MICE RF Cavities and RFCC Module Update Allan DeMello and Derun Li Lawrence Berkeley National Laboratory MICE CM32 at RAL, UK February 9, 2012 February 9, 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 CM32 at RAL, UK Page 2 Allan DeMello- Lawrence Berkeley National Lab – February 9, 2012 Current Status of RFCC Module RF Cavities: 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 complete Mechanical smoothing of the cavity inside surface before EP Single cavity vacuum vessel, being fabricated at Keller Technology in Buffalo New York, is complete and should be at Fermilab this wk.

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 CM32 at RAL, UK Page 3 Allan DeMello- Lawrence Berkeley National Lab – February 9, 2012 Beryllium Windows Eleven beryllium windows have been fabricated so far: 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.

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 CM32 at RAL, UK Page 4 Allan DeMello- Lawrence Berkeley National Lab – February 9, 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 5 Derun Li - Lawrence Berkeley National Lab – May 24, 2011 MICE RFCC Module Update – MICE CM32 at RAL, UK Page 5 Allan DeMello- Lawrence Berkeley National Lab – February 9, 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 6 Derun Li - Lawrence Berkeley National Lab – May 24, 2011 MICE RFCC Module Update – MICE CM32 at RAL, UK Page 6 Allan DeMello- Lawrence Berkeley National Lab – February 9, 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 7 Derun Li - Lawrence Berkeley National Lab – May 24, 2011 MICE RFCC Module Update – MICE CM32 at RAL, UK Page 7 Allan DeMello- Lawrence Berkeley National Lab – February 9, 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 8 Derun Li - Lawrence Berkeley National Lab – May 24, 2011 MICE RFCC Module Update – MICE CM32 at RAL, UK Page 8 Allan DeMello- Lawrence Berkeley National Lab – February 9, 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 9 Derun Li - Lawrence Berkeley National Lab – May 24, 2011 MICE RFCC Module Update – MICE CM32 at RAL, UK Page 9 Allan DeMello- Lawrence Berkeley National Lab – February 9, 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 will start soon Cross-section view

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 CM32 at RAL, UK Page 10 Allan DeMello- Lawrence Berkeley National Lab – February 9, 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 EP

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 CM32 at RAL, UK Page 11 Allan DeMello- Lawrence Berkeley National Lab – February 9, 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 (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 12 Derun Li - Lawrence Berkeley National Lab – May 24, 2011 MICE RFCC Module Update – MICE CM32 at RAL, UK Page 12 Allan DeMello- Lawrence Berkeley National Lab – February 9, 2012 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 13 Derun Li - Lawrence Berkeley National Lab – May 24, 2011 MICE RFCC Module Update – MICE CM32 at RAL, UK Page 13 Allan DeMello- Lawrence Berkeley National Lab – February 9, 2012 Single RF Cavity Vacuum Vessel Single Cavity Vacuum Vessel Exploded View

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 CM32 at RAL, UK Page 14 Allan DeMello- Lawrence Berkeley National Lab – February 9, 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 15 Derun Li - Lawrence Berkeley National Lab – May 24, 2011 MICE RFCC Module Update – MICE CM32 at RAL, UK Page 15 Allan DeMello- Lawrence Berkeley National Lab – February 9, 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 RF control/analysis : RF control/analysis : Diagnostics/control/analysis/interfaces Diagnostics/control/analysis/interfaces LLRF control (amplitude/phase) and correlations with detectors LLRF control (amplitude/phase) and correlations with detectors Timing signal from detector, and calibration & synchronization with RF Timing signal from detector, and calibration & synchronization with RF