The highly efficient multistage plasma (HEMP) thruster, a new electric propulsion concept derived from tube technology

In this paper, a new Thales Electron Devices GmbH (TEDG) patented thruster concept is presented, which was successfully investigated. The results showed, that the concept advances the electric propulsion (EP) capabilities by relying on plasma confinement with the means of PPM structures used in TWTs to focus electron beams through delay lines and multistage depressed collectors (MDC). The performance improvements obtained recently are summarised. The total efficiency shown is the product of electrical and the ionisation efficiency. The ionisation efficiency approaches values close to 1 for higher Xe flows. For DM6 MS1 version, this is the case at Xe flows above 10 sccm, resulting at 14 sccm in a total efficiency of about 50%.