IPAC2021 - List of Authors (Yang, R.J.)

Paper	Title	Page
MOPAB231	Tunability Study of the Ultra-Low β* Optics at ATF2 with New Octupole Setup and Tuning Knobs	752
	A. Pastushenko, R. Tomás García CERN, Geneva, Switzerland A. Faus-Golfe Université Paris-Saclay, CNRS/IN2P3, IJCLab, Orsay, France K. Kubo, S. Kuroda, T. Naito, T. Okugi, N. Terunuma, R.J. Yang KEK, Ibaraki, Japan
	The main goal of the Accelerator Test Facility 2 (ATF2) is to demonstrate the feasibility of future linear colliders’ final focus systems. The Ultra-low β^* optics of ATF2 is designed to have the same chromaticity level as CLIC. To ease the tuning procedure, a pair of octupoles was installed in ATF2 in 2017. This paper reports the optimizations performed to the octupoles’ setup for Ultra-low β^* optics including the new alignment technique, based on the waist shift and the new tunning knobs constructed for this optics. The full tuning procedure including the static errors is simulated for this setup.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB231
About •	paper received ※ 19 May 2021 paper accepted ※ 28 July 2021 issue date ※ 12 August 2021
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TUPAB009	SuperKEKB Optics Measurements Using Turn-by-Turn Beam Position Data	1352
	J. Keintzel, R. Tomás García CERN, Geneva, Switzerland H. Koiso, G. Mitsuka, A. Morita, K. Ohmi, Y. Ohnishi, H. Sugimoto, M. Tobiyama, R.J. Yang KEK, Ibaraki, Japan
	SuperKEKB, an asymmetric electron-positron collider, has recently achieved the world record instantaneous luminosity of 2.8 × 10³⁴ \si{cm^-2s^-1} using crab-waist collision scheme. In order to reach the design value of 6×10³⁵ \si{cm^-2s^-1} a vertical beta function at the interaction point of §I{0.3}{mm} is required, demanding unprecedented optics control. Turn-by-turn beam position data could enable fast optics measurements for rapid identification of unexpected error sources. Experiments exploring various data acquisition techniques at different squeezing steps during commissioning are presented and compared to results obtained from closed orbit distortion.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB009
About •	paper received ※ 18 May 2021 paper accepted ※ 10 June 2021 issue date ※ 24 August 2021
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAB010	Impact of Bunch Current on Optics Measurements in SuperKEKB	1356
	J. Keintzel, R. Tomás García, F. Zimmermann CERN, Geneva, Switzerland T. Ishibashi, H. Koiso, G. Mitsuka, A. Morita, K. Ohmi, Y. Ohnishi, H. Sugimoto, S. Terui, M. Tobiyama, R.J. Yang, D. Zhou KEK, Ibaraki, Japan
	SuperKEKB has recently achieved the world record instantaneous luminosity of 2.8 × 10³⁴ \si{cm^-2s^-1} and aims at reaching a target luminosity of about 6 × 10³⁵ \si{cm^-2s^-1}. To accomplish this goal it is planned to increase beam currents up to §I{3.6}{A} and §I{2.6}{A} for the positron and the electron ring, respectively. Increasing the beam currents and, in particular, the number of leptons per bunch, can impact the optics parameters obtained by turn-by-turn measurements, such as the betatron tune or phase advance. Optics measurements performed at various bunch currents can give first indications of possible intensity dependent effects. In this paper, the effect of varying bunch current on optics measurements at SuperKEKB is explored.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB010
About •	paper received ※ 18 May 2021 paper accepted ※ 10 June 2021 issue date ※ 30 August 2021
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Tunability Study of the Ultra-Low β* Optics at ATF2 with New Octupole Setup and Tuning Knobs

752

A. Pastushenko, R. Tomás García
CERN, Geneva, Switzerland
A. Faus-Golfe
Université Paris-Saclay, CNRS/IN2P3, IJCLab, Orsay, France
K. Kubo, S. Kuroda, T. Naito, T. Okugi, N. Terunuma, R.J. Yang
KEK, Ibaraki, Japan

The main goal of the Accelerator Test Facility 2 (ATF2) is to demonstrate the feasibility of future linear colliders’ final focus systems. The Ultra-low β^* optics of ATF2 is designed to have the same chromaticity level as CLIC. To ease the tuning procedure, a pair of octupoles was installed in ATF2 in 2017. This paper reports the optimizations performed to the octupoles’ setup for Ultra-low β^* optics including the new alignment technique, based on the waist shift and the new tunning knobs constructed for this optics. The full tuning procedure including the static errors is simulated for this setup.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB231

About •

paper received ※ 19 May 2021 paper accepted ※ 28 July 2021 issue date ※ 12 August 2021

Export •

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

TUPAB009

SuperKEKB Optics Measurements Using Turn-by-Turn Beam Position Data

1352

J. Keintzel, R. Tomás García
CERN, Geneva, Switzerland
H. Koiso, G. Mitsuka, A. Morita, K. Ohmi, Y. Ohnishi, H. Sugimoto, M. Tobiyama, R.J. Yang
KEK, Ibaraki, Japan

SuperKEKB, an asymmetric electron-positron collider, has recently achieved the world record instantaneous luminosity of 2.8 × 10³⁴ \si{cm^-2s^-1} using crab-waist collision scheme. In order to reach the design value of 6×10³⁵ \si{cm^-2s^-1} a vertical beta function at the interaction point of §I{0.3}{mm} is required, demanding unprecedented optics control. Turn-by-turn beam position data could enable fast optics measurements for rapid identification of unexpected error sources. Experiments exploring various data acquisition techniques at different squeezing steps during commissioning are presented and compared to results obtained from closed orbit distortion.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB009

About •

paper received ※ 18 May 2021 paper accepted ※ 10 June 2021 issue date ※ 24 August 2021

Export •

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

TUPAB010

Impact of Bunch Current on Optics Measurements in SuperKEKB

1356

J. Keintzel, R. Tomás García, F. Zimmermann
CERN, Geneva, Switzerland
T. Ishibashi, H. Koiso, G. Mitsuka, A. Morita, K. Ohmi, Y. Ohnishi, H. Sugimoto, S. Terui, M. Tobiyama, R.J. Yang, D. Zhou
KEK, Ibaraki, Japan

SuperKEKB has recently achieved the world record instantaneous luminosity of 2.8 × 10³⁴ \si{cm^-2s^-1} and aims at reaching a target luminosity of about 6 × 10³⁵ \si{cm^-2s^-1}. To accomplish this goal it is planned to increase beam currents up to §I{3.6}{A} and §I{2.6}{A} for the positron and the electron ring, respectively. Increasing the beam currents and, in particular, the number of leptons per bunch, can impact the optics parameters obtained by turn-by-turn measurements, such as the betatron tune or phase advance. Optics measurements performed at various bunch currents can give first indications of possible intensity dependent effects. In this paper, the effect of varying bunch current on optics measurements at SuperKEKB is explored.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB010

About •

paper received ※ 18 May 2021 paper accepted ※ 10 June 2021 issue date ※ 30 August 2021

Export •

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