Dual stage 4 grid ion propulsion
The Dual-Stage 4-Grid (DS4G ion propulsion, English dual-stage four-grid ion thruster ) is one of the European Space Agency (ESA) and the Australian National University developed (ANU) ion engine principle.
Prototypes can generate an ion beam that is four times faster than the most powerful ion thrusters to date, without damaging the electrodes as before. Compared to the ion engine of the SMART-1 lunar probe , the engine accelerates the emerging ions to over ten times the speed (210 km / s).
principle
Problems that would otherwise arise with increasing acceleration voltage are avoided in that the ion beam is accelerated in two stages ( dual stage ) using four electrodes ( 4 grid ).
The principle is already known from fusion experiments in which fast hydrogen jets (1 MeV) are required.
First, as with the two- or three-electrode thruster, ions are extracted from the ion source with two grids. They then already have a high speed, which is limited to energies <5 keV in order to avoid beam divergence and electrode erosion. This is followed by post-acceleration of the beam with 15 to 30 kV and a customary fourth electrode (braking grid).
As with previous ion thrusters, the noble gas xenon was used as the ionizable support mass .
Results
The arrangement increases performance and power density. A specific impulse of 15,000 s was achieved in the prototype (limit of 3-electrode drives is 10,000 s).
See also
further reading
- C. Bramanti, R. Walker, et al. a .: The innovative dual-stage 4-grid ion thruster concept - Theory and experimental results. (PDF; 548 kB) International Astronautical Federation, IAC-06-C4.4.7, 2006.
Web links
- Federal Ministry of Education and Research : ESA and Australian team achieve breakthrough in space propulsion. January 23, 2006, archived from the original on January 27, 2016 ; accessed on October 9, 2018 .
Individual evidence
- ↑ Super-powerful new ion engine revealed . In: New Scientist . ( newscientist.com [accessed October 9, 2018]).