DFG Pro­ject PEPICO

 “PEPICO in Combustion Research“          

Isomeric radicals play a key role in understanding the branching ratios of reaction pathways in combustion systems. In particular, fuel radicals, which are formed by hydrogen abstraction from the fuel molecule, are starting points for branching during fuel oxidation. It is particularly important to determine their (relative) concentrations as accurately as possible in order to examine reaction mechanisms. In cooperation with Dr. Hemberger (Swiss Light Source, PSI, Switzerland), my group has set up several kinetic experiments at the VUV beamline of the Swiss Light Source, in which the intermediates are detected after molecular beam extraction from the reactors and VUV ionization by photoelectron photoion coincidence spectroscopy. As synchrotron-based experiments require a particularly high level of personnel, they are usually carried out by several groups working together. The measurements at the Swiss Light Source were carried out together with Dr. Oßwald and Dr. Köhler (DLR, Stuttgart).

Numerous published results show that this novel combination of methods can generate important data for mechanism development that are not accessible with other methods, such as the concentration ratio of radicals in the first step of fuel decay. These activities are currently on hold as the SLS is being modernized. They are to be resumed from 2026.