Diagnostics of low-density glow discharge plasmas using Thomson scattering

In recent years, the method of incoherent Thomson scattering has been applied to make measurements of electron properties of glow discharges used for industrial applications. These plasmas have electron density of the order of 10¹⁷ m^-3 and electron temperature of a few eV. This paper reviews the recent progress in this research area. Details of the experimental systems are given and examples of measurements made in several different types of glow discharges are presented. A method in which Thomson scattering is combined with Rayleigh scattering to provide direct measurements of the neutral density is also described and an example of measurements is given. The electron velocity and energy distribution functions are also an important property of these plasmas, and the extent to which Thomson scattering can measure the distribution function is discussed. Future trends for Thomson scattering in glow discharges are also discussed.