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Title: Numerical simulation of cathode plasma dynamics in magnetically insulated vacuum transmission lines

A novel algorithm for the simulation of cathode plasmas in particle-in-cell codes is described and applied to investigate cathode plasma evolution in magnetically insulated transmission lines (MITLs). The MITL electron sheath is modeled by a fully kinetic electron species. Electron and ion macroparticles, both modeled as fluid species, form a dense plasma which is initially localized at the cathode surface. Energetic plasma electron particles can be converted to kinetic electrons to resupply the electron flux at the plasma edge (the “effective” cathode). Using this model, we compare results for the time evolution of the cathode plasma and MITL electron flow with a simplified (isothermal) diffusion model. Simulations in 1D show a slow diffusive expansion of the plasma from the cathode surface. But in multiple dimensions, the plasma can expand much more rapidly due to anomalous diffusion caused by an instability due to the strong coupling of a transverse magnetic mode in the electron sheath with the expanding resistive plasma layer.
Authors:
; ; ; ; ;  [1] ; ;  [2]
  1. Voss Scientific, LLC, Albuquerque, New Mexico 87108 (United States)
  2. Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States)
Publication Date:
OSTI Identifier:
22408174
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Plasmas; Journal Volume: 22; Journal Issue: 3; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; CATHODES; COMPUTERIZED SIMULATION; DIFFUSION; ELECTRONS; FLOW MODELS; KINETICS; MAGNETIC FIELDS; PLASMA INSTABILITY; PLASMA SHEATH; PLASMA SIMULATION; STRONG-COUPLING MODEL