IPAC2016 - List of Authors (Matsumoto, T.)

Paper	Title	Page
MOPMY011	LLRF System Performance during SC Cavity Conditioning at STF KEK	536
	S.B. Wibowo Sokendai, Ibaraki, Japan T. Matsumoto, S. Michizono, T. Miura, F. Qiu KEK, Ibaraki, Japan
	High Energy Accelerator Research Organization (KEK) is now developing a digital low-level radio frequency (LLRF) control system based on digital feedback control at superconducting RF test facility (STF). The goal is to achieve the amplitude and phase stability of the accelerating field in the superconducting accelerator. Testing and evaluation of the digital LLRF system were conducted during the cavity conditioning performed between October and December 2015 to determine the level of performance. To enable cavity signal monitoring, direct sampling system was constructed and evaluated.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMY011
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPOW036	Recent Developments and Operational Status of the Compact ERL at KEK	1835
	T. Obina, M. Adachi, S. Adachi, T. Akagi, M. Akemoto, D.A. Arakawa, S. Araki, S. Asaoka, M. Egi, K. Enami, K. Endo, S. Fukuda, T. Furuya, K. Haga, K. Hara, K. Harada, T. Honda, Y. Honda, H. Honma, T. Honma, K. Hosoyama, K. Hozumi, A. Ishii, X.J. Jin, E. Kako, Y. Kamiya, H. Katagiri, R. Kato, H. Kawata, Y. Kobayashi, Y. Kojima, Y. Kondo, T. Konomi, A. Kosuge, T. Kume, T. Matsumoto, H. Matsumura, H. Matsushita, S. Michizono, T. Miura, T. Miyajima, H. Miyauchi, S. Nagahashi, H. Nakai, H. Nakajima, N. Nakamura, K. Nakanishi, K. Nakao, K.N. Nigorikawa, T. Nogami, S. Noguchi, S. Nozawa, T. Ozaki, F. Qiu, H. Sagehashi, H. Sakai, S. Sakanaka, S. Sasaki, K. Satoh, Y. Seimiya, T. Shidara, M. Shimada, K. Shinoe, T. Shioya, T. Shishido, M. Tadano, T. Tahara, T. Takahashi, R. Takai, H. Takaki, T. Takenaka, O. Tanaka, Y. Tanimoto, N. Terunuma, M. Tobiyama, K. Tsuchiya, T. Uchiyama, A. Ueda, K. Umemori, J. Urakawa, K. Watanabe, M. Yamamoto, N. Yamamoto, Y. Yamamoto, Y. Yano, M. Yoshida KEK, Ibaraki, Japan R. Hajima, M. Mori, R. Nagai, N. Nishimori, M. Sawamura, T. Shizuma QST, Tokai, Japan M. Kuriki Hiroshima University, Graduate School of Science, Higashi-Hiroshima, Japan
	The Compact Energy Recovery Linac (cERL) at KEK is a test accelerator in order to develop key components to realize remarkable ERL performance as a future light source. After the beam commissioning in December 2013, the legal current limit has been increased step-by-step like 1 uA, 10 uA, and 100 uA. Survey for the source of beam losses has been conducted in each step, and the study on beam dynamics and tuning has also been carried out. As a next step, 1 mA operation is scheduled in February 2016. In parallel to the increase in beam current, a laser Compton scattering (LCS) system which can provide high-flux X-ray to a beamline has been successfully commissioned. We report recent progress in various kinds of beam tuning: improvement of electron gun performance, high bunch charge operation, mitigation of beam losses, LCS optics tuning and bunch compression for THz radiation.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPOW036
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPMB017	High Gradient Cavity Performance in STF-2 Cryomodule for the ILC at KEK	2158
	Y. Yamamoto, T. Honma, E. Kako, Y. Kojima, T. Matsumoto, H. Nakai, T. Shishido KEK, Ibaraki, Japan
	The high power test for STF-2 cryomodule has completed successfully in 2015. Before cooldown of cryomodule, at first, the input coupler conditioning at room temperature is done with detuned cavities. After cooldown, the cavity conditioning, which is the main part in the performance test, is done by monitoring the radiation level measured at three locations around the cryomodule, and the heating and RF output at two HOM (Higher Order Mode) couplers. Consequently, it became clear the average accelerating gradient is 30 MV/m for STF-2 cryomodule (39 MV/m at max. and 15 MV/m at min.), and the second cavity string with four cavities had the significant performance degradation by heavy field emission due to the additional clean room work in the STF tunnel. As the following next steps, there are the LFD (Lorenz Force Detuning) measurement, LFD compensation by piezo, and long run for check of stable operation at high gradient. In the long run around 32 MV/m, each cavity without degradation showed the stable operation with the successful LFD compensation by piezo and RF feedback system. In this paper, the detailed test result will be presented.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPMB017
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPOR033	Progress in the Work on the Tuner Control System of the cERL at KEK	2742
	F. Qiu, T. Matsumoto, S. Michizono, T. Miura KEK, Ibaraki, Japan S.B. Wibowo Sokendai, Ibaraki, Japan
	A compact energy recovery linac (cERL), which is a test machine for future 3 GeV ERL project, was constructed at KEK. Five superconducting (SC) cavities were installed in the injector and main linac of the cERL. The SC cavities in cERL are prone to detuning by disturbances such as microphonics. Therefore, a piezo-based tuner system was used to compensate for the detuning of the SC cavity in the cERL. We have proposed advanced control methods that aim at improving the performance of the cERL tuner systems. In this paper, we present the progress in our work on the cERL tuner systems. The preliminary results of the beam-commissioning are also presented.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPOR033
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)

Paper

Title

Page

LLRF System Performance during SC Cavity Conditioning at STF KEK

536

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

High Energy Accelerator Research Organization (KEK) is now developing a digital low-level radio frequency (LLRF) control system based on digital feedback control at superconducting RF test facility (STF). The goal is to achieve the amplitude and phase stability of the accelerating field in the superconducting accelerator. Testing and evaluation of the digital LLRF system were conducted during the cavity conditioning performed between October and December 2015 to determine the level of performance. To enable cavity signal monitoring, direct sampling system was constructed and evaluated.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMY011

Export •

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

TUPOW036

Recent Developments and Operational Status of the Compact ERL at KEK

1835

T. Obina, M. Adachi, S. Adachi, T. Akagi, M. Akemoto, D.A. Arakawa, S. Araki, S. Asaoka, M. Egi, K. Enami, K. Endo, S. Fukuda, T. Furuya, K. Haga, K. Hara, K. Harada, T. Honda, Y. Honda, H. Honma, T. Honma, K. Hosoyama, K. Hozumi, A. Ishii, X.J. Jin, E. Kako, Y. Kamiya, H. Katagiri, R. Kato, H. Kawata, Y. Kobayashi, Y. Kojima, Y. Kondo, T. Konomi, A. Kosuge, T. Kume, T. Matsumoto, H. Matsumura, H. Matsushita, S. Michizono, T. Miura, T. Miyajima, H. Miyauchi, S. Nagahashi, H. Nakai, H. Nakajima, N. Nakamura, K. Nakanishi, K. Nakao, K.N. Nigorikawa, T. Nogami, S. Noguchi, S. Nozawa, T. Ozaki, F. Qiu, H. Sagehashi, H. Sakai, S. Sakanaka, S. Sasaki, K. Satoh, Y. Seimiya, T. Shidara, M. Shimada, K. Shinoe, T. Shioya, T. Shishido, M. Tadano, T. Tahara, T. Takahashi, R. Takai, H. Takaki, T. Takenaka, O. Tanaka, Y. Tanimoto, N. Terunuma, M. Tobiyama, K. Tsuchiya, T. Uchiyama, A. Ueda, K. Umemori, J. Urakawa, K. Watanabe, M. Yamamoto, N. Yamamoto, Y. Yamamoto, Y. Yano, M. Yoshida
KEK, Ibaraki, Japan
R. Hajima, M. Mori, R. Nagai, N. Nishimori, M. Sawamura, T. Shizuma
QST, Tokai, Japan
M. Kuriki
Hiroshima University, Graduate School of Science, Higashi-Hiroshima, Japan

The Compact Energy Recovery Linac (cERL) at KEK is a test accelerator in order to develop key components to realize remarkable ERL performance as a future light source. After the beam commissioning in December 2013, the legal current limit has been increased step-by-step like 1 uA, 10 uA, and 100 uA. Survey for the source of beam losses has been conducted in each step, and the study on beam dynamics and tuning has also been carried out. As a next step, 1 mA operation is scheduled in February 2016. In parallel to the increase in beam current, a laser Compton scattering (LCS) system which can provide high-flux X-ray to a beamline has been successfully commissioned. We report recent progress in various kinds of beam tuning: improvement of electron gun performance, high bunch charge operation, mitigation of beam losses, LCS optics tuning and bunch compression for THz radiation.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPOW036

Export •

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

WEPMB017

High Gradient Cavity Performance in STF-2 Cryomodule for the ILC at KEK

2158

Y. Yamamoto, T. Honma, E. Kako, Y. Kojima, T. Matsumoto, H. Nakai, T. Shishido
KEK, Ibaraki, Japan

The high power test for STF-2 cryomodule has completed successfully in 2015. Before cooldown of cryomodule, at first, the input coupler conditioning at room temperature is done with detuned cavities. After cooldown, the cavity conditioning, which is the main part in the performance test, is done by monitoring the radiation level measured at three locations around the cryomodule, and the heating and RF output at two HOM (Higher Order Mode) couplers. Consequently, it became clear the average accelerating gradient is 30 MV/m for STF-2 cryomodule (39 MV/m at max. and 15 MV/m at min.), and the second cavity string with four cavities had the significant performance degradation by heavy field emission due to the additional clean room work in the STF tunnel. As the following next steps, there are the LFD (Lorenz Force Detuning) measurement, LFD compensation by piezo, and long run for check of stable operation at high gradient. In the long run around 32 MV/m, each cavity without degradation showed the stable operation with the successful LFD compensation by piezo and RF feedback system. In this paper, the detailed test result will be presented.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPMB017

Export •

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

WEPOR033

Progress in the Work on the Tuner Control System of the cERL at KEK

2742

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

A compact energy recovery linac (cERL), which is a test machine for future 3 GeV ERL project, was constructed at KEK. Five superconducting (SC) cavities were installed in the injector and main linac of the cERL. The SC cavities in cERL are prone to detuning by disturbances such as microphonics. Therefore, a piezo-based tuner system was used to compensate for the detuning of the SC cavity in the cERL. We have proposed advanced control methods that aim at improving the performance of the cERL tuner systems. In this paper, we present the progress in our work on the cERL tuner systems. The preliminary results of the beam-commissioning are also presented.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPOR033

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)