Transition from ambipolar to free diffusion in a decaying plasma
Abstract
The problem of transition from ambipolar to free diffusion due to charged particle density gradients in a decaying plasma of spherical symmetry is investigated in this paper. This investigation is carried out within the framework of the approximate procedure set forth by Allis & Rose (1954). A further simplification is introduced by using only the time-dependent ‘imperfect’ ambipolar diffusion coefficients for the electrons and ions evaluated at the centre of the plasma for carrying out calculations. The results for the time dependence of these ‘imperfect’ ambipolar diffusion coefficients and spatial distributions for the charge density, electric field, and potential which are obtained by this procedure are valid for all values of time in the neighbourhood of the centre of the plasma and for all other positions of space only during the time while the plasma is diffusing in an almost ‘perfect’ ambipolar manner.
- Publication:
-
Journal of Plasma Physics
- Pub Date:
- June 1968
- DOI:
- 10.1017/S002237780000372X
- Bibcode:
- 1968JPlPh...2..167M