Spectroscopic measurements of a 5 – 30 kHz , high voltage atmospheric pressure discharge

A 5 – 30 kHz, high voltage atmospheric pressure discharge device is being investigated as an excitation source for atomic emission spectroscopy. Electron excitation energy and molecular rotational temperature of nitrogen have been measured in this plasma at voltages of approximately 2 kV and average power levels of 130 300 Watts with a 2 mm gap between electrodes. Iron and titanium lines have been used for the electron excitation temperature measurements. These measurements show that the electron excitation energy is about 0.5 eV and does not vary with frequency or power over the ranges studied. The rotational temperature of the second negative system of nitrogen molecule ion (N2) was found to be 1840 K (0.16 eV) showing that this discharge is a non-equilibrium plasma. Subject classification numbers: 52.80.–s, 52.77.–j, 52.50.Dg, 39.30.+w Submitted to: Journal of Applied Physics