Author: Egawa, K.
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.  
slides icon Slides MOPLXGD1 [6.235 MB]  
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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TUOZSP2
Chromatic X-Y Coupling Correction by Tilting Sextupole Magnets in the SuperKEKB Positron Ring  
 
  • M. Masuzawa, K. Egawa, Y. Funakoshi, T. Kawamoto, H. Koiso, A. Morita, S. Nakamura, K. Ohmi, Y. Ohnishi, R. Sugahara, H. Sugimoto, R. Ueki, D. Zhou
    KEK, Ibaraki, Japan
  • K. Oide
    CERN, Meyrin, Switzerland
 
  Chromatic x-y coupling correction at the interaction point was carried out using skew sextupole field created by tilting the sextupole magnets in the SuperKEKB positron ring. Twenty four sextupole magnets are mounted on a tilting table and their tilt angles can be varied form - 30 degree to + 30 degree remotely to control the ratio of the skew to normal sextupole magnetic field components. In the 2021c run, one of the chromatic coupling parameters was varied using different setups of the tilting angles of the 24 sextupole magnets for the first time in a collider. It was found that the emittance growth at the primary (nux-nuy-nus=n) and secondary (nux-nuy-2nus=n) synchro-beta resonance lines can be controlled by tilting the sextupole magnets. Luminosity increase followed after optimizing the chromatic coupling parameters and finding a better tune working point. The study results are summarized in the paper.  
slides icon Slides TUOZSP2 [19.499 MB]  
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