IPAC2018 - List of Keywords (injection)

Paper	Title	Other Keywords	Page
MOPMF001	Bunch Schedules for the FCC-ee Pre-injector	linac, collider, booster, positron	79
	S. Ogur, K. Oide, Y. Papaphilippou, F. Zimmermann CERN, Geneva, Switzerland D.N. Shatilov BINP SB RAS, Novosibirsk, Russia
	The latest design of the Future Circular electron-positron Collider (FCC-ee) foresees a luminosity per interaction point above 2.0·10³⁶/cm²/s for operation at the Z pole. The filling from zero current occurs in collision to profit from the bunch lengthening due to beamstrahlung (so-called bootstrapping). At any time when new e^- and e⁺ buckets or bunchlets are injected into the collider, they will collide instantly. For this reason, we may provide the charge in each injected bunch in a way to pre-compensate for anticipated beam loss, and to reach the target luminosity as soon as possible after the first injection. In this way, we optimise the injection schedules for Z-mode so as to reach the peak luminosity in less than 20 minutes by interleaved injection of the two species at some portion of full bucket charge. Filling from zero the injector should allow accumulating 1.7·10¹¹ particles in one collider bucket within at least 10 injections, assuming a total transmission above 80%. In steady-state operation, the injector chain continually produces and accelerates lower bunch charges so as to maintain nearly constant bunch currents and constant peak luminosity.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMF001
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMF005	Beam Formation in the Alternative JLEIC Ion Complex	booster, linac, collider, proton	91
	B. Mustapha, J.L. Martinez Marin ANL, Argonne, USA Y.S. Derbenev, F. Lin, V.S. Morozov, Y. Zhang JLab, Newport News, Virginia, USA
	Funding: Work supported by the U.S. Department of Energy / ONP, under Contract No. DE-AC02-06CH11357 for ANL and by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. The proposed alternative design approach for the JLab-EIC (JLEIC) ion complex uses a more compact linac and pre-booster, and consolidates the electron storage ring (e-ring) as a large booster for the ions. Following a parameter study* showing the feasibility of this alternative design approach, we have adapted the e-ring lattice by adding RF sections to accelerate ion beams*. In this study, we focus on the beam formation for protons and lead ions from the linac to the pre-booster, then into the e-ring until injection to the ion collider ring. Effects such as space charge, intra-beam scattering and the need for beam cooling will determine the total accumulated charge in each ring and the time required from injection from the injector linac to collision in the collider ring. B. Mustapha et al, Proceedings of NAPAC-2016, October 9-14, Chicago, IL. ** B. Mustapha et al, Proceedings of IPAC-2017, May 14-19, Copenhagen, Denmark.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMF005
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMF018	Numerical Simulation of Spin Dynamics with Spin Flipper in RHIC	resonance, dipole, simulation, polarization	118
	P. Adams, H. Huang, J. Kewisch, F. Méot, P. Oddo, V. Ptitsyn, V.H. Ranjbar, G. Robert-Demolaize, T. Roser 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. Spin flipper experiments during RHIC Run 17 were performed to study its effectiveness as a method for polarization sign reversal during stores. Numerical simulations are reported here, which were performed in accompaniment of these, and are being pursued with the aim of accurately reproducing the experimental conditions and providing thorough insight in the role of various key parameters participating in the dynamics of the spin flip, such as the sweep rate of the AC dipole, chromatic orbit control at RHIC snakes, RF parameters, possible effects of non-linear spin resonances, mirror resonance, tolerance on flipper magnet parameters, etc. The ultimate goal is for these simulations to serve as a guidance toward perfect flip to allow routine use during physics Runs.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMF018
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMF023	Updates on the Optic Corrections of FCC-hh	quadrupole, coupling, 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
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMF024	Dipole Field Quality and Dynamic Aperture for FCC-hh	dipole, alignment, dynamic-aperture, optics	137
	B. Dalena CEA/IRFU, Gif-sur-Yvette, France D. Boutin, A. Chancé CEA/DRF/IRFU, Gif-sur-Yvette, France B.J. Holzer, S. Izquierdo Bermudez, D. Schoerling, D. Schulte CERN, Geneva, Switzerland
	Funding: This Research and Innovation Action project submitted to call H2020-INFRADEV-1-2014-1 receives funding from the European Union's H2020 Framework Program under grant agreement No. 654305. The Nb₃Sn dipole design for the hadron machine option of the Future Circular Colliders enters in an intense and long R&D phase. As a result, more realistic dipole field quality evaluations are available for beam dynamics studies. The paper discusses the impact of the main dipole field quality on the first and second order design of the hadron machine and on its dynamic aperture.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMF024
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMF029	FCC-hh transverse impedance budget	impedance, feedback, laser, electron	149
	S. Arsenyev, D. Schulte CERN, Geneva, Switzerland O. Boine-Frankenheim GSI, Darmstadt, Germany
	Contributions of different machine elements of the proposed Future Circular Collider (FCC-hh) impedance budget are calculated based on beam stability considerations. For each element (the beamscreen, the collimators, etc), effective impedances are calculated at the injection energy and at the collision energy for considered instabilities. The considered instabilities include the transverse coupled bunch instability (TCBI) and the transverse mode coupling instability (TMCI). Limitations to each total effective impedance are estimated and the critical points in the impedance budget are determined.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMF029
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMF030	Broadband Impedance of Pumping Holes and Interconnects in the FCC-hh Beamscreen	impedance, wakefield, coupling, electronics	153
	S. Arsenyev, D. Schulte CERN, Geneva, Switzerland
	In the proposed Future Circular Collider (FCC-hh) pumping holes and interconnects between sections of the beamscreen can be sources of unwanted broadband impedance, potentially leading to the transverse mode coupling instability (TMCI). The pumping holes pose a greater challenge to the impedance calculation due to their small contribution per hole. Unlike for the Large Hadron Collider (LHC), analytical methods cannot be applied due to the complex beamscreen geometry and the greater size of the holes. Instead, two computational methods are used and compared to each other. For the interconnects, the impedance due to a sophisticated system of tapers is also estimated using computational methods.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMF030
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMF034	Layout and Performance of the FCC-ee Pre-Injector Chain	linac, emittance, damping, cavity	169
	S. Ogur, T.K. Charles, K. Oide, Y. Papaphilippou, L. Rinolfi, F. Zimmermann CERN, Geneva, Switzerland A.M. Barnyakov, A.E. Levichev, P.V. Martyshkin, D.A. Nikiforov BINP SB RAS, Novosibirsk, Russia I. Chaikovska, R. Chehab LAL, Orsay, France K. Furukawa, N. Iida, T. Kamitani, F. Miyahara KEK, Ibaraki, Japan E.V. Ozcan Bogazici University, Bebek / Istanbul, Turkey S.M. Polozov MEPhI, Moscow, Russia
	The Future Circular e⁺e⁻ Collider pre-injector chain consists of a 6 GeV S-Band linac, a damping ring at 1.54 GeV and pre-booster ring to reach 20 GeV for injection to the main booster. The electron and positron beams use the same accelerator chain alternatively. The e⁺ beam is generated from a novel low level RF-gun providing 6.5 nC charge at 11 MeV with 0.5 micron geometric emittance. The e⁺ beam is produced by the impact of a 4.46 GeV e^- beam onto a hybrid target, accelerated in the linac up to 1.54 GeV, and injected to the damping ring for emittance cooling. Simulations on the performance of the DR are presented for reaching the required equilibrium emittances at the required damping time. As an alternative option, a 20 GeV linac is considered utilising C-Band cavities and simulations studies have been undertaken regarding the beam transport and transmission efficiency up to that energy.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMF034
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMF039	First Xenon-Xenon Collisions in the LHC	luminosity, experiment, proton, emittance	180
	M. Schaumann, R. Alemany-Fernández, P. Baudrenghien, T. Bohl, C. Bracco, R. Bruce, N. Fuster-Martínez, M.A. Jebramcik, J.M. Jowett, T. Mertens, D. Mirarchi, S. Redaelli, B. Salvachua, M. Solfaroli, H. Timko, J. Wenninger CERN, Geneva, Switzerland
	In 2017, the CERN accelerator complex once again demonstrated its flexibility by producing beams of a new ion species, xenon, that were successfully injected into LHC. On 12 October, collisions of fully stripped xenon nuclei were recorded for the first time in the LHC at a centre-of-mass energy per colliding nucleon pair of 5.44 TeV. Physics data taking started 9.5 h after the first injection of xenon beams and lasted a total of 6 h. The integrated luminosity delivered to the four LHC experiments was sufficient that new physics results can be expected soon. We provide a general overview of this Xe-Xe pilot run before focussing on beam data at injection energy and at flat-top.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMF039
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMF047	Transverse Coupling Measurements With High Intensity Beams Using Driven Oscillations	coupling, dipole, controls, resonance	208
	T. Persson, G. Baud, X. Buffat, J.M. Coello de Portugal, E. Fol, K. Fuchsberger, M. Gabriel, M. Gąsior, M. Giovannozzi, G.H. Hemelsoet, M. Hostettler, M. Hruska, D. Jacquet, E.H. Maclean, L. Malina, J. Olexa, P.K. Skowroński, M. Solfaroli Camillocci, M.E. Söderén, R. Tomás, D. Valuch, A. Wegscheider, J. Wenninger CERN, Geneva, Switzerland
	Transverse coupling has been linked to instabilities and reduction in dynamic aperture and is hence a crucial parameter to control in the LHC. In this article we describe the development to use driven oscillations to measure the transverse coupling with high intensity beams. The method relies on the use of the transverse damper to drive an oscillation in a similar way as with an AC-dipole. The calculation of the coupling is based on the turn-by-turn data from all available BPMs gated for the excited bunch.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMF047
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMF048	Aperture Measurements with AC Dipole at the Large Hadron Collider	dipole, optics, MMI, emittance	212
	N. Fuster-Martínez, R. Bruce, J. Dilly, E.H. Maclean, T. Persson, S. Redaelli, R. Tomás CERN, Geneva, Switzerland L.J. Nevay Royal Holloway, University of London, Surrey, United Kingdom
	Global aperture measurements are crucial for a safe operation and to push the performance of the LHC, in particular, the knowledge of aperture at top energy allows pushing the optics to reduce the colliding beam sizes. The standard method used in the LHC commissioning requires using several bunches for one measurement and makes bunches un-usable for other activities. This paper presents first global aperture measurements performed at injection with a new method using the AC dipole. This method consists in exciting large coherent oscillations of the beam without spoiling its emittance. A gentle control of the oscillation amplitude enables re-using the beams for several measurements. These measurements are compared with aperture measurements performed using the standard method and possible benefits, for example for optics measurements, at top energy with squeezed optics, are elaborated.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMF048
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMF058	Status of the LHC Schottky Monitors	emittance, octupole, sextupole, damping	247
	T. Tydecks, D. Alves, T.E. Levens, M. Wendt, J. Wenninger CERN, Geneva, Switzerland
	The Large Hadron Collider (LHC) features four transverse Schottky monitors detecting Schottky noise from the beam. From the Schottky noise signal, beam properties like tune, chromaticity, and bunch by bunch relative emittances, can be extracted. Being a non-destructive and purely parasitic method of measurement, the Schottky system is of great interest for real-time determination of beam chromaticities especially. Studies, including a dedicated machine development shift as well as parasitic measurements, concerning its capability to accurately measure the beam chromaticities are presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMF058
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMF059	Status of the FCC-ee Top-Up Booster Synchrotron	booster, collider, optics, emittance	250
	B. Härer, B.J. Holzer, Y. Papaphilippou, T. Tydecks CERN, Geneva, Switzerland
	This contribution presents the status of the top-up booster synchrotron for the FCC electron-positron collider FCC-ee, which is a 100 km electron-positron collider being designed for precision studies and rare decay observations in the range of 90 to 365 GeV centre-of-mass energy. In order to keep the luminosity at a level of the order of 10³⁵ cm^-2s^-1 continuous top-up injection is required, because of the short beam lifetime of less than one hour. The top-up booster synchrotron will be housed in the same tunnel as the collider rings and will ramp up the beam energy from 20 GeV at injection to the full energy between 45.5 GeV and 182.5 GeV depending on operation mode. The lattice design and two possible optics will be presented. The dynamic aperture was investigated for different sextupole schemes with and without misalignments of the lattice components. In addition, wigglers were installed to decrease the damping time and mitigate intra-beam-scattering.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMF059
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMF064	High-Energy LHC Design	impedance, optics, luminosity, proton	269
	F. Zimmermann, D. Amorim, S. A. Antipov, S. Arsenyev, M. Benedikt, R. Bruce, M.P. Crouch, S.D. Fartoukh, M. Giovannozzi, B. Goddard, M. Hofer, R. Kersevan, V. Mertens, Y. Muttoni, J.A. Osborne, V. Parma, V. Raginel, S. Redaelli, T. Risselada, I. Ruehl, B. Salvant, D. Schoerling, E.N. Shaposhnikova, L.J. Tavian, E. Todesco, R. Tomás, D. Tommasini, F. Valchkova-Georgieva, V. Venturi, D. Wollmann CERN, Geneva, Switzerland J.L. Abelleira, E. Cruz Alaniz, P. Martinez Mirave, A. Seryi, L. van Riesen-Haupt JAI, Oxford, United Kingdom A. Apyan ANSL, Yerevan, Armenia J. Barranco García, L. Mether, T. Pieloni, L. Rivkin, C. Tambasco EPFL, Lausanne, Switzerland F. Burkart DESY, Hamburg, Germany Y. Cai, Y.M. Nosochkov SLAC, Menlo Park, California, USA G. Guillermo Cantón CINVESTAV, Mérida, Mexico K. Ohmi, K. Oide, D. Zhou KEK, Ibaraki, Japan
	In the frame of the FCC study we are designing a 27 TeV hadron collider in the LHC tunnel, called the High Energy LHC (HE-LHC).
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMF064
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMF067	Optimized Arc Optics for the HE-LHC	dipole, lattice, sextupole, optics	277
	Y.M. Nosochkov, Y. Cai SLAC, Menlo Park, California, USA M.P. Crouch, M. Giovannozzi, M. Hofer, J. Keintzel, T. Risselada, E. Todesco, R. Tomás, F. Zimmermann CERN, Geneva, Switzerland D. Zhou KEK, Ibaraki, Japan L. van Riesen-Haupt JAI, Oxford, United Kingdom
	Funding: Work supported by the European Commission under Capacities 7th Framework Programme project EuCARD-2, grant agreement 312453, and the HORIZON 2020 project EuroCirCol, grant agreement 654305. The High Energy LHC (HE-LHC) proton-proton collider is a proposed replacement of the LHC in the existing 27-km tunnel, with the goal of reaching the centre-of-mass beam energy of 27 TeV. The required higher dipole field can be realized by using 16-T dipoles being developed for the FCC-hh design. A major concern is the dynamic aperture at injection energy due to degraded field quality of the new dipole based on Nb3Sn superconductor, the potentially large energy swing between injection and collision, and the slightly reduced magnet aperture. Another issue is the field in quadrupoles and sextupoles at top energy, for which it may be cost-effective, wherever possible, to stay with Nb-Ti technology. In this study, we explore design options differed by arc lattice, for three choices of injection energy, with the goal of attaining acceptable magnet field and maximum injection dynamic aperture with dipole non-linear field errors.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMF067
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMF073	Rejuvenation of 7-Gev SuperKEKB Injector Linac	positron, linac, electron, emittance	300
	K. Furukawa, M. Akemoto, D.A. Arakawa, Y. Arakida, H. Ego, A. Enomoto, Y. Enomoto, T. Higo, H. Honma, N. Iida, M. Ikeda, H. Kaji, K. Kakihara, T. Kamitani, H. Katagiri, M. Kawamura, M. Kurashina, S. Matsumoto, T. Matsumoto, H. Matsushita, S. Michizono, K. Mikawa, T. Miura, F. Miyahara, H. Nakajima, K. Nakao, T. Natsui, M. Nishida, Y. Ogawa, Y. Ohnishi, S. Ohsawa, F. Qiu, I. Satake, M. Satoh, Y. Seimiya, A. Shirakawa, H. Sugimura, T. Suwada, T. Takenaka, M. Tanaka, N. Toge, Y. Yano, K. Yokoyama, M. Yoshida, R. Zhang, X. Zhou KEK, Ibaraki, Japan
	KEK injector linac has delivered electrons and positrons for particle physics and photon science experiments for more than 30 years. It was upgraded for the SuperKEKB project, which aims at a 40-fold increase in luminosity over the previous project KEKB, in order to increase our understanding of flavor physics beyond the standard model of elementary particle physics. SuperKEKB energy-asymmetric electron-positron collider with its extremely high luminosity requires a high current, low emittance and low energy spread injection beam from the injector. The electron beam is generated by a new type of RF gun, that provides a much higher beam current to correspond to a large stored beam current and a short lifetime in the ring. The positron source is another major challenge that enhances the positron bunch intensity from 1 to 4 nC by increasing the positron capture efficiency, and the positron beam emittance is reduced from 2000 μm to 10 μm in the vertical plane by introducing a damping ring, followed by the bunch compressor and energy compressor. The summary of the rejuvenation is reported.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMF073
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMF089	DAΦNE Luminosity Monitor	luminosity, detector, experiment, scattering	338
	A. De Santis, C. Bisegni, O.R. Blanco-García, O. Coiro, A. Michelotti, C. Milardi, A. Stecchi INFN/LNF, Frascati (Roma), Italy
	This work presents a new method to measure the DAΦNE collider instantaneous luminosity. The method is based on the identification of Bhabha scattering events at low polar angle (∼10 degree) around the beam axis by using two small crystal calorimeters shared with the KLOE-2 experiment. A new experimental setup has been designed and realized in order to implement the fast luminosity monitor, also in view of the DAΦNE future physics runs. Besides total instantaneous luminosity the new diagnostic measures also Bunch-by-Bunch (BBB) luminosity. This peculiarity allows to investigate the beam-beam interaction for the Crab- Waist collisions at DAΦNE and luminosity dependence on the bunch train structure.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMF089
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMK002	Integrated Full HE-LHC Optics and Its Performance	lattice, dipole, insertion, target	348
	M. Hofer TU Vienna, Wien, Austria M.P. Crouch, J. Keintzel, T. Risselada, R. Tomás, F. Zimmermann CERN, Geneva, Switzerland Y.M. Nosochkov SLAC, Menlo Park, California, USA D. Zhou KEK, Ibaraki, Japan L. van Riesen-Haupt JAI, Oxford, United Kingdom
	One possible future hadron collider design investigated in the framework of the Future Circular Collider (FCC) study is the High-Energy LHC (HE-LHC). Using the 16 T dipoles developed for the FCC-hh the center of mass energy of the LHC is set to increase to 27 TeV. To achieve this set energy goal, a new optics design is required, taking into account the constraint from the LHC tunnel geometry. In this paper, two different lattices for the HE-LHC are presented. Initial considerations take into account the physical aperture at the proposed injection energy as well as the energy reach of these lattices. The dynamic aperture at the injection energies is determined using latest evaluations of the field quality of the main dipoles.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMK002
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMK007	An Optimised Triplet for the Final Focus of the FCC-HH with a 40m Final Drift	optics, luminosity, quadrupole, collider	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.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMK007
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMK011	VEPP-5 Injection Complex: New Possibilities for BINP Electron-Positron Colliders	positron, electron, collider, gun	371
	Yu. Maltseva, A.V. Andrianov, K.V. Astrelina, V.V. Balakin, A.M. Batrakov, O.V. Belikov, D.E. Berkaev, M.F. Blinov, D. Bolkhovityanov, A. Butakov, E.V. Bykov, N.S. Dikansky, F.A. Emanov, A.R. Frolov, V.V. Gambaryan, K. Gorchakov, Ye.A. Gusev, S.E. Karnaev, G.V. Karpov, A.S. Kasaev, E. Kenzhbulatov, V.A. Kiselev, S. Kluschev, A.A. Kondakov, I. Koop, I.E. Korenev, N.Kh. Kot, V.R. Kozak, A.A. Krasnov, S.A. Krutikhin, I.V. Kuptsov, G.Y. Kurkin, N.N. Lebedev, A.E. Levichev, P.V. Logatchov, A.A. Murasev, V. Muslivets, D.A. Nikiforov, An.A. Novikov, A.V. Ottmar, A.V. Pavlenko, I.L. Pivovarov, V.V. Rashchenko, Yu. A. Rogovsky, S.L. Samoylov, N. Sazonov, A.V. Semenov, D.B. Shwartz, A.N. Skrinsky, A.A. Starostenko, D.A. Starostenko, A.G. Tribendis, A.S. Tsyganov, S.P. Vasichev, S.V. Vasiliev, V.D. Yudin, I.M. Zemlyansky, A.N. Zhuravlev BINP SB RAS, Novosibirsk, Russia A.V. Andrianov, V.V. Balakin, F.A. Emanov, I. Koop, A.A. Krasnov, A.E. Levichev, D.A. Nikiforov, A.V. Pavlenko, Yu. A. Rogovsky, D.B. Shwartz, A.A. Starostenko NSU, Novosibirsk, Russia A.I. Mickailov Budker INP & NSU, Novosibirsk, Russia A.G. Tribendis NSTU, Novosibirsk, Russia
	VEPP-5 Injection Complex (IC) is designed to supply BINP RAS colliders with high energy electron and positron beams. Recently constructed K-500 beam transfer line connects IC to both VEPP-4M and VEPP-2000 colliders. IC two collider operation was successfully performed in 2016. Nowadays, research on improvement of IC productivity is carried out, in particular 10.94 MHz RF cavity instead of 700 MHz one was installed and a new electron gun installation is expected to be this summer. Moreover, longitudinal beam profile measurements in IC damping ring using a streak-camera were carried out. Operation experience of IC and results of longitudinal beam profile measurements are reported.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMK011
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUXGBE4	Beam Quality Limitations of Plasma-Based Accelerators	plasma, electron, laser, acceleration	607
	A. Ferran Pousa, R.W. Aßmann DESY, Hamburg, Germany A. Martinez de la Ossa University of Hamburg, Institut für Experimentalphysik, Hamburg, Germany
	Plasma-based accelerators are a promising novel technology that could significantly reduce the size and cost of future accelerator facilities. However, the typical quality and stability of the produced beams is still inferior to the requirements of Free Electron Lasers (FELs) and other applications. We present here our recent work in understanding the limitations of this type of accelerators, particularly on the energy spread and bunch length, and possible mitigating measures for future applications, like the plasma-based FEL in the EuPRAXIA design study.
	Slides TUXGBE4 [4.905 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUXGBE4
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUXGBF4	ORBIT Simulation, Measurement and Mitigation of Transverse Beam Instability in the Presence of Strong Space Charge in the 3-GeV RCS of J-PARC	simulation, impedance, acceleration, space-charge	620
	P.K. Saha, H. Harada, N. Hayashi, H. Hotchi, Y. Shobuda, F. Tamura JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
	The transverse impedance of eight extraction pulse kicker magnets (KM) is extremely strong source of transverse beam instability in the 3-GeV RCS (Rapid Cycling Synchrotron) at J-PARC. To realize the designed 1 MW beam power, collective beam dynamics with including the space charge effect for the coupled bunch instabilities excited by the KM impedance and associated measures were studied by incorporating all realistic time-dependent machine parameters in the ORBIT 3-D particle tracking code. The simulation results were all reproduced by measurements and, as a consequence, an acceleration of 1 MW beam power has been successfully demonstrated. In order to maintain variation of the RCS parameters required for multi-user operation, realistic measures for beam instability mitigation were proposed and also been successfully implemented in reality. To further increase the RCS beam power, beam stability issues and possible measures beyond 1 MW beam power are also considered.
	Slides TUXGBF4 [2.241 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUXGBF4
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUYGBE4	Optically-pumped Polarized H⁻ and 3 He++ Ion Sources Development at RHIC	polarization, ion-source, electron, solenoid	644
	A. Zelenski, G. Atoian, E.N. Beebe, A. Poblaguev, D. Raparia, J. Ritter BNL, Upton, Long Island, New York, USA J.D. Maxwell, R. Milner, M. Musgrave MIT, Cambridge, Massachusetts, USA
	The RHIC Optically-pumped Polarized H⁻ Ion Source (OPPIS) upgrade with the atomic beam hydrogen injector and the He-ionizer cell was commissioned for operation in the Run-2013. The use of the high brightness primary proton source resulted in higher polarized beam intensity and polarization delivered for injection to Linac-Booster-AGS-RHIC accelerator complex. The proposed polarized 3He++ acceleration in RHIC and future electron- ion col-lider (eRHIC) will require about 2·10¹¹ ions in the source pulse. A new technique had been proposed for production of high intensity polarized 3He++ ion beam. It is based on ionization and accumulation of the 3He gas (polarized by optical-pumping and metastability-exchange technique in the high magnetic field of a 5.0 T) in the Electron Beam Ion Source (EBIS). We present a status of the 3He++ ion source development.
	Slides TUYGBE4 [4.596 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUYGBE4
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAF006	Operation of RHIC Injectors with Isobaric Ruthenium and Zirconium Ions	laser, target, booster, ion-source	672
	H. Huang, E.N. Beebe, I. Blacker, J.J. Butler, C. Carlson, P.S. Dyer, W. Fischer, C.J. Gardner, D.M. Gassner, D. Goldberg, T. Hayes, S. Ikeda, J.P. Jamilkowski, T. Kanesue, N.A. Kling, C. Liu, D. Maffei, G.J. Marr, B. Martin, J. Morris, C. Naylor, M. Okamura, D. Raparia, V. Schoefer, F. Severino, T.C. Shrey, K.S. Smith, D. Steski, P. Thieberger, K. Zeno, I.Y. Zhang BNL, Upton, Long Island, New York, USA H. Haba RIKEN Nishina Center, Wako, Japan T. Karino Utsunomiya University, Utsunomiya, Japan
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. The FY18 RHIC physics program calls for Ru-Ru and Zr-Zr collisions at 100GeV using isobaric Ruthenium and Zirconium ions, each having 96 nucleons. In the injector chain, these two ions have to come from tandem and EBIS source, respectively. To reduce systematic errors in the detector, the luminosity between the two species combinations is matched as closely as possible, and the species are switched frequently. Several bunch merges are needed in the Booster and AGS to reach the desired bunch intensity for RHIC. The setup and performance of Booster and AGS with these ions are reviewed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAF006
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAF011	Btrain Calibration with RF-Master Method	dipole, cavity, synchrotron, pick-up	679
	L. Falbo, E. Bressi, M. Pezzetta, C. Priano CNAO Foundation, Milan, Italy
	CNAO is the only Italian hadrontherapy facility able to treat tumors with beams of protons and carbon ions. It is based on a synchrotron with a 77 m ring equipped with 16 normal conducting dipoles characterized by a long delay in the field stabilization. B-Train system is a fundamental device of the whole machine; it is used in feedback to the dipole power supply in order to regulate the magnetic field reducing the natural stabilization times that would cause long treatments. B-Train system allows to obtain the magnetic field starting from measurements of magnetic field changes: it works as an integrator and then it needs a system to reset the counts compensating the electronic and numerical drift of the system itself. An innovative method has been implemented at CNAO to reset Btrain counts exploiting beam measurements after the RF cavity trapping. This procedure has the advantage to avoid external and additional element like NMR probes. The paper shows the use of B-train system at CNAO and its calibration with this method, called "RF-master method".
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAF011
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAF020	Performance of the CERN Low Energy Ion Ring (LEIR) with Xenon beams	MMI, linac, controls, extraction	705
	R. Alemany-Fernández, S.C.P. Albright, O. Andujar, M.E. Angoletta, J. Axensalva, H. Bartosik, G. Baud, N. Biancacci, M. Bozzolan, S. Cettour Cave, K. Cornelis, J. Dalla-Costa, M. Delrieux, A. Dworak, A. Findlay, F. Follin, A. Frassier, M. Gabriel, A. Guerrero, M. Haase, S. Hirlaender, S. Jensen, V. Kain, L.V. Kolbeck, Y. Le Borgne, D. Manglunki, O. Marqversen, S. Massot, D. Moreno Garcia, D.J.P. Nicosia, S. Pasinelli, L. Pereira, D. Perez, A. Rey, J.P. Ridewood, F. Roncarolo, A. Saá Hernández, R. Scrivens, O.G. Sveen, G. Tranquille, E. Veyrunes CERN, Geneva, Switzerland
	In 2017 the CERN Low Energy Ion Ring demonstrated once more the feasibility of injecting, accumulating, cooling and accelerating a new nuclei, 129Xe39 . The operation of this new ion species started at the beginning of March with the start up of the xenon ion source and the Linac3. Ten weeks later the beam arrived to the Low Energy Ion Ring (LEIR) triggering the start of several weeks of beam commissioning in view of providing the injector complex with Xenon beams for different experiments and a series of machine development experiments in LEIR. Two types of beams were setup, the so called EARLY beam, with a single injection into LEIR from Linac3, and the NOMINAL beam with up to seven injections. 2017 was as well an interesting year for LEIR because several improvements in the control system of the accelerator and in the beam instrumentation were done in view of increasing the machine reliability. This paper summarises the beam commissioning phase and all the improvements carried out during 2017.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAF020
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAF021	Identification and Removal of SPS Aperture Limitations	optics, vacuum, target, proton	709
	V. Kain, R. Alemany-Fernández, H. Bartosik, S. Cettour Cave, K. Cornelis, P. Cruikshank, J.A. Ferreira Somoza, B. Goddard, C. Pasquino CERN, Geneva, Switzerland
	The CERN SPS (Super Proton Synchrotron) serves as LHC injector and provides beam for the North Area fixed target experiments. Since the 2016 run automated local aperture scans have been performed with the main focus on the vertical plane where limitations typically arise due to the flat vacuum chambers in most SPS elements. For LHC beams the aperture limitations with the present low integer tune optics also occur at locations with large dispersion. Aperture measurements in the horizontal plane using a variety of techniques were performed and showed surprising results, which could partially explain the unexpected losses of high intensity LHC beams at the SPS flat bottom. In this paper, reference measurements from 2016 are compared with the ones taken at the beginning of the run in 2017. Several aperture restrictions in the vertical plane could be found and cured, and a potential systematic restriction in the horizontal plane has been identified. The results of the measurements and the origin of the restrictions are presented in this paper, and the outlook for partial mitigation is discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAF021
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAF024	Impedance and Instability Studies in LEIR with Xenon	impedance, space-charge, coupling, accumulation	720
	N. Biancacci, H. Bartosik, M. Gąsior, S. Hirlaender, V. Kain, T.E. Levens, E. Métral CERN, Geneva, Switzerland M. Migliorati Rome University La Sapienza, Roma, Italy
	In 2017, the LEIR accelerator has been operated with Xe³⁹⁺ beam for fixed target experiments in the SPS North Area. The different ion species, with respect to the usually operated Pb⁵⁴⁺, allowed for additional comparative measurements of tune shift versus intensity at injection energy both in coasting and bunched beams. The fast transverse instability observed for high accumulated intensities has been as well characterized and additional observations relevant to impedance have been collected from longitudinal Schottky signal and BTF measurements. The results of these measurements are summarised and compared to the currently developed machine impedance model.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAF024
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAF027	CERN PS Kicker for Proton Injection: from Beam-Based Waveform Measurements to Hardware Improvements	kicker, simulation, emittance, flattop	732
	V. Forte, A. Ferrero Colomo, M.A. Fraser, T. Kramer CERN, Geneva, Switzerland
	For 2017 operation, the termination mode of the CERN Proton Synchrotron (PS) horizontal injection kicker was permanently changed to short-circuited, to be compliant with the future performances requested by the LHC Injectors Upgrade (LIU) project. An extensive campaign of measurements was performed through a dedicated beam-based technique. The measurements identified possibilities for optimisation of the kicker system and were fundamental to properly tune the PSpice simulation model of the kicker, as well as for validating the hardware changes. The model was finally used to estimate the horizontal emittance growth for the future injection schemes in the PS.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAF027
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAF031	Beam Simulation Studies for the Upgrade of the SPS Beam Dumping System	kicker, simulation, dumping, operation	747
	C. Heßler, W. Bartmann, E. Carlier, L. Ducimetière, B. Goddard, F.M. Velotti CERN, Geneva, Switzerland
	The SPS at CERN currently uses a beam dumping system that is installed in the long straight section 1 (LSS1) of the SPS. This system consists of two beam stopper blocks for low and high energy beams, as well as two vertical and three horizontal kicker magnets, which deflect and dilute the beam on the dumps. Within the frame of the LHC injector upgrade project (LIU) the beam dumping system will be relocated to long straight section 5 (LSS5) and upgraded with an additional vertical kicker, new main switches and a single new beam dump, which covers the full energy range. The impact of a possible increase of the vertical kicker rise time on the beam has been studied in simulations with MAD-X for the different optics in the SPS. Furthermore, the impact on the beam in failure scenarios such as the non-firing of one kicker has been investigated. The results of these studies will be presented and discussed in this paper. Operational mitigation methods to deal with an increased rise time will also be discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAF031
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAF034	LEIR Injection Efficiency Studies as a Function of the Beam Energy Distribution from Linac3	linac, cavity, bunching, optics	758
	S. Hirlaender, R. Alemany-Fernández, H. Bartosik, G. Bellodi, N. Biancacci, V. Kain, R. Scrivens CERN, Geneva, Switzerland
	High intensities in the CERN Low Energy Ion Ring (LEIR) are achieved using multi-turn injections from the pre-accelerator Linac3 combined with simultaneous stacking in momentum and transverse phase spaces. Up to seven consecutive 200 μs long, 200 ms spaced pulses are injected from Linac3 into LEIR by stacking each of them into the six-dimensional phase-space over 70 turns. An inclined septum magnet allows proper filling of the transverse phase-space plane, while longitudinal stacking requires momentum variation achieved by a shift of mean momentum over time provided by phase shifting a combination of 2 RF cavities at the exit of Linac3. The achievable maximum accumulated intensity depends strongly on the longitudinal beam quality of the injected beam. The longitudinal Schottky signal is used to measure the received energy distribution of the circulating beam which is then correlated with the obtained injection efficiency. This paper presents the experimental studies to understand and further improve the injection reliability and the longitudinal stacking.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAF034
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAF036	Studies of the Injection and Cooling Efficiency in LEIR Using the Longitudinal Schottky Spectrum	linac, diagnostics, electron, pick-up	765
	S. Hirlaender, R. Alemany-Fernández, H. Bartosik, N. Biancacci, V. Kain CERN, Geneva, Switzerland
	The CERN Low Energy Ion Ring (LEIR) has two main operational beams with their associated cycles, the so-called EARLY and the NOMINAL beam. The EARLY beam consists of a single injected pulse from the LINAC3 accelerator, whereas seven consecutive injections are accumulated, and electron cooled for the NOMINAL beam. In both cases, the longitudinal Schottky monitor allows assessing the longitudinal particle distribution during the cooling process on the injection plateau. A method has been established to analyze the Schottky signal, reconstruct the initial particle momentum distribution and derive relevant parameters such as the cooling time, energy off-set of injected and stacked beam or the momentum distribution of the lost beam. The variations of the obtained parameters and the impact on the LEIR performance will be addressed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAF036
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAF037	Validation of the CERN PS Eddy Current Injection Septa	septum, simulation, vacuum, HOM	768
	M. Hourican, B. Balhan, J.C.C.M. Borburgh, T. Masson, A. Sanz Ull CERN, Geneva, Switzerland
	As part of the upgrade of the CERN PS accelerator from 1.4 GeV to 2 GeV, new injection septa have been developed. The system is comprised of a pulsed eddy current septum magnet and a pulsed eddy current bumper magnet. Both magnets will be housed in a common vacuum vessel and powered by independent power converters. In-depth studies and simulations have been performed to reduce as much as possible the leak field by designing specific magnetic shielding, combined with dual function beam impedance shielding. A prototype magnet was built and measured to validate the simulations. The final complete system will be bake-able at 200C and uses demineralised water for cooling. Closed circuit cooling systems have been integrated to reduce risks of vacuum leaks. This report describes the electromechanical design from the concept and simulation stages to the prototyping and final manufacturing. Results of the initial magnetic measurements, including field homogeneity and leak field mitigation methods are presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAF037
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAF046	Conceptual Design of a Collimation System for the CERN Super Proton Synchrotron	collimation, optics, proton, simulation	802
	M. Patecki, A. Mereghetti, D. Mirarchi, S. Redaelli CERN, Geneva, Switzerland
	The Super Proton Synchrotron (SPS) is the last accelerator in the LHC Injectors Chain. Its performance is constantly being improved in frame of the LHC Injectors Upgrade (LIU) Project in order to prepare it for the future HL-LHC (High Luminosity LHC) operation. One of the LIU goals is to nearly double the intensity extracted from the SPS, up to 2.32×10¹¹ p/bunch. In recent years, nearly 10% of losses are observed for nominal intensity and LHC-type beams; they grow to about 20% for the intensity approaching the HL-LHC target. Beam losses imply activation and aging of the SPS hardware; the possibility to add a collimation system is being considered to mitigate this problem. In this paper we present studies of a collimation system design for the SPS. The concept is based on a primary horizontal collimator located in an available position with high enough dispersion, and a secondary collimator to intercept the particles leaking out from the primary collimator. Performance of the proposed collimation system is evaluated by means of numerical simulations.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAF046
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAF048	LIU Space Charge Studies for the LHC Pre-Accelerators	space-charge, proton, resonance, simulation	810
	F. Schmidt, H. Bartosik CERN, Geneva, Switzerland
	In 2011 a working group has been started to study performance limitations due to Space Charge (SC) in the four LHC pre-accelerators, LEIR, PSB, PS & SPS, in view of the LHC Injector Upgrade (LIU) project. To this end external and in-house simulation tools have been benchmarked for the LIU study cases with the long-term goal of providing a full sequence of tested CERN Space Charge tools. It became clear that SC studies must be combined with trustworthy models of the machines, including linear and non-linear errors. In particular an effective s-dependent non-linear model is required. Recent studies indicate that also the low frequency ripple spectrum due to conventional power supplies might play an important role for the beam dynamics in presence of space charge in the pre-injectors.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAF048
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAF059	Design and Evaluation of FCC-hh Injection Protection Schemes	kicker, dipole, collider, collimation	854
	E. Renner, M.J. Barnes, W. Bartmann, C. Bracco, R. Bruce, F. Burkart, B. Goddard, A. Lechner, L.S. Stoel, F.M. Velotti, C. Wiesner, D. Woog CERN, Geneva, Switzerland
	The Future Circular Collider (FCC) study considers several injector scenarios for FCC-hh, the proposed 100~TeV centre of mass hadron collider located at CERN. The investigated options include amongst others to use the LHC at 3.3~TeV or a superconducting SPS at 1.3~TeV as a High Energy Booster (HEB). Due to the high energy of the injected proton beam and the short time constant of injection failures, a thorough consideration of potential failure cases is of major importance. Further attention has to be given to the fact that the injection is - as in LHC - located upstream of the side experiments. Failure scenarios are identified for both injector options, appropriate designs of injection protection schemes are proposed and first simulations are conducted to validate the protection efficiency.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAF059
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAF060	Injection and Dump Systems for a 13.5 TeV Hadron Synchrotron HE-LHC	kicker, extraction, septum, experiment	858
	W. Bartmann, M.J. Barnes, L. Ducimetière, B. Goddard, M. Hofer, T. Kramer, A. Lechner, E. Renner, A. Sanz Ull, V. Senaj, L.S. Stoel, C. Wiesner CERN, Geneva, Switzerland
	One option for a future circular collider at CERN is to build a 13.5 TeV hadron synchrotron, or High Energy LHC (HE-LHC) in the LHC tunnel. Injection and dump systems will have to be upgraded to cope with the higher beam rigidity and increased damage potential of the beam. The required modifications of the beam transfer hardware are highlighted in view of technology advancements in the field of kicker switch technology. An optimised straight section optics is shown.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAF060
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAK005	Upgrade Plan of J-PARC MR - Toward 1.3 MW Beam Power	operation, experiment, proton, cavity	966
	T. Koseki KEK, Ibaraki, Japan
	The Main Ring Synchrotron (MR), a 30-GeV slow cycling proton synchrotron, delivers intense proton beam to a long-baseline neutrino oscillation experiment, T2K, by fast extraction and to an experimental facility, which is called hadron hall by slow extraction. The achieved beam intensities for routine operations are 470 kW ( 2.4 x 10¹⁴ ppp) for the fast extraction and 44 kW ( 5.1 x 10¹³ ppp) for the slow extraction. In order to increase the beam intensity, a plan to replace the magnet power supplies are now in progress for operation with a higher repetition rate. After the replacement, the cycle time will be shortened about a half and increase beam intensities two times larger for the fast extraction. In addition, a further upgrade plan for the fast extraction is mainly reinforcement of rf power supplies. The goal of the upgrade plan is reaching 1.3 MW beam power for the neutrino experiment.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAK005
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAL002	Numerical Calibration of the Injection Bump Sizes During the Beam Commissioning for CSNS	MMI, flattop, experiment, neutron	1011
	M.Y. Huang, S. Wang, S.Y. Xu IHEP, Beijing, People's Republic of China
	In order to control the strong space charge effects, which cause large beam loss during the injection and acceleration processes, phase space painting method was used for injecting a small emittance beam from the linac into the large acceptance of the Rapid Cycling Synchrotron (RCS). During the beam commissioning, in order to control and optimize the painting results, the positions and ranges of the horizontal and vertical painting should be adjusted accurately. Therefore, the numerical calibration of the injection bump sizes was very important and need to be done as soon as possible. In this paper, a method to calibrate the horizontal and vertical bump sizes was presented and applied to China Spallation Neutron Source (CSNS). The numerical calibration results would be given and discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAL002
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAL003	Measurement of the Injection Beam Parameters by the Multi-Wire Scanner for CSNS	proton, MMI, linac, neutron	1014
	M.Y. Huang, H.C. Liu, S. Wang, Zh.H. Xu, P. Zhu IHEP, Beijing, People's Republic of China X.H. Lu CSNS, Guangdong Province, People's Republic of China
	In order to inject the H⁻ beam to the Rapid Cycling Synchrotron (RCS) with high precision and high transport efficiency, the injection beam parameters need to be measured and then corrected while its eccentric position or direction angle is too large. In this paper, firstly, a method to measure the injection beam parameters by using two of the four multi-wire scanners (MWSs) is presented. The injection commissioning results confirmed that this method works well. Secondly, a method to measure the signals of injection beam and circular beam by the INMWS02 is presented and the method work well during the beam commissioning.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAL003
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAL005	Study on the Fixed Point Injection during the Beam Commissioning for CSNS	MMI, timing, neutron, proton	1017
	M.Y. Huang, H.C. Liu, S. Wang, S.Y. Xu IHEP, Beijing, People's Republic of China
	In order to inject the H⁻ beam into the Rapid Cycling Synchrotron (RCS) of China Spallation Neutron Source (CSNS) accurately, different injection methods were used in different periods of beam commissioning for CSNS. In the early stage of beam commissioning, since the precise relative position of the injection beam and circular beam was unknown and the injection beam power was relatively small, the fixed point injection method was used. In this paper, the fixed point injection method is studied in detail and the beam commissioning results are given and discussed. In addition, a method to adjust the timing of the injection pulse power is presented and confirmed by the beam commissioning.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAL005
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAL018	Pulse-by-Pulse Switching of Operational Parameters in J-PARC 3-GeV RCS	emittance, operation, extraction, betatron	1041
	H. Hotchi, H. Harada, K. Okabe, P.K. Saha, Y. Shobuda, F. Tamura, Y. Watanabe, M. Yoshimoto JAEA/J-PARC, Tokai-mura, Japan
	J-PARC 3-GeV RCS (rapid cycling synchrotron) provides a high-power beam both to MLF (materials and life science experimental facility) and MR (main ring synchrotron) by switching the beam destination pulse by pulse. The beam properties required from MLF and MR are different; MLF needs a wide-emittance beam with less charge density, while MR requires a low-emittance beam with less beam halo. To meet the antithetic requirements while keeping beam loss at permissible levels, RCS has recently initiated pulse-by-pulse switching of operational parameters (betatron tune, chromaticity, painting emittance, etc.). This paper presents the recent efforts toward the performance upgrade of RCS while discussing the related beam dynamics issues.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAL018
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAL020	Recent Status of J-PARC Rapid Cycling Synchrotron	operation, target, emittance, proton	1045
	K. Yamamoto, P.K. Saha JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
	The 3 GeV Rapid Cycling Synchrotron (RCS) of the Japan Proton Accelerator Research Complex (J-PARC) provides more than 300 kW beam to the Material and Life Science Facility (MLF) and the Main Ring (MR). In such high intensity hadron accelerator, the lost protons that are a fraction of the beam less than 0.1 % cause many problems. Those particles bring about a serious radioactivation and a malfunction of the accelerator components. Therefore, we carried out the beam study to achieve high power beam operation. Moreover, we also maintain the accelerator components to keep a steady operation. We report present status of the J-PARC RCS.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAL020
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAL030	Improvement of RF Capture with Multi-Turn H⁻ Injection in KURRI FFAG Synchrotron	acceleration, proton, scattering, closed-orbit	1066
	T. Uesugi, Y. Fuwa, Y. Ishi, Y. Kuriyama, Y. Mori, H. Okita Kyoto University, Research Reactor Institute, Osaka, Japan
	In the KURRI FFAG synchrotron, charge-exchanging multi-turn injection is adopted with a stripping foil located on the closed orbit of injection energy. No injection bump orbit system is used and the beam escapes from the foil according to the closed-orbit shift by acceleration. The particles hit the foil many times and the emittance grows up during the injection. In this paper, the capture efficiencies are studied with different rf process, including adiabatic capture.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAL030
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAL047	Strain Measurement in the Recent SNS Mercury Target with Gas Injection	target, proton, radiation, neutron	1117
	Y. Liu, W. Blokland, C.D. Long, S.N. Murray, B.W. Riemer, R.L. Sangrey, M. W. Wendel, D.E. Winder ORNL, Oak Ridge, Tennessee, USA
	Funding: ORNL is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. DOE. High-radiation-tolerant fiber-optic strain sensors were recently developed to measure the transient proton-beam-induced strain profiles on the mercury target vessel at the Spallation Neutron Source (SNS). Here we report the strain measurement results and radiation-resistance performance on the latest SNS mercury target vessel equipped with helium gas injection. The results have demonstrated the efficacy of gas injection to reduce the cyclic stress on the target module.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAL047
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAL049	SNS Proton Power Upgrade Status	linac, scattering, proton, cavity	1120
	M.A. Plum, G. A. Bloom, M.S. Champion, J. Galambos, M.P. Howell, S.-H. Kim, J. Moss, B.W. Riemer, K.S. White ORNL, Oak Ridge, Tennessee, USA R.B. Saethre, R. W. Steffey ORNL RAD, Oak Ridge, Tennessee, USA
	Funding: ORNL is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. DOE. This research was supported by the DOE Office of Science, Basic Energy Science, Scientific User Facilities. The Spallation Neutron Source (SNS) Proton Power Upgrade (PPU) project aims to double the proton accelerator beam power from 1.4 to 2.8 MW. Over the past year PPU has completed the reviews necessary for Critical Decision-1 approval. The baseline design choices are being refined, and a cost-effective approach has been identified. The beam energy will be increased by 30% and the beam current capability improved by ~50%. The sub-system improvements and anticipated schedule will be discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAL049
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAL055	Progress with Carbon Stripping Foils at ISIS	operation, synchrotron, vacuum, proton	1136
	B. Jones, H.V. Cavanagh STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
	The ISIS Facility at the Rutherford Appleton Laboratory produces intense neutron and muon beams for condensed matter research. The facility's 50Hz rapid cycling synchrotron accelerates protons from 70 to 800MeV to deliver a mean beam power of 0.2MW to two target stations. Since 2016, ISIS has routinely used commercially produced carbon based foils for beam stripping during charge-exchange injection. Recent experience and developments to increase useful foil lifetime are presented including in-house high temperature annealing of foils prior to use. The installation and performance of a new foil imaging system are described and, finally, the procedure to change the stripping foil is described. Issues with the current arrangements and options for redesign are discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAL055
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAL058	Studies for Major ISIS Upgrades via Conventional RCS and Accumulator Ring Designs	simulation, lattice, space-charge, emittance	1148
	C.M. Warsop, D.J. Adams, H.V. Cavanagh, P.T. Griffin-Hicks, B. Jones, B.G. Pine, R.E. Williamson STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
	ISIS is the spallation neutron source at the Rutherford Appleton Laboratory in the UK, which provides 0.2 MW of beam power via a 50 Hz, 800 MeV proton RCS. Detailed studies are now under way to find the optimal configuration for a next generation, short pulsed neutron source that will define a major ISIS upgrade in ~2031. Accelerator configurations being considered for the MW beam powers required include designs exploiting FFAG rings as well as conventional accumulator and synchrotron rings. This paper describes work exploring the latter, conventional options, but includes the possibility of pushing further toward intensity limits to reduce facility costs. The scope of planned studies is summarised, looking at optimal exploitation of existing ISIS infrastructure, and incorporating results from recent target studies and user consultations. Results from initial baseline studies for an accumulator ring and RCS located in the existing ISIS synchrotron hall are presented. Injection scheme, foil limits, longitudinal and transverse beam dynamics optimization with related beam loss and activation are outlined, as are results from detailed 3D PIC simulations.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAL058
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAL059	Commissioning of Shanghai Advance Proton Therapy	extraction, proton, MMI, dipole	1151
	M.Z. Zhang, D.M. Li, K. Wang, Q.L. Zhang, Z.T. Zhao SINAP, Shanghai, People's Republic of China X.C. Xie Shanghai APACTRON Particle Equipment Company Limited, Shanghai, People's Republic of China
	Shanghai advance proton therapy (SAPT) is a dedicate facility for cancer treatment. The commissioning of the accelerator started at the end of April 2017, and the proton beam has been already transported to the treatment room. This paper shows the commissioning results of synchrotron and transport line.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAL059
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUZGBD4	Impact of a Wideband Feedback Prototype System on TMCI in the SPS	feedback, optics, kicker, emittance	1208
	W. Höfle, H. Bartosik, E.R. Bjørsvik, G. Kotzian, T.E. Levens, K.S.B. Li CERN, Geneva, Switzerland J.E. Dusatko, J.D. Fox, C.H. Rivetta SLAC, Menlo Park, California, USA O. Turgut Stanford University, Stanford, California, USA
	The transverse mode coupling instability (TMCI) in the SPS has been identified as one of the potential performance limitations for future high intensity LHC beams that will be required for the High Luminosity (HL)-LHC era and is being addressed by the LHC Injector Upgrade Project (LIU). A potential mitigation can be provided by wideband feedback systems with a frequency reach of about 1 GHz . For this reason, the development of a prototype system has been started in a CERN collaboration within the US-LARP framework in 2008. In this report we present latest experimental results in 2017 where this prototype system was used in single and multi-bunch studies. In particular, a successful mitigation against TMCI at injection could be demonstrated in single bunch studies.
	Slides TUZGBD4 [15.116 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUZGBD4
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPMF014	Synchrotron Accumulation on Off-Energy Closed-Orbit with Anti-Septum or Nonlinear Kicker	kicker, septum, accumulation, closed-orbit	1280
	Y.P. Sun 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. Off-axis accumulation on off-energy closed-orbit (so-called synchrotron injection/accumulation) was studied and implemented in the 1990s for LEP at CERN. The idea of using pulsed multipole injection on off-energy closed-orbit was first proposed in 2014 and then developed for Swiss Light Source (SLS) upgrade in 2015. In 2017, the anti-septum was proposed for SLS upgrade injection. In this paper, two similar injection schemes are proposed which combine off-axis accumulation on off-energy closed-orbit (no betatron oscillations), with the anti-septum or pulsed nonlinear kicker schemes. Preliminary lattice solutions are developed for Advanced Photon Source upgrade (APS-U) where a special injection straight (with length of 5.8 m) is designed with horizontal dispersion of 0.15m. The impact on the ring emittance is relatively small. The injection elements are all placed in this injection straight, including 1 thin septum and 3 slow kickers (or 1 pulsed nonlinear kicker). No fast kickers are needed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPMF014
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPMF017	Transport Line Design and Injection Configuration Optimization for the Advanced Photon Source Upgrade	septum, kicker, dipole, emittance	1287
	A. Xiao, M. Borland 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. On-axis swap-out injection was chosen for the Advanced Photon Source Upgrade (APS-U) to allow pushing the beam emittance to an extremely low value. The injection section configuration was optimized within a multi-dimensional parameter space and made consistent with up-to-date technical developments. The booster-to-storage ring (BTS) transport line was designed to bring the electron beam from the existing Booster to the new storage ring (SR). Due to various limitations, this new BTS line is twisted both horizontally and vertically when approaching the injection point, which introduces challenges in both geometrical and optical matching. This paper presents our simple solution to these issues. The coupling effect caused by the twisted BTS line is also discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPMF017
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPMF036	Top Off of NSLS-II with Inefficient Injector	booster, linac, storage-ring, operation	1327
	R.P. Fliller, A.A. Derbenev, V.V. Smaluk, X. Yang BNL, Upton, Long Island, New York, USA
	Funding: This manuscript has been authored by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy The NSLS-II is a 3 GeV storage with a full energy injector capable of top off injection. The injector consists of a 200 MeV linac injecting a 3 GeV booster. Recent operational events have caused us to investigate 100 MeV injection into the booster. As the booster was not designed for injection at this low energy, beam loss is observed with this low energy booster injection. This beam loss not only results of overall charge loss from the train, but a change in the overall charge distribution in the bunch train. In this paper we discuss the performance of injecting into the storage ring with the inefficient charge transfer through the injector. The changes to the top off method are discussed, as well as the achieved storage ring current stability and fill pattern.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPMF036
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPMF037	Development of New Operational Mode for NSLS-II Injector: Low Energy 100MeV Linac-to-Booster Injection	booster, operation, klystron, linac	1330
	X. Yang, A.A. Derbenev, R.P. Fliller, T.V. Shaftan, V.V. Smaluk BNL, Upton, Long Island, New York, USA
	The NSLS-II injector consists of a 200 MeV linac and a 3 GeV full-energy booster synchrotron. The linac contains five traveling-wave S-band accelerating structures driven by two high-power klystrons, with a third klystron as spare. In the event that the spare klystron is not available, the failure of one klystron will prohibit the linac from injecting into the booster as the energy is too low. Therefore, we wish to develop a new operational mode that the NSLS-II injector can operate with a single klystron providing 100 MeV beam from the linac. A decremented approach with intermediate energies 170 MeV, 150 MeV, etc., takes advantages of pre-calculated booster ramps and beam based online optimization. By lowering the booster injection energy in a small step and online optimizing at each step, we were able to achieve 100 MeV booster injection. 170 MeV operation mode of the NSLS-II injector has been implemented since May 31, 2017, with a similar overall performance compared to the standard 200 MeV operation but fewer klystron trips. 100 MeV single-klystron operation has been successfully demonstrated with 20-30% overall efficiency, which is limited by booster acceptance.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPMF037
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPMF039	Recommissioning of the Canadian Light Source Booster Synchrotron	booster, MMI, optics, extraction	1338
	W.A. Wurtz, D. Bertwistle, L.O. Dallin, X. Shen, J.M. Vogt CLS, Saskatoon, Saskatchewan, Canada
	The Canadian Light Source booster synchrotron was originally commissioned in 2002 and has worked reliably for many years. However, the operating point was not the design operating point and the booster suffered from poor quantum lifetime at the extraction energy. The low quantum lifetime caused current loss of approximately 25% in the microseconds before extraction. We have recommissioned the booster using the design optics, and the current loss before extraction is now only 6%. In this paper, we discuss the measurements and simulations involved in our recommissioning work.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPMF039
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPMF046	The Injection and Extraction Design of the Booster for the HEPS Project	extraction, kicker, storage-ring, booster	1356
	Y.Y. Guo, J. Chen, Z. Duan, Y. Jiao, Y.M. Peng, G. Xu IHEP, Beijing, People's Republic of China
	The HEPS booster is a 1Hz electron synchrotron. It accelerates electron bunches from 500 MeV to final energy of 6 GeV. The vertical scheme was chosen for the injection and extraction system of the booster. What's more, an injection system from storage ring is required. The layout of the injection and extraction system were introduced in this paper. The parameter optimization and other considerations are presented in detail.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPMF046
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPMF048	On-Axis Beam Accumulation Based on a Triple-Frequency RF System for Diffraction-Limited Storage Rings	cavity, simulation, accumulation, photon	1359
	S.C. Jiang, Z. Duan, G. Xu IHEP, Beijing, People's Republic of China
	Since the multi-bend achromats have been applied to lattice design in the future light source to achieve ultralow emittance, strong sextupoles and concomitant nonlinearities restrict its performance to a certain extent. The empirical understanding is the exclusion of conventional off-axis injection scheme on these light sources. In this paper, we will present a new on-axis beam accumulation scheme, which is based on the triple-frequency RF system. By means of delicate superposition of RF voltage with fundamental and two other harmonic frequencies, a commodious and steady main bucket is able to be formed. The electron bunch from the injector will be kicked into the main bucket on-axis with a reasonable time offset to the circular bunch, and this process may make the minimal disturbance to the experiment users while operating on the top-up mode. The application of this scheme to the High Energy Photon Source (HEPS) will be discussed in the paper, corresponding simulation results are also presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPMF048
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPMF049	Evolution of the Lattice Design for the High Energy Photon Source	lattice, emittance, storage-ring, photon	1363
	G. Xu, S.Y. Chen, Y. Jiao, J.L. Li, Y.M. Peng, Q. Qin, J.Q. Wang, C.H. Yu IHEP, Beijing, People's Republic of China
	The High Energy Photon Source (HEPS) is a high-energy, ultralow-emittance, kilometer-scale storage ring light source to be built in China. The HEPS lattice design has been started since 2008. In this paper we will review the evolution of the HEPS lattice design over the past ten years, focusing mainly on the linear optics design and nonlinear optimization.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPMF049
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPMF052	Progress of Lattice Design and Physics Studies on the High Energy Photon Source	lattice, booster, storage-ring, emittance	1375
	G. Xu, X. Cui, Z. Duan, Z. Duan, Y.Y. Guo, D. Ji, Y. Jiao, J.L. Li, X.Y. Li, C. Meng, Y.M. Peng, Q. Qin, S.K. Tian, J.Q. Wang, N. Wang, Y. Wei, H.S. Xu, F. Yan, C.H. Yu, Y.L. Zhao IHEP, Beijing, People's Republic of China
	The High Energy Photon Source (HEPS) is an ultralow-emittance, kilometer-scale storage ring light source to be built in China. In this paper we will introduce the progress of the physical design and studies on HEPS over the past one year, covering issues of storage lattice design and optimization, booster design, injection design, collective effects, error study, insertion device effects, beam lifetime, etc.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPMF052
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPMF058	Conceptual Design of HEPS Injector	booster, storage-ring, linac, dipole	1394
	J.L. Li, H. Dong, Z. Duan, Y.Y. Guo, D.Y. He, Y. Jiao, W. Kang, C. Meng, S. Pei, Y.M. Peng, J.R. Zhang, P. Zhang, Z.S. Zhou IHEP, Beijing, People's Republic of China
	Abstract The High Energy Photon Source (HEPS) will be constructed in the following few years. The light source is comprised of an ultra-low emittance storage ring and a full energy injector. The energy of the storage ring is 6 GeV. The injector is comprised of a 500 MeV linac, a 500 MeV to 6 GeV booster synchrotron and transport lines connecting the machines. In the present design, the linac uses normal conducting S-band bunching and accelerating structures. The booster adopts FODO cells, has a circumference of about 454 m and an emittance lower than 40 nmrad. The injector can provide a single-bunch charge up to 2 nC at 6 GeV for the storage ring. This paper briefly introduces the conceptual design of the injector of the HEPS.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPMF058
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPMF062	Status of HEPS Booster Lattice Design and Physics Studies	booster, lattice, storage-ring, extraction	1407
	Y.M. Peng, Z. Duan, Y.Y. Guo, D. Ji, Y. Jiao, J.L. Li, C. Meng, S.K. Tian, H.S. Xu IHEP, Beijing, People's Republic of China
	The High Energy Photon Source (HEPS) with an ul-tralow emittance is proposed to be built in Beijing, Chi-na. It will utilize a booster as its full energy injector. On-axis swap-out injection is chosen as the baseline injec-tion scheme for the storage ring. As required by the stor-age ring, a beam with a bunch charge up to 2.5 nC is needed to be injected in the booster. However, limited by the transverse mode coupling instability (TMCI), such a high bunch charge is challenging. To overcome this problem, a lattice with a considerable large momentum compaction factor is designed. This paper reports the lattice design and physics studies of the HEPS booster, including injection and extraction design, error studies, eddy current effects, collective effects, and so on.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPMF062
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPMF063	The Considerations of Improving TMCI Threshhold on HEPS Booster	booster, lattice, linac, storage-ring	1411
	Y.M. Peng, J.L. Li, C. Meng, S. Pei, H.S. Xu IHEP, Beijing, People's Republic of China
	The High Energy Photon Source (HEPS) is proposed in Beijing, China. The on-axis swap-out injection scheme will be used in the storage ring mainly because of the small dynamic aperture. Therefore, the booster needs to store more than 2.5 nC bunch charge. Under this requirement, the transverse mode coupling instability (TMCI) at the injection energy becomes the bunch charge restriction in the booster. Several changes in booster and linac for improving bunch charge threshold limited by TMCI are considered. The details will be expressed in this paper.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPMF063
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPMF068	Beam Dynamics on a Coupling Resonance at PETRA III	resonance, coupling, optics, lattice	1417
	I.V. Agapov, J. Keil, G. Kube, G.K. Sahoo, R. Wanzenberg DESY, Hamburg, Germany Y.-C. Chae ANL, Argonne, Illinois, USA A.I. Novokshonov TPU, Tomsk, Russia
	Working on a coupling resonance is a usual way of producing round beams in a synchrotron. The beam dynamics in this regime is however more complicated, and the emittance is sensitive to the working point, coupling correction, and bunch current drop with time, which complicates the operation. We present experience with optics setup for working on a coupling resonance in PETRA III, including linear and nonlinear beam optics characteristics, and the measurement of the horizontal and vertical beam emittances with a 2D interferometer. Beam dynamics on a coupling resonance for PETRA IV, the MBA upgrade of PETRA III currently under consideration, is also presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPMF068
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPMF084	Optimization of the Injection Kicker Bump Leakage at PETRA III	kicker, septum, feedback, electron	1467
	J. Keil, G. Kube, F. Obier, G.K. Sahoo, R. Wanzenberg DESY, Hamburg, Germany
	PETRA III is a third generation synchrotron light source at DESY delivering high brightness photon beams for users at 21 beam lines. It is operated at 6 GeV with a beam current of 100 mA in top-up mode and is in operation for users since 2010. An off-axis injection scheme is used to accumulate beam from the booster synchrotron DESY II in PETRA III. Three fast injection kicker magnets generate a closed orbit bump for one turn to move the stored beam near to the injection septum magnet. Ideally the orbit bump generated by the 10 μs long half-sine pulses of the kickers should be closed. Due to differences in pulse shape as well as timing and amplitude errors of the pulses there is some leakage of the injection bump which disturbs the closed orbit and affects the beam quality during top-up operation. Turn-by-turn data from the beam position monitor (BPM) system of PETRA III have been used to measure the bump leakage for different bucket positions in the filling pattern. The procedure to reduce the injection kicker bump leakage and the achieved improvement will be discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPMF084
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPMK001	Removal of RF-Fingers at the Edges of the Injection Kickers	impedance, resonance, kicker, storage-ring	1485
	T.F.G. Günzel, N. Ayala, F.F.B. Fernández, U. Iriso, M. Pont ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
	The ALBA storage ring injection kickers are equipped with RF-fingers to close a 2.5 mm gap between the ceramic tube and the metallic flange. After two distortion incidents that required the replacement of the fingers, their removal was decided. The decision could be supported by the observation that most of the additional impedance is created above the cut-off frequency of the beam pipe. This was later confirmed by a temperature decrease in that zone after the removal. Furthermore it was checked that the thresholds of the longitudinal coupled bunch instabilities of modes trapped around the resulting open gap are above the maximal applied beam current of 400 mA.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPMK001
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPMK016	Using Time Evolution of the Bunch Structure to Extract the Muon Momentum Distribution in the Fermilab Muon g-2 Experiment	experiment, positron, storage-ring, bunching	1526
	W. Wu, B. Quinn UMiss, University, Mississippi, USA J.D. Crnkovic BNL, Upton, Long Island, New York, USA
	Beam dynamics plays an important role in achieving the unprecedented precision on measurement of the muon anomalous magnetic moment in the Fermilab Muon g-2 Experiment. It needs to find the muon momentum distribution in the storage ring in order to evaluate the electric field correction to muon anomalous precession frequency. We will show how to use time evolution of the beam bunch structure to extract the muon momentum distribution by applying a fast rotation analysis on the decay electron signals.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPMK016
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPML016	High-Intensity Magnetron H⁻ Ion Sources and Injector Development at BNL Linac	operation, rfq, ion-source, linac	1564
	A. Zelenski, G. Atoian, T. Lehn, D. Raparia, J. Ritter BNL, Upton, Long Island, New York, USA
	The BNL magnetron-type H⁻ ion source and the injec-tor are being upgraded to higher duty-factor as a part of Linac intensity increase project [1]. The BNL magnetron source presently delivers 110 -120 mA H⁻ ion current with 650 us pulse duration and 7 Hz repetition rate. The pulse duration was increased to 1000 μs by modifications of the gas injector pulsed valve and the use of the new arc-discharge power supply (with the arc-current stabilization circuit) which improved current stability and reduced current noise. The Low Energy Beam Transport (LEBT) lines combine two beams. The first line is the polarized OPPIS (Optically Pumped Polarized H⁻ Ion Source) beam-line and the second is the high-intensity un-polarized beam-line from the magnetron source, which transports beam to the RFQ after the passage of 45 degree bending magnet. The second magnetron source was installed in the straight LEBT section in 2017, in which the polarized OPPIS beam was not planned. In this, optimal for H⁻ beam transport configuration, the beam intensity was increased to 80 mA after the RFQ. The experience of the two sources layout operation (one source in operation the second source in standby) might be useful for facilities with the high downtime cost (like high-energy collider LHC or multi-user facilities like SNS).
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPML016
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPML055	Beam Optics Designs of a Strecher Ring and a Transfer Line for J-PARC Slow Extraction	extraction, quadrupole, optics, sextupole	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.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPML055
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPML060	Three-Dimentional Spiral Beam Injection for a Compact Storage Ring	solenoid, experiment, coupling, electron	1673
	H. Iinuma Ibaraki University, Hitachi, Ibaraki, Japan M.R. Abdul Sokendai, Ibaraki, Japan Y. Fukao, K. Furukawa, H. Hisamatsu, T. Mibe, H. Nakayama, S. Ohsawa, K. Oide, K. Sasaki KEK, Tsukuba, Japan
	Funding: This work is supported by JSPS KAKENHI Grant Numbers JP26287055 and JP 23740216. A newly developed three-dimensional spiral injection scheme for beam insertion into a compact (medical MRI size) solenoidal storage ring is introduced. This is a one of key R&D items for a new planned muon g-2/EDM experiment at J-PARC, which aims to measure g-2 to a factor 5 better statistical precision and a factor of 100 better sensitivity for the electric dipole moment measurement (EDM) compared to the previous experiments. The new scheme provides a smooth injection utilizing a radial solenoidal fringe field, without causing any error field in the storage volume. Magnetic pulsed kicker will guide and set the beam in the storage field volume. The strongest point of this new scheme is that any source of the electric field is removed in this scheme to perform ideal EDM measurement. We have performed a test bench experimental work to demonstrate a feasibility of this new injection scheme. Instead of the muon beam, we inject electron beam, from an electron-gun, into the solenoid magnet, and detect three-dimensional spiral beam trajectory inside of the storage chamber by CCD camera. We will discuss outline of a new injection scheme and the latest results from the test bench works. *H. Iinuma et al.,Nuclear Instruments and Methods in Physics Research A, 832, 51-62 (2016)
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPML060
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEXGBE1	Review of Top-up Injection Schemes for Electron Storage Rings	kicker, synchrotron, septum, storage-ring	1745
	M. Aiba PSI, Villigen PSI, Switzerland
	Top-up operation, which nowadays is standard for lepton colliders and synchrotron light sources, has been developed over last decades. The accelerator performances have been drastically improved through top-up operation. However, future electron storage rings are designed, aiming at further high performance, to operate with strong nonlinear magnetic fields that may restrict their dynamic aperture. Consequently, the conventional off-axis injection and accumulation may become impossible. New injection schemes have been proposed and under development to overcome the difficulties and limitations expected in these machines. This paper reviews top-up injection schemes, including novel ideas recently proposed.
	Slides WEXGBE1 [3.584 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEXGBE1
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEYGBF4	Development of a Solid-State Pulse Generator Driving Kicker Magnets for a Novel Injection System of a Low Emittance Storage Ring	kicker, timing, high-voltage, storage-ring	1804
	T. Inagaki, H. Tanaka RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan H. Akikawa, K. Sato Nihon Koshuha Co. Ltd, Yokohama, Japan K. Fukami, C. Kondo, S. Takano Japan Synchrotron Radiation Research Institute (JASRI), RIKEN SPring-8 Center, Hyogo, Japan
	Funding: Funded by MEXT Japan A next generation electron storage ring represented by a diffraction-limited light source pursues an extremely low emittance leading to a small dynamic aperture and short beam lifetime. The top-up injection is hence indispensable to keep the stored beam current. The beam orbit fluctuation caused by the injection magnets should seriously obstruct utilization of an electron beam with sharp transverse profile. In order to solve these problems, a novel off-axis in-vacuum beam injection system was proposed. In the system, twin kicker magnets driven by a single solid-state pulsed power supply to launch a linear pi- bump orbit is the key to suppress the horizontal orbit fluctuation down to a level of several microns. Here, a big challenge is to achieve the magnetic field identity of the two kickers within an accuracy of 0.1%. This presentation overviews the proposed injection system and reports the development status focusing on the solid-state pulse generator.
	Slides WEYGBF4 [3.062 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEYGBF4
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPAF007	A Scheme for Asynchronous Operation of the APS-U Booster Synchrotron	booster, storage-ring, extraction, timing	1823
	U. Wienands, T.G. Berenc, T. Fors, F. Lenkszus, N. Sereno, G.J. Waldschmidt ANL, Argonne, Illinois, USA
	Funding: Work supported by US DOE The APS-U 6-GeV MBA storage ring will have 42 pm beam emittance and relatively tight acceptance. This requires limiting the beam emittance out of the Booster synchrotron which is achieved by operating the Booster off-momentum, thus manipulating the damping partitions. However, the much higher charge for the APS-U strongly favors injecting on momentum into the Booster for maximum acceptance. An rf-frequency ramping scheme is proposed to allow injecting on momentum and then moving the beam off momentum. The ramp is adjusted from cycle to cycle to vary the total time taken by the beam from injection to extraction, thus aligning the Booster bunch with any chosen MBA storage ring bucket. The two rf systems will not be locked at any time of the cycle. The proposed scheme is compatible with the existing synchronization of the APS injector cycle to the 60-Hz line voltage which induces a variation in the start time of the acceleration cycle. The scheme removes the need to realign the Booster ring for total path length while optimizing its operation for high charge acceleration. A ferrite tuner is being considered for dynamic tuning of the rf cavities.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAF007
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPAF010	Fast Glitch Detection of Coupled Bunch Instabilities and Orbit Motions	feedback, vacuum, storage-ring, operation	1829
	W.X. Cheng, B. Bacha, K. Ha, Y. Li BNL, Upton, Long Island, New York, USA
	Funding: Work supported by DOE contract No: DE-SC0012704 During high current operation at NSLS-II storage ring, vertical beam size spikes have been noticed. The spikes are believed due to ion instability associates with vacuum activities localized in the ring. A new tool has been developed using gated BPM turn-by-turn (TBT) data to detect beam centroid glitches. When one turn orbit deviates outside the predefined window, a global event will be generated. This allows synchronized data acquisition of TBT beam positions around the ring. Bunch by bunch data is acquired at the same time to analyze the possible coupled bunch instabilities (CBI). Besides CBI mainly due to ion bursts, fast orbit glitches have been captured with the new tool. Sources of the glitches can be identified.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAF010
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPAF014	Commissioning the Superconducting Magnetic Inflector System for the Muon g-2 Experiment	storage-ring, experiment, MMI, simulation	1844
	N.S. Froemming CENPA, Seattle, Washington, USA K.E. Badgley, H. Nguyen, D. Stratakis Fermilab, Batavia, Illinois, USA J.D. Crnkovic BNL, Upton, Long Island, New York, USA L.E. Kelton UKY, Kentucky, USA M.J. Syphers Northern Illinois University, DeKalb, Illinois, USA
	The Fermilab muon g-2 experiment aims to measure the muon anomalous magnetic moment with a precision of 140 ppb - a fourfold improvement over the 540 ppb precision obtained in the BNL muon g-2 experiment. Both of these high-precision experiments require an extremely uniform magnetic field in the muon storage ring. A superconducting magnetic inflector system is used to inject beam into the storage ring as close as possible to the design orbit while minimizing disturbances to the storage-region magnetic field. The Fermilab experiment is currently in its first data-taking run, where the Fermilab inflector system is the refurbished BNL inflector system. This discussion reviews the Fermilab inflector system refurbishment and commissioning.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAF014
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPAF026	Beam Induced Fluorescence Measurements of 100 keV Deuterons in LIPAc Accelerator	electron, detector, plasma, emittance	1877
	R. Varela, A. Guirao, L.M. Martínez, J. Mollá, I. Podadera CIEMAT, Madrid, Spain T. Akagi, R. Ichimiya, Y. Ikeda, M. Sugimoto QST, Aomori, Japan B. Bolzon, N. Chauvin CEA/IRFU, Gif-sur-Yvette, France P. Cara Fusion for Energy, Garching, Germany H. Dzitko F4E, Germany J. Knaster IFMIF/EVEDA, Rokkasho, Japan
	Funding: Work partially supported by the Spanish Ministry of Science and Innovation under project FIS2013-40860-R The LIPAc accelerator will be a linear CW deuteron accelerator capable of delivering a 9 MeV, 125 mA beam which aims to validate the technology that will be used in the future high power accelerator-driven neutron source, IFMIF. In summer 2017 a campaign of measurements was done during the injector commissioning, in which a Fluorescence Profile Monitor based on an Intensified CID camera (ICID) was used to measure the beam transverse profile at the extraction of the ion source. In this contribution we review the design of the ICID, its performance and discuss the measurements carried out. The performance of ICID monitors for its use in future accelerators will be assessed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAF026
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPAF054	Online Multi Objective Optimisation at Diamond Light Source	sextupole, controls, lattice, EPICS	1944
	M. Apollonio, R. Bartolini, R.T. Fielder, I.P.S. Martin DLS, Oxfordshire, United Kingdom R. Bartolini JAI, Oxford, United Kingdom G. Henderson Oxford University, Physics Department, Oxford, Oxon, United Kingdom J. Rogers Imperial College of Science and Technology, Department of Physics, London, United Kingdom
	At Diamond Light Source we have developed an Optimization Package currently used online to improve the performance of the machine, usually measured in terms of lifetime, injection efficiency or beam disturbance at injection. The tool is flexible in that control variables in order to optimise objectives (or their functions) can be easily specified by means of EPICS process variables (PV), making it suitable for virtually any sort of optimization. At present three different algorithms can be used to perform optimizations in a multi-objective fashion: Multi-Objective Genetic Algorithm (MOGA), Particle Swarm Optimizer (MOPSO) and Simulated Annealing (MOSA). We present a series of tests aimed at characterizing the algorithm as well as improving the performance of the machine itself.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAF054
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPAF055	Time-Synchronized Beam Diagnostics at SPEAR3	diagnostics, feedback, kicker, timing	1948
	Q. Lin, Z.H. Sun Donghua University, Shanghai, People's Republic of China P. Boussina, W.J. Corbett, D.J. Martin, J.A. Safranek, K. Tian SLAC, Menlo Park, California, USA D. Teytelman Dimtel, San Jose, USA
	The SPEAR3 timing system supplies a 10Hz trigger pulse synchronous with charge injection into the main storage ring. In the past the 10Hz pulse train has been used to study injected charge transients as seen by visible-light synchrotron radiation diagnostics and turn-by-turn BPMs. More recently the 10Hz pulse has been used to synchronize the bunch-by-bunch feedback data acquisition system with other triggered diagnostic systems. The suite of measurement systems can be used to study injected beam dynamics, grow/damp instability transients and drive/damp physics.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAF055
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPAF072	Transverse Feedback System for the CERN FCC-hh Collider	feedback, damping, kicker, emittance	1997
	W. Höfle, J. Komppula, G. Kotzian, K.S.B. Li, D. Valuch CERN, Geneva, Switzerland
	For the future hadron Collider (FCC-hh) being studied at CERN a strong transverse feedback system is required to damp coupled bunch instabilities. This system is also planned to be used for injection damping. Based on the LHC transverse feedback design we derive requirements for power and kick strength for this system for the different options of bunch spacing, 25 ns and 5 ns, and injection energy. Operation at high gain and close to a half integer tune is being considered and constrains the layout and signal processing. Requirements for the pick-up resolution are derived from the need to keep the emittance increase small. The performance is evaluated using numerical simulations based on the headtail code. Future areas of research and development and possible prototype developments are outlined.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAF072
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPAF078	Machine Learning Applied at the LHC for Beam Loss Pattern Classification	beam-losses, collimation, proton, flattop	2020
	G. Valentino University of Malta, Information and Communication Technology, Msida, Malta B. Salvachua CERN, Geneva, Switzerland
	Beam losses at the LHC are constantly monitored because they can heavily impact the performance of the machine. One of the highest risks is to quench the LHC superconducting magnets in the presence of losses leading to a long machine downtime in order to recover cryogenic conditions. Smaller losses are more likely to occur and have an impact on the machine performance, reducing the luminosity production or reducing the lifetime of accelerator systems due to radiation effects, such as magnets. Understanding the characteristics of the beam loss, such as the beam and the plane, is crucial in order to correct them. Regularly during the year, dedicated loss map measurements are performed in order to validate the beam halo cleaning of the collimation system. These loss maps have the particular advantage that they are performed in well controlled conditions and can therefore be used by a machine learning algorithm to classify the type of losses during the LHC machine cycle. This study shows the result of the beam loss classification and its retrospective application to beam loss data from the 2017 run.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAF078
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPAK004	Beam Instrumentation for CRYRING@ESR	instrumentation, rfq, hardware, detector	2084
	A. Reiter, C. Andre, H. Bräuning, C. Dorn, P. Forck, R. Haseitl, T. Hoffmann, W. Kaufmann, N. Kotovski, P. Kowina, K. Lang, R. Lonsing, P.B. Miedzik, T. Milosic, A. Petit, H. Reeg, C. Schmidt, M. Schwickert, T. Sieber, R. Singh, G. Vorobjev, B. Walasek-Höhne, M. Witthaus GSI, Darmstadt, Germany
	We present the beam instrumentation of CRYRING@ESR, a low-energy experiment facility at the GSI Helmholtz-Centre for heavy ion research. The 1.44 Tm synchrotron and storage ring, formerly hosted at the Manne Siegbahn laboratory in Stockholm, Sweden, was modified in its configuration and installed behind the existing ESR, the experimental storage ring. As the first machine within the ongoing FAIR project, the facility for antiproton and ion research, it is built on the future timing system and frameworks for data supply and acquisition. Throughout the past year CRYRING was commissioned including its electron cooler with hydrogen beams from the local linear accelerator. Storage, acceleration and cooling have been demonstrated. The contribution provides an overview of the beam instrumentation. The design of the detector systems and their current performance are presented. Emphasis is given to beam position monitors, detectors for intensity measurements, and the ionization profile monitors.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAK004
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPAK015	Beam Gate Control System for SuperKEKB	controls, operation, hardware, software	2124
	H. Kaji, Y. Ohnishi, S. Sasaki, M. Satoh, H. Sugimura KEK, Ibaraki, Japan Y. Iitsuka EJIT, Hitachi, Ibaraki, Japan T. Kudou Mitsubishi Electric System & Service Co., Ltd, Tsukuba, Japan
	The electron beam pulses of injector linac for the SuperKEKB collider are enabled and disabled by Beam Gate control system. This system controls the delivery of triggers to the electron guns at the injector. Also, the septum and kicker magnets for injection point of main ring are controlled with this Beam Gate to avoid unnecessary operation and to prolong their lifetime. The Beam Gate synchronizes the enabling and disabling operations of these hardware even though they are about 1km distant. Besides, from the phase-2 operation, the kicker and septum magnets for newly constructed damping ring becomes controlled apparatus of this system. We develop the new Beam Gate control system with the Event Timing System network. The new system improves the unsatisfied performance of Beam Gate in the phase-1 operation and realizes the complicated control for phase-2. The advantages of new system are: the control signal is delivered via Event nettork, so that we do not need to cable new network. The enabling and disabling operations for distant hardware are surely synchronized by the Event Timing System. H. Kaji et al., "Construction and Commissioning Event Timing System at SuperKEKB", Proceedings of IPAC14, Dresden, Germany (2014).
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAK015
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPAK017	Low-level RF System for the SuperKEKB Injector LINAC	linac, booster, controls, positron	2131
	T. Matsumoto, M. Akemoto, D.A. Arakawa, H. Katagiri, T. Miura, F. Qiu, Y. Yano KEK, Ibaraki, Japan M. Akemoto, T. Miura, F. Qiu Sokendai, Ibaraki, Japan
	The low-level RF (LLRF) system of the KEK injector linac has been upgraded for the SuperKEKB. As a major change, a low-emittance and high-current RF gun was installed to satisfy 40-times higher luminosity at the SuperKEKB. In order to balance the stable RF gun operation and the electron/positron beam acceleration, the phase shifter is developed and the configuration of main drive system in the LLRF system is modified. The present status and future plan of the LLRF system upgraded for the SuperKEKB will be reported.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAK017
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPAL001	LLRF Control and Master Oscillator System for Damping Ring at SuperKEKB	controls, cavity, LLRF, linac	2137
	T. Kobayashi, K. Akai, A. Kabe, K. Nakanishi, M. Nishiwaki, J.-I. Odagiri KEK, Ibaraki, Japan H. Deguchi, K. Hayashi, J. Mizuno Mitsubishi Electric TOKKI Systems, Amagasaki, Hyogo, Japan K. Hirosawa Sokendai, Ibaraki, Japan

Paper

Title

Other Keywords

Page

MOPMF001

Bunch Schedules for the FCC-ee Pre-injector

linac, collider, booster, positron

79

S. Ogur, K. Oide, Y. Papaphilippou, F. Zimmermann
CERN, Geneva, Switzerland
D.N. Shatilov
BINP SB RAS, Novosibirsk, Russia

The latest design of the Future Circular electron-positron Collider (FCC-ee) foresees a luminosity per interaction point above 2.0·10³⁶/cm²/s for operation at the Z pole. The filling from zero current occurs in collision to profit from the bunch lengthening due to beamstrahlung (so-called bootstrapping). At any time when new e^- and e⁺ buckets or bunchlets are injected into the collider, they will collide instantly. For this reason, we may provide the charge in each injected bunch in a way to pre-compensate for anticipated beam loss, and to reach the target luminosity as soon as possible after the first injection. In this way, we optimise the injection schedules for Z-mode so as to reach the peak luminosity in less than 20 minutes by interleaved injection of the two species at some portion of full bucket charge. Filling from zero the injector should allow accumulating 1.7·10¹¹ particles in one collider bucket within at least 10 injections, assuming a total transmission above 80%. In steady-state operation, the injector chain continually produces and accelerates lower bunch charges so as to maintain nearly constant bunch currents and constant peak luminosity.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMF001

Export •

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

MOPMF005

Beam Formation in the Alternative JLEIC Ion Complex

booster, linac, collider, proton

91

B. Mustapha, J.L. Martinez Marin
ANL, Argonne, USA
Y.S. Derbenev, F. Lin, V.S. Morozov, Y. Zhang
JLab, Newport News, Virginia, USA

Funding: Work supported by the U.S. Department of Energy / ONP, under Contract No. DE-AC02-06CH11357 for ANL and by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177.
The proposed alternative design approach for the JLab-EIC (JLEIC) ion complex uses a more compact linac and pre-booster, and consolidates the electron storage ring (e-ring) as a large booster for the ions. Following a parameter study* showing the feasibility of this alternative design approach, we have adapted the e-ring lattice by adding RF sections to accelerate ion beams**. In this study, we focus on the beam formation for protons and lead ions from the linac to the pre-booster, then into the e-ring until injection to the ion collider ring. Effects such as space charge, intra-beam scattering and the need for beam cooling will determine the total accumulated charge in each ring and the time required from injection from the injector linac to collision in the collider ring.
* B. Mustapha et al, Proceedings of NAPAC-2016, October 9-14, Chicago, IL.
** B. Mustapha et al, Proceedings of IPAC-2017, May 14-19, Copenhagen, Denmark.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMF005

Export •

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

MOPMF018

Numerical Simulation of Spin Dynamics with Spin Flipper in RHIC

resonance, dipole, simulation, polarization

118

P. Adams, H. Huang, J. Kewisch, F. Méot, P. Oddo, V. Ptitsyn, V.H. Ranjbar, G. Robert-Demolaize, T. Roser
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.
Spin flipper experiments during RHIC Run 17 were performed to study its effectiveness as a method for polarization sign reversal during stores. Numerical simulations are reported here, which were performed in accompaniment of these, and are being pursued with the aim of accurately reproducing the experimental conditions and providing thorough insight in the role of various key parameters participating in the dynamics of the spin flip, such as the sweep rate of the AC dipole, chromatic orbit control at RHIC snakes, RF parameters, possible effects of non-linear spin resonances, mirror resonance, tolerance on flipper magnet parameters, etc. The ultimate goal is for these simulations to serve as a guidance toward perfect flip to allow routine use during physics Runs.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMF018

Export •

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

MOPMF023

Updates on the Optic Corrections of FCC-hh

quadrupole, coupling, 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

Export •

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

MOPMF024

Dipole Field Quality and Dynamic Aperture for FCC-hh

dipole, alignment, dynamic-aperture, optics

137

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

Funding: This Research and Innovation Action project submitted to call H2020-INFRADEV-1-2014-1 receives funding from the European Union's H2020 Framework Program under grant agreement No. 654305.
The Nb₃Sn dipole design for the hadron machine option of the Future Circular Colliders enters in an intense and long R&D phase. As a result, more realistic dipole field quality evaluations are available for beam dynamics studies. The paper discusses the impact of the main dipole field quality on the first and second order design of the hadron machine and on its dynamic aperture.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMF024

Export •

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

MOPMF029

FCC-hh transverse impedance budget

impedance, feedback, laser, electron

149

S. Arsenyev, D. Schulte
CERN, Geneva, Switzerland
O. Boine-Frankenheim
GSI, Darmstadt, Germany

Contributions of different machine elements of the proposed Future Circular Collider (FCC-hh) impedance budget are calculated based on beam stability considerations. For each element (the beamscreen, the collimators, etc), effective impedances are calculated at the injection energy and at the collision energy for considered instabilities. The considered instabilities include the transverse coupled bunch instability (TCBI) and the transverse mode coupling instability (TMCI). Limitations to each total effective impedance are estimated and the critical points in the impedance budget are determined.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMF029

Export •

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

MOPMF030

Broadband Impedance of Pumping Holes and Interconnects in the FCC-hh Beamscreen

impedance, wakefield, coupling, electronics

153

S. Arsenyev, D. Schulte
CERN, Geneva, Switzerland

In the proposed Future Circular Collider (FCC-hh) pumping holes and interconnects between sections of the beamscreen can be sources of unwanted broadband impedance, potentially leading to the transverse mode coupling instability (TMCI). The pumping holes pose a greater challenge to the impedance calculation due to their small contribution per hole. Unlike for the Large Hadron Collider (LHC), analytical methods cannot be applied due to the complex beamscreen geometry and the greater size of the holes. Instead, two computational methods are used and compared to each other. For the interconnects, the impedance due to a sophisticated system of tapers is also estimated using computational methods.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMF030

Export •

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

MOPMF034

Layout and Performance of the FCC-ee Pre-Injector Chain

linac, emittance, damping, cavity

169

S. Ogur, T.K. Charles, K. Oide, Y. Papaphilippou, L. Rinolfi, F. Zimmermann
CERN, Geneva, Switzerland
A.M. Barnyakov, A.E. Levichev, P.V. Martyshkin, D.A. Nikiforov
BINP SB RAS, Novosibirsk, Russia
I. Chaikovska, R. Chehab
LAL, Orsay, France
K. Furukawa, N. Iida, T. Kamitani, F. Miyahara
KEK, Ibaraki, Japan
E.V. Ozcan
Bogazici University, Bebek / Istanbul, Turkey
S.M. Polozov
MEPhI, Moscow, Russia

The Future Circular e⁺e⁻ Collider pre-injector chain consists of a 6 GeV S-Band linac, a damping ring at 1.54 GeV and pre-booster ring to reach 20 GeV for injection to the main booster. The electron and positron beams use the same accelerator chain alternatively. The e⁺ beam is generated from a novel low level RF-gun providing 6.5 nC charge at 11 MeV with 0.5 micron geometric emittance. The e⁺ beam is produced by the impact of a 4.46 GeV e^- beam onto a hybrid target, accelerated in the linac up to 1.54 GeV, and injected to the damping ring for emittance cooling. Simulations on the performance of the DR are presented for reaching the required equilibrium emittances at the required damping time. As an alternative option, a 20 GeV linac is considered utilising C-Band cavities and simulations studies have been undertaken regarding the beam transport and transmission efficiency up to that energy.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMF034

Export •

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

MOPMF039

First Xenon-Xenon Collisions in the LHC

luminosity, experiment, proton, emittance

180

M. Schaumann, R. Alemany-Fernández, P. Baudrenghien, T. Bohl, C. Bracco, R. Bruce, N. Fuster-Martínez, M.A. Jebramcik, J.M. Jowett, T. Mertens, D. Mirarchi, S. Redaelli, B. Salvachua, M. Solfaroli, H. Timko, J. Wenninger
CERN, Geneva, Switzerland

In 2017, the CERN accelerator complex once again demonstrated its flexibility by producing beams of a new ion species, xenon, that were successfully injected into LHC. On 12 October, collisions of fully stripped xenon nuclei were recorded for the first time in the LHC at a centre-of-mass energy per colliding nucleon pair of 5.44 TeV. Physics data taking started 9.5 h after the first injection of xenon beams and lasted a total of 6 h. The integrated luminosity delivered to the four LHC experiments was sufficient that new physics results can be expected soon. We provide a general overview of this Xe-Xe pilot run before focussing on beam data at injection energy and at flat-top.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMF039

Export •

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

MOPMF047

Transverse Coupling Measurements With High Intensity Beams Using Driven Oscillations

coupling, dipole, controls, resonance

208

T. Persson, G. Baud, X. Buffat, J.M. Coello de Portugal, E. Fol, K. Fuchsberger, M. Gabriel, M. Gąsior, M. Giovannozzi, G.H. Hemelsoet, M. Hostettler, M. Hruska, D. Jacquet, E.H. Maclean, L. Malina, J. Olexa, P.K. Skowroński, M. Solfaroli Camillocci, M.E. Söderén, R. Tomás, D. Valuch, A. Wegscheider, J. Wenninger
CERN, Geneva, Switzerland

Transverse coupling has been linked to instabilities and reduction in dynamic aperture and is hence a crucial parameter to control in the LHC. In this article we describe the development to use driven oscillations to measure the transverse coupling with high intensity beams. The method relies on the use of the transverse damper to drive an oscillation in a similar way as with an AC-dipole. The calculation of the coupling is based on the turn-by-turn data from all available BPMs gated for the excited bunch.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMF047

Export •

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

MOPMF048

Aperture Measurements with AC Dipole at the Large Hadron Collider

dipole, optics, MMI, emittance

212

N. Fuster-Martínez, R. Bruce, J. Dilly, E.H. Maclean, T. Persson, S. Redaelli, R. Tomás
CERN, Geneva, Switzerland
L.J. Nevay
Royal Holloway, University of London, Surrey, United Kingdom

Global aperture measurements are crucial for a safe operation and to push the performance of the LHC, in particular, the knowledge of aperture at top energy allows pushing the optics to reduce the colliding beam sizes. The standard method used in the LHC commissioning requires using several bunches for one measurement and makes bunches un-usable for other activities. This paper presents first global aperture measurements performed at injection with a new method using the AC dipole. This method consists in exciting large coherent oscillations of the beam without spoiling its emittance. A gentle control of the oscillation amplitude enables re-using the beams for several measurements. These measurements are compared with aperture measurements performed using the standard method and possible benefits, for example for optics measurements, at top energy with squeezed optics, are elaborated.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMF048

Export •

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

MOPMF058

Status of the LHC Schottky Monitors

emittance, octupole, sextupole, damping

247

T. Tydecks, D. Alves, T.E. Levens, M. Wendt, J. Wenninger
CERN, Geneva, Switzerland

The Large Hadron Collider (LHC) features four transverse Schottky monitors detecting Schottky noise from the beam. From the Schottky noise signal, beam properties like tune, chromaticity, and bunch by bunch relative emittances, can be extracted. Being a non-destructive and purely parasitic method of measurement, the Schottky system is of great interest for real-time determination of beam chromaticities especially. Studies, including a dedicated machine development shift as well as parasitic measurements, concerning its capability to accurately measure the beam chromaticities are presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMF058

Export •

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

MOPMF059

Status of the FCC-ee Top-Up Booster Synchrotron

booster, collider, optics, emittance

250

B. Härer, B.J. Holzer, Y. Papaphilippou, T. Tydecks
CERN, Geneva, Switzerland

This contribution presents the status of the top-up booster synchrotron for the FCC electron-positron collider FCC-ee, which is a 100 km electron-positron collider being designed for precision studies and rare decay observations in the range of 90 to 365 GeV centre-of-mass energy. In order to keep the luminosity at a level of the order of 10³⁵ cm^-2s^-1 continuous top-up injection is required, because of the short beam lifetime of less than one hour. The top-up booster synchrotron will be housed in the same tunnel as the collider rings and will ramp up the beam energy from 20 GeV at injection to the full energy between 45.5 GeV and 182.5 GeV depending on operation mode. The lattice design and two possible optics will be presented. The dynamic aperture was investigated for different sextupole schemes with and without misalignments of the lattice components. In addition, wigglers were installed to decrease the damping time and mitigate intra-beam-scattering.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMF059

Export •

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

MOPMF064

High-Energy LHC Design

impedance, optics, luminosity, proton

269

F. Zimmermann, D. Amorim, S. A. Antipov, S. Arsenyev, M. Benedikt, R. Bruce, M.P. Crouch, S.D. Fartoukh, M. Giovannozzi, B. Goddard, M. Hofer, R. Kersevan, V. Mertens, Y. Muttoni, J.A. Osborne, V. Parma, V. Raginel, S. Redaelli, T. Risselada, I. Ruehl, B. Salvant, D. Schoerling, E.N. Shaposhnikova, L.J. Tavian, E. Todesco, R. Tomás, D. Tommasini, F. Valchkova-Georgieva, V. Venturi, D. Wollmann
CERN, Geneva, Switzerland
J.L. Abelleira, E. Cruz Alaniz, P. Martinez Mirave, A. Seryi, L. van Riesen-Haupt
JAI, Oxford, United Kingdom
A. Apyan
ANSL, Yerevan, Armenia
J. Barranco García, L. Mether, T. Pieloni, L. Rivkin, C. Tambasco
EPFL, Lausanne, Switzerland
F. Burkart
DESY, Hamburg, Germany
Y. Cai, Y.M. Nosochkov
SLAC, Menlo Park, California, USA
G. Guillermo Cantón
CINVESTAV, Mérida, Mexico
K. Ohmi, K. Oide, D. Zhou
KEK, Ibaraki, Japan

In the frame of the FCC study we are designing a 27 TeV hadron collider in the LHC tunnel, called the High Energy LHC (HE-LHC).

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMF064

Export •

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

MOPMF067

Optimized Arc Optics for the HE-LHC

dipole, lattice, sextupole, optics

277

Y.M. Nosochkov, Y. Cai
SLAC, Menlo Park, California, USA
M.P. Crouch, M. Giovannozzi, M. Hofer, J. Keintzel, T. Risselada, E. Todesco, R. Tomás, F. Zimmermann
CERN, Geneva, Switzerland
D. Zhou
KEK, Ibaraki, Japan
L. van Riesen-Haupt
JAI, Oxford, United Kingdom

Funding: Work supported by the European Commission under Capacities 7th Framework Programme project EuCARD-2, grant agreement 312453, and the HORIZON 2020 project EuroCirCol, grant agreement 654305.
The High Energy LHC (HE-LHC) proton-proton collider is a proposed replacement of the LHC in the existing 27-km tunnel, with the goal of reaching the centre-of-mass beam energy of 27 TeV. The required higher dipole field can be realized by using 16-T dipoles being developed for the FCC-hh design. A major concern is the dynamic aperture at injection energy due to degraded field quality of the new dipole based on Nb3Sn superconductor, the potentially large energy swing between injection and collision, and the slightly reduced magnet aperture. Another issue is the field in quadrupoles and sextupoles at top energy, for which it may be cost-effective, wherever possible, to stay with Nb-Ti technology. In this study, we explore design options differed by arc lattice, for three choices of injection energy, with the goal of attaining acceptable magnet field and maximum injection dynamic aperture with dipole non-linear field errors.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMF067

Export •

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

MOPMF073

Rejuvenation of 7-Gev SuperKEKB Injector Linac

positron, linac, electron, emittance

300

K. Furukawa, M. Akemoto, D.A. Arakawa, Y. Arakida, H. Ego, A. Enomoto, Y. Enomoto, T. Higo, H. Honma, N. Iida, M. Ikeda, H. Kaji, K. Kakihara, T. Kamitani, H. Katagiri, M. Kawamura, M. Kurashina, S. Matsumoto, T. Matsumoto, H. Matsushita, S. Michizono, K. Mikawa, T. Miura, F. Miyahara, H. Nakajima, K. Nakao, T. Natsui, M. Nishida, Y. Ogawa, Y. Ohnishi, S. Ohsawa, F. Qiu, I. Satake, M. Satoh, Y. Seimiya, A. Shirakawa, H. Sugimura, T. Suwada, T. Takenaka, M. Tanaka, N. Toge, Y. Yano, K. Yokoyama, M. Yoshida, R. Zhang, X. Zhou
KEK, Ibaraki, Japan

KEK injector linac has delivered electrons and positrons for particle physics and photon science experiments for more than 30 years. It was upgraded for the SuperKEKB project, which aims at a 40-fold increase in luminosity over the previous project KEKB, in order to increase our understanding of flavor physics beyond the standard model of elementary particle physics. SuperKEKB energy-asymmetric electron-positron collider with its extremely high luminosity requires a high current, low emittance and low energy spread injection beam from the injector. The electron beam is generated by a new type of RF gun, that provides a much higher beam current to correspond to a large stored beam current and a short lifetime in the ring. The positron source is another major challenge that enhances the positron bunch intensity from 1 to 4 nC by increasing the positron capture efficiency, and the positron beam emittance is reduced from 2000 μm to 10 μm in the vertical plane by introducing a damping ring, followed by the bunch compressor and energy compressor. The summary of the rejuvenation is reported.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMF073

Export •

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

MOPMF089

DAΦNE Luminosity Monitor

luminosity, detector, experiment, scattering

338

A. De Santis, C. Bisegni, O.R. Blanco-García, O. Coiro, A. Michelotti, C. Milardi, A. Stecchi
INFN/LNF, Frascati (Roma), Italy

This work presents a new method to measure the DAΦNE collider instantaneous luminosity. The method is based on the identification of Bhabha scattering events at low polar angle (∼10 degree) around the beam axis by using two small crystal calorimeters shared with the KLOE-2 experiment. A new experimental setup has been designed and realized in order to implement the fast luminosity monitor, also in view of the DAΦNE future physics runs. Besides total instantaneous luminosity the new diagnostic measures also Bunch-by-Bunch (BBB) luminosity. This peculiarity allows to investigate the beam-beam interaction for the Crab- Waist collisions at DAΦNE and luminosity dependence on the bunch train structure.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMF089

Export •

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

MOPMK002

Integrated Full HE-LHC Optics and Its Performance

lattice, dipole, insertion, target

348

M. Hofer
TU Vienna, Wien, Austria
M.P. Crouch, J. Keintzel, T. Risselada, R. Tomás, F. Zimmermann
CERN, Geneva, Switzerland
Y.M. Nosochkov
SLAC, Menlo Park, California, USA
D. Zhou
KEK, Ibaraki, Japan
L. van Riesen-Haupt
JAI, Oxford, United Kingdom

One possible future hadron collider design investigated in the framework of the Future Circular Collider (FCC) study is the High-Energy LHC (HE-LHC). Using the 16 T dipoles developed for the FCC-hh the center of mass energy of the LHC is set to increase to 27 TeV. To achieve this set energy goal, a new optics design is required, taking into account the constraint from the LHC tunnel geometry. In this paper, two different lattices for the HE-LHC are presented. Initial considerations take into account the physical aperture at the proposed injection energy as well as the energy reach of these lattices. The dynamic aperture at the injection energies is determined using latest evaluations of the field quality of the main dipoles.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMK002

Export •

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

MOPMK007

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

optics, luminosity, quadrupole, collider

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.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMK007

Export •

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

MOPMK011

VEPP-5 Injection Complex: New Possibilities for BINP Electron-Positron Colliders

positron, electron, collider, gun

371

Yu. Maltseva, A.V. Andrianov, K.V. Astrelina, V.V. Balakin, A.M. Batrakov, O.V. Belikov, D.E. Berkaev, M.F. Blinov, D. Bolkhovityanov, A. Butakov, E.V. Bykov, N.S. Dikansky, F.A. Emanov, A.R. Frolov, V.V. Gambaryan, K. Gorchakov, Ye.A. Gusev, S.E. Karnaev, G.V. Karpov, A.S. Kasaev, E. Kenzhbulatov, V.A. Kiselev, S. Kluschev, A.A. Kondakov, I. Koop, I.E. Korenev, N.Kh. Kot, V.R. Kozak, A.A. Krasnov, S.A. Krutikhin, I.V. Kuptsov, G.Y. Kurkin, N.N. Lebedev, A.E. Levichev, P.V. Logatchov, A.A. Murasev, V. Muslivets, D.A. Nikiforov, An.A. Novikov, A.V. Ottmar, A.V. Pavlenko, I.L. Pivovarov, V.V. Rashchenko, Yu. A. Rogovsky, S.L. Samoylov, N. Sazonov, A.V. Semenov, D.B. Shwartz, A.N. Skrinsky, A.A. Starostenko, D.A. Starostenko, A.G. Tribendis, A.S. Tsyganov, S.P. Vasichev, S.V. Vasiliev, V.D. Yudin, I.M. Zemlyansky, A.N. Zhuravlev
BINP SB RAS, Novosibirsk, Russia
A.V. Andrianov, V.V. Balakin, F.A. Emanov, I. Koop, A.A. Krasnov, A.E. Levichev, D.A. Nikiforov, A.V. Pavlenko, Yu. A. Rogovsky, D.B. Shwartz, A.A. Starostenko
NSU, Novosibirsk, Russia
A.I. Mickailov
Budker INP & NSU, Novosibirsk, Russia
A.G. Tribendis
NSTU, Novosibirsk, Russia

VEPP-5 Injection Complex (IC) is designed to supply BINP RAS colliders with high energy electron and positron beams. Recently constructed K-500 beam transfer line connects IC to both VEPP-4M and VEPP-2000 colliders. IC two collider operation was successfully performed in 2016. Nowadays, research on improvement of IC productivity is carried out, in particular 10.94 MHz RF cavity instead of 700 MHz one was installed and a new electron gun installation is expected to be this summer. Moreover, longitudinal beam profile measurements in IC damping ring using a streak-camera were carried out. Operation experience of IC and results of longitudinal beam profile measurements are reported.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMK011

Export •

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

TUXGBE4

Beam Quality Limitations of Plasma-Based Accelerators

plasma, electron, laser, acceleration

607

A. Ferran Pousa, R.W. Aßmann
DESY, Hamburg, Germany
A. Martinez de la Ossa
University of Hamburg, Institut für Experimentalphysik, Hamburg, Germany

Plasma-based accelerators are a promising novel technology that could significantly reduce the size and cost of future accelerator facilities. However, the typical quality and stability of the produced beams is still inferior to the requirements of Free Electron Lasers (FELs) and other applications. We present here our recent work in understanding the limitations of this type of accelerators, particularly on the energy spread and bunch length, and possible mitigating measures for future applications, like the plasma-based FEL in the EuPRAXIA design study.

Slides TUXGBE4 [4.905 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUXGBE4

Export •

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

TUXGBF4

ORBIT Simulation, Measurement and Mitigation of Transverse Beam Instability in the Presence of Strong Space Charge in the 3-GeV RCS of J-PARC

simulation, impedance, acceleration, space-charge

620

P.K. Saha, H. Harada, N. Hayashi, H. Hotchi, Y. Shobuda, F. Tamura
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan

The transverse impedance of eight extraction pulse kicker magnets (KM) is extremely strong source of transverse beam instability in the 3-GeV RCS (Rapid Cycling Synchrotron) at J-PARC. To realize the designed 1 MW beam power, collective beam dynamics with including the space charge effect for the coupled bunch instabilities excited by the KM impedance and associated measures were studied by incorporating all realistic time-dependent machine parameters in the ORBIT 3-D particle tracking code. The simulation results were all reproduced by measurements and, as a consequence, an acceleration of 1 MW beam power has been successfully demonstrated. In order to maintain variation of the RCS parameters required for multi-user operation, realistic measures for beam instability mitigation were proposed and also been successfully implemented in reality. To further increase the RCS beam power, beam stability issues and possible measures beyond 1 MW beam power are also considered.

Slides TUXGBF4 [2.241 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUXGBF4

Export •

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

TUYGBE4

Optically-pumped Polarized H⁻ and 3 He++ Ion Sources Development at RHIC

polarization, ion-source, electron, solenoid

644

A. Zelenski, G. Atoian, E.N. Beebe, A. Poblaguev, D. Raparia, J. Ritter
BNL, Upton, Long Island, New York, USA
J.D. Maxwell, R. Milner, M. Musgrave
MIT, Cambridge, Massachusetts, USA

The RHIC Optically-pumped Polarized H⁻ Ion Source (OPPIS) upgrade with the atomic beam hydrogen injector and the He-ionizer cell was commissioned for operation in the Run-2013. The use of the high brightness primary proton source resulted in higher polarized beam intensity and polarization delivered for injection to Linac-Booster-AGS-RHIC accelerator complex. The proposed polarized 3He++ acceleration in RHIC and future electron- ion col-lider (eRHIC) will require about 2·10¹¹ ions in the source pulse. A new technique had been proposed for production of high intensity polarized 3He++ ion beam. It is based on ionization and accumulation of the 3He gas (polarized by optical-pumping and metastability-exchange technique in the high magnetic field of a 5.0 T) in the Electron Beam Ion Source (EBIS). We present a status of the 3He++ ion source development.

Slides TUYGBE4 [4.596 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUYGBE4

Export •

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

TUPAF006

Operation of RHIC Injectors with Isobaric Ruthenium and Zirconium Ions

laser, target, booster, ion-source

672

H. Huang, E.N. Beebe, I. Blacker, J.J. Butler, C. Carlson, P.S. Dyer, W. Fischer, C.J. Gardner, D.M. Gassner, D. Goldberg, T. Hayes, S. Ikeda, J.P. Jamilkowski, T. Kanesue, N.A. Kling, C. Liu, D. Maffei, G.J. Marr, B. Martin, J. Morris, C. Naylor, M. Okamura, D. Raparia, V. Schoefer, F. Severino, T.C. Shrey, K.S. Smith, D. Steski, P. Thieberger, K. Zeno, I.Y. Zhang
BNL, Upton, Long Island, New York, USA
H. Haba
RIKEN Nishina Center, Wako, Japan
T. Karino
Utsunomiya University, Utsunomiya, Japan

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
The FY18 RHIC physics program calls for Ru-Ru and Zr-Zr collisions at 100GeV using isobaric Ruthenium and Zirconium ions, each having 96 nucleons. In the injector chain, these two ions have to come from tandem and EBIS source, respectively. To reduce systematic errors in the detector, the luminosity between the two species combinations is matched as closely as possible, and the species are switched frequently. Several bunch merges are needed in the Booster and AGS to reach the desired bunch intensity for RHIC. The setup and performance of Booster and AGS with these ions are reviewed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAF006

Export •

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

TUPAF011

Btrain Calibration with RF-Master Method

dipole, cavity, synchrotron, pick-up

679

L. Falbo, E. Bressi, M. Pezzetta, C. Priano
CNAO Foundation, Milan, Italy

CNAO is the only Italian hadrontherapy facility able to treat tumors with beams of protons and carbon ions. It is based on a synchrotron with a 77 m ring equipped with 16 normal conducting dipoles characterized by a long delay in the field stabilization. B-Train system is a fundamental device of the whole machine; it is used in feedback to the dipole power supply in order to regulate the magnetic field reducing the natural stabilization times that would cause long treatments. B-Train system allows to obtain the magnetic field starting from measurements of magnetic field changes: it works as an integrator and then it needs a system to reset the counts compensating the electronic and numerical drift of the system itself. An innovative method has been implemented at CNAO to reset Btrain counts exploiting beam measurements after the RF cavity trapping. This procedure has the advantage to avoid external and additional element like NMR probes. The paper shows the use of B-train system at CNAO and its calibration with this method, called "RF-master method".

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAF011

Export •

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

TUPAF020

Performance of the CERN Low Energy Ion Ring (LEIR) with Xenon beams

MMI, linac, controls, extraction

705

R. Alemany-Fernández, S.C.P. Albright, O. Andujar, M.E. Angoletta, J. Axensalva, H. Bartosik, G. Baud, N. Biancacci, M. Bozzolan, S. Cettour Cave, K. Cornelis, J. Dalla-Costa, M. Delrieux, A. Dworak, A. Findlay, F. Follin, A. Frassier, M. Gabriel, A. Guerrero, M. Haase, S. Hirlaender, S. Jensen, V. Kain, L.V. Kolbeck, Y. Le Borgne, D. Manglunki, O. Marqversen, S. Massot, D. Moreno Garcia, D.J.P. Nicosia, S. Pasinelli, L. Pereira, D. Perez, A. Rey, J.P. Ridewood, F. Roncarolo, A. Saá Hernández, R. Scrivens, O.G. Sveen, G. Tranquille, E. Veyrunes
CERN, Geneva, Switzerland

In 2017 the CERN Low Energy Ion Ring demonstrated once more the feasibility of injecting, accumulating, cooling and accelerating a new nuclei, 129Xe39 . The operation of this new ion species started at the beginning of March with the start up of the xenon ion source and the Linac3. Ten weeks later the beam arrived to the Low Energy Ion Ring (LEIR) triggering the start of several weeks of beam commissioning in view of providing the injector complex with Xenon beams for different experiments and a series of machine development experiments in LEIR. Two types of beams were setup, the so called EARLY beam, with a single injection into LEIR from Linac3, and the NOMINAL beam with up to seven injections. 2017 was as well an interesting year for LEIR because several improvements in the control system of the accelerator and in the beam instrumentation were done in view of increasing the machine reliability. This paper summarises the beam commissioning phase and all the improvements carried out during 2017.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAF020

Export •

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

TUPAF021

Identification and Removal of SPS Aperture Limitations

optics, vacuum, target, proton

709

V. Kain, R. Alemany-Fernández, H. Bartosik, S. Cettour Cave, K. Cornelis, P. Cruikshank, J.A. Ferreira Somoza, B. Goddard, C. Pasquino
CERN, Geneva, Switzerland

The CERN SPS (Super Proton Synchrotron) serves as LHC injector and provides beam for the North Area fixed target experiments. Since the 2016 run automated local aperture scans have been performed with the main focus on the vertical plane where limitations typically arise due to the flat vacuum chambers in most SPS elements. For LHC beams the aperture limitations with the present low integer tune optics also occur at locations with large dispersion. Aperture measurements in the horizontal plane using a variety of techniques were performed and showed surprising results, which could partially explain the unexpected losses of high intensity LHC beams at the SPS flat bottom. In this paper, reference measurements from 2016 are compared with the ones taken at the beginning of the run in 2017. Several aperture restrictions in the vertical plane could be found and cured, and a potential systematic restriction in the horizontal plane has been identified. The results of the measurements and the origin of the restrictions are presented in this paper, and the outlook for partial mitigation is discussed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAF021

Export •

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

TUPAF024

Impedance and Instability Studies in LEIR with Xenon

impedance, space-charge, coupling, accumulation

720

N. Biancacci, H. Bartosik, M. Gąsior, S. Hirlaender, V. Kain, T.E. Levens, E. Métral
CERN, Geneva, Switzerland
M. Migliorati
Rome University La Sapienza, Roma, Italy

In 2017, the LEIR accelerator has been operated with Xe³⁹⁺ beam for fixed target experiments in the SPS North Area. The different ion species, with respect to the usually operated Pb⁵⁴⁺, allowed for additional comparative measurements of tune shift versus intensity at injection energy both in coasting and bunched beams. The fast transverse instability observed for high accumulated intensities has been as well characterized and additional observations relevant to impedance have been collected from longitudinal Schottky signal and BTF measurements. The results of these measurements are summarised and compared to the currently developed machine impedance model.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAF024

Export •

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

TUPAF027

CERN PS Kicker for Proton Injection: from Beam-Based Waveform Measurements to Hardware Improvements

kicker, simulation, emittance, flattop

732

V. Forte, A. Ferrero Colomo, M.A. Fraser, T. Kramer
CERN, Geneva, Switzerland

For 2017 operation, the termination mode of the CERN Proton Synchrotron (PS) horizontal injection kicker was permanently changed to short-circuited, to be compliant with the future performances requested by the LHC Injectors Upgrade (LIU) project. An extensive campaign of measurements was performed through a dedicated beam-based technique. The measurements identified possibilities for optimisation of the kicker system and were fundamental to properly tune the PSpice simulation model of the kicker, as well as for validating the hardware changes. The model was finally used to estimate the horizontal emittance growth for the future injection schemes in the PS.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAF027

Export •

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

TUPAF031

Beam Simulation Studies for the Upgrade of the SPS Beam Dumping System

kicker, simulation, dumping, operation

747

C. Heßler, W. Bartmann, E. Carlier, L. Ducimetière, B. Goddard, F.M. Velotti
CERN, Geneva, Switzerland

The SPS at CERN currently uses a beam dumping system that is installed in the long straight section 1 (LSS1) of the SPS. This system consists of two beam stopper blocks for low and high energy beams, as well as two vertical and three horizontal kicker magnets, which deflect and dilute the beam on the dumps. Within the frame of the LHC injector upgrade project (LIU) the beam dumping system will be relocated to long straight section 5 (LSS5) and upgraded with an additional vertical kicker, new main switches and a single new beam dump, which covers the full energy range. The impact of a possible increase of the vertical kicker rise time on the beam has been studied in simulations with MAD-X for the different optics in the SPS. Furthermore, the impact on the beam in failure scenarios such as the non-firing of one kicker has been investigated. The results of these studies will be presented and discussed in this paper. Operational mitigation methods to deal with an increased rise time will also be discussed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAF031

Export •

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

TUPAF034

LEIR Injection Efficiency Studies as a Function of the Beam Energy Distribution from Linac3

linac, cavity, bunching, optics

758

S. Hirlaender, R. Alemany-Fernández, H. Bartosik, G. Bellodi, N. Biancacci, V. Kain, R. Scrivens
CERN, Geneva, Switzerland

High intensities in the CERN Low Energy Ion Ring (LEIR) are achieved using multi-turn injections from the pre-accelerator Linac3 combined with simultaneous stacking in momentum and transverse phase spaces. Up to seven consecutive 200 μs long, 200 ms spaced pulses are injected from Linac3 into LEIR by stacking each of them into the six-dimensional phase-space over 70 turns. An inclined septum magnet allows proper filling of the transverse phase-space plane, while longitudinal stacking requires momentum variation achieved by a shift of mean momentum over time provided by phase shifting a combination of 2 RF cavities at the exit of Linac3. The achievable maximum accumulated intensity depends strongly on the longitudinal beam quality of the injected beam. The longitudinal Schottky signal is used to measure the received energy distribution of the circulating beam which is then correlated with the obtained injection efficiency. This paper presents the experimental studies to understand and further improve the injection reliability and the longitudinal stacking.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAF034

Export •

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

TUPAF036

Studies of the Injection and Cooling Efficiency in LEIR Using the Longitudinal Schottky Spectrum

linac, diagnostics, electron, pick-up

765

S. Hirlaender, R. Alemany-Fernández, H. Bartosik, N. Biancacci, V. Kain
CERN, Geneva, Switzerland

The CERN Low Energy Ion Ring (LEIR) has two main operational beams with their associated cycles, the so-called EARLY and the NOMINAL beam. The EARLY beam consists of a single injected pulse from the LINAC3 accelerator, whereas seven consecutive injections are accumulated, and electron cooled for the NOMINAL beam. In both cases, the longitudinal Schottky monitor allows assessing the longitudinal particle distribution during the cooling process on the injection plateau. A method has been established to analyze the Schottky signal, reconstruct the initial particle momentum distribution and derive relevant parameters such as the cooling time, energy off-set of injected and stacked beam or the momentum distribution of the lost beam. The variations of the obtained parameters and the impact on the LEIR performance will be addressed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAF036

Export •

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

TUPAF037

Validation of the CERN PS Eddy Current Injection Septa

septum, simulation, vacuum, HOM

768

M. Hourican, B. Balhan, J.C.C.M. Borburgh, T. Masson, A. Sanz Ull
CERN, Geneva, Switzerland

As part of the upgrade of the CERN PS accelerator from 1.4 GeV to 2 GeV, new injection septa have been developed. The system is comprised of a pulsed eddy current septum magnet and a pulsed eddy current bumper magnet. Both magnets will be housed in a common vacuum vessel and powered by independent power converters. In-depth studies and simulations have been performed to reduce as much as possible the leak field by designing specific magnetic shielding, combined with dual function beam impedance shielding. A prototype magnet was built and measured to validate the simulations. The final complete system will be bake-able at 200C and uses demineralised water for cooling. Closed circuit cooling systems have been integrated to reduce risks of vacuum leaks. This report describes the electromechanical design from the concept and simulation stages to the prototyping and final manufacturing. Results of the initial magnetic measurements, including field homogeneity and leak field mitigation methods are presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAF037

Export •

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

TUPAF046

Conceptual Design of a Collimation System for the CERN Super Proton Synchrotron

collimation, optics, proton, simulation

802

M. Patecki, A. Mereghetti, D. Mirarchi, S. Redaelli
CERN, Geneva, Switzerland

The Super Proton Synchrotron (SPS) is the last accelerator in the LHC Injectors Chain. Its performance is constantly being improved in frame of the LHC Injectors Upgrade (LIU) Project in order to prepare it for the future HL-LHC (High Luminosity LHC) operation. One of the LIU goals is to nearly double the intensity extracted from the SPS, up to 2.32×10¹¹ p/bunch. In recent years, nearly 10% of losses are observed for nominal intensity and LHC-type beams; they grow to about 20% for the intensity approaching the HL-LHC target. Beam losses imply activation and aging of the SPS hardware; the possibility to add a collimation system is being considered to mitigate this problem. In this paper we present studies of a collimation system design for the SPS. The concept is based on a primary horizontal collimator located in an available position with high enough dispersion, and a secondary collimator to intercept the particles leaking out from the primary collimator. Performance of the proposed collimation system is evaluated by means of numerical simulations.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAF046

Export •

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

TUPAF048

LIU Space Charge Studies for the LHC Pre-Accelerators

space-charge, proton, resonance, simulation

810

F. Schmidt, H. Bartosik
CERN, Geneva, Switzerland

In 2011 a working group has been started to study performance limitations due to Space Charge (SC) in the four LHC pre-accelerators, LEIR, PSB, PS & SPS, in view of the LHC Injector Upgrade (LIU) project. To this end external and in-house simulation tools have been benchmarked for the LIU study cases with the long-term goal of providing a full sequence of tested CERN Space Charge tools. It became clear that SC studies must be combined with trustworthy models of the machines, including linear and non-linear errors. In particular an effective s-dependent non-linear model is required. Recent studies indicate that also the low frequency ripple spectrum due to conventional power supplies might play an important role for the beam dynamics in presence of space charge in the pre-injectors.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAF048

Export •

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

TUPAF059

Design and Evaluation of FCC-hh Injection Protection Schemes

kicker, dipole, collider, collimation

854

E. Renner, M.J. Barnes, W. Bartmann, C. Bracco, R. Bruce, F. Burkart, B. Goddard, A. Lechner, L.S. Stoel, F.M. Velotti, C. Wiesner, D. Woog
CERN, Geneva, Switzerland

The Future Circular Collider (FCC) study considers several injector scenarios for FCC-hh, the proposed 100~TeV centre of mass hadron collider located at CERN. The investigated options include amongst others to use the LHC at 3.3~TeV or a superconducting SPS at 1.3~TeV as a High Energy Booster (HEB). Due to the high energy of the injected proton beam and the short time constant of injection failures, a thorough consideration of potential failure cases is of major importance. Further attention has to be given to the fact that the injection is - as in LHC - located upstream of the side experiments. Failure scenarios are identified for both injector options, appropriate designs of injection protection schemes are proposed and first simulations are conducted to validate the protection efficiency.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAF059

Export •

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

TUPAF060

Injection and Dump Systems for a 13.5 TeV Hadron Synchrotron HE-LHC

kicker, extraction, septum, experiment

858

W. Bartmann, M.J. Barnes, L. Ducimetière, B. Goddard, M. Hofer, T. Kramer, A. Lechner, E. Renner, A. Sanz Ull, V. Senaj, L.S. Stoel, C. Wiesner
CERN, Geneva, Switzerland

One option for a future circular collider at CERN is to build a 13.5 TeV hadron synchrotron, or High Energy LHC (HE-LHC) in the LHC tunnel. Injection and dump systems will have to be upgraded to cope with the higher beam rigidity and increased damage potential of the beam. The required modifications of the beam transfer hardware are highlighted in view of technology advancements in the field of kicker switch technology. An optimised straight section optics is shown.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAF060

Export •

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

TUPAK005

Upgrade Plan of J-PARC MR - Toward 1.3 MW Beam Power

operation, experiment, proton, cavity

966

T. Koseki
KEK, Ibaraki, Japan

The Main Ring Synchrotron (MR), a 30-GeV slow cycling proton synchrotron, delivers intense proton beam to a long-baseline neutrino oscillation experiment, T2K, by fast extraction and to an experimental facility, which is called hadron hall by slow extraction. The achieved beam intensities for routine operations are 470 kW ( 2.4 x 10¹⁴ ppp) for the fast extraction and 44 kW ( 5.1 x 10¹³ ppp) for the slow extraction. In order to increase the beam intensity, a plan to replace the magnet power supplies are now in progress for operation with a higher repetition rate. After the replacement, the cycle time will be shortened about a half and increase beam intensities two times larger for the fast extraction. In addition, a further upgrade plan for the fast extraction is mainly reinforcement of rf power supplies. The goal of the upgrade plan is reaching 1.3 MW beam power for the neutrino experiment.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAK005

Export •

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

TUPAL002

Numerical Calibration of the Injection Bump Sizes During the Beam Commissioning for CSNS

MMI, flattop, experiment, neutron

1011

M.Y. Huang, S. Wang, S.Y. Xu
IHEP, Beijing, People's Republic of China

In order to control the strong space charge effects, which cause large beam loss during the injection and acceleration processes, phase space painting method was used for injecting a small emittance beam from the linac into the large acceptance of the Rapid Cycling Synchrotron (RCS). During the beam commissioning, in order to control and optimize the painting results, the positions and ranges of the horizontal and vertical painting should be adjusted accurately. Therefore, the numerical calibration of the injection bump sizes was very important and need to be done as soon as possible. In this paper, a method to calibrate the horizontal and vertical bump sizes was presented and applied to China Spallation Neutron Source (CSNS). The numerical calibration results would be given and discussed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAL002

Export •

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

TUPAL003

Measurement of the Injection Beam Parameters by the Multi-Wire Scanner for CSNS

proton, MMI, linac, neutron

1014

M.Y. Huang, H.C. Liu, S. Wang, Zh.H. Xu, P. Zhu
IHEP, Beijing, People's Republic of China
X.H. Lu
CSNS, Guangdong Province, People's Republic of China

In order to inject the H⁻ beam to the Rapid Cycling Synchrotron (RCS) with high precision and high transport efficiency, the injection beam parameters need to be measured and then corrected while its eccentric position or direction angle is too large. In this paper, firstly, a method to measure the injection beam parameters by using two of the four multi-wire scanners (MWSs) is presented. The injection commissioning results confirmed that this method works well. Secondly, a method to measure the signals of injection beam and circular beam by the INMWS02 is presented and the method work well during the beam commissioning.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAL003

Export •

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

TUPAL005

Study on the Fixed Point Injection during the Beam Commissioning for CSNS

MMI, timing, neutron, proton

1017

M.Y. Huang, H.C. Liu, S. Wang, S.Y. Xu
IHEP, Beijing, People's Republic of China

In order to inject the H⁻ beam into the Rapid Cycling Synchrotron (RCS) of China Spallation Neutron Source (CSNS) accurately, different injection methods were used in different periods of beam commissioning for CSNS. In the early stage of beam commissioning, since the precise relative position of the injection beam and circular beam was unknown and the injection beam power was relatively small, the fixed point injection method was used. In this paper, the fixed point injection method is studied in detail and the beam commissioning results are given and discussed. In addition, a method to adjust the timing of the injection pulse power is presented and confirmed by the beam commissioning.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAL005

Export •

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

TUPAL018

Pulse-by-Pulse Switching of Operational Parameters in J-PARC 3-GeV RCS

emittance, operation, extraction, betatron

1041

H. Hotchi, H. Harada, K. Okabe, P.K. Saha, Y. Shobuda, F. Tamura, Y. Watanabe, M. Yoshimoto
JAEA/J-PARC, Tokai-mura, Japan

J-PARC 3-GeV RCS (rapid cycling synchrotron) provides a high-power beam both to MLF (materials and life science experimental facility) and MR (main ring synchrotron) by switching the beam destination pulse by pulse. The beam properties required from MLF and MR are different; MLF needs a wide-emittance beam with less charge density, while MR requires a low-emittance beam with less beam halo. To meet the antithetic requirements while keeping beam loss at permissible levels, RCS has recently initiated pulse-by-pulse switching of operational parameters (betatron tune, chromaticity, painting emittance, etc.). This paper presents the recent efforts toward the performance upgrade of RCS while discussing the related beam dynamics issues.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAL018

Export •

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

TUPAL020

Recent Status of J-PARC Rapid Cycling Synchrotron

operation, target, emittance, proton

1045

K. Yamamoto, P.K. Saha
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan

The 3 GeV Rapid Cycling Synchrotron (RCS) of the Japan Proton Accelerator Research Complex (J-PARC) provides more than 300 kW beam to the Material and Life Science Facility (MLF) and the Main Ring (MR). In such high intensity hadron accelerator, the lost protons that are a fraction of the beam less than 0.1 % cause many problems. Those particles bring about a serious radioactivation and a malfunction of the accelerator components. Therefore, we carried out the beam study to achieve high power beam operation. Moreover, we also maintain the accelerator components to keep a steady operation. We report present status of the J-PARC RCS.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAL020

Export •

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

TUPAL030

Improvement of RF Capture with Multi-Turn H⁻ Injection in KURRI FFAG Synchrotron

acceleration, proton, scattering, closed-orbit

1066

T. Uesugi, Y. Fuwa, Y. Ishi, Y. Kuriyama, Y. Mori, H. Okita
Kyoto University, Research Reactor Institute, Osaka, Japan

In the KURRI FFAG synchrotron, charge-exchanging multi-turn injection is adopted with a stripping foil located on the closed orbit of injection energy. No injection bump orbit system is used and the beam escapes from the foil according to the closed-orbit shift by acceleration. The particles hit the foil many times and the emittance grows up during the injection. In this paper, the capture efficiencies are studied with different rf process, including adiabatic capture.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAL030

Export •

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

TUPAL047

Strain Measurement in the Recent SNS Mercury Target with Gas Injection

target, proton, radiation, neutron

1117

Y. Liu, W. Blokland, C.D. Long, S.N. Murray, B.W. Riemer, R.L. Sangrey, M. W. Wendel, D.E. Winder
ORNL, Oak Ridge, Tennessee, USA

Funding: ORNL is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. DOE.
High-radiation-tolerant fiber-optic strain sensors were recently developed to measure the transient proton-beam-induced strain profiles on the mercury target vessel at the Spallation Neutron Source (SNS). Here we report the strain measurement results and radiation-resistance performance on the latest SNS mercury target vessel equipped with helium gas injection. The results have demonstrated the efficacy of gas injection to reduce the cyclic stress on the target module.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAL047

Export •

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

TUPAL049

SNS Proton Power Upgrade Status

linac, scattering, proton, cavity

1120

M.A. Plum, G. A. Bloom, M.S. Champion, J. Galambos, M.P. Howell, S.-H. Kim, J. Moss, B.W. Riemer, K.S. White
ORNL, Oak Ridge, Tennessee, USA
R.B. Saethre, R. W. Steffey
ORNL RAD, Oak Ridge, Tennessee, USA

Funding: ORNL is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. DOE. This research was supported by the DOE Office of Science, Basic Energy Science, Scientific User Facilities.
The Spallation Neutron Source (SNS) Proton Power Upgrade (PPU) project aims to double the proton accelerator beam power from 1.4 to 2.8 MW. Over the past year PPU has completed the reviews necessary for Critical Decision-1 approval. The baseline design choices are being refined, and a cost-effective approach has been identified. The beam energy will be increased by 30% and the beam current capability improved by ~50%. The sub-system improvements and anticipated schedule will be discussed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAL049

Export •

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

TUPAL055

Progress with Carbon Stripping Foils at ISIS

operation, synchrotron, vacuum, proton

1136

B. Jones, H.V. Cavanagh
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom

The ISIS Facility at the Rutherford Appleton Laboratory produces intense neutron and muon beams for condensed matter research. The facility's 50Hz rapid cycling synchrotron accelerates protons from 70 to 800MeV to deliver a mean beam power of 0.2MW to two target stations. Since 2016, ISIS has routinely used commercially produced carbon based foils for beam stripping during charge-exchange injection. Recent experience and developments to increase useful foil lifetime are presented including in-house high temperature annealing of foils prior to use. The installation and performance of a new foil imaging system are described and, finally, the procedure to change the stripping foil is described. Issues with the current arrangements and options for redesign are discussed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAL055

Export •

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

TUPAL058

Studies for Major ISIS Upgrades via Conventional RCS and Accumulator Ring Designs

simulation, lattice, space-charge, emittance

1148

C.M. Warsop, D.J. Adams, H.V. Cavanagh, P.T. Griffin-Hicks, B. Jones, B.G. Pine, R.E. Williamson
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom

ISIS is the spallation neutron source at the Rutherford Appleton Laboratory in the UK, which provides 0.2 MW of beam power via a 50 Hz, 800 MeV proton RCS. Detailed studies are now under way to find the optimal configuration for a next generation, short pulsed neutron source that will define a major ISIS upgrade in ~2031. Accelerator configurations being considered for the MW beam powers required include designs exploiting FFAG rings as well as conventional accumulator and synchrotron rings. This paper describes work exploring the latter, conventional options, but includes the possibility of pushing further toward intensity limits to reduce facility costs. The scope of planned studies is summarised, looking at optimal exploitation of existing ISIS infrastructure, and incorporating results from recent target studies and user consultations. Results from initial baseline studies for an accumulator ring and RCS located in the existing ISIS synchrotron hall are presented. Injection scheme, foil limits, longitudinal and transverse beam dynamics optimization with related beam loss and activation are outlined, as are results from detailed 3D PIC simulations.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAL058

Export •

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

TUPAL059

Commissioning of Shanghai Advance Proton Therapy

extraction, proton, MMI, dipole

1151

M.Z. Zhang, D.M. Li, K. Wang, Q.L. Zhang, Z.T. Zhao
SINAP, Shanghai, People's Republic of China
X.C. Xie
Shanghai APACTRON Particle Equipment Company Limited, Shanghai, People's Republic of China

Shanghai advance proton therapy (SAPT) is a dedicate facility for cancer treatment. The commissioning of the accelerator started at the end of April 2017, and the proton beam has been already transported to the treatment room. This paper shows the commissioning results of synchrotron and transport line.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAL059

Export •

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

TUZGBD4

Impact of a Wideband Feedback Prototype System on TMCI in the SPS

feedback, optics, kicker, emittance

1208

W. Höfle, H. Bartosik, E.R. Bjørsvik, G. Kotzian, T.E. Levens, K.S.B. Li
CERN, Geneva, Switzerland
J.E. Dusatko, J.D. Fox, C.H. Rivetta
SLAC, Menlo Park, California, USA
O. Turgut
Stanford University, Stanford, California, USA

The transverse mode coupling instability (TMCI) in the SPS has been identified as one of the potential performance limitations for future high intensity LHC beams that will be required for the High Luminosity (HL)-LHC era and is being addressed by the LHC Injector Upgrade Project (LIU). A potential mitigation can be provided by wideband feedback systems with a frequency reach of about 1 GHz . For this reason, the development of a prototype system has been started in a CERN collaboration within the US-LARP framework in 2008. In this report we present latest experimental results in 2017 where this prototype system was used in single and multi-bunch studies. In particular, a successful mitigation against TMCI at injection could be demonstrated in single bunch studies.

Slides TUZGBD4 [15.116 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUZGBD4

Export •

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

TUPMF014

Synchrotron Accumulation on Off-Energy Closed-Orbit with Anti-Septum or Nonlinear Kicker

kicker, septum, accumulation, closed-orbit

1280

Y.P. Sun
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.
Off-axis accumulation on off-energy closed-orbit (so-called synchrotron injection/accumulation) was studied and implemented in the 1990s for LEP at CERN. The idea of using pulsed multipole injection on off-energy closed-orbit was first proposed in 2014 and then developed for Swiss Light Source (SLS) upgrade in 2015. In 2017, the anti-septum was proposed for SLS upgrade injection. In this paper, two similar injection schemes are proposed which combine off-axis accumulation on off-energy closed-orbit (no betatron oscillations), with the anti-septum or pulsed nonlinear kicker schemes. Preliminary lattice solutions are developed for Advanced Photon Source upgrade (APS-U) where a special injection straight (with length of 5.8 m) is designed with horizontal dispersion of 0.15m. The impact on the ring emittance is relatively small. The injection elements are all placed in this injection straight, including 1 thin septum and 3 slow kickers (or 1 pulsed nonlinear kicker). No fast kickers are needed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPMF014

Export •

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

TUPMF017

Transport Line Design and Injection Configuration Optimization for the Advanced Photon Source Upgrade

septum, kicker, dipole, emittance

1287

A. Xiao, M. Borland
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.
On-axis swap-out injection was chosen for the Advanced Photon Source Upgrade (APS-U) to allow pushing the beam emittance to an extremely low value. The injection section configuration was optimized within a multi-dimensional parameter space and made consistent with up-to-date technical developments. The booster-to-storage ring (BTS) transport line was designed to bring the electron beam from the existing Booster to the new storage ring (SR). Due to various limitations, this new BTS line is twisted both horizontally and vertically when approaching the injection point, which introduces challenges in both geometrical and optical matching. This paper presents our simple solution to these issues. The coupling effect caused by the twisted BTS line is also discussed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPMF017

Export •

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

TUPMF036

Top Off of NSLS-II with Inefficient Injector

booster, linac, storage-ring, operation

1327

R.P. Fliller, A.A. Derbenev, V.V. Smaluk, X. Yang
BNL, Upton, Long Island, New York, USA

Funding: This manuscript has been authored by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy
The NSLS-II is a 3 GeV storage with a full energy injector capable of top off injection. The injector consists of a 200 MeV linac injecting a 3 GeV booster. Recent operational events have caused us to investigate 100 MeV injection into the booster. As the booster was not designed for injection at this low energy, beam loss is observed with this low energy booster injection. This beam loss not only results of overall charge loss from the train, but a change in the overall charge distribution in the bunch train. In this paper we discuss the performance of injecting into the storage ring with the inefficient charge transfer through the injector. The changes to the top off method are discussed, as well as the achieved storage ring current stability and fill pattern.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPMF036

Export •

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

TUPMF037

Development of New Operational Mode for NSLS-II Injector: Low Energy 100MeV Linac-to-Booster Injection

booster, operation, klystron, linac

1330

X. Yang, A.A. Derbenev, R.P. Fliller, T.V. Shaftan, V.V. Smaluk
BNL, Upton, Long Island, New York, USA

The NSLS-II injector consists of a 200 MeV linac and a 3 GeV full-energy booster synchrotron. The linac contains five traveling-wave S-band accelerating structures driven by two high-power klystrons, with a third klystron as spare. In the event that the spare klystron is not available, the failure of one klystron will prohibit the linac from injecting into the booster as the energy is too low. Therefore, we wish to develop a new operational mode that the NSLS-II injector can operate with a single klystron providing 100 MeV beam from the linac. A decremented approach with intermediate energies 170 MeV, 150 MeV, etc., takes advantages of pre-calculated booster ramps and beam based online optimization. By lowering the booster injection energy in a small step and online optimizing at each step, we were able to achieve 100 MeV booster injection. 170 MeV operation mode of the NSLS-II injector has been implemented since May 31, 2017, with a similar overall performance compared to the standard 200 MeV operation but fewer klystron trips. 100 MeV single-klystron operation has been successfully demonstrated with 20-30% overall efficiency, which is limited by booster acceptance.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPMF037

Export •

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

TUPMF039

Recommissioning of the Canadian Light Source Booster Synchrotron

booster, MMI, optics, extraction

1338

W.A. Wurtz, D. Bertwistle, L.O. Dallin, X. Shen, J.M. Vogt
CLS, Saskatoon, Saskatchewan, Canada

The Canadian Light Source booster synchrotron was originally commissioned in 2002 and has worked reliably for many years. However, the operating point was not the design operating point and the booster suffered from poor quantum lifetime at the extraction energy. The low quantum lifetime caused current loss of approximately 25% in the microseconds before extraction. We have recommissioned the booster using the design optics, and the current loss before extraction is now only 6%. In this paper, we discuss the measurements and simulations involved in our recommissioning work.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPMF039

Export •

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

TUPMF046

The Injection and Extraction Design of the Booster for the HEPS Project

extraction, kicker, storage-ring, booster

1356

Y.Y. Guo, J. Chen, Z. Duan, Y. Jiao, Y.M. Peng, G. Xu
IHEP, Beijing, People's Republic of China

The HEPS booster is a 1Hz electron synchrotron. It accelerates electron bunches from 500 MeV to final energy of 6 GeV. The vertical scheme was chosen for the injection and extraction system of the booster. What's more, an injection system from storage ring is required. The layout of the injection and extraction system were introduced in this paper. The parameter optimization and other considerations are presented in detail.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPMF046

Export •

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

TUPMF048

On-Axis Beam Accumulation Based on a Triple-Frequency RF System for Diffraction-Limited Storage Rings

cavity, simulation, accumulation, photon

1359

S.C. Jiang, Z. Duan, G. Xu
IHEP, Beijing, People's Republic of China

Since the multi-bend achromats have been applied to lattice design in the future light source to achieve ultralow emittance, strong sextupoles and concomitant nonlinearities restrict its performance to a certain extent. The empirical understanding is the exclusion of conventional off-axis injection scheme on these light sources. In this paper, we will present a new on-axis beam accumulation scheme, which is based on the triple-frequency RF system. By means of delicate superposition of RF voltage with fundamental and two other harmonic frequencies, a commodious and steady main bucket is able to be formed. The electron bunch from the injector will be kicked into the main bucket on-axis with a reasonable time offset to the circular bunch, and this process may make the minimal disturbance to the experiment users while operating on the top-up mode. The application of this scheme to the High Energy Photon Source (HEPS) will be discussed in the paper, corresponding simulation results are also presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPMF048

Export •

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

TUPMF049

Evolution of the Lattice Design for the High Energy Photon Source

lattice, emittance, storage-ring, photon

1363

G. Xu, S.Y. Chen, Y. Jiao, J.L. Li, Y.M. Peng, Q. Qin, J.Q. Wang, C.H. Yu
IHEP, Beijing, People's Republic of China

The High Energy Photon Source (HEPS) is a high-energy, ultralow-emittance, kilometer-scale storage ring light source to be built in China. The HEPS lattice design has been started since 2008. In this paper we will review the evolution of the HEPS lattice design over the past ten years, focusing mainly on the linear optics design and nonlinear optimization.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPMF049

Export •

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

TUPMF052

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

lattice, booster, storage-ring, emittance

1375

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

The High Energy Photon Source (HEPS) is an ultralow-emittance, kilometer-scale storage ring light source to be built in China. In this paper we will introduce the progress of the physical design and studies on HEPS over the past one year, covering issues of storage lattice design and optimization, booster design, injection design, collective effects, error study, insertion device effects, beam lifetime, etc.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPMF052

Export •

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

TUPMF058

Conceptual Design of HEPS Injector

booster, storage-ring, linac, dipole

1394

J.L. Li, H. Dong, Z. Duan, Y.Y. Guo, D.Y. He, Y. Jiao, W. Kang, C. Meng, S. Pei, Y.M. Peng, J.R. Zhang, P. Zhang, Z.S. Zhou
IHEP, Beijing, People's Republic of China

Abstract The High Energy Photon Source (HEPS) will be constructed in the following few years. The light source is comprised of an ultra-low emittance storage ring and a full energy injector. The energy of the storage ring is 6 GeV. The injector is comprised of a 500 MeV linac, a 500 MeV to 6 GeV booster synchrotron and transport lines connecting the machines. In the present design, the linac uses normal conducting S-band bunching and accelerating structures. The booster adopts FODO cells, has a circumference of about 454 m and an emittance lower than 40 nmrad. The injector can provide a single-bunch charge up to 2 nC at 6 GeV for the storage ring. This paper briefly introduces the conceptual design of the injector of the HEPS.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPMF058

Export •

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

TUPMF062

Status of HEPS Booster Lattice Design and Physics Studies

booster, lattice, storage-ring, extraction

1407

Y.M. Peng, Z. Duan, Y.Y. Guo, D. Ji, Y. Jiao, J.L. Li, C. Meng, S.K. Tian, H.S. Xu
IHEP, Beijing, People's Republic of China

The High Energy Photon Source (HEPS) with an ul-tralow emittance is proposed to be built in Beijing, Chi-na. It will utilize a booster as its full energy injector. On-axis swap-out injection is chosen as the baseline injec-tion scheme for the storage ring. As required by the stor-age ring, a beam with a bunch charge up to 2.5 nC is needed to be injected in the booster. However, limited by the transverse mode coupling instability (TMCI), such a high bunch charge is challenging. To overcome this problem, a lattice with a considerable large momentum compaction factor is designed. This paper reports the lattice design and physics studies of the HEPS booster, including injection and extraction design, error studies, eddy current effects, collective effects, and so on.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPMF062

Export •

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

TUPMF063

The Considerations of Improving TMCI Threshhold on HEPS Booster

booster, lattice, linac, storage-ring

1411

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

The High Energy Photon Source (HEPS) is proposed in Beijing, China. The on-axis swap-out injection scheme will be used in the storage ring mainly because of the small dynamic aperture. Therefore, the booster needs to store more than 2.5 nC bunch charge. Under this requirement, the transverse mode coupling instability (TMCI) at the injection energy becomes the bunch charge restriction in the booster. Several changes in booster and linac for improving bunch charge threshold limited by TMCI are considered. The details will be expressed in this paper.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPMF063

Export •

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

TUPMF068

Beam Dynamics on a Coupling Resonance at PETRA III

resonance, coupling, optics, lattice

1417

I.V. Agapov, J. Keil, G. Kube, G.K. Sahoo, R. Wanzenberg
DESY, Hamburg, Germany
Y.-C. Chae
ANL, Argonne, Illinois, USA
A.I. Novokshonov
TPU, Tomsk, Russia

Working on a coupling resonance is a usual way of producing round beams in a synchrotron. The beam dynamics in this regime is however more complicated, and the emittance is sensitive to the working point, coupling correction, and bunch current drop with time, which complicates the operation. We present experience with optics setup for working on a coupling resonance in PETRA III, including linear and nonlinear beam optics characteristics, and the measurement of the horizontal and vertical beam emittances with a 2D interferometer. Beam dynamics on a coupling resonance for PETRA IV, the MBA upgrade of PETRA III currently under consideration, is also presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPMF068

Export •

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

TUPMF084

Optimization of the Injection Kicker Bump Leakage at PETRA III

kicker, septum, feedback, electron

1467

J. Keil, G. Kube, F. Obier, G.K. Sahoo, R. Wanzenberg
DESY, Hamburg, Germany

PETRA III is a third generation synchrotron light source at DESY delivering high brightness photon beams for users at 21 beam lines. It is operated at 6 GeV with a beam current of 100 mA in top-up mode and is in operation for users since 2010. An off-axis injection scheme is used to accumulate beam from the booster synchrotron DESY II in PETRA III. Three fast injection kicker magnets generate a closed orbit bump for one turn to move the stored beam near to the injection septum magnet. Ideally the orbit bump generated by the 10 μs long half-sine pulses of the kickers should be closed. Due to differences in pulse shape as well as timing and amplitude errors of the pulses there is some leakage of the injection bump which disturbs the closed orbit and affects the beam quality during top-up operation. Turn-by-turn data from the beam position monitor (BPM) system of PETRA III have been used to measure the bump leakage for different bucket positions in the filling pattern. The procedure to reduce the injection kicker bump leakage and the achieved improvement will be discussed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPMF084

Export •

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

TUPMK001

Removal of RF-Fingers at the Edges of the Injection Kickers

impedance, resonance, kicker, storage-ring

1485

T.F.G. Günzel, N. Ayala, F.F.B. Fernández, U. Iriso, M. Pont
ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain

The ALBA storage ring injection kickers are equipped with RF-fingers to close a 2.5 mm gap between the ceramic tube and the metallic flange. After two distortion incidents that required the replacement of the fingers, their removal was decided. The decision could be supported by the observation that most of the additional impedance is created above the cut-off frequency of the beam pipe. This was later confirmed by a temperature decrease in that zone after the removal. Furthermore it was checked that the thresholds of the longitudinal coupled bunch instabilities of modes trapped around the resulting open gap are above the maximal applied beam current of 400 mA.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPMK001

Export •

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

TUPMK016

Using Time Evolution of the Bunch Structure to Extract the Muon Momentum Distribution in the Fermilab Muon g-2 Experiment

experiment, positron, storage-ring, bunching

1526

W. Wu, B. Quinn
UMiss, University, Mississippi, USA
J.D. Crnkovic
BNL, Upton, Long Island, New York, USA

Beam dynamics plays an important role in achieving the unprecedented precision on measurement of the muon anomalous magnetic moment in the Fermilab Muon g-2 Experiment. It needs to find the muon momentum distribution in the storage ring in order to evaluate the electric field correction to muon anomalous precession frequency. We will show how to use time evolution of the beam bunch structure to extract the muon momentum distribution by applying a fast rotation analysis on the decay electron signals.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPMK016

Export •

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

TUPML016

High-Intensity Magnetron H⁻ Ion Sources and Injector Development at BNL Linac

operation, rfq, ion-source, linac

1564

A. Zelenski, G. Atoian, T. Lehn, D. Raparia, J. Ritter
BNL, Upton, Long Island, New York, USA

The BNL magnetron-type H⁻ ion source and the injec-tor are being upgraded to higher duty-factor as a part of Linac intensity increase project [1]. The BNL magnetron source presently delivers 110 -120 mA H⁻ ion current with 650 us pulse duration and 7 Hz repetition rate. The pulse duration was increased to 1000 μs by modifications of the gas injector pulsed valve and the use of the new arc-discharge power supply (with the arc-current stabilization circuit) which improved current stability and reduced current noise. The Low Energy Beam Transport (LEBT) lines combine two beams. The first line is the polarized OPPIS (Optically Pumped Polarized H⁻ Ion Source) beam-line and the second is the high-intensity un-polarized beam-line from the magnetron source, which transports beam to the RFQ after the passage of 45 degree bending magnet. The second magnetron source was installed in the straight LEBT section in 2017, in which the polarized OPPIS beam was not planned. In this, optimal for H⁻ beam transport configuration, the beam intensity was increased to 80 mA after the RFQ. The experience of the two sources layout operation (one source in operation the second source in standby) might be useful for facilities with the high downtime cost (like high-energy collider LHC or multi-user facilities like SNS).

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPML016

Export •

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

TUPML055

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

extraction, quadrupole, optics, sextupole

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.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPML055

Export •

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

TUPML060

Three-Dimentional Spiral Beam Injection for a Compact Storage Ring

solenoid, experiment, coupling, electron

1673

H. Iinuma
Ibaraki University, Hitachi, Ibaraki, Japan
M.R. Abdul
Sokendai, Ibaraki, Japan
Y. Fukao, K. Furukawa, H. Hisamatsu, T. Mibe, H. Nakayama, S. Ohsawa, K. Oide, K. Sasaki
KEK, Tsukuba, Japan

Funding: This work is supported by JSPS KAKENHI Grant Numbers JP26287055 and JP 23740216.
A newly developed three-dimensional spiral injection scheme for beam insertion into a compact (medical MRI size) solenoidal storage ring is introduced. This is a one of key R&D items for a new planned muon g-2/EDM experiment at J-PARC, which aims to measure g-2 to a factor 5 better statistical precision and a factor of 100 better sensitivity for the electric dipole moment measurement (EDM) compared to the previous experiments. The new scheme provides a smooth injection utilizing a radial solenoidal fringe field, without causing any error field in the storage volume. Magnetic pulsed kicker will guide and set the beam in the storage field volume. The strongest point of this new scheme is that any source of the electric field is removed in this scheme to perform ideal EDM measurement. We have performed a test bench experimental work to demonstrate a feasibility of this new injection scheme. Instead of the muon beam, we inject electron beam, from an electron-gun, into the solenoid magnet, and detect three-dimensional spiral beam trajectory inside of the storage chamber by CCD camera. We will discuss outline of a new injection scheme and the latest results from the test bench works.
*H. Iinuma et al.,Nuclear Instruments and Methods in Physics Research A, 832, 51-62 (2016)

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPML060

Export •

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

WEXGBE1

Review of Top-up Injection Schemes for Electron Storage Rings

kicker, synchrotron, septum, storage-ring

1745

M. Aiba
PSI, Villigen PSI, Switzerland

Top-up operation, which nowadays is standard for lepton colliders and synchrotron light sources, has been developed over last decades. The accelerator performances have been drastically improved through top-up operation. However, future electron storage rings are designed, aiming at further high performance, to operate with strong nonlinear magnetic fields that may restrict their dynamic aperture. Consequently, the conventional off-axis injection and accumulation may become impossible. New injection schemes have been proposed and under development to overcome the difficulties and limitations expected in these machines. This paper reviews top-up injection schemes, including novel ideas recently proposed.

Slides WEXGBE1 [3.584 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEXGBE1

Export •

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

WEYGBF4

Development of a Solid-State Pulse Generator Driving Kicker Magnets for a Novel Injection System of a Low Emittance Storage Ring

kicker, timing, high-voltage, storage-ring

1804

T. Inagaki, H. Tanaka
RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan
H. Akikawa, K. Sato
Nihon Koshuha Co. Ltd, Yokohama, Japan
K. Fukami, C. Kondo, S. Takano
Japan Synchrotron Radiation Research Institute (JASRI), RIKEN SPring-8 Center, Hyogo, Japan

Funding: Funded by MEXT Japan
A next generation electron storage ring represented by a diffraction-limited light source pursues an extremely low emittance leading to a small dynamic aperture and short beam lifetime. The top-up injection is hence indispensable to keep the stored beam current. The beam orbit fluctuation caused by the injection magnets should seriously obstruct utilization of an electron beam with sharp transverse profile. In order to solve these problems, a novel off-axis in-vacuum beam injection system was proposed. In the system, twin kicker magnets driven by a single solid-state pulsed power supply to launch a linear pi- bump orbit is the key to suppress the horizontal orbit fluctuation down to a level of several microns. Here, a big challenge is to achieve the magnetic field identity of the two kickers within an accuracy of 0.1%. This presentation overviews the proposed injection system and reports the development status focusing on the solid-state pulse generator.

Slides WEYGBF4 [3.062 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEYGBF4

Export •

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

WEPAF007

A Scheme for Asynchronous Operation of the APS-U Booster Synchrotron

booster, storage-ring, extraction, timing

1823

U. Wienands, T.G. Berenc, T. Fors, F. Lenkszus, N. Sereno, G.J. Waldschmidt
ANL, Argonne, Illinois, USA

Funding: Work supported by US DOE
The APS-U 6-GeV MBA storage ring will have 42 pm beam emittance and relatively tight acceptance. This requires limiting the beam emittance out of the Booster synchrotron which is achieved by operating the Booster off-momentum, thus manipulating the damping partitions. However, the much higher charge for the APS-U strongly favors injecting on momentum into the Booster for maximum acceptance. An rf-frequency ramping scheme is proposed to allow injecting on momentum and then moving the beam off momentum. The ramp is adjusted from cycle to cycle to vary the total time taken by the beam from injection to extraction, thus aligning the Booster bunch with any chosen MBA storage ring bucket. The two rf systems will not be locked at any time of the cycle. The proposed scheme is compatible with the existing synchronization of the APS injector cycle to the 60-Hz line voltage which induces a variation in the start time of the acceleration cycle. The scheme removes the need to realign the Booster ring for total path length while optimizing its operation for high charge acceleration. A ferrite tuner is being considered for dynamic tuning of the rf cavities.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAF007

Export •

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

WEPAF010

Fast Glitch Detection of Coupled Bunch Instabilities and Orbit Motions

feedback, vacuum, storage-ring, operation

1829

W.X. Cheng, B. Bacha, K. Ha, Y. Li
BNL, Upton, Long Island, New York, USA

Funding: Work supported by DOE contract No: DE-SC0012704
During high current operation at NSLS-II storage ring, vertical beam size spikes have been noticed. The spikes are believed due to ion instability associates with vacuum activities localized in the ring. A new tool has been developed using gated BPM turn-by-turn (TBT) data to detect beam centroid glitches. When one turn orbit deviates outside the predefined window, a global event will be generated. This allows synchronized data acquisition of TBT beam positions around the ring. Bunch by bunch data is acquired at the same time to analyze the possible coupled bunch instabilities (CBI). Besides CBI mainly due to ion bursts, fast orbit glitches have been captured with the new tool. Sources of the glitches can be identified.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAF010

Export •

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

WEPAF014

Commissioning the Superconducting Magnetic Inflector System for the Muon g-2 Experiment

storage-ring, experiment, MMI, simulation

1844

N.S. Froemming
CENPA, Seattle, Washington, USA
K.E. Badgley, H. Nguyen, D. Stratakis
Fermilab, Batavia, Illinois, USA
J.D. Crnkovic
BNL, Upton, Long Island, New York, USA
L.E. Kelton
UKY, Kentucky, USA
M.J. Syphers
Northern Illinois University, DeKalb, Illinois, USA

The Fermilab muon g-2 experiment aims to measure the muon anomalous magnetic moment with a precision of 140 ppb - a fourfold improvement over the 540 ppb precision obtained in the BNL muon g-2 experiment. Both of these high-precision experiments require an extremely uniform magnetic field in the muon storage ring. A superconducting magnetic inflector system is used to inject beam into the storage ring as close as possible to the design orbit while minimizing disturbances to the storage-region magnetic field. The Fermilab experiment is currently in its first data-taking run, where the Fermilab inflector system is the refurbished BNL inflector system. This discussion reviews the Fermilab inflector system refurbishment and commissioning.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAF014

Export •

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

WEPAF026

Beam Induced Fluorescence Measurements of 100 keV Deuterons in LIPAc Accelerator

electron, detector, plasma, emittance

1877

R. Varela, A. Guirao, L.M. Martínez, J. Mollá, I. Podadera
CIEMAT, Madrid, Spain
T. Akagi, R. Ichimiya, Y. Ikeda, M. Sugimoto
QST, Aomori, Japan
B. Bolzon, N. Chauvin
CEA/IRFU, Gif-sur-Yvette, France
P. Cara
Fusion for Energy, Garching, Germany
H. Dzitko
F4E, Germany
J. Knaster
IFMIF/EVEDA, Rokkasho, Japan

Funding: Work partially supported by the Spanish Ministry of Science and Innovation under project FIS2013-40860-R
The LIPAc accelerator will be a linear CW deuteron accelerator capable of delivering a 9 MeV, 125 mA beam which aims to validate the technology that will be used in the future high power accelerator-driven neutron source, IFMIF. In summer 2017 a campaign of measurements was done during the injector commissioning, in which a Fluorescence Profile Monitor based on an Intensified CID camera (ICID) was used to measure the beam transverse profile at the extraction of the ion source. In this contribution we review the design of the ICID, its performance and discuss the measurements carried out. The performance of ICID monitors for its use in future accelerators will be assessed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAF026

Export •

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

WEPAF054

Online Multi Objective Optimisation at Diamond Light Source

sextupole, controls, lattice, EPICS

1944

M. Apollonio, R. Bartolini, R.T. Fielder, I.P.S. Martin
DLS, Oxfordshire, United Kingdom
R. Bartolini
JAI, Oxford, United Kingdom
G. Henderson
Oxford University, Physics Department, Oxford, Oxon, United Kingdom
J. Rogers
Imperial College of Science and Technology, Department of Physics, London, United Kingdom

At Diamond Light Source we have developed an Optimization Package currently used online to improve the performance of the machine, usually measured in terms of lifetime, injection efficiency or beam disturbance at injection. The tool is flexible in that control variables in order to optimise objectives (or their functions) can be easily specified by means of EPICS process variables (PV), making it suitable for virtually any sort of optimization. At present three different algorithms can be used to perform optimizations in a multi-objective fashion: Multi-Objective Genetic Algorithm (MOGA), Particle Swarm Optimizer (MOPSO) and Simulated Annealing (MOSA). We present a series of tests aimed at characterizing the algorithm as well as improving the performance of the machine itself.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAF054

Export •

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

WEPAF055

Time-Synchronized Beam Diagnostics at SPEAR3

diagnostics, feedback, kicker, timing

1948

Q. Lin, Z.H. Sun
Donghua University, Shanghai, People's Republic of China
P. Boussina, W.J. Corbett, D.J. Martin, J.A. Safranek, K. Tian
SLAC, Menlo Park, California, USA
D. Teytelman
Dimtel, San Jose, USA

The SPEAR3 timing system supplies a 10Hz trigger pulse synchronous with charge injection into the main storage ring. In the past the 10Hz pulse train has been used to study injected charge transients as seen by visible-light synchrotron radiation diagnostics and turn-by-turn BPMs. More recently the 10Hz pulse has been used to synchronize the bunch-by-bunch feedback data acquisition system with other triggered diagnostic systems. The suite of measurement systems can be used to study injected beam dynamics, grow/damp instability transients and drive/damp physics.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAF055

Export •

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

WEPAF072

Transverse Feedback System for the CERN FCC-hh Collider

feedback, damping, kicker, emittance

1997

W. Höfle, J. Komppula, G. Kotzian, K.S.B. Li, D. Valuch
CERN, Geneva, Switzerland

For the future hadron Collider (FCC-hh) being studied at CERN a strong transverse feedback system is required to damp coupled bunch instabilities. This system is also planned to be used for injection damping. Based on the LHC transverse feedback design we derive requirements for power and kick strength for this system for the different options of bunch spacing, 25 ns and 5 ns, and injection energy. Operation at high gain and close to a half integer tune is being considered and constrains the layout and signal processing. Requirements for the pick-up resolution are derived from the need to keep the emittance increase small. The performance is evaluated using numerical simulations based on the headtail code. Future areas of research and development and possible prototype developments are outlined.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAF072

Export •

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

WEPAF078

Machine Learning Applied at the LHC for Beam Loss Pattern Classification

beam-losses, collimation, proton, flattop

2020

G. Valentino
University of Malta, Information and Communication Technology, Msida, Malta
B. Salvachua
CERN, Geneva, Switzerland

Beam losses at the LHC are constantly monitored because they can heavily impact the performance of the machine. One of the highest risks is to quench the LHC superconducting magnets in the presence of losses leading to a long machine downtime in order to recover cryogenic conditions. Smaller losses are more likely to occur and have an impact on the machine performance, reducing the luminosity production or reducing the lifetime of accelerator systems due to radiation effects, such as magnets. Understanding the characteristics of the beam loss, such as the beam and the plane, is crucial in order to correct them. Regularly during the year, dedicated loss map measurements are performed in order to validate the beam halo cleaning of the collimation system. These loss maps have the particular advantage that they are performed in well controlled conditions and can therefore be used by a machine learning algorithm to classify the type of losses during the LHC machine cycle. This study shows the result of the beam loss classification and its retrospective application to beam loss data from the 2017 run.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAF078

Export •

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

WEPAK004

Beam Instrumentation for CRYRING@ESR

instrumentation, rfq, hardware, detector

2084

A. Reiter, C. Andre, H. Bräuning, C. Dorn, P. Forck, R. Haseitl, T. Hoffmann, W. Kaufmann, N. Kotovski, P. Kowina, K. Lang, R. Lonsing, P.B. Miedzik, T. Milosic, A. Petit, H. Reeg, C. Schmidt, M. Schwickert, T. Sieber, R. Singh, G. Vorobjev, B. Walasek-Höhne, M. Witthaus
GSI, Darmstadt, Germany

We present the beam instrumentation of CRYRING@ESR, a low-energy experiment facility at the GSI Helmholtz-Centre for heavy ion research. The 1.44 Tm synchrotron and storage ring, formerly hosted at the Manne Siegbahn laboratory in Stockholm, Sweden, was modified in its configuration and installed behind the existing ESR, the experimental storage ring. As the first machine within the ongoing FAIR project, the facility for antiproton and ion research, it is built on the future timing system and frameworks for data supply and acquisition. Throughout the past year CRYRING was commissioned including its electron cooler with hydrogen beams from the local linear accelerator. Storage, acceleration and cooling have been demonstrated. The contribution provides an overview of the beam instrumentation. The design of the detector systems and their current performance are presented. Emphasis is given to beam position monitors, detectors for intensity measurements, and the ionization profile monitors.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAK004

Export •

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

WEPAK015

Beam Gate Control System for SuperKEKB

controls, operation, hardware, software

2124

H. Kaji, Y. Ohnishi, S. Sasaki, M. Satoh, H. Sugimura
KEK, Ibaraki, Japan
Y. Iitsuka
EJIT, Hitachi, Ibaraki, Japan
T. Kudou
Mitsubishi Electric System & Service Co., Ltd, Tsukuba, Japan

The electron beam pulses of injector linac for the SuperKEKB collider are enabled and disabled by Beam Gate control system. This system controls the delivery of triggers to the electron guns at the injector. Also, the septum and kicker magnets for injection point of main ring are controlled with this Beam Gate to avoid unnecessary operation and to prolong their lifetime. The Beam Gate synchronizes the enabling and disabling operations of these hardware even though they are about 1km distant. Besides, from the phase-2 operation, the kicker and septum magnets for newly constructed damping ring becomes controlled apparatus of this system. We develop the new Beam Gate control system with the Event Timing System network*. The new system improves the unsatisfied performance of Beam Gate in the phase-1 operation and realizes the complicated control for phase-2. The advantages of new system are: the control signal is delivered via Event nettork, so that we do not need to cable new network. The enabling and disabling operations for distant hardware are surely synchronized by the Event Timing System.
* H. Kaji et al., "Construction and Commissioning Event Timing System at SuperKEKB", Proceedings of IPAC14, Dresden, Germany (2014).

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAK015

Export •

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

WEPAK017

Low-level RF System for the SuperKEKB Injector LINAC

linac, booster, controls, positron

2131

T. Matsumoto, M. Akemoto, D.A. Arakawa, H. Katagiri, T. Miura, F. Qiu, Y. Yano
KEK, Ibaraki, Japan
M. Akemoto, T. Miura, F. Qiu
Sokendai, Ibaraki, Japan

The low-level RF (LLRF) system of the KEK injector linac has been upgraded for the SuperKEKB. As a major change, a low-emittance and high-current RF gun was installed to satisfy 40-times higher luminosity at the SuperKEKB. In order to balance the stable RF gun operation and the electron/positron beam acceleration, the phase shifter is developed and the configuration of main drive system in the LLRF system is modified. The present status and future plan of the LLRF system upgraded for the SuperKEKB will be reported.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAK017

Export •

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

WEPAL001

LLRF Control and Master Oscillator System for Damping Ring at SuperKEKB

controls, cavity, LLRF, linac

2137

T. Kobayashi, K. Akai, A. Kabe, K. Nakanishi, M. Nishiwaki, J.-I. Odagiri
KEK, Ibaraki, Japan
H. Deguchi, K. Hayashi, J. Mizuno
Mitsubishi Electric TOKKI Systems, Amagasaki, Hyogo, Japan
K. Hirosawa
Sokendai, Ibaraki, Japan

For SuperKEKB, new low level RF (LLRF) control systems has ben developed and they worked successfully in the first beam commissioning (Phase-1) of SuperKEKB, which was accomplished in 2016. Damping ring (DR) was newly constructed for positron beam injection, in order to make significantly emittance smaller for SuperKEKB. The beam commissioning of DR will be conducted in JFY2017 for the Phase-2 commissioning. Phase-2 is scheduled in the last quater of JFY2017. DR has an RF station, and two cavities (or three cavities in future) are driven by a klystron. New LLRF control system for DR (DR-LLRF) was also developed and installed. RF frequency of DR operation is common with the main storage rings (MR) of SuperKEKB. The good performance of DR-LLRF was demonstrated in test operation, and RF conditioning of the pair of two cavities was successfully completed in June 2017. This paper reports the detail of the performance results of DR-LLRF controls, and also the other some relevant issues in LLRF controls for DR, including the master oscillator system (synchronization with the injection linac), are introduced.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAL001

Export •

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

WEPAL004

The Algorithm Research of DBPM for HEPS

synchrotron, radiation, synchrotron-radiation, collider

2147

F. Liu, J.S. Cao, Y.Y. Du, S.J. Wei
IHEP, People's Republic of China

The High Energy Photon Source (HEPS) is a 6-GeV, low-emittance, 1300m scale new generation photon source to be built in China [1]. As a key component, digital beam positon monitor (DBPM) needs to make the beam slow acquisition's resolution up to 0.1um. Because of the high requirements and large expenses, we designed our own DBPM system. In this paper, I will present the algorithm of our BPM. The algorithm is based on Discrete Fourier Transform (DFT) method and tested in BEPCII with using our own designed hardware. The Turn-by-Turn's resolution tested in BEPCII is 0.62um (STD value, 65080 counts, 1.2432MHz), the fast acquisition's resolution is 0.32um (STD value, 65080 counts, 10kHz), the slow acquisition's resolution is 0.18um (STD value, 65080 counts, 10Hz).

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAL004

Export •

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

WEPAL014

Non-Distructive 2-D Beam Profile Monitor Using Gas Sheet in J-PARC LINAC

linac, electron, vacuum, cavity

2177

J. Kamiya, Y. Hikichi, M. Kinsho, A. Miura, N. Ogiwara
JAEA/J-PARC, Tokai-mura, Japan

We have been developed a beam profile monitor using interaction between the beam and the gas molecules distributed in sheet shape*. Generated luminescence or ions by passing the beam through the gas sheet has the information of cross-section shape of the beam. The gas sheet beam monitor will become a useful tool to measure the profile of high power beams because it has no breakable element such as wires and a 2-D beam profile at a certain position of beam line can be immediately obtained by just injecting the gas. Previously, the development of the gas sheet generator and successful demonstration of the beam profile measurement were reported. This time, we applied a gas sheet monitor to J-PARC LINAC, where the negative hydrogen atoms (H⁻) are accelerated to the energy of 400 MeV in the normal operation. Most challenging factor was the development of the gas sheet monitor system, which generates the enough dense gas sheet to detect the clear image of the beam profile without harmful effect on the ultra-high vacuum in the beam line. We will report the gas sheet beam monitor system for J-PARC LINAC and the results of the first measurement of the beam profile.
* N. Ogiwara, et al., Proceedings of IPAC2016, p.2102.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAL014

Export •

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

WEPAL036

Implementation of CSNS RCS Beam Injection and Extraction Modes in Timing System

extraction, timing, linac, kicker

2247

P. Zhu, M.Y. Huang, D.P. Jin, G. Lei, G.L. Xu, Y.L. Zhang
IHEP, Beijing, People's Republic of China
L. Wang
CSNS, Guangdong Province, People's Republic of China

Funding: Institute of High Energy Physics， Chinese Academy of Sciences, Beijing 100049, China; Dong guan Neutron Science Center, Dong guan 523803, China
Based on the physical design of the accelerator and the demand of the beam research, we designed four RCS beam injection modes and two RCS beam extraction modes, each of which corresponds to a series of specific timing for the accelerator. RCS beam injection and extraction modes are implemented on "VME + customized boards" hardware platform. In this paper, we will introduce the design and implementation of RCS beam injection and extraction modes as well as the RCS timing requirements and implementation in detail.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAL036

Export •

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

WEPAL057

Methods to Detect Error Sources and Their Application at the TPS

photon, kicker, storage-ring, cavity

2305

C.H. Huang, Y.-S. Cheng, P.C. Chiu, K.T. Hsu, K.H. Hu, C.Y. Wu
NSRRC, Hsinchu, Taiwan

For a low-emittance photon light source, beam stability is a very important property to attain a high-quality photon beam. While it is hard to avoid beam perturbations in a storage ring, it is more important to quickly find the source locations and to remove or eliminate the sources as soon as possible. In this report, we develop a method to identify the locations of multiple sources. For a source with a particular frequency, the relative phase between sources can also be obtained. This method has been a useful tool during TPS operation and its methodology and practical applications are described in this report.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAL057

Export •

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

WEPAL058

Beam Loss Studies at the Taiwan Photon Source

radiation, vacuum, scattering, undulator

2309

C.H. Huang, J. Chen, Y.-S. Cheng, K.T. Hsu, K.H. Hu, D. Lee, C.Y. Wu
NSRRC, Hsinchu, Taiwan

PIN-photodiodes and RadFETs are installed in the storage ring of the Taiwan Photon Source (TPS) to study beam loss distributions and mechanisms. In the highest dose area, the radiation comes mainly from hard X-rays produced by synchrotron bending magnets. During beam cleaning and after replacing a vacuum chamber, losses due to inelastic Coulomb scattering occur mostly downstream from bending magnets while elastic scattering causes electrons to get lost mainly after an elliptically polarizing undulator which has a limited vertical aperture. During the injection period, the beam loss pattern can be changed by modifying injection conditions or lattice settings. The beam loss usually happens in the injection section and small-aperture section. The injection efficiency can be improved by minimizing the detected injection loss.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAL058

Export •

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

WEPAL063

A Method to Tune Pulse Magnets' Waveforms

kicker, power-supply, GUI, septum

2320

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

Pulse magnets are used in storage ring injection kickers. The waveform of the the four kickers have strong relation with injection efficiency. A slightly offset of waveform may cause the four kickers mismatched, which would lead to storaged beam loss and decrease injection efficiency. In order to define the peak value and timing of the half-sine waveform which has noises interfering diagnosis, a curve-fitting method was introduced to monitor and fine-tuning the waveform. The waveforms' data are also archived for reference in case of replacing power supplies. By using this method, it helps to retain a consistent injection efficiency after the power supplies maintenance or replacement.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAL063

Export •

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

WEPAL079

Control of Intra-Bunch Vertical Motion in the SPS with GHz Bandwidth Feedback

feedback, controls, damping, kicker

2365

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

Funding: Work supported by the U.S. Department of Energy DE-AC02-76SF00515, US LHC Accelerator Research program, CERN LHC Injector Upgrade Project and the US-Japan Cooperative Program in High Energy Physics.
A GHz bandwidth vertical beam feedback system has been in development at the CERN SPS to explore control of unstable beam motion in single bunch and bunch train configurations. We present measurements and recent studies of stable and unstable motion for intensities up to 2x10¹¹ p/bunch. The system has been operated at 3.2GS/s with 16 samples across a 5 ns RF bucket (4.2 ns 3 σ bunch at injection). Experimental results confirm damping of intra-bunch instabilities in Q20, Q22 and Q26 optics configurations. Instabilities with growth times of 200 turns are well-controlled from injection, consistent with the achievable gains for the 2 installed stripline kickers with 1 kW broadband total power. Studies of the damping achieved with the diagonal FIR controllers and existing system noise floors are highlighted to evaluate benefits of MIMO feedback controllers. The work is motivated by anticipated intensity increases from the LIU and HL-LHC upgrade programs, and has included the development of a new 1 GHz bandwidth slotline kicker structure and associated amplifier system

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAL079

Export •

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

WEPMF020

Pulsed Systems for eRHIC Beam Injection and Extraction

kicker, extraction, storage-ring, electron

2410

W. Zhang, M. Blaskiewicz, A. Hershcovitch, C.J. Liaw, H. Lovelace III, M. Mapes, G.T. McIntyre, J.-L. Mi, C. Montag, C. Pai, V. Ptitsyn, J. Sandberg, N. Tsoupas, J.E. Tuozzolo, G.M. Wang, W.-T. Weng, F.J. Willeke, H. Witte, Q. Wu
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 electron-ion collider eRHIC requires a variety of kickers and septa for injection and extraction of beams throughout the entire collider complex. We plan to use pulsed systems for beam injection and extraction in Electron RCS, Electron Storage Ring, and Hadron ring. In this paper, we describe the pulsed systems required for beam transfer in the eRHIC Ring-Ring Pre-conceptual Design. We will outline the parameter ranges, technology choices, and opportunities for research and development in pulsed power technology.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPMF020

Export •

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

WEPMF075

Performance Measurements and Analysis of Jitter Like Events for the PS Injection Kicker System

kicker, controls, operation, simulation

2549

A. Ferrero Colomo, J.C.C.M. Borburgh, L. Ducimetière, L.M.C. Feliciano, V. Forte, M.A. Fraser, T. Kramer, L. Sermeus
CERN, Geneva, Switzerland

In the framework of the LIU project, several modifications have been made to the CERN PS injection kicker system during the winter stop 2016-2017 (EYETS). Current waveform and beam-based measurements were carried out in 2017 to validate the implemented design changes by observing the magnetic field impact on the beam. During these long-term measurements, increased values for the rise and fall times were observed when compared to single shot observations of the current waveform. An unknown source of jitter-like pre-firing in the main switch has been identified, creating an additional challenge to meet the already tight system rise and fall time specifications. This paper briefly describes the efforts made to fine tune the pulse generator after the EYETS, summarises the optimised configuration and analyses the observed jitter events. A new triggering system design is briefly outlined to address the issue.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPMF075

Export •

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

WEPMF076

First Prototype Inductive Adder for the FCC Injection

kicker, distributed, impedance, high-voltage

2553

D. Woog, M.J. Barnes, A. Ferrero Colomo, J. Holma, T. Kramer
CERN, Geneva, Switzerland

A highly reliable kicker system is required as part of the injection for the FCC. A significant weak point of conventional kicker systems is often the pulse generator, where a Pulse Forming Network/Line (PFN/PFL) is discharged through a thyratron switch to generate the current pulse for the kicker magnet. This design has several disadvantages: in particular the occasional erratic turn-on of the switch which cannot be accepted for the FCC. A potential replacement is the inductive adder (IA) that uses semiconductor switches and distributed capacitors as energy storage. The modular design, low maintenance and high flexibility make the IA a very interesting alternative. In addition, the ability to both turn-on and off the current also permits the replacement of PFN/PFL by the capacitors. A first FCC prototype IA, capable of generating 9 kV and 2.4 kA pulses, has been designed and built at CERN. It will be upgrade to a full-scale prototype (15 kV, 2.4 kA) in 2018. This paper presents measurement results from the 9 kV prototype and outlines the conceptual changes and expected performance of the 15 kV prototype.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPMF076

Export •

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

WEPMF082

Design and Construction of the CERN PS Booster Charge Exchange Injection Chicane Bumpers

vacuum, septum, simulation, linac

2575

B. Balhan, C. Baud, J.C.C.M. Borburgh, M. Hourican
CERN, Geneva, Switzerland

In the framework of the LIU project and the connection from LINAC4 to PS Booster, the 160 MeV H⁻ beam will be injected horizontally into the PSB by means of one charge-exchange injection system for each PSB ring. A set of four outside vacuum pulsed dipole magnets (BSW) creating the required injection bump has been designed and built. The dynamic requirements for the bump ramp down determine, to a large extent, the field homogeneity due to the eddy currents induced in the corrugated Inconel vacuum chamber. Magnetic simulations were performed to determine the field harmonics during bump ramp down, and the results subsequently used for the dynamic tracking of the beam during injection. The mechanical design and construction of the magnets will be briefly outlined, and the article will conclude with the magnetic measurements of the magnets. The magnetic performance of the as built magnets will be compared with the simulations and the influence of the vacuum chambers on the magnetic field will be quantified.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPMF082

Export •

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

WEPMF089

Measurements of Electromagnetic Properties of Ferrites as a Function of Frequency and Temperature

kicker, impedance, coupling, simulation

2592

A. Chmielinska, M.J. Barnes, F. Caspers, B.K. Popovic, C. Vollinger
CERN, Geneva, Switzerland

Fast kicker magnets are used to inject beam into and extract beam out of the CERN accelerator rings. These kickers are often ferrite loaded transmission line type magnets with a rectangular shaped aperture through which the beam passes. The interaction of the beam with the resistive part of the longitudinal beam coupling impedance leads to power dissipation and heating of different elements in the accelerator ring. In particular, power deposition in the kicker magnets can be a limitation: if the temperature of the ferrite yoke exceeds the Curie temperature, the beam will not be properly deflected. In addition, the imaginary portion of the beam coupling impedance contributes to beam instabilities. A good knowledge of electromagnetic properties of materials up to GHz frequency range is essential for a correct impedance evaluation. This paper presents the results of transmission line measurements of complex initial permeability and permittivity for different ferrite types. We present an approach for deriving electromagnetic properties as a function of both frequency and temperature; this information is required for simulating ferrite behaviour under realistic operating conditions.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPMF089

Export •

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

WEPMK001

Preliminary Design of a Cooling System for the LHC Injection Kicker Magnets

kicker, vacuum, operation, impedance

2624

L. Vega Cid, M.J. Barnes, L. Ducimetière, M.T. Moester, V. Vlachodimitropoulos, W.J.M. Weterings
CERN, Geneva, Switzerland
A. Abánades
ETSII UPM, Madrid, Spain

The CERN Large Hadron Collider (LHC) is equipped with two fast pulsed magnet systems (MKIs) that inject particle beams from the injector chain. Future operation for High Luminosity LHC (HL-LHC) with high intensity beams will cause heating of the ferrite yokes of the MKIs beyond their Curie temperature, preventing injection until the yokes cool down. Beam coupling impedance studies show that it is possible to move a substantial portion of the beam induced power deposition from the upstream ferrite yokes, which are the yokes with the highest power deposition, to ferrite rings located at the upstream end of the magnet. Thermal predictions show that this power redistribution, combined with the installation of a cooling system around the rings, will maintain the temperatures of all the yokes and ferrite rings below their Curie point. Since the rings are not pulsed to high voltage, whereas the ferrite yokes are, the installation of a cooling system is feasible around the rings. The proposed design of the cooling system will be tested to ensure good performance before its installation on the MKIs. The details of the simulations and the design process are reported.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPMK001

Export •

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

WEPMK002

Longitudinal Impedance Analysis of an Upgraded LHC Injection Kicker Magnet

impedance, kicker, simulation, vacuum

2628

V. Vlachodimitropoulos, M.J. Barnes, L. Vega Cid, W.J.M. Weterings
CERN, Geneva, Switzerland

Prior to Long Shutdown 1 (LS1) one of the LHC injection kickers (MKIs) occasionally exhibited high temperatures leading to significant turnaround times. After a successful impedance mitigation campaign during LS1, the MKI ferrite yokes have remained below their Curie point and have not limited LHC's availability. However, for HL-LHC operation the MKI yokes are expected to exceed their Curie temperatures after long physics runs. To ensure uninterrupted future HL-LHC operation, a modified beam screen design, relocating some of the heat load to more easily cooled parts, and a suitable cooling system are under development as the current baseline for the HL-LHC upgrade of the MKIs. An upgraded beam screen providing such relocation has been designed, simulated and compared to the existing model. To validate simulations, two longitudinal beam coupling impedance measurement techniques have been used and the results are compared to predictions. The modified beam screen was implemented in an upgraded MKI installed in the LHC during the Year End Technical Stop (YETS) 2017/18.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPMK002

Export •

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

WEPMK003

An Upgraded LHC Injection Kicker Magnet

kicker, vacuum, electron, impedance

2632

M.J. Barnes, C. Bracco, G. Bregliozzi, A. Chmielinska, L. Ducimetière, B. Goddard, T. Kramer, H. Neupert, L. Vega Cid, V. Vlachodimitropoulos, W.J.M. Weterings, C. Yin Vallgren
CERN, Geneva, Switzerland
A. Chmielinska
EPFL, Lausanne, Switzerland

Funding: Work supported by the HL-LHC project.
An upgrade of the LHC injection kickers is necessary for HL-LHC to avoid excessive beam induced heating of these magnets: the intensity of the HL-LHC beam will be twice that of LHC. In addition, in the event that it is necessary to exchange an injection kicker magnet, the newly installed kicker magnet would limit HL-LHC operation for a few hundred hours due to dynamic vacuum activity. Extensive studies have been carried out to identify practical solutions to these problems: these include redistributing a significant portion of the beam induced power deposition to ferrite parts of the kicker magnet which are not at pulsed high voltage and water cooling of these parts. Furthermore a surface coating, to mitigate dynamic vacuum activity, has been selected. The results of these studies, except for water cooling, have been implemented on an upgraded LHC injection kicker magnet: this magnet was installed in the LHC during the 2017-18 Year End Technical Stop. This paper presents the upgrades, including some test and measurement results.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPMK003

Export •

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

WEPMK005

Preliminary Results from Validation Measurements of the Longitudinal Power Deposition Model for the LHC Injection Kicker Magnet

impedance, kicker, coupling, operation

2636

V. Vlachodimitropoulos, M.J. Barnes, A. Chmielinska
CERN, Geneva, Switzerland
A. Chmielinska
EPFL, Lausanne, Switzerland

During Run 1 of the LHC, one of the injection kicker magnets (MKIs) exhibited an excessively high ferrite temperature, caused by coupling of the high intensity beam to the real impedance of the magnet. Beam-screen upgrades, implemented during Long Shutdown 1 (LS1), have been very effective in reducing beam coupling impedance and since then the MKIs have not limited LHC's availability. However, temperature measurements during operation have shown that one end of the MKI's ferrite yoke is consistently hotter than the other. Detailed simulation models and data post-processing algorithms have been developed to understand and mitigate the observed behaviour. In the present paper, the model used to obtain the power loss distribution along the magnet is presented. The model is subsequently applied to two MKI design configurations under study: (i) the one currently in operation and (ii) an upgraded magnet that was installed in the LHC tunnel during the Year End Technical Stop (YETS) 2017/18. In order to validate the expected behaviour a novel measurement technique was developed, applied in both configurations and compared to predictions. The results obtained are reported and conclusions regarding the effectiveness of the design are drawn.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPMK005

Export •

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

WEPML029

Vacuum System of the HESR at FAIR, Status of Tests, Layout and Manufacturing

vacuum, dipole, kicker, controls

2748

F.M. Esser, N.B. Bongers, J. Böker, P. Chaumet, R. Gebel, R. Greven, S. Hamzic, H. Jagdfeld, F. Klehr, B. Laatsch, G. Langenberg, D. Marschall, A. Mauel, G. Natour, D. Prasuhn, L. Reifferscheidt, M. Schmitt, L. Semke, R. Tölle
FZJ, Jülich, Germany

The Research Center Jülich is leading a consortium being responsible for the design and manufacturing of the High-Energy Storage Ring (HESR) which is part of the FAIR project in Darmstadt, Germany. The HESR is designed for antiprotons within a momentum range of 1.5-15 GeV/c but can also be used for heavy ion experiments. Therefore the vacuum quality is expected to be 10^-11 mbar or better which is a great challenge on the overall vacuum layout as well as on the surface quality of the chambers and beam tubes. Whereas all bent dipole chambers are installed, the manufacturing of the pumping bodies with integrated RF meshes as well as several diagnostic chambers are in the focus of investigation. To validate the intended pumping concept of both the bake-out arc sections and the non-bakable straight sections, final tests at the operational test benches are planned. In parallel, the purchasing of valves and first pumps will be prepared. The actual layout of the HESR vacuum system and its components will be presented as well as the progress of manufacturing of several vacuum chambers. The latest experimental test results will be presented also.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPML029

Export •

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

WEPML036

Truncated Cosine Theta Magnet and the Applications

septum, extraction, collider, heavy-ion

2772

K. Sugita, E.S. Fischer, P.J. Spiller
GSI, Darmstadt, Germany

Typically septum magnets are designed with a combination of a C-shape iron yoke and a copper cable. Due to leakage of a magnetic field at a circulating beam passing through a saturated iron area, high field septum magnets with this concept is not feasible. Thus, this conventional design approach is limited magnetic field strength below 2 Tesla. For high energy machines, like SIS300 at FAIR or FCC at CERN, high field septum magnets are required to shorten the injection and extraction branch lines. Recently superconducting magnets, which enable to reduce the size of a building, are being introduced to medical accelerators. However, even if bending magnets are replaced by high field magnets, long straight sections, which is partly composed by a conventional septum magnet, remain. By introducing high field septum magnets, more compact accelerator can be designed. To get over the limitation of 2 Tesla, a novel concept of a septum magnet generating high magnetic field has been developed and design studies are ongoing. By using superconducting technology, a septum magnet can be designed to generate more than 2 Tesla. We present the concept and various application for the accelerators.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPML036

Export •

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

WEPML060

Yb/Nd Doped Hybrid Solid Laser of RF Gun and Beam Commissioning for Phase-II of SuperKEKB

laser, gun, electron, MMI

2836

R. Zhang, T. Natsui, Y. Ogawa, M. Yoshida, X. Zhou
KEK, Ibaraki, Japan

For SuperKEKB project schedule of the phase-II, low emittance 1 nC electron beams were required with good stability and reliability at end of the linac. In the injector linac, several instruments have been installed. An Nd/Yb hybrid laser system is development with two beam lines light source. The both side of quasi-traveling wave side coupled cavity S-band RF gun were injected by the two sub μJ UV picosecond laser pulses at same times. And beam commissioning with the RF gun is in progress.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPML060

Export •

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

WEPML069

Fast Kicker and Pulser R&D for the HEPS on-Axis Injection System

kicker, impedance, vacuum, simulation

2846

H. Shi, J. Chen, Z. Duan, L. Huo, P. Liu, X.L. Shi, G. Wang, L. Wang, N. Wang
IHEP, Beijing, People's Republic of China

The HEPS plans to adopt on-axis injection scheme because the dynamic aperture of machine is not large enough for off-axis injection for its baseline 7BA lattice design. A sets of super fast kicker and pulser of ±15kV amplitude, 15ns pulse bottom width are needed for bunch spacing of 10ns to minimize perturbation on adjacent bunches. To achieve these requirement, a multifaceted R&D program including the strip-line kicker and HV pulser, was initiated last 2 years. So far, the prototype development of a 750mm long strip-line kicker and a DSRD pulser was completed and the preliminary test results show they can meet the baseline requirement of the HEPS.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPML069

Export •

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

THXGBD3

Status of the ESRF-Extremely Brilliant Source Project

SRF, vacuum, operation, dipole

2882

J.-L. Revol, C. Benabderrahmane, P. Berkvens, J.C. Biasci, J-F. B. Bouteille, T. Brochard, N. Carmignani, J.M. Chaize, J. Chavanne, F. Cianciosi, A. D'Elia, R.D. Dimper, M. Dubrulle, D. Einfeld, F. Ewald, L. Eybert, G. Gautier, L. Goirand, L. Hardy, J. Jacob, B. Joly, M.L. Langlois, G. Le Bec, I. Leconte, S.M. Liuzzo, C. Maccarrone, T.R. Mairs, T. Marchial, H.P. Marques, D. Martin, J.M. Mercier, A. Meunier, M. Morati, J. Pasquaud, T.P. Perron, E. Plouviez, E. Rabeuf, P. Raimondi, P. Renaud, B. Roche, K.B. Scheidt, V. Serrière, P. Van Vaerenbergh, R. Versteegen, S.M. White
ESRF, Grenoble, France

The ESRF - the European Synchrotron Radiation Facility - is a user facility in Grenoble, France, and the source of intense high-energy (6 GeV) X-rays. In 2019, the existing storage ring will be removed and a new lattice will be installed in its place, dramatically reducing the equilibrium horizontal emittance. This 'fourth-generation' synchrotron will produce an X-ray beam 100 times more brilliant and coherent than the ESRF source today. The Extremely Brilliant Source (EBS) project was launched in 2015 and is now well underway, on track for its scheduled completion in 2020. The design is completed, the procurement in full swing, the assembly has started, and critical installation activities are being prepared. The current status, three years into the project, will be revealed, along with the expected performance of the accelerator and the technical challenges involved. This paper will focus on the implementation of the project.

Slides THXGBD3 [13.547 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THXGBD3

Export •

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

THXGBD4

Sirius Light Source Status Report

storage-ring, kicker, booster, MMI

2886

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

Sirius is a Synchrotron Light Source Facility based on a 4th generation 3 GeV low emittance electron storage ring that is under construction in Campinas, Brazil. Presently the main tunnel for the accelerators is ready to start installations. The Linac tunnel was delivered earlier and the 150 MeV Linac from SINAP is almost ready to start commissioning early May. Commissioning of the storage ring is expected to start by the end of this year (2018). In this paper we briefly review the overall project parameters and design concepts and focus on highlights from the main subsystems.

Slides THXGBD4 [28.400 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THXGBD4

Export •

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

THYGBD1

FCC: Colliders at the Energy Frontier

collider, luminosity, hadron, cavity

2908

M. Benedikt, F. Zimmermann
CERN, Geneva, Switzerland

The international Future Circular Collider study, launched in 2014, is finalizing a multi-volume conceptual design report. The FCC develops high-energy circular collider options based on a new 100 km tunnel. Long-term goal is a 100 TeV proton-proton collider (FCC-hh). The study also includes a high-luminosity electron-positron collider (FCC-ee), and it also examines lepton-hadron scenarios (FCC-he). Civil engineering and technical infrastructure studies were carried out. Global programs advance the development of high-field superconducting magnet technology based on Nb3Sn, the optimization of a suitable large superconducting RF system, and schemes for synchrotron radiation handling. In addition, the FCC study includes the design of the HE-LHC, housed in the LHC tunnel, and based on the same high-field magnet technology as the FCC-hh. The FCC study further includes an elaboration of the physics cases, including for heavy-ion collisions, and detector concepts, as well as staging and implementation scenarios. The FCC collaboration has grown to more than 120 institutes from 30 countries around the world. This invited talk summarizes the study achievements and the final designs.

Slides THYGBD1 [12.503 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THYGBD1

Export •

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

THPAF012

The Influence of Chromaticity on Transverse Single-Bunch Instability in the Booster of HEPS

simulation, booster, damping, radiation

2968

H.S. Xu, N. Wang
IHEP, Beijing, People's Republic of China

The study of the transverse single-bunch instability has been carried out for the HEPS booster to double check whether the required single-bunch charge can be achieved. The chromaticity has been varied in our study to see how the threshold changes accordingly. Usually, the slightly positive chromaticity is expected for stabilizing the beam. However, our simulations show that the single-bunch threshold current drops significantly when the chromaticity becomes non-zero. We present the simulation methods and results in details in this paper. The analysis of the simulation results is also presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAF012

Export •

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

THPAF014

Studies of the Single-Bunch Instabilities in the Booster of HEPS

booster, impedance, storage-ring, lattice

2971

H.S. Xu, Z. Duan, J.L. Li, Y.M. Peng, S.K. Tian, N. Wang
IHEP, Beijing, People's Republic of China

High Energy Photon Source (HEPS), which is proposed in China, is an ultra-low emittance storage ring based synchrotron light source. Because of the requirement of the relatively high single-bunch charge, the booster may suffer from the single-bunch instabilities. A preliminary impedance model has been developed for the studies of collective instabilities in the booster. Based on this impedance model, the longitudinal and transverse single-bunch instabilities have been studied.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAF014

Export •

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

THPAF028

Multi-Objectives Genetic Algorithms (MOGA) Optimization of PETRA IV Scenarios

lattice, sextupole, SRF, dynamic-aperture

3015

X.N. Gavaldà, J. Keil, R. Wanzenberg
DESY, Hamburg, Germany

This paper reports the application of Multi-Objective Genetic Algorithms (MOGA) to optimize the linear and nonlinear beam dynamics of the different PETRA IV scenarios to transform PETRA III storage ring in a diffracted limited one. As it is well known, the dynamic aperture and momentum acceptance of these kinds of lattices are dramatically reduced due to the increase of the sextupoles strengths to compensate its strong focusing. The reduction of the dynamic aperture jeopardizes the current off-axis injection system and lower beam lifetimes increase the beam instabilities and the radiation safety concerns of the storage ring. MOGA searches the best settings of quadrupoles and sextupoles in a multi-dimensional parameter space taking into account the dynamic properties and the natural emittance as objectives at the level of ten picometers. The lattices studied are the so-called 'Twist lattice' based in a phase space exchange lattice, a solution based in the ESRF-Hybrid Multi-bend Achromat (HMA) design and finally the 'double 'I' lattice combining a non-interleaved sextupoles cell with an ESRF-HMA cell.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAF028

Export •

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

THPAF030

PETRA III Storage Ring Performance Improvement Based on Multi-Objective Genetic Algorithms (MOGA)

storage-ring, operation, multipole, dynamic-aperture

3018

X.N. Gavaldà, J. Keil, G.K. Sahoo, R. Wanzenberg
DESY, Hamburg, Germany

The performance of the 3th generation light sources relies on the beam lifetime and the injection efficiency, both related with the beam dynamic properties of the storage ring as momentum acceptance and dynamic aperture, respectively. High values of beam lifetime and injection efficiency are desirable to reduce the storage ring instabilities during injection, the radiation losses and the energy consumption of the facility. This paper reports the first application of Multi-Objective Genetic Algorithms (MOGA) to optimize the linear and non-linear beam dynamics of PETRA III storage ring. Genetic algorithms are a heuristic search that mimics the process of natural evolution to optimize problems with a high level of complexity, as in the case of PETRA III storage ring composed by hundreds of magnets. This computational method uses hundreds of CPUs. MOGA is used to maximize the dynamic aperture and the momentum acceptance finding new combinations of quadrupole and sextupole settings in a multi-dimensional parameter space maintaining the solutions in the level of ten picometers.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAF030

Export •

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

THPAF032

Simulation Study of an RF Injector for the LWFA Configuration at EuPRAXIA

linac, plasma, emittance, simulation

3025

J. Zhu, R.W. Aßmann, A. Ferran Pousa, B. Marchetti, P.A. Walker
DESY, Hamburg, Germany

The Horizon 2020 Project EuPRAXIA (EuropeanPlasma Research Accelerator with eXcellence In Applications) aims at producing a design report of a highly compact and cost-effective European facility with multi-GeV electron beams using a plasma accelerator. LWFA with external injection from an RF accelerator is one of the most promising configurations. In order to achieve the goal parameters for the 5 GeV, 30 pC electron beam at the entrance of the undulator, a high-quality electron beam with bunch length of less than 10 fs (FWHM) and matched beta functions (~1 mm) at the plasma entrance is required. In addition, from the compactness point of view, the injection energy is desired to be as low as possible. A hybrid compression scheme is considered in this paper and a detailed start-to-end simulation is presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAF032

Export •

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

THPAF054

Characterization of Losses and Emittance Growth for Ion Beams on the SPS Injection Plateau

emittance, resonance, space-charge, scattering

3091

Á. Saá Hernández, F. Antoniou, H. Bartosik, A. Huschauer
CERN, Geneva, Switzerland

Losses and transverse emittance growth in the Super Protron Synchrotron (SPS) impose presently the main performance limitation on the Large Hadron Collider (LHC) ion injector chain. In this paper we present the measurements performed in 2016 with Pb⁸²⁺ ions and the analysis to characterize the observations of beam degradation during the long injection plateau. Residual gas scattering, intrabeam scattering (IBS) and resonance excitation have been studied.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAF054

Export •

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

THPAF077

Ion-optical Measurements at CRYRING@ESR during Commissioning

MMI, acceleration, simulation, closed-orbit

3161

O. Geithner, Z. Andelkovic, M. Bai, A. Bräuning-Demian, V. Chetvertkova, O. Chorniy, C. Dimopoulou, W. Geithner, O.E. Gorda, F. Herfurth, M. Lestinsky, S.A. Litvinov, S. Reimann, A. Reiter, M. Sapinski, R. Singh, T. Stöhlker, G. Vorobjev, U. Weinrich
GSI, Darmstadt, Germany
A. Källberg
Stockholm University, Stockholm, Sweden

CRYRING@ESR is a heavy ion storage ring, which can cool and decelerate highly charged ions down to a few 100 keV/u. It has been relocated from Sweden to GSI, downstream of the experimental storage ring (ESR), within the FAIR project. The ring will be used as a test facility for FAIR technologies as well as for physics experiments with slow exotic ion beams for several FAIR collaborations: SPARC, BioMat, FLAIR and NUSTAR. CRYRING@ESR is in its commissioning phase since summer 2016. Several ion-optical measurements such as tunes, tune diagram, dispersion, chromaticity and orbit response matrix were performed at the ring. The measurements will be used for several purposes such as improvement of the theoretical model, closed orbit control and correction of unacceptable misalignments, calibration coefficients and field errors.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAF077

Export •

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

THPAK002

Updated Model of the Resistive Wall Impedance for the Main Ring of J-PARC

impedance, space-charge, kicker, hadron

3204

B. Yee-Rendón, Y.H. Chin, H. Kuboki, T. Toyama
KEK, Ibaraki, Japan
M. Schenk
CERN, Geneva, Switzerland

The resistive wall impedance is one of the major contributors of the impedance in the Main Ring of J-PARC. The present model assumes round chambers of stainless steel with perfect magnet boundary conditions for its surroundings. This work presents the model of the resistive wall impedances taking into account the different chamber geometries of Main Ring, the materials and more realistic surroundings. The models were benchmarked with measurements of the coherent tune shift of the Main Ring of J-PARC. The simulation of beam instabilities is a helpful tool to evaluate potential threats against the machine protection of the high intensity beams.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAK002

Export •

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

THPAK008

Space Charge and Microbunching Studies for the Injection Arc of MESA

space-charge, bunching, simulation, lattice

3221

A. Khan, O. Boine-Frankenheim
Institut Theorie Elektromagnetischer Felder, TU Darmstadt, Darmstadt, Germany
C.P. Stoll
IKP, Mainz, Germany

For intense electron bunches traversing through bends, as for example the recirculation arcs of an ERL, space charge (SC) may result in beam phase space deterioration. SC modifies the electron transverse dynamics in dispersive regions along the beam line and causes emittance growth for mismatched beams or for specific phase advances. On the other hand, longitudinal space charge together with dispersion can lead to the microbunching instability. The present study focuses on the 180° low energy (5 MeV) injection arc lattice for the multi-turn Mainz Energy-recovering Superconducting Accelerator (MESA), which should deliver a CW beam at 10⁵ MeV for physics experiments with an internal target. We will discuss matching conditions with space charge together with the estimated microbunching gain for the arc. The implication for the ERL operation will be outlined, using 3D envelope and tracking simulations.
Supported by the DFG through GRK 2128

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAK008

Export •

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

THPAK015

Impedance and Heat Load Analysis of the Stripline Kicker in HEPS

kicker, impedance, simulation, coupling

3234

N. Wang, J. Chen, Z. Duan, H. Shi, S.K. Tian, L. Wang, H.S. Xu
IHEP, Beijing, People's Republic of China

In the High Energy Photon Source (HEPS), strip-line kickers are adopted for beam injection and extraction. Beam coupling impedance contribution from the strip-line kicker is calculated. Detailed studies on the heat load dissipation have been performed. The peak electric field on the blade and the induced voltage on the feedthroughs due to the beam passage are also calculated.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAK015

Export •

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

THPAK020

Optics Model and Measurements of the DAΦNE Transfer Lines

operation, optics, dipole, positron

3249

O.R. Blanco-García, A. De Santis, G. Di Pirro, C. Milardi, D. Pellegrini, A. Stecchi, A. Stella
INFN/LNF, Frascati (Roma), Italy

The different components of the DAΦNE accelerator complex: LINAC, Damping Ring and two colliding rings are connected by a composite system of Transfer Lines which, thanks to adaptive configurations, are able to transport electron and positron beams at 510~MeV. Recently, thanks to the introduction of new diagnostics tools, the optics model of the DAΦNE Transfer Lines has been improved and succesfully used to make the collider operations more efficient. The measurements done by using the new tools and their impact on the optics model optimization process are presented and discussed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAK020

Export •

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

THPAK067

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

solenoid, kicker, simulation, quadrupole

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.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAK067

Export •

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

THPAK092

Analysis on the Mechanical Effects Induced by Beam Impedance Heating on the HL-LHC Target Dump Injection Segmented (TDIS) Absorber

impedance, simulation, HOM, shielding

3448

L. Teofili, M. Migliorati
Sapienza University of Rome, Rome, Italy
M. Calviani, D. Carbajo Perez, S.S. Gilardoni, F. Giordano, I. Lamas Garcia, G. Mazzacano, A. Perillo-Marcone
CERN, Geneva, Switzerland

The High Luminosity Large Hadron Collider (HL-LHC) Project at CERN calls for increasing beam brightness and intensity. In such a scenario, critical accelerator devices need to be redesigned and rebuilt. Impedance is among the design drivers, since its thermo-mechanical effects could lead to premature device failures. In this context, the current work reports the results of a multiphysics study to assess the electromagnetic and thermo-mechanical behaviour of the Target Dump Injection Segmented (TDIS). It first discusses the outcomes of the impedance analysis performed to characterise the resistive wall and the high order resonant modes (HOMs) trapped in the TDIS structures. Then, their RF-heating effects and the related temperature distribution are considered. Finally, mechanical stresses induced by thermal gradients are studied in order to give a final validation on the design quality.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAK092

Export •

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

THPAK093

A Multi-Physics Approach to Simulate the RF Heating 3D Power Map Induced by the Proton Beam in a Beam Intercepting Device

impedance, HOM, simulation, proton

3452

L. Teofili, M. Migliorati
Sapienza University of Rome, Rome, Italy
D. Carbajo Perez, F. Giordano, I. Lamas Garcia, G. Mazzacano
CERN, Geneva, Switzerland

The project High Luminosity Large Hadron Collider (HL- LHC) calls for a streaking beam intensity and brightness in the LHC machine. In such a scenario, beam-environment electromagnetic interactions are a crucial topic: they could lead to uneven power deposition in machine equipment. The resulting irregular temperature distribution would gener- ates local thermal gradients, this would create mechanical stresses which could lead to cracks and premature failure of accelerator devices. This work presents a method to study this phenomenon by means of coupled electro-thermo- mechanical simulations. Further, examples of applications on real HL-LHC devices is also discussed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAK093

Export •

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

THPAK111

Envelope Calculations on the Ion Beam Injection and Extraction of CANREB EBIS

electron, simulation, extraction, TRIUMF

3496

M.H. Pereira-Wilson
UW/Physics, Waterloo, Ontario, Canada
R.A. Baartman, S. Saminathan
TRIUMF, Vancouver, Canada

An electron beam ion source (EBIS) is being developed as a charge state breeder for the production of highly charged ions in the CANREB (CANadian Rare isotope facility with Electron Beam ion source) project at TRIUMF. The multiple tunable electrodes of the EBIS, coupled with the necessity of directing both an electron beam and an ion beam of varying charge, impose a challenging task for the optimization of the beam optics. With this in mind, beam envelope simulations have been performed to determine the acceptance of the EBIS and the emittance of the extracted ion beam. The electric field of the different EBIS electrodes were modelled using finite element analysis software and the envelope simulations were executed using beam envelope code TRANSOPTR. Preliminary results show envelope calculation as a viable candidate for tuning the injection and extraction optics of the EBIS.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAK111

Export •

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

THPAK126

Revised Optics Design for the JLEIC Ion Booster

booster, lattice, sextupole, betatron

3537

E.W. Nissen, T. Satogata
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.
We outline the recently redesigned booster for the pro-posed Jefferson Lab Electron Ion Collider (JLEIC). This booster will inject protons (or ions of equivalent rigidity) at 280 MeV and accelerate them to 8 GeV kinetic energy. To avoid transition crossing, the booster uses flexible momentum compaction (FMC) lattices to raise the transi-tion gamma above the reach of the machine. We also include several families of sextupoles to simultaneously control the chromaticities, and nonlinear dispersions that were excited by the FMC cells.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAK126

Export •

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

THPAL008

A RFQ Cooler Development

rfq, ion-source, emittance, quadrupole

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.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAL008

Export •

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

THPAL042

Injection Locked 1497 MHz Magnetron

superconducting-cavity, site, cavity, medical-accelerators

3736

M.L. Neubauer, A. Dudas, S.A. Kahn
Muons, Inc, Illinois, USA
R.A. Rimmer, H. Wang
JLab, Newport News, Virginia, USA

A novel injection-locked 1497 MHz 13 kW AM magnetron design is presented. The anode design to minimized eddy currents due to the changing magnetic field is presented. Thermal calculations of two design options are also presented. An extra degree of freedom in the anode construction is made possible by the fact that the magnetron is injection locked. This fact presents some additional design details that can be utilized in the cooling network for the magnetron anode.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAL042

Export •

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

THPAL046

Energy-Savings for the TPS Booster RF System at the NSRRC in Taiwan

controls, booster, timing, storage-ring

3748

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

In this paper, we discuss an energy-savings control sys-tem for the Taiwan Photon Source (TPS) booster RF sys-tem. During top-up storage ring operation, a timing con-trol is activated to reduce the booster RF transmitter en-ergy consumption when no injection is required. When-ever injection into the TPS storage ring is needed, the booster RF transmitter is immediately adjusted to operat-ing conditions. This timing-control system will save an energy of 380, 000 kWh annually.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAL046

Export •

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

THPAL078

In-Vacuum Lambertson Septum for SPEAR3 Low Emittance Injection

septum, simulation, vacuum, storage-ring

3831

M.A.G. Johansson, J. Langton, J.A. Safranek
SLAC, Menlo Park, California, USA
S.C. Gottschalk
STI Magnetics LLC, Woodinville, USA

Funding: Work supported by DOE Contract No. DE-AC02-76SF00515
A new in-vacuum Lambertson septum magnet is being designed for the SPEAR3 storage ring, intended to replace the existing septum to allow injection into a new lower emittance operation mode for SPEAR3. The new septum design is constrained to fit in the same length and have the same bend angle as the existing injection septum, so as to minimize changes to surrounding storage ring and transfer line components, while also meeting stringent requirements on the stored beam leakage field. This has led to a design using Vanadium Permendur alloy for the septum pole pieces, with shaping of the inner profile of the stored beam channel to minimize the leakage fields indicated in 2D and 3D magnetic simulations.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAL078

Export •

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

THPAL098

Pumping Properties of Single Metal Zirconium Non-Evaporable Getter Coating

vacuum, target, site, experiment

3869

Sirvinskaite, R. Sirvinskaite, M.D. Cropper, M.D. Cropper
Loughborough University, Loughborough, Leicestershire, United Kingdom
A.N. Hannah, O.B. Malyshev, R. Valizadeh
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
O.B. Malyshev, R. Valizadeh
Cockcroft Institute, Warrington, Cheshire, United Kingdom

Non-evaporable getter (NEG) coating has been used for years in many particle accelerator facilities due to its evenly distributed pumping speed, low thermal outgassing, and low photon and electron stimulated desorption yields. We have previously demonstrated that quaternary Ti-Zr-Hf-V coating deposited from an alloy wire has the lowest desorption yields, the highest sticking probability and sorption capacity. In this work, we explore the single element targets which are widely available and can be produced in a form of a wire that is easy to apply for a uniform coating of various shapes of vacuum chamber. Single metal Zr coatings have been tested to find a more efficient and cheaper way of producing the NEG-coated vacuum chambers. Two samples coated with Zr of dense and columnar structure were analysed and results of the pumping properties are reported. The results show that pure Zr coating could be an economic solution, despite not being as effective as can be achieved with quaternary NEG film. It shows that columnar Zr coating can be activated and reaches full pumping capacity at 160°C. This is close to the activation temperature of Ti-Zr-Hf-V and lower than that for the widely used ternary Ti-Zr-V alloy.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAL098

Export •

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

THPAL145

Magnetron R&D toward the Amplitude Modulation Control for SRF Accelerator

controls, cavity, simulation, SRF

3986

R.A. Rimmer, T. E. Plawski, H. Wang
JLab, Newport News, Virginia, USA
A. Dudas, S.A. Kahn, M.L. Neubauer
Muons, Inc, Illinois, USA

Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177 and SBIR grant DE-SC0013203
The scheme of using a high efficiency magnetron to drive a superconducting radio frequency (SRF) accelerator cavity needs not only the injection phase locking but also the amplitude modulation to compensate the cavity's microphomics caused cavity voltage change and the beam loading variation. To be able to do a fast and efficient modulation, the magnetron's magnetic field has to be trimmed by an external coil to compensate the frequency pushing effect due to the anode current change [1]. A low eddy current magnetron body has been designed and built [2]. This paper will present the analytical prediction, simulation and experimental results on the 2.45 GHz magnetron test stand with the modulation frequency up to 1 kHz. In addition, the progresses on the injection lock to a copper cavity, new 1497 MHz magnetron prototype, 13 kW high power magnetron test stand development and newly built low level RF (LLRF) controller for the amplitude modulation will be reported.
[1] M. Neubauer et al, THPIK123, Proceedings of IPAC 2017, Copenhagen, Denmark
[2] S. A. Kahn et al, THPIK121, Proceedings of IPAC 2017, Copenhagen, Denmark

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAL145

Export •

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

THPMF002

Studies for Injection with a Pulsed Multipole Kicker at ALBA

kicker, storage-ring, lattice, octupole

4030

G. Benedetti, U. Iriso, M. Pont, D. Ramos Santesmases
ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
E. Ahmadi
ILSF, Tehran, Iran

Injection into the ALBA storage ring presently uses a conventional local injection bump with four dipole kickers. However, following the promising results of the first tests with single multipole kicker injection at other light sources, studies to implement this new injection scheme have been started for ALBA. Two possible designs for the kicker have been considered: a pure octupole and a non-linear magnet similar to the BESSY type. A comparison between the expected performances of the two kicker designs has been carried out in terms of injection efficiency and transparency for the users. This paper summarises the beam dynamics results from multi-particle tracking simulations and the proposed kicker magnet design.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMF002

Export •

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

THPMF008

Conceptual Design of an Accumulator Ring for the Diamond II Upgrade

emittance, storage-ring, lattice, dynamic-aperture

4046

I.P.S. Martin, R. Bartolini
DLS, Oxfordshire, United Kingdom
R. Bartolini
JAI, Oxford, United Kingdom

Diamond Light Source is in the process of reviewing several lattice options for a potential storage ring upgrade. As part of these studies, it has become clear that a substantial reduction in emittance can be achieved by adopting an on-axis injection scheme, thereby relaxing the constraints on the dynamic aperture. In order to achieve the necessary injected bunch properties for this to be viable, a new accumulator ring would be needed. In this paper we review the requirements placed on the accumulator ring design, describe the lattice development process and analyse the performance of the initial, conceptual design.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMF008

Export •

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

THPMF009

Lattice Options for DIAMOND-II

lattice, emittance, sextupole, linear-dynamics

4050

B. Singh, R. Bartolini, J. Bengtsson, H. Ghasem
DLS, Oxfordshire, United Kingdom
R. Bartolini
JAI, Oxford, United Kingdom
A. Streun
PSI, Villigen PSI, Switzerland

Funding: Diamond Light Source Ltd
Generalized MBA (Multi-Bend-Achromat) Chasman-Green type lattices, with a low-dispersion mid-straight, have been studied and refined by pursuing a generalized Higher Order Achromat to control the non-linear dynamics to obtain a robust design. New candidate lattice have been produced aiming for a horizontal emittance of 150 pm×rad for off-axis injection and 75 pm×rad for on-axis, the latter making use of reverse bends. The results of these studies and evaluations have been summarized in this paper.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMF009

Export •

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

THPMF015

Lifetime and Beam Losses Studies of Partially Strip Ions in the SPS (129Xe³⁹⁺)

vacuum, factory, beam-losses, electron

4070

S. Hirlaender, R. Alemany-Fernández, H. Bartosik, N. Biancacci, T. Bohl, S. Cettour Cave, K. Cornelis, B. Goddard, V. Kain, M.W. Krasny, M. Lamont, D. Manglunki, G. Papotti, M. Schaumann, F. Zimmermann
CERN, Geneva, Switzerland
K. Kroeger
FSU Jena, Jena, Germany
V.P. Shevelko
LPI RAS, Moscow, Russia
T. Stöhlker, G. Weber
IOQ, Jena, Germany

The CERN multipurpose Gamma Factory proposal relies on using Partially Stripped Ion (PSI) beams, instead of electron beams, as the drivers of its light source. If such beams could be successfully stored in the LHC ring, fluxes of the order of 10¹⁷ photons/s, in the gamma-ray energy domain between 1 MeV and 400 MeV could be achieved. This energy domain is out of reach for the FEL-based light sources as long as the multi TeV electron beams are not available. The CERN Gamma Factory proposal has the potential of increasing by 7 orders of magnitude the intensity limits of the present Inverse Compton Scattering sources. In 2017 the CERN accelerator complex demonstrated its flexibility by producing a new, xenon, ion beam. The Gamma Factory study group, based on this achievement, requested special studies. Its aim was to inject and to accelerate, in the SPS, partially stripped xenon ions Xe³⁹⁺ measure their life time, and determine the relative strength of the processes responsible for the PSI beam losses. This study, the results of which are presented in this contribution, was an initial step in view of the the future studies programmed for 2018 with lead PSI beams.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMF015

Export •

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

THPMF021

ESRF Operation Status

SRF, operation, power-supply, booster

4088

J.-L. Revol, J.C. Biasci, N. Carmignani, A. D'Elia, A. Franchi, L. Hardy, J. Jacob, I. Leconte, S.M. Liuzzo, H.P. Marques, T.P. Perron, E. Plouviez, P. Raimondi, B. Roche, K.B. Scheidt, L. Torino, S.M. White
ESRF, Grenoble, France

The European Synchrotron Radiation Facility (ESRF) is undergoing the second phase (2015-2022) of an Up-grade which concerns its infrastructure, beamlines and X-ray source. This paper reports on the present operational source performance, highlighting the most recent developments, and the preparation of the Extremely Brilliant Source project. The renovation of the injector and the recent operation in top-up mode are also detailed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMF021

Export •

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

THPMF030

VSR Injector Upgrade at BESSY II

booster, cavity, storage-ring, kicker

4110

T. Atkinson, P. Goslawski, J.G. Hwang, M. Ries
HZB, Berlin, Germany
T. Flisgen, T. Mertens
Helmholtz-Zentrum Berlin für Materialien und Energie GmbH (HZB), Berlin, Germany

BESSY VSR is a fully funded project at the Helmholtz-Zentrum in Berlin (HZB). The objective is to produce simultaneously both long and short pulses in the storage ring. The implications for the existing injector systems and the upgrade strategy are presented. Envisaged is a global upgrade which includes additional accelerating structures to reduce the bunch length in the booster, orbit measurements and implementing longitudinal feedback.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMF030

Export •

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

THPMF041

Low Emittance Lattice for PF-AR

optics, emittance, cavity, operation

4148

N. Higashi, K. Harada, S. Nagahashi, N. Nakamura, T. Obina, R. Takai, H. Takaki
KEK, Ibaraki, Japan
K. Hirano
Hiroshima University, Graduate School of Science, Higashi-Hiroshima, Japan

PF-AR is a synchrotron-type 6.5 GeV light source in KEK. The user-run was started in 1987, and the lattice is almost the same as the original one. Now we consider the emittance improvement to enlarge the horizontal tune advance in the normal cell. Thanks to this manipulation, the emittance will be improved to about a half of the current value.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMF041

Export •

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

THPMF042

Beam Based Measurement of Injection Parameters at KEK-PF

kicker, septum, beam-transport, storage-ring

4152

K. Hirano
Hiroshima University, Graduate School of Science, Higashi-Hiroshima, Japan
K. Harada, N. Higashi, Y. Kobayashi, S. Nagahashi, T. Obina, R. Takai, H. Takaki, A. Ueda
KEK, Ibaraki, Japan

KEK-PF is a 2.5 GeV synchrotron radiation facility. In recent years, the injection efficiency using conventional pulsed septum and kicker magnets has decreased. The main cause of this problem seems to be the change of the injection parameters due to the accumulation of the errors including the effect of the earthquake on March 11, 2011. For the improvement of the injection efficiency, the precise and detailed parameters of the beam injection under present configuration are essential. In order to fix these parameters, we measure the response of the pulsed magnets by using injected and stored beams. In this presentation, we show the beam based measurement and the simulation results for the PF ring injection system.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMF042

Export •

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

THPMF043

Development and Present Status of Photon Factory Light Sources

septum, operation, vacuum, storage-ring

4155

T. Honda, Y. Kobayashi, S. Nagahashi, R. Takai
KEK, Ibaraki, Japan

Photon Factory of KEK manages two light sources, Photon Factory storage ring (PF-ring) and Photon Factory Advanced Ring (PF-AR) with an energy of 2.5 GeV and 6.5 GeV, respectively. Although it is unfortunate that the operation time of the accelerators is decreasing recent years due to a budget shortage and some unavoidable reconstructions, we are continuing the operation with a low failure rate and constructing a new beamline based on a novel undulator. Preparing for the start of the physics run of Super KEKB Factory, a new full energy beam transport line from the injector LINAC to PF-AR was constructed. With an installation of pulsed quadrupole magnets for the LINAC, continuous top-up injection has been established simultaneously for the four storage rings of PF and Super KEKB, and the operation of them has become compatible. As a result of increasing the injection energy of PF-AR form 3 GeV to 6.5 GeV, the beam instability during the injection disappeared, and the stability and efficiency of the injection improved significantly.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMF043

Export •

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

THPMF046

Precision Charge Measurement of 40~MeV Electron-Beam to Calibrate Air Fluorescence Telescope for Cosmic Ray Observation

electron, vacuum, ECR, ISOL

4163

T. Shibata
KEK, Ibaraki, Japan
O.C. Shin
OCU, Osaka, Japan

The Telescope Array (TA) is ultra-high energy cosmic ray observation (UHECR). TA is using the fluorescence detectors (FD) for observation the air fluorescence(AFY) which are emitted in the cascade generated by an UHECR in atmosphere. One of the important observables is primary energy of UHECR, however it has 21% systematic uncertainty. For reduction of the uncertainty, we have been operated an 40-MeV electron linear accelerator from 2010 which we have constructed for absolute energy calibration. The accelerator is located at 100 m from FD station, and can shot electron beam which the direction is vertical into the air, the energy is 40-MeV, the pulse width is 1 micro-second, and the beam charge is 160 pC. The AFY efficiency and FD calibration parameters can be calibrated, which means energy scale of UHECR, by observation of the AFY which are generated by the electron beam in the air. The most important beam parameter is beam charge. The requirement of the accuracy of charge measurement is a few %, then we have developed the double faraday cups and one current transfer system. We calibrated the current transfer by the double faraday cups, and we could achieve about 1% accuracy.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMF046

Export •

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

THPMF052

The Swap-Out Injection Scheme for the High Energy Photon Source

booster, storage-ring, kicker, extraction

4178

Z. Duan, J. Chen, Y.Y. Guo, Y. Jiao, J.L. Li, Y.M. Peng, J.Q. Wang, N. Wang, G. Xu, H.S. Xu
IHEP, Beijing, People's Republic of China

Funding: Work supported by Natural Science Foundation of China (No.11605212).
The on-axis swap-out scheme is a promising injection scheme for di raction-limited storage rings, since it only re- quires a rather small dynamic aperture and thus potentially allows a higher brightness compared to traditional o -axis injection schemes. However, a full charge injector is neces- sary for this scheme and its design can be nontrivial, in par- ticular to satisfy the large single bunch charge requirements in special lling patterns for timing experiments. In the High Energy Photon Source, we propose using the booster also as a high energy accumulator ring to recapture the spent bunches extracted from the storage ring, so as to relax the challenges in generation and acceleration of bunches with a high charge, and as a cost-e ective solution compared to building a dedicated full energy accumulator ring. In this paper, the beam dynamics issues of this scheme will be presented, trade-o s between the storage ring and booster beam parameters and hardware specifications will also be discussed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMF052

Export •

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

THPMF069

Perturbation to Stored Beam by Pulse Sextupole Magnet and Disturbance of the Sextupole Magnetic Field in Aichi Synchrotron Radiation Center

synchrotron, radiation, synchrotron-radiation, simulation

4232

A. Mochihashi
KIT, Eggenstein-Leopoldshafen, Germany
M. Fujimoto, M. Katoh
UVSOR, Okazaki, Japan
M. Hosaka, M. Hosaka, Y. Takashima, Y. Takashima, K. Y. Yamamura
Nagoya University, Nagoya, Japan
M. Hosaka, H. Ohkuma, Y. Takashima
Aichi Synchrotron Radiation Center, Aichi, Japan
M. Katoh
Sokendai - Okazaki, Okazaki, Aichi, Japan
H. Ohkuma
JASRI/SPring-8, Hyogo-ken, Japan

In the Aichi synchrotron radiation center (Aichi-SR), a pulse sextupole magnet (PSM) has been installed as a pulse magnet for beam injection. This leads to the injection scheme without using a bump orbit and stable supply of the synchrotron radiation. In Aichi-SR we have performed usual injection scheme with 4 kicker magnets and making the bump. Because the circumference of the Aichi-SR is only 72 m, 3 beam lines are inside the bump. The Aichi-SR has performed top-up operation since its public open, so it is a crucial subject to eliminate the disturbance of the synchrotron radiation during the injection. We have installed the PSM in 2015 and developed the beam study continuously. At present, however, a perturbation to the stored beam by the PSM still has been observed and is not acceptable. We have performed beam diagnostic experiment and concluded that an additional dipole kick affects the beam. From the magnetic field measurement data, we have discussed the source of the additional kick; most likely is an eddy current on the Ti coating inside the ceramics duct of the PSM. The beam diagnostics experiment and the magnetic field measurement will be discussed in the presentation.
Present affiliation of the first auther : Karlsruhe Institute of Technology

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMF069

Export •

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

THPMF070

Non-Linear Optics and Low Alpha Operation at the Storage Ring KARA at KIT

wiggler, operation, octupole, resonance

4235

A.I. Papash, E. Blomley, M. Brosi, J. Gethmann, B. Kehrer, A.-S. Müller, M. Schuh, P. Schönfeldt, J.L. Steinmann
KIT, Karlsruhe, Germany

The storage ring Karlsruhe Research Accelerator (KARA) at KIT operate in a wide energy range from 0.5 to 2.5 GeV. Different non-linear effects, in particular, residual octupole components of the magnetic field of the CATACT wiggler at high field level (2.5 T), proximity of the working point to a vertical sextupole resonance Qy=8/3 and weak coupling octupole resonance 2Qx+2Qy=19, high chromaticity, etc. decrease the beam life time. This is because of the reduced dynamic aperture and momentum acceptance for off-momentum particles. A new operation point at high vertical tune Qy=2.81 was tested. For this, injection and ramping tables have been modified. First the values were optimized by simulations, then during beam tests, to minimize betatron tune shaking during beam-energy ramps. It stabilized high-current beams by the fast-feedback system the whole process: injection at 0.5 GeV, ramping, and operation at 1.3 GeV cycles. It essentially improved life time and beam current. In addition, new low-alpha tables have been created and tested, resulting in the reduction of the momentum compaction factor to 10^-4. Short bunch operation at 0.5GeV injection energy was also tested successfully.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMF070

Export •

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

THPMK008

Commissioning of the Storage Ring for the Kharkov Generator of X-Ray Radiation NESTOR

storage-ring, electron, MMI, laser

4307

A.A. Shcherbakov, V.P. Androsov, S.V. Bazarov, V.N. Berezka, O. Bezditko, A.V. Cherkashin, A.V. Gevchuk, P. Gladkikh, S.P. Gokov, A.N. Gordienko, V.A. Grevtsev, A. Gvozd, V.E. Ivashchenko, A.A. Kalamayko, I.I. Karnaukhov, I.M. Karnaukhov, V.P. Kozin, V.P. Lyashchenko, V.S. Margin, N.I. Mocheshnikov, M. Moisieienko, A. Mytsykov, F.A. Peev, O.V. Ryezayev, V.P. Sergienko, V.O. Shpagina, N.F. Shul'ga, V. Skomorokhov, D.V. Tarasov, V.I. Trotsenko, V.V. Tsyats'ko, A.Y. Zelinsky, O.P. Zolochevskij, O.D. Zvonarjova
NSC/KIPT, Kharkov, Ukraine
J.I.M. Botman
TUE, Eindhoven, The Netherlands

During 2015-2017 the X-ray source NESTOR (New Electron STOrage Ring) based on a storage ring with low beam energy and Compton scattering of intense laser beam is under commissioning at the National Science Center "Kharkov Institute of Physics and Technology Institute" (NSC KIPT). The start-up of the injector and storage ring is one of the basic task for the facility commissioning. In the paper, the results of the NESTOR X-ray source 225 MeV electron storage ring commissioning are described and further plans are discussed

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMK008

Export •

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

THPMK029

Towards an Upgrade of the Swiss Light Source

lattice, storage-ring, emittance, sextupole

4358

A. Streun, M. Aiba, M. Böge, T. Garvey, V. Schlott
PSI, Villigen PSI, Switzerland

An upgrade of the Swiss Light Source (SLS) is planned for the period 2021-24. The existing 12-TBA (triple bend achromat) lattice will be exchanged by a 12-7BA (7-bend achromat) lattice in order to reduce the emittance from present 5.5 nm down to about 125 pm at 2.4 GeV / 400 mA (IBS included). The new lattice is based on longitudinal gradient bends and reverse bends to realize low emittance despite the small circumference of 290 m. A conceptual design has been established. We present project status, lattice design and work in progress with emphasis on beam dynamics issues.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMK029

Export •

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

THPMK105

PERLE - Lattice Design and Beam Dynamics Studies

linac, bunching, lattice, electron

4556

S.A. Bogacz, D. Douglas, F.E. Hannon, A. Hutton, F. Marhauser, R.A. Rimmer, Y. Roblin, C. Tennant
JLab, Newport News, Virginia, USA
D. Angal-Kalinin, J.W. McKenzie, B.L. Militsyn, P.H. Williams
Cockcroft Institute, Warrington, Cheshire, United Kingdom
G. Arduini, O.S. Brüning, R. Calaga, K.M. Dr. Schirm, F. Gerigk, B.J. Holzer, E. Jensen, A. Milanese, E. Montesinos, D. Pellegrini, P.A. Thonet, A. Valloni
CERN, Geneva, Switzerland
S. Bousson, D. Longuevergne, G. Olivier, G. Olry
IPN, Orsay, France
I. Chaikovska, W. Kaabi, A. Stocchi, C. Vallerand
LAL, Orsay, France
B. Hounsell, M. Klein, U.K. Klein, P. Kostka, C.P. Welsch
The University of Liverpool, Liverpool, United Kingdom
E.B. Levichev, Yu.A. Pupkov
BINP SB RAS, Novosibirsk, Russia

Funding: Work has been authored by Jefferson Science Associates, LLC under Contract No. DE-AC05-06OR23177 with the U.S. Department of Energy.
PERLE (Powerful ERL for Experiments) is a novel ERL test facility, initially proposed to validate choices for a 60 GeV ERL foreseen in the design of the LHeC and the FCC-eh. Its main thrust is to probe high current, CW, multi-pass operation with superconducting cavities at 802 MHz (and perhaps testing other frequencies of interest). With very high virtual beam power (~ 10 MW), PERLE offers an opportunity for controllable study of every beam dynamic effect of interest in the next generation of ERL design; becoming a ‘stepping stone' between present state-of-art 1 MW ERLs and future 100 MW scale applications. PERLE design features Flexible Momentum Compaction lattice architecture for six vertically stacked return arcs and a high-current, 6 MeV, photo-injector. With only one pair of 4 cavity cryomodules, 400 MeV beam energy can be reached in 3 re-circulation passes, with beam currents in excess of 15 mA. The beam is decelerated in 3 consecutive passes back to the injection energy, transferring virtually stored energy back to the RF. This unique facility will serve as a test-bed for high current ERL technologies, as well as a user facility in low energy electron and photon physics.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMK105

Export •

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

THPMK120

Hefei Advanced Light Source: A Future Soft X-Ray Diffraction-Limited Storage Ring at NSRL

storage-ring, lattice, emittance, radiation

4598

L. Wang, Z.H. Bai, N. Hu, H.T. Li, W. Li, G. Liu, Y. Lu, Q. Luo, D.R. Xu, W. Xu, P.H. Yang, Z.H. Yang, S.C. Zhang
USTC/NSRL, Hefei, Anhui, People's Republic of China

To meet the fast-growing demands for high-quality low-energy photon beams, a new synchrotron radiation light source conception was brought forward several years ago by National Synchrotron Radiation Laboratory, which was named Hefei Advanced Light Source (HALS). The dominant radiation of HALS will be located in the VUV and soft X-ray region, which will be complementary with that of SSRF and HEPS. Except for high brilliance, high transverse coherence will be another signature feature of HALS. To achieve these goals, a multi-bend achromat based diffraction-limited storage ring was adopted as the main body of HALS. The general description and preliminary design of HALS will be briefly presented in this paper. Under the support of the Chinese Academy of Sciences and local government, the preliminary research and development (R&D) for HALS is undergoing. Several key technologies will be developed in the R&D project, which will lay good foundation for the construction of HALS.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMK120

Export •

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

THPMK129

Lattice Tweaking Using A Tune Knob Based On Global Mechanism

storage-ring, quadrupole, 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.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMK129

Export •

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

THPMK147

Measurement of Slice-Emittance of Electron Bunch Using RF Transverse Deflector

emittance, experiment, acceleration, electron

4648

T. Sasaki, Y. Nakazato, M. Washio
Waseda University, Tokyo, Japan
Y. Koshiba
RISE, Tokyo, Japan
K. Sakaue
Waseda University, Waseda Institute for Advanced Study, Tokyo, Japan

We have been studying a compact electron accelerator based on an S-band Cs-Te photocathode rf electron gun at Waseda University. We are applying this high quality electron beam to soft X-ray generation, coherent THz wave generation and pulse radiolysis experiment. In these applications, longitudinal parameters of the electron beam are important. Thus, we developed the RF deflecting cavity which can directly convert longitudinal distribution of the beam to transverse with high temporal resolution, and succeeded in measuring longitudinal profile of an electron beam from the RF gun. Encouraged by these successful results, we started to measure slice emittance. Slice emittance would be very useful for improving the RF electron gun cavity. Therefore, we tried to measure the slice emittance of the electron beam by applying the Q-scan method to deflected beam by RF deflecting cavity. In this conference, we will report the principle, experimental results of the slice emittance measurement, and future prospects.
C. Vaccarezza et al., "Slice emittance measurements at SPARC photoinjector with a RF deflector", Proc. of EPAC08, Genoa, Italy

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMK147

Export •

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

THPML017

Beam Dynamics Calculation of a New Injection System for LINAC II

gun, electron, linac, operation

4687

J.X. Zhang, M. Hüning
DESY, Hamburg, Germany

The Linac II at DESY (Deutsches Elektronen Synchrotron) is an electron/positron linear accelerator with a 400 MeV primary electron linac, an 800 MW positron converter, and a 450 MeV secondary electron/positron linac. For reliability two injection systems can be switched, a 150 kV bombarder diode gun dating from 1969 and a 100 kV triode gun commissioned in 2014. The older bombarder gun shall be replaced with a triode gun optimized for injection into the synchrotron radiation facility PETRA III. In this paper, the parameters of the existing injectors and the design considerations for the new injector are presented. The preliminary beam dynamics calculation of the new injection system will be performed; the future plan of the replacement will be discussed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPML017

Export •

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

THPML034

Baseline Lattice for the Upgrade of SOLEIL

emittance, lattice, photon, storage-ring

4726

A. Loulergue, P. Alexandre, P. Brunelle, O. Marcouillé, A. Nadji, L.S. Nadolski, R. Nagaoka, K.T. Tavakoli, M.-A. Tordeux, A. Vivoli
SOLEIL, Gif-sur-Yvette, France
L. Hoummi
Cockcroft Institute, Warrington, Cheshire, United Kingdom

Previous MBA studies converged to a lattice composed of 7BA-6BA with a natural emittance value of 200- 250 pm.rad range. Due to the difficulties of non-linear optimization in targeting lower emittance values, a decision was made to symmetrize totally the ring with 20 identical cells having long free straight sections longer than 4 m. A 7BA solution elaborated by adopting the sextupole paring scheme with dispersion bumps originally developed at the ESRF-EBS, including reverse-bends, enabling an emittance of 72 pm.rad has been defined as the baseline lattice. The sufficient on-momentum dynamic aperture obtained allows to consider off-axis injection. The linear and nonlinear dynamic properties of the lattice along with the expected performance in terms of brilliance and transverse coherence are presented. In particular, the beta functions tuned down to 1 m in both transverse planes at the center of straight sections allow matching diffraction limited photons up to 3 keV.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPML034

Export •

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

THPML044

Operation of a Cryogenic Current Comparator with Nanoampere Resolution for Continuous Beam Intensity Measurements in the Antiproton Decelerator at CERN

cryogenics, operation, proton, antiproton

4741

M.F. Fernandes, D. Alves, T. Koettig, A. Lees, J. Tan
CERN, Geneva, Switzerland
M.F. Fernandes, C.P. Welsch
The University of Liverpool, Liverpool, United Kingdom
M. Schwickert, T. Stöhlker
GSI, Darmstadt, Germany
T. Stöhlker
IOQ, Jena, Germany
C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom

Funding: This project has received funding from the European Union's Seventh Framework Programme, under grant agreement number 289485.
Low-intensity charged particle beams are particularly challenging for non-perturbative beam diagnostics due to the small amplitude of induced electromagnetic fields. The Antiproton Decelerator (AD) and Extra Low ENergy Antiproton (ELENA) rings at CERN decelerate beams containing 10⁷ antiprotons. An absolute intensity measurement of the circulating beam is essential to monitor the operational efficiency and to provide important calibration data for the antimatter experiments. This paper reviews the design of an operational Cryogenic Current Comparator (CCC) based on Superconducting QUantum Interference Device (SQUID) for current and intensity monitoring in the AD. Such a system has been operational throughout 2017, relying on a stand-alone cryogenic infrastructure based on a pulse-tube cryocooler. System performance is presented and correlated with different working environments, confirming a resolution in the nanoampere range.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPML044

Export •

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

THPML066

Filling Pattern Measurement System Upgrade in SSRF*

operation, storage-ring, SRF, synchrotron

4791

N. Zhang, F.Z. Chen, Y.M. Zhou
SSRF, Shanghai, People's Republic of China

Funding: Work supported by National Natural Science Foundation of China (No.11575282 No.11375255 No.11305253)
Filling pattern affects various operation performance of a synchrotron light source. A new diagnostic beam charge monitor (BCM) with high bandwidth multi-channels digitizer was developed to perform bunch-by-bunch charge measurement and record filling pattern for SSRF storage ring. Signals picked up from button elec-trodes were sampled synchronously with RF frequency, and IQ (In-phase and Quadrature phase) sampling meth-od was employed for noise-filtering and phase independ-ence calibration. Layout and evaluation experiment of the system are presented in this paper.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPML066

Export •

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

THPML068

Upgrade of Bunch Phase Monitor at SSRF Storage Ring

SRF, storage-ring, pick-up, experiment

4797

Y.M. Zhou, Y.B. Leng, T. Wu, N. Zhang
SSRF, Shanghai, People's Republic of China

Beam instability is a serious problem for physics in beam diagnosis technology. With regard to the evaluation of longitudinal phase oscillations during the transient injection process, bunch-by-bunch phase measurement is a useful tool for studying the behavior of the refilled bunches. A new upgraded beam phase monitor system with 1.2GHz bandwidth PXI waveform digitizer has been developed at Shanghai synchrotron radiation source (SSRF). Bunch-by-bunch phase information, retrieved from button pickup signals, is calculated by the zero-crossing detection method with the best phase resolution of 0.4ps. The refilled bunches can be separated from the stored ones, and the longitudinal offset of each refilled bunch has been measured. Several groups of experiments have been performed to verify the repeatability of bunch-by-bunch phase measurement, and some results regarding refilled bunches will be discussed in this paper.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPML068

Export •

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

THPML072

Injection Comparison using Bunch-by-Bunch Beam Size Measurement System at SSRF

damping, SRF, storage-ring, betatron

4811

H.J. Chen, J. Chen, B. Gao, Y.B. Leng
SINAP, Shanghai, People's Republic of China

Injection transient process happens every 5-10 minutes in storage ring during normal top-up operating mode at SSRF, which is a proper window for machine status and injection performance evaluation. In the recent year, a bunch-by-bunch beam size measurement system has been implemented at SSRF, which has the capability to offer transverse bunch-by-bunch position and size information and is a powerful tool for injection study. In this paper, we summarize three injection study results from July 2017 to April 2018, including betatron oscillation amplitude, spectrum, horizontal tune and damping time comparison. The oscillation amplitude and temporal behavior of recent injection are all better than results before contributed to the injection optimization work during maintenance in 2018 winter. In addition, the principal component analysis method is also applied to further study the injection behavior in turn-by-turn or bunch-by-bunch direction to the refilled bucket.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPML072

Export •

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

THPML107

Steering Optimizations for the University of Maryland Electron Ring

closed-orbit, dipole, lattice, experiment

4913

L. Dovlatyan, B.L. Beaudoin, R.A. Kishek, K.J. Ruisard
UMD, College Park, Maryland, USA

Funding: This work is supported by the US Dept. of Energy, Office of High Energy Physics award # DE-SC0010301
The University of Maryland Electron Ring (UMER) has the flexibility to set up alternative lattices for different research experiments, including nonlinear optics studies using octupoles. Each alternative lattice requires an acceptable steering solution for use in experiments. Existing beam-based alignment tools can take a significant amount of time to run and become difficult to process with a low number of BPMs. The Robust Conjugate Directional Search (RCDS) optimizer* is used to quickly obtain steering solutions for different lattice configurations and has been adopted for beam steering at UMER. Steering magnets are optimized online to reduce scraping, correct equilibrium orbits, and increase beam lifetimes. This study presents the application of the optimizer at UMER.
* X. Huang, J. Corbett, J. Safranek, J. Wu, Nucl. Instr. Meth. A vol. 726, pp. 77-83, 2013.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPML107

Export •

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

THPML117

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

coupling, resonance, dynamic-aperture, quadrupole

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.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPML117

Export •

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

THPML130

Applications of a Distributed Beam Loss Monitor at the Australian Synchrotron

storage-ring, synchrotron, target, detector

4986

P.J. Giansiracusa, T.G. Lucas, R.P. Rassool, M. Volpi
The University of Melbourne, Melbourne, Victoria, Australia
M.J. Boland
CLS, Saskatoon, Saskatchewan, Canada
G. LeBlanc
SLSA, Clayton, Australia

A distributed beam loss monitoring system, based on Cherenkov silica fibres, has been installed at the Australian Synchrotron. The fibres are installed parallel to the beam pipe and cover the majority of the injection system and storage ring. Relativistic charged particles from beam loss events that have a velocity above the Cherenkov threshold produce photons in the fibres. These photons are then guided along the fibres to detectors outside of the accelerator tunnels. Originally the system was installed to determine its suitability for measuring losses at a future linear collider, such as the Compact Linear Collider, with single pass 150 ns bunch trains. This study builds on these results and attempts to use the system to measure loss locations with a circulating beam. We present the preliminary results and describe how the system could be improved.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPML130

Export •

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

THPML138

Efficiency and Error Analysis of the HALS Injection Scheme

simulation, kicker, lattice, storage-ring

5008

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

Hefei Advanced Light Source (HALS) is a newly designed diffraction-limited storage ring.. The latest version of HALS has a 7BA lattice. One of the most important parts about HALS design is its injection system. Since conventional injection scheme is not suitable for DLSRs, many new injection schemes are proposed, including longitudinal injection scheme. In this paper, we investigate the feasibility of longitudinal injection scheme for HALS. In order to evaluate the injection performance, various errors have been considered. A series of tracking simulations are carried out and injection efficiency is obtained under different error levels.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPML138

Export •

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

FRXGBE2

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

quadrupole, storage-ring, 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]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-FRXGBE2

Export •

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