简介:Inordertoinvestigatetheinjectioncurrentuniformityaroundtheinductioncellbores,twofullyelectromagnetic(EM)modelsarerespectivelyestablishedforasingle-stageinductioncellandaninductionvoltageadder(IVA)withthreecellsstackedinseries,withoutconsideringelectronemission.Bymeansofthesetwomodels,somefactorsaffectingtheinjectioncurrentuniformityaresimulatedandanalyzed,suchastheimpedancesofaddersandloads,celllocations,andfeedtimingofparalleldrivingpulses.Simulationresultsindicatethathigherimpedancesofadderandloadsareslightlybeneficialtoimproveinjectioncurrentuniformity.Astheimpedancesofadderandloadsincreasefrom5Ωto30Ω,theasymmetriccoefficientoffeedcurrentsdecreasesfrom10.3%to6.6%.Thecurrentnon-uniformitywithinthefirstcellisalittleworsethanthatinotherdownstreamcells.Simulationresultsalsoshowthatthefeedtimingwouldgreatlyaffectcurrentwaveforms,andconsequentlycausesomedistortioninpulsefrontsofcelloutputvoltages.Foragivendrivingpulsewithdurationtimeof70-80ns,thefeedtimingwithatimedeviationoflessthan20nsisacceptableforthethree-cellIVAs,justcausingtherisetimeofoutputvoltagestoincreaseabout5nsatmostandmakingthepeakvoltagedecreaseby3.5%.
简介:Togetanoptimizedpulsedelectricalplasmadischargereactorandtoincreasetheenergyutilizationefficiencyintheremovalofpollutants,twohybridplasmadischargereactorsweredesignedandoptimized.Thereactorswerecomparedviathedischargecharacteristics,energytransferefficiency,theyieldsoftheactivespeciesandtheenergyutilizationindyewastewaterdegradation.TheresultsshowedthatunderthesameACinputpower,thecharacteristicsofthedischargewaveformofthepoint-to-platereactorwerebetter.UnderthesameACinputpower,thetworeactorsbothhadalmostthesamepeakvoltageof22kV.Thepeakcurrentofthepoint-to-platereactorwas146A,whilethatofthewire-to-cylinderreactorwasonly48.8A.Thepeakpowersofthepoint-to-platereactorandthewire-to-cylinderreactorwere1.38MWand1.01MW,respectively.Theenergyperpulseofthepoint-to-platereactorwas0.2221J,whichwasabout29.4%higherthanthatofthewire-to-cylinderreactor(0.1716J).Toremove50%AcidOrange7(A07),theenergyutilizationsofthepoint-to-platereactorandthewireto-cylinderreactorwere1.02×10-9mol/Land0.61×10-9mol/L,respectively.Inthepoint-toplatereactor,theconcentrationofhydrogenperoxideinpurewaterwas3.6mmol/Lafter40minofdischarge,whichwashigherthanthatofthewire-to-cylinderreactor(2.5mmol/L).Theconcentrationofliquidphaseozoneinthepoint-to-platereactor(5.7×10-2mmol/L)wasabout26.7%higherthanthatinthewire-to-cylinderreactor(4.5×10-2mmol/L).Theanalysisresultsofthevarianceshowedthatthetypeofreactorandreactiontimehadsignificantimpactsontheyieldsofthehydrogenperoxideandozone.ThemaindegradationintermediatesofA07identifiedbygaschromatographyandmassspectrometry(GCMS)wereaceticacid,maleicanhydride,pbenzoquinone,phenol,benzoicacid,phthalicanhydride,coumarinand2-naphthol.Proposeddegradationpathwayswereelucidatedinlightoftheanalyzeddegradationproducts.
简介:Theinstabilityofterahertz(THz)plasmawavesintwo-dimensional(2D)quantumelectrongasinananometerfieldeffecttransistor(FET)withasymmetricalboundaryconditionshasbeeninvestigated.WeanalyzeTHzplasmawavesoftwopartsofthe2Dquantumelectrongas:gatedandungatedregions.Theresultsshowthattheradiationfrequencyandtheincrement(radiationpower)in2Dungatedquantumelectrongasaremuchhigherthanthatin2Dgatedquantumelectrongas.Thequantumeffectsalwaysenhancetheradiationpowerandenlargetheregionofinstabilityinbothcases.Thisallowsustoconcludethat2Dquantumelectrongasinthetransistorchannelisimportantfortheemissionanddetectionprocessandbothgatedandungatedpartstakepartinthatprocess.
简介:Synchronousoutputofonebeamline’stwomegawatthotcathodebucketionsourcesisrequiredwhenNeutralBeamInjector(NBI)worksontheExperimentalAdvancedSuperconductingTokamak(EAST).NeutralBeamInjectorControlSystem(NBICS)realizessynchronousoutputandasynchronousoutputoftwoionsourceswithnetworkcommunicationandhardwaretriggers.Andthesynchronoustimecanbesetbyoperator.Insynchronousmode,twomegawatthotcathodebucketionsourcescanproduceneutralbeamsatanyrelativetimewithhigherenergythantwosources’asynchronousoutput.Twomegawatthotcathodebucketionsources’synchronousoutputmakesanimportantcontributiontoNBIsystemof4-8MWwith10-100spulselengthandprovidesmoreandbetterparametersforEASTphysicalexperiments.
简介:Atwo-dimensionalhybridcodeisdevelopedtomodelthetransportofahigh-currentelectronbeaminadenseplasmatarget.Thebeamelectronsaretreatedasparticlesanddescribedbyparticle-in-cellsimulationincludingcollisionswiththetargetplasmaparticles.Thebackgroundtargetplasmaisassumedtobeastationaryfluidwithtemperaturevariations.Thereturncurrentandtheself-generatedelectricandmagneticfieldsareobtainedbycombiningAmpere’slawwithoutthedisplacementcurrent,theresistiveOhm’slawandFaraday’slaw.Theequationsaresolvedintwo-dimensionalcylindricalgeometrywithrotationalsymmetryonaregulargrid,withcenteredspatialdifferencingandfirst-orderimplicittimedifferencing.Thealgorithmsimplementedinthecodearedescribed,andanumericalexperimentisperformedforanelectronbeamwithMaxwelliandistributionejectedintoauniformdeuterium-tritiumplasmatarget.
简介:Inthispaper,aone-dimensionparticle-in-cell(PIC)code(EDIPIC)isemployedtosimulatetheparallel-plateionextractionprocessunderanexternallyappliedelectrostaticfield,focusingontheanalysisoftheinflueneeoftheinitialelectrontemperatureontheextractedionfluxestothemetalplatesduringtheionextractionprocess.Comparedwithpreviouslypublishedresults,theplasmaoscillationsonatimescaleoftheelectronplasmaperiod,andtheexcitationoftheionacousticrarefactionwavesresultingfromtheplasmaoscillationsoriginatingfromboththenegativeandpositiveelectrodes,arestudiedforthefirsttime.Themodelingresultsshowthatboththenegativeandpositiveextractorscancollectionsduetotheplasmaoscillationsandthepropagationoftheionacousticrarefactionwaves.Withtheincreaseoftheinitialelectrontemperatureachievedbykeepingotherparametersunchanged,ontheonehand,boththeionspeedandfluxtothenegativeandpositiveplatesincrease,whichleadstoasignificantdecreaseoftheionextractiontime,whileontheotherhand,theionfluxtothepositiveplateaftertheformationofaChild-Langmuirsheathismuchmoresensitivetoanincreaseoftheinitialelectrontemperaturethanthattothenegativeplate.ThePICsimulationresultsprovideadeeperphysicalunderstandingoftheinfluenceoftheinitialelectrontemperatureonthecharacteristicsoftheentireionextractionprocessinadecayingplasma.
简介:Interactionbetweenhigh-intensitypulsedionbeam(HIPIB)andadouble-layertargetwithtitaniumfilmontopofaluminumsubstratewassimulated.Thetwo-dimensionalnonlinearthermalconductionequations,withthedepositedenergyinthetargettakenassourceterm,werederivedandsolvedbyfinitedifferentialmethod.Asaresult,thetwo-dimensionalspatialandtemporalevolutionprofilesoftemperaturewereobtainedforatitanium/aluminumdouble-layertargetirradiatedbyapulseofHIPIB.Theeffectsofionbeamcurrentdensityonthephasestateofthetargetmaterialsnearthefilmandsubstrateinterfacewereanalyzed.BothtitaniumandaluminumweremeltedneartheinterfaceaRerashotwhentheionbeamcurrentdensityfellintherangeof100A/cm~2to200A/cm~2.