Crab RFD prototype Production Status Update M Garlasch

Crab – RFD prototype: Production Status Update M. Garlaschè & L. Prever-Loiri with contributions from all 15 th September, 2017 The Hi. Lumi LHC Design Study is included in the High Luminosity LHC project and is partly funded by the European Commission within the Framework Programme 7 Capacities Specific Programme, Grant Agreement 284404.

RFD Manufacturing Strategy • • Initial feasibility well advanced (cut-out & technologies) Major Differences (w. r. t. U. S. ): • Transitions between end cover and ports: machining from bulk • Welding interface of waveguide on cavity sides Internal welding RFD Cavity AD-HOC Meeting - L. Prever-Loiri 2

RFD Manufacturing Strategy 3 x main subassemblies V-HOM and antenna side Central Body H-HOM an FPC side RFD Cavity AD-HOC Meeting - L. Prever-Loiri 3

RFD Manufacturing Strategy: Sides TRANSITION FROM BULK SPINNING TUBE SHAPING RFD Cavity AD-HOC Meeting - L. Prever-Loiri 4

1 Shaping + coining RIGHT LEFT 3 3 Welding 3 511 Geometry adjustement FPC, H-HOM, V-HOM PORTS 2 Machining half pieces Thickness 3. 0 mm and height 4 Machining of transitions edge 511 RFD Cavity AD-HOC Meeting - L. Prever-Loiri 5

FPC, H-HOM, V-HOM PORT 5 Machining of bulk transitions 6 Welding transitions Backing to avoid transversal shrinkage 7 Machining transitions 3 511 Final machining RFD Cavity AD-HOC Meeting - L. Prever-Loiri 6

FPC, H-HOM, V-HOM PORT 8 Spinning tube 9 DQW extremities (as per DQW) Machining from bulk material and spinned tube Machining of: • External Ø • Internal Ø • Length Vacuum brazing of flanges 3 511 Welding with backing Nb 55 Ti flanges Machining after welding 10 511 Machining after welding 3 11 Welding with backing 3 511 Welding with backing Machining after welding RFD Cavity AD-HOC Meeting - L. Prever-Loiri 7

Shaping + coining Machining after calibration 3 Machining Edges Machining after welding Geometry adjustement 1 End Caps Welding spinned tubes 3 2 511 Welding extremities 3 4 511 RFD Cavity AD-HOC Meeting - L. Prever-Loiri 8

End Caps: Aperture Machining OPTION 1 : Vertical cut Thickness variation 4. 2 mm to 5. 9 mm OPTION 2: 20° cut Thickness variation 4 mm to 4. 6 mm EBW direction RFD Cavity AD-HOC Meeting - L. Prever-Loiri 9

Welding Ports to End Caps Welding H-HOM and FPC Welding V-HOM Antenna tube from bulk material 4 511 Machining after welding and geometry adjustement Sides + thickness 3. 0 mm RFD Cavity AD-HOC Meeting - L. Prever-Loiri 10

Manufacturing Strategy: Central Body Half body Corner Bowl Extra length Manufacturing process: Extra length Machining after welding and geometry adjustement 1. 2. 3. 4. 5. 6. 7. 8. 9. Bowl forming and machining Corner forming and machining Bending of Central body (extra length) Machining aperture of half body Welding Bowl/Corner (internal) Geometry adjustement and machining Welding Corner/Central Body (internal) Geometry adjustement Machining of linear welding seam RFD Cavity AD-HOC Meeting - L. Prever-Loiri 11

Manufacturing Strategy: Corner Transition Manufacturing process: • External edge Bending • Internal edge: extrusion • Coining • Edges machining Butt welding seam Thickness RFD Cavity AD-HOC Meeting - L. Prever-Loiri 12

Manufacturing Strategy: Bowl Geometry of welding seam to be defined Manufacturing Process: • deep drawing • Coining • Machining (edges plus eventual features) Sheet size provide by FE analyses Welding seam simplified RFD Cavity AD-HOC Meeting - L. Prever-Loiri 13

Body Assembly Two linear welds with possible internal re-welding (RF surface improvement) 511 4 4 511 Machining after welding and geometry adjustement Length + thickness reduction to 3. 0 mm RFD Cavity AD-HOC Meeting - L. Prever-Loiri 14

RFD Final Assembly 511 3 4 Tuning plots 511 4 3 511 4 511 Stiffeners RFD Cavity AD-HOC Meeting - L. Prever-Loiri 15

RFD-Shaping • Shaping philosophy & draft tools finished (thanks to DQW experience) • Initial FE analyses started (max stress strain, indicative sheet size, pleating, forces. . . ) End cap: BOWL: deep drawing + coining Deepdrawing (w. central hole) Trimming Extrusion coining RFD Cavity AD-HOC Meeting - L. Prever-Loiri 16

Finite Elements Analyses Effective Plastic strain εplastic distributions DQW bowl Max. Effective Plastic strain: 0. 56 Compression RFD bowl (Radius 15 mm) Should we worry about these peaks in strain? • εUTS is 0. 5 – 0. 8 in unidirectional tests – but considering the triaxility, there is a larger margin • Peak is due to compression on surface opposite to RF • We have already observed some buckling of the material in the DQW bowl (rather than compression-driven failure)

Finite Elements Analyses Thickness distribution Comparison DQW bowl RFD bowl (Radius 15 mm) RFD Cavity AD-HOC Meeting - L. Prever-Loiri 18

Material Estimation: Nb & Nb 55 Ti Niobium sheet thickness 4. 0 mm Niobium sheet thickness 5. 5 mm 520 kg 310000 € Round bar Ø 42 kg 25000 € Nb 55 Ti sheet thickness 15 mm Round bar Ø 55 mm 37 kg 20000 € Niobium sheet thickness 6. 4 mm Niobium plate thickness 42. 0 mm RFD Cavity AD-HOC Meeting - L. Prever-Loiri 19

Conclusions • Initial feasibility study well advanced (cut-out & technologies) • Shaping: • Bowl & End Caps: philosophy of tools finished (thanks to DQW experience) • Ports: philosophy of tool to be defined • Initial FE analyses on going (max stress strain, indicative sheet size, pleating, forces. . . ) • NEXT: • Purchase Nb & Nb 55 Ti • launch ‘standard’ manufacturing (extremities) • Cavity design (cut out, components definition…) • Tools design RFD Cavity AD-HOC Meeting - L. Prever-Loiri 20

Thanks for your attention! RFD Cavity AD-HOC Meeting - L. Prever-Loiri 21