Electron Temperature Relaxation in Afterglow Plasmas: Diffusion Cooling
| Authors | |
|---|---|
| Year of publication | 1994 |
| Type | Article in Periodical |
| Magazine / Source | Contributions to Plasma Physics |
| MU Faculty or unit | |
| Citation | |
| Field | Plasma physics |
| Description | We have carried out a thorough theoretical analysis of the cooling and heating processes of the electron gas in Ne, Ar and Kr afterglow plasmas. Thus the rate of relaxation of the electron temperature, T(e), is seen to be in good agreement with the experimental measurements when spatial gradients of T(e) in the early afterglow and heating of the electron gas by superelastic collisions between the electrons and metastable atoms are accounted for. Al low pressures of the rare gases, p(g), the phenomenon of diffusion cooling occurs in which T(e) relaxes to an equilibrium temperature, T(ee), which is less than the gas temperature, T(g). This reduction in T(ee) below T(g) is mirrored in a reduction in the ambipolar diffusion coefficient, D(a), for the rare gas atomic ions and electrons. Thus the D(a) can be calculated as a function of p(g) using the values of T(ee), and when this is done, properly accounting for the heating by metastable atoms, the calculated and experimental values of D(a) in all three rare gas afterglows are seen to be in agreement. |
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