EPJ D Colloquium - Modelling low energy electron and positron tracks in biologically relevant media

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Published on 27 September 2013

This EPJD colloquium describes an approach whereby the effect of low and intermediate energy (0-100 eV) electrons and positrons can be incorporated into radiation damage models, in particular the deceleration of these particles in biologically-relevant materials (water and representative biomolecules). At the heart of the modelling procedure is a C++ computer program called Low Energy Particle Track Simulation (LEPTS), which is compatible with commonly available general purpose Monte Carlo packages. Input parameters are carefully selected from theoretical and experimental cross-section data and energy loss distribution functions.

The data sources used for this purpose are reviewed, and examples of electron and positron cross-section and energy loss data for interactions with different media of increasing complexity (atoms, molecules, clusters and condensed matter) are presented. Finally, the authors show how such a model can be used to develop an effective dosimetric tool at the molecular level (i.e. nanodosimetry). Recent experimental developments in the study of molecular fragmentation induced by charge transfer from neutrals and negative ions in biological materials are also discussed.