1. MICE RFCC Module Status: RF Cavities Derun Li A. DeMello, S. Virostek, M. Zisman Lawrence Berkeley National Laboratory NFMCC Collaboration Meeting The University of Mississippi, Oxford, MS January 16, 2010 January 16, 2010

2. MICE RF Cavity Status – NFMCC Meeting, Univ. of Mississippi, Oxford, MS Page 2Derun Li - Lawrence Berkeley National Laboratory - January 16, 2010 Overview First five RF cavities (one spare) are completeFirst five RF cavities (one spare) are complete –Cavity fabrication awarded to Applied Fusion in February 2009 –Cavity body fabrication started in April 2009 –Welding the stiffener ring to the shell and cutting the irises –E-beam welding 10 copper shells with the stiffener rings to 5 cavities –Ports extruding –Welding the nose ring into the cavity irises –Welding the strut mounting posts onto the cavity –Welding of the water cooling tubing onto the cavity –The first 5 cavities are scheduled were delivered to LBNL on December 2009 Coupling coil design (MICE/MuCool) and fabrication are being provided by ICST of HIT, Harbin, ChinaCoupling coil design (MICE/MuCool) and fabrication are being provided by ICST of HIT, Harbin, China –Fabrication contract expects to be awarded on March 15, 2010 MICE cavity design is heavily based on MuCool 201-MHz prototype RF cavity: fabrication techniques + post processingMICE cavity design is heavily based on MuCool 201-MHz prototype RF cavity: fabrication techniques + post processing

3. 4 Completed Cavities, 1 Spare Cavity MICE RF Cavity Status – NFMCC Meeting, Univ. of Mississippi, Oxford, MS Page 3Derun Li - Lawrence Berkeley National Laboratory - January 16, 2010 Photo taken Jan. 2010 at LBNL

4. MICE RF Cavity Status – NFMCC Meeting, Univ. of Mississippi, Oxford, MS Page 4Derun Li - Lawrence Berkeley National Laboratory - January 16, 2010 RFCC Module SC coupling Coil Cavity Couplers Vacuum Pump 201-MHz cavity Curved Be window

5. MICE RF Cavity Status – NFMCC Meeting, Univ. of Mississippi, Oxford, MS Page 5Derun Li - Lawrence Berkeley National Laboratory - January 16, 2010 Eight 201-MHz Cavities & Two CC Magnets Eight 201-MHz RF cavities RFCC modules

6. MICE RF Cavity Status – NFMCC Meeting, Univ. of Mississippi, Oxford, MS Page 6Derun Li - Lawrence Berkeley National Laboratory - January 16, 2010 MICE RF Cavity Design 3-D CST MWS parameterized RF model including ports and curved Be windows to simulate frequency, E peak, power loss & etc.3-D CST MWS parameterized RF model including ports and curved Be windows to simulate frequency, E peak, power loss & etc. Estimated frequency variations between cavities should be within  100 kHz (after fabrication)Estimated frequency variations between cavities should be within  100 kHz (after fabrication) Absolute frequency: 201.25-MHz  400-KHzAbsolute frequency: 201.25-MHz  400-KHz ApproachApproach –Slightly modify prototype cavity diameter –Target a higher cavity frequency –Tune cavities close to design frequency by deformation of cavity body (if needed) –Tuners operate in the push-pull mode

7. MICE RF Cavity Status – NFMCC Meeting, Univ. of Mississippi, Oxford, MS Page 7 Derun Li - Lawrence Berkeley National Laboratory - January 16, 2010 Strut Mounting Post Cooling Tubing Cavity Component Parts Stiffener Ring Nose Ring Cavity Shells Extruded Port Flange

8. MICE RF Cavity Status – NFMCC Meeting, Univ. of Mississippi, Oxford, MS Page 8Derun Li - Lawrence Berkeley National Laboratory - January 16, 2010 Applied Fusion’s e-beam welder is a German made machine 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) Applied Fusion has the machining equipment necessary to fabricate the complete RF cavity (minus spinning) Electron beam welding machine Cavity Inspection Cavity Fabricator - Applied Fusion, Inc.

9. MICE RF Cavity Status – NFMCC Meeting, Univ. of Mississippi, Oxford, MS Page 9Derun Li - Lawrence Berkeley National Laboratory - January 16, 2010 Title Here 1.Spun shells from Acme, MN 2.The stiffener ring is welded on to the half shell 3.Equator welding 4.The iris is machined out Cavity Stiffener Ring

10. MICE RF Cavity Status – NFMCC Meeting, Univ. of Mississippi, Oxford, MS Page 10Derun Li - Lawrence Berkeley National Laboratory - January 16, 2010 The cavity shells were inspected at LBNL and paired for best inside edge matchThe cavity shells were inspected at LBNL and paired for best inside edge match The cavity shells are oriented (clocked) to the stiffener rings with a pinThe cavity shells are oriented (clocked) to the stiffener rings with a pin Matched shells were e-beamMatched shells were e-beam welded into a cavity welded into a cavity E-beam Weld Shells into a Cavity

11. MICE RF Cavity Status – NFMCC Meeting, Univ. of Mississippi, Oxford, MS Page 11Derun Li - Lawrence Berkeley National Laboratory - January 16, 2010 Cavity is placed on a horizontal milling machine to bore the pilot hole for the extruded portsCavity 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 holesThe shell alignment key is bored out as one of these pilot holes Preparation for Extruded Port

12. MICE RF Cavity Status – NFMCC Meeting, Univ. of Mississippi, Oxford, MS Page 12Derun Li - Lawrence Berkeley National Laboratory - January 16, 2010 Ports are extruded using LBNL- Jlab provided toolPorts are extruded using LBNL- Jlab provided tool The inside of the perimeter weld is ground to blend the two shell halvesThe inside of the perimeter weld is ground to blend the two shell halves Port flange is e-beam welded to a machined port facePort flange is e-beam welded to a machined port face Extruded Port

13. MICE RF Cavity Status – NFMCC Meeting, Univ. of Mississippi, Oxford, MS Page 13Derun Li - Lawrence Berkeley National Laboratory - January 16, 2010 The nose ring is welded into the irisThe nose ring is welded into the iris The inside weld is ground down to blend the nose ring into the cavity wallThe inside weld is ground down to blend the nose ring into the cavity wall Threaded holes for mounting the Be window to the cavityThreaded holes for mounting the Be window to the cavity Nose Ring Welded into Cavity Iris

14. MICE RF Cavity Status – NFMCC Meeting, Univ. of Mississippi, Oxford, MS Page 14Derun Li - Lawrence Berkeley National Laboratory - January 16, 2010 The cavities will be suspended inside the vacuum vessel with 6 struts in a hexapod arrangementThe cavities will be suspended inside the vacuum vessel with 6 struts in a hexapod arrangement Strut Mounting Post Strut mounting posts are TIG welded to the cavity Strut mounting posts are TIG welded to the cavity Strut mounting posts will have a Heli-coil thread insert for strengthStrut mounting posts will have a Heli-coil thread insert for strength

15. MICE RF Cavity Status – NFMCC Meeting, Univ. of Mississippi, Oxford, MS Page 15Derun Li - Lawrence Berkeley National Laboratory - January 16, 2010 Cooling Tubing Cavity cooling circuit uses one continuous tubeCavity cooling circuit uses one continuous tube No in vacuum cooling tube jointsNo in vacuum cooling tube joints Tubing is TIG brazed to the (pre-heated) cavity with argon gas flow inside the tubeTubing is TIG brazed to the (pre-heated) cavity with argon gas flow inside the tube Minimizing cavity distortion

16. MICE RF Cavity Status – NFMCC Meeting, Univ. of Mississippi, Oxford, MS Page 16Derun Li - Lawrence Berkeley National Laboratory - January 16, 2010 Cooling Tubing (cont’d) Visual inspection did not find any surface deformation Slightly sagging of the nose ring (surface) for mounting the Be window Visible discoloration both outside and inside the cavity after (nearly continuous) TIG brazing

17. MICE RF Cavity Status – NFMCC Meeting, Univ. of Mississippi, Oxford, MS Page 17Derun Li - Lawrence Berkeley National Laboratory - January 16, 2010 Completed Cavity With beryllium window on to check the alignment of mounting holes and surface flatness One spare cavity (No.5)

18. MICE RF Cavity Status – NFMCC Meeting, Univ. of Mississippi, Oxford, MS Page 18Derun Li - Lawrence Berkeley National Laboratory - January 16, 2010 Cavities must be “tuned” to each other for best center frequency (four cavities) by plastic deformation (will be done at LBNL)Cavities must be “tuned” to each other for best center frequency (four cavities) by plastic deformation (will be done at LBNL) Measure cavity frequencies and find the average frequency (to be completed by next MICE CM)Measure cavity frequencies and find the average frequency (to be completed by next MICE CM) Cavity post-processingCavity post-processing The inside surface of each cavity needs to be cleaned and electro- polished (to be done at LBNL)The inside surface of each cavity needs to be cleaned and electro- polished (to be done at LBNL) Frequency tuner system testing and verification will be conducted on a finished cavityFrequency tuner system testing and verification will be conducted on a finished cavity Prototype for tuner test is in fabrication + MTA testsPrototype for tuner test is in fabrication + MTA tests Option to order the remaining 5 cavities (four plus one spare) for the second RFCC moduleOption to order the remaining 5 cavities (four plus one spare) for the second RFCC module Decision needs to be made soonDecision needs to be made soon Continue to work on other accessory components: coupler, ceramic windows and Be windows, support structures and vacuum vesselsContinue to work on other accessory components: coupler, ceramic windows and Be windows, support structures and vacuum vessels Future Plans

19. MICE RF Cavity Status – NFMCC Meeting, Univ. of Mississippi, Oxford, MS Page 19Derun Li - Lawrence Berkeley National Laboratory - January 16, 2010 Cavity Tuner Design o Six tuners, spaced evenly every 60º around cavity, provide frequency adjustment; o Clocking of tuner position between adjacent cavities avoids interference; o Tuners touch cavity and apply loads only at the stiffener rings; o Tuner/actuators are thermally independent of the vacuum vessel o Tuners operate in a bi-directional Push-Pull mode. The design parameters are based on a finite element analysis of the cavity shell, and tuning range is limited by material yield stress: o Overall cavity stiffness: 7950 N/mm o Tuning sensitivity: ±230-kHz/mm per side o Total tuning range: 460 kHz (±1 mm per side) ‏ o Number of tuners: 6 o Maximum ring load/tuner: 5.3 kN o Max actuator press. (  100 mm): 200 psi

20. MICE RF Cavity Status – NFMCC Meeting, Univ. of Mississippi, Oxford, MS Page 20Derun Li - Lawrence Berkeley National Laboratory - January 16, 2010 Cavity Tuner Prototype Dual bellows vacuum sealing Dual–action tuner actuator Flexure tuner arm Screws fix the tuner to the cavity stiffener ring (both sides) Actuator is screwed into the tuner arm 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. The tuner prototype is in fabrication at LBNL

21. MICE RF Cavity Status – NFMCC Meeting, Univ. of Mississippi, Oxford, MS Page 21Derun Li - Lawrence Berkeley National Laboratory - January 16, 2010 Stiffener Ring Analysis (Prototype test): Applied Displacement The Von Mises stress at the flexure is 29.7Kpsi The Von Mises stress at the flexure is 29.7Kpsi The input load by the air actuator is 800 lbs The input load by the air actuator is 800 lbs The flex-arm displacement is 0.214” (~0.43” bi- directional) The flex-arm displacement is 0.214” (~0.43” bi- directional) The cavity displacement is 1.05mm per side The cavity displacement is 1.05mm per side

22. MICE RF Cavity Status – NFMCC Meeting, Univ. of Mississippi, Oxford, MS Page 22Derun Li - Lawrence Berkeley National Laboratory - January 16, 2010 We have received two “good” beryllium windows at LBNLWe have received two “good” beryllium windows at LBNL Curved thin beryllium window brazed (sandwiched) between) two annular copper rings;Curved thin beryllium window brazed (sandwiched) between) two annular copper rings; Beryllium windows coated with TiN on both sides (can be installed on either side of the cavity)Beryllium windows coated with TiN on both sides (can be installed on either side of the cavity) 41-cm in diameter;41-cm in diameter; 0.38-mm in thickness.0.38-mm in thickness. The two windows will be usedThe two windows will be used for frequency measurements of for frequency measurements of the five MICE cavities; the five MICE cavities; Eight more windows are coming Eight more windows are coming soon. soon. Beryllium Windows

23. MICE RF Cavity Status – NFMCC Meeting, Univ. of Mississippi, Oxford, MS Page 23Derun Li - Lawrence Berkeley National Laboratory - January 16, 2010 MICE Cavity RF Couplers A bellows connection between the coupler and the vacuum vessel provides compliance for mating with the cavity Off the shelf flange “V” clamp secures RF coupler to cavity

24. MICE RF Cavity Status – NFMCC Meeting, Univ. of Mississippi, Oxford, MS Page 24Derun Li - Lawrence Berkeley National Laboratory - January 16, 2010 Progress: MuCool/MICE CC Magnets Collaboration between LBNL and ICST of HIT, HarbinCollaboration between LBNL and ICST of HIT, Harbin Final design review was held in Harbin (Dec. 2008)Final design review was held in Harbin (Dec. 2008) Little progress since the review due to personnel, funding issues and cryogenic test systemLittle progress since the review due to personnel, funding issues and cryogenic test system Recent visit to HIT (Dec. 2009)Recent visit to HIT (Dec. 2009) New management team formed and near term plan developedNew management team formed and near term plan developed Good progress on drawing reviews and initiating contractGood progress on drawing reviews and initiating contract CC fabrication contract open for bidding: three registered vendors (deadline was Jan. 9 th 2010)CC fabrication contract open for bidding: three registered vendors (deadline was Jan. 9 th 2010) Fabrication contract to be awarded on March 15 th 2010Fabrication contract to be awarded on March 15 th 2010 OutlookOutlook Cautiously optimistic on the fabrication contractCautiously optimistic on the fabrication contract Management and monitoring the contractManagement and monitoring the contract MuCool CC magnet (1 st ) could be ready around end of 2010MuCool CC magnet (1 st ) could be ready around end of 2010 Three forged Al mandrels expect to arrive Qi Huan Company, Beijing in March 2010Three forged Al mandrels expect to arrive Qi Huan Company, Beijing in March 2010

25. MICE RF Cavity Status – NFMCC Meeting, Univ. of Mississippi, Oxford, MS Page 25Derun Li - Lawrence Berkeley National Laboratory - January 16, 2010 Cryocoolers Power leads Cold mass supports He cooling pipes Thermal shields and intercepts Vacuumvessel He condenser MICE Coupling Coil Magnets

26. MICE RF Cavity Status – NFMCC Meeting, Univ. of Mississippi, Oxford, MS Page 26Derun Li - Lawrence Berkeley National Laboratory - January 16, 2010 Summary Completed five MICE RF cavitiesCompleted five MICE RF cavities Continue working on accessory componentsContinue working on accessory components Cavity testsCavity tests Progress on MuCool/MICE CC magnetsProgress on MuCool/MICE CC magnets Fabrication contract to be awarded on March 15 th 2010Fabrication contract to be awarded on March 15 th 2010 Continue working on the RFCC moduleContinue working on the RFCC module Vacuum vessel, module assembly, packing, shipping and etc.Vacuum vessel, module assembly, packing, shipping and etc. MTA RF tests, Be cavity and moreMTA RF tests, Be cavity and more