Non-Uniform Axial Electric Field in Argon Glow Discharge Plasma

The non-uniform argon dc glow discharge plasma system has been constructed in a very special design to investigate the effects of variable tube radius on plasma parameters. By using isolated computer controlled three couples of a double probe (TCDP) system, the electron temperature, electron density, the reduced electric field, and electron drift velocity are measured at low and intermediate pressures. It is shown that the electron temperature and reduced electric field (density) decreases (increases) as the radius decreases, at low discharge current and pressures. For large radius regions, at high discharge currents and pressures, the behaviour of the plasma parameters of specially reduced electric field change similarly to those in a uniform discharge system.