Cavity and Cryomodule R&D

1. Cavity and Cryomodule R&D Shekhar Mishra ILC Program Fermilab Talk presented at DOE Annual Program Review Breakout Sessions   –   Wednesday, May 17

2. ILC Cavity and Cryomodule R&D Goals • ILC R&D at Fermilab is focused to address the high priority ILC design and technical issues as recommended by ILC-TRC and recently by ILC-GDE R&D Board. • The main thrust of the ILC Cavity and Cryomodule R&D is to establish technical capabilities in the Superconducting Radio Frequency (SRF) Cavity and Cryomodule technology. The main goals are • Cavity technology development in the US to routinely achieve > 35 MV/m and Q ~0.5-1e10, • ILC Cryomodule design, fabrication (cost reduction) • Fully tested basic building blocks of the Main Linac (Evaluate the integration, reliabilities issues and value engineering). • LLRF, Instrumentation and Controls development for Main Linac • Development of U.S. laboratories and industrial infrastructure for the fabrication, processing and testing of high performance SRF cavities, Coupler, Tuner, HOM and Cryomodule.

3. Plans for 35 MV/m • Cavity Fabrication, Preparation, Surface Processing, Clean Surface and Clean environment is the key to achieving a high gradient in the ILC cavities. • Fermilab is leading the US effort with collaborating laboratories. • Niobium is being scanned at Fermilab. (Need larger inventory. There are variation from batch to batch, vendor to vendor etc.) • Cavity is being fabricated at industry under the supervision of Fermilab and Cornell. Jlab will join this soon. • Cavity is being processed (BCP and EP) and vertical tested at Cornell, Jlab and will be processed at ANL/FNAL • The processing infrastructure needs more focused effort. Experiences from DESY and KEK suggest that we build this facility at where cavity is dressed, horizontally tested and put in a string. • We are in process of having this facility at Fermilab by 07. • Fermilab is fabricating 8 (FY05), 16(FY06), 24-36 (FY07) ILC cavities. More could be needed to • These cavities will be systematically processed and testing. We would systematically collect data during the fabrication, processing and testing. • These data would be analyzed for co-relations to understand the process.

4. ILC Cavity: R&D • Material R&D: Fine, Large, Single Crystal • Fabrication • A number of minor modifications and improvements could be implemented without impact to the basic cavity design. • Cavity Preparation • Buffer Chemical Processing • Cavity Processing R&D • Electro-polishing (EP) System • High Pressure Rinsing (HPR) • Clean Assembly Procedure

5. Cavity Fabrication • Industrial production of the cavity by Fermilab (ACCEL, AES) • 8 TESLA Design Cavities ordered • 10 ILC Baseline Design Cavities in FY06 • Cavity fabrication at Jlab • 2 ILC Baseline design and Type-IV • 2 Low Loss Cavity • Several single cell for Process and Material R&D • Material R&D (Fine Grain, Large Grain, Single Crystal) • Cavity fabrication at Cornell • Re-Entrant Cavities (70 mm) • Re-Entrant Cavities (60 mm) • Several single cell for Process R&D • Cavity fabrication at KEK (US-Japan) • Cavities of TESLA, Low Loss and ICHIRO design

6. Cavity Fabrication, Processing and Testing Road Map Cavity Fabrication By Industry BCP and EP Processing @ Cornell BCP and EP Processing @ ANL/FNAL BCP and EP Processing @ Jlab Vertical Testing @ Jlab Vertical Testing @ Cornell Vertical Testing @ FNAL Cavity Dressing & Horizontal Testing @ Fermilab Exists Developing

7. Cavity Measurements • RF measurement of the ACCEL Cavities at Fermilab.

8. ILC Cavity Material Grain size R&D at Jlab Ningxia • Study of Single Cell large grain niobium from CBMM, Heraeus and Ningxia • 5 single cell cavities each from these vendors will be fabricated for statistics. • Two 9-cell cavities are being fabricated for Fermilab using CBMM ingot. Heraeus

9. Re-entrant CornellKEK Low Loss Jlab KEK Tesla Shape 50 MV/m in Single Cells !Lower Surface Magnetic Field & Lower Losses New Shapes Breakthrough Need Multi-cells Next

10. Proof of Principle Results: Eacc = 47 - 52 MV/m Fabricated at Cornell /Ichiro

11. New Reentrant Cavity Shape 60 mm aperture similar to LL shape -> 16% lower Hpk/Eacc Work done in Collaboration with KEK

12. ILC Cavity Processing • We are using infrastructures at the collaborating laboratories to develop the processing capabilities and parameters in USA to achieve 25 MV/m with BCP and 35 MV/m with EP. • These facilities are also being used to train people. • Cornell: • BCP and HPR • Vertical EP • Jlab • EP • Fermilab and ANL (New Facility) • BCP • EP • We are also sending Fermilab staff to DESY for participation and training in surface processing, vertical and Horizontal testing.

13. 3.9.9 Check Reproducibility of HPR 3.9.10 Cornell Re-entrant Cavity Work done in Collaboration with KEK

14. First ACCEL ILC Cavity at Cornell 3.9.3.1 BCP Complete HPR Complete

15. Vertical Test of ACCEL Cavity 60 um BCP (nominal) + 50 um at ACCEL Low Field: Q >1010, Eacc = 17 MV/m, (Quench) Q Eacc (Mv/m) Fermilab is sending engineering staff and technician to participate in the BCP and vertical testing at Cornell.

16. Goals for EP Development at Jlab Establish EP processing for ILC 9-cell cavities at Jlab • Commissioning EP cabinet with Spare DESY 9-cell cavity • Perform HPR, assembly and testing with S35 cavity to analyze procedure effectiveness and reproducibility • Investigate standard process procedures to gain a better understanding of current issues (Sulfur precipitation, HF loss during use) • Identify and develop relevant process metrics and QA steps • Establish and document procedures • Aim is uniform reproducible etching with clean surfaces after rinsing • Process, test, qualify and prep cavities for FNAL string assembly

17. Electropolish Development for ILC 3.9.3.2 Jlab EP Cabinet HPR and Assembly Alignment Cage

18. EP System Alignment Frame and Cathode with ILC Cavity 3.9.3.2

19. ILC Surface Processing Facility Development at ANL/FNAL • The Joint ANL/FNAL Superconducting Surface Processing Facility (SCSPF), located at Argonne National Laboratory, is a major chemical processing facility capable of electro-polishing and buffered chemical polishing a large quantity and variety of superconducting structures. • This BCP part of the facility is ready and going through the safety approval. It is expected to be operational end of 06. • An initial plans has been developed for an EP facility to be build (FY06-07) at ANL/Fermilab Surface Processing Facility at ANL. • This facility should include the knowledge of EP from the ILC Collaboration.

20. Cryomodule Design and Fabrication • In FY05 Fermilab started on converting the DESY/INFN design of the ILC cryomodule (Type-III+). • We have formed an ILC Cryomodule working group that is working towards a design of an ILC cryomodule. This design will evolve. • The Goal is to design an improved ILC cryomodule (Type-IV) and build one at Fermilab by FY08. High Power testing of the cavities and the fabrication of 1st ILC cryomodule with new design 2008.

21. Cryomodule Fabrication Plans for an RF Unit test at ILCTA Cryomodule 3 Cryomodule 1 Cryomodule 2 ILC Length Cavity Purchased By Fermilab (AES/Jlab) Standard Length Cavity Purchased By Fermilab Dressed Cavity Provided By DESY BCP & VT In USA BCP & VT At Cornell Cold Mass By DESY/INFN EP & VT In USA EP & VT At Jlab Dressed New Design and HT At Fermilab Dressed and HT At Fermilab Cryomodule Assembled at Fermilab Cold Mass From Zanon By Fermilab Cold Mass Type-IV From US Company By Fermilab March 07 Mid 08 Dec 07

22. 1st US Assembled Cryomodule: Fermilab, DESY and INFN • DESY will send Fermilab eight 9-Cell 1.3 GHz dressed and horizontally tested cavities. • The present schedule for the delivery of these 8 cavities is around end of 2006. DESY will attempt to advance this schedule. • DESY and INFN have ordered two cold masses for Type-III cryomodules from Zanon. • DESY will send one of these cold masses to Fermilab for the 1st cryomodule assembly at Fermilab. • It is expected that this cold mass will be available about Sept.-Oct. 2006. • Some parts for the 1.3 GHz cryomodule are not provided by Zanon but rather by INFN. • It was agreed that INFN will send these associated parts to Fermilab and provide parts needed for a 3rd cold mass.  • INFN-DESY will also send the assembly documentation to Fermilab. • Fermilab will work to achieve the earliest possible delivery date for the DESY four cavity 3.9 GHz cryomodule. This is currently expected to be early in  2007.

23. ILC Cryomodule Design Considerations • Move quad package to middle of cryomodule to achieve better support and alignment. • Shorten cavity-to-cavity interconnect and simplify for ease of fabrication and cost reduction. Possible superconducting joint. • Overall improved packing factor. • Minimize direct heat load to cavity through MC. • Simplify the assembly procedure. • MLI redesign to reduce hands-on labor costs. • More robust design to survive shipping. • Reliability of tuner motors in cold operation. • Etc. (we’ve heard many suggestions)

24. ILC Cryomodule: Conceptual Model

25. Increase diameter beyond X-FEL Increase diameter beyond X-FEL Review 2-phase pipe size and effect of slope Change in Cryogenic Distribution

26. Active length = 1036.2 mm x 24 cavities = 24868.6 mm Packing Factor = 24868.6 / 35068 = 0.71 35068mm 1036.2 mm ILC Cavity Spacing, Dimensions with Blade Tuner Blade Tuner

27. 1st Cryomodule Assembly Plans • Cavity String Assembly Procedures & Fixtures Learning at DESY (February 20 –March 3) • A draft traveler was written during this visit. It is currently being reviewed by Axel Matheisen for comments. • Tooling & Fixturing used to assemble the cavity string were identified. Drawing were brought back to Fermilab. • Assembly sketches, movies and took a lot of pictures and notes. • Cryomodule #6 Assembly Procedures Learning at DESY (May-June 06) • CAF Infrastructure ready & operational: May-June 06 • MP9 Clean Room installation finished • Cold Mass and Vacuum Vessel Assembly Fixtures received at Fermilab. • Cavity String Assembly Fixtures are being fabricated to be installed • Assemble 1st Cryomodule (4 months): Start date depends when we receive the kit from DESY

28. Cavity and Cryomodule Assembly Fixtures

29. FY07 Plans: Cavities & Cryomodule • The FY07 plan of the ART will be the continuation of the plan we are undertaking in FY07. • Cavity Fabrication • ILC Design • New Shape (LL and RE) • Fine, Large and Single Crystal • R&D on material, fabrication etc • 3.9 GHz deflecting cavity design and fabrication • Cavity Processing and Vertical Testing • BCP, EP and Vertical Testing at Cornell • BCP, EP and Vertical Testing at Jlab • BCP, EP and Vertical Testing at FNAL/ANL (New Facility) • R&D on surface treatment • Cryomodule Design and Fabrication • Type III+ Fabrication • Type IV Design • US Industrial involvement in Cavity and Cryomodule Design and Fabrication • Enhanced University participation in ILC R&D

30. Summary • US-ILC Main Linac: Cavity and Cryomodule R&D program is established to address the key technology issues. • Cavity Gradient • ILC Cryomodule design and fabrication • R&D is focused on the Baseline design of the cavity and cryomodule. • We are also working on alternate design for Cavity and material. • We are upgrading existing infrastructure at US laboratories to cost effectively advance the R&D program on a ambitious schedule. • We are developing infrastructure at Fermilab for cavity processing and testing and fabrication of cryomodule. • We are leading the ILC effort in the ILC Cryomodule design. • We are working with US industry in fabrication. • We are also working with US industry in ILC Cost Study.

31. Could lab really spend the Money Faster on ILC than its currently funded? • Yes, Yes and Yes • Fermilab has qualified scientists and engineers who wants to work on ILC. • We continue to defer investment that would be needed for more focused R&D. • Cavity R&D: (This is the highest R&D priority for ILC-GDE) • Niobium • More cavities fabrication at industry. We should fabricate enough to saturate the pipeline at existing and upcoming processing facilities. • Electron Beam Welding • Surface Processing: We need a pre-production BCP, EP and HPR system at Fermilab • Vendor development • Cavity Tuning Device ( A copy of DESY Design) • Vertical testing temperature study • Cryomodule Testing • 10 MWatt Klystron • Cryogenic plant • Industrial fabrication • US industries could fabricate an RF unit using laboratory infrastructure.

32. FTE in ILC R&D at Fermilab: FY06 and FY07