IPAC2017 - List of Authors (Yamamoto, Y.)

Paper	Title	Page
MOPVA073	Development of Peak Hold Module for Electron Emission in STF-Type Power Coupler for the ILC	1034
	Y. Yamamoto, E. Kako, T. Shishido KEK, Ibaraki, Japan
	In STF, the RF conditioning for power coupler is done in several steps from 10 to 1650 μs as specified in TDR for the ILC. The most important signals during the RF conditioning are vacuum level, and electron emission by multipacting. The vacuum level changes continuously, and electron emission has pulse-like behavior, which has much faster response. Therefore, it was necessary to develop the peak hold and isolation modules to evaluate electron emission in short pulse width. This module has two kinds of feature. One is pulse height detection, and the other is total charge detection (integrated signal). During the RF conditioning for power couplers in STF-2 cryomodule, this module perfectly worked, and detected different trend between the pulse height and the total charge. In this paper, the detailed result for the peak hold module will be presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPVA073
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MOPVA075	Development of High Sensitive X-Ray Mapping for SC Cavities	1040
	H. Tongu, H. Hokonohara, Y. Iwashita Kyoto ICR, Uji, Kyoto, Japan R.L. Geng, A.D. Palczewski JLab, Newport News, Virginia, USA H. Hayano, T. Kubo, T. Saeki, Y. Yamamoto KEK, Ibaraki, Japan H. Oikawa Utsunomiya University, Utsunomiya, Japan
	We developed an X-ray mapping system sX-map for superconducting cavities. The sensors are inserted under the stiffener rings between cavity cells, whose locations are close to the iris areas. The whole circuits are im-mersed in liquid He and the multiplexed signals reduces the number of cables to the room temperature region. sX-map has the advantages in its compact size, low cost and simple setup for nondestructive inspections. The sX-map system detected X-rays from field emissions in vertical RF tests of ILC 9-cell cavities at Jefferson Lab (JLab) and KEK. sX-map showed an excellent performance in the meas-urement test at JLab, it exhibited a high sensitivity com-pared with an the fixed diode rings colocated at irises and ion chamber located out side of the vertical test cryostat.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPVA075
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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
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Paper

Title

Page

Development of Peak Hold Module for Electron Emission in STF-Type Power Coupler for the ILC

1034

Y. Yamamoto, E. Kako, T. Shishido
KEK, Ibaraki, Japan

In STF, the RF conditioning for power coupler is done in several steps from 10 to 1650 μs as specified in TDR for the ILC. The most important signals during the RF conditioning are vacuum level, and electron emission by multipacting. The vacuum level changes continuously, and electron emission has pulse-like behavior, which has much faster response. Therefore, it was necessary to develop the peak hold and isolation modules to evaluate electron emission in short pulse width. This module has two kinds of feature. One is pulse height detection, and the other is total charge detection (integrated signal). During the RF conditioning for power couplers in STF-2 cryomodule, this module perfectly worked, and detected different trend between the pulse height and the total charge. In this paper, the detailed result for the peak hold module will be presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPVA073

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MOPVA075

Development of High Sensitive X-Ray Mapping for SC Cavities

1040

H. Tongu, H. Hokonohara, Y. Iwashita
Kyoto ICR, Uji, Kyoto, Japan
R.L. Geng, A.D. Palczewski
JLab, Newport News, Virginia, USA
H. Hayano, T. Kubo, T. Saeki, Y. Yamamoto
KEK, Ibaraki, Japan
H. Oikawa
Utsunomiya University, Utsunomiya, Japan

We developed an X-ray mapping system sX-map for superconducting cavities. The sensors are inserted under the stiffener rings between cavity cells, whose locations are close to the iris areas. The whole circuits are im-mersed in liquid He and the multiplexed signals reduces the number of cables to the room temperature region. sX-map has the advantages in its compact size, low cost and simple setup for nondestructive inspections. The sX-map system detected X-rays from field emissions in vertical RF tests of ILC 9-cell cavities at Jefferson Lab (JLab) and KEK. sX-map showed an excellent performance in the meas-urement test at JLab, it exhibited a high sensitivity com-pared with an the fixed diode rings colocated at irises and ion chamber located out side of the vertical test cryostat.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPVA075

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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)