The influence of Hall physics on power-flow along a coaxial transmission line

Extended-MHD simulations of a coaxial transmission line are performed in axisymmetric cylindrical geometry, in particular, in examining the influence of Hall physics on a plasma layer initialized against the anode versus the cathode, for which an MHD model is insensitive. The results indicate that Hall physics is required in order to model an electron E × B drift current in the electrode plasma, which is parallel to the anode current and opposite the cathode current. This results in confinement of the electrode plasma when initialized against the cathode and expansion of the plasma layer when initialized against the anode. The expansion in the anode-initialized case results in filaments of plasma bridging the gap, causing substantial power-flow losses. These results represent the first fluid simulations of power-flow, to our knowledge, that, by including Hall physics, recover fundamental aspects of anode and cathode dynamics predicted by kinetic theory while simulating over a dynamic range (nine orders of...