1. Allan DeMello Lawrence Berkeley National Lab RFCC Module Design Review October 21, 2008 RFCC Module and Subcomponents Mechanical Design

2. Allan DeMello - Lawrence Berkeley National Lab - October 20, 2008Page 2 Allan DeMello - Lawrence Berkeley National Lab - June 4, 2008 RFCC Module and Subcomponents Mechanical Design Page 2Allan DeMello - Lawrence Berkeley National Lab - October 21, 2008 RFCC Module Components Dynamic Cavity Frequency Tuners Hexapod Strut Cavity Suspension RF Cavity Water Cooling Mechanical Joining of the Coupling Coil and the Vacuum Vessel Vacuum System RF Coupler RFCC Support Stand

3. RFCC Module and Subcomponents Mechanical Design Allan DeMello - Lawrence Berkeley National Lab - October 20, 2008 MICE RF Cavity – Mechanical Design and Analysis Page 3 Allan DeMello - Lawrence Berkeley National Lab - June 4, 2008 RFCC Module and Subcomponents Mechanical Design Page 3Allan DeMello - Lawrence Berkeley National Lab - October 21, 2008 Four Cavity Layout in Vacuum Vessel Clocking of tuner position between adjacent cavities avoids interference Actuators offset from cavity center plane due to width of coupling coil No contact between pairs of close packed cavities Tuning deflections increase cavity gap

4. RFCC Module and Subcomponents Mechanical Design Allan DeMello - Lawrence Berkeley National Lab - October 20, 2008 MICE RF Cavity – Mechanical Design and Analysis Page 4 Allan DeMello - Lawrence Berkeley National Lab - June 4, 2008 RFCC Module and Subcomponents Mechanical Design Page 4Allan DeMello - Lawrence Berkeley National Lab - October 21, 2008 Module End View with Tuners Six tuners per cavity provide individual frequency adjustment Tuning automatically achieved through a feedback loop 24 tuners required for each RFCC module Soft connection only (bellows) between tuner/actuators and vacuum vessel shell

5. RFCC Module and Subcomponents Mechanical Design Allan DeMello - Lawrence Berkeley National Lab - October 20, 2008 MICE RF Cavity – Mechanical Design and Analysis Page 5 Allan DeMello - Lawrence Berkeley National Lab - June 4, 2008 RFCC Module and Subcomponents Mechanical Design Page 5Allan DeMello - Lawrence Berkeley National Lab - October 21, 2008 Cavity Tuner Design Features Tuners are spaced evenly every 60 º around cavity Layout is offset by 15 º from vertical to avoid conflict with cavity ports Tuners touch cavity and apply loads only at the stiffener rings Tuners operate in “push” mode only (i.e. squeezing) ‏

6. RFCC Module and Subcomponents Mechanical Design Allan DeMello - Lawrence Berkeley National Lab - October 20, 2008 MICE RF Cavity – Mechanical Design and Analysis Page 6 Allan DeMello - Lawrence Berkeley National Lab - June 4, 2008 RFCC Module and Subcomponents Mechanical Design Page 6Allan DeMello - Lawrence Berkeley National Lab - October 21, 2008 Cavity Tuner Components - Section View Ball contact only Dual bellows vacuum sealing Tuner actuator Pivot pin Fixed (bolted) ‏ connection Ceramic contact wear plate between actuator ball end and tuner arm

7. RFCC Module and Subcomponents Mechanical Design Allan DeMello - Lawrence Berkeley National Lab - October 20, 2008 MICE RF Cavity – Mechanical Design and Analysis Page 7 Allan DeMello - Lawrence Berkeley National Lab - June 4, 2008 RFCC Module and Subcomponents Mechanical Design Page 7Allan DeMello - Lawrence Berkeley National Lab - October 21, 2008 Tuner Component Details Fixed arm Pivoting arm Actuator with integrated bellows assembly Screws to attach tuner to the cavity stiffener ring Pivot pin Cylinder attachment bracket Forces are transmitted to the stiffener ring by means of “push” loads applied to the tuner lever arms by the actuator assembly Ceramic wear plate

8. RFCC Module and Subcomponents Mechanical Design Allan DeMello - Lawrence Berkeley National Lab - October 20, 2008 MICE RF Cavity – Mechanical Design and Analysis Page 8 Allan DeMello - Lawrence Berkeley National Lab - June 4, 2008 Actuator Design RFCC Module and Subcomponents Mechanical Design Page 8Allan DeMello - Lawrence Berkeley National Lab - October 21, 2008 Actuator design incorporates bellows sealing between vacuum and air (no rubber). Actuator is “soft” mounted to the vacuum vessel with a bellows Ceramic plate attached to the tuner arm Hemisphere attached to the end of actuator rod

9. Page 9 Senior Aerospace Bellows will be fabricating the actuators (near off the shelf) Actuator Supplier RFCC Module and Subcomponents Mechanical Design Allan DeMello - Lawrence Berkeley National Lab - October 21, 2008

10. Stiffener Ring Analysis - Applied Displacement Page 10 A displacement of 2 mm is applied to both sides of the cavity stiffener ring in 6 locations Maximum observed distortion of 0.05 mm (0.002”) in the stiffener ring This level of distortion is not expected to affect the RF performance of the cavity or the overall stress on the Be window RFCC Module and Subcomponents Mechanical Design Allan DeMello - Lawrence Berkeley National Lab - October 21, 2008

11. Page 11 A reaction force of 31811 N (per side) on the stiffener ring is calculated in ANSYS 31811 N (per side) must be supplied by the 6 tuners Each tuner must apply 5300 N per side Tuner System Analysis – Reaction Force RFCC Module and Subcomponents Mechanical Design Allan DeMello - Lawrence Berkeley National Lab - October 21, 2008

12. RFCC Module and Subcomponents Mechanical Design Allan DeMello - Lawrence Berkeley National Lab - October 20, 2008Page 12 Allan DeMello - Lawrence Berkeley National Lab - June 4, 2008 RFCC Module and Subcomponents Mechanical Design Page 12Allan DeMello - Lawrence Berkeley National Lab - October 21, 2008 Tuner System Analysis - Deformation ANSYS FEA of one tuner on 1/6 cavity segment Input pressure of 1.38 MPa (200 psi) is applied to actuator piston Deformation at the stiffener ring in the 2 mm range Movement of the arm at the actuator is in the 3 mm range

13. RFCC Module and Subcomponents Mechanical Design Allan DeMello - Lawrence Berkeley National Lab - October 20, 2008Page 13 Allan DeMello - Lawrence Berkeley National Lab - June 4, 2008 RFCC Module and Subcomponents Mechanical Design Page 13Allan DeMello - Lawrence Berkeley National Lab - October 21, 2008 Tuner System Analysis - Stress ANSYS FEA of one tuner on 1/6 cavity segment Maximum stress in the cavity in the 100 MPa (14500 psi) range The yield strength of the copper cavity is 275 MPa This analysis show that the cavity will not yield when compressed by the tuner arms

14. RFCC Module and Subcomponents Mechanical Design Allan DeMello - Lawrence Berkeley National Lab - October 20, 2008 MICE RF Cavity – Mechanical Design and Analysis Page 14 Allan DeMello - Lawrence Berkeley National Lab - June 4, 2008 RFCC Module and Subcomponents Mechanical Design Page 14Allan DeMello - Lawrence Berkeley National Lab - October 21, 2008 Cavity Tuning Parameters The following parameters are based on a finite element analysis of the cavity shell. Tuning range is limited by material yield stress. Overall cavity stiffness: 7950 N/mm Tuning sensitivity: +230 kHz/mm per side Tuning range: 0 to -460 kHz (0 to -2 mm per side) ‏ Number of tuners: 6 Maximum ring load/tuner: 5.3 kN Max actuator press. (  100 mm): 1.38 MPa (200 psi) ‏

15. RFCC Module and Subcomponents Mechanical Design Allan DeMello - Lawrence Berkeley National Lab - October 20, 2008 MICE RF Cavity – Mechanical Design and Analysis Page 15 Allan DeMello - Lawrence Berkeley National Lab - June 4, 2008 RFCC Module and Subcomponents Mechanical Design Page 15Allan DeMello - Lawrence Berkeley National Lab - October 21, 2008 Cavity Suspension System Each cavity contains a dedicated set of suspension struts The suspension struts are designed to axially fix the cavity inside the vacuum vessel

16. RFCC Module and Subcomponents Mechanical Design Allan DeMello - Lawrence Berkeley National Lab - October 20, 2008 MICE RF Cavity – Mechanical Design and Analysis Page 16 Allan DeMello - Lawrence Berkeley National Lab - June 4, 2008 RFCC Module and Subcomponents Mechanical Design Page 16Allan DeMello - Lawrence Berkeley National Lab - October 21, 2008 Hexapod Strut Arrangement Hexapod six strut system will provide kinematic cavity support Each cavity requires a dedicated set of 6 suspension struts arranged in a hexapod type formation This system spreads the gravity load of the cavity across several struts Hexapod layout of struts allows accurate cavity alignment and positioning Six strut kinematic mounts prevent high cavity stresses caused by thermal distortion and over-constraint

17. RFCC Module and Subcomponents Mechanical Design Allan DeMello - Lawrence Berkeley National Lab - October 20, 2008 MICE RF Cavity – Mechanical Design and Analysis Page 17 Allan DeMello - Lawrence Berkeley National Lab - June 4, 2008 Hexapod Strut Cavity Mounting RFCC Module and Subcomponents Mechanical Design Page 17Allan DeMello - Lawrence Berkeley National Lab - October 21, 2008 Copper mounting post will be e-beam welded directly to the RF cavity The cavity experiences very little deformation on the radius at mounting post location during tuner deflection Stainless steel mounting post welded directly to the vacuum vessel

18. RFCC Module and Subcomponents Mechanical Design Allan DeMello - Lawrence Berkeley National Lab - October 20, 2008 MICE RF Cavity – Mechanical Design and Analysis Page 18 Allan DeMello - Lawrence Berkeley National Lab - June 4, 2008 Hexapod Strut Mounting to Vessel RFCC Module and Subcomponents Mechanical Design Page 18Allan DeMello - Lawrence Berkeley National Lab - October 21, 2008 Stainless steel strut mounts welded to the inside of the vacuum vessel Copper strut mounts e-beam welded to the outside of the cavity

19. RFCC Module and Subcomponents Mechanical Design Allan DeMello - Lawrence Berkeley National Lab - October 20, 2008 MICE RF Cavity – Mechanical Design and Analysis Page 19 Allan DeMello - Lawrence Berkeley National Lab - June 4, 2008 RFCC Module and Subcomponents Mechanical Design Page 19Allan DeMello - Lawrence Berkeley National Lab - October 21, 2008 ANSYS FE Analysis - Deformation ANSYS FE analysis of the hexapod strut cavity suspension system Total mass of the cavity and tuners is approximately 410 kg. (900-lbs) ‏ Total deflection due to gravity alone is 0.115 mm

20. ANSYS FE Analysis - Stress Page 20 Maximum stress in the strut suspended cavity, due to gravity alone, is in the 20-30 MPa (2900- 4350 psi) range Yield strength of cavity is in the 275 MPa range RFCC Module and Subcomponents Mechanical Design Allan DeMello - Lawrence Berkeley National Lab - October 21, 2008

21. ANSYS FE Analysis - Stress Page 21 Maximum stress due to gravity in the strut suspended cavity is in the 20- 30 MPa (4500 psi) range Yield strength of cavity is in the 275 MPa range No yielding will take place in the cavity at the strut mounting locations RFCC Module and Subcomponents Mechanical Design Allan DeMello - Lawrence Berkeley National Lab - October 21, 2008

22. Page 22 ANSYS FE analysis showing first mode natural frequency result of 43 Hz ANSYS FEA – Modal Analysis RFCC Module and Subcomponents Mechanical Design Allan DeMello - Lawrence Berkeley National Lab - October 21, 2008 Support systems with a first mode frequency of 20 Hz or higher are generally considered a stiff structure

23. RFCC Module and Subcomponents Mechanical Design Allan DeMello - Lawrence Berkeley National Lab - October 20, 2008 MICE RF Cavity – Mechanical Design and Analysis Page 13 Allan DeMello - Lawrence Berkeley National Lab - June 4, 2008 RFCC Module and Subcomponents Mechanical Design Page 23Allan DeMello - Lawrence Berkeley National Lab - October 21, 2008 Cavity Cooling System Single circuit water cooling tube for each cavity One inlet and one outlet 8 penetrations in the vacuum vessel

24. RFCC Module and Subcomponents Mechanical Design Allan DeMello - Lawrence Berkeley National Lab - October 20, 2008 MICE RF Cavity – Mechanical Design and Analysis Page 13 Allan DeMello - Lawrence Berkeley National Lab - June 4, 2008 RFCC Module and Subcomponents Mechanical Design Page 24Allan DeMello - Lawrence Berkeley National Lab - October 21, 2008 Cavity Cooling Water Feedthroughs All cavity water connections are made outside of the vacuum vessel Continuous water tube wrapped around the cavity A compliance coil inside of the vacuum vessel One inlet and one outlet per cavity

25. RFCC Module and Subcomponents Mechanical Design Allan DeMello - Lawrence Berkeley National Lab - October 20, 2008 MICE RF Cavity – Mechanical Design and Analysis Page 13 Allan DeMello - Lawrence Berkeley National Lab - June 4, 2008 RFCC Module and Subcomponents Mechanical Design Page 25Allan DeMello - Lawrence Berkeley National Lab - October 21, 2008 Section View of Water Feedthroughs A special conflat flange is welded into the wall of the vacuum vessel Both ends of the continuous copper tube are soft solder brazed (individually) into a second special conflat flange The second flange is fastened from the outside of the vacuum vessel Vacuum side Air side

26. RFCC Module and Subcomponents Mechanical Design Allan DeMello - Lawrence Berkeley National Lab - October 20, 2008 MICE RF Cavity – Mechanical Design and Analysis Page 26 Allan DeMello - Lawrence Berkeley National Lab - June 4, 2008 Prototype Cavity RF Couplers RFCC Module and Subcomponents Mechanical Design Page 26Allan DeMello - Lawrence Berkeley National Lab - October 21, 2008 Coupling loops are fabricated using standard copper co-ax Parts to be joined by e-beam welding (where possible) and torch brazing Coupling loop has integrated cooling The RF coupler will be based on the SNS design using the off the shelf Toshiba RF window

27. RFCC Module and Subcomponents Mechanical Design Allan DeMello - Lawrence Berkeley National Lab - October 20, 2008 MICE RF Cavity – Mechanical Design and Analysis Page 27 Allan DeMello - Lawrence Berkeley National Lab - June 4, 2008 MICE Cavity RF Couplers RFCC Module and Subcomponents Mechanical Design Page 27Allan DeMello - Lawrence Berkeley National Lab - October 21, 2008 A bellows connection between the coupler and the vacuum vessel provides compliance for mating with the cavity A simple copper flange is used to electrically connect the RF coupler to the cavity

28. RFCC Module and Subcomponents Mechanical Design Allan DeMello - Lawrence Berkeley National Lab - October 20, 2008 MICE RF Cavity – Mechanical Design and Analysis Page 28 Allan DeMello - Lawrence Berkeley National Lab - June 4, 2008 MICE Cavity RF Couplers RFCC Module and Subcomponents Mechanical Design Page 28Allan DeMello - Lawrence Berkeley National Lab - October 21, 2008 Off the shelf stainless steel flange “V” clamp secures RF coupler to cavity

29. RFCC Module and Subcomponents Mechanical Design Allan DeMello - Lawrence Berkeley National Lab - October 20, 2008 MICE RF Cavity – Mechanical Design and Analysis Page 29 Allan DeMello - Lawrence Berkeley National Lab - June 4, 2008 Vacuum System RFCC Module and Subcomponents Mechanical Design Page 29Allan DeMello - Lawrence Berkeley National Lab - October 21, 2008 A NEG pump has been chosen because it will be unaffected by the large magnetic field A vacuum path between the inside and outside of the cavity eliminates the risk of high pressure differentials and the possible rupture of the thin beryllium window NEG (non-evaporable getter) pump Cross sectional view of vacuum system

30. Page 30 Vacuum Vessel Fabrication Page 30 Vacuum vessel material must be non-magnetic and strong: therefore 304 stainless steel will be used throughout The vacuum vessel will be fabricated by rolling stainless steel sheets into cylinders Two identical vessel halves will be fabricated with all ports and feedthroughs Main 1400mm rolled tube Smaller diameter rolled tube Bellows flange RFCC Module and Subcomponents Mechanical Design Allan DeMello - Lawrence Berkeley National Lab - October 21, 2008

31. Page 31 The Two Halves Joined (coupling coil not shown) ‏ Page 31 Central under-cut provides clearance for the coupling coil RFCC Module and Subcomponents Mechanical Design Allan DeMello - Lawrence Berkeley National Lab - October 21, 2008

32. Page 32 Cross Sectional View with the Coupling Coil Page 32 Gap between the vacuum vessel and the coupling coil provides clearance for assembly Vessel welded around the inside after coupling coil and the second vessel half are in place RFCC Module and Subcomponents Mechanical Design Allan DeMello - Lawrence Berkeley National Lab - October 21, 2008

33. Page 13Page 33 Interface of Coupling Coil to the Vacuum Vessel Two 25 mm thick special gussets are welded to the coupling coil at ICST in Harbin These gussets are designed to match LBNL’s large load carrying gussets RFCC Module and Subcomponents Mechanical Design Allan DeMello - Lawrence Berkeley National Lab - October 21, 2008

34. Page 13Page 34 Interface of Coupling Coil to the Vacuum Vessel LBNL will weld 25 mm thick special gussets between the coupling coil and the vacuum vessel These gussets are designed to match the gussets welded to the coupling coil at ICST No welding will be applied to the coupling coil external surfaces Opening in gusset provides access to the tuner actuator RFCC Module and Subcomponents Mechanical Design Allan DeMello - Lawrence Berkeley National Lab - October 21, 2008

35. Page 13Page 35 Interface of Coupling Coil to the Vacuum Vessel Sixteen gussets will be used (8 on each side) to secure the coupling coil to the vacuum vessel Analysis still needs to be performed to confirm this design RFCC Module and Subcomponents Mechanical Design Allan DeMello - Lawrence Berkeley National Lab - October 21, 2008

36. Page 36 RFCC Module Support Stand Page 36 Because the plan is to ship the RFCC module from Berkeley to RAL horizontally a special support stand will be fabricated that supports the coupling coil/vacuum vessel horizontally (without cavities installed) The RFCC will be moved into the experiment hall in the horizontal position on the shipping stand The permanent stand will be fabricated out of non-magnetic stainless steel RFCC Module and Subcomponents Mechanical Design Allan DeMello - Lawrence Berkeley National Lab - October 21, 2008 The Permanent RFCC Stand

37. Page 37 RFCC Attachment to Support Stand Page 37 The permanent support stand is bolted onto the vacuum vessel once the module is inside the experiment hall The vacuum vessel is bolted to a saddle made up of stainless steel plates welded to the support stand RFCC Module and Subcomponents Mechanical Design Allan DeMello - Lawrence Berkeley National Lab - October 21, 2008 Stainless steel bars are welded onto the vacuum vessel for attaching bolted gusset plates

38. Page 38 RFCC Support Stand Page 38 RFCC support stand must withstand a longitudinal force of 50 tons transferred from the coupling coil Bolted stainless steel gusset plates and rectangular tube cross bracing provide shear strength in the axial direction (analysis will be done to confirm this stand design) ‏ RFCC Module and Subcomponents Mechanical Design Allan DeMello - Lawrence Berkeley National Lab - October 21, 2008

39. Page 39 RFCC Module Design Summary Page 39 Conceptual design of the cavity frequency tuners is complete (further detailed analysis will be performed to optimize design) ‏ The hexapod cavity suspension system has been analyzed and will provide accurate alignment and rigid support for the cavities Cavity water cooling feed through system has been developed – minimum vacuum vessel penetrations needed The RF coupler will be based on the SNS design using the off the shelf Toshiba RF window The vacuum system includes an annular feature coupling the inside and the outside of the cavity (further analysis of vacuum needs to be done) ‏ RFCC Module and Subcomponents Mechanical Design Allan DeMello - Lawrence Berkeley National Lab - October 21, 2008

40. Page 40 Engineering 3D CAD model of the vacuum vessel mechanical design is nearing completion Standard machining and manufacturing method will be used in the vacuum vessel’s fabrication Meyer Tool & Manufacturing has shown an interest in fabricating the vacuum vessel for us A plan for attaching the coupling coil and the vacuum vessel together has been developed and communicated to ICST for deployment Conceptual design of the support stand is complete (analysis will need to be performed) ‏ RFCC Module Design Summary RFCC Module and Subcomponents Mechanical Design Allan DeMello - Lawrence Berkeley National Lab - October 21, 2008