MICE RF Cavities and RFCC Module Update Derun Li Lawrence Berkeley National Laboratory MICE RF Workshop Daresbury Laboratory, UK April 17, 2012 April 17, 2012

MICE RFCC Module – MICE Schedule Review at RAL, UK Page 2 Derun Li - Lawrence Berkeley National Lab – May 24, 2011 MICE RFCC Module Update – MICE RF Workshop, Daresbury Lab, UK Page 2 Derun Li - Lawrence Berkeley National Lab – April 17, 2012 MICE Cooling Channel Two RFCC modules, four 201-MHz cavities per module, four ports per cavity: two of them for RF couplers, one for vacuum pump and one for RF probe; Two beryllium windows per cavity.

MICE RFCC Module – MICE Schedule Review at RAL, UK Page 3 Derun Li - Lawrence Berkeley National Lab – May 24, 2011 MICE RFCC Module Update – MICE RF Workshop, Daresbury Lab, UK Page 3 Derun Li - Lawrence Berkeley National Lab – April 17, 2012 RFCC Module Six tuner arms & actuators per cavity, and cavity is supported by strut system.

MICE RFCC Module – MICE Schedule Review at RAL, UK Page 4 Derun Li - Lawrence Berkeley National Lab – May 24, 2011 MICE RFCC Module Update – MICE RF Workshop, Daresbury Lab, UK Page 4 Derun Li - Lawrence Berkeley National Lab – April 17, 2012 Current Status of RFCC Module RF Cavities and single cavity vessel: All 11 beryllium windows received at LBNL (1 st RFCC module) Ten ceramic RF windows received Six tuner flexures are being fabricated at Fermilab Components for 6 actuators are being fabricated RF coupler design has been modified to eliminate the gap between the outer coax and the RF loop Fabrication of fixturing for the electropolishing is nearly complete Mechanical smoothing of the cavity inside surface before EP Single cavity vacuum vessel, fabricated at Keller Technology in Buffalo New York, is complete and is at Fermilab now.

MICE RFCC Module – MICE Schedule Review at RAL, UK Page 5 Derun Li - Lawrence Berkeley National Lab – May 24, 2011 MICE RFCC Module Update – MICE RF Workshop, Daresbury Lab, UK Page 5 Derun Li - Lawrence Berkeley National Lab – April 17, 2012 Beryllium Windows Eleven beryllium windows have been fabricated so far: Eleven beryllium windows have been fabricated so far: Curved thin (0.38-mm thick) window with TiN-coating on both sides Curved thin (0.38-mm thick) window with TiN-coating on both sides Received two new beryllium windows recently, these two windows have been fabricated by Materion Electrofusion (fomer Brush-Wellman) to replace the windows rejected due to excess distortion with improved brazing design/technique: no distortion is observed. Received two new beryllium windows recently, these two windows have been fabricated by Materion Electrofusion (fomer Brush-Wellman) to replace the windows rejected due to excess distortion with improved brazing design/technique: no distortion is observed.

MICE RFCC Module – MICE Schedule Review at RAL, UK Page 6 Derun Li - Lawrence Berkeley National Lab – May 24, 2011 MICE RFCC Module Update – MICE RF Workshop, Daresbury Lab, UK Page 6 Derun Li - Lawrence Berkeley National Lab – April 17, 2012 RF Cavity Frequency Tuner Components Dual – action actuator Flexure tuner arm RF cavity Cross-section view Tuning range:  230 kHz

MICE RFCC Module – MICE Schedule Review at RAL, UK Page 7 Derun Li - Lawrence Berkeley National Lab – May 24, 2011 MICE RFCC Module Update – MICE RF Workshop, Daresbury Lab, UK Page 7 Derun Li - Lawrence Berkeley National Lab – April 17, 2012 Cavity Frequency Tuner Flexure Six full size tuner flexures are being fabricated at Fermilab Jan , 2012 in Fermilab Finished tuner arm

MICE RFCC Module – MICE Schedule Review at RAL, UK Page 8 Derun Li - Lawrence Berkeley National Lab – May 24, 2011 MICE RFCC Module Update – MICE RF Workshop, Daresbury Lab, UK Page 8 Derun Li - Lawrence Berkeley National Lab – April 17, 2012 Actuator Component Fabrication Center plate Lower piston Upper piston Lower support Component for six actuators are currently being fabricated by a local vendor The actuators will be assembled at LBNL

MICE RFCC Module – MICE Schedule Review at RAL, UK Page 9 Derun Li - Lawrence Berkeley National Lab – May 24, 2011 MICE RFCC Module Update – MICE RF Workshop, Daresbury Lab, UK Page 9 Derun Li - Lawrence Berkeley National Lab – April 17, 2012 RF power (loop) coupler RF power (loop) coupler design has been modified to eliminate the gap between the loop and the outer coax tube

MICE RFCC Module – MICE Schedule Review at RAL, UK Page 10 Derun Li - Lawrence Berkeley National Lab – May 24, 2011 MICE RFCC Module Update – MICE RF Workshop, Daresbury Lab, UK Page 10 Derun Li - Lawrence Berkeley National Lab – April 17, 2012 Testing/experience of the prototype cavity at MTA: sparking at the coupler The coupler design has been changed slightly to increase the gap spacing The sparking region can be TiN coated if necessary (plan to be tested at MTA using the prototype cavity) Adding diagnostics: arc detector at the coupler region. RF Power (loop) Coupler (old) Old MICE design Cross-section view MTA RF coupler

MICE RFCC Module – MICE Schedule Review at RAL, UK Page 11 Derun Li - Lawrence Berkeley National Lab – May 24, 2011 MICE RFCC Module Update – MICE RF Workshop, Daresbury Lab, UK Page 11 Derun Li - Lawrence Berkeley National Lab – April 17, 2012 RF power (loop) coupler Modified MICE RF power coupler design is complete, drawing package has been delivered to FNAL, and ready for fabrication Fabrication of the couplers should start soon Cross-section view

MICE RFCC Module – MICE Schedule Review at RAL, UK Page 12 Derun Li - Lawrence Berkeley National Lab – May 24, 2011 MICE RFCC Module Update – MICE RF Workshop, Daresbury Lab, UK Page 12 Derun Li - Lawrence Berkeley National Lab – April 17, 2012 Cavity Measurements Cavity Measurements Cavity physical measurementCavity frequency measurement Physical measurements for the six remaining cavities expected to take approximately 1-1/2 weeks (60 hours) RF measurements and tuning to a center frequency after the EP of all ten cavities (two spares) at LBNL.

MICE RFCC Module – MICE Schedule Review at RAL, UK Page 13 Derun Li - Lawrence Berkeley National Lab – May 24, 2011 MICE RFCC Module Update – MICE RF Workshop, Daresbury Lab, UK Page 13 Derun Li - Lawrence Berkeley National Lab – April 17, 2012 Cavity Electropolish at LBNL Cavity Electropolish at LBNL The inner surface of each cavity will be mechanically smoothed and then electropolished at LBNL using the similar techniques developed at JLab for the prototype cavity Fabrication of EP fixturing is complete and electropolishing will start in soon after ES & H approval Electropolishing process will take approximately 1- 2 days for each cavity or 4 weeks to complete all 10 cavities Cavity section view EP rotation fixture at LBNL

MICE RFCC Module – MICE Schedule Review at RAL, UK Page 14 Derun Li - Lawrence Berkeley National Lab – May 24, 2011 MICE RFCC Module Update – MICE RF Workshop, Daresbury Lab, UK Page 14 Derun Li - Lawrence Berkeley National Lab – April 17, 2012 Cavity Electropolish at LBNL (cont’d) Cavity Electropolish at LBNL (cont’d) New fixture for EP exhaust fabricated, testing and meeting with ES&H personnel scheduled. Cavity section view

MICE RFCC Module – MICE Schedule Review at RAL, UK Page 15 Derun Li - Lawrence Berkeley National Lab – May 24, 2011 MICE RFCC Module Update – MICE RF Workshop, Daresbury Lab, UK Page 15 Derun Li - Lawrence Berkeley National Lab – April 17, 2012 Ongoing Simulations of MICE RF Cavity Study of external magnetic field on MICE RF cavity and coupler (Dr. Tianhuan Luo) 3D simulations (from CAD model) using SLAC’s Omega-3P code: f = MHz 3D simulations (from CAD model) using SLAC’s Omega-3P code: f = MHz MP simulations, and RF breakdown studies with an external magnetic field MP simulations, and RF breakdown studies with an external magnetic field

MICE RFCC Module – MICE Schedule Review at RAL, UK Page 16 Derun Li - Lawrence Berkeley National Lab – May 24, 2011 MICE RFCC Module Update – MICE RF Workshop, Daresbury Lab, UK Page 16 Derun Li - Lawrence Berkeley National Lab – April 17, 2012 Fabrication of the single cavity vacuum vessel is complete at Keller Technology in Buffalo New York Single Cavity Vacuum Vessel Single Cavity Vacuum Vessel and MuCool Coupling Coil Magnet Vacuum vessel stand Vacuum vessel Vacuum vessel cover plate

MICE RFCC Module – MICE Schedule Review at RAL, UK Page 17 Derun Li - Lawrence Berkeley National Lab – May 24, 2011 MICE RFCC Module Update – MICE RF Workshop, Daresbury Lab, UK Page 17 Derun Li - Lawrence Berkeley National Lab – April 17, 2012 RFCC Future Work RFCC Vacuum Vessel: RFCC Vacuum Vessel: Vessel design is complete but needs to be updated to incorporate changes to the interface with the new coupling coil cryostat design Vessel design is complete but needs to be updated to incorporate changes to the interface with the new coupling coil cryostat design Fixturing for the assembly process needs to be finalized and drawings for fabrication generated Fixturing for the assembly process needs to be finalized and drawings for fabrication generated RFCC Module: RFCC Module: Finalize fixturing for module assembly and shipping Finalize fixturing for module assembly and shipping for aligning the frequency tuners onto cavities for aligning the frequency tuners onto cavities for inserting the cavities into vacuum vessel for inserting the cavities into vacuum vessel shipping skid/tilt fixturing for shipping RFCC to RAL shipping skid/tilt fixturing for shipping RFCC to RAL

MICE RFCC Module – MICE Schedule Review at RAL, UK Page 18 Derun Li - Lawrence Berkeley National Lab – May 24, 2011 MICE RFCC Module Update – MICE RF Workshop, Daresbury Lab, UK Page 18 Derun Li - Lawrence Berkeley National Lab – April 17, 2012 RFCC Future Work (cont’d) RF control/analysis: this workshopRF control/analysis: this workshop Diagnostics/control/analysis/interfacesDiagnostics/control/analysis/interfaces LLRF control (amplitude/phase) and correlations with detectorsLLRF control (amplitude/phase) and correlations with detectors Timing signal from detector, and calibration & synchronization with RFTiming signal from detector, and calibration & synchronization with RF DL group should take the leadership and ownership DL group should take the leadership and ownership LBNL group will assist under MAP support LBNL group will assist under MAP support Understanding the engineering approach and scope of work Understanding the engineering approach and scope of work Development of future plan and define responsibilities of each group. Development of future plan and define responsibilities of each group.