Magnetic field oscillating amplified thruster
The magnetic field oscillating amplified thruster (MOA; often named as plasma engine by the media) is a versatile electrothermodynamic system, which is able to accelerate nearly every electrically charged gaseous medium (plasma application) to extremely high velocities, thereby generating a high energetic plasma jet in the exhaust and also electrical conductive fluids (hydrodynamic application) in general.
To do so, MOA utilizes a so-called Alfvén wave, a physical principle within magnetohydrodynamics that was described first in 1942 by the later Nobel Prize winner Hannes Alfvén and which states that fluctuating magnetic fields can induce density waves in electric conductive media (e.g., plasma, salty water, etc.). These density waves can reach very high velocities and as the particles inside the medium are coupled to them, the particles are as well accelerated to very high velocities, accordingly reaching very high kinetic energies.
Due to the heating mechanism based on
Application areas
Because of the high exhaust velocities and the associated high
An additional advantage of the MOA concept is its corrosion free behaviour, leading to a long lifetime of the system. The same magnetic fields that generate the Alfvén waves, prohibit high energy particles from hitting the thruster's wall or any other of MOA's structural components, therefore avoiding any particle induced damage almost inherently.
Set-up of the MOA System
Plasma Application
In principle the MOA thruster is composed of five subsystems:
- Plasma generator,
- Central tube,
- Primary coil,
- Secondary coil,
- Supply and control units.
The plasma generator produces a continuous flow of
As the concept requires a plasma generator to produce the ionized particles, MOA can in principle be described as an electric propulsion system, similar to an ion engine. However, because of the interaction of the magnetic fields, the particles are as well compressed and adiabatically heated up, thereby turning the whole system into a electrothermodynamic system. The combination of electric and thermodynamic principles leads also to a unification of the respective advantages. As such MOA features on one hand the high efficiency of the electric propulsion systems and on the other hand the ability to accelerate a high number of particles – just like a thermal system – therefore achieving a relatively high thrust at a high specific impulse. The combination of high particle energy/exhaust velocity and relatively high thrust in this form is a novel proposal. The high flexibility of changing thrust and specific impulse in-flight by adapting massflow and power consumption is at the moment a unique feature provided by this novel thruster concept.
Hydrodynamic Application
In the hydro-dynamic application MOA differs primarily in that the plasma source is no longer required. Fundamentally for its function is the support with an electrical conductive fluid or an electrolyte available from a tank or an environmental reservoir (salty sea water, etc.).
History and Current status
MOA was originally invented and defined by Manfred Hettmer in 1982. He also developed the system from a theoretical model into a practical device after reaching a basic level of own funding by his entrepreneurship in the IT-branche. In the first logical step in 1998 he began coding a
In an expert opinion by Horst Loeb (winner of the
Finally a laboratory at the
The dedicated company called QASAR Technologieentwicklung Ges.m.b.H. (Austrian
After QASAR Technologieentwicklung Ges.m.b.H. was closed at the beginning of 2009 due to internal difficulties with shareholders and investors, Hettmer continued the project largely with its own funds within the given possibilities. The implementation of a commercial application is planned.
See also
References
- ^ "Raumfahrt Concret" 2/2006
External links
- QASAR Technologie(s)
- First filed Patent AT502984 (A1)
- Patent within the esp@cenet of the European Patent Office
- Abstract of the International Astronautical Congress 2005
- Abstract of the International Astronautical Congress 2010
- Acta Astronautica - Volume 63
- Alfvén waves in the Encyclopedia of Mathematics
- Thermal velocities in the plasma of a MOA Device, M.Hettmer, Int J Aeronautics Aerospace Res. 2023;10(1):297-300