LAUSR

A novel flow-driven dielectric barrier discharge concept is presented, which uses a Venturi pump to transfer plasma-generated reactive oxygen and nitrogen species from a sub-atmospheric pressure () discharge region to ambient pressure and can be operated with air. By adjusting the working pressure of the device, the plasma chemistry can be tuned continuously from an ozone ()-dominated mode to a nitrogen oxides ()-only mode. The plasma source is characterized focusing on the mechanisms effecting this mode change. The composition of the device's output gas was determined using Fourier-transform infrared spectroscopy. The results are correlated to measurements of discharge chamber pressure and temperature as well as of input power. It is found that the mode-change temperature can be controlled by the discharge chamber pressure. The source concept is capable of generating an -dominated plasma chemistry at gas temperatures distinctly below . Through mixing of the processed gas stream with a second flow of pressurized air required for the operation of the Venturi pump, the resulting product gas stream remains close to room temperature. A reduced zero-dimensional reaction kinetics model with only seven reactions is capable of describing the observed pressure- and temperature-dependence of the to mode-change.