Modeling power flow in magnetically insulated transmission lines

Summary form only given. The electric field stresses on the cathode of a magnetically insulated transmission line (MITL) exceed the explosive-emission threshold, however, electrons emitted into the vacuum line are magnetically insulated from reaching the anode due to the high currents. Thus, the total current flow is divided between current flowing in the metal and electron current flowing in vacuum. As a result of the vacuum electron flow, the impedance of the MITL is reduced below its vacuum value Z₀, altering its power coupling to both the generator and the load. Various analytic models for MITL flow have been developed in which, to a good approximation, MITL behavior is determined by a single parameter termed the flow impedance Z_f, which is a function of the geometry, voltage and boundary currents. Here, these models are compared and their predictions carefully benchmarked with PIC simulations with the goal of choosing the model best suited for use in circuit code modeling. This process has also illuminated a number of important physics details of MITL flow that have not been fully appreciated in the past. These new details will be presented and their impact discussed. This physics model is now being incorporated into the BERTHA transmission line code including methods for treating impedance transitions and voltage adders. Available results from the transmission line code model of MITL flow will be presented and compared with PIC simulations and future work will be described