Keyword: collider
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MOPWA065 Affordable, Short Pulse MARX Modulator controls, high-voltage, shielding, linear-collider 828
 
  • R.A. Phillips, M.P.J. Gaudreau, M.K. Kempkes, B.E. Simpson
    Diversified Technologies, Inc., Bedford, Massachusetts, USA
  • J.A. Casey
    Rockfield Research Inc., Las Vegas, Nevada, USA
  
  Under a U.S. Department of Energy grant, Diversified Technologies, Inc. (DTI) is developing a short pulse, solid-state Marx modulator for the next generation of klystrons and accelerators. For short-pulse modulators, this Marx topology provides a means to achieve astounding risetimes and flattop control that are simply not available with hard switch or transformer coupled topologies. The design is a high peak-power pulse modulator of greater efficiency than presently available, in the 100 kV to 1 MV range, for currents of 0.1 to 1 kA, pulse lengths of 0.2 to 5.0 us, and rise/fall times 10% of pulse length. A key objective of the development effort is a design which is modular and scalable, yet low cost, and easy to manufacture and maintain. The modulator will be delivered to Yale Beam Physics Laboratory for evaluation, and will be affordable for deployment at other national labs for klystron and modulator evaluation. In this paper, DTI will describe the new design and provide an update on progress.  
 
MOPWO036 Civil Engineering Feasibility Studies for Future Ring Colliders at CERN linac, civil-engineering, hadron, electron 969
 
  • J.A. Osborne, O.S. Brüning, M. Klein, S. Myers, S. Myers, L. Rossi, C.S. Waaijer, F. Zimmermann
    CERN, Geneva, Switzerland
  • M. Klein
    DESY Zeuthen, Zeuthen, Germany
  
  CERN civil engineers are studying the feasibility of future ring colliders to complement the LHC. Infrastructure works typically represent one third of the cost of major physics projects, so it's critical that the construction costs are well understood from the conceptual stage. This poster presents the first results of the feasibility studies for two potential ring colliders at CERN: the racetrack shaped Linac-Ring LHeC and an 80km circular tunnel to house the High Energy LHC (SHE-LHC) and the TLEP. Some of the key civil engineering challenges faced in such large scale projects are presented with particular emphasis on geology, design and risk.  
 
MOPWO049 Lifetime Analysis at High Intensity Colliders Applied to the LHC proton, collimation, beam-losses, luminosity 1005
 
  • B. Salvachua, R.W. Aßmann, R. Bruce, F. Burkart, S. Redaelli, G. Valentino, D. Wollmann
    CERN, Geneva, Switzerland
  • G. Valentino
    University of Malta, Information and Communication Technology, Msida, Malta
  
  The beam lifetime is one of the main parameters to define the performance of a collider. In a super-conducting machine like the LHC, the lifetime determines the intensity reach for a given collimation cleaning. The beam lifetime can be calculated from the direct measurement of beam current. However, due to the noise in the beam current signal only an average lifetime over several seconds can be calculated. We propose here an alternative method, which uses the signal of the beam loss monitors in the vicinity of the primary collimators to get the instantaneous beam lifetime at the collimators. In this paper we compare the lifetime from the two methods and investigate the minimum lifetime over the LHC cycle for all the physics fills in 2011 and 2012. These data provide a reference for estimates of performance reach from collimator cleaning.  
 
MOPWO053 Evolution of the Tracking Code PLACET wakefield, simulation, linac, cavity 1014
 
  • A. Latina, Y.I. Levinsen, D. Schulte
    CERN, Geneva, Switzerland
  • J. Snuverink
    JAI, Egham, Surrey, United Kingdom
  
  The tracking code PLACET simulates beam transport and orbit corrections in linear accelerators. It incorporates single- and multi-bunch effects, static and dynamic imperfections. A major restructuring of its core has resulted in an improvement in its modularity, with some immediate advantages: its tracking core, which is one of the fastest available for this kind of simulations, is now interfaced toward three different scripting languages to offer great simulation capabilities: Tcl/Tk, Octave and Python. These three languages provide access to a vast library of scientific tools, mechanisms for parallel computing, and access to Java interfaces for control systems (such as that of CTF3). Also, new functionalities have been added: parallel tracking to exploit modern multicore CPUs, the possibility to track through the interaction region in presence of external magnetic fields (detector solenoid) and higher order imperfections in magnets. PLACET is currently used to simulate the CLIC Drive Beam, the CLIC Main Beam, CTF3, FACET at SLAC, and ATF2 at KEK.  
 
MOPWO077 Design of the Proposed Low Energy Ion Collider Ring at Jefferson Lab ion, booster, electron, interaction-region 1058
 
  • E.W. Nissen, F. Lin, V.S. Morozov, Y. Zhang
    JLAB, Newport News, Virginia, USA
  
  Funding: Supported by the U.S. Department of Energy, Office of Nuclear Physics, under Contract No. DE-AC05-06OR23177 and DE-AC02-06CH11357.
The polarized Medium energy Electron-Ion Collider (MEIC) envisioned at Jefferson Lab will cover a range of center-of-mass energies up to 65 GeV. The present MEIC design could also allow the accommodation of low energy electron-ion collisions (LEIC) for additional science reach. This paper presents the first design of the low energy ion collider ring which is converted from the large ion booster of MEIC. It can reach up to 25 GeV energy for protons and equivalent ion energies of the same magnetic rigidity. An interaction region and an electron cooler designed for MEIC are integrated into the low energy collider ring, in addition to other required new elements including crab cavities and ion spin rotators, for later reuse in MEIC itself. A pair of vertical chicanes which brings the low energy ion beams to the plane of the electron ring and back to the low energy ion ring are also part of the design. 		 
 
MOPWO078 A Harmonic Kicker Scheme for the Circulator Cooler Ring in the Medium Energy Electron-ion Collider kicker, electron, ion, FEL 1061
 
  • E.W. Nissen, A. Hutton, A.J. Kimber
    JLAB, Newport News, Virginia, USA
  
  Funding: Supported by the U.S. Department of Energy, Office of Nuclear Physics, under Contract No. DE-AC05-06OR23177 and DE-AC02-06CH11357.
The current electron cooler design for the proposed Medium Energy Electron-Ion collider (MEIC) at Jefferson Lab utilizes a circulator ring for reuse of the cooling electron bunch up to 100 times to cool the ion beams. This cooler requires a fast kicker system for injecting and extracting individual bunches in the circulator ring. Such a kicker must work at a high repetition rate, up to 7.5 to 75 MHz depending on the number of turns in the recirculator ring. It also must have a very short rise and fall time (of order of 1 ns) such that it will kick an individual bunch without disturbing the others in the ring. Both requirements are orders of magnitude beyond the present state-of-the-art as well as the goals of other on-going kicker R&D programs such as that for the ILC damping rings. In this paper we report a scheme of creating this fast, high repetition rate kicker by combining RF waveforms at multiple frequencies to create a kicker waveform that will, for example, kick every eleventh bunch while leaving the other ten unperturbed. We also present a possible implementation of this scheme as well as discuss its limitations. 		 
 
MOPWO080 GPU-optimized Code for Long-term Simulations of Beam-beam Effects in Colliders simulation, luminosity, electron, damping 1064
 
  • Y. Roblin, V.S. Morozov, B. Terzić
    JLAB, Newport News, Virginia, USA
  • M. Aturban, D. Ranjan, M. Zubair
    ODU CS, Norfolk, USA
  
  Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177.
We report on the development of the new code for long-term simulation of beam-beam effects in particle colliders. The underlying physical model relies on a matrix-based arbitrary-order symplectic particle tracking for beam transport and the Bassetti-Erskine approximation for beam-beam interaction. The computations are accelerated through a parallel implementation on a hybrid GPU/CPU platform. With the new code, a previously computationally prohibitive long-term simulations become tractable. We use the new code to model the proposed medium-energy electron-ion collider (MEIC) at Jefferson Lab. 		 
 
MOPWO081 The Scheme of Beam Synchronization in MEIC ion, electron, proton, SRF 1067
 
  • Y. Zhang, Y.S. Derbenev, A. Hutton
    JLAB, Newport News, Virginia, USA
  
  Funding: Supported by the U.S. Department of Energy, Office of Nuclear Physics, under Contract No. DE-AC05-06OR23177 and DE-AC02-06CH11357.
Synchronizing colliding beams at single or multiple collision points is a critical R&D issue in the design of a medium energy electron-ion collider (MEIC) at Jefferson Lab. The path-length variation due to changes in the ion energy, which varies over 20 to 100 GeV, could be more than several times the bunch spacing. The scheme adopted in the present MEIC baseline is centered on varying the number of bunches (i.e., harmonic number) stored in the collider ring. This could provide a set of discrete energies for proton or ions such that the beam synchronization condition is satisfied. To cover the ion energy between these synchronized values, we further propose to vary simultaneously the electron ring circumference and the frequency of the RF systems in both collider rings. We also present in this paper the requirement of frequency tunability of SRF cavities to support the scheme. 		 
 
MOPWO083 LEIC - A Polarized Low Energy Electron-ion Collider at Jefferson Lab ion, electron, booster, proton 1070
 
  • Y. Zhang, Y.S. Derbenev, A. Hutton, G.A. Krafft, R. Li, F. Lin, V.S. Morozov, E.W. Nissen, R.A. Rimmer, H. Wang, S. Wang, B.C. Yunn, H. Zhang
    JLAB, Newport News, Virginia, USA
  • M.K. Sullivan
    SLAC, Menlo Park, California, USA
  
  Funding: Supported by the U.S. Department of Energy, Office of Nuclear Physics, under Contract No. DE-AC05-06OR23177 and DE-AC02-06CH11357.
A polarized electron-ion collider is envisioned as the future nuclear science program at JLab beyond the 12 GeV CEBAF. Presently, a medium energy collider (MEIC) is set as an immediate goal with options for a future energy upgrade. A comprehensive design report for MEIC has been released recently. The MEIC facility could also accommodate electron and proton/ion collisions in a low CM energy range, covering proton energies from 10 to 25 GeV and ion energies with a similar magnetic rigidity, for additional science reach. In this paper, we present a conceptual design of this low energy collider, LEIC, showing its luminosity can reach above 1033 cm-2s−1. The design specifies that the large booster of the MEIC is converted to a low energy ion collider ring with an interaction region and an electron cooler integrated into it. The design provides options for either sharing the detector with the MEIC or a dedicated low energy detector in a third collision point, with advantages of either a minimum cost or extra detection parallel to the MEIC operation, respectively. The LEIC could be positioned as the first and low cost phase of a multi-stage approach to realize the full MEIC. 		 
 
TUOCB203 In Vacuum High Accuracy Mechanical Positioning System of Nano Resolution Beam Position Monitor at the Interaction Point of ATF2 feedback, vacuum, alignment, linear-collider 1149
 
  • P. Bambade, O.R. Blanco, F. Bogard, P. Cornebise, S. Wallon
    LAL, Orsay, France
  • T. Tauchi, N. Terunuma
    KEK, Ibaraki, Japan
  
  ATF2 is a low energy (1.3GeV) prototype of the final focus system for ILC and CLIC linear collider projects. A major goal of ATF2 is to demonstrate the ability to stabilise the beam position at the interaction point, where the beam can be focused down to about 35 nm. For this purpose, a set of new Beam Position Monitors (BPM) has been designed, with an expected resolution of about 2 nm. These BPMs must be very well aligned with respect to the beam, at the few micron level, to fully exploit their fine resolution. In this paper, the mechanical positioning system which has been developed to enable such a precise alignment is presented. It is based on a set of eight piezo actuators with nanometer range displacement resolution, mounted in a new specially made vacuum chamber. Due to the expected resolution of the piezo actuators, this system also brings a new functionality, the possibility to calibrate the BPMs by mechanically scanning the beam.  
slides icon Slides TUOCB203 [2.276 MB]  
 
TUPEA021 Calculation of Wakefields in Plasma Filled Dielectric Capillaries Generated by a Relativistic Electron Beam plasma, wakefield, electron, positron 1205
 
  • C. Li, W. Gai
    ANL, Argonne, USA
  • C. Li, C.-X. Tang, H. Zha
    TUB, Beijing, People's Republic of China
  
  In this paper we give an analytical solution of TM0n mode for wakefields generated by a relativistic electron beam passing through plasma-filled capillary waveguides. The numerical solution shows that the fields of TM0n modes could not be ignored when the plasma wave length is comparable with the effective radius of the capillary tube, which means that the boundaries are not shielded completely by plasma. Numerical examples are given in several typical cases.  
 
TUPEA088 Argonne Flexible Linear Collider linac, linear-collider, klystron, wakefield 1322
 
  • C.-J. Jing, S.P. Antipov, A. Kanareykin, P. Schoessow
    Euclid TechLabs, LLC, Solon, Ohio, USA
  • M.E. Conde, W. Gai, J.G. Power
    ANL, Argonne, USA
  
  We propose a linear collider based on a short rf pulse (~22ns flat top), high gradient (~120MV/m loaded gradient), high frequency (26GHz) two beam accelerator design. This is a modular design and its unique locally repetitive drive beam structure allows a flexible configuration to meet different needs. Major parameters of a conceptual 250GeV linear collider are presented. This preliminary study shows that an efficient (~5% overall), 4MW beam power collider may be achievable. The concept is extendable to the TeV scale.  
 
TUPFI009 NICA project at JINR ion, booster, luminosity, heavy-ion 1343
 
  • G.V. Trubnikov, N.N. Agapov, E.D. Donets, V.V. Fimushkin, E.V. Gorbachev, A. Govorov, E.V. Ivanov, V. Karpinsky, V.D. Kekelidze, H.G. Khodzhibagiyan, A.D. Kovalenko, K.A. Levterov, V.A. Matveev, I.N. Meshkov, V.A. Mikhailov, V. Monchinsky, S. Romanov, N. Shurkhno, A.O. Sidorin, V. Slepnev, A.V. Smirnov, A. Sorin, N.D. Topilin
    JINR, Dubna, Moscow Region, Russia
  • O.I. Brovko, A.V. Butenko, E.E. Donets, A.V. Eliseev, O.S. Kozlov, A.V. Philippov, N.V. Semin, A. Tuzikov, V. Volkov
    JINR/VBLHEP, Moscow, Russia
  
  The Nuclotron-based Ion Collider fAcility (NICA) is a new accelerator complex being constructed at JINR aimed to provide the collider experiments with ion-ion (Au79+) and ion-proton collisions at the energy range of 1-4.5 GeV/n and also the collisions of polarized proton-proton and deuteron-deuteron beams. Progress in the project realization is reported.  
 
TUPFI012 HL-LHC: Integrated Luminosity and Availability luminosity, target, simulation, hadron 1352
 
  • A. Apollonio, M. Jonker, R. Schmidt, B. Todd, S. Wagner, D. Wollmann, M. Zerlauth
    CERN, Geneva, Switzerland
  
  The objective of LHC operation is to optimise the output for particle physics by maximising the integrated luminosity. An important constraint comes from the event pile–up for one bunch crossing that should not exceed 140 events per bunch crossing. With bunches every 25 ns the luminosity for data taking of the experiments should therefore not exceed 5*1034 s−1cm-2. For the optimisation of the integrated luminosity it is planned to design HL-LHC for much higher luminosity than acceptable for the experiments and to limit the initial luminosity by operating with larger beam size at the collision points. During the fill, the beam size will be slowly reduced to keep the luminosity constant. The gain from luminosity levelling depends on the average length of the fills. Today, with the LHC operating at 4 TeV, most fills are terminated due to equipment failures, resulting in an average fill length of about 5 h. In this paper we discuss the expected integrated luminosity for HL-LHC as a function of fill length and time between fills, depending on the expected MTBF of the LHC systems with HL-LHC parameters. We derive an availability target for HL-LHC and discuss steps to achieve this.  
 
TUPFI020 Towards a Symmetric Momentum Distribution in the Muon Ionization Cooling Experiment simulation, solenoid, quadrupole, emittance 1376
 
  • O.M. Hansen
    University of Oslo, Oslo, Norway
  • A.P. Blondel
    DPNC, Genève, Switzerland
  • I. Efthymiopoulos, O.M. Hansen
    CERN, Geneva, Switzerland
  
  The Muon Ionization Cooling Experiment (MICE) is under development at Rutherford Appleton Laboratory (UK). It's a proof-of-principle experiment for ionization cooling, which is a prerequisite for a future Neutrino Factory(NF) or a Muon Collider. The muon beam is designed to have a symmetrical momentum distribution in the cooling channel of the NF. In the MICE beamline pions are captured by a quadrupole triplet, then pion momentum is selected by dipole 1 (D1) after which the pions decay to muons in the decay solenoid. After the decay solenoid, the muon beam momentum is selected by dipole 2 (D2), the beam is focused in two quadrupole triplets and is finally characterized by a set of detectors. By doing a D1-scan of the currents, where the optics parameters are scaled according to the pion momentum, from 238-450 MeV/c the muon momentum distribution is changed. In this paper simulation results from G4Beamline and real data from MICE are presented and compared.  
 
TUPFI024 Influence of the Ats Optics on Intra-Beam Scattering for HL-LHC optics, luminosity, emittance, simulation 1388
 
  • M. Schaumann, R. Bruce, J.M. Jowett
    CERN, Geneva, Switzerland
  • M. Schaumann
    RWTH, Aachen, Germany
  
  In the future High Luminosity (HL-)LHC the influence of intra-beam scattering (IBS) will be stronger than in the present LHC, because of higher bunch intensity, small emittance and new optics. The new ATS-optics scheme modifies the lattice in the arcs around the main interaction points (IP) to provide β* values as small as 0.15m in the IP, however those modifications affect the IBS growth rates. In this paper proton IBS emittance growth rates are calculated with MADX and the Collider Time Evolution (CTE) program for two ATS-optics versions, different settings of the crossing angles and required corrections and various beam conditions at injection (450 GeV) and collision (7 TeV) energy. CTE simulations of the expected luminosity, intensity, emittance and bunch length evolution during fills are also presented  
 
TUPFI031 Effect of Collision Pattern in the LHC on the Beam Stability: Requirements from Experiments and Operational Considerations luminosity, damping, injection, proton 1409
 
  • W. Herr, G. Arduini, R. Giachino, E. Métral, G. Papotti, T. Pieloni
    CERN, Geneva, Switzerland
  • X. Buffat, N. Mounet
    EPFL, Lausanne, Switzerland
  • S.M. White
    BNL, Upton, Long Island, New York, USA
  
  Coherent instabilities of bunches in the LHC bunch train can be observed when the tune spread from beam-beam interactions becomes insufficient to ensure Landau damping. In particular these effects are seen on bunches with a reduced number of beam-beam interactions due to their collision pattern. Furthermore, such a reduction of the necessary stability can occur during the processes when the beams are prepared for collisions or during the optimization procedure. We discuss the observations and possible countermeasures, in particular alternatives to the existing beam manipulation processes where such a situation can occur.  
 
TUPFI033 Colliding During the Squeeze and β* Leveling in the LHC luminosity, impedance, controls, optics 1415
 
  • X. Buffat
    EPFL, Lausanne, Switzerland
  • W. Herr, M. Lamont, T. Pieloni, S. Redaelli, J. Wenninger
    CERN, Geneva, Switzerland
  
  While more challenging operationally, bringing the beams into collisions during the β squeeze rather than after presents some advantages. The large tune spread arising from the non-linearity of head-on beam-beam interactions can damp impedance-driven instabilities much more efficiently than external non-linearity such as octupoles presently used in operation. Moreover, colliding during the squeeze allows to level the luminosity, optimizing the pile-up in the experiments without changing the longitudinal distribution of collisions. Operational issues are discussed and experimental results from the LHC are presented.  
 
TUPFI040 Experimental Verification of the CLIC Two-Beam Acceleration Technology in CTF3 linac, acceleration, feedback, bunching 1436
 
  • P. Skowroński, A. Andersson, J. Barranco, B. Constance, R. Corsini, S. Döbert, A. Dubrovskiy, W. Farabolini, E. Ikarios, R.L. Lillestøl, T. Persson, F. Tecker
    CERN, Geneva, Switzerland
  • W. Farabolini
    CEA/DSM/IRFU, France
  • E. Ikarios
    National Technical University of Athens, Athens, Greece
  • M. Jacewicz, A. Palaia, R.J.M.Y. Ruber
    Uppsala University, Uppsala, Sweden
  • R.L. Lillestøl
    University of Oslo, Oslo, Norway
  • T. Persson
    Chalmers University of Technology, Chalmers Tekniska Högskola, Gothenburg, Sweden
  
  The Compact Linear Collider (CLIC) International Collaboration is pursuing an extensive R&D program towards a multi-TeV electron-positron collider. In particular, the development of two beam acceleration technology is the focus of the CLIC test facility CTF3. In this paper we summarize the most recent results obtained at CTF3: the results of the studies on the drive beam generation are presented, the achieved two beam acceleration performance is reported and the measured break-down rates and related observations are summarized. The stability of deceleration process performed over 13 subsequent modules and the comparison of the obtained results with the theoretical expectations are discussed. We also outline and discuss the future experimental program.  
 
TUPFI042 Beam Parameters and Luminosity Time Evolution for an 80-km VHE-LHC emittance, luminosity, radiation, damping 1442
 
  • C.O. Domínguez, F. Zimmermann
    CERN, Geneva, Switzerland
  
  The Very High Energy LHC (VHE-LHC) is a recently proposed proton-proton collider in a new 80-km tunnel. With a dipole field of 15-20 T it would provide a collision energy of 76-100 TeV c.m. We discuss the VHE-LHC beam parameters and compute the time evolution of luminosity, beam current, emittances, bunch length, and beam-beam tune shift during a physics store. The results for VHE-LHC are compared with those for HE-LHC, a 33-TeV (20-T field) collider located in the existing LHC tunnel.  
 
TUPFI043 Matching Antisymmetric Arc Optics to Symmetric Interaction Region optics, quadrupole, focusing, hadron 1445
 
  • J.L. Abelleira, F. Zimmermann
    CERN, Geneva, Switzerland
  • J.L. Abelleira
    EPFL, Lausanne, Switzerland
  
  Funding: Work supported by the European Commission under the FP7 Research Infrastructures project Eu- CARD, grant agreement no. 227579.
Considering a generic double-ring collider, we discuss the matching from an antisymmetric optics in the arcs to a symmetric optics in the interaction region (IR) by means of an antisymmetric matching section (MS). As an example, we present an application to the LHC, for which a symmetric IR with extremely flat beams is under study. 		 
 
TUPFI056 A Muon Collider as a Higgs Factory luminosity, emittance, factory, target 1472
 
  • D.V. Neuffer, Y.I. Alexahin, M.A. Palmer
    Fermilab, Batavia, USA
  • C.M. Ankenbrandt
    Muons. Inc., USA
  • J.-P. Delahaye
    SLAC, Menlo Park, California, USA
  
  Because muons connect directly to a standard-model Higgs particle in s-channel production, a muon collider would be an ideal device for precision measurement of the mass and width of a Higgs-like particle, and for further exploration of its production and decay properties. The LHC has seen evidence for a 126 GeV Higgs particle, and a muon collider at that energy could be constructed. Parameters of a high-precision muon collider are presented and the necessary components and performance are described. An important advantage of the muon collider approach is that the spin precession of the muons will enable energy measurements at extremely high accuracy (E/E to 10-6 or better). Extension to a higher-energy higher-luminosity device is also discussed.  
 
TUPFI057 Muon Accelerators for the Next Generation of High Energy Physics Experiments factory, proton, target, background 1475
 
  • M.A. Palmer, S. Brice, A.D. Bross, D.S. Denisov, E. Eichten, R.J. Lipton, D.V. Neuffer
    Fermilab, Batavia, USA
  • C.M. Ankenbrandt
    Muons. Inc., USA
  • S.A. Bogacz
    JLAB, Newport News, Virginia, USA
  • J.-P. Delahaye
    SLAC, Menlo Park, California, USA
  • P. Huber
    Virginia Polytechnic Institute and State University, Blacksburg, USA
  • D.M. Kaplan, P. Snopok
    Illinois Institute of Technology, Chicago, Illinois, USA
  • H.G. Kirk, R.B. Palmer
    BNL, Upton, Long Island, New York, USA
  • R.D. Ryne
    LBNL, Berkeley, California, USA
  
  Funding: Work supported by the U.S. Department of Energy and the U.S. National Science Foundation
Muon accelerator technology offers a unique and very promising avenue to a facility capable of producing high intensity muon beams for neutrino factory and multi-TeV lepton collider applications. The goal of the US Muon Accelerator Program is to provide an assessment, within the next 6 years, of the physics potential and technical feasibility of such a facility. This talk will describe the physics opportunities that are envisioned, along with the R&D efforts that are being undertaken to address key accelerator physics and technology questions. 		 
 
TUPFI061 Preliminary Design of a Higgs Factory μ+μ- Storage Ring quadrupole, dipole, factory, storage-ring 1487
 
  • A.V. Zlobin, Y.I. Alexahin, V.V. Kapin, V.V. Kashikhin, N.V. Mokhov, I.S. Tropin
    Fermilab, Batavia, USA
  
  Funding: Work supported by Fermi Research Alliance, LLC, under contract No. DE-AC02-07CH11359 with the U.S. Department of Energy, and by the US Department of Energy through the Muon Accelerator Program (MAP).
A Muon Collider offers unique possibilities for studying the recently found Higgs boson. Higgs bosons can be produced in reasonable amounts in the s-channel, so that the colliding muon beam energy of just 62.5GeV is required. Precision direct measurements of the Higgs boson mass and width is possible due to absence of brems- and beam-strahlung. At the same time, there are difficulties specific to muon colliders: relatively large beam emittance which necessitates quite small beta-function values (~ a few cm) at the interaction point in order to obtain sufficiently high luminosity, as well as superconducting magnet and detector protection from showers generated by muon decay products. Due to these factors, the required aperture of the final focus quadrupoles is very large (up to 0.5 m) posing challenging engineering constraints as well as beam dynamics issues with fringe fields. The first results of a complex approach to these problems in the Higgs Factory collider design are presented which promise luminosities in excess of 1031 cm-2s−1 with a 4 MW proton driver. 		 
 
TUPFI068 High Power Tests of Alumina in High Pressure RF Cavities for Muon Ionization Cooling Channel cavity, pick-up, resonance, klystron 1508
 
  • L.M. Nash
    University of Chicago, Chicago, Illinois, USA
  • G. Flanagan, R.P. Johnson, F. Marhauser, J.H. Nipper
    Muons. Inc., USA
  • M.A. Leonova, A. Moretti, M. Popovic, A.V. Tollestrup, K. Yonehara
    Fermilab, Batavia, USA
  • Y. Torun
    IIT, Chicago, Illinois, USA
  
  It is important to make a compact muon ionization cooling channel to increase the cooling efficiency (muon survival rate, cooling decrement, etc). A proposed scheme to reduce the radial size of RF cavities at a given resonance frequency is to insert a dielectric material into the RF cavity. In vacuum cavities, however, dielectric materials are extremely susceptible to breakdown in high power conditions. High-pressure hydrogen gas has been shown to inhibit breakdown events in RF cavities in strong magnetic fields. An experiment has been designed to test surface breakdown of alumina in RF cavities. A structure has been designed to maximize the parallel field parallel to the surface while bringing the cavity into a desired frequency range (800-810MHz). Alumina is tested in this configuration under high power conditions. The experimental result will be shown in this presentation.  
 
TUPFI069 Influence of Proton Beam Emittances on Particle Production off a Muon Collider Target target, proton, emittance, factory 1511
 
  • X.P. Ding, D.B. Cline
    UCLA, Los Angeles, California, USA
  • J.S. Berg, H.G. Kirk, H. K. Sayed
    BNL, Upton, Long Island, New York, USA
  • V.B. Graves
    ORNL, Oak Ridge, Tennessee, USA
  • K.T. McDonald
    PU, Princeton, New Jersey, USA
  • N. Souchlas, R.J. Weggel
    Particle Beam Lasers, Inc., Northridge, California, USA
  
  Funding: Work supported in part by US DOE Contract NO. DE-AC02-98CHI10886.
A free-mercury-jet or a free-gallium-jet is considered for the pion-production target at a Muon Collider or Neutrino Factory. Based on a simple Gaussian incident proton beams with an infinitely large Courant-Snyder β parameters, we have previously optimized the geometric parameters of the target to maximize particle production initiated by incoming protons with kinetic energies (KE) between 2 and 16 GeV by using the MARS15 code. In this paper, we extend our optimization to focused proton beams with various transverse emittances. For the special cases of proton beams with emittances of 2.5, 5 or 10 μm-rad and a kinetic energy of 8 GeV, we optimized the geometric parameters of the target: the radius of the proton beam, the radius of the liquid jet, the crossing angle between the jet and the proton beam, and the incoming proton beam angle. We also study the influence of a shift of the beam focal point relative to the intersection point of the beam and the jet. 		 
 
TUPFI073 Design of Magnets for the Target and Decay Region of a Muon Collider/Neutrino Factory Target target, factory, solenoid, proton 1514
 
  • R.J. Weggel, N. Souchlas
    Particle Beam Lasers, Inc., Northridge, California, USA
  • X.P. Ding
    UCLA, Los Angeles, California, USA
  • V.B. Graves
    ORNL, Oak Ridge, Tennessee, USA
  • H.G. Kirk, H. K. Sayed
    BNL, Upton, Long Island, New York, USA
  • K.T. McDonald
    PU, Princeton, New Jersey, USA
  
  The target and decay region of a Muon Collider/Neutrino Factory transports pions and muons in a superconducting solenoid channel that must be protected from radiation damage secondary particles produced by the 4-MW proton beam. For this, He-gas-cooled tungsten beads will be arrayed inside the magnet coils, which leads to large coil radii and high stored magnetic energy (~3 GJ). The design of the superconducting coils, and the tungsten shielding for the ~ 50-m-long target and decay region is reviewed.  
 
TUPFI074 Design of the Final Focus of the Proton Beam for a Neutrino Factory target, proton, factory, quadrupole 1517
 
  • J. Pasternak, M. Aslaninejad
    Imperial College of Science and Technology, Department of Physics, London, United Kingdom
  • K. E. Gollwitzer
    Fermilab, Batavia, USA
  • H.G. Kirk
    BNL, Upton, Long Island, New York, USA
  • K.T. McDonald
    PU, Princeton, New Jersey, USA
  
  The ~ 8-GeV, 4-MW proton beam that drives a Neutrino Factory has a nominal 50-Hz macropulse structure with 2-3 micropulses ~ 100 ns apart. The nominal geometric beam emittance is 5 micron, and the desired rms beam radius at the liquid-metal-jet target is 1.2 mm. A quadrupole-triplet focusing system to deliver this beam spot is described.  
 
TUPFI075 Optimizing Muon Capture and Transport for a Neutrino Factory/Muon Collider Front End target, solenoid, proton, factory 1520
 
  • H. K. Sayed, J.S. Berg, H.G. Kirk
    BNL, Upton, Long Island, New York, USA
  • X.P. Ding
    UCLA, Los Angeles, California, USA
  • K.T. McDonald
    PU, Princeton, New Jersey, USA
  
  In the baseline scheme of the Neutrino Factory/Muon Collider a muon beam from pion decay is produced by bombarding a liquid-mercury-jet target with a 4-MW pulsed proton beam. The target is embedded in a high-field solenoid magnet that is followed by a lower field Decay Channel. The adiabatic variation in solenoid field strength along the beam near the target performs an emittance exchange that affects the performance of the downstream Buncher, Phase Rotator, and Cooling Channel. An optimization was performed using MARS1510 and ICOOL codes in which the initial and final solenoid fields strengths, as well as the rate of change of the field along the beam, were varied to maximize the number of muons delivered to the Cooling Channel that fall within the acceptance cuts of the subsequent muon-acceleration systems.  
 
TUPFI086 A Tapered Six Dimensional Cooling Lattice for a Muon Collider emittance, lattice, simulation, focusing 1547
 
  • D. Stratakis, R.C. Fernow, R.B. Palmer
    BNL, Upton, Long Island, New York, USA
  
  Designs for Neutrino Factories and Muon Colliders use ionization cooling to reduce the emittance of the muon beam prior to acceleration. Two lattices based on the original RFOFO ring design representing different configurations of the magnetic field are considered. One is with a flip magnetic field and one with a non-flip magnetic field configuration that is used to eliminate for possible space-charge effects. The details of the G4Beamline tracking studies of both channels are presented and compared to the independent ICOOL code.  
 
TUPFI088 Space-charge Studies for Ionization Cooling Lattices emittance, lattice, space-charge, simulation 1553
 
  • D. Stratakis, R.B. Palmer
    BNL, Upton, Long Island, New York, USA
  • D.P. Grote
    LLNL, Livermore, California, USA
  
  Funding: This work is funded by US Dept. of Energy grant numbers DE AC02-98CH10886
Intense muon beams provide a promising solution to a variety of applications ranging from nanotechnology to nuclear detections systems and from medical sciences to high energy physics. Production of such intense beam requires the beam to be cooled and ionization cooling via particle matter interaction is considered one of the most practical methods. Here a theoretical and numerical study on space-charge effects on such ionization cooling channels is presented. We show that space-charge can strongly affect the design of muon cooling systems by limiting their minimum cooling rate. Space-charge compensation solutions are discussed and the minimum cooling emittance as a function of the beam charge and pulse width is identified. 		 
 
TUPME009 Measurement and Vibration Studies on the Final Focus Doublet at DAΦNE and new collider Implications damping, luminosity, resonance, factory 1580
 
  • S. Tomassini
    INFN/LNF, Frascati (Roma), Italy
  
  Funding: Work supported by the European Commission under the FP7 Research Infrastructures project Eu-CARD, grant agreement no. 227579.
A Super Flavour Factory, to be built in the Tor Vergata University campus near Frascati, Italy, will have nano-beams in order to reach the design luminosity. The knowledge and compensation of the vibrations induced on the beams by the anthropic noise is then fundamental. The DAΦNE Phi-factory at LNF, Frascati, was upgraded in the second half of 2007 in order to implement the large Piwinski angle and crab waist collision scheme and in 2010 the KLOE experiment was rolled in for a new data taking and physic program. A measurement campaign has been performed on DAΦNE to find out the actual vibration sensitivity of the final focus doublets. Vibration measurements were performed on the Final Focus doublet because of luminosity losses and photon beam lines instability evidences. Results and stabilization technique to mitigate the effects of the ground motion induced by the “cultural noise” are presented. Implications on the design and stabilization of a Flavour Factory Final Focus doublets will be discussed. 		 
 
TUPME020 Design of a TeV Beam Driven Plasma-wakefield Linear Collider plasma, linac, acceleration, linear-collider 1613
 
  • E. Adli
    University of Oslo, Oslo, Norway
  • W. An, C. Joshi, W.B. Mori
    UCLA, Los Angeles, California, USA
  • J.-P. Delahaye, S.J. Gessner, M.J. Hogan, T.O. Raubenheimer
    SLAC, Menlo Park, California, USA
  • P. Muggli
    MPI, Muenchen, Germany
  
  Funding: This work is supported by the Research Council of Norway and U.S. Department of Energy under contract number DE-AC02-76SF00515.
A novel design of a 500 GeV c.m. beam-driven PWFA linear collider with effective accelerating gradient on the order of 1 GV/m and extendable in the multi-TeV energy range is presented. The main bunches collide in CW mode at several kHz repetition frequency. They are accelerated and focused with several GV/m fields generated in plasma cells by drive bunches with very good transfer efficiency. The drive bunches are themselves accelerated by a CW superconducting rf recirculating linac. We consider the overall optimizations for the proposed design, compare the efficiency with similar collider designs like ILC and CLIC and we outline the major R&D challenges. 		 
 
TUPME021 Optimization Parameter Design of a Circular e+e− Higgs Factory luminosity, factory, emittance, synchrotron 1616
 
  • D. Wang, Y.W. An, J. Gao, H. Geng, Y.Y. Guo, Q. Qin, N. Wang, S. Wang, M. Xiao, G. Xu, S.Y. Xu
    IHEP, Beijing, People's Republic of China
  
  Funding: NSFC:11175192
In this paper we will show a genral method of how to make an optimized parameter design of a circular e+e− Higgs Factory by using analytical expression of maximum beam-beam parameter and beamstrahlung beam lifetime started from given design goal and technical limitations. A parameter space has been explored. 		 
 
TUPME024 Re-optimization of the Final Focus System Optics with Vertical Chromatic Correction sextupole, luminosity, linear-collider, optics 1622
 
  • Y. Wang, J. Gao
    IHEP, Beijing, People's Republic of China
  • P. Bambade
    LAL, Orsay, France
  
  Funding: The France China Particle Physics Laboratory (FCPPL) and The National Natural Science Foundation of China (NSFC, Project 11175192)
The purpose of the final focus (FF) system of the future linear collider (ILC and CLIC) is to demagnify the beam to the required size at the IP. This can be done in a compact way based on a local chromaticity correction. Two important issues are beam-beam induced radiation effects and the optical correction strategy to mitigate static and dynamic imperfections. For a small enough beam energy spread, we investigate the possibility to get a smaller vertical beam size, at the expense of a larger horizontal beam size, by re-optimising the final focus optics with chromatic correction mainly in the vertical plane. Firstly, we track the beam with MAD-X, with and without chromaticity correction, to estimate the optimum betax and betay values by rematching the linear optics, and cross-check and improve the rematching procedure with MAPCLASS. Then, we study the original design and an alternative simplified optical system, using a set of enlarged betax values, and optimize the sextupoles as a function of betay to minimize the vertical beam size for different assumptions on the energy spread. 		 
 
TUPME029 VEPP-4: Application Beyond the High Energy Physics electron, positron, radiation, target 1637
 
  • O.I. Meshkov
    BINP SB RAS, Novosibirsk, Russia
  
  The current status of VEPP-4M electron-positron collider has been described. During fall of 2011 the accelerator was shut down for planned reconstruction of KEDR detector. The next long run of the collider will be dedicated to the experiments at high energy physics within area of 2-5 GeV. Nevertheless, the set of experiments at booster VEPP-3 were continued. VEPP-3 was operated as an SR source, the experiment with internal target was performed and electron/positron scattering at proton was studied. The short runs of VEPP-4M were used as for commissioning of the new “warm” 3T wiggler as for experiments with an extracted electron beam dedicated for testing of different high energy physics detectors. The experiment of comparing of anomalous magnetic moment of electron and positron is con-tinued at VEPP-4M. The system of RF beam shifting is installed at a straight section of the accelerator. It is applied for elimination of parasitic interaction points of electron and positron beams. The first experiments with this system are described. KEDR detector reconstruction should be finished at autumn of 2013. The future experiments with KEDR detector are discussed.  
 
TUPME031 Considerations for a Higgs Facility Based on Laser Wakefield Acceleration plasma, laser, luminosity, electron 1643
 
  • S. Hillenbrand, A.-S. Müller
    KIT, Karlsruhe, Germany
  • R.W. Aßmann, S. Hillenbrand, D. Schulte
    CERN, Geneva, Switzerland
  
  Laser Wakefield Accelerators have seen tremendous progress over the last decades. It is hoped that they will allow to significantly reduce the size and cost of a future liner collider. Based on scaling laws, laser-driven plasma accelerators are investigated as drivers for smaller scale facilities capable of producing Z and Higgs bosons.  
 
TUPME040 TLEP: High-performance Circular e+e− Collider to Study the Higgs Boson polarization, luminosity, cryogenics, wiggler 1658
 
  • M. Koratzinos, O. Brunner, A.C. Butterworth, J.R. Ellis, P. Janot, E. Jensen, J.A. Osborne, F. Zimmermann
    CERN, Geneva, Switzerland
  • R. Aleksan
    CEA/DSM/IRFU, France
  • A.P. Blondel
    DPNC, Genève, Switzerland
  • M. Zanetti
    MIT, Cambridge, Massachusetts, USA
  
  The recent discovery of a light Higgs boson has opened up considerable interest in circular e+e− Higgs factories around the world. We report on the progress of the “TLEP3” concept since last year. Two options are considered: LEP3, a 240 GeV centre-of-mass (Ecm) e+e− machine in the LHC tunnel with cost only a fraction of the cost of an equivalent linear collider, due to the use of existing infrastructure and the two general-purpose LHC detectors, and TLEP, an e+e− machine in a new 80 km tunnel that can operate up to an Ecm of 350 GeV. Both concepts enjoy the extensive know-how on circular colliders and how to deliver their design luminosity, and the existence of up to four interaction points. The attainable luminosities are 1034/cm2/s and 5x1034/cm2/s per interaction point for LEP3 and TLEP respectively. Both machines can operate as Tera-Z and Mega-W boson factories, giving decisive opportunities for over-constraining the electroweak sector of the Standard Model. The technical challenges and possible ways to improve the performance further will be discussed.  
 
TUPME047 Sub-Harmonic Bunching System of CLIC Drive Beam Injector space-charge, bunching, klystron, acceleration 1670
 
  • S. Sanaye Hajari, S. Döbert, S. Döbert, H. Shaker
    CERN, Geneva, Switzerland
  • S. Sanaye Hajari, H. Shaker
    IPM, Tehran, Iran
  
  In the Compact Linear Collider (CLIC) the RF power for the acceleration of the Main Beam is extracted from a high-current Drive Beam that runs parallel with the main linac. The sub-harmonic bunching system of the drive beam injector has been studied in detail and optimized. The model consists of a thermionic gun, three travelling wave sub-harmonic bunchers followed by a tapered travelling wave buncher. The simulation of the beam dynamics has been carried out with PARMELA with the goal of optimizing the overall bunching process and in particular capturing particles as much as possible in the buncher acceptance and decreasing the satellite population.  
 
TUPME049 Status of the Exploration of an Alternative CLIC First Energy Stage Based on Klystrons klystron, linac, luminosity, linear-collider 1676
 
  • D. Schulte, A. Grudiev, P. Lebrun, G. McMonagle, I. Syratchev, W. Wuensch
    CERN, Geneva, Switzerland
  
  The Compact Linear Collider is based on a two-beam scheme to accelerate the main, colliding beams. This scheme allows to reach very high centre-of-mass energies. At low collision energies the main beams could be accelerated by powering the accelerating structures with X-band instead of a second beam. We explore this option and indicate the parameters and conceptual design.  
 
TUPME052 Sub-harmonic Buncher Design for the CLIC Drive Beam Injector coupling, beam-loading, electron, linear-collider 1685
 
  • H. Shaker, S. Döbert, R. Leuxe, S. Sanaye Hajari
    CERN, Geneva, Switzerland
  • L. Dassa
    Università di Brescia, Brescia, Italy
  • S. Sanaye Hajari, H. Shaker
    IPM, Tehran, Iran
  
  The CLIC (Compact LInear Collider) is based on two beam concept where a high current drive beam provides the energy needed for acceleration of the main beam. The CLIC drive beam accelerator starts with a high current injector using a sophisticated sub-harmonic bunching system. This paper will focus on the design of the Sub Harmonic Bunchers (SHBs) the first RF components of the injector. A backward traveling wave structure has been optimized for this task. It will be shown also how to avoid asymmetrical fields inside the coupler cells and how to compensate beam loading by changing the phase velocity in comparison to the beam velocity.  
 
TUPME059 Collisional Effects in Particle-in-Cell Beam-Beam Simulations emittance, simulation, luminosity, proton 1700
 
  • S. Paret, J. Qiang
    LBNL, Berkeley, California, USA
  
  Funding: This work was partially supported by the U.S. LARP and the NERSC of the U.S. Department of Energy under contract No. DE-AC02-05CH11231.
Self-consistent particle tracking simulations (strong-strong) can be used to investigate the deterioration of colliding beams in a storage ring. However, the use of a small number of macroparticles copmared to the real number of particles magnifies the collisional effects and causes numerical noise. In particular, predictions of the emittance lifetime suffer from this numerical noise. In order to produce usable emittance predictions, the contribution of numerical noise to the simulated emittance growth has to be known. In this paper, we apply a diffusion model to strong-strong beam-beam simulations to study the numerical noise driven emittance growth. The scaling of emittance growth with numerical and physical parameters is discussed. 		 
 
TUPME060 Tune Studies with Beam-Beam Effects in LHC emittance, resonance, simulation, luminosity 1703
 
  • S. Paret, J. Qiang
    LBNL, Berkeley, California, USA
  • R. Alemany-Fernandez, X. Buffat, R. Calaga, K. Cornelis, M. Fitterer, R. Giachino, W. Herr, A. Macpherson, G. Papotti, T. Pieloni, S. Redaelli, F. Roncarolo, M. Schaumann, R. Suykerbuyk, G. Trad
    CERN, Geneva, Switzerland
  • R. Miyamoto
    ESS, Lund, Sweden
  
  Funding: This work was partially supported by the U.S. LARP and the NERSC of the U.S. Department of Energy under contract No. DE-AC02-05CH11231.
In high brightness colliders, the tune spread due to the collisions has a significant impact on the quality of the beams. The impact of the working point on emittance growth and beam lifetime has been observed in beam experiments in LHC. Strong-strong beam-beam simulations that were accomplished to better understand such observations are shown. Compared to experiments, wide ranged parameter scans can be done easily. Tune footprints and scans of the emittance growth obtained from simulations are discussed. Three cases are considered: Very high intensity, moderate intensity and collisions with separated beams. 		 
 
TUPME067 Design Concept of a Gamma-gamma Higgs Factory Driven by Thin Laser Targets and Energy Recovery Linacs laser, photon, electron, target 1721
 
  • Y. Zhang
    JLAB, Newport News, Virginia, USA
  
  Funding: Supported by the U.S. Department of Energy, Office of Nuclear Physics, under Contract No. DE-AC05-06OR23177.
A gamma-gamma collider has long been considered an option for a Higgs Factory. Such photon colliders usually rely on Compton back-scattering for generating high energy gamma photons and further Higgs bosons through gamma-gamma collisions. The presently existing proposals or design concepts all have chosen a very thick laser target (i.e., high laser photon intensity) for Compton scatterings. In this paper, we present a new design concept of a gamma-gamma collider utilizing a thin laser target (i.e., relatively low photon density), thus leading to a low electron to gamma photon conversion rate. This new concept eliminates most useless and harmful low energy soft gamma photons from multiple Compton scattering so the detector background is improved. It also greatly relaxes the requirement of the high peak power of the laser, a significant technical challenge. A high luminosity for such a gamma-gamma collider can be achieved through an increase of the bunch repetition rate and current of the driven electron beam. Further, multi-pass recirculating linac could greatly reduce the linac cost and energy recovery is required to reduce the needed RF power. 		 
 
WEIB202 Industrialization of the ILC Project SRF, linac, cavity, linear-collider 2105
 
  • M.C. Ross
    SLAC, Menlo Park, California, USA
  
  Funding: Work supported by U.S. Department of Energy, Contract DE-AC02-76SF00515.
The International Linear Collider Global Design Effort (GDE) team completed the Technical Design Report (TDR) in early 2013. The TDR consists of a description of the machine design, a summary of the R&D program carried out in support of the design, a cost estimate and a project plan. The number of high technology components to be fabricated for ILC is large, similar to that built for the Large Hadron Collider*, and industrial partners have had an important role throughout the technical development and design period. It is recognized that transfer of new technology to industrial partners and subsequent collaborative development can be difficult**. To counter this, the ILC Technical Design Phase (TDP) team arranged a series of vendor visits, component development contracts, workshop satellite meetings and industrial production study contracts. The GDE collaboration provided the framework for development through an agreed-upon performance parameter set and project implementation scheme. The latter includes a ‘plug-compatibility’ policy that promotes innovation as long as specified interface conditions are met. In this paper we show the evolution of the technology from the labs where it was developed to the companies where high performance cavities are now routinely produced.
* The longest journey: the LHC dipoles arrive on time.
http://cerncourier.com/cws/article/cern/29723
** Office of High Energy Physics Accelerator R&D Task Force Report
http://www.acceleratorsamerica.org/report/acceleratortaskforcereport.pdf 		 
slides icon Slides WEIB202 [5.181 MB]  
 
WEPWO015 Electron Beam Welding for High Gradient Superconducting Cavity electron, cavity, superconducting-cavity, linear-collider 2346
 
  • T. Kubo, Y. Ajima, H. Hayano, H. Inoue, S. Kato, T. Saeki, M. Sawabe, K. Umemori, Y. Watanabe, S. Yamaguchi, M. Yamanaka
    KEK, Ibaraki, Japan
  • Y. Iwashita
    Kyoto ICR, Uji, Kyoto, Japan
  • T. Nagata
    ULVAC, Inc., Tsukuba, Japan
  
  Relations between electron beam welding parameters and appearances of weld beads are studied. It was found that a beam generator position and a welding direction affect a geometry of weld bead dramatically. Carbon including contaminants found after the chemistry are also commented.  
 
WEPEA059 Study of the Impact of Fringe Fields of the Large Aperture Triplets on the Linear Optics of the HL-LHC optics, quadrupole, luminosity, focusing 2642
 
  • B.J. Holzer, R. De Maria, S. Russenschuck
    CERN, Geneva, Switzerland
  • R. Appleby, S. Kelly, M.B. Thomas, L.N.S. Thompson
    UMAN, Manchester, United Kingdom
  • L.N.S. Thompson
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
  
  Funding: The HiLumi LHC Design Study is included in the HL-LHC project and is partly funded by the European Commission within the Framework Programme 7 Capacities Specific Programme, Grant Agreement 284404
High-luminosity hadron colliders such as the High Luminosity LHC (HL-LHC) project place demanding requirements on existing and new magnet technology. The very low β* achieved by the Achromatic Telescopic Squeeze (ATS) optics scheme* for the HL-LHC in particular, requires large apertures in the high gradient Nb3Sn final focusing inner triplet triplet. Such magnets have extended fringe fields which perturb the linear and non-linear optics. This paper presents results of studies into the liner optics of the LHC using a range of fringe field models, including measurements of fringe fields from prototype magnets, and presents calculations of the beta-beating in the machine. Furthermore a similar study is presented on the nominal LHC optics, which uses final focus quadrupoles of higher gradient but significantly smaller aperture.
* S. Fartoukh, ‘’An Achromatic Telescopic Squeezing (ATS) Scheme for
LHC Upgrade’’, in proceedings of IPAC11, p. 2088. 		 
 
WEPEA076 Comparison of Taylor Maps with Radio Frequency Multipoles in a Thin Lens 6D Tracking Code cavity, multipole, luminosity, hadron 2687
 
  • D.R. Brett, R. Appleby
    UMAN, Manchester, United Kingdom
  • J. Barranco, R. De Maria, R. Tomás
    CERN, Geneva, Switzerland
  
  Funding: HiLumi LHC Design Study is part of the High Luminosity LHC project and is part funded by the European Commission within the Framework Programme 7 Capacities Specific Programme, Grant Agreement 284404.
SixTrack is a general purpose 6D thin lens tracking code used for dynamic aperture studies. In the high luminosity LHC upgrade it is proposed that crab cavities are used to enhance the luminosity. In this study, for the current proposed optics, we consider the use of RF multipoles and Taylor maps as methods to simulate crab cavity elements in the lattice. 		 
 
WEPFI032 New Calibration Method for Radial Line Experiment wakefield, cavity, damping, linear-collider 2774
 
  • X.W. Wu, H.B. Chen, J. Shi, H. Zha
    TUB, Beijing, People's Republic of China
  
  A radial line experiment is proposed to test the SiC load disks of the choke-mode structure. However, the general calibration cannot work out in this situation due to lack of matched load. A new calibration method named multi-offset short calibration is proposed. The principles of the method and the calibration steps involved are presented and the results of actual experimentation are used to validate the method. The results show multi-offset short calibration is a feasible method and that this method can provide a viable calibration scheme for radial line measurements.  
 
WEPFI056 Study of the Thermo-Mechanical Behavior of the CLIC Two-Beam Modules alignment, RF-structure, controls, linac 2818
 
  • F. Rossi, R. Mondello, G. Riddone
    CERN, Geneva, Switzerland
  • D. Gudkov, A. Samoshkin
    JINR, Dubna, Moscow Region, Russia
  • I. Kossyvakis
    National Technical University of Athens, Zografou, Greece
  • K. Österberg
    HIP, University of Helsinki, Finland
  
  The final luminosity target of the Compact LInear Collider (CLIC) imposes a micron-level stability of the two-meter repetitive two-beam modules constituting the main linacs. Two-beam prototype modules have been assembled to extensively study their thermo-mechanical behaviour under different operation modes. The power dissipation occurring in the modules will be reproduced and the efficiency of the corresponding cooling systems validated. At the same time, the real environmental conditions present in the CLIC tunnel will be studied. Air conditioning and ventilation systems will be installed in the dedicated laboratory. Air temperature will be varied from 20 to 40 °C, while air flow rate will be regulated up to 0.8 m/s. During all experimental tests, the alignment of the RF structures will be monitored to investigate the influence of power dissipation and air temperature on the overall thermo-mechanical behaviour. This test program will allow for better understanding the behaviour of CLIC modules and the results will be propagated back to both numerical modelling and engineering design.  
 
WEPFI074 RF Cavity Spark Localization Using Acoustic Measurement cavity, diagnostics, background, LabView 2863
 
  • P. Snopok
    IIT, Chicago, Illinois, USA
  • A.D. Bross
    Fermilab, Batavia, USA
  • P.G. Lane, Y. Torun
    Illinois Institute of Technology, Chicago, Illinois, USA
  
  Current designs for muon cooling channels require high-gradient RF cavities to be placed in solenoidal magnetic fields in order to contain muons with large transverse emittances. It has been found that doing so reduces the threshold at which RF cavity breakdown occurs. To aid the effort to study RF cavity breakdown in magnetic fields it would be helpful to have a diagnostic tool which can detect breakdown and localize the source of the breakdown inside the cavity. We report here on progress towards developing a diagnostic tool for detecting and localizing sparks in an RF cavity by using piezoelectric transducers.  
 
WEPFI083 High Power Tests of the 2-Pin Waveguide Structures factory, linear-collider, site, electron 2890
 
  • F.Y. Wang, Z. Li
    SLAC, Menlo Park, California, USA
  
  An X-band Two-Pin Waveguide Structure has been designed to study the influence of power flow on rf breakdown. Three different sets of pins will be tested at SLAC. These sets were designed to achieve a similar peak surface electric field on one of the pins for input rf power levels that vary by about an order of magnitude (the other pin is used for matching). Two sets of pins have been tested so far, and the breakdown rate was found to be strongly dependent on the power flow. In this paper, we review the experimental setup, the complete set of results and their implications.  
 
WEPFI086 Normal Conducting Radio Frequency X-band Deflecting Cavity Fabrication, Validation and Tuning cavity, electron, vacuum, linear-collider 2899
 
  • R.B. Agustsson, L. Faillace, A.Y. Murokh, E. Spranza, S. Storms
    RadiaBeam, Santa Monica, USA
  • D. Alesini
    INFN/LNF, Frascati (Roma), Italy
  • V.A. Dolgashev, J.R. Lewandowski
    SLAC, Menlo Park, California, USA
  • J.B. Rosenzweig
    UCLA, Los Angeles, California, USA
  • V. Yakimenko
    BNL, Upton, Long Island, New York, USA
  
  An X-band Traveling wave Deflector mode cavity (XTD) has been developed, fabricated, tuned and characterized by Radiabeam Technologies to perform longitudinal measurement of the sub-picosecond ultra-relativistic electron beams. The device is optimized for the 100 MeV electron beam parameters at the Accelerator Test Facility (ATF) at Brookhaven National Laboratory, and is scalable to higher energies. The XTD is designed to operate at 11.424 GHz, and features short filling time, femtosecond resolution, and a small footprint. RF design, structure fabrication, cold testing and tuning results are presented.  
 
WEPME046 Alignment Challenges for a Future Linear Collider alignment, linac, linear-collider, laser 3031
 
  • H. Mainaud Durand, D.P. Missiaen, G. Stern
    CERN, Geneva, Switzerland
  
  The preservation of ultra-low emittances in the main linac and Beam Delivery System area is one of the main challenges for linear colliders. This requires alignment tolerances never achieved before at that scale, down to the micrometre level. As a matter of fact, in the LHC, the goal for the smoothing of the components was to obtain a 1σ deviation with respect to a smooth curve of 0.15 mm in a 150 m long sliding window, while for the CLIC project for example, it corresponds to 10 micrometres over a sliding window of 200m in the Beam Delivery System area. Two complementary strategies are being studied to fulfill these requirements: the development and validation of long range alignment systems to propagate precision and accuracy over a few hundreds of metres and short range alignment systems over a few metres. The studies undertaken, with associated test setups and the latest results will be detailed, as well as their application for the alignment of both CLIC and ILC colliders.  
 
THPEA043 An Equipment Hub for Managing a Small Town and a Complex Machine radiation, controls, coupling, status 3237
 
  • P. Martel, A. Alexandre Metola, Ch. Delamare, M.P. Kepinski, S. Mallon Amerigo, L. Pater, S. Petit, D. Widegren
    CERN, Geneva, Switzerland
  
  Effective maintenance of the accelerators’ complex is vital for CERN’s mission. While this work is highly dependent on operational planning and constraints, it also needs to be coordinated with the maintenance of the infrastructure where the complex is embedded. The nature and degree of the logistics problems that arise from this interdependence cannot be handled by partial, decoupled solutions from each of the stakeholders. CERN’s Enterprise Asset Management system is the central hub where all relevant data about equipment and its maintenance is kept. It is also where data and documents about the manufacturing, installation, safety inspection, radiation measurements, disposal, etc. of the scientific equipment reside. This hub allows the effective sharing of consistent equipment data, accessed by a large number of people and systems, and supplies a wide range of interfaces – ranging from the user in the field with no access to a desktop computer, to scheduling systems that need to interact with it through Web services; this is achieved by means of a series of systems, tools and mechanisms, all dedicated to different needs but working on the same data and sharing common policies.  
 
THPFI013 Development of Cylindrical-type 1.2 MW High Power Water-load for Super KEKB klystron, positron, cavity, factory 3318
 
  • K. Watanabe, K. Ebihara, A. Kabe, K. Marutsuka, M. Nishiwaki
    KEK, Ibaraki, Japan
  • Y. Kawane, A. Miura
    Nihon Koshuha Co. Ltd, Yokohama, Japan
  
  We have developed and manufactured CW 1.2 MW high power water-load for the use of the Super KEKB, an electron – positron double-ring collider at KEK. The tank and rf window of the water-load is the circular and cylindrical-type. The material to absorb the rf power is a tap water. This load is equipped on the 3rd port of the circulators to safe the 1.2 MW CW klystrons to drive the ARES cavities in main ring. The operational frequency is 508.9 MHz. A proto-type model of this water-load was fabricated at Sep 2012, and tested using by high power klystron (1 MW) at Oct 2012 at KEK D2-ET station. The result of high power test will be reported in this paper.  
 
THPFI061 Design Process of the Interlock Systems for the Compact Linear Collider controls, target, linear-collider, hadron 3433
 
  • P. Nouvel, M. Jonker, B. Puccio
    CERN, Geneva, Switzerland
  • H. Tap
    INPT, Toulouse, France
  
  Interlock systems are a critical part for the machine protection of linear colliders. Their goal is to inhibit the next pulse either on failure of critical equipment and/or on low beam quality evaluation. This paper presents the on-going process to validate design choices for the Compact Linear Collider (CLIC) interlock systems. The design process starts by establishing requirements. In mission-critical system case, they are mainly focused on the dependability. Moreover, the new concept of fast beam quality analysis has been introduced into the CLIC interlock system and will be discussed in this paper. To support the design process, experimentation on this concept has been launched. In addition, a hardware demonstration of the interlock systems has been set-up. It allows validating the design in concordance with the requirements.  
 
THPFI092 Design of the Mercury Handling System for a Muon Collider/Neutrino Factory Target target, shielding, factory, proton 3505
 
  • K.T. McDonald
    PU, Princeton, New Jersey, USA
  • J.S. Berg, H.G. Kirk, H. K. Sayed
    BNL, Upton, Long Island, New York, USA
  • X.P. Ding
    UCLA, Los Angeles, California, USA
  • V.B. Graves
    ORNL, Oak Ridge, Tennessee, USA
  • N. Souchlas, R.J. Weggel
    Particle Beam Lasers, Inc., Northridge, California, USA
  
  The baseline target concept for a Muon Collider or Neutrino Factory is a free mercury jet within a 20-T magnetic field being impacted by an 8-GeV proton beam. A pool of mercury serves as a receiving reservoir for the mercury and a dump for the unexpended proton beam. Modifications to this baseline are discussed in which the field at the target is reduced from 20 to 15 T, and in which the magnetic field drops from its peak value down to 1.5 T over 7 rather than 15 m.  
 
THPME028 Prototype Superconducting Magnets for the NICA Accelerator Complex dipole, booster, quadrupole, ion 3567
 
  • H.G. Khodzhibagiyan, A.V. Bychkov, A.R. Galimov, O.S. Kozlov, G.L. Kuznetsov, I.N. Meshkov, V.A. Mikhaylov, A.V. Shabunov, A.Y. Starikov, G.V. Trubnikov
    JINR, Dubna, Moscow Region, Russia
  
  NICA is a new accelerator complex being under design and construction at the Joint Institute for Nuclear Research (JINR) in Dubna. Full-size prototype dipole and quadrupole magnets for the booster synchrotron and the NICA collider have been designed, manufactured and tested. The magnets are based on a cold window frame iron yoke and a saddle-shaped superconducting winding made from a hollow NbTi composite superconducting cable cooled with a forced two-phase helium flow at T = 4.5 K. The maximal operating magnetic field in the aperture is 1.8 T. The magnetic field ramp rate of 1.2 T/s should be achievable. The quench history, AC losses as a function of the magnetic field ramp rate and pressure drop in the cooling channels of the magnets at different pulsed operation modes are presented.  
 
THPME034 The LHC Cryogenic Operation Availability Results from the First Physics Run of Three Years cryogenics, controls, instrumentation, monitoring 3585
 
  • D. Delikaris, K. Brodzinski, S.D. Claudet, G. Ferlin, L.J. Tavian, U. Wagner
    CERN, Geneva, Switzerland
  
  The LHC (Large Hadron Collider) accelerator consists in eight cryogenically independent sectors, each 3.3 km long with a cold mass of 4500 ton cooled at 1.9 K. Each helium cryogenic plant combines an 18 kW at 4.5 K refrigerator and a 2.4 kW at 1.8 K refrigeration unit. Since early operation for physics in November 2009, the availability has been above 90% for more than 260 days per year, ending at 94.8% in 2012 and corresponding to an equivalent availability of more than 99% per independent sector. The operation and support methodology as well as the achieved performance results are presented. Emphasis is given on implementing operational return for short, medium and long term consolidations. Perspective for restart after the first long shutdown of the LHC works will be described.  
 
THPME043 Prototype Adjustable Permanent Magnet Quadrupoles For CLIC quadrupole, permanent-magnet, linear-collider, magnet-design 3606
 
  • B.J.A. Shepherd, J.A. Clarke
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
  • A. Bartalesi, M. Modena, M. Struik
    CERN, Geneva, Switzerland
  • N.A. Collomb
    STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom
  
  The 42km long Drive Beam Decelerator for the Compact Linear Collider (CLIC) requires over 41,000 quadrupole magnets. ASTeC and CERN are investigating the possibility of permanent magnet quadrupoles (PMQs) to reduce running costs and heat load inside the CLIC tunnel. A prototype of a high-strength adjustable PMQ has been built, based on a simple concept using two moving sections each containing a pair of large permanent magnets. The gradient can be adjusted within a range of 15-60 T/m (3-15T integrated gradient). The prototype has undergone extensive magnetic testing at Daresbury Laboratory and CERN, and performs well in line with expectations. A prototype of the low-strength version (0.9-9T) is currently under construction.  
 
THPME045 TEST RESULTS OF A NB3SN QUADRUPOLE COIL IMPREGNATED WITH RADIATION-RESISTANT MATRIMID 5292 quadrupole, dipole, radiation, controls 3612
 
  • A.V. Zlobin, G. Ambrosio, N. Andreev, E.Z. Barzi, R. Bossert, G. Chlachidze, V.V. Kashikhin, S. Krave, A. Nobrega, I. Novitski
    Fermilab, Batavia, USA
  
  Funding: Work supported by Fermi Research Alliance, LLC, under contract No. DE-AC02-07CH11359 with the U.S. Department of Energy.
FNAL is developing advanced Nb3Sn magnets for present and future accelerators. Insulation is one of the primary elements of magnet design, essential for maintaining its electrical, mechanical and thermal performance. The Nb3Sn magnet fabrication process involves coil reaction at high temperature and then impregnation with epoxy to restore the insulation electrical and mechanical properties. The traditional epoxy offers adequate structural and electrical properties, but has a low radiation strength which limits the lifetime of accelerator magnets operating in severe radiation environments. Studies to replace epoxy as impregnation material for Nb3Sn coils with high radiation-resistant material have started at FNAL ten years ago. The studies concentrated on the Matrimid® 5292, a bismaleimide based material, which has appropriate viscosity and potlife as well as provides excellent mechanical, electrical and thermal coil properties. A 1 m long Nb3Sn quadrupole coil was recently fabricated, impregnated with Matrimid and tested in a quadrupole magnetic mirror at 4.2 and 1.9 K. Coil test results are presented and compared to the results for similar coils impregnated with epoxy.