Peter J. M. van der Burgt

This research project studies electron and photon impact fragmentation of molecules and clusters that are of interest to radiation damage studies, plasma physics, atmospheric physics and other fields. The experiment consists of a differentially pumped vacuum system, with an expansion chamber to generate a pulsed supersonic beam of molecules or clusters, and a collision chamber where the molecules or clusters are fragmented using a pulsed electron or laser beam. A reflectron time-of-flight mass spectrometer with a microchannel plate detector is used for the mass-resolved detection of ions.

Current research involves the study of electron impact fragmentation of nucleobases and polycyclic aromatic hydrocarbons.  Detailed knowledge of electron interactions with the nucleobases is important in order to understand and potentially model the nanoscale processes leading to radiation damage in biological material.  When high-energy ionizing radiation passes through tissue, a large amount of low-energy secondary electrons are produced along the tracks, causing DNA strand breaks via excitation, ionization and dissociative electron attachment to the DNA components. Low-energy collisions of electrons with molecules are important elementary processes in gaseous environments such as discharges, gas lasers and the Earth's atmosphere. 

Polycyclic aromatic hydrocarbons have been studied extensively in recent years, because of their relevance in astrophysical processes and in environmental chemistry.