Full Performance Mapping of the IFM Nano Thruster, Including Direct Thrust Measurements

The IFM Nano Thruster is a Field Emission Electric Propulsion (FEEP) system using Indium as propellant. The core element of this propulsion technology is a passively fed, porous ion emitter consisting of 28 sharp emitter tips. Using differential biasing of the emitter and extractor electrodes, the IFM Nano Thruster can operate over a wide range of specific impulse from 2000 to 6000 s and beyond. At a total input power of 40 W, including heater for propellant liquefaction and neutralization to maintain neutral spacecraft potential, the IFM Nano Thruster can provide up to 350 μN. This work presents a test campaign conducted at the ESA Propulsion Laboratory (EPL), located at ESA ESTEC. Direct thrust measurements obtained on two thrusters are compared to analytical thrust models. Full performance envelope mapping, including direct thrust measurements, were performed for both thrusters, and a comparison to modelled performance envelope is presented herein, including a discussion of the major emitter parameters concerning their impact on the performance envelope.