Temporal investigation of a fast spark discharge in chemically inert gases

Abstract

The evolution of a fast pin-to-pin spark discharge in nitrogen is studied during the first s of its development with a single-wavelength interferometry method. The growth of the plasma kernel, the particle number densities, the temperature distribution and shock-wave position are measured with this technique. The energy dissipated into the gap is measured with a calorimetric bomb. The voltage across the gap and the electrical current flowing through the gap are measured simultaneously. The measured waveform of the electrical current is used as an input to a two-dimensional simulation model based upon the equations from continuum mechanics. The model successfully describes the shock-wave position, the particle number densities and the temperature. The model can therefore be used to produce realistic initial conditions for studies of ignition of combustible gases.