Full Kinetic and Drift Kinetic Descriptions of Electrons Within MITLs Near a Load*

In this study, we examine the dynamics of electrons in cylindrically symmetric magnetically insulated transmission lines (MITLs) near a load.  Our analytical model of MITLs considers the electron motion in the presence of vacuum electric and magnetic fields for current drives that are similar to power flow experiments at the Sandia National Laboratories Z Pulsed Power Facility.  Our study considers two types of MITLs, namely the radial MITL and a spherically curved MITL. We examine the motion of the electrons using both an exact Lagrangian/Hamiltonian framework as well as an approximate drift kinetic model that incorporates both ExB and grad B drift motion.  In general, the drift kinetic model allows for fast calculations of electron dynamics, and yields excellent comparisons to the full kinetic model.   Drift kinetic results can show some disagreement with the full kinetic results when the electric field gradient length becomes comparable to the Larmor radius of the electron.  Additionally, we compare both of these models to fully electromagnetic and fully kinetic calculations using the code EMPIRE developed at Sandia National Laboratories.