Investigation of Laser-induced plasma formation in water by double-pulse LIBS at hydrostatic pressures of 60 MPa (LIBS60)

• Applicants: Dr.-Ing. Diego Gonzalez, since 1/2023; Dr.-Ing. Jörg Hermsdorf
• Subject Area: Measurement Systems ; Analytical Chemistry ; Optics, Quantum Optics and Physics of Atoms, Molecules and Plasmas ; Oceanography ; Physical Chemistry of Solids and Surfaces, Material Characterisation
• Term: since 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 454848899

The aim of the research project is the fundamental investigation of cavity/plasma formation and plasma radiation in a double-pulse LIBS application on metallic samples under water at a water pressure of up to 60 MPa. First of all, the laser-induced cavity has to be analyzed in order to derive information about the geometry, lifetime and the resulting shock wave. Of particular interest here is how the essential process parameters affect the cavity and how the lifetime of the cavity can be increased. Furthermore, sources of interference for cavity or plasma generation are of interest, such as the optical breakthrough behaviour in water in dependence on water pressure. Furthermore, it is necessary to work out the conditions and the time periods for the emission of line radiation in relation to continuum radiation. For elemental analysis by LIBS, the investigation of line profiles is of interest, in particular the absorption and broadening mechanisms of a laser-induced plasma at high water pressure with respect to the evaluability of individual lines. With this knowledge, conclusions should be drawn on the required technology, suitable evaluation methods and the achievable accuracy for LIBS in the deep sea.

• DFG Programme: Research Grants
• Co-Investigators: Dr.-Ing. Benjamin Emde; Professor Dr.-Ing. Ludger Overmeyer; Dr. Dirk Uhrlandt
• Ehemaliger Antragsteller: Dr. Steffen Franke, until 12/2022