1. 5 th CLIC-ACE Structure production in laboratories and industries G. Riddone, 02/02/2010 (contribution from KEK/SLAC colleagues) 1

2. Content Introduction to RF structures and components Fabrication baseline procedure for accelerating structures Application to CERN accelerating structure fabrication Fabrication of PETS RF structure production capability RF structure master schedule Present structures (CERN, KEK, SLAC, Elettra, PSI) Towards CLIC structures (CDR, TDR) G. Riddone, 5th CLIC-ACE, 02/02/20102

3. Introduction G. Riddone, 5th CLIC-ACE, 02/02/20103 TD18#3 at SLAC TD18#2 at KEK TD24#2 at CERN (12 GHz) PETS (12 GHz, TBTS) PETS (11.4 GHz, test at SLAC) High-power dry load Hybrid Variable high power splitter

4. Fabrication of accelerating structures G. Riddone, 5th CLIC-ACE, 02/02/20104 T18 structures tested at SLAC/KEK showed excellent test results consequent validation of design, machining and assembly procedure NLC/JLC fabrication technology: validated to 100 MV/m (baseline for future CERN X-band accelerating structures)

5. Baseline procedure G. Riddone, 5th CLIC-ACE, 02/02/20105 Diamond machining (sealed structures) H2 diffusion bonding/brazing at ~ 1000 ˚C Cleaning with light etch Vacuum baking 650 ˚C > 10 days J. Wuang

6. Application to CERN accelerating structures CERN previous assembly procedure was based on vacuum brazing at 800 ˚C  several changes were needed for implementing the baseline procedure Following the post-mortem analysis of the two CERN accelerating structures T18 and T24, contamination (C, Ca) resulted to be the main problem  cleanliness had to be seriously improved G. Riddone, 5th CLIC-ACE, 02/02/2010 6

7. Baseline manufacturing flow High precision diamond machining Cleaning (light etch) Cleaning (light etch) Brazing of coupler bodies, cooling circuits, tuning studs (AuCu, 1020 °C) Brazing of coupler bodies, cooling circuits, tuning studs (AuCu, 1020 °C) Packaging and shipping Brazing of couplers (H 2, 1045 °C, AuCu) Brazing of couplers (H 2, 1045 °C, AuCu) Machining of couplers Diffusion bonding of disk stack (H 2, 1020 °C) Diffusion bonding of disk stack (H 2, 1020 °C) RF check and tuning Baking (vacuum, 650 °C, >10 d) Baking (vacuum, 650 °C, >10 d) QC G. Riddone, 5th CLIC-ACE, 02/02/20107 New for CERN

8. Inspections G. Riddone, 5th CLIC-ACE, 02/02/20108 Microscopic inspection of disks before and after cleaning (on witness pieces) Video inspections, SEM and microscopic inspections Microscopic inspections before and after each relevant fabrication step T18 KEK/SLAC design

9. Machining at VDL 9 G. Riddone, 5th CLIC-ACE, 02/02/2010 New CMM (Coordinate Measuring Machine) under procurement at CERN

10. Cleaning G. Riddone, 5th CLIC-ACE, 02/02/201010 SLAC cleaning procedure as a baseline For degreasing Trichloroethane  at SLAC replaced by Perchloroethylene CERN procedure: (Firm AVANTEC Performance Chemicals): - TOPKLEAN MC 20A - PROMOSOLV 71IPA Tool for holding the disks Etching J. Wuang

11. Diffusion bonding G. Riddone, 5th CLIC-ACE, 02/02/201011 1045 °C, 2 h couplers Couplers + disks 1020 °C, 1.5 h TD24 T18KS Disks Bonding at CERN: few mbar H 2 partial pressure (difference with SLAC): we are actively looking for a furnace at 1 bar H 2 in Europe.

12. Accelerating structure TD24 after diffusion bonding under H 2 12G. Riddone, 5th CLIC-ACE, 02/02/2010

13. Assembly G. Riddone, 5th CLIC-ACE, 02/02/201013 Assembly made on V-blocks Verification of the assembly (before and after bonding) with a new measurement column: straightness and tilt At SLAC

14. RF check and tuning G. Riddone, 5th CLIC-ACE, 02/02/201014 Bead pulling at 11.421GHz (old test-set-up) Before shipping RF check and tuning were done and results were good T24#1 New test set-up is under procurement for RF measurements

15. Vacuum baking G. Riddone, 5th CLIC-ACE, 02/02/201015 J. Wuang 1 st baking: TD24 for CLEX, two-beam test stand CERN furnace  several mechanical adaptations were needed 10 -9 mbar

16. VESTIBULE CLEAN ROOM with AIR CONDITIONING Clean room G. Riddone, 5th CLIC-ACE, 02/02/201016 Clean room layout Boxes under N2 Clean pieces -After the failure of CERN ac. structures, it became clear that a clean room was indispensable - Audits for relevant steps organized Sealed bag under N2 RF measurement

17. Fabrication of PETS at 11.4 GHz with damping material G. Riddone, 5th CLIC-ACE, 02/02/201017 PETS for feasibility demonstration - under assembly - to be tested at SLAC PETS for feasibility demonstration - under assembly - to be tested at SLAC Damping material Coupler Minitank with bars inside

18. Fabrication flow for PETS (11,4 GHz) G. Riddone, 5th CLIC-ACE, 02/02/201018 Procedure as close as possible to the baseline, but some difference due to design and infrastructures Cleaning (NGL+solvent) Cleaning (NGL+solvent) EB welding of the bars QC PETS bars Baking (vacuum, 200 C, 2 h) Baking (vacuum, 200 C, 2 h) Assembly of the 8 bars Assembly of the 8 bars Vacuum test EB welding of the bars Packaging (N2) RF check Shipping to SLAC Assembly of couplers-bars and mini-tank EB welding of tank Final bake-out (150 C, 2h) RF check FINAL ASSEMBLY

19. Fabrication of TBL PETS G. Riddone, 5th CLIC-ACE, 02/02/201019 Prototype made by CIEMAT using conventional UHV best practice for cleaning and handling Coupler is brazed, no heat treatment for PETS itself The CERN production will be assembled in a clean room, The coupler will be vacuum brazed at CERN Status: parts fabrication, assembly should start in April S. Doebert

20. Production capability G. Riddone, 5th CLIC-ACE, 02/02/2010 20 3 laboratories: - ac. structures  SLAC/KEK and CERN - PETS  CERN 5 qualified vendors for ac. structures: 2 (CERN), 2 (KEK), 1 (SLAC) 3 qualified vendors for PETS For each structure, at least two units per lab. are manufactured (almost in parallel) For KEK/SLAC made structure, the assembly/baking is made at SLAC - e.g. baking of two structures in parallel At present, potential capability up to 20. structures per year

21. Present structures: CERN, KEK, SLAC (base and fundamental program) G. Riddone, 5th CLIC-ACE, 02/02/2010 21 CD10 TD24

22. Present structures: CERN (base program) G. Riddone, 5th CLIC-ACE, 02/02/2010 22 1 ac. structure (CLEX, TBTS) 2 ac. structures with wakefield monitors (CLEX, TBTS) TBTS: two beam test stand SATS: stand-alone test stand

23. Master schedule G. Riddone, 5th CLIC-ACE, 02/02/201023 Monthly revised during the KEK-SLAC-CERN collaboration WebEX meetings Last revision:” 28.01.2010

24. Comparison to Jan 2009 schedule For production overall delay of about 4 months, although not on critical path Priorities change as a function of test results CERN structures: break of few weeks before decision to adopt baseline procedure Several steps of baseline procedure were new for CERN: process qualification needed before application to a real structure Baseline procedure takes longer than the previous based on vacuum brazing at 800 °C Qualification of new vendors: several trials before achieving disks within specification G. Riddone, 5th CLIC-ACE, 02/02/2010 24

25. Other structures G. Riddone, 5th CLIC-ACE, 02/02/201025 Important involvement of other laboratories to exchange experience and to increase the market  900-mm long structures for PSI (X-FEL) and Elettra (Sincrotone Trieste) with wakefield monitors  72 cells Wakefield monitor design Structure assembly

26. Towards CLIC structures CDR Accelerating structure with all features: damping material, wakefield monitor and technical systems; under eng. design (first structure at the end of 2010). Assembly test with a prototype structure are scheduled in the coming weeks. PETS with on-off system: under design. On-off system to be tested in Q3, 2010 Cost estimate in needed by 2010: launched dedicated studies with three companies/institutes G. Riddone, 5th CLIC-ACE, 02/02/2010 26 Wakefield monitor Damping material Coupler On-off system AS PETS

27. T4 T1 T0 Towards CLIC structures From CDR to TDR Main linac prototype modules (3 by end of 2012) will be built to validate the technical systems in an integrated approach. G. Riddone, 5th CLIC-ACE, 02/02/2010 27 These modules will contain accelerating structures and PETS with all required features Industrialization and mass production development in collaboration with companies

28. Conclusions G. Riddone, 5th CLIC-ACE, 02/02/2010 28 NLC/JLC fabrication technology validated for CLIC accelerating structures to 100 MV/m CERN is implementing NLC/JLC procedures (still in learning process) Cleaning (etching) Diffusion bonding at ~1040 °C (H 2 ) Vacuum baking Production capability up to 20 structures per year  higher than available testing slots Involvement of other laboratories to exchange experience and expertise CLIC structures with all features under design: first unit ready by end of this year Main linac prototype modules for CLEX will include CLIC several structures Industrialization, mass production and cost study launched for few structure configurations

29. SPARE G. Riddone, 5th CLIC-ACE, 02/02/2010 29

30. G. Riddone, 5th CLIC-ACE, 02/02/201030 Assembly of accelerating structures T24T18 and before

31. Comparison SLAC/CERN 31G. Riddone, 5th CLIC-ACE, 02/02/2010

32. Summary of comparison G. Riddone, 5th CLIC-ACE, 02/02/201032 SLAC/KEKFermilabCERN old CERN new (SLAC/KEK based) Diamond machining√√√√ Etch√√√√ 1000 ˚C pre-fire √ (Ar) ~ 1000 ˚C diffusion bonding√√ ~ 1000 ˚C brazing√ ~ 800 ˚C brazing √ (Ar, Au/Cu) √ (Vacuum, Ag/Cu) √ Vacuum baking√√√ Tank/sealedSEALEDSEALEDSEALED TANK/SEALED

33. QUADRANTS - HDS thick qualification part according to CLIAAS300062 - KERN (DE) Achieved shape accuracy ± 2.1 µm Roughness Ra = 86 nm – 30 nm according to ISO 97 Achieved shape accuracy ± 1.3 µm S. Atieh G. Riddone, 5th CLIC-ACE, 02/02/2010 33

34. Origins translation: X 16 µm and Z -8 µm Shape accuracy is respected ± 2.5 µm QUADRANTS - HDS thick qualification part according to CLIAAS300062 – DMP (SP) G. Riddone, 5th CLIC-ACE, 02/02/2010 34 S. Atieh

35. 35 T18 CERN - Inspection on iris 12 Contamination between brazing and testing 35GR, BE/RF, 19.06.2009 C C Ca

36. T24#1 – CERN G. Riddone, 5th CLIC-ACE, 02/02/201036