IPAC2011 - List of Authors (Saeki, T.)

Paper

Title

Page

S1-Global Module Tests at STF/KEK

38

D. Kostin, K. Jensch, L. Lilje, A. Matheisen, W.-D. Möller, P. Schilling, M. Schmökel, N.J. Walker, H. Weise
DESY, Hamburg, Germany
C. Adolphsen, C.D. Nantista
SLAC, Menlo Park, California, USA
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, Y. Yamamoto, K. Yokoya
KEK, Ibaraki, Japan
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

S1-Global collaborative effort of INFN, DESY, FNAL, SLAC and KEK, recently successfully finished at KEK as a part of ILC GDE, is an important milestone for the ILC. International collaboration of three regions, Asia, North America and Europe, proved to be efficient on the construction and cold tests of the accelerating module consisting of 8 SRF cavities; 2 from FNAL, 2 from DESY and 4 from KEK. Three different cavity tuning systems were tested together with two types of high power couplers. The module was cooled down three times which enabled extensive high power tests with cavities, performance limits investigation, Lorentz force detuning tests, simultaneous multiple cavities operation and other activities such as an operation test of distributed RF scheme with low level RF feedback. The results of this S1-Global module test are presented and discussed.

Slides MOODA02 [2.982 MB]

MOPC092

Effect of Current Densities on Sulfur Generation at Electropolished Niobium Surface

292

P.V. Tyagi
Sokendai, Ibaraki, Japan
H. Hayano, S. Kato, M. Nishiwaki, T. Noguchi, T. Saeki, M. Sawabe
KEK, Ibaraki, Japan

We conducted a series of electropolishing (EP) experiments in aged EP acid with high (≈50 mA/cm²) and low (≈30 mA/cm²) current densities on Nb surfaces. The experiments were carried out both for laboratory coupons and a real Nb single cell cavity with six witness samples located at three typical positions (equator, iris and beam pipe). All the samples surface were investigated by XPS (x-ray photoelectron spectroscopy), SEM (scanning electron microscope) and EDX (energy dispersive x-ray spectroscopy). The surface analysis showed the EP with a high current density produced a huge amount sulfate particles at Nb surface whereas the EP with a low current density is very helpful to mitigate sulfate at Nb surface in both the experiments.

WEPO035

Thermal Performance of the S1-Global Cryomodule for ILC

2472

N. Ohuchi, M. Akemoto, S. Fukuda, K. Hara, H. Hayano, N. Higashi, E. Kako, Y. Kojima, Y. Kondo, T. Matsumoto, S. Michizono, T. Miura, H. Nakai, H. Nakajima, K. Nakanishi, S. Noguchi, T. Saeki, M. Satoh, T. Shidara, T. Shishido, T. Takenaka, A. Terashima, N. Toge, K. Tsuchiya, K. Watanabe, S. Yamaguchi, A. Yamamoto, Y. Yamamoto, K. Yokoya
KEK, Ibaraki, Japan
T.T. Arkan, S. Barbanotti, 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
Fermilab, Batavia, USA
A. Bosotti, C. Pagani, R. Paparella, P. Pierini
INFN/LASA, Segrate (MI), Italy
D. Kostin, L. Lilje, A. Matheisen, W.-D. Möller, N.J. Walker, H. Weise
DESY, Hamburg, Germany

The S1-Global program is the international research collaboration among INFN, FNAL, DESY, SLAC and KEK as one of the GDE R&D for construction of ILC. The S1-Global cryomodule consists of two half-size cryomodules of 6 meter. One was designed by IFNF, and it contained two FNAL cavities and two DESY cavities. The associated components, like input couplers and RF cables, were same as the TTF-III cryomodule. The other was designed by KEK, and the thermal design was based on the TTF-III cryomodule. This cryomodule contains four KEK cavities with the associated components which were designed by KEK. For characterizing the thermal performances of two cryomodules, the static heat load and the temperature profiles of the cold components were measured. The temperature profiles of the components were compared between two cryomodules and the static heat load was evaluated with the design values of the cryomodules. The dynamic losses of the DESY, FNAL and two KEK cavities at their maximum operative gradients were measured and, with the measured losses, Q values were calculated. In this paper, we will make the summary of the thermal measurements of the S1-Global cryomodule.

Paper	Title	Page
MOODA02	S1-Global Module Tests at STF/KEK	38
	D. Kostin, K. Jensch, L. Lilje, A. Matheisen, W.-D. Möller, P. Schilling, M. Schmökel, N.J. Walker, H. Weise DESY, Hamburg, Germany C. Adolphsen, C.D. Nantista SLAC, Menlo Park, California, USA 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, Y. Yamamoto, K. Yokoya KEK, Ibaraki, Japan 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
	S1-Global collaborative effort of INFN, DESY, FNAL, SLAC and KEK, recently successfully finished at KEK as a part of ILC GDE, is an important milestone for the ILC. International collaboration of three regions, Asia, North America and Europe, proved to be efficient on the construction and cold tests of the accelerating module consisting of 8 SRF cavities; 2 from FNAL, 2 from DESY and 4 from KEK. Three different cavity tuning systems were tested together with two types of high power couplers. The module was cooled down three times which enabled extensive high power tests with cavities, performance limits investigation, Lorentz force detuning tests, simultaneous multiple cavities operation and other activities such as an operation test of distributed RF scheme with low level RF feedback. The results of this S1-Global module test are presented and discussed.
	Slides MOODA02 [2.982 MB]

MOPC092	Effect of Current Densities on Sulfur Generation at Electropolished Niobium Surface	292
	P.V. Tyagi Sokendai, Ibaraki, Japan H. Hayano, S. Kato, M. Nishiwaki, T. Noguchi, T. Saeki, M. Sawabe KEK, Ibaraki, Japan
	We conducted a series of electropolishing (EP) experiments in aged EP acid with high (≈50 mA/cm²) and low (≈30 mA/cm²) current densities on Nb surfaces. The experiments were carried out both for laboratory coupons and a real Nb single cell cavity with six witness samples located at three typical positions (equator, iris and beam pipe). All the samples surface were investigated by XPS (x-ray photoelectron spectroscopy), SEM (scanning electron microscope) and EDX (energy dispersive x-ray spectroscopy). The surface analysis showed the EP with a high current density produced a huge amount sulfate particles at Nb surface whereas the EP with a low current density is very helpful to mitigate sulfate at Nb surface in both the experiments.

WEPO035	Thermal Performance of the S1-Global Cryomodule for ILC	2472
	N. Ohuchi, M. Akemoto, S. Fukuda, K. Hara, H. Hayano, N. Higashi, E. Kako, Y. Kojima, Y. Kondo, T. Matsumoto, S. Michizono, T. Miura, H. Nakai, H. Nakajima, K. Nakanishi, S. Noguchi, T. Saeki, M. Satoh, T. Shidara, T. Shishido, T. Takenaka, A. Terashima, N. Toge, K. Tsuchiya, K. Watanabe, S. Yamaguchi, A. Yamamoto, Y. Yamamoto, K. Yokoya KEK, Ibaraki, Japan T.T. Arkan, S. Barbanotti, 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 Fermilab, Batavia, USA A. Bosotti, C. Pagani, R. Paparella, P. Pierini INFN/LASA, Segrate (MI), Italy D. Kostin, L. Lilje, A. Matheisen, W.-D. Möller, N.J. Walker, H. Weise DESY, Hamburg, Germany
	The S1-Global program is the international research collaboration among INFN, FNAL, DESY, SLAC and KEK as one of the GDE R&D for construction of ILC. The S1-Global cryomodule consists of two half-size cryomodules of 6 meter. One was designed by IFNF, and it contained two FNAL cavities and two DESY cavities. The associated components, like input couplers and RF cables, were same as the TTF-III cryomodule. The other was designed by KEK, and the thermal design was based on the TTF-III cryomodule. This cryomodule contains four KEK cavities with the associated components which were designed by KEK. For characterizing the thermal performances of two cryomodules, the static heat load and the temperature profiles of the cold components were measured. The temperature profiles of the components were compared between two cryomodules and the static heat load was evaluated with the design values of the cryomodules. The dynamic losses of the DESY, FNAL and two KEK cavities at their maximum operative gradients were measured and, with the measured losses, Q values were calculated. In this paper, we will make the summary of the thermal measurements of the S1-Global cryomodule.