The behavior of the electric field together with the electron and ion densities in the vicinity of a nonemitting,
plane anode is investigated. The selected approach involves non-linear analysis techniques on
the continuum equations for steady-state, isothermal conditions where both ionization and two-body
recombination are included. Ions, created through electron bombardment of neutral atoms, are repelled
toward two stagnation regions: within or near the sheath boundary and near the plasma interface.
These equilibria form as a result of the chemistry present: recombination establishes the latter while
ionization stipulates the former. As presented, the sheath is fundamentally unstable - ions are driven
toward the negative electrode. Using nitrogen data for a numeric example, the following observations
are made: a sufficiently strong applied electric field pushes the ion density toward that ofthe electrons
through a well - a constrictive phenomenon. Both a transition region, dominated by density gradients,
and a diffusion-driven zone are found to move the system toward the plasma interface. The
characteristics of this process are influenced by the applied electric field, but the instability of the
chemistry-induced stagnation regions precludes numeric convergence. Insufficient dissipation may
prevent the stability of the anode fall model as presented. Suggested improvements to the model
descriptions include considering the effects of temperature gradients, magnetic fields, three-body
recombination, diffusion written in terms of the electric field, multi-dimensionality and/or timedependencies^
| Identifer | oai:union.ndltd.org:nps.edu/oai:calhoun.nps.edu:10945/23461 |
| Date | 06 1900 |
| Creators | Horner, Brigitte |
| Contributors | Biblarz, Oscar, Frenzen, Christopher L. |
| Publisher | Monterey, California. Naval Postgraduate School |
| Source Sets | Naval Postgraduate School |
| Language | en_US |
| Detected Language | English |
| Type | Thesis |
| Rights | Approved for public release; distribution is unlimited. |
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