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简介：TheExperimentalAdvanced.SuperconductingTokamak(EAST)isbeingbuiltinChinatoachievehighpowerandlongpulseoperationforstudiesofreactor-relevantissuesundersteady-stateconditions.AmajorconcernforEASTisthepowerhandlingcapabilityofthedivertortargetplates,whichisacriticalissueforfuturehigh-poweredsteady-statetokamaks,suchasITER.DetailedmodelingusingB2/EIRENEcodepackageandthemostrecentchemicalsputteringdatashowsthatthepresenceofstrongchemicalsputteringatthemainchamberwallleadstostrongcarbonradiationintheperipheryoftheconfinedplasma,significantlyreducingtheheatfluxestothetargetplatesandfacilitatingplasmadetachmentatalowerdensitydesiredforlowerhybridcurrentdriveinEAST,withonlyaslightincreaseinZ_(eff)attheedge.Thetargetheatloadcanbefurtherreducedbyoperatingwithadouble-nulldivertorconfiguration,whichalsoleadstoasignificantreductionintheedgeZ_(eff).However,thecodepredictsthatthedouble-nulloperationwouldresultinastrongdivertorasymmetryintargetpowerloading,favoringtheoutsidetargets.

简介：Anexperimentaladvancedsuperconductingtokamak(EAST)operationwindowwiththelowerhybridcurrentdrive(LHCD)inH-modeisestimatedbyusingacore-SOL-divertor(C-S-D)modelvalidatedbythepresentEASTdivertorexperiments.Theoperationwindowconsistsoffourlimitsincludingtwousuallimits,oneofwhichisthemaximumallowableheatloadontothedivertorplate,andtwoadditionallimitsassociatedwiththeLHCD.ThepredictiveEASToperationwindowisnotqualifiedtofulfillitsmissionforhighinputpower.Toextendtheoperationwindow,gaspuffingandimpurityseedingarepresentedastwoeffectivemethods.Inaddition,theeffectoftheLHCDcurrentontheoperationwindowisalsodiscussed.OurnumericalanalysisresultsprovideareferenceforthesafeoperationofEASTexperimentswithLHCDinfuture.

简介：Ioncyclotronrangeoffrequency(ICRF)heatinghasbeenusedintokamaksasoneofthemostsuccessfulauxiliaryheatingtoolsandhasbeenadoptedintheEAST.However,theantennaloadwillfluctuatewiththechangeofplasmaparametersintheICRFheatingprocess.ToensurethesteadyoperationoftheICRFheatingsystemintheEAST,fastferritetuner(FFT)hasbeencarriedouttoachievereal-timeimpedancematching.FortherequirementsoftheFFTimpedancematchingsystem,themagnetsystemoftheferritetuner(FT)wasdesignedbynumericalsimulationsandexperimentalanalysis,wherethebiasingmagneticcircuitandalternatingmagneticcircuitwerethekeyresearchedpartsoftheferritemagnet.TheintegraldesigngoaloftheFTmagneticcircuitisthatDCbiasmagneticfieldis2000Gsandalternatingmagneticfieldis±400Gs.IntheFTT,E-typemagneticcircuitwasadopted.FerritematerialisNdFeBwithathicknessof30mmbysettingtheworkingpointofNdFeB,andtheampereturnofexcitationcoilis25throughthetheoreticalcalculationandsimulationanalysis.Thecoilinductancetogeneratealternatingmagneticfieldisabout7mH.Eddy-currenteffecthasbeenanalyzed,whilethemagneticfielddistributionhasbeenmeasuredbyaHallprobeinthemediumplaneofthebiasingmagnet.Finally,thetestresultsshowthegoodperformanceofthebiasingmagnetsatisfyingthedesignandoperatingrequirementsoftheFFT.

简介：Neutralbeaminjection(NBI)isrecognizedasoneofthemosteffectivemeansforplasmaheating.A100slongpulseneutralbeamwith30keVbeamenergy,10Abeamcurrentanda100slongpulsemodulatingneutralbeamwith50keVbeamenergy,16AbeamcurrentwereachievedintheEASTneutralbeaminjectoronthetest-stand.ThepreliminaryresultssuggestthatEAST-NBIsysteminitiallypossesstheabilityoflongpulsebeamextraction.

简介：StationarylongpulseplasmaofhighelectrontemperaturewasproducedonEASTforthefirsttimethroughanintegratedcontrolofplasmashape,divertorheatflux,particleexhaust,wallconditioning,impuritymanagement,andthecouplingofmultipleheatingandcurrentdrivepower.Adischargewithalowersinglenulldivertorconfigurationwasmaintainedfor103sataplasmacurrentof0.4MA,q95≈7.0,apeakelectrontemperatureof>4.5keV,andacentraldensityne（0）2.5×1019m-3.Theplasmacurrentwasnearlynon-inductive(Vloop<0.05V,poloidalbeta0.9)drivenbyacombinationof0.6MWlowerhybridwaveat2.45GHz,1.4MWlowerhybridwaveat4.6GHz,0.5MWelectroncyclotronheatingat140GHz,and0.4MWmodulatedneutraldeuteriumbeaminjectedat60kV.Thisprogressdemonstratedstrongsynergyofelectroncyclotronandlowerhybridelectronheating,currentdrive,andenergyconfinementofstationaryplasmaonEAST.Itfurtherintroducedanexampleofintegrated'hybrid'operatingscenarioofinteresttoITERandCFETR.

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简介：InthedischargeofEASTtokamak,itisobservedthat（2,1）neoclassicaltearingmode（NTM）istriggeredbymodecouplingwitha（1,1）internalmode.Usingsingularvaluedecomposition（SVD）methodforsoftX-rayemissionandforelectroncyclotronemission（ECE）,thecouplingspatialstructuresandcouplingprocessbetweenthesetwomodesareanalyzedindetail.TheresultsofSVDforECErevealthatthephasedifferencebetweenthesetwomodesequalstozero.Thisisconsistentwiththeperfectcouplingcondition.Finally,performingstatisticalanalysisofγ1/1,ζ1/1andω2/1,wefindthatγ1/1moreaccuratelyrepresentsthecouplingstrengththanζ1/1,andγ1/1isalsostronglyrelatedtothe（2,1）NTMtriggering,whereγ1/1isthewidthof（1,1）internalmode,ζ1/1istheperturbedamplitudeof（1,1）internalmode,andω2/1denotesthemagneticislandwidthof（2,1）NTM.