EMP mitigation technique based on low pressure SF6 gas filled surge suppressor

Summary form only given. The aim of this study was to develop a device to suppress fast electromagnetic pulse (EMP) in a few nanoseconds. When electronic equipment or a power line is subjected to a transient from intense and fast electromagnetic interference (EMI) sources, the consequences are temporary upset or permanent damage of the equipment. Important among such intense EMI sources are lightning strikes, high power microwave (HPM) and nuclear electromagnetic pulse (NEMP). EMI coupling to these equipments can be through conduction or radiation. To protect the equipment against such surges, the surge suppressors are connected across power lines and/or signal lines. The impedance of an arrestor is a function of the voltage impressed on it. Commonly used surge suppressors are metal oxide varistors, transient absorbers and spark gaps. Among these protective elements, the spark gaps have the outstanding advantages of high-energy absorption, low self-capacitance, low clamping voltage and high speed. Results of detailed experimental study are presented for the fast surge suppression using low-pressure SF₆ spark gaps.