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Nakamura, N.

 
Paper Title Page
TUPCH132 Higher Order Mode (HOM) Damper of 500 MHz Damped Cavity for ASP Storage Ring 1325
 
  • J. Watanabe, K. Nakayama, K. Sato, H. Suzuki
    Toshiba, Yokohama
  • M. Izawa
    KEK, Ibaraki
  • A. Jackson, G. LeBlanc, K. Zingre
    ASP, Clayton, Victoria
  • T. Koseki
    RIKEN/RARF/CC, Saitama
  • N. Nakamura, H. Sakai, H. Takaki
    ISSP/SRL, Chiba
  
  TOSHIBA has delivered the storage ring RF system for the Australian Synchrotron Project(ASP). Two pairs of the 500MHz Higher Order Mode(HOM) damped cavities were applied for this system. Two on-centered and one off-centered dampers were attached for damping the longitudinal HOM impedance down to less than 20kOhm/GHz. In order to reduce the coupling of off-center damper for accelerating mode and improve cooling power of damper, New HOM damper was designed by optimizing SiC absorber structure and damper antenna length using HFSS code. The design and manufacture of the new HOM damper and the test are described.  
WEPCH025 COD Correction at the PF Ring by New Orbit Feedback Scheme 1978
 
  • K. Harada, T. Obina
    KEK, Ibaraki
  • N. Nakamura, H. Sakai, H. Takaki
    ISSP/SRL, Chiba
  
  When we correct the global COD (closed orbit distortion), if we use the modified conversion matrix calculated by the eigen vector method with constraint conditions (EVC), the local orbit correction can be simultaneously done to fix the light source point in the insertion device. In the EVC, the local orbit correction is combined to the global orbit correction by the Lagrange's undetermined multiple method. In this paper, we show the machine study results at the PF Ring.  
THOBFI02 Measurement of the Beam Profiles with the Improved Fresnel Zone Plate Monitor 2784
 
  • H. Sakai, N. Nakamura
    ISSP/SRL, Chiba
  • H. Hayano, T. Muto
    KEK, Ibaraki
  
  We present the recent progress of the FZP (Fresnel Zone Plate) beam profile monitor constructed at KEK-ATF damping ring. This monitor based on an X-ray imaging optics with two FZPs*. In this monitor, the transverse electron beam image at bending magnet is twenty-times magnified by the two FZPs and detected on an X-ray CCD camera. Then the real-time and 2-dimentional transverse beam profiles can be obtained with non-destructive manner by using this monitor. The expected spatial resolution is less than 1 micro-meter. Recently, we install the new mechanical shutter to improve time resolution of the monitor and avoid the effects of the short-term movement of the beam or the monitor itself. By applying this shutter, the shutter opening time was reduced less than 1ms and the beam profile could be measured more accurately. In this paper, we report the new shutter performance and the measurement results of beam profiles by the improved FZP beam profile monitor.

*K. Iida, et al. Nucl. Instrum. Meth. A 506 (2003) 41-49.

 
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