Absolute CO number densities measured using TALIF in a non-thermal plasma environment

• Published in: Plasma sources science & technology 2019-11, Vol.28 (11), p.115006
• Main Authors: Damen, M A, Hage, D A C M, van de Steeg, A W, Martini, L M, Engeln, R
• Format: Article
• Language: English
• Subjects: absolute number densities; carbon dioxide plasma; carbon monoxide; glow discharge; rotational temperatures; two-photon absorption laser-induced fluorescence
• ISSN: 0963-0252; 1361-6595; 1361-6595
• DOI: 10.1088/1361-6595/ab496e

We report first measurements of time-resolved absolute CO number densities and rotational temperatures in a non-thermal CO2 plasma environment using TALIF with a nanosecond pulsed laser. Two-photon excitation spectra from the B 1 + (v′ = 0) ← X 1 + (v″ = 0) Q-branch are recorded and fitted to extract rotational temperatures. Absolute number densities are determined from the frequency-integrated excitation spectrum. The plasma under investigation is a pulsed glow discharge operated at a frequency of 60 Hz with an plasma-on time of 5 ms per plasma cycle, 50 mA plasma current and a pressure of 6.67 mbar. CO number densities range from ( 2.6 0.6 ) × 10 22 m−3 to ( 1.2 0.3 ) × 10 22 m−3, while rotational temperatures range from 370 40 K to 700 70 K at the beginning and end of the plasma-on phase, respectively. Our results show fair agreement with literature data.