Mohammad Askari - Radiation Application Department, Shahid Beheshti University, Tehran, Iran
Nikoo Darestani Farahani - Plasma and Nuclear Fusion Research School, Nuclear Science and Technology Research Institute, Tehran, Iran
Mehdi Bakhshzad Mahmoudi - Plasma and Nuclear Fusion Research School, Nuclear Science and Technology Research Institute, Tehran, Iran
Fereydoun Abbasi Davani - Radiation Application Department, Shahid Beheshti University, Tehran, Iran

Metal surface cleaning or etching techniques using reactive plasma are emerging as one of the dry processing techniques for surface contaminants with high bond energy, especially for cleaning and decontamination of nuclear components and equipment. In this study, the plasma reaction due to the discharge of a dielectric barrier of a mixture of ۹۵% helium and ۵% fluorine with cobalt oxide film (Co۳O۴) grown on the surface of stainless steel ۳۰۴ was studied experimentally. Experimental results show that cobalt oxide becomes a powder after plasma irradiation and is easily separated from the surface of the base metal. The optimal plasma generating conditions of the dielectric barrier discharge used in this experimental study were obtained at atmospheric pressure, voltage ۴.۵ kV, and frequency ۲۵ kHz with an etching rate of ۱۰.۸۷۵ μmol.min-۱. The samples were analyzed before and after plasma irradiation, using Scanning Electron Microscopy with Energy Dispersive X-ray spectroscopy and the purification rate was performed using a sequential weighting of the samples with scales ۱۰-۴ g accurately obtained. The results show the ability of this method to effectively remove the surface contamination of cobalt from the surface of stainless steel ۳۰۴.

Metal waste decontamination, Plasma surface cleaning, Etching rate, Cobalt oxide, Dielectric Barrier Discharge