The low-pressure positive column in electronegative gases including space charge-matching plasma and sheath

This paper describes the low-pressure positive column in electronegative gases laking into account space charge effects. It shows how the plasma joins to the sheath via a transition layer as in electropositive gases, but also demonstrates significant differences in the particle and potential distributions and the scale of the sheath. The treatment is in the main computational, but is related to the analytical sheath approximation and to the plasma approximation. The application of matched asymptotic expansions to the problem is also considered. The analogous situation in two-electron-temperature plasmas is also treated.