Performance of a three electrode triggered high-energy spark switch

High-energy switch is one of important components in many pulse power systems. The most popular switch up-to-date is spark-gap switch. Although spark switch is capable of handling voltages and currents great, they have one main disadvantage. They have a finite lifetime, the main reason is related to electrode erosion. To extend the switch lifetime by minimizing electrode erosion, rotary arc gap-switches (RAG) were proposed in the literatures. The rotation of the arc can be achieved by providing an external rotating magnetic field from outside or by self-induced magnetic field. Since the rail-gap switch has the advantages of low impedance, long burn-out life, wide operating range and low jitter time. In this paper we combine the RAG and rail-gap together, designed a switch, and the characteristic of the switch has been studied. The switch has low jitter and wide operating voltage range. The results indicate that the RAG switch employing a sharp knife-edge electrode as a third trigger electrode can distinctly reduce the electrode erosion and prolong the lifetime of the switch. The surface conditions and photomicrographs of the electrode surface of two materials (aluminum and brass) are presented.