IPAC2011 - List of Keywords (collider)

Paper	Title	Other Keywords	Page
MOYBA01	Present Status of the ILC Project and Developments	cavity, linac, linear-collider, electron	16
	M.C. Ross Fermilab, Batavia, USA N.J. Walker DESY, Hamburg, Germany A. Yamamoto KEK, Ibaraki, Japan
	Funding: FNAL is operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy. The Technical Design of the ILC Project will be finished in late 2012. The Technical Design Report will include a description of the updated design, with a cost estimate and a project plan, and the results of R & D done in support of the ILC. Results from directed ILC R & D are used to reduce the cost and risk associated with the ILC design. We present a summary of key challenges and show how the global R & D effort has addressed them. The most important activity has been in pursuit of very high gradient superconducting RF linac technology. There has been excellent progress toward the goal of practical industrial production of niobium sheet-metal cavities with gradient performance in excess of 35 MV/m. In addition, three purpose-built beam test facilities have been constructed and used to study and demonstrate high current linac performance, electron-cloud beam dynamics and precision beam control. The report also includes a summary of component design studies and conventional facilities cost optimization design studies.
	Slides MOYBA01 [9.755 MB]

MOPO017	Latest Performance Results from the FONT5 Intra-train Position and Angle Feedback System at ATF2	feedback, kicker, linear-collider, positron	520
	G.B. Christian, D.R. Bett, M.R. Davis, C. Perry JAI, Oxford, United Kingdom R. Apsimon, P. Burrows Oxford University, Physics Department, Oxford, Oxon, United Kingdom B. Constance, A. Gerbershagen CERN, Geneva, Switzerland J. Resta-López IFIC, Valencia, Spain
	A prototype Interaction Point beam-based feedback system for future electron-positron colliders, such as the International Linear Collider, has been designed and tested on the extraction line of the KEK Accelerator Test Facility (ATF). The FONT5 intra-train feedback system aims to stabilize the beam orbit by correcting both the position and angle jitter in the vertical plane on bunch-to-bunch timescales, providing micron-level stability at the entrance to the ATF2 final-focus system. The system comprises three stripline beam position monitors (BPMs) and two stripline kickers, custom low-latency analogue front-end BPM processors, a custom FPGA-based digital processing board with fast ADCs, and custom kicker-drive amplifiers. An overview of the hardware, and the latest results from beam tests at ATF2, will be presented. A total system latency as low as approximately 140 ns has been demonstrated.

MOPS003	Coherent Beam-beam Resonances in SuperB with Asymmetric Rings	resonance, luminosity, simulation, dynamic-aperture	592
	M. Zobov INFN/LNF, Frascati (Roma), Italy Y. Zhang IHEP Beijing, Beijing, People's Republic of China
	One of the latest options of SuperB foresees exploiting rings with unequal circumferences. In such a configuration additional coherent beam-beam resonances can arise. In this paper we discuss the possible impact of the resonances on beam dynamics in SuperB, maximum achievable tune shifts and working point choice.

MOPS006	Beam Tilt due to Transverse Wakefields for DAΦNE, SuperB, KEKB and SuperKEKB	impedance, closed-orbit, wakefield, vacuum	601
	D.M. Zhou, K. Ohmi KEK, Ibaraki, Japan A. Chao SLAC, Menlo Park, California, USA
	When a beam bunch traverses a transverse impedance, the bunch head generates a transverse wakefield that kicks the bunch tail, generating a betatron motion of the tail relative to the head. In a storage ring, in a steady state, this kick to the bunch tail produces a transverse closed orbit (e.g. in the y-direction) of the bunch tail relative to the bunch head, which means the beam now has a y-z tilt. Such beam tilt due to transverse wakefields may cause a loss of luminosity in storage ring colliders or loss of brightness in light sources. In this paper, we present a preliminary study of the beam tilt effect for the colliders DAΦNE, SuperB, KEKB and SuperKEKB.

MOPZ011	An Automated Conditioning System for the MUCOOL Experiments at Fermilab	cavity, controls, pick-up, vacuum	844
	A. Kurup Imperial College of Science and Technology, Department of Physics, London, United Kingdom
	The MUCOOL project aims to study RF cavities for the Neutrino Factory and the Muon Collider. The large emittance muon beams in these accelerators require high-gradient RF cavities at low-frequencies and they need to operate in the presence of relatively strong magnetic fields. MUCOOL is conducting a number of tests on 805MHz and 201 MHz cavities in order to develop a technology that can meet all of these requirements. An automated conditioning system was developed for the 805MHz test program for MUCOOL. This system was designed to replicate the logic a human operator would use when conditioning an RF cavity and to provide automated logging of the conditioning process. This paper describes the hardware and software of the system developed.

MOPZ016	MICE Step I: First Measurement of Emittance with Particle Physics Detectors*	emittance, simulation, quadrupole, factory	853
	L. Coney UCR, Riverside, California, USA M. Popovic Fermilab, Batavia, USA M.A. Rayner DPNC, Genève, Switzerland
	The muon ionization cooling experiment (MICE) is a strategic R&D project intending to demonstrate the only practical solution to prepare high brilliance beams necessary for a neutrino factory or muon colliders. MICE is under development at the Rutherford Appleton Laboratory (UK). It comprises a dedicated beam line to generate a range of input emittance and momentum, with time-of-flight and Cherenkov detectors to ensure a pure muon beam. The emittance of the incoming beam is measured in the upstream magnetic spectrometer with a sci-fiber tracker. A cooling cell will then follow, alternating energy loss in Li-H absorbers and RF acceleration. A second spectrometer identical to the first and a second muon identification system measure the outgoing emittance. In the 2010 run the beam and most detectors have been fully commissioned and a first measurement of the emittance of a beam with particle physics (time-of-flight) detectors has been performed. The analysis of these data should be completed by the time of the Conference. The next steps of more precise measurements, of emittance and emittance reduction (cooling), that will follow in 2011 and later, will also be outlined. Abstract is submitted by the MICE Speakers Bureau. If accepted, most likely Dr. Kaplan will present it. As a first result in a novel sector, we propose it for an oral presentation

TUYA01	Achievements and Lessons from the Tevatron	antiproton, luminosity, proton, electron	903
	V.D. Shiltsev Fermilab, Batavia, USA
	The Tevatron Run-2 will come to an end at the time of IPAC'11. This talk will concentrate on exploration of the accelerator physics issues that were dealt with in achieving the current (very high) level of performance in the Tevatron and will review achievements, challenges and lessons learned on the way.
	Slides TUYA01 [5.881 MB]

TUYA02	LHC Upgrade Plans: Options and Strategy	luminosity, cavity, quadrupole, cryogenics	908
	L. Rossi CERN, Geneva, Switzerland
	Presentation of options for future luminosity and/or energy upgrades of the LHC ring. The presentation should cover the different ideas, short term, medium term and long term, and discuss the research programme that is needed to prepare the upgrades.
	Slides TUYA02 [5.139 MB]

TUPC001	Simulations of the Interaction Point for TeV-scale e⁺ e− Colliders	photon, electron, simulation, radiation	985
	J. Esberg Aarhus University, Aarhus, Denmark
	The design of a detector and post collisional line of a future linear collider calls for detailed knowledge of the beam-beam dynamics at the interaction point. We here describe the implementation and results of new simulation tools in the program GUINEA-PIG. The subjects are direct trident production relevant in the deep quantum-regime, incoherent muon generation, synchrotron radiation from secondary particles and depolarization effects. We choose beam parameters in the range relevant for CLIC and comment on the implications for the design of such a machine.

TUPC002	Study of a Large Piwinski’s Angle Configuration for Linear Colliders	luminosity, linear-collider, radiation, background	988
	R. Versteegen, O. Napoly CEA/DSM/IRFU, France
	The application of a Large Piwinski’s Angle configuration to the interaction region of a linear collider is studied. The calculation of the equivalent disruption parameter and beamstrahlung parameter in the presence of a crossing angle are necessary to estimate the beam-beam effects in such a configuration. The reduction of the beam-beam interaction effects, based on these parameters, while keeping same luminosity is presented for both ILC and CLIC parameters.

TUPC004	The Luminosity for the ILC Travelling Focus Regime with Offsets and Angle Scans*	luminosity, emittance, simulation, wakefield	991
	L.I. Malysheva, O.S. Adeyemi, V.S. Kovalenko, A. Ushakov University of Hamburg, Hamburg, Germany K. Buesser, A.F. Hartin, G.A. Moortgat-Pick, N.J. Walker DESY, Hamburg, Germany S. Riemann, F. Staufenbiel DESY Zeuthen, Zeuthen, Germany
	One of the crucial challenges of a future linear collider is to provide high luminosity. In the current ILC design a luminosity of 2x10³⁴ is foreseen. In order to enhance the luminosity, use of the “travelling focus” scheme is under discussion. Within this regime the hourglass effect at the interaction point can be effectively overcome by judiciously arranging for the head and tail of the bunches to be focused at a proportionally displaced longitudinal position. The effect is further enhanced by the strong beam-beam interaction which continuously focuses the bunches during collision. In principle travelling focus could provide an additional 30% luminosity. Nevertheless the regime is highly sensitive to beam-beam transverse and angular offsets at the collision point. The study of the luminosity stability for various ILC parameters using traveling focus will be presented.

TUPC005	Evolution of Pressure in Positron Source for Future Linear e⁺e⁻ Collider	target, photon, positron, linear-collider	994
	O.S. Adeyemi, V.S. Kovalenko, L.I. Malysheva University of Hamburg, Hamburg, Germany A.F. Hartin, G.A. Moortgat-Pick, S. Riemann, A. Ushakov DESY, Hamburg, Germany A. Schälicke, F. Staufenbiel DESY Zeuthen, Zeuthen, Germany
	Funding: This work is supported by the German Federal Ministry of Education and Research, Joint Research Project R&D Accelerator "Spin Management", contract number 05H10GUE Energy deposition in the conversion targets of positron sources for future linear colliders induces an immense thermal load and create pressure waves in the material. This stress could substantially reduce the lifetime of the target or other target materials impinged by the incident intense photon or electron beam. We have studied the evolution of acoustic pressure waves in target materials based on the parameter assumptions for the International Linear Collider (ILC) baseline source. The fluid model is employed by taking into account the target and the incident photon beam parameters. Initial results of these new simulations are presented and compared with earlier studies. Prospects for further studies are outlined.

TUPC007	Kicker and Monitor for CTF3 Phase Feed Forward	kicker, impedance, pick-up, coupling	1000
	F. Marcellini, D. Alesini, A. Ghigo INFN/LNF, Frascati (Roma), Italy
	Funding: Work partially supported by the EuCARD research programme, Grant Agreement 227579, within the 'Assessment of Novel Accelerator Concepts'. In the Compact LInear Collider (CLIC) the synchronization of the Drive Beam and the Main Beam has to be assured in the femtosecond range to avoid luminosity reduction of the collider. The Drive and Main Beams arrival time is measured with longitudinal monitors and the correction is applied changing the path length of one beam respect to the other in a magnetic chicane by means of two transverse fast stripline kicker. The performance of the feed forward system will be tested in the CLIC Test Facility (CTF3) measuring the phase at the linac exit, correcting in the chicane after the combination rings and comparing the longitudinal position change before the power RF production system. The developed phase monitors and kicker magnets for the test in CTF3 are described.

TUPC013	Simulation of Phase Stability at the Flat Top of the CLIC Drive Beam	linac, simulation, luminosity, kicker	1018
	A. Gerbershagen, D. Schulte CERN, Geneva, Switzerland P. Burrows Oxford University, Physics Department, Oxford, Oxon, United Kingdom
	Funding: University of Oxford The drive beam phase stability is one of the critical issues of the Compact Linear Collider (CLIC). In this paper the generation and propagation of drive beam phase errors is studied for effects that vary during the drive beam pulse. This includes the influence of drive beam current and phase errors as well as of drive beam accelerator RF phase and amplitude errors on the drive beam phase after the compressor chicanes and the analysis of the propagation of these errors through the drive beam combination scheme. The impact of the imperfections on the main beam is studied including the possible correction with help of a feedforward system.

TUPC017	Civil Engineering Studies for Major Projects after LHC	interaction-region, civil-engineering, site, linac	1030
	J.A. Osborne, F.J. Magnin, E. Perez-Duenas CERN, Geneva, Switzerland
	CERN civil engineers are heavily involved in studying several major projects to succeed/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. For example, CERN are studying infrastructure requirements for the Linear Collider (CLIC & ILC) and the LHeC projects. This poster presents some of the key civil engineering challenges faced in such large scale projects.

TUPC018	Progress on Modelling of the Thermo-Mechanical Behavior of the CLIC Two-Beam Module	vacuum, RF-structure, simulation, linac	1033
	R.J. Raatikainen, K. Osterberg HIP, University of Helsinki, Finland T.O. Niinikoski, G. Riddone CERN, Geneva, Switzerland
	The luminosity goal of the CLIC collider, currently under study, imposes micrometer mechanical stability of the 2-m long two-beam modules, the shortest repetitive elements of the main linacs. These modules will be exposed to variable high power dissipation during operation resulting in mechanical distortions in and between module components. The stability of the CLIC module will be tested in laboratory conditions at CERN in a full-scale prototype module. In this paper, the FEA model developed for CLIC prototype module is described. The thermal and structural results for the new module configuration are presented considering the thermo-mechanical behavior of the CLIC collider in its primary operation modes. These results will be compared to the laboratory measurements to be done during 2011 and 2012 with the full-scale prototype module. The experimental results will allow for better understanding of the module behaviour and they will be propagated back to the present thermo-mechanical model.

TUPC118	Test Results on Beam Position Resolution for Low-Q IP-BPM at KEK-ATF2	cavity, feedback, alignment, dipole	1293
	S.W. Jang, A. Heo, J.G. Hwang, E.-S. Kim, H.-S. Kim Kyungpook National University, Daegu, Republic of Korea H.K. Park CHEP, Daegu, Republic of Korea
	We have performed the beam tests on the beam position resolution for the Low-Q IP-BPM (Interaction Point-Beam Position Monitor) at ATF2 which is an accelerator test facility for the International Linear Collider. The main goals of KEK-ATF2 are to achieve beam size of 37 nm and beam resolution of nano-meter for beam stabilization. Resolution tests for the Low-Q IP-BPM were performed with KEK BPM doublet in Jan. 2011. We got the results of beam position resolution 70 nm during the experimental periods and will present the detailed experimental procedures and results.

TUPC124	Laser Wire Emittance Measurement Line at CLIC*	laser, emittance, photon, electron	1308
	H. Garcia, Yu.A. Kubyshin UPC, Barcelona, Spain T. Aumeyr, G.A. Blair JAI, Egham, Surrey, United Kingdom D. Schulte, F. Stulle CERN, Geneva, Switzerland
	A precise measurement of the transverse beam size and beam emittances upstream of the final focus is essential for ensuring the full luminosity at future linear colliders. A scheme for the emittance measurements at the RTML line of the CLIC using laser-wire beam profile monitors is described. A lattice of the measurement line is discussed and results of simulations of statistical and machine-related errors and of their impact on the accuracy of the emittance reconstruction are given. Modes of operation of the laser wire system and its main characteristics are discussed.

TUPC141	LHC Beam Loss Pattern Recognition	beam-losses, monitoring, proton, resonance	1353
	A. Marsili, E.B. Holzer, P.M. Puzo CERN, Geneva, Switzerland
	One of the systems protecting CERN's Large Hadron Collider (LHC) is the Beam Loss Monitoring system (BLM). More than 3600 monitors are installed around the ring. The beam losses are permanently integrated over 12 different time intervals (from 40 microseconds to 84 seconds). When any loss exceeds the thresholds defined for the integration window, the beam is removed from the machine. Understanding the origin of a beam loss is crucial for machine operation, as it can help to avoid a repeat of the same scenario. The signals read from given monitors can be considered as entries of a vector. This article presents how a loss map of unknown cause can be decomposed using vector based analysis derived from well-known loss scenarios. The algorithms achieving this decomposition are described, as well as the accuracy of the results.

TUPC164	Position Determination of Closely Spaced Bunches using Cavity BPMs	cavity, single-bunch, quadrupole, linear-collider	1419
	N.Y. Joshi, S.T. Boogert, F.J. Cullinan, A. Lyapin JAI, Egham, Surrey, United Kingdom
	Cavity Beam Position Monitor (BPM) systems with high-Q form a major part of precision position measurement diagnostics for linear accelerators with low emittance beam. Using cavity BPMs, the position resolution of less than 100 nm has been demonstrated in single bunch mode operation. In the case of closely spaced bunches, where the decay time of the cavity is comparable to the time separation between bunches, the BPM signal from a bunch is polluted by the signal induced from the previous bunches in the same bunch-train. This paper discuss our ongoing work to develop the methods to extract the position of the closely spaced bunches using cavity BPMs. A signal subtraction code is being developed to remove the signal pollution from previous bunches and to determine the individual bunch position. Another code has been developed to simulate the BPM data for the cross check. Performance of the code is studied on the experimental and simulated data. Application of the analysis techniques to the linear colliders, such as International Linear Collider (ILC) and Compact LInear Collider (CLIC), are briefly discussed.

TUPS024	Development of Beryllium Vacuum Chamber Technology for the LHC	vacuum, electron, controls, background	1578
	R. Veness CERN, Geneva, Switzerland C. Dorn, G. Simmons Materion Electrofusion, Fremont, California, USA
	Beryllium is the material of choice for the beam vacuum chambers around collision points in particle colliders due to a combination of transparency to particles, high specific stiffness and compatibility with ultra-high vacuum. New requirements for these chambers in the LHC experiments have driven the development of new methods for the manufacture of beryllium chambers. This paper reviews the requirements for experimental vacuum chambers. It describes the new beryllium technology adopted for the LHC and experience gained in the manufacture and installation.

TUPS025	Design of a Highly Optimised Vacuum Chamber Support for the LHCb Experiment	radiation, vacuum, background, interaction-region	1581
	L. Leduc, G. Corti, R. Veness CERN, Geneva, Switzerland
	The beam vacuum chamber in the LHCb experimental area passes through the centre of a large aperture dipole magnet. The vacuum chamber and all its support systems lie in the acceptance of the detector, so must be highly optimised for transparency to particles. As part of the upgrade programme for the LHCb vacuum system, the support system has been re-designed using advanced lightweight materials. In this paper we discuss the physics motivation for the modifications, the criteria for the selection of materials and tests performed to qualify them for the particular environment of a particle physics experiment. We also present the design of the re-optimised support system.

TUPS053	A Target Magnet System for a Muon Collider and Neutrino Factory	shielding, target, radiation, factory	1650
	H.G. Kirk 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: This work is supported in part by the US DOE Contract NO. DE-AC02-98CH10886. The target system envisioned for a Muon Collider or Neutrino Factory includes a 20-T solenoid field surrounding a mercury jet target with the field tapering to 1.5 T 15 m downstream of the target. A principal challenge is to shield the superconducting magnets from the radiation issuing from the 4-MW proton beam impacting the target. We describe a solution which will deliver the desired field while being capable of tolerating the intense radiation environment surrounding the target.

TUPS055	Organizing the ILC Technical Design Documentation	lattice, positron, linear-collider, damping	1656
	L. Hagge, S. Eucker, B. List, N.J. Walker, N. Welle DESY, Hamburg, Germany
	The Global Design Effort (GDE) for the International Linear Collider (ILC) is currently preparing the Technical Design Report (TDR), which will be released at the end of 2012 and will serve as the basis for a decision process. The TDR will be written based on the Technical Design Documentation (TDD), which captures the entire design efforts, results and rationale, including e. g. parameter lists, specifications, CAD models and drawings, cost estimation, simulations and calculations, and summary reports. Formal review meetings help making the documentation complete, correct and consistent. The TDD is stored in an Engineering Data Management System (EDMS), which ensures that it remains accessible beyond the GDE in an organized way and at a well-defined location. The EDMS provides traceability (e. g. from design decisions to corresponding cost estimates), version management and change control. The poster presents the process and tools that were established for the organization of the TDD and provides an overview of the emerging documentation.

TUPS070	An Experiment at HiRadMat: Irradiation of High-Z Materials	target, simulation, proton, ion	1698
	J. Blanco, C. Maglioni, R. Schmidt CERN, Geneva, Switzerland N.A. Tahir GSI, Darmstadt, Germany
	Calculations of the impact of dense high intensity proton beams at SPS and LHC into material have been presented in several papers,,*. This paper presents the plans for an experiment to validate the theoretical results with experimental data. The experiment will be performed at the High Radiation to Materials (HiRadMat) facility at the CERN-SPS. The HiRadMat facility is dedicated to shock beam impact experiments. It allows testing of accelerator components with respect to the impact of high-intensity pulsed beams. It will provide a 440 GeV proton beam with a focal size down to 0.1 mm, thus providing very dense beam (energy/cross section). The transversal profile of the beam is considered to be Gaussian with a tunable σ from 0.1 mm to 2 mm. This facility will allow to study “high energy density” physics as the energy density will be high enough to create strong coupled plasma in the core of high-Z materials (copper, tungsten) and to produce strong enough shock waves to create a density depletion channel along the beam axis (tunneling effect). The paper introduces the layout of the experiment and the monitoring system to detect tunneling of protons through the target. N.A.Tahir et al. HB2010 Proc., Morschach, Switzerland. N.A.Tahir et al. NIMA 606(1-2) 2009 186. * N.A.Tahir et al. 11th EPAC, Genoa, Italy, 2008, WEPP073.

TUPS081	3D Visualization, Simulation and Virtual Reality in Accelerator Development	simulation, linear-collider, site	1728
	L. Hagge, A. Herz, J. Kreutzkamp, S. Lang, V. Rupprecht, S. Sühl, N. Welle DESY, Hamburg, Germany
	Visualizing complex beamline designs, animating installation procedures and virtually walking through planned facilities - 3D modelling is a powerful tool with a broad range of applications in accelerator development. The poster describes established and emerging 3D modelling applications at the European XFEL and their benefits: 3D visualization enables inspection and compliance analysis of interfacing systems and components. Simulations enable early verification of e.g. safety and transportation concepts. Digital humans can be inserted into accelerator models to perform e.g. reachability and field-of-sight studies for installation works. Movies of transport and installation procedures can be created for staff training. And ultimately, stereo projection can be used to inspect and simulate designs and processes in virtual environments. 3D modelling helps discovering and resolving design issues earlier and leads to large savings in time and cost.

TUPS098	Machining and Characterizing X-band RF-structures for CLIC	controls, cavity, damping, electron	1768
	S. Atieh, M. Aicheler, G. Arnau-Izquierdo, A. Cherif, L. Deparis, D. Glaude, L. Remandet, G. Riddone, M. Scheubel CERN, Geneva, Switzerland D. Gudkov, A. Samoshkin, A. Solodko JINR, Dubna, Moscow Region, Russia
	The Compact Linear Collider (CLIC) is currently under study at CERN as a potential multi-TeV e+e collider. The manufacturing and assembling tolerances for making the required RF components are essential for CLIC to perform efficiently. Machining techniques are relevant to the construction of ultra-high-precision parts for the Accelerating Structures (AS). Optical-quality turning and ultra-precision milling using diamond tools are the main manufacturing techniques identified to produce ultra-high shape accuracy parts. A shape error of less than 5 micrometres and roughness of Ra 0.025 are achieved. Scanning Electron Microscopy (SEM) observation as well as sub-micron precision Coordinate Measuring Machines (CMM), roughness measurements and their crucial environment were implemented at CERN for quality assurance and further development. This paper focuses on the enhancements of precision machining and characterizing the fabrication of AS parts.

TUPS099	A Study of the Surface Quality of High Purity Copper after Heat Treatment	vacuum, electron, damping, linear-collider	1771
	M. Aicheler, G. Arnau-Izquierdo, S. Atieh, S. Calatroni, S. Lebet, G. Riddone, A. Samoshkin CERN, Geneva, Switzerland
	The manufacturing flow of accelerating structures for the compact linear collider, based on diamond-machined high purity copper components, include several thermal cycles (diffusion bonding, brazing of cooling circuits, baking in vacuum, etc.). The high temperature cycles may be carried out following different schedules and environments (vacuum, reducing hydrogen atmosphere, argon, etc.) and develop peculiar surface topographies which have been the object of extended observations. This study presents and discusses the results of scanning electron microscopy (SEM) and optical microscopy investigations.

TUPZ004	The NICA Facility in Polarized Proton Operation Mode	proton, ion, injection, booster	1804
	A.D. Kovalenko, N.N. Agapov, Y. Filatov, V.D. Kekelidze, R.I. Lednicky, I.N. Meshkov, V.A. Mikhaylov, A.O. Sidorin, A. Sorin, G.V. Trubnikov JINR, Dubna, Moscow Region, Russia
	Basic goal of the planned NICA facility at JINR is focused on the studying of heavy ion collisions over the energy range √s ~ 411 GeV/u. Capabilities of the proposed scheme were carefully analyzed in this case and reaching of the desired average luminosity, L = 1·10²⁷ cm^-2 s⁻¹ for gold-gold collisions at √s = 9 GeV/u, have been confirmed. The other important NICA research domain is the experiments with polarized proton beams at the highest possible energy, the highest luminosity and polarization degree as well. The main aim is to provide √s ~ 25 GeV and L ~ 1·10³¹ cm^-2 s⁻¹. The unsolved aspects of the problem are discussed, possible solutions are analyzed and necessary modifications of the NICA scheme are considered as well.

TUPZ005	Design of the NICA Collider Rings	luminosity, ion, lattice, betatron	1807
	O.S. Kozlov, H.G. Khodzhibagiyan, S.A. Kostromin, I.N. Meshkov, A.O. Sidorin, N.D. Topilin, G.V. Trubnikov JINR, Dubna, Moscow Region, 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. Superconducting collider rings accumulate beam injected from Nuclotron and realize the conditions for beam-beam interactions to achieve the required luminosity. Each ring has the racetrack shape with two arcs and two long straight sections. Its circumference is about 500 m. The collider lattice design is subjected to have possibility of the gamma transition variation, mainly by the arcs retuning. The long straight sections contain the most of the insertion devices and are matched to the arcs, optimized to provide the final focusing of the beams in IP and accurate betatron tune adjustment.

TUPZ029	Observation of Coherent Beam-beam Effects in the LHC	simulation, emittance, damping, beam-beam-effects	1870
	X. Buffat EPFL, Lausanne, Switzerland R. Calaga, S.M. White BNL, Upton, Long Island, New York, USA R. Giachino, W. Herr, G. Papotti, T. Pieloni CERN, Geneva, Switzerland
	Early collisions in the LHC with a very limited number of bunches with high intensities indicated the presence of coherent beam-beam driven oscillations. Here we discuss the experimental results and compare with the expectations.

TUPZ030	Simulation of Linear Beam Parameters to Minimize the Duration of the Squeeze at the LHC	optics, simulation, controls, acceleration	1873
	X. Buffat EPFL, Lausanne, Switzerland G.J. Müller, S. Redaelli, M. Strzelczyk CERN, Geneva, Switzerland
	The betatron squeeze allows to increase the luminosity of a collider by reducing the β function at the interaction points. This operation has shown to be very critical in previous colliders. In this state of mind, the squeezing was performed extremely safely during the first year of operation of the Large Hadron Collider, at the expense of the duration of the process. As the turnaround time is a relevant parameter for the integrated luminosity, a squeeze of shorter duration is proposed for 2011 and further. MadX simulation of linear beam parameters based on settings extracted from the LHC control system are used to justify the proposal. Further optimization of the squeeze setting generation is also discussed.

TUPZ032	LHC Luminosity Upgrade with Large Piwinski Angle Scheme: A Recent Look	luminosity, simulation, emittance, single-bunch	1879
	C.M. Bhat Fermilab, Batavia, USA F. Zimmermann CERN, Geneva, Switzerland
	Funding: Work is supported by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the U.S. Department of Energy and US LARP. Luminosity upgrade at the LHC collider using bunches with constant line charge density (longitudinally flat bunches) but with same beam-beam tune shift at collision, the so called large Piwinski angle scheme* is being studied with renewed interest in recent years*. By design the total beam-beam tune shift at the LHC is less than 0.015. But the initial operational experience at the LHC indicates the possibility of operating with beam-beam tune shifts as high as 0.02. In view of this development we have revisited the requirements for the Large Piwinski Angle scheme at the LHC. In this paper we present a new parameter list supported by 1) calculations on the luminosity gain, 2) reduction of e-cloud issues on nearly flat bunches and 3) longitudinal beam dynamics simulations. We also make some remarks on the needed upgrades on the LHC injector accelerators. F. Ruggiero and F. Zimmermann, PRST-AB 5, 061001 (2002). ** C. M. Bhat, CERN-2009-004, pp. 10⁶-114. Thanks to O.Bruning, E.Shaposhnikova, H.Damerau, E.Mahner, F.Caspers & CERN BE/ABP & RF Depts.

TUPZ033	Measurements of Transverse Beam Diffusion Rates in the Fermilab Tevatron Collider	antiproton, background, electron, emittance	1882
	G. Stancari, G. Annala, T.R. Johnson, D.A. Still, A. Valishev Fermilab, Batavia, USA
	Funding: Fermi Research Alliance, LLC operates Fermilab under Contract DE-AC02-07CH11359 with the US Department of Energy. This work was partially supported by the US LHC Accelerator Research Program (LARP). The transverse beam diffusion rate vs. particle oscillation amplitude was measured in the Tevatron using collimator scans. All collimator jaws except one were retracted. As the jaw of interest was moved in small steps, the local shower rates were recorded as a function of time. By using a diffusion model, the time evolution of losses could be related to the diffusion rate at the collimator position. Preliminary results of these measurements are presented.
	Poster TUPZ033 [1.036 MB]

TUPZ041	Site Studies for the SuperB Collider and Synchrotron Radiation Facility Project	site, ground-motion, linac, injection	1900
	S. Tomassini, M.E. Biagini, P. Raimondi, C. Sanelli INFN/LNF, Frascati (Roma), Italy B. Bolzon CERN, Geneva, Switzerland G. Deleglise, A. Jeremie IN2P3-LAPP, Annecy-le-Vieux, France J.T. Seeman SLAC, Menlo Park, California, USA
	The SuperB project aims at the construction of a very high luminosity (10³⁶ cm^-2 s⁻¹) asymmetric electron-positron collider. Due to its large beam current (~2 A) high energy (~7 GeV) and low vertical emittance (less than 10^-11 m) the facility looks very attractive as an x-ray synchrotron radiation source, and therefore few beam lines are also foreseen. Possible locations are the campus of the University of Rome Tor Vergata or near another Italian INFN laboratory site. This paper presents and describes the status of the preliminary design of the civil infrastructure layout and related site issues.

WEODA03	Design Concepts for the Large Hadron Electron Collider	linac, electron, cavity, luminosity	1942
	M. Klein The University of Liverpool, Liverpool, United Kingdom
	A report is presented on the design concepts for a high luminosity electron-nucleon collider of 1.3 TeV centre of mass energy, realized with the addition of a 60 GeV electron ring or linear accelerator to the existing proton and ion LHC beam facility, comprising machine magnets, optics, interaction region, cryogenics, rf, civil engineering and further components of the LHeC. The report on behalf of the LHeC study team is a summary of the 2011 LHeC CDR and feedback received from an international review panel.
	Slides WEODA03 [9.780 MB]

WEPC028	Record Low Beta-beat of 10% in the LHC	optics, injection, hadron, quadrupole	2061
	G. Vanbavinckhove NIKHEF, Amsterdam, The Netherlands M. Aiba PSI, Villigen, Switzerland R. Calaga, R. Miyamoto BNL, Upton, Long Island, New York, USA R. Tomás CERN, Geneva, Switzerland
	During the 2011 LHC run several measurements and correction campaigns were conducted. As a result a peak beta-beat of 10% level was achieved. This level, well below the specified tolerances of the LHC, improves the aperture margins and helps minimize the luminosity imbalance between the different experiments. A combination of local corrections at the insertion regions and an overall global correction were used to achieve this record low beta-beat. The sequence of the optics corrections and stability along the 2011 run are reported.

WEPC047	Crab Crossing Schemes and Studies for Electron Ion Collider	cavity, electron, lattice, ion	2115
	S. Ahmed, S.U. De Silva, Y.S. Derbenev, G.A. Krafft, V.S. Morozov, B.C. Yunn, Y. Zhang JLAB, Newport News, Virginia, USA A. Castilla, J.R. Delayen ODU, Norfolk, Virginia, USA
	Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. Medium Energy Electron Ion Collider (MEIC) at JLab has been envisioned as future high energy particle accelerator beyond 12 GeV upgrade of CEBAF. Crab crossing of colliding electron and ion beams is essential for accommodating high bunch repetition frequency in the conceptual design of MEIC. The scheme eliminates parasitic beam-beam interactions and avoids luminosity reduction by restoring head-on collisions at interaction points. This requires the separation of two beams quickly to avoid parasitic collisions and the minimization of synchrotron-betatron resonance near IP which can be fulfilled by employing the crab crossing concept first proposed by R. Palmer. Let us call this original scheme as transverse crabbing for the sake of comparison with dispersive crabbing which employs the existing accelerating/bunching RF cavities and dispersion function in the section where the cavity is installed as originally proposed by G. Jackson. In this paper, we report the beam transport and optics for both transverse and dispersive crabbing schemes followed by basic beam dynamics. Moreover, alignment and stability calculations together with synchro-betatron beam dynamics will be discussed.

WEPC081	Beam-Beam Induced Orbit Effects at LHC	luminosity, simulation, closed-orbit, beam-beam-effects	2208
	M. Schaumann, R. Alemany-Fernandez CERN, Geneva, Switzerland
	For high bunch intensities the beam-beam force is strong enough to expect orbit effects if the two beams do not collide head-on but with a crossing angle or with a given offset. As a consequence the closed orbit changes. The closed orbit of an unperturbed machine with respect to a machine where the beam-beam force becomes more and more important has been studied and the results are presented in this paper.

WEPC116	A Matrix Presentation for a Beam Propagator including Particles Spin	storage-ring, controls, heavy-ion, scattering	2283
	M. Kosovtsov, S.N. Andrianov, A.N. Ivanov St. Petersburg State University, St. Petersburg, Russia
	Particles beam dynamics in magnetic and electrical fields with spin is discussed. This approach provides a constructive method of matrix presentation derivation for a beam propagator in magnetic and electrical fields. The beam propagator is evaluated in according to the well-known Lie algebraic tools. But in contrast to traditional approaches matrix presentation for Lie propagators bases on two-indexes matrices. This approach permit to apply all of matrix algebra opportunities and advantages in contrast with the tenzor presentation based on multi-indexes description. The necessary computation can be realized in symbolic (using computer algebra codes as Mathematica, Maple, Maxima and so on). The corresponding symbolic objects itself can be stored in special databases and used then in numerical computing. Parallel and distributed conception is well acceptable with the suggested matrix formalism. Some symbolic and numerical results are discussed for problems of long term evolution of particles with spin.

WEPC142	High Performance Web Applications for Particle Accelerator Control Systems	controls, luminosity, optics, diagnostics	2322
	G. Mazzitelli, C. Bisegni, P. Ciuffetti, G. Di Pirro, A. Stecchi INFN/LNF, Frascati (Roma), Italy S. Calabrò, L.G. Foggetta IN2P3-CNRS, Orsay, France L. Catani, F. Zani INFN-Roma II, Roma, Italy
	The integration of web technologies and applications has been one of the major trends for the development of new services for control systems of particle accelerators and large experimental apparatuses. Nowadays, high performance web technologies exhibit some features that would allow their deeper integration in a control system and their employment in developing control system's core components. In this paper we discuss the results of preliminary investigations of a new paradigm for a particle accelerator control system and associated machine data acquisition system based on a synergic combination of network distributed cache memory and a non-relational key/value database. Storage speed, network memory data retrieve throughput and database queries execution, as well as scalability and redundancy of the systems, are presented and critically reviewed.
	Poster WEPC142 [8.902 MB]

WEPO026	Advances in the Design of the SuperB Final Doublet	quadrupole, luminosity, controls, positron	2454
	E. Paoloni, N. Carmignani, F. Pilo University of Pisa and INFN, Pisa, Italy S. Bettoni CERN, Geneva, Switzerland M.E. Biagini, P. Raimondi INFN/LNF, Frascati (Roma), Italy F. Bosi INFN-Pisa, Pisa, Italy P. Fabbricatore, S. Farinon, R. Musenich INFN Genova, Genova, Italy M.K. Sullivan SLAC, Menlo Park, California, USA
	SuperB is an asymmetric (6.7 GeV HER, 4.18 GeV LER) e⁺ e− collider operating at the Y(4S) peak with a design peak luminosity of 10³6 Hz/cm² to be built in Italy in the very near future. The design luminosity is almost a factor hundred higher than that of the present generation comparable facilities. To get the design luminosity a novel collision scheme, the so called “large Piwinski angle with crab waist”, has been designed. The scheme requires a short focus final doublet to reduce the vertical beta function down to betay*=0.2 mm at the interaction point (IP). The final doublet will be composed by a set of permanent and superconducting (SC) quadrupoles. The SC quadrupole doublets QD0/QF1 have to be placed as close to the IP as possible. This layout is critical because the space available for the doublets is very small. An advanced design of the quadrupole has been developed, based on the double helical coil concept. The paper discusses the design concept, the construction and the results of test of a model of the superconducting quadrupole based on NbTi technology. Future developments are also presented.

WEPS014	RF Systems and Bunch Formation at NICA	ion, booster, cavity, injection	2511
	A.V. Eliseev, I.N. Meshkov, A.O. Sidorin, G.V. Trubnikov JINR, Dubna, Moscow Region, Russia O.I. Brovko JINR/VBLHEP, Moscow, Russia G.Y. Kurkin, V.M. Petrov BINP SB RAS, Novosibirsk, Russia
	The NICA facility being constructed at JINR will consists of two synchrotrons (Booster and Nuclotron) and collider working at constant magnetic field. To reach required luminosity level the collider rings will be operated with short ion bunches. The bunch formation in the collider as well as longitudinal dynamics in all the rings is described. The parameters and preliminary design of RF systems are presented.

WEPZ024	Some Considerations in Realizing a TeV Linear Collider Based on the PDPWA Scheme	proton, electron, plasma, wakefield	2817
	G.X. Xia, A. Caldwell MPI-P, München, Germany P. Muggli MPI, Muenchen, Germany
	Proton-driven plasma wakefield acceleration (PDPWA) has recently been proposed as an approach to bring the electron beam to the energy frontier in a single passage of acceleration. Particle-in-Cell (PIC) simulation shows that a TeV proton bunch, with a bunch intensity of 10¹¹, and a bunch length as short as 10⁰ microns can resonantly excite a large amplitude plasma wakefield and accelerate an externally injected electron bunch to 600 GeV in a single stage of 500 m long plasma. This novel PDPWA scheme may open a new path for designing a TeV linear lepton collider by using the currently available proton drivers. In this paper, we investigate some key issues, e.g. bunch length, centre-of-mass (CoM) energy, luminosity and dephasing in realizing a TeV linear collider based on the PDPWA scheme.

THPO032	Preliminary Design of an Inductive Adder for CLIC Damping Rings	kicker, damping, emittance, impedance	3409
	J. Holma, M.J. Barnes CERN, Geneva, Switzerland
	The Compact Linear Collider (CLIC) study is exploring the scheme for an electron-positron collider with high luminosity and a nominal centre-of-mass energy of 3 TeV. The CLIC damping rings will produce ultra-low emittance, with high bunch charge, necessary for the luminosity performance of the collider. To limit the beam emittance blow-up due to oscillations, the pulse power modulators for the damping rings kickers must provide extremely flat, high-voltage pulses: specifications call for a 160 ns duration flattop of 12.5 kV, 250 A, with a combined ripple and droop of not more than ±0.02 %. A solid-state modulator, the inductive adder, is a very promising approach to meeting the demanding specifications; this topology allows the use of both digital and analogue modulation. To effectively use modulation techniques to achieve such low ripple and droop requires an in-depth knowledge of the behaviour of the solid-state switching components and their gate drivers, as well as a good understanding of the overall circuit behaviour. This paper describes the initial design of the inductive adder.

THPS046	Transport Beam Lines for NICA Accelerator Complex	booster, ion, quadrupole, lattice	3526
	O.S. Kozlov, A.V. Eliseev, I.N. Meshkov, V.A. Mikhailov, A.O. Sidorin, N.D. Topilin, G.V. Trubnikov, A. Tuzikov JINR, Dubna, Moscow Region, Russia
	In the last years Nuclotron-based Ion Collider fAcility (NICA) project is being developed by Joint Institute for Nuclear Research (JINR), Dubna, Russia. The goal of the project is to construct new accelerator complex that will be used for colliding ion beams on first stage and colliding polarized proton/deuteron beams on second stage of the project. NICA accelerator complex will consist of two linear accelerators, two superconducting synchrotrons, two superconducting storage rings of the collider and transport beamlines. Geometry and magnetic system of NICA beamlines are presented in this report. Results of beam dynamics simulations within the beamlines are considered.

THPZ001	Spin Dynamic Tool Developments and Study Regarding the Super-B Project	closed-orbit, simulation, lattice, polarization	3681
	N. Monseu, J.-M. De Conto LPSC, Grenoble Cedex, France F. Méot BNL, Upton, Long Island, New York, USA U. Wienands SLAC, Menlo Park, California, USA
	The study of polarization is essential for e+/e^- colliders like the SuperB machine. The ZGOUBI integrator is a good and universal tool for particle tracking as well as spin tracking, and takes into account all machine realistic aspects, like real fields, non-linearities, fringing fields or misalignments. We present ZGOUBI implementation and the methods carried out to estimate invariant spin field and beam polarization evolution on some simple models (for validation) and on SuperB, and we investigate for some specific polarization behavior.

THPZ033	Operational Experience and Performance of the LHC Collimator Controls System	controls, collimation, monitoring, optics	3765
	S. Redaelli, A. Masi CERN, Geneva, Switzerland
	In order to handle stored energies up to 360 MJ, the LHC relies on a collimation system that consists of 100 movable collimators. Compared to other accelerator, the complexity of this system is unique: more than 400 motors and about 600 interlocked position sensors must be controlled in all the machine phases in order to ensure the cleaning and machine protection roles of the system. In this paper, the controls system and the setting management are presented and the operational experience accumulated in the 2 first years of operation is discussed, focussing in particular on failure and availability statistics during the LHC operation.

Paper

Title

Other Keywords

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MOYBA01

Present Status of the ILC Project and Developments

cavity, linac, linear-collider, electron

16

M.C. Ross
Fermilab, Batavia, USA
N.J. Walker
DESY, Hamburg, Germany
A. Yamamoto
KEK, Ibaraki, Japan

Funding: FNAL is operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy.
The Technical Design of the ILC Project will be finished in late 2012. The Technical Design Report will include a description of the updated design, with a cost estimate and a project plan, and the results of R & D done in support of the ILC. Results from directed ILC R & D are used to reduce the cost and risk associated with the ILC design. We present a summary of key challenges and show how the global R & D effort has addressed them. The most important activity has been in pursuit of very high gradient superconducting RF linac technology. There has been excellent progress toward the goal of practical industrial production of niobium sheet-metal cavities with gradient performance in excess of 35 MV/m. In addition, three purpose-built beam test facilities have been constructed and used to study and demonstrate high current linac performance, electron-cloud beam dynamics and precision beam control. The report also includes a summary of component design studies and conventional facilities cost optimization design studies.

Slides MOYBA01 [9.755 MB]

MOPO017

Latest Performance Results from the FONT5 Intra-train Position and Angle Feedback System at ATF2

feedback, kicker, linear-collider, positron

520

G.B. Christian, D.R. Bett, M.R. Davis, C. Perry
JAI, Oxford, United Kingdom
R. Apsimon, P. Burrows
Oxford University, Physics Department, Oxford, Oxon, United Kingdom
B. Constance, A. Gerbershagen
CERN, Geneva, Switzerland
J. Resta-López
IFIC, Valencia, Spain

A prototype Interaction Point beam-based feedback system for future electron-positron colliders, such as the International Linear Collider, has been designed and tested on the extraction line of the KEK Accelerator Test Facility (ATF). The FONT5 intra-train feedback system aims to stabilize the beam orbit by correcting both the position and angle jitter in the vertical plane on bunch-to-bunch timescales, providing micron-level stability at the entrance to the ATF2 final-focus system. The system comprises three stripline beam position monitors (BPMs) and two stripline kickers, custom low-latency analogue front-end BPM processors, a custom FPGA-based digital processing board with fast ADCs, and custom kicker-drive amplifiers. An overview of the hardware, and the latest results from beam tests at ATF2, will be presented. A total system latency as low as approximately 140 ns has been demonstrated.

MOPS003

Coherent Beam-beam Resonances in SuperB with Asymmetric Rings

resonance, luminosity, simulation, dynamic-aperture

592

M. Zobov
INFN/LNF, Frascati (Roma), Italy
Y. Zhang
IHEP Beijing, Beijing, People's Republic of China

One of the latest options of SuperB foresees exploiting rings with unequal circumferences. In such a configuration additional coherent beam-beam resonances can arise. In this paper we discuss the possible impact of the resonances on beam dynamics in SuperB, maximum achievable tune shifts and working point choice.

MOPS006

Beam Tilt due to Transverse Wakefields for DAΦNE, SuperB, KEKB and SuperKEKB

impedance, closed-orbit, wakefield, vacuum

601

D.M. Zhou, K. Ohmi
KEK, Ibaraki, Japan
A. Chao
SLAC, Menlo Park, California, USA

When a beam bunch traverses a transverse impedance, the bunch head generates a transverse wakefield that kicks the bunch tail, generating a betatron motion of the tail relative to the head. In a storage ring, in a steady state, this kick to the bunch tail produces a transverse closed orbit (e.g. in the y-direction) of the bunch tail relative to the bunch head, which means the beam now has a y-z tilt. Such beam tilt due to transverse wakefields may cause a loss of luminosity in storage ring colliders or loss of brightness in light sources. In this paper, we present a preliminary study of the beam tilt effect for the colliders DAΦNE, SuperB, KEKB and SuperKEKB.

MOPZ011

An Automated Conditioning System for the MUCOOL Experiments at Fermilab

cavity, controls, pick-up, vacuum

844

A. Kurup
Imperial College of Science and Technology, Department of Physics, London, United Kingdom

The MUCOOL project aims to study RF cavities for the Neutrino Factory and the Muon Collider. The large emittance muon beams in these accelerators require high-gradient RF cavities at low-frequencies and they need to operate in the presence of relatively strong magnetic fields. MUCOOL is conducting a number of tests on 805MHz and 201 MHz cavities in order to develop a technology that can meet all of these requirements. An automated conditioning system was developed for the 805MHz test program for MUCOOL. This system was designed to replicate the logic a human operator would use when conditioning an RF cavity and to provide automated logging of the conditioning process. This paper describes the hardware and software of the system developed.

MOPZ016

MICE Step I: First Measurement of Emittance with Particle Physics Detectors*

emittance, simulation, quadrupole, factory

853

L. Coney
UCR, Riverside, California, USA
M. Popovic
Fermilab, Batavia, USA
M.A. Rayner
DPNC, Genève, Switzerland

The muon ionization cooling experiment (MICE) is a strategic R&D project intending to demonstrate the only practical solution to prepare high brilliance beams necessary for a neutrino factory or muon colliders. MICE is under development at the Rutherford Appleton Laboratory (UK). It comprises a dedicated beam line to generate a range of input emittance and momentum, with time-of-flight and Cherenkov detectors to ensure a pure muon beam. The emittance of the incoming beam is measured in the upstream magnetic spectrometer with a sci-fiber tracker. A cooling cell will then follow, alternating energy loss in Li-H absorbers and RF acceleration. A second spectrometer identical to the first and a second muon identification system measure the outgoing emittance. In the 2010 run the beam and most detectors have been fully commissioned and a first measurement of the emittance of a beam with particle physics (time-of-flight) detectors has been performed. The analysis of these data should be completed by the time of the Conference. The next steps of more precise measurements, of emittance and emittance reduction (cooling), that will follow in 2011 and later, will also be outlined.
Abstract is submitted by the MICE Speakers Bureau.
If accepted, most likely Dr. Kaplan will present it.
As a first result in a novel sector, we propose it for an oral presentation

TUYA01

Achievements and Lessons from the Tevatron

antiproton, luminosity, proton, electron

903

V.D. Shiltsev
Fermilab, Batavia, USA

The Tevatron Run-2 will come to an end at the time of IPAC'11. This talk will concentrate on exploration of the accelerator physics issues that were dealt with in achieving the current (very high) level of performance in the Tevatron and will review achievements, challenges and lessons learned on the way.

Slides TUYA01 [5.881 MB]

TUYA02

LHC Upgrade Plans: Options and Strategy

luminosity, cavity, quadrupole, cryogenics

908

L. Rossi
CERN, Geneva, Switzerland

Presentation of options for future luminosity and/or energy upgrades of the LHC ring. The presentation should cover the different ideas, short term, medium term and long term, and discuss the research programme that is needed to prepare the upgrades.

Slides TUYA02 [5.139 MB]

TUPC001

Simulations of the Interaction Point for TeV-scale e⁺ e− Colliders

photon, electron, simulation, radiation

985

J. Esberg
Aarhus University, Aarhus, Denmark

The design of a detector and post collisional line of a future linear collider calls for detailed knowledge of the beam-beam dynamics at the interaction point. We here describe the implementation and results of new simulation tools in the program GUINEA-PIG. The subjects are direct trident production relevant in the deep quantum-regime, incoherent muon generation, synchrotron radiation from secondary particles and depolarization effects. We choose beam parameters in the range relevant for CLIC and comment on the implications for the design of such a machine.

TUPC002

Study of a Large Piwinski’s Angle Configuration for Linear Colliders

luminosity, linear-collider, radiation, background

988

R. Versteegen, O. Napoly
CEA/DSM/IRFU, France

The application of a Large Piwinski’s Angle configuration to the interaction region of a linear collider is studied. The calculation of the equivalent disruption parameter and beamstrahlung parameter in the presence of a crossing angle are necessary to estimate the beam-beam effects in such a configuration. The reduction of the beam-beam interaction effects, based on these parameters, while keeping same luminosity is presented for both ILC and CLIC parameters.

TUPC004

The Luminosity for the ILC Travelling Focus Regime with Offsets and Angle Scans*

luminosity, emittance, simulation, wakefield

991

L.I. Malysheva, O.S. Adeyemi, V.S. Kovalenko, A. Ushakov
University of Hamburg, Hamburg, Germany
K. Buesser, A.F. Hartin, G.A. Moortgat-Pick, N.J. Walker
DESY, Hamburg, Germany
S. Riemann, F. Staufenbiel
DESY Zeuthen, Zeuthen, Germany

One of the crucial challenges of a future linear collider is to provide high luminosity. In the current ILC design a luminosity of 2x10³⁴ is foreseen. In order to enhance the luminosity, use of the “travelling focus” scheme is under discussion. Within this regime the hourglass effect at the interaction point can be effectively overcome by judiciously arranging for the head and tail of the bunches to be focused at a proportionally displaced longitudinal position. The effect is further enhanced by the strong beam-beam interaction which continuously focuses the bunches during collision. In principle travelling focus could provide an additional 30% luminosity. Nevertheless the regime is highly sensitive to beam-beam transverse and angular offsets at the collision point. The study of the luminosity stability for various ILC parameters using traveling focus will be presented.

TUPC005

Evolution of Pressure in Positron Source for Future Linear e⁺e⁻ Collider

target, photon, positron, linear-collider

994

O.S. Adeyemi, V.S. Kovalenko, L.I. Malysheva
University of Hamburg, Hamburg, Germany
A.F. Hartin, G.A. Moortgat-Pick, S. Riemann, A. Ushakov
DESY, Hamburg, Germany
A. Schälicke, F. Staufenbiel
DESY Zeuthen, Zeuthen, Germany

Funding: This work is supported by the German Federal Ministry of Education and Research, Joint Research Project R&D Accelerator "Spin Management", contract number 05H10GUE
Energy deposition in the conversion targets of positron sources for future linear colliders induces an immense thermal load and create pressure waves in the material. This stress could substantially reduce the lifetime of the target or other target materials impinged by the incident intense photon or electron beam. We have studied the evolution of acoustic pressure waves in target materials based on the parameter assumptions for the International Linear Collider (ILC) baseline source. The fluid model is employed by taking into account the target and the incident photon beam parameters. Initial results of these new simulations are presented and compared with earlier studies. Prospects for further studies are outlined.

TUPC007

Kicker and Monitor for CTF3 Phase Feed Forward

kicker, impedance, pick-up, coupling

1000

F. Marcellini, D. Alesini, A. Ghigo
INFN/LNF, Frascati (Roma), Italy

Funding: Work partially supported by the EuCARD research programme, Grant Agreement 227579, within the 'Assessment of Novel Accelerator Concepts'.
In the Compact LInear Collider (CLIC) the synchronization of the Drive Beam and the Main Beam has to be assured in the femtosecond range to avoid luminosity reduction of the collider. The Drive and Main Beams arrival time is measured with longitudinal monitors and the correction is applied changing the path length of one beam respect to the other in a magnetic chicane by means of two transverse fast stripline kicker. The performance of the feed forward system will be tested in the CLIC Test Facility (CTF3) measuring the phase at the linac exit, correcting in the chicane after the combination rings and comparing the longitudinal position change before the power RF production system. The developed phase monitors and kicker magnets for the test in CTF3 are described.

TUPC013

Simulation of Phase Stability at the Flat Top of the CLIC Drive Beam

linac, simulation, luminosity, kicker

1018

A. Gerbershagen, D. Schulte
CERN, Geneva, Switzerland
P. Burrows
Oxford University, Physics Department, Oxford, Oxon, United Kingdom

Funding: University of Oxford
The drive beam phase stability is one of the critical issues of the Compact Linear Collider (CLIC). In this paper the generation and propagation of drive beam phase errors is studied for effects that vary during the drive beam pulse. This includes the influence of drive beam current and phase errors as well as of drive beam accelerator RF phase and amplitude errors on the drive beam phase after the compressor chicanes and the analysis of the propagation of these errors through the drive beam combination scheme. The impact of the imperfections on the main beam is studied including the possible correction with help of a feedforward system.

TUPC017

Civil Engineering Studies for Major Projects after LHC

interaction-region, civil-engineering, site, linac

1030

J.A. Osborne, F.J. Magnin, E. Perez-Duenas
CERN, Geneva, Switzerland

CERN civil engineers are heavily involved in studying several major projects to succeed/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. For example, CERN are studying infrastructure requirements for the Linear Collider (CLIC & ILC) and the LHeC projects. This poster presents some of the key civil engineering challenges faced in such large scale projects.

TUPC018

Progress on Modelling of the Thermo-Mechanical Behavior of the CLIC Two-Beam Module

vacuum, RF-structure, simulation, linac

1033

R.J. Raatikainen, K. Osterberg
HIP, University of Helsinki, Finland
T.O. Niinikoski, G. Riddone
CERN, Geneva, Switzerland

The luminosity goal of the CLIC collider, currently under study, imposes micrometer mechanical stability of the 2-m long two-beam modules, the shortest repetitive elements of the main linacs. These modules will be exposed to variable high power dissipation during operation resulting in mechanical distortions in and between module components. The stability of the CLIC module will be tested in laboratory conditions at CERN in a full-scale prototype module. In this paper, the FEA model developed for CLIC prototype module is described. The thermal and structural results for the new module configuration are presented considering the thermo-mechanical behavior of the CLIC collider in its primary operation modes. These results will be compared to the laboratory measurements to be done during 2011 and 2012 with the full-scale prototype module. The experimental results will allow for better understanding of the module behaviour and they will be propagated back to the present thermo-mechanical model.

TUPC118

Test Results on Beam Position Resolution for Low-Q IP-BPM at KEK-ATF2

cavity, feedback, alignment, dipole

1293

S.W. Jang, A. Heo, J.G. Hwang, E.-S. Kim, H.-S. Kim
Kyungpook National University, Daegu, Republic of Korea
H.K. Park
CHEP, Daegu, Republic of Korea

We have performed the beam tests on the beam position resolution for the Low-Q IP-BPM (Interaction Point-Beam Position Monitor) at ATF2 which is an accelerator test facility for the International Linear Collider. The main goals of KEK-ATF2 are to achieve beam size of 37 nm and beam resolution of nano-meter for beam stabilization. Resolution tests for the Low-Q IP-BPM were performed with KEK BPM doublet in Jan. 2011. We got the results of beam position resolution 70 nm during the experimental periods and will present the detailed experimental procedures and results.

TUPC124

Laser Wire Emittance Measurement Line at CLIC*

laser, emittance, photon, electron

1308

H. Garcia, Yu.A. Kubyshin
UPC, Barcelona, Spain
T. Aumeyr, G.A. Blair
JAI, Egham, Surrey, United Kingdom
D. Schulte, F. Stulle
CERN, Geneva, Switzerland

A precise measurement of the transverse beam size and beam emittances upstream of the final focus is essential for ensuring the full luminosity at future linear colliders. A scheme for the emittance measurements at the RTML line of the CLIC using laser-wire beam profile monitors is described. A lattice of the measurement line is discussed and results of simulations of statistical and machine-related errors and of their impact on the accuracy of the emittance reconstruction are given. Modes of operation of the laser wire system and its main characteristics are discussed.

TUPC141

LHC Beam Loss Pattern Recognition

beam-losses, monitoring, proton, resonance

1353

A. Marsili, E.B. Holzer, P.M. Puzo
CERN, Geneva, Switzerland

One of the systems protecting CERN's Large Hadron Collider (LHC) is the Beam Loss Monitoring system (BLM). More than 3600 monitors are installed around the ring. The beam losses are permanently integrated over 12 different time intervals (from 40 microseconds to 84 seconds). When any loss exceeds the thresholds defined for the integration window, the beam is removed from the machine. Understanding the origin of a beam loss is crucial for machine operation, as it can help to avoid a repeat of the same scenario. The signals read from given monitors can be considered as entries of a vector. This article presents how a loss map of unknown cause can be decomposed using vector based analysis derived from well-known loss scenarios. The algorithms achieving this decomposition are described, as well as the accuracy of the results.

TUPC164

Position Determination of Closely Spaced Bunches using Cavity BPMs

cavity, single-bunch, quadrupole, linear-collider

1419

N.Y. Joshi, S.T. Boogert, F.J. Cullinan, A. Lyapin
JAI, Egham, Surrey, United Kingdom

Cavity Beam Position Monitor (BPM) systems with high-Q form a major part of precision position measurement diagnostics for linear accelerators with low emittance beam. Using cavity BPMs, the position resolution of less than 100 nm has been demonstrated in single bunch mode operation. In the case of closely spaced bunches, where the decay time of the cavity is comparable to the time separation between bunches, the BPM signal from a bunch is polluted by the signal induced from the previous bunches in the same bunch-train. This paper discuss our ongoing work to develop the methods to extract the position of the closely spaced bunches using cavity BPMs. A signal subtraction code is being developed to remove the signal pollution from previous bunches and to determine the individual bunch position. Another code has been developed to simulate the BPM data for the cross check. Performance of the code is studied on the experimental and simulated data. Application of the analysis techniques to the linear colliders, such as International Linear Collider (ILC) and Compact LInear Collider (CLIC), are briefly discussed.

TUPS024

Development of Beryllium Vacuum Chamber Technology for the LHC

vacuum, electron, controls, background

1578

R. Veness
CERN, Geneva, Switzerland
C. Dorn, G. Simmons
Materion Electrofusion, Fremont, California, USA

Beryllium is the material of choice for the beam vacuum chambers around collision points in particle colliders due to a combination of transparency to particles, high specific stiffness and compatibility with ultra-high vacuum. New requirements for these chambers in the LHC experiments have driven the development of new methods for the manufacture of beryllium chambers. This paper reviews the requirements for experimental vacuum chambers. It describes the new beryllium technology adopted for the LHC and experience gained in the manufacture and installation.

TUPS025

Design of a Highly Optimised Vacuum Chamber Support for the LHCb Experiment

radiation, vacuum, background, interaction-region

1581

L. Leduc, G. Corti, R. Veness
CERN, Geneva, Switzerland

The beam vacuum chamber in the LHCb experimental area passes through the centre of a large aperture dipole magnet. The vacuum chamber and all its support systems lie in the acceptance of the detector, so must be highly optimised for transparency to particles. As part of the upgrade programme for the LHCb vacuum system, the support system has been re-designed using advanced lightweight materials. In this paper we discuss the physics motivation for the modifications, the criteria for the selection of materials and tests performed to qualify them for the particular environment of a particle physics experiment. We also present the design of the re-optimised support system.

TUPS053

A Target Magnet System for a Muon Collider and Neutrino Factory

shielding, target, radiation, factory

1650

H.G. Kirk
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: This work is supported in part by the US DOE Contract NO. DE-AC02-98CH10886.
The target system envisioned for a Muon Collider or Neutrino Factory includes a 20-T solenoid field surrounding a mercury jet target with the field tapering to 1.5 T 15 m downstream of the target. A principal challenge is to shield the superconducting magnets from the radiation issuing from the 4-MW proton beam impacting the target. We describe a solution which will deliver the desired field while being capable of tolerating the intense radiation environment surrounding the target.

TUPS055

Organizing the ILC Technical Design Documentation

lattice, positron, linear-collider, damping

1656

L. Hagge, S. Eucker, B. List, N.J. Walker, N. Welle
DESY, Hamburg, Germany

The Global Design Effort (GDE) for the International Linear Collider (ILC) is currently preparing the Technical Design Report (TDR), which will be released at the end of 2012 and will serve as the basis for a decision process. The TDR will be written based on the Technical Design Documentation (TDD), which captures the entire design efforts, results and rationale, including e. g. parameter lists, specifications, CAD models and drawings, cost estimation, simulations and calculations, and summary reports. Formal review meetings help making the documentation complete, correct and consistent. The TDD is stored in an Engineering Data Management System (EDMS), which ensures that it remains accessible beyond the GDE in an organized way and at a well-defined location. The EDMS provides traceability (e. g. from design decisions to corresponding cost estimates), version management and change control. The poster presents the process and tools that were established for the organization of the TDD and provides an overview of the emerging documentation.

TUPS070

An Experiment at HiRadMat: Irradiation of High-Z Materials

target, simulation, proton, ion

1698

J. Blanco, C. Maglioni, R. Schmidt
CERN, Geneva, Switzerland
N.A. Tahir
GSI, Darmstadt, Germany

Calculations of the impact of dense high intensity proton beams at SPS and LHC into material have been presented in several papers*,**,***. This paper presents the plans for an experiment to validate the theoretical results with experimental data. The experiment will be performed at the High Radiation to Materials (HiRadMat) facility at the CERN-SPS. The HiRadMat facility is dedicated to shock beam impact experiments. It allows testing of accelerator components with respect to the impact of high-intensity pulsed beams. It will provide a 440 GeV proton beam with a focal size down to 0.1 mm, thus providing very dense beam (energy/cross section). The transversal profile of the beam is considered to be Gaussian with a tunable σ from 0.1 mm to 2 mm. This facility will allow to study “high energy density” physics as the energy density will be high enough to create strong coupled plasma in the core of high-Z materials (copper, tungsten) and to produce strong enough shock waves to create a density depletion channel along the beam axis (tunneling effect). The paper introduces the layout of the experiment and the monitoring system to detect tunneling of protons through the target.
* N.A.Tahir et al. HB2010 Proc., Morschach, Switzerland.
** N.A.Tahir et al. NIMA 606(1-2) 2009 186.
*** N.A.Tahir et al. 11th EPAC, Genoa, Italy, 2008, WEPP073.

TUPS081

3D Visualization, Simulation and Virtual Reality in Accelerator Development

simulation, linear-collider, site

1728

L. Hagge, A. Herz, J. Kreutzkamp, S. Lang, V. Rupprecht, S. Sühl, N. Welle
DESY, Hamburg, Germany

Visualizing complex beamline designs, animating installation procedures and virtually walking through planned facilities - 3D modelling is a powerful tool with a broad range of applications in accelerator development. The poster describes established and emerging 3D modelling applications at the European XFEL and their benefits: 3D visualization enables inspection and compliance analysis of interfacing systems and components. Simulations enable early verification of e.g. safety and transportation concepts. Digital humans can be inserted into accelerator models to perform e.g. reachability and field-of-sight studies for installation works. Movies of transport and installation procedures can be created for staff training. And ultimately, stereo projection can be used to inspect and simulate designs and processes in virtual environments. 3D modelling helps discovering and resolving design issues earlier and leads to large savings in time and cost.

TUPS098

Machining and Characterizing X-band RF-structures for CLIC

controls, cavity, damping, electron

1768

S. Atieh, M. Aicheler, G. Arnau-Izquierdo, A. Cherif, L. Deparis, D. Glaude, L. Remandet, G. Riddone, M. Scheubel
CERN, Geneva, Switzerland
D. Gudkov, A. Samoshkin, A. Solodko
JINR, Dubna, Moscow Region, Russia

The Compact Linear Collider (CLIC) is currently under study at CERN as a potential multi-TeV e+e collider. The manufacturing and assembling tolerances for making the required RF components are essential for CLIC to perform efficiently. Machining techniques are relevant to the construction of ultra-high-precision parts for the Accelerating Structures (AS). Optical-quality turning and ultra-precision milling using diamond tools are the main manufacturing techniques identified to produce ultra-high shape accuracy parts. A shape error of less than 5 micrometres and roughness of Ra 0.025 are achieved. Scanning Electron Microscopy (SEM) observation as well as sub-micron precision Coordinate Measuring Machines (CMM), roughness measurements and their crucial environment were implemented at CERN for quality assurance and further development. This paper focuses on the enhancements of precision machining and characterizing the fabrication of AS parts.

TUPS099

A Study of the Surface Quality of High Purity Copper after Heat Treatment

vacuum, electron, damping, linear-collider

1771

M. Aicheler, G. Arnau-Izquierdo, S. Atieh, S. Calatroni, S. Lebet, G. Riddone, A. Samoshkin
CERN, Geneva, Switzerland

The manufacturing flow of accelerating structures for the compact linear collider, based on diamond-machined high purity copper components, include several thermal cycles (diffusion bonding, brazing of cooling circuits, baking in vacuum, etc.). The high temperature cycles may be carried out following different schedules and environments (vacuum, reducing hydrogen atmosphere, argon, etc.) and develop peculiar surface topographies which have been the object of extended observations. This study presents and discusses the results of scanning electron microscopy (SEM) and optical microscopy investigations.

TUPZ004

The NICA Facility in Polarized Proton Operation Mode

proton, ion, injection, booster

1804

A.D. Kovalenko, N.N. Agapov, Y. Filatov, V.D. Kekelidze, R.I. Lednicky, I.N. Meshkov, V.A. Mikhaylov, A.O. Sidorin, A. Sorin, G.V. Trubnikov
JINR, Dubna, Moscow Region, Russia

Basic goal of the planned NICA facility at JINR is focused on the studying of heavy ion collisions over the energy range √s ~ 411 GeV/u. Capabilities of the proposed scheme were carefully analyzed in this case and reaching of the desired average luminosity, L = 1·10²⁷ cm^-2 s⁻¹ for gold-gold collisions at √s = 9 GeV/u, have been confirmed. The other important NICA research domain is the experiments with polarized proton beams at the highest possible energy, the highest luminosity and polarization degree as well. The main aim is to provide √s ~ 25 GeV and L ~ 1·10³¹ cm^-2 s⁻¹. The unsolved aspects of the problem are discussed, possible solutions are analyzed and necessary modifications of the NICA scheme are considered as well.

TUPZ005

Design of the NICA Collider Rings

luminosity, ion, lattice, betatron

1807

O.S. Kozlov, H.G. Khodzhibagiyan, S.A. Kostromin, I.N. Meshkov, A.O. Sidorin, N.D. Topilin, G.V. Trubnikov
JINR, Dubna, Moscow Region, 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. Superconducting collider rings accumulate beam injected from Nuclotron and realize the conditions for beam-beam interactions to achieve the required luminosity. Each ring has the racetrack shape with two arcs and two long straight sections. Its circumference is about 500 m. The collider lattice design is subjected to have possibility of the gamma transition variation, mainly by the arcs retuning. The long straight sections contain the most of the insertion devices and are matched to the arcs, optimized to provide the final focusing of the beams in IP and accurate betatron tune adjustment.

TUPZ029

Observation of Coherent Beam-beam Effects in the LHC

simulation, emittance, damping, beam-beam-effects

1870

X. Buffat
EPFL, Lausanne, Switzerland
R. Calaga, S.M. White
BNL, Upton, Long Island, New York, USA
R. Giachino, W. Herr, G. Papotti, T. Pieloni
CERN, Geneva, Switzerland

Early collisions in the LHC with a very limited number of bunches with high intensities indicated the presence of coherent beam-beam driven oscillations. Here we discuss the experimental results and compare with the expectations.

TUPZ030

Simulation of Linear Beam Parameters to Minimize the Duration of the Squeeze at the LHC

optics, simulation, controls, acceleration

1873

X. Buffat
EPFL, Lausanne, Switzerland
G.J. Müller, S. Redaelli, M. Strzelczyk
CERN, Geneva, Switzerland

The betatron squeeze allows to increase the luminosity of a collider by reducing the β function at the interaction points. This operation has shown to be very critical in previous colliders. In this state of mind, the squeezing was performed extremely safely during the first year of operation of the Large Hadron Collider, at the expense of the duration of the process. As the turnaround time is a relevant parameter for the integrated luminosity, a squeeze of shorter duration is proposed for 2011 and further. MadX simulation of linear beam parameters based on settings extracted from the LHC control system are used to justify the proposal. Further optimization of the squeeze setting generation is also discussed.

TUPZ032

LHC Luminosity Upgrade with Large Piwinski Angle Scheme: A Recent Look

luminosity, simulation, emittance, single-bunch

1879

C.M. Bhat
Fermilab, Batavia, USA
F. Zimmermann
CERN, Geneva, Switzerland

Funding: Work is supported by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the U.S. Department of Energy and US LARP.
Luminosity upgrade at the LHC collider using bunches with constant line charge density (longitudinally flat bunches) but with same beam-beam tune shift at collision, the so called large Piwinski angle scheme* is being studied with renewed interest in recent years**. By design the total beam-beam tune shift at the LHC is less than 0.015. But the initial operational experience at the LHC indicates the possibility of operating with beam-beam tune shifts as high as 0.02. In view of this development we have revisited the requirements for the Large Piwinski Angle scheme at the LHC. In this paper we present a new parameter list supported by 1) calculations on the luminosity gain, 2) reduction of e-cloud issues on nearly flat bunches and 3) longitudinal beam dynamics simulations. We also make some remarks on the needed upgrades on the LHC injector accelerators.
* F. Ruggiero and F. Zimmermann, PRST-AB 5, 061001 (2002).
** C. M. Bhat, CERN-2009-004, pp. 10⁶-114.
Thanks to O.Bruning, E.Shaposhnikova, H.Damerau, E.Mahner, F.Caspers & CERN BE/ABP & RF Depts.

TUPZ033

Measurements of Transverse Beam Diffusion Rates in the Fermilab Tevatron Collider

antiproton, background, electron, emittance

1882

G. Stancari, G. Annala, T.R. Johnson, D.A. Still, A. Valishev
Fermilab, Batavia, USA

Funding: Fermi Research Alliance, LLC operates Fermilab under Contract DE-AC02-07CH11359 with the US Department of Energy. This work was partially supported by the US LHC Accelerator Research Program (LARP).
The transverse beam diffusion rate vs. particle oscillation amplitude was measured in the Tevatron using collimator scans. All collimator jaws except one were retracted. As the jaw of interest was moved in small steps, the local shower rates were recorded as a function of time. By using a diffusion model, the time evolution of losses could be related to the diffusion rate at the collimator position. Preliminary results of these measurements are presented.

Poster TUPZ033 [1.036 MB]

TUPZ041

Site Studies for the SuperB Collider and Synchrotron Radiation Facility Project

site, ground-motion, linac, injection

1900

S. Tomassini, M.E. Biagini, P. Raimondi, C. Sanelli
INFN/LNF, Frascati (Roma), Italy
B. Bolzon
CERN, Geneva, Switzerland
G. Deleglise, A. Jeremie
IN2P3-LAPP, Annecy-le-Vieux, France
J.T. Seeman
SLAC, Menlo Park, California, USA

The SuperB project aims at the construction of a very high luminosity (10³⁶ cm^-2 s⁻¹) asymmetric electron-positron collider. Due to its large beam current (~2 A) high energy (~7 GeV) and low vertical emittance (less than 10^-11 m) the facility looks very attractive as an x-ray synchrotron radiation source, and therefore few beam lines are also foreseen. Possible locations are the campus of the University of Rome Tor Vergata or near another Italian INFN laboratory site. This paper presents and describes the status of the preliminary design of the civil infrastructure layout and related site issues.

WEODA03

Design Concepts for the Large Hadron Electron Collider

linac, electron, cavity, luminosity

1942

M. Klein
The University of Liverpool, Liverpool, United Kingdom

A report is presented on the design concepts for a high luminosity electron-nucleon collider of 1.3 TeV centre of mass energy, realized with the addition of a 60 GeV electron ring or linear accelerator to the existing proton and ion LHC beam facility, comprising machine magnets, optics, interaction region, cryogenics, rf, civil engineering and further components of the LHeC. The report on behalf of the LHeC study team is a summary of the 2011 LHeC CDR and feedback received from an international review panel.

Slides WEODA03 [9.780 MB]

WEPC028

Record Low Beta-beat of 10% in the LHC

optics, injection, hadron, quadrupole

2061

G. Vanbavinckhove
NIKHEF, Amsterdam, The Netherlands
M. Aiba
PSI, Villigen, Switzerland
R. Calaga, R. Miyamoto
BNL, Upton, Long Island, New York, USA
R. Tomás
CERN, Geneva, Switzerland

During the 2011 LHC run several measurements and correction campaigns were conducted. As a result a peak beta-beat of 10% level was achieved. This level, well below the specified tolerances of the LHC, improves the aperture margins and helps minimize the luminosity imbalance between the different experiments. A combination of local corrections at the insertion regions and an overall global correction were used to achieve this record low beta-beat. The sequence of the optics corrections and stability along the 2011 run are reported.

WEPC047

Crab Crossing Schemes and Studies for Electron Ion Collider

cavity, electron, lattice, ion

2115

S. Ahmed, S.U. De Silva, Y.S. Derbenev, G.A. Krafft, V.S. Morozov, B.C. Yunn, Y. Zhang
JLAB, Newport News, Virginia, USA
A. Castilla, J.R. Delayen
ODU, Norfolk, Virginia, USA

Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177.
Medium Energy Electron Ion Collider (MEIC) at JLab has been envisioned as future high energy particle accelerator beyond 12 GeV upgrade of CEBAF. Crab crossing of colliding electron and ion beams is essential for accommodating high bunch repetition frequency in the conceptual design of MEIC. The scheme eliminates parasitic beam-beam interactions and avoids luminosity reduction by restoring head-on collisions at interaction points. This requires the separation of two beams quickly to avoid parasitic collisions and the minimization of synchrotron-betatron resonance near IP which can be fulfilled by employing the crab crossing concept first proposed by R. Palmer. Let us call this original scheme as transverse crabbing for the sake of comparison with dispersive crabbing which employs the existing accelerating/bunching RF cavities and dispersion function in the section where the cavity is installed as originally proposed by G. Jackson. In this paper, we report the beam transport and optics for both transverse and dispersive crabbing schemes followed by basic beam dynamics. Moreover, alignment and stability calculations together with synchro-betatron beam dynamics will be discussed.

WEPC081

Beam-Beam Induced Orbit Effects at LHC

luminosity, simulation, closed-orbit, beam-beam-effects

2208

M. Schaumann, R. Alemany-Fernandez
CERN, Geneva, Switzerland

For high bunch intensities the beam-beam force is strong enough to expect orbit effects if the two beams do not collide head-on but with a crossing angle or with a given offset. As a consequence the closed orbit changes. The closed orbit of an unperturbed machine with respect to a machine where the beam-beam force becomes more and more important has been studied and the results are presented in this paper.

WEPC116

A Matrix Presentation for a Beam Propagator including Particles Spin

storage-ring, controls, heavy-ion, scattering

2283

M. Kosovtsov, S.N. Andrianov, A.N. Ivanov
St. Petersburg State University, St. Petersburg, Russia

Particles beam dynamics in magnetic and electrical fields with spin is discussed. This approach provides a constructive method of matrix presentation derivation for a beam propagator in magnetic and electrical fields. The beam propagator is evaluated in according to the well-known Lie algebraic tools. But in contrast to traditional approaches matrix presentation for Lie propagators bases on two-indexes matrices. This approach permit to apply all of matrix algebra opportunities and advantages in contrast with the tenzor presentation based on multi-indexes description. The necessary computation can be realized in symbolic (using computer algebra codes as Mathematica, Maple, Maxima and so on). The corresponding symbolic objects itself can be stored in special databases and used then in numerical computing. Parallel and distributed conception is well acceptable with the suggested matrix formalism. Some symbolic and numerical results are discussed for problems of long term evolution of particles with spin.

WEPC142

High Performance Web Applications for Particle Accelerator Control Systems

controls, luminosity, optics, diagnostics

2322

G. Mazzitelli, C. Bisegni, P. Ciuffetti, G. Di Pirro, A. Stecchi
INFN/LNF, Frascati (Roma), Italy
S. Calabrò, L.G. Foggetta
IN2P3-CNRS, Orsay, France
L. Catani, F. Zani
INFN-Roma II, Roma, Italy

The integration of web technologies and applications has been one of the major trends for the development of new services for control systems of particle accelerators and large experimental apparatuses. Nowadays, high performance web technologies exhibit some features that would allow their deeper integration in a control system and their employment in developing control system's core components. In this paper we discuss the results of preliminary investigations of a new paradigm for a particle accelerator control system and associated machine data acquisition system based on a synergic combination of network distributed cache memory and a non-relational key/value database. Storage speed, network memory data retrieve throughput and database queries execution, as well as scalability and redundancy of the systems, are presented and critically reviewed.

Poster WEPC142 [8.902 MB]

WEPO026

Advances in the Design of the SuperB Final Doublet

quadrupole, luminosity, controls, positron

2454

E. Paoloni, N. Carmignani, F. Pilo
University of Pisa and INFN, Pisa, Italy
S. Bettoni
CERN, Geneva, Switzerland
M.E. Biagini, P. Raimondi
INFN/LNF, Frascati (Roma), Italy
F. Bosi
INFN-Pisa, Pisa, Italy
P. Fabbricatore, S. Farinon, R. Musenich
INFN Genova, Genova, Italy
M.K. Sullivan
SLAC, Menlo Park, California, USA

SuperB is an asymmetric (6.7 GeV HER, 4.18 GeV LER) e⁺ e− collider operating at the Y(4S) peak with a design peak luminosity of 10³6 Hz/cm² to be built in Italy in the very near future. The design luminosity is almost a factor hundred higher than that of the present generation comparable facilities. To get the design luminosity a novel collision scheme, the so called “large Piwinski angle with crab waist”, has been designed. The scheme requires a short focus final doublet to reduce the vertical beta function down to betay*=0.2 mm at the interaction point (IP). The final doublet will be composed by a set of permanent and superconducting (SC) quadrupoles. The SC quadrupole doublets QD0/QF1 have to be placed as close to the IP as possible. This layout is critical because the space available for the doublets is very small. An advanced design of the quadrupole has been developed, based on the double helical coil concept. The paper discusses the design concept, the construction and the results of test of a model of the superconducting quadrupole based on NbTi technology. Future developments are also presented.

WEPS014

RF Systems and Bunch Formation at NICA

ion, booster, cavity, injection

2511

A.V. Eliseev, I.N. Meshkov, A.O. Sidorin, G.V. Trubnikov
JINR, Dubna, Moscow Region, Russia
O.I. Brovko
JINR/VBLHEP, Moscow, Russia
G.Y. Kurkin, V.M. Petrov
BINP SB RAS, Novosibirsk, Russia

The NICA facility being constructed at JINR will consists of two synchrotrons (Booster and Nuclotron) and collider working at constant magnetic field. To reach required luminosity level the collider rings will be operated with short ion bunches. The bunch formation in the collider as well as longitudinal dynamics in all the rings is described. The parameters and preliminary design of RF systems are presented.

WEPZ024

Some Considerations in Realizing a TeV Linear Collider Based on the PDPWA Scheme

proton, electron, plasma, wakefield

2817

G.X. Xia, A. Caldwell
MPI-P, München, Germany
P. Muggli
MPI, Muenchen, Germany

Proton-driven plasma wakefield acceleration (PDPWA) has recently been proposed as an approach to bring the electron beam to the energy frontier in a single passage of acceleration. Particle-in-Cell (PIC) simulation shows that a TeV proton bunch, with a bunch intensity of 10¹¹, and a bunch length as short as 10⁰ microns can resonantly excite a large amplitude plasma wakefield and accelerate an externally injected electron bunch to 600 GeV in a single stage of 500 m long plasma. This novel PDPWA scheme may open a new path for designing a TeV linear lepton collider by using the currently available proton drivers. In this paper, we investigate some key issues, e.g. bunch length, centre-of-mass (CoM) energy, luminosity and dephasing in realizing a TeV linear collider based on the PDPWA scheme.

THPO032

Preliminary Design of an Inductive Adder for CLIC Damping Rings

kicker, damping, emittance, impedance

3409

J. Holma, M.J. Barnes
CERN, Geneva, Switzerland

The Compact Linear Collider (CLIC) study is exploring the scheme for an electron-positron collider with high luminosity and a nominal centre-of-mass energy of 3 TeV. The CLIC damping rings will produce ultra-low emittance, with high bunch charge, necessary for the luminosity performance of the collider. To limit the beam emittance blow-up due to oscillations, the pulse power modulators for the damping rings kickers must provide extremely flat, high-voltage pulses: specifications call for a 160 ns duration flattop of 12.5 kV, 250 A, with a combined ripple and droop of not more than ±0.02 %. A solid-state modulator, the inductive adder, is a very promising approach to meeting the demanding specifications; this topology allows the use of both digital and analogue modulation. To effectively use modulation techniques to achieve such low ripple and droop requires an in-depth knowledge of the behaviour of the solid-state switching components and their gate drivers, as well as a good understanding of the overall circuit behaviour. This paper describes the initial design of the inductive adder.

THPS046

Transport Beam Lines for NICA Accelerator Complex

booster, ion, quadrupole, lattice

3526

O.S. Kozlov, A.V. Eliseev, I.N. Meshkov, V.A. Mikhailov, A.O. Sidorin, N.D. Topilin, G.V. Trubnikov, A. Tuzikov
JINR, Dubna, Moscow Region, Russia

In the last years Nuclotron-based Ion Collider fAcility (NICA) project is being developed by Joint Institute for Nuclear Research (JINR), Dubna, Russia. The goal of the project is to construct new accelerator complex that will be used for colliding ion beams on first stage and colliding polarized proton/deuteron beams on second stage of the project. NICA accelerator complex will consist of two linear accelerators, two superconducting synchrotrons, two superconducting storage rings of the collider and transport beamlines. Geometry and magnetic system of NICA beamlines are presented in this report. Results of beam dynamics simulations within the beamlines are considered.

THPZ001

Spin Dynamic Tool Developments and Study Regarding the Super-B Project

closed-orbit, simulation, lattice, polarization

3681

N. Monseu, J.-M. De Conto
LPSC, Grenoble Cedex, France
F. Méot
BNL, Upton, Long Island, New York, USA
U. Wienands
SLAC, Menlo Park, California, USA

The study of polarization is essential for e+/e^- colliders like the SuperB machine. The ZGOUBI integrator is a good and universal tool for particle tracking as well as spin tracking, and takes into account all machine realistic aspects, like real fields, non-linearities, fringing fields or misalignments. We present ZGOUBI implementation and the methods carried out to estimate invariant spin field and beam polarization evolution on some simple models (for validation) and on SuperB, and we investigate for some specific polarization behavior.

THPZ033

Operational Experience and Performance of the LHC Collimator Controls System

controls, collimation, monitoring, optics

3765

S. Redaelli, A. Masi
CERN, Geneva, Switzerland

In order to handle stored energies up to 360 MJ, the LHC relies on a collimation system that consists of 100 movable collimators. Compared to other accelerator, the complexity of this system is unique: more than 400 motors and about 600 interlocked position sensors must be controlled in all the machine phases in order to ensure the cleaning and machine protection roles of the system. In this paper, the controls system and the setting management are presented and the operational experience accumulated in the 2 first years of operation is discussed, focussing in particular on failure and availability statistics during the LHC operation.