SRF2021 - List of Authors (Chandrasekaran, S.K.)

Paper	Title	Page
SUPTEV013	Validation of the 650 MHz SRF Cavity Tuner for PIP-II at 2 K	151
	C. Contreras-Martinez FRIB, East Lansing, Michigan, USA S.K. Chandrasekaran, S. Cheban, G.V. Eremeev, F. Furuta, T.N. Khabiboulline, Y.M. Pischalnikov, O.V. Prokofiev, A.I. Sukhanov, J.C. Yun Fermilab, Batavia, Illinois, USA
	The PIP-II linac will include thirty-six β=0.61 and twenty-four β=0.92 650 MHz 5 cell elliptical SRF cavities. Each cavity will be equipped with a tuning system consisting of a double lever slow tuner for coarse frequency tuning and a piezoelectric actuator for fine frequency tuning. One dressed cavity equipped with an SRF tuner has been tested in the horizontal test stand at Fermilab. Results of testing the cavity-tuner system will be presented.
	Poster SUPTEV013 [0.835 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2021-SUPTEV013
About •	Received ※ 22 June 2021 — Revised ※ 13 August 2021 — Accepted ※ 26 February 2022 — Issue date ※ 02 May 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOOFAV05	Proton Improvement Plan – II: Overview of Progress in the Construction	182
	A.L. Klebaner, C. Boffo, S.K. Chandrasekaran, D. Passarelli, G. Wu Fermilab, Batavia, Illinois, USA
	Funding: US Department of Energy The Proton Improvement Plan II (PIP-II) project is an essential upgrade to Fermilab’s particle accelerator complex to enable the world’s most intense neutrino beam for LBNF/DUNE and a broad particle physics program for many decades to come. PIP-II will deliver 1.2 MW of proton beam power from the Main Injector, upgradeable to multi-MW capability. The central element of PIP-II is an 800 MeV linac, which comprises a room temperature front end followed by an SRF accelerator. The front end has been constructed and operated with (pulsed & CW) beam in the PIP-II Injector Test facility (PIP2IT). The SRF accelerator consists of five different types of cavities/cryomodules, including Half Wave Resonators (HWR), Single Spoke and elliptical resonators operating at state-of-the-art parameters. The first two PIP-II cryomodules, HWR and Single Spoke Resonator 1 (SSR1) are installed in PIP2IT and have accelerated beam to 17 MeV. PIP-II is the first U.S. accelerator project that will be constructed with significant contributions from international partners, including India, Italy, France, United Kingdom and Poland. The project was recently baselined, and site construction is underway
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2021-MOOFAV05
About •	Received ※ 13 August 2021 — Revised ※ 14 January 2022 — Accepted ※ 21 February 2022 — Issue date ※ 13 March 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPCAV005	Toward Qualifications of HB and LB 650 MHz Cavities for the Prototype Cryomodules for the PIP-II Project	448
	M. Martinello, D.J. Bice, C. Boffo, S.K. Chandrasekaran, G.V. Eremeev, F. Furuta, T.N. Khabiboulline, K.E. McGee, A.V. Netepenko, J.P. Ozelis, A.I. Sukhanov, G. Wu Fermilab, Batavia, Illinois, USA M. Bagre, V. Jain, A. Puntambekar, S. Raghvendra, P. Shrivastava RRCAT, Indore (M.P.), India M. Bertucci, A. Bosotti, C. Pagani, R. Paparella INFN/LASA, Segrate (MI), Italy P. Bhattacharyya, S. Ghosh, S. Ghosh, A. Mandal, S. Seth, S. Som VECC, Kolkata, India M.P. Kelly, T. Reid ANL, Lemont, Illinois, USA S.H. Kim, K.E. McGee, P.N. Ostroumov FRIB, East Lansing, Michigan, USA K.K. Mistri, P.N. Prakash IUAC, New Delhi, India
	High-beta (HB) and low-beta (LB) 650 MHz cryomodules are key components of the Proton Improvement Plan II (PIP-II) project. In this contribution we present the results of several 5-cell HB650 cavities that have been processed and tested with the purpose of qualifying them for the prototype cryomodule assembly, which will take place later this year. We also present the first results obtained in LB650 single-cell cavities process optimization. Taking advantage of their very similar geometry, we are also analyzing the effect of different surface treatments in FRIB’s 5-cell medium-beta 644MHz cavities. Cavities processed with N-doping and mid-T baking showed very promising results in term of both Q-factors and accelerating gradient for these low-beta structures.
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2021-TUPCAV005
About •	Received ※ 01 July 2021 — Accepted ※ 02 November 2021 — Issue date ※ 16 May 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPCAV013	STC Qualification Tests of PIP-II HB650 Cavities	465
	A.I. Sukhanov, S.K. Chandrasekaran, G.V. Eremeev, F. Furuta, S. Kazakov, T.N. Khabiboulline, T.H. Nicol, Y.M. Pischalnikov, O.V. Prokofiev, V. Roger, G. Wu, V.P. Yakovlev, J.C. Yun 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 > 3.3 · 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. The Fermilab Spoke Test Cryostat (STC) has been upgraded to accommodate testing of 650 MHz cavities. Commissioning of upgraded STC has been reported at SRF’19 conference. In this paper we present results of testing of the prototype HB650 cavity in upgraded STC facility. We characterize cavity performance and qualify it for the prototype HB650 cryomodule assembly.
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2021-TUPCAV013
About •	Received ※ 21 June 2021 — Accepted ※ 21 August 2021 — Issue date ※ 04 October 2021
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPTEV015	Design of the 650 MHz High Beta Prototype Cryomodule for PIP-II at Fermilab	671
	V. Roger, S.K. Chandrasekaran, S. Cheban, M. Chen, J. Helsper, J.P. Holzbauer, Y.M. Orlov, V. Poloubotko, B. Squires, N. Tanovic, G. Wu Fermilab, Batavia, Illinois, USA N. Bazin, O. Napoly, C. Simon CEA-DRF-IRFU, France R. Cubizolles, M. Lacroix CEA-IRFU, Gif-sur-Yvette, France M.T.W. Kane STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom P. Khare RRCAT, Indore (M.P.), India
	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. The prototype High Beta 650 MHz cryomodule (pHB650 CM) is designed by an integrated design team, consisting of Fermilab (USA), CEA (France), UKRI-STFC (UK), and RRCAT (India). The manufacturing & assembly of this prototype cryomodule will be done at Fermilab, whereas the production cryomodules will be manufactured and/or assembled by UKRI-STFC, RRCAT, or Fermilab. Similar to the prototype Single Spoke Resonator 1 cryomodule (pSSR1 CM), this cryomodule is based on a strong-back at room temperature supporting the coldmass. The pSSR1 CM led to significant lessons being learnt on the design, procurement, and assembly processes. These lessons were incorporated into the design and processes for the pHB650 CM. Amongst many challenges faced, the main challenges of the pHB650 CM design were to make the cryomodule compatible to overseas transportation and to design components that can be procured in USA, Europe, and India.
	Poster WEPTEV015 [0.937 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2021-WEPTEV015
About •	Received ※ 21 June 2021 — Revised ※ 28 February 2022 — Accepted ※ 20 April 2022 — Issue date ※ 16 May 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPTEV006	Design of the PIP-II 650 MHz Low Beta Cryomodule	841
	N. Bazin, S. Berry, G. Maitre, O. Napoly, C. Simon CEA-DRF-IRFU, France S. Bouaziz, R. Cubizolles, M. Lacroix CEA-IRFU, Gif-sur-Yvette, France S.K. Chandrasekaran, Y.M. Orlov, V. Roger Fermilab, Batavia, Illinois, USA
	The Proton Improvement Plan II (PIP-II) that will be installed at Fermilab is the first U.S. accelerator project that will have significant contributions from international partners. CEA joined the international collaboration in 2018, and is responsible of the 650 MHz low-beta section made of 9 cryomodules, with the design of the cryostat (i.e the cryomodule without the cavities, the power couplers and the frequency tuning systems) and the manufacturing of its components, the assembly and tests of the pre-production cryomodule and the 9 series ones. This paper will present the design of the 650 MHz low-beta cryomodule.
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2021-THPTEV006
About •	Received ※ 02 July 2021 — Accepted ※ 30 January 2022 — Issue date ※ 01 May 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Validation of the 650 MHz SRF Cavity Tuner for PIP-II at 2 K

151

C. Contreras-Martinez
FRIB, East Lansing, Michigan, USA
S.K. Chandrasekaran, S. Cheban, G.V. Eremeev, F. Furuta, T.N. Khabiboulline, Y.M. Pischalnikov, O.V. Prokofiev, A.I. Sukhanov, J.C. Yun
Fermilab, Batavia, Illinois, USA

The PIP-II linac will include thirty-six β=0.61 and twenty-four β=0.92 650 MHz 5 cell elliptical SRF cavities. Each cavity will be equipped with a tuning system consisting of a double lever slow tuner for coarse frequency tuning and a piezoelectric actuator for fine frequency tuning. One dressed cavity equipped with an SRF tuner has been tested in the horizontal test stand at Fermilab. Results of testing the cavity-tuner system will be presented.

Poster SUPTEV013 [0.835 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2021-SUPTEV013

About •

Received ※ 22 June 2021 — Revised ※ 13 August 2021 — Accepted ※ 26 February 2022 — Issue date ※ 02 May 2022

Cite •

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

MOOFAV05

Proton Improvement Plan – II: Overview of Progress in the Construction

182

A.L. Klebaner, C. Boffo, S.K. Chandrasekaran, D. Passarelli, G. Wu
Fermilab, Batavia, Illinois, USA

Funding: US Department of Energy
The Proton Improvement Plan II (PIP-II) project is an essential upgrade to Fermilab’s particle accelerator complex to enable the world’s most intense neutrino beam for LBNF/DUNE and a broad particle physics program for many decades to come. PIP-II will deliver 1.2 MW of proton beam power from the Main Injector, upgradeable to multi-MW capability. The central element of PIP-II is an 800 MeV linac, which comprises a room temperature front end followed by an SRF accelerator. The front end has been constructed and operated with (pulsed & CW) beam in the PIP-II Injector Test facility (PIP2IT). The SRF accelerator consists of five different types of cavities/cryomodules, including Half Wave Resonators (HWR), Single Spoke and elliptical resonators operating at state-of-the-art parameters. The first two PIP-II cryomodules, HWR and Single Spoke Resonator 1 (SSR1) are installed in PIP2IT and have accelerated beam to 17 MeV. PIP-II is the first U.S. accelerator project that will be constructed with significant contributions from international partners, including India, Italy, France, United Kingdom and Poland. The project was recently baselined, and site construction is underway

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2021-MOOFAV05

About •

Received ※ 13 August 2021 — Revised ※ 14 January 2022 — Accepted ※ 21 February 2022 — Issue date ※ 13 March 2022

Cite •

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

TUPCAV005

Toward Qualifications of HB and LB 650 MHz Cavities for the Prototype Cryomodules for the PIP-II Project

448

M. Martinello, D.J. Bice, C. Boffo, S.K. Chandrasekaran, G.V. Eremeev, F. Furuta, T.N. Khabiboulline, K.E. McGee, A.V. Netepenko, J.P. Ozelis, A.I. Sukhanov, G. Wu
Fermilab, Batavia, Illinois, USA
M. Bagre, V. Jain, A. Puntambekar, S. Raghvendra, P. Shrivastava
RRCAT, Indore (M.P.), India
M. Bertucci, A. Bosotti, C. Pagani, R. Paparella
INFN/LASA, Segrate (MI), Italy
P. Bhattacharyya, S. Ghosh, S. Ghosh, A. Mandal, S. Seth, S. Som
VECC, Kolkata, India
M.P. Kelly, T. Reid
ANL, Lemont, Illinois, USA
S.H. Kim, K.E. McGee, P.N. Ostroumov
FRIB, East Lansing, Michigan, USA
K.K. Mistri, P.N. Prakash
IUAC, New Delhi, India

High-beta (HB) and low-beta (LB) 650 MHz cryomodules are key components of the Proton Improvement Plan II (PIP-II) project. In this contribution we present the results of several 5-cell HB650 cavities that have been processed and tested with the purpose of qualifying them for the prototype cryomodule assembly, which will take place later this year. We also present the first results obtained in LB650 single-cell cavities process optimization. Taking advantage of their very similar geometry, we are also analyzing the effect of different surface treatments in FRIB’s 5-cell medium-beta 644MHz cavities. Cavities processed with N-doping and mid-T baking showed very promising results in term of both Q-factors and accelerating gradient for these low-beta structures.

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2021-TUPCAV005

About •

Received ※ 01 July 2021 — Accepted ※ 02 November 2021 — Issue date ※ 16 May 2022

Cite •

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

TUPCAV013

STC Qualification Tests of PIP-II HB650 Cavities

465

A.I. Sukhanov, S.K. Chandrasekaran, G.V. Eremeev, F. Furuta, S. Kazakov, T.N. Khabiboulline, T.H. Nicol, Y.M. Pischalnikov, O.V. Prokofiev, V. Roger, G. Wu, V.P. Yakovlev, J.C. Yun
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 > 3.3 · 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. The Fermilab Spoke Test Cryostat (STC) has been upgraded to accommodate testing of 650 MHz cavities. Commissioning of upgraded STC has been reported at SRF’19 conference. In this paper we present results of testing of the prototype HB650 cavity in upgraded STC facility. We characterize cavity performance and qualify it for the prototype HB650 cryomodule assembly.

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2021-TUPCAV013

About •

Received ※ 21 June 2021 — Accepted ※ 21 August 2021 — Issue date ※ 04 October 2021

Cite •

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

WEPTEV015

Design of the 650 MHz High Beta Prototype Cryomodule for PIP-II at Fermilab

671

V. Roger, S.K. Chandrasekaran, S. Cheban, M. Chen, J. Helsper, J.P. Holzbauer, Y.M. Orlov, V. Poloubotko, B. Squires, N. Tanovic, G. Wu
Fermilab, Batavia, Illinois, USA
N. Bazin, O. Napoly, C. Simon
CEA-DRF-IRFU, France
R. Cubizolles, M. Lacroix
CEA-IRFU, Gif-sur-Yvette, France
M.T.W. Kane
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
P. Khare
RRCAT, Indore (M.P.), India

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. The prototype High Beta 650 MHz cryomodule (pHB650 CM) is designed by an integrated design team, consisting of Fermilab (USA), CEA (France), UKRI-STFC (UK), and RRCAT (India). The manufacturing & assembly of this prototype cryomodule will be done at Fermilab, whereas the production cryomodules will be manufactured and/or assembled by UKRI-STFC, RRCAT, or Fermilab. Similar to the prototype Single Spoke Resonator 1 cryomodule (pSSR1 CM), this cryomodule is based on a strong-back at room temperature supporting the coldmass. The pSSR1 CM led to significant lessons being learnt on the design, procurement, and assembly processes. These lessons were incorporated into the design and processes for the pHB650 CM. Amongst many challenges faced, the main challenges of the pHB650 CM design were to make the cryomodule compatible to overseas transportation and to design components that can be procured in USA, Europe, and India.

Poster WEPTEV015 [0.937 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2021-WEPTEV015

About •

Received ※ 21 June 2021 — Revised ※ 28 February 2022 — Accepted ※ 20 April 2022 — Issue date ※ 16 May 2022

Cite •

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

THPTEV006

Design of the PIP-II 650 MHz Low Beta Cryomodule

841

N. Bazin, S. Berry, G. Maitre, O. Napoly, C. Simon
CEA-DRF-IRFU, France
S. Bouaziz, R. Cubizolles, M. Lacroix
CEA-IRFU, Gif-sur-Yvette, France
S.K. Chandrasekaran, Y.M. Orlov, V. Roger
Fermilab, Batavia, Illinois, USA

The Proton Improvement Plan II (PIP-II) that will be installed at Fermilab is the first U.S. accelerator project that will have significant contributions from international partners. CEA joined the international collaboration in 2018, and is responsible of the 650 MHz low-beta section made of 9 cryomodules, with the design of the cryostat (i.e the cryomodule without the cavities, the power couplers and the frequency tuning systems) and the manufacturing of its components, the assembly and tests of the pre-production cryomodule and the 9 series ones. This paper will present the design of the 650 MHz low-beta cryomodule.

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2021-THPTEV006

About •

Received ※ 02 July 2021 — Accepted ※ 30 January 2022 — Issue date ※ 01 May 2022

Cite •

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