Keyword: alignment
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MOOBC03 A Multi Purpose X Band Accelerating Structure wakefield, FEL, linac, resonance 70
 
  • M.M. Dehler, A. Citterio, R. Zennaro
    Paul Scherrer Institut, Villigen, Switzerland
  • G. D'Auria, C. Serpico
    ELETTRA, Basovizza, Italy
  • D. Gudkov, A. Samoshkin
    JINR, Dubna, Moscow Region, Russia
  • S. Lebet, G. Riddone, J. Shi
    CERN, Geneva, Switzerland
  
  In a collaboration between CERN, PSI and Sincrotrone Trieste (ST), a series of four multipurpose X-band accelerating structures has been designed and fabricated. The structures have 72 cells with a phase advance of 5 pi/6 and include upstream and downstream wakefield monitors to measure the beam alignment. We give an overview of the electrical and mechanical design and describe the fabrication of the first units. We also present the results of the low level RF tests. Using measurements of the internal cell to cell misalignment, the residual transverse wake and the noise floor of the wake field monitors are computed. Furthermore, we present the first experiences running the structures under high power.  
slides icon Slides MOOBC03 [15.521 MB]  
 
MOPPC073 Improvements in the PLACET Tracking Code simulation, ground-motion, linac, multipole 301
 
  • A. Latina, E. Adli, D. Schulte, J. Snuverink
    CERN, Geneva, Switzerland
  • B. Dalena
    CEA/IRFU, Gif-sur-Yvette, France
  
  The tracking code PLACET simulates beam transport and orbit corrections in linear accelerators. It incorporates single- and multi-bunch effects, static and dynamic imperfections. It has an interface based on both Tcl/Tk and Octave to provide maximum flexibility and easy programming of complex scenarios. Recently, new functionality has been added to expand its simulation and tuning capabilities, such as: tools to perform beam-based alignment of non-linear optical systems, possibility to track through the interaction region in presence of external magnetic fields (detector solenoid), higher order imperfections in magnets, better tools for integrated feedback loops. Moreover, self contained frameworks have been created to ease the simulation of CLIC Drive Beam, CLIC Main Beam, and other existing electron machines such as CTF3 and FACET.  
 
MOPPC078 Simulation Studies of Injection Scheme in TPS Storage Ring injection, lattice, simulation, storage-ring 316
 
  • Y.C. Lee, H.-P. Chang, P.J. Chou
    NSRRC, Hsinchu, Taiwan
  
  Funding: NSRRC, Hsinchu, Taiwan.
The baseline lattice of TPS storage ring was finalized in October 2009. Later upon users’ request, we plan to implement the double mini-βy lattice in three 12-m straight sections of TPS storage ring. These locations were chosen to maintain the symmetry of the storage ring lattice. Particle tracking for the first few turns were used to check the injection scheme of storage ring, including errors introduced in manufacturing and installation process. Results of simulation studies will be presented. 		 
 
MOPPD080 Improved Robustness of the LHC Collimation System by Operating with a Jaw-beam Angle proton, collimation, radiation, scattering 553
 
  • L. Lari, R.W. Assmann, A. Rossi
    CERN, Geneva, Switzerland
  • M. Cauchi
    UoM, Msida, Malta
  • A. Faus-Golfe, L. Lari
    IFIC, Valencia, Spain
  
  Funding: This work has been carried out through of the European Coordination for Accelerator Research and Development (EuCARD), co-sponsored by EU 7th Framework Program.
The robustness of the Phase I collimation system could be improved playing with the angular orientation of each single jaw. A preliminary study on the asymmetric misalignment of the collimator jaws, scanning through different jaw angles and varying beam sizes and energy, have been carried out, aiming at minimizing the energy deposited on metallic collimators, following an asynchronous dump. 		 
 
MOPPD084 Optimization of Extinction Efficiency in the 8-GeV Mu2e Beam Line proton, target, background, dipole 565
 
  • I.L. Rakhno, A.I. Drozhdin, C. Johnstone, N.V. Mokhov, E. Prebys
    Fermilab, Batavia, USA
  
  Funding: Work supported by Fermi Research Alliance, LLC, under contract No. DE-AC02-07CH11359 with the U.S. Department of Energy.
A muon-to-electron conversion experiment at Fermilab is being designed to probe for new physics beyond the standard model at mass scales up to 10000 TeV*. The advance in experimental sensitivity is four orders of magnitude when compared to existing data on charged lepton flavor violation. The critical requirement of the experiment is the ability to deliver a proton beam contained in short 100-ns bunches onto a muon production target, with an inter-bunch separation of about 1700 ns. In order to insure the low level of background at the muon detector consistent with the required sensitivity, protons that reach the target between bunches must be suppressed by an enormous factor, 109. This paper describes the results of numerical modeling with STRUCT and MARS codes for a beam line with a collimation system**,*** and optics that achieves an experimental extinction factor of one per billion.
* R.M. Carey et al., Mu2e Proposal, Fermilab (2008).
** W. Molzon, “Proton Beam Extinction,” MECO-EXT-05-002 (2005).
*** E. Prebys, Mu2e-doc-534 (2009), http://mu2e-docdb.fnal.gov. 		 
 
TUOAA03 Tests of Low Emittance Tuning Techniques at SLS and DAΦNE quadrupole, emittance, coupling, collider 1065
 
  • S.M. Liuzzo, M.E. Biagini, P. Raimondi
    INFN/LNF, Frascati (Roma), Italy
  • M. Aiba
    Paul Scherrer Institut, Villigen, Switzerland
  • M. Böge
    PSI, Villigen, Switzerland
  
  The SuperB collider design is based on extremely low emittances, comparable to those of synchrotron light sources. A Low Emittance Tuning (LET) algorithm was developed for SuperB and has been tested last year at DIAMOND. This paper will report on the results of the application of LET to SLS (PSI) and DAΦNE (LNF) in order to compare and confirm the previous results. In this tests, the correction of orbit, dispersion and coupling is applied simultaneously to the detection of Beam Position Monitors tilts. The effect of beam based alignment at DAΦNE is also presented, together with an evaluation of the effects of other possible sources of emittance growth.  
slides icon Slides TUOAA03 [4.313 MB]  
 
TUPPC019 Beam Dynamics Simulations of J-PARC Main Ring for Damage Recovery from the Tohoku Earthquake in Japan and Upgrade Plan of Fast Extraction Operation simulation, injection, acceleration, linac 1200
 
  • Y. Sato, K. Hara, S. Igarashi, T. Koseki, K. Ohmi, C. Ohmori
    KEK, Ibaraki, Japan
  • H. Hotchi
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
  
  Magnets of Japan Proton Accelerator Research Complex (J-PARC) were shaken by the Tohoku Earthquake in Japan on March 11th, 2011. The alignment of J-PARC Main Ring (MR) received 20 mm displacement horizontally and 6 mm vertically. Beam dynamics simulations were performed to estimate the effect of the displacement on closed orbit distortions and beam loss in fast extraction (FX) operation of J-PARC MR. Based on the simulation results, we concluded that re-alignment of J-PARC MR was needed to achieve high-power beam. The re-alignment of MR was finished on October 28th, 2011. We also considered the effects of the earthquake on the upstream of MR to establish our upgrade plan, which was based on beam dynamics simulations optimizing collimator balance of injection beam transport (3-50BT) and MR, and RF patterns. J-PARC MR FX operation was resumed from December 2011.  
 
TUPPC023 Waist Corrections at the Interaction Point of ATF2 in the Presence of IPBSM Fringe Rotations and Input Beam Sigma13, Sigma24 sextupole, coupling, simulation, quadrupole 1212
 
  • S. Bai, J. Gao
    IHEP, Beijing, People's Republic of China
  • P. Bambade
    LAL, Orsay, France
  
  The ATF2 project is the final focus system prototype for ILC and CLIC linear collider projects, with a purpose to reach a 37nm vertical beam size at the interaction point. In beam tuning towards the goal beam size, the presence of a tilt of the IP Shintake monitor fringe pattern with respect to the x-y coordinate system of the beam (or equivalently a σ13 correlation), as well as a σ24 correlation, can break the orthogonality in the main σ34 and σ32 waist corrections during the minimization and result in larger vertical beam sizes at IP. Both effects are studied, analytically and in simulation, and a practical procedure is suggested for diagnosing the presence of a residual fringe tilt, by measuring the influence of the horizontal waist correction on the minimum vertical beam size.  
 
TUPPD035 SuperKEKB Injector Upgrade for High Charge and Low Emittance Electron Beam emittance, gun, wakefield, cathode 1482
 
  • M. Yoshida, N. Iida, Y. Ogawa, M. Sato, L. Zang
    KEK, Ibaraki, Japan
  
  The design strategy of SuperKEKB is based on the nano-beam scheme. The dynamic aperture decreases due to the very small beta function at the interaction point. Thus the injector upgrade is required to obtain the low emittance and high charge beam corresponding to the short beam life and small injection acceptance. The required beam parameters are 5 nC, 20 mm mrad and 4 nC, 6 mm mrad for the electron and positron respectively. For the electron beam, new photocathode RF-Gun with the focusing electric field was installed. Further the emittance growth in the linac is an important issue for the low emittance injection. We will report the machine study of the RF-Gun and the emittance growth through the linac.  
 
TUPPD056 Development of a Photo-injector Laser System for KEK ERL Test Accelerator laser, cavity, cathode, controls 1530
 
  • Y. Honda
    KEK, Ibaraki, Japan
  
  As a test accelerator for future light source, Compact Energy Recovery Linac has been constructed in KEK. For its photo-injector, we have been developing a laser system. It requires high repetition rate and high average power at a visible wavelength. Development of an high power fiber amplifier and high efficiency wavelength conversion system utilizing an optical cavity will be reported.  
 
TUPPP063 Electron-beam Optimization Studies for the FERMI@Elettra Free-electron Laser linac, electron, emittance, simulation 1741
 
  • E. Ferrari, G. De Ninno
    University of Nova Gorica, Nova Gorica, Slovenia
  • P. Craievich, S. Di Mitri, E. Ferrari, L. Fröhlich, G. Gaio, G. Penco, C. Spezzani, M. Trovò
    ELETTRA, Basovizza, Italy
  
  FERMI@Elettra is a single-pass free-electron laser, based on seeded high-gain harmonic generation. Presently, the first phase of the project (covering the spectral range between 100 and 20 nm) is under commissioning. The free-electron laser performance depends on the quality of the electron beam. In the case of the FERMI linear accelerator, the latter is strongly influenced both by the wake-fields present in the accelerating sections and by possible misalignments of the various accelerator components. In order to investigate and compensate these effects, we performed a study based on local trajectory bumps. We demonstrate that this approach significantly improves the electron-beam quality and, eventually, the free-electron laser performance.  
 
TUPPR005 Linac Upgrade in Intensity and Emittance for SuperKEKB linac, emittance, positron, electron 1819
 
  • T. Higo, M. Akemoto, D.A. Arakawa, Y. Arakida, A. Enomoto, S. Fukuda, K. Furukawa, Y. Higashi, H. Honma, N. Iida, M. Ikeda, E. Kadokura, K. Kakihara, T. Kamitani, H. Katagiri, M. Kurashina, S. Matsumoto, T. Matsumoto, H. Matsushita, S. Michizono, K. Mikawa, T. Miura, F. Miyahara, T. Mori, H. Nakajima, K. Nakao, T. Natsui, Y. Ogawa, S. Ohsawa, M. Satoh, T. Shidara, A. Shirakawa, H. Sugimoto, T. Suwada, T. Takatomi, T. Takenaka, Y. Yano, K. Yokoyama, M. Yoshida, L. Zang, X. Zhou
    KEK, Ibaraki, Japan
  • D. Satoh
    TIT, Tokyo, Japan
  
  The SuperKEKB is designed to produce 40 times luminosity than that of the KEKB. In order to realize such a high luminosity, the injector linac should provide both electron and positron beams of about 4-5 nC/bunch, which is several times higher than before. In addition, their emittance requirement of the injection beam to the rings is 20 microns, which is a factor of a few tens smaller than before. The intensity and emittance of the electron beam are realized directly by developing the photo RF gun. In contrast, the positron intensity is increased by adopting a higher capture efficiency system with flux concentrator followed by large-aperture accelerators, while its emittance is reduced by a damping ring. For preserving such a low emittance of both beams toward the injection to the rings, the suppression of the emittance growth is crucial. To this end, the alignment of the accelerator components should be a few tens of microns, where we need an improvement by more than a factor 10. The beam-based alignment is definitely needed with better-resolution BPMs. In the present paper are reviewed the overall progress and perspective of the design and the associated component developments.  
 
TUPPR029 Performance of Linear Collider Beam-Based Alignment Algorithms at FACET linac, simulation, emittance, optics 1879
 
  • A. Latina, J. Pfingstner, D. Schulte
    CERN, Geneva, Switzerland
  • E. Adli
    University of Oslo, Oslo, Norway
  
  The performance of future linear colliders will depend critically on beam-based alignment (BBA) and feedback systems, which will play a crucial role both in the linear and in the non-linear systems of such machines, e.g., the linac and the final-focus. Due to its characteristics, FACET is an ideal test-bench for BBA algorithms and linear collider beam-dynamics in general. We present the results of extensive computer simulations and their experimental verification.  
 
TUPPR031 Experimental Verification of the CLIC Decelerator with theTest Beam Line in the CLIC Test Facility 3 extraction, quadrupole, lattice, linac 1885
 
  • R.L. Lillestøl, S. Döbert, M. Olvegård, A. Rabiller, G. Sterbini
    CERN, Geneva, Switzerland
  • E. Adli
    University of Oslo, Oslo, Norway
  
  The Test Beam Line in the CLIC Test Facility 3 is the first prototype of the CLIC drive beam decelerator. The main purpose of the experiment is to demonstrate efficient 12 GHz rf power production and stable transport of an electron drive beam during deceleration. The Test Beam Line consists of a FODO structure with high precision BPMs and quadrupoles mounted on mechanical movers for precise beam alignment. Nine out of the planned 16 Power Extraction and Transfer Structures have currently been installed and commissioned. We correlate rf power production measurements with the drive beam deceleration measurements, and compare the two measurements to the theoretical predictions. We also discuss the impact of the drive beam bunch length and bunch combination on the measurements.  
 
TUPPR033 Improved Modelling of the Thermo-mechanical Behavior of the CLIC Two-Beam Module vacuum, RF-structure, linac, simulation 1891
 
  • G. Riddone, T.O. Niinikoski, F. Rossi
    CERN, Geneva, Switzerland
  • R.J. Raatikainen, K. Österberg
    HIP, University of Helsinki, Finland
  • A. Samoshkin
    JINR, Dubna, Moscow Region, Russia
  
  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 is being tested in laboratory conditions at CERN in a full-scale prototype module. In this paper, the revised finite element model developed for the CLIC two-beam module is described. In the current model, the structural behavior of the module is studied in more detail compared to the earlier configurations, in particular for what regards the contact modeling. The thermal and structural results for the module 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 in 2012 with the full-scale prototype module. The experimental results will allow for better understanding of the module behavior and they will be propagated back to the present thermo-mechanical model.  
 
TUPPR034 Beam-based Alignment in CTF3 Test Beam Line quadrupole, feedback, beam-losses, injection 1894
 
  • G. Sterbini, S. Döbert, R.L. Lillestøl, E. Marín, D. Schulte
    CERN, Geneva, Switzerland
  • E. Adli
    University of Oslo, Oslo, Norway
  
  The CLIC linear collider is based on the two beams acceleration scheme. During acceleration, the drive beam suffers a large increase in its energy spread. In order to efficiently transport such a beam, beam-based alignment techniques together with tight pre-alignment tolerances are crucial. A beam-based steering campaign has been conducted at the Test Beam Line of the CLIC Test Facility to evaluate the performance of several algorithms. In the following we present and discuss the obtained results.  
 
TUPPR035 A Comparative Study for the CLIC Drive Beam Decelerator Optics optics, quadrupole, injection, lattice 1897
 
  • G. Sterbini, D. Schulte
    CERN, Geneva, Switzerland
  • E. Adli
    University of Oslo, Oslo, Norway
  
  The baseline for the CLIC drive beam decelerators optics consists of a 2-m-long FODO cell. This solution was adopted to have strong focusing in order to mitigate the effect of the PETS wakefields and to minimize the drive beam envelope. Taking into account the most recent PETS design, we compare the performance of the baseline FODO cell with a proposal that consider twice longer FODO cell. Despite of the expected cost in term of performance, the reduction of the complexity of the system due to the halving of the number of quadrupoles can be beneficial for the overall optimization of the decelerator design.  
 
TUPPR096 Angular Alignment of the LHC Injection Protection Stopper injection, kicker, proton, beam-losses 2056
 
  • C. Bracco, R.W. Assmann, W. Bartmann, B. Goddard, V. Kain, J.A. Uythoven
    CERN, Geneva, Switzerland
  
  Machine safety depends critically on the correct setup of the protection elements. One of the injection protection collimators is constituted by exceptionally long jaws (4 m). For this element, an angular offset of the jaws could affect significantly the measured beam size and, as a consequence, the correct setup with respect to the beam. Dedicated studies and cross-calibrations have been performed to quantify the effect of tilts and offsets on the setup of this collimator and to check the provided passive protection.  
 
TUPPR097 Modeling and Simulation of LHC Beam-Based Collimator Setup beam-losses, simulation, emittance, collider 2059
 
  • G. Valentino, N.J. Sammut
    University of Malta, Information and Communication Technology, Msida, Malta
  • R.W. Assmann, F. Burkart, S. Redaelli, A. Rossi, D. Wollmann
    CERN, Geneva, Switzerland
  • L. Lari
    IFIC, Valencia, Spain
  
  In the 2011 Large Hadron Collider run, collimators were aligned for proton and heavy ion beams using a semi-automatic setup algorithm. The algorithm provided a reduction in the beam time required for setup, an elimination of beam dumps during setup and higher accuracy with respect to manual alignment. A collimator setup simulator was developed based on a Gaussian model of the beam distribution as well as a parametric model of the beam losses. A time-varying beam loss signal can be simulated for a given collimator movement into the beam. The simulation results and comparison to measurement data obtained during collimator setups and dedicated fills for beam halo scraping are presented. The simulator will then be used to develop a fully automatic collimator alignment algorithm.  
 
TUPPR098 Comparison of LHC Collimator Beam-Based Alignment Centers to BPM-Interpolated Centers injection, hadron, collimation, collider 2062
 
  • G. Valentino, N.J. Sammut
    University of Malta, Information and Communication Technology, Msida, Malta
  • R.W. Assmann, R. Bruce, G.J. Müller, S. Redaelli, A. Rossi, G. Valentino
    CERN, Geneva, Switzerland
  • L. Lari
    IFIC, Valencia, Spain
  
  The beam centers at the Large Hadron Collider collimators are determined by beam-based alignment, where both jaws of a collimator are moved in separately until a loss spike is detected on a Beam Loss Monitor downstream. Orbit drifts of more than a few hundred micrometers cannot be tolerated, as they would reduce the efficiency of the collimation system. Beam Position Monitors (BPMs) are installed at various locations around the LHC ring, and a linear interpolation of the orbit can be obtained at the collimator positions. In this paper, the results obtained from beam-based alignment are compared with the orbit interpolated from the BPM data throughout the 2011 LHC proton run. The stability of the orbit determined by collimator alignment during the run is evaluated.  
 
WEYA01 CLIC Status and Outlook linac, luminosity, target, emittance 2076
 
  • S. Stapnes
    CERN, Geneva, Switzerland
  
  The Compact Linear Collider study (CLIC) is in the process of completing a Conceptual Design Report for a multi-TeV linear electron-positron collider. The CLIC-concept is based on high gradient normal-conducting accelerating structures. The RF power for the acceleration of the colliding beams is produced by a novel two beam acceleration scheme, where power is extracted from a high current drive beam that runs parallel with the main linac. In order to establish the feasibility of this concept a number of key issues have been addressed. A short summary of the progress and status of the corresponding studies will be given, as well as an outline of the preparation and work towards an implementation plan by 2016.  
slides icon Slides WEYA01 [11.960 MB]  
 
WEPPC043 Transverse Kick Analysis of SSR1 Due to Possible Geometrical Variations in Fabrication cavity, simulation, linac, solenoid 2306
 
  • M.H. Awida, P. Berrutti, I.V. Gonin, T.N. Khabiboulline, V.P. Yakovlev
    Fermilab, Batavia, USA
  
  Funding: Operated by Fermi Research Alliance, LLC, under Contract DE-AC02-07CH11359 with the U.S. DOE
Due to fabrication tolerance, it is expected that some geometrical variations could happen to the SSR1 cavities of Project X, like small shifts in the transverse direction of the beam pipe or the spoke. It is necessary to evaluate the resultant transverse kick due to these geometrical variations, in order to make sure that they are within the limits of the correctors in the solenoids. In this paper, we report the transverse kick values for various fabrications errors and the sensitivity of the beam to these errors. 		 
 
WEPPD006 Design of the FRIB Cryomodule cryomodule, cryogenics, solenoid, vacuum 2507
 
  • M.J. Johnson, M. Barrios, J. Binkowski, S. Bricker, F. Casagrande, A.D. Fox, B.R. Lang, M. Leitner, S.J. Miller, T. Nellis, J.P. Ozelis, X. Rao, J. Weisend, Y. Xu
    FRIB, East Lansing, Michigan, USA
  • D. Arenius, V. Ganni, W.J. Schneider, M. Wiseman
    JLAB, Newport News, Virginia, USA
  
  Funding: This material is based upon work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661
An advanced, modular bottom-supported cryomodule design is described which is highly optimized for mass-production and efficient precision-assembly. The FRIB driver linac uses 4 types of superconducting resonators and 2 solenoid lengths which in turn require 7 individual cryomodule configurations. To meet alignment tolerances a precision-machined bolted cryomodule rail system is described. A novel, kinematic mounting system of the cold mass is introduced which allows for thermal contractions while preserving alignment. A first prototype will incorporate a wire position monitor for alignment verification. The cold alignment structure is supported by composite posts which also function as thermal isolators. The cryogenic system provides separate 2 K and 4.5 K liquid helium lines to cavities and solenoids. Details of the JT valves, heat exchanger, cool-down circuit and junction to cryogenic line will be provided. Transient cool-down was simulated for stresses and buckling failure. A 1100-O Aluminum shield is used as a thermal radiation shield. The paper also describes cryomodule interfaces with the linac tunnel, the RF input cables, and the cryogenic distribution system.
Michigan State University designs and establishes FRIB as a DOE Office of Science National User Facility in support of the mission of the Office of Nuclear Physics. 		 
 
WEPPD065 Development of a Laser-based Alignment System Utilizing Fresnel Zone Plates at the KEKB Injector Linac laser, scattering, linac, focusing 2672
 
  • T. Suwada, M. Satoh
    KEK, Ibaraki, Japan
  • K. Minoshima, S. Telada
    AIST, Tsukuba, Japan
  
  A new laser-based alignment system is under development in order to precisely align accelerator components along an ideal straight line at the 600-m-long KEKB injector linac. A well-known sequential three-point method with Fresnel zone plates and a CCD camera is revisited in the alignment system. The high-precision alignment system is strongly required in order to stably accelerate high-brightness electron and positron beams with high bunch charges and also to keep the beam stability with higher quality towards the Super B-factory at KEK. A new laser optics has been developed and the laser propagation characteristics has been systematically investigated at a 100-m-long straight section in vacuum. In this report, the experimental developments and investigations are reported along with the design of the new laser-based alignment system.  
 
WEPPD073 Strategy and Validation of Fiducialization for the Pre-alignment of CLIC Components laser, controls, linac, target 2693
 
  • S. griffet, A. Cherif, J. Kemppinen, H. Mainaud Durand, V. Rude, G. Sterbini
    CERN, Geneva, Switzerland
  
  The feasibility of the high energy e+ e− linear collider CLIC (Compact Linear Collider) is very dependent on the ability to accurately pre-align its components. There are two 20-km-long Main Linacs which meet in an interaction point (IP). The Main Linacs are composed of thousands of 2 m long modules. One of the challenges is to meet very tight alignment tolerances at the level of CLIC module: for example, the center of a Drive Beam Quad needs to be aligned within 20 μm rms with respect to a straight line. Such accuracies cannot be achieved using usual measurement devices. Thus it is necessary to work in close collaboration with the metrology lab. To test and improve many critical points, including alignment, a CLIC mock-up is being assembled at CERN. This paper describes the application of the strategy of fiducialization for the pre-alignment of CLIC mock-up components. It also deals with the first results obtained by performing measurements using a CMM (Coordinate Measuring Machine) to ensure the fiducialization, using a Laser Tracker to adjust or check components’ positions on a girder and finally using a Measuring Arm to perform dimensional control after assembling steps.  
 
WEPPD074 Issues and Feasibility Demonstration of Positioning Closed Loop Control for the CLIC Supporting System Using a Test Mock-up with Five Degrees of Freedom controls, feedback, collider, linear-collider 2696
 
  • M. Sosin, M. Anastasopoulos, N. Chritin, J. Kemppinen, H. Mainaud Durand, V. Rude, G. Sterbini, S. griffet
    CERN, Geneva, Switzerland
  
  Since several years, CERN is studying the feasibility of building a high energy e+ e− linear collider: the CLIC (Compact LInear Collider). One of the challenges of such a collider is the pre-alignment precision and accuracy requirement on the transverse positions of the linac components, which is typically 14 μm over a window of 200 m. To ensure the possibility of positioning within such tight constraints, CERN Beams Department’s Survey team has worked intensively at developing the methods and technology needed to achieve that objective. This paper describes activities which were performed on a test bench (mock-up) with five degrees of freedom (DOF) for the qualification of control algorithms for the CLIC supporting system active-pre-alignment. Present understanding, lessons learned (“know how”), issues of sensors noise and mechanical components nonlinearities are presented.  
 
WEPPP085 Study on the Realignment Plan for J-PARC 3 GeV RCS after the Tohoku Earthquake in Japan injection, extraction, quadrupole, survey 2909
 
  • N. Tani, H. Hotchi
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
  
  J-PARC 3GeV RCS suffered the big damage to its building and cooling and electric facilities by the Tohoku Region Pacific Coast Earthquake on March 11, 2011. After the earthquake, RCS magnets were measured to confirm the state of accelerator beam line. As a result, it was found out that there was an alignment error of several millimeters in both horizontal and vertical directions that caused a deformation in the J-PARC 3GeV RCS tunnel. In this paper, we report the survey result in the accelerator tunnel after the earthquake and the realignment plan for J-PARC 3GeV RCS.  
 
WEPPP086 Positioning the 100MeV Linac and Magnets with Two Laser Trackers linac, proton, target, klystron 2912
 
  • B.-S. Park, Y.-S. Cho, J.-H. Jang, D.I. Kim, H.S. Kim, H.-J. Kwon, J.Y. Ryu, K.T. Seol, Y.-G. Song, S.P. Yun
    KAERI, Daejon, Republic of Korea
  
  Funding: * This work is supported by the Ministry of Education, Science and Technology of the Korean Government.
Proton Engineering Frontier Project(PEFP) is developing a 100MeV high-duty-factor proton linac and 10 beam lines. The total length of PEFP linac is about 80m and each beam line is about 30m in length. The reference points were set up on the wall of the tunnel in the lst floor, the klystron gallery in the 2nd floor and the modulator gallery in the 3rd floor to built a survey network. Before the beam commissioning, the accelerator components and beam line magnets have been positioned within the tolerance limit by using two laser tracker systems. In this paper, the schemes for the alignment and the network survey are presented together with the results. 		 
 
WEPPP087 The Improvement and Test of Laser Positioning System for TPS Magnets Alignment Inspection laser, quadrupole, sextupole, insertion 2915
 
  • M.L. Chen, J.-R. Chen, H.C. Ho, K.H. Hsu, W.Y. Lai, C.-S. Lin, C.J. Lin, H.C. Lin, H.M. Luo, S.Y. Perng, P.L. Sung, Y.L. Tsai, T.C. Tseng, H.S. Wang, M.H. Wu
    NSRRC, Hsinchu, Taiwan
  
  A Laser positioning system, consist of a laser, laser position sensing devices (PSD) module and two granite blocks, is developed for the alignment inspection of TPS (Taiwan Photon Source) quadrupole and sextupole magnets during installation on a girder. The PSD module is adapted on the pole center of magnet and is designed to stand for mechanical center of magnets. For high accuracy, eliminating the influence of magnets manufacturing errors between PSD module is a major work. The PSD is mounted on a precise diameter expansible jig to absorb the manufacturing errors. The real roundness of the expansible jig can keep under 3um when diameter is expanded 80um. The PSD position is adjusted and corrected in advance, and then the PSD module center can be identical to the ideal pole position of magnets on the girder within 15um. The magnet will be aligned and adjusted by laser position on PSD. This paper describes how to eliminate the measuring error caused by magnet manufacturing error and the detail of alignment inspection procedure of magnets during the installation on a girder.  
 
WEPPP088 Auto-alignment System and CalibrationPprocedure in TPS Girder System laser, survey, storage-ring, photon 2918
 
  • W.Y. Lai, J.-R. Chen, M.L. Chen, H.C. Ho, K.H. Hsu, D.-G. Huang, C.K. Kuan, C.-S. Lin, C.J. Lin, H.M. Luo, S.Y. Perng, P.L. Sung, Y.L. Tsai, T.C. Tseng, H.S. Wang, M.H. Wu
    NSRRC, Hsinchu, Taiwan
  
  The TPS (Taiwan photon source) project is under construction and will be finished in the December 2012. Considering the floor’s deformation with time and frequent earthquakes at Taiwan, the survey and alignment procedure should be taken quite often. For dealing with these difficulties and improving accuracy of girder’s position, a highly accurate auto-tuning girders system was designed to accomplish the alignment tasks. There are two cells of TPS girders and varied sensor modulus set up for testing the auto-tuning system. The adjustment of the system converges to less than 6um, and the repeatability of the testing is under 10 um. For improving the accuracy of girders position, that is critical thing to make sure all the calibration of sensors modulus correctly and accurately. The calibration procedure about sensor modular and testing results is described in this paper.  
 
WEPPR040 Intensity Effects of the FACET Beam in the SLAC Linac linac, emittance, quadrupole, wakefield 3024
 
  • F.-J. Decker, N. Lipkowitz, J. Sheppard, G.R. White, U. Wienands, M. Woodley, G. Yocky
    SLAC, Menlo Park, California, USA
  
  Funding: Work supported by U.S. Department of Energy, Contract DE-AC02-76SF00515.
The beam for FACET (Facility for Advanced aCcelerator Experimental Tests) at SLAC requires an energy-time correlation ("chirp") along the linac, so it can be compressed in two chicanes, one at the mid point in sector 10 and one W-shaped chicane just before the FACET experimental area. The induced correlation has the opposite sign to the typical used for BNS damping, and therefore any orbit variations away from the center kick the tail of the beam more than the head, causing a shear in the beam and emittance growth. Any dispersion created along the linac has similar effects due to the high (>1.2% rms) energy spread necessary for compression. The initial huge emittances could be reduced by a factor of 10, but were still bigger than expected by a factor of 2-3. Normalized emittance of 2 um-rad in Sector 2 blew up to 150 um-rad in Sector 11 but could be reduced to about 6-12 um-rad for the vertical plane although the results were not very stable. Investigating possible root causes for this, we found locations where up to 10 mm dispersion was created along the linac, which were finally verified with strong steering and up to 7 mm settling of the linac accelerator at these locations. 		 
 
THYA01 High Field Magnet Developments dipole, quadrupole, luminosity, collider 3185
 
  • T. Nakamoto
    KEK, Ibaraki, Japan
  
  Superconducting magnets for future accelerators need to generate a field beyond 10 T. However, mature NbTi superconductors which have been already operated at its performance limit at LHC cannot be adopted. Instead, A15 type superconductors have been considered to be promising materials for the high field magnets. Especially, intensive R&D efforts for the LHC luminosity upgrade with state-of-the-art Nb3Sn superconductors have been carried out. Further future accelerators such as the High-Energy LHC and muon accelerators must require the high field reaching 20 T or more. This means that utilization of HTS (high Tc superconductors) would be the only possible solution. However, it is known that these advanced superconductors are not mechanically robust in comparison with the practical NbTi and the performance is influenced by mechanical stress and strain. In addition, magnetization effects caused by larger effective filament diameters may compromise the field quality in the accelerators. The magnet developments to overcome these issues are ongoing. This presentation will try to review the US and worldwide high field accelerator magnet developments: achievements, status, and plans.  
slides icon Slides THYA01 [7.578 MB]  
 
THEPPB001 Design and Fabrication of The ESS-Bilbao RFQ Prototype Models rfq, vacuum, laser, simulation 3228
 
  • I. Bustinduy, F.J. Bermejo, J. Feuchtwanger, N. Garmendia, A. Ghiglino, O. González, P.J. González, I. Madariaga, J.L. Muñoz, I. Rueda, F. Sordo Balbin, A. Vélez, D. de Cos
    ESS Bilbao, Bilbao, Spain
  • V. Etxebarria, J. Portilla
    University of the Basque Country, Faculty of Science and Technology, Bilbao, Spain
  • A. Garbayo
    AVS, Eibar, Gipuzkoa, Spain
  • S. Jolly
    UCL, London, United Kingdom
  • S.R. Lawrie, A.P. Letchford
    STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
  • J.K. Pozimski, P. Savage
    Imperial College of Science and Technology, Department of Physics, London, United Kingdom
  
  As part of the development of the ESS-Bilbao Accelerator in Spain, two different sets of radio frequency quadrupole (RFQ) models have been developed. On one hand, a set of four oxygen free high conductivity copper weld test models has been designed and manufactured, in order to test different welding methods as well as other mechanical aspects involved in the fabrication of the RFQ. On the other hand, a 352.2 MHz four vane RFQ cold model, with a length of 1 meter, has been designed and built in Aluminum. It serves as a good test bench to investigate the validity of different finite element analysis (FEA) software packages. This is a critical part, since the design of the final RFQ will be based on such simulations. The cold model also includes 16 slug tuners and 8 couplers/pick-up ports, which will allow to use the bead-pull perturbation method, by measuring the electric field profile, Q-value and resonant modes. In order to investigate fabrication tolerances, the cold model also comprises a longitudinal test modulation in the vanes, which is similar to the one designed for the final RFQ.  
 
THEPPB011 Apparatus and Experimental Procedures to Test Crystal Collimation collimation, instrumentation, proton, ion 3254
 
  • S. Montesano
    CERN, Geneva, Switzerland
  • W. Scandale
    LAL, Orsay, France
  
  UA9 is an experimental setup operated in the CERN-SPS in view of investigating the feasibility of halo collimation assisted by bent crystals. The UA9 collimation system is composed only of one crystal acting as primary halo deflector and one single absorber. Different crystals are tested in turn using two-arm goniometers with an angular reproducibility of better than 10 microrad. The performance of the system are assessed through the study of the secondary and tertiary halo in critical areas, by using standard machine instrumentation and few customized equipments. The alignment of the crystal is verified by measuring the loss rate close to the crystal position. The collimation efficiency is computed by intercepting the deflected halo with a massive collimator or with an imaging device installed into a Roman Pot. The leakage of the system is evaluated in the dispersion suppressor by means of movable aperture restrictions. In this contribution the setup and the experimental methods in use are revisited in a critical way and thoroughly discussed. Particular emphasis is given on feasibility, reproducibility and effectiveness of the operational procedures.
For the UA9 Collaboration 		 
 
THPPC046 Normal Conducting Radio Frequency x-band Deflecting Cavity Fabrication and Validation cavity, electron, vacuum, linear-collider 3389
 
  • R.B. Agustsson, L. Faillace, A.Y. Murokh, S. Storms
    RadiaBeam, Santa Monica, USA
  • D. Alesini
    INFN/LNF, Frascati (Roma), Italy
  • V.A. Dolgashev
    SLAC, Menlo Park, California, USA
  • J.B. Rosenzweig
    UCLA, Los Angeles, California, USA
  • V. Yakimenko
    BNL, Upton, Long Island, New York, USA
  
  Funding: U.S. DOE SBIR grant DE-FG02-05ER84370
An X-band Traveling wave Deflector mode cavity (XTD) has been developed and fabricated at Radiabeam Technologies to perform longitudinal characterization of the sub-picosecond ultra-relativistic electron beams. The device is optimized for the 100 MeV electron beam parameters at the Accelerator Test Facility (ATF) at Brookhaven National Laboratory, and is scalable to higher energies. An XTD is designed to operate at 11.424 GHz, and features short filling time, femtosecond resolution, and a small footprint. RF design, structure fabrication, cold testing results and commissioning plans are presented. 		 
 
THPPD001 Stretched-wire Measurements of Small Bore Multipole Magnets multipole, quadrupole, permanent-magnet, simulation 3500
 
  • G. Lebec, J. Chavanne, C. Penel
    ESRF, Grenoble, France
  
  Stretched-wire (SW) measurements of magnetic multipoles have been performed at radii ranging from 0.5 mm to 4 mm, with an accuracy of 10-3 of the main multipole component. Theoretical aspects of SW measurements were investigated. The processing of the measured signals is based on a least square approach, instead of the Fourier transform widely used for rotating coil measurements. It allows correcting numerically the position errors of the SW and designing SW trajectory which are not sensitive to the main multipole, as with “bucked” rotating coils. This SW measurement bench was developed for the characterization of new ESRF magnets. It has been tested first with large aperture multipole magnets. An accuracy of 10-4 has been obtained for a measurement radius of 30 mm. There is a demand in the magnetic measurement community for measuring small bore multipole magnets, with radius smaller than 5 mm. A small permanent magnet quadrupole was built in order to test the bench at small measurement radii.  
 
THPPD018 Precision Magnet Measurements for X-band Accelerator Quadrupole Triplets quadrupole, emittance, dipole, controls 3536
 
  • R.A. Marsh, S.G. Anderson, J.P. Armstrong
    LLNL, Livermore, California, USA
  
  Funding: This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344
An X-band test station is being developed at LLNL to investigate accelerator optimization for future upgrades to mono-energetic gamma-ray (MEGa-Ray) technology at LLNL. Beamline magnets will include an emittance compensation solenoid, windowpane steering dipoles, and quadrupole magnets. Demanding tolerances have been placed on the alignment of these magnets, which directly affects the electron bunch beam quality. A magnet mapping system has been established at LLNL in order to ensure the delivered magnets match their field specification, and the mountings are aligned and capable of reaching the specified alignment tolerances. The magnet measurement system will be described which uses a 3-axis Lakeshore gauss probe mounted on a 3-axis translation stage. Alignment accuracy and precision will be discussed, as well as centering measurements and analysis. The dependence on data analysis over direct multi-pole measurement allows a significant improvement in useful alignment information. Detailed analysis of measurements on the beamline quadrupoles will be discussed, including multi-pole content both from alignment of the magnets, and the intrinsic level of multi-pole magnetic field. 		 
 
THPPD034 Quench Performance and Field Quality of 90-mm Nb3Sn Quadrupoles of TQC Series quadrupole, dipole, collider, controls 3581
 
  • G. Chlachidze, N. Andreev, R. Bossert, J. DiMarco, V. Kashikhin, M.J. Lamm, A. Nobrega, I. Novitski, M.A. Tartaglia, G. Velev, A.V. Zlobin
    Fermilab, Batavia, USA
  
  Funding: Work is supported by Fermi Research Alliance, LLC, under contract No. DE-AC02-07CH11359 with the U.S. Department of Energy
A series of accelerator quality Nb3Sn quadrupole models has been developed, fabricated and tested at Fermilab. The magnet design includes a 90 mm aperture surrounded by four two-layer Nb3Sn coils supported by a stainless steel collar, iron yoke and stainless steel skin. This paper describes the design and fabrication features of the quadrupole models and presents the summary of model tests including quench performance and field quality at 4.5 and 1.9 K. 		 
 
THPPP024 Alignment and Aperture Scan at the Fermilab Booster booster, injection, proton, lattice 3785
 
  • K. Seiya, J.R. Lackey, W.L. Marsh, W. Pellico, D.A. Still, A.K. Triplett, A.M. Waller
    Fermilab, Batavia, USA
  
  The Fermilab booster has an intensity upgrade plan called the Proton Improvement plan (PIP). The flux throughput goal is 2·1017 protons/hour, which is almost double the current operation at 1.1017 protons/hour. The beam loss in the machine is going to be the source of issues. The booster accelerates beam from 400 MeV to 8 GeV and extracts to the Main Injector. Several percent of the beam is lost within 3 msec after the injection. The aperture at injection energy was measured and compared with the survey data. The magnets are going to be realigned in March 2012 in order to increase the aperture. The beam studies, analysis of the scan and alignment data, and the result of the magnet moves will be discussed in this paper.  
 
THPPP053 The Manufacture and Assembly of the FETS RFQ rfq, vacuum, simulation, controls 3862
 
  • P. Savage, J.K. Pozimski
    Imperial College of Science and Technology, Department of Physics, London, United Kingdom
  • A. Garbayo
    AVS, Eibar, Gipuzkoa, Spain
  • A.P. Letchford
    STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
  • D.S. Wilsher
    STFC/RAL, Chilton, Didcot, Oxon, United Kingdom
  
  The Rutherford Appleton Laboratory (RAL) Front End Test Stand (FETS) uses a 324 MHz 4-vane RFQ to accelerate H− ions from 65keV to 3MeV. The RFQ is a copper structure that has been designed as 4 nominally one metre long assemblies. Each assembly consists of 2 major vanes and 2 minor vanes that are bolted together and sealed using an O ring. The mechanical design for the FETS RFQ is complete and the manufacture is underway. In order to achieve the designed physics performance the vanes must be machined and assembled to high degree of accuracy. This requirement has demanded a tight synergy between the design, manufacture and metrology services. Together they have developed detailed procedures for the manufacturing, inspection, alignment and assembly phases. The key points of these procedures will be detailed in this paper.  
 
THPPP054 A New Half-Wave Resonator Cryomodule Design for Project-X cryomodule, cavity, vacuum, focusing 3865
 
  • Z.A. Conway, A.O. Bergado, R.L. Fischer, M. Kedzie, M.P. Kelly, B. Mustapha, P.N. Ostroumov
    ANL, Argonne, USA
  • V.A. Lebedev
    Fermilab, Batavia, USA
  
  Funding: This work was supported by the U.S. Department of Energy, Office of High Energy Physics and Nuclear Physics, under Contract DE-AC02-76CH03000 and DE-AC02-06CH11357.
We present the current status of our Project-X half-wave resonator cryomodule development effort. The Project-X injector requires a single cryomodule with 9 superconducting, 162.5-MHz, β = 0.11, half-wave resonators interleaved with 6 integrated superconducting solenoids/steering coils. This cryomodule is being designed and build by ANL with the intent of delivering a device which has all external connections to the cryogenic, RF, and instrumentation systems located at removable junctions separated from the clean cavity vacuum system. Issues include the ease of assembly, cavity cleanliness, interfacing to subsystems (e.g., cryogenics, couplers, tuners, etc.), and satisfying the ANL/FNAL/DOE guidelines for vacuum vessels. We employ proven warm-to-cold low-particulate beamline transitions to minimize unused space along the linac, a top-loading box design that minimizes the size of the clean room assembly, and compact beamline devices to minimize the length of the focusing period. 		 
 
THPPP070 Comparison of the Residual Doses Before and After Resumption of User Operation in J-PARC RCS injection, target, scattering, neutron 3901
 
  • K. Yamamoto, H. Harada, S. Hatakeyama, N. Hayashi, H. Hotchi, M. Kinsho, R. Saeki, P.K. Saha, M. Yoshimoto
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
  
  J-PARC Facilities were damaged by East Japan Earthquake in March 2011, but All Facirities resumed a beam operation from December 2012. In this paper, we report and compare the beam loss distribution and the residual doses before and after resumption of user operation in J-PARC RCS.  
 
THPPR018 Development Progress of NSLS-II Accelerator Physics High Level Applications controls, lattice, linac, EPICS 4005
 
  • L. Yang, J. Choi, Y. Hidaka, G. Shen, G.M. Wang
    BNL, Upton, Long Island, New York, USA
  
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the Department of Energy.
The High Level Applications (HLA) for NSLS-II commissioning is a development in progress. It is in a client-server framework and uses Python programming language for scripting and graphical user interface application development. This new development provides both scripting and graphical user interface (GUI) controls. The services developed in controls group provide name server, archiving, machine snapshot etc. The clients are developed mainly in the physics group and have measurement, analysis and modeling capabilities. 		 
 
THPPR075 The UK MEIS Facility : A New Future ion, scattering, target, quadrupole 4151
 
  • R.J. Barlow
    University of Huddersfield, Huddersfield, United Kingdom
  
  The Medium Energy Ion Scattering facility at the Daresbury Laboratory, one of only ~10 such facilities in the world, has served the UK community since 1996. It provides a 50-400 keV ion beam and a very comprehensive experimental station where samples can be studied and the energies and angles of the recoil ions measured. It is now closing, but will be be relocated some 50 miles to the University of Huddersfield: it should be recommissioned and available to users in early 2012. We will report on progress, and on the facilities which will be available for users at the new site and under the new management.  
 
FRXAA02 Advanced Solid State Lasers are Merging with Accelerators laser, cavity, acceleration, higher-order-mode 4157
 
  • A. Tünnermann, J. Limpert
    Friedrich Schiller Universität, Jena, Germany
  • T. Schreiber
    Fraunhofer-Institute for Applied Optics and Precision Engineering, Jena, Germany
  
  In recent years, lasers have been developed to an essential tool in accelerator science, for acceleration and diagnostics. Novel applications require for high average power lasers in continuous and pulsed operation with diffraction limited beam quality. Lasers are known as sophisticated systems with a notorious poor efficiency. Most recently, rare-earth-doped fibers have established themselves as an attractive and power scalable solid-state laser concept. Using advanced large mode area fibers, in continuous-wave operation output powers in the 10 kW-regime with diffraction-limited beam quality at electrical to optical efficiencies of 30 percent have been demonstrated. In the pulsed regime average powers of the order of 1 kW even for femtosecond fiber laser systems have been reported. Coherent beam combination of these lasers allows for the generation of high peak power pulses at high repetition rates and output powers. In this contribution the state of the art in solid state laser technology operating at high average powers with inherent high efficiencies is reviewed. The prospects for future developments that will meet the demands set by the accelerator community will be discussed.  
slides icon Slides FRXAA02 [11.729 MB]