1. MICE RF and Coupling Coil Module Outstanding Issues Steve Virostek Lawrence Berkeley National Laboratory MICE Collaboration Meeting October 26, 2004

2. RF/CC Module Issues Steve Virostek - LBNLPage 2 Design Status Summary Progress since MICE meeting in 10/03: Module-to-module joint concept incorporated with bellows Module support structure concept completed (height will accommodate rails) Conceptual design of cavity and vessel vacuum system complete Fabrication of cavity prototype is nearly complete RF coupler for prototype cavity designed, being fabricated Currently outstanding issues: Detailed structural and seismic analysis of system and components Detailed design of cavity automatic tuning system Coupling coil cold mass support interface and cryocooler arrangement Detailed vacuum system analysis Cavity assembly to vacuum vessel, vessel feedthrough designs Thermal and structural consideration of LN 2 operation

3. RF/CC Module Issues Steve Virostek - LBNLPage 3 Module-to-Module Joint New module-to-module joint design incorporates a commercially available bellows Flexibility allows sufficient room for module installation/removal while providing for relaxed tolerances Magnet forces can be carried through vessel and across joint through bolts

4. RF/CC Module Issues Steve Virostek - LBNLPage 4 Support Structure Support structure concept uses large stiff plates welded directly to the vacuum vessel Structure will be designed to be strong and stiff enough to transmit coil forces to the ground Current support design height would allow the use of lateral rails for module installation/removal

5. RF/CC Module Issues Steve Virostek - LBNLPage 5 RF Coupling Loop Design Coupling loops design will use standard off-the-shelf copper co-ax Parts to be joined by torch brazing Coupling loop has integrated cooling Design incorporates SNS style RF windows manufactured by Toshiba Bellows connection is required to accommodate hard RF connection to cavity Need to integrate with MICE layout

6. RF/CC Module Issues Steve Virostek - LBNLPage 6 Vacuum System Vacuum system concept uses a pair of cryo pumps per module Pumps are connected to a manifold to pump two cavities plus the vacuum vessel Cavity extension tube limits conduction between vessel and cavity vacuum while providing protection for Be windows

7. RF/CC Module Issues Steve Virostek - LBNLPage 7 Prototype Fabrication Fabrication of prototype RF cavity is nearing completion All e-beam welds have been performed and ports with flanges have been added Remaining tasks are: cavity interior buffing, chemical cleaning and high pressure water rinse, electropolishing, low power RF testing, high power RF conditioning

8. RF/CC Module Issues Steve Virostek - LBNLPage 8 Component Structural Analysis Load and stress analysis of the bellows joints based on calculated worst case magnet loads must be carried out Detailed design and stress analysis of the module support structure is necessary to ensure forces are carried to the floor and not transmitted to AFC modules Modal and seismic analysis of the supports and other subcomponents will be needed to confirm the system is sufficiently stiff and can withstand an earthquake The details of interfacing with a lateral rail system must be explored in detail

9. RF/CC Module Issues Steve Virostek - LBNLPage 9 Cavity Tuning System Six mechanical tuners per cavity needed Tuners push or pull on stiffener rings to deform cavity and adjust frequency ±1 to 2 mm of motion required Current concept incorporates a scissor jack type linkage to gain both mechanical advantage and resolution Actuation forces likely to be hydraulic due to high magnetic fields Detailed design remains to be done

10. RF/CC Module Issues Steve Virostek - LBNLPage 10 Coupling Coil Issues Connections and support arrangement between coil cryostat and the vacuum vessel need to be worked out in detail Final arrangement of cryo-coolers for maintaining coil temperature to be determined Mike Green to provide details

11. RF/CC Module Issues Steve Virostek - LBNLPage 11 Other Topics Detailed analysis of the vacuum loads, conductances and effective pumping speeds Assembly of cavities into vacuum vessel, including design of mounting scheme using tuners Detailed design of vessel feedthroughs for making internal connections to cooling water, tuners and RF couplers Thermal and structural consideration of operating the cavities at LN 2 temperature (heat leaks, thermal contraction stresses, etc.)