Abstract: Amodelingstudywasperformedtoinvestigatetheworkingprocessofacoaxialmicrocathodearcthrusterwithparticleincell(PIC)method,andtheselfsimilarmethodwasappliedtosimplifythesimulationmodel.Thedistributionofelectronnumberdensity,ionnumberdensity,electricpotentialandaxialaverageionvelocityinthethrusterplumeregionwasobtained.Theinfluencesofmagneticfieldonplasmamotioncharacteristicsandthrusterperformancewerestudiedbychangingmagneticfluxdensityandmagneticfieldtopology.Theresultsshowthatelectronsareconstrainedbytheappliedmagneticfield,cyclingaroundmagneticfieldlines,andthationsareacceleratedbytheambipolardiffusionelectricfieldproducedbyslowerionsandfasterelectrons.Withthesamemassflowrate,theionrefluxisseverewhenthemagneticfluxdensityis002T,whiletheionvelocityislessaffectedbythemagneticfluxdensitywhenthemagneticfluxdensityis005~030T.Magneticfieldtopologyhasgreatinfluenceontheionmotionandthrusterperformance.Theionvelocitydecreasesobviouslywhentheanglebetweentheaxisandmagneticfieldlinesissmall,whiletheionrefluxisseverewhentheangleislarge.

Key words: coaxialmicrocathodearcthruster, particleincell, selfsimilarity, magneticfluxdensity, magneticfieldtopology