Plasma Behavior in Classical Versus Rod-Bounded Coaxial Gun Geometries

This study presents a comparative analysis of plasma parameters in two coaxial plasma gun configurations: a classical design featuring a solid outer cylindrical wall and a modified version where conductive rods replace the outer wall. Time resolved measurements of electron temperature (Te) and electron number density (ne) were obtained with triple Langmuir probe diagnostics under identical discharge conditions for both systems. The results show noticeable differences in plasma behavior attributable to the altered outer boundary conditions and information on instabilities because of the missing walls. In the rod bound configuration plasma non uniformities and altered sheath dynamics lead to variations in both Te and ne profiles when compared to the classical coaxial gun.