Patent ID: 8080930

Claim:
A method for regenerating a field-emission cathode for an electronic propulsion system, the method comprising: providing an electric propulsion system including a field-emission cathode, the field-emission cathode comprising an electrode adjacent to an extraction site, wherein the extraction site has a base metal comprising indium associated therewith; applying a negative bias to the electrode, the negative bias producing a discharge current of greater than 5 μA, wherein the electrode is downstream from the extraction site, to create a Taylor cone having a cone tip in the base metal at the extraction site; solidifying the base metal to preserve the Taylor cone; applying a positive bias to the electrode so that the Taylor cone functions as a field-emission cathode; and regenerating the cone tip after it has become damaged by re-liquefying the base metal, applying a negative bias to the electrode to regenerate the Taylor cone tip, and re-solidifying the base metal to preserve the cone tip.