Author: Seimiya, Y.
Paper Title Page
MOPLXGD1 The SuperKEKB Has Broken the World Record of the Luminosity 1
 
  • Y. Funakoshi, T. Abe, K. Akai, Y. Arimoto, K. Egawa, S. Enomoto, H. Fukuma, K. Furukawa, N. Iida, H. Ikeda, T. Ishibashi, S.H. Iwabuchi, H. Kaji, T. Kamitani, T. Kawamoto, M. Kikuchi, T. Kobayashi, K. Kodama, H. Koiso, M. Masuzawa, K. Matsuoka, T. Mimashi, G. Mitsuka, F. Miyahara, T. Miyajima, T. Mori, A. Morita, S. Nakamura, T.T. Nakamura, K. Nakanishi, H.N. Nakayama, M. Nishiwaki, S. Ogasawara, K. Ohmi, Y. Ohnishi, N. Ohuchi, T. Okada, T. Oki, M.A. Rehman, Y. Seimiya, K. Shibata, Y. Suetsugu, H. Sugimoto, H. Sugimura, M. Tawada, S. Terui, M. Tobiyama, R. Ueki, X. Wang, K. Watanabe, S.I. Yoshimoto, T. Yoshimoto, D. Zhou, X. Zhou, Z.G. Zong
    KEK, Ibaraki, Japan
  • A. Natochii
    University of Hawaii, Honolulu,, USA
  • K. Oide
    CERN, Meyrin, Switzerland
  • R.J. Yang
    CAEP/IAE, Mianyang, Sichuan, People’s Republic of China
  • K. Yoshihara
    Nagoya University, Nagoya, Aichi, Japan
 
  The SuperKEKB broke the world record of the luminosity in June 2020 in the Phase 3 operation. The luminosity has been increasing since then and the present highest luminosity is 4.65 x 1034 cm-2s-1 with βy* of 1 mm. The increase of the luminosity was brought with an application of crab waist, by increasing beam currents and by other improvements in the specific luminosity. In this paper, we describe what we have achieved and what we are struggling with. Finally, we mention a future plan briefly.  
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DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPLXGD1  
About • Received ※ 10 June 2022 — Accepted ※ 08 July 2022 — Issue date ※ 10 July 2022  
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WEPOPT023 A Design of ILC E-Driven Positron Source 1889
 
  • M. Kuriki, S. Konno, Z.J. Liptak
    HU/AdSM, Higashi-Hiroshima, Japan
  • M.K. Fukuda, T. Omori, Y. Seimiya, J. Urakawa, K. Yokoya
    KEK, Ibaraki, Japan
  • S. Kashiwagi
    Tohoku University, Research Center for Electron Photon Science, Sendai, Japan
  • H. Tajino
    HU ADSE, Hiroshima, Japan
  • T. Takahashi
    Hiroshima University, Graduate School of Science, Higashi-Hiroshima, Japan
 
  ILC is an electron-positron linear collider based on Superconducting linear accelerator. Linear collider is an only solution to realinze high energy electron-positron collision beyond the limit of synchrotron radiation energy loss by ring colliders. Beam current of injector of linear colliders is much larger than that of ring colliders because the beam is not reusable. Providing an enough amount of particles, especially positron is a technical issue. In this article, we present a design of electron driven positron source for ILC. After optimizations, the system design is established with an enough technical margin, e.g. avoiding potential damage on the production target.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOPT023  
About • Received ※ 20 May 2022 — Revised ※ 11 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 23 June 2022
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WEPOPT024 Beam Loading Compensation of Standing Wave Linac with Off-Crest Acceleration 1893
 
  • M. Kuriki, S. Konno, Z.J. Liptak
    HU/AdSM, Higashi-Hiroshima, Japan
  • M.K. Fukuda, T. Omori, Y. Seimiya, J. Urakawa, K. Yokoya
    KEK, Ibaraki, Japan
  • S. Kashiwagi
    Tohoku University, Research Center for Electron Photon Science, Sendai, Japan
  • H. Tajino
    HU ADSE, Hiroshima, Japan
  • T. Takahashi
    Hiroshima University, Graduate School of Science, Higashi-Hiroshima, Japan
 
  In E-Driven positron source of ILC, the generated positron is captured by a standing wave cavity. Because the deceleration capture method is employed, the positron is off-crest over the linac. Because the beam-loading is expected to be more than 1A in a multi-bunch format, the compensation is essential to obtain uniform intensity over the pulse. A conventional method for the compensation controlling the timing doesn’t work because RF and Beam induced field are in different phase. In this manuscript, we discuss the compensation with the off-crest acceleration case. A simple phase modulation on the input RF is a solution.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOPT024  
About • Received ※ 20 May 2022 — Revised ※ 10 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 16 June 2022
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WEPOPT025 Flat Beam Generation with the Phase Space Rotation Technique at KEK-STF 1897
 
  • M. Kuriki, Z.J. Liptak
    HU/AdSM, Higashi-Hiroshima, Japan
  • S. Aramoto
    Hiroshima University, Higashi-Hiroshima, Japan
  • H. Hayano, X.J. Jin, Y. Seimiya, N. Yamamoto, Y. Yamamoto
    KEK, Ibaraki, Japan
  • S. Kashiwagi
    Tohoku University, Research Center for Electron Photon Science, Sendai, Japan
  • K. Sakaue
    The University of Tokyo, Graduate School of Engineering, Bunkyo, Japan
  • M. Washio
    RISE, Tokyo, Japan
 
  Flat beam generation from angular momentum dominated beam with a phase-space rotation technique is an unique method to manipulate the phase-space distribution of beam. As an application, the asymmetric emittance beam generation for linear colliders is considered to compensate the Beamstrahlung effect at Interaction point. By using this technique, the asymmetric beam can be generated directly with the injector, instead of radiation damping with a huge damping ring. We present the result of a proof-of-principle experiment at KEK-STF.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOPT025  
About • Received ※ 07 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 23 June 2022
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THPOST012 Achievement of 200, 000 Hours of Operation at KEK 7-GeV Electron 4-GeV Positron Injector Linac 2465
 
  • K. Furukawa, M. Akemoto, D.A. Arakawa, Y. Arakida, H. Ego, Y. Enomoto, T. Higo, H. Honma, N. Iida, K. Kakihara, T. Kamitani, H. Katagiri, M. Kawamura, S. Matsumoto, T. Matsumoto, H. Matsushita, K. Mikawa, T. Miura, F. Miyahara, H. Nakajima, T. Natsui, Y. Ogawa, S. Ohsawa, Y. Okayasu, T. Oogoe, M.A. Rehman, I. Satake, M. Satoh, Y. Seimiya, T. Shidara, A. Shirakawa, H. Someya, T. Suwada, M. Tanaka, D. Wang, Y. Yano, K. Yokoyama, M. Yoshida, T. Yoshimoto, R. Zhang, X. Zhou
    KEK, Ibaraki, Japan
  • Y. Bando
    Sokendai, Ibaraki, Japan
 
  KEK electron positron injector linac initiated the injection operation into Photon Factory (PF) light source in 1982. Since then for 39 years, it has served for multiple projects, namely, TRISTAN, PF-AR, KEKB, and SuperKEKB. Its total operation time has accumulated 200 thousand hours on May 7, 2020. We are extremely proud of the achievement following continuous efforts by our seniors. The construction of the injector linac started in 1978, and it was commissioned for PF with 2.5 GeV electron in 1982. In parallel, the positron generator linac was constructed for the TRISTAN collider project. The slow positron facility was also commissioned in 1992. After the KEKB asymmetric-energy collider project was commissioned in 1998 with direct energy injections, the techniques such as two-bunch acceleration and simultaneous injection were developed. As the soft structure design of the linac was too weak against the great east Japan earthquake, it took three years to recover. Then the construction and commissioning for the SuperKEKB project went on, and the simultaneous top-up injection into four storage rings contributes to the both elementary particle physics and photon science.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOST012  
About • Received ※ 20 May 2022 — Revised ※ 15 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 08 July 2022
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