IBIC2018 - List of Authors (Tobiyama, M.)

Paper	Title	Page
MOOB01	Beam Commissioning of SuperKEKB Rings at Phase-2	6
	M. Tobiyama, M. Arinaga, J.W. Flanagan, H. Fukuma, H. Ikeda, H. Ishii, S.H. Iwabuchi, G.M. Mitsuka, K. Mori, M. Tejima KEK, Ibaraki, Japan G. Bonvicini Wayne State University, Detroit, Michigan, USA E. Mulyani Sokendai, Ibaraki, Japan G.S. Varner University of Hawaii, Honolulu,, USA
	The Phase 2 commissioning of SuperKEKB rings with Belle II detector began in Feb. 2018. Staring the commissioning of positron damping ring (DR), the injection and storage of the main rings (HER and LER) smoothly continued in Apr., 2018. The first collision has been achieved on 26th Apr. with the detuned optics (200 mm x 8 mm). Performance of beam instrumentation systems and the difficulties encountered during commissioning time will be shown.
	Slides MOOB01 [11.232 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2018-MOOB01
About •	paper received ※ 05 September 2018 paper accepted ※ 11 September 2018 issue date ※ 29 January 2019
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MOPA02	Beam Diagnostics for SuperKEKB Damping Ring in Phase-II Operation	29
	H. Ikeda, M. Arinaga, J.W. Flanagan, H. Fukuma, H. Ishii, S.H. Iwabuchi, G.M. Mitsuka, K. Mori, M. Tejima, M. Tobiyama KEK, Ibaraki, Japan
	The SuperKEKB damping ring (DR) commissioning started in February 2018, before main ring (MR) Phase-II operation. We constructed the DR in order to deliver a low-emittance positron beam. The design luminosity of SuperKEKB is 40 times that of KEKB with high current and low emittance. A turn-by- turn beam position monitor (BPM), transverse feedback system, synchrotron radiation monitor (SRM), DCCT, loss monitor using ion chambers, bunch current monitor and tune meter were installed for beam diagnostics at the DR. An overview of the instrumentation and status will be presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2018-MOPA02
About •	paper received ※ 05 September 2018 paper accepted ※ 14 September 2018 issue date ※ 29 January 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPC13	Early Commissioning of the Luminosity Dither Feedback for SuperKEKB	328
	M. Masuzawa, Y. Funakoshi, T. Kawamoto, S. Nakamura, T. Oki, M. Tobiyama, S. Uehara KEK, Ibaraki, Japan P. Bambade, S. Di Carlo, D. Jehanno, C.G. Pang LAL, Orsay, France D.G. Brown, A.S. Fisher, M.K. Sullivan SLAC, Menlo Park, California, USA D. El Khechen CERN, Geneva, Switzerland U. Wienands ANL, Argonne, Illinois, USA
	SuperKEKB is an electron-positron collider, which aims to achieve a peak luminosity of 8×10³⁵ cm^-2 s⁻¹ using what is known as the "nano-beam" scheme. This paper reports on the commissioning and performance of a luminosity dither feedback. The system, based on one previously used at SLAC for PEP-II, is employed for collision orbit feedback in the horizontal plane. Twelve air-core Helmholtz coils drive the positron beam sinusoidally at a frequency near 80 Hz, forming a closed bump at the interaction point. A lock-in amplifier detects the amplitude and phase of the corresponding frequency component of the luminosity signal. When the beams are aligned for peak luminosity, the magnitude of the luminosity component at the dithering frequency becomes zero. The magnitude grows as the beams are offset, and the phase shifts by 180 degrees when the direction of the necessary correction reverses. The hardware and algorithm were tested during SuperKEKB Phase II run. The electron beam orbit was successfully adjusted to minimize the amplitude of the dither frequency component of the luminosity signal, and the optimal condition was maintained by continuously adjusting the electron beam orbit.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2018-TUPC13
About •	paper received ※ 09 September 2018 paper accepted ※ 10 September 2018 issue date ※ 29 January 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Beam Commissioning of SuperKEKB Rings at Phase-2

6

M. Tobiyama, M. Arinaga, J.W. Flanagan, H. Fukuma, H. Ikeda, H. Ishii, S.H. Iwabuchi, G.M. Mitsuka, K. Mori, M. Tejima
KEK, Ibaraki, Japan
G. Bonvicini
Wayne State University, Detroit, Michigan, USA
E. Mulyani
Sokendai, Ibaraki, Japan
G.S. Varner
University of Hawaii, Honolulu,, USA

The Phase 2 commissioning of SuperKEKB rings with Belle II detector began in Feb. 2018. Staring the commissioning of positron damping ring (DR), the injection and storage of the main rings (HER and LER) smoothly continued in Apr., 2018. The first collision has been achieved on 26th Apr. with the detuned optics (200 mm x 8 mm). Performance of beam instrumentation systems and the difficulties encountered during commissioning time will be shown.

Slides MOOB01 [11.232 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2018-MOOB01

About •

paper received ※ 05 September 2018 paper accepted ※ 11 September 2018 issue date ※ 29 January 2019

Export •

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

MOPA02

Beam Diagnostics for SuperKEKB Damping Ring in Phase-II Operation

29

H. Ikeda, M. Arinaga, J.W. Flanagan, H. Fukuma, H. Ishii, S.H. Iwabuchi, G.M. Mitsuka, K. Mori, M. Tejima, M. Tobiyama
KEK, Ibaraki, Japan

The SuperKEKB damping ring (DR) commissioning started in February 2018, before main ring (MR) Phase-II operation. We constructed the DR in order to deliver a low-emittance positron beam. The design luminosity of SuperKEKB is 40 times that of KEKB with high current and low emittance. A turn-by- turn beam position monitor (BPM), transverse feedback system, synchrotron radiation monitor (SRM), DCCT, loss monitor using ion chambers, bunch current monitor and tune meter were installed for beam diagnostics at the DR. An overview of the instrumentation and status will be presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2018-MOPA02

About •

paper received ※ 05 September 2018 paper accepted ※ 14 September 2018 issue date ※ 29 January 2019

Export •

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

TUPC13

Early Commissioning of the Luminosity Dither Feedback for SuperKEKB

328

M. Masuzawa, Y. Funakoshi, T. Kawamoto, S. Nakamura, T. Oki, M. Tobiyama, S. Uehara
KEK, Ibaraki, Japan
P. Bambade, S. Di Carlo, D. Jehanno, C.G. Pang
LAL, Orsay, France
D.G. Brown, A.S. Fisher, M.K. Sullivan
SLAC, Menlo Park, California, USA
D. El Khechen
CERN, Geneva, Switzerland
U. Wienands
ANL, Argonne, Illinois, USA

SuperKEKB is an electron-positron collider, which aims to achieve a peak luminosity of 8×10³⁵ cm^-2 s⁻¹ using what is known as the "nano-beam" scheme. This paper reports on the commissioning and performance of a luminosity dither feedback. The system, based on one previously used at SLAC for PEP-II, is employed for collision orbit feedback in the horizontal plane. Twelve air-core Helmholtz coils drive the positron beam sinusoidally at a frequency near 80 Hz, forming a closed bump at the interaction point. A lock-in amplifier detects the amplitude and phase of the corresponding frequency component of the luminosity signal. When the beams are aligned for peak luminosity, the magnitude of the luminosity component at the dithering frequency becomes zero. The magnitude grows as the beams are offset, and the phase shifts by 180 degrees when the direction of the necessary correction reverses. The hardware and algorithm were tested during SuperKEKB Phase II run. The electron beam orbit was successfully adjusted to minimize the amplitude of the dither frequency component of the luminosity signal, and the optimal condition was maintained by continuously adjusting the electron beam orbit.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2018-TUPC13

About •

paper received ※ 09 September 2018 paper accepted ※ 10 September 2018 issue date ※ 29 January 2019

Export •

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