A Computer Analysis of the Plasma-Boundary Layer Behavior over a Positive Electrode.
Abstract
A stable numerical procedure for solving the coupled, nonlinear equations of electron and ion conservation and electrical potential (Poisson's equation), is described. A two-dimensional model with periodic active sites on a flat plate is utilized to obtain both qualitative and quantitative results which clearly illustrate the self-generating sheath and ambipolar regions adjacent to a non-emitting electrode. The active sites are characterized as voltage sources and by electron densities depressed from both the non-active wall and the free-stream values. Various cases of species density at the nonactive wall are evaluated. Recombination/ionization plays an important role in establishing the boundary layer behavior in the ambipolar region and in the dimensionality of the problem formulation. Application is for Nitrogen gas at one amagat in pulsed discharge of about 50 micro-seconds in duration. Results clearly demonstrate the boundary layer nature of the species density at the electrode. A sheath length of 38 microns about a 35-volt active site and 5-20 microns along the non-active portion of the electrode is established. Joule heating is determined to be not important. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1981
- Accession Number
- ADA107455
Entities
People
- Stephen Ted Van Brocklin
Organizations
- Naval Postgraduate School