MICE RFCC Module Update

1. Allan DeMello Lawrence Berkeley National Lab MICE RFCC ModuleUpdate MICE CM25 at RAL, UK November 6, 2009

2. MICE RFCC Module201 MHz RF Cavity Fabrication Update

3. Progress Summary • Cavity fabrication awarded to Applied Fusion in Feb. 2009 • Cavity body fabrication started in April 2009 • Welding the stiffener ring to the shell and cutting the iris is complete • Copper shells with the stiffener ring have been e-beam welded into 5 cavities • Ports have been extruded into the perimeter of all cavities • Welding the nose ring into the cavity irises is complete • Welding the strut mounting posts onto the cavity is complete • Welding of the cooling tubing onto the cavity is on going • The first 5 cavities are scheduled to be delivered by end of CY2009

4. Cavity Component Parts • Cooling Tubing • Strut • Mounting Post • Stiffener Ring • Cavity Shells • Extruded • Port Flange • Nose Ring

5. Cavity Fabricator - Applied Fusion, Inc. • Applied Fusion’s e-beam welder is a German made machine • Applied Fusion has the machining equipment necessary to fabricate the complete RF cavity (minus spinning) Electron beam welding machine Applied Fusion, Inc. 1915 Republic Ave. San Leandro, CA 94577 Inspection Milling Machines

6. Cavity Stiffener Ring Title Here • The stiffener ring is welded on to the half shell • The iris is machined out

7. E-beam Weld Shells into a Cavity • The cavity shells were inspected at LBNL and paired for best inside edge match • Matched shells were e-beam welded into a cavity • The cavity shells are oriented (clocked) to the stiffener rings with a pin

8. Bore Hole for Extruded Port • Cavity is placed on a horizontal milling machine to bore the pilot hole for the extruded ports • The shell alignment key is bored out as one of these pilot holes

9. Extruded Port • Ports are extruded using LBNL provided tool • The inside of the perimeter weld is ground to blend the two shell halves • Port flange is e-beam welded to a machined port face

10. Nose Ring Welded into Cavity Iris • The nose ring is welded into the iris of the cavity • The inside weld is ground down to blend the nose ring into the cavity wall • Threaded holes for mounting the Be window to the cavity

11. Strut Mounting Post • The cavities will be suspended inside the vacuum vessel with 6 struts in a hexapod arrangement • Strut mounting posts are TIG welded to the cavity • Strut mounting posts will have a Heli-coil thread insert for strength

12. Cooling Tubing • Cavity cooling circuit uses one continuous tube • No in vacuum cooling tube joints • Tubing is TIG brazed to the cavity

13. Cavity Cooling Tubing Finished • Cavity cooling circuit completely TIG brazed onto cavity • Tubing is fully leak checked

14. Cavity Beryllium Windows • Cavity Be windows are being fabricated by Brush Wellcome • LBNL has received several finished windows

15. Cavity Be Window • Cavity Be window alignment to nose ring looks good • Some machining of the nose ring may be necessary to flatten mounting surface • Inside look at the Be window

16. Cavity Progress Summary • Most fabrication operations for the first 5 cavities (four plus one spare) are complete • Cooling tube welding is on going • Cavities are due to be delivered to LBNL by the end of the year

17. Future Work • Cavities must be “tuned” to each other for best center frequency (four cavities) by plastic deformation (will be done at LBNL) • The inside surface of each cavity needs to be electro-polished (done at LBNL) • Frequency tuner system testing and verification will be done on a finished cavity • Exercise option to order the remaining 5 cavities (four plus one spare) for the second RFCC module

18. MICE RFCC ModuleCavity Frequency TunerDesign Update

19. Progress Summary • Tuner design is complete • ¼ scale model has been fabricated to test concept • One full size tuner arm (for testing the system) is in fabrication • Three RFQs for the bellows style actuator have been issued • Control system components have been identified

20. Cavity Frequency Tuners • 24 Dynamic Cavity Frequency Tuners per Module • Tuner Actuator • Tuners operate in a bi-directional “push - pull” mode (±2mm) • Tuning automatically achieved through a frequency feedback loop

21. Cavity Frequency Tuner Design Overview • Designed around a flexure concept • Stress levels seen in the FEA model are within material limits • A bi-directional tuner and actuator design reduces bellows diameter and/or pressure requirements. • Two Emerson ER3000 electronic pressure controllers [regulators] per cavity (one for each side of actuator piston) will control the 6 actuators • Use of a high pressure regulator between N2 tank and supply lines to reduce supply pressure to 120 psi

22. Cavity Frequency Tuner Components • Dual – action tuner actuator • Tuner/actuators are thermally independent of the vacuum vessel • Dual bellows • vacuum sealing • Flexure • tuner arm • Actuator is • screwed into • the tuner arm • Screws fix the tuner to the cavity stiffener ring (both sides) • Fixed‏ • connection • Forces are transmitted to the stiffener ring by means of “push-pull” loads applied to the tuner lever arms by the dual action actuator assembly

23. Actuator Design • Actuator design incorporates a sealed enclosure between vacuum and air. • Actuator is mounted to the tuner arm only • Bellows allows angular movement for actuator • Piston plates are joined at the perimeter • Piston plates incorporate hard stops

24. Actuator Design Details • Actuator inlet and outlet penetrate the rigid enclosure • Actuator design incorporates push and pull actuation through holes in the center plate

25. Tuner System Analysis Model • FEA model with tuning arm and a test ring • Tuning arm made from 3.0” stainless steel plate • Cylindrical test ring replicates 1/6 of cavity

26. Tuner System Test Ring Analysis • FEA of one tuner on 1/6 test ring cavity segment • Test ring: 440 lbs applied force • 1/6th of measured cavity spring rate value (2600lbs @ 2mm) • 1.04mm displacement per side (Ring ID=14.3”)

27. Tuner System Analysis • The maximum Von Mises stress at the flexure is 29.7Kpsi • At the actuator the tuner arm displacement is 0.214” (~0.43” bi-directional) • The cavity displacement is 1.05mm per side

28. Tuner System Analysis • The Von Mises stress at the flexure is 29.7Kpsi • The input load by the air actuator is 800 lbs • The tuner arm displacement is 0.214” (~0.43” bi-directional) [movement exaggerated] • The cavity displacement is 1.05mm per side

29. Pressure System Requirements • Bi-directional actuator design requires two electronic pressure controllers [regulators] (one for each side of actuator piston) • 2. Regulators and pressure supply: • a. Use high pressure regulator between N2 tank and supply lines to reduce supply pressure to 120 psi • b. Actuator pressure controller: • i. Emerson ER3000 electronic pressure controllers • c. Use burst disc or safety valve in supply line • d. A constant leak or valved-leak is required in actuator manifold to allow for relaxation of the tuner (design on going)

30. Emerson ER3000 electronic pressure controller • ± 0.1% accuracy (over 110 psi range) • 110 psi normal operating range (120 Max.) • Remote computer controlled • 16 required for two RFCC modules ($1,292.00 ea.)

31. Cavity Frequency Tuner Design Summary • Designed around a flexure concept • Stress levels seen in the FEA model are within material limits • A bi-directional tuner and actuator design reduces bellows diameter and/or pressure requirements. • Two Emerson ER3000 electronic pressure controllers [regulators] per cavity (one for each side of actuator piston) will control the 6 actuators • Use of a high pressure regulator between N2 tank and supply lines to reduce supply pressure to 120 psi

32. Schedule Summary