A 5,000 hour xenon hollow cathode life testA cathode life test voluntary terminated after 5024 hours of operation at 25 A is reported. The cathode including a 6.35-mm diameter by 57.12-mm long molybdenum tube with a nominal wall thickness of 0.38 mm is described along with a test facility and start-up procedure. It is shown that over the time of the experiment, the cathode-orifice diameter eroded from 1.80 mm to 2.08 mm, which corresponds to a ratio of the emission current to the orifice diameter at the end of the test of 12.0 A/mm. Tungsten deposits on the interior surface of the insert are detected in post-test analyses, and complete depletion of the original impregnate is suggested by X-ray diffraction analyses. A cathode-jet phenomenon in which energetic ions are produced during hollow-cathode operation at emission currents above 20 A is confirmed.
Document ID
19910057080
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Brophy, John R. (Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Garner, Charles E. (JPL Pasadena, CA, United States)