This paper presents spatially resolved measurements of absolute particle densities of N 2, N
2+, N, O, N+, O+, e− and excitation temperatures of electronic, rotational and vibrational
modes of an air plasma free stream. All results are based on optical emission spectroscopy
data. The measured parameters are combined to determine the local mass–specific
enthalpy of the free stream. The analysis of the radiative transport, relative and absolute
intensities, and spectral shape is used to determine various thermochemical parameters …