Author: Shobuda, Y.
Paper Title Page
MOIPI1 1 MW J-PARC RCS Beam Operation and Further Beyond 1
 
  • H. Hotchi
    KEK, Tokai, Ibaraki, Japan
  • H. Harada, N. Hayashi, M. Kinsho, K. Okabe, P.K. Saha, Y. Shobuda, F. Tamura, K. Yamamoto, M. Yamamoto, M. Yoshimoto
    JAEA/J-PARC, Tokai-mura, Japan
 
  The J-PARC RCS have recently established a 1 MW beam operation with low fractional beam loss of the order of 10-3. In this talk, our approaches to beam loss issues that we faced in the course of beam power ramp-up are reviewed. Our recent efforts to further beam power ramp-up beyond 1 MW are also presented.  
slides icon Slides MOIPI1 [2.210 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-HB2021-MOIPI1  
About • Received ※ 04 October 2021 — Revised ※ 18 October 2021 — Accepted ※ 10 November 2021 — Issue date ※ 22 November 2021
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THAC1 Beam Instability Issue and Transverse Feedback System in the MR of J-PARC 208
 
  • T. Toyama, A. Kobayashi, T. Nakamura, M. Okada, M. Tobiyama
    KEK, Ibaraki, Japan
  • Y. Shobuda
    JAEA/J-PARC, Tokai-mura, Japan
 
  In the J-PARC MR, according to the beam power upgrade over 100 kW, beam losses due to transverse collective beam instabilities had started to appear. We had introduced "bunch-by-bunch feedback" system in 2010. Continuing beam power upgrade over 250 kW again caused the transverse instabilities. We introduced "intra-bunch feedback" system in 2014. This has been suppressing those instabilities very effectively. But further beam power upgrade over 500 kW (2.6·10+14 ppp, 8 bunches) needs upgrade of "intra-bunch feedback" system. The current understanding of the transverse instabilities in the MR and the effect of the feedback system are presented from the view points of simplified simulation without the space charge effect and measurements. We are upgrading the system in two steps. The first step is "time-interleaved sampling and kicking" with two feedback systems. The second step is getting the sampling rate twice as much as the current rate, ~110 MHz. Details are explained using simulation.  
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slides icon Slides THAC1 [4.347 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-HB2021-THAC1  
About • Received ※ 07 October 2021 — Revised ※ 28 October 2021 — Accepted ※ 22 November 2021 — Issue date ※ 07 January 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)