Plasma processes at atmospheric and low pressures

In the last few decades there has been an intense development in non-equilibrium (“cold”) plasma surface processing systems at atmospheric pressure. This new trend is stimulated mainly to decrease equipment costs by avoiding expensive pumping systems of conventional low-pressure plasma devices. This work summarizes physical and practical limitations where atmospheric plasmas cannot compete with low-pressure plasma and vice-versa. As the processing conditions for atmospheric plasma are rather different from reduced pressure systems in many cases these conditions may increase final equipment costs substantially. In this work we briefly review the main principles, advantages and drawbacks of atmospheric plasma for a better understanding of the capabilities and limitations of the atmospheric plasma processing technology compared with conventional low-pressure plasma processing.