ElectronDensityDistributioninHSX：在XX电子密度分布.ppt

ElectronDensityDistributioninHSX C Deng D L BrowerElectricalEngineeringDepartmentUniversityofCalifornia LosAngelesJ Canik S P Gerhardt D T Anderson P Probert F S B AndersonTheHSXPlasmaLaboratoryUniversityofWisconsin Madison Abstract Amultichannelinterferometersystemisnowroutinelyoperatingonthenewquasi helicallysymmetricstellarator HSX tomeasuretheequilibriumprofileandelectrondensitydynamics Theinterferometersystemhas9viewingchordswith1 5cmspacing Thedensityspatialdistributionisreconstructedfromthemeasuredline integrateddensity Athighdensity anm 1densityoscillationwithfrequencyof 1 2 kHzisobserved Perturbativeparticletransportstudieswillbecarriedoutusingmodulatedgaspuffing Theparticlesourcewillbemeasuredbyamulti channelHasystem Byusingthecontinuityequation thetotalradialparticlefluxGrcanthenbeestimated ThediffusioncoefficientDandconvectionvelocityVwillalsobemodeled SupportedbyUSDOEundergrantDE FG03 01ER 54615 TaskIIandDE FG02 93ER54222 InterferometerCapabilities Spatialresolution 9chords 1 5cmspacingandwidth Fasttimeresponse analog 100 200msec realtimedigital 10msecmaximumbandwidth250kHz with2MHzsampling Lowphasenoise 24mrad 1 6o Dnedl min 9x1011cm 20 4 leveldensityfluctuationscanbemeasuredDensityfluctuations wavenumberresolution i k 2 1cm 1 ii k 0 07cm 1 SolidStateSource SolidStateSource bias tunedGunndiodeat96GHzwithpassivesolid stateTriplerprovidingoutputat288GHz 8mW SupportofOpticalTransmissionSystem 2 5metertall 1tonreactionmass mountedonstructureindependentofHSXdevice Reducesstructurevibrationandminimizesphasenoise DichroicFilters mountedonportwindowstoshieldinterferometerfrom28GHzgyrotronradiationCut offfrequency 220GHz 10 lossattenuationrangingfrom92dbat28GHzto68dbat150GHz EdgeFilters mountedinsideportwindowstoreducediffractionofthewindow InterferometerSchematic HSXInterferometerLayout HSXInterferometerSystem BeamExpansionOpticsandReceiverArray FluxSurfacesandInterferometerChords DensityProfileInversion Method Abelinversion SingularValueDecomposition flexibleboundaryconditions non circulargeometry plasmascrape off layerSOLestimateModel splinefitto9channelline densityprofile noShafranovShiftPathlengths calculatedfortwentyvacuumfluxsurfaces SOLplasmacontribution Oneviewingchordisoutsidetheseparatrix ThisprovidesinformationontheSOLcontribution Refractioncorrection necessaryforchordlengthandposition HSXDensityProfile QHS MeasuredLine IntegratedDensityProfileandfitting InvertedDensityProfile HSXDensityProfile Mirror MeasuredLine IntegratedDensityProfileandfitting InvertedDensityProfile HSXDensityProfile Anti Mirror MeasuredLine IntegratedDensityProfileandfitting InvertedDensityProfile PerturbativeParticleTransportStudy Densityperturbationobtainedbygaspuffingmodulationprovideagoodtoolforparticletransportstudy PrevioussuccessfulexperimentsonTEXT ASDEX W7 ASDiffusiveandconvectiveeffectscanbeobtainedbyanalyzingprofiletimeevolution Sinusoidalwaveisidealforthisanalysis whichgivehigheraccuracyoftheanalysis Andafewcycleswillbeneededtoobtaincertainaccuracy Theamplitudewillbearoundlessthan10 toreducetheeffectsofplasmaparametersdependency Theelectrondensitycanbeconstantonmagneticfluxsurfaces WeusecylindricalgeometrytransportEquation ParametersnandScanbeseparatedintotwopart 1 stationarypartn0andS0 and 2 perturbedpartand wherewisthefrequencyofthedensityperturbationgeneratedbymodulatingthegasfeed AlsoassumeDandVareindependentoftime Linearizingequation 1 leadsto ContinuityEquation 2 1 Theboundaryconditionsare atr 0 atr a LinearizedEquations 5 6 7 modulatedgasfeed Fouriercoefficients TheFouriercoefficientsoftheline integrateddensitywereobtainedbyfittingthefollowingfunctiontothemeasureddata HereandaretherealandimaginarypartsoftheFouriercoefficientsattheithHarmonicofthemodulationfrequency Thea0 a1anda2correspondtoconstant linearandquadratictimedependenceandtakeintoaccountapossibleslowtimeevolution DensityPerturbationAmplitudeandPhase Amplitudeandphaseofthefirstharmonicofthemodulationfrequencyfortheline integrateddensities EstimatedSource Atthismoment electronsourceprofileunknown Assumesourceprofilehasexponentialfall off AmplitudeandpositionoftheSourcewerechosen roughly accordingtotheHameasurement ResultsforD const andV 0 AroughestimateofDfrommeasuredparticleconfinementtime gives 3ms Dest a2 6tp 1 0m2 s ResultsforsteppedD withV 0 ThemodelingisnotsensitivetothedetailedstructureofD SensitivityofModelingtoD SensitivityofModelingtoV SensitivityofModelingtoSourceProfile ifxxcS no exp abs x xc xl2 xl2 5cmPeakposition xc 3 4cm DensityPerturbationatdifferentfrequencies TheParticletransportisunchangedwiththefrequencyofgasfeedmodulations DensityPerturbationwithdifferentDensities TheParticletransportchangesalittlewithdensity whichwouldgivesmallerDathigherdensity Modelingoftherecentexperiment D 2 0m2 secV 0m sec Betterfitwithoutwardconvection D 2 0m2 secV 300m secSourcesameaslastslide Summary EquilibriumDensityDistributionsforQHS Mirror Anti mirro