Electron Stark Broadening Database for Atomic N, O, and C Lines

Abstract

A database for efficiently computing the electron Stark broadening line widths for atomic N, O, and C lines is constructed. The line width is expressed in terms of the electron number density and electronatom scattering cross sections based on the Baranger impact theory. The state-to-state cross sections are computed using the semiclassical approximation, in which the atom is treated quantum mechanically whereas the motion of the free electron follows a classical trajectory. These state-to-state cross sections are calculated based on newly compiled line lists. Each atomic line list consists of a careful merger of NIST, Vanderbilt, and TOPbase line datasets from wavelength 50 nm to 50 µm covering the VUV to IR spectral regions. There are over 10,000 lines in each atomic line list. The widths for each line are computed at 13 electron temperatures between 1,000 K -50,000 K. A linear least squares method using a four-term fractional power series is then employed to obtain an analytical fit for each line-width variation as a function of the electron temperature. The maximum L 2 error of the analytic fits for all lines in our line lists is about 5%.

Ionization and recombination in nanosecond repetitively pulsed microplasmas in air at atmospheric pressure

“…For the lines of N and O of interest, we use tabulated values for the Stark width ω e as well as α e found in table 4.5 of [32]. For N, from T e = 2.5 to 80 kK the values of ω e and α e vary [33] and also validate the model used to derive equation ( 7) against experimental work published after [32]. For O, the variations of ω e with T e are of similar magnitude.…”

Measurements and modeling of CO 4th positive (A–X) radiation

“…The spectroscopic data based on the ETMF of Kirby, as well as the measured temperature profile and CO(4+) spectrum, are available for download and linked to this article on the journal website. 16 show CO(4+) spectra calculated in the optically thin limit for a temperature of 6300 K, which corresponds approximately to the centerline temperature of the jet. Figure A.15 identifies the bands coming from various vibrational levels of the A electronic state.…”

“…[5,10,11,12,13] In 2013, researchers at NASA Ames studied the radiation of CO(4+) in the EAST facility [9,2] to characterize the radiative heat flux under Venus and Mars entry conditions. They compared measurements of CO(4+) radiation with predictions made with the HARA [14,15], HyperRad [16] and NEQAIR [17] radiation codes. When the equilibrium post-shock temperature was used, the models underestimated the measured radiation by a factor of 2.…”

Analysis of Shockwave Radiation Data in Nitrogen

“…These lines have, however, been evaluated in other atomic spectral databases as multiplets. [21] The series of lines involves transitions from 7 upper states to 3 lower states, producing 21 lines (7 triplets) total which are not individually resolved. The two most prominent triplets are given in Table 2.…”

“…These lines are given in Table 5, with A coefficients taken from Ref. [21]. The relative intensities of the 517 nm multiplet are estimated.…”