Author: Eremeev, G.V.
Paper Title Page
MOPMB030 Medium Temperature Furnace Baking of Low-beta 650 MHz Five-cell Cavities 158
 
  • G. Wu, S.K. Chandrasekaran, V. Chouhan, G.V. Eremeev, F. Furuta, K.E. McGee, A.A. Murthy, A.V. Netepenko, J.P. Ozelis, H. Park, S. Posen
    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.
Medium Tem­per­a­ture bak­ing of low beta 650 MHz cav­i­ties was con­ducted in a UHV fur­nace. A sys­tem­atic study of cav­ity sur­face re­sis­tance com­po­nents, resid­ual and BCS, was con­ducted, in­clud­ing an­a­lyz­ing sur­face re­sis­tance due to trapped mag­netic flux. Cav­i­ties showed an av­er­age 4.5 nano-ohm sur­face re­sis­tance at 17 MV/m under 2 K, which meets PIP-II spec­i­fi­ca­tions with a 40% mar­gin. The re­sults pro­vided help­ful in­for­ma­tion for the PIP-II pro­ject to op­ti­mize the cav­ity pro­cess­ing recipe for cry­omod­ule ap­pli­ca­tion. The re­sults were com­pared to the 1.3 GHz cav­ity that re­ceived a sim­i­lar fur­nace bak­ing. 		 
DOI • reference for this paper ※ doi:10.18429/JACoW-SRF2023-MOPMB030  
About • Received ※ 19 June 2023 — Revised ※ 23 June 2023 — Accepted ※ 26 June 2023 — Issue date ※ 18 July 2023
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MOPMB047 Commissioning of Dedicated Furnace for Nb₃Sn Coatings of 2.6 GHz Single Cell Cavities 216
SUSPB018   use link to see paper's listing under its alternate paper code  
 
  • P.A. Kulyavtsev, G.V. Eremeev, S. Posen, B. Tennis
    Fermilab, Batavia, Illinois, USA
  • J. Zasadzinski
    IIT, Chicago, 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.
We pre­sent the re­sults of com­mis­sion­ing a ded­i­cated fur­nace for Nb₃Sn coat­ings of 2.6GHz sin­gle cell cav­i­ties. Nb₃Sn is a de­sired coat­ing due to its high crit­i­cal tem­per­a­ture and smaller sur­face re­sis­tance com­pared to bulk Nb. Usage of Nb₃Sn coated cav­i­ties will greatly re­duce op­er­at­ing costs due to its higher op­er­at­ing tem­per­a­ture pro­vid­ing de­creased cool­ing costs. Tin is de­posited in the bulk Nb cav­ity by use of a tin chlo­ride nu­cle­ation agent and tin vapor dif­fu­sion. Analy­sis of the re­sul­tant coat­ing was per­formed using SEM/EDS to ver­ify suc­cess­ful for­ma­tion of de­sired Nb:Sn phase. Wit­ness sam­ples lo­cated in line of sight of the source were an­a­lyzed in order to un­der­stand the coat­ing ef­fi­cacy. The cav­ity’s per­for­mance was as­sessed in the Ver­ti­cal Test Stand (VTS) at Fer­mi­lab. 		 
poster icon Poster MOPMB047 [4.858 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-SRF2023-MOPMB047  
About • Received ※ 26 June 2023 — Revised ※ 28 June 2023 — Accepted ※ 29 June 2023 — Issue date ※ 08 July 2023
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TUPTB001 Demonstration of Niobium Tin in 218 MHz Low-Beta Quarter Wave Accelerator Cavity 388
 
  • T.B. Petersen, G. Chen, B.M. Guilfoyle, M. Kedzie, M.P. Kelly, T. Reid
    ANL, Lemont, Illinois, USA
  • G.V. Eremeev, S. Posen, B. Tennis
    Fermilab, Batavia, Illinois, USA
  
  A 218 MHz quar­ter wave nio­bium cav­ity has been fab­ri­cated for the pur­pose of demon­strat­ing Nb₃Sn tech­nol­ogy on a low-beta ac­cel­er­a­tor cav­ity. Nio­bium-tin has been es­tab­lished as a promis­ing next gen­er­a­tion SRF ma­te­r­ial, but de­vel­op­ment has fo­cused pri­mar­ily in high-beta el­lip­ti­cal cell cav­i­ties. This ma­te­r­ial has a sig­nif­i­cantly higher TC than nio­bium, al­low­ing for de­sign of higher fre­quency quar­ter wave cav­i­ties (that are sub­se­quently smaller) as well as for sig­nif­i­cantly low­ered cool­ing re­quire­ments (pos­si­bly lead­ing to cry­ocooler based de-signs). The fab­ri­ca­tion, ini­tial cold test­ing, and Nb₃Sn coat­ing are dis­cussed as well as test plans and de­tails of fu­ture ap­pli­ca­tions.  
poster icon Poster TUPTB001 [0.653 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-SRF2023-TUPTB001  
About • Received ※ 16 June 2023 — Revised ※ 23 June 2023 — Accepted ※ 27 June 2023 — Issue date ※ 08 July 2023
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TUPTB010 Preservation of the High Quality Factor and Accelerating Gradient of Nb₃Sn-Coated Cavity During Pair Assembly 405
 
  • G.V. Eremeev, S. Cheban, S. Posen, B. Tennis
    Fermilab, Batavia, Illinois, USA
  • J.F. Fischer, D. Forehand, U. Pudasaini, A.V. Reilly, R.A. Rimmer
    JLab, Newport News, Virginia, 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.
Two CEBAF 5-cell ac­cel­er­a­tor cav­i­ties have been coated with Nb₃Sn film using the vapor dif­fu­sion tech­nique. One cav­ity was coated in the Jef­fer­son Lab Nb₃Sn cav­ity coat­ing sys­tem, and the other in the Fer­mi­lab Nb₃Sn coat­ing sys­tem. Both cav­i­ties were mea­sured at 4 K and 2 K in the ver­ti­cal dewar test in each lab and then as­sem­bled into a cav­ity pair at Jef­fer­son Lab. Pre­vi­ous at­tempts to as­sem­ble Nb₃Sn cav­i­ties into a cav­ity pair de­graded the su­per­con­duct­ing prop­er­ties of Nb₃Sn-coated cav­i­ties. This con­tri­bu­tion dis­cusses the ef­forts to iden­tify and mit­i­gate the pair as­sem­bly chal­lenges and will pre­sent the re­sults of the ver­ti­cal tests be­fore and after pair as­sem­bly. No­tably, one of the cav­i­ties reached the high­est gra­di­ent above 80 mT in the ver­ti­cal test after the pair as­sem­bly. 		 
DOI • reference for this paper ※ doi:10.18429/JACoW-SRF2023-TUPTB010  
About • Received ※ 23 June 2023 — Revised ※ 28 June 2023 — Accepted ※ 02 July 2023 — Issue date ※ 09 July 2023
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TUPTB019 First Results from Nb₃Sn Coatings of 2.6 GHz Nb SRF Cavities Using DC Cylindrical Magnetron Sputtering System 429
SUSPB047   use link to see paper's listing under its alternate paper code  
 
  • M.S. Shakel, H. Elsayed-Ali
    ODU, Norfolk, Virginia, USA
  • G.V. Eremeev
    Fermilab, Batavia, Illinois, USA
  • U. Pudasaini, A-M. Valente-Feliciano
    JLab, Newport News, Virginia, USA
  
  Funding: Supported by DOE, Office of Accelerator R&D and Production, Contact No. DE-SC0022284, with partial support by DOE, Office of Nuclear Physics DE-AC05-06OR23177, Early Career Award to G. Eremeev.
A DC cylin­dri­cal mag­netron sput­ter­ing sys­tem has been com­mis­sioned and op­er­ated to de­posit Nb₃Sn onto 2.6 GHz Nb SRF cav­i­ties. After op­ti­miz­ing the de­po­si­tion con­di­tions in a mock-up cav­ity, Nb-Sn films are de­posited first on flat sam­ples by mul­ti­layer se­quen­tial sput­ter­ing of Nb and Sn, and later an­nealed at 950 °C for 3 hours. X-ray dif­frac­tion of the films showed mul­ti­ple peaks for the Nb₃Sn phase and Nb (sub­strate). No peaks from any Nb-Sn com­pound other than Nb₃Sn were de­tected. Later three 2.6 GHz Nb SRF cav­i­ties are coated with ~1 µm thick Nb₃Sn. The first Nb₃Sn coated cav­ity reached close to Eacc = 8 MV/m, demon­strat­ing a qual­ity fac­tor Q₀ of 3.2 × 108 at Tbath = 4.4 K and Eacc = 5 MV/m, about a fac­tor of three higher than that of Nb at this tem­per­a­ture. Q₀ was close to 1.1 × 109, dom­i­nated by the resid­ual re­sis­tance, at 2 K and Eacc = 5 MV/m. The Nb₃Sn coated cav­i­ties demon­strated Tc in the range of 17.9 ¿ 18 K. Here we pre­sent the com­mis­sion­ing ex­pe­ri­ence, sys­tem op­ti­miza­tion, and the first re­sults from the Nb₃Sn fab­ri­ca­tion on flat sam­ples and SRF cav­i­ties. 		 
poster icon Poster TUPTB019 [1.216 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-SRF2023-TUPTB019  
About • Received ※ 16 June 2023 — Revised ※ 24 June 2023 — Accepted ※ 26 June 2023 — Issue date ※ 10 July 2023
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TUPTB020 Surface Properties and RF Performance of Vapor Diffused Nb₃Sn on Nb after Sequential Anneals below 1000 °C 433
 
  • J.K. Tiskumara, J.R. Delayen
    ODU, Norfolk, Virginia, USA
  • G.V. Eremeev
    Fermilab, Batavia, Illinois, USA
  • U. Pudasaini
    JLab, Newport News, Virginia, USA
  
  Nb₃Sn is a next-gen­er­a­tion su­per­con­duct­ing ma­te­r­ial that can be used for fu­ture su­per­con­duct­ing ra­diofre­quency (SRF) ac­cel­er­a­tor cav­i­ties, promis­ing bet­ter per­for­mance, cost re­duc­tion, and higher op­er­at­ing tem­per­a­ture than Nb. The Sn vapor dif­fu­sion method is cur­rently the most pre­ferred and suc­cess­ful tech­nique to coat nio­bium cav­i­ties with Nb₃Sn. Among post-coat­ing treat­ments to op­ti­mize the coat­ing qual­ity, higher tem­per­a­ture an­neal­ing with­out Sn is known to de­grade Nb₃Sn be­cause of Sn loss. We have in­ves­ti­gated Nb₃Sn/Nb sam­ples briefly an­nealed at 800-1000 °C, for 10 and 20 min­utes to po­ten­tially im­prove the sur­face to en­hance the per­for­mance of Nb₃Sn-coated cav­i­ties. Fol­low­ing the sam­ple stud­ies, a coated sin­gle-cell cav­ity was se­quen­tially an­nealed at 900 °C and tested its per­for­mance each time, im­prov­ing the cav­ity’s qual­ity fac­tor rel­a­tively. This paper sum­ma­rizes the sam­ple stud­ies and dis­cusses the RF test re­sults from se­quen­tially an­nealed SRF Nb₃Sn/Nb cav­ity.  
DOI • reference for this paper ※ doi:10.18429/JACoW-SRF2023-TUPTB020  
About • Received ※ 19 June 2023 — Revised ※ 29 June 2023 — Accepted ※ 01 July 2023 — Issue date ※ 07 July 2023
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TUPTB042 Latest Development of Electropolishing Optimization for 650 MHz Cavity 512
 
  • V. Chouhan, D.J. Bice, D.A. Burk, S.K. Chandrasekaran, A.T. Cravatta, P.F. Dubiel, G.V. Eremeev, F. Furuta, O.S. Melnychuk, A.V. Netepenko, M.K. Ng, J.P. Ozelis, H. Park, T.J. Ring, G. Wu
    Fermilab, Batavia, Illinois, USA
  • B.M. Guilfoyle, M.P. Kelly, T. Reid
    ANL, Lemont, Illinois, USA
  
  Elec­trop­o­l­ish­ing (EP) of 1.3 GHz nio­bium (Nb) su­per­con­duct­ing RF cav­i­ties is con­ducted to achieve a de­sired smooth and con­t­a­m­i­nant-free sur­face that yields good RF per­for­mance. Achiev­ing a smooth sur­face of a large-sized el­lip­ti­cal cav­ity with the stan­dard EP con­di­tions was found to be chal­leng­ing. This work aimed to con­duct a sys­tem­atic para­met­ric EP study to un­der­stand the ef­fects of var­i­ous EP pa­ra­me­ters on the sur­face of 650 MHz cav­i­ties used in PIP-II linac. Pa­ra­me­ters op­ti­mized in this study pro­vided a smooth sur­face of the cav­i­ties. The elec­trop­o­l­ished cav­i­ties met the base­line re­quire­ment of field gra­di­ent and qual­i­fied for fur­ther sur­face treat­ment to im­prove the cav­ity qual­ity fac­tor.  
DOI • reference for this paper ※ doi:10.18429/JACoW-SRF2023-TUPTB042  
About • Received ※ 19 June 2023 — Revised ※ 24 June 2023 — Accepted ※ 28 June 2023 — Issue date ※ 06 July 2023
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WEPWB126 First Results from Nanoindentation of Vapor Diffused Nb₃Sn Films on Nb 888
 
  • U. Pudasaini
    JLab, Newport News, Virginia, USA
  • S. Cheban, G.V. Eremeev
    Fermilab, Batavia, Illinois, USA
  
  Funding: U.S. Department of Energy, Office of Science, Office of Nuclear Physics & Office of High Energy Physics.
The me­chan­i­cal vul­ner­a­bil­ity of the Nb₃Sn-coated cav­i­ties is iden­ti­fied as one of the sig­nif­i­cant tech­ni­cal hur­dles to­ward de­ploy­ing them in prac­ti­cal ac­cel­er­a­tor ap­pli­ca­tions in the not-so-dis­tant fu­ture. It is cru­cial to char­ac­ter­ize the ma­te­r­ial’s me­chan­i­cal prop­er­ties in ways to ad­dress such vul­ner­a­bil­ity. Nanoin­den­ta­tion is a widely used tech­nique for mea­sur­ing the me­chan­i­cal prop­er­ties of thin films that in­volves in­dent­ing the film with a small di­a­mond tip and mea­sur­ing the force-dis­place­ment re­sponse to cal­cu­late the film’s elas­tic mod­u­lus, hard­ness, and other me­chan­i­cal prop­er­ties. The nanoin­den­ta­tion analy­sis was per­formed on mul­ti­ple va­por-dif­fused Nb₃Sn sam­ples coated at Jef­fer­son Lab and Fer­mi­lab coat­ing fa­cil­i­ties for the first time. This con­tri­bu­tion will dis­cuss the first re­sults ob­tained from the nanoin­den­ta­tion of Nb₃Sn-coated Nb sam­ples pre­pared via the Sn vapor dif­fu­sion tech­nique. 		 
DOI • reference for this paper ※ doi:10.18429/JACoW-SRF2023-WEPWB126  
About • Received ※ 19 June 2023 — Revised ※ 28 June 2023 — Accepted ※ 30 June 2023 — Issue date ※ 16 July 2023
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FRIBA01
 SRF R&D for FRIB Linac Energy Upgrade with High-performance Medium-beta Elliptical Cavity CW Cryomodules  
 
  • S.H. Kim, W. Chang, K. Elliott, W. Hartung, K.E. McGee, E.S. Metzgar, P.N. Ostroumov, L. Popielarski, J. Rathke, T. Xu, S. Zhao
    FRIB, East Lansing, Michigan, USA
  • D.J. Bice, C. Contreras-Martinez, G.V. Eremeev, Y.M. Pischalnikov
    Fermilab, Batavia, Illinois, USA
  • B.M. Guilfoyle, M.P. Kelly, T. Reid
    ANL, Lemont, Illinois, USA
  
  Funding: Work supported by the U.S. Department of Energy under Award Number DE-SC0000661. Further support provided by the US Department of Energy under Cooperative Agreement award number DE-SC0018362.
Michi­gan State Uni­ver­sity is pur­su­ing SRF R&D for FRIB400 up­grade, dou­bling the FRIB linac beam en­ergy (400 MeV/u for the heav­i­est ura­nium beam) using ßopt=0.65 644 MHz 5-cell el­lip­ti­cal cav­i­ties. We have achieved un­prece­dented Q₀ in this cav­ity class, Q₀ = 3.5·1010 at Eacc of 17.5 MV/m in a ni­tro­gen-doped bare nio­bium cav­ity in col­lab­o­ra­tion with FNAL and ANL. The next mis­sions are achiev­ing such high Q₀ in jack­eted cav­i­ties and in cry­omod­ules, achiev­ing field-emis­sion free per­for­mance at Epeak of 40 MV/m with re­pro­ducibil­ity, de­vel­op­ing a com­pact two-win­dow high-power fun­da­men­tal power cou­pler (15 kW CW), and achiev­ing sta­ble res­o­nance con­trol of cav­i­ties in­te­grated with tuners in cry­omod­ules. In this talk, we will pre­sent progress of the SRF R&D and dis­cuss fu­ture plan. 		 
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