Breakdown characteristics of spark gap switch in distilled water by high voltage pulses

Summary form only given. SF6 gas is known as an effective insulator due to its high dielectric characteristics. Because of this property, it is widely used in the field of high voltage pulse systems and compact electrical distribution sites. But this gas belongs to one of greenhouse gases, and is shrinking in use throughout the world. On the other hand, distilled water is very good insulating material for the spark gap switch. However, phenomena such as oxidation stability issues should be solved for the future applications to the wide areas.