LINAC2018 - List of Authors (Miura, T.)

Paper	Title	Page
MOPO107	Performance Evaluation of the RF Reference Phase Stabilization System on Fiber-optical Link for KEK e⁻/e⁺ Injector LINAC	230
SPWR027	use link to see paper's listing under its alternate paper code
	N. Liu, B. Du Sokendai - Hayama, Hayama, Japan D.A. Arakawa, H. Katagiri, T. Matsumoto, S. Michizono, T. Miura, F. Qiu, Y. Yano KEK, Ibaraki, Japan T. Matsumoto, T. Miura, F. Qiu Sokendai, Ibaraki, Japan
	KEK e⁻/e⁺ injector is the 600 m J-shaped LINAC which has 8 RF sectors. Stabilization of RF phase reference for long distance transmission is necessary for stable RF operation. In the present system, single-mode fiber-optical links without feedback control are used from sector 2 to 5. For the SuperKEKB, the phase stability requirement is within 0.1 deg. rms. The more stable RF phase reference is necessary to improve the phase stability. In this paper, a feedback control system for RF reference phase stabilization is tested for system performance evaluation. The temperature and humidity characteristics of the electric and optical components and phase stabilized optical fiber (PSOF) with different wavelengths will also be presented.
	Poster MOPO107 [2.026 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO107
About •	paper received ※ 12 September 2018 paper accepted ※ 21 September 2018 issue date ※ 18 January 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPO003	L-band Resonant Ring for Testing RF Windows for ILC	679
SPWR005	use link to see paper's listing under its alternate paper code
	B. Du, N. Liu Sokendai - Hayama, Hayama, Japan T. Matsumoto, S. Michizono, T. Miura, F. Qiu KEK, Ibaraki, Japan T. Matsumoto, T. Miura, F. Qiu Sokendai, Ibaraki, Japan
	A resonant ring is widely used for the breakdown test of RF components under high power. It can reach power gain of more than 10dB, which is limited by the attenua-tion of the ring. An L-band resonant ring is constructed for testing RF components of International Linear Collid-er (ILC) which is based on an RF frequency of 1.3GHz. The target of the high power test is 5 MW. We have fin-ished the test of an input power of 500 W using a solid state amplifier, and the principle of the resonant ring is verified. The resonant ring is tuned to an optimal condi-tion, which is preparation for high power operation. This paper details the principle, construction, and test of the L-band resonant ring.
	Poster THPO003 [2.301 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO003
About •	paper received ※ 13 September 2018 paper accepted ※ 21 September 2018 issue date ※ 18 January 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPO008	Long-term 0peration with Beam and Cavity Performance Degradation in Compact-ERL Main Linac at KEK	695
	H. Sakai, T. Furuya, E. Kako, T. Konomi, T. Miura, F. Qiu, K. Umemori KEK, Ibaraki, Japan
	We developed ERL main linac cryomodule for Compact ERL (cERL) in KEK. The module consists of two 9-cell 1.3 GHz superconducting cavities. After construction of cERL recirculation loop, beam operation was started in 2013 Dec. First electron beam of 20 MeV successfully passed the main linac cavities. Beam current increased step by step and currently reached to 1mA (CW). Energy recovery has successfully achieved. However, field emission was one of the problems for long term operation. Therefore, the performance of the SRF cavities through long term beam operation has been investigated. In this paper, we express the measurement of the cavity performances and its degradation during long term beam operation. We also described the details of the cavity performance degradation and some trial for the cavity performance recovery.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO008
About •	paper received ※ 11 September 2018 paper accepted ※ 20 September 2018 issue date ※ 18 January 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPO096	Design Study of a High Efficiency Klystron for SuperKEKB Linac	901
	F. Qiu, S. Fukuda, S. Matsumoto, T. Matsumoto, T. Miura, T. Natsui KEK, Ibaraki, Japan
	The injector linear accelerator (linac) for the SuperKEKB particle accelerator requires a higher efficiency klystron than the currently used 50 MW, S-band, pulsed unit (PV3050/E3730), which operates at the same voltage, to increase the power redundancy. The efficiency is expected to improve from the currently observed 45% to more than 60%. We propose a type of high efficiency klystron using novel bunching mechanisms. The 1-D disk model based code is used for preliminary optimization of the tube parameters; these parameters are further checked by 2-D codes known as field charge interaction (FCI) and MAGIC. In this paper, the design consideration of the high efficiency klystron is presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO096
About •	paper received ※ 12 September 2018 paper accepted ※ 20 September 2018 issue date ※ 18 January 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Performance Evaluation of the RF Reference Phase Stabilization System on Fiber-optical Link for KEK e⁻/e⁺ Injector LINAC

230

SPWR027

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

N. Liu, B. Du
Sokendai - Hayama, Hayama, Japan
D.A. Arakawa, H. Katagiri, T. Matsumoto, S. Michizono, T. Miura, F. Qiu, Y. Yano
KEK, Ibaraki, Japan
T. Matsumoto, T. Miura, F. Qiu
Sokendai, Ibaraki, Japan

KEK e⁻/e⁺ injector is the 600 m J-shaped LINAC which has 8 RF sectors. Stabilization of RF phase reference for long distance transmission is necessary for stable RF operation. In the present system, single-mode fiber-optical links without feedback control are used from sector 2 to 5. For the SuperKEKB, the phase stability requirement is within 0.1 deg. rms. The more stable RF phase reference is necessary to improve the phase stability. In this paper, a feedback control system for RF reference phase stabilization is tested for system performance evaluation. The temperature and humidity characteristics of the electric and optical components and phase stabilized optical fiber (PSOF) with different wavelengths will also be presented.

Poster MOPO107 [2.026 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO107

About •

paper received ※ 12 September 2018 paper accepted ※ 21 September 2018 issue date ※ 18 January 2019

Export •

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

THPO003

L-band Resonant Ring for Testing RF Windows for ILC

679

SPWR005

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

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

A resonant ring is widely used for the breakdown test of RF components under high power. It can reach power gain of more than 10dB, which is limited by the attenua-tion of the ring. An L-band resonant ring is constructed for testing RF components of International Linear Collid-er (ILC) which is based on an RF frequency of 1.3GHz. The target of the high power test is 5 MW. We have fin-ished the test of an input power of 500 W using a solid state amplifier, and the principle of the resonant ring is verified. The resonant ring is tuned to an optimal condi-tion, which is preparation for high power operation. This paper details the principle, construction, and test of the L-band resonant ring.

Poster THPO003 [2.301 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO003

About •

paper received ※ 13 September 2018 paper accepted ※ 21 September 2018 issue date ※ 18 January 2019

Export •

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

THPO008

Long-term 0peration with Beam and Cavity Performance Degradation in Compact-ERL Main Linac at KEK

695

H. Sakai, T. Furuya, E. Kako, T. Konomi, T. Miura, F. Qiu, K. Umemori
KEK, Ibaraki, Japan

We developed ERL main linac cryomodule for Compact ERL (cERL) in KEK. The module consists of two 9-cell 1.3 GHz superconducting cavities. After construction of cERL recirculation loop, beam operation was started in 2013 Dec. First electron beam of 20 MeV successfully passed the main linac cavities. Beam current increased step by step and currently reached to 1mA (CW). Energy recovery has successfully achieved. However, field emission was one of the problems for long term operation. Therefore, the performance of the SRF cavities through long term beam operation has been investigated. In this paper, we express the measurement of the cavity performances and its degradation during long term beam operation. We also described the details of the cavity performance degradation and some trial for the cavity performance recovery.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO008

About •

paper received ※ 11 September 2018 paper accepted ※ 20 September 2018 issue date ※ 18 January 2019

Export •

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

THPO096

Design Study of a High Efficiency Klystron for SuperKEKB Linac

901

F. Qiu, S. Fukuda, S. Matsumoto, T. Matsumoto, T. Miura, T. Natsui
KEK, Ibaraki, Japan

The injector linear accelerator (linac) for the SuperKEKB particle accelerator requires a higher efficiency klystron than the currently used 50 MW, S-band, pulsed unit (PV3050/E3730), which operates at the same voltage, to increase the power redundancy. The efficiency is expected to improve from the currently observed 45% to more than 60%. We propose a type of high efficiency klystron using novel bunching mechanisms. The 1-D disk model based code is used for preliminary optimization of the tube parameters; these parameters are further checked by 2-D codes known as field charge interaction (FCI) and MAGIC. In this paper, the design consideration of the high efficiency klystron is presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO096

About •

paper received ※ 12 September 2018 paper accepted ※ 20 September 2018 issue date ※ 18 January 2019

Export •

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