Effects of dielectric material on arc plasma pressure and ablation measurement in high-power apparatus

We measure some characteristic parameters to investigate the electrical discharge in different types of insulators in the energy range 150-500 J. By varying the type of insulator and the confining geometry, we quantify their specific influence on the pressure, the dissipated energy, and the ablated mass. These considerations are useful to increase the knowledge of the physical mechanisms which play a role in the high-current plasma-wall interaction. In agreement with previous theoretical works, we show two opposite behaviors between polyethylene and polyoxymethylene in terms of ablated mass and graphite formation.