SRF2019 - List of Authors (Chandrasekaran, S.K.)

Paper	Title	Page
MOP094	Design Strategy of the PIP-II Cryomodules	307
	V. Roger, S.K. Chandrasekaran, D. Passarelli Fermilab, Batavia, Illinois, USA
	Funding: This manuscript has been authored by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the U.S. Department of Energy, Office of Science, Office of High Energy Physics The Proton Improvement Plan II (PIP-II) is the first U.S. accelerator project that will have significant contributions from international partners. Research institutions in India, Italy, UK and France will build major components of the particle accelerator. The High Beta 650 MHz (HB650) prototype cryomodule is being designed jointly between Fermilab (USA), CEA (France), STFC (UK) and RRCAT (India). The assembly of this prototype cryomodule will be done at Fermilab whereas the production cryomodules will be assembled in UK. Concerning the Low Beta 650 MHz (LB650) cryomodules, they will be designed and assembled at CEA. To reduce the cost of the project and to increase the quality it is essential to define a design strategy for each cryomodule which includes a degree of standardization. In this way, the lessons learned of each prototype cryomodule will have a great impact not only on one cryomodule type but on all cryomodules. An international joint design brings also additional challenges to the project: which unit system should be used? Should a common project lifecycle management system be used for all partners? How to transport the cryomodules overseas.
	Poster MOP094 [1.117 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-MOP094
About •	paper received ※ 21 June 2019 paper accepted ※ 30 June 2019 issue date ※ 14 August 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUP083	Performance of the 650 MHz SRF Cavity Tuner for PIP II Project	652
	Y.M. Pischalnikov, S.K. Chandrasekaran, S. Cheban, I.V. Gonin, T.N. Khabiboulline, V.P. Yakovlev, J.C. Yun Fermilab, Batavia, Illinois, USA C. Contreras-Martinez FRIB, East Lansing, Michigan, USA
	The PIP-II linac will include fifty seven 650MHz SRF cavities. Each cavity will be equipped with tuner for coarse and fine frequency tuning. Design and operations parameters will be discussed. Results from room temperature tests with prototype tuner installed on a 650MHz ¿_G=0.90 elliptical cavity will be presented.
	Poster TUP083 [1.567 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-TUP083
About •	paper received ※ 23 June 2019 paper accepted ※ 02 July 2019 issue date ※ 14 August 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THP055	Magnetic Field Induced by Thermo Electric Current in LCLS-II Cryomodules	1003
	G. Wu, S.K. Chandrasekaran Fermilab, Batavia, Illinois, USA
	Funding: The work is supported by Fermilab which is operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy. Seebeck effect of metals play an important role in cryomodule design. As cryomodule cools down from room temperature down to nominal cavity operating temperature, components in a cryomodule experiences different temperatures. Some components such as power couplers cross from room temperature to 2 K. Thermo electric current forms loops circulating through and around cavities. Such current loops will generate additional magnetic field that could be trapped into cavity wall during superconducting transition as well as during cavity quench. These trapped field can degrade cavity quality factor and increase heat load. Simple circuit model is proposed and compared to calculated trapped field during cryomodule tests.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THP055
About •	paper received ※ 26 June 2019 paper accepted ※ 30 June 2019 issue date ※ 14 August 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THP091	Upgrade of the Fermilab Spoke Test Cryostat for Testing of PIP-II 650 MHz 5-Cell Elliptical Cavities	1124
	A.I. Sukhanov, S.K. Chandrasekaran, B.M. Hanna, T.H. Nicol, J.P. Ozelis, Y.M. Pischalnikov, D. Plant, O.V. Prokofiev, O.V. Pronitchev, V. Roger, W. Schappert, I. Terechkine, V.P. Yakovlev Fermilab, Batavia, Illinois, USA C. Contreras-Martinez FRIB, East Lansing, Michigan, USA
	Design of the high beta 650 MHz prototype cryomodule for PIP-II is currently undergoing at Fermilab. The cryomodule includes six 5-cell elliptical SRF cavities with accelerating voltage up to 20 MV and low heat dissipation (Q₀ > 3·10^zEhNZeHn). Characterization of performance of fully integrated jacketed cavities with high power coupler and tuner is crucial for the project. Such a characterization of jacketed cavity requires a horizontal test cryostat. Existing horizontal testing facilities at Fermilab, Horizontal Test Stand (HTS) and Spoke Test Cryostat (STC), are not large enough to accommodate jacketed 650 MHz 5-cell cavity. An upgrade of the STC is proposed to install extension to the cryostat and modify cryogenic connections and RF infrastructure to provide testing of 650 MHz cavities. In this paper we describe STC upgrade and commissioning of the upgraded facility. We discuss mitigation of issues and problems specific for testing of high Q₀ 650 MHz cavities, which require low residual magnetic field and low acoustic and mechanical vibrations environment.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THP091
About •	paper received ※ 23 June 2019 paper accepted ※ 30 June 2019 issue date ※ 14 August 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Design Strategy of the PIP-II Cryomodules

307

V. Roger, S.K. Chandrasekaran, D. Passarelli
Fermilab, Batavia, Illinois, USA

Funding: This manuscript has been authored by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the U.S. Department of Energy, Office of Science, Office of High Energy Physics
The Proton Improvement Plan II (PIP-II) is the first U.S. accelerator project that will have significant contributions from international partners. Research institutions in India, Italy, UK and France will build major components of the particle accelerator. The High Beta 650 MHz (HB650) prototype cryomodule is being designed jointly between Fermilab (USA), CEA (France), STFC (UK) and RRCAT (India). The assembly of this prototype cryomodule will be done at Fermilab whereas the production cryomodules will be assembled in UK. Concerning the Low Beta 650 MHz (LB650) cryomodules, they will be designed and assembled at CEA. To reduce the cost of the project and to increase the quality it is essential to define a design strategy for each cryomodule which includes a degree of standardization. In this way, the lessons learned of each prototype cryomodule will have a great impact not only on one cryomodule type but on all cryomodules. An international joint design brings also additional challenges to the project: which unit system should be used? Should a common project lifecycle management system be used for all partners? How to transport the cryomodules overseas.

Poster MOP094 [1.117 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-MOP094

About •

paper received ※ 21 June 2019 paper accepted ※ 30 June 2019 issue date ※ 14 August 2019

Export •

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

TUP083

Performance of the 650 MHz SRF Cavity Tuner for PIP II Project

652

Y.M. Pischalnikov, S.K. Chandrasekaran, S. Cheban, I.V. Gonin, T.N. Khabiboulline, V.P. Yakovlev, J.C. Yun
Fermilab, Batavia, Illinois, USA
C. Contreras-Martinez
FRIB, East Lansing, Michigan, USA

The PIP-II linac will include fifty seven 650MHz SRF cavities. Each cavity will be equipped with tuner for coarse and fine frequency tuning. Design and operations parameters will be discussed. Results from room temperature tests with prototype tuner installed on a 650MHz ¿_G=0.90 elliptical cavity will be presented.

Poster TUP083 [1.567 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-TUP083

About •

paper received ※ 23 June 2019 paper accepted ※ 02 July 2019 issue date ※ 14 August 2019

Export •

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

THP055

Magnetic Field Induced by Thermo Electric Current in LCLS-II Cryomodules

1003

G. Wu, S.K. Chandrasekaran
Fermilab, Batavia, Illinois, USA

Funding: The work is supported by Fermilab which is operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy.
Seebeck effect of metals play an important role in cryomodule design. As cryomodule cools down from room temperature down to nominal cavity operating temperature, components in a cryomodule experiences different temperatures. Some components such as power couplers cross from room temperature to 2 K. Thermo electric current forms loops circulating through and around cavities. Such current loops will generate additional magnetic field that could be trapped into cavity wall during superconducting transition as well as during cavity quench. These trapped field can degrade cavity quality factor and increase heat load. Simple circuit model is proposed and compared to calculated trapped field during cryomodule tests.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THP055

About •

paper received ※ 26 June 2019 paper accepted ※ 30 June 2019 issue date ※ 14 August 2019

Export •

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

THP091

Upgrade of the Fermilab Spoke Test Cryostat for Testing of PIP-II 650 MHz 5-Cell Elliptical Cavities

1124

A.I. Sukhanov, S.K. Chandrasekaran, B.M. Hanna, T.H. Nicol, J.P. Ozelis, Y.M. Pischalnikov, D. Plant, O.V. Prokofiev, O.V. Pronitchev, V. Roger, W. Schappert, I. Terechkine, V.P. Yakovlev
Fermilab, Batavia, Illinois, USA
C. Contreras-Martinez
FRIB, East Lansing, Michigan, USA

Design of the high beta 650 MHz prototype cryomodule for PIP-II is currently undergoing at Fermilab. The cryomodule includes six 5-cell elliptical SRF cavities with accelerating voltage up to 20 MV and low heat dissipation (Q₀ > 3·10^zEhNZeHn). Characterization of performance of fully integrated jacketed cavities with high power coupler and tuner is crucial for the project. Such a characterization of jacketed cavity requires a horizontal test cryostat. Existing horizontal testing facilities at Fermilab, Horizontal Test Stand (HTS) and Spoke Test Cryostat (STC), are not large enough to accommodate jacketed 650 MHz 5-cell cavity. An upgrade of the STC is proposed to install extension to the cryostat and modify cryogenic connections and RF infrastructure to provide testing of 650 MHz cavities. In this paper we describe STC upgrade and commissioning of the upgraded facility. We discuss mitigation of issues and problems specific for testing of high Q₀ 650 MHz cavities, which require low residual magnetic field and low acoustic and mechanical vibrations environment.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THP091

About •

paper received ※ 23 June 2019 paper accepted ※ 30 June 2019 issue date ※ 14 August 2019

Export •

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