Author: Iwashita, Y.
Paper Title Page
MOPME029 Multi-strip Current Monitor for Pulsed Laser Plasma Diagnostics 538
  • Y. Fuwa, Y. Iwashita
    Kyoto ICR, Uji, Kyoto, Japan
  • M. Okamura
    BNL, Upton, Long Island, New York, USA
  A compact position-sensitive beam instrumentation devise is under development. The beam detection area of this devise is composed of multi-strip electrodes and scanned by multiplexers, which reduces the number of read-out lines and feed-through connectors. Combined with an electrostatic deflector and ToF information, this monitor can discriminate charge to mass ratios of particles. A prototype of this monitor is fabricated for measurement of ion distribution and charge state in laser induced plasma. This model has fifteen strip electrodes and the multiplexed signal and the clock signal are read out through two coaxial cables. Thus, only three cables are needed including a +5V power supply line. The test result will be presented.  
TUPEA012 Rebunching Ultracold Neutrons by Magnetic Deceleration for the neutron EDM experiment at J-PARC 1187
  • S. Imajo
    Kyoto University, Kyoto, Japan
  • Y. Arimoto
    KEK, Ibaraki, Japan
  • P.W. Geltenbort
    ILL, Grenoble, France
  • Y. Iwashita
    Kyoto ICR, Uji, Kyoto, Japan
  • M. Kitaguchi
    Kyoto University, Research Reactor Institute, Osaka, Japan
  • Y. Seki
    RIKEN Nishina Center, Wako, Japan
  • H.M. Shimizu
    Nagoya University, Nagoya, Japan
  • T. Yoshioka
    Kyushu University, Fukuoka, Japan
  Ultra cold neutrons (UCN) - neutrons with energies less than 300 neV - can be accelerated or decelerated by means of static magnetic and RF fields. Neutron have a magnetic dipole moment, and hence their kinetic energies vary depending on their spin in magnetic fields. Their kinetic energies are restored when they get out from the magnetic field area if their spin did not flip. A spin flip can be triggered by applying an RF field whose frequency coincides with the spin precession frequency of a neutron in this magnetic field. This allows to tune the kinetic energy of neutrons. This method can be used to rebunch a pulsed beam of neutrons to a storage bottle that can store UCN. By open and close the storage bottle synchronously with the rebuncher, high UCN densities can be achieved for precision measurements of neutron properties such as the Electric Dipole Moment. The method and experimental setup are described in detail and the results of a recent first test experiments are presented.  
WEPWO014 Rf Field-Attenuation Formulae for the Multilayer Coating Model 2343
  • T. Kubo, T. Saeki
    KEK, Ibaraki, Japan
  • Y. Iwashita
    Kyoto ICR, Uji, Kyoto, Japan
  Formulae that describe the RF electromagnetic field attenuation in the multilayer coating model with a single superconductor layer and a single insulator layer deposited on a bulk superconductor are derived with a rigorous calculation based on the Maxwell equations and the London equation.  
WEPWO015 Electron Beam Welding for High Gradient Superconducting Cavity 2346
  • T. Kubo, Y. Ajima, H. Hayano, H. Inoue, S. Kato, T. Saeki, M. Sawabe, K. Umemori, Y. Watanabe, S. Yamaguchi, M. Yamanaka
    KEK, Ibaraki, Japan
  • Y. Iwashita
    Kyoto ICR, Uji, Kyoto, Japan
  • T. Nagata
    ULVAC, Inc., Tsukuba, Japan
  Relations between electron beam welding parameters and appearances of weld beads are studied. It was found that a beam generator position and a welding direction affect a geometry of weld bead dramatically. Carbon including contaminants found after the chemistry are also commented.  
WEPWO017 Efforts on Nondestructive Inspections for SC Cavities 2352
  • Y. Iwashita, Y. Fuwa, M. Hashida, S. Sakabe, S. Tokita, H. Tongu
    Kyoto ICR, Uji, Kyoto, Japan
  • H. Hayano, K. Watanabe, Y. Yamamoto
    KEK, Ibaraki, Japan
  • K. Otani
    INRS-EMT, Varennes (Québec), Canada
  The high resolution camera, so-called Kyoto Camera, inspecting the Sc cavity inner surface showed the importance of nondestructive inspections to improve yield in production of high performance SC Cavities. Further efforts have been continued for the inspection and the high resolution T-map, X-map and eddy current scanner have been developed. A radiography to detect small voids inside the Nb EBW seam with the target resolution of 0.1 mm is under investigation. We have carried out radiography tests with X-rays induced from an ultra short pulse intense laser.  
WEPFI024 Anisotropic Ferrite Magnet Focusing System for Klystrons 2756
  • Y. Fuwa, H. Ikeda, Y. Iwashita, R. Kitahara, Y. Nasu, H. Tongu
    Kyoto ICR, Uji, Kyoto, Japan
  • S. Fukuda, T. Matsumoto, S. Michizono
    KEK, Ibaraki, Japan
  The permanent magnet beam focusing for klystrons can eliminate the solenoid coil with the water cooling system and the power supply that consumes electricity. Hence the failure rate and the operating cost of RF systems should decrease. This feature is suitable for a large facility that requires a lot of klystrons such as ILC. Since the required magnetic field for klystron beam is moderate, inexpensive anisotropic ferrite magnets can be applied. The test model is fabricated for a 1.3 GHz klystron whose output power is 800 kW. Each magnet block in the model is movable for magnetic field adjustment and the iron yoke in the oil tank improves magnetic field distribution around cathode area. The result of a klystron power test will be presented.  
THOBB203 Study on Fabrication of Superconducting RF 9-cell Cavity for ILC at KEK 3132
  • T. Saeki, Y. Ajima, K. Enami, H. Hayano, H. Inoue, E. Kako, S. Kato, S. Koike, T. Kubo, S. Noguchi, M. Satoh, M. Sawabe, T. Shishido, A. Terashima, N. Toge, K. Ueno, K. Umemori, K. Watanabe, Y. Watanabe, S. Yamaguchi, A. Yamamoto, Y. Yamamoto, M. Yamanaka, K. Yokoya
    KEK, Ibaraki, Japan
  • Y. Iwashita
    Kyoto ICR, Uji, Kyoto, Japan
  • N. Kawabata, H. Nakamura, K. Nohara, M. Shinohara
    SPS, Funabashi-shi, Japan
  • F. Yasuda
    The University of Tokyo, Institute of Physics, Tokyo, Japan
  We constructed a new facility for the fabrication of superconducting RF cavity at KEK from 2009 to 2011. In the facility, we have installed a deep-drawing machine, a half-cell trimming machine, an electron-beam welding machine, and a chemical etching room in one place. We started the study on the fabrication of 9-cell cavity for International Linear Collier (ILC) from 2009 using this facility. The study is focusing on the cost reduction with keeping high performance of cavity, and the goal is the establishment of mass-production procedure for ILC. This article reports the current status of the studies in CFF.  
slides icon Slides THOBB203 [3.983 MB]  
THPFI017 Development of Harmonic Field Measurement System with Higher Resolution ADC 3330
  • R. Kitahara, Y. Fuwa, Y. Iwashita, Y. Nasu
    Kyoto ICR, Uji, Kyoto, Japan
  Quadrupole magnets for ILC final focus should be enough strong with the limitation on the external radius, while the vibration of the magnetic center has to be highly avoided to keep the nm sized beam focusing stable at the interaction point a few m downstream from the lens. Gluckstern's 5-ring PMQ singlet seems a good candidate for the purpose, which is under investigation. The precise magnetic harmonic field measurement system is also under development for adjusting each magnet ring and evaluation of the assembled singlet. A rotating magnet system and a rotating coil system are prepared for the former and the latter purposes, respectively. Both systems have 24-bit ADC's for higher resolution. For the rotation coil, a flexible print circuit sheet, where a pair of one turn coils is printed on, is glued on a quartz rod. The two coils located on the quarts rod with the angle difference of 180 degree can separate the odd and even harmonics components by recording both the signals simultaneously to get their sum and difference. The two digitized signals are integrated digitally.