Abstract
The aim of the present study concerns the effect of the chamber pressure on the structure of a plasma jet. Conventional vacuum plasma spray equipments are currently designed to operate at chamber pressures higher than 10 mbar. Nevertheless, recently, the exploration of lower pressure level conditions seems to have become a new challenge. In the present study, pressure levels as low as 0.5 mbar have been achieved and tested. It is shown that a decrease in the chamber pressure provides a longer and enlarged plasma jet whose length may be longer than one meter for the lowest pressure levels considered. CFD modeling results and photographs performed under vacuum conditions are proposed for the case a standard conical nozzle. Some additional characterizations (using thermocouples and emission spectroscopy) were also conducted but the results are currently being analyzed.
