承建單位項目法人單位上海應(yīng)用物理所概況-DESYIndico課件

DesignofasuperconductingthirdharmoniccavityforSSRFHongtaoHOUOnbehalfofRFgroup2018-06-28ContentsBackgroundDesignSpecificationHarmonicCryomoduleDesignSummary1.Background:MotivationSSRFbeamlinephase-IIprojectInstallationofmoreinsertiondeviceswilldecreasethebeamlifetimeFunctionLifetimeincreaseBeamperformanceimprovementInstabilitiessuppressionAdvantagesProvideLandaudampingofsynchrotronoscillations:

suppresscoupled-bunchandmicrowaveinstabilitiesIncreasethresholdofsinglebunchinstabilitiesHarmoniccavitiesforbunchlengtheningResonantatfharm=nfRF(oftenn=3)Passive/active:noexternalpowersourcerequiredforpassivesystemNC/SC:SChassufficientimpedanceevenatlowcurrentSSRFoperationstatus(~2017)Scheduled/hrsAccomplished/hrsAvailabilityMTBFMDT20092215209494.6%28.31.65201040033829.195.3%40.441.8420114477437097.6%55.31.57201246104535.498.469.81.19201347274638.798.1%70.31.36201446924624.598.6%81.11.220154634455698.3%79.91.5420164606453097%45.761.4520174246415297.8%54.61.25260mAtop-upoperationSLS:passiveEmax=2.4GeVIbeam=400mA1

Nb/CuHC’sfharm=3fRF3timeslength2.2timeslifetime

Elettra:passiveEmax=2.0GeVIbeam=320mA1

Nb/CuHC’sfharm=3fRF3timeslength3.5timeslifetime

APS-U:passive+FPCEmax=6.0GeVIbeam=200mA1

Nbcavityfharm=4fRF3timeslength3.5timeslifetime

NSLS-II:passive,Emax=3.0GeVIbeam=500mA2-cellNbcavityfharm=3fRF~2timeslifetime

WorldwideSCharmoniccavitiesInoperationUnderdevelopmentContentsBackgroundDesignSpecificationHarmonicCryomoduleDesignControlandinterlockSummary2.DesignSpecificationGoal:Lifetimeincreasefactor≥2，bunchlengtheningfactor≥2Lowtransientbeamloading:

R/Q~90Ohm；Passivecavity,1.5GHzQ0≥1.0E10@Eacc=10MV/m(VT)

HighstableandreliableSRFmodule:highperformanceniobiumcavity,reliabletuner,HOMheavilydamped;PLC-basedcontrolforcryomodule;Harmoniccavityvoltagecontrol:constantvoltageoperationmode,digitalLLRF,mechanic+pizeotuner;Interlockandmachineprotectionsystem:PLCbased,cryomodulemonitoring,interlockwithmainrfsystemLimitedbyinstallationspaceavailable(~2m)andhigherharmonicvoltagerequired(1.8MV),resultinginonemodulewithadouble-cellcavityoperationat2.0K.(lowgradient,easiertoreachand2Koperationstable)SpecificationHarmonicsystemBunchlengtheningfactor:≥2Beamlifetimeincreasefactor:≥2ParameterDescriptionValueEBeamenergy3.5GeVCCircumference432mIdcDCbeamcurrent0.2~0.3AfrfRFfrequency499.654MHzhHarmonicnumber720αMomentumcompaction4.2e-4σεEnergyspread0.001U0Radiationlossperturn1.4MeVVrfMainrfvoltage4.5~5.4MVQsNominalsynchrotrontune0.0075σlNominalrmsbunchlength3.8mmVhHarmonicrfvoltage1.4~1.8MVSchematicDiagramofThirdHarmonicModuleTable-1:ParametersofSSRFStorageRingPhysicscalculation

1)、Doublerfsystem：optimallengtheningfactor~4BunchshapelengthenedMomentumacceptanceBunchshapewithharmonicvoltage2)、Lengtheningeffectwithdifferentfillingpattern：factor>2Longbunchtrain：500

filling

+220

gapShort

bunch

train：100

filling

+44

gaps,5trains500

bunches+1highcurrentbunch(9mA)ContentsBackgroundDesignSpecificationHarmonicCryomoduleDesignSummary3.1ChoiceofcavityshapeSimilarto3HCatSLSandElettraRequiredHOMcouplersonthepipesbetweencellsTheHOMcouplerswillneedcryogeniccooling2-cell

wo

coupling2-cellwocoupling2-cell

wicouplingenlargedpipe2-cellwicouplingflutedpipe2-cellstructurewithcellcouplingHOMpropagationbythebeampipe；Fluted

beampiperesultedinashorterniobiumcavityBeamlineHOMdamper,outsidethecryomodule,watercoolingispossible2-cell

withFPCI=300mA2-cellstructurewithfundamentalcouplers,Qextadjustable,canreachoptimallengtheningRequired~47kWbeampower,addingmainrfload;LbandCWcouplerisachallengeCavityshape:2-cellstructure,flutedbeampipeforHOMpropagation3.2Cavity

simulationRi=40mm,r_blend=10.0mmCSTE-modesimulationInstabilitythresholdvalueofSSRFstorageringEigenmodesimulationresultsshowbothmonopolemodesanddipolesimpedancemeetSSRFrequirementMultiphysics-MechanicalsimulationNbProperties300K4KYoung’smodulus1.05e111.26e11Poisson’sratio0.380.38density85708570Yieldstrength(MPa)65.5577.1Tensilestrength(MPa)181.3819.1Allowablestress(MPa)43.7234df/dl1.48MHz/mmdf/dp(wostiffnessring)5.2Hz/mbarCooldown~2.2MHzTuning1MHz~0.7mmResults3.2Niobiumcavitysimulation3.3CavitysimulationwithHOMdampers

SiCmaterial:ε=45,tanδ=0.45@2.0GHz3.3CavitysimulationwithHOMdampersD=80mmD=110mmLoss

factor

of

different

thermaltransition:

flutedtypehasalowerlossfactorDifferentHOMdamperslocation:smallinfluenceonimpedance3.4OperationmodeconsiderationOperationNormaloperation：SSRFtop-up(>250mA)，3HCconstantvoltageoperation；3HCtripmodeCryomodulebreakdown：warm-up,influenceSSRFoperation.Ifkeeping300mAoperation,3HCcavityneedstobecooledbycoldheliumgasorpureN2cooling；RTpartsbreakdown：keeps2.0K，3HCcavityparkedwithdetuningdf=347kHz，noinfluenceonSSRFoperation；example:coolingwater……；Tunerisimportant，evenlocatedoutsidecryomodule，tunerproblemwillinfluenceSSRFoperation；2.0Ksystembreakdown3HCkeeps4.2K,andparkedwithdf=347kHz；4.2K

cryogenicbreakdown：switchtothesparecryogenicsystemACB&2Kcoldbox2KMulti-transferlineCryoplantHarmoniccryomoduleMainSRFmodules&ValveBoxesTestCaveRFHallLocationintunnelSuperconductingCryomodulerequirementHOMpower:300mA,500bunchesfillingpattern,@4mmTaperwithionpump(downstream)Gate-valveHOMDamperMulti-transferlinesTunerAssemblyHOMDamperGate-valveTaperwithionpump(upstream)AdjustableModulebaseNbCavitySlidingJointsCryostatHighpurefinegrainniobiummaterial:RRR>300Surfacetreatment:mechanicalpolishing+BCP+HPR+650℃

annealing

+

light

BCP

+

120℃baking(~48hours)3.5NiobiumcavityfabricationBCP:HF(49%):HNO3(69.5%):H3PO4(85%)=1:1:2Pre-tuning：bead-pullVertical

testing：testdewar,lowmagneticfiled,2.0Ksystem，specification:Q0≥1E10@10MV/m@2.0KPhaselock,dataacquisition,Q0~EaccVerticaltestinsert:adjustableinputcoupler,pumpingVTCryostat:2magneticshielding(Perm-alloy)lowmagneticfield,<10mGauss(h<1.0m).3.6

HOMdamperSiCmaterialSC-35ε=45,tanδ=0.45@2.0GHzMechanicalandthermalpropertyComponentSang-hoonKim,ICFAHOMworkshop,2016SiCOFHCSSShrinkagefitfabricationHeliumvessel:316LstainlesssteelLN2thermalshielding,aluminum,without5Kthermalshielding,calculatedstaticlossis~6.2W,morethan50%frombeampipeconduction;Multilayershielding+magneticshielding(2layers)Operationpressure:31mbar+/-0.1mbar3.7CryostatSafetyvalves:2reliefvalves(~0.35bar)1burstdisc(~0.49bar)Transferlines:Lhe:VCRLN2:VCRGhe:CFOringsealing3.8TunerPlan：roomtemperature，easiermaintenance,mechanic+piezoTuningrange：>+/-347kHz(revolutionfrequency694kHz)，decision:+/-500kHz；component：tunerarm(1:2)，steppermotor，gearbox，piezoandpowersupply，controlunit；SpecificationTuningrange：+/-500kHzResolution：~10Hz3.9State

monitor

and

ready-chain

interlockFunction：temperature,pressure,vacuum,level,andheatercontrol

PLC-basedtechniqueSignaltocryogenicforcontrol：cavitytemperature,heliumlevel,pressureinheliumvessel,LN2coolingoutlettemperatureBCL01/02BDT03/04BDT01/02BDT05/06BDT07/08BDT09/10BDT11/12BDT13/14BCL03/04BCL05BCL06BCL07BCL08BPT01BPT02BPT03BPT04BPT05BPT06CLTSLakeshorePT100Pira