US 12,309,909 B2
Magnetoplasmadynamic thruster with reverse polarity and tailored mass flux
Rodney Lane Burton, Northbrook, IL (US); David L. Carroll, Champaign, IL (US); and Joseph William Zimmerman, Champaign, IL (US)
Assigned to CU Aerospace, LLC, Champaign, IL (US)
Filed by CU Aerospace, LLC, Champaign, IL (US)
Filed on Jun. 9, 2023, as Appl. No. 18/332,533.
Claims priority of provisional application 63/350,882, filed on Jun. 10, 2022.
Prior Publication US 2023/0413414 A1, Dec. 21, 2023
Int. Cl. H05H 1/54 (2006.01); B64G 1/40 (2006.01)
CPC H05H 1/54 (2013.01) [B64G 1/413 (2023.08)] 8 Claims
OG exemplary drawing
 
1. An electromagnetic plasma accelerator used as a space thruster operating in a gaseous propellant-injected steady or quasisteady pulse mode comprising:
a cylindrical discharge chamber of length sufficient to contain the discharge, formed by a central metal anode with a high positive voltage, a cylindrical outer cathode at a lower voltage than the anode coaxial with the central electrode,
the cylindrical discharge chamber being closed at one end by an electrical insulator radially between the cylindrical outer cathode and the central electrode, and a gaseous propellant fed axially through ports at different radial locations formed in the electrical insulator, and
wherein the ports are configured to inject more gas closer to the central electrode with a radial distribution of mass flux that approximates the inverse square of a radius 1/r2, and the cylindrical discharge chamber being open at an opposite end to allow an accelerated propellant to exit at high velocity to create thrust, such that the primary direction of current is radially outward, and wherein a magnitude of the current is sufficiently high that the azimuthal magnetic B field created by a radial current combines with the radial current to accelerate an ionized plasma created by the current predominantly by electromagnetic forces in the predominantly axial direction with a smaller component in the outward radial direction.