Magnetoplasmadynamic Thrusters
Computer generated image of the thruster
Magnetoplasmadynamic thrusters, or MPDs, are also used by the military. A central conducting bar, in a box like configuration, allows a current to run across it creating an azimuthal magnetic field. This in turn meshes with the current that runs from the point of bar to the wall. The force is called a Lorentz force and creates a pumping inward force constricting the flow and a force along the main axis, the pushing force. This funnels and produces directional thrust.
Mass density of directional thrust
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