The influence of electrode gap width on plasma properties of diffuse coplanar surface barrier discharge in nitrogen

In this work we have studied the influence of electrode gap width (inter-electrode distance) on plasma properties of the diffuse coplanar surface barrier discharge. The outer conditions and discharge configuration can substantially influence properties of the discharge. Better understanding of these effects can lead to optimization of the discharge parameters for industrial applications. In this work the discharge was operated in nitrogen at atmospheric pressure. The electrode gap width was varied in the range from 0.6 to 2.2 mm. The input voltage, electrode temperature and gas flow was kept constant for all cases. Plasma parameters were studied by the means of time and space resolved optical emission spectroscopy and oscilloscopic measurements. These measurements gave us time and space distribution of discharge luminosity (e.g. intensities of second positive and first negative systems of nitrogen) and 1D-spatial profiles of rotational and vibrational temperature of nitrogen.