DIAGNOSTICS AND KINETIC MODELING OF A HOLLOW-CATHODE N2O DISCHARGE

The present work describes a systematic experimental investigation of a N2O hollow cathode discharge. The local electron mean energy and den sity have been determined with a double Langmuir probe. Fourier transf orm infrared spectroscopy and mass spectrometry have been employed for the measurement of the concentration of the stable species present in the discharge. N2O, N-2, O-2, and NO are always identified as the mai n constituents of the discharge plasma. In addition, NO2 is found for the first time in a glow discharge of nitrous oxide. As a plausible ex planation, a reaction of NO with oxygen atoms adsorbed on the cathode walls is proposed, although homogeneous reactions of vibrationally exc ited species cannot be discarded. A model based on a reduced set of ki netic equations including electron dissociation, gas-phase reactions, and gas-surface processes can give a global account of the measured da ta for all the experimental conditions used. The results are discussed and, when possible, compared to previous works on other types of N2O glow discharges.