1. HiGrade-Kickoff DESY 29.8.2008 Global Design Effort 1 ILC-HiGrade WP6 High-Gradient cavities Lutz Lilje DESY

2. HiGrade-Kickoff Lutz Lilje DESY 29.8.2008 Global Design Effort 2 Outline Where are we? –America and Asia New vendors and new preparation setups –Europe Previous production cycle Current production cycle –Preliminary data Goals for ILC HiGrade –XFEL as an Asset Model for Cavity Fabrication and Preparation

3. Date Event3

4. HiGrade-Kickoff Lutz Lilje DESY 29.8.2008 Global Design Effort 4 References for Americas Data R. L. Geng et al., Proc. SRF2007, Beijing, WEP28 (2007). R. L. Geng et al., Proc. LINAC08, Victoria, Canada, in preparation. C. M. Ginsburg (FNAL), private communication. W. J. Ashmanskas and H. S. Padamsee, Proc. SRF2007, Beijing, WEP39 (2007).

5. HiGrade-Kickoff Lutz Lilje DESY 29.8.2008 Global Design Effort 5

6. HiGrade-Kickoff Lutz Lilje DESY 29.8.2008 Global Design Effort 6 DESY 4th: Field Emission Analysis

7. HiGrade-Kickoff Lutz Lilje DESY 29.8.2008 Global Design Effort 7 DESY 4th: Field Emission Analysis Optical Inspection done

8. HiGrade-Kickoff Lutz Lilje DESY 29.8.2008 Global Design Effort 8

9. 9 TESLA cavity Z110: #8 cell equator Quench location #8 equator 250 ~ 300 deg 1mm #8 equator, t=288 ~ 299 deg 10mm t=292 deg t=297 deg T-map data in test 2, 14.2 MV/m group of beads(?) with 10mm wide were observed. Similar beads group were also observed in several places. see following slides.

10. 10 TESLA cavity Z111: #6 cell equator T-map data in test 2, 16.0 MV/m Quench location #6 equator 175 ~ 225 deg #6 equator, t=193 ~ 204 deg 1mm 1.5mm t=198 deg t=199 deg group of beads(?) with 1.5mm wide were observed.

11. 11 0 360 deg18090270 #1 #2 #7 #6 #5 #4 #3 #9 #8 #1-#2i #2-#3i #3-#4i #4-#5i #5-#6i #6-#7i #7-#8i #8-#9i Group of spot Scratch Z110 summary 08/05/12 Iris equator T-map Heat spot cell equator Iris

12. 12 0 360 deg18090270 #1 #2 #7 #6 #5 #4 #3 #9 #8 #1-#2i #2-#3i #3-#4i #4-#5i #5-#6i #6-#7i #7-#8i #8-#9i Group of spot Scratch Z111 summary 08/05/15 Iris equator T-map Heat spot cell equator Iris

13. HiGrade-Kickoff Lutz Lilje DESY 29.8.2008 Global Design Effort 13 DESY Current Production: Comparison of Final Treatment

14. HiGrade-Kickoff Lutz Lilje DESY 29.8.2008 Global Design Effort 14 DESY 4th: Field Emission Analysis

15. HiGrade-Kickoff Lutz Lilje DESY 29.8.2008 Global Design Effort 15 DESY Current Production: Comparison of Final Treatment Optical Inspection next

16. HiGrade-Kickoff Lutz Lilje DESY 29.8.2008 Global Design Effort 16 Where are we? II Production issues –Low-gradient cavities show defects found by temperature map and optical inspection –Training of manufacturers is mandatory Preparation issues –Have less impact currently Rinses developped within ILC R&D are successful –Ethanol (DESY), Ultrasound (JLab), Short EP (KEK) Clear path forward –Apply high resolution inspection systematically to improve weld quality –Apply optimum surface preparation e.g. ethanol rinse

17. HiGrade-Kickoff Lutz Lilje DESY 29.8.2008 Global Design Effort 17 Tools to be used XFEL cavities will be a well advanced standard –E.g. HOM Design is well proven Advanced high-resolution optical inspection –Option to include this into the XFEL production cycle –Improve performance of manufacturers online T-mapping on all cavities –Essential tool to pin down high-gradient hot spots –Need bare cavities

18. HiGrade-Kickoff Lutz Lilje DESY 29.8.2008 Global Design Effort 18 Goals of HiGrade WP6 Improve over XFEL performance –XFEL will make a choice on the cavity preparation cycle soon –Ongoing R&D might show improved methods for cavity preparation –HiGrade will implement these steps on a subset of XFEL cavities Therefore maximum synergy is achieved between the projects –HiGrade can jump onto XFEL production Quality control by –Support optical inspection of all cavities –Thermal mapping of cavities –XFEL can use HiGrade Cavities in the long run Spares or higher energy Deliver ~30 cavities after a well-defined fabrication and preparation –Demonstrate yield acceptable for ILC mass production in low-power tests –Could add on horizontal high-power test

19. HiGrade-Kickoff Lutz Lilje DESY 29.8.2008 Global Design Effort 19 Model for ILC-HiGrade Cavity Production and Preparation Technical ChoicesLocationRemark FabricationXFEL-likeCompanyMight include optical inspection already Rough Surface PreparationXFEL-likeCompany Optical Inspection IXFEL-likeCompany FurnaceXFEL-likeCompany Final Surface PreparationXFEL or ILC recipeCompany, DESY, CEA QC Argument would necessitate XFEL prep Test IT-map mandatoryDESY, CEANo t-map at CEA yet Optical Inspection IICompare with T-mapDESY, CEAGuided repair option? Final Surface PreparationILC recipeDESY, CEACEA time line? Company? Test IIT-map mandatoryDESY, CEANo t-map at CEA yet Tank weldingBladetuner with PiezosCompany, DESY, CEA Tuner from INFN Coupler assembly and Final rinse High-pressure water rinse after assy DESY, CEACoupler from LAL High-power testDESY, CEACHECHIA, CryHoLab

20. HiGrade-Kickoff Lutz Lilje DESY 29.8.2008 Global Design Effort 20 Summary Issues with cavities are identified –Fabrication quality to be improved –Final surface preparation has been improved within ILC R&D work ILC-HiGrade and XFEL will profit from each other –Quality control support via HiGrade –XFEL Cavities as well defined tool to start from Model for a cavity production has been presented –CEA and DESY are the key institutes Need some discussion on available infrastructure

21. 21 #1 equator, t=123 deg Z110: group of beads(?) (1) #2 equator, t=68 deg 1mm #2 equator, t=152 deg

22. 22 1mm Z110: group of spot(?), scratch iris (1) #1-#2 iris, t=25 deg, group of spot?#1-#2 iris, t=143 deg, scratch #1-#2 iris, t=192 deg, scratch along Z-axis scratch along Z-axis #1-#2 iris, t=311 deg, Normal