Author: Futatsukawa, K.
Paper Title Page
TUPAK009 Muon Profile Measurement After Acceleration With a Radio-Frequency Quadrupole Linac 977
 
  • M. Otani, Y. Fukao, K. Futatsukawa, N. Kawamura, T. Mibe, Y. Miyake, T. Yamazaki
    KEK, Ibaraki, Japan
  • S. Bae, H. Choi, S. Choi, B. Kim, H.S. Ko
    SNU, Seoul, Republic of Korea
  • K. Hasegawa, Y. Kondo, T. Morishita
    JAEA/J-PARC, Tokai-mura, Japan
  • T. Iijima, Y. Sue
    Nagoya University, Graduate School of Science, Chikusa-ku, Nagoya, Japan
  • H. Iinuma, Y. Nakazawa
    Ibaraki University, Ibaraki, Japan
  • K. Ishida
    RIKEN Nishina Center, Wako, Japan
  • R. Kitamura
    University of Tokyo, Tokyo, Japan
  • S. Li
    The University of Tokyo, Graduate School of Science, Tokyo, Japan
  • G.P. Razuvaev
    Budker INP & NSU, Novosibirsk, Russia
  • N. Saito
    J-PARC, KEK & JAEA, Ibaraki-ken, Japan
  • E. Won
    Korea University, Seoul, Republic of Korea
 
  Funding: This work is supported by JSPS KAKENHI Grant Numbers JP15H03666, JP16H03987, and JP16J07784.
The E34 experiment aims to measure muon anomalous magnetic moment with a precision of 0.1ppm. The experiment utilizes low emittance muon beam with a muon linac to sweep out beam related uncertainties, which limit the g-2 precision in past experiments. A beam matching with precise beam measurements is required to avoid substantial emittance growth and satisfy the experimental requirement on the beam emittance of around 1.5 pi mm mrad. We conduct profile measurement of muon after acceleration with a radio-frequency quadrupole (RFQ) on December 2017 following a first muon acceleration experiment on October. In the experiment of profile measurement, epi-thermal negative muonium ions are generated by injecting surface muons to a thin metal foil. The muonium ions are accelerated to 5 keV. by an electro-static lens and accelerated to 90 keV by the RFQ. Then the muonium ions are transported to a profile detector consisting of a micro-channel plate and a ccd camera via a quadrupole pair and a bending magnet. In this poster, the experimental result and comparison to the simulation are reported.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAK009  
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WEPML051 Improvement of the Chopper System for rf Deflector at the J-PARC Linac 2816
 
  • K. Futatsukawa, Z. Fang, Y. Fukui
    KEK, Ibaraki, Japan
  • Y. Sato
    Nippon Advanced Technology Co., Ltd., Tokai, Japan
  • S. Shinozaki
    JAEA/J-PARC, Tokai-mura, Japan
 
  In the J-PARC linac, the RF deflector has been operated to kick the wasted beam and to shape the intermediate-pulse like the comb structure. Then about 50% of the beam current is removed by leading the scraper and the rest beam current is injected to the downstream synchrotron ring RCS. The fast rising time and falling time, the cavity with low loading Q value in the chopper system are required to decrease the incomplete kicked beam. However, there was the ringing of the RF field on the chopper cavity, and it influenced the beam rising time. The chopper controllers, which has the fast RF -switch to make the particular RF according to the intermediate-pulses, were improved for the RF falling time by outputting short pulses with inverting phase. The beam study for the new system was successfully done. In this paper, I would like to introduce this system and to show the results of the beam study.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPML051  
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FRXGBF1 Re-Acceleration of Ultra Cold Muon in J-PARC Muon Facility 5041
 
  • Y. Kondo, K. Hasegawa, T. Morishita
    JAEA/J-PARC, Tokai-mura, Japan
  • S. Bae, H. Choi, S. Choi, B. Kim, H.S. Ko
    SNU, Seoul, Republic of Korea
  • Y. Fukao, K. Futatsukawa, N. Kawamura, T. Mibe, Y. Miyake, M. Otani, K. Shimomura, T. Yamazaki, M. Yoshida
    KEK, Ibaraki, Japan
  • N. Hayashizaki
    RLNR, Tokyo, Japan
  • T. Iijima, Y. Sue
    Nagoya University, Graduate School of Science, Chikusa-ku, Nagoya, Japan
  • H. Iinuma, Y. Nakazawa
    Ibaraki University, Ibaraki, Japan
  • K. Ishida
    RIKEN Nishina Center, Wako, Japan
  • Y. Iwashita
    Kyoto ICR, Uji, Kyoto, Japan
  • Y. Iwata
    NIRS, Chiba-shi, Japan
  • R. Kitamura
    University of Tokyo, Tokyo, Japan
  • S. Li
    The University of Tokyo, Graduate School of Science, Tokyo, Japan
  • G.P. Razuvaev
    Budker INP & NSU, Novosibirsk, Russia
  • N. Saito
    J-PARC, KEK & JAEA, Ibaraki-ken, Japan
 
  Funding: This work is supported by JSPS KAKENHI Grant Numbers JP15H03666, JP16H03987, and JP16J07784.
J-PARC is developing the reacceleration system of the ultra slow (30 meV) muon (USM) obtained by two-photon laser resonant ionization of muonium atoms. The muon beam thus obtained has low emittance, meeting the requirement for the g-2/EDM experiment. J-PARC E34 experiment aims to measure the muon anomalous magnetic moment (g-2) with a precision of 0.1 ppm and search for EDM with a sensitivity to 10-21 e cm. The USM's are accelerated to 212 MeV by using a muon dedicated linac to be a ultra cold muon beam. The muon LINAC consists of an RFQ, a inter-digital H-mode DTL, disk and washer coupled cell structures, and disk loaded structures. The ultra-cold muons will have an extremely small transverse momentum spread of 0.1% with a normalized transverse emittance of around 1.5 pi mm-mrad. Proof of the slow muon acceleration scheme is an essential step to realize the world first muon linac. In October 2017, we have succeeded to accelerate slow negative muoniums generated using a simpler muonium source to 89 keV. In this talk, present design of the muon linac and the result of the world first muon acceleration experiment are reported.
 
slides icon Slides FRXGBF1 [8.378 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-FRXGBF1  
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