IPAC2017 - List of Authors (Miura, T.)

Paper	Title	Page
MOPVA019	60 pC Bunch Charge Operation of the Compact ERL at KEK	890
	T. Miyajima, K. Harada, Y. Honda, E. Kako, R. Kato, T. Miura, N. Nakamura, T. Obina, M. Shimada, R. Takai, K. Umemori, M. Yamamoto KEK, Ibaraki, Japan R. Hajima, R. Nagai QST, Tokai, Japan T. Hotei Sokendai, Ibaraki, Japan N. Nishimori Tohoku University, Research Center for Electron Photon Science, Sendai, Japan
	The compact ERL (cERL) at KEK was operated in March 2017 to demonstrate generation, acceleration and transportation of the target bunch charge of 60 pC without energy recovery. However, the maximum bunch charge was limited to 40 pC due to the limitation of the excitation laser power. For the bunch charge of 40 pC, the bunch length and the normalized emittance were measured in the injector diagnostic line. The results of the bunch length measurement gave good agreement with the values that had been obtained by model simulation. The measured normalized rms emittances for 40 pC were 0.9 to 2.4 mm mrad, and they were lager than the design value of 0.6 mm mrad. To achieve the design emittance, we have studied the source of the emittance growth for the bunch charge of 40 pC.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPVA019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAB004	Progress of 7-GeV SuperKEKB Injector Linac Upgrade and Commissioning	1300
	K. Furukawa, M. Akemoto, D.A. Arakawa, Y. Arakida, H. Ego, A. Enomoto, Y. Enomoto, S. Fukuda, Y. Funahashi, T. Higo, H. Honma, N. Iida, M. Ikeda, H. Kaji, K. Kakihara, T. Kamitani, H. Katagiri, M. Kawamura, M. Kurashina, S. Matsumoto, T. Matsumoto, H. Matsushita, S. Michizono, K. Mikawa, T. Miura, F. Miyahara, H. Nakajima, K. Nakao, T. Natsui, M. Nishida, Y. Ogawa, Y. Ohnishi, S. Ohsawa, F. Qiu, I. Satake, D. Satoh, M. Satoh, Y. Seimiya, A. Shirakawa, H. Sugimoto, H. Sugimura, T. Suwada, T. Takatomi, T. Takenaka, M. Tanaka, N. Toge, Y. Yano, K. Yokoyama, M. Yoshida, R. Zhang, X. Zhou KEK, Ibaraki, Japan
	KEK injector linac has delivered electrons and positrons for particle physics and photon science experiments for more than 30 years. It is being upgraded for the SuperKEKB project, which aims at a 40-fold increase in luminosity over the previous project KEKB, in order to increase our understanding of new physics beyond the standard model of elementary particle physics. SuperKEKB asymmetric electron and positron collider with its extremely high luminosity requires a high current, low emittance and low energy spread injection beam from the injector. Electron beams will be generated by a new type of RF gun, that will provide a much higher beam current to correspond to a large stored beam current and a short lifetime in the ring. The positron source is another major challenge that enhances the positron bunch intensity from 1 to 4 nC by increasing the positron capture efficiency, and the positron beam emittance is reduced from 2000 micron to 20 micron in the vertical plane by introducing a damping ring, followed by the bunch compressor and energy compressor. The recent status of the upgrade and beam commissioning is reported.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB004
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAB006	Achievement of Stable Pulsed Operation at 31 MV/m in the STF-2 Cryomodule for the ILC	1308
	Y. Yamamoto, T. Dohmae, M. Egi, K. Hara, T. Honma, E. Kako, Y. Kojima, T. Konomi, N. Kota, T. Kubo, T. Matsumoto, T. Miura, H. Nakai, K. Nakanishi, G.-T. Park, T. Saeki, H. Shimizu, T. Shishido, T. Takenaka, K. Umemori KEK, Ibaraki, Japan
	In the Superconducting RF Test Facility (STF) in KEK, the cooldown test for the STF-2 cryomodule with 12 cavities has been done totally three times since 2014. In 2016, the 3rd cooldown test for the STF-2 cryomodule including the capture cryomodule with 2 cavities, which was used for Quantum Beam Project in 2012, was successfully done. The main purpose is the vector-sum operation with 8 cavities at average accelerating gradient of 31 MV/m as the ILC specification, and the others are the measurement for Lorenz Force Detuning (LFD) and unloaded Q value, and Low Level RF (LLRF) study, etc. During 8 cavities operation, piezo actuators were used for the compensation of LFD, and the feed-forward and vector-sum control system by LLRF worked perfectly for keeping the lowest forward power and the stable flat-top of accelerating gradient. In this paper, the result for the STF-2 cryomodule in the 3rd cooldown test will be presented in detail.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB006
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPAB116	Evaluation of Digital LLRF Control System Performance at STF in KEK	3992
SUSPSIK087	use link to see paper's listing under its alternate paper code
	S.B. Wibowo, N. Liu Sokendai, Ibaraki, Japan T. Matsumoto, S. Michizono, T. Miura, F. Qiu KEK, Ibaraki, Japan
	The Superconducting RF Test Facility (STF) at the High Energy Accelerator Research Organization (KEK) was built for research and development of the International Linear Collider (ILC). Several digital low-level radio frequency (LLRF) control systems were developed at the STF. The purposes of these developments are to construct a minimal configuration of the ILC LLRF system and achieve the amplitude and phase stability of the accelerating field in the superconducting accelerator. Evaluations of digital LLRF control systems were conducted during the conditioning of eight superconducting cavities performed between October and November 2016. The digital LLRF control system configured for ILC was demonstrated and the performance fulfilled the required stability criteria of the accelerating field in the ILC. These evaluations are reported in this paper.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-THPAB116
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

60 pC Bunch Charge Operation of the Compact ERL at KEK

890

T. Miyajima, K. Harada, Y. Honda, E. Kako, R. Kato, T. Miura, N. Nakamura, T. Obina, M. Shimada, R. Takai, K. Umemori, M. Yamamoto
KEK, Ibaraki, Japan
R. Hajima, R. Nagai
QST, Tokai, Japan
T. Hotei
Sokendai, Ibaraki, Japan
N. Nishimori
Tohoku University, Research Center for Electron Photon Science, Sendai, Japan

The compact ERL (cERL) at KEK was operated in March 2017 to demonstrate generation, acceleration and transportation of the target bunch charge of 60 pC without energy recovery. However, the maximum bunch charge was limited to 40 pC due to the limitation of the excitation laser power. For the bunch charge of 40 pC, the bunch length and the normalized emittance were measured in the injector diagnostic line. The results of the bunch length measurement gave good agreement with the values that had been obtained by model simulation. The measured normalized rms emittances for 40 pC were 0.9 to 2.4 mm mrad, and they were lager than the design value of 0.6 mm mrad. To achieve the design emittance, we have studied the source of the emittance growth for the bunch charge of 40 pC.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPVA019

Export •

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

TUPAB004

Progress of 7-GeV SuperKEKB Injector Linac Upgrade and Commissioning

1300

K. Furukawa, M. Akemoto, D.A. Arakawa, Y. Arakida, H. Ego, A. Enomoto, Y. Enomoto, S. Fukuda, Y. Funahashi, T. Higo, H. Honma, N. Iida, M. Ikeda, H. Kaji, K. Kakihara, T. Kamitani, H. Katagiri, M. Kawamura, M. Kurashina, S. Matsumoto, T. Matsumoto, H. Matsushita, S. Michizono, K. Mikawa, T. Miura, F. Miyahara, H. Nakajima, K. Nakao, T. Natsui, M. Nishida, Y. Ogawa, Y. Ohnishi, S. Ohsawa, F. Qiu, I. Satake, D. Satoh, M. Satoh, Y. Seimiya, A. Shirakawa, H. Sugimoto, H. Sugimura, T. Suwada, T. Takatomi, T. Takenaka, M. Tanaka, N. Toge, Y. Yano, K. Yokoyama, M. Yoshida, R. Zhang, X. Zhou
KEK, Ibaraki, Japan

KEK injector linac has delivered electrons and positrons for particle physics and photon science experiments for more than 30 years. It is being upgraded for the SuperKEKB project, which aims at a 40-fold increase in luminosity over the previous project KEKB, in order to increase our understanding of new physics beyond the standard model of elementary particle physics. SuperKEKB asymmetric electron and positron collider with its extremely high luminosity requires a high current, low emittance and low energy spread injection beam from the injector. Electron beams will be generated by a new type of RF gun, that will provide a much higher beam current to correspond to a large stored beam current and a short lifetime in the ring. The positron source is another major challenge that enhances the positron bunch intensity from 1 to 4 nC by increasing the positron capture efficiency, and the positron beam emittance is reduced from 2000 micron to 20 micron in the vertical plane by introducing a damping ring, followed by the bunch compressor and energy compressor. The recent status of the upgrade and beam commissioning is reported.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB004

Export •

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

TUPAB006

Achievement of Stable Pulsed Operation at 31 MV/m in the STF-2 Cryomodule for the ILC

1308

Y. Yamamoto, T. Dohmae, M. Egi, K. Hara, T. Honma, E. Kako, Y. Kojima, T. Konomi, N. Kota, T. Kubo, T. Matsumoto, T. Miura, H. Nakai, K. Nakanishi, G.-T. Park, T. Saeki, H. Shimizu, T. Shishido, T. Takenaka, K. Umemori
KEK, Ibaraki, Japan

In the Superconducting RF Test Facility (STF) in KEK, the cooldown test for the STF-2 cryomodule with 12 cavities has been done totally three times since 2014. In 2016, the 3rd cooldown test for the STF-2 cryomodule including the capture cryomodule with 2 cavities, which was used for Quantum Beam Project in 2012, was successfully done. The main purpose is the vector-sum operation with 8 cavities at average accelerating gradient of 31 MV/m as the ILC specification, and the others are the measurement for Lorenz Force Detuning (LFD) and unloaded Q value, and Low Level RF (LLRF) study, etc. During 8 cavities operation, piezo actuators were used for the compensation of LFD, and the feed-forward and vector-sum control system by LLRF worked perfectly for keeping the lowest forward power and the stable flat-top of accelerating gradient. In this paper, the result for the STF-2 cryomodule in the 3rd cooldown test will be presented in detail.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB006

Export •

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

THPAB116

Evaluation of Digital LLRF Control System Performance at STF in KEK

3992

SUSPSIK087

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

S.B. Wibowo, N. Liu
Sokendai, Ibaraki, Japan
T. Matsumoto, S. Michizono, T. Miura, F. Qiu
KEK, Ibaraki, Japan

The Superconducting RF Test Facility (STF) at the High Energy Accelerator Research Organization (KEK) was built for research and development of the International Linear Collider (ILC). Several digital low-level radio frequency (LLRF) control systems were developed at the STF. The purposes of these developments are to construct a minimal configuration of the ILC LLRF system and achieve the amplitude and phase stability of the accelerating field in the superconducting accelerator. Evaluations of digital LLRF control systems were conducted during the conditioning of eight superconducting cavities performed between October and November 2016. The digital LLRF control system configured for ILC was demonstrated and the performance fulfilled the required stability criteria of the accelerating field in the ILC. These evaluations are reported in this paper.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-THPAB116

Export •

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