Analysis of Electron Drift Velocities in Molecular Gas-Rare Gas Mixtures Using a Flowing Afterglow Plasma.
Abstract
Electron drift velocities are obtained in mixtures of Ar-N2, Ar-CO, and He-N2 using a flowing afterglow. Theoretical development of drift velocities in the molecular gas-rare gas mixture is discussed. Two factors are discussed which determine the electron collision frequency: the shape and magnitude of the electron elastic cross section of the buffer gas, and the threshold energy and magnitude of the inelastic processes. Drift velocity enhancement and differential negative conductivity caused by the presence of small amounts of molecular gas are discussed. Experimental drift velocity curves show good agreement with theoretical curves obtained by a numerical solution to the Boltzmann equation. Minor deviations indicate that metastable ionization should be included in the computer analog to better model electron density in the flowing afterglow. A drift tube design using up-to-date electronics is proposed. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1979
- Accession Number
- ADA080178
Entities
People
- Richard F. Wittler
Organizations
- Air Force Institute of Technology