eeFACT2022 - List of Authors (Kobayashi, T.)

Paper	Title	Page
WEXAS0102	SuperKEKB Operating Experience of RF System at High Current	131
	M. Nishiwaki, T. Abe, K. Akai, S. Enomoto, T. Furuya, A. Kabe, T. Kageyama, T. Kobayashi, K. Marutsuka, S. Mitsunobu, Y. Morita, K. Nakanishi, S. Ogasawara, T. Okada, M. Ono, H. Sakai, Y. Takeuchi, K. Watanabe, Ma. Yoshida, S.I. Yoshimoto, K. Yoshino KEK, Ibaraki, Japan
	SuperKEKB aims for high luminosity on the order of 10³⁵ cm^-2s^-1 with high beam currents of 2.6 A for electron and 3.6 A for positron to search a new physics beyond the Standard Model in the B meson regime. In recent operations, we achieved new record of the luminosity of 4.7x10³⁴ cm^-2s^-1 with 1.1 A for electron and 1.3 A for positron. The RF system that is basically reused from KEKB is operating stably in the high current operation owing to the measures against to large beam power and HOM power. To cope with the large beam power, it has been increased the number of klystrons that drive only one normal conducting cavity (ARES) and reinforced the input couplers of ARES. As a measure against HOM power, the additional HOM dampers have been installed to superconducting cavities. One-third of LLRF control systems have been replaced with newly developed digital system to improve accuracy and flexibility. New damper system for coupled bunch instability expected in high current has been installed to new digital system. In this report, operation status of RF system under the high current operation will be presented.
	Slides WEXAS0102 [8.011 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-eeFACT2022-WEXAS0102
About •	Received ※ 28 November 2022 — Accepted ※ 07 February 2023 — Issue date ※ 15 February 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEZAS0202	SuperKEKB Beam Instabilities Challenges and Experience	202
	H. Ikeda, H. Fukuma, T. Kobayashi, T. Mimashi, T.M. Mitsuhashi, G. Mitsuka, S. Sasaki, M. Tobiyama KEK, Ibaraki, Japan
	KEKB was upgraded from 2011 over 5 years in order to increase the luminosity and started SuperKEKB commissioning in 2018 after the test operation. In order to cope with large beam currents and small beam sizes, various updates have been applied to the beam instrumentation system. This talk summarizes the performance of beam instrumentation in SuperKEKB Phase-III and challenges to it.
	Slides WEZAS0202 [7.068 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-eeFACT2022-WEZAS0202
About •	Received ※ 30 November 2022 — Revised ※ 03 February 2023 — Accepted ※ 08 February 2023 — Issue date ※ 13 February 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

SuperKEKB Operating Experience of RF System at High Current

131

M. Nishiwaki, T. Abe, K. Akai, S. Enomoto, T. Furuya, A. Kabe, T. Kageyama, T. Kobayashi, K. Marutsuka, S. Mitsunobu, Y. Morita, K. Nakanishi, S. Ogasawara, T. Okada, M. Ono, H. Sakai, Y. Takeuchi, K. Watanabe, Ma. Yoshida, S.I. Yoshimoto, K. Yoshino
KEK, Ibaraki, Japan

SuperKEKB aims for high luminosity on the order of 10³⁵ cm^-2s^-1 with high beam currents of 2.6 A for electron and 3.6 A for positron to search a new physics beyond the Standard Model in the B meson regime. In recent operations, we achieved new record of the luminosity of 4.7x10³⁴ cm^-2s^-1 with 1.1 A for electron and 1.3 A for positron. The RF system that is basically reused from KEKB is operating stably in the high current operation owing to the measures against to large beam power and HOM power. To cope with the large beam power, it has been increased the number of klystrons that drive only one normal conducting cavity (ARES) and reinforced the input couplers of ARES. As a measure against HOM power, the additional HOM dampers have been installed to superconducting cavities. One-third of LLRF control systems have been replaced with newly developed digital system to improve accuracy and flexibility. New damper system for coupled bunch instability expected in high current has been installed to new digital system. In this report, operation status of RF system under the high current operation will be presented.

Slides WEXAS0102 [8.011 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-eeFACT2022-WEXAS0102

About •

Received ※ 28 November 2022 — Accepted ※ 07 February 2023 — Issue date ※ 15 February 2023

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEZAS0202

SuperKEKB Beam Instabilities Challenges and Experience

202

H. Ikeda, H. Fukuma, T. Kobayashi, T. Mimashi, T.M. Mitsuhashi, G. Mitsuka, S. Sasaki, M. Tobiyama
KEK, Ibaraki, Japan

KEKB was upgraded from 2011 over 5 years in order to increase the luminosity and started SuperKEKB commissioning in 2018 after the test operation. In order to cope with large beam currents and small beam sizes, various updates have been applied to the beam instrumentation system. This talk summarizes the performance of beam instrumentation in SuperKEKB Phase-III and challenges to it.

Slides WEZAS0202 [7.068 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-eeFACT2022-WEZAS0202

About •

Received ※ 30 November 2022 — Revised ※ 03 February 2023 — Accepted ※ 08 February 2023 — Issue date ※ 13 February 2023

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)