简介:AsimulationonthepropagationoflowerhybridwaveinEASTisconducted.Raytracing,evolutionoftheparallelrefractiveindex,andpowerdepositionprofilesinaD-shapedconfigurationwerecalculated.Resultsshowthatwavepropagationisaffectedbytheplasmacurrent,density,magneticfield,andpowerspectrum,etc.leadingtoadifferentpowerdeposition.ThisishelpfulinunderstandingtheLHCDexperimentsonEAST.
简介:Intheplasmasheathanarrowplasmachannelgeneratedbyultraintenselaserpulsesissimplifiedasaspecialcylindricalandhollowplasmawaveguidewiththeinfinitethicknessoftheplasmacladding.Theelectromagneticwave(EM)propagationpropertiesoftheplasmachannelnearthecutoffandfarfromthecutoffareconsidered.TheoreticalanalysisshowsthatTE0mandTM0mandhybridmodesemergeintheplasmachannel,whichisinfluencedbythenormalizedfrequencyparameterBandnumericalapertureNA.Thecutoffsofthevariousmodesareapproximated.Single-modeoperationispossiblewithoutahigh-frequencylimitationinthechannel.
简介:Experimentsonlowerhybridwave(LHW)couplingwereinvestigatedintheHT-7tokamak.GoodcouplingofLHWplasmahasbeendemonstratedatdifferentconditionsintheHT-7tokamak.RelevantresultshaveprovedthatLHW-plasmacouplingisaffectedbythephasedifferencebetweenadjacentwaveguides.Furthermore,theedgedensityaroundthegrillandrelevantcouplingcanbeadjustedbychangingtheplasmalineaveragedensityorthegapvaluebetweentheLHgrillandthelastclosedfluxsurfaces(LCFS).ItisfoundthatthecouplingofLHWsbecomespoorwhentheedgedensityaroundtheLHgrillislargeenoughintheHT-7tokamak,andthatcouplingremainsgoodwithaproperedgedensity.WithincreasingLHWpower,itisalsofoundthatthereflectioncoefficients(RCs)increaseduetonon-lineareffectsunderconditionsoflowedgerecycling,butcandecreaseunderhighedgerecycling.Theedgedensitydependsmainlyonthecompetitionbetweentheponderomotiveforce(PMF)andtheedgerecyclingintensityintheHT-7tokamak.
简介:Basedontheprinciplethatone-endedelectromagneticsurfacewavecandriveaplasmaantenna,therelationbetweentheeffectivelengthofanantennacolumnandtheappliedradiofrequency(RF)powerwasstudiedboththeoreticallyandexperimentally.Thedensitydistributionalongthcantennacolumnaswellastheelectrontemperatureindifferentconditionswereinvestigated.Thecharacteristicsofthereceptionoflocalfrequencymodulated(FM)electromagneticwavebytheplasmaantennawerecomparedwiththatbyacopperantennawithsamedimensions.Theresultsshowthatitisfeasibletotakeplasmaantennasasreceivingones.更多还原
简介:Anovelsurfacewaveplasma(SWP)sourceexcitedwithcylindricalTeflonwaveguidehasbeendevelopedinourpreviouswork.Theplasmacharacteristicshavebeensimplystudied.Inthiswork,ourexperimentaldevicehasbeensignificantlyimprovedbyreplacingtheTeflonwaveguidewithaquartzrod,andthenbettermicrowavecouplingandhighergaspuritycanbeobtainedduringplasmadischarge.Theplasmaspatialdistributions,bothinradialandaxialdirections,havebeenmeasuredandtheeffectofgaspressurehasbeeninvestigated.Plasmadensityprofilesindicatethatthisplasmasourcecanproduceuniformplasmainanaxialdirectionatlowpressure,whichshowsitspotentialinplasmaprocessingonacurvedsurfacesuchasaninnertubewall.Asimplifiedcircularwaveguidemodelhasbeenusedtoexplaintheprincipleofplasmaexcitation.Thedistinguishingfeaturesandpotentialapplicationofthiskindofplasmasourcewithahardwareimprovementhavebeenshown.
简介:Theprocessofionheatingbyamonochromaticobliquelypropagatinglow-frequencyAlfvenwaveisinvestigated.Thisprocesscanberoughlydividedintothreestages:atfirst,theionsarepickedupbytheAlfvenwaveinseveralgyro-periodsandabulkvelocityinthetransversedirectionisachieved;then,theionsarescatteredinthetransversedirectionbythewave,whichproducesphasedifferencesbetweentheionsandleadstoionheating,especiallyintheperpendiculardirection;andfinally,theionsarestochasticallyheatedduetothesubcyclotronresonance.Inthispaper,withatestparticlemethod,theefficiencyandtimescaleoftheionstochasticheatingbyamonochromaticobliquelypropagatinglow-frequencyAlfvenwavearestudied.Theresultsshowthatwiththeincreaseoftheamplitude,frequency,andpropagationangleoftheAlfvenwave,theefficiencyoftheionstochasticheatingincreases,whilethetimescaleoftheionstochasticheatingdecreases.Withtheincreaseoftheplasmabetaβ,theionsarestochasticallyheatedwithlessefficiency,andthetimescaleincreases.Wealsoinvestigatetheheatingofheavyionspecies(He2+andO5+),whichcanbeheatedwithahigherefficiencybytheobliqueAlfvenwave.
简介:Ananalyticalstudyispresentedonthemodaldispersioncharacteristics,groupvelocity,andeffectivegroup,aswellasthephaseindexofaternaryonedimensionalplasmaphotoniccrystalforanobliquelyincidentelectromagneticwaveconsideringtheeffectofcollisionsinplasmalayers.Thedispersionrelationisderivedbyusingthetransfermatrixmethodandtheboundaryconditionsbasedonelectromagnetictheory.Thedispersioncurvesareplottedforboththenormalphotonicbandgapstructureandtheabsorptionphotonicbandgapstructure.Itisfoundthattheincreaseintheangleofincidenceshiftsthephotonicbandgaptowardhigherfrequencies.Also,thecutofffrequencyisindependentofcollisions.
简介:Neutralbeaminjection(NBI)isrecognizedasoneofthemosteffectivemeansforplasmaheating.A100slongpulseneutralbeamwith30keVbeamenergy,10Abeamcurrentanda100slongpulsemodulatingneutralbeamwith50keVbeamenergy,16AbeamcurrentwereachievedintheEASTneutralbeaminjectoronthetest-stand.ThepreliminaryresultssuggestthatEAST-NBIsysteminitiallypossesstheabilityoflongpulsebeamextraction.
简介:IntheframeworkoftheITER,qualificationtests,thefirstChinaTFconductorsample(CNTFl)wastestedattheSULTANfacility.ThesamplewasmadeoftwoTFconductorsectionsmanufacturedfromidenticalinternalstannumstrandsprovidedbytheOxfordSuperconductingtechnologycompany(OST).Inordertoevaluatetheconductorperformance,thecurrentsharingtemperature(Tcs)wasmeasuredatspecifiedelectromagneticloadcyclingsteps.BothconductorsectionsoftheCNTFlsampleshowedidenticalperformance.Tcswas7.2Kbeforecyclingloading,and6.9Kevenafter950cycles,withoutsignificantdegradation,whichsubstantiallyexceedstheITERrequirementof5.7K.ThetestsoftheCNTFlconductorsampleshowedthattheelectromagneticcyclicloadexhibitedanegligibleeffectontheconductorperformance.Thecouplingtimeconstant8forAClosswas214msand71.52msbeforeandafterthecyclingload,respectively.Thetestresultsofthesamplearecomparedwiththestrandperformanceandparametermodelanalysis.