Abstract: Thedischargeprocess〖JP+2〗andperformancecharacterizationofaplanarablationmicropulsedplasmathruster(〖WT〗μ〖WTF2〗PPT) 〖HJ5.5p〗 wereinvestigated.Basedontheelectricalmeasurementsofthedischargeprocessandopticalbehavioroftheplasmaregion,thebasicdischargecharacteristicsandtheevolutionofthedischargepatternofμPPTwerestudied.Fromthespatialpattern,μPPTdischargegapcanbedividedintothreeregions(cathoderegion,arccolumnregionandanoderegion);withthedischargegapdecreasing,theanodeareagraduallydisappears.Fromthetemporalbehavior,μPPTiscomposedofseveralpulsedischargeswithdifferentamplitude.Thenumberofdischargepulsesisdeterminedbytheimpedancedetailofthedischargecircuitanddischargegap.Singlepulsedischargecanoccurundersuitableconditions.BasedonthecurrentsheetmodeloftheμPPTplasmaregion,thebasicperformanceparameterssuchasimpulsebitandspecificimpulseofμPPTwereestimated.TheresultsshowthatthedischargegapandablationvolumehaveanimportanteffectontheμPPTperformanceparameters.Withsamedischargeenergypulse,thelargerthegapis,thelargertheimpulsebitis,leadingtolargerablationamountandsmallerspecificimpulse.DischargetimespacemorphologyisthekeyfactorthataffectstheimpulsebitandspecificimpulseofμPPT.Therefore,itisaneffectivewaytoimprovetheμPPTperformancebystudyingtheoptimizationofdischargecircuitanddischargegapimpedance.

Key words: micropulsedplasmathruster, electricalcharacteristics, opticalproperties, performanceprediction, microelectricpropulsion