SRF2017 - List of Authors (Egi, M.)

Paper	Title	Page
THYA02	Achievement of Stable Pulsed Operation at 36 MV/m in STF-2 Cryomodule at KEK	722
	Y. Yamamoto, T. Dohmae, M. Egi, K. Hara, T. Honma, E. Kako, Y. Kojima, T. Konomi, 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 cryomdoule 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 was successfully carried out. The main achievement is the vector-sum operation with 8 cavities at average accelerating gradient of 31 MV/m as the ILC specification (2 of 8 cavities achieved 36 MV/m with piezo compensation), and the others are the measurement for Lorenz Force Detuning (LFD) and unloaded Q value, and Low Level RF (LLRF) study, etc. In this paper, the result for the STF-2 cryomodule in three cooldown tests will be presented in detail.
	Slides THYA02 [4.042 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2017-THYA02
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THYA06	Long-term Operation Experience with Beams in Compact ERL Cryomodules	736
	K. Umemori, M. Egi, K. Enami, T. Furuya, Y. Honda, E. Kako, T. Konomi, H. Sakai KEK, Ibaraki, Japan T. Okada Sokendai, Ibaraki, Japan M. Sawamura QST, Tokai, Japan
	Compact ERL (cERL) was constructed at KEK as a prototype for 3GeV ERL light source. It consists of two types of SRF cavities. Three injector 2-cell SRF cavities and two main linac 9-cell SRF cavities. The beam operation started at 2013, with 100 nA (CW). Beam current increased step by step and currently reached to 1 mA (CW). Energy recovery has successfully achieved. Performance of the SRF cavities through long term beam operation has been investigated. With the beam induced HOMs, the beam position and the beam timing were studied. cERL has suffered from heavy field emissions in operation. Field emissions of the main linac cavity started just after module assembly work, and during beam operation, performances of both the main linac and the injector SRF cavities sometimes degraded. One reason of degradation was discharges occurred at beamline components due to charge up of electrons. Pulse aging technique helped to recover SRF performances. In this presentation, details of SRF beam operation, degradation, applied recovery methods are described.
	Slides THYA06 [4.973 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2017-THYA06
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Achievement of Stable Pulsed Operation at 36 MV/m in STF-2 Cryomodule at KEK

722

Y. Yamamoto, T. Dohmae, M. Egi, K. Hara, T. Honma, E. Kako, Y. Kojima, T. Konomi, 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 cryomdoule 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 was successfully carried out. The main achievement is the vector-sum operation with 8 cavities at average accelerating gradient of 31 MV/m as the ILC specification (2 of 8 cavities achieved 36 MV/m with piezo compensation), and the others are the measurement for Lorenz Force Detuning (LFD) and unloaded Q value, and Low Level RF (LLRF) study, etc. In this paper, the result for the STF-2 cryomodule in three cooldown tests will be presented in detail.

Slides THYA02 [4.042 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2017-THYA02

Export •

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

THYA06

Long-term Operation Experience with Beams in Compact ERL Cryomodules

736

K. Umemori, M. Egi, K. Enami, T. Furuya, Y. Honda, E. Kako, T. Konomi, H. Sakai
KEK, Ibaraki, Japan
T. Okada
Sokendai, Ibaraki, Japan
M. Sawamura
QST, Tokai, Japan

Compact ERL (cERL) was constructed at KEK as a prototype for 3GeV ERL light source. It consists of two types of SRF cavities. Three injector 2-cell SRF cavities and two main linac 9-cell SRF cavities. The beam operation started at 2013, with 100 nA (CW). Beam current increased step by step and currently reached to 1 mA (CW). Energy recovery has successfully achieved. Performance of the SRF cavities through long term beam operation has been investigated. With the beam induced HOMs, the beam position and the beam timing were studied. cERL has suffered from heavy field emissions in operation. Field emissions of the main linac cavity started just after module assembly work, and during beam operation, performances of both the main linac and the injector SRF cavities sometimes degraded. One reason of degradation was discharges occurred at beamline components due to charge up of electrons. Pulse aging technique helped to recover SRF performances. In this presentation, details of SRF beam operation, degradation, applied recovery methods are described.

Slides THYA06 [4.973 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2017-THYA06

Export •

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