| dc.description |
The thermionic vacuum arc (TVA) is a new type of plasma source, which generates a pure metal and ceramic vapour plasma containing ions with a directed energy. TVA discharges can be ignited in high vacuum conditions between a heated cathode (electron gun) and an anode (tungsten crucible) containing the material. The accelerated electron beam, incident on the anode, heats the crucible, together with its contents, to a high temperature. After establishing a steady-state density of the evaporating anode material atoms, and when the voltage applied is high enough, a bright discharge is ignited between the electrodes. We generated silver and Al<sub>2</sub>O<sub>3</sub> TVA discharges in order to compare the metal and ceramic TVA discharges. The electrical and optical characteristics of silver and Al<sub>2</sub>O<sub>3</sub> TVA discharges were analysed. The TVA is also a new technique for the deposition of thin films. The film condenses on the sample from the plasma state of the vapour phase of the anode material, generated by a TVA. We deposited silver and Al<sub>2</sub>O<sub>3</sub> thin films onto an aluminium substrate layer-by-layer using their TVA discharges, and produced micro and/or nano-layer Ag-Al<sub>2</sub>O<sub>3</sub> composite samples. The composite samples using scanning electron microscopy was also analysed. |
