Study of the interaction of a free burning arc and an aluminium panel

We developed at ONERA a 400 A dc current generator at a voltage of 1600 V to analyse the free burning arc interaction with a material for lightning applications. This voltage allows the generation of a long arc with a channel length ranging from 10 to more than 40 cm in some cases. With this experiment we studied the interaction of a generated arc root and a material under test; aluminium in this study. In particular, we focused on a regime exhibiting a stable plasma jet ejected from the panel. The aim is to gather experimental data to perform a comparison with previously published numerical results showing a similar behaviour [1]. In a first part, we present the experimental set-up namely the generator, the ignition method of the arc and the experimental set-up. In a second part we describe the results obtained on the plasma using fast imaging (100 kHz) and fast emission spectroscopy (10 kHz). In a third part we use fitting methods on the emission spectra and deduced electronic temperature. Finally, the presence of some magnesium metallic lines due to the vaporisation of the panel is discussed.