduct-ing quadrupoles in the transverse collimation section. Multiple particle simulations have proven the effectiveness of the methods. This paper presents the study results on the collimation scheme.
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TUPAL011	Low Power Test and Tuning of the LEAF RFQ	rfq, cavity, dipole, operation	1028
	L. Lu, T. He, Y. He, W. Ma, L.B. Shi, L.P. Sun, C.C. Xing, X.B. Xu, L. Yang, H.W. Zhao IMP/CAS, Lanzhou, People's Republic of China
	A continuous wave (CW) four-vane radio frequency quadrupole (RFQ) accelerator is under construction for the Low Energy Accelerator Facility (LEAF) at Institute of Modern Physics (IMP). The 5.96 m RFQ will operate with the capability of accelerating all ion species from proton to uranium from 14 keV/u up to 500 keV/u. In this paper, the low power test and tuning results of the RFQ accelerator, including the test of the separate sections and the whole cavity, will be presented. After the final tuning, the relative error of the quadrupole field is within 2% and the admixture of the dipole modes are below 4% of the quadrupole mode.
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TUPAL031	Errors Study of a Double-Pass Recirculating Superconducting Proton Linac	linac, proton, cavity, emittance	1069
	Y. Tao, K. Hwang, J. Qiang LBNL, Berkeley, California, USA
	The concept of recirculating superconducting proton linac was recently proposed. Beam dynamics simulations were carried out in a double-pass recirculating proton linac using a single bunch. Although all the beam line elements should be installed following the designed values, in reality, there exist machine imperfections that will cause beam off-centering and even particle losses. In this paper, we report on the study of the static and dynamic errors from RF cavities and magnetic focusing elements in the double-pass recirculating proton linac.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAL031
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TUPAL035	3D Beam Dynamics Modeling of MEBT for the New LANSCE RFQ Injector	emittance, rfq, proton, simulation	1081
	S.S. Kurennoy LANL, Los Alamos, New Mexico, USA
	The new RFQ-based proton injector at LANSCE requires a specialized medium-energy beam transfer (MEBT) after the RFQ at 750 keV due to a following long (~3 m) existing common transfer line that also serves for transporting negative-ion beams to the DTL entrance. The horizontal space for MEBT elements is limited because two beam lines merge at 18-degree angle. The MEBT design developed with envelope codes includes two compact quarter-wave RF bunchers and four short quadrupoles with steerers, all within the length of about 1 m. The beam size in the MEBT is large, comparable to the beam-pipe aperture, hence non-linear 3D field effects at large radii become important. Using CST Studio codes, we calculate buncher RF fields and quadrupole magnetic fields and use them to perform particle-in-cell beam dynamics modeling of MEBT with realistic beam distributions from the RFQ. Our results indicate a significant emittance growth not predicted by standard beam dynamics codes. Its origin was traced mainly to the quadrupole edge fields. Quadrupole design modifications are proposed to improve the MEBT performance.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAL035
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TUZGBE2	Final-focus Superconducting Magnets for SuperKEKB	solenoid, MMI, operation, detector	1215
	N. Ohuchi, K.A. Aoki, Y. Arimoto, M.K. Kawai, T. Kawamoto, H. Koiso, Y. Kondo, M. Masuzawa, A. Morita, S. Nakamura, Y. Ohnishi, Y. Ohsawa, T. Oki, H. Sugimoto, K. Tsuchiya, R. Ueki, X. Wang, H. Yamaoka, Z.G. Zong KEK, Ibaraki, Japan M. Anerella, J. Escallier, A.K. Jain, A. Marone, B. Parker, P. Wanderer BNL, Upton, Long Island, New York, USA J. DiMarco, T.G. Gardner, J.M. Nogiec, M.A. Tartaglia, G. Velev Fermilab, Batavia, Illinois, USA T.-H. Kim Mitsubishi Electric Corp, Advanced Technology R & D Center, Hyogo, Japan
	The SuperKEKB collider aims at 40 times higher luminosity than that achieved at KEKB, based on the nano-beam scheme. The vertical beta function at the interaction point will be squeezed to 300μmeter. Final-focus superconducting magnet system which consists of eight main quadrupole magnets, 43 corrector windings, and compensation solenoids is a key component to achieve high luminosity. This invited talk presents the construction and commissioning of the final-focus magnet system.
	Slides TUZGBE2 [4.235 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUZGBE2
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TUZGBF1	Superconducting Gantry for Carbon-Ion Radiotherapy	superconducting-magnet, dipole, radiation, MMI	1232
	Y. Iwata, T. Furukawa, Y. Hara, S. Matsuba, T. Murakami, K. Noda, N. S. Saotome, S. Sato, T. Shirai NIRS, Chiba-shi, Japan N. Amemiya Kyoto University, Kyoto, Japan H. Arai, T. Fujimoto AEC, Chiba, Japan T.F. Fujita, K. Mizushima, Y. Saraya National Institute of Radiological Sciences, Chiba, Japan S. Matsuba HSRC, Higashi-Hiroshima, Japan T. Obana NIFS, Gifu, Japan T. Ogitsu KEK, Ibaraki, Japan T. Orikasa, S. Takayama Toshiba, Yokohama, Japan R. Tansho QST-NIRS, Chiba, Japan
	A superconducting magnet gantry has been used at HIMAC in NIRS, transporting beams for carbon ion radiotherapy. A second superconducting gantry, with a different design, is under construction in Yamagata University. This invited talk presents an overview of these gantry designs, their advantages for light ion radiotherapy, their operational experiences, and future perspectives for superconducting radiotherapy gantries.
	Slides TUZGBF1 [26.678 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUZGBF1
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TUPMF006	Pulsed Wire Measurements of a High Field Gradient Quadrupole Wiggler	wiggler, alignment, laser, wakefield	1257
	M. Kasa, A. Zholents ANL, Argonne, Illinois, USA
	Funding: Work supported by the U.S. Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11357. Alignment of the quadrupoles in a quadrupole wiggler to sub micrometer precision is required for the collinear wakefield accelerator that is under consideration at Argonne National Laboratory for a compact Free-Electron Laser [1]. The pulsed wire measurement method is the only technique that we are aware of that allows for sub micrometer precision and the ability to distinguish between the various quadrupoles within the wiggler. A one period prototype wiggler was manufactured and subsequently measured using the pulsed wire technique. The goal of the measurements was to verify that the magnetic centers of each quadrupole could be located and aligned to each other within the required precision. The method and results are described. [1] A. Zholents, et al., "A preliminary design of the collinear dielectric wakefield accelerator", Nucl. Instrum. Meth. A829 (2016) 190-193.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPMF006
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TUPMF010	A Conceptual Design of a Compact Wakefield Accelerator for a High Repetition Rate Multi User X-ray Free-Electron Laser Facility	wakefield, electron, GUI, wiggler	1266
	A. Zholents, D.S. Doran, W.G. Jansma, M. Kasa, R. Kustom, J.G. Power, N.O. Strelnikov, K.J. Suthar, E. Trakhtenberg, I. Vasserman, G.J. Waldschmidt, J.Z. Xu ANL, Argonne, Illinois, USA S. Baturin Enrico Fermi Institute, University of Chicago, Chicago, Illinois, USA H. Perez IIT, Chicago, Illinois, USA
	Funding: Supported by U.S. Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11357 A preliminary design of a collinear wakefield accelerator is described. It is assumed that the array of such accelerators will play a central role in a free-electron laser-based x-ray user facility under consideration at Argonne National Laborator [1].
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPMF010
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TUPMF011	Calculation of Expected Orbit Motion Due to Girder Resonant Vibration at the APS Upgrade	ground-motion, factory, resonance, lattice	1269
	V. Sajaev, Z. Liu, J. Nudell, C.A. Preissner ANL, Argonne, Illinois, USA
	Funding: Work supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357. The Advanced Photon Source (APS) is pursuing an upgrade to the storage ring that will provide electron beam with extremely low emittance. To allow users to take advantage of this small beam size, the beam orbit motion has to be kept stable to within a fraction of the beam size. To keep the beam orbit stable on a sub-micron level, one needs to carefully design magnet supports/girders so that the ground motion does not lead to excessive orbit motion due to resonant modes of magnet supports. In this paper, we will describe the process of calculating the expected orbit motion due to girder resonant vibration. First, we will present the simulation results for the girder resonant modes, then we will calculate the orbit amplification factors for the girder deformation modes, then calculate the expected orbit motion using measured ground motion spectrum. This process can be used to evaluate the design of the magnet supports.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPMF011
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TUPMF024	Validation of the Halbach FFAG Cell of Cornell-BNL Energy Recovery Linac	linac, permanent-magnet, collider, focusing	1304
	F. Méot, S.J. Brooks, D. Trbojevic, N. Tsoupas BNL, Upton, Long Island, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. The optical properties of the Halbach technology based CBETA ERL return FFAG arc cell are investigated, using its 3-D OPERA field map model. This includes paraxial and large amplitude motion, tune path, study of resonances, dynamic acceptance, effects of various defects, 300-cell 10k-particle bunches 6D transmission trials. These investigations, a 2~3 year investment, have validated the Halbach technology in the linear FFAG cell application, from the point of view of the beam dynamics, so supporting its approval as the required technology for CBETA, in December 2016.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPMF024
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TUPMF027	Impedance Modeling for eRHIC	impedance, vacuum, dipole, electron	1309
	A. Blednykh, G. Bassi, M. Blaskiewicz, C. Hetzel, V. Ptitsyn, V.V. Smaluk, F.J. Willeke BNL, Upton, Long Island, New York, USA
	Funding: Work supported by the US DOE under contract number DE-SC0012704 The impedance budget for the eRHIC project is discussed at its earlier stage of development. As a first step, with the eRHIC lattice and beam parameters , we use the geometric impedances of the vacuum chamber components simulated for the NSLS-II project. The impedance budged will be updated next with more impedance data simulated for the optimized eRHIC vacuum components. It will allows us to keep track on the collective effects changes with more realistic components added to the ring.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPMF027
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TUPMF038	Design Considerations for an Ultralow Emittance Storage Ring for the Canadian Light Source	emittance, sextupole, lattice, electron	1334
	L.O. Dallin CLS, Saskatoon, Saskatchewan, Canada
	Demands from light source scientists for more brilliant xray beams have resulted in the emergence of 4th generation storage rings. These demands include photon beams that are highly focussed and beams with high transverse coherence. Both these requirements are achieved with ultralow electron beam emittance. The practical development of the multi-bend achromat (MBA) concept by MAX IV has spurred many synchrotron light sources around the world to develop similar machines. For existing facilities two options are available: upgrading existing machines or building a new structure. The Canadian Light Source (CLS) has explored both options and has determined a new storage ring is required. Several design options for a 3.0 GeV ring have been developed. Best results are achieved when tracking is used to optimize the phase advance through the MBA structure to reduce the impact of the sextupoles on the dynamic aperture. Structures where no geometric sextupoles are required have been achieved while producing ultralow emittances.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPMF038
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TUPMF054	Performance Comparison of Different Ultralow Emittance Unit Cells	emittance, lattice, dipole, storage-ring	1382
	Y. Jiao, X.Y. Li, G. Xu IHEP, Beijing, People's Republic of China
	The available minimum emittance of a storage ring and the ring performance is closely related to the unit cell of the lattice. Up to now, several ultralow-emittance unit cells have been proposed and applied in the lattice design of the diffraction-limited storage ring light sources. In this study we quantitatively compared the performance of three typical unit cells, based on mainly the parameters of the High Energy Photon Source. The results indicate that the modified-TME unit cell with antibend and longitudinal gradient dipole allows the lowest possible emittance, given a long enough cell length.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPMF054
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TUPMF072	Microwave Instability and Energy Spread Measurement via Vertical Dispersion Bump in PETRA III	emittance, experiment, undulator, wiggler	1427
	Y.-C. Chae, D. Dzhingaev, M. Ebert, G. Falkenberg, J. Keil, G. Kube, G.K. Sahoo, M. Sprung, R. Wanzenberg, F. Westermeier DESY, Hamburg, Germany A.I. Novokshonov TPU, Tomsk, Russia
	The recent measurement of bunch length versus current indicated that the longitudinal impedance (Z/n) is 0.15 Ω in close agreement with the impedance model. Naive application of Keil-Schnell criteria predicts the threshold of microwave instability at 0.25 mA. Since the single bunch intensity is in the range of 0.2-2.5 mA depending on the fill-pattern of PETRA III, we expect to observe the fill-pattern dependent energy spread according to the theory. However, the 3rd generation light sources comparable to PETRA III often reported the observation which was much greater than the theoretical one. In order to induce the beam size variation we had used skew quadrupoles to generate the dispersion in vertical plane. In particular we made dispersion bump at the undulator sector so that we were able to use the X-ray optics for the precise determination of small vertical beam size. In this paper we report the experimental setup and measurement data with the estimate on the instability threshold. We also report the vertical emittance and energy spread based on the X-ray beam size measurement as well as the RF signal which was excited by the beam at the longitudinal feedback cavity. K. Balewski, R. Wanzenberg, "OBSERVATION OF INTENSITY DEPENDENT SINGLE BUNCH EFFECTS AT THE SYNCHROTRON LIGHT SOURCE PETRA III", Proc. of IPAC2011, p. 730.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPMF072
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TUPML003	Design of an L-band Accelerating Structure for the Argonne Wakefield Accelerator Facility Witness Beam Line Energy Upgrade	linac, impedance, coupling, acceleration	1533
	J.H. Shao, M.E. Conde, D.S. Doran, J.F. Power ANL, Argonne, Illinois, USA C.-J. Jing Euclid TechLabs, LLC, Solon, Ohio, USA
	The Argonne Wakefield Accelerator (AWA) facility has been devoting much effort to the fundamental R&D of two-beam acceleration (TBA) technology with two parallel L-band beam lines. Beginning from the 70 MeV drive beam line, the high frequency (C-band and above) rf power is extracted from the beam by a decelerating structure (a.k.a. power extractor), transferred to an accelerating structure in the witness beam line, and used to accelerate the 15 MeV main beam. These high frequency accelerating structures usually have a small aperture to obtain high gradient and high efficiency, making it difficult for the low energy main beam to pass. To address this issue, one proposal is to increase the main beam energy to above 30 MeV by replacing the current witness linac. A 9-cell 𝜋-mode L-band standing-wave accelerating structure has therefore been designed to meet the high shunt impedance and low cost requirements. In addition, the single-feed coupling cell has been optimized with additional symmetrical ports to eliminate field distortion. The detailed design of the new accelerating structure will be presented in this paper.
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TUPML021	A Beamline Design to Transport Laser Wakefield Electrons to a Transverse Gradient Undulator	laser, electron, undulator, plasma	1577
	K.A. Dewhurst, H.L. Owen UMAN, Manchester, United Kingdom E. Brunetti, D.A. Jaroszynski, S.M. Wiggins USTRAT/SUPA, Glasgow, United Kingdom B.D. Muratori STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom B.D. Muratori Cockcroft Institute, Warrington, Cheshire, United Kingdom
	Funding: This work was supported by the UK Science and Technology Facilities Council, Grant No. ST/G008248/1. The Cockcroft Beamline is to be installed at the Scottish Centre for the Application of Plasma-based Accelerators (SCAPA). The beamline is designed to transport 1 GeV electrons from a laser wakefield acceleration (LWFA) source to a pair of transverse gradient undulators. The project aims to produce X-ray undulator radiation in the first phase and free-electron laser (FEL) radiation in the second phase. The total beamline will be less than 23 m long, thus the Cockcroft Beamline has the potential to be the UK's first compact X-ray FEL. Here we present the main features of the beamline design.
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TUPML038	Simulation of Phase-Dependent Transverse Focusing in Dielectric Laser Accelerator Based Lattices	lattice, focusing, laser, emittance	1622
	F. Mayet, R.W. Aßmann, U. Dorda, W. Kuropka DESY, Hamburg, Germany W. Kuropka, F. Mayet University of Hamburg, Institut für Experimentalphysik, Hamburg, Germany
	Funding: Gordon and Betty Moore Foundation. Grant GBMF4744 The Accelerator on a CHip International Program (ACHIP) funded by the Gordon and Betty Moore Foundation aims to demonstrate a prototype of a fully integrated accelerator on a microchip based on laser-driven dielectric structures until 2021. Such an accelerator on a chip needs all components known from classical accelerators. This includes an electron source, accelerating structures and transverse focusing arrangements. Since the period of the accelerating field is connected to the drive laser wavelength of typically a few microns, not only longitudinal but also transverse effects are strongly phase-dependent even for few femtosecond long bunches. If both the accelerating and focusing elements are DLA-based, this needs to be taken into account. In this work we study in detail the implications of a phase-dependent focusing lattice on the evolution of the transverse phase space of a transported bunch.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPML038
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TUPML055	Beam Optics Designs of a Strecher Ring and a Transfer Line for J-PARC Slow Extraction	extraction, optics, sextupole, injection	1667
	M. Tomizawa, R. Muto, T. Ogitsu KEK, Ibaraki, Japan A. Konaka TRIUMF, Vancouver, Canada
	The J-PARC main ring (MR) provides 30 GeV high intensity beams for neutrino experimental facility (NU) by fast extraction and hadron experimental facility (HD) by slow extraction. It is a serious issue to ensure sufficient integrated proton number on target (POT) for each facility. A stretcher ring (ST) can solve this serious problem. A beam accelerated by the MR is transferred to the ST and is slowly extracted over several second. While the beam is slowly extracted in the ST, the MR can accelerate and deliver a beam to the NU. The ST is put above the MR and fitted in the MR tunnel. Arc sections in the ST consist of superconducting combined function magnets (dipole, quadrupole and sextupole components), and separated function quadruple and sextupole magnets (hybrid lattice). A 30 GeV beam transfer line (BT) from the MR to the ST uses superconducting combined magnets with dipole and quadrupole functions to shorten the BT. The transferred beam is injected into an arc section in the ST. The adoption of the superconducting magnets in the ST and the BT saves operation cost drastically. Beam optics designs for the ST and the BT will be described in this paper.
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TUPML078	Fast Quadrupole Beam Based Alignment Using AC Corrector Excitations	alignment, closed-orbit, optics, synchrotron	1727
	Z. Martí, G. Benedetti, U. Iriso ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
	A novel method to perform Beam Based Alignment has been tested at ALBA using the 10kHz fast acquisition BPMs together with an AC excitation of the corrector magnets allowing to speed up the beam based alignment process. The former approach relies on software synchronization and tango device servers to execute a series of DC corrector magnets and quadrupoles settings designed to avoid the quadrupole hysteresis effects. The approach that we present here is simpler, gives the same level of accuracy and precision and speeds up the measurement by a factor 10. The total measurement time has changed from 5 hours to 10 minutes.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPML078
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WEPAF003	Beamline Architect	interface, simulation, software, solenoid	1812
	J.D. Kunz, C.M. Conrad, L.M. Romero Anderson University, Anderson, USA
	Funding: Indiana Space Grant Fellowship Program 2015-2018, subaward number 4103-82252 Beamline Architect is a new particle accelerator simulation tool. Currently, two of the most widely used tools in this field are G4beamline and COSY Infinity. While these codes are fast and quite accurate, sometimes their interfaces can be time-consuming for students to learn, particularly undergraduate students or students whose primary field is not accelerator physics. Without Beamline Architect, each code has its own high-level language that must be manually written into a file and then executed on the command line. Moreover, sometimes the use of both simulation tools is warranted in order to check for consistency between the codes. Writing the codes by hand or translating between software can sometimes be cumbersome, even for experts. Furthermore, knowledge of an additional language, such as Python, is required in order to analyze the outputs of the codes (which may be in different formats from one another). Beamline Architect is a tool that provides a graphical user interface to G4beamline and COSY Infinity. This lets the user build a particle accelerator channel in 3D with or without using code. The channel may then be saved, exported, translated, or run. Any output data will be plotted in Beamline Architect using Python, since it is both flexible aesthetically and quite standard in the particle accelerator community. For undergraduate and non-accelerator students, Beamline Architect allows a hands-on experience with accelerator simulations. Some applications for these students include health physics radiation dosimetry problems, medical imaging mechanics, security scanner simulations, and (of course) accelerator channel design for particle physics experiments. For experts, Beamline Architect provides visual confirmation of the channel and a faster, more consistent way of cross-referencing results between the codes.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAF003
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WEPAF009	Optimising Response Matrix Measurements for LOCO Analysis	storage-ring, coupling, lattice, distributed	1826
	Y.E. Tan AS - ANSTO, Clayton, Australia
	The Linear Optics from Closed Orbit (LOCO) method is a common tool for determining storage ring lattice functions and requires a measured BPM to Corrector response matrix. For very large rings with many correctors, such measurements can be time consuming. The following study investigates how the number of correctors and the signal-to-noise ratio (SNR) affects the LOCO analysis results. For the Australian Synchrotron, the results show that four distributed correctors per plane with a SNR of >1000 is sufficient to fit the betatron functions to an accuracy of less than 0.2%.
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WEPAF015	Commissioning the Muon g-2 Experiment Electrostatic Quadrupole System	storage-ring, experiment, positron, resonance	1848
	J.D. Crnkovic, V. Tishchenko BNL, Upton, Long Island, New York, USA K.E. Badgley, H. Nguyen, E. Ramberg Fermilab, Batavia, Illinois, USA E. Barlas Yucel, M. Yucel Istanbul Technical University, Maslak, Istanbul, Turkey J.M. Grange ANL, Argonne, Illinois, USA A.T. Herrod Cockcroft Institute, Warrington, Cheshire, United Kingdom A.T. Herrod The University of Liverpool, Liverpool, United Kingdom J.L. Holzbauer, W. Wu UMiss, University, Mississippi, USA H.D. Sanders APP, Freeville, New York, USA H.D. Sanders Sanders Pulsed Power LLC, Batavia, Illinois, USA N.H. Tran BUphy, Boston, Massachusetts, USA
	The Fermilab Muon g-2 experiment aims to measure the muon anomaly with a precision of 140 parts-per-billion (ppb) - a fourfold improvement over the 540 ppb precision obtained by the BNL Muon g-2 experiment. These high precision experiments both require a very uniform muon storage ring magnetic field that precludes the use of vertical-focusing magnetic quadrupoles. The Fermilab Electrostatic Quadrupole System (EQS) is the refurbished and upgraded BNL EQS, where this overview describes the Fermilab EQS and its recent operations.
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WEPAF016	Application of Quad-Scan Measurement Techniques to Muon Beams in the Muon g-2 Experiment	experiment, emittance, storage-ring, scattering	1852
	J. Bradley Edinburgh University, Edinburgh, United Kingdom J.D. Crnkovic BNL, Upton, Long Island, New York, USA B.E. Drendel, D. Stratakis Fermilab, Batavia, Illinois, USA N.S. Froemming CENPA, Seattle, Washington, USA
	Determination of the properties of a beam during transport is a vital process for most accelerator-related experiments; for example Fermilab's Muon g-2 experiment requires large numbers of muons to be stored in a storage ring of 7 meter radius, and the transmission fraction has been shown to depend strongly on the properties of the beam, specifically the Twiss parameters. The current equipment in the muon campus beamlines allows only measurement of beam profiles which limits how well propagation can be predicted, however by using the well-studied quad-scan technique it is possible to obtain all of the Twiss parameters at a point using these profiles. Experimental quad-scans of muon beams have not yet been reported, this paper introduces the quad-scan technique and then goes on to discuss the analysis of one such experiment and the results obtained, showing that such a technique is applicable in the muon g-2 experiment to obtain the Twiss parameters without requiring installation of new equipment.
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WEPAF017	Correction of ID-Induced Transverse Linear Coupling at NSLS-II	coupling, emittance, operation, resonance	1856
	Y. Hidaka, Y. Li, T.V. Shaftan, T. Tanabe, Y. Tian, G.M. Wang BNL, Upton, Long Island, New York, USA
	Funding: The study is supported by U.S. DOE under Contract No. DE-AC02-98CH10886. Sizeable lifetime jumps have been observed sporadically since March 2016 at NSLS-II. These jumps were found to coincide with insertion device (ID) gap motions. Particularly, one of the in-vacuum undulators (IVUs) at Cell 17 was discovered to have large localized skew quadrupole component variation with gap. To allow the machine to operate stably in the low-emittance mode, a global coupling feedforward system has been recently implemented and successfully deployed. After installation of a new additional skew quadrupole, coupling compensation of this ID is now performed by a local coupling feedforward system. Furthermore, the maximum gap limit of all the existing IVUs has been decreased from 40 mm to 25 mm to limit the skew component variation during user operation.
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WEPAF062	Machine Learning Methods for Optics Measurements and Corrections at LHC	optics, network, controls, data-analysis	1967
	E. Fol, F.S. Carlier, J.M. Coello de Portugal, A. Garcia-Tabares, R. Tomás CERN, Geneva, Switzerland
	The application of machine learning methods and concepts of artificial intelligence can be found in various industry and scientific branches. In Accelerator Physics the machine learning approach has not found a wide application yet. This paper is devoted to evaluation of machine learning methods aiming to improve the optics measurements and corrections at LHC. The main subjects of the study are devoted to recognition and analysis of faulty beam position monitors and prediction of quadrupole errors using clustering algorithms, decision trees and artificial neural networks. The results presented in this paper clearly show the suitability of machine learning methods for the optics control at LHC and the potential for further investigation on appropriate approaches.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAF062
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WEPAF066	The New CLIC Main Linac Installation and Alignment Strategy	alignment, target, linac, collider	1979
	H. Mainaud Durand, J. Gayde, J. Jaros, M. Sosin, A. P. Zemanek CERN, Geneva, Switzerland V. Rude ESGT-CNAM, Le Mans, France
	A complete solution has been proposed for the pre-alignment of the CLIC main linac in 2012 for the Conceptual Design Report. Two recent studies provide new perspectives for such a pre-alignment. First in a study on Particle Accelerator Components' Metrology and Alignment to the Nanometre scale (PACMAN), new solutions to fiducialise and align different types of components within a micrometric accuracy on the same support were proposed and validated, using a stretched wire. Secondly, a 5 degree of freedom adjustment platform with plug-in motors showed a very accurate and efficient way to adjust remotely components. By combining the results of both studies, two scenarios of installation and alignment for the CLIC main linac are proposed, providing micrometric and automatized solutions of micrometric assembly, fiducialisation and alignment in metrological labs or in the tunnel. In this paper, the outcome of the two studies are presented; the two scenarios of installation and alignment are then detailed and discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAF066
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WEPAF080	Beam Size Measurements Based on Movable Quadrupolar Pick-ups	pick-up, emittance, alignment, embedded	2028
	A. Sounas, M. Gąsior, T. Lefèvre, A. Mereghetti, J. Olexa, S. Redaelli, G. Valentino CERN, Geneva, Switzerland
	Measurements with quadrupolar pick-ups (PU) have attracted particular interest as non-intercepting diagnostics for determining the transverse beam size. They are based on processing the signals of an electromagnetic PU for the extraction of the second-order moment, which contains information about the beam size. Despite the simplicity of the concept, quadrupololar measurements have always been highly challenging in reality. This comes from the fact that the quadrupolar moment constitutes only a very small part of the total PU signal dominated by the intensity and the position signals. Therefore, the beam size information can easily be lost due to small imperfections in the signal processing chain, such as asymmetries in the electronics and cables. In this paper, we present a new method for quadrupolar measurements using movable PUs. Through position and aperture scans, our technique minimizes the parasitic beam position signal and takes into account imperfections of the PU, cables and electronics, thus enabling an efficient auto-calibration of the measurement system. Preliminary studies, using collimators with embedded electrostatic PUs in the LHC at CERN, have shown very promising results.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAF080
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WEPAF081	An Enhanced Quench Detection System for Main Quadrupole Magnets in the Large Hadron Collider	monitoring, controls, power-supply, radiation	2032
	J. Spasic, D.O. Calcoen, R. Denz, V. Froidbise, S. Georgakakis, T. Podzorny, A.P. Siemko, J. Steckert CERN, Geneva, Switzerland
	To further improve the performance and reliability of the quench detection system (QDS) for main quadrupole magnets in the Large Hadron Collider (LHC), there is a planned upgrade of the system during the long shutdown period of the LHC in 2019-2020. While improving the already existing functionalities of quench detection for quadrupole magnets and field-bus data acquisition, the enhanced QDS will incorporate new functionalities to strengthen and improve the system operation and maintenance. The new functionalities comprise quench heater supervision, interlock loop monitoring, power cycling possibility for the whole QDS and its data acquisition part, monitoring and synchronization of trigger signals, and monitoring of power supplies. In addition, the system will have two redundant power supply feeds. Given that the enhanced QDS units will replace the existing QDS units in the LHC tunnel, the units will be exposed to elevated levels of ionizing radiation. Therefore, it is necessary to design a radiation tolerant detection system. In this work, an overview of the design solution for such enhanced QDS is presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAF081
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WEPAK003	Effect of Model Errors on the Closed Orbit Correction at the SIS18 Synchrotron of GSI	synchrotron, closed-orbit, controls, focusing	2080
	S.H. Mirza, P. Forck, H. Klingbeil, R. Singh GSI, Darmstadt, Germany H. Klingbeil TEMF, TU Darmstadt, Darmstadt, Germany
	Funding: Deutscher Akademischer Austauschdienst under contract No. 91605207 A fast closed orbit feedback system (bandwidth in the order of 1 kHz) is under development at the GSI SIS18 synchrotron for the orbit correction from injection to extraction including the acceleration ramp. The static process model, represented as the orbit response matrix (ORM), is subjected to the systematic optics changes during ramp e.g. beta function and phase advance variations at the locations of BPMs and steerers. In addition to these systematic variations, model mismatches may arise from dipole and quadrupole magnet errors, space charge dependent tune shift as well as BPM and steerer calibration errors. In this contribution, the effects of these model errors on the closed orbit correction are investigated which is necessary for the robust stability analysis of the feedback controller. For the robustness tests, the traditional SVD-based matrix pseudo-inversion is compared to a Fourier-based analysis. The results are achieved by detailed simulations in MADX.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAK003
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WEPAL020	Measurement of Transverse Dipole and Quadrupole Moments with the BPMS in the J-PARC 3-50 BT	dipole, emittance, beam-transport, optics	2197
	T. Toyama J-PARC, KEK & JAEA, Ibaraki-ken, Japan H. Kuboki, K. Satou, M. Tejima KEK, Tokai, Ibaraki, Japan
	We measure dipole and quadrupole moments of the beam using the BPMs in the beam transport line 3-50BT of J-PARC and obtain differences of squared horizontal- and vertical-rms-sizes for those BPMs. Then we obtain rms emittances and rms momentum by fitting with given Twiss parameters.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAL020
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WEPAL064	Diagnosis Application by Great Amount Operation Data Analysis Program for Taiwan Photon Source	power-supply, LabView, hardware, interface	2323
	C.C. Liang, B.Y. Chen, C.H. Chen, S. Fann, C.S. Huang, C.H. Kuo, T.Y. Lee, W.Y. Lin, Z.-D. Tsai, Y.C. Yang, T.-C. Yu NSRRC, Hsinchu, Taiwan
	To find out abnormal situations of the machine for preventive maintenance or machine trip tracking or instability source diagnosis, a large amount of operating data in an accelerator is thus can be used to build a series data analysis program. When the archived data is classified accordingly, the standard deviation (STD), peak-to-peak value and other statistic indexes within the inspection time zone by the belonging families can be used to point out the especially abnormal signals. The analysis program adopts the techniques of parallel calculation and memory optimization to greatly reduce the time for data transmission and analysis and also displays the correlation signals to opera-tors for deeper analysis. This paper illustrated a simple yet effective method for quickly identifying a not-so-obscure hardware issue by simply using a personal computer (PC).
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WEPAL068	Improving Machine and Target Protection in the SINQ Beam Line at PSI-HIPA	target, proton, diagnostics, operation	2337
	D. Reggiani, P.-A. Duperrex, R. Dölling, D.C. Kiselev, J. Welte, M. Wohlmuther PSI, Villigen PSI, Switzerland
	With a nominal beam power of nearly 1.4 MW, the PSI High Intensity Proton Accelerator (HIPA) facility is currently at the forefront of the high intensity frontier of particle accelerators. A key issue of this facility is to ensure safe operation of the SINQ spallation source. In particular, too large beam current density and/or inaccurate beam steering can seriously compromise the integrity of the spallation target. Recently, a campaign has been launched in order to improve the fast detection of improper beam delivery and therefore the reliability of the system. New beam diagnostics elements such as an absolute intensity monitor, a beam ellipticity monitor and additional loss monitors have been installed during the 2017 shutdown. In 2018 a new SINQ target will be installed featuring a system of thermocouples which will keep track of the beam position. Moreover, an additional monitor is currently under study which should reliably detect small beam fractions accidentally bypassing the muon production target TE and which are intrinsically dangerous for the SINQ spallation target. This contribution reviews the all efforts to increase the efficiency of the SINQ protection system.
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WEPMF001	Upgrade of the ALBA Magnetic Laboratory for Measuring LIPAc HEBT Quadrupoles and Dipole	controls, hardware, software, dipole	2369
	J. Campmany, F. Becheri, L.G.O. Garcia-Orta, J. Marcos, V. Massana, R. Petrocelli ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain B. Brañas, J. Castellanos CIEMAT, Madrid, Spain
	Along 2017 ALBA magnetic measurements facility has measured LIPAc HEBT quadrupoles and dipole designed by CIEMAT and built by ELYTT company. ALBA magnetic measurements laboratory has been improved through an upgrade program of its measurement benches to complete their measurements. One of the main aims of the upgrade has been to standardize both the hardware and software and therefore ensure an easy maintenance. Especially relevant has been the upgrade of the flipping coil bench, in which the DC motors and the obsolete controller have been replaced by step-motors and ICEPAP controller. Also, software has been migrated to Tango package. Hardware and software of Hall probe bench has been upgraded as well, using the last DeltaTau motion controller. Tango has been upgraded too, using Devian 8 as operative system. Next step will be the upgrade of the rotating coil hardware and software using also step-motor and ICEPAP controller. In parallel, new shafts have been build and tested, with specific designs to improve the sensitivity and minimize the noise to signal ratio. In this contribution we detail the upgrades and the results of performance tests.
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WEPMF014	Fast Track Actively Shielded Nb3Sn IR Quadrupole R&D	site, hadron, collider, coupling	2398
	B. Parker, M. Anerella, J.P. Cozzolino, R.C. Gupta, R.B. Palmer, J. Schmalzle, H. Witte BNL, Upton, Long Island, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy. The Interaction Region (IR) magnets for future Electron Ion Colliders (EIC), such as eRHIC at BNL, JLEIC at JLab and LHeC at CERN, must satisfy strongly opposing requirements. EIC IR superconducting quadrupole coils must provide strong focusing gradients, leading to large peak fields, for the high momentum hadron beam while permitting the nearby electron beam to pass through a nearly field free region. An actively shielded coil geometry does this using nested, opposite polarity, quadrupoles where the combined external fields cancel while leaving a net gradient inside. In order to fabricate and test this concept in a timely and cost effective manner we propose to reuse the inner coils from an existing high gradient Nb3Sn LARP quadrupole inside a new structure with a new NbTi active shield coil. The main challenge is to design a compact structure for applying prestress to the Nb3Sn coil that fits the restricted space inside the shield coil. We first construct a 15 cm long mechanical model of this structure with coil strain gauges to verify the design concept before proceeding with the full coil. Mechanical modeling results and our preliminary design concept are reported here.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPMF014
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WEPMF018	Magnet Designs for the eRHIC Rapid Cycling Synchrotron	dipole, sextupole, synchrotron, magnet-design	2404
	H. Witte, I. Marneris, V.H. Ranjbar BNL, Upton, Long Island, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. Presently the electron-ion collider eRHIC is under design, which aims to provide a facility with a peak luminosity of 10³⁴cm^-2sec^-1. Part of the eRHIC design is a rapid cycling synchrotron, which accelerates electrons from 1-18 GeV. In this paper we present conceptual designs of the required dipole, quadrupole and sextupole magnets. The magnets meet the specifications in terms of performance and field quality with an acceptable power dissipation. The power supply requirements are also discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPMF018
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WEPMF019	Conceptual Design of the eRHIC Storage Ring Magnets	storage-ring, dipole, sextupole, simulation	2407
	H. Witte, J.S. Berg, S. Tepikian BNL, Upton, Long Island, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. Presently the electron-ion collider eRHIC is under design, which aims to provide a facility with a peak luminosity of 10³⁴cm^-2sec^-1. Part of the eRHIC accelerator is the addition of an electron storage ring to the existing tunnel. This paper describes the magnets required for this storage ring. The necessary bending is provided by a triplet of dipole magnets, which generate excess bending to create additional radiation damping to allow a larger beam-beam tune shift. Each triplet consists of two long, low field magnets and a short, high-field magnet. This paper also describes the quadrupole and sextupole magnets necessary for this machine. All magnets require a large aperture to accommodate the beam-pipe.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPMF019
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WEPMF021	Magnet Design Considerations for an Ultralow Emittance Canadian Light Source	lattice, emittance, storage-ring, FEL	2413
	L.O. Dallin, D. Bertwistle CLS, Saskatoon, Saskatchewan, Canada
	The strong focusing requirements for ultralow emittance light sources result in high field magnets that are very close together. High fields are readily achieved by using small magnet gaps. This is possible due to the small beam sizes involved. Reduction in the physical aperture and the reduction in the good field region requirements results in magnets with compact transverse dimensions. The very strong focusing of the magnets results in very small drift spaces between the various magnetic elements. To keep these drift spaces clear magnets with recessed coils have been studied. In such magnets the coils do not stick out beyond the end of the magnet yoke in the longitudinal direction. By placing the coils on the outer yoke loss of efficiency can be avoided while maintaining good control of the higher order field harmonics. This is very well suited for quadrupole magnets where only two coils are required. Possible designs for gradient dipoles and sexutpoles are also considered.
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WEPMF061	High Gradient Pulsed Quadrupoles for Novel Accelerators and Space Charge Limited Beam Transport	plasma, focusing, electron, wakefield	2505
	C. Tenholt CERN, Geneva, Switzerland G. Loisch, F. Stephan DESY Zeuthen, Zeuthen, Germany B. Marchetti DESY, Hamburg, Germany
	Novel acceleration schemes like plasma wake-field based accelerators demand for high gradient focusing elements to match the Twiss parameters in the plasma to the transport lattice of the conventional accelerator beamlines, with typically much higher beta-functions. There are multiple candidates for achieving high gradient focusing fields, each one having certain drawbacks. Permanent magnets are limited in tunability, plasma lenses might degrade the transverse beam quality significantly and conventional magnets cannot reach very high gradients and often cannot be placed in direct proximity of the plasma accelerator because of their size. In this paper we present design considerations and simulations on compact, high gradient, pulsed quadrupoles, that could be used e.g. for final focusing of space charge dominated bunches into a LWFA (Laser Wake-Field Accelerator) at SINBAD or other facilities with similar demands. The target design gradient is 200 T/m at a physical aperture on the order of 10 mm.
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WEPMG006	Experimental Setup to Characterize the Radiation Hardness of Cryogenic Bypass Diodes for the HL-LHC Inner Triplet Circuits	radiation, cryogenics, MMI, target	2620
	A. Will, G. D'Angelo, R. Denz, M.F. Favre, D. Hagedorn, G. Kirby, T. Koettig, A. Monteuuis, F. Rodriguez-Mateos, A.P. Siemko, K. Stachon, M. Valette, A.P. Verweij, D. Wollmann CERN, Geneva, Switzerland A. Bernhard, A.-S. Müller KIT, Karlsruhe, Germany L. Kistrup KEA, Copenhagen, Denmark
	Funding: Work supported by the Wolfgang Gentner Programme of the German Federal Ministry of Education and Research For the high luminosity upgrade of the Large Hadron Collider (LHC), it is planned to replace the existing triplet quadrupole magnets with Nb₃Sn quadrupole magnets, which provide a comparable integrated field gradient with a significantly increased aperture. These magnets will be powered through a novel superconducting link based on MgB₂ cables. One option for the powering layout of this triplet circuit is the use of cryogenic bypass diodes, where the diodes are located inside an extension to the magnet cryostat and operated in superfluid helium. Hence, they are exposed to radiation. For this reason the radiation hardness of existing LHC type bypass diodes and more radiation tolerant prototype diodes needs to be tested up to the radiation doses expected at their planned position during their lifetime. A first irradiation test is planned in CERN's CHARM facility starting in spring 2018. Therefore, a cryo-cooler based cryostat to irradiate and test LHC type diodes in-situ has been designed and constructed. This paper will describe the properties of the sample diodes, the experimental roadmap and the setup installed in CHARM. Finally, the first measurement results will be discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPMG006
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WEPMK009	Status of the ESRF-EBS Magnets	SRF, dipole, sextupole, octupole	2648
	C. Benabderrahmane, J.C. Biasci, J-F. B. Bouteille, J. Chavanne, L. Eybert, L. Goirand, G. Le Bec, L. Lefebvre, S.M. Liuzzo, D. Martin, C. Penel, P. Raimondi, J.-L. Revol, F. Villar, S.M. White ESRF, Grenoble, France
	The ESRF-EBS (Extremely Brilliant Source) is an upgrade project planned at the European Synchrotron Radiation Facility (ESRF) in the period 2015-2022. A new storage ring will be built, aiming to decrease the horizontal emittance and to improve the brilliance and coherence of the X-ray beams. The lattice of the new storage ring relies on magnets with demanding specifications: dipoles with longitudinal gradient (field ranging from 0.17 T up to 0.67 T), strong quadrupoles (up to 90 T/m), combined function dipole-quadrupoles with high gradient (0.57 T and 37 T/m), strong sextupoles and octupoles. The design of these magnets is based on innovative solutions; in particular, the longitudinal gradient dipoles are permanent magnets and the combined dipole-quadrupoles are single-sided devices. The longitudinal gradient dipoles have been assembled and measured in house. The design of the magnets, production status and magnetic measurement results will be presented.
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WEPML009	Superconducting Magnet Performance in LCLS-II Cryomodules	cryomodule, superconducting-magnet, operation, dipole	2693
	V.S. Kashikhin, S. Cheban, J. DiMarco, E.R. Harms, A.V. Makarov, T. Strauss, M.A. Tartaglia Fermilab, Batavia, Illinois, USA
	Abstract' New LCLS-II Linear Superconducting Accelerator Cryomodules under construction at Fermilab. Inside each SCRF Cryomodule installed superconducting magnet package to focus and steer an electron beam. The magnet package has the iron dominated configuration with racetrack type quadrupole and dipole conductively cooled coils. For easier installation the magnet could be split in the vertical plane. Initially the magnet was tested in a liquid helium bath, and were performed high precision magnetic field measurements. Several Cryomodules with magnets inside were built and successfully tested at Fermilab test facility. In the paper presented Cryomodule magnet packages test results, discussed the magnet, and current leads conduction cooling performance.
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WEPML027	Conceptual Design of a 17 T Nb3Sn Accelerator Dipole Magnet	dipole, magnet-design, collider, luminosity	2742
	A.V. Zlobin, J.R. Carmichael, V.V. Kashikhin, I. Novitski Fermilab, Batavia, Illinois, USA
	Funding: Work is supported by Fermi Research Alliance, LLC, under contract No. DE-AC02-07CH11359 with the U.S. Department of Energy Nb3Sn dipole magnets with a nominal field of 16 T and sufficient operation margins are being considered for the LHC energy upgrade or a future Very High Energy Hadron Collider. Magnet design studies are being performed in the framework of the US Magnet Development Program to explore the limits of the Nb3Sn accelerator magnet technology and feasibility of such magnets, as well as to optimize the magnet design, performance parameters and cost. This paper describes the conceptual design of a 17 T dipole magnet with 60 mm aperture and 4-layer cos-theta coil being developed at Fermilab. The results of magnetic and mechanical analyses, including the non-linear effects in magnetic field and the possible stress management techniques, are also presented and discussed.
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WEPML028	NEG Coated Vacuum Chambers and Bake-Out-Concept for the HESR at FAIR	dipole, vacuum, heavy-ion, storage-ring	2745
	H. Jagdfeld, N.B. Bongers, J. Böker, P. Chaumet, F.M. Esser, F. Jordan, F. Klehr, G. Langenberg, D. Prasuhn, L. Semke, R. Tölle FZJ, Jülich, Germany A. Mauel, G. Natour, U. Pabst Forschungszentrum Jülich GmbH, Central Institute of Engineering, Electronics and Analytics, Jülich, Germany
	The High-Energy Storage Ring (HESR) is part of the international Facility for Antiproton and Ion Research (FAIR) at GSI Darmstadt. Forschungszentrum Jülich (IKP and ZEA-1) is responsible for the design and installation of the HESR. The HESR is designed for antiprotons and heavy ion experiments as well. Therefore the vacuum is required to be 10^-11 mbar or better. To achieve this extreme high vacuum (XHV), NEG coated chambers will be used in combination with common vacuum pumps to reach the needed pumping speed and capacity everywhere in the accelerator ring. For activation of the NEG material a bake-out system will be developed and installed. A bake-out test bench was used for checking the achievable end pressure and developing the bake-out system for the NEG coated chambers of the HESR. The results of the tests and the bake-out concept including the layout of the control system are presented. In addition, the temperature distribution of the dedicated heater jackets inside the dipole and quadrupole magnets are shown.
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WEPML030	First Tests of the Main Quadrupole and Corrector Magnets for the SIS100 Synchrotron of FAIR	operation, sextupole, dipole, cryogenics	2751
	E.S. Fischer, A. Bleile, V.I. Datskov, V.M. Marusov, J.P. Meier, C. Omet, P.J. Spiller, K. Sugita GSI, Darmstadt, Germany P.G. Akishin, V.V. Borisov, H.G. Khodzhibagiyan, S.A. Kostromin, D.N. Nikiforov, M.M. Shandov, A.V. Shemchuk JINR, Dubna, Moscow Region, Russia
	The heavy ion synchrotron SIS100 is the main accelerator of the FAIR complex (Facility for Antiproton and Ion Research) in Darmstadt, Germany. Currently the construction site and facility are advancing fast. The series production of the main dipoles was already started in 2017. In parallel, the first two quadrupoles, a chromaticity sextupole and a steerer were built and tested in cooperation between GSI and JINR at the cryogenic test facility in Dubna. We present the operation performance of these two first of series quadrupole units (consisting both of a corrector magnet mechanically and hydraulically combined with a quadrupole). Besides the thermal stability of the fast ramped superconducting magnets special attention is directed to their magnetic field properties. The obtained results provide the basis for starting the series production of all SIS100 quadrupole and corrector magnets in 2018.
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WEPML049	The Challenge to Measure nΩ Surface Resistance on SRF Samples	SRF, pick-up, cavity, simulation	2812
	S. Keckert, T. Junginger, J. Knobloch, O. Kugeler HZB, Berlin, Germany T. Junginger Lancaster University, Lancaster, United Kingdom
	Systematic research on fundamental limits of superconducting materials for SRF applications and their intrinsic material properties relevant for use in an accelerator requires studies in a wide parameter space of temperature, RF field and frequency. The Quadrupole Resonator at HZB enables precision measurements on planar samples at temperatures of 1.8 K to >20 K, RF fields of up to 120 mT, and frequencies of 420 MHz, 850 MHz and 1285 MHz. In the past years the capabilities of the setup were studied intensively and developed further. Sources of systematic errors, such as microphonics or misalignment have been identified and eliminated. In this contribution the current status of the QPR and its systematic limitations are discussed.
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WEPML073	Research on Magnetic Center Measurement of Quadrupole and Sextupole Using Vibrating Wire Alignment Technique in HEPS-TF	sextupole, alignment, background, multipole	2860
	L. Wu, C. H. Li, H. Qu, H. Wang, X.L. Wang IHEP, Beijing, People's Republic of China H.Y. Zhu Institute of High Energy Physics (IHEP), People's Republic of China
	In order to meet the extremely low emittance re-quirement, the magnets in the storage ring of High Energy Photon Source(HEPS) need to have a stable support and precise positioning. Vibrating wire align-ment technique can be used to pre-align the quadru-poles and sextupoles on one girder with high preci-sion. Research of vibrating wire alignment technique is one important project of HEPS Test Facility (HEPS-TF). In HEPS-TF, the key and difficult technologies of HEPS should be researched and developed. This paper introduces the principle of the vibrating wire align-ment technique and the measurement system in brief. The magnetic center measurement of quadrupole and sextupole using vibrating wire will be introduced in detail. It concludes the measurement procedure, mag-netic field distribution, measurement repeatability, sag correction and magnet adjustment measurement. The research of vibrating wire has get a better precision than the aim. The magnetic center measurement preci-sion reach to ±3μm and the magnet adjustment error is less than 6μm.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPML073
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THXGBE1	6D Beam Measurement, Challenges and Possibilities	simulation, rfq, experiment, linac	2890
	A.V. Aleksandrov, S.M. Cousineau, A.P. Zhukov ORNL, Oak Ridge, Tennessee, USA B.L. Cathey ORNL RAD, Oak Ridge, Tennessee, USA
	A system to measure the full 6D beam parameters (not 3x2D) has been built at the SNS RFQ test stand. Such a measurement will allow detailed analysis of the beam physics from a properly measured input term. This invited provides an overview of the principles and design of this system, and reports on status and results.
	Slides THXGBE1 [4.471 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THXGBE1
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THYGBF1	High Power Beam Operation of the J-PARC RCS and MR	operation, extraction, emittance, betatron	2938
	Y. Sato KEK, Ibaraki, Japan
	This invited talk presents the most recent status of improving J-PARC main ring (MR) beam operation together with the rapid cycling synchrotron (RCS) effort. The RCS has optimized the beam performance for the MR injection as well as the muon and neutron targets, where each requires different emittance and beam halo size. The MR has two extraction modes; fast extraction (FX) for the long baseline neutrino oscillation experiment, T2K, and slow extraction (SX) for experiments in the hadron experimental facility. At present, achieved beam intensities are 2.4·10¹⁴ protons per pulse (ppp) with cycle time 2.48 s (470 kW) in the FX mode and 5.10¹³ ppp with cycle time 5.52 s (44 kW) in the SX mode. For the FX operation, recent improvements are settings of new betatron tune, corrections of resonances near the betatron tune, and adopting 2nd harmonic rf voltage to reduce space charge effect. Beam instabilities have been suppressed with controlling chromaticity correction and transverse feedback systems. For the SX mode, a dynamic bump scheme for reducing extracted beam loss is successfully adopted. A high extraction efficiency of 99.5 % is achieved at the 44 kW beam operation.
	Slides THYGBF1 [6.664 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THYGBF1
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THPAF005	Simulations of Modulator for Coherent Electron Cooling	electron, simulation, bunching, plasma	2953
	J. Ma, V. Litvinenko, G. Wang BNL, Upton, Long Island, New York, USA V. Litvinenko Stony Brook University, Stony Brook, USA
	Highly resolved numerical simulations have been performed using the code SPACE for the modulator, the first section of the Coherent electron cooling (CeC) device installed in the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL). Simulation results have been benchmarked with analytical solution using uniform electron beam with realistic thermal velocities. Electron bunches with Gaussian distribution and quadrupole field with realistic settings have been applied in the simulations to predict the modulation process and final bunching factors induced by ions with reference and off-reference energies in the CeC experiment at BNL RHIC.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAF005
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THPAF010	Reduction of Coherent Betatron Oscillations Using RF Electric Fields in the Fermilab Muon g-2 Experiment	dipole, experiment, simulation, betatron	2961
	O. Kim, S. Hacıömeroğlu, Y.I. Kim, Y.K. Semertzidis CAPP/IBS, Daejeon, Republic of Korea Y.F. Orlov Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
	The Fermilab Muon g-2 experiment aims to measure the muon anomalous magnetic moment with a 140 parts-per-billion precision to investigate the greater than 3 standard deviation difference between the Standard Model prediction and the previous measurement by the BNL Muon g-2 experiment. The coherent betatron oscillation (CBO) beam effects must be corrected for in the decay-positron time spectra fits used in high precision muon storage ring based anomalous magnetic moment measurements. This MC simulation study indicates that the application of radio frequency (RF) electric fields to the muon storage ring beam can reduce the CBO amplitude by up to a factor of 10, as well to increase the symmetry of the beam phase space. This is achieved by correcting the mismatched oscillation phases between the high and low momentum muon populations by modulating the muon beam betatron oscillation frequencies with off-resonance RF fields.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAF010
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THPAF016	3D Tracking Methods in a GEANT4 Environment Through Electrostatic Beamlines	simulation, experiment, proton, antiproton	2979
	J.R. Hunt, J. Resta-López, V. Rodin, B. Veglia, C.P. Welsch The University of Liverpool, Liverpool, United Kingdom J.R. Hunt, J. Resta-López, V. Rodin, B. Veglia, C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom
	Funding: Work supported by the EU under Grant Agreement 721559 and the STFC Cockcroft Institute core Grant No. ST/G008248/1. Due to the relatively infrequent use of electrostatic beamline elements compared with their magnetic counterparts, there are few particle tracking codes which allow for the straightforward implementation of such beamlines. In this contribution, we present 3D tracking methods for beamlines containing electrostatic elements utilising a modified version of the Geant4 based tracking code 'G4beamline'. In 2020 transfer lines will begin transporting extremely low energy (100 keV) antiproton beams from the Extra Low Energy Antiproton (ELENA) ring to the antimatter experiments at CERN. Electrostatic bending and focusing elements have been chosen for the beamlines due to their mass independence and focusing efficiency in the low energy regime. These beamlines form the basis of our model which is benchmarked against simplified tracking simulations. Realistic beam distributions obtained via tracking around ELENA in the presence of collective effects and electron cooling will be propagated along the optimised 3D transfer model to achieve the best beam quality possible for the experiments.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAF016
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THPAF019	Initial Performance of the Magnet System in the Splitter/Combiner Section of the Cornell-Brookhaven Energy-Recovery Linac Test Accelerator	linac, dipole, cavity, optics	2986
	J.A. Crittenden, A.C. Bartnik, R.M. Bass, D.C. Burke, J. Dobbins, C.M. Gulliford, Y. Li, D. Sagan, K.W. Smolenski, Turco, J. Turco Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA J.S. Berg BNL, Upton, Long Island, New York, USA D. Jusic Cornell University, Ithaca, New York, USA
	Funding: This work is supported by NSF award DMR-0807731, DOE grant DE-AC02- 76SF00515, and New York State Energy Research and Development Authority. The Cornell-Brookhaven Energy-recovery Linac Test Accelerator is a four-pass, 150-MeV electron accelerator with a six-cell 1.3 GHz superconducting-RF linear accelerator and a fixed-field alternating-gradient (FFAG) return loop made up of Halbach-style quadrupole magnets. The optics matching between the linear accelerator and the return loop is achieved with a conventional magnet system comprised of 50 dipole magnets and 64 quadrupole magnets in four beamlines at each end of the linac. The 42-, 78-, 114- and 150-MeV electron beams are separated into independent vacuum chambers in order to allow for the path-length adjustment required by energy recovery. We report on the first beam tests of the initial installation of the splitter/combiner section at the exit of the linac. The vacuum system of the 42-MeV S1 line was installed during the first week of April. Nine dipole and four quadrupole magnets were installed and surveyed into position the following week, and the water cooling system was commissioned. A 6-MeV beam passed through the line on April~11 with no need for adjusting pre-set magnet excitation currents. One week later, time-of-flight measurements were used to calibrate and phase the individual superconducting RF cavities. The S1 magnet settings were then scaled up to achieve 5-cavity, 42-MeV operation through the first nine FFAG permanent-magnet quadrupoles. This initial Fractional Arc Test will conclude on May 18, when the installation of the remaining seven splitter/combiner lines and the return loop will begin. CBETA operations are scheduled to begin in early 2019.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAF019
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THPAF023	The Beam Optics of the FFAG Cell of the CBETA ERL Accelerator	optics, focusing, linac, electron	3000
	W. Lou, A.C. Bartnik, J.A. Crittenden, C.M. Gulliford, G.H. Hoffstaetter, D. Sagan Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA J.S. Berg, S.J. Brooks, F. Méot, D. Trbojevic, N. Tsoupas BNL, Upton, Long Island, New York, USA C.E. Mayes SLAC, Menlo Park, California, USA
	Funding: This manuscript has been authored by employees of Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy. The Cornell-Brookhaven Energy Recovery Linac Test Accelerator now under construction will accelerate electrons from 6 MeV to 150 MeV in four linac passes, using a single return line accepting all energies from 42 to 150 MeV. We describe the optical design of the machine, with emphasis on recent updates. We explain how we choose parameters for the wide energy acceptance return arc, taking into account 3D field maps generated from magnet designs. We give the final machine parameters resulting from iterations between desired lattice properties and magnet design. We modified the optics to improve the periodicity of the return arc near its ends and to create adequate space for vacuum hardware. The return arc is connected to the linac with splitter lines that serve to match the optics for each beam energy. We describe how matching conditions were chosen for the splitter lines and how we use them to control longitudinal motion. We simulate the injection and low energy extraction systems including space charge effects, matching the beam properties to the optical parameters of the rest of the machine.
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THPAF039	IP Orbit Correction Update for HL-LHC	alignment, optics, dipole, cavity	3048
	D. Gamba, R. De Maria CERN, Geneva, Switzerland
	Funding: Research supported by the HL-LHC project. The HL-LHC design foresees a substantial modification of the LHC layout next to the low beta Interaction Points (IPs), namely IP1 and IP5. The inner triplets will be replaced by larger aperture ones to achieve lower beta at the IPs and crab cavities (CCs) will be installed. This will add new constraints to the orbit control, which required a careful choice of location and strength of the new orbit correctors to be installed in the area. The new orbit correction system will need to correct for the unavoidable imperfections, but also provide the necessary flexibility for implementing and optimising the crossing scheme. Detailed studies of the HL-LHC layout versions HLLHCV1.0 and HLLHCV1.1 were already performed. This paper is the continuation of these works and is based on the latest layout HLLHCV1.3. A simplification of the previous analysis is proposed that helps to identify the dominant imperfections. The expected performance and tolerances of the present layout are presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAF039
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THPAF040	Estimated Impact of Ground Motion on HL-LHC Beam Orbit	ground-motion, luminosity, emittance, closed-orbit	3052
	D. Gamba, R. Corsini, M. Guinchard, M. Schaumann, J. Wenninger CERN, Geneva, Switzerland
	Funding: Research supported by the HL-LHC project. The High Luminosity LHC (HL-LHC) will require unprecedented orbit stability at the low beta collision points (IP1 and IP5), and the effect of seismic noise might become a relevant source of luminosity loss. Many studies have been conducted in the past to characterise the actual ground motion in the LHC tunnel, and recently a few geo-phones have been installed to permanently monitor the ground stability at IP1 and IP5. An estimate of the impact of the main machine element vibration on orbit at the IPs and collimators is presented, together with a first look at the data collected by the installed geo-phones.
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THPAF060	A Benchmark Study of a High Order Symplectic Integration Method With Only Positive Steps	lattice, sextupole, multipole, target	3111
	K. Skoufaris, Y. Papaphilippou CERN, Geneva, Switzerland J. Laskar IMCCE, Paris, France Ch. Skokos University of Cape Town, Cape Town, South Africa
	The symplectic integrators CSABA & CSBAB are used in order to calculate single particles dynamics in accelerators and storage rings. These integrators include only forward drift steps while being highly accurate. Their efficiency to describe various optical and dynamical quantities for main magnetic elements and non-linear lattices is calculated and compared with the efficiency of the splitting methods used in MAD-X - PTC.
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THPAF062	Impact of Superconducting Magnet Protection Equipment on the Circulating Beam in HL-LHC	dipole, simulation, shielding, experiment	3115
	M. Valette, L. Bortot, A.M. Fernandez Navarro, B. Lindstrom, M. Mentink, R. Schmidt, E. Stubberud, A.P. Verweij, D. Wollmann CERN, Geneva, Switzerland E. Ravaioli LBNL, Berkeley, California, USA
	Funding: Work supported by the HL-LHC project. The new superconducting quadrupole and dipole magnets for the High Luminosity LHC (HL-LHC) will rely on quench heaters or Coupling-Loss Induced Quench (CLIQ) units or a combination of both to protect the magnet coils in case of a quench. After the detection of a quench, the quench heater power supplies will discharge currents of several hundreds of amperes into the quench heater strips glued to the coils, and the CLIQ units will discharge an oscillating current in the order of 1~kA directly into the coils. These currents can have a significant effect on the circulating beam if the discharge occurs before the beam is dumped. In the HL-LHC inner triplet quadrupole magnets and 11 T dipole magnets, which will be installed in the collimation region dispersion suppressor, this effect will even be stronger due to the larger number of quench heaters and use of CLIQ units (triplet magnets only) as well as due to the greater value of beta function in comparison with the present LHC. In this paper, the expected effects of quench heater and CLIQ discharges on the circulating beam are summarized, and several mitigation methods are proposed and evaluated. Matthieu. Valette@cern.ch
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THPAF070	Design of a One-Dimensional Sextupole Using Semi-Analytic Methods	sextupole, lattice, coupling, focusing	3140
	L. Gupta Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA S. Baturin Enrico Fermi Institute, University of Chicago, Chicago, Illinois, USA Y.K. Kim University of Chicago, Chicago, Illinois, USA S. Nagaitsev Fermilab, Batavia, Illinois, USA
	Funding: Work supported by the U.S. National Science Foundation under Award No. PHY-1549132, the Center for Bright Beams Sextupole magnets provide position-dependent momentum kicks and are tuned to provide the correct kicks to particles within a small acceptance region in phase space. Sextupoles are useful and even necessary in circular accelerators for chromaticity corrections. They are routinely used in most rings, i.e. CESR. Although sextupole magnets are necessary for particle energy corrections, they also have undesirable effects on dynamic aperture, especially because of their non-linear coupling term in the momentum kick. Studies of integrable systems suggest that there is an analytic way to create transport lattices with specific transfer matrices that limit the momentum kick to one dimension. A one-dimension sextupole is needed for chromaticity corrections: a horizontal sextupole for horizontal bending magnets. We know how to make a "composite" horizontal sextupole using regular 2D sextupoles and linear transfer matrices in an ideal thin-lens approximation. Thus, one could create an accelerator lattice using linear elements, in series with sextupole magnets to create a '1d sextupole'. This paper describes progress towards realizing a realistic focusing lattice resulting in a 1d sextupole.* *S.A. Antipov, et. al., Single-particle dynamics in a nonlinear accelerator lattice: attaining a large tune spread with octupoles in IOTA, Journal of Instrumentation, Volume 12, April 2017.
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THPAF071	McMillan Lens in a System with Space Charge	emittance, simulation, resonance, lattice	3143
	I. Lobach University of Chicago, Chicago, Illinois, USA S. Nagaitsev, E.G. Stern, T. Zolkin Fermilab, Batavia, Illinois, USA
	Space charge (SC) in a circulating beam in a ring produces both betatron tune shift and betatron tune spread. These effects make some particles move on to a machine resonance and become unstable. Linear elements of beam optics cannot reduce the tune spread induced by SC because of its intrinsic nonlinear nature. We investigate the possibility to mitigate it by a thin McMillan lens providing a nonlinear axially symmetric kick, which is qualitatively opposite to the accumulated kick by SC. Experimentally, the proposed concept can be tested in Fermilab's IOTA ring. A thin McMillan lens can be implemented by a short (70 cm) insertion of an electron beam with specifically chosen density distribution in transverse directions. In this article, to see if McMillan lenses reduce the tune spread induced by SC, we make several simulations with particle tracking code Synergia. We choose such beam and lattice parameters that tune spread is roughly 0.5 and a beam instability due to the half-integer resonance 0.5 is observed. Then, we try to reduce emittance growth by shifting betatron tunes by adjusting quadrupoles and reducing the tune spread by McMillan lenses.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAF071
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THPAF076	Using Graphic-Turtle with the Particle Beam Optics Laboratory (PBO Lab)	optics, simulation, scattering, software	3158
	G.H. Gillespie G.H. Gillespie Associates, Inc., Del Mar, California, USA
	A Particle Beam Optics Laboratory (PBO Lab) module has been developed for the Paul Scherrer Institute (PSI) version of the TURTLE program commonly known as Graphic-Turtle. The PSI-TURTLE version extends the original TURTLE program by including several unique beam optics capabilities, as well as by providing a self-contained graphics package. The unique optics modeling, together with the data visualization enhancements, make the PSI-TURTLE program ideal for certain types of beam simulations. The PBO Lab environment provides a single graphic user interface (GUI) that features an easy-to-learn and easy-to-use drag-and-drop beamline construction kit. Underlying the GUI is a sophisticated object model developed specifically for the accelerator community. PBO Lab provides a common interface for multiple charged particle optics codes. Modules have been developed for a number of popular beam optics programs that cover a range of accelerator types and applications. The PSI-TURTLE Module extends those capabilities. The module is described and its main capabilities and limitations are summarized.
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THPAF079	Landau Damping and Tune-Spread Requirements for Transverse Beam Stability	octupole, simulation, damping, impedance	3168
	V. Kornilov, O. Boine-Frankenheim GSI, Darmstadt, Germany
	Passive mitigation methods are effective cures for collective instabilities in ring accelerators. For decades, octupole magnets have been used as an established and well-understood passive mitigation method. Present and the future accelerator facilities, like FAIR or FCC, impose new challenges on the passive mitigation due to higher energies and smaller beam emittances. Lattice resonances usually restrict the tolerable tune-spreads which are essential for the passive mitigation methods. We study the stability of transverse bunch oscillations provided by octupole magnets and radio-frequency quadrupoles. The special focus of our study is on the interplay and role of decoherence, phase-mixing and Landau damping for the different mitigation schemes. Particle tracking simulations are performed and the tune spreads for the different mechanisms are compared with each other and also with analytical dispersion relations.
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THPAF080	SIS100 Beam Dynamics Challenges Related to the Magnet System	dipole, resonance, sextupole, extraction	3172
	V. Kornilov, O. Boine-Frankenheim, V. Chetvertkova, S. Sorge, P.J. Spiller GSI, Darmstadt, Germany
	The SIS100 synchrotron is the central accelerator of the upcoming FAIR project at GSI, Darmstadt, Germany. The major challenges of the future operation are related to high-intensity, low beam loss operation for a wide range of ion species and charge states, for different operational cycles and extraction schemes. The magnet system consists of 108 dipole, 166 quadrupole and additional correction superconducting superferric magnets. The magnets are presently under production and testing, with detailed measurements of the magnetic field imperfections. This results in the construction of a complete database for the SIS100 magnet system. We analyse implications of the magnetic field imperfections for the single-particle stability, space charge induced tune-shifts and resonance crossing for the different SIS100 operation modi. Resonance compensation and magnet sorting schemes are discussed as possible measures.
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THPAK004	Accurate and Efficient Tracking in Electromagnetic Quadrupoles	dynamic-aperture, multipole, HOM, optics	3207
	T. Pugnat, B. Dalena, A. Simona CEA/IRFU, Gif-sur-Yvette, France L. Bonaventura Politecnico di Milano, Milano, Italy R. De Maria, J. Molson CERN, Geneva, Switzerland
	Accelerator physics needs advanced modeling and simulation techniques, in particular for beam stability studies. A deeper understanding of the effects of magnetic fields nonlinearities will greatly help in the improvement of future colliders design and performance. This paper presents a study of quadrupole tracking using realistic field maps and measured or simulated longitudinal harmonics. The main goal is to describe the effect of the longitudinal dependence of high order non-homogeneity of the field in the case of the HL-LHC inner triplet.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAK004

Paper

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MOPMF010

Measurement and Simulation of Betatron Coupling Beam Transfer Function in RHIC

coupling, betatron, simulation, experiment

99

Y. Luo, W. Fischer, A. Marusic, M.G. Minty
BNL, Upton, Long Island, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
Transfer function measurements are important for characterizing betatron tunes, betatron coupling, and beam spectrum in the routine operation of the Relativistic Heavy Ion Collider (RHIC). To counteract the linear betatron coupling, we developed a technique to continuously measure the betatron coupling coefficient with a base band phase lock loop tune meter in 2006. Based on this technique, we demonstrated and built a robust tune/coupling feedback in RHIC. In this article, we revisit the BTF measurement with betatron coupling to benchmark our BTF simulation code. We also compared the values of eigenmode projection ratios from BTF with those calculated with the single particle model.

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MOPMF023

Updates on the Optic Corrections of FCC-hh

coupling, injection, dipole, interaction-region

133

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

The FCC-hh (Future Hadron-Hadron Circular Collider) is one of the options considered for the next generation accelerator in high-energy physics as recommended by the European Strategy Group, and the natural evolution of existing LHC. The evaluation of the various magnets mechanical error and field error tolerances in the arc sections of FCC-hh, as well as an estimation of the correctors strengths necessary to perform the error corrections, are important aspects of the collider design. In this study recommended values for the mechanical errors, dipole and quadrupole field errors tolerances are proposed, with the possible consequences on the correctors technological choice and on the beam screen design. Advanced correction schemes of the linear coupling (with skew quadrupoles) and of the beam tunes (with normal quadrupoles) are discussed. Also a combined correction scheme including the interaction regions is tested.

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MOPMF025

Overview of Arc Optics of FCC-hh

dipole, optics, insertion, sextupole

141

A. Chancé, B. Dalena
CEA/IRFU, Gif-sur-Yvette, France
D. Boutin
CEA/DRF/IRFU, Gif-sur-Yvette, France
B.J. Holzer, 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 options considered for the next generation accelerator in high-energy physics as recommended by the European Strategy Group. In this overview the status and the evolution of the design of optics integration of FCC-hh are described, focusing on design of the arcs, alternatives, and tuning procedures.

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MOPMF063

Asynchronous Beam Dump Tests at LHC

proton, extraction, beam-losses, operation

265

C. Wiesner, W. Bartmann, C. Bracco, E. Carlier, L. Ducimetière, M.I. Frankl, M.A. Fraser, B. Goddard, C. Heßler, T. Kramer, A. Lechner, N. Magnin, V. Senaj, D. Wollmann
CERN, Geneva, Switzerland

The detailed understanding of the beam-loss pattern in case of an asynchronous beam dump is essential for the safe operation of the future High Luminosity LHC (HL-LHC) with nearly twice the nominal LHC beam intensity, leading to correspondingly higher energy deposition on the protection elements. An asynchronous beam dump is provoked when the rise time of the extraction kickers is not synchronized to the 3 us long particle-free abort gap. Thus, particles that are not absorbed by dedicated protection elements can be lost on the machine aperture. Since asynchronous beam dumps are among the most critical failure cases of the LHC, experimental tests at low intensity are performed routinely. This paper reviews recent asynchronous beam dump tests performed in the LHC. It describes the test conditions, discusses the beam-loss behaviour and presents simulation and measurement results. In particular, it examines a test event from May 2016, which led to the quench of four superconducting magnets in the extraction region and which was studied by a dedicated beam experiment in December 2017.

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MOPMF088

Preparation Activity for the Siddharta-2 Run at DAΦNE

experiment, luminosity, controls, feedback

334

C. Milardi, D. Alesini, S. Bini, O.R. Blanco-García, M. Boscolo, B. Buonomo, S. Cantarella, S. Caschera, A. D'Uffizi, A. De Santis, G.O. Delle Monache, D.G.C. Di Giulio, G. Di Pirro, A. Drago, L.G. Foggetta, A. Gallo, R. Gargana, A. Ghigo, S. Guiducci, S. Incremona, F. Iungo, C. Ligi, M. Maestri, A. Michelotti, L. Pellegrino, R. Ricci, U. Rotundo, L. Sabbatini, C. Sanelli, G. Sensolini, A. Stecchi, A. Stella, A. Vannozzi, M. Zobov
INFN/LNF, Frascati (Roma), Italy
G. Castorina
INFN-Roma1, Rome, Italy
J. Chavanne, G. Le Bec, P. Raimondi
ESRF, Grenoble, France

DAΦNE, the Frascati lepton collider working at the c.m. energy of the F resonance, continues to be a very suitable infrastructure to realize experiments aimed at studying elementary particles and nuclear physics. The motivations of this long lasting interest are related to the DAΦNE ability of increasing its performances in terms of luminosity thanks to the innovative Crab-Waist collision scheme. In this framework, a new run for the SIDDHARTA-2 experiment has been planned in the year 2019. The detector presently installed in the interaction region, KLOE-2, will be removed and a new low-beta session, equipped with new permanent magnets quadrupoles, will be installed. Diagnostics tools will be improved especially the ones used to keep under control the beam-beam interaction. The horizontal feedback in the positron ring will be potentiated in order to achieve a higher positron current. The design and development work done in view of the SIDDHARTA-2 run is presented and discussed.

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MOPMK001

Optics for RF Acceleration Section for the High Energy Large Hadron Collider

optics, cavity, dipole, instrumentation

345

L. van Riesen-Haupt, J.L. Abelleira
University of Oxford, Oxford, United Kingdom
J.L. Abelleira, E. Cruz Alaniz, P. Martinez Mirave, A. Seryi
JAI, Oxford, United Kingdom
M. Hofer, F. Zimmermann
CERN, Geneva, Switzerland
D. Zhou
KEK, Ibaraki, Japan

Funding: Work supported by the Horizon 2020 project EuroCirCol, grant 654305 and by the Science and Technology Facilities Council
As part of the FCC study, the design of the High Energy LHC (HE-LHC) is addressed. A proposed layout for the interaction region for the containing the radio frequency (RF) cavities and various beam instrumentation will be discussed. The higher energy requires more RF cavities, which strongly restricts the space available for optics and instrumentation. Another challenge arises because the beam rigidity increases whilst the LHC geometry has to be conserved. To this end, next generation dipoles have to be used in order to achieve sufficient beam to beam separation. A design that provides enough beam stay clear (BSC) in all the magnets will be presented. The design introduces an additional quadrupole on either side of the RF region to be used for phase advance adjustments that can increase the dynamic aperture.

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MOPMK003

Energy Deposition Studies and Luminosity Evolution for the Alternative FCC-hh Triplet

optics, luminosity, radiation, dipole

352

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

Funding: Work supported by EuroCircol, EU's Horizon 2020 grant No 654305 & STFC grant to the John Adams Institute
The international Future Circular Collider (FCC) study comprises the development of a new scientific structure in a tunnel of 100 km. This will allow the installation of a proton collider with a centre of mass energy of 100 TeV, called FCC-hh. An alternative design of the final focus triplet for the FCC-hh has been developed in parallel to the alternative one, and adapted to the constraint of a free length (L*) of 40 m. We discuss in this paper the energy deposition issues as well as the luminosity evolution for two different optics choices: round and flat beams.

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MOPMK005

HE-LHC Final Focus: Flat Beam Parameters and Energy Deposition Studies

optics, luminosity, cavity, dipole

356

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

Funding: Work supported by EuroCircol, EU's Horizon 2020 grant No 654305 & STFC grant to the John Adams Institute
The High Energy LHC (HE-LHC) project is studying the feasibility of a new proton-proton collider with a beam energy of 13.5 TeV. The nominal optics features a β^* of 0.25 m and crab-cavities. Here we present a flat-beam optics that can be used with a non-zero crossing angle, in the absence of crab cavities. This is followed by energy deposition studies for the superconducting quadrupoles and dipole separators. The total dose in these magnets coming from the collision debris is evaluated.

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MOPMK006

Experimental Interaction Region Optics for the High Energy LHC

optics, dipole, shielding, dynamic-aperture

360

L. van Riesen-Haupt, J.L. Abelleira
University of Oxford, Oxford, United Kingdom
J.L. Abelleira, E. Cruz Alaniz, A. Seryi
JAI, Oxford, United Kingdom
M.P. Crouch, F. Zimmermann
CERN, Geneva, Switzerland
D. Zhou
KEK, Ibaraki, Japan

Funding: Work supported by the Horizon 2020 project EuroCirCol, grant 654305 and by the Science and Technology Facilities Council
The High Energy LHC (HE-LHC) is one option for a next generation hadron collider explored in the FCC-hh program. The core concept of the HE-LHC is to install FCC-hh technology magnets in the LHC tunnel. The higher beam rigidity and the increased radiation debris, however, impose severe challenges on the design of the triplet for the low beta insertions. In order to achieve 25 cm β^* optics and survive a lifetime integrated luminosity of 10 ab-1 a new longer triplet was designed that provides sufficient shielding and enough beam stay clear. This triplet has been designed using complimentary radiation studies to optimise the shielding that will also be presented. The optics for the rest of the interaction region had to be adjusted in order to host this more rigid beam and longer triplet whilst leaving enough room for crab cavities. Moreover, the effects non-linear errors in this triplet have on the dynamic aperture will be outlined.

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MOPMK007

An Optimised Triplet for the Final Focus of the FCC-HH with a 40m Final Drift

optics, luminosity, collider, injection

364

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

Funding: Work supported by the Horizon 2020 project EuroCirCol, grant 654305 and by the Science and Technology Facilities Council
The sizes of the beta functions in the final focus triplet of a synchrotron collider have a great impact on the chromaticity and dynamic aperture of the machine. These beta functions are proportional to the square of the length of the final drift so it is desirable to keep it as short as possible whilst leaving enough room for the experiment. In the latest design of the FCC-hh this drift was reduced from 45 m to 40 m. In the following an alternative final focus for this new design will be presented. The effects this change has on the interaction region will examined and discussed.

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MOPMK012

Electron Cloud Studies in FCC-ee

electron, collider, simulation, vacuum

374

E. Belli
Sapienza University of Rome, Rome, Italy
P. Costa Pinto, G. Rumolo, T.F. Sinkovits, M. Taborelli
CERN, Geneva, Switzerland
M. Migliorati
INFN-Roma1, Rome, Italy

Electron cloud effects are one of the most critical aspects for the LHC and the future circular colliders. In the frame of the electron-positron collider FCC-ee, an estimation of the electron cloud build up in the machine will be discussed in this paper. A preliminary evaluation of the heat load in the arc components and interaction region magnets will be presented, together with possible mitigation strategies.

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MOPML039

Comparison of Two Types of Steerers Applied in Proton Therapy Gantry

proton, simulation, superconductivity, radiation

488

Z.F. Zhao, Q.S. Chen, S. Hu, X. Liu, B. Qin, W. Wei
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

A proton therapy project HUST-PTF (HUST Proton Therapy Facility) based on a 250MeV isochronous superconducting cyclotron is under development in Huazhong University of Science and Technology (HUST). Based on the optics design of the gantry, the steering magnets need to be placed in a compact structure, as well as meet the magnetic field requirement with a maximum deflection angle of ±5mrad@250MeV. In the paper, two types of steerers (O-shape and H-shape) were introduced and discussed in detail. The magnetic fringe field interference effects between quadrupoles and steerers were studied by using OPERA/TOSCA code. The result based on the contrastive analysis will give us a valuable reference to choose suitable steerers for proton therapy beamline.

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TUPAF028

Energy Deposition Studies and Analysis of the Quench Behavior in the Case of Asynchronous Dumps During 6.5 TeV LHC Proton Beam Operation

simulation, superconducting-magnet, proton, kicker

736

M.I. Frankl, W. Bartmann, M. Bednarek, C. Bracco, A. Lechner, A.P. Verweij, C. Wiesner, D. Wollmann
CERN, Geneva, Switzerland

The CERN LHC beam dumping system comprises a series of septa and fast-pulsed kicker magnets for extracting the stored proton beams to the external beam dumps. Different absorbers in the extraction region protect superconducting magnets and other machine elements in case of abnormal beam aborts, where bunches are swept across the machine aperture. During Run 2 of the LHC, controlled beam loss experiments were carried out at 6.5 TeV probing the particle leakage from protection devices under realistic operation conditions. This paper presents particle shower simulations analyzing the energy deposition in superconducting coils and assessing if the observed magnet quenches are compatible with the presently known quench limits.

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TUPAF032

Beam Transfer Line Design to the SPS Beam Dump Facility

target, proton, experiment, extraction

751

Y. Dutheil, J. Bauche, M. Calviani, L.A. Dougherty, M.A. Fraser, B. Goddard, C. Heßler, J. Kurdej, E. Lopez Sola
CERN, Geneva, Switzerland

Studies for the SPS Beam Dump Facility (BDF) are ongoing within the scope of the Physics Beyond Collider project. The BDF is a proposed fixed target facility to be installed in the SPS North Area, to accommodate the SHiP experiment (Search for Hidden Particles), which is most notably aiming at studying hidden sector particles. This experiment requires a high intensity slowly extracted 400 GeV proton beam with 4·10¹³ protons per 1 s spill to achieve 4·10¹⁹ protons on target per year. The extraction and transport scheme will make use of the first 600 m of the existing North Area extraction line. In this paper, we will present the design of the additional 600 m of transfer line towards BDF branching off from the existing line and discuss the detailed design of the BDF beam line, its components and optics. We present the latest results on the study and design of a new laminated Lambertson splitter magnet to provide fast switch between the current North Area experiments and the BDF. The latest specification of a dipole dilution system used to reduce the local peak power of the beam on the target is also presented.

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TUPAF035

Observations of SPS Slow-Extracted Spill Quality Degradation and Possible Improvements

extraction, power-supply, simulation, experiment

761

F.M. Velotti, H. Bartosik, K. Cornelis, M.A. Fraser, B. Goddard, S. Hirlaender, V. Kain, O. Michels, M. Pari
CERN, Geneva, Switzerland

The SPS delivers slow extracted proton and heavy ion spills of several seconds to the North Area fixed target experiments with a very high duty factor. Reduced machine reproducibility due to magnetic history and power supply ripples on the main circuits lead however to frequent degradation of the spill duty factor. In this paper, the measured effect of the SPS magnetic history on spill quality and principal machine parameters is presented. Another detailed measurement campaign was aimed at characterising the frequency content and response of the spill to noise on the main power supplies ripples. The main findings of this study will also be reported. Finally, simulations of possible improvements based on the data acquired are discussed, as well as an extrapolation to the possible spill quality after the implementation of the improvements.

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TUPAF050

Beam Dynamics Simulations of the Effect of Power Converter Ripple on Slow Extraction at the CERN SPS

extraction, emittance, sextupole, experiment

818

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

The SPS provides slowly extracted protons at 400 GeV/c to CERN's North Area Fixed Target experiments over spills of duration from 1-10 seconds. Low frequency ripple on the current in the main magnets originating from their power converters is a common issue that degrades the slow-extracted spill quality. In order to better understand how the stability of the power converters affects losses, beam emittance and spill quality, particle tracking simulations were carried out using MAD-X and compared to measurements, with the impact of each magnet circuit investigated systematically. The implications for the performance of the SPS slow extraction are discussed.

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TUPAF077

Beam Optics Measurements in Medium Energy Beam Transport at PIP-II Injector Test Facility

optics, rfq, beam-transport, emittance

909

A. Saini, J.-P. Carneiro, B.M. Hanna, L.R. Prost, A.V. Shemyakin
Fermilab, Batavia, Illinois, USA
V.L. Sista
BARC, Mumbai, India

Funding: This manuscript has been authored by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the U.S. Department of Energy, Office of Science, Office of High Energy Physics
The Proton Improvement Plan-II Injector Test (PIP2IT) is an accelerator test facility under construction at Fermilab that will provide a platform to demonstrate critical technologies and concept of the front-end of the PIP-II linear accelerator (linac). The PIP2IT warm front-end comprises a H⁻ ion source capable of delivering 15 mA, 30 keV DC or pulsed beam, a Low Energy Beam Transport (LEBT), a 162.5 MHz, CW Radio Frequency Quadrupole (RFQ) that accelerates the beam to 2.1 MeV and, a 14 m medium energy beam transport (MEBT). Presently, beamline up to the MEBT has been commissioned and operates routinely at the PIP2IT facility. In this paper, we discuss beam measurements performed at the MEBT to analyze beam emittance and its RMS sizes along the MEBT. In addition, beam based calibration of the beamline elements using differential trajectory measurement is also presented.

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TUPAF080

Final Design of the FoS Alvarez-Cavity-Section for the Upgraded UNILAC

cavity, DTL, operation, simulation

920

M. Heilmann, X. Du, L. Groening, M. Kaiser, S. Mickat, C. Mühle, A. Rubin, V. Srinivasan
GSI, Darmstadt, Germany
A. Seibel
IAP, Frankfurt am Main, Germany

The final design describes the First-of-Series (FoS) Alvarez-Cavity-section of the first tank being part of the new post-stripper DTL of the UNILAC. The FoS-cavity has an input energy of 1.358 MeV/u with 11 drift tubes (including quadrupole singlets) in a total length of 1.9 m and a diameter of 2 m with an operation frequency of 10⁸.4 MHz. The drift tubes will have a new shape profile at the end plates. The single layered quadruple singlets inside the drift tubes are pulsed with 10 Hz and will have a maximum field gradient of 51 T/m. The new drift tube design combines the new shape profile with the transverse and longitudinal installation space of the magnet. The FoS Alvarez-cavity will be part of the first section of the new Alvarez DTL. It shall be operated at nominal RF- and magnetic fields prior to procurement of the series.

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TUPAK001

Progress of the Modulated 325 MHz Ladder RFQ

rfq, linac, proton, operation

952

M. Schuett, U. Ratzinger, M. Syha
IAP, Frankfurt am Main, Germany

Funding: BMBF 05P15RFRBA
Based on the positive results of the unmodulated 325 MHz Ladder-RFQ prototype from 2013 to 2016, we developed and designed a modulated 3.3 m Ladder-RFQ*. The unmodulated Ladder-RFQ features a very constant voltage along the axis. It accepted 3 times the operating power of which is needed in operation**. That level corresponds to a Kilpatrick factor of 3.1 with a pulse length of 200 μs. The 325 MHz RFQ is designed to accelerate protons from 95 keV to 3.0 MeV according to the design parameters of the proton linac within the FAIR project. This particular high frequency creates difficulties for a 4-ROD type RFQ, which triggered the development of a Ladder RFQ with its high symmetry. The results of the unmodulated prototype have shown, that the Ladder-RFQ is a suitable candidate for that frequency. The duty cycle is suitable up to 5%. The basic design and tendering of the RFQ has been successfully completed in 2016. Manufacturing will be completed in May 2018. We will show the latest results of manufacturing, beam dynamics simulations for the matching between LEBT and RFQ.
*Journal of Physics: Conf. Series 874 (2017) 012048
**Proceedings of LINAC2016, East Lansing, TUPLR053

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TUPAK016

Commissioning of the Diagnostic Beam Line for the Muon RF Acceleration with H⁻ Ion Beam Derived from the Ultraviolet Light

acceleration, diagnostics, experiment, MMI

997

Y. Nakazawa, H. Iinuma
Ibaraki University, Ibaraki, Japan
N. Kawamura, T. Mibe, M. Otani, T. Yamazaki
KEK, Ibaraki, Japan
R. Kitamura
University of Tokyo, Tokyo, Japan
Y. Kondo
JAEA/J-PARC, Tokai-mura, Japan
N. Saito
J-PARC, KEK & JAEA, Ibaraki-ken, Japan
Y. Sue
Nagoya University, Graduate School of Science, Chikusa-ku, Nagoya, Japan

Funding: This work is supported by JSPS KAKENHI Grant Numbers JP15H03666, JP16H03987, and JP16J07784.
A muon LINAC is under development for a precise measurement of muon g-2 / EDM at J-PARC. We conducted an experiment of a muon RF acceleration on October and December 2017. The surface muon beam is irradiated to a metal degrader to generate slow negative muonium. The slow negative muoniums are accelerated to 90 keV with an electrostatic accelerator and an RFQ. Prior to muon RF acceleration, we conducted a commissioning of the diagnostic beam line consisting of two quadrupole magnets and a bending magnet. The ultraviolet light is irradiated to an aluminum foil and H⁻ ion is generated. It simulates a negative muonium and is accelerated with an electrostatic accelerator. This system allowed us to check operation for the diagnostic beam line, which is essential task for transportation and momentum selection of the negative muonium. In this paper, I would like to report the performance evaluation of the diagnostic beam line by H⁻ ions.

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TUPAK018

Study on the Collimation Method for a Future Proton-Proton Collider

collimation, proton, insertion, superconducting-magnet

1004

J.Q. Yang, Y. Bao, J.Y. Tang, J.Y. Tang, Y. Zou
IHEP, Beijing, People's Republic of China

As the second phase of CEPC-SPPC project, SPPC (Super Proton-Proton Collider) is to explore new physics beyond the standard model in the energy frontier with a center-of-mass energy of 75 TeV. In order to handle extremely-high stored energy in beam, the collimation system of extremely high efficiency is required for safe operation. SPPC has been studying a collimation method which arranges both the transverse and momentum collimations in one long straight section. In this way, the downstream momentum collimation section can clean those particles related to the single diffractive effect in the transverse collimation section thus eliminate beam losses in the arc section. In addition, one more collimation stage is obtained with use of special superconduct-ing quadrupoles in the transverse collimation section. Multiple particle simulations have proven the effectiveness of the methods. This paper presents the study results on the collimation scheme.

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TUPAL011

Low Power Test and Tuning of the LEAF RFQ

rfq, cavity, dipole, operation

1028

L. Lu, T. He, Y. He, W. Ma, L.B. Shi, L.P. Sun, C.C. Xing, X.B. Xu, L. Yang, H.W. Zhao
IMP/CAS, Lanzhou, People's Republic of China

A continuous wave (CW) four-vane radio frequency quadrupole (RFQ) accelerator is under construction for the Low Energy Accelerator Facility (LEAF) at Institute of Modern Physics (IMP). The 5.96 m RFQ will operate with the capability of accelerating all ion species from proton to uranium from 14 keV/u up to 500 keV/u. In this paper, the low power test and tuning results of the RFQ accelerator, including the test of the separate sections and the whole cavity, will be presented. After the final tuning, the relative error of the quadrupole field is within 2% and the admixture of the dipole modes are below 4% of the quadrupole mode.

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TUPAL031

Errors Study of a Double-Pass Recirculating Superconducting Proton Linac

linac, proton, cavity, emittance

1069

Y. Tao, K. Hwang, J. Qiang
LBNL, Berkeley, California, USA

The concept of recirculating superconducting proton linac was recently proposed. Beam dynamics simulations were carried out in a double-pass recirculating proton linac using a single bunch. Although all the beam line elements should be installed following the designed values, in reality, there exist machine imperfections that will cause beam off-centering and even particle losses. In this paper, we report on the study of the static and dynamic errors from RF cavities and magnetic focusing elements in the double-pass recirculating proton linac.

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TUPAL035

3D Beam Dynamics Modeling of MEBT for the New LANSCE RFQ Injector

emittance, rfq, proton, simulation

1081

S.S. Kurennoy
LANL, Los Alamos, New Mexico, USA

The new RFQ-based proton injector at LANSCE requires a specialized medium-energy beam transfer (MEBT) after the RFQ at 750 keV due to a following long (~3 m) existing common transfer line that also serves for transporting negative-ion beams to the DTL entrance. The horizontal space for MEBT elements is limited because two beam lines merge at 18-degree angle. The MEBT design developed with envelope codes includes two compact quarter-wave RF bunchers and four short quadrupoles with steerers, all within the length of about 1 m. The beam size in the MEBT is large, comparable to the beam-pipe aperture, hence non-linear 3D field effects at large radii become important. Using CST Studio codes, we calculate buncher RF fields and quadrupole magnetic fields and use them to perform particle-in-cell beam dynamics modeling of MEBT with realistic beam distributions from the RFQ. Our results indicate a significant emittance growth not predicted by standard beam dynamics codes. Its origin was traced mainly to the quadrupole edge fields. Quadrupole design modifications are proposed to improve the MEBT performance.

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TUZGBE2

Final-focus Superconducting Magnets for SuperKEKB

solenoid, MMI, operation, detector

1215

N. Ohuchi, K.A. Aoki, Y. Arimoto, M.K. Kawai, T. Kawamoto, H. Koiso, Y. Kondo, M. Masuzawa, A. Morita, S. Nakamura, Y. Ohnishi, Y. Ohsawa, T. Oki, H. Sugimoto, K. Tsuchiya, R. Ueki, X. Wang, H. Yamaoka, Z.G. Zong
KEK, Ibaraki, Japan
M. Anerella, J. Escallier, A.K. Jain, A. Marone, B. Parker, P. Wanderer
BNL, Upton, Long Island, New York, USA
J. DiMarco, T.G. Gardner, J.M. Nogiec, M.A. Tartaglia, G. Velev
Fermilab, Batavia, Illinois, USA
T.-H. Kim
Mitsubishi Electric Corp, Advanced Technology R & D Center, Hyogo, Japan

The SuperKEKB collider aims at 40 times higher luminosity than that achieved at KEKB, based on the nano-beam scheme. The vertical beta function at the interaction point will be squeezed to 300μmeter. Final-focus superconducting magnet system which consists of eight main quadrupole magnets, 43 corrector windings, and compensation solenoids is a key component to achieve high luminosity. This invited talk presents the construction and commissioning of the final-focus magnet system.

Slides TUZGBE2 [4.235 MB]

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TUZGBF1

Superconducting Gantry for Carbon-Ion Radiotherapy

superconducting-magnet, dipole, radiation, MMI

1232

Y. Iwata, T. Furukawa, Y. Hara, S. Matsuba, T. Murakami, K. Noda, N. S. Saotome, S. Sato, T. Shirai
NIRS, Chiba-shi, Japan
N. Amemiya
Kyoto University, Kyoto, Japan
H. Arai, T. Fujimoto
AEC, Chiba, Japan
T.F. Fujita, K. Mizushima, Y. Saraya
National Institute of Radiological Sciences, Chiba, Japan
S. Matsuba
HSRC, Higashi-Hiroshima, Japan
T. Obana
NIFS, Gifu, Japan
T. Ogitsu
KEK, Ibaraki, Japan
T. Orikasa, S. Takayama
Toshiba, Yokohama, Japan
R. Tansho
QST-NIRS, Chiba, Japan

A superconducting magnet gantry has been used at HIMAC in NIRS, transporting beams for carbon ion radiotherapy. A second superconducting gantry, with a different design, is under construction in Yamagata University. This invited talk presents an overview of these gantry designs, their advantages for light ion radiotherapy, their operational experiences, and future perspectives for superconducting radiotherapy gantries.

Slides TUZGBF1 [26.678 MB]

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TUPMF006

Pulsed Wire Measurements of a High Field Gradient Quadrupole Wiggler

wiggler, alignment, laser, wakefield

1257

M. Kasa, A. Zholents
ANL, Argonne, Illinois, USA

Funding: Work supported by the U.S. Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11357.
Alignment of the quadrupoles in a quadrupole wiggler to sub micrometer precision is required for the collinear wakefield accelerator that is under consideration at Argonne National Laboratory for a compact Free-Electron Laser [1]. The pulsed wire measurement method is the only technique that we are aware of that allows for sub micrometer precision and the ability to distinguish between the various quadrupoles within the wiggler. A one period prototype wiggler was manufactured and subsequently measured using the pulsed wire technique. The goal of the measurements was to verify that the magnetic centers of each quadrupole could be located and aligned to each other within the required precision. The method and results are described.
[1] A. Zholents, et al., "A preliminary design of the collinear dielectric wakefield accelerator", Nucl. Instrum. Meth. A829 (2016) 190-193.

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TUPMF010

A Conceptual Design of a Compact Wakefield Accelerator for a High Repetition Rate Multi User X-ray Free-Electron Laser Facility

wakefield, electron, GUI, wiggler

1266

A. Zholents, D.S. Doran, W.G. Jansma, M. Kasa, R. Kustom, J.G. Power, N.O. Strelnikov, K.J. Suthar, E. Trakhtenberg, I. Vasserman, G.J. Waldschmidt, J.Z. Xu
ANL, Argonne, Illinois, USA
S. Baturin
Enrico Fermi Institute, University of Chicago, Chicago, Illinois, USA
H. Perez
IIT, Chicago, Illinois, USA

Funding: Supported by U.S. Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11357
A preliminary design of a collinear wakefield accelerator is described. It is assumed that the array of such accelerators will play a central role in a free-electron laser-based x-ray user facility under consideration at Argonne National Laborator [1].

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TUPMF011

Calculation of Expected Orbit Motion Due to Girder Resonant Vibration at the APS Upgrade

ground-motion, factory, resonance, lattice

1269

V. Sajaev, Z. Liu, J. Nudell, C.A. Preissner
ANL, Argonne, Illinois, USA

Funding: Work supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357.
The Advanced Photon Source (APS) is pursuing an upgrade to the storage ring that will provide electron beam with extremely low emittance. To allow users to take advantage of this small beam size, the beam orbit motion has to be kept stable to within a fraction of the beam size. To keep the beam orbit stable on a sub-micron level, one needs to carefully design magnet supports/girders so that the ground motion does not lead to excessive orbit motion due to resonant modes of magnet supports. In this paper, we will describe the process of calculating the expected orbit motion due to girder resonant vibration. First, we will present the simulation results for the girder resonant modes, then we will calculate the orbit amplification factors for the girder deformation modes, then calculate the expected orbit motion using measured ground motion spectrum. This process can be used to evaluate the design of the magnet supports.

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TUPMF024

Validation of the Halbach FFAG Cell of Cornell-BNL Energy Recovery Linac

linac, permanent-magnet, collider, focusing

1304

F. Méot, S.J. Brooks, D. Trbojevic, N. Tsoupas
BNL, Upton, Long Island, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
The optical properties of the Halbach technology based CBETA ERL return FFAG arc cell are investigated, using its 3-D OPERA field map model. This includes paraxial and large amplitude motion, tune path, study of resonances, dynamic acceptance, effects of various defects, 300-cell 10k-particle bunches 6D transmission trials. These investigations, a 2~3 year investment, have validated the Halbach technology in the linear FFAG cell application, from the point of view of the beam dynamics, so supporting its approval as the required technology for CBETA, in December 2016.

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TUPMF027

Impedance Modeling for eRHIC

impedance, vacuum, dipole, electron

1309

A. Blednykh, G. Bassi, M. Blaskiewicz, C. Hetzel, V. Ptitsyn, V.V. Smaluk, F.J. Willeke
BNL, Upton, Long Island, New York, USA

Funding: Work supported by the US DOE under contract number DE-SC0012704
The impedance budget for the eRHIC project is discussed at its earlier stage of development. As a first step, with the eRHIC lattice and beam parameters , we use the geometric impedances of the vacuum chamber components simulated for the NSLS-II project. The impedance budged will be updated next with more impedance data simulated for the optimized eRHIC vacuum components. It will allows us to keep track on the collective effects changes with more realistic components added to the ring.

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TUPMF038

Design Considerations for an Ultralow Emittance Storage Ring for the Canadian Light Source

emittance, sextupole, lattice, electron

1334

L.O. Dallin
CLS, Saskatoon, Saskatchewan, Canada

Demands from light source scientists for more brilliant xray beams have resulted in the emergence of 4th generation storage rings. These demands include photon beams that are highly focussed and beams with high transverse coherence. Both these requirements are achieved with ultralow electron beam emittance. The practical development of the multi-bend achromat (MBA) concept by MAX IV has spurred many synchrotron light sources around the world to develop similar machines. For existing facilities two options are available: upgrading existing machines or building a new structure. The Canadian Light Source (CLS) has explored both options and has determined a new storage ring is required. Several design options for a 3.0 GeV ring have been developed. Best results are achieved when tracking is used to optimize the phase advance through the MBA structure to reduce the impact of the sextupoles on the dynamic aperture. Structures where no geometric sextupoles are required have been achieved while producing ultralow emittances.

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TUPMF054

Performance Comparison of Different Ultralow Emittance Unit Cells

emittance, lattice, dipole, storage-ring

1382

Y. Jiao, X.Y. Li, G. Xu
IHEP, Beijing, People's Republic of China

The available minimum emittance of a storage ring and the ring performance is closely related to the unit cell of the lattice. Up to now, several ultralow-emittance unit cells have been proposed and applied in the lattice design of the diffraction-limited storage ring light sources. In this study we quantitatively compared the performance of three typical unit cells, based on mainly the parameters of the High Energy Photon Source. The results indicate that the modified-TME unit cell with antibend and longitudinal gradient dipole allows the lowest possible emittance, given a long enough cell length.

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TUPMF072

Microwave Instability and Energy Spread Measurement via Vertical Dispersion Bump in PETRA III

emittance, experiment, undulator, wiggler

1427

Y.-C. Chae, D. Dzhingaev, M. Ebert, G. Falkenberg, J. Keil, G. Kube, G.K. Sahoo, M. Sprung, R. Wanzenberg, F. Westermeier
DESY, Hamburg, Germany
A.I. Novokshonov
TPU, Tomsk, Russia

The recent measurement of bunch length versus current indicated that the longitudinal impedance (Z/n) is 0.15 Ω in close agreement with the impedance model*. Naive application of Keil-Schnell criteria predicts the threshold of microwave instability at 0.25 mA. Since the single bunch intensity is in the range of 0.2-2.5 mA depending on the fill-pattern of PETRA III, we expect to observe the fill-pattern dependent energy spread according to the theory. However, the 3rd generation light sources comparable to PETRA III often reported the observation which was much greater than the theoretical one. In order to induce the beam size variation we had used skew quadrupoles to generate the dispersion in vertical plane. In particular we made dispersion bump at the undulator sector so that we were able to use the X-ray optics for the precise determination of small vertical beam size. In this paper we report the experimental setup and measurement data with the estimate on the instability threshold. We also report the vertical emittance and energy spread based on the X-ray beam size measurement as well as the RF signal which was excited by the beam at the longitudinal feedback cavity.
* K. Balewski, R. Wanzenberg, "OBSERVATION OF INTENSITY DEPENDENT SINGLE BUNCH EFFECTS AT THE SYNCHROTRON LIGHT SOURCE PETRA III", Proc. of IPAC2011, p. 730.

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TUPML003

Design of an L-band Accelerating Structure for the Argonne Wakefield Accelerator Facility Witness Beam Line Energy Upgrade

linac, impedance, coupling, acceleration

1533

J.H. Shao, M.E. Conde, D.S. Doran, J.F. Power
ANL, Argonne, Illinois, USA
C.-J. Jing
Euclid TechLabs, LLC, Solon, Ohio, USA

The Argonne Wakefield Accelerator (AWA) facility has been devoting much effort to the fundamental R&D of two-beam acceleration (TBA) technology with two parallel L-band beam lines. Beginning from the 70 MeV drive beam line, the high frequency (C-band and above) rf power is extracted from the beam by a decelerating structure (a.k.a. power extractor), transferred to an accelerating structure in the witness beam line, and used to accelerate the 15 MeV main beam. These high frequency accelerating structures usually have a small aperture to obtain high gradient and high efficiency, making it difficult for the low energy main beam to pass. To address this issue, one proposal is to increase the main beam energy to above 30 MeV by replacing the current witness linac. A 9-cell 𝜋-mode L-band standing-wave accelerating structure has therefore been designed to meet the high shunt impedance and low cost requirements. In addition, the single-feed coupling cell has been optimized with additional symmetrical ports to eliminate field distortion. The detailed design of the new accelerating structure will be presented in this paper.

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TUPML021

A Beamline Design to Transport Laser Wakefield Electrons to a Transverse Gradient Undulator

laser, electron, undulator, plasma

1577

K.A. Dewhurst, H.L. Owen
UMAN, Manchester, United Kingdom
E. Brunetti, D.A. Jaroszynski, S.M. Wiggins
USTRAT/SUPA, Glasgow, United Kingdom
B.D. Muratori
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
B.D. Muratori
Cockcroft Institute, Warrington, Cheshire, United Kingdom

Funding: This work was supported by the UK Science and Technology Facilities Council, Grant No. ST/G008248/1.
The Cockcroft Beamline is to be installed at the Scottish Centre for the Application of Plasma-based Accelerators (SCAPA). The beamline is designed to transport 1 GeV electrons from a laser wakefield acceleration (LWFA) source to a pair of transverse gradient undulators. The project aims to produce X-ray undulator radiation in the first phase and free-electron laser (FEL) radiation in the second phase. The total beamline will be less than 23 m long, thus the Cockcroft Beamline has the potential to be the UK's first compact X-ray FEL. Here we present the main features of the beamline design.

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TUPML038

Simulation of Phase-Dependent Transverse Focusing in Dielectric Laser Accelerator Based Lattices

lattice, focusing, laser, emittance

1622

F. Mayet, R.W. Aßmann, U. Dorda, W. Kuropka
DESY, Hamburg, Germany
W. Kuropka, F. Mayet
University of Hamburg, Institut für Experimentalphysik, Hamburg, Germany

Funding: Gordon and Betty Moore Foundation. Grant GBMF4744
The Accelerator on a CHip International Program (ACHIP) funded by the Gordon and Betty Moore Foundation aims to demonstrate a prototype of a fully integrated accelerator on a microchip based on laser-driven dielectric structures until 2021. Such an accelerator on a chip needs all components known from classical accelerators. This includes an electron source, accelerating structures and transverse focusing arrangements. Since the period of the accelerating field is connected to the drive laser wavelength of typically a few microns, not only longitudinal but also transverse effects are strongly phase-dependent even for few femtosecond long bunches. If both the accelerating and focusing elements are DLA-based, this needs to be taken into account. In this work we study in detail the implications of a phase-dependent focusing lattice on the evolution of the transverse phase space of a transported bunch.

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TUPML055

Beam Optics Designs of a Strecher Ring and a Transfer Line for J-PARC Slow Extraction

extraction, optics, sextupole, injection

1667

M. Tomizawa, R. Muto, T. Ogitsu
KEK, Ibaraki, Japan
A. Konaka
TRIUMF, Vancouver, Canada

The J-PARC main ring (MR) provides 30 GeV high intensity beams for neutrino experimental facility (NU) by fast extraction and hadron experimental facility (HD) by slow extraction. It is a serious issue to ensure sufficient integrated proton number on target (POT) for each facility. A stretcher ring (ST) can solve this serious problem. A beam accelerated by the MR is transferred to the ST and is slowly extracted over several second. While the beam is slowly extracted in the ST, the MR can accelerate and deliver a beam to the NU. The ST is put above the MR and fitted in the MR tunnel. Arc sections in the ST consist of superconducting combined function magnets (dipole, quadrupole and sextupole components), and separated function quadruple and sextupole magnets (hybrid lattice). A 30 GeV beam transfer line (BT) from the MR to the ST uses superconducting combined magnets with dipole and quadrupole functions to shorten the BT. The transferred beam is injected into an arc section in the ST. The adoption of the superconducting magnets in the ST and the BT saves operation cost drastically. Beam optics designs for the ST and the BT will be described in this paper.

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TUPML078

Fast Quadrupole Beam Based Alignment Using AC Corrector Excitations

alignment, closed-orbit, optics, synchrotron

1727

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

A novel method to perform Beam Based Alignment has been tested at ALBA using the 10kHz fast acquisition BPMs together with an AC excitation of the corrector magnets allowing to speed up the beam based alignment process. The former approach relies on software synchronization and tango device servers to execute a series of DC corrector magnets and quadrupoles settings designed to avoid the quadrupole hysteresis effects. The approach that we present here is simpler, gives the same level of accuracy and precision and speeds up the measurement by a factor 10. The total measurement time has changed from 5 hours to 10 minutes.

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WEPAF003

Beamline Architect

interface, simulation, software, solenoid

1812

J.D. Kunz, C.M. Conrad, L.M. Romero
Anderson University, Anderson, USA

Funding: Indiana Space Grant Fellowship Program 2015-2018, subaward number 4103-82252
Beamline Architect is a new particle accelerator simulation tool. Currently, two of the most widely used tools in this field are G4beamline and COSY Infinity. While these codes are fast and quite accurate, sometimes their interfaces can be time-consuming for students to learn, particularly undergraduate students or students whose primary field is not accelerator physics. Without Beamline Architect, each code has its own high-level language that must be manually written into a file and then executed on the command line. Moreover, sometimes the use of both simulation tools is warranted in order to check for consistency between the codes. Writing the codes by hand or translating between software can sometimes be cumbersome, even for experts. Furthermore, knowledge of an additional language, such as Python, is required in order to analyze the outputs of the codes (which may be in different formats from one another). Beamline Architect is a tool that provides a graphical user interface to G4beamline and COSY Infinity. This lets the user build a particle accelerator channel in 3D with or without using code. The channel may then be saved, exported, translated, or run. Any output data will be plotted in Beamline Architect using Python, since it is both flexible aesthetically and quite standard in the particle accelerator community. For undergraduate and non-accelerator students, Beamline Architect allows a hands-on experience with accelerator simulations. Some applications for these students include health physics radiation dosimetry problems, medical imaging mechanics, security scanner simulations, and (of course) accelerator channel design for particle physics experiments. For experts, Beamline Architect provides visual confirmation of the channel and a faster, more consistent way of cross-referencing results between the codes.

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WEPAF009

Optimising Response Matrix Measurements for LOCO Analysis

storage-ring, coupling, lattice, distributed

1826

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

The Linear Optics from Closed Orbit (LOCO) method is a common tool for determining storage ring lattice functions and requires a measured BPM to Corrector response matrix. For very large rings with many correctors, such measurements can be time consuming. The following study investigates how the number of correctors and the signal-to-noise ratio (SNR) affects the LOCO analysis results. For the Australian Synchrotron, the results show that four distributed correctors per plane with a SNR of >1000 is sufficient to fit the betatron functions to an accuracy of less than 0.2%.

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WEPAF015

Commissioning the Muon g-2 Experiment Electrostatic Quadrupole System

storage-ring, experiment, positron, resonance

1848

J.D. Crnkovic, V. Tishchenko
BNL, Upton, Long Island, New York, USA
K.E. Badgley, H. Nguyen, E. Ramberg
Fermilab, Batavia, Illinois, USA
E. Barlas Yucel, M. Yucel
Istanbul Technical University, Maslak, Istanbul, Turkey
J.M. Grange
ANL, Argonne, Illinois, USA
A.T. Herrod
Cockcroft Institute, Warrington, Cheshire, United Kingdom
A.T. Herrod
The University of Liverpool, Liverpool, United Kingdom
J.L. Holzbauer, W. Wu
UMiss, University, Mississippi, USA
H.D. Sanders
APP, Freeville, New York, USA
H.D. Sanders
Sanders Pulsed Power LLC, Batavia, Illinois, USA
N.H. Tran
BUphy, Boston, Massachusetts, USA

The Fermilab Muon g-2 experiment aims to measure the muon anomaly with a precision of 140 parts-per-billion (ppb) - a fourfold improvement over the 540 ppb precision obtained by the BNL Muon g-2 experiment. These high precision experiments both require a very uniform muon storage ring magnetic field that precludes the use of vertical-focusing magnetic quadrupoles. The Fermilab Electrostatic Quadrupole System (EQS) is the refurbished and upgraded BNL EQS, where this overview describes the Fermilab EQS and its recent operations.

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WEPAF016

Application of Quad-Scan Measurement Techniques to Muon Beams in the Muon g-2 Experiment

experiment, emittance, storage-ring, scattering

1852

J. Bradley
Edinburgh University, Edinburgh, United Kingdom
J.D. Crnkovic
BNL, Upton, Long Island, New York, USA
B.E. Drendel, D. Stratakis
Fermilab, Batavia, Illinois, USA
N.S. Froemming
CENPA, Seattle, Washington, USA

Determination of the properties of a beam during transport is a vital process for most accelerator-related experiments; for example Fermilab's Muon g-2 experiment requires large numbers of muons to be stored in a storage ring of 7 meter radius, and the transmission fraction has been shown to depend strongly on the properties of the beam, specifically the Twiss parameters. The current equipment in the muon campus beamlines allows only measurement of beam profiles which limits how well propagation can be predicted, however by using the well-studied quad-scan technique it is possible to obtain all of the Twiss parameters at a point using these profiles. Experimental quad-scans of muon beams have not yet been reported, this paper introduces the quad-scan technique and then goes on to discuss the analysis of one such experiment and the results obtained, showing that such a technique is applicable in the muon g-2 experiment to obtain the Twiss parameters without requiring installation of new equipment.

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WEPAF017

Correction of ID-Induced Transverse Linear Coupling at NSLS-II

coupling, emittance, operation, resonance

1856

Y. Hidaka, Y. Li, T.V. Shaftan, T. Tanabe, Y. Tian, G.M. Wang
BNL, Upton, Long Island, New York, USA

Funding: The study is supported by U.S. DOE under Contract No. DE-AC02-98CH10886.
Sizeable lifetime jumps have been observed sporadically since March 2016 at NSLS-II. These jumps were found to coincide with insertion device (ID) gap motions. Particularly, one of the in-vacuum undulators (IVUs) at Cell 17 was discovered to have large localized skew quadrupole component variation with gap. To allow the machine to operate stably in the low-emittance mode, a global coupling feedforward system has been recently implemented and successfully deployed. After installation of a new additional skew quadrupole, coupling compensation of this ID is now performed by a local coupling feedforward system. Furthermore, the maximum gap limit of all the existing IVUs has been decreased from 40 mm to 25 mm to limit the skew component variation during user operation.

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WEPAF062

Machine Learning Methods for Optics Measurements and Corrections at LHC

optics, network, controls, data-analysis

1967

E. Fol, F.S. Carlier, J.M. Coello de Portugal, A. Garcia-Tabares, R. Tomás
CERN, Geneva, Switzerland

The application of machine learning methods and concepts of artificial intelligence can be found in various industry and scientific branches. In Accelerator Physics the machine learning approach has not found a wide application yet. This paper is devoted to evaluation of machine learning methods aiming to improve the optics measurements and corrections at LHC. The main subjects of the study are devoted to recognition and analysis of faulty beam position monitors and prediction of quadrupole errors using clustering algorithms, decision trees and artificial neural networks. The results presented in this paper clearly show the suitability of machine learning methods for the optics control at LHC and the potential for further investigation on appropriate approaches.

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WEPAF066

The New CLIC Main Linac Installation and Alignment Strategy

alignment, target, linac, collider

1979

H. Mainaud Durand, J. Gayde, J. Jaros, M. Sosin, A. P. Zemanek
CERN, Geneva, Switzerland
V. Rude
ESGT-CNAM, Le Mans, France

A complete solution has been proposed for the pre-alignment of the CLIC main linac in 2012 for the Conceptual Design Report. Two recent studies provide new perspectives for such a pre-alignment. First in a study on Particle Accelerator Components' Metrology and Alignment to the Nanometre scale (PACMAN), new solutions to fiducialise and align different types of components within a micrometric accuracy on the same support were proposed and validated, using a stretched wire. Secondly, a 5 degree of freedom adjustment platform with plug-in motors showed a very accurate and efficient way to adjust remotely components. By combining the results of both studies, two scenarios of installation and alignment for the CLIC main linac are proposed, providing micrometric and automatized solutions of micrometric assembly, fiducialisation and alignment in metrological labs or in the tunnel. In this paper, the outcome of the two studies are presented; the two scenarios of installation and alignment are then detailed and discussed.

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WEPAF080

Beam Size Measurements Based on Movable Quadrupolar Pick-ups

pick-up, emittance, alignment, embedded

2028

A. Sounas, M. Gąsior, T. Lefèvre, A. Mereghetti, J. Olexa, S. Redaelli, G. Valentino
CERN, Geneva, Switzerland

Measurements with quadrupolar pick-ups (PU) have attracted particular interest as non-intercepting diagnostics for determining the transverse beam size. They are based on processing the signals of an electromagnetic PU for the extraction of the second-order moment, which contains information about the beam size. Despite the simplicity of the concept, quadrupololar measurements have always been highly challenging in reality. This comes from the fact that the quadrupolar moment constitutes only a very small part of the total PU signal dominated by the intensity and the position signals. Therefore, the beam size information can easily be lost due to small imperfections in the signal processing chain, such as asymmetries in the electronics and cables. In this paper, we present a new method for quadrupolar measurements using movable PUs. Through position and aperture scans, our technique minimizes the parasitic beam position signal and takes into account imperfections of the PU, cables and electronics, thus enabling an efficient auto-calibration of the measurement system. Preliminary studies, using collimators with embedded electrostatic PUs in the LHC at CERN, have shown very promising results.

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WEPAF081

An Enhanced Quench Detection System for Main Quadrupole Magnets in the Large Hadron Collider

monitoring, controls, power-supply, radiation

2032

J. Spasic, D.O. Calcoen, R. Denz, V. Froidbise, S. Georgakakis, T. Podzorny, A.P. Siemko, J. Steckert
CERN, Geneva, Switzerland

To further improve the performance and reliability of the quench detection system (QDS) for main quadrupole magnets in the Large Hadron Collider (LHC), there is a planned upgrade of the system during the long shutdown period of the LHC in 2019-2020. While improving the already existing functionalities of quench detection for quadrupole magnets and field-bus data acquisition, the enhanced QDS will incorporate new functionalities to strengthen and improve the system operation and maintenance. The new functionalities comprise quench heater supervision, interlock loop monitoring, power cycling possibility for the whole QDS and its data acquisition part, monitoring and synchronization of trigger signals, and monitoring of power supplies. In addition, the system will have two redundant power supply feeds. Given that the enhanced QDS units will replace the existing QDS units in the LHC tunnel, the units will be exposed to elevated levels of ionizing radiation. Therefore, it is necessary to design a radiation tolerant detection system. In this work, an overview of the design solution for such enhanced QDS is presented.

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WEPAK003

Effect of Model Errors on the Closed Orbit Correction at the SIS18 Synchrotron of GSI

synchrotron, closed-orbit, controls, focusing

2080

S.H. Mirza, P. Forck, H. Klingbeil, R. Singh
GSI, Darmstadt, Germany
H. Klingbeil
TEMF, TU Darmstadt, Darmstadt, Germany

Funding: Deutscher Akademischer Austauschdienst under contract No. 91605207
A fast closed orbit feedback system (bandwidth in the order of 1 kHz) is under development at the GSI SIS18 synchrotron for the orbit correction from injection to extraction including the acceleration ramp. The static process model, represented as the orbit response matrix (ORM), is subjected to the systematic optics changes during ramp e.g. beta function and phase advance variations at the locations of BPMs and steerers. In addition to these systematic variations, model mismatches may arise from dipole and quadrupole magnet errors, space charge dependent tune shift as well as BPM and steerer calibration errors. In this contribution, the effects of these model errors on the closed orbit correction are investigated which is necessary for the robust stability analysis of the feedback controller. For the robustness tests, the traditional SVD-based matrix pseudo-inversion is compared to a Fourier-based analysis. The results are achieved by detailed simulations in MADX.

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WEPAL020

Measurement of Transverse Dipole and Quadrupole Moments with the BPMS in the J-PARC 3-50 BT

dipole, emittance, beam-transport, optics

2197

T. Toyama
J-PARC, KEK & JAEA, Ibaraki-ken, Japan
H. Kuboki, K. Satou, M. Tejima
KEK, Tokai, Ibaraki, Japan

We measure dipole and quadrupole moments of the beam using the BPMs in the beam transport line 3-50BT of J-PARC and obtain differences of squared horizontal- and vertical-rms-sizes for those BPMs. Then we obtain rms emittances and rms momentum by fitting with given Twiss parameters.

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WEPAL064

Diagnosis Application by Great Amount Operation Data Analysis Program for Taiwan Photon Source

power-supply, LabView, hardware, interface

2323

C.C. Liang, B.Y. Chen, C.H. Chen, S. Fann, C.S. Huang, C.H. Kuo, T.Y. Lee, W.Y. Lin, Z.-D. Tsai, Y.C. Yang, T.-C. Yu
NSRRC, Hsinchu, Taiwan

To find out abnormal situations of the machine for preventive maintenance or machine trip tracking or instability source diagnosis, a large amount of operating data in an accelerator is thus can be used to build a series data analysis program. When the archived data is classified accordingly, the standard deviation (STD), peak-to-peak value and other statistic indexes within the inspection time zone by the belonging families can be used to point out the especially abnormal signals. The analysis program adopts the techniques of parallel calculation and memory optimization to greatly reduce the time for data transmission and analysis and also displays the correlation signals to opera-tors for deeper analysis. This paper illustrated a simple yet effective method for quickly identifying a not-so-obscure hardware issue by simply using a personal computer (PC).

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WEPAL068

Improving Machine and Target Protection in the SINQ Beam Line at PSI-HIPA

target, proton, diagnostics, operation

2337

D. Reggiani, P.-A. Duperrex, R. Dölling, D.C. Kiselev, J. Welte, M. Wohlmuther
PSI, Villigen PSI, Switzerland

With a nominal beam power of nearly 1.4 MW, the PSI High Intensity Proton Accelerator (HIPA) facility is currently at the forefront of the high intensity frontier of particle accelerators. A key issue of this facility is to ensure safe operation of the SINQ spallation source. In particular, too large beam current density and/or inaccurate beam steering can seriously compromise the integrity of the spallation target. Recently, a campaign has been launched in order to improve the fast detection of improper beam delivery and therefore the reliability of the system. New beam diagnostics elements such as an absolute intensity monitor, a beam ellipticity monitor and additional loss monitors have been installed during the 2017 shutdown. In 2018 a new SINQ target will be installed featuring a system of thermocouples which will keep track of the beam position. Moreover, an additional monitor is currently under study which should reliably detect small beam fractions accidentally bypassing the muon production target TE and which are intrinsically dangerous for the SINQ spallation target. This contribution reviews the all efforts to increase the efficiency of the SINQ protection system.

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WEPMF001

Upgrade of the ALBA Magnetic Laboratory for Measuring LIPAc HEBT Quadrupoles and Dipole

controls, hardware, software, dipole

2369

J. Campmany, F. Becheri, L.G.O. Garcia-Orta, J. Marcos, V. Massana, R. Petrocelli
ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
B. Brañas, J. Castellanos
CIEMAT, Madrid, Spain

Along 2017 ALBA magnetic measurements facility has measured LIPAc HEBT quadrupoles and dipole designed by CIEMAT and built by ELYTT company. ALBA magnetic measurements laboratory has been improved through an upgrade program of its measurement benches to complete their measurements. One of the main aims of the upgrade has been to standardize both the hardware and software and therefore ensure an easy maintenance. Especially relevant has been the upgrade of the flipping coil bench, in which the DC motors and the obsolete controller have been replaced by step-motors and ICEPAP controller. Also, software has been migrated to Tango package. Hardware and software of Hall probe bench has been upgraded as well, using the last DeltaTau motion controller. Tango has been upgraded too, using Devian 8 as operative system. Next step will be the upgrade of the rotating coil hardware and software using also step-motor and ICEPAP controller. In parallel, new shafts have been build and tested, with specific designs to improve the sensitivity and minimize the noise to signal ratio. In this contribution we detail the upgrades and the results of performance tests.

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WEPMF014

Fast Track Actively Shielded Nb3Sn IR Quadrupole R&D

site, hadron, collider, coupling

2398

B. Parker, M. Anerella, J.P. Cozzolino, R.C. Gupta, R.B. Palmer, J. Schmalzle, H. Witte
BNL, Upton, Long Island, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy.
The Interaction Region (IR) magnets for future Electron Ion Colliders (EIC), such as eRHIC at BNL, JLEIC at JLab and LHeC at CERN, must satisfy strongly opposing requirements. EIC IR superconducting quadrupole coils must provide strong focusing gradients, leading to large peak fields, for the high momentum hadron beam while permitting the nearby electron beam to pass through a nearly field free region. An actively shielded coil geometry does this using nested, opposite polarity, quadrupoles where the combined external fields cancel while leaving a net gradient inside. In order to fabricate and test this concept in a timely and cost effective manner we propose to reuse the inner coils from an existing high gradient Nb3Sn LARP quadrupole inside a new structure with a new NbTi active shield coil. The main challenge is to design a compact structure for applying prestress to the Nb3Sn coil that fits the restricted space inside the shield coil. We first construct a 15 cm long mechanical model of this structure with coil strain gauges to verify the design concept before proceeding with the full coil. Mechanical modeling results and our preliminary design concept are reported here.

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WEPMF018

Magnet Designs for the eRHIC Rapid Cycling Synchrotron

dipole, sextupole, synchrotron, magnet-design

2404

H. Witte, I. Marneris, V.H. Ranjbar
BNL, Upton, Long Island, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
Presently the electron-ion collider eRHIC is under design, which aims to provide a facility with a peak luminosity of 10³⁴cm^-2sec^-1. Part of the eRHIC design is a rapid cycling synchrotron, which accelerates electrons from 1-18 GeV. In this paper we present conceptual designs of the required dipole, quadrupole and sextupole magnets. The magnets meet the specifications in terms of performance and field quality with an acceptable power dissipation. The power supply requirements are also discussed.

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WEPMF019

Conceptual Design of the eRHIC Storage Ring Magnets

storage-ring, dipole, sextupole, simulation

2407

H. Witte, J.S. Berg, S. Tepikian
BNL, Upton, Long Island, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
Presently the electron-ion collider eRHIC is under design, which aims to provide a facility with a peak luminosity of 10³⁴cm^-2sec^-1. Part of the eRHIC accelerator is the addition of an electron storage ring to the existing tunnel. This paper describes the magnets required for this storage ring. The necessary bending is provided by a triplet of dipole magnets, which generate excess bending to create additional radiation damping to allow a larger beam-beam tune shift. Each triplet consists of two long, low field magnets and a short, high-field magnet. This paper also describes the quadrupole and sextupole magnets necessary for this machine. All magnets require a large aperture to accommodate the beam-pipe.

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WEPMF021

Magnet Design Considerations for an Ultralow Emittance Canadian Light Source

lattice, emittance, storage-ring, FEL

2413

L.O. Dallin, D. Bertwistle
CLS, Saskatoon, Saskatchewan, Canada

The strong focusing requirements for ultralow emittance light sources result in high field magnets that are very close together. High fields are readily achieved by using small magnet gaps. This is possible due to the small beam sizes involved. Reduction in the physical aperture and the reduction in the good field region requirements results in magnets with compact transverse dimensions. The very strong focusing of the magnets results in very small drift spaces between the various magnetic elements. To keep these drift spaces clear magnets with recessed coils have been studied. In such magnets the coils do not stick out beyond the end of the magnet yoke in the longitudinal direction. By placing the coils on the outer yoke loss of efficiency can be avoided while maintaining good control of the higher order field harmonics. This is very well suited for quadrupole magnets where only two coils are required. Possible designs for gradient dipoles and sexutpoles are also considered.

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WEPMF061

High Gradient Pulsed Quadrupoles for Novel Accelerators and Space Charge Limited Beam Transport

plasma, focusing, electron, wakefield

2505

C. Tenholt
CERN, Geneva, Switzerland
G. Loisch, F. Stephan
DESY Zeuthen, Zeuthen, Germany
B. Marchetti
DESY, Hamburg, Germany

Novel acceleration schemes like plasma wake-field based accelerators demand for high gradient focusing elements to match the Twiss parameters in the plasma to the transport lattice of the conventional accelerator beamlines, with typically much higher beta-functions. There are multiple candidates for achieving high gradient focusing fields, each one having certain drawbacks. Permanent magnets are limited in tunability, plasma lenses might degrade the transverse beam quality significantly and conventional magnets cannot reach very high gradients and often cannot be placed in direct proximity of the plasma accelerator because of their size. In this paper we present design considerations and simulations on compact, high gradient, pulsed quadrupoles, that could be used e.g. for final focusing of space charge dominated bunches into a LWFA (Laser Wake-Field Accelerator) at SINBAD or other facilities with similar demands. The target design gradient is 200 T/m at a physical aperture on the order of 10 mm.

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WEPMG006

Experimental Setup to Characterize the Radiation Hardness of Cryogenic Bypass Diodes for the HL-LHC Inner Triplet Circuits

radiation, cryogenics, MMI, target

2620

A. Will, G. D'Angelo, R. Denz, M.F. Favre, D. Hagedorn, G. Kirby, T. Koettig, A. Monteuuis, F. Rodriguez-Mateos, A.P. Siemko, K. Stachon, M. Valette, A.P. Verweij, D. Wollmann
CERN, Geneva, Switzerland
A. Bernhard, A.-S. Müller
KIT, Karlsruhe, Germany
L. Kistrup
KEA, Copenhagen, Denmark

Funding: Work supported by the Wolfgang Gentner Programme of the German Federal Ministry of Education and Research
For the high luminosity upgrade of the Large Hadron Collider (LHC), it is planned to replace the existing triplet quadrupole magnets with Nb₃Sn quadrupole magnets, which provide a comparable integrated field gradient with a significantly increased aperture. These magnets will be powered through a novel superconducting link based on MgB₂ cables. One option for the powering layout of this triplet circuit is the use of cryogenic bypass diodes, where the diodes are located inside an extension to the magnet cryostat and operated in superfluid helium. Hence, they are exposed to radiation. For this reason the radiation hardness of existing LHC type bypass diodes and more radiation tolerant prototype diodes needs to be tested up to the radiation doses expected at their planned position during their lifetime. A first irradiation test is planned in CERN's CHARM facility starting in spring 2018. Therefore, a cryo-cooler based cryostat to irradiate and test LHC type diodes in-situ has been designed and constructed. This paper will describe the properties of the sample diodes, the experimental roadmap and the setup installed in CHARM. Finally, the first measurement results will be discussed.

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WEPMK009

Status of the ESRF-EBS Magnets

SRF, dipole, sextupole, octupole

2648

C. Benabderrahmane, J.C. Biasci, J-F. B. Bouteille, J. Chavanne, L. Eybert, L. Goirand, G. Le Bec, L. Lefebvre, S.M. Liuzzo, D. Martin, C. Penel, P. Raimondi, J.-L. Revol, F. Villar, S.M. White
ESRF, Grenoble, France

The ESRF-EBS (Extremely Brilliant Source) is an upgrade project planned at the European Synchrotron Radiation Facility (ESRF) in the period 2015-2022. A new storage ring will be built, aiming to decrease the horizontal emittance and to improve the brilliance and coherence of the X-ray beams. The lattice of the new storage ring relies on magnets with demanding specifications: dipoles with longitudinal gradient (field ranging from 0.17 T up to 0.67 T), strong quadrupoles (up to 90 T/m), combined function dipole-quadrupoles with high gradient (0.57 T and 37 T/m), strong sextupoles and octupoles. The design of these magnets is based on innovative solutions; in particular, the longitudinal gradient dipoles are permanent magnets and the combined dipole-quadrupoles are single-sided devices. The longitudinal gradient dipoles have been assembled and measured in house. The design of the magnets, production status and magnetic measurement results will be presented.

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WEPML009

Superconducting Magnet Performance in LCLS-II Cryomodules

cryomodule, superconducting-magnet, operation, dipole

2693

V.S. Kashikhin, S. Cheban, J. DiMarco, E.R. Harms, A.V. Makarov, T. Strauss, M.A. Tartaglia
Fermilab, Batavia, Illinois, USA

Abstract' New LCLS-II Linear Superconducting Accelerator Cryomodules under construction at Fermilab. Inside each SCRF Cryomodule installed superconducting magnet package to focus and steer an electron beam. The magnet package has the iron dominated configuration with racetrack type quadrupole and dipole conductively cooled coils. For easier installation the magnet could be split in the vertical plane. Initially the magnet was tested in a liquid helium bath, and were performed high precision magnetic field measurements. Several Cryomodules with magnets inside were built and successfully tested at Fermilab test facility. In the paper presented Cryomodule magnet packages test results, discussed the magnet, and current leads conduction cooling performance.

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WEPML027

Conceptual Design of a 17 T Nb3Sn Accelerator Dipole Magnet

dipole, magnet-design, collider, luminosity

2742

A.V. Zlobin, J.R. Carmichael, V.V. Kashikhin, I. Novitski
Fermilab, Batavia, Illinois, USA

Funding: Work is supported by Fermi Research Alliance, LLC, under contract No. DE-AC02-07CH11359 with the U.S. Department of Energy
Nb3Sn dipole magnets with a nominal field of 16 T and sufficient operation margins are being considered for the LHC energy upgrade or a future Very High Energy Hadron Collider. Magnet design studies are being performed in the framework of the US Magnet Development Program to explore the limits of the Nb3Sn accelerator magnet technology and feasibility of such magnets, as well as to optimize the magnet design, performance parameters and cost. This paper describes the conceptual design of a 17 T dipole magnet with 60 mm aperture and 4-layer cos-theta coil being developed at Fermilab. The results of magnetic and mechanical analyses, including the non-linear effects in magnetic field and the possible stress management techniques, are also presented and discussed.

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WEPML028

NEG Coated Vacuum Chambers and Bake-Out-Concept for the HESR at FAIR

dipole, vacuum, heavy-ion, storage-ring

2745

H. Jagdfeld, N.B. Bongers, J. Böker, P. Chaumet, F.M. Esser, F. Jordan, F. Klehr, G. Langenberg, D. Prasuhn, L. Semke, R. Tölle
FZJ, Jülich, Germany
A. Mauel, G. Natour, U. Pabst
Forschungszentrum Jülich GmbH, Central Institute of Engineering, Electronics and Analytics, Jülich, Germany

The High-Energy Storage Ring (HESR) is part of the international Facility for Antiproton and Ion Research (FAIR) at GSI Darmstadt. Forschungszentrum Jülich (IKP and ZEA-1) is responsible for the design and installation of the HESR. The HESR is designed for antiprotons and heavy ion experiments as well. Therefore the vacuum is required to be 10^-11 mbar or better. To achieve this extreme high vacuum (XHV), NEG coated chambers will be used in combination with common vacuum pumps to reach the needed pumping speed and capacity everywhere in the accelerator ring. For activation of the NEG material a bake-out system will be developed and installed. A bake-out test bench was used for checking the achievable end pressure and developing the bake-out system for the NEG coated chambers of the HESR. The results of the tests and the bake-out concept including the layout of the control system are presented. In addition, the temperature distribution of the dedicated heater jackets inside the dipole and quadrupole magnets are shown.

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WEPML030

First Tests of the Main Quadrupole and Corrector Magnets for the SIS100 Synchrotron of FAIR

operation, sextupole, dipole, cryogenics

2751

E.S. Fischer, A. Bleile, V.I. Datskov, V.M. Marusov, J.P. Meier, C. Omet, P.J. Spiller, K. Sugita
GSI, Darmstadt, Germany
P.G. Akishin, V.V. Borisov, H.G. Khodzhibagiyan, S.A. Kostromin, D.N. Nikiforov, M.M. Shandov, A.V. Shemchuk
JINR, Dubna, Moscow Region, Russia

The heavy ion synchrotron SIS100 is the main accelerator of the FAIR complex (Facility for Antiproton and Ion Research) in Darmstadt, Germany. Currently the construction site and facility are advancing fast. The series production of the main dipoles was already started in 2017. In parallel, the first two quadrupoles, a chromaticity sextupole and a steerer were built and tested in cooperation between GSI and JINR at the cryogenic test facility in Dubna. We present the operation performance of these two first of series quadrupole units (consisting both of a corrector magnet mechanically and hydraulically combined with a quadrupole). Besides the thermal stability of the fast ramped superconducting magnets special attention is directed to their magnetic field properties. The obtained results provide the basis for starting the series production of all SIS100 quadrupole and corrector magnets in 2018.

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WEPML049

The Challenge to Measure nΩ Surface Resistance on SRF Samples

SRF, pick-up, cavity, simulation

2812

S. Keckert, T. Junginger, J. Knobloch, O. Kugeler
HZB, Berlin, Germany
T. Junginger
Lancaster University, Lancaster, United Kingdom

Systematic research on fundamental limits of superconducting materials for SRF applications and their intrinsic material properties relevant for use in an accelerator requires studies in a wide parameter space of temperature, RF field and frequency. The Quadrupole Resonator at HZB enables precision measurements on planar samples at temperatures of 1.8 K to >20 K, RF fields of up to 120 mT, and frequencies of 420 MHz, 850 MHz and 1285 MHz. In the past years the capabilities of the setup were studied intensively and developed further. Sources of systematic errors, such as microphonics or misalignment have been identified and eliminated. In this contribution the current status of the QPR and its systematic limitations are discussed.

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WEPML073

Research on Magnetic Center Measurement of Quadrupole and Sextupole Using Vibrating Wire Alignment Technique in HEPS-TF

sextupole, alignment, background, multipole

2860

L. Wu, C. H. Li, H. Qu, H. Wang, X.L. Wang
IHEP, Beijing, People's Republic of China
H.Y. Zhu
Institute of High Energy Physics (IHEP), People's Republic of China

In order to meet the extremely low emittance re-quirement, the magnets in the storage ring of High Energy Photon Source(HEPS) need to have a stable support and precise positioning. Vibrating wire align-ment technique can be used to pre-align the quadru-poles and sextupoles on one girder with high preci-sion. Research of vibrating wire alignment technique is one important project of HEPS Test Facility (HEPS-TF). In HEPS-TF, the key and difficult technologies of HEPS should be researched and developed. This paper introduces the principle of the vibrating wire align-ment technique and the measurement system in brief. The magnetic center measurement of quadrupole and sextupole using vibrating wire will be introduced in detail. It concludes the measurement procedure, mag-netic field distribution, measurement repeatability, sag correction and magnet adjustment measurement. The research of vibrating wire has get a better precision than the aim. The magnetic center measurement preci-sion reach to ±3μm and the magnet adjustment error is less than 6μm.

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THXGBE1

6D Beam Measurement, Challenges and Possibilities

simulation, rfq, experiment, linac

2890

A.V. Aleksandrov, S.M. Cousineau, A.P. Zhukov
ORNL, Oak Ridge, Tennessee, USA
B.L. Cathey
ORNL RAD, Oak Ridge, Tennessee, USA

A system to measure the full 6D beam parameters (not 3x2D) has been built at the SNS RFQ test stand. Such a measurement will allow detailed analysis of the beam physics from a properly measured input term. This invited provides an overview of the principles and design of this system, and reports on status and results.

Slides THXGBE1 [4.471 MB]

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THYGBF1

High Power Beam Operation of the J-PARC RCS and MR

operation, extraction, emittance, betatron

2938

Y. Sato
KEK, Ibaraki, Japan

This invited talk presents the most recent status of improving J-PARC main ring (MR) beam operation together with the rapid cycling synchrotron (RCS) effort. The RCS has optimized the beam performance for the MR injection as well as the muon and neutron targets, where each requires different emittance and beam halo size. The MR has two extraction modes; fast extraction (FX) for the long baseline neutrino oscillation experiment, T2K, and slow extraction (SX) for experiments in the hadron experimental facility. At present, achieved beam intensities are 2.4·10¹⁴ protons per pulse (ppp) with cycle time 2.48 s (470 kW) in the FX mode and 5.10¹³ ppp with cycle time 5.52 s (44 kW) in the SX mode. For the FX operation, recent improvements are settings of new betatron tune, corrections of resonances near the betatron tune, and adopting 2nd harmonic rf voltage to reduce space charge effect. Beam instabilities have been suppressed with controlling chromaticity correction and transverse feedback systems. For the SX mode, a dynamic bump scheme for reducing extracted beam loss is successfully adopted. A high extraction efficiency of 99.5 % is achieved at the 44 kW beam operation.

Slides THYGBF1 [6.664 MB]

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THPAF005

Simulations of Modulator for Coherent Electron Cooling

electron, simulation, bunching, plasma

2953

J. Ma, V. Litvinenko, G. Wang
BNL, Upton, Long Island, New York, USA
V. Litvinenko
Stony Brook University, Stony Brook, USA

Highly resolved numerical simulations have been performed using the code SPACE for the modulator, the first section of the Coherent electron cooling (CeC) device installed in the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL). Simulation results have been benchmarked with analytical solution using uniform electron beam with realistic thermal velocities. Electron bunches with Gaussian distribution and quadrupole field with realistic settings have been applied in the simulations to predict the modulation process and final bunching factors induced by ions with reference and off-reference energies in the CeC experiment at BNL RHIC.

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THPAF010

Reduction of Coherent Betatron Oscillations Using RF Electric Fields in the Fermilab Muon g-2 Experiment

dipole, experiment, simulation, betatron

2961

O. Kim, S. Hacıömeroğlu, Y.I. Kim, Y.K. Semertzidis
CAPP/IBS, Daejeon, Republic of Korea
Y.F. Orlov
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

The Fermilab Muon g-2 experiment aims to measure the muon anomalous magnetic moment with a 140 parts-per-billion precision to investigate the greater than 3 standard deviation difference between the Standard Model prediction and the previous measurement by the BNL Muon g-2 experiment. The coherent betatron oscillation (CBO) beam effects must be corrected for in the decay-positron time spectra fits used in high precision muon storage ring based anomalous magnetic moment measurements. This MC simulation study indicates that the application of radio frequency (RF) electric fields to the muon storage ring beam can reduce the CBO amplitude by up to a factor of 10, as well to increase the symmetry of the beam phase space. This is achieved by correcting the mismatched oscillation phases between the high and low momentum muon populations by modulating the muon beam betatron oscillation frequencies with off-resonance RF fields.

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THPAF016

3D Tracking Methods in a GEANT4 Environment Through Electrostatic Beamlines

simulation, experiment, proton, antiproton

2979

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

Funding: Work supported by the EU under Grant Agreement 721559 and the STFC Cockcroft Institute core Grant No. ST/G008248/1.
Due to the relatively infrequent use of electrostatic beamline elements compared with their magnetic counterparts, there are few particle tracking codes which allow for the straightforward implementation of such beamlines. In this contribution, we present 3D tracking methods for beamlines containing electrostatic elements utilising a modified version of the Geant4 based tracking code 'G4beamline'. In 2020 transfer lines will begin transporting extremely low energy (100 keV) antiproton beams from the Extra Low Energy Antiproton (ELENA) ring to the antimatter experiments at CERN. Electrostatic bending and focusing elements have been chosen for the beamlines due to their mass independence and focusing efficiency in the low energy regime. These beamlines form the basis of our model which is benchmarked against simplified tracking simulations. Realistic beam distributions obtained via tracking around ELENA in the presence of collective effects and electron cooling will be propagated along the optimised 3D transfer model to achieve the best beam quality possible for the experiments.

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THPAF019

Initial Performance of the Magnet System in the Splitter/Combiner Section of the Cornell-Brookhaven Energy-Recovery Linac Test Accelerator

linac, dipole, cavity, optics

2986

J.A. Crittenden, A.C. Bartnik, R.M. Bass, D.C. Burke, J. Dobbins, C.M. Gulliford, Y. Li, D. Sagan, K.W. Smolenski, Turco, J. Turco
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
J.S. Berg
BNL, Upton, Long Island, New York, USA
D. Jusic
Cornell University, Ithaca, New York, USA

Funding: This work is supported by NSF award DMR-0807731, DOE grant DE-AC02- 76SF00515, and New York State Energy Research and Development Authority.
The Cornell-Brookhaven Energy-recovery Linac Test Accelerator is a four-pass, 150-MeV electron accelerator with a six-cell 1.3 GHz superconducting-RF linear accelerator and a fixed-field alternating-gradient (FFAG) return loop made up of Halbach-style quadrupole magnets. The optics matching between the linear accelerator and the return loop is achieved with a conventional magnet system comprised of 50 dipole magnets and 64 quadrupole magnets in four beamlines at each end of the linac. The 42-, 78-, 114- and 150-MeV electron beams are separated into independent vacuum chambers in order to allow for the path-length adjustment required by energy recovery. We report on the first beam tests of the initial installation of the splitter/combiner section at the exit of the linac. The vacuum system of the 42-MeV S1 line was installed during the first week of April. Nine dipole and four quadrupole magnets were installed and surveyed into position the following week, and the water cooling system was commissioned. A 6-MeV beam passed through the line on April~11 with no need for adjusting pre-set magnet excitation currents. One week later, time-of-flight measurements were used to calibrate and phase the individual superconducting RF cavities. The S1 magnet settings were then scaled up to achieve 5-cavity, 42-MeV operation through the first nine FFAG permanent-magnet quadrupoles. This initial Fractional Arc Test will conclude on May 18, when the installation of the remaining seven splitter/combiner lines and the return loop will begin. CBETA operations are scheduled to begin in early 2019.

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THPAF023

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

optics, focusing, linac, electron

3000

W. Lou, A.C. Bartnik, J.A. Crittenden, C.M. Gulliford, G.H. Hoffstaetter, D. Sagan
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
J.S. Berg, S.J. Brooks, F. Méot, D. Trbojevic, N. Tsoupas
BNL, Upton, Long Island, New York, USA
C.E. Mayes
SLAC, Menlo Park, California, USA

Funding: This manuscript has been authored by employees of Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy.
The Cornell-Brookhaven Energy Recovery Linac Test Accelerator now under construction will accelerate electrons from 6 MeV to 150 MeV in four linac passes, using a single return line accepting all energies from 42 to 150 MeV. We describe the optical design of the machine, with emphasis on recent updates. We explain how we choose parameters for the wide energy acceptance return arc, taking into account 3D field maps generated from magnet designs. We give the final machine parameters resulting from iterations between desired lattice properties and magnet design. We modified the optics to improve the periodicity of the return arc near its ends and to create adequate space for vacuum hardware. The return arc is connected to the linac with splitter lines that serve to match the optics for each beam energy. We describe how matching conditions were chosen for the splitter lines and how we use them to control longitudinal motion. We simulate the injection and low energy extraction systems including space charge effects, matching the beam properties to the optical parameters of the rest of the machine.

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THPAF039

IP Orbit Correction Update for HL-LHC

alignment, optics, dipole, cavity

3048

D. Gamba, R. De Maria
CERN, Geneva, Switzerland

Funding: Research supported by the HL-LHC project.
The HL-LHC design foresees a substantial modification of the LHC layout next to the low beta Interaction Points (IPs), namely IP1 and IP5. The inner triplets will be replaced by larger aperture ones to achieve lower beta at the IPs and crab cavities (CCs) will be installed. This will add new constraints to the orbit control, which required a careful choice of location and strength of the new orbit correctors to be installed in the area. The new orbit correction system will need to correct for the unavoidable imperfections, but also provide the necessary flexibility for implementing and optimising the crossing scheme. Detailed studies of the HL-LHC layout versions HLLHCV1.0 and HLLHCV1.1 were already performed. This paper is the continuation of these works and is based on the latest layout HLLHCV1.3. A simplification of the previous analysis is proposed that helps to identify the dominant imperfections. The expected performance and tolerances of the present layout are presented.

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THPAF040

Estimated Impact of Ground Motion on HL-LHC Beam Orbit

ground-motion, luminosity, emittance, closed-orbit

3052

D. Gamba, R. Corsini, M. Guinchard, M. Schaumann, J. Wenninger
CERN, Geneva, Switzerland

Funding: Research supported by the HL-LHC project.
The High Luminosity LHC (HL-LHC) will require unprecedented orbit stability at the low beta collision points (IP1 and IP5), and the effect of seismic noise might become a relevant source of luminosity loss. Many studies have been conducted in the past to characterise the actual ground motion in the LHC tunnel, and recently a few geo-phones have been installed to permanently monitor the ground stability at IP1 and IP5. An estimate of the impact of the main machine element vibration on orbit at the IPs and collimators is presented, together with a first look at the data collected by the installed geo-phones.

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THPAF060

A Benchmark Study of a High Order Symplectic Integration Method With Only Positive Steps

lattice, sextupole, multipole, target

3111

K. Skoufaris, Y. Papaphilippou
CERN, Geneva, Switzerland
J. Laskar
IMCCE, Paris, France
Ch. Skokos
University of Cape Town, Cape Town, South Africa

The symplectic integrators CSABA & CSBAB are used in order to calculate single particles dynamics in accelerators and storage rings. These integrators include only forward drift steps while being highly accurate. Their efficiency to describe various optical and dynamical quantities for main magnetic elements and non-linear lattices is calculated and compared with the efficiency of the splitting methods used in MAD-X - PTC.

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THPAF062

Impact of Superconducting Magnet Protection Equipment on the Circulating Beam in HL-LHC

dipole, simulation, shielding, experiment

3115

M. Valette, L. Bortot, A.M. Fernandez Navarro, B. Lindstrom, M. Mentink, R. Schmidt, E. Stubberud, A.P. Verweij, D. Wollmann
CERN, Geneva, Switzerland
E. Ravaioli
LBNL, Berkeley, California, USA

Funding: Work supported by the HL-LHC project.
The new superconducting quadrupole and dipole magnets for the High Luminosity LHC (HL-LHC) will rely on quench heaters or Coupling-Loss Induced Quench (CLIQ) units or a combination of both to protect the magnet coils in case of a quench. After the detection of a quench, the quench heater power supplies will discharge currents of several hundreds of amperes into the quench heater strips glued to the coils, and the CLIQ units will discharge an oscillating current in the order of 1~kA directly into the coils. These currents can have a significant effect on the circulating beam if the discharge occurs before the beam is dumped. In the HL-LHC inner triplet quadrupole magnets and 11 T dipole magnets, which will be installed in the collimation region dispersion suppressor, this effect will even be stronger due to the larger number of quench heaters and use of CLIQ units (triplet magnets only) as well as due to the greater value of beta function in comparison with the present LHC. In this paper, the expected effects of quench heater and CLIQ discharges on the circulating beam are summarized, and several mitigation methods are proposed and evaluated.
Matthieu. Valette@cern.ch

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THPAF070

Design of a One-Dimensional Sextupole Using Semi-Analytic Methods

sextupole, lattice, coupling, focusing

3140

L. Gupta
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
S. Baturin
Enrico Fermi Institute, University of Chicago, Chicago, Illinois, USA
Y.K. Kim
University of Chicago, Chicago, Illinois, USA
S. Nagaitsev
Fermilab, Batavia, Illinois, USA

Funding: Work supported by the U.S. National Science Foundation under Award No. PHY-1549132, the Center for Bright Beams
Sextupole magnets provide position-dependent momentum kicks and are tuned to provide the correct kicks to particles within a small acceptance region in phase space. Sextupoles are useful and even necessary in circular accelerators for chromaticity corrections. They are routinely used in most rings, i.e. CESR. Although sextupole magnets are necessary for particle energy corrections, they also have undesirable effects on dynamic aperture, especially because of their non-linear coupling term in the momentum kick. Studies of integrable systems suggest that there is an analytic way to create transport lattices with specific transfer matrices that limit the momentum kick to one dimension. A one-dimension sextupole is needed for chromaticity corrections: a horizontal sextupole for horizontal bending magnets. We know how to make a "composite" horizontal sextupole using regular 2D sextupoles and linear transfer matrices in an ideal thin-lens approximation. Thus, one could create an accelerator lattice using linear elements, in series with sextupole magnets to create a '1d sextupole'. This paper describes progress towards realizing a realistic focusing lattice resulting in a 1d sextupole.*
*S.A. Antipov, et. al., Single-particle dynamics in a nonlinear accelerator lattice: attaining a large tune spread with octupoles in IOTA, Journal of Instrumentation, Volume 12, April 2017.

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THPAF071

McMillan Lens in a System with Space Charge

emittance, simulation, resonance, lattice

3143

I. Lobach
University of Chicago, Chicago, Illinois, USA
S. Nagaitsev, E.G. Stern, T. Zolkin
Fermilab, Batavia, Illinois, USA

Space charge (SC) in a circulating beam in a ring produces both betatron tune shift and betatron tune spread. These effects make some particles move on to a machine resonance and become unstable. Linear elements of beam optics cannot reduce the tune spread induced by SC because of its intrinsic nonlinear nature. We investigate the possibility to mitigate it by a thin McMillan lens providing a nonlinear axially symmetric kick, which is qualitatively opposite to the accumulated kick by SC. Experimentally, the proposed concept can be tested in Fermilab's IOTA ring. A thin McMillan lens can be implemented by a short (70 cm) insertion of an electron beam with specifically chosen density distribution in transverse directions. In this article, to see if McMillan lenses reduce the tune spread induced by SC, we make several simulations with particle tracking code Synergia. We choose such beam and lattice parameters that tune spread is roughly 0.5 and a beam instability due to the half-integer resonance 0.5 is observed. Then, we try to reduce emittance growth by shifting betatron tunes by adjusting quadrupoles and reducing the tune spread by McMillan lenses.

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THPAF076

Using Graphic-Turtle with the Particle Beam Optics Laboratory (PBO Lab)

optics, simulation, scattering, software

3158

G.H. Gillespie
G.H. Gillespie Associates, Inc., Del Mar, California, USA

A Particle Beam Optics Laboratory (PBO Lab) module has been developed for the Paul Scherrer Institute (PSI) version of the TURTLE program commonly known as Graphic-Turtle. The PSI-TURTLE version extends the original TURTLE program by including several unique beam optics capabilities, as well as by providing a self-contained graphics package. The unique optics modeling, together with the data visualization enhancements, make the PSI-TURTLE program ideal for certain types of beam simulations. The PBO Lab environment provides a single graphic user interface (GUI) that features an easy-to-learn and easy-to-use drag-and-drop beamline construction kit. Underlying the GUI is a sophisticated object model developed specifically for the accelerator community. PBO Lab provides a common interface for multiple charged particle optics codes. Modules have been developed for a number of popular beam optics programs that cover a range of accelerator types and applications. The PSI-TURTLE Module extends those capabilities. The module is described and its main capabilities and limitations are summarized.

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THPAF079

Landau Damping and Tune-Spread Requirements for Transverse Beam Stability

octupole, simulation, damping, impedance

3168

V. Kornilov, O. Boine-Frankenheim
GSI, Darmstadt, Germany

Passive mitigation methods are effective cures for collective instabilities in ring accelerators. For decades, octupole magnets have been used as an established and well-understood passive mitigation method. Present and the future accelerator facilities, like FAIR or FCC, impose new challenges on the passive mitigation due to higher energies and smaller beam emittances. Lattice resonances usually restrict the tolerable tune-spreads which are essential for the passive mitigation methods. We study the stability of transverse bunch oscillations provided by octupole magnets and radio-frequency quadrupoles. The special focus of our study is on the interplay and role of decoherence, phase-mixing and Landau damping for the different mitigation schemes. Particle tracking simulations are performed and the tune spreads for the different mechanisms are compared with each other and also with analytical dispersion relations.

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THPAF080

SIS100 Beam Dynamics Challenges Related to the Magnet System

dipole, resonance, sextupole, extraction

3172

V. Kornilov, O. Boine-Frankenheim, V. Chetvertkova, S. Sorge, P.J. Spiller
GSI, Darmstadt, Germany

The SIS100 synchrotron is the central accelerator of the upcoming FAIR project at GSI, Darmstadt, Germany. The major challenges of the future operation are related to high-intensity, low beam loss operation for a wide range of ion species and charge states, for different operational cycles and extraction schemes. The magnet system consists of 108 dipole, 166 quadrupole and additional correction superconducting superferric magnets. The magnets are presently under production and testing, with detailed measurements of the magnetic field imperfections. This results in the construction of a complete database for the SIS100 magnet system. We analyse implications of the magnetic field imperfections for the single-particle stability, space charge induced tune-shifts and resonance crossing for the different SIS100 operation modi. Resonance compensation and magnet sorting schemes are discussed as possible measures.

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THPAK004

Accurate and Efficient Tracking in Electromagnetic Quadrupoles

dynamic-aperture, multipole, HOM, optics

3207

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

Accelerator physics needs advanced modeling and simulation techniques, in particular for beam stability studies. A deeper understanding of the effects of magnetic fields nonlinearities will greatly help in the improvement of future colliders design and performance. This paper presents a study of quadrupole tracking using realistic field maps and measured or simulated longitudinal harmonics. The main goal is to describe the effect of the longitudinal dependence of high order non-homogeneity of the field in the case of the HL-LHC inner triplet.

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THPAK006

Design Status of the Beam Switchyard for ESSnuSB

proton, target, linac, emittance

3215

E. Bouquerel
IPHC, Strasbourg Cedex 2, France

Funding: This project is now supported by the COST Action CA15139/EuroNuNet and EU/H2020 innovation programme ESSnuSB under grant agreement No 777419.
The ESSnuSB project, recently granted by the EU H2020 framework programme for a 4-year design study, proposes to use the proton linac (2 GeV, 5 MW) of the European Spallation Source (ESS) currently in construction in Lund (Sweden) to deliver a neutrino super beam. One of the work packages of this design study is dedicated to the primary proton beam-line completing the linac. It will mainly consist of an accumulator ring to compress the 2.86 ms long beam pulse to 1.32 μs and of a switchyard to distribute the protons onto a 4-target station. Dipoles, steerers, quadrupoles, collimators and several diagnostics will compose the switchyard to ensure the protons to hit the target with desired characteristics. This paper presents the objectives of this work package and the design status of this switchyard system.

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THPAK009

Benchmark Analyses of Electrostatic Devices for SPIRAL2-DESIR Beam Lines

simulation, optics, emittance, electrostatic-devices

3225

L. Perrot, M. Kemel, S. Rousselot
IPN, Orsay, France

Funding: French ANR, Investissements d'Avenir, EQUIPEX. Contract number ANR-11-EQPX-0012.
The new ISOL facility SPIRAL2 is currently being built at GANIL, Caen France. The commissioning of the accelerator is in progress since 2015. SPIRAL2 will produce a large number of new radioactive ion beams (RIB) at high intensities. In 2023, the DESIR facility will receive beams from the upgraded SPIRAL1 facility of GANIL (stable beam and target fragmentation), from the S3 Low Energy Branch (fusion-evaporation and deep-inelastic reactions). In order to deliver the RIB to the experimental set-ups installed in the DESIR hall, 140 meters of beam line are studied since 2014. The transfert lines are today fully design and building will start in 2018. Electrostatic devices (quadrupoles, steerers and deflectors) have been intensively study using various tools. This paper will focus on the detail results of a benchmark using OPERA3D and Comsol Multiphysics apply to the DESIR quadrupole conception.

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THPAK022

Beam Dynamic Simulation for the Beam Line from Charge Breeder to ALPI for SPES Project

rfq, simulation, linac, experiment

3255

M. Comunian, L. Bellan, A. Pisent
INFN/LNL, Legnaro (PD), Italy
A.V. Ziiatdinova
ITEP, Moscow, Russia
A.V. Ziiatdinova
MEPhI, Moscow, Russia

The SPES project (Selective Production of Exotic Species) is under development at INFN-LNL. This facility is intended for production of neutron-rich Radioactive Ion Beams (RIBs) by ISOL method. The +1 charged beam will be transformed to n+ charge by Charge Breeder (Electron Cyclotron resonance ion source) and reaccelerated by the ALPI (Acceleratore Lineare Per Ioni) superconducting Linac . This paper includes results of beam dynamic simulation at the beam line from Charge Breeder to ALPI.

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THPAK036

Accurate Modeling of Fringe Field Effects on Nonlinear Integrable Optics in IOTA

optics, octupole, betatron, lattice

3294

C.E. Mitchell, R.D. Ryne
LBNL, Berkeley, California, USA
F.H. O'Shea
RadiaBeam, Santa Monica, California, USA

Funding: This work is supported by the U.S. Department of Energy, Office of High Energy Physics.
The Integrable Optics Test Accelerator (IOTA) is a novel storage ring under commissioning at Fermi National Accelerator Laboratory designed to investigate the dynamics of beams with large transverse tune spread in the presence of strongly nonlinear integrable optics. Uncontrolled nonlinear effects resulting from magnetic fringe fields can affect the integrability of particle motion, and long-term numerical tracking requires an accurate representation of these effects. Surface fitting algorithms provide a robust and reliable method for extracting this information from 3-dimensional magnetic field data provided on a grid. These algorithms are applied to investigate the unique nonlinear magnetic insert of the IOTA ring, and consequences of the fringe fields to the long-term dynamics of the beam are discussed.

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THPAK053

Side Effects of Local Bump in TPS Storage Ring

sextupole, radiation, storage-ring, dipole

3340

M.-S. Chiu, C.H. Chen, J.Y. Chen, P.J. Chou, F.H. Tseng
NSRRC, Hsinchu, Taiwan

The Taiwan Photon Source (TPS) is a low-emittance 3-GeV light source at National Synchrotron Radiation Research Center. Five in-vacuum undulator beamlines were delivered to users on Sep. 22, 2016. Another 2 EPU beamlines will be open to user in near future. In the beginning, the local bump was used to do ID spectrum optimization since 2016. After this procedure, the ID spectrum are consistent between theoretical simulation and measurement. Recently, we found the local bump will cause tune shift and orbit distortion. In this paper, we will present the effect of local bump in TPS.

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THPAK060

Transverse-to-Longitudinal Photocathode Distribution Imaging

laser, electron, cathode, experiment

3361

A. Halavanau, P. Piot
Northern Illinois University, DeKalb, Illinois, USA
W. Gai, G. Ha, J.G. Power, E.E. Wisniewski
ANL, Argonne, Illinois, USA
G. Ha
PAL, Pohang, Republic of Korea
P. Piot
Fermilab, Batavia, Illinois, USA
G. Qiang
TUB, Beijing, People's Republic of China

In this paper, we present a tunable picosecond-scale bunch train generation technique combining a microlens array (MLA) transverse laser shaper and a transverse-to-longitudinal emittance exchange (EEX) beamline. The modulated beamlet array is formed at the photocathode with the MLA setup. The resulting patterned electron beam is accelerated to 50 MeV and transported to the entrance of the EEX setup. A quadrupole channel is used to adjust the transverse spacing of the beamlet array upstream of the EEX, thereby enabling the generation of a bunch train with tunable separation downstream of the EEX beamline. Additionally, the MLA is mounted on a rotation stage which provides additional flexibility to produce high-frequency beam density modulation downstream of the EEX. Experimental results obtained at the Argonne Wakefield Accelerator (AWA) facility are presented and compared with numerical simulations.

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THPAK061

Magnetized and Flat Beam Generation at the Fermilab's FAST Facility

emittance, cathode, simulation, solenoid

3364

A. Halavanau, P. Piot
Northern Illinois University, DeKalb, Illinois, USA
D.J. Crawford, D.R. Edstrom, D. Mihalcea, S. Nagaitsev, P. Piot, A.L. Romanov, J. Ruan, V.D. Shiltsev
Fermilab, Batavia, Illinois, USA

Funding: This work is supported by the DOE contract No.DEAC02-07CH11359 to the Fermi Research Alliance LLC. A.H. is supported by the DOE under contract No. DE-SC0011831 with Northern Illinois University.
Canonical angular momentum (CAM) dominated beams can be formed in photoinjectors by applying an axial magnetic field on the photocathode surface. Such a beam possess asymmetric eigenemittances and is characterized by the measure of its magnetization. CAM removal using a set skew-quadrupole magnets maps the beam eigenemittances to the conventional emittance along each transverse degree of freedom thereby yielding flat beam with asymmetric transverse emittance. In this paper we report on the experimental generation of CAM dominated beam and their subsequent transformation into flat beams at the Fermilab Accelerator Science and Technology (FAST) facility. Our results are compared with numerical simulations and possible applications of the produced beams are discussed.

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THPAK065

Application of Transverse-to-Longitudinal Phase-Space-Exchanged Beam Produced from a Nano-Structure Photocathode to a Soft X-Ray Free-Electron Laser

cathode, acceleration, simulation, laser

3379

A. Lueangaramwong, P. Piot
Northern Illinois University, DeKalb, Illinois, USA
G. Andonian
RadiaBeam, Santa Monica, California, USA
P. Piot
Fermilab, Batavia, Illinois, USA

Nano-structured cathodes can form transversely modulated beams which can be subsequently converted to temporally modulated beam via a transverse-to-longitudinal phase space-exchanging beamline. We demonstrate via numerical simulation the generation of transversely modulated beam at the nm scale and investigate the corresponding enhancement in a soft-X-ray SASE free-electron laser. Our study is supported by start-to-end simulation combining WARP, IMPACT-T and GENESIS(FEL process) and focuses on the optimization of the beamline to preserve initial modulation at the nanometer level. We also discuss the scaling of the concept to shorter-wavelengths.

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THPAK067

Progress Toward a Self-Consistent Beam at the Spallation Neutron Source

injection, solenoid, kicker, simulation

3382

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

Funding: ORNL is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the US DOE. This research was supported by the DOE Office of Science, Accelerator and Detector Research Program.
We have proposed to inject a self-consistent "rotating" beam into the Spallation Neutron Source (SNS). Self-consistent beam distributions are defined to be ellipsoidal, or elliptical in 2D, distributions that have uniform density and that retain these properties under all linear transformations. We have made much progress since the original proposal. We have demonstrated computationally the feasibility of injecting a rotating beam under realistic physics assumptions. We have optimized the injection scheme with respect to beam loss and to minimum necessary hardware changes. We have also determined how existing SNS beam diagnostic equipment can be used to verify the self-consistency of the injected beam. This paper will report the details of this work as well as the status of plans to carry out the self-consistency experiments.

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THPAK068

Fringe Field Effect of Solenoids

solenoid, optics, neutron, ECR

3385

T.V. Gorlov, J.A. Holmes
ORNL, Oak Ridge, Tennessee, USA

Funding: This work has been supported by Oak Ridge National Laboratory, man-aged by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. Department of Energy.
We derive a precise analytical nonlinear transverse map for single particle transport through a solenoid with hard edge fringe fields. The transfer map is two dimensional for transverse coordinates and momenta with fixed longitudinal momentum. Because it is an accurate analytic map, it is also symplectic. The transfer map is compared with ex-act numerical tracking.

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THPAK072

Generation of Flat Ultra-Low Emittance Beams

emittance, cathode, simulation, permanent-magnet

3398

N.R. Bell
UCLA, Los Angeles, USA
L. Phillips
PBPL, Los Angeles, USA

By placing a cathode in a longitudinal magnetic field generated by a solenoid or permanent magnet, angular-momentum dominated electron beams can be produced. Such beams can be uncoupled using a skew-quadrupole channel to remove the angular momentum and yield flat beams with an ultralow emittance in one of the transverse dimensions. Flat beams have immediate relevance in our pursuit of ultrahigh brightness in two dimensions for dielectric laser accelerator (DLA) or slab beam applications. We are currently investigating the possibility of implementing flat beam generation at the UCLA Pegasus beamline. We utilize particle tracking simulations to optimize the transverse emittance ratio and normalized transverse emittance. Our simulations show emittance ratios of more than 100 and normalized emittances in the <5 nm range in the vertical dimension, matching analytic estimates. In addition to simulation results, experimental plans to implement and test the flat beam transform (FBT) are also discussed.

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THPAK090

Symbolic Presentation of Nonlinear Dynamic Systems in Terms of Lego-Objects

octupole, database, controls, dipole

3441

E. Sboeva, E. Krushinevskii
Saint Petersburg State University, Saint Petersburg, Russia
S.N. Andrianov, A.N. Ivanov
St. Petersburg State University, St. Petersburg, Russia

In this paper we propose a symbolic representation of the solutions of the equations of evolution of dynamical systems in the framework of matrix formalism and Lie algebra for a number of elements of the accelerator (in particular, dipole, quadrupole and octupole) up to the 4th order. The considered solutions are Lego-objects*, which are include into the general scheme of the representation beam dynamics. It allows modeling of schemes of various accelerators and thereby to increasing performance of parametrical optimization. Let us note that the symbolic approach to solving such problems is more preferable than the numerical one, which is widely used. This leads to a reduction in the time and resources spent on solving optimization problems, as well as the ability to create universal Lego objects. The paper considers the verification of the obtained formulas from the experimental data. The corresponding Lego objects are the main components of the special software for both symbolic and numerical dynamics analysis. This software is planned to be used for modeling within the framework of the NICA accelerator project.
*S.N. Andrianov. Dynamic Modeling of Particle Beam Control Systems.
Saint Petersburg State University, 2002.

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THPAK094

High Acceptance Beamline for the Capture of a Laser Wakefield Accelerated Beam

plasma, focusing, permanent-magnet, laser

3456

B.D. Muratori, J.K. Jones
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
K.A. Dewhurst
University of Manchester, Manchester, United Kingdom
K.A. Dewhurst, J.K. Jones, H.L. Owen
Cockcroft Institute, Warrington, Cheshire, United Kingdom
H.L. Owen
UMAN, Manchester, United Kingdom

Laser wakefield acceleration, together with other types of novel acceleration techniques, has seen considerable progress of late. Together with this progress comes a question, which has only recently started to be addressed, of how to transport and utilise such beams. This is a challenge because of the high initial divergence of these beams. There are several approaches to this problem and we concentrate on one in this paper and look at the implications of it in some detail.

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THPAK097

Ion Optic Design of the Microprobe System at Sichuan University

brightness, target, proton, focusing

3460

Z. Li, Z. An, J.F. Han, G.Q. Zheng
SCU, Chengdu, People's Republic of China

Funding: Supported by the National Natural Science Foundation of China (11375122, 11511140277)
At the end of 2016, the first beam was extracted from the 3.0 MV Tandetron accelerator system at Sichuan University, China. The accelerator is imported from the HVEE as a multi-purpose research platform. For one of the main applications, the system will be connected to a micro-beamline to achieve submicron resolution, so the accelerator is designed with energy stability as high as 0.01%. The measured brightness for 3 MeV proton beam is 5.06 pA/um2mrad2MeV and the energy stability is reached the goal of design. The ion optic design of the microprobe beam line will be presented in this paper.

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THPAK100

Design and Fabrication of a Combined Function Magnet Prototype for Siam Photon Source

simulation, dipole, multipole, synchrotron

3466

P. Sunwong, B. Boonwanna, S. Chaichuay, P. Klysubun, A. Kwankasem, C.P. Preecha, V. Sooksrimuang
SLRI, Nakhon Ratchasima, Thailand

A prototype of combined function magnet has been developed for a new facility of Siam Photon Source (SPS). The magnet is a combined dipole and quadrupole with the required dipole field and quadrupole gradient of 0.6 T and 30 T/m, respectively. The high field gradient is attained from an offset quadrupole design pioneered by the European Synchrotron Radiation Facility (ESRF). The prototype magnet is fabricated and tested in-house. Magnetic field quality is characterized by the field homogeneity in the central field region and multipole components of the magnetic field. Calculated results show that the gradient deviation and the normalized multipole error are less than 0.01 within the good field region of ±8 mm. Preliminary measurements show a good agreement with the calculation, although further measurements are required to verify the results and the multipole error of magnetic field.

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THPAK133

Magnetic Field Tolerances of Dipole and Quadrupole Magnets for XiPAF Synchrotron

dipole, multipole, dynamic-aperture, synchrotron

3551

H.J. Zeng, X. Guan, P.F. Ma, X.W. Wang, H.J. Yao, S.X. Zheng
TUB, Beijing, People's Republic of China
H. Ning
NINT, Xi'an, People's Republic of China

The magnets are being constructed for Xi'an Proton Application Facility (XiPAF) synchrotron. A study is started to obtain the specifications and tolerances of the magnets to avoid beam lost by the excessive magnetic field errors. The study includes the effect of field and alignment errors of the magnets on the closed orbit and beam optics. Also a preliminary study of effect due to multipole components in dipole and quadrupole magnets on dynamic aperture has been done. The tolerances of dipole and quadrupole magnets on field errors, including multipole components, and alignment errors are described in this paper.

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THPAK135

Assessment of Linear and Non-Linear Optics Errors due to Beam-Beam with Multipoles for the High Luminosity LHC

luminosity, optics, hadron, beam-beam-effects

3557

L.E. Medina Medrano
Universidad de Guanajuato, División de Ciencias e Ingenierías, León, Mexico
J. Barranco García, T. Pieloni
EPFL, Lausanne, Switzerland
X. Buffat, L.E. Medina Medrano, R. Tomás
CERN, Geneva, Switzerland

Funding: HL-LHC project, European Circular Energy-Frontier Collider Study, H2020 programme (Grant 654305), Swiss State Secretariat for Education, Research and Innovation (SERI), Beam project (CONACYT, Mexico).
Study of the head-on and long-range beam-beam effects in the High Luminosity LHC (HL-LHC) is of interest to evaluate their potential impact on performance (in the form of luminosity imbalance) and machine operation (collimator system), and, depending on their magnitude, correction schemes might be necessary to minimize them. In this work, both the β-beating at zero amplitude and its amplitude-dependence are computed for the current HL-LHC baseline optics and parameters, as well as the amplitude detuning, at the main interaction points and collimators. Correction of the β-beating, tune shift and footprint for the HL-LHC, as originally proposed for the LHC, via compensation of the multipolar terms of the beam-beam force with corrector magnets, is also discussed.

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THPAK143

Tuning Low-Current Beam for Nonlinear Quasi-Integrable Optics Experiments at the University of Maryland Electron Ring

lattice, octupole, optics, experiment

3585

K.J. Ruisard, H. Baumgartner, B.L. Beaudoin, S. Bernal, B. M. Cannon, L. Dovlatyan, I. Haber, T.W. Koeth
UMD, College Park, Maryland, USA

Funding: Travel was supported by the NSF, the APS DPB, and TRIUMF. Funding for the work was provided through DOE-HEP Award DESC0010301, NSF Award PHY1414681 and the NSF GRFP program.
Design of accelerator lattices with nonlinear integrable optics is a novel approach to suppress transverse resonances and may be crucial for enabling low-loss high-intensity beam transport. Lattices with large amplitude-dependent tune spreads, driven by strong nonlinear magnet inserts, have reduced response to resonant driving perturbations [*]. This paper describes preparations for tests of a quasi-integrable octupole lattice at the University of Maryland Electron Ring (UMER). The planned tests employ a low-current highemittance beam with low space charge tune shift (∼ 0.005) to probe the dynamics of a lattice with large external tune spread (∼ 0.26).
* V. Danilov and S. Nagaitsev, Nonlinear accelerator lattices
with one and two analytic invariants, PRSTAB, 13, 084002, 2010.

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THPAK145

Methods to Increase the Dynamic Aperture of the FCC-hh Lattice

lattice, dynamic-aperture, luminosity, interaction-region

3593

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
R. Martin, R. Tomás
CERN, Geneva, Switzerland

The Future Circular Collider (FCC) design study aims to develop the designs of possible circular colliders in the post LHC era. In particular the FCC-hh will aim to produce proton-proton collisions at a center of mass energy of 100 TeV. Initial tracking studies for the FCC-hh lattice at collision energy including field errors on the final focus triplet showed a very low dynamic aperture, most likely affected by the large beta functions and integrated length of the quadrupoles. Using non-linear correctors, the dynamic aperture was increased to acceptable levels; however, the difficulty to have an accurate magnetic model of the magnets required for this correction motivates the development of alternative methods. This work explores the possibility to increase the dynamic aperture by optimizing the phase advance between the main interaction regions. The description of this method along with its impact on the dynamic aperture will be given on this paper.

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THPAK153

Linac Optics Correction With Trajectory Scan Data

linac, optics, lattice, storage-ring

3606

X. Huang, Y.-C. Chao, T.J. Maxwell
SLAC, Menlo Park, California, USA
T. Zhang
USTC/NSRL, Hefei, Anhui, People's Republic of China

We proposed and tested a scheme to measure and correct linac optics by scanning the beam trajectory in the horizontal and vertical phase spaces. The trajectory data are compared to tracking data in a fitting scheme, from which we can derive the quadrupole strength errors. Simulation is carried out to evaluate the requirements and the performance of the method. The method is experimentally applied to FEL linacs.

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THPAL008

A RFQ Cooler Development

rfq, ion-source, emittance, injection

3627

M. Cavenago, L. Bellan, M. Comunian, M. Maggiore, L. Pranovi
INFN/LNL, Legnaro (PD), Italy
G. Maero, N. Panzeri, M. Romé
Universita' degli Studi di Milano e INFN, Milano, Italy

Funding: INFN group 5 (exp. PLASMA4BEAM)
The cooling of beams of exotic nuclei (both in energy spread and in transverse oscillations) is critical to downstream mass spectrometry devices and can be provided by collisions with light gases as in the Radio Frequency Quadrupole Cooler (RFQC). As in other traps, several electromagnetic systems can be used for beam deceleration confinement and deceleration, as a radiofrequency (rf) quadrupole, a magnetic solenoid and electrostatic acceleration. Since rf contributes both to beam cooling and heating, operational parameters should be carefully optimized. The LNL RFQC prototype is going to be placed inside the existing Eltrap solenoid, capable of providing a magnetic flux density component B_z up to 0.2 T, where z is the solenoid axis. Setup progress and related rf component development are reported; in particular simple matching boxes are discussed; the differential gas pumping system is also described.

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THPAL009

A TM01 Mode Launcher With Quadrupole Field Components Cancellation for High Brightness Applications

network, GUI, gun, brightness

3631

G. Castorina
INFN-Roma1, Rome, Italy
A.D. Cahill, J.B. Rosenzweig
UCLA, Los Angeles, California, USA
F. Cardelli, G. Franzini, A. Marcelli, B. Spataro
INFN/LNF, Frascati (Roma), Italy
L. Celona, S. Gammino, G. Torrisi
INFN/LNS, Catania, Italy
V.A. Dolgashev
SLAC, Menlo Park, California, USA
L. Ficcadenti
Rome University La Sapienza, Roma, Italy
M. Migliorati, A. Mostacci, L. Palumbo
Sapienza University of Rome, Rome, Italy
G. Sorbello
University of Catania, Catania, Italy

The R&D of high gradient radiofrequency (RF) devices is aimed to develop innovative accelerating structures based on new manufacturing techniques and materials in order to construct devices operating with the highest accelerating gradient. Recent studies have shown a large increase in the maximum sustained RF surface electric fields in copper structures operating at cryogenic temperatures. These novel approaches allow significant performance improvements of RF photoinjectors. Indeed the operation at high surface fields results in considerable increase of electron beam brilliance. This increased brilliance requires high field quality in the RF photoinjector and specifically in its power coupler. In this work we present a novel power coupler for the RF photoinjector. The coupler is a compact X-band TM01 mode launcher with a fourfold symmetry which minimized both the dipole and the quadrupole RF components.

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THPAL010

Sector DC Dipoles Design for the Beam Test Facility Upgrade

dipole, linac, electron, experiment

3634

A. Vannozzi, S. Lauciani, L. Pellegrino, L. Sabbatini, C. Sanelli, G. Sensolini
INFN/LNF, Frascati (Roma), Italy
P. Valente
INFN-Roma, Roma, Italy

The Beam Test Facility is part of the DAΦNE accelerators system of INFN Frascati National Laboratory. It is a transfer-line optimized for electrons and positrons extracted from the DAΦNE LINAC. An upgrade of the line is scheduled for two purposes: reach a beam energy of 920 MeV (with respect to the actual 750 MeV) and add a new branch to the present transfer line. This new layout foresees six new quadrupoles one fast ramped dipole, two H-shape and one C-shape sector dipoles. The design of the magnets has been completely performed at INFN involving Electromechanical Enterprise partner in the design phase in order to optimise the manufacturing process. This effort lead to a complete set of detailed CAD drawings that can be directly used by manufacturer to build the magnets. The goal is to boost the manufacturing of prototypes and small series from Small and Medium Enterprises. Magnetic measurements will be performed at INFN. This poster is focused on the realization of the two full iron yoke H-shape and C-shape dipoles, respectively with 45 and 15 bending angle. They are characterized by a high flux density of 1.7 T in a gap of 35 mm. They have a bending radius of 1.8 m

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THPAL011

Fast Ramped Dipole and DC Quadrupoles Design for the Beam Test Facility Upgrade

dipole, linac, electron, positron

3638

L. Sabbatini, E. Di Pasquale, L. Pellegrino, C. Sanelli, G. Sensolini
INFN/LNF, Frascati (Roma), Italy
P. Valente
INFN-Roma, Roma, Italy
A. Vannozzi
Sapienza University of Rome, Rome, Italy

The Beam Test Facility (BTF) is part of the DAΦNE accelerators system of INFN Frascati National Laboratory. It is a transfer-line optimized for electrons and positrons extracted from the DAΦNE LINAC. An upgrade of the line is planned in order to reach a beam energy of 920 MeV (with respect to the present 750 MeV), adding a new branch to the present transfer line. The design of the magnets for this new layout has been completely performed at INFN, including electromagnetic, mechanical, thermal and hydraulic aspects. This effort lead to a complete set of detailed CAD drawings that can be used by Industrial partners to build the magnets. The manufacturing processes have been studied in detail: the goal is to boost the manufacturing of prototypes and small series from Small and Medium Enterprises. Magnetic measurements will be performed at our Institute. In this report we describe two types of magnets for this project. The first magnet is a C-shape fast ramped dipole, designed for a beam deflection of 15 degrees; the rise time is 100ms, the gap is 25mm with a magnetic field of 1.11 T. The second is a family of seven quadrupoles with a gradient of 20 T/m and a bore of 45mm.

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THPAL014

Serial Magnetic Measurements for the NICA Quadruple Magnets of the NICA Booster Synchrotron

booster, cryogenics, superconducting-magnet, collider

3649

A.V. Shemchuk
JINR/VBLHEP, Dubna, Moscow region, Russia
V.V. Borisov, A.V. Bychkov, A.M. Donyagin, O. Golubitsky, H.G. Khodzhibagiyan, S.A. Kostromin, M.M. Shandov
JINR, Dubna, Moscow Region, Russia

NICA is a new accelerator collider complex under con-struction at JINR, Dubna. More than 250 superconducting magnets are needed for the NICA booster and collider. The NICA Booster magnetic system includes 48 quadrupole superconducting magnets. The rotating coils probe developed for series magnetic measurements of booster quadrupoles doublets, as well as measuring methods are described. Results of magnetic measurements in cryogenic conditions for 12 doublets are presented and discussed.

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THPAL017

From design to alignment of ThomX quadrupoles

simulation, multipole, HOM, alignment

3660

C. Vallerand, R. Marie, H. Monard
LAL, Orsay, France
J. Campmany, J. Marcos, V. Massana
ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
J. Chavanne, G. Le Bec
ESRF, Grenoble, France
M.-E. Couprie, A. Lestrade, A. Loulergue, F. Marteau, M. Ros
SOLEIL, Gif-sur-Yvette, France

Quadrupoles for Thomx Facility have been carefully designed and measured due to high constraints of the storage ring. The need of a compact accelerator, 70 m2 on floor, as well as a beam life time of 20 ms, led to the following requirements for the quadrupole : a gradient of 5 T/m with 20.5 mm radius bore, harmonic content better than few 1.10^-3 at the reference radius of 18 mm, no cross-talk with sextupole placed within 5 cm and a precision of the magnetic axis of 100 μm and the roll angle of 300 μrad for measurements and alignment. Total of 41 quadrupoles have been built and all measured by a rotating coil at ALBA and SOLEIL, providing multipole components, transfer function and magnetic center. Cross-check measurements have also been carried out with a versatile stretched wire from ESRF at LAL. This paper mainly describes results of simulations with OPERA and RADIA and provides the results of measurements with these three benches. These results will be compared and highlighted important points for the alignment and installation of quadrupoles in an accelerator.

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THPAL020

Design of Asymmetric Quadrupole Gradient Bending R&D Magnet for the Advanced Light Source Upgrade (ALS-U)

dipole, multipole, simulation, lattice

3667

J.-Y. Jung, M. Leitner, N. Li, E.R. San Mateo, C. Steier, C.A. Swenson, M. Venturini
LBNL, Berkeley, California, USA

Lawrence Bekerley National Laboratory (LBNL) is en-gaged in the development of magnets for the upgrade of the ALS synchrotron (ALS-U) [1]. The proposed ALS-U lattice is a 9-bend achromat reproducing the existing 12-fold symmetric ALS foot print. The ALS-U lattice requires strong focusing elements and the dipole magnet requires high gradient larger than 46 T/m. This paper presents the detailed design of the R&D dipoles under construction.

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THPAL022

Precision Magnet Measurements for Deuteron Beam Transport

dipole, multipole, alignment, neutron

3670

R.A. Marsh, D.J. Gibson, B. Rusnak
LLNL, Livermore, California, USA

Funding: This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.
A versatile 4 MeV and 7 MeV deuteron beam transport line is being developed at Lawrence Livermore National Laboratory in support of an accelerator-driven source for fast neutron imaging. The beamline design requires precise alignment and high quality quadrupole magnets to transport a low emittance beam to the target through diagnostics, a bending dipole, and a differential pumping line with minimum beam loss and emittance growth. Vector magnetic field measurements of these magnets have been completed using a mobile version of an existing magnet mapping capability. This magnet mapping system is being used to ensure the delivered magnets meet the field uniformity specification, and that the mountings are aligned and capable of reaching the specified alignment tolerances. Details of the magnet measurement and calibration process that enable accurate field measurements to represent the intrinsic magnet field quality and not the systematic error of the measurement setup are presented.

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THPAL071

Preliminary Emittance Measurement of Laser Driven Proton Beam Employing a Quadruple Triplet Magnet

proton, emittance, laser, experiment

3818

Wu,M.J. Wu, Y.X. Geng, Q. Liao, C. Lin, H.Y. Lu, Y.R. Lu, W.J. Ma, Y.R. Shou, X. Xu, X.Q. Yan, Y.Y. Zhao, J.G. Zhu, K. Zhu
PKU, Beijing, People's Republic of China

The Compact Laser Plasma Accelerator (CLAPA) has been built recently at Peking University, which composed of a 200TW laser acceleration platform and a beam line system. Proton with energy spread of <1%, up to 10 pC charge and different energies below 10 MeV have been produced and transported to the irradiation platform. Emittance is a critical parameter for beam transportation. The preliminary emittance measurement has been per-formed for CLAPA's proton beams using the quadrupole scan technique (QST). In the experiment, the focal spot size of the proton beam was changed by scanning the current of a quadrupole triplet magnet. The result shows that the normalized emittance is smaller than 0.01 mm·mrad for 5 MeV laser driven protons, which is on the same level of the previously reported work.

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THPMF017

Operation Improvements and Emittance Reduction of the ESRF Booster

emittance, booster, operation, SRF

4077

N. Carmignani, N. Benoist, J-F. B. Bouteille, M.G. Di Vito, F. Ewald, L. Farvacque, A. Franchi, O. Goudard, J.M. Koch, S. Lagarde, S.M. Liuzzo, B. Ogier, T.P. Perron, P. Raimondi, D. Robinson, F. Taoutaou, E.T. Taurel, P.V. Verdier, R. Versteegen, P. Vidal, S.M. White
ESRF, Grenoble, France

The ESRF storage ring will be replaced by the Extremely Brilliant Source (EBS) in 2020 and the equilibrium emittance will decrease from the present 4 nmrad to 134 pmrad. The current injector system, composed by a linac and a synchrotron booster, will be used to inject into the new storage ring. To increase the injection efficiency in the new storage ring, three methods to reduce the horizontal emittance of the booster have been considered and tested. This paper presents the studies and achievements in terms of operation improvements and emittance reduction.

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THPMF019

ESRF-EBS Lattice Model with Canted Beamlines

lattice, SRF, optics, MMI

4081

S.M. Liuzzo, N. Carmignani, J. Chavanne, L. Farvacque, T.P. Perron, P. Raimondi, S.M. White
ESRF, Grenoble, France

The ESRF Extremely Brilliant Source (ESRF-EBS) lattice model is updated to include three canted beamlines. The cells are modified where necessary to include 3-Pole Wiggler (3PW), 2-Pole Wiggler (2PW) and Short Bending Magnet (SBM) sources. Several lattices are obtained for the different stages that will bring from commissioning to operation with users. A scheme for tune modification keeping key optics knobs unchanged is proposed.

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THPMF053

Study of the Dynamic Aperture Reduction Due to Error Effects for the High Energy Photon Source

sextupole, lattice, optics, closed-orbit

4182

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

Funding: Work supported by Natural Science Foundation of China(No.11605212).
The 6 GeV High Energy Photon Source (HEPS) employs a lattice of 48 hybrid 7BA cells, aims to achieve a natural emittance between 30 to 60 pm, within a circumference of about 1.3 km. In the performance evaluation of optimized lattices, we found that the dynamic aperture of the bare lat- tice were su cient for on-axis swap-out injection, but a large reduction in the dynamic aperture was observed in the simu- lation when including lattice imperfections and even after dedicated lattice corrections. In this paper, we identi ed the feed-down e ects of sextupoles as the major source of DA reduction, and proposed to use dedicated sextupole movers to e ciently reduce the orbit o sets in sextupoles, to par- tially recover the dynamic aperture, sextupole mover-based optics correction schemes were also discussed.

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THPMF059

Simulation Studies of Beam Commissioning and Expected Performance of the SPring-8-II Storage Ring

emittance, lattice, simulation, sextupole

4203

Y. Shimosaki
JASRI, Hyogo, Japan
K. Soutome, M. Takao
JASRI/SPring-8, Hyogo-ken, Japan
H. Tanaka
RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan

In the SPring-8 upgrade project, the 5-bend achromat lattice is adopted for achieving a very low emittance of 157 pm.rad at 6 GeV. Since the dynamic aperture (DA) and the beam performance become sensitive against errors due to the strong quadrupoles and sextupoles, we carried out tracking simulations to evaluate the tolerance of machine imperfections such as the misalignment, magnetic field errors, the BPM offset, etc. It is found that the first-turn-steering (FTS) with the use of single-pass BPM's is indispensable because even under strict (but attainable) tolerances the beam cannot be stored without steering kicks. We then confirmed that after the FTS a sufficiently large DA can be obtained for accumulating the beam by the off-axis injection. By performing the orbit and optics corrections for the stored beam, we can finally achieve an emittance value of 160 ~ 180 pm.rad, being close to the design value. We also found that a naive application of the SVD algorithm to orbit corrections yields unwanted local bumps between BPM's and this deteriorates the vertical emittance. A possible scheme to avoid such local bumps by effectively interpolating the measured orbit will be discussed.

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THPMK015

Low Momentum Compaction Lattice Operation of the Taiwan Photon Source

lattice, emittance, storage-ring, operation

4325

C.-C. Kuo, C.H. Chen, J.Y. Chen, P.C. Chiu, K.T. Hsu, K.H. Hu, C.H. Huang, C.C. Liang, C.Y. Liao, Y.-C. Liu, Z.K. Liu, H.-J. Tsai, F.H. Tseng
NSRRC, Hsinchu, Taiwan

In order to provide short bunch length for picosecond time-resolved experiments and for coherent IR/THz radiation, low momentum compaction factor (alpha) lattices have been commissioned recently at the Taiwan Photon Source (TPS). The momentum compaction can be positive or negative and its value can be reduced by more than two orders of magnitude. In this paper, we discuss variable low alpha lattice optics, its beam dynamics issues, the measured momentum compaction and bunch lengths as well as beam orbit stability issues, etc.

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THPMK082

Micro Bunch Rotation and Coherent Undulator Radiation From a Kicked Beam

undulator, electron, focusing, radiation

4489

J.P. MacArthur
Stanford University, Stanford, California, USA
Z. Huang, J. Krzywinski, A.A. Lutman
SLAC, Menlo Park, California, USA

Recent observations of x-rays from a microbunched beam that has been kicked off-axis have shown coherent radiation at surprisingly large angles, in some cases reaching 30-50 uRad. Previous work on the topic has suggested that radiation at such large angles is inconsistent with classical radiation theory because microbunches cannot tilt. Here we show that, when kicked in a quadrupole lattice, microbunches can automatically tilt toward a new direction of propagation. This allows for coherent radiation farther off axis.

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THPMK129

Lattice Tweaking Using A Tune Knob Based On Global Mechanism

storage-ring, injection, lattice, simulation

4620

S.W. Wang, B. Li, J.L. Li, W.B. Wu, W. Xu, X. Zhou
USTC/NSRL, Hefei, Anhui, People's Republic of China
J.L. Li
IHEP, Beijing, People's Republic of China

The transverse tunes are important parameters for a storage ring and tune knobs are used to adjust the tunes in a specific range. Usually for large rings, a set of quadrupoles is set on the straight sections for the use of tune knob. A tune knob has been designed for the HLS-II storage ring without affecting the twiss parameters of the injection section. This paper introduces the design and online test of this tune knob. The quadrupoles are adjusted according to the simulation results and the tunes are measured and calibrated. The online test results show that the tune knob design works well on the HLS-II storage ring and can be applied for various machine studies.

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THPMK130

Study of Beam Instabilities with a Higher-Harmonic Cavity for the HALS

cavity, coupling, storage-ring, HOM

4623

Y.G. Tang, W. Li, Z.B. Sun, L. Wang, C.-F. Wu
USTC/NSRL, Hefei, Anhui, People's Republic of China

Hefei Advanced Light Source (HALS), a diffrac-tion-limited storage ring is on the design. In HALS project, a passive higher-harmonic cavity may be added in order to increase the beam lifetime of the storage ring. When the storage ring is operated with a small momentum compaction, instabilities limit the utility of the high-er-harmonic cavity. In this paper, we run an algorithm (analytic modeling) to consider the Robinson instabilities for normal and superconducting cavity respectively. The Robinson instabilities are predicted with and without mode coupling. Coupled-bunch instability induced by resonant interaction with parasitic longitudinal mode is also considered. The analytic modeling may be used to give rf-cavity parameters that are more conducive to stability. The results show that the storage ring can oper-ate at a higher beam current and the parasitic high-er-order mode of the fundamental cavity has less impact on the beam by using superconducting harmonic cavity.

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THPML024

Monoenergetic Beam Generated by Laser Accelerator at Peking University

laser, proton, experiment, acceleration

4702

K. Zhu, J.E. Chen, Y.X. Geng, C. Li, D.Y. Li, Q. Liao, C. Lin, H.Y. Lu, W.J. Ma, Y.R. Shou, Wu,M.J. Wu, X.H. Xu, X.Q. Yan, J.Q. Yu, Y.Y. Zhao, J.G. Zhu
PKU, Beijing, People's Republic of China

An ultrahigh-intensity laser incident on a target sets up a very strong electrostatic field exceeding 100 GV/m, it will few orders magnitude shrink down the traditional radio frequency accelerators. Whereas, to build a real accelerator for routine operation, many scientific and technical challenges for laser acceleration need to overcome before they could be applied to these applications. Recently A laser accelerator− Compact Laser Plasma Accelerator (CLAPA) is being built with a beam line to deliver proton beam with the energy of 1~15MeV, energy spread of ¡À1% and 10⁷-8 protons per pulse. The very high current proton beam is accelerated in laser ultrathin-foil interaction and transported by a beam line consisting of the electric quadruple and analyzing magnets. It makes sure the good beam qualities such as energy spread, charge, repeatability and availability of different energy, which means that for the first laser acceleration becomes a real laser accelerator. With the development of high-rep rate PW laser technology, we can now envision a compact beam therapeutic machine of cancer treatment in the near future soon.

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THPML062

A Beam Based Method to Optimize the SBPM System

FEL, experiment, electron, site

4780

J. Chen
SINAP, Shanghai, People's Republic of China
L.W. Lai, Y.B. Leng, T. Wu, R.X. Yuan
SSRF, Shanghai, People's Republic of China

For the electron accelerator, it is hoped that the trajec-tory of the beam can pass through the magnetic center of the quadrupole to minimize the orbital motion caused by the instability of the power supply. The relative deviation between the magnetic center of quadrupole and the elec-tric center of adjacent BPM is measured by electron beam usually in various accelerator facilities. But for the stripline BPM (SBPM) system, in order to achieve the best performance, the beam trajectory should also need to pass through the electrical center of the SBPM system. In this paper, a beam based method to optimize the SBPM system was proposed, the intensity of the magnet power was scanned to change the beam position in two-dimension and combine the change trend of the sum signal of adjacent SBPM to find out the relative deviation of BPM electric center and mechanical center. Relevant beam experiment work on the Shanghai Soft X-ray free electron laser (SXFEL) and the benefit of this method will be addressed as well.

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THPML063

Micro-Bunched Beam Production at FAST for Narrow Band THz Generation Using a Slit-Mask

electron, radiation, simulation, cavity

4784

J. Hyun
Sokendai, Ibaraki, Japan
D.J. Crawford, D.R. Edstrom, J. Ruan, J.K. Santucci, T. Sen, J.C.T. Thangaraj, R.M. Thurman-Keup
Fermilab, Batavia, Illinois, USA

We discuss simulations and experiments on creating micro-bunch beams for generating narrow band THz radiation at the Fermilab Accelerator Science and Technology (FAST) facility. The low-energy electron beamline at FAST consists of a photoinjector-based RF gun, two L-band superconducting accelerating cavities, a chicane, and a beam dump. The electron bunches are lengthened with cavity phases set off-crest for better longitudinal separation and then micro-bunched with a slit-mask installed in the chicane. We carried out the experiments with 30 MeV electron beams and detected signals of the micro-bunching using a skew quadrupole magnet in the chicane. In this paper, the details of micro-bunch beam production, the detection of micro-bunching and comparison with simulations are described.

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THPML079

Multipole Tuning Algorithm for the CANREB HRS at TRIUMF

multipole, TRIUMF, dipole, emittance

4836

D. Sehayek, R.A. Baartman, C.B. Barquest, J.A. Maloney, M. Marchetto, T. Planche
TRIUMF, Vancouver, Canada

The TRIUMF CANadian Rare isotope facility with Electron Beam ion source (CANREB) High Resolution Separator (HRS) has been designed to separate rare isotopes with mass/charge differences of only one part in 20,000 for beams with transverse emittances of 3 μm. To reach this resolution, high-order aberrations must be corrected using a multipole corrector. From experience, tuning such a multipole is very challenging. The unique geometry of our multipole motivated a novel tuning method based on determining the desired pole voltages directly from measured emmitance. This novel tuning algorithm is presented alongside a web application which has been developed in anticipation of the commissioning of the HRS.

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THPML094

New Methods for Dispersion Measurement and Correction for 12 GeV CEBAF

cavity, software, controls, simulation

4882

D.L. Turner
JLab, Newport News, Virginia, USA

Funding: This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics under contract DE-AC05-06OR23177.
This paper discusses methods for dispersion measurement and correction for the Continuous Electron Beam Accelerator Facility (CEBAF) for the 12GeV era. New methods will be compared with methods used during the 6GeV era. New software tools which implement the new methods will be discussed, along with a method for automating dispersion measurement and correction. New dispersion measurement and correction methods and tools are being implemented to provide more deterministic results and to reduce machine setup time.

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THPML102

Field and Cost Optimization of a 5 T/m Normal Conducting Quadrupole for the 10-MeV Beam Line of the eLINAC of the Mexican Particle Accelerator Community

power-supply, multipole, operation, linac

4905

D. Chavez Valenzuela, G.H.I. Maury Cuna, M. Napsuciale Mendivil
Universidad de Guanajuato, División de Ciencias e Ingenierías, León, Mexico
J. C. Basilio Ortiz
CINVESTAV, Mexico City, Mexico
P.M. McIntyre, A. Sattarov
Texas A&M University, College Station, USA
C.A. Valerio
ECFM-UAS, Culiacan, Sinaloa, Mexico
B. Yee-Rendón
KEK, Ibaraki, Japan

The Mexican Particle Accelerator Community is currently designing the first Mexican RF eLINAC that will have three beamlines at 10, 60 and 100 MeV. In this work, we present an optimized design in terms of field quality and production cost for the 5 T/m normal conducting quadrupoles of the 10-MeV beamline. Several candidate materials for the yoke were studied based on their availability and machinability, with the aim to optimize in-house production cost (Mexico) while restricting a low multipole content.

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THPML117

Study of the Impact of Linear Coupling on Off-Axis Injection

coupling, resonance, injection, dynamic-aperture

4943

X. Huang
SLAC, Menlo Park, California, USA
T. Zhang
USTC/NSRL, Hefei, Anhui, People's Republic of China

The next generation of storage ring light sources will likely operate with high linear coupling, which could potentially prevent the use of off-axis injection as large horizontal oscillation of the injected beam is coupled to the vertical plane. We did experiments on the SPEAR3 storage ring to study how linear coupling impact the dynamic aperture and the off-axis injection efficiency. The results show that the dynamic aperture is significantly reduced and injection efficiency can drop to zero when operated on the coupling resonance. However, with large nonlinear detuning, the dynamic aperture and high injection efficiency can survive with the stored beam at full coupling because the injected beam is shifted away from the coupling resonance.

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THPML134

Design of the Magnets of the HALS Project

sextupole, dipole, lattice, emittance

4998

Z.L. Ren, C. Chen, T.L. He, L. Wang, X.Q. Wang, H. Xu, B. Zhang
USTC/NSRL, Hefei, Anhui, People's Republic of China

Funding: Work supported by the National Nature Science Foundation of China under Grant Nos.11375176 * hlxu@ustc.edu.cn ** zhbo@ustc.edu.cn
The Hefei Advanced Light Source (HALS) is a future soft X-ray diffraction-limited storage ring at NSRL, this project aims to improve the brilliance and coherence of the X-ray beams and to decrease the horizontal emittance. The lattice of the HALS ring relies on magnets with demanding specifications, including combined function dipole-quadrupoles (DQs) with high gradients, dipoles with longitudinal gradients (DLs), high gradient quadrupoles and strong sextupoles. The combined dipole-quadrupole design developed is between the offset quadrupole and septum quadrupole types. The longitudinal-gradient dipoles are permanent magnets. The quadrupoles and sextupoles rely on a more conventional design. All the magnets have been designed using POSSION, Radia, and OPERA-3D.

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THPML135

Design of the Combined Function Dipole-Quadrupoles (DQS) with High Gradients

dipole, vacuum, lattice, storage-ring

5001

Z.L. Ren, C. Chen, T.L. He, L. Wang, X.Q. Wang, H. Xu, B. Zhang
USTC/NSRL, Hefei, Anhui, People's Republic of China

Funding: Work supported by the National Nature Science Foundation of China under Grant Nos.11375176 * hlxu@ustc.edu.cn **zhbo@ustc.edu.cn
Combined dipole-quadrupoles (DQs) can be obtained with the design of tapered dipole or offset quadrupole. However, the tapered dipole design can not achieve a high gradient field, as it will lead to poor field quality in the low field area of the magnet bore, and the design of offset quadrupole will increase the magnet size and power consumption. Finally, the dipole-quadrupole design developed is between the offset quadrupole and septum quadrupole types. The dimensions of the poles and the coils of the low field side have been reduced. The 2D pole profile is simulated and optimized by using POSSION and Radia, while the 3D modle using Radia and OPERA-3D. The end shimming and chamfer are modelled to meet the field uniformity requirement.

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FRXGBE2

Muon Beam Dynamics and Spin Dynamics in the g-2 Storage Ring

storage-ring, injection, positron, experiment

5029

D. L. Rubin, A.T. Chapelain
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
S. Charity, J. Price
The University of Liverpool, Liverpool, United Kingdom
J.D. Crnkovic, W. Morse, V. Tishchenko
BNL, Upton, Long Island, New York, USA
F.E. Gray
Regis University, Denver, USA
J. E. Mott
BUphy, Boston, Massachusetts, USA
W. Wu
UMiss, University, Mississippi, USA

Funding: This work was supported in part by the U.S. Department of Energy DOE HEP DE-SC0008037
The goal of the new g-2 experiment at fermilab is a measurement of the anomalous magnetic moment of the muon, with uncertainty of less than 140 ppb. The experimental method is to store a beam of polarized muons in a storage ring with pure vertical dipole field and electrostatic focusing, and to measure the precession frequency. Control of the systematics depends on unprecedented knowledge of the details of the phase space of the muon distribution. That knowledge is derived from direct measurements with scintillating fiber detectors that are inserted into the muon beam for diagnostic measurements, traceback straw tube tracking chambers, as well as the calorimeters that measure energy, time and position of the decay positrons. The interpretation of the measurements depends on a detailed model of the storage ring guide field. This invited talk presents results of studies of the distribution from the commissioning run of the experiment.

Slides FRXGBE2 [12.809 MB]

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