Sparking Potentials at Low Pressures

Abstract

Sparking potentials were observed between outgassed nickel electrodes in air at low pressures. The spark length $d$ was varied from 2-10 mm and the pressure $p$ reduced from 1 mm of mercury to 0.06 mm. Sparking potentials as high as 80,000 volts were observed, and agreed approximately with Paschen's law. The sparking potential $V$ for $p·d<\mathrm{}0.95\mathrm{}$ is given by $p·d·e^{\frac{V}{136,500}}=1\mathrm{}$.