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Chin, Y. H.

Paper Title Page
WEPMN023 Development of 10 MW L-Band Multi-Beam Klystron (MBK) for European X-FEL Project 2098
 
  • Y. H. Chin
    KEK, Ibaraki
  • K. Hayashi
    TETD, Otawara
  • M. Y. Miyake, Y. Yano
    Toshiba, Yokohama
 
  A 10MW L-band Multi-Beam Klystron (MBK) has been developed and tested by Toshiba, Japan for the European XFEL and a future linear collider projects.? The Toshiba MBK has six low-perveance beams operated at low voltage of 115kV (for 10MW) and six ring-shaped cavities to enable a higher efficiency than a single-beam klystron for a similar power. After the successful acceptance testing at the Toshiba Nasu factory in March 2006, attended by a DESY stuff, the final acceptance test was done at DESY laboratory in June 2006. In these tests, the output power of 10.2MW, more than the design goal (10MW), has been demonstrated at the standard beam voltage of 115kV at the RF pulse length of 1.5ms and the beam pulse of 1.7ms at 10Hz. The efficiency was 66%. The robustness of the tube was also demonstrated by being operated continuously more than 24 hours above 10MW. A horizontal version of the Toshiba MBK is now under construction.  
THPAN036 ABCI Progresses and Plans: Parallel Computing and Transverse Napoly-Shobuda Integral 3306
 
  • Y. H. Chin, K. Takata
    KEK, Ibaraki
  • Y. Shobuda
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
 
  In this paper, we report the recent progress and future plans of ABCI. First, ABCI now supports parallel processing in OpenMP for a shared memory system, such as a PC with multiple CPUs or a CPU with multiple cores. The new ABCI also supports the dynamic memory allocation for nearly all arrays for field calculations so that the amount of memory needed for a run is determined dynamically during runtime. A user can use any number of mesh points as far as the total allocated memory is within a physical memory of his PC. As a important progress of the features, the transverse extension of Napoly integral (derived by Shobuda) has been implemented to the new ABCI: it permits calculations of wake potentials in structures extending to the inside of the beam tube radius or having unequal tube radii at the two sides not only for longitudinal but also for transverse cases, and still the integration path can be confined to a finite length, by having the integration contour beginning and ending on the beam tubes. The future upgrade plans will be also discussed. The new ABCI is available as a Windows stand-alone executable module so that no installation of the program is necessary.  
THPAN046 Extension of Napoly Integral for Transverse Wake Potentials to General Axisymmetric Structure 3333
 
  • Y. Shobuda
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
  • Y. H. Chin, K. Takata
    KEK, Ibaraki
 
  The Napoly integral for wake potential calculations in the axisymmetric structure is a very useful method because the integration of Ez field can be confined in a finite length instead of infinite length by deforming the integration path, which reduces CPU time for accurate calculations. However, his original method cannot be applied to the transverse wake potentials in a structure where the two beam tubes on both sides have unequal radii. In this case, the integration path needs be a straight line and the integration stretches out to an infinite in principle. We generalize the Napoly integrals so that integrals are always confined in a finite length even when the two beam tubes have unequal radii, for both longitudinal and transverse wake potential calculations. The extended method has been successfully implemented to ABCI.  
THPAN090 Fourier Spectral Simulation for Wake Field in Conducting Cavities 3432
 
  • M. Min, Y.-C. Chae, P. F. Fischer, K.-J. Kim
    ANL, Argonne, Illinois
  • Y. H. Chin
    KEK, Ibaraki
 
  Recent demand of short-bunch beams poses high-order computational tools for investigating beam dynamics in order to improve the beam quality. We have studied a new computational approach with spectrally accurate high-order approximation for wake field calculations. The technique employs the standard Fourier basis combined with a post-processing procedure for noise reduction by Gegenbauer reconstruction. We integrate this scheme into the existing 2D wake field calculation code ABCI and investigate possible enhancemance of its performance on the same grid base. We will demontrate 2D wake potential simulations for various cylindrically symmetric structures with the quality improvement in comparison to the conventional lower-order method.