High Precision Beam Diagnostics for Ion Thrusters

The Thales diagnostic equipment for ion beam characterization consists of a gridded and single orifice retarding potential analyzer (RPA) and an energy selective mass spectrometer (ESMS). During the development phase of these sensors considerable effort was put into the removal of ion optical effects as well as to ensure equal ion transmission ratios for low and high energetic ions for both devices. To this end simulation software was used to look into the trajectories of ions from a wide range of potential energy, angle of incidence and charge state. The simulations verified effects due to RPA grid misalignment and were the foundation for the development of a single orifice RPA and the adaptation of the ESMS. Experimental testing verified the improved performance of the sensory equipment due to ion trajectory simulation.