The visualization of mixing gas flows is important in many process both on the lab-scale and in practical devices. To this end, fluorescing tracers are frequently used and added to the respective gas flow at low concentrations. Upon excitation in the ultraviolet, laser-induced fluorescence (LIF) can be used to locally measure the species concentration often in imaging configurations that yield two-dimensional concentration maps.

As tracers, most frequently, small organic molecules are used. Typical tracers include aromatics (toluene, naphthalene, etc.), ketones (acetone, 3-pentanone), and amines (triethylamine). For extracting quantitative information from measured LIF signal intensities, the absorption and fluorescence behaviour must be known.

In many practical applications such as gas turbines, chemical reactors, or internal combustion engines, the local conditions of temperature, pressure, and gas composition change in space and time. These conditions influence the fluorescence properties in terms of intensity, spectral distribution, and lifetime. Therefore, the variation of absorption and fluorescence properties depending on these conditions are investigated and often the underlying photo-physical processes are investigated and compiled in models that can then be used to select tracers best suited for a specific application and to interpret measured signals.

This website aims at building a comprehensive data base for measurements and models for tracer LIF.

The choice of suitable tracers depends on the application. A compilation of thermodynamic and photophysical properties, temperature-dependent absorption and fluorescence spectra is provided for various tracers. Photophysical data (fluorescence quantum yield, absorption cross-sections, fluorescence lifetimes, absorption and fluorescence spectra) are compiled in a growing open database. The data can be plotted within the range of temperature, pressure and oxygen concentration of the original experiments.

The corresponding sources are available as a literature supplement or links to the respective journal articles. Unpublished sources are marked accordingly. The individual data sets were collected from the original publications, either copied from tables, or digitized from figures in those cases where raw data could no longer be obtained.

In a future step, photophysical modeling approaches will be implemented in the database.

This work is supported by funding from the German Research Foundation, DFG within grant SCHU1369/28