简介：Radiationsimulationutilizingplasmaradiationsources(PRS)generatesalargenumberofundesirabledebris,whichmaydamagetheexpensivediagnosingdetectors.Anultrafastshutter(UFS)drivenbypulsedhighcurrentcanerectaphysicalbarriertotheslowlymovingdebrisafterallowingthepassageofX-rayphotons.TheUFSconsistsofapairofthinmetalfoilstwistingtheparallelaxesinaNyloncassette,compressedwithanoutermagneticfield,generatedfromafastcapacitorbank,dischargingintoasingleturnloop.Atypicalcapacitorbankisof7.5μFchargingvoltagesvaryingfrom30kVto45kV,withcorrespondingcurrentsofapproximately90kAto140kAanddischargingcurrentperiodsofapproximately13.1μs.Ashutterclosingtimeasfastas38microsecondshasbeenobtainedwithanaluminiumfoilthicknessof100micrometersandacross-sectionalareaof15mmby20mm.Thedesign,constructionandtheexpressionsofthevalve-closingtimeoftheUFSarepresentedalongwiththemeasuredresultsofvalve-closingvelocities.

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

简介：Generationofzonalflowsbysmall-scaledrift-Alfvenmodesisinvestigatedbyadoptingtheapproachofparametricinstabilitywiththeelectronpolarizationdriftincluded.Thezonalmodecanbeexcitedbyprimarymodespropagatingatbothelectronandiondiamagneticdriftdirectionsincontrasttotheassertioninpreviousstudiesthatonlyprimarymodespropagatingintheiondiamagneticdriftdirectionscandrivezonalinstabilities.Generally,thegrowthrateofthedrivenzonalmodeisinthesameorderasthatinpreviousstudy.However,differentfromthepreviouswork,thegrowthrateisnolongerproportionaltothedifferencebetweenthediamagneticdriftfrequenciesofelectronsandions.

简介：Basedontheprinciplethatone-endedelectromagneticsurfacewavecandriveaplasmaantenna,therelationbetweentheeffectivelengthofanantennacolumnandtheappliedradiofrequency(RF)powerwasstudiedboththeoreticallyandexperimentally.Thedensitydistributionalongthcantennacolumnaswellastheelectrontemperatureindifferentconditionswereinvestigated.Thecharacteristicsofthereceptionoflocalfrequencymodulated(FM)electromagneticwavebytheplasmaantennawerecomparedwiththatbyacopperantennawithsamedimensions.Theresultsshowthatitisfeasibletotakeplasmaantennasasreceivingones.更多还原

简介：Atypeofelectricaldischargecalledslidingdischargewasdevelopedtogenerateplasmaaerodynamicactuationforflowcontrol.Athree-electrodeplasmasheetactuatordrivenbyrepetitivenanosecondpulseswithanegativeDCcomponentwasusedtogenerateslidingdischarge,whichcanbecallednanosecond-pulseslidingdischarge.Thephenomenologyandbehaviouroftheplasmasheetactuatorwereinvestigatedexperimentally.Dischargemorphologyshowsthattheformationofnanosecond-pulseslidingdischargeisdependentonthepeakvalueoftherepetitivenanosecondpulsesandnegativeDCcomponentappliedontheplasmasheetactuator.Comparedtodielectricbarrierdischarge(DBD),theextensionofplasmainnanosecond-pulseslidingdischargeisquasi-diffusive,stable,longerandmoreintensive.TestresultsofparticleimagevelocimetrydemonstratethatthenegativeDCcomponentappliedtoathirdelectrodecouldsignificantlymodifythetopologyoftheflowinducedbynanosecond-pulseDBD.Bodyforceinducedbythenanosecond-pulseslidingdischargecanbeapproximatelyintheorderofmN.BoththemaximumvelocityandthebodyforceinducedbyslidingdischargeincreasesignificantlyascomparedtosingleDBD.Therefore,nanosecond-pulseslidingdischargeisapreferableplasmaaerodynamicactuationgenerationmode,whichisverypromisinginthefieldofaerodynamics.

简介：Wedevelopedaone-dimensionalhybridmodeltosimulatetheDC/RFcombineddrivencapacitivelycoupledplasmaforargondischarges.ThenumericalresultsareusedtoanalyzetheinfluenceoftheDCsourceontheplasmadensitydistribution,ionenergydistributions(IEDs)andionangledistributions(IADs)onboththeRFandDCelectrodes.TheincreaseinDCvoltagedrivesmorehigh-energyionstotheelectrodeappliedtotheDCsource,whichmakestheIEDsattheDCelectrodeshifttowardshigherenergy,andthepeaksintheIADsshifttowardssmallangleregions.Atthesametime,italsodecreasestheionenergyattheRFelectrodeandenlargestheincidentanglesoftheions,whichstriketheRFelectrode.