Surface Morphology of Cu-W Alloy Electrodes in a Long Lifetime Gas Spark Switch

Considering the complex circumstances in real applications such as the underground mine environment, the gas switch is required for long lifetime, high current capability, repetition rate, small breakdown voltage variance while working in a small sealed cavity. In order to simulate the electrode erosion process and acquire the performance of the two electrode switch resembling the ones in the practical application, a simple test platform had been designed and fabricated. A Dynamic 3-D Aspheric Profiler and a Confocal Laser Scanning Microscope (CLSM) were utilized to help analyze the erosion characteristics by providing quantitative descriptions of 1-D, 2-D, and 3-D profiles. The results demonstrate that the surface roughness of both electrodes rose with the increase of accumulated transfer charge. Specifically, the edge position has a larger value of surface roughness than the central position. Moreover, the surface of cathode seems rougher than that of anode in the same area. For example, the surface roughness of cathode was 7.752 μm at edge position whereas that of anode was 5.573 μm after 20000 shots. In sum, the erosion in cathode is more severe and the surface morphology is too complex to be described by simple models. Therefore, the research of the two electrode gas switch under such rigorous conditions can both investigate the new phenomena which are not concerned before and provide useful guidance to the applications. Thus, this research is essential in scientific research and industrial applications.