Hybrid simulation of electrode plasmas in high-power diodes

Journal Article · Tue Dec 15 04:00:00 EST 2009 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.3270471· OSTI ID:21371254

Welch, Dale R; Rose, David V; Bruner, Nichelle; Clark, Robert E ^[1]; Oliver, Bryan V; Hahn, Kelly D; Johnston, Mark D ^[2]

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1. Voss Scientific, LLC, 418 Washington St., Albuquerque, New Mexico 87108 (United States)
2. Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States)

New numerical techniques for simulating the formation and evolution of cathode and anode plasmas have been successfully implemented in a hybrid code. The dynamics of expanding electrode plasmas has long been recognized as a limiting factor in the impedance lifetimes of high-power vacuum diodes and magnetically insulated transmission lines. Realistic modeling of such plasmas is being pursued to aid in understanding the operating characteristics of these devices as well as establishing scaling relations for reliable extrapolation to higher voltages. Here, in addition to kinetic and fluid modeling, a hybrid particle-in-cell technique is described that models high density, thermal plasmas as an inertial fluid which transitions to kinetic electron or ion macroparticles above a prescribed energy. The hybrid technique is computationally efficient and does not require resolution of the Debye length. These techniques are first tested on a simple planar diode then applied to the evolution of both cathode and anode plasmas in a high-power self-magnetic pinch diode. The impact of an intense electron flux on the anode surface leads to rapid heating of contaminant material and diode impedance loss.

• OSTI ID: 21371254
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 12 Vol. 16; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ANODES
CATHODES
CHARGED PARTICLES
DIODE TUBES
ELECTRODES
ELECTRON TUBES
ELECTRONS
ELEMENTARY PARTICLES
FERMIONS
IONS
LEPTONS
MATHEMATICS
NUMERICAL ANALYSIS
PLASMA
PLASMA DENSITY
PLASMA SIMULATION
SIMULATION
THERMIONIC DIODES
THERMIONIC TUBES