Publication Date:
2019-07-13
Description:
Voltage fluctuations in a multi-megawatt quasi-steady MPD accelerator, indicative of increased ablation and a consequent degradation in performance, are found to exist only over a narrow range of currents, above which the ablation continues. Within this range, the discharge is characterized by a thin cylindrical shell, 4.0 cm in diameter, concentric with the cathode surface, containing steep radial gradients in plasma luminosity, number density, current density, electric field and Hall parameter, and within which a significant fraction of the propellant is first ionized. Experiments have shown that this cylindrical shell can be totally eliminated by immersing a small object at critical locations within it, thereby increasing the local mass density by preferential ablation and suggesting further means of improving the accelerator design.
Keywords:
SPACECRAFT PROPULSION AND POWER
Type:
AIAA PAPER 78-653
,
International Electric Propulsion Conference; Apr 25, 1978 - Apr 27, 1978; San Diego, CA; US
Format:
text
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