IPAC2013 - List of Authors (Michizono, S.)

Paper

Title

Page

High-intensity and Low-emittance Upgrade of 7-GeV Injector Linac towards SuperKEKB

1583

K. Furukawa, M. Akemoto, D.A. Arakawa, Y. Arakida, A. Enomoto, S. Fukuda, H. Honma, R. Ichimiya, N. Iida, M. Ikeda, E. Kadokura, K. Kakihara, T. Kamitani, H. Katagiri, M. Kurashina, S. Matsumoto, T. Matsumoto, H. Matsushita, S. Michizono, K. Mikawa, T. Miura, F. Miyahara, T. Mori, H. Nakajima, K. Nakao, T. Natsui, Y. Ogawa, S. Ohsawa, F. Qiu, M. Satoh, T. Shidara, A. Shirakawa, H. Sugimoto, T. Suwada, T. Takatomi, T. Takenaka, M. Tanaka, Y. Yano, K. Yokoyama, M. Yoshida, L. Zang, X. Zhou
KEK, Ibaraki, Japan
D. Satoh
TIT, Tokyo, Japan

After a decade of successful operation at KEKB a new electron/positron collider, SuperKEKB, is being constructed to commission within FY2014. It aims at a luminosity of 8 x 10³⁵ /s.cm², 40-times higher than that of KEKB, in order to study the flavor physics of elementary particles further, by mainly squeezing the beams at the collision point. The injector linac should provide high-intensity and low-emittance beams of 7-GeV electron and 4-GeV positron by newly installing a RF-gun, a flux concentrator, and a damping ring with careful emittance and energy management. It also have to perform simultaneous top-up injections into four storage rings by pulse-to-pulse beam modulations not to interfare between three facilities of SuperKEKB, Photon Factory and PF-AR. This paper describes the injector design decisions and present status of the construction.

WEPWA015

Progress in Construction of the 35 MeV Compact Energy Recovery Linac at KEK

2159

S. Sakanaka, S. Adachi, M. Akemoto, D.A. Arakawa, S. Asaoka, 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, E. Kako, Y. Kamiya, H. Katagiri, H. Kawata, Y. Kobayashi, Y. Kojima, Y. Kondou, T. Kume, T. Matsumoto, H. Matsumura, H. Matsushita, S. Michizono, T. Miura, T. Miyajima, S. Nagahashi, H. Nakai, H. Nakajima, N. Nakamura, K. Nakanishi, K. Nakao, K.N. Nigorikawa, T. Nogami, S. Noguchi, S. Nozawa, T. Obina, T. Ozaki, F. Qiu, H. Sagehashi, H. Sakai, S. Sasaki, K. Satoh, M. Satoh, T. Shidara, M. Shimada, K. Shinoe, T. Shioya, T. Shishido, M. Tadano, T. Takahashi, R. Takai, T. Takenaka, Y. Tanimoto, M. Tobiyama, K. Tsuchiya, T. Uchiyama, A. Ueda, K. Umemori, K. Watanabe, M. Yamamoto, Y. Yamamoto, Y. Yano, M. Yoshida
KEK, Ibaraki, Japan
E. Cenni
Sokendai, Ibaraki, Japan
R. Hajima, S.M. Matsuba, R. Nagai, N. Nishimori, M. Sawamura, T. Shizuma
JAEA, Ibaraki-ken, Japan
H. Takaki
ISSP/SRL, Chiba, Japan

The 35-MeV Compact Energy Recovery Linac (the Compact ERL or cERL) is under construction at the High Energy Accelerator Research Organization (KEK) in Japan. With the Compact ERL, we aim at establishing cutting-edge technologies for the GeV-class ERL-based synchrotron light source. To install the accelerator components of the cERL, we have constructed a shielding room having an area of about 60 m x 20 m. We have then installed a 500-kV DC photocathode gun, a 5-MV superconducting (SC) cryomodule for the injector, a 30-MV SC cryomodule for the main linac, and some of the other components. High-power test on the main SC cryomodule is underway in December, 2012. High-power or high-voltage tests on the injector cryomodule and on the DC gun are planned during January to March, 2013. An injector of the Compact ERL will be commissioned in April, 2013. We report the newest status of its construction.

WEPWO013

High Power Tests of Injector Cryomodule for Compact-ERL

2340

E. Kako, D.A. Arakawa, K. Hara, T. Honma, H. Katagiri, Y. Kojima, Y. Kondo, S. Michizono, T. Miura, H. Nakai, H. Nakajima, K. Nakanishi, S. Noguchi, T. Shishido, T. Takenaka, K. Watanabe, Y. Yamamoto
KEK, Ibaraki, Japan
H. Hara, H. Hitomi, K. Sennyu
MHI, Hiroshima, Japan

In the cERL injector cryomodule, electron beams of 10 mA are accelerated from the beam energy of 500 keV to 5 MeV. A three 2-cell cavity system was chosen for the cERL injector. Each cavity is driven by two input couplers to reduce a required RF power handling capacity and also to compensate a coupler kick. In the cERL injector cryomodule, critical hardware components are not superconducting cavities but RF input couplers operating in CW mode. Six input couplers for the installation in the cryomodule were fabricated, and three pairs of input couplers were carefully conditioned. Costruction status, cool-down tests and high power RF test results on injector cryomodule for compact-ERL at KEK will be discussed in this paper.

WEPFI017

Performance of Cavity Phase Monitor at J-PARC Linac

2738

K. Futatsukawa, S. Anami, Z. Fang, Y. Fukui, T. Kobayashi, S. Michizono
KEK, Ibaraki, Japan
F. Sato, S. Shinozaki
JAEA/J-PARC, Tokai-mura, Japan

The amplitude and the phase stabilities of the RF system play an important role for the cavity of a high intensity proton accelerator. For the J-PARC Linac, the accelerating field ambiguity must be maintained within ±1% in amplitude and ±1 degree in phase due to the momentum acceptance of the next synchrotron. To realize the requirement, a digital feedback (FB) control is used in the low level RF (LLRF) control system, and a feed-forward (FF) technique is combined with the FB control for the beam loading compensation. The stability of ±0.2% in amplitude and ±0.2 degree in phase of the cavity was achieved including the beam loading in a macro pulse. Additionally, the cavity phase monitors, which can measure the phase difference between any two cavities, were installed in summer, 2011. The monitor has the three different types, which are for the present 324-MHz RF system, the 972-MHz RF system and the combined system of 324-MHz RF and 972-MHz RF. The phase monitor for the 324-MHz RF has been in operated since Dec. 2011. We would like to introduce the phase monitor and indicate the phase stability at the J-PARC linac.

WEPFI024

Anisotropic Ferrite Magnet Focusing System for Klystrons

2756

Y. Fuwa, H. Ikeda, Y. Iwashita, R. Kitahara, Y. Nasu, H. Tongu
Kyoto ICR, Uji, Kyoto, Japan
S. Fukuda, T. Matsumoto, S. Michizono
KEK, Ibaraki, Japan

The permanent magnet beam focusing for klystrons can eliminate the solenoid coil with the water cooling system and the power supply that consumes electricity. Hence the failure rate and the operating cost of RF systems should decrease. This feature is suitable for a large facility that requires a lot of klystrons such as ILC. Since the required magnetic field for klystron beam is moderate, inexpensive anisotropic ferrite magnets can be applied. The test model is fabricated for a 1.3 GHz klystron whose output power is 800 kW. Each magnet block in the model is movable for magnetic field adjustment and the iron yoke in the oil tank improves magnetic field distribution around cathode area. The result of a klystron power test will be presented.

WEPME013

Development and Test of a Fully Automated PkQl Control Procedure at KEK STF

2950

M. Omet, A. Kuramoto
Sokendai, Ibaraki, Japan
H. Hayano, T. Matsumoto, S. Michizono
KEK, Ibaraki, Japan

In order to operate the cavities near their maximum gradients, cavity input (Pk) and cavity loaded Q (QL) should be controlled individually (PkQL control) at the International Linear Collider (ILC). A manual PkQL operation procedure was developed and performed at the linear electron accelerator at the Superconducting RF Test Facility (STF), in which the beam is accelerated up to 40 MeV by two superconducting 9-cell TESLA type L band cavities. The cavity gradients were set to 16 MV/m and 24 MV/m with QL values of 110⁶ and 3·10⁶. A 6.2 mA beam with a pulse length of 154 us was used. The field stabilities in amplitude were 0.160% and 0.097% for the cavities and 0.016% for the vector sum. The stabilities without beam are 0.057% and 0.054% for the cavities and 0.009% for the vector sum. For stability improvement during beam transient an adaptive beam feedforward for beam loading compensation is under development. So far an amplitude field stability of 0.013% for the vector sum was achieved at cavity gradients of 15 MV/m and 25 MV/m (no PkQL control) during a 6.8 mA beam with a pulse length of 123 us. Furthermore a fully automated PkQL control procedure is currently developed and tested.

Poster WEPME013 [0.647 MB]

WEPME015

Evaluation of the Superconducting LLRF system at cERL in KEK

2956

F. Qiu, D.A. Arakawa, H. Katagiri, T. Matsumoto, S. Michizono, T. Miura, T. Miyajima, K. Tsuchiya
KEK, Ibaraki, Japan

A low level RF (LLRF) design is being currently developed within the compact Energy Recover Linac (cERL) at KEK. One challenging task is to achieve the high amplitude and high phase stability required by the accelerating fields of up to 0.1% and 0.1°, respectively. To improve the performance of the LLRF system, a gain scanning experiment for determining the optimal controller gain was carried out on the cERL. Furthermore, as a substitute for the traditional PI controller, a more robust H∞-based multiple input multiple output (MIMO) controller was realized. This controller requires more detailed system information (transfer function or state equation), which can be acquired by using modern system identification methods. In this paper, we describe the current status of these experiments on the cERL.

THPWA012

The Development of a New Type of Electron Microscope using Superconducting RF Acceleration

3654

N. Higashi
The University of Tokyo, Graduate School of Science, Tokyo, Japan
A. Enomoto, Y. Funahashi, T. Furuya, Y. Kamiya, S. Michizono, M. Nishiwaki, H. Sakai, M. Sawabe, K. Ueno, M. Yamamoto
KEK, Ibaraki, Japan
M. Kuriki
HU/AdSM, Higashi-Hiroshima, Japan
S. Yamashita
ICEPP, Tokyo, Japan

We are developing a new type of electron microscope (EM), which adopts RF acceleration in order to exceed the energy limit of DC acceleration used in conventional EMs. It enables us to make a high-voltage EM more compact and to examine thicker specimens, and possibly to get better spatial resolution. Using a superconducting RF cavity, we can operate the EM in CW mode to obtain a beam flux comparable to that in DC mode. Low energy dispersion ΔE/E , e.g. 10^-6 or better, is required for good spatial resolution in EMs, while it is usually between 10^-3 to 10^-4 in accelerators. We have thus designed a special type of cavity that can be excited with the fundamental and second-harmonic frequencies simultaneously; TM010 and TM020. With the two-mode cavity, the energy dispersion of the order of 10^-5 would be obtained by modifying the peak of accelerating field to be flattened. As the proof-of-principle of our concept, we are developing the prototype using a 300 keV transmission electron microscope (TEM), to which a new photocathode gun and the two-mode cavity are attached. We have already manufactured the cavity and it is under test, and the gun is under construction.

Paper	Title	Page
TUPME010	High-intensity and Low-emittance Upgrade of 7-GeV Injector Linac towards SuperKEKB	1583
	K. Furukawa, M. Akemoto, D.A. Arakawa, Y. Arakida, A. Enomoto, S. Fukuda, H. Honma, R. Ichimiya, N. Iida, M. Ikeda, E. Kadokura, K. Kakihara, T. Kamitani, H. Katagiri, M. Kurashina, S. Matsumoto, T. Matsumoto, H. Matsushita, S. Michizono, K. Mikawa, T. Miura, F. Miyahara, T. Mori, H. Nakajima, K. Nakao, T. Natsui, Y. Ogawa, S. Ohsawa, F. Qiu, M. Satoh, T. Shidara, A. Shirakawa, H. Sugimoto, T. Suwada, T. Takatomi, T. Takenaka, M. Tanaka, Y. Yano, K. Yokoyama, M. Yoshida, L. Zang, X. Zhou KEK, Ibaraki, Japan D. Satoh TIT, Tokyo, Japan
	After a decade of successful operation at KEKB a new electron/positron collider, SuperKEKB, is being constructed to commission within FY2014. It aims at a luminosity of 8 x 10³⁵ /s.cm², 40-times higher than that of KEKB, in order to study the flavor physics of elementary particles further, by mainly squeezing the beams at the collision point. The injector linac should provide high-intensity and low-emittance beams of 7-GeV electron and 4-GeV positron by newly installing a RF-gun, a flux concentrator, and a damping ring with careful emittance and energy management. It also have to perform simultaneous top-up injections into four storage rings by pulse-to-pulse beam modulations not to interfare between three facilities of SuperKEKB, Photon Factory and PF-AR. This paper describes the injector design decisions and present status of the construction.

WEPWA015	Progress in Construction of the 35 MeV Compact Energy Recovery Linac at KEK	2159
	S. Sakanaka, S. Adachi, M. Akemoto, D.A. Arakawa, S. Asaoka, 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, E. Kako, Y. Kamiya, H. Katagiri, H. Kawata, Y. Kobayashi, Y. Kojima, Y. Kondou, T. Kume, T. Matsumoto, H. Matsumura, H. Matsushita, S. Michizono, T. Miura, T. Miyajima, S. Nagahashi, H. Nakai, H. Nakajima, N. Nakamura, K. Nakanishi, K. Nakao, K.N. Nigorikawa, T. Nogami, S. Noguchi, S. Nozawa, T. Obina, T. Ozaki, F. Qiu, H. Sagehashi, H. Sakai, S. Sasaki, K. Satoh, M. Satoh, T. Shidara, M. Shimada, K. Shinoe, T. Shioya, T. Shishido, M. Tadano, T. Takahashi, R. Takai, T. Takenaka, Y. Tanimoto, M. Tobiyama, K. Tsuchiya, T. Uchiyama, A. Ueda, K. Umemori, K. Watanabe, M. Yamamoto, Y. Yamamoto, Y. Yano, M. Yoshida KEK, Ibaraki, Japan E. Cenni Sokendai, Ibaraki, Japan R. Hajima, S.M. Matsuba, R. Nagai, N. Nishimori, M. Sawamura, T. Shizuma JAEA, Ibaraki-ken, Japan H. Takaki ISSP/SRL, Chiba, Japan
	The 35-MeV Compact Energy Recovery Linac (the Compact ERL or cERL) is under construction at the High Energy Accelerator Research Organization (KEK) in Japan. With the Compact ERL, we aim at establishing cutting-edge technologies for the GeV-class ERL-based synchrotron light source. To install the accelerator components of the cERL, we have constructed a shielding room having an area of about 60 m x 20 m. We have then installed a 500-kV DC photocathode gun, a 5-MV superconducting (SC) cryomodule for the injector, a 30-MV SC cryomodule for the main linac, and some of the other components. High-power test on the main SC cryomodule is underway in December, 2012. High-power or high-voltage tests on the injector cryomodule and on the DC gun are planned during January to March, 2013. An injector of the Compact ERL will be commissioned in April, 2013. We report the newest status of its construction.

WEPWO013	High Power Tests of Injector Cryomodule for Compact-ERL	2340
	E. Kako, D.A. Arakawa, K. Hara, T. Honma, H. Katagiri, Y. Kojima, Y. Kondo, S. Michizono, T. Miura, H. Nakai, H. Nakajima, K. Nakanishi, S. Noguchi, T. Shishido, T. Takenaka, K. Watanabe, Y. Yamamoto KEK, Ibaraki, Japan H. Hara, H. Hitomi, K. Sennyu MHI, Hiroshima, Japan
	In the cERL injector cryomodule, electron beams of 10 mA are accelerated from the beam energy of 500 keV to 5 MeV. A three 2-cell cavity system was chosen for the cERL injector. Each cavity is driven by two input couplers to reduce a required RF power handling capacity and also to compensate a coupler kick. In the cERL injector cryomodule, critical hardware components are not superconducting cavities but RF input couplers operating in CW mode. Six input couplers for the installation in the cryomodule were fabricated, and three pairs of input couplers were carefully conditioned. Costruction status, cool-down tests and high power RF test results on injector cryomodule for compact-ERL at KEK will be discussed in this paper.

WEPFI017	Performance of Cavity Phase Monitor at J-PARC Linac	2738
	K. Futatsukawa, S. Anami, Z. Fang, Y. Fukui, T. Kobayashi, S. Michizono KEK, Ibaraki, Japan F. Sato, S. Shinozaki JAEA/J-PARC, Tokai-mura, Japan
	The amplitude and the phase stabilities of the RF system play an important role for the cavity of a high intensity proton accelerator. For the J-PARC Linac, the accelerating field ambiguity must be maintained within ±1% in amplitude and ±1 degree in phase due to the momentum acceptance of the next synchrotron. To realize the requirement, a digital feedback (FB) control is used in the low level RF (LLRF) control system, and a feed-forward (FF) technique is combined with the FB control for the beam loading compensation. The stability of ±0.2% in amplitude and ±0.2 degree in phase of the cavity was achieved including the beam loading in a macro pulse. Additionally, the cavity phase monitors, which can measure the phase difference between any two cavities, were installed in summer, 2011. The monitor has the three different types, which are for the present 324-MHz RF system, the 972-MHz RF system and the combined system of 324-MHz RF and 972-MHz RF. The phase monitor for the 324-MHz RF has been in operated since Dec. 2011. We would like to introduce the phase monitor and indicate the phase stability at the J-PARC linac.

WEPFI024	Anisotropic Ferrite Magnet Focusing System for Klystrons	2756
	Y. Fuwa, H. Ikeda, Y. Iwashita, R. Kitahara, Y. Nasu, H. Tongu Kyoto ICR, Uji, Kyoto, Japan S. Fukuda, T. Matsumoto, S. Michizono KEK, Ibaraki, Japan
	The permanent magnet beam focusing for klystrons can eliminate the solenoid coil with the water cooling system and the power supply that consumes electricity. Hence the failure rate and the operating cost of RF systems should decrease. This feature is suitable for a large facility that requires a lot of klystrons such as ILC. Since the required magnetic field for klystron beam is moderate, inexpensive anisotropic ferrite magnets can be applied. The test model is fabricated for a 1.3 GHz klystron whose output power is 800 kW. Each magnet block in the model is movable for magnetic field adjustment and the iron yoke in the oil tank improves magnetic field distribution around cathode area. The result of a klystron power test will be presented.

WEPME013	Development and Test of a Fully Automated PkQl Control Procedure at KEK STF	2950
	M. Omet, A. Kuramoto Sokendai, Ibaraki, Japan H. Hayano, T. Matsumoto, S. Michizono KEK, Ibaraki, Japan
	In order to operate the cavities near their maximum gradients, cavity input (Pk) and cavity loaded Q (QL) should be controlled individually (PkQL control) at the International Linear Collider (ILC). A manual PkQL operation procedure was developed and performed at the linear electron accelerator at the Superconducting RF Test Facility (STF), in which the beam is accelerated up to 40 MeV by two superconducting 9-cell TESLA type L band cavities. The cavity gradients were set to 16 MV/m and 24 MV/m with QL values of 110⁶ and 3·10⁶. A 6.2 mA beam with a pulse length of 154 us was used. The field stabilities in amplitude were 0.160% and 0.097% for the cavities and 0.016% for the vector sum. The stabilities without beam are 0.057% and 0.054% for the cavities and 0.009% for the vector sum. For stability improvement during beam transient an adaptive beam feedforward for beam loading compensation is under development. So far an amplitude field stability of 0.013% for the vector sum was achieved at cavity gradients of 15 MV/m and 25 MV/m (no PkQL control) during a 6.8 mA beam with a pulse length of 123 us. Furthermore a fully automated PkQL control procedure is currently developed and tested.
	Poster WEPME013 [0.647 MB]

WEPME015	Evaluation of the Superconducting LLRF system at cERL in KEK	2956
	F. Qiu, D.A. Arakawa, H. Katagiri, T. Matsumoto, S. Michizono, T. Miura, T. Miyajima, K. Tsuchiya KEK, Ibaraki, Japan
	A low level RF (LLRF) design is being currently developed within the compact Energy Recover Linac (cERL) at KEK. One challenging task is to achieve the high amplitude and high phase stability required by the accelerating fields of up to 0.1% and 0.1°, respectively. To improve the performance of the LLRF system, a gain scanning experiment for determining the optimal controller gain was carried out on the cERL. Furthermore, as a substitute for the traditional PI controller, a more robust H∞-based multiple input multiple output (MIMO) controller was realized. This controller requires more detailed system information (transfer function or state equation), which can be acquired by using modern system identification methods. In this paper, we describe the current status of these experiments on the cERL.

THPWA012	The Development of a New Type of Electron Microscope using Superconducting RF Acceleration	3654
	N. Higashi The University of Tokyo, Graduate School of Science, Tokyo, Japan A. Enomoto, Y. Funahashi, T. Furuya, Y. Kamiya, S. Michizono, M. Nishiwaki, H. Sakai, M. Sawabe, K. Ueno, M. Yamamoto KEK, Ibaraki, Japan M. Kuriki HU/AdSM, Higashi-Hiroshima, Japan S. Yamashita ICEPP, Tokyo, Japan
	We are developing a new type of electron microscope (EM), which adopts RF acceleration in order to exceed the energy limit of DC acceleration used in conventional EMs. It enables us to make a high-voltage EM more compact and to examine thicker specimens, and possibly to get better spatial resolution. Using a superconducting RF cavity, we can operate the EM in CW mode to obtain a beam flux comparable to that in DC mode. Low energy dispersion ΔE/E , e.g. 10^-6 or better, is required for good spatial resolution in EMs, while it is usually between 10^-3 to 10^-4 in accelerators. We have thus designed a special type of cavity that can be excited with the fundamental and second-harmonic frequencies simultaneously; TM010 and TM020. With the two-mode cavity, the energy dispersion of the order of 10^-5 would be obtained by modifying the peak of accelerating field to be flattened. As the proof-of-principle of our concept, we are developing the prototype using a 300 keV transmission electron microscope (TEM), to which a new photocathode gun and the two-mode cavity are attached. We have already manufactured the cavity and it is under test, and the gun is under construction.