Observation of D.C. Glow Discharge and Influence of Metal Vapor on The Discharge Phenomena

The purpose of the present report is to comprehend the property in the D.C. glow discharge under the conditions which is used for the actual plasma process. We observed the glow discharge morphologies, using the Langmuir probe method. We examined the influence of the metal (Al, Ag and Sn) vapor on the glow discharge phenomena. It was found that the morphologies of the glow discharge was classified into four types. Evaporation of Al into glow discharge increased the discharge current but decreased the discharge voltage. On the other hand, the introduction of Ag-vapor or Sn-vapor decreased the discharge current and increased the discharge voltage. These results suggest that there are the different states for metal vapor in glow discharge. It is concluded that these phenomena are mainly caused by the value of the ionization energy.