Author: Toyama, T.
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TUPP021 Development of 16 Electrodes Beam-size Monitors for J-PARC MR 342
  • M. Tajima, T. Nakaya
    Kyoto University, Kyoto, Japan
  • T. Koseki, T. Toyama
    KEK, Tokai, Ibaraki, Japan
  For J-PARC, 16 electrodes beam-monitors are developed. It is possible to measure the transverse moments of beams from the induced voltages. A beam size is calculated from these in two locations with different values of beta functions. Beam-monitors such as a Flying Wire Monitor and an Ionization Profile Monitor (IPM) are already installed. However, the two monitors have issues in measuring higher intensity beams. The former is that the wire gets easily burned out and the latter is that there is a sign of the saturation by a space charge effect. Therefore, these aim at measuring the sizes of high intensity proton beams up to 4.2·10+13 protons/bunch, which corresponds to 1.3 MW in 1.16 s cycle operation of the MR. Furthermore, with high accuracy measurements, the injection mismatch from the RCS is to be decreased. In the beam test in February 2019, the signal-noise ratio (SNR) of this monitor in bunch-by-bunch measurements was nearly 40 dB and lower than the SNR > 50 dB which is comparable to IPM. To improve the SNR, we developed new LPFs for anti-aliasing and improved signal processing. In addition, the second monitor will be installed in August 2019 and tested with beams in November.  
DOI • reference for this paper ※  
About • paper received ※ 04 September 2019       paper accepted ※ 09 September 2019       issue date ※ 10 November 2019  
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WEPP007 Calibration for Beam Energy Position Monitor System for Riken Superconducting Acceleration Cavity 519
  • T. Watanabe, M. Fujimaki, N. Fukunishi, H. Imao, O. Kamigaito, N. Sakamoto, Y. Watanabe, K. Yamada
    RIKEN Nishina Center, Wako, Japan
  • K. Hanamura, T. Kawachi
    Mitsubishi Electric System & Service Co., Ltd, Tsukuba, Japan
  • A. Kamoshida
    National Instruments Japan Corporation, MInato-ku, Tokyo, Japan
  • R. Koyama
    SHI Accelerator Service Ltd., Tokyo, Japan
  • A. Miura
    JAEA/J-PARC, Tokai-mura, Japan
  • T. Miyao, T. Toyama
    KEK, Tokai, Ibaraki, Japan
  Upgrades for the RIKEN Heavy-ion Linac (RILAC) involving a new Superconducting Linac (SRILAC) are currently underway to promote super-heavy element searches and Radio Isotope (RI) production (211At) for medical use at the RIKEN radioactive isotope beam factory (RIBF). If destructive monitors are used, since they generate outgassing, it becomes difficult to maintain the Q value and surface resistance indicating the performance of the superconducting radio frequency (SRF) cavities over a long period of time. Therefore it is crucially important to develop nondestructive beam measurement diagnostics. We have developed a beam energy position monitor (BEPM) system which can measure not only the beam position but also the beam energy simultaneously by measuring the time of flight of the beam. By using parabolic cut, ideal linear response of the quadrupole moments is realized, keeping a good linear position sensitivity at the same time. We fabricated 11 BEPMs and the position calibration system employing a wire method has been used to obtain the sensitivity and offset of BEPMs. We will describe details concerning the BEPM, calibration system and measured results.  
DOI • reference for this paper ※  
About • paper received ※ 05 September 2019       paper accepted ※ 10 September 2019       issue date ※ 10 November 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)