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Because the voltage is difficult to measure in a magnetically insulated transmission line (MITL), measurement of the currents flowing in the cathode and anode are often used with MITL theory to estimate the voltage in a given experiment. However, that estimate contains a space charge correction term whose magnitude depends on what is referred to as the g factor that describes the distribution of charge and current in the electron flow layer in the MITL. Typically, g is on the order of unity but the accuracy of the voltage estimate depends on its actual value. While the space charge correctionmore » term is small when the MITL flow is strongly insulated, it is particularly important near self-limited MITL flow. System parameters that affect the distribution of electron flow are studied here at self-limited flow in order to illustrate this matter and develop a methodology to improve the voltage determination.« less

Kinetic, time-dependent, electromagnetic, particle-in-cell simulations of the inductive current divider are presented. The inductive current divider is a passive method for controlling the trajectory of an intense, hollow electron beam using a vacuum structure that inductively splits the beam’s return current. The current divider concept was proposed and studied theoretically in a previous publication [Phys. Plasmas 22, 023107 (2015)] A central post carries a portion of the return current (I₁) while the outer conductor carries the remainder (I₂) with the injected beam current given by I_b=I₁+I₂. The simulations are in agreement with the theory which predicts that the total forcemore » on the beam trajectory is proportional to (I₂-I₁) and the force on the beam envelope is proportional to I_b. For a fixed central post, the beam trajectory is controlled by varying the outer conductor radius which changes the inductance in the return-current path. The simulations show that the beam emittance is approximately constant as the beam propagates through the current divider to the target. As a result, independent control over both the current density and the beam angle at the target is possible by choosing the appropriate return-current geometry.« less