MOPMP —  Poster Session - Magpie   (20-May-19   16:00—18:00)
Paper Title Page
MOPMP001 Optic Corrections for FCC-hh 417

• D. Boutin
CEA-DRF-IRFU, France
• A. Chancé,
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. 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 required correctors strengths, are important aspects of the collider design. In this study the mechanical tolerances, dipole and quadrupole field error tolerances for the arc sections of FCC-hh are evaluated. The consolidated correction schemes of the linear coupling (with skew quadrupoles) and of the beam tunes (with normal quadrupoles) are presented. The integration of the different ring insertions (interaction region, collimation, injection, etc) is also discussed.
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP001
About • paper received ※ 14 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019
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MOPMP002 Linac and Damping Ring Designs for the FCC-ee 420

• S. Ogur, 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
• , R. Chehab
LAL, Orsay, France
• K. Furukawa, N. Iida, T. Kamitani, F. Miyahara, K. Oide
KEK, Ibaraki, Japan
• E.V. Ozcan
Bogazici University, Bebek / Istanbul, Turkey
• S.M. Polozov
MEPhI, Moscow, Russia
• L. Rinolfi
ESI, Archamps, France
• F. Yaman
IZTECH, Izmir, Turkey

We report the design of the pre-injector chain for the Future Circular e+ e Collider (FCC-ee) system. The electron beam from a low-emittance RF gun is accelerated by an S-band linac up to 6 GeV. A damping ring at 1.54 GeV is required for emittance cooling of the positron beam. The intermediate energy step from the exit of the S-band linac at 6 GeV to the 20 GeV injection energy of the top-up booster can be provided by the modified Super Proton Synchrotron (SPS), serving as a pre-booster ring (PBR). An alternative option to reach 20 GeV energy would be to extend the S-band linac with a C- or X-band linac. An overall cost optimisation will determine the choice of the final configuration. Beam loss and emittance dilution in the linac due to space charge effects, wakefields, and misalignment of accelerator components can be mitigated by RF phasing and orbit steering. Start-to-end simulations examine the beam transport through the linac up to either 6 GeV or 20 GeV. The results indicate large design margins. Simulations of the beam dynamics in the damping ring (DR) demonstrate a sufficiently large momentum acceptance. Effects of intrabeam scattering and electron cloud instability in the DR are also studied.
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP002
About • paper received ※ 13 May 2019       paper accepted ※ 21 May 2019       issue date ※ 21 June 2019
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MOPMP003 Positron Source for FCC-ee 424

• I. Chaikovska, R. Chehab, A. Faus-Golfe, Y. Han
LAL, Orsay, France
• A. Apyan
ANSL, Yerevan, Armenia
• Y. Enomoto, K. Furukawa, T. Kamitani, F. Miyahara, M. Satoh, Y. Seimiya, T. Suwada
KEK, Ibaraki, Japan
• P.V. Martyshkin
BINP SB RAS, Novosibirsk, Russia
• S. Ogur, K. Oide, Y. Papaphilippou, L. Rinolfi, P. Sievers, F. Zimmermann
CERN, Geneva, Switzerland

The FCC-ee is a high-luminosity, high-precision circular collider to be constructed in a new 100 km tunnel in the Geneva area. The physics case is well established and the FCC-ee operation is foreseen at 91 GeV (Z-pole), 160 GeV (W pair production threshold), 240 GeV (Higgs resonance) and 365 GeV (t-tbar threshold). Due to the large 6D production emittance and important thermal load in the production target, the positron injector, in particular the positron source, is one of the key elements of the FCC-ee, requiring special attention. To ensure high reliability of the positron source, conventional and hybrid targets are currently under study. The final choice of the positron target will be made based on the estimated performances. In this framework, we present a preliminary design of the FCC-ee positron source, with detailed simulation studies of positron production, capture and primary acceleration.
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP003
About • paper received ※ 03 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019
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MOPMP004 Consolidated Lattice of the Collider FCC-hh 428

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

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

DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP004
About • paper received ※ 14 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019
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MOPMP006 Magnetic Measurement With Single Stretched Wire Method on SuperKEKB Final Focus Quadrupoles 432

• Y. Arimoto, K. Egawa, T. Kawamoto, M. Masuzawa, Y. Ohsawa, N. Ohuchi, R. Ueki, X. Wang, H. Yamaoka, Z.G. Zong
KEK, Ibaraki, Japan
• J. DiMarco, J.M. Nogiec, G. Velev
Fermilab, Batavia, Illinois, USA

Superconducting-final-focus-quadrupole magnet system (QCS) were installed on an interaction region (IR) of SuperKEKB on Feb. 2017. The QCS consists of eight quadrupole magnets and four compensation solenoids; these magnets are contained in the two cryostats and are installed into Belle II detector which generates a solenoid field of 1.5 T. We determined the quadrupole centers with respect to accelerator beam lines with a single stretched wire (SSW) method. Here the results of the magnetic measurement with SSW are presented.
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP006
About • paper received ※ 15 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019
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MOPMP007 Design of a Compact Power Distribution System for the ILC 436
SUSPFO038   use link to see paper's listing under its alternate paper code

• B. Du, N. Liu
Sokendai - Hayama, Hayama, Japan
• T. Matsumoto, S. Michizono, T. Miura, F. Qiu
KEK, Ibaraki, Japan
• T. Matsumoto, T. Miura, F. Qiu
Sokendai, Ibaraki, Japan

The Local power distribution system (LPDS) of the In-ternational Linear Collider (ILC) is constructed to transmit RF power from the 10 MW klystron to 39 cavi-ties. Each eight or nine 9-cell cavities is assembled in one cryomodule. The variable hybrid is used to adjust the power dividing ratio due to the different required power of each cavity and the variable phase shifter is used to compensate the phase drift caused by the variable hybrid. More compact LPDS is expected to be integrated on the cryomodule decreasing financial cost. We re-design the shorter variable hybrid with a margin of power ratio of ±25% and phase shifter of total phase range being 35° for compensating hybrid and on-crest searching. Fixed phase shifters are designed to adjust the phase difference between adjacent cavities for beam acceleration. Simu-lated results of total compact LPDS can meet the re-quirements of ILC.
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP007
About • paper received ※ 16 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019
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MOPMP008 Electron Driven Positron Source for International Linear Collider 439

• M. Kuriki, T. Okugi, T. Omori, M. Satoh, Y. Seimiya, J. Urakawa, K. Yokoya
KEK, Ibaraki, Japan
• H. Nagoshi
• K. Negishi
Iwate University, Morioka, Iwate, Japan
• Y. Sumitomo
LEBRA, Funabashi, Japan
• T. Takahashi
Hiroshima University, Graduate School of Science, Higashi-Hiroshima, Japan

Funding: This work is partly supported by Japan-US Cooperative grant for scientific studies, Grant aid for scientific study by MEXT Japan (KAKENHI)
To linear colliders, huge amount of positron has to be provided comparing to ring colliders, because the beam is dumped after the collision. Electron Driven ILC Positron source has been designed as a technical backup of the undulator position source including the beam loading effect, etc. The design of the detail will be presented. To linear colliders, huge amount of positron has to be provided comparing to ring colliders, because the beam is dumped after the collision. Electron Driven ILC Positron source has been designed as a technical backup of the undulator position source including the beam loading effect, etc. The design of the detail will be presented.

DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP008
About • paper received ※ 13 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019
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MOPMP009 Effect of Initial Parameters on the Super Flat Beam Generation with the Phase-Space Rotation for Linear Colliders 442

• M. Kuriki, R. Tamura
• H. Hayano, X.J. Jin, T. Konomi, Y. Seimiya, N. Yamamoto
KEK, Ibaraki, Japan
• S. Kashiwagi
Tohoku University, Research Center for Electron Photon Science, Sendai, Japan
• P. Piot
Northern Illinois University, DeKalb, Illinois, USA
• J.G. Power
ANL, Argonne, Illinois, USA
• K. Sakaue
The University of Tokyo, The School of Engineering, Tokyo, Japan
• M. Washio
RISE, Tokyo, Japan

Funding: This work is partly supported by Japan-US Cooperative grant for scientific studies, Grant aid for scientific study by MEXT Japan (KAKENHI) Kiban B.
Linear collider is a concept to realize e+e collision beyond the limitation of the ring colliders by the synchrotron radiation. To obtain an enough luminosity, eg. 1.0·10+34 cm-2sec-1, the beam is focused down to nano-meter size with a high aspect ratio. This super flat beam is useful to improve the luminosity and to compensate the beam-beam effect, eg. Beamstrahlung. In a conventional design, the super-flat beam is produced by radiation damping in a storage ring. We propose to produce this super-flat beam with phase-space rotation techniques. We employ both Round to Flat Beam Transformation and Transverse to Longitudinal Emittance eXchange, the super flat beam can be generated by controlling the space-charge effect which spoiled the performance. We present the RFBT performance with respect to the initial conditions, i.e. beam size, initial emittance, solenoid field (strength and profile), etc.

DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP009
About • paper received ※ 13 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019
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MOPMP012 Concepts of Longitudinally Polarized Electron and Positron Colliding Beams in the Circular Electron Positron Collider 445

• Z. Duan, J. Gao, X.P. Li, D. Wang, Y. Wang, W.H. Xia, Q.J. Xu, , Y. Zhang
IHEP, Beijing, People’s Republic of China

Funding: Work supported by National Key Research and Development Program of China (No.2018YFA0404300).
This paper reports some preliminary study into the imple- mentation of longitudinally polarized e+/e colliding beams in the Circular Electron Positron Collider, at a center of mass energy of 91 GeV as a Z factory and energies beyond.

DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP012
About • paper received ※ 15 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019
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MOPMP013 New Nuclotron Beam Lines and Stations for Applied Researches 449

• E. Syresin, A.A. Baldin, A.V. Butenko, G.A. Filatov, A.A. Slivin, G.N. Timoshenko, G.V. Trubnikov, A. Tuzikov
JINR, Dubna, Moscow Region, Russia
• D.V. Bobrovskiy, A.I. Chumakov
MEPhI, Moscow, Russia
• M.M. Kats, T. Kulevoy, D.A. Liakin, Y.E. Titarenko
ITEP, Moscow, Russia

New beamlines for applied researches on the Nuclotron are under development within the framework of implementation of the NICA accelerator facility. Ion beams with energies of 150-800 MeV/n extracted from the Nuclotron will be used for radiobiological researches and modeling of cosmic rays interactions with microchips. Equipment of two experimental stations is under development by the JINR-ITEP-MEPhi collaboration for these applied researches. Ion beams with the energy of 3.2 MeV/n extracted from the heavy ion linac HILAc will also be used for irradiation and testing of microchips. The specialized channel will be reconstructed for investigations in the field of relativistic nuclear power at light ion energies of 0.3-4.5 GeV/n. Three new experimental areas are organized for applied physics researches within the framework of implementation of the NICA accelerator facility.
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP013
About • paper received ※ 29 April 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019
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MOPMP014 NICA Accelerator Complex at JINR 452

• E. Syresin, O.I. Brovko, A.V. Butenko, E.E. Donets, A.R. Galimov, E.V. Gorbachev, A. Govorov, V. Karpinsky, V. Kekelidze, H.G. Khodzhibagiyan, S.A. Kostromin, A.D. Kovalenko, O.S. Kozlov, I.N. Meshkov, A.V. Philippov, A.O. Sidorin, V. Slepnev, A.V. Smirnov, G.V. Trubnikov, A. Tuzikov, V. Volkov
JINR, Dubna, Moscow Region, Russia

Status of the project of NICA accelerator complex, which is under construction at JINR (Dubna, Russia), is presented. The main goal of the project is to provide ion beams for experimental studies of hot and dense baryon-ic matter and spin physics. The NICA collider will pro-vide heavy ion collisions in the energy range of √sNN=4/11 GeV at average luminosity of L=1.1027cm−2·s−1 for 197Au79+ nuclei and polarized proton collisions in energy range of √sNN=12/27 GeV at lumi-nosity of L ≥ 1031cm−2·s−1. NICA accelerator complex will consist of two injector chains, 578 MeV/u supercon-ducting (SC) booster synchrotron, the existing SC syn-chrotron (Nuclotron), and the new SC collider that has two storage rings each of 503 m circumference. Con-structing facility is based on Nuclotron-technology of SC magnets with iron yoke. Hollow SC cable cooled by two-phase He-flux used for operation with 10 kA currents and 1Hz cycling rate. Both stochastic and electron cooling methods are used for the beam accumulation and its stability maintenance.
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP014
About • paper received ※ 29 April 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019
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MOPMP015 Longitudinal Particle Dynamics in NICA Collider 455

• E. Syresin, A.V. Eliseev, A.V. Smirnov
JINR, Dubna, Moscow Region, Russia
• N. Mityanina, V.M. Petrov, E. Rotov, A.G. Tribendis
BINP SB RAS, Novosibirsk, Russia

A specific feature of the NICA acceleration complex is high luminosity of colliding beams. Three types of RF stations will be used in the NICA Collider to reach the necessary beam parameters. The first one is for accumulation of particles in the longitudinal phase space with the moving burrier buckets under action of stochastic and/or electron cooling systems. The second and third RF stations are for formation of the final bunch size in the colliding regime. This report presents numerical simulations of longitudinal beam dynamics which taken into account the longitudinal space charge effect during the accumulation and bunching procedures. Influence of space effects leads to some decrease in the accumulation efficiency and requires special manipulation with the 2nd and 3rd RF stations during the adiabatic capture and bunching procedures.
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP015
About • paper received ※ 29 April 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019
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MOPMP016 Intra-Bunch Energy Spread Minimisation for CLIC Operation at a Centre-of-Mass Energy of 350 GeV 458

• N. Blaskovic Kraljevic, D. Arominski, D. Schulte
CERN, Meyrin, Switzerland

The first stage of the electron-positron Compact Linear Collider (CLIC) is designed with a centre-of-mass energy of 380 GeV. A dedicated threshold scan in the vicinity of 350 GeV is envisioned with a total integrated luminosity of 100 fb-1. This scan calls for a very small intra-bunch energy spread in order to achieve an excellent collision energy resolution. This paper presents an optimised assignment of RF accelerating gradients and phases in the CLIC main linac for operation at 350 GeV, which minimises the energy spread at the end of the main linac whilst preserving a small emittance growth. Variation of the bunch length and charge is studied in order to further reduce the energy spread; the effect on both the peak and total luminosity is discussed.
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP016
About • paper received ※ 13 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019
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MOPMP017 Beam Orbit Correction in the CLIC Main Linac Using a Small Subset of Correctors 461

• N. Blaskovic Kraljevic, D. Schulte
CERN, Meyrin, Switzerland

Beam orbit correction in future linear colliders, such as the Compact Linear Collider (CLIC), is essential to mitigate the effect of accelerator element misalignment due to ground motion. The correction is performed using correctors distributed along the accelerator, based on the beam position monitor (BPM) readout from the preceding bunch train, with a train repetition frequency of 50 Hz. This paper presents the use of the MICADO algorithm* to select a subset of N ~ 10 correctors (from a total of 576) to be used for orbit correction in the designed 380 GeV centre-of-mass energy first-stage of CLIC. The optimisation of the number N of correctors, the algorithm’s gain and the corrector step size is described, and the impact of a number of BPMs and correctors becoming unavailable is addressed. The application of a MICADO algorithm to perform dispersion free steering, by reducing the beam orbit difference between two beams with different energies, is discussed.
* B. Autin & Y. Marti, "Closed orbit correction of A.G. machines using a small number of magnets", CERN-ISR-MA/73-17, 1973.

DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP017
About • paper received ※ 13 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019
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MOPMP018 Beam-Based Beamline Element Alignment for the Main Linac of the 380 GeV Stage of CLIC 465

• N. Blaskovic Kraljevic, D. Schulte
CERN, Meyrin, Switzerland

The extremely small vertical beam size required at the interaction point of future linear colliders, such as the Compact Linear Collider (CLIC), calls for a very small vertical emittance. The strong wakefields in the high frequency 12 GHz CLIC accelerating structures set tight tolerances on the alignment of the main linac’s beamline elements and on the correction of the beam orbit through them in order to mantain a small emittance growth. This paper presents the emittance growth due to each type of beamline element misalignment in the designed 380 GeV centre-of-mass energy first-stage of CLIC, and the emittance growth following a series of beam-based alignment (BBA) procedures. The BBA techniques used are one-to-one steering, followed by dispersion free steering and finally accelerating structure alignment using wakefield monitors.
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP018
About • paper received ※ 13 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019
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MOPMP019 High Luminosity LHC Optics and Layout HLLHCV1.4 468

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

The goal of the High Luminosity Project is the upgrade of the LHC to deliver an integrated luminosity of at least 250 \rm fb-1 per year in each of the two high-luminosity, general-purpose detectors ATLAS and CMS. This article presents the latest layout design and the corresponding optics features, which comprise optimisation of the orbit corrector and crab cavity systems, and new estimates of the performance reach thanks to the new concept of fully remote alignment. In addition, the new optics version incorporates improvements required by beam instrumentation, dump system, and collimation system, as well as low-beta solutions for the LHCb experiment.
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP019
About • paper received ※ 17 April 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019
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MOPMP020 Smooth and Beta-Beating-Free Optics Transitions for HL-LHC 472

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

In the CERN LHC, optics transitions are mainly required to control the beam size at the four experimental interaction points. The current method, based on linearly-interpolated optics functions over a small set of matched optics and parabolic time-domain segments, introduces non-zero beta-beating and it is not optimal in time. This contribution presents an alternative approach, based on continuously-matched optics solutions distributed in time domain by using a realistic model of the superconducting circuits, which optimises the overall process duration. This method requires a change in the paradigm used in the control system and it is proposed for the future High Luminosity LHC (HL-LHC) runs.
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP020
About • paper received ※ 18 April 2019       paper accepted ※ 17 May 2019       issue date ※ 21 June 2019
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MOPMP022 K-Modulation in Future High Energy Colliders 476

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

K-Modulation of the quadrupoles closest to the interaction point (IP) has been an indispensable tool to accurately measure the beta-function in the interaction point (β*) in the Large Hadron Collider (LHC) at CERN. K-Modulation may become even more important to control the lower β* and reach the design luminosities in the High-Luminosity LHC (HL-LHC) and the Future Circular Collider (FCC). K-Modulation results also provide important input for the luminosity calibration and help in the identification and correction of errors in the machines. This paper presents a method for determining β* using K-Modulation adapted to the characteristic layout of both colliders. Using the latest models for the HL-LHC and the FCC-hh, estimated uncertainties on the measurements are presented. The results are compared to the accuracy of an alternative modulation scheme using a different powering scheme.
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP022
About • paper received ※ 06 May 2019       paper accepted ※ 18 May 2019       issue date ※ 21 June 2019
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MOPMP023 Dynamic Aperture at Injection Energy for the HE-LHC 480
SUSPFO101   use link to see paper's listing under its alternate paper code

• M. Hofer, M. Giovannozzi, J. Keintzel, R. Tomás, F. Zimmermann
CERN, Geneva, Switzerland
• L. van Riesen-Haupt
JAI, Oxford, United Kingdom

As part of the Future Circular Collider study, the High Energy LHC (HE-LHC) is a proposed hadron collider situated in the already existing LHC tunnel. It aims at achieving a center of mass energy of 27 TeV, almost doubling the design c.o.m. energy of the LHC. This increase in energy relies on the use of 16 T Nb3Sn dipoles to be developed for the FCC-hh. The field quality of these dipoles is expected to have a big impact on the Dynamic Aperture (DA) at injection energy and subsequently tracking studies are conducted to evaluate the impact of magnetic field errors on the beam dynamics. In the following the results of these studies for the different injection energies considered for the HE-LHC are presented and a possible strategy for increasing the DA are discussed.
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP023
About • paper received ※ 06 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019
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MOPMP024 Prospects for Future Asymmetric Collisions in the LHC 484

• M.A. Jebramcik, J.M. Jowett
CERN, Geneva, Switzerland

The proton-lead runs of the LHC in 2012, 2013 and 2016 provided luminosity far beyond expectations in a diversity of operating conditions and led to important new results in high-density QCD. This has permitted the scope of the future physics programme to be expanded in a recent review. Besides further high-luminosity p-Pb collisions, lighter nuclei are also under consideration. A short proton-oxygen run, on the model of the 2012 p-Pb run, would be of interest for cosmic-ray physics. Other collision systems like proton-argon or collisions of protons with other noble gases are also discussed. We provide an overview of the operational strategies and potential performance of various asymmetric collision options. Potential performance limits from moving beam-beam encounters at injection and various beam-loss mechanisms are evaluated in the light of our understanding of the LHC to date.
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP024
About • paper received ※ 18 April 2019       paper accepted ※ 18 May 2019       issue date ※ 21 June 2019
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MOPMP025 Moving Long-range Beam-beam Encounters in Heavy-ion Colliders 488
SUSPFO102   use link to see paper's listing under its alternate paper code

• M.A. Jebramcik, J.M. Jowett
CERN, Geneva, Switzerland

Asymmetric ion beam collisions like proton-lead in the LHC or gold-deuteron in RHIC have become major components of heavy-ion physics programmes. The injection and ramp of two different ion species with the same magnetic rigidity and consequently unequal revolution frequencies generate moving long-range beam-beam encounters in the interactions regions of the collider. These encounters led to fast beam losses and can cause emittance blow-up as observed in RHIC in the early 2000s and, more recently, in 2015. Yet such effects are absent at the LHC so the difference between the two colliders requires explanation. Tools and models have been developed to describe the beam dynamics of moving long-range beam-beam encounters and to predict the evolution of emittance and other beam parameters. Besides presenting results for RHIC and the LHC we give an outlook for the HL-LHC and potential operational restrictions.
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP025
About • paper received ※ 18 April 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019
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MOPMP026 HE-LHC Optics Design Options 492
SUSPFO103   use link to see paper's listing under its alternate paper code

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

The High Energy Large Hadron Collider (HE-LHC), a possible successor of the High Luminosity Large Hadron Collider (HL-LHC) aims at reaching a centre-of-mass energy of about 27 TeV using basically the same 16 T dipoles as for the hadron-hadron Future Circular Collider FCC-hh. Designing the HE-LHC results in a trade off between energy reach, beam stay clear as well as geometry offset with respect to the LHC. In order to best meet the requirements, various arc cell and dispersion suppressor options have been generated and analysed, before concluding on two baseline options, which are presented in this paper. Merits of each design are highlighted and possible solutions for beam stay clear minima are presented.
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP026
About • paper received ※ 02 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019
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MOPMP027 Second Order Dispersion Measurements in LHC 496

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

The quadratic dependence of the orbit on the relative momentum offset, also known as second order dispersion, is analysed for the first time for the LHC. In this paper, the measurement and analysis procedure are described. Results and implications on future optics are discussed.
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP027
About • paper received ※ 02 May 2019       paper accepted ※ 17 May 2019       issue date ※ 21 June 2019
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MOPMP029 Analysis on Bunch-by-Bunch Beam Losses at 6.5 TeV in the Large Hadron Collider 500
SUSPFO105   use link to see paper's listing under its alternate paper code

• K. Paraschou, G. Iadarola, N. Karastathis, S. Kostoglou, Y. Papaphilippou, L. Sabato
CERN, Geneva, Switzerland
• S. Kostoglou
National Technical University of Athens, Zografou, Greece
• K. Paraschou
AUTH, Thessaloniki, Greece

In 2018, a large fraction of the physics data taking at the Large Hadron Collider has been performed with a beam energy of 6.5 TeV, the nominal bunch spacing of 25 ns and beta functions at the high luminosity interaction points of 30 cm. In order to maximize the integrated luminosity, the crossing angles are gradually reduced as the beam intensity reduces due to luminosity burn-off. In these conditions the beam lifetime is visibly affected by collective effects and in particular by beam-beam interaction and electron cloud effects. By analyzing the beam losses at a bunch-by-bunch level, it is possible to disentangle the contributions from different effects and to assess the impact on the losses of changes applied to the machine configuration.
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP029
About • paper received ※ 10 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019
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MOPMP031 Operation and Performance of the Cern Large Hadron Collider During Proton Run 2 504

• R. Steerenberg, M. Albert, R. Alemany-Fernández, T. Argyropoulos, E. Bravin, G.E. Crockford, J.-C. Dumont, K. Fuchsberger, R. Giachino, M. Giovannozzi, G.H. Hemelsoet, W. Höfle, D. Jacquet, M. Lamont, E. Métral, D. Nisbet, G. Papotti, M. Pojer, L. Ponce, S. Redaelli, B. Salvachua, , M. Solfaroli, R. Suykerbuyk, G. Trad, J.A. Uythoven, S. Uznanski, D.J. Walsh, J. Wenninger, M. Zerlauth
CERN, Geneva, Switzerland

Run 2 of the CERN Large Hadron Collider (LHC) was successfully completed on 10th December 2018, achieving largely all goals set in terms of luminosity production. Following the first two-year long shutdown and the re-commissioning in 2015 at 6.5 TeV, the beam performance was increased to reach a peak luminosity of more than twice the design value and a colliding beam time ratio of 50%. This was accomplished thanks to the increased beam brightness from the injector chain, the high machine availability and the performance enhancements made in the LHC for which some methods and tools, foreseen for the High Luminosity LHC (HL-LHC) were tested and deployed operationally. This contribution provides an overview of the operational aspects, main limitations and achievements for the proton Run 2.
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP031
About • paper received ※ 13 May 2019       paper accepted ※ 17 May 2019       issue date ※ 21 June 2019
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MOPMP033 LHC Run 2 Optics Commissioning Experience in View of HL-LHC 508

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

LHC Run 2 has achieved a beta lower than a factor 2 below design. This has significantly challenged optics measurement and correction techniques in the linear and non-linear regimes, leading to the development of new approaches. Furthermore, experimenting with a large variety of optics has allowed facing the difficulties of future optics and gaining understanding of the machine imperfections. A summary of these aspects is given in view of their implications for the HL-LHC Project.
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP033
About • paper received ※ 07 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019
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MOPMP034 Tuning Studies of the CLIC 380 Gev Final Focus System 512

• J. Ögren, A. Latina, D. Schulte,
CERN, Meyrin, Switzerland

We present tuning studies of the Compact Linear Collider final-focus system under static imperfections including transverse misalignments, roll errors and magnetic strength errors. The tuning procedure consists of beam-based alignment for correcting the linear part of the system followed by sextupole pre-alignment and use of multipole tuning knobs. The sextupole pre-alignment is very robust and allows the tuning time to be greatly reduced.
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP034
About • paper received ※ 06 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019
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MOPMP035 Effect of Emittance Constraints on Monochromatization at the Future  Circular e+e Collider 516

• M.A. Valdivia García, F. Zimmermann
CERN, Meyrin, Switzerland

Direct s-channel Higgs production in e+e− collisions is of interest if the collision energy spread can be comparable to the natural width of the standard model Higgs boson. At the Future Circular e+e Collider (FCC-ee), a monochromatization scheme could be employed in order to reduce the collision energy spread to the target value. This may be achieved by introducing a non-zero horizontal dispersion of opposite sign for the two colliding beams at the interaction point. In this case, the beamstrahlung increases the horizontal emittance in addition to energy spread and bunch length.  The vertical emittance could either be tuned to a certain minimum value, possibly limited by the diagnostics resolution, or it could scale linearly with the horizontal emittance. For the FCC-ee at 62.5 GeV beam energy, we optimize the IP optics and beam parameters, considering these two different assumptions for the vertical emittance. We derive the maximum achievable luminosity as a function of collision energy spread for either case.
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP035
About • paper received ※ 16 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019
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MOPMP036 Machine Protection Experience from Beam Tests with Crab Cavity Prototypes in the CERN SPS 520

• B. Lindstrom, H. Bartosik, T. Bohl, A.C. Butterworth, R. Calaga, L.R. Carver, V. Kain, T.E. Levens, G. Papotti, R. Secondo, J.A. Uythoven, M. Valette, G. Vandoni, J. Wenninger, , M. Zerlauth
CERN, Meyrin, Switzerland

Funding: Work supported by the High Luminosity LHC project.
Crab cavities (CCs) constitute a key component of the High Luminosity LHC (HL-LHC) project. In case of a failure, they can induce significant transverse beam offsets within tens of microseconds, necessitating a fast removal of the circulating beam to avoid damage to accelerator components due to losses from the displaced beam halo. In preparation for the final design to be employed in the LHC, a series of tests were conducted on prototype crab cavities installed in the Super Proton Synchrotron (SPS) at CERN. This paper summarizes the machine protection requirements and observations during the first tests of crab cavities with proton beams in the SPS. In addition, the machine protection implications for future SPS tests and for the use of such equipment in the HL-LHC are discussed.

DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP036
About • paper received ※ 01 May 2019       paper accepted ※ 18 May 2019       issue date ※ 21 June 2019
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MOPMP037 Updated High-Energy LHC Design 524

• 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, J. Keintzel, R. Kersevan, V. Mertens, J. Molson, 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, A. Abramov, E. Cruz Alaniz, H. Pikhartova, 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

Funding: This work was supported in part by the European Commission under the HORIZON 2020 project ARIES no.730871, and by the Swiss Accelerator Research and Technology collaboration CHART.
We present updated design parameters for a future High-Energy LHC. A more realistic turnaround time has led to a revision of the target peak luminosity, as well as a choice of a larger IP beta function, and longer physics fills. Pushed parameters of the Nb3Sn superconducting cable together with a modified layout of the 16 T dipole magnets resulted in revised field errors, updated dynamic-aperture simulations, and an associated re-evaluation of injector options. Collimators in the dispersion suppressors help achieve satisfactory cleaning performance. Longitudinal beam parameters ensure beam stability throughout the cycle. Intrabeam scattering rates and Touschek lifetime appear benign.

DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP037
About • paper received ※ 10 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019
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MOPMP038 Investigation of CLIC 380 GeV Post-Collision Line 528

• R.M. Bodenstein, A. Abramov, S.T. Boogert, P. Burrows,
JAI, Oxford, United Kingdom
• D. Schulte, R. Tomás
CERN, Meyrin, Switzerland

It has been proposed that the Compact Linear Collider (CLIC) be commissioned in stages, starting with a lower-energy, 380 GeV version for the first stage, and concluding with a 3 TeV version for the final stage. In the Conceptual Design Report (CDR) published in 2012, the post-collision line is described for the 3 TeV and 500 GeV stages. However, the post-collision line for the 380 GeV design was not investigated. This work will describe the simulation studies performed in BDSIM for the 380 GeV post-collision line.
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP038
About • paper received ※ 13 May 2019       paper accepted ※ 18 May 2019       issue date ※ 21 June 2019
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MOPMP039 Developments in the Experimental Interaction Regions of the High Energy LHC 532

• L. van Riesen-Haupt, J.L. Abelleira
University of Oxford, Oxford, United Kingdom
• J.L. Abelleira, E. Cruz Alaniz
JAI, Oxford, United Kingdom
• J. Barranco García, T. Pieloni, C. Tambasco
EPFL, Lausanne, Switzerland
• M. Hofer, J. Keintzel, R. Tomás, F. Zimmermann
CERN, Geneva, Switzerland

Funding: Work supported by the Swiss institute for Accelerator Research and Technology , CHART.
The High Energy LHC (HE-LHC) aims to collide 13.5 TeV protons in two high luminosity experiments and two low luminosity experiments. In the following, the recent updates in the two high luminosity experimental interaction regions (EIR) of the HE-LHC will be illustrated. These EIR aim to focus the beams to a β* of 0.45 m at the interaction point (IP) to achieve a lifetime integrated luminosity of 10 ab-1. On top of the triplet optics designed to achieve this, it will present energy deposition driven separation dipole designs, optics solutions for the matching section and dispersion suppressors as well as studies involving the integration into the lattice options. In particular it will outline geometric considerations, spurious dispersion suppression as well as results from dynamic aperture studies.

DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP039
About • paper received ※ 14 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019
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MOPMP040 US Contributions to the High Luminosity LHC Upgrade - Focusing Quadrupoles and Crab Cavities 536

• G. Apollinari, G. Ambrosio, R.H. Carcagno, SF. Feher, L. Ristori
Fermilab, Batavia, Illinois, USA

In the early 2000’s, the US High Energy Physics community contributing to the Large Hadron Collider (LHC) launched the LHC Accelerator R&D Program) (LARP), a long-vision focused R&D program, intended to bring the Nb3Sn and other technologies to a maturity level that would allow applications in HEP machines. Around 2015, the technologies developed by LARP were mature enough to allow the spin-off of a major upgrade project to the LHC complex, the High Luminosity LHC (HL-LHC). This paper will focus on the US contribution to HL-LHC, namely the large-aperture low-beta focusing Nb3Sn quadrupoles and the Radio Frequency Dipole (RFD) Crab Cavities, located in close proximity to the ATLAS and CMS experiments. This contribution, called the HL-LHC Accelerator Upgrade Project (HL-LHC AUP), focuses on production of these quadrupoles and cavities by sharing the work among a consortium of US Laboratories (FNAL, LBNL, BNL and SLAC) and Universities and in close connection with the CERN-led HL-LHC Collaboration. The collaboration achieved commonality of specifications and uniformity of performance. Final development of design, construction and first results from the prototypes are described to indi-cate the status of these critical components for HL-LHC.
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP040
About • paper received ※ 30 April 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019
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MOPMP044 Improving the Luminosity for Beam Energy Scan II at RHIC 540

• C. Liu, M. Blaskiewicz, K.A. Drees, A.V. Fedotov, W. Fischer, C.J. Gardner, H. Huang, D. Kayran, Y. Luo, G.J. Marr, A. Marusic, K. Mernick, M.G. Minty, C. Montag, I. Pinayev, S. Polizzo, V.H. Ranjbar, D. Raparia, G. Robert-Demolaize, T. Roser, J. Sandberg, V. Schoefer, T.C. Shrey, S. Tepikian, P. Thieberger, A. Zaltsman, K. Zeno, I.Y. Zhang, W. Zhang
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 QCD (Quantum Chromodynamics) phase diagram has many uncharted territories, particularly the nature of the transformation from Quark-Gluon plasma (QGP) to the state of Hadronic gas. The Beam Energy Scan I (BES-I) at the Relativistic Heavy Ion Collider (RHIC) was completed but measurements had large statistical errors. To improve the statistical error and expand the search for first-order phase transition and location of the critical point, Beam Energy Scan II will commence in 2019 with a goal of improving the luminosity by a factor of 3-4. The beam lifetime at low energies was and will be limited by some physical effects of which the most significant are intrabeam scattering, space charge, beam-beam, persistent current effects. This article will review these potential limiting factors and introduce the countermeasures which will be in place to improve BES-II luminosity.

DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP044
About • paper received ※ 14 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019
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MOPMP045 RHIC Heavy Ion Operation With Near-Integer Working Point 544

• C. Liu, G.J. Marr, A. Marusic, M.G. Minty, V. Schoefer
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 interplay of space charge and beam-beam effects limits the beam lifetime at low energies at the Relativistic Heavy Ion Collider (RHIC). To improve the beam lifetime, a near-integer working point (0.096/0.094) was tested at fixed energy and during acceleration. In the demonstration experiments, we observed the benefit of the near-integer working point on beam lifetime, however, did not achieve the desired level of orbit correction. This article will present the experimental results of operation with a near-integer working point, and analyze the causes of the orbit control problem.

DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP045
About • paper received ※ 14 May 2019       paper accepted ※ 21 May 2019       issue date ※ 21 June 2019
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MOPMP046 Mitigation of Persistent Current Effects in the RHIC Superconducting Magnets 548

• C. Liu, D. Bruno, A. Marusic, M.G. Minty, P. Thieberger
BNL, Upton, Long Island, New York, USA
• X. Wang
LBNL, Berkeley, California, USA

Funding: This work was supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy.
Persistent currents in superconducting magnet introduce errors in the magnetic fields especially at low operating currents. In addition, their decay cause magnetic field variations therefore drifts of beam orbits, tunes and chromaticities. To reduce field errors and suppress magnetic field variations, new magnetic cycles were proposed for low energy beam operation at RHIC. In the new magnetic cycles, the magnet current oscillates around the operating current with diminishing amplitude a few times before it settles. The new magnetic cycle has been demonstrated experimentally to reduce field errors and the amplitude of magnetic field variations significantly and is essential for the ongoing RHIC Beam Energy Scan II (BES-II) program. This article will present beam-based experimental studies of the persistent current effects with the new magnetic cycle, and discuss its application in RHIC and accelerators based on superconducting magnet in general.

DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP046
About • paper received ※ 30 April 2019       paper accepted ※ 21 May 2019       issue date ※ 21 June 2019
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MOPMP048 LHC Doubler: CIC Dipole Technology May Make It Feasible and Affordable 552

• P.M. McIntyre
Texas A&M University, College Station, USA
• J. Breitschopf, J.N. Kellams, A. Sattarov
ATC, College Station, Texas, USA
• D.C.V. Chavez
Universidad de Guanajuato, División de Ciencias e Ingenierías, León, Mexico

There is new physics-driven interest in the concept of an LHC doubler with collision energy of 30 TeV and high luminosity. The cost-driver challenge for its feasibility is the ring of 16 T dual dipoles. Recent developments in cable-in-conduit (CIC) technology offer significant benefit for this purpose. The CIC windings provide robust stress management at the cable level and facilitate forming of the flared ends without degradation. The CIC windings provide a basis for hybrid windings, in which the innermost layers that operate in high field utilize Bi-2212, the center layers utilize Nb3Sn, and the outer layers utilize NbTi. Cryogen flows through the interior of all cables, so that heat transfer can be optimized throughout the windings. The design of the 18 T dipole and the 23 kA CIC conductor will be presented. Particular challenges for integration in an LHC doubler will be discussed.
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP048
About • paper received ※ 18 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019
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MOPMP049 6 T Cable-in-conduit Dipole to Double the Ion Energy for JLEIC 556

• P.M. McIntyre, J. Breitschopf, J. Gerity
Texas A&M University, College Station, USA
• J. Breitschopf, D.C.V. Chavez, J.N. Kellams, A. Sattarov
ATC, College Station, Texas, USA

The proposed electron-ion collider JLEIC would make high-luminosity collisions of polarized ions and polarized electrons with electron energy up to 12 GeV and ion energy up to 40 GeV/u. Both the luminosity and the collision energy could be increased by doubling the dipole field in the ion ring from 3 T to 6 T, and the enhanced performance would access the full range of parameters for the physics objectives of the project. The Texas A&M group has developed the large-aperture 3 T dipoles for the baseline project, based upon a novel superconducting cable-in-conduit. (CIC). A closely similar 6 T design is being developed, utilizing a 2-layer CIC. Details of the magnet design and development of the 2-layer CIC will be presented.
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP049
About • paper received ※ 19 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019
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MOPMP050 Performance of CeC PoP Accelerator 559

• I. Pinayev, Z. Altinbas, J.C. Brutus, A.J. Curcio, A. Di Lieto, T. Hayes, R.L. Hulsart, P. Inacker, Y.C. Jing, V. Litvinenko, J. Ma, G.J. Mahler, M. Mapes, K. Mernick, K. Mihara, T.A. Miller, M.G. Minty, G. Narayan, F. Severino, K. Shih, Z. Sorrell, J.E. Tuozzolo, E. Wang, G. Wang, A. Zaltsman
BNL, Upton, Long Island, New York, USA
• I. Petrushina
SUNY SB, Stony Brook, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
Coherent electron cooling experiment is aimed for demonstration of the proof-of-principle demonstration of reduction energy spread of a single hadron bunch circulating in RHIC. The electron beam should have the required parameters and its orbit and energy should be matched to the hadron beam. In this paper we present the achieved electron beam parameters including emittance, energy spread, and other critical indicators. The operational issues as well as future plans are also discussed.

DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP050
About • paper received ※ 15 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019
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MOPMP051 56 MHz SRF System for SPHENIX Experiments at RHIC 562

• Q. Wu, M. Blaskiewicz, K. Mernick, S. Polizzo, F. Severino, K.S. Smith, T. Xin
BNL, Upton, Long Island, New York, USA

Funding: Work supported by by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy
The sPHENIX experiment is a proposal for a new detector at the Relativistic Heavy Ion Collider (RHIC), that plans to expand on discoveries made by RHIC’s existing STAR and PHENIX research groups. To minimize the luminosity outside the 20 cm vertex detector and keeping the radiation to other detector components as low as possible, a 56 MHz SRF system is added to the existing RHIC RF systems to compress the bunches with less beam loss. The existing 56 MHz SRF cavity was commissioned in previous RHIC runs, and contributed to the luminosity at a voltage of 300kV with thermal limitations from the Higher Order Mode coupler at high field, and at 1MV while using its fundamental damper for HOM damping. In this paper, we will analyze and compare the effect of different RF systems at various scenarios, and discuss possible solutions to the Higher Order Mode (HOM) damping scheme to bring the cavity to 2 MV.

DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP051
About • paper received ※ 15 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019
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MOPMP052 Numerical Simulations of the DC Wire Prototypes in LHC for Enhancing the HL-LHC Performances 566

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

For the last 15 years, the compensation of the Beam-Beam Long-Range (BBLR) interaction in colliders using DC wires has been studied. In 2015, in the frame of the HL-LHC project, it has been shown that a compensation of all the Resonance Driving Terms (RDTs) generated by the BBLR interaction is possible using wires with constraints on their transverse and longitudinal positions. In 2017, an experimental campaign has been launched in the present LHC, with wires installed in sub-optimal positions due to integration constraints. The aim of this paper is therefore to apply the formalism developped for HL-LHC to the LHC case and to compare the experimental results to the numerical tracking studies of the compensation using wires.
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP052
About • paper received ※ 06 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019
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MOPMP053 Numerical Optimization of DC Wire Compensation in HL-LHC 570

• K. Skoufaris, S.D. Fartoukh, N. Karastathis, Y. Papaphilippou, D. Pellegrini, A. Poyet, A. Rossi,
CERN, Meyrin, Switzerland

The electromagnetic field generated from a set of DC wires parallel to the beam opens the path to the compensation of the beam-beam long-range (BBLR) interactions for the future operation of large hadron colliders, in particular for the upcoming High Luminosity upgrade of the Large Hadron Collider (HL-LHC). The effectiveness and simplicity of a current carrying wire are critical for overcoming some technical constraints of the machine. In order to better understand the potential of this device for the HL-LHC, various simulation studies are presented. The different observables are the dynamic aperture and the frequency analysis.
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP053
About • paper received ※ 03 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019
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