New 2d Far Field Beam Scanning Device at DLR's Electric Propulsion Test Facility

Abstract

DLR’s electric propulsion test facility has a large vacuum chamber of 12m length. This size enables plasma plume measurements at a longer than usual distance, e.g. beyond 5m, compared to the usual distance of 0.5-1m. The beam shape at such long distances is of importance for spacecraft interaction and for a space debris removal technique that is based on momentum transfer by ion beams. In designing such a system we selected an x-y scanner working in a flat plane. Movements of the scanner, and data acquisition are controlled by a computer. The systems is intended for beam profiling of gridded ion thrusters in the first place, because these usually have a narrow beam with low divergence. On the other hand, as the system is not fixed to the vacuum chamber, measurements could also be taken closer to the thruster. This paper presents the new system for 2d beam scanning in the far field of electric propulsion thrusters.