Journal of the Particle Accelerator Society of Japan
Online ISSN : 2436-1488
Print ISSN : 1349-3833
Volume 9, Issue 2
Displaying 1-14 of 14 articles from this issue
Preface
Topics
  • Hitoshi TANAKA, Arnaud AMSELEM, Hideki AOYAGI, Takao ASAKA, Yoshihiro ...
    2012Volume 9Issue 2 Pages 60-71
    Published: July 31, 2012
    Released on J-STAGE: March 01, 2023
    JOURNAL FREE ACCESS

    After 8 months of beam commissioning of SPring-8 Angstrom Compact free electron LAser, SACLA reached the primary target performance, i.e., a shortest laser wavelength of ~0.6 Angstrom and a laser pulse energy value of submJ at a wavelength of 1.2 Angstrom. This success was due to the following four factors; (1) performance estimation of each component of SACLA required for the target laser performance and its achievement, (2) elaboration of beam diagnostics and control systems enabling precise accelerator and undulator tuning, (3) a rational and strategic commissioning plan, (4) most adequate response to various accidental events during the beam commissioning period. This article, in order to light up the above four factors leading us to the success, starts with the features of SACLA and critical tolerance for the sub-system components, and then, explains our approach to achieve the target laser performance and how the beam commissioning of SACLA proceeded. At last, the article summarizes the present laser and operational status.

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  • Chihiro OHMORI
    2012Volume 9Issue 2 Pages 72-81
    Published: July 31, 2012
    Released on J-STAGE: March 01, 2023
    JOURNAL FREE ACCESS

    The Magnetic Alloy loaded RF cavity using the material FT3L is expected to be an excellent technology to improve the performance of proton accelerators around the world. J-PARC is planning to replace the existing RF cavities by FT3L cavities. CERN is also planning to employ the FT3L cavities to replace old ferrite cavities in the PS booster ring for the LIU(LHC Injector Upgrade)project. The FT3L has better characteristics for RF cavity performance than ordinary magnetic alloy and ferrite materials. On the behalf of the J-PARC Ring RF group, I describe the history of developments, principle of cavity, characteristics of FT3L material and design of cavities.

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  • Ken WATANABE, Hitoshi HAYANO, Jyunji URAKAWA, Toshihiro MATSUMOTO, Mas ...
    2012Volume 9Issue 2 Pages 82-91
    Published: July 31, 2012
    Released on J-STAGE: March 01, 2023
    JOURNAL FREE ACCESS

    We report successful generation of 1 ms long pulse and multi-bunch electron beam by a normal conducting photocathode RF gun at KEK-STF (Superconducting accelerator Test Facility). The 1 ms long Pulse beam generated by the RF gun is delivered to the injection line to examine stable acceleration and precise RF control. The 1 ms pulse beam is also used to demonstrate high brightness X-ray generation by inverse laser Compton scattering which will be also carried out at STF, supported by MEXT Quantum Beam project. The RF gun cavity has been fabricated by DESY-FNAL-KEK collaboration. Performing high power RF process and ethanol rinse to the cavity, a stable operation of the cavity up to 4.0 MW RF input power with ~1 ms pulse length was achieved by keeping even low dark current. The beam generation test has been started since February 2012, 1 ms pulse was generated in March 2012. We explain about the STF injector and report the basic property of this 1 ms beam generation.

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  • Hiroyuki HAMA
    2012Volume 9Issue 2 Pages 92-98
    Published: July 31, 2012
    Released on J-STAGE: March 01, 2023
    JOURNAL FREE ACCESS

    Everyone living in Tohoku area was beaten both physically and psychologically due to the Tohoku Earthquake March 11, 2011, and recovery of the towns suffered the tsunami damage is not yet under way. An old accelerator facility in Electron Light Science Centre, Tohoku University suffered serious damage as well. A 46-year-old 300 MeV electron linac has gotten into malfunction. Though we gave up to recover the 300 MeV linac, the low energy part of the linac is going to be rebuilt. A small linac will be constructed as an injector for the booster ring. Because of limited budget, the upper bound of the beam energy will be 90 MeV. In addition, power supplies for a 1.2 GeV booster synchrotron that have mostly failed will be replaced.

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  • Takashi WAKUI, Masatoshi ITOH, Kenzi SHIMADA, Hidetomo YOSHIDA, Tsutom ...
    2012Volume 9Issue 2 Pages 99-107
    Published: July 31, 2012
    Released on J-STAGE: March 01, 2023
    JOURNAL FREE ACCESS

    The Great East Japan Earthquake has inflicted damages on the accelerator facility of the Cyclotron and Radioisotope Center(CYRIC), Tohoku University. The K=110 MeV cyclotron was slanted due to the damage of props supporting the cyclotron. The cyclotron building has also been slightly inclined. This situation requires the re-alignment of all the beam transport line and the cyclotron. Some of the shield doors at experimental rooms were broken and blocked the entrance. The earthquake caused also a lot of damages to some components of the cyclotron as well as the beam transport lines, such as beam ducts, magnets, vacuum pumps and power supplies. Fortunately, no one was injured at CYRIC. The restoration work was started on July 2011 and will be completed by July 2012. This report describes the situation of damages and the current status of the restoration work.

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