简介：AtypeofsilicondetectorknownasAXUV(absoluteextremeultraviolet)photodiodesissuccessfullyusedtomeasuretheradiatedpowerinEAST.Thedetectorischaracterizedbycompactstructure,fasttemporalresponse(<0.5s)andflatspectralsensitivityintherangefromultra-violettoX-ray.Two16-channelAXUVarraysareinstalledinEASTtoviewthewholepoloidalcross-sectionofplasma.Basedonthediagnosticsystem,typicalradiationdistributionsforbothlimiteranddivertorplasmaareobtainedandcompared.Asdivertordetachmentoccurs,theradiationdistributioninX-pointregionisobservedtovarydistinctly.Thetotalradiationpowerlossesindischargeswithdifferentplasmaparametersarebrieflyanalyzed.

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简介：Anovelnanosecondpulsedpowerunitwasdevelopedforplasmatreatmentofwastewater,basedonthetheoryofmagneticpulsecompressionandsemiconductoropeningswitch(SOS).Thepeakvalue,risetimeandpulsedurationoftheoutputvoltagewereobservedtobe-51kV,60nsand120ns,respectively.Theconcentrationsof·OHgeneratedbythenovelnanosecondpulsedplasmapowerweredeterminedusingthemethodofhigh-performanceliquidchromatography(HPLC).Theresultsshowedthattheconcentrationsof·OHincreasedwiththeincreaseinpeakvoltage,andthegenerationratesof·OHwere4.1×10-10mol/s,5.7×10-10mol/s,and7.7×10-10mol/sat30kV,35kV,and40kV,respectively.TheefficiencyofOHgenerationwasfoundtobeindependentoftheinputparametersforappliedpower,withanaveragevalueof3.23×10-12mol/Jobtained.

简介：Thispaperreportsforthefirsttimeanexperimentalstudyonthepowerdepositionprofileoftheioncyclotronrangefrequencies(ICRF)powerdepositingonelectronsinHT-7.ThefastFouriertransform(FFT)analysisandthebreakinslope(BIS)methodareutilizedtoobtaintheinformationofthepowerdeposition.Theresultsindicatethattheelectronswereheateddirectly,andtheelectronsabsorbedaround20%oftheinputpowerofthedischargeofinterest.

简介：TooptimizetheoperationparametersofthebeamlineofNBIonHL-2A,featuresofthebeamline,includingthebeamprofileandthepowerdepositedoncomponentsandinjectedintothetokamakplasma,weremeasured.Theoperationalparametersofthefoursourcesonthebeamlinewereoptimizedwiththemonitorofthebeamprofileandbeampower,andthetransmissionefficiencyoftheNBIinjectedpowerwasthereforeincreased.AbeamdiagnosticsystemforthebeamlineoftheNBIsystemonHL-2Aaswellasthediagnosedresultswasalsopresented.

简介：Plasmafillingcandramaticallyimprovetheperformanceofhighpowermicrowavedevices.Thecharacteristicsofhigh-powermicrowavepropagationalongplasmafilledwaveguidesinanaxialmagneticfieldareanalyzedinthispaper,andtheponderomotiveforceeffectofhighpowermicrowaveistakenintoconsideration.Theoreticalanalysisandpreliminarynumericalcalculationsareperformed.Theanalysesshowthattheponderomotiveeffectwouldchangetheplasmadensity,distributionofmicrowavefieldintensity,anddispersionofwavepropagation.Thehigherthemicrowavepower,thestrongertheponderomotiveeffect.Indifferentmagneticfields,theponderomotiveeffectisdifferent.

简介：Inlowerhybridcurrentdrive(LHCD)experimentsinHT-7,LHwavecoupledtotheplasmafrom12klystronsislaunchedbyaphasedmulti-junctiongrill.Highpowermicrowavereflectionorarc,whichthreatenstheklystrons,thewave-guideceramicwindowsandthevacuumofthetokamak,occursometimesduringtheexperiments.Forthesakeofsafety,ahighpowermicrowavetestsystemtoperformsimulationswasdeveloped.Inthetestexperiments,theklystronandwindowcanbewellprotectedwithanoptimizedmicrowavemonitorandaPINswitch.ThelayoutofthetestsystemandthesimulatedexperimentsforHT-7aredescribedinthispaper.

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：Alowpoweratmosphericpressureplasmajetdrivenbya24kHzACpowersourceandoperatedwithaCH4/airgasmixturehasbeeninvestigatedbyopticalemissionspectrometer.Theplasmaparametersincludingtheelectronexcitationtemperature,vibrationaltemperatureandrotationaltemperatureoftheplasmajetatdifferentdischargepowersarediagnosedbasedontheassumptionthatthekineticenergyofthespeciesobeystheBoltzmanndistribution.TheelectrondensityatdifferentpowerisalsoinvestigatedbyHβStarkbroadening.Theresultsshowthattheplasmasourceworksundernon-equilibriumconditions.Itisalsofoundthatthevibrationaltemperatureandrotationaltemperatureincreasewithdischargepower,whereastheelectronexcitationtemperatureseemstohaveadownwardtrend.Theelectrondensityincreasesfrom0.8×1021m-3to1.1×1021m-3whenthedischargepowerincreasesfrom53Wto94W.

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简介：Netemissioncoefficientsofradiationwerecalculatedforisothermalplasmaofmethaneasafunctionoftheplasmatemperature5,000～30,000Kandthearcradius0mmto10mmatatmosphericpressure.Calculationstakeintoaccountcontinuumandlineradiations,specialattentionhasalsobeengiventotheinfluenceofoverlappingspectrallines.ThelineshapesinourcalculationsaregivenbyconvolutionofDopplerandLorentzprofiles,resultinginasimplifiedVoigtprofile.Inthecaseofahydrogenprofile,weusedtheVidaltables,andthefourfirstLymanlinesandthefourfirstBalmerlineswereconsidered.Thiscalculationwascarriedoutontheassumptionoflocalthermodynamicequilibriumandinanondiffusiveenvironment.ThenetemissioncoefficientcalculationforpureargonplasmawascomparedwiththeexperimentalresultsofEvansinourpreviouswork.Weusedtheescapefactor,andourresultswerehigherthanthoseoftheexperiment.Inthispaper,weexplainwhy,usingtheescapefactor,theradiationisoverestimated.ThenetemissioncoefficientobtainedfromarealspectrumwascomparedwithEssoltaniwork’swhichusedtheline-by-linemethodforpureargonplasma.

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简介：BasedonthetransmissionlinecodeTLCODE,a1Dcircuitmodelforatransmissionlineimpedancetransformerwasdevelopedandthesimulationresultswerecomparedwiththoseintheliterature.Themodelwasusedtoquantifytheefficienciesofvoltage-transport,energytransportandpower-transportforatransmission-lineimpedancetransformerasfunctionsofΨ(theratiooftheoutputimpedancetotheinputimpedanceofthetransformer)andΓ(theratioofthepulsewidthtotheone-waytransittimeofthetransformer)underalargescaleofm(thecoefficientofthegeneralizedexponentialimpedanceprofile).SimulationresultssuggestthatwiththeincreaseinΓ,fromOto∞,thepowertransportefficiencyfirstincreasesandthendecreases.Themaximumpowertransportefficiencycanreach90%orevenhigherforanexponentialimpedanceprofile(m=1).Withaconsiderationofdissipativelossinthedielectricandelectrodesofthetransformer,tworepresentativedesignsofthewater-insulatedtransformerareinvestigatedforthenextgenerationofpetawatt-classz-pinchdrivers.Itisfoundthatthedissipativelossesintheelectrodesarenegligiblysmall,below0.1%,butthedissipativelossinthewaterdielectricisabout1%to4%.

简介：Thedeviceofacetyleneproductionbyhydrogen(H-)plasmapyrolysiscoalisexaminedanddevelopednotonlyforstudyingtheapplicationoflowtemperatureplasmabutalsoforstudyingthecleanuseofcoal.Thepower-supplycontrolsystemisusedtoensuresupplyingasteadyenergytogenerateandmaintaintheplasmaelectricarcofthedevice.Thehardwareconfigurationandthesoftwaredesignofthesystemaredescribedinthispaper.Verifiedbyexperiments,thissystemcanmeettherequirementsofreal-timeperformance,reliabilityandextensibilityforthedevice.

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简介：Dielectric-barrierdischarges(DBDs)inatmosphericpressureairhavebeenstudiedbyusingapower-frequencyvoltagesource.InthispapertheelectricalcharacteristicsofDBDsus-ingglassandaluminadielectricshavebeeninvestigatedexperimentally.AccordingtotheLissajousfiguresofvoltage-charges,itisdiscoveredthatthedischargepowerforanaluminadielectricismuchhigherthanthatforaglassdielectricatthesameappliedvoltage.Also,thevoltage-currentcurvesoftheglassandaluminadielectricsconfirmthefactthatthedielectricbarriersbehavelikesemiconductingmaterialsatcertainappliedvoltages.

简介：Amodellingstudyisperformedtocomparetheplasmaflowandheattransfercharacteristicsoflow-powerarc-heatedthrusters(arcjets)forthreedifferentpropellants:hydrogen,nitrogenandargon.Theall-speedSIMPLEalgorithmisemployedtosolvethegoverningequations,whichtakeintoaccounttheeffectsofcompressibility,LorentzforceandJouleheating,aswellasthetemperature-andpressure-dependenceofthegasproperties.Thetemperature,velocityandMachnumberdistributionscalculatedwithinthethrusternozzleobtainedwithdifferentpropellantgasesarecomparedforthesamethrusterstructure,dimensions,inlet-gasstagnantpressureandarccurrents.Thetemperaturedistributionsinthesolidregionoftheanode-nozzlewallarealsogiven.Itisfoundthattheflowandenergyconversionprocessesinthethrusternozzleshowmanysimilarfeaturesforallthreepropellants.Forexample,thepropellantisheatedmainlyinthenear-cathodeandconstrictorregion,withthehighestplasmatemperatureappearingnearthecathodetip;theflowtransitionfromthesubsonictosupersonicregimeoccurswithintheconstrictorregion;thehighestaxialvelocityappearsinsidethenozzle;andmostoftheinputpropellantflowstowardsthethrusterexitthroughthecoolergasregionneartheanode-nozzlewall.However,sincethepropertiesofhydrogen,nitrogenandargon,especiallytheirmolecularweights,specificenthalpiesandthermalconductivities,aredifferent,thereareappreciabledifferencesinarcjetperformance.Forexample,comparedtotheothertwopropellants,thehydrogenarcjetthrustershowsahigherplasmatemperatureinthearcregion,andhigheraxialvelocitybutlowertemperatureatthethrusterexit.Correspondingly,thehydrogenarcjetthrusterhasthehighestspecificimpulseandarcvoltageforthesameinletstagnantpressureandarccurrent.Thepredictionsofthemodellingarecomparedfavourablywithavailableexperimentalresults.