Ultrafast laser-collision-induced fluorescence in atmospheric pressure plasma. (7th March 2017)

• Record Type: Journal Article
• Authors: Barnat, E V; Fierro, A
• Is Part Of: Journal of physics. Volume 50:Number 14(2017)
• Publication Date: 2017-03-07
• Subjects: atmospheric pressure plasma -- diagnostics -- laser-collision-induced fluorescence -- ultrafast laser -- laser-induced fluorescence -- helium; Physics -- Periodicals; 530
• DOI: 10.1088/1361-6463/aa5f1e
• Languages: English
• ISSNs: 0022-3727

Abstract

Abstract: The implementation and demonstration of laser-collision-induced fluorescence (LCIF) generated in atmospheric pressure helium environments is presented in this communication. As collision times are observed to be fast (~10 ns), ultrashort pulse laser excitation (<100 fs) of the 2 3 S to 3 3 P (388.9 nm) is utilized to initiate the LCIF process. Both neutral-induced and electron-induced components of the LCIF are observed in the helium afterglow plasma as the reduced electric field ( E / N ) is tuned from <0.1 Td to over 5 Td. Under the discharge conditions presented in this study (640 Torr He), the lower limit of electron density detection is ~10 12 e cm −3 . The spatial profiles of the 2 3 S helium metastable and electrons are presented as functions of E / N to demonstrate the spatial resolving capabilities of the LCIF method.