Parametric studies of high-heat-flux-induced erosion of surfaces in an electrothermal accelerator

Summary form only given, as follows. The plasma device called SIRENS was designed and constructed to study the phenomena occurring during the interaction of a high-heat flux with a material surface. The device works on the same principle as an electrothermal mass accelerator. A plasma is produced by the ablation of an insulating cylindrical sleeve of Lexan between two tungsten alloy electrodes. The plasma is joule-heated by currents of up to 100 kA and pressure-driven through a stainless steel barrel. A cylindrical material sample (aluminum or Lexan) is placed inside the barrel. A series of experiments were performed to study the erosion/ablation process of the Lexan insulator sleeve and the barrel samples (aluminum and Lexan) for different discharge energies. Erosion measurements were made by individually weighing the sample sections. Selected sections were analyzed using SEM and EDXA, and optical emission spectroscopy of visible light was performed. Other diagnostics used included Rogowski coils, B-dot probes, high-voltage probes, and pressure transducers. The ablation of the Lexan insulator sleeve compared well with predicted results for 10% transmission of heat flux to the surface.<>