1. Status of 201 MHz Prototype and RFCC Module Derun Li, S. Virostek, M. Zisman Center for Beam Physics Lawrence Berkeley National Laboratory In collaboration with R. Rimmer, L. Phillips, G. Wu (J-Lab) M. Green, W. Lau and S. Yang (Oxford Univ.) MICE Collaboration Meeting at Osaka University August 1-3, 2004

2. MICE Collaboration Mgt in Osaka August 1-3, 2004 Status of 201 MHz Prototype Cavity and RFCC Module Derun Li Center for Beam Physics LBNL Page 2 Outline Updates of MICE RFCC Module Status 201 MHz Prototype Cavity MICE RF Power Source Development (Paul Drumm) Summary

3. MICE Collaboration Mgt in Osaka August 1-3, 2004 Status of 201 MHz Prototype Cavity and RFCC Module Derun Li Center for Beam Physics LBNL Page 3 Updates of RFCC Module Integration and support of the module 201 MHz cavity prototype (MUCOOL) Coupling coils updates ( inputs from M. Green) –Design –Cooling –Stress Interface between absorber and RFCC modules

4. MICE Collaboration Mgt in Osaka August 1-3, 2004 Status of 201 MHz Prototype Cavity and RFCC Module Derun Li Center for Beam Physics LBNL Page 4 MICE Cooling Channel Layout Coupling coils Eight 201 MHz cavitiesLH absorber

5. MICE Collaboration Mgt in Osaka August 1-3, 2004 Status of 201 MHz Prototype Cavity and RFCC Module Derun Li Center for Beam Physics LBNL Page 5 201 MHz Cavity Update Propose to use NASA e-beam welder –Due to lower priority and busy schedule for using e-beam welder at J-Lab –Proposed to use NASA e-beam welder ~ 3 months ago >Convenient location (~ 20 minutes driving) >Better equipped and bigger vacuum chamber >Competent technical capability –Two to three months of delay for paper work between J-Lab and NASA –Ready to proceed now (finally) Work at NASA –Nose piece welding –Port annealing + extruding –Cosmetic welding on the equator joints –…

6. MICE Collaboration Mgt in Osaka August 1-3, 2004 Status of 201 MHz Prototype Cavity and RFCC Module Derun Li Center for Beam Physics LBNL Page 6 Last MICE mgt: Ready for Equator Welding (March, 04) HISTORY!

7. MICE Collaboration Mgt in Osaka August 1-3, 2004 Status of 201 MHz Prototype Cavity and RFCC Module Derun Li Center for Beam Physics LBNL Page 7 The Cavity Status Now Cavity has been cleaned at J-Lab and ready for nose welding and ports annealing next week (August 2 nd 2004) at NASA Pilot holes for extruding Beam iris (Be window)

8. MICE Collaboration Mgt in Osaka August 1-3, 2004 Status of 201 MHz Prototype Cavity and RFCC Module Derun Li Center for Beam Physics LBNL Page 8 201 MHz Cavity (cont’d) Layout of water cooling lines  Development of water cooling line layout  Ports and flanges  RF loop coupler  Cavity support structure  Cavity tuner  RF windows (4” ceramic)  Curved Be windows (ordered)  MICE specifics  Tuners  Integration  joints and flanges  Possible LN 2 operation

9. MICE Collaboration Mgt in Osaka August 1-3, 2004 Status of 201 MHz Prototype Cavity and RFCC Module Derun Li Center for Beam Physics LBNL Page 9 201 MHz Test Plan at MTA (preliminary) Test plans (not necessarily in sequence) ( assume a clean and vacuum tight cavity, and available RF test stand ) –Start with Cu windows (flat or curved) –May condition RF windows (ceramic) in advance –Low power measurements >Tuners for MICE RF cavities –Cavity conditioning –Curved Be windows with Ti-N coating –External magnetic fields? –LN 2 operation? Comments and suggestions are welcome!

10. MICE Collaboration Mgt in Osaka August 1-3, 2004 Status of 201 MHz Prototype Cavity and RFCC Module Derun Li Center for Beam Physics LBNL Page 10 The design for coupling coil (dimensions) has not changed since the last MICE Collaboration Meeting at CERN (March 2004) The coupling coil can be cooled by a single small cooler of either type (pulse tube cooler ~1 W or a GM cooler ~1.5 W), provided a liquid interface is used to connect the cooler cold head to the magnet The stress and deflections for the coil and its case has been calculated using FEA. The peak stress in the coil and the case is reasonable at 240 MeV/c Progress on Coupling Coil

11. MICE Collaboration Mgt in Osaka August 1-3, 2004 Status of 201 MHz Prototype Cavity and RFCC Module Derun Li Center for Beam Physics LBNL Page 11 The New Coupling Magnet  The new coil is longer and thinner  The coil length is limited by the feeds to the 201 MHz RF cavity  The coil design has better quench properties  The coupling magnet stored energy is about 8 MJ y z

12. MICE Collaboration Mgt in Osaka August 1-3, 2004 Status of 201 MHz Prototype Cavity and RFCC Module Derun Li Center for Beam Physics LBNL Page 12 Coupling Coil Structure Displacement and Stress Results for 200 MeV/c Case * * Data from S. Yang of Oxford University

13. MICE Collaboration Mgt in Osaka August 1-3, 2004 Status of 201 MHz Prototype Cavity and RFCC Module Derun Li Center for Beam Physics LBNL Page 13 Coupling Coil Structure Displacement and Stress Results for 240 MeV/c Case

14. MICE Collaboration Mgt in Osaka August 1-3, 2004 Status of 201 MHz Prototype Cavity and RFCC Module Derun Li Center for Beam Physics LBNL Page 14 Interface between AFC & RFCC Sealing only bolts (24 each) Sealing/force transmission/opening studs (12 each) – closed position Open position  Bellows with flanges would be welded to both sides of RF Modules  Bellows and oversized holes in flanges can accommodate misalignments between vessels in all 6 DOF  Magnetic forces can be handled by both supports and interconnecting studs Details of the interface RFCC AFC

15. MICE Collaboration Mgt in Osaka August 1-3, 2004 Status of 201 MHz Prototype Cavity and RFCC Module Derun Li Center for Beam Physics LBNL Page 15 Module Support Concept Module Configuration Assembled Modules

16. MICE Collaboration Mgt in Osaka August 1-3, 2004 Status of 201 MHz Prototype Cavity and RFCC Module Derun Li Center for Beam Physics LBNL Page 16 Summary Excellent progress on RFCC Modules since last MICE Collaboration Meeting at CERN –Integration and support –The 201 MHz cavity (MUCOOL) construction goes reasonably well regardless of the delay at NASA Significant progress on curved window design and fabrication >Placed purchase order of 3 curved Be windows at Brush-Wellman company –Excellent progress on coupling coils RF power sources (P. Drumm)