Ionopticsisacriticalcomponentofionthrusters.Atwo-dimensionalaxisymmetricmodelisdevelopedtostudythecharacteristicsofthree-gridelectroncyclotronresonanceionthrusteroptics.Thecodeisbasedonaparticle-in-cellcombinedwiththeMonteCarlocollisionmethodtosimulateiondynamicsandcharge-exchangeprocessesinthegridregion.Thesimulationresultsshowthatthemodecangiveareasonableestimateofthephysicscharacteristicsoftheionoptics.Thedesignoftheionopticssatisfiestherequirementofpreventingelectronbackstreaming.Charge-exchangeionscancausedamagetothegrids,especiallytotheacceleratorgrid.'Barrel'erosioncanincreasetheacceleratorgridapertureradiusatarateof1.91×10~(-11)m/s,whilethedeceleratorgridplaysanimportantroleinreducing'pits-and-grooves'erosion.
