06 Beam Instrumentation and Feedback
T17 Alignment and Survey
Paper Title Page
MOOCB01 Study on the Realignment Plan for J-PARC Linac after the Tohoku Earthquake in Japan 44
 
  • M. Ikegami
    KEK, Ibaraki, Japan
  • T. Morishita
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
 
  A 9.0-magnitude earthquake struck eastern Japan on March 11, 2011, and it gave rise to damages to the buildings of the J-PARC facilities. In particular, the earthquake caused a deformation of the J-PARC linac tunnel resulting an alignment error of several tens of millimeters in both horizontal and vertical directions. It also caused a change in the relative position between the linac and other facilities of J-PARC complex. To restore the beam operation, we should establish a reasonable realignment plan for J-PARC linac taking various constraints into account and possibly tolerating some residual misalignment. In this paper, we show a study on the realignment plan for J-PARC linac including evaluation of the effect of residual misalignment with particle simulations.  
slides icon Slides MOOCB01 [2.659 MB]  
 
MOPO023 Laser-based Alignment System at the KEKB Injector Linac 529
 
  • M. Satoh, N. Iida, T. Suwada
    KEK, Ibaraki, Japan
  • K. Minoshima, S. Telada
    AIST, Tsukuba, Japan
 
  A laser-based alignment system is under development at the 500-m-long KEKB injector linac. The original system was designed and constructed more than thirty-years ago, and thus, we are revisiting our alignment system because the previous alignment system has become too obsolete. The new alignment system is again strongly required for the next generation SuperKEKB project. The new laser alignment system is similar to the previous one, which comprises a helium-neon laser and quadrant photodetectors installed in vacuum light pipes. A girder displacement of the accelerating structure can be precisely measured in the direction of the laser-ray trace, where the laser light must stably propagate up to 500-m downstream without any orbital and beam-size fluctuation. We tested the laser-ray propagation and the stability along a 100-m-long beam line under a vacuum condition of 0.1-1 Torr. In this paper, we will report the system description and test results in detail.    
 
MOPO025 Experimental Study on New Laser-based Alignment System utilizing a Sequential Three-point Method at the KEKB Injector Linac 532
 
  • T. Suwada, M. Satoh
    KEK, Ibaraki, Japan
  • K. Minoshima, S. Terada
    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 lenses and a CCD camera is revisited in a preliminary design of the new alignment system. The new 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 200-m-long straight section at atmospheric pressure. In this report, the preliminary experimental results are reported along with the basic design of the new laser-based alignment system.  
 
MOPO026 Design, Manufacturing and Tests of Closed-loop Quadrupole Mover Prototypes for European XFEL 535
 
  • J. Munilla, J. Calero, J.M. Cela-Ruiz, L. García-Tabarés, A. Guirao, J.L. Gutiérrez, T. Martínez de Alvaro, E. Molina Marinas, S. Sanz, F. Toral, C. Vazquez
    CIEMAT, Madrid, Spain
 
  Funding: Work partially supported by Spanish Ministry of Science and Innovation under SEI Resolution on 17-September-2009
In this report the development of a quadrupole mover with submicron repeatability is reported, which will be used in the intersections of the Undulator Systems of the European XFEL (EXFEL). It is part of the Spanish in-kind contribution to this facility. The main specifications include submicron repeatability for a 70 kg quadrupole magnet within compact dimensions and a ±1.5 mm stroke in the vertical and horizontal direction. Compact linear actuators based on 5-phase stepping motors have been chosen. Vertical actuator works in a wedge configuration to take mechanical advantage. A closed-loop control system has been developed to achieve this repeatability. For the feedback, one LVDT sensor for each axis was used. Mechanical switches are used to limit movement. In addition, hard-stops are included for emergency. Prototyping stage is done and a serial production of more than 90 devices is expected, so intense work has been done to achieve a reliable industrial production and validation. In this report, results of mechanical measurements including reproducibility, tests of different operation strategies and critical situations will be reported.
 
 
MOPO027 Status of a Study of Stabilization and Fine Positioning of CLIC Quadrupoles to the Nanometre Level* 538
 
  • K. Artoos, C.G.R.L. Collette, M. Esposito, P. Fernandez Carmona, M. Guinchard, C. Hauviller, S.M. Janssens, A.M. Kuzmin, R. Leuxe, R. Moron Ballester
    CERN, Geneva, Switzerland
 
  Funding: The research leading to these results has received funding from the European Commission under the FP7 Research Infrastructures project EuCARD, grant agreement no.227579
Mechanical stability to the nanometre and below is required for the CLIC quadrupoles to frequencies as low as 1 Hz. An active stabilization and positioning system based on very stiff piezo electric actuators and inertial reference masses is under study for the Main Beam Quadrupoles (MBQ). The stiff support was selected for robustness against direct forces and for the option of incrementally repositioning the magnet with nanometre resolution. The technical feasibility was demonstrated by a representative test mass being stabilized and repositioned to the required level in the vertical and lateral direction. Technical issues were identified and the development programme of the support, sensors, and controller was continued to increase the performance, integrate the system in the overall controller, adapt to the accelerator environment, and reduce costs. The improvements are implemented in models, test benches, and design of the first stabilized prototype CLIC magnet. The characterization of vibration sources was extended to forces acting directly on the magnet, such as water-cooling induced vibrations. This paper shows the achievements, improvements, and an outlook on further R&D.
 
 
MOPO028 Modal Analysis and Measurement of Water Cooling Induced Vibrations on a CLIC Main Beam Quadrupole Prototype* 541
 
  • K. Artoos, C.G.R.L. Collette, M. Esposito, P. Fernandez Carmona, M. Guinchard, S.M. Janssens, R. Leuxe, M. Modena, R. Moron Ballester, M. Struik
    CERN, Geneva, Switzerland
  • G. Deleglise, A. Jeremie
    IN2P3-LAPP, Annecy-le-Vieux, France
 
  Funding: The research leading to these results has received funding from the European Commission under the FP7 Research Infrastructures project EuCARD, grant agreement no. 227579.
To reach the Compact Linear Collider (CLIC) design luminosity, the mechanical jitter of the CLIC main beam quadrupoles should be smaller than 1.5 nm integrated root mean square (r.m.s.) displacement above 1 Hz. A stiff stabilization and nano-positioning system is being developed but the design and effectiveness of such a system will greatly depend on the stiffness of the quadrupole magnet which should be as high as possible. Modal vibration measurements were therefore performed on a first assembled prototype magnet to evaluate the different mechanical modes and their frequencies. The results were then compared with a Finite Element (FE) model. The vibrations induced by water-cooling without stabilization were measured with different flow rates. This paper describes and analyzes the measurement results.
 
 
MOPO029 Validation of a Micrometric Remotely Controlled Pre-alignment System for the CLIC Linear Collider using a Test Setup (Mock-up) with 5 Degrees of Freedom 544
 
  • H. Mainaud Durand, M. Anastasopoulos, J. Kemppinen, R. Leuxe, M. Sosin, S. griffet
    CERN, Geneva, Switzerland
 
  The CLIC main beam quadrupoles need to be pre-aligned within 17μm rms with respect to a straight reference line along a sliding window of 200 m. A re-adjustment system based on eccentric cam movers, which will provide stiffness to the support assembly, is being studied. The cam movers were qualified on a 1 degree of freedom (DOF) test setup, where a repeatability of adjustment below 1 μm was measured along their whole range. This paper presents the 5 DOF mock-up, built for the validation of the eccentric cam movers, as well as the first results of tests carried out: resolution of displacement along the whole range, measurements of the support eigenfrequencies.  
 
MOPO030 Theoretical and Practical Feasibility Demonstration of a Micrometric Remotely Controlled Pre-alignment System for the CLIC Linear Collider 547
 
  • H. Mainaud Durand, M. Anastasopoulos, N.C. Chritin, J. Kemppinen, M. Sosin, S. griffet
    CERN, Geneva, Switzerland
  • T. Touzé
    ENSTA, Brest, France
 
  The active pre-alignment of the Compact Linear Collider (CLIC) is one of the key points of the project: the components must be pre-aligned w.r.t. to a straight line within a few microns over a sliding window of 200 m, along the two linacs of 20 km each. The proposed solution consists of stretched wires of more than 200 m, overlapping over half of their length, which will be the reference of alignment. Wire Positioning Sensors (WPS), coupled to the supports to be pre-aligned, will perform precise and accurate measurements within a few microns, w.r.t. these wires. A micrometric fiducialisation of the components and a micrometric alignment of the components on common supports will make the strategy of pre-alignment complete. In this paper, the global strategy of active pre-alignment is detailed and illustrated by the latest results demonstrating the feasibility of the proposed solution.  
 
MOPO031 Alignment of theTPS Front-End Prototype 550
 
  • C.K. Kuan, Y.T. Cheng, W.Y. Lai, I.C. Sheng, T.C. Tseng, H.Y. Yan
    NSRRC, Hsinchu, Taiwan
  • J.-R. Chen
    National Tsing Hua University, Hsinchu, Taiwan
 
  The Taiwan Photon Source (TPS) is a 3-GeV third-generation source of synchrotron radiation with beam current 500 mA stored in the storage ring. A front end allows intense synchrotron light generated in the storage ring to pass through to a beamline. Most heat load of the synchrotron light is removed in the front ends to protect the beamline components. Alignment of front-end components becomes important to prevent damage from the large heat load. Because of the many front ends and the brief period of installation, the alignment work should be easy, quick and reliable. Using a shim method, the adjustable degrees of freedom are decreased from six to two. This adjustment work becomes easier and quicker. The alignment of a front-end prototype is described here.  
 
MOPO032 The Survey Status at NSRRC during the TPS Civil Construction 553
 
  • H.M. Luo, J.-R. Chen, Chen, M. L. Chen, H.C. Ho, K.H. Hsu, W.Y. Lai, C.J. Lin, S.Y. Perng, P.L. Sung, Y.L. Tsai, T.C. Tseng, H.S. Wang
    NSRRC, Hsinchu, Taiwan
 
  In this paper, the survey status at NSRRC site duirng the TPS (Taiwan Photon Source) civil construction is described. The TLS (Taiwan Light Source) ring is still under operation in the meantime. In order to maintain the TLS for normal operation and also monitoring the building construction, an expanded survey setups including permanent leveling and GPS monuments were installed both on the site and TPS building. Combined with the orignal TLS survey sockets and sensor monitoring system (hydrostatic leveling system and precision inclination sensors) installed both in the TLS storage ring and beamlines, an extensive survey tasks were performed. The ground deformation situation of the TLS and deviation of the TPS building construction are presented.  
 
MOPO033 Design and Development of a Laser Positioning System for TPS Magnets Alignment Inspection during the Installation on a Girder 556
 
  • Chen, M. L. Chen, H.C. Ho, K.H. Hsu, W.Y. Lai, S.Y. Perng, Y.L. Tsai, T.C. Tseng, H.S. Wang
    NSRRC, Hsinchu, Taiwan
  • J.-R. Chen
    National Tsing Hua University, Hsinchu, Taiwan
 
  A novel optical inspection architecture is designed and developed for positioning the TPS (Taiwan Photon Source) quadrupole and sextupole magnets on the girder within 30 um. This positioning system is a laser-based scheme consists of two laser position sensing devices (PSD) and two granite blocks as the standard reference of magnets. The laser position sensing device (PSD) is mounted on an adjustable circular steel module and the module is installed in a granite block. With the PSD position being adjusted and corrected, the PSD module center can be identical to the ideal pole position of magnets on the girder within 10um. The Laser ray is also adjusted and aligned according to the ideal reference line of magnets. Finally the granite blocks are replaced with the quadrupole and sextupole magnets at installation, the assembling error of magnets can be detected from the PSD module. This paper describes the detail of the system development and testing results.  
 
MOPO034 From Survey Alignment toward Auto-alignment for the Installation of the TPS Storage Ring Girder System 559
 
  • T.C. Tseng, Chen, M. L. Chen, H.C. Ho, K.H. Hsu, W.Y. Lai, C.J. Lin, H.M. Luo, S.Y. Perng, P.L. Sung, Y.L. Tsai, H.S. Wang
    NSRRC, Hsinchu, Taiwan
  • J.-R. Chen
    National Tsing Hua University, Hsinchu, Taiwan
 
  The TPS (Taiwan Photon Source) project is now under civil construction. The whole building is constructed half underground and 12m deep compared to the TLS due to the stability consideration, so the survey and alignment works are quite confined and difficult. For positioning the magnets precisely and quickly, a high accuracy auto-tuning girders system combined with survey network procedures were established to accomplish the installation tasks. The position data from the survey network will define a basis for the motorized girder system to auto-tune and improve the accuracy. A mockup of one twenty-fourth section (one cell) had been installed at NSRRC for interface examination and further testing. In this paper, the procedures from the traditional survey network to auto-aliment system design and algorithm are described. Meanwhile, a preliminary testing result is also included.  
 
MOPO035 Stability of the Floor Slab at Diamond Light Source 562
 
  • J. Kay, K.A.R. Baker, W.J. Hoffman
    Diamond, Oxfordshire, United Kingdom
  • I.P.S. Martin
    JAI, Oxford, United Kingdom
 
  A Hydrostatic Leveling System (HLS) has been installed at Diamond Light Source. 8 sensors have been positioned along a 60 metre portion of the floor of the Storage Ring and the Experimental Hall, stretching out along a typical beamline route from Insertion Device to sample. Results since June 2008 are presented comparing actual performance with the original specification as well as identifying movements associated with environmental factors.