Properties of Loss Front in Long Magnetically Insulated Transmission Lines

Based on particle-in-cell (PIC) simulation, a robust method is developed to calculate varied loss-front velocity of long magnetically insulated transmission line (MITL) in pulse-propagating direction. In this method, the MITL is divided into several segments, and the loss front moves from one segment to the next one. Assumptions for this method include: 1) the interval between loss front and precursor is determined by loss-front velocity; 2) the waveform of voltage below the loss front does not change; and 3) the width of loss front is determined by the voltage after the loss front. Empirical expression of loss-front width is got through PIC simulation. Loss-front velocity and energy efficiency calculated from this robust method are compared with PIC simulation results. The calculated results agree well with simulation results when high voltage and short rise time are applied. These results may help to quickly estimate loss-front properties of long MITLs in large-scaled pulsed power systems.