Overview of the RFCC Module and 201-MHz Cavity Design

Overview of the RFCC Module Overview of the RFCC Module and 201-MHz Cavity Designand 201-MHz Cavity Design

Derun LiDerun LiLawrence Berkeley National LaboratoryLawrence Berkeley National Laboratory

RFCC Module RF Cavity Design Review

October 21, 2008

Overview of the RFCC Module and 201-MHz Cavity DesignOverview of the RFCC Module and 201-MHz Cavity Design

Derun Li - Lawrence Berkeley National Lab - October Derun Li - Lawrence Berkeley National Lab - October 21, 200821, 2008

OutlineOutline• Introduction of RFCC module of MICE cooling Introduction of RFCC module of MICE cooling

channel and charge of the reviewchannel and charge of the review• Review of the 201-MHz cavity designReview of the 201-MHz cavity design

– MuCool 201-MHz prototype cavity: baseline design MuCool 201-MHz prototype cavity: baseline design for MICEfor MICE

• Physics design and cavity fabricationsPhysics design and cavity fabrications– Cavity bodyCavity body– RF couplerRF coupler– Be windowsBe windows– TunersTuners

– Recent progress Recent progress • Vendor identificationVendor identification• Engineering CAD model and FEA analysisEngineering CAD model and FEA analysis

– Tuners and cavity supportTuners and cavity support• Integration and interfaceIntegration and interface

• ScheduleSchedule



Eight 201-MHz Cavities for Eight 201-MHz Cavities for MICEMICE

EightEight 201-MHz RF cavities201-MHz RF cavities

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RFCC modulesRFCC modules



RFCC ModuleRFCC Module

SC coupling Coil

Cavity Couplers

Vacuum Pump201-MHz cavity201-MHz cavity

Curved Be window



Charge of this ReviewCharge of this Review• Evaluate the engineering design of RFCC module and Evaluate the engineering design of RFCC module and

the RF cavitythe RF cavity– Evaluate engineering design and fabrication schemes of Evaluate engineering design and fabrication schemes of

the 201-MHz cavity the 201-MHz cavity • Spinning of cavity shells Spinning of cavity shells • e-beam weldinge-beam welding• Port extrudingPort extruding• TunersTuners• Cavity supportCavity support• Cavity assembly Cavity assembly

– Evaluate overall module conceptEvaluate overall module concept• Interface with other modulesInterface with other modules• Site interfacesSite interfaces• Integration and shippingIntegration and shipping

• Detailed design of CC is not part of this reviewDetailed design of CC is not part of this review– CC design review scheduled: Dec. 6-8, 2008 at ICST of HIT, CC design review scheduled: Dec. 6-8, 2008 at ICST of HIT,

HarbinHarbin



RFCC & Cavity Design Review RFCC & Cavity Design Review AgendaAgenda

15:300 – 18:30 October 21, 2008 at RAL15:300 – 18:30 October 21, 2008 at RAL

•Overview of RFCC Module and Recent ProgressOverview of RFCC Module and Recent Progress

LiLi•201 MHz Cavity Fabrication Plan201 MHz Cavity Fabrication Plan

DeMelloDeMello•Assembly, Installation and Interface Assembly, Installation and Interface

VirostekVirostek

•Coffee breakCoffee break

•RFCC Module and Subcomponents Mechanical DesignRFCC Module and Subcomponents Mechanical Design

DeMelloDeMello

•Schedule and ManpowerSchedule and Manpower

VirostekVirostek•DiscussionDiscussion•Executive Session CommitteeExecutive Session Committee•CloseoutCloseout



MICE RF Cavity Summary• MICE RF cavity design is based on the successful MICE RF cavity design is based on the successful

prototype cavity for the US MuCool program prototype cavity for the US MuCool program

• Fabrication of the prototype cavity was successfulFabrication of the prototype cavity was successful

• A slight reduction in cavity diameter to raise the A slight reduction in cavity diameter to raise the frequency has been specified and analyzedfrequency has been specified and analyzed

• The fabrication techniques used to produce the The fabrication techniques used to produce the prototype will be used to fabricate the MICE RF prototype will be used to fabricate the MICE RF cavitiescavities

• Preliminary cavity design was reviewed at CM21 at DLPreliminary cavity design was reviewed at CM21 at DL

• Copper sheets have been ordered and expected to Copper sheets have been ordered and expected to arrive mid-December 2008arrive mid-December 2008

• A detailed WBS schedule for the design and A detailed WBS schedule for the design and fabrication of the MICE RF cavities has been fabrication of the MICE RF cavities has been developeddeveloped



MICE RF Cavity DesignMICE RF Cavity Design

– 3-D Microwave Studio RF parameterized 3-D Microwave Studio RF parameterized model including ports and curved Be model including ports and curved Be windows to simulate frequency, Ewindows to simulate frequency, Epeakpeak, , etc.etc.

– Hard to reach the design frequency by Hard to reach the design frequency by spinning techniquespinning technique

– Frequencies between cavities should be Frequencies between cavities should be able to achieve within able to achieve within 100 kHz 100 kHz

– ApproachesApproaches• Modification the prototype spinning Modification the prototype spinning

form form • Targeting for higher frequencyTargeting for higher frequency• Fixed tuner to tune cavity close to Fixed tuner to tune cavity close to

design frequency (deformation of design frequency (deformation of cavity body)cavity body)

• Tuners are in push-in mode Tuners are in push-in mode lower lower frequencyfrequency



Cavity Design ParametersCavity Design Parameters• The cavity design parametersThe cavity design parameters

– Frequency: 201.25 MHzFrequency: 201.25 MHz– ββ = 0.87 = 0.87– Shunt impedance (VTShunt impedance (VT22/P): ~ 22 MΩ/m/P): ~ 22 MΩ/m– Quality factor (QQuality factor (Q00): ~ 53,500): ~ 53,500– Be window diameter and thickness: 42-cm and 0.38-mmBe window diameter and thickness: 42-cm and 0.38-mm

• Nominal parameters for Nominal parameters for MICEMICE and cooling and cooling channels in a neutrino factorychannels in a neutrino factory – 8 MV/m8 MV/m ( (~16 MV/m~16 MV/m) peak accelerating field) peak accelerating field– Peak input RF power: Peak input RF power: 1 MW1 MW ( (~4.6 MW~4.6 MW) per cavity ) per cavity – Average power dissipation per cavity: Average power dissipation per cavity: 1 kW1 kW ( (~8.4 kW~8.4 kW))– Average power dissipation per Be window: Average power dissipation per Be window: 12 watts12 watts ( (~100 ~100

wattswatts))



201 MHz Cavity Concept201 MHz Cavity Concept

Spinning of half shells using thin copper sheets and e-beam welding to join the shells; extruding of four ports; each cavity has two pre-curved Beryllium windows, but also

accommodates different windows



RF Cavity Fabrication RF Cavity Fabrication OverviewOverview

• Cavity half-shells to be formed by metal spinning

• Precision milling of large parts (1.2 m diameter)

• Precision turning of mid-sized parts (0.6 m dia.)

• Precision manufacture of smaller parts

• CMM measurements throughout the process

• To limit any annealing and maintain cavity strength, e-beam welding will be used for all cavity welding

• cavity equator, stiffener rings, nose rings, port annealing and port flanges

• Cavity inside surfaces are finished by electro-polishing

Engineering CAD

Model of the RF Cavity

Prototype RF Cavity

The same fabrication techniques used to make the prototype cavity will be used for the MICE RF cavities



Progress SummaryProgress SummaryRF CavitiesRF Cavities• Material to arrive 12/08Material to arrive 12/08• Fabrication steps identifiedFabrication steps identified• RF, thermal, structural analyses doneRF, thermal, structural analyses done• Detailed design completeDetailed design complete• Fabrication drawings nearly doneFabrication drawings nearly done• Vendor qualification under wayVendor qualification under way• Be windows being orderedBe windows being ordered• Final vendor selection not completeFinal vendor selection not complete• Electropolish not fully definedElectropolish not fully defined

Cavity tunersCavity tuners• RF, structural analyses completeRF, structural analyses complete• Actuation cylinder type identifiedActuation cylinder type identified• Detailed design, drawings not completeDetailed design, drawings not complete



Progress Summary (cont.)Progress Summary (cont.)Cavity StrutsCavity Struts• Structural analysis completeStructural analysis complete• LBNL standard detailed designLBNL standard detailed design• Fabrication, installation dwgs not doneFabrication, installation dwgs not done

Coupling Coil InterfaceCoupling Coil Interface• Magnet gusset mod sent to ICSTMagnet gusset mod sent to ICST• Additional interface details TBDAdditional interface details TBD

Cavity Cooling WaterCavity Cooling Water• Feedthrough concept developedFeedthrough concept developed• Detailed design not completeDetailed design not complete



Progress Summary (cont.)Progress Summary (cont.)Module Vacuum VesselModule Vacuum Vessel• Conceptual design/CAD model completeConceptual design/CAD model complete• Structural analysis not completeStructural analysis not complete• Detailed design, drawings not completeDetailed design, drawings not complete

Module Vacuum SystemModule Vacuum System• Conceptual design completeConceptual design complete• Lumped parameter analysis soonLumped parameter analysis soon• Failure analysis not completeFailure analysis not complete• Detailed design, drawings not completeDetailed design, drawings not complete

RF CouplersRF Couplers• Design previously developed for MuCool cavityDesign previously developed for MuCool cavity• Modifications for MICE not completeModifications for MICE not complete• Detailed design, drawings not completeDetailed design, drawings not complete vacuumvacuum



Progress: Other Module Progress: Other Module ComponentsComponents

Beryllium Window

Dynamic Tuners

Cavity Suspension

Vacuum System

RF Coupler

Module Support

DeMello’s talk for more detailsDeMello’s talk for more details



Liquid Nitrogen Cooling Considerations

•Suspension of cavities on struts provides low heat leak from cavity to vacuum vessel

•Beryllium window FEA thermal analysis will need to be performed with new parameters

•The cavity frequency will be shifted (approximately 600 kHz), therefore tuning system or RF power source modifications will be needed

•Insulators will need to be added to the RF couplers

•Coaxial LN feedthrough tubes will be needed to insulate the connection outside of vacuum



SummarySummary• Good progress since last CM and review, details of Good progress since last CM and review, details of

technical designs, interface and schedules (DeMello technical designs, interface and schedules (DeMello and Virostek)and Virostek)

• Responses to last review (DeMello)Responses to last review (DeMello)

RFCC & Cavity Design Review AgendaRFCC & Cavity Design Review Agenda(15:30 – 18:30 October 21, 2008 at RAL)(15:30 – 18:30 October 21, 2008 at RAL)• Overview of RFCC Module and Recent ProgressOverview of RFCC Module and Recent Progress LiLi

• 201 MHz Cavity Fabrication Plan201 MHz Cavity Fabrication Plan

DeMelloDeMello• Assembly, Installation and Interface Assembly, Installation and Interface

VirostekVirostek• Coffee breakCoffee break• RFCC Module and Subcomponents Mechanical DesignRFCC Module and Subcomponents Mechanical Design

DeMelloDeMello• Schedule and ManpowerSchedule and Manpower

VirostekVirostek• DiscussionDiscussion• Executive Session CommitteeExecutive Session Committee• CloseoutCloseout

Overview of the RFCC Module and 201-MHz Cavity Design

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