Laser-Plasma Spectroscopy of Hydroxyl with Applications

Area of Science:

• Atomic and Molecular Spectroscopy
• Plasma Physics
• Laser-Induced Breakdown Spectroscopy (LIBS)

Background:

• Accurate spectral data are crucial for analyzing molecular species in laboratory plasmas.
• Hydroxyl (OH) radical is a key species in atmospheric and combustion plasmas.
• Previous line strength data required further validation and broader application.

Purpose of the Study:

• To present novel computations of hydroxyl (OH) ultraviolet spectra.
• To introduce newly developed and validated OH spectral line strength data.
• To demonstrate the application of these data in laser-induced plasma analysis.

Main Methods:

• Utilized previously developed line strength data for OH ultraviolet spectra computations.
• Performed new experiments using Q-switched laser pulses to study plasma evolution.
• Incorporated centrifugal stretching of Franck-Condon factors and r-centroids for line strength determination.

Main Results:

• Communicated new, well-tested line strength data for OH ultraviolet spectra.
• Observed molecular recombination spectra in laboratory air plasma at microsecond delays.
• Demonstrated the utility of OH signals arising from natural air humidity.

Conclusions:

• The presented OH spectral data and computations are valuable for interpreting molecular emission spectra.
• These data are well-suited for laser-induced fluorescence applications, including temperature diagnostics.
• The findings support applications in laser-induced plasma and combustion analyses.