Experimental Study of a Submillimeter Spark-Gap

This paper describes an experimental study on a submillimeter spark-gap and the effect of the gas type, pressure and interelectrode distance on the gas discharge. A coaxial transmission-line test switch and stainless steel electrodes have been used for the laboratory tests. The results presented in this paper are obtained using air, SF6, and argon, at gas pressures between 174 and 774 kPa and interelectrode distances from 330 to 450 μm. Results show that there is a linear change in breakdown voltage as the pd-relation increases. Important differences are observed when the time of the resistive phase is calculated and compared with the one obtained with some empirical models. It is also found that the arc-resistance depends on the gas type, and it is almost proportional to pd. The Kushner arc-resistance model fits well with the laboratory test results. From these results, a new constant of proportionality depending on electric field, pressure, and interelectrode distance is proposed. Additionally, for the studied pd-range, the gas with the best-fitting results was SF6. Finally, a good fit is observed between the laboratory test results and the obtained models programed in the computer program electromagnetic transient program.