Thermal and Recombination Emission of NO2

Abstract

Metastable resolved recombination, ionization and emission coefficients of impurity ions in thermal plasmas AIP Conf.The visible emission from electronically excited N02 has been studied both with thermal excitation in an electric oven and with recombination excitation from the nitric oxide-atomic oxygen reaction. In both cases the emission is continuous with weaker, diffuse bands superimposed. The correlation of these bands with N02 absorption bands has been extended. The thermal emission continuum begins near 3300 A and increases in intensity to the end of our range at 8600 A. The recombination emission continuum begins near 3800 A and has a broad maximum at 6200 A, in general agreement with previous workers. The absolute intensity of the thermal emission has been obtained at 100-A intervals between 4600 and 8600 A for temperatures between 972 and 1335°K. Excitation energies, which are obtained from the variation of intensity with temperature, range from 66 kcal at 4600 A to a minimum of 44±1 kcal near 8300 A. This latter value is Eo, the minimum energy of the emitting state of N02• Radiative lifetimes are obtained for thermal emission which range from 100 to 1 J.Lsec depending on emission wavelength and which approximately agree with fluorescent lifetimes for comparable excitation energies. The results are compared with shock tube measurements and are discussed in relation to air emissivity and opacity problems.If the choice is limited to quadratic forms, it is impossible to find representations of quantum states by positive distributions on phase space, either in the ordinary or in an extended "coarse-grained" sense.

Shock Wave Induced Decomposition of RDX: Time-Resolved Spectroscopy

“…The NO 2 radical likely plays an important role in RDX decomposition. The luminescence spectrum of excited NO 2 is very broad, almost forming a continuum. – The peak of this continuum emission varies depending on the conditions under which the excited NO 2 was produced, and can vary from the visible (500−600 nm) – to the near-infrared (1200 nm). ,,,, Because of the differences in the experimental conditions, our results are not directly comparable to these other studies. Temperature and pressure effects likely change the emission spectrum of NO 2 .…”

Electron characterization in weakly ionized collisional plasmas: from principles to techniques

“…Continuum radiation from sources other than H 2 and He 2 + can also arise from the photorecombination of electrons with Ar þ 2 (Ar þ 2 þ e À ! Ar à 2 þ hν) [164] and the chemi- [165]. However, Park et al [84] reported that in atmospheric-pressure discharges, the contribution of these continuum spectra on the emission spectrum can be considered negligible.…”

Spatial and spectral characterization of laboratory shuttle glow simulations

“…[1986] measured a value of 79 tzs for heterogeneously formed NO•. Variations between the lifetimes of NO2 have been attributed to mixing of the 2B and 2B 2 states or explained in terms of one or more of these excited states being coupled to the high vibrational levels of the 2A1 ground state [Douglas, 1966;Paulsen et al, 1970;Adler-Golden, 1989], yielding a wide range of values. The common assumption for the lifetime is ---70 tzs The e-folding distance on orbiter surfaces had been measured to be 20 cm [ Yee and Dalgarno, 1983;Swenson et al, 1986b].…”