Physical Science International Journal

The distribution of electron temperature T_e and density N_e in a dc glow discharge that is created by a pair of circular parallel electrodes is studied using double probes. The measurement are carried out for the following two modes: in the presence and in the absence of the magnetic field. In the absence of the magnetic field, for the radial distribution, temperatures have same values with small variation, in the same discharge region [cathode fall or negative glow or positive column region], except at the edge. For the axial distribution, the distribution profiles of T_e shows that T_e is decreased, and N_e continues to increase toward the anode. In the presence of the magnetic field, the radial distribution of the electron density has its highest value at the edge where the magnetic field is maximum. The electron temperature changes very little. The density begins to increases also from the cathode fall region, at the edge, to the negative glow region and then it decreases sharply at the positive column region. The plasma is very intense in the cathode fall region (very thin bright ring) and very brighter and sharp in the negative glow region (extends several mm from the cathode fall region). But in the positive column, the density begins to decrease.