| Autor: |
Yongshu, Wang, Yaode, Deng, Qi, Wang |
| Zdroj: |
Journal of Electronics; Oct1987, Vol. 4 Issue 4, p282-289, 8p |
| Abstrakt: |
In this paper, some proposals to explain the emission, properties of the La-WC cathode and its resistance to poisoning of oil vapour are presented and they are demonstrated to be correct by experiments. In the operating temperature range of the La-WC cathode, lanthanum would react chemically with tungsten carbide and form LaC which is a kind of good emissive material with a work function approximate to that of lanthanum and can also combine with lanthanum into a eutectic. The eutectic easily wets the tungsten matrix and migrates over its surface to form a thin emission film. As a result, cathode emission is greatly increased. Morever, the La-WC cathode has the capability to resist poisoning of oil vapour. The reason is that the carbon from oil vapour reacts with lanthanum in the eutectic, thus forming LaC which is also a good emissive material. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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