Composition of the beam of an SPT-100 stationary plasma thruster

Measurements of the particle-charge composition in a plasma jet of an SPT-100 stationary plasma thruster during its operation on xenon in the range of discharge voltages 150–750 V have been performed with an MX-7303 mass spectrometer. The measured angular distributions of singly, doubly, and triply charged xenon ions over the beam cross section and their energy spectra are presented. The changes in the beam composition due to its interaction with neutral xenon atoms during its transport to the measurement point are estimated.