SRF2011 - List of Authors (Hayano, H.)

Paper

Title

Page

Adaptive Lorentz Force Detuning Compensation in the ILC S1-G Cryomodule at KEK

254

W. Schappert, R.V. Pilipenko, Y.M. Pischalnikov
Fermilab, Batavia, USA
H. Hayano, E. Kako, S. Noguchi, N. Ohuchi, Y. Yamamoto
KEK, Ibaraki, Japan

The recent tests of the S1-Global cryomodule at KEK provided a unique opportunity to compare the performance of four different styles of 1.3 GHz SRF cavities and tuners under similar operating conditions. Results of adaptive LFD compensation at gradients of up to 35 MV/m for DESY/Saclay, FNAL/INFN and KEK cavity/tuner designs are compared.

Poster MOPO064 [1.506 MB]

TUPO029

Gradient Improvement by Removal of Identified Local Defects

436

R.L. Geng, W.A. Clemens
JLAB, Newport News, Virginia, USA
C.A. Cooper
Fermilab, Batavia, USA
H. Hayano, K. Watanabe
KEK, Ibaraki, Japan

Funding: This work was authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177
Recent experience of ILC cavity processing and testing at Jefferson Lab has shown that some 9-cell cavities are quench limited at a gradient in the range of 15-25 MV/m. Further studies reveal that these quench limits are often correlated with sub-mm sized and highly localized geometrical defects at or near the equator weld. There are increasing evidence to show that these genetic defects have their origin in the material or in the electron beam welding process (for example due to weld irregularities or splatters on the RF surface and welding porosity underneath the surface). A local defect removal method has been proposed at Jefferson Lab by locally re-melting the niobium material. Several 1-cell cavities with known local defects have been treated by using the JLab local e-beam re-melting method, resulting in gradient and Q0 improvement. We also sent 9-cell cavities with known gradient limiting local defects to KEK for local grinding and to FNAL for global mechanical polishing. We report on the results of gradient improvements by removal of local defects in these cavities.

TUPO030

Status of the 9-Cell Superconducting Cavity R&D for ILC at Hitachi

439

T. Watanuki, T. Semba, M. Watanabe
Hitachi Ltd., Ibaraki-ken, Japan
H. Hayano, E. Kako, S. Noguchi, T. Saeki, T. Shishido, K. Watanabe, Y. Yamamoto
KEK, Ibaraki, Japan

Hitachi is developing 9-cell superconducting cavities for ILC project in collaboration with KEK. We focus on electron beam welding (EBW) and plastic forming techniques. In 2010, Hitachi’s first 9-cell cavity without HOM couplers was completed successfully. Surface treatments and performance test of the cavity were carried out at KEK and the accelerating gradient reached 35.2 MV/m. We have undertaken the next 9-cell cavity with HOM couplers since January 2011. We will report the fabrication procedure and test result of first cavity and the current status of the next cavity.

TUPO032

Updates on R&D of Nondestructive Inspection Systems for SRF Cavities

447

Y. Iwashita, H. Tongu
Kyoto ICR, Uji, Kyoto, Japan
H. Hayano, T. Saeki, K. Watanabe
KEK, Ibaraki, Japan

We are developing high resolution eddy current scan and High density Tmap and X-map. The high resolution eddy current scan showed 100 μm diameter hole with 50μm depth that was drilled on a Nb plate. The surface mount print circuit technology is applied to the high density Tmap and X-map devices, which will be ready soon to test at a vertical test bench. In addition, radiography using Xrays and neutrons are also under study. The results and status will be presented.

Poster TUPO032 [2.362 MB]

TUPO037

Study on Electro-Polishing Process by Niobium-Plate Sample With Artificial Pits

461

T. Saeki, H. Hayano, S. Kato, M. Nishiwaki, M. Sawabe
KEK, Ibaraki, Japan
W.A. Clemens, R.L. Geng, R. Manus
JLAB, Newport News, Virginia, USA
P.V. Tyagi
Sokendai, Ibaraki, Japan

The Electro-polishing (EP) process is the best candidate of final surface-treatment for the production of ILC cavities. Nevertheless, the development of defects on the inner-surface of the Superconducting RF cavity during EP process has not been studied by experimental method. We made artificial pits on the surface of a Nb-plate sample and observed the development of the pit-shapes after each step of 30um-EP process where 120um was removed by EP in total. This article describes the results of this EP-test of Nb-sample with artificial pits.

TUPO039

Long-Term Monitoring of 2nd–Period EP-Electrolyte in STF-EP Facility at KEK

467

M. Sawabe, H. Hayano, A. Komiya, H. Monjushiro, T. Saeki, M. Satou
KEK, Ibaraki, Japan

We have constructed an Electro-polishing (EP) Facility in the Superconducting RF Test Facility (STF) at KEK at the end of 2007. We have begun to operate the EP facility since 2008 and performed the EP process of cavity about 140 times up to now. During this period, we exchanged EP-electrolyte twice in the 2,000L tank. We are performing EP processes with the 3rd–period EP-electrolyte at the present moment. By this report, we report the long-term monitoring results of the 2nd–period EP-electrolyte used from May, 2009 to July, 2010.

WEIOB02

Cavity Inspection and Repair Techniques

598

K. Watanabe, H. Hayano
KEK, Ibaraki, Japan
Y. Iwashita
Kyoto ICR, Uji, Kyoto, Japan

The cavity inspection and repair techniques are important to study a quality control of the superconducting rf cavity for better yield with high accelerating gradient. A high-resolution camera system was developed for optical inspection in 2008. It enables 2-D analysis by image processing on inner surface of the cavity. Therefore, the cause to limit the cavity performance can be categorized into a geometrical defect or an assembly work and the surface treatment. In addition, by perfoming the optical inspection at each treatment, we can obtain an information when a defect appeared. The cavities that quenched at the low field were inspected. One or few geometrical defects were found around quench location on some of these cavities. It is a possibility that the cavity performance can be recovered by removing the geometrical defect at the quench location. A local grinding machine was developed for this purpose. This method was tested on the 9-cell cavities, and we succeeded to recover the cavity performance with combination of local grinding and light EP. The method and results of the cavity inspection as well as the replica techniques will be presented in this talk.

THIOA01

Test Results of the International S1-Global Cryomodule

615

Y. Yamamoto, M. Akemoto, S. Fukuda, K. Hara, H. Hayano, N. Higashi, E. Kako, H. Katagiri, Y. Kojima, Y. Kondo, T. Matsumoto, H. Matsushita, S. Michizono, T. Miura, H. Nakai, H. Nakajima, K. Nakanishi, S. Noguchi, N. Ohuchi, T. Saeki, M. Satoh, T. Shidara, T. Shishido, T. Takenaka, A. Terashima, N. Toge, K. Tsuchiya, K. Watanabe, S. Yamaguchi, A. Yamamoto, K. Yokoya, M. Yoshida
KEK, Ibaraki, Japan
C. Adolphsen, C.D. Nantista
SLAC, Menlo Park, California, USA
T.T. Arkan, S. Barbanotti, M.A. Battistoni, H. Carter, M.S. Champion, A. Hocker, R.D. Kephart, J.S. Kerby, D.V. Mitchell, T.J. Peterson, Y.M. Pischalnikov, M.C. Ross, W. Schappert, B.E. Smith
Fermilab, Batavia, USA
A. Bosotti, C. Pagani, R. Paparella, P. Pierini
INFN/LASA, Segrate (MI), Italy
K. Jensch, D. Kostin, L. Lilje, A. Matheisen, W.-D. Möller, P. Schilling, M. Schmökel, N.J. Walker, H. Weise
DESY, Hamburg, Germany

S1-Global collaborative project by joint efforts of INFN, DESY, FNAL, SLAC and KEK, finished successfully at KEK- STF on February in 2011, is a crucial project for ILC. For this project, 8 SRF cavities, 2 from DESY, 2 from FNAL and 4 from KEK, were installed into one cryomodule with the thermal shields and the cooling pipes of liquid helium and nitrogen, cooled down to 2K totally three times, and cold-tested by using the three different frequency tuning systems (Blade tuner from INFN/FNAL, Saclay tuner from DESY and Slide-Jack tuner from KEK) and two types of input couplers (TTF III from DESY and STF#2 from KEK). During the cold test with high power, cavity performance, LFD (Lorentz Force Detuning) compensation by Piezo actuator, simultaneous 7 SRF cavities operation, dynamic heating loss measurement including static loss and DRFS (Distributed RF Scheme) operation with LLRF (Low Level RF) feedback system, were established successfully. In this talk, the results of the S1-Global cryomodule test are reported, discussed and summarized.

Slides THIOA01 [11.254 MB]

Paper	Title	Page
MOPO064	Adaptive Lorentz Force Detuning Compensation in the ILC S1-G Cryomodule at KEK	254
	W. Schappert, R.V. Pilipenko, Y.M. Pischalnikov Fermilab, Batavia, USA H. Hayano, E. Kako, S. Noguchi, N. Ohuchi, Y. Yamamoto KEK, Ibaraki, Japan
	The recent tests of the S1-Global cryomodule at KEK provided a unique opportunity to compare the performance of four different styles of 1.3 GHz SRF cavities and tuners under similar operating conditions. Results of adaptive LFD compensation at gradients of up to 35 MV/m for DESY/Saclay, FNAL/INFN and KEK cavity/tuner designs are compared.
	Poster MOPO064 [1.506 MB]

TUPO029	Gradient Improvement by Removal of Identified Local Defects	436
	R.L. Geng, W.A. Clemens JLAB, Newport News, Virginia, USA C.A. Cooper Fermilab, Batavia, USA H. Hayano, K. Watanabe KEK, Ibaraki, Japan
	Funding: This work was authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177 Recent experience of ILC cavity processing and testing at Jefferson Lab has shown that some 9-cell cavities are quench limited at a gradient in the range of 15-25 MV/m. Further studies reveal that these quench limits are often correlated with sub-mm sized and highly localized geometrical defects at or near the equator weld. There are increasing evidence to show that these genetic defects have their origin in the material or in the electron beam welding process (for example due to weld irregularities or splatters on the RF surface and welding porosity underneath the surface). A local defect removal method has been proposed at Jefferson Lab by locally re-melting the niobium material. Several 1-cell cavities with known local defects have been treated by using the JLab local e-beam re-melting method, resulting in gradient and Q0 improvement. We also sent 9-cell cavities with known gradient limiting local defects to KEK for local grinding and to FNAL for global mechanical polishing. We report on the results of gradient improvements by removal of local defects in these cavities.

TUPO030	Status of the 9-Cell Superconducting Cavity R&D for ILC at Hitachi	439
	T. Watanuki, T. Semba, M. Watanabe Hitachi Ltd., Ibaraki-ken, Japan H. Hayano, E. Kako, S. Noguchi, T. Saeki, T. Shishido, K. Watanabe, Y. Yamamoto KEK, Ibaraki, Japan
	Hitachi is developing 9-cell superconducting cavities for ILC project in collaboration with KEK. We focus on electron beam welding (EBW) and plastic forming techniques. In 2010, Hitachi’s first 9-cell cavity without HOM couplers was completed successfully. Surface treatments and performance test of the cavity were carried out at KEK and the accelerating gradient reached 35.2 MV/m. We have undertaken the next 9-cell cavity with HOM couplers since January 2011. We will report the fabrication procedure and test result of first cavity and the current status of the next cavity.

TUPO032	Updates on R&D of Nondestructive Inspection Systems for SRF Cavities	447
	Y. Iwashita, H. Tongu Kyoto ICR, Uji, Kyoto, Japan H. Hayano, T. Saeki, K. Watanabe KEK, Ibaraki, Japan
	We are developing high resolution eddy current scan and High density Tmap and X-map. The high resolution eddy current scan showed 100 μm diameter hole with 50μm depth that was drilled on a Nb plate. The surface mount print circuit technology is applied to the high density Tmap and X-map devices, which will be ready soon to test at a vertical test bench. In addition, radiography using Xrays and neutrons are also under study. The results and status will be presented.
	Poster TUPO032 [2.362 MB]

TUPO037	Study on Electro-Polishing Process by Niobium-Plate Sample With Artificial Pits	461
	T. Saeki, H. Hayano, S. Kato, M. Nishiwaki, M. Sawabe KEK, Ibaraki, Japan W.A. Clemens, R.L. Geng, R. Manus JLAB, Newport News, Virginia, USA P.V. Tyagi Sokendai, Ibaraki, Japan
	The Electro-polishing (EP) process is the best candidate of final surface-treatment for the production of ILC cavities. Nevertheless, the development of defects on the inner-surface of the Superconducting RF cavity during EP process has not been studied by experimental method. We made artificial pits on the surface of a Nb-plate sample and observed the development of the pit-shapes after each step of 30um-EP process where 120um was removed by EP in total. This article describes the results of this EP-test of Nb-sample with artificial pits.

TUPO039	Long-Term Monitoring of 2nd–Period EP-Electrolyte in STF-EP Facility at KEK	467
	M. Sawabe, H. Hayano, A. Komiya, H. Monjushiro, T. Saeki, M. Satou KEK, Ibaraki, Japan
	We have constructed an Electro-polishing (EP) Facility in the Superconducting RF Test Facility (STF) at KEK at the end of 2007. We have begun to operate the EP facility since 2008 and performed the EP process of cavity about 140 times up to now. During this period, we exchanged EP-electrolyte twice in the 2,000L tank. We are performing EP processes with the 3rd–period EP-electrolyte at the present moment. By this report, we report the long-term monitoring results of the 2nd–period EP-electrolyte used from May, 2009 to July, 2010.

WEIOB02	Cavity Inspection and Repair Techniques	598
	K. Watanabe, H. Hayano KEK, Ibaraki, Japan Y. Iwashita Kyoto ICR, Uji, Kyoto, Japan
	The cavity inspection and repair techniques are important to study a quality control of the superconducting rf cavity for better yield with high accelerating gradient. A high-resolution camera system was developed for optical inspection in 2008. It enables 2-D analysis by image processing on inner surface of the cavity. Therefore, the cause to limit the cavity performance can be categorized into a geometrical defect or an assembly work and the surface treatment. In addition, by perfoming the optical inspection at each treatment, we can obtain an information when a defect appeared. The cavities that quenched at the low field were inspected. One or few geometrical defects were found around quench location on some of these cavities. It is a possibility that the cavity performance can be recovered by removing the geometrical defect at the quench location. A local grinding machine was developed for this purpose. This method was tested on the 9-cell cavities, and we succeeded to recover the cavity performance with combination of local grinding and light EP. The method and results of the cavity inspection as well as the replica techniques will be presented in this talk.

THIOA01	Test Results of the International S1-Global Cryomodule	615
	Y. Yamamoto, M. Akemoto, S. Fukuda, K. Hara, H. Hayano, N. Higashi, E. Kako, H. Katagiri, Y. Kojima, Y. Kondo, T. Matsumoto, H. Matsushita, S. Michizono, T. Miura, H. Nakai, H. Nakajima, K. Nakanishi, S. Noguchi, N. Ohuchi, T. Saeki, M. Satoh, T. Shidara, T. Shishido, T. Takenaka, A. Terashima, N. Toge, K. Tsuchiya, K. Watanabe, S. Yamaguchi, A. Yamamoto, K. Yokoya, M. Yoshida KEK, Ibaraki, Japan C. Adolphsen, C.D. Nantista SLAC, Menlo Park, California, USA T.T. Arkan, S. Barbanotti, M.A. Battistoni, H. Carter, M.S. Champion, A. Hocker, R.D. Kephart, J.S. Kerby, D.V. Mitchell, T.J. Peterson, Y.M. Pischalnikov, M.C. Ross, W. Schappert, B.E. Smith Fermilab, Batavia, USA A. Bosotti, C. Pagani, R. Paparella, P. Pierini INFN/LASA, Segrate (MI), Italy K. Jensch, D. Kostin, L. Lilje, A. Matheisen, W.-D. Möller, P. Schilling, M. Schmökel, N.J. Walker, H. Weise DESY, Hamburg, Germany
	S1-Global collaborative project by joint efforts of INFN, DESY, FNAL, SLAC and KEK, finished successfully at KEK- STF on February in 2011, is a crucial project for ILC. For this project, 8 SRF cavities, 2 from DESY, 2 from FNAL and 4 from KEK, were installed into one cryomodule with the thermal shields and the cooling pipes of liquid helium and nitrogen, cooled down to 2K totally three times, and cold-tested by using the three different frequency tuning systems (Blade tuner from INFN/FNAL, Saclay tuner from DESY and Slide-Jack tuner from KEK) and two types of input couplers (TTF III from DESY and STF#2 from KEK). During the cold test with high power, cavity performance, LFD (Lorentz Force Detuning) compensation by Piezo actuator, simultaneous 7 SRF cavities operation, dynamic heating loss measurement including static loss and DRFS (Distributed RF Scheme) operation with LLRF (Low Level RF) feedback system, were established successfully. In this talk, the results of the S1-Global cryomodule test are reported, discussed and summarized.
	Slides THIOA01 [11.254 MB]