The scattering of Electrical Breakdown Voltages and Breakdown Points in a Sphere Gap

A series of electrical breakdown by impulse voltage in a sphere gap arrangement shows that the breakdown voltages are scattered in a certain range of voltage and the sparks are not always along the central axis line. A nearly circular distribution of spark points is formed and centered on the axis of the gap. To make these phenomena clear, the distribution of electrical breakdown voltages and breakdown points in the sphere gap is analyzed by alculating the breakdown voltage along electric field lines by integrating the effective ionization coefficient and also calculating the probability of breakdown by initial electron emitted from the cathode surface.