简介：Energytransmissionefficiencyinthemagneticpulsegeneratorsvarieswithsaturatedtimeofmagneticswitch.Anoptimalmatchingtimeexistsanddependsonthecompressionratio,underwhich,theenergytransmissionefficiencycanreachapproximate100%.Theequationofrequiredmagneticcorevolumeisobtainedbytakenintoaccounttheoptimalmatchingmode.Itindicatesthatagreatreductiononthevolumeisfeasibleundertheoptimalmatchingmode.Thecircuitsimulationcode-PSPICEisalsointroducedtosimulatea3-stagemagneticpulsecompressor,andtheresultsareinaccordancewiththoseofequivalentcircuitanalyses.

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简介：MotivatedbyITER(theInternationalThermonuclearExperimentalReactor),researchonamagneticshieldagainstastrongfieldhasbeencarriedout.Inthispaper,acylindricmagneticshieldisstudiedbyusingthefiniteelementmethodwithanonlinearmagnetizationcurve.Thegeometricalaspectsofshieldingperformanceareidentifiedandcorrespondingsuggestionsforapplicationareprovided.Amongthem,theeffectsoftheedgeandcoverthicknesshavenotbeenmentionedelsewheretoourknowledge.

简介：Theglidingarccanofferhighenergyefficiencyandselectivityforchemicalreactionsandhasbeenwidelyappliedinmaterialprocessing,environmentalprotectionandotherindustrialareas.Butthedischargeproperties,measurementofplasmaparametersandrelatedphysicalpro-cessesoftheglidingarcdischargestillneedtofurtherstudied.Inthisstudy,theglidingarcwasdrivenbythetransversemagneticfieldtoproducethenon-equilibriumplasmaathighpressure.Theparametersoftheplasmaatourobservedpointweremeasuredbyopticalmethods.Theexperimentalresultshowsthattheelectrontemperatureisabout0.6eVandtheheavyparticletemperatureisapproximately2987±250K.

简介：Non-lineardevelopmentofdoubletearingmodesinducedbyelectronviscosityisnumericallysimulated.MHDflowlayersaredemonstratedtomergeinthedevelopmentofthemodes.Theshearedflowsareshowntoliejustattheboundariesofthemagneticislands,andtohavesuffcientlevelsrequiredforinternaltransportbarrier(ITB)formation.PossiblecorrelationbetweenthelayerformationandtriggeringofexperimentallyobservedITBs,preferentiallyformedinproximitiesofrationalfluxsurfacesoflowsafetyfactors,isdiscussed.

简介：Inthiswork,laserinducedtungstenplasmahasbeeninvestigatedintheabsenceandpresenceof0.6Tstatictransversemagneticfieldatatmosphericpressureinair.Thespectroscopiccharacterizationoflaserinducedtungstenplasmawasexperimentallystudiedusingspace-resolvedemissionspectroscopy.Theatomicemissionlinesoftungstenshowedasignificantenhancementinthepresenceofamagneticfield,whiletheionicemissionlinesoftungstenpresentedlittlechange.Temporalvariationoftheopticalemissionlinesoftungstenindicatedthattheatomicemissiontimeinthepresenceofamagneticfieldwaslongerthanthatintheabsenceofamagneticfield,whilenosignificantchangesoccurredfortheionicemissiontime.Thespatialresolutionofopticalemissionlinesoftungstendemonstratedthatthespatialdistributionofatomsandionswereseparated.Theinfluenceofamagneticfieldonthespatialdistributionofatomswasremarkable,whereasthespatialdistributionofionswaslittleinfluencedbythemagneticfield.Thedifferentbehaviorsbetweenionsandatomswithandwithoutmagneticfieldinairwererelatedtothevariousatomicprocessesespeciallytheelectronsandionsrecombinationprocessduringtheplasmaexpansionandcoolingprocess.

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简介：ARogowskicoilisdevelopedtodetectthenanosecondpulsesignalsofthedischargecurrentwithawidebandwidthof800kHzto106MHzandhighsensitivityof2.22V/A.Perfor-mancetestsshowthattheRogowskicoilhasbothexcellentdynamicandstaticcharacteristics.CalibratingresultsandthecomparisonbetweenthestandardcurrentshuntandthedevelopedRo-gowskicoilforthemeasurementofnanoseconddischargepulsesdemonstratethatthedevelopedRogowskicoilcanreproducetheactualwaveformofthedischargecurrentaccurately.

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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.

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简介：Non-contactmagneticmeasurementmethodisaneffectivewaytostudytheairarcbehaviorexperimentally.Oneofthecrucialtechniquesistosolveaninverseproblemfortheelectromagneticfield.Thisstudyisdevotedtoinvestigatingdifferentalgorithmsforthiskindofinverseproblempreliminarily,includingthepreconditionedconjugategradientmethod,penaltyfunctionmethodandgeneticalgorithm.Thefeasibilityofeachalgorithmisanalyzed.Itisshownthatthepreconditionedconjugategradientmethodisvalidonlyforfewarcsegments,theestimationaccuracyofthepenaltyfunctionmethodisdependentontheinitialconditions,andtheconvergenceofgeneticalgorithmshouldbestudiedfurtherformoresegmentsinanarccurrent.

简介：ThesolutionofGrad-Shafranovequationdeterminesthestationarybehavioroffusionplasmainsideatokamak.Tosolvetheequationitisnecessarytoknowthetoroidalcurrentdensityprofile.Recentworksshowthatitispossibletodetermineamagnetohydrodynamic(MHD)equilibriumwithreversedcurrentdensity(RCD)profilesthatpresentsmagneticislands.InthisworkweshowanalyticalMHDequilibriumwithaRCDprofileandanalyzethestructureofthevacuumvectorpotentialassociatedwiththeseequilibriausingthevirtualcasingprinciple.

简介：Thecurrentsheathvelocityin0.25TorrgaspressureofFilippovtypeplasmafocusisstudiedexperimentally.Byusingtwotridimensionalmagneticprobesontopoftheanodesurface,thecurrentsheathvelocityismeasuredforargon,oxygenandnitrogen.Additionally,theeffectofchargingvoltageonthecurrentsheathvelocityisstudiedinbothaxialandradialphases.Wefoundthat,themaximumcurrentsheathvelocitiesatbothradialandaxialphasesarerespectively4.33±0.28(cm/μs)and3.92±0.75(cm/μs)withargonastheworkinggasat17kV.Also,theminimumvaluesofcurrentsheathvelocityare1.48±0.15(cm/μs)attheradialphaseand1.14±0.09(cm/μs)attheaxialphasewithoxygenat12kV.Thecurrentsheathvelocityattheradialphaseishigherthanthatattheaxialphaseforallgasesandvoltages.Inthisstudy,variationofthefullwidthhalfmaximum(FWHM)ofmagneticprobesignalswithvoltageisinvestigatedfordifferentgasesatradialandaxialphases.

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简介：Magneticspectrumoftheelectromagneticioncyclotronwavesintheterrestrialplasmadepletionlayer（PDL）aresometimesobservedtohaveaBIF（bifurcated）signature,whereadiminutionaround0.5ΩpwithΩptheprotongyrofrequency,occursbetweentwoactivitypeaksinthespectrum.Byone-dimensionalhybridsimulations,theeffectofrelativedriftvelocitiesbetweenprotonsandHe2+onthemagneticspectralsignaturesinthePDLisstudied.Theresultsshowthattherelativedriftvelocityenhancesthedevelopmentofprotoncyclotronwavesanddeclinesthedevelopmentofheliumcyclotronwaves.Theprotoncyclotronwavesarefirstlyexcited,andfollowedbytheexcitationofheliumcyclotronwavesduetotheincreaseintherelativedriftvelocity.Moreover,theboundarybetweentwoactivitypeaksgetsobscure.

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