Electrode erosion and particulate sputtering would be inevitable in gas spark gap

which could affect its dielectric performance and reliability. To analyze the process of electrode-to-electrode sputtering in gas spark gap

we conducted discharge experiments between Mo and WCu electrodes in the inflatable vacuum dynamic system and analyzed the results with SEM. Results indicated that WCu

no matter as anode or cathode

turned out to be more easily and early eroded than Mo in their first 500 shots and even sputtered 4 μm particles after only one shot. Anode and cathode began sputtering particles to each other after 50 shots

and its distribution range extended to the region 1 mm apart from cathode hole. Consequently

it was imperfect that electrode erosion rate acted as single index to estimate the anti-erosion performance of electrode

which hardly eliminated sputtering particles’ effects. Sputtering particles

scattered widely and shed easily

could be the key factor to influence dielectric performance of the gap.