Basic characteristics in two different regions of helium Glow Discharge Plasma

Measurements by Langmuir probe have been performed in a direct current glow discharge plasma of Helium. The single Langmuir probe measurements yielded electron temperature and number densities of electrons that are needed to calculate some of electron. transport coefficients, namely electron mobility and electron diffusion coefficients. The operating conditions of the glow discharge source, the discharge voltage, gases pressure and location of measurements, were varied to investigate, their influence on the plasma properties. The electron properties investigated are the electron temperature, the electron density, electron mobility and electron diffusion coefficient as a function of the gas pressure which varied from 0.1 to 1.0 ton at 550 to 900 V discharge voltage in two different regions, the cathode dark space and negative glow regions, of helium glow discharge plasma. It has been found, that the plasma electron temperature in the negative glow varies between 2.9-7 eV, while the electron density varies between 4x108-1.5x10I0 cm-3. It was found that the pressure a nd voltage greatly affect the plasma properties in these two regions of the plasma