简介:ThisstudypresentstheLangmuirandFaradayprobemeasurementsconductedtodeterminetheplumecharacteristicsoftheBUSTLabmicrowaveelectrothermalthruster(MET).Thethruster,designedtooperateat2.45GHzfrequency,isrunwithhelium,argonandnitrogengasesasthepropellant.Forthemeasurements,thepropellantvolumeflowrateandthedeliveredmicrowavepowerlevelsarevaried.Experimentswithnitrogengasrevealedcertainoperationregimeswhereaveryluminousplumeisobserved.Withtheuseofin-house-builtLangmuirprobesandaFaradayprobewithguardring,thrusterplumeelectrontemperature,plasmadensityandioncurrentdensityvaluesaremeasured,andtheresultsarepresented.ThemeasurementsshowthatMETthrusterplumeeffectsonspacecraftwilllikelybesimilartothoseofthearcjetplume.Itisobservedthatthemeasuredplumeionfluxlevelsareverylowforthehighvolumeflowratesusedfortheoperationofthisthruster.