Proceedings Article | 30 May 2022
KEYWORDS: Infrared spectroscopy, Infrared radiation, Spectroscopy, Time resolved spectroscopy, Fiber reinforced polymers, Spectrographs, Combustion, Weapons, Visible radiation, Temperature metrology
Time resolved infrared spectroscopic measurement techniques during CW-laser matter interaction of Fiber-Reinforced-Polymers (FRP)
Hartmut Borchert, Robert Paetzold, Vadim Allheily
French-German Research Institute of Saint-Louis, 5 rue du Général Cassagnou, BP 70034, 68301 Saint-Louis, France
corresponding author: hartmut.borchert@isl.eu
Composite materials have shown a marked increase in their use in aerospace and military applications in recent years. The matrix phase of many common aerospace composite materials are made of polymeric materials and a fiber material. Future laser-based weapons with solid-state high energy laser sources are considered to neutralize that kind of threat. The thermodynamics as well as the thermo-mechanical behavior of such heterogeneous materials submitted to a typical laser weapon irradiation need therefore to be further explored to understand the deterioration process induced by the illumination process. One common measurement technique to visualize the heating and decomposition process is the use of time resolved emission spectroscopy in the visible (λ = 400 nm - 850 nm) [1,2,3] and infrared (λ = 1µm - 5.5µm) wavelength regime to retrieve the onset and time distribution of decomposition products as well as the temperature distribution from typical line and molecular emission involved.
In the current work, we introduce the potential of time resolved emission and absorption spectroscopy in the infrared wavelength band from λ = 1µm up to λ = 5.5µm for monitoring thermal decomposition and combustion in the gas and fire plumes generated by laser irradiation of surfaces containing carbon, glass and polymer materials. The effectiveness of high-energy lasers to render a target nonfunctional depends on the propagation of the laser light through these evolving gas- and fire-plumes. First results on time- and wavelength-resolved infrared emission signals of decomposition gases and their influence on temperature determination are presented.
1. C.Th.Alkemade, Fundamentals of analytical flame spectroscopy, Hilger Bristol, 1972
2. V.Allheily, L.Merlat, F.Lacroix, A.Eichhorn, G.L’Hostos, Physics Procedia, 83 (2016) 1044-1054
3. H.Borchert, Time resolved spectroscopic temperature measurement techniques during CW-laser matter interaction of glass-fiber-reinforced-polymers (GFRP), Proc.SPIE 11162, doi: 10.1117/12.2532324, 7.October 2019
