Rebecca Meißner

Research Areas

PhD Thesis: “Low-Energy Electron Interactions with Radiosensitisers and Hydrated Biomolecular Clusters" (2016-2020)

Advisers: Prof. Doutor Stephan Denifl and Prof. Doutor Paulo Limão-Vieira

Interactions of low-energetic electrons (LEEs) with matter can result in excitation, ionisation or dissociative electron attachment. In the latter, a transient negative ion is formed which undergoes subsequent fragmentation into a smaller anion and one or several neutral fragments. Since LEEs are an abundant species of secondary particles in biological tissue upon interaction with high energetic radiation, special interest is given to the interaction of LEEs with biomolecules and radiosensitisers, in particular to compounds based on an imidazole ring with different functional groups.

Thus, the influence of the functional groups regarding fragmentation and the overall stability of the molecule can be investigated. Additionally, some of these molecules will be solvated with water. This allows for a study of the interaction process in a more natural environment than in gas phase and enables conclusions on the effects of the surrounding water molecules. For the experiments, the experimental setup WIPPI is used, consisting mainly out of a hemispherical electron monochromator, a quadrupole mass analyser and a channeltron detector. A water cluster source with separate water and sample container can be attached to WIPPI and can be operated in either pulsed or continuous mode. The whole thesis is embedded in the Radiation Biology and Biophysics Doctoral Training Programme, RaBBiT.