Fraunhofer Institute for Interfacial Engineering and Biotechnology IGBWith plasma-diagnostic methods, a distinction has to be made between non-invasive and invasive methods. As invasive methods like probes can influence the plasma, we employ mainly non-invasive optical methods at the Fraunhofer IGB:
- Microwave interferometry to determine the electron density
- Laser-induced fluorescence for the dissipated determination of particle densities in the plasma
- Optical emission spectroscopy to identify emitting species
- Surface temperature detection by measuring the fluorescence decay time of an excited crystal
The invasive methods we use are:
- Mass spectrometry to trace chemical reactions in the plasma
- Langmuir probes to measure the electron energy distribution, the density of the electrons and ions