Abstract
Magnetically insulated transmission lines (MITLs) under high-power operation are dominated by space-charge current flowing between an anode and a cathode. When MITLs have geometrical discontinuity, the interaction between the disturbed electrons and the nonlinearly coupled electromagnetic field makes their behavior difficult to predict. The results of particle simulation show that the space-charge electrons tend to maintain the effective impedance of the transmission lines, by changing their distribution and the boundary of the electron cloud. Although a fraction of the space-charge flow shunts the gap at the discontinuity when the discontinuity is larger than a critical value, the total upstream current is still preserved. To discuss this impedance adjustment process and the critical value, we propose a laminar flow model with constant current density.