Bremen 2017 – wissenschaftliches Programm
P 8.1: Fachvortrag
Dienstag, 14. März 2017, 08:30–08:55, HS 1010
Characterizing atmospheric pressure plasma jets using cavity-enhanced absorption spectroscopy — •Jean-Pierre van Helden1, Stephan Reuter1, Ana Lawry Aguila2, Michele Gianella2, and Grant Ritchie2 — 1Leibniz Institute for Plasma Science and Technology (INP Greifswald), Greifswald, Germany — 2Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, Oxford, UK
Cold non-equilibrium atmospheric pressure plasma jets are increasingly applied in material processing and plasma medicine. Hence, it is essential to diagnose the fluxes of the species generated by these plasma sources to identify relevant fundamental processes and to improve process efficiency. Especially, high precision measurements of reactive molecular precursors, free radicals and short lived species are of crucial importance. However, their small dimensions make the detection of generated transient species a challenge. We have overcome these limitations by using optical cavities to achieve effective absorption path lengths of up to 100 meters in mm sized plasma jets . Here we report on the detection of the hydroperoxyl radical, HO2, in the effluent of a plasma jet by the use of optical feedback cavity-enhanced absorption spectroscopy (OF-CEAS). The achieved detection levels indicate that such a spectrometer will find broad application in future studies of the chemical network in the effluents of plasma jets and provides a new way of testing and improving our modelling of these complex plasma environments.  M. Gianella, S. Reuter, A. Lawry Aguila, G.A.D. Ritchie, and J. H. van Helden, New J. Phys. 18 (2016) 113027.