A magnetically-nozzled, quasi-steady, multimegawatt, coaxial plasma thruster

• Published in: IEEE transactions on plasma science Vol. 22; no. 6; pp. 1015 - 1033
• Main Authors: Scheuer, J.T., Schoenberg, K.F., Gerwin, R.A., Hoyt, R.P., Henins, I., Black, D.C., Mayo, R.M., Moses, R.W.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.12.1994; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Accelerators and propulsion; ADVANCED PROPULSION SYSTEMS; ANALYTICAL SOLUTION; Coaxial components; DATA; Data analysis; Deuterium; ELECTRIC DISCHARGES; Engines; Exact sciences and technology; EXPERIMENTAL DATA; INFORMATION; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Ion and plasma propulsion; Magnetic analysis; Magnetic field measurement; Magnetohydrodynamics; MATHEMATICAL MODELS; NUMERICAL DATA NESDPS Office of Nuclear Energy Space and Defense Power Systems 330000 > Advanced Propulsion Systems; OPERATION; Physics; Physics of gases, plasmas and electric discharges; Physics of plasmas and electric discharges; Plasma devices; Plasma measurements; Plasma temperature; Propellants; PROPULSION SYSTEMS; SPACE FLIGHT; Spaceborne and space research instruments, apparatus and components (satellites, space vehicles, etc.); TEST FACILITIES; THRUSTERS; Steady-state conditions; Space propulsion reactors; Magnetohydrodynamics; Plasma devices; Experimental study; Performance
• ISSN: 0093-3813; 1939-9375
• DOI: 10.1109/27.370254

The Los Alamos National Laboratory Coaxial Thruster Experiment (CTX) has been upgraded to enable 10 ms quasi-steady-state (QSS) operation of magnetohydrodynamic type thrusters at power levels from 1 to 40 MW. Here we report on experimental observations and associated analysis for QSS discharges using deuterium, helium, and argon propellants. Measurements of thruster current and voltage, magnetic field fluctuations, electron density and temperature, and plasma potential indicate true quasi-steady operation over 10 ms with propellant exhaust velocities of 1-2/spl times/10/sup 5/ m/s in helium and deuterium. The application of unique applied magnetic nozzle configurations result in a substantial reduction of the measured anode fall potential. Data analysis and analytical MHD modeling imply an impulsive start in the propellant flow that is limited to the Alfven critical ionization velocity and the presence of an effective constriction or "nozzling" in the how channel. This research indicates that efficiency optimization of MHD class thrusters will most likely occur at megawatt power levels. This implies repetitively pulsed, high-power operation for near term, low-mean-power solar electric propulsion missions.< >