| 摘要 |
An arcjet thruster comprises a cathode body and anode body tandemly arranged and separated by an insulative propellant injection ring. The cathode body has a cathode cavity therein having a convergent and a divergent portion forming a throat therebetween. The anode body has a divergent cavity therein for producing thrust. The divergent cavity has an upstream portion and a downstream portion. The divergent portion of the cathode and the upstream portion of the anode cavity form a constrictor. A power supply connected between the anode and the cathode bodies is used to produce an arc between the anode and cathode that passes through the constrictor. Propellant is injected in a vortex flow radially into the constrictor so that it divides. A portion of the flow is directed upstream through the throat into the convergent portion of the cathode cavity thus also pushing the cathode arc attachment point into the convergent portion to cause diffuse attachment thereof. The other portion of the propellant pushes the downstream end of the arc into the divergent portion of the anode cavity to cause diffuse attachment of the arc. Thus the vortex flow of the propellant into the constrictor causes diffuse attachment of both the cathode and anode foot attachments which in turn minimizes cathode erosion and lengthens effective arcjet lifetime.
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