THEORETICAL-STUDY ON NONSTATIONARITY OF ELECTRON-ENERGY DISTRIBUTION FUNCTION FOR DISCHARGE-PUMPED XECL LASER

The nonstationarity of electron energy distribution function (EEDF) ha s been studied for a discharge-pumped XeCl laser, where a self-consist ent model is considered. The energy relaxation time has been observed by solving a time-dependent Boltzmann equation. The importance of a no nstationary treatment in determining EEDF, electron average energy, el ectron-impact rate coefficients, and species densities has been discus sed. It has been found that a pronounced nonstationarity is likely to occur at a relatively low electric field (< 2 Td). The quasi-stationar y treatment tends to underestimate the electron average energy and som e electron-impact rate coefficients around the inversion points of the discharge voltage. Electron-electron collisions induce a strong nonst ationarity when the electron density exceeds a certain value. The elec tron-impact rate coefficients selected by neglecting the nonstationari ty result in an incorrect determination of species densities. (C) 1996 American Institute of Physics.