A comparative study of spectral line broadening used to determine the temperature and copper number density in an arc-heated air plasma

An examination is made of detailed spectral line broadening in an attempt to determine whether the simplified broadening approach of A. A. Boiarski (Air Force Flight Dynamics Laboratory) is sufficient in evaluating the temperature and copper number density using a self-absorption line-ratio technique. A Lennard-Jones potential is used instead of a van der Waals potential for neutral-neutral particle broadening. The Stark broadening approach of Cooper and Oertel is considered over the Vainshtein-Sobelman approach used by Boiarski. And Resonance and hyperfine broadening effects are treated which are not considered by Boiarski.

The results are lower overall predicted temperatures (≤8%) and higher overall predicted copper number densities (≤38%). The main cause of these deviations comes from the difference in the resulting full half-width of the two neutral-neutral broadening approaches. The inclusion of resonance broadening had a nonnegligible effect on some of the results.