Direct Observation of Cathode Surface : Gas-Tungsten-Arc Electrode (3)(Physics, Process, Instrument & Measurement)
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Direct observation of cathode tip during arc burning was carried out by using stereoscope. The important phenomena concerning the current density, morphorogical change near emission area as a function of arcing time and current in pure argon and pure helium shielding gases, and rim formation in Ar+0.2%O_2 and He+0.2%O_2 shielding gases were studied. La_2O_3-W electrodes are superior to ThO_2-W electrodes in these characteristics. Also, the effective work functions of these electrodes were estimated showing that the work function of La_2O_3-W electrode is lower than that of ThO_2-W electrode.
- Transactions of JWRI
Transactions of JWRI 16(2), 247-254, 1987-12