Transcript RFCC module
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 Updates of RFCC Module • 201 MHz cavity – 201 MHz cavity prototype (MUCOOL) – Layout (integration) of the cavities • Coupling coils updates – Design – Cooling – Stress • Interface between AFC and RFCC modules • Support of the module 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 MICE Cooling Channel Layout Coupling coils RFCC Module LH absorber MICE Collaboration Mgt in Osaka August 1-3, 2004 RFCC Module Eight 201 MHz cavities Status of 201 MHz Prototype Cavity and RFCC Module Derun Li Center for Beam Physics LBNL Page 3 MICE 201 MHz Cavity Update Cavity layout has not changed since last MICE mgt. – Two pairs of cavities with the curved Be windows pointing in different directions – More room for tuners – Continue working on the details of tuners, interface between ports and vacuum vessel, interface of RF couplers and vacuum ports Ports MICE Collaboration Mgt in Osaka August 1-3, 2004 Status of 201 MHz Prototype Cavity and RFCC Module Derun Li Coupling Coil Center for Beam Physics LBNL Page 4 201 MHz Cavity Prototype • 201 MHz cavity prototype (MUCOOL) – 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) > Already have ports annealed today for port extruding – What’s next at NASA > Nose piece welding > Port annealing + extruding > Cosmetic welding on the equator joints 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 Last MICE mgt: Ready for Equator Welding (March, 04) HISTORY! 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 The Cavity Status Now Beam iris (Be window) Pilot holes for extruding Cavity has been cleaned at J-Lab and started nose welding and ports annealing at NASA yesterday 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 7 201 MHz Cavity (cont’d) 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 LN2 operation MICE Collaboration Mgt in Osaka August 1-3, 2004 Layout of water cooling lines Status of 201 MHz Prototype Cavity and RFCC Module Derun Li Center for Beam Physics LBNL Page 8 201 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? LN2 operation? Comments and suggestions are welcome! 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 Progress on Coupling Coil • 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 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 New Coupling Magnet 386 mm The new coil is longer and thinner 30 to 40 K S h i el d C ol d Mas sS u pport C ooli n g Tu be C ryos tat Vacu u m Ves s e l 116.6 mm S /C C oil 2 50 mm >1080 mm 7 25 mm The coil length is limited by the feeds to the 201 MHz RF cavity ~697mm The coil design has better quench properties 201 MHz RF Cavity Vacuum Space The coupling magnet stored energy is about 8 MJ y z 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 Coupling Coil Structure Displacement and Stress Results for 200 MeV/c Case * * Data from S. Yang of Oxford University 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 240 MeV/c Case 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 Interface between AFC & RFCC 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 Sealing only bolts (24 each) Sealing/force transmission/opening studs (12 each) – closed position RFCC Details of the interface Open position AFC 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 Module Support AFC Module RFCC Module 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 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 for 3 curved Be windows at Brush-Wellman company – Excellent progress on coupling coils 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