Hannover 2020 – scientific programme

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K: Fachverband Kurzzeit- und angewandte Laserphysik

K 7: Laser Beam Interaction and Laser Diagnostics

K 7.4: Talk

Wednesday, March 11, 2020, 14:45–15:00, f428

Quantitative determination of molecules in cooling laser-induced plasmas — •Joshua Klose, Thomas Dietz, Peter Kohns, and Georg Ankerhold — University of Applied Sciences, RheinAhrCampus, Laser Spectroscopy and Photonics, Joseph-Rovan-Allee 2, 53424 Remagen

Laser induced plasma spectroscopy ("LIBS") is a promising method to determine the elemental contribution of samples which has found a lot of applications. While most LIBS analyses use the emission of atoms the quantitative analysis of molecular emission ("Molecular LIBS") can achieve additional information.

For example, the quantitative determination of atomic chlorine emission can be performed using atomic LIBS. However, this requires sophisticated setups under helium atmosphere. Very often the samples under examination contain Calcium. In this case in the generated LIBS plasma atomic chlorine and calcium form calcium-mono-chloride (CaCl) radicals which emit strongly in the visible range. No additional buffer gas is needed to acquire the CaCl emission which allows an indirect determination of the chlorine concentration within the sample.

While the simple observation of CaCl emission allows the qualitative detection of chlorine the determination of the intensity ratio of chlorine dependent and independent band emission can be used to create a linear calibration of the chlorine contamination. Thus, the quantitative determination of the chloride concentration becomes possible. As an application we show measurements obtained with chloride contaminated samples of concrete.