03 Technology
3H Other Technology
Paper Title Page
Synchronization of Accelerator Sub-systems with Ultimate Precision  
  • H. Schlarb
    DESY, Hamburg, Germany
  Precise synchronization of accelerator sub-systems such as LLRF stations, gun or seeding lasers, is a pre-requisite for the successful operation of modern linear accelerators. The synchronization demand is often below 10 fs. Using examples like FLASH at DESY, the European XFEL, or different seeding proposals and studies, a general overview should be given.  
slides icon Slides TU3A01 [3.855 MB]  
Advances in Photonic and Metamaterial RF structures  
  • R. Seviour
    University of Huddersfield, Huddersfield, United Kingdom
  Interest in the use of novel electromagnetic media for particle acceleration and EM wave generation is growing. In part driven by the possibility to overcome limiting issues in conventional technologies, and offer novel ways in which to accelerate particles. Photonic media can confine a single EM frequency whilst forcing all other frequencies to propagate away, significantly reducing the long range wakefield of a structure. The novel dispersion curves of metamaterials define unique particle-wave interactions enabling compact inverse Cherenkov acceleration. In this presentation we examine the use of photonic media and metamaterials for RF generation and particle acceleration. We review the physical processes and defining length scales, energy exchange mechanisms, examining the advantages offered by these media and the issues that can arise from their use.  
slides icon Slides TU3A02 [28.697 MB]  
TH1A04 Superconducting Linac and Associated Developments at IUAC Delhi 763
  • A. Roy
    IUAC, New Delhi, India
  A superconducting linear accelerator system consisting of a series of independently phase locked niobium quarter wave resonators has been developed as a booster of heavy ion beams available from the existing 15UD Pelletron accelerator. Two superconducting linac booster modules having eight niobium quarter wave resonators (QWRs) each have been installed and are fully operational for regular scheduled experiments. The third module is being added to the system. A new high current injector has been planned to couple to the superconducting linac. For this a high temperature superconducting electron cyclotron resonance ion source (HTS-ECRIS) was designed, fabricated and installed successfully. A radio frequency quadrupole (RFQ) accelerator is being developed for accelerating accelerate ions from the ECR (A/Q ~ 6) to an energy to of about 180 keV/A. The beams will then be accelerated further by drift tube linacs (DTL) to the required velocity to inject them to the existing superconducting linac booster. Prototypes of both these have been tested for power and thermal studies. Details of these developments and associated systems will be presented.  
slides icon Slides TH1A04 [7.830 MB]  
THPB079 Development of a Superconducting Focusing Solenoid for CADS 1011
  • W. Wu, S.F. Han, Y. He, L.Z. Ma, D.S. Ni, Z.J. Wang, B.M. Wu, W.J. Yang, X.L. Yang, S.J. Zheng, L. Zhu
    IMP, Lanzhou, People's Republic of China
  A superconducting focusing solenoid has been designed and developed for the China Accelerator Driven System (CADS). In order to meet the requirement of focusing strength and fringe field while minimizing physical size of the solenoid, the novel optimizing design method based on linear programming method was employed. In this report, we will introduce the design of the solenoid including magnetic field optimization, mechanical design and quench protection. The fabrication and the test results of the solenoid will also be introduced in this report.  
THPB091 Machine Protection Issues and Solutions for Linear Accelerator Complexes 1032
  • M. Jonker, H. Schmickler, R. Schmidt, D. Schulte
    CERN, Geneva, Switzerland
  • M.C. Ross
    SLAC, Menlo Park, California, USA
  The workshop “Machine Protection focusing on Linear Accelerator Complexes” was held from 6-8 June 2012 at Cern. This workshop brought together experts working on machine protection systems for accelerator facilities with high brilliance or large stored beam energies, with the main focus on linear accelerators and their injectors. An overview of the machine protection systems for several accelerators was given. Beam loss mechanisms and their detection were discussed. Mitigation of failures and protection systems were presented. This paper summarises the workshop and reviews the current state of the art in machine protection systems.  
THPB092 Recent Improvements in SPring-8 Linac for Early Recovery from Beam Interruption 1035
  • S. Suzuki, T. Asaka, H. Dewa, H. Hanaki, T. Kobayashi, T. Magome, A. Mizuno, T. Taniuchi, H. Tomizawa, K. Yanagida
    JASRI/SPring-8, Hyogo-ken, Japan
  The 1GeV SPring-8 linac is an injector for the SPring-8 synchrotron radiation storage ring with 8GeV booster synchrotron. In recent years, backup systems were installed to eliminate long-time interruption of the beam injections: The main gun system is usually operated, and the second gun is always pre-heated and can inject electron beams into a buncher section with an interval of several minutes in case the main gun failed. The first klystron, that feeds RF powers to the buncher system and the downstream klystrons, can be relieved by the next klystron with an interval of about 20 minutes by switching the waveguide circuit. When one of the eleven working klystrons faults, one of standby klystrons, which are kept for hot spares on line, is automatically activated to accelerate beams instead of the failed one without beam interruption. The total downtime in FY2012 was 0.12% in top-up operation user time. The averaged fault frequency was 0.2 times per day.  
THPB094 Performance of Beam Chopper at SARAF via RF Deflector Before the RFQ 1038
  • A. Shor, D. Berkovits, I. Fishman, A. Grin, B. Kaizer, L. Weissman
    Soreq NRC, Yavne, Israel
  We describe performance of a beam chopper at the SARAF accelerator consisting of an HV deflector preceding the RFQ. The deflector and electronics, developed at LNS Catania, was designed to provide slow beam chopping for beam testing and diagnostics where low beam power is necessary. The HV deflector sweeps away the low energy beam onto a water cooled beam catcher, while a fast HV switch momentarily switches off the HV whenever a transmitted beam to the RFQ is desired. We report on measurements with this chopping system, where minimum transmitted beam pulse of 180 ns duration is attained with a rise and fall time of several nano-seconds. We performed beam dynamics simulations of SARAF Phase-I, including the deflector, where the short rise and fall times of the chopped beam is attributed to the tight collimation of the deflected beam provided by the RFQ and the fast Faraday Cup. We also describe beam dynamics simulations which suggest that single RFQ bunch selection can be achieved with the existing chopping system, during zero-crossover for positive-negative deflecting HV waveform.