Spatial evolution of the electron-energy distribution in the vicinity of a discharge-tube constriction

We report experimental and calculational results of the spatial evolution of the electron-energy distribution function (EEDF) mean electron energy ū \={u}{}, electric field E, and plasma density Nₑ, in the vicinity of a sharp constriction in a low-pressure mercury--rare-gas discharge. We explain many of the features of the EEDF by noting the absence of equilibrium between the electrons and the electric field. Our one-dimensional model of the spatial evolution of the EEDF is in good agreement with experimental results.