Effect of different electrode materials on electrode erosion characteristics and failure modes of gas spark switch

Summary form only given. As one of the key components in the pulsed power system, the two-electrode gas spark switch has many advantages such aslarge charge transfer, high current capability, stability and long lifetime. But some practical engineering issues, like the extraction of unconventional gas resources, set strictly demands on switch´s work environment and output characteristics, such as high current capability, high breakdown voltage stability, long lifetime, high-frequency operation while working in a small airtight chamber without gas blowing system. The performances of the switch directly influence the output characteristics of the system. The electrode erosion of electrodes caused by high current directly influences the performances of the switch. But few studies have done on the effect of different electrode materials on electrode erosion characteristics and failure modes of gas spark switch. Analyses of the physical characteristics and chemical characteristics of different electrodes´ surfaces at different stage of life were shown. By analysing the erosion characteristics and special failure phenomenon of electrodes, some relationships between different electrode materials and failure modes were proposed. to investigate the Cu-W (90 wt%) two-electrode spark-gap switch working in an airtight cavity (1.18 L) without gas blowing system. A test stand was established and could been divided into five parts, a DC power, a pulse capacitor, a two-electrode gas spark switch, a low inductance load resistor and measurement systems. The gas spark switch was working in an airtight cavity (1.18 L) without gas blowing system. The switch was tested with frequency of 0.1 Hz, self-breakdown voltage of 30 kV, peak current of 50 kA. A scanning electron microscope and a Dynamic 3D aspheric profiler were used to observe the surface roughness of the electrodes. A Bruker Tensor 27 FT-IR Spectrometer and an X-ray photoelectron spectroscopy were used to analyze the chemical - omposition of erosion product.