Spectroscopic characterisation of a cross-flow plasma jet

The aim of this work is to study the thermal characteristics and electron density based on atomic and molecular emission of a new plasma jet at atmospheric pressure. The novelty of our jet is its generation with a single electrode, the plasma gas flowing perpendicularly to the RF powered electrode (13.56 MHz, 103 V). Optical emission of the plasma was collected in two ways: the normal viewing mode and the axial viewing mode. The plasma characteristic parameters as function of helium flow-rate, plasma power and position of the investigated zone were studied. The excitation, vibrational and rotational temperatures are in the range of 1500-2350 K, 3500-4400 K and 450-1100 K, respectively. The electron number densities are in the range of 1013-1014 cm−3. For qualitative observations regarding the atomic and molecular processes in the plasma we used the relative intensities of the most representative lines of He, N2, O, H and N2+.