Time-synchronized continuous wave laser-induced fluorescence on an oscillatory xenon discharge

• Published in: Review of scientific instruments 2012-11, Vol.83 (11), p.113506-113506
• Main Authors: MacDonald, N. A., Cappelli, M. A., Hargus, W. A.
• Format: Article
• Language: English
• Subjects: CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; Continuous wave; Continuous wave lasers; Discharge; ELECTRIC DISCHARGES; Evolution; EXCITATION; FLUORESCENCE; INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; LASER RADIATION; Line shape; LOCK-IN AMPLIFIERS; Phases; PLASMA; PLASMA DIAGNOSTICS; PLASMA WAVES; XENON
• ISSN: 0034-6748; 1089-7623
• DOI: 10.1063/1.4766958

A novel approach to time-synchronizing laser-induced fluorescence measurements to an oscillating current in a 60 Hz xenon discharge lamp using a continuous wave laser is presented. A sample-hold circuit is implemented to separate out signals at different phases along a current cycle, and is followed by a lock-in amplifier to pull out the resulting time-synchronized fluorescence trace from the large background signal. The time evolution of lower state population is derived from the changes in intensity of the fluorescence excitation line shape resulting from laser-induced fluorescence measurements of the \documentclass[12pt]{minimal}\begin{document}$6s^{\prime }[1/2]_{1}^{0} - 6p^{\prime }[3/2]_{2}$\end{document} 6 s ′ [ 1 / 2 ] 1 0 − 6 p ′ [ 3 / 2 ] 2 xenon atomic transition at λ = 834.68 nm. Results show that the lower state population oscillates at twice the frequency of the discharge current, 120 Hz.