IPAC2016 - List of Authors (Ohnishi, Y.)

Paper	Title	Page
MOPMB006	First Tests of SuperKEKB Luminosity Monitors during 2016 Single Beam Commissioning	81
SUPSS067	use link to see paper's listing under its alternate paper code
	D. El Khechen, P. Bambade, A. Blin, P. Cornebise, D. Jehanno, V. Kubytskyi, Y. Peinaud, C. Rimbault LAL, Orsay, France Y. Funakoshi, Y. Ohnishi, S. Uehara KEK, Ibaraki, Japan
	The SuperKEKB e⁺e⁻ collider aims to reach a very high luminosity of 8 10³⁵ cm^-2s⁻¹, using highly focused ultra-low emittance bunches colliding every 4ns. Fast luminosity monitoring is required for luminosity feedback and optimisation in presence of dynamic imperfections. The aimed relative precision is about 10^-3 in 1ms, which can be in principle achieved thanks to the very large cross-section of the radiative Bhabha process at zero degree scattering angle. Diamond, Cherenkov and scintillator sensors are to be placed just outside the beam pipe, downstream of the interaction point in both rings, at locations with event rates consistent with the aimed precision and small enough backgrounds from single-beam particle losses. The initial configuration installed for the 2016 "phase 1" single beam commissioning will be described, including the sensors, mechanical setup, readout electronics and first stage DAQ. Preliminary measurements and analysis of beam gas Bremsstrahlung loss data collected with the luminosity monitors will be reported and compared with a detailed simulation, for several experimental conditions during the SuperKEKB commissioning.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMB006
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TUOBA01	Beam Commissioning of SuperKEKB	1019
	Y. Funakoshi, T. Abe, T. Adachi, K. Akai, Y. Arimoto, K. Egawa, Y. Enomoto, J.W. Flanagan, H. Fukuma, K. Furukawa, N. Iida, H. Iinuma, H. Ikeda, T. Ishibashi, M. Iwasaki, T. Kageyama, H. Kaji, T. Kamitani, T. Kawamoto, S. Kazama, M. Kikuchi, T. Kobayashi, K. Kodama, H. Koiso, M. Masuzawa, T. Mimashi, T. Miura, F. Miyahara, T. Mori, A. Morita, S. Nakamura, T.T. Nakamura, H. Nakayama, T. Natsui, M. Nishiwaki, K. Ohmi, Y. Ohnishi, T. Oki, S. Sasaki, M. Satoh, Y. Seimiya, K. Shibata, M. Suetake, Y. Suetsugu, H. Sugimoto, M. Tanaka, M. Tawada, S. Terui, M. Tobiyama, S. Uehara, S. Uno, X. Wang, K. Watanabe, Y. Yano, S.I. Yoshimoto, R. Zhang, D. Zhou, X. Zhou, Z.G. Zong KEK, Ibaraki, Japan D. El Khechen LAL, Orsay, France
	In this report, we describe the machine operation in the first 3 months of the Phase 1 commissioning of SuperKEKB. The beam commissioning is smoothly going on. Vacuum scrubbing, the optics corrections and others are described.
	Slides TUOBA01 [9.346 MB]
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUOBA01
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WEPOY040	Lattice Translation Between Accelerator Simulation Codes for Superkekb	3077
	D. Zhou, H. Koiso, A. Morita, Y. Ohnishi, K. Oide, H. Sugimoto KEK, Ibaraki, Japan M.E. Biagini INFN/LNF, Frascati (Roma), Italy N. Carmignani, S.M. Liuzzo ESRF, Grenoble, France D. Sagan Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
	To improve collaborative studies on beam dynamics for SuperKEKB between several labs, efforts have been made to translate the SAD lattices of SuperKEKB rings to the versions for other codes: AT, Bmad, MAD-X, and PTC. It turns out that lattice translations between these codes are not straightforward because of the complexity of the SuperKEKB lattices. In this paper, we describe our experiences of lattice translations, and present some results of benchmarks for the case of SuperKEKB.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPOY040
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THPOR007	Optics Measurements and Corrections at the Early Commissioning of SuperKEKB	3782
	Y. Ohnishi, Y. Funakoshi, H. Koiso, A. Morita, K. Ohmi, K. Oide, H. Sugimoto, D. Zhou KEK, Ibaraki, Japan M.E. Biagini, M. Boscolo, S. Guiducci INFN/LNF, Frascati (Roma), Italy N. Carmignani, S.M. Liuzzo ESRF, Grenoble, France
	We present experimental results of measurements and corrections of the optics at the early Phase-1 commissioning of SuperKEKB which is a positron-electron collider built to achieve the target luminosity of 8x10³⁵ cm^-2s^-1. We have three stages; the Phase-1 is the commissioning of the machine without the final focus magnets and detector solenoid(no collision); the collision with the final focus system and the Belle II detector will be performed at the Phase-2 and Phase-3. The strategy for the luminosity upgrade is a novel "nano-beam'' scheme found elsewhere. In order to achieve the target luminosity, the vertical emittance has to be reduced by corrections of machine error measured by orbit responses. The vertical emittance should be achieved to be less than 6 pm(0.2 % coupling) during the Phase-1 by fully utilizing correction tools of skew quadrupole-like coils wound on sextupole magnets and power supplies for each correction coil in quadrupole magnets. In addition to the linear optics, the optics for off-momentum particles is also studied to understand a dynamic aperture affects the Touschek lifetime. "SuperB Conceptual Design Report", INFN/AE-07/2, SLAV-R-856, LAL 07-15, (2007).
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR007
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THPOR040	Emittance Growth by Misalignments and Jitters in SuperKEKB Injector Linac	3871
	Y. Seimiya, Y. Enomoto, K. Furukawa, T. Higo, T. Kamitani, F. Miyahara, Y. Ohnishi, M. Satoh, T. Suwada, M. Tanaka KEK, Ibaraki, Japan
	Funding: This work was partly supported by JSPS KAKENHI Grant Number 16K17545. SuperKEKB injector linac have to transport high-charged beam with low emittance to SuperKEKB ring for high luminosity, 8¥times10³⁵. For the low emittance, photocathode RF gun was adopted as electron source. One of the main reason of the beam emittance blow-up electron linac is generally induced by wakefield in acceleration cavities. A charged beam with a offset from a center of a cavity is affected by the wakefield depending on the offset size in the acceleration cavity and the beam emittance is increased. This emittance blow-up can be eliminated by appropriate steering magnet control so as to cancel the wake effect in the acceleration cavity. We perform particle tracking simulation with some misalignments and beam jitter. Emittance growth by the misalignments and the beam jitter is evaluated in this report.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR040
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THPOY027	Commissioning Status of SuperKEKB Injector Linac	4152
	M. Satoh, M. Akemoto, D.A. Arakawa, Y. Arakida, A. Enomoto, Y. Enomoto, S. Fukuda, Y. Funakoshi, K. Furukawa, T. Higo, H. Honma, N. Iida, M. Ikeda, H. Iwase, H. Kaji, K. Kakihara, T. Kamitani, H. Katagiri, S. Kazama, M. Kikuchi, H. Koiso, S. Matsumoto, T. Matsumoto, H. Matsushita, S. Michizono, K. Mikawa, T. Mimashi, T. Miura, F. Miyahara, T. Mori, A. Morita, H. Nakajima, K. Nakao, T. Natsui, Y. Ogawa, Y. Ohnishi, S. Ohsawa, F. Qiu, I. Satake, D. Satoh, Y. Seimiya, T. Shidara, A. Shirakawa, M. Suetake, H. Sugimoto, T. Suwada, M. Tanaka, M. Tawada, Y. Yano, K. Yokoyama, M. Yoshida, R. Zhang, X. Zhou KEK, Ibaraki, Japan
	The SuperKEKB main ring is currently being constructed for aiming at the peak luminosity of 8 x 10³⁵ cm^-2s⁻¹. The electron/positron injector linac upgrade is also going on for increasing the intensity of bunch charge with keeping the small emittance. The key upgrade issues are the construction of positron damping ring, a new positron capture system, and a low emittance photo-cathode rf electron source. The injector linac beam commissioning started in the October of 2013. In this paper, we report the present status and future plan of SuperKEKB injector commissioning.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOY027
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

MOPMB006

First Tests of SuperKEKB Luminosity Monitors during 2016 Single Beam Commissioning

81

SUPSS067

use link to see paper's listing under its alternate paper code

D. El Khechen, P. Bambade, A. Blin, P. Cornebise, D. Jehanno, V. Kubytskyi, Y. Peinaud, C. Rimbault
LAL, Orsay, France
Y. Funakoshi, Y. Ohnishi, S. Uehara
KEK, Ibaraki, Japan

The SuperKEKB e⁺e⁻ collider aims to reach a very high luminosity of 8 10³⁵ cm^-2s⁻¹, using highly focused ultra-low emittance bunches colliding every 4ns. Fast luminosity monitoring is required for luminosity feedback and optimisation in presence of dynamic imperfections. The aimed relative precision is about 10^-3 in 1ms, which can be in principle achieved thanks to the very large cross-section of the radiative Bhabha process at zero degree scattering angle. Diamond, Cherenkov and scintillator sensors are to be placed just outside the beam pipe, downstream of the interaction point in both rings, at locations with event rates consistent with the aimed precision and small enough backgrounds from single-beam particle losses. The initial configuration installed for the 2016 "phase 1" single beam commissioning will be described, including the sensors, mechanical setup, readout electronics and first stage DAQ. Preliminary measurements and analysis of beam gas Bremsstrahlung loss data collected with the luminosity monitors will be reported and compared with a detailed simulation, for several experimental conditions during the SuperKEKB commissioning.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMB006

Export •

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

TUOBA01

Beam Commissioning of SuperKEKB

1019

Y. Funakoshi, T. Abe, T. Adachi, K. Akai, Y. Arimoto, K. Egawa, Y. Enomoto, J.W. Flanagan, H. Fukuma, K. Furukawa, N. Iida, H. Iinuma, H. Ikeda, T. Ishibashi, M. Iwasaki, T. Kageyama, H. Kaji, T. Kamitani, T. Kawamoto, S. Kazama, M. Kikuchi, T. Kobayashi, K. Kodama, H. Koiso, M. Masuzawa, T. Mimashi, T. Miura, F. Miyahara, T. Mori, A. Morita, S. Nakamura, T.T. Nakamura, H. Nakayama, T. Natsui, M. Nishiwaki, K. Ohmi, Y. Ohnishi, T. Oki, S. Sasaki, M. Satoh, Y. Seimiya, K. Shibata, M. Suetake, Y. Suetsugu, H. Sugimoto, M. Tanaka, M. Tawada, S. Terui, M. Tobiyama, S. Uehara, S. Uno, X. Wang, K. Watanabe, Y. Yano, S.I. Yoshimoto, R. Zhang, D. Zhou, X. Zhou, Z.G. Zong
KEK, Ibaraki, Japan
D. El Khechen
LAL, Orsay, France

In this report, we describe the machine operation in the first 3 months of the Phase 1 commissioning of SuperKEKB. The beam commissioning is smoothly going on. Vacuum scrubbing, the optics corrections and others are described.

Slides TUOBA01 [9.346 MB]

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUOBA01

Export •

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

WEPOY040

Lattice Translation Between Accelerator Simulation Codes for Superkekb

3077

D. Zhou, H. Koiso, A. Morita, Y. Ohnishi, K. Oide, H. Sugimoto
KEK, Ibaraki, Japan
M.E. Biagini
INFN/LNF, Frascati (Roma), Italy
N. Carmignani, S.M. Liuzzo
ESRF, Grenoble, France
D. Sagan
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

To improve collaborative studies on beam dynamics for SuperKEKB between several labs, efforts have been made to translate the SAD lattices of SuperKEKB rings to the versions for other codes: AT, Bmad, MAD-X, and PTC. It turns out that lattice translations between these codes are not straightforward because of the complexity of the SuperKEKB lattices. In this paper, we describe our experiences of lattice translations, and present some results of benchmarks for the case of SuperKEKB.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPOY040

Export •

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

THPOR007

Optics Measurements and Corrections at the Early Commissioning of SuperKEKB

3782

Y. Ohnishi, Y. Funakoshi, H. Koiso, A. Morita, K. Ohmi, K. Oide, H. Sugimoto, D. Zhou
KEK, Ibaraki, Japan
M.E. Biagini, M. Boscolo, S. Guiducci
INFN/LNF, Frascati (Roma), Italy
N. Carmignani, S.M. Liuzzo
ESRF, Grenoble, France

We present experimental results of measurements and corrections of the optics at the early Phase-1 commissioning of SuperKEKB which is a positron-electron collider built to achieve the target luminosity of 8x10³⁵ cm^-2s^-1. We have three stages; the Phase-1 is the commissioning of the machine without the final focus magnets and detector solenoid(no collision); the collision with the final focus system and the Belle II detector will be performed at the Phase-2 and Phase-3. The strategy for the luminosity upgrade is a novel "nano-beam'' scheme found elsewhere*. In order to achieve the target luminosity, the vertical emittance has to be reduced by corrections of machine error measured by orbit responses. The vertical emittance should be achieved to be less than 6 pm(0.2 % coupling) during the Phase-1 by fully utilizing correction tools of skew quadrupole-like coils wound on sextupole magnets and power supplies for each correction coil in quadrupole magnets. In addition to the linear optics, the optics for off-momentum particles is also studied to understand a dynamic aperture affects the Touschek lifetime.
* "SuperB Conceptual Design Report", INFN/AE-07/2, SLAV-R-856, LAL 07-15, (2007).

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR007

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

THPOR040

Emittance Growth by Misalignments and Jitters in SuperKEKB Injector Linac

3871

Y. Seimiya, Y. Enomoto, K. Furukawa, T. Higo, T. Kamitani, F. Miyahara, Y. Ohnishi, M. Satoh, T. Suwada, M. Tanaka
KEK, Ibaraki, Japan

Funding: This work was partly supported by JSPS KAKENHI Grant Number 16K17545.
SuperKEKB injector linac have to transport high-charged beam with low emittance to SuperKEKB ring for high luminosity, 8¥times10³⁵. For the low emittance, photocathode RF gun was adopted as electron source. One of the main reason of the beam emittance blow-up electron linac is generally induced by wakefield in acceleration cavities. A charged beam with a offset from a center of a cavity is affected by the wakefield depending on the offset size in the acceleration cavity and the beam emittance is increased. This emittance blow-up can be eliminated by appropriate steering magnet control so as to cancel the wake effect in the acceleration cavity. We perform particle tracking simulation with some misalignments and beam jitter. Emittance growth by the misalignments and the beam jitter is evaluated in this report.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR040

Export •

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

THPOY027

Commissioning Status of SuperKEKB Injector Linac

4152

M. Satoh, M. Akemoto, D.A. Arakawa, Y. Arakida, A. Enomoto, Y. Enomoto, S. Fukuda, Y. Funakoshi, K. Furukawa, T. Higo, H. Honma, N. Iida, M. Ikeda, H. Iwase, H. Kaji, K. Kakihara, T. Kamitani, H. Katagiri, S. Kazama, M. Kikuchi, H. Koiso, S. Matsumoto, T. Matsumoto, H. Matsushita, S. Michizono, K. Mikawa, T. Mimashi, T. Miura, F. Miyahara, T. Mori, A. Morita, H. Nakajima, K. Nakao, T. Natsui, Y. Ogawa, Y. Ohnishi, S. Ohsawa, F. Qiu, I. Satake, D. Satoh, Y. Seimiya, T. Shidara, A. Shirakawa, M. Suetake, H. Sugimoto, T. Suwada, M. Tanaka, M. Tawada, Y. Yano, K. Yokoyama, M. Yoshida, R. Zhang, X. Zhou
KEK, Ibaraki, Japan

The SuperKEKB main ring is currently being constructed for aiming at the peak luminosity of 8 x 10³⁵ cm^-2s⁻¹. The electron/positron injector linac upgrade is also going on for increasing the intensity of bunch charge with keeping the small emittance. The key upgrade issues are the construction of positron damping ring, a new positron capture system, and a low emittance photo-cathode rf electron source. The injector linac beam commissioning started in the October of 2013. In this paper, we report the present status and future plan of SuperKEKB injector commissioning.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOY027

Export •

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