Microwave Energy Deposition, Breakdown and Heating of Nitrogen and Air.

A comprehensive code is developed for the microwave energy deposition in N2 to describe the breakdown and heating of nitrogen. The microwave absorption and reflection from a nitrogen plasma is based on wave optics. The ionization and the deionization of N2, however, is described in detail by an N2 chemistry code CHEM-N2 which provides plasma diagnostics capabilities by calculating emission intensities of the second positive and the first negative band systems of N2 and N2. The code is applied to breakdown calculations in N2 and the results are in reasonable accord with experimental data. The wave optics code for energy deposition is also coupled to an air chemistry code CHMAIR to describe the breakdown off a reflecting surface. An insight is provided into the plasma absorption by using a simple lab density profile for the electrons. This models roughly the profile expected in air breakdown off a reflecting surface. Simulation results show a steep localized electron density profile at the interference maximum.