Laser-scattering instrument for fundamental studies on a glow discharge

An instrument is described to perform laser-scattering fundamental studies on an analytical planar-cathode glow discharge. Electron properties such as electron number-density, electron temperature and the shape of the electron energy distribution function were successfully obtained via Thomson scattering. It is observed that several groups of electrons contribute to the Thomson scattering spectrum and the existence of a non-Maxwellian electron energy distribution was confirmed. The measured temperature for slow electrons is comparable to that found in previous studies performed with alternative methods. In addition, Rayleigh scattering was used to acquire argon gas-kinetic temperatures. The performance of the instrument as well as the significance of the results will be discussed.