SRF2011 - List of Authors (Khabiboulline, T.N.)

Paper

Title

Page

Design of Single Spoke Resonators for Project X

122

L. Ristori, S. Barbanotti, P. Berrutti, M.S. Champion, M.H. Foley, C.M. Ginsburg, I.G. Gonin, C.J. Grimm, T.N. Khabiboulline, D. Passarelli, N. Solyak, A. Vostrikov, V.P. Yakovlev
Fermilab, Batavia, USA

Funding: Operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the U.S. Department of Energy.
Project X is based on a 3 GeV CW superconducting linac and is currently in the R&D phase awaiting CD-0 approval. The low-energy section of the Project X H⁻ linac (starting at 2.5 MeV) includes three types of super-conducting single spoke cavities operating at 325 MHz. The first three cryomodules will each house 7 SSR0 cavities at β = 0.11. The following two cryomodules will each contain 10 SSR1 cavities each at β = 0.21. The last four cryomodules will contain 11 SSR2 cavities each at β = 0.4. Single spoke cavities were selected for the linac in virtue of their higher r/Q values compared to standard Half Wave Resonator. Quarter Wave Resonators were not considered for such a high frequency. In this paper we present the decisions and analyses that lead to the final design of SSR0. Electro-magnetic and mechanical finite element analyses were performed with the purpose of optimizing the electro-magnetic design, minimizing frequency shifts due to helium bath pressure fluctuations and providing a pressure rating for the resonators that allow their use in the cryomodules.

TUPO001

Development of Quality Assurance Procedures for the Fast/Slow Tuners on the 1.3 GHz SRF Cavities for the SRF Accelerator Test Facility at Fermilab

344

Y.M. Pischalnikov, S. Barbanotti, C.J. Grimm, T.N. Khabiboulline, R.V. Pilipenko, W. Schappert
Fermilab, Batavia, USA

The 1.3 GHz elliptical SRF cavities being prepared for cryomodules of the Fermilab SRF Accelerator Test Facility are equipped with coaxial blade tuners. Quality Assurance tests of these tuners during initial installation, cold testing in the Horizontal Test Stand and during string assembly are described.

Poster TUPO001 [1.811 MB]

TUPO006

High Power Couplers for the Project X Linac

361

S. Kazakov, M.S. Champion, S. Cheban, T.N. Khabiboulline, M. Kramp, Y. Orlov, O. Pronitchev, V.P. Yakovlev
Fermilab, Batavia, USA

Project X, a multi-megawatt proton source under development at Fermi National Accelerator Laboratory. [1]. The key element of the project is a superconducting (SC) 3GV continuous wave (CW) proton linac. The linac includes 5 types of SC accelerating cavities of two frequencies.(325 and 650MHz) The cavities consume up to 30 kW average RF power and need proper main couplers. Requirements and approach to the coupler design are discussed in the report. Results of electrodynamics and thermal simulations are presented. New cost effective schemes are described.

TUPO048

Commissioning and Upgrade of Automatic Cavity Tuning Machines for the European Xfel

495

J.H. Thie, A. Gössel, J. Iversen, D. Klinke, G. Kreps, W.-D. Möller, C. Mueller, H.-B. Peters, A.A. Sulimov, D. Tischhauser
DESY, Hamburg, Germany
D. Bhogadi, R.H. Carcagno, T.N. Khabiboulline, S. Kotelnikov, A. Makulski, R. Nehring, J.M. Nogiec, W. Schappert, C. Sylvester
Fermilab, Batavia, USA

Four new tuning machines were developed and built in a collaborating effort among FNAL, KEK and DESY. Two machines were commissioned at DESY in a close teamwork with FNAL. For several months, these machines have been used regularly for the automatic tuning of different types of cavities for FLASH. Due to this operating experience and the requirements for the European XFEL cavity Specification, it was necessary to implement the following improvements: improve the precision of the eccentricity measurement; change the tuning sequence according to the different production stages in the cavity fabrication and preparation process; review and change the machine access procedures according to the safety aspects of the EC Directive of Machinery. These improvements required changes in both the mechanical parts developed by DESY and the electronics and software developed by FNAL. We report in detail about the commissioning, our tuning experience and the necessary improvements.

Poster TUPO048 [0.257 MB]

THIOA07

Single-cell SC Cavity Development in India

659

A. Puntambekar, J. Dwivedi, P.D. Gupta, S.C. Joshi, G. Mundra, P. Shrivastava
RRCAT, Indore (M.P.), India
C.A. Cooper, M.H. Foley, T.N. Khabiboulline, C.S. Mishra, J.P. Ozelis, A.M. Rowe
Fermilab, Batavia, USA
P.N. Potukuchi
IUAC, New Delhi, India
G. Wu
ANL, Argonne, USA

Under Indian Institutions and Fermilab Collaboration (IIFC), Raja Ramanna Centre for Advanced Technology (RRCAT) Indore, India has initiated the development of SCRF cavity technology in collaboration with Fermi National Accelerator Laboratory (FNAL) USA. The R & D efforts are focused on the proposed Project-X accelerator complex at FNAL and High Intensity Proton Accelerator activities in India. As an initial effort, two prototype 1.3 GHz single cell bulk niobium cavities have been developed in collaboration with the Inter University Accelerator Centre (IUAC), New Delhi. Learning from the experience gained and the initial results of these prototypes (achieving Eacc ~23 MV/m), two more improved 1.3 GHz single cell cavities are being developed. These two improved single cell cavities will also be processed and tested at FNAL. Development of a 1.3 GHz, 5-cell SCRF cavity with simple end groups, development of end group, and fabrication of a single -cell 650 MHz (β=0.9) prototype cavity are being undertaken as the next stage in these efforts. This paper will present the development and test results on the 1.3 GHz single cell cavities and status of the ongoing work.

Slides THIOA07 [2.937 MB]

THPO023

External Magnetic Fields and Operating SRF Cavity

763

D.A. Sergatskov, T.N. Khabiboulline, R.L. Madrak, J.P. Ozelis, I. Terechkine
Fermilab, Batavia, USA

Funding: The work herein has been performed at Fermilab, which is operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy.
When an SRF cavity is undergoing a transition to the superconducting state in an external magnetic field it traps some of the flux which results in an increase of surface resistance. This effect was extensively studied, is well understood by now and results in stringent requirements for an ambient magnetic field on the surface of an SRF cavity. The situation is quite different when magnetic field is applied to a cavity already in the superconducting state. During normal operation the bulk of the superconducting Nb should protect the RF surface of the cavity from fields on the outside. So we expect that the requirements on an external magnetic field applied to an operating cavity could be significantly relaxed. One possible failure mode is when the cavity quenches while the external field is applied. The magnetic field would penetrate through a normal zone formed during the quench and can get trapped during the subsequent post-quench cooling. We studied the effects of an external magnetic field applied to an operating SRF cavity and report the results.

Poster THPO023 [1.370 MB]

Paper	Title	Page
MOPO024	Design of Single Spoke Resonators for Project X	122
	L. Ristori, S. Barbanotti, P. Berrutti, M.S. Champion, M.H. Foley, C.M. Ginsburg, I.G. Gonin, C.J. Grimm, T.N. Khabiboulline, D. Passarelli, N. Solyak, A. Vostrikov, V.P. Yakovlev Fermilab, Batavia, USA
	Funding: Operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the U.S. Department of Energy. Project X is based on a 3 GeV CW superconducting linac and is currently in the R&D phase awaiting CD-0 approval. The low-energy section of the Project X H⁻ linac (starting at 2.5 MeV) includes three types of super-conducting single spoke cavities operating at 325 MHz. The first three cryomodules will each house 7 SSR0 cavities at β = 0.11. The following two cryomodules will each contain 10 SSR1 cavities each at β = 0.21. The last four cryomodules will contain 11 SSR2 cavities each at β = 0.4. Single spoke cavities were selected for the linac in virtue of their higher r/Q values compared to standard Half Wave Resonator. Quarter Wave Resonators were not considered for such a high frequency. In this paper we present the decisions and analyses that lead to the final design of SSR0. Electro-magnetic and mechanical finite element analyses were performed with the purpose of optimizing the electro-magnetic design, minimizing frequency shifts due to helium bath pressure fluctuations and providing a pressure rating for the resonators that allow their use in the cryomodules.

TUPO001	Development of Quality Assurance Procedures for the Fast/Slow Tuners on the 1.3 GHz SRF Cavities for the SRF Accelerator Test Facility at Fermilab	344
	Y.M. Pischalnikov, S. Barbanotti, C.J. Grimm, T.N. Khabiboulline, R.V. Pilipenko, W. Schappert Fermilab, Batavia, USA
	The 1.3 GHz elliptical SRF cavities being prepared for cryomodules of the Fermilab SRF Accelerator Test Facility are equipped with coaxial blade tuners. Quality Assurance tests of these tuners during initial installation, cold testing in the Horizontal Test Stand and during string assembly are described.
	Poster TUPO001 [1.811 MB]

TUPO006	High Power Couplers for the Project X Linac	361
	S. Kazakov, M.S. Champion, S. Cheban, T.N. Khabiboulline, M. Kramp, Y. Orlov, O. Pronitchev, V.P. Yakovlev Fermilab, Batavia, USA
	Project X, a multi-megawatt proton source under development at Fermi National Accelerator Laboratory. [1]. The key element of the project is a superconducting (SC) 3GV continuous wave (CW) proton linac. The linac includes 5 types of SC accelerating cavities of two frequencies.(325 and 650MHz) The cavities consume up to 30 kW average RF power and need proper main couplers. Requirements and approach to the coupler design are discussed in the report. Results of electrodynamics and thermal simulations are presented. New cost effective schemes are described.

TUPO048	Commissioning and Upgrade of Automatic Cavity Tuning Machines for the European Xfel	495
	J.H. Thie, A. Gössel, J. Iversen, D. Klinke, G. Kreps, W.-D. Möller, C. Mueller, H.-B. Peters, A.A. Sulimov, D. Tischhauser DESY, Hamburg, Germany D. Bhogadi, R.H. Carcagno, T.N. Khabiboulline, S. Kotelnikov, A. Makulski, R. Nehring, J.M. Nogiec, W. Schappert, C. Sylvester Fermilab, Batavia, USA
	Four new tuning machines were developed and built in a collaborating effort among FNAL, KEK and DESY. Two machines were commissioned at DESY in a close teamwork with FNAL. For several months, these machines have been used regularly for the automatic tuning of different types of cavities for FLASH. Due to this operating experience and the requirements for the European XFEL cavity Specification, it was necessary to implement the following improvements: improve the precision of the eccentricity measurement; change the tuning sequence according to the different production stages in the cavity fabrication and preparation process; review and change the machine access procedures according to the safety aspects of the EC Directive of Machinery. These improvements required changes in both the mechanical parts developed by DESY and the electronics and software developed by FNAL. We report in detail about the commissioning, our tuning experience and the necessary improvements.
	Poster TUPO048 [0.257 MB]

THIOA07	Single-cell SC Cavity Development in India	659
	A. Puntambekar, J. Dwivedi, P.D. Gupta, S.C. Joshi, G. Mundra, P. Shrivastava RRCAT, Indore (M.P.), India C.A. Cooper, M.H. Foley, T.N. Khabiboulline, C.S. Mishra, J.P. Ozelis, A.M. Rowe Fermilab, Batavia, USA P.N. Potukuchi IUAC, New Delhi, India G. Wu ANL, Argonne, USA
	Under Indian Institutions and Fermilab Collaboration (IIFC), Raja Ramanna Centre for Advanced Technology (RRCAT) Indore, India has initiated the development of SCRF cavity technology in collaboration with Fermi National Accelerator Laboratory (FNAL) USA. The R & D efforts are focused on the proposed Project-X accelerator complex at FNAL and High Intensity Proton Accelerator activities in India. As an initial effort, two prototype 1.3 GHz single cell bulk niobium cavities have been developed in collaboration with the Inter University Accelerator Centre (IUAC), New Delhi. Learning from the experience gained and the initial results of these prototypes (achieving Eacc ~23 MV/m), two more improved 1.3 GHz single cell cavities are being developed. These two improved single cell cavities will also be processed and tested at FNAL. Development of a 1.3 GHz, 5-cell SCRF cavity with simple end groups, development of end group, and fabrication of a single -cell 650 MHz (β=0.9) prototype cavity are being undertaken as the next stage in these efforts. This paper will present the development and test results on the 1.3 GHz single cell cavities and status of the ongoing work.
	Slides THIOA07 [2.937 MB]

THPO023	External Magnetic Fields and Operating SRF Cavity	763
	D.A. Sergatskov, T.N. Khabiboulline, R.L. Madrak, J.P. Ozelis, I. Terechkine Fermilab, Batavia, USA
	Funding: The work herein has been performed at Fermilab, which is operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy. When an SRF cavity is undergoing a transition to the superconducting state in an external magnetic field it traps some of the flux which results in an increase of surface resistance. This effect was extensively studied, is well understood by now and results in stringent requirements for an ambient magnetic field on the surface of an SRF cavity. The situation is quite different when magnetic field is applied to a cavity already in the superconducting state. During normal operation the bulk of the superconducting Nb should protect the RF surface of the cavity from fields on the outside. So we expect that the requirements on an external magnetic field applied to an operating cavity could be significantly relaxed. One possible failure mode is when the cavity quenches while the external field is applied. The magnetic field would penetrate through a normal zone formed during the quench and can get trapped during the subsequent post-quench cooling. We studied the effects of an external magnetic field applied to an operating SRF cavity and report the results.
	Poster THPO023 [1.370 MB]