简介：SawtoothcontrolexperimentswereperformedonHT-7withalimiterconfigurationandontheExperimentalAdvancedSuperconductingTokamak(EAST)withadoublenullcon-figuration.Thesawtoothperiodcanbemodifiedbylowerhybridwave(LHW)andioncyclotronresonancefrequency(ICRF).Differentsawtoothbehaviorwasobservedwiththesameplasmadensity,LHWpowerbutdifferentplasmacurrentsonHT-7.TherewasadwelltimebetweenLHWaddedandthesawtoothstabilizationonHT-7whilethesawtoothstabilizationimmediatelyhappenedwhenLHWpowerwasinjectedonEAST.Thepossiblemechanismofthesawtoothcontrolisdiscussedinthispaper.Alltheexperimentalresultshaveprovedthatpowerdepositionoftheradiofrequency(RF)shouldbethekeyfactorforsawtoothcontrol.

简介：Anexperimentalinvestigationonairfoil(NACA64-215)shockcontrolisperformedbyplasmaaerodynamicactuationinasupersonictunnel(Ma=2).Theresultsofschlierenandpressuremeasurementshowthatwhenplasmaaerodynamicactuationisapplied,thepositionmovesforwardandtheintensityofshockattheheadoftheairfoilweakens.Withtheincreaseinactuatingvoltage,thetotalpressuremeasuredattheheadoftheairfoilincreases,whichmeansthattheshockintensitydecreasesandthecontrolefectincreases.Thebestactuationefectiscausedbyupwind-directionactuationwithamagneticfield,andthendownwind-directionactuationwithamagneticfield,whilethecontrolefectofaerodynamicactuationwithoutamagneticfieldisthemostinconspicuous.Themeanintensityofthenormalshockattheheadoftheairfoilisrelativelydecreasedby16.33%,andthenormalshockintensityisrelativelyreducedby27.5%when1000Vactuatingvoltageandupwind-directionactuationareappliedwithamagneticfield.ThispapertheoreticallyanalyzestheJouleheatingefectgeneratedbyDCdischargeandtheLorentzforceefectcausedbythemagneticfield.Thedischargecharacteristicsarecomparedforallkindsofactuationconditionstorevealthemechanismofshockcontrolbyplasmaaerodynamicactuation.

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简介：Duty-cyclemodulationalternatelyblowingfromtwoopposite-facingplasmaactuatorsontheleewardsurfaceneartheapexofaconewitha10semi-apexangleisadoptedtocontrolmeanlateralforceandmoment,andtheflowcontrolmechanismsarepresented.Pressuredistributionsovertheforebodyoftheconearemeasuredbysteadypressuretappings.Theexperimentsareperformedina3.0×1.6mopen-circuitwindtunnelatawindspeedof20m/s,a45angleofattackandaReynoldsnumberof2×105,basedonthediameterofthebaseofthecone.Almostlinearlyproportionalcontrolofthelateralforcesandmomentsoveraslenderconicalforebodyatahighangleofattackhasbeendemonstratedbyemployingapairofsingledielectricbarrierdischargeplasmaactuatorsneartheapexofthecone,combinedwithaduty-cycletechnique.Thepressuredistributionmeasurementsindicatethatthebi-stablevortexpatternappearstobeshiftedintheoppositedirectionwhentheportorstarboardactuatorisactivated,whiletheotheriskeptoffduringthetest.Itisshownthatthereducedpulse-repetitionfrequencybasedonthelocaldiameterattheplasmaactuatorequaltooneyieldsthehighesteffectivenessamongthecasesconsidered.

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简介：Synchronousoutputofonebeamline’stwomegawatthotcathodebucketionsourcesisrequiredwhenNeutralBeamInjector(NBI)worksontheExperimentalAdvancedSuperconductingTokamak(EAST).NeutralBeamInjectorControlSystem(NBICS)realizessynchronousoutputandasynchronousoutputoftwoionsourceswithnetworkcommunicationandhardwaretriggers.Andthesynchronoustimecanbesetbyoperator.Insynchronousmode,twomegawatthotcathodebucketionsourcescanproduceneutralbeamsatanyrelativetimewithhigherenergythantwosources’asynchronousoutput.Twomegawatthotcathodebucketionsources’synchronousoutputmakesanimportantcontributiontoNBIsystemof4-8MWwith10-100spulselengthandprovidesmoreandbetterparametersforEASTphysicalexperiments.

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简介：TheprecisionofplasmaelectrondensityandFaradayrotationanglemeasurementisakeyindicatorforfar-infraredlaserinterferometer/polarimeterplasmadiagnosis.Toimprovetheprecision,anewmulti-channelhighsignal-to-noiseratioHCOOHinterferometer/polarimeterhasbeendevelopedontheHL-2Atokamak.Ithasahigherlevelrequirementforphasedemodulationprecision.Thispaperintroducesanimprovedreal-timefastFouriertransformalgorithmbasedonthefieldprogrammablegatearray,whichsignificantlyimprovestheprecision.Wealsoapplyareal-timeerrormonitoringmodule(REMM)andastableerrorinhibitingmodule(SEIM)forprecisioncontroltodealwiththeweaksignal.Wetesttheinterferometer/polarimetersystemwiththisimprovedprecisioncontrolmethodinplasmadischargeexperimentsandsimulationexperiments.Theexperimentalresultsconfirmthattheplasmaelectrondensityprecisionisbetterthan1/3600fringeandtheFaradayrotationanglemeasurementprecisionisbetterthan1/900fringe,whilethetemporalresolutionis80ns.ThisperformancecanfullymeettherequirementsofHL-2A.

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

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简介：Thesurfacedielectricbarrierdischarge(SDBD)plasmaactuatorhasshowngreatpromiseasanaerodynamicflowcontroldevice.Inthispaper,theencapsulatedelectrodewidthofaSDBDactuatorischangedtostudytheairflowaccelerationbehavior.Theeffectsofencapsulatedelectrodewidthontheactuatorperformanceareexperimentallyinvestigatedbymeasuringthedielectriclayersurfacepotential,time-averagedionicwindvelocityandthrustforce.Experimentalresultsshowthattheairflowvelocityandthrustforceincreasewiththeencapsulatedelectrodewidth.Theresultscanbeattributedtothedistinctplasmadistributionatdifferentencapsulatedelectrodewidths.

简介：Theq-profilecontrolproblemintheramp-upphaseofplasmadischargesisconsid-eredinthiswork.Themagneticdiffusionpartialdifferentialequation(PDE)modelsthedynamicsofthepoloidalmagneticfluxprofile,whichisusedinthisworktoformulateaPDE-constrainedop-timizationproblemunderaquasi-staticassumption.Theminimumsurfacetheoryandconstrainednumericoptimizationarethenappliedtoachievesuboptimalsolutions.Sincethetransientdy-namicsispre-givenbytheminimumsurfacetheory,thenthismethodcandramaticallyacceleratethesolutionprocess.Inordertoberobustunderexternaluncertaintiesinrealimplementations,PID(proportional-integral-derivative)controllersareusedtoforcetheactuatorstofollowthecomputationalinputtrajectories.Ithasthepotentialtoimplementinreal-timeforlongtimedischargesbycombiningthismethodwiththemagneticequilibriumupdate.