Diffusion Plasmas and Diffusion.
Abstract
The mechanism of diffusion, and some boundary problems, have been investigated in both electropositive (ep) and electronegative (en) gases. A method is described for distinguishing between diffusion-dominated and recombination-dominated ep negative glows, recombination being either collisional-radiative or dissociative in practice. In an ep negative glow and Faraday dark space, the mode of diffusion changes from nearly ambipolar to nearly free as the wall sheath expands on proceeding away from the cathode, until the resulting throttling is relieved by formation of a positive column via an intermediate shock-like layer and complex double space-charge. Diffusion into a side-arm involves a similar ambipolar to free transition with unrelieved closure. A survey made of the literature on production of metastable atoms and molecules in discharge tubes has shown that whilst a wide range of discharge forms may be employed, conditions in few are known in sufficient detail for plasma data to be used with confidence in deriving forbidden radiation lifetimes and quenching collision cross-sections. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1970
- Accession Number
- AD0718430
Entities
People
- K. G. Emeleus
Organizations
- Queen's University Belfast