Tungsten cathode may be divided into pure tungsten cathode, potassium tungsten cathode, tungsten-tungsten oxide cathode, WC-ThO2 cathode, and multiple composite rare earth oxide cathode, etc.
Pure tungsten cathode does not add any oxide with low thermal electron emission efficiency so that it is little used in vacuum devices. The producing process of this type of cathode material is simple, so, it cost less. While the arc starting performance and ablation resistance performance of the tungsten cathode are relatively poor. Therefore, in general, it is only applicable to occasions where the working conditions are not very strict. It is often used in detachable systems, such as electron microscope, electronic energy spectrometer, large launch tube and other equipment or instruments.
The dynamic changes of the physical properties of the cathode head surface material determine the performance and working life of the material. In order to improve the performance and service life of the electrode, it is necessary to know the ablation mechanism of the cathode material and the influence of oxide on the electrode performance.
More details, please visit: