Title :
Characteristics of W-ThO2 thermionic cathode activated with nanoscale oxide
Author :
Zhang, Hui ; Yang, Zhimao ; Ding, Bingjun
Author_Institution :
Sch. of Mater. Sci. & Eng., Xian Jiaotong Univ., China
fDate :
9/1/1999 12:00:00 AM
Abstract :
A novel tungsten cathode consisting of tungsten matrix of equiaxed 4-μm-fine grains with nanooxide (homogeneous dopants of ThO2 powder less than 200 nm in size) has been prepared by hot-pressing (HP) sintering. The microstructure of the cathode is completely different from that of a commercial cathode. A comparative study has been performed on the effect of the microstructure on the operating characteristics of the cathode. The results show that the microstructure of the cathode has a strong effect on its characteristics. The nanooxide cathode demonstrated superior performances compared to the commercial electrode in arc starting voltage, voltage-current characteristics and arc stability during arcing
Keywords :
hot pressing; plasma applications; plasma torches; sintering; thermionic cathodes; thorium compounds; tungsten; 4 micron; W-ThO2; arc stability; arc starting voltage; hot-pressing sintering; nanoscale oxide; operating characteristics; thermionic cathode; voltage-current characteristics; Cathodes; Electrodes; Microstructure; Plasma chemistry; Plasma materials processing; Plasma properties; Plasma stability; Plasma welding; Powders; Tungsten;
Journal_Title :
Components and Packaging Technologies, IEEE Transactions on
DOI :
10.1109/6144.796550
