Agglomeration process of carbon dusts in laboratory plasmas

Micro-meter size carbon dusts have been formed in a 70 mm diameter, 370 mm long plasma container after running a 16 hour steady state Ar discharge. The formed carbon dusts have been observed by a scanning electron microscope (SEM) to identify their surface structures. The observed images have indicated that dusts with both flake and cauliflower structures were present on the surfaces of sample collectors. Carbon dusts with the flake structures exhibited smoother surfaces than dusts with cauliflower structures. Dust samples were also collected from arc spot parts of the carbon electrode surfaces by placing carbon compound adhesive tapes. Micro-meter size dusts were found collected on the surface of the tapes, indicating formation of dusts during arc discharges. (author)