Double Quarter Wave Crab Cavity Helium Vessel

1. Double Quarter Wave Crab CavityHelium Vessel Silvia Verdú-Andrés on behalf of the DQWCC team May 5, 2014

2. Outline • Conceptual design of the helium vessel and tuning system for the SPS DQWCC • Overview: dimensions, weight, He volume • Cavity stiffening, pre-tuning and tuning systems • Helium vessel and tuning system: assembly sequence, connections and interfaces, materials and joints • Engineering studies • Pre-tuning and tuning range • Mechanical stresses • Thermal loads • Summary

3. PoP helium vessel to introduce smoothly the conceptual design

4. Helium vessel - concept Ribs for additional stiffening Cryo jumper HOM Can CERN provide drawing of tuning system with piezo part? PU FPC PU Adjacent beam pipe through the vessel • Titaniumand Niobium similar • thermal expansion coefficient •  rigid connections for all ports • Piezooutside vessel  larger tuning range • Prep rings for eventual disassembly • All liquid helium – vacuum interfaces welded for best vacuum tightness • Clearance to access to ports beam HOM Tuner + stiffening

5. Pre-tuning and tuning systems Tuning by actuation on the central plates Silvia: PoP SPS H-field E-field Combined function: tuning + stiffening

6. Pre-tuning system Nicer cross-section to show pre-tuning with bolts to be fixed onto helium vessel top plate?? • Pre-tuning ~ 1.6 MHz/mm (during assembly of cavity-vessel) for machining tolerances Put Qiong’s table with machining tolerances pre-tuning

7. Tuning system • Tuning (after installation) push-pull ~ 1.6 MHz/mm (during operation) piezo~ 30 mm for Lorentz detuning and microphonics Can CERN provide drawing with piezo location??? Symmetric actuation onto both central plates tuning

8. Lorentz detuning E-field H-field Fixed all ports and central plates (best case scenario) Lorentz detuning: 0.17 Hz/ (10J) – best case scenario

9. Stiffening for cavity and helium vessel All port connections are rigid but PU • Any additional stiffening for the cavity???? Ribs Stiffening during cooling down and pressure changes Combined function: tuning + stiffening on central plates

10. Helium vessel - dimensions 390mm 470mm Integration into cryomodule 660mm

11. Cavity assembly 1

12. HOM: NbTi flange welded to Ti adaptor and Nb tube Cavity assembly 316LN SS DN63CF Flanges for FPC and BP; others are NbTi 1 SS flange, Nb tube, Ti ring/adaptor Ti brazed welded

13. Tuning system assembly Ti rod 2 1 brazed welded

14. Tuning system assembly 2 1 Ti housing 3 brazed welded

15. Helium vessel assembly Grade 2 titanium. Cryo tube in SS brazed to prep tube in Ti. SS – H ; Ti-V Ti prep ring 4 2 Ti vessel Integrated section of adjacent beam pipe in which material?? Ti prep ring 1 brazed 3 welded

16. Helium – vacuum interfaces No flow! Find another word • All liquid helium – vacuum interfaces welded

17. Cooling and heat-stationing Heat-stationing for tuning frame Heat-stationing for tuning tube Helium chamber for HOM filter He

18. Heat loads – tuning system • Picture with temperature to show gradients • Picture of simulation result CERN: heat load for tuning system

19. Total heat load To be updated: Skaritka

20. Mechanical stresses • Helium pressure • 300 K  2K • Actuation of tuning system

21. Mechanical stresses • Helium pressure • 300 K  2K • Actuation of tuning system Helium

22. Mechanical stresses due to helium pressure • Constrains (fixed boundaries, etc) • Load(s) and number of cycles (if applies) • Max. stress allowed • Picture of mesh • Picture of initial constrains and loads • Picture of stress value and deformation arrows • Design elements incorporated to counter-act load effects • Young modulus and Poisson’s ratio

23. Mechanical stresses • Helium pressure • 300 K2K • Actuation of tuning system

24. Mechanical stresses due to thermal contraction (300K  2K) • Constrains (fixed boundaries, etc) • Load(s) and number of cycles (if applies) • Max. stress allowed • Picture of mesh • Picture of initial constrains and loads • Picture of stress value and deformation arrows • Design elements incorporated to counter-act load effects • Thermal expansion coefficient for Niobium and Titanium, Young modulus and Poisson’s ratio

25. Mechanical stresses • Helium pressure • 300 K  2K • Actuation of tuning system

26. Mechanical stresses due to tuning system actuation • Constrains (fixed boundaries, etc) • Load(s) and number of cycles (if applies) • Max. stress allowed • Picture of initial constrains and loads • Picture of mesh • Picture of stress value and deformation arrows • Design elements incorporated to counter-act load effects • Young modulus and Poisson’s ratio

27. Integration into cryomodule  Tomorrow’s presentation by John Skaritka

28. Summary • Compact vessel for compact cavity • Dedicated vessel design to: • minimize liquid helium leak chances(all helium-vacuum interfaces welded) • ease assembly, particularly the access to cavity ports • ease disassembly (prep rings) • Robust vessel design?? • Appropriate stiffening of the cavity provided by rigid connection of cavity ports to vessel and tuning system • Manifold tuning : pre-tuning + push-pull + piezo • Optimized design for reduced heat load??

29. BNL Sergey Belomestnykh, Ilan Ben-Zvi, John Skaritka, Silvia Verdú-Andrés, Binping Xiao, Qiong Wu CERN Luis Alberty, Rama Calaga, Ofelia Capatina, Federico Carra, Giuseppe Foffano, Norbert Kuder, Raphael Leuxe, Thierry Renaglia SLAC Zenghai Li

30. Thanks for your attention Long Island Blue Claw Crabs

31. Cavity mounting

33. Integration into cryomodule